Commit Graph

36 Commits

Author SHA1 Message Date
Daniel P. Berrangé dd154c4d9f io: fix handling of EOF / error conditions in websock GSource
We were never reporting the G_IO_HUP event when an end of file was hit
on the websocket channel.

We also didn't report G_IO_ERR when we hit a fatal error processing the
websocket protocol.

The latter in particular meant that the chardev code would not notice
when an eof/error was encountered on the websocket channel, unless the
guest OS happened to trigger a write operation.

This meant that once the first client had quit, the chardev would never
listen to accept a new client.

Fixes launchpad bug 1816819
Acked-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-03-20 16:56:30 +00:00
Marc-André Lureau ad824bdc63 websock: fix handshake leak
Missed in f69a8bde29.
Thanks Valgrind:

==955== 217 bytes in 1 blocks are definitely lost in loss record 275 of 321
==955==    at 0x483A965: realloc (vg_replace_malloc.c:785)
==955==    by 0x50B6839: __vasprintf_chk (in /usr/lib64/libc-2.28.so)
==955==    by 0x49AA05C: g_vasprintf (in /usr/lib64/libglib-2.0.so.0.5800.1)
==955==    by 0x4983440: g_strdup_vprintf (in /usr/lib64/libglib-2.0.so.0.5800.1)
==955==    by 0x126048: qio_channel_websock_handshake_send_res (channel-websock.c:162)
==955==    by 0x1266E6: qio_channel_websock_handshake_send_res_ok (channel-websock.c:362)
==955==    by 0x126D3E: qio_channel_websock_handshake_process (channel-websock.c:468)
==955==    by 0x126EF2: qio_channel_websock_handshake_read (channel-websock.c:511)
==955==    by 0x12715B: qio_channel_websock_handshake_io (channel-websock.c:571)
==955==    by 0x125027: qio_channel_fd_source_dispatch (channel-watch.c:84)
==955==    by 0x496326C: g_main_context_dispatch (in /usr/lib64/libglib-2.0.so.0.5800.1)
==955==    by 0x169EC3: glib_pollfds_poll (main-loop.c:215)

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2018-11-01 12:12:09 +04:00
Laurent Vivier 710c263407 error: Remove NULL checks on error_propagate() calls
Re-run Coccinelle patch
scripts/coccinelle/error_propagate_null.cocci

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Message-Id: <20180323143202.28879-4-lvivier@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2018-03-27 10:17:32 -05:00
Edgar Kaziakhmedov a46ded1de5 io/channel-websock: handle continuous reads without any data
According to the current implementation of websocket protocol in QEMU,
qio_channel_websock_handshake_io tries to read handshake from the
channel to start communication over socket. But this approach
doesn't cover scenario when socket was closed while handshaking.
Therefore, if G_IO_IN is caught and qio_channel_read returns zero,
error has to be set and connection has to be done.

Such behaviour causes 100% CPU load in main QEMU loop, because main loop
poll continues to receive and handle G_IO_IN events from websocket.

Step to reproduce 100% CPU load:
1) start qemu with the simplest configuration
$ qemu -vnc [::1]:1,websocket=7500
2) open any vnc listener (which doesn't follow websocket
protocol)
$ vncviewer :7500
3) kill listener
4) qemu main thread eats 100% CPU

Signed-off-by: Edgar Kaziakhmedov <edgar.kaziakhmedov@virtuozzo.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2018-02-15 16:54:57 +00:00
Markus Armbruster 8f0a3716e4 Clean up includes
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.

This commit was created with scripts/clean-includes, with the change
to target/s390x/gen-features.c manually reverted, and blank lines
around deletions collapsed.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180201111846.21846-3-armbru@redhat.com>
2018-02-09 05:05:11 +01:00
Peter Maydell a9038e5e19 trivial patches for 2017-10-16
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Merge remote-tracking branch 'remotes/mjt/tags/trivial-patches-fetch' into staging

trivial patches for 2017-10-16

# gpg: Signature made Mon 16 Oct 2017 21:32:05 BST
# gpg:                using RSA key 0x701B4F6B1A693E59
# gpg: Good signature from "Michael Tokarev <mjt@tls.msk.ru>"
# gpg:                 aka "Michael Tokarev <mjt@corpit.ru>"
# gpg:                 aka "Michael Tokarev <mjt@debian.org>"
# Primary key fingerprint: 6EE1 95D1 886E 8FFB 810D  4324 457C E0A0 8044 65C5
#      Subkey fingerprint: 7B73 BAD6 8BE7 A2C2 8931  4B22 701B 4F6B 1A69 3E59

