2019-06-04 10:11:33 +02:00
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// SPDX-License-Identifier: GPL-2.0-only
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strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
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/*
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* Stream Parser
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*
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* Copyright (c) 2016 Tom Herbert <tom@herbertland.com>
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*/
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#include <linux/bpf.h>
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#include <linux/errno.h>
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#include <linux/errqueue.h>
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#include <linux/file.h>
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#include <linux/in.h>
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#include <linux/kernel.h>
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2019-04-21 05:29:48 +02:00
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#include <linux/export.h>
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#include <linux/init.h>
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strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
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#include <linux/net.h>
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#include <linux/netdevice.h>
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#include <linux/poll.h>
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#include <linux/rculist.h>
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#include <linux/skbuff.h>
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#include <linux/socket.h>
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#include <linux/uaccess.h>
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#include <linux/workqueue.h>
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#include <net/strparser.h>
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#include <net/netns/generic.h>
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#include <net/sock.h>
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static struct workqueue_struct *strp_wq;
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2017-07-29 01:22:43 +02:00
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struct _strp_msg {
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/* Internal cb structure. struct strp_msg must be first for passing
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strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
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* to upper layer.
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*/
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2017-07-29 01:22:43 +02:00
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struct strp_msg strp;
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strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
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int accum_len;
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};
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2017-07-29 01:22:43 +02:00
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static inline struct _strp_msg *_strp_msg(struct sk_buff *skb)
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strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
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{
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2017-07-29 01:22:43 +02:00
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return (struct _strp_msg *)((void *)skb->cb +
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strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
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offsetof(struct qdisc_skb_cb, data));
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}
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/* Lower lock held */
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2017-07-29 01:22:43 +02:00
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static void strp_abort_strp(struct strparser *strp, int err)
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strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
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{
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/* Unrecoverable error in receive */
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2017-10-21 01:40:43 +02:00
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cancel_delayed_work(&strp->msg_timer_work);
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strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
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2017-07-29 01:22:43 +02:00
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if (strp->stopped)
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strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
return;
|
|
|
|
|
2017-07-29 01:22:43 +02:00
|
|
|
strp->stopped = 1;
|
|
|
|
|
|
|
|
if (strp->sk) {
|
|
|
|
struct sock *sk = strp->sk;
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
|
2017-07-29 01:22:43 +02:00
|
|
|
/* Report an error on the lower socket */
|
2018-03-26 21:31:21 +02:00
|
|
|
sk->sk_err = -err;
|
2017-07-29 01:22:43 +02:00
|
|
|
sk->sk_error_report(sk);
|
|
|
|
}
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
}
|
|
|
|
|
2017-07-29 01:22:43 +02:00
|
|
|
static void strp_start_timer(struct strparser *strp, long timeo)
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
{
|
2018-04-20 21:11:11 +02:00
|
|
|
if (timeo && timeo != LONG_MAX)
|
2017-10-21 01:40:43 +02:00
|
|
|
mod_delayed_work(strp_wq, &strp->msg_timer_work, timeo);
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
}
|
|
|
|
|
|
|
|
/* Lower lock held */
|
|
|
|
static void strp_parser_err(struct strparser *strp, int err,
|
|
|
|
read_descriptor_t *desc)
|
|
|
|
{
|
|
|
|
desc->error = err;
|
2017-07-29 01:22:43 +02:00
|
|
|
kfree_skb(strp->skb_head);
|
|
|
|
strp->skb_head = NULL;
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
strp->cb.abort_parser(strp, err);
|
|
|
|
}
|
|
|
|
|
2016-08-28 23:43:19 +02:00
|
|
|
static inline int strp_peek_len(struct strparser *strp)
|
|
|
|
{
|
2017-07-29 01:22:43 +02:00
|
|
|
if (strp->sk) {
|
|
|
|
struct socket *sock = strp->sk->sk_socket;
|
|
|
|
|
|
|
|
return sock->ops->peek_len(sock);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* If we don't have an associated socket there's nothing to peek.
|
|
|
|
* Return int max to avoid stopping the strparser.
