19f6d3f3c8
This patch adds a new socket option, TCP_FASTOPEN_CONNECT, as an
alternative way to perform Fast Open on the active side (client). Prior
to this patch, a client needs to replace the connect() call with
sendto(MSG_FASTOPEN). This can be cumbersome for applications who want
to use Fast Open: these socket operations are often done in lower layer
libraries used by many other applications. Changing these libraries
and/or the socket call sequences are not trivial. A more convenient
approach is to perform Fast Open by simply enabling a socket option when
the socket is created w/o changing other socket calls sequence:
s = socket()
create a new socket
setsockopt(s, IPPROTO_TCP, TCP_FASTOPEN_CONNECT …);
newly introduced sockopt
If set, new functionality described below will be used.
Return ENOTSUPP if TFO is not supported or not enabled in the
kernel.
connect()
With cookie present, return 0 immediately.
With no cookie, initiate 3WHS with TFO cookie-request option and
return -1 with errno = EINPROGRESS.
write()/sendmsg()
With cookie present, send out SYN with data and return the number of
bytes buffered.
With no cookie, and 3WHS not yet completed, return -1 with errno =
EINPROGRESS.
No MSG_FASTOPEN flag is needed.
read()
Return -1 with errno = EWOULDBLOCK/EAGAIN if connect() is called but
write() is not called yet.
Return -1 with errno = EWOULDBLOCK/EAGAIN if connection is
established but no msg is received yet.
Return number of bytes read if socket is established and there is
msg received.
The new API simplifies life for applications that always perform a write()
immediately after a successful connect(). Such applications can now take
advantage of Fast Open by merely making one new setsockopt() call at the time
of creating the socket. Nothing else about the application's socket call
sequence needs to change.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
332 lines
8.3 KiB
C
332 lines
8.3 KiB
C
/*
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* INET An implementation of the TCP/IP protocol suite for the LINUX
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* operating system. INET is implemented using the BSD Socket
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* interface as the means of communication with the user level.
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*
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* Definitions for inet_sock
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*
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* Authors: Many, reorganised here by
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* Arnaldo Carvalho de Melo <acme@mandriva.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#ifndef _INET_SOCK_H
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#define _INET_SOCK_H
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#include <linux/bitops.h>
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#include <linux/kmemcheck.h>
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#include <linux/string.h>
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#include <linux/types.h>
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#include <linux/jhash.h>
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#include <linux/netdevice.h>
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#include <net/flow.h>
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#include <net/sock.h>
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#include <net/request_sock.h>
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#include <net/netns/hash.h>
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#include <net/tcp_states.h>
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#include <net/l3mdev.h>
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/** struct ip_options - IP Options
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*
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* @faddr - Saved first hop address
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* @nexthop - Saved nexthop address in LSRR and SSRR
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* @is_strictroute - Strict source route
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* @srr_is_hit - Packet destination addr was our one
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* @is_changed - IP checksum more not valid
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* @rr_needaddr - Need to record addr of outgoing dev
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* @ts_needtime - Need to record timestamp
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* @ts_needaddr - Need to record addr of outgoing dev
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*/
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struct ip_options {
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__be32 faddr;
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__be32 nexthop;
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unsigned char optlen;
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unsigned char srr;
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unsigned char rr;
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unsigned char ts;
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unsigned char is_strictroute:1,
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srr_is_hit:1,
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is_changed:1,
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rr_needaddr:1,
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ts_needtime:1,
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ts_needaddr:1;
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unsigned char router_alert;
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unsigned char cipso;
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unsigned char __pad2;
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unsigned char __data[0];
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};
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struct ip_options_rcu {
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struct rcu_head rcu;
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struct ip_options opt;
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};
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struct ip_options_data {
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struct ip_options_rcu opt;
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char data[40];
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};
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struct inet_request_sock {
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struct request_sock req;
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#define ir_loc_addr req.__req_common.skc_rcv_saddr
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#define ir_rmt_addr req.__req_common.skc_daddr
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#define ir_num req.__req_common.skc_num
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#define ir_rmt_port req.__req_common.skc_dport
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#define ir_v6_rmt_addr req.__req_common.skc_v6_daddr
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#define ir_v6_loc_addr req.__req_common.skc_v6_rcv_saddr
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#define ir_iif req.__req_common.skc_bound_dev_if