* remotes/mjt/tags/trivial-patches-fetch:
  Add myself as maintainer for TPM code
  filter-mirror: segfault when specifying non existent device
  MAINTAINERS: Track default-configs/pci.mak
  MAINTAINERS: Fix Sun4v file
  MAINTAINERS: Clean up SCSI device section
  include/hw/or-irq.h: Drop unused in_irqs field
  io: Add missing GCC_FMT_ATTR (fix -Werror=suggest-attribute=format)
  os-posix: Drop misleading comment
  linux-user: Add some random ioctls
  futex: add missing header guards
  ui/gtk: Fix deprecation of vte_terminal_copy_clipboard
  gitignore: ignore check-qlit test
  linux-user: remove duplicate break in syscall
  qemu-doc.texi: remove trailing whitespace

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-10-17 13:13:03 +01:00
Stefan Weil 52aa5644e8 io: Add missing GCC_FMT_ATTR (fix -Werror=suggest-attribute=format)
This fixes a compiler warning:

/qemu/io/channel-websock.c:163:5: error:
 function might be possible candidate for ‘gnu_printf’ format attribute
 [-Werror=suggest-attribute=format]

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Acked-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2017-10-16 21:03:47 +03:00
Daniel P. Berrange 7fc3fcefe2 io: fix mem leak in websock error path
Coverity pointed out the 'date' is not free()d in the error
path

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-16 16:57:08 +01:00
Daniel P. Berrange 0efd6c9ec1 io: add trace points for websocket HTTP protocol headers
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-16 16:57:08 +01:00
Daniel P. Berrange 6d5d23b007 io: cope with websock 'Connection' header having multiple values
The noVNC server sends a header "Connection: keep-alive, Upgrade" which
fails our simple equality test. Split the header on ',', trim whitespace
and then check for 'upgrade' token.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-16 16:57:08 +01:00
Daniel P. Berrange 8dfd5f9651 io: get rid of bounce buffering in websock write path
Currently most outbound I/O on the websock channel gets copied into the
rawoutput buffer, and then immediately copied again into the encoutput
buffer, with a header prepended. Now that qio_channel_websock_encode
accepts a struct iovec, we can trivially remove this bounce buffering
and write directly to encoutput.

In doing so, we also now correctly validate the encoutput size against
the QIO_CHANNEL_WEBSOCK_MAX_BUFFER limit.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-16 16:57:08 +01:00
Daniel P. Berrange fb74e59039 io: pass a struct iovec into qio_channel_websock_encode
Instead of requiring use of another Buffer, pass a struct iovec
into qio_channel_websock_encode, which gives callers more
flexibility in how they process data.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-16 16:57:08 +01:00
Daniel P. Berrange bac6c95415 io: get rid of qio_channel_websock_encode helper method
The qio_channel_websock_encode method is only used in one place,
everything else calls qio_channel_websock_encode_buffer directly.
It can also be pushed up a level into the qio_channel_websock_writev
method, since every other caller of qio_channel_websock_write_wire
has already filled encoutput.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-16 16:57:08 +01:00
Daniel P. Berrange 57b0cdf152 io: simplify websocket ping reply handling
We must ensure we don't get flooded with ping replies if the outbound
channel is slow. Currently we do this by keeping the ping reply in a
separate temporary buffer and only writing it if the encoutput buffer
is completely empty. This is overly pessimistic, as it is reasonable
to add a ping reply to the encoutput buffer even if it has previous
data in it, as long as that previous data doesn't include a ping
reply.

To track this better, put the ping reply directly into the encoutput
buffer, and then record the size of encoutput at this time in
pong_remain. As we write encoutput to the underlying channel, we
can decrement the pong_remain counter. Once it hits zero, we can
accept further ping replies for transmission.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-16 16:57:08 +01:00
Daniel P. Berrange a7b20a8efa io: monitor encoutput buffer size from websocket GSource
The websocket GSource is monitoring the size of the rawoutput
buffer to determine if the channel can accepts more writes.
The rawoutput buffer, however, is merely a temporary staging
buffer before data is copied into the encoutput buffer. Thus
its size will always be zero when the GSource runs.

This flaw causes the encoutput buffer to grow without bound
if the other end of the underlying data channel doesn't
read data being sent. This can be seen with VNC if a client
is on a slow WAN link and the guest OS is sending many screen
updates. A malicious VNC client can act like it is on a slow
link by playing a video in the guest and then reading data
very slowly, causing QEMU host memory to expand arbitrarily.