|
|
|
|
*/
|
2016-08-28 23:43:19 +02:00
|
|
|
|
2017-07-29 01:22:43 +02:00
|
|
|
return INT_MAX;
|
2016-08-28 23:43:19 +02:00
|
|
|
}
|
|
|
|
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
/* Lower socket lock held */
|
2017-07-29 01:22:43 +02:00
|
|
|
static int __strp_recv(read_descriptor_t *desc, struct sk_buff *orig_skb,
|
|
|
|
unsigned int orig_offset, size_t orig_len,
|
|
|
|
size_t max_msg_size, long timeo)
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
{
|
|
|
|
struct strparser *strp = (struct strparser *)desc->arg.data;
|
2017-07-29 01:22:43 +02:00
|
|
|
struct _strp_msg *stm;
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
struct sk_buff *head, *skb;
|
|
|
|
size_t eaten = 0, cand_len;
|
|
|
|
ssize_t extra;
|
|
|
|
int err;
|
|
|
|
bool cloned_orig = false;
|
|
|
|
|
2017-07-29 01:22:43 +02:00
|
|
|
if (strp->paused)
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
return 0;
|
|
|
|
|
2017-07-29 01:22:43 +02:00
|
|
|
head = strp->skb_head;
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
if (head) {
|
|
|
|
/* Message already in progress */
|
|
|
|
if (unlikely(orig_offset)) {
|
|
|
|
/* Getting data with a non-zero offset when a message is
|
|
|
|
* in progress is not expected. If it does happen, we
|
|
|
|
* need to clone and pull since we can't deal with
|
|
|
|
* offsets in the skbs for a message expect in the head.
|
|
|
|
*/
|
|
|
|
orig_skb = skb_clone(orig_skb, GFP_ATOMIC);
|
|
|
|
if (!orig_skb) {
|
2017-07-29 01:22:43 +02:00
|
|
|
STRP_STATS_INCR(strp->stats.mem_fail);
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
desc->error = -ENOMEM;
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
if (!pskb_pull(orig_skb, orig_offset)) {
|
2017-07-29 01:22:43 +02:00
|
|
|
STRP_STATS_INCR(strp->stats.mem_fail);
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
kfree_skb(orig_skb);
|
|
|
|
desc->error = -ENOMEM;
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
cloned_orig = true;
|
|
|
|
orig_offset = 0;
|
|
|
|
}
|
|
|
|
|
2017-07-29 01:22:43 +02:00
|
|
|
if (!strp->skb_nextp) {
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
/* We are going to append to the frags_list of head.
|
|
|
|
* Need to unshare the frag_list.
|
|
|
|
*/
|
2019-04-10 20:04:32 +02:00
|
|
|
err = skb_unclone(head, GFP_ATOMIC);
|
|
|
|
if (err) {
|
|
|
|
STRP_STATS_INCR(strp->stats.mem_fail);
|
|
|
|
desc->error = err;
|
|
|
|
return 0;
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
}
|
|
|
|
|
|
|
|
if (unlikely(skb_shinfo(head)->frag_list)) {
|
|
|
|
/* We can't append to an sk_buff that already
|
|
|
|
* has a frag_list. We create a new head, point
|
|
|
|
* the frag_list of that to the old head, and
|
|
|
|
* then are able to use the old head->next for
|
|
|
|
* appending to the message.
|
|
|
|
*/
|
|
|
|
if (WARN_ON(head->next)) {
|
|
|
|
desc->error = -EINVAL;
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
skb = alloc_skb(0, GFP_ATOMIC);
|
|
|
|
if (!skb) {
|
2017-07-29 01:22:43 +02:00
|
|
|
STRP_STATS_INCR(strp->stats.mem_fail);
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
desc->error = -ENOMEM;
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
skb->len = head->len;
|
|
|
|
skb->data_len = head->len;
|
|
|
|
skb->truesize = head->truesize;
|
2017-07-29 01:22:43 +02:00
|
|
|
*_strp_msg(skb) = *_strp_msg(head);
|
|
|
|
strp->skb_nextp = &head->next;
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
skb_shinfo(skb)->frag_list = head;
|
2017-07-29 01:22:43 +02:00
|
|
|
strp->skb_head = skb;
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
head = skb;
|
|
|
|
} else {
|
2017-07-29 01:22:43 +02:00
|
|
|
strp->skb_nextp =
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
&skb_shinfo(head)->frag_list;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
while (eaten < orig_len) {
|
|
|
|
/* Always clone since we will consume something */
|
|
|
|
skb = skb_clone(orig_skb, GFP_ATOMIC);
|
|
|
|
if (!skb) {
|
2017-07-29 01:22:43 +02:00
|
|
|
STRP_STATS_INCR(strp->stats.mem_fail);
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
desc->error = -ENOMEM;
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
cand_len = orig_len - eaten;
|
|
|
|
|
2017-07-29 01:22:43 +02:00
|
|
|
head = strp->skb_head;
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
if (!head) {
|
|
|
|
head = skb;
|
2017-07-29 01:22:43 +02:00
|
|
|
strp->skb_head = head;
|
|
|
|
/* Will set skb_nextp on next packet if needed */
|
|
|
|
strp->skb_nextp = NULL;
|
|
|
|
stm = _strp_msg(head);
|
|
|
|
memset(stm, 0, sizeof(*stm));
|
|
|
|
stm->strp.offset = orig_offset + eaten;
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
} else {
|
2018-06-29 21:15:55 +02:00
|
|
|
/* Unclone if we are appending to an skb that we
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
* already share a frag_list with.
|
|
|
|
*/
|
2018-06-29 21:15:55 +02:00
|
|
|
if (skb_has_frag_list(skb)) {
|
|
|
|
err = skb_unclone(skb, GFP_ATOMIC);
|
|
|
|
if (err) {
|
|
|
|
STRP_STATS_INCR(strp->stats.mem_fail);
|
|
|
|
desc->error = err;
|
|
|
|
break;
|
|
|
|
}
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
}
|
|
|
|
|
2017-07-29 01:22:43 +02:00
|
|
|
stm = _strp_msg(head);
|
|
|
|
*strp->skb_nextp = skb;
|
|
|
|
strp->skb_nextp = &skb->next;
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
head->data_len += skb->len;
|
|
|
|
head->len += skb->len;
|
|
|
|
head->truesize += skb->truesize;
|
|
|
|
}
|
|
|
|
|
2017-07-29 01:22:43 +02:00
|
|
|
if (!stm->strp.full_len) {
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
ssize_t len;
|
|
|
|
|
|
|
|
len = (*strp->cb.parse_msg)(strp, head);
|
|
|
|
|
|
|
|
if (!len) {
|
|
|
|
/* Need more header to determine length */
|
2017-07-29 01:22:43 +02:00
|
|
|
if (!stm->accum_len) {
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
/* Start RX timer for new message */
|
2017-07-29 01:22:43 +02:00
|
|
|
strp_start_timer(strp, timeo);
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
}
|
2017-07-29 01:22:43 +02:00
|
|
|
stm->accum_len += cand_len;
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
eaten += cand_len;
|
2017-07-29 01:22:43 +02:00
|
|
|
STRP_STATS_INCR(strp->stats.need_more_hdr);
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
WARN_ON(eaten != orig_len);
|
|
|
|
break;
|
|
|
|
} else if (len < 0) {
|
2017-07-29 01:22:43 +02:00
|
|
|
if (len == -ESTRPIPE && stm->accum_len) {
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
len = -ENODATA;
|
2017-07-29 01:22:43 +02:00
|
|
|
strp->unrecov_intr = 1;
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
} else {
|
2017-07-29 01:22:43 +02:00
|
|
|
strp->interrupted = 1;
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