This issue is assigned CVE-2017-15268, publically reported in

  https://bugs.launchpad.net/qemu/+bug/1718964

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-16 16:57:08 +01:00
Daniel P. Berrange 59f183bbd5 io: add trace events for websockets frame handling
It is useful to trace websockets frame encoding/decoding when debugging
problems.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-04 13:21:53 +01:00
Brandon Carpenter 530ca60c16 io: Attempt to send websocket close messages to client
Make a best effort attempt to close websocket connections according to
the RFC. Sends the close message, as room permits in the socket buffer,
and immediately closes the socket.

Signed-off-by: Brandon Carpenter <brandon.carpenter@cypherpath.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-04 13:21:53 +01:00
Brandon Carpenter 268a53f50d io: Reply to ping frames
Add an immediate ping reply (pong) to the outgoing stream when a ping
is received. Unsolicited pongs are ignored.

Signed-off-by: Brandon Carpenter <brandon.carpenter@cypherpath.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-04 13:21:53 +01:00
Brandon Carpenter 01af17fc00 io: Ignore websocket PING and PONG frames
Keep pings and gratuitous pongs generated by web browsers from killing
websocket connections.

Signed-off-by: Brandon Carpenter <brandon.carpenter@cypherpath.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-04 13:21:53 +01:00
Brandon Carpenter 3a29640e2c io: Allow empty websocket payload
Some browsers send pings/pongs with no payload, so allow empty payloads
instead of closing the connection.

Signed-off-by: Brandon Carpenter <brandon.carpenter@cypherpath.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-04 13:21:53 +01:00
Brandon Carpenter ff1300e626 io: Add support for fragmented websocket binary frames
Allows fragmented binary frames by saving the previous opcode. Handles
the case where an intermediary (i.e., web proxy) fragments frames
originally sent unfragmented by the client.

Signed-off-by: Brandon Carpenter <brandon.carpenter@cypherpath.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-04 13:21:53 +01:00
Brandon Carpenter eefa3d8ef6 io: Small updates in preparation for websocket changes
Gets rid of unnecessary bit shifting and performs proper EOF checking to
avoid a large number of repeated calls to recvmsg() when a client
abruptly terminates a connection (bug fix).

Signed-off-by: Brandon Carpenter <brandon.carpenter@cypherpath.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-04 13:21:53 +01:00
Daniel P. Berrange 33badfd1e3 io: use case insensitive check for Connection & Upgrade websock headers
When checking the value of the Connection and Upgrade HTTP headers
the websock RFC (6455) requires the comparison to be case insensitive.
The Connection value should be an exact match not a substring.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-04 13:21:53 +01:00
Daniel P. Berrange 3a3f870596 io: include full error message in websocket handshake trace
When the websocket handshake fails it is useful to log the real
error message via the trace points for debugging purposes.

Fixes bug: #1715186

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-04 13:21:53 +01:00
Daniel P. Berrange f69a8bde29 io: send proper HTTP response for websocket errors
When any error occurs while processing the websockets handshake,
QEMU just terminates the connection abruptly. This is in violation
of the HTTP specs and does not help the client understand what they
did wrong. This is particularly bad when the client gives the wrong
path, as a "404 Not Found" would be very helpful.

Refactor the handshake code so that it always sends a response to
the client unless there was an I/O error.

Fixes bug: #1715186

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-10-04 13:21:53 +01:00
Eduardo Habkost e79ea67a97 websock: Don't try to set *errp directly
Assigning directly to *errp is not valid, as errp may be NULL,
&error_fatal, or &error_abort.  Use error_propagate() instead.

Cc: "Daniel P. Berrange" <berrange@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20170608133906.12737-4-ehabkost@redhat.com>
Reviewed-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-07-13 13:45:53 +02:00
Daniel P. Berrange 07e95cd529 io: fully parse & validate HTTP headers for websocket protocol handshake
The current websockets protocol handshake code is very relaxed, just
doing crude string searching across the HTTP header data. This causes
it to both reject valid connections and fail to reject invalid
connections. For example, according to the RFC 6455 it:

 - MUST reject any method other than "GET"
 - MUST reject any HTTP version less than "HTTP/1.1"
 - MUST reject Connection header without "Upgrade" listed
 - MUST reject Upgrade header which is not 'websocket'
 - MUST reject missing Host header
 - MUST treat HTTP header names as case insensitive

To do all this validation correctly requires that we fully parse the
HTTP headers, populating a data structure containing the header
fields.