}
|
2016-10-06 15:41:49 +02:00
|
|
|
strp_parser_err(strp, len, desc);
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
break;
|
2017-07-29 01:22:43 +02:00
|
|
|
} else if (len > max_msg_size) {
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
/* Message length exceeds maximum allowed */
|
2017-07-29 01:22:43 +02:00
|
|
|
STRP_STATS_INCR(strp->stats.msg_too_big);
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
strp_parser_err(strp, -EMSGSIZE, desc);
|
|
|
|
break;
|
|
|
|
} else if (len <= (ssize_t)head->len -
|
2017-07-29 01:22:43 +02:00
|
|
|
skb->len - stm->strp.offset) {
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
/* Length must be into new skb (and also
|
|
|
|
* greater than zero)
|
|
|
|
*/
|
2017-07-29 01:22:43 +02:00
|
|
|
STRP_STATS_INCR(strp->stats.bad_hdr_len);
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
strp_parser_err(strp, -EPROTO, desc);
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
2017-07-29 01:22:43 +02:00
|
|
|
stm->strp.full_len = len;
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
}
|
|
|
|
|
2017-07-29 01:22:43 +02:00
|
|
|
extra = (ssize_t)(stm->accum_len + cand_len) -
|
|
|
|
stm->strp.full_len;
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
|
|
|
|
if (extra < 0) {
|
|
|
|
/* Message not complete yet. */
|
2017-07-29 01:22:43 +02:00
|
|
|
if (stm->strp.full_len - stm->accum_len >
|
2016-08-28 23:43:19 +02:00
|
|
|
strp_peek_len(strp)) {
|
2017-07-29 01:22:43 +02:00
|
|
|
/* Don't have the whole message in the socket
|
|
|
|
* buffer. Set strp->need_bytes to wait for
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
* the rest of the message. Also, set "early
|
|
|
|
* eaten" since we've already buffered the skb
|
2016-08-28 23:43:19 +02:00
|
|
|
* but don't consume yet per strp_read_sock.
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
*/
|
|
|
|
|
2017-07-29 01:22:43 +02:00
|
|
|
if (!stm->accum_len) {
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
/* Start RX timer for new message */
|
2017-07-29 01:22:43 +02:00
|
|
|
strp_start_timer(strp, timeo);
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
}
|
|
|
|
|
2018-04-12 00:05:16 +02:00
|
|
|
stm->accum_len += cand_len;
|
2018-06-27 03:33:33 +02:00
|
|
|
eaten += cand_len;
|
2017-07-29 01:22:43 +02:00
|
|
|
strp->need_bytes = stm->strp.full_len -
|
|
|
|
stm->accum_len;
|
|
|
|
STRP_STATS_ADD(strp->stats.bytes, cand_len);
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
desc->count = 0; /* Stop reading socket */
|
|
|
|
break;
|
|
|
|
}
|
2017-07-29 01:22:43 +02:00
|
|
|
stm->accum_len += cand_len;
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
eaten += cand_len;
|
|
|
|
WARN_ON(eaten != orig_len);
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
2019-04-10 22:18:57 +02:00
|
|
|
/* Positive extra indicates more bytes than needed for the
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
* message
|
|
|
|
*/
|
|
|
|
|
|
|
|
WARN_ON(extra > cand_len);
|
|
|
|
|
|
|
|
eaten += (cand_len - extra);
|
|
|
|
|
|
|
|
/* Hurray, we have a new message! */
|
2017-10-21 01:40:43 +02:00
|
|
|
cancel_delayed_work(&strp->msg_timer_work);
|
2017-07-29 01:22:43 +02:00
|
|
|
strp->skb_head = NULL;
|
2018-04-12 00:05:16 +02:00
|
|
|
strp->need_bytes = 0;
|
2017-07-29 01:22:43 +02:00
|
|
|
STRP_STATS_INCR(strp->stats.msgs);
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
|
|
|
|
/* Give skb to upper layer */
|
|
|
|
strp->cb.rcv_msg(strp, head);
|
|
|
|
|
2017-07-29 01:22:43 +02:00
|
|
|
if (unlikely(strp->paused)) {
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
/* Upper layer paused strp */
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
if (cloned_orig)
|
|
|
|
kfree_skb(orig_skb);
|
|
|
|
|
2017-07-29 01:22:43 +02:00
|
|
|
STRP_STATS_ADD(strp->stats.bytes, eaten);
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
|
|
|
|
return eaten;
|
|
|
|
}
|
|
|
|
|
2017-07-29 01:22:43 +02:00
|
|
|
int strp_process(struct strparser *strp, struct sk_buff *orig_skb,
|
|
|
|
unsigned int orig_offset, size_t orig_len,
|
|
|
|
size_t max_msg_size, long timeo)
|
|
|
|
{
|
|
|
|
read_descriptor_t desc; /* Dummy arg to strp_recv */
|
|
|
|
|
|
|
|
desc.arg.data = strp;
|
|
|
|
|
|
|
|
return __strp_recv(&desc, orig_skb, orig_offset, orig_len,
|
|
|
|
max_msg_size, timeo);
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(strp_process);
|
|
|
|
|
|
|
|
static int strp_recv(read_descriptor_t *desc, struct sk_buff *orig_skb,
|
|
|
|
unsigned int orig_offset, size_t orig_len)
|
|
|
|
{
|
|
|
|
struct strparser *strp = (struct strparser *)desc->arg.data;
|
|
|
|
|
|
|
|
return __strp_recv(desc, orig_skb, orig_offset, orig_len,
|
|
|
|
strp->sk->sk_rcvbuf, strp->sk->sk_rcvtimeo);
|
|
|
|
}
|
|
|
|
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
static int default_read_sock_done(struct strparser *strp, int err)
|
|
|
|
{
|
|
|
|
return err;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Called with lock held on lower socket */
|
2016-08-28 23:43:19 +02:00
|
|
|
static int strp_read_sock(struct strparser *strp)
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
{
|
2016-08-28 23:43:19 +02:00
|
|
|
struct socket *sock = strp->sk->sk_socket;
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
read_descriptor_t desc;
|
|
|
|
|
2017-08-16 07:30:47 +02:00
|
|
|
if (unlikely(!sock || !sock->ops || !sock->ops->read_sock))
|
|
|
|
return -EBUSY;
|
|
|
|
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
desc.arg.data = strp;
|
|
|
|
desc.error = 0;
|
|
|
|
desc.count = 1; /* give more than one skb per call */
|
|
|
|
|
2016-08-28 23:43:19 +02:00
|
|
|
/* sk should be locked here, so okay to do read_sock */
|
|
|
|
sock->ops->read_sock(strp->sk, &desc, strp_recv);
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
|
|
|
|
desc.error = strp->cb.read_sock_done(strp, desc.error);
|
|
|
|
|
|
|
|
return desc.error;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Lower sock lock held */
|
2016-08-28 23:43:19 +02:00
|
|
|
void strp_data_ready(struct strparser *strp)
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
{
|
2018-06-20 23:59:49 +02:00
|
|
|
if (unlikely(strp->stopped) || strp->paused)
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
return;
|
|
|
|
|
2017-07-29 01:22:43 +02:00
|
|
|
/* This check is needed to synchronize with do_strp_work.
|
|
|
|
* do_strp_work acquires a process lock (lock_sock) whereas
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
* the lock held here is bh_lock_sock. The two locks can be
|
|
|
|
* held by different threads at the same time, but bh_lock_sock
|
|
|
|
* allows a thread in BH context to safely check if the process
|
|
|
|
* lock is held. In this case, if the lock is held, queue work.
|
|
|
|
*/
|
2017-12-28 20:00:44 +01:00
|
|
|
if (sock_owned_by_user_nocheck(strp->sk)) {
|
2017-07-29 01:22:43 +02:00
|
|
|
queue_work(strp_wq, &strp->work);
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
2017-07-29 01:22:43 +02:00
|
|
|
if (strp->need_bytes) {
|
2018-04-12 00:05:16 +02:00
|
|
|
if (strp_peek_len(strp) < strp->need_bytes)
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
2016-08-28 23:43:19 +02:00
|
|
|
if (strp_read_sock(strp) == -ENOMEM)
|
2017-07-29 01:22:43 +02:00
|
|
|
queue_work(strp_wq, &strp->work);
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
}
|
2016-08-28 23:43:19 +02:00
|
|
|
EXPORT_SYMBOL_GPL(strp_data_ready);
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
|
2017-07-29 01:22:43 +02:00
|
|
|
static void do_strp_work(struct strparser *strp)
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
{
|
2016-08-28 23:43:19 +02:00
|
|
|
/* We need the read lock to synchronize with strp_data_ready. We
|
|
|
|
* need the socket lock for calling strp_read_sock.