After this change, we also reject any path other than '/'

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-02-28 11:51:16 +00:00
Daniel P. Berrange cd892a2efc io: fix decoding when multiple websockets frames arrive at once
The qio_channel_websock_read_wire() method will read upto 4096
bytes off the socket and then decode the websockets header and
payload. The code was only decoding a single websockets frame,
even if the buffered data contained multiple frames. This meant
that decoding of subsequent frames was delayed until further
input arrived on the socket. This backlog of delayed frames
gets worse & worse over time.

Symptom was that when connecting to the VNC server via the
built-in websockets server, mouse/keyboard interaction would
start out fine, but slowly get more & more delayed until it
was unusable.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-02-28 10:36:31 +00:00
Daniel P. Berrange 60e705c51c io: change the QIOTask callback signature
Currently the QIOTaskFunc signature takes an Object * for
the source, and an Error * for any error. We also need to
be able to provide a result pointer. Rather than continue
to add parameters to QIOTaskFunc, remove the existing
ones and simply pass the QIOTask object instead. This
has methods to access all the other data items required
in the callback impl.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-01-23 15:32:18 +00:00
Felipe Franciosi d8d3c7cc67 io: Introduce a qio_channel_set_feature() helper
Testing QIOChannel feature support can be done with a helper called
qio_channel_has_feature(). Setting feature support, however, was
done manually with a logical OR. This patch introduces a new helper
called qio_channel_set_feature() and makes use of it where applicable.

Signed-off-by: Felipe Franciosi <felipe@nutanix.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-10-26 18:19:53 +02:00
Felipe Franciosi e413ae0c04 io: Use qio_channel_has_feature() where applicable
Parts of the code have been testing QIOChannel features directly with a
logical AND. This patch makes it all consistent by using the
qio_channel_has_feature() function to test if a feature is present.

Signed-off-by: Felipe Franciosi <felipe@nutanix.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-10-26 18:19:53 +02:00
Daniel P. Berrange bc35d51077 io: remove mistaken call to object_ref on QTask
The QTask struct is just a standalone struct, not a QOM Object,
so calling object_ref() on it is not appropriate. This results
in mangling the 'destroy' field in the QTask struct, causing
the later call to qtask_free() to try to call the function
at address 0x1, with predictably segfault happy results.

There is in fact no need for ref counting with QTask, as the
call to qtask_abort() or qtask_complete() will automatically
free associated memory.

This fixes the crash shown in

  https://bugs.launchpad.net/qemu/+bug/1589923

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-08-03 10:28:50 +01:00
Paolo Bonzini 58369e22cf qemu-common: stop including qemu/bswap.h from qemu-common.h
Move it to the actual users.  There are still a few includes of
qemu/bswap.h in headers; removing them is left for future work.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-05-19 16:42:28 +02:00
Markus Armbruster da34e65cb4 include/qemu/osdep.h: Don't include qapi/error.h
Commit 57cb38b included qapi/error.h into qemu/osdep.h to get the
Error typedef.  Since then, we've moved to include qemu/osdep.h
everywhere.  Its file comment explains: "To avoid getting into
possible circular include dependencies, this file should not include
any other QEMU headers, with the exceptions of config-host.h,
compiler.h, os-posix.h and os-win32.h, all of which are doing a
similar job to this file and are under similar constraints."
qapi/error.h doesn't do a similar job, and it doesn't adhere to
similar constraints: it includes qapi-types.h.  That's in excess of
100KiB of crap most .c files don't actually need.

Add the typedef to qemu/typedefs.h, and include that instead of
qapi/error.h.  Include qapi/error.h in .c files that need it and don't
get it now.  Include qapi-types.h in qom/object.h for uint16List.

Update scripts/clean-includes accordingly.  Update it further to match
reality: replace config.h by config-target.h, add sysemu/os-posix.h,
sysemu/os-win32.h.  Update the list of includes in the qemu/osdep.h
comment quoted above similarly.

This reduces the number of objects depending on qapi/error.h from "all
of them" to less than a third.  Unfortunately, the number depending on
qapi-types.h shrinks only a little.  More work is needed for that one.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
[Fix compilation without the spice devel packages. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22 22:20:15 +01:00
Peter Maydell cae9fc567d io: Clean up includes
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.

This commit was created with scripts/clean-includes.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1454089805-5470-14-git-send-email-peter.maydell@linaro.org
2016-02-04 17:41:30 +00:00
Daniel P. Berrange 2d1d0e70cf io: add QIOChannelWebsock class
Add a QIOChannel subclass that can run the websocket protocol over
the top of another QIOChannel instance. This initial implementation
is only capable of acting as a websockets server. There is no support
for acting as a websockets client yet.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2015-12-18 12:18:31 +00:00