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
*/
|
2017-07-29 01:22:43 +02:00
|
|
|
strp->cb.lock(strp);
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
|
2017-07-29 01:22:43 +02:00
|
|
|
if (unlikely(strp->stopped))
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
goto out;
|
|
|
|
|
2017-07-29 01:22:43 +02:00
|
|
|
if (strp->paused)
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
goto out;
|
|
|
|
|
2016-08-28 23:43:19 +02:00
|
|
|
if (strp_read_sock(strp) == -ENOMEM)
|
2017-07-29 01:22:43 +02:00
|
|
|
queue_work(strp_wq, &strp->work);
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
|
|
|
|
out:
|
2017-07-29 01:22:43 +02:00
|
|
|
strp->cb.unlock(strp);
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
}
|
|
|
|
|
2017-07-29 01:22:43 +02:00
|
|
|
static void strp_work(struct work_struct *w)
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
{
|
2017-07-29 01:22:43 +02:00
|
|
|
do_strp_work(container_of(w, struct strparser, work));
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
}
|
|
|
|
|
2017-10-21 01:40:43 +02:00
|
|
|
static void strp_msg_timeout(struct work_struct *w)
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
{
|
2017-10-21 01:40:43 +02:00
|
|
|
struct strparser *strp = container_of(w, struct strparser,
|
|
|
|
msg_timer_work.work);
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
|
|
|
|
/* Message assembly timed out */
|
2017-07-29 01:22:43 +02:00
|
|
|
STRP_STATS_INCR(strp->stats.msg_timeouts);
|
|
|
|
strp->cb.lock(strp);
|
2018-03-26 21:31:21 +02:00
|
|
|
strp->cb.abort_parser(strp, -ETIMEDOUT);
|
2017-07-29 01:22:43 +02:00
|
|
|
strp->cb.unlock(strp);
|
|
|
|
}
|
|
|
|
|
|
|
|
static void strp_sock_lock(struct strparser *strp)
|
|
|
|
{
|
|
|
|
lock_sock(strp->sk);
|
|
|
|
}
|
|
|
|
|
|
|
|
static void strp_sock_unlock(struct strparser *strp)
|
|
|
|
{
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
release_sock(strp->sk);
|
|
|
|
}
|
|
|
|
|
2017-07-29 01:22:43 +02:00
|
|
|
int strp_init(struct strparser *strp, struct sock *sk,
|
strparser: initialize all callbacks
commit bbb03029a899 ("strparser: Generalize strparser") added more
function pointers to 'struct strp_callbacks'; however, kcm_attach() was
not updated to initialize them. This could cause the ->lock() and/or
->unlock() function pointers to be set to garbage values, causing a
crash in strp_work().
Fix the bug by moving the callback structs into static memory, so
unspecified members are zeroed. Also constify them while we're at it.
This bug was found by syzkaller, which encountered the following splat:
IP: 0x55
PGD 3b1ca067
P4D 3b1ca067
PUD 3b12f067
PMD 0
Oops: 0010 [#1] SMP KASAN
Dumping ftrace buffer:
(ftrace buffer empty)
Modules linked in:
CPU: 2 PID: 1194 Comm: kworker/u8:1 Not tainted 4.13.0-rc4-next-20170811 #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Workqueue: kstrp strp_work
task: ffff88006bb0e480 task.stack: ffff88006bb10000
RIP: 0010:0x55
RSP: 0018:ffff88006bb17540 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffff88006ce4bd60 RCX: 0000000000000000
RDX: 1ffff1000d9c97bd RSI: 0000000000000000 RDI: ffff88006ce4bc48
RBP: ffff88006bb17558 R08: ffffffff81467ab2 R09: 0000000000000000
R10: ffff88006bb17438 R11: ffff88006bb17940 R12: ffff88006ce4bc48
R13: ffff88003c683018 R14: ffff88006bb17980 R15: ffff88003c683000
FS: 0000000000000000(0000) GS:ffff88006de00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000055 CR3: 000000003c145000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
process_one_work+0xbf3/0x1bc0 kernel/workqueue.c:2098
worker_thread+0x223/0x1860 kernel/workqueue.c:2233
kthread+0x35e/0x430 kernel/kthread.c:231
ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431
Code: Bad RIP value.
RIP: 0x55 RSP: ffff88006bb17540
CR2: 0000000000000055
---[ end trace f0e4920047069cee ]---
Here is a C reproducer (requires CONFIG_BPF_SYSCALL=y and
CONFIG_AF_KCM=y):
#include <linux/bpf.h>
#include <linux/kcm.h>
#include <linux/types.h>
#include <stdint.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/syscall.h>
#include <unistd.h>
static const struct bpf_insn bpf_insns[3] = {
{ .code = 0xb7 }, /* BPF_MOV64_IMM(0, 0) */
{ .code = 0x95 }, /* BPF_EXIT_INSN() */
};
static const union bpf_attr bpf_attr = {
.prog_type = 1,
.insn_cnt = 2,
.insns = (uintptr_t)&bpf_insns,
.license = (uintptr_t)"",
};
int main(void)
{
int bpf_fd = syscall(__NR_bpf, BPF_PROG_LOAD,
&bpf_attr, sizeof(bpf_attr));
int inet_fd = socket(AF_INET, SOCK_STREAM, 0);
int kcm_fd = socket(AF_KCM, SOCK_DGRAM, 0);
ioctl(kcm_fd, SIOCKCMATTACH,
&(struct kcm_attach) { .fd = inet_fd, .bpf_fd = bpf_fd });
}
Fixes: bbb03029a899 ("strparser: Generalize strparser")
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Tom Herbert <tom@quantonium.net>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-24 23:38:51 +02:00
|
|
|
const struct strp_callbacks *cb)
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
{
|
2016-08-28 23:43:19 +02:00
|
|
|
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
if (!cb || !cb->rcv_msg || !cb->parse_msg)
|
|
|
|
return -EINVAL;
|
|
|
|
|
2017-07-29 01:22:43 +02:00
|
|
|
/* The sk (sock) arg determines the mode of the stream parser.
|
|
|
|
*
|
|
|
|
* If the sock is set then the strparser is in receive callback mode.
|
|
|
|
* The upper layer calls strp_data_ready to kick receive processing
|
|
|
|
* and strparser calls the read_sock function on the socket to
|
|
|
|
* get packets.
|
|
|
|
*
|
|
|
|
* If the sock is not set then the strparser is in general mode.
|
|
|
|
* The upper layer calls strp_process for each skb to be parsed.
|
|
|
|
*/
|
2016-08-28 23:43:19 +02:00
|
|
|
|
2017-08-16 07:30:47 +02:00
|
|
|
if (!sk) {
|
2017-07-29 01:22:43 +02:00
|
|
|
if (!cb->lock || !cb->unlock)
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
|
2017-07-29 01:22:43 +02:00
|
|
|
memset(strp, 0, sizeof(*strp));
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
|
2017-07-29 01:22:43 +02:00
|
|
|
strp->sk = sk;
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
|
2017-07-29 01:22:43 +02:00
|
|
|
strp->cb.lock = cb->lock ? : strp_sock_lock;
|
|
|
|
strp->cb.unlock = cb->unlock ? : strp_sock_unlock;
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
strp->cb.rcv_msg = cb->rcv_msg;
|
|
|
|
strp->cb.parse_msg = cb->parse_msg;
|
|
|
|
strp->cb.read_sock_done = cb->read_sock_done ? : default_read_sock_done;
|
2017-07-29 01:22:43 +02:00
|
|
|
strp->cb.abort_parser = cb->abort_parser ? : strp_abort_strp;
|
|
|
|
|
2017-10-21 01:40:43 +02:00
|
|
|
INIT_DELAYED_WORK(&strp->msg_timer_work, strp_msg_timeout);
|
2017-07-29 01:22:43 +02:00
|
|
|
INIT_WORK(&strp->work, strp_work);
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(strp_init);
|
|
|
|
|
2018-06-06 18:33:28 +02:00
|
|
|
/* Sock process lock held (lock_sock) */
|
|
|
|
void __strp_unpause(struct strparser *strp)
|
|
|
|
{
|
|
|
|
strp->paused = 0;
|
|
|
|
|
|
|
|
if (strp->need_bytes) {
|
|
|
|
if (strp_peek_len(strp) < strp->need_bytes)
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
strp_read_sock(strp);
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(__strp_unpause);
|
|
|
|
|
2016-08-23 20:55:30 +02:00
|
|
|
void strp_unpause(struct strparser *strp)
|
|
|
|
{
|
2017-07-29 01:22:43 +02:00
|
|
|
strp->paused = 0;
|
2016-08-23 20:55:30 +02:00
|
|
|
|
2017-07-29 01:22:43 +02:00
|
|
|
/* Sync setting paused with RX work */
|
2016-08-23 20:55:30 +02:00
|
|
|
smp_mb();
|
|
|
|
|
2017-07-29 01:22:43 +02:00
|
|
|
queue_work(strp_wq, &strp->work);
|
2016-08-23 20:55:30 +02:00
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(strp_unpause);
|
|
|
|
|
2016-08-28 23:43:19 +02:00
|
|
|
/* strp must already be stopped so that strp_recv will no longer be called.
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
* Note that strp_done is not called with the lower socket held.
|
|
|
|
*/
|
|
|
|
void strp_done(struct strparser *strp)
|
|
|
|
{
|
2017-07-29 01:22:43 +02:00
|
|
|
WARN_ON(!strp->stopped);
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
|
2017-10-21 01:40:43 +02:00
|
|
|
cancel_delayed_work_sync(&strp->msg_timer_work);
|
2017-07-29 01:22:43 +02:00
|
|
|
cancel_work_sync(&strp->work);
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
|
2017-07-29 01:22:43 +02:00
|
|
|
if (strp->skb_head) {
|
|
|
|
kfree_skb(strp->skb_head);
|
|
|
|
strp->skb_head = NULL;
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
}
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(strp_done);
|
|
|
|
|
|
|
|
void strp_stop(struct strparser *strp)
|
|
|
|
{
|
2017-07-29 01:22:43 +02:00
|
|
|
strp->stopped = 1;
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(strp_stop);
|
|
|
|
|
|
|
|
void strp_check_rcv(struct strparser *strp)
|
|
|
|
{
|
2017-07-29 01:22:43 +02:00
|
|
|
queue_work(strp_wq, &strp->work);
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(strp_check_rcv);
|
|
|
|
|
2019-04-21 05:29:48 +02:00
|
|
|
static int __init strp_dev_init(void)
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
{
|
|
|
|
strp_wq = create_singlethread_workqueue("kstrp");
|
2019-03-15 05:12:06 +01:00
|
|
|
if (unlikely(!strp_wq))
|
|
|
|
return -ENOMEM;
|
strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.
The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.
A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:
int strp_init(struct strparser *strp, struct sock *csk,
struct strp_callbacks *cb);
csk is the TCP socket being bound to and cb are the parser callbacks.
The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:
void strp_tcp_data_ready(struct strparser *strp);
A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.
There are four callbacks.
- parse_msg is called to parse the message (returns length or error).
- rcv_msg is called when a complete message has been received
- read_sock_done is called when data_ready function exits
- abort_parser is called to abort the parser
The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:
>0 : indicates length of successfully parsed message
0 : indicates more data must be received to parse the message
-ESTRPIPE : current message should not be processed by the
kernel, return control of the socket to userspace which
can proceed to read the messages itself
other < 0 : Error is parsing, give control back to userspace
assuming that synchronzation is lost and the stream
is unrecoverable (application expected to close TCP socket)
In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.
Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).
strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 23:51:01 +02:00
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
2019-04-21 05:29:48 +02:00
|
|
|
device_initcall(strp_dev_init);
|