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#define ir_cookie req.__req_common.skc_cookie
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#define ireq_net req.__req_common.skc_net
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#define ireq_state req.__req_common.skc_state
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#define ireq_family req.__req_common.skc_family
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kmemcheck_bitfield_begin(flags);
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u16 snd_wscale : 4,
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rcv_wscale : 4,
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tstamp_ok : 1,
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sack_ok : 1,
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wscale_ok : 1,
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ecn_ok : 1,
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acked : 1,
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no_srccheck: 1;
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kmemcheck_bitfield_end(flags);
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u32 ir_mark;
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union {
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struct ip_options_rcu *opt;
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#if IS_ENABLED(CONFIG_IPV6)
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struct {
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struct ipv6_txoptions *ipv6_opt;
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struct sk_buff *pktopts;
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};
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#endif
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};
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};
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static inline struct inet_request_sock *inet_rsk(const struct request_sock *sk)
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{
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return (struct inet_request_sock *)sk;
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}
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static inline u32 inet_request_mark(const struct sock *sk, struct sk_buff *skb)
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{
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if (!sk->sk_mark && sock_net(sk)->ipv4.sysctl_tcp_fwmark_accept)
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return skb->mark;
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return sk->sk_mark;
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}
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static inline int inet_request_bound_dev_if(const struct sock *sk,
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struct sk_buff *skb)
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{
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#ifdef CONFIG_NET_L3_MASTER_DEV
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struct net *net = sock_net(sk);
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if (!sk->sk_bound_dev_if && net->ipv4.sysctl_tcp_l3mdev_accept)
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return l3mdev_master_ifindex_by_index(net, skb->skb_iif);
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#endif
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return sk->sk_bound_dev_if;
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}
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struct inet_cork {
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unsigned int flags;
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__be32 addr;
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struct ip_options *opt;
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unsigned int fragsize;
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int length; /* Total length of all frames */
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struct dst_entry *dst;
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u8 tx_flags;
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__u8 ttl;
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__s16 tos;
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char priority;
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};
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struct inet_cork_full {
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struct inet_cork base;
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struct flowi fl;
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};
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struct ip_mc_socklist;
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struct ipv6_pinfo;
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struct rtable;
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/** struct inet_sock - representation of INET sockets
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*
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* @sk - ancestor class
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* @pinet6 - pointer to IPv6 control block
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* @inet_daddr - Foreign IPv4 addr
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* @inet_rcv_saddr - Bound local IPv4 addr
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* @inet_dport - Destination port
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* @inet_num - Local port
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* @inet_saddr - Sending source
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* @uc_ttl - Unicast TTL
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* @inet_sport - Source port
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* @inet_id - ID counter for DF pkts
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* @tos - TOS
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* @mc_ttl - Multicasting TTL
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* @is_icsk - is this an inet_connection_sock?
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* @uc_index - Unicast outgoing device index
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* @mc_index - Multicast device index
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* @mc_list - Group array
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* @cork - info to build ip hdr on each ip frag while socket is corked
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*/
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struct inet_sock {
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/* sk and pinet6 has to be the first two members of inet_sock */
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struct sock sk;
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#if IS_ENABLED(CONFIG_IPV6)
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struct ipv6_pinfo *pinet6;
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#endif
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/* Socket demultiplex comparisons on incoming packets. */
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#define inet_daddr sk.__sk_common.skc_daddr
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#define inet_rcv_saddr sk.__sk_common.skc_rcv_saddr
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#define inet_dport sk.__sk_common.skc_dport
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#define inet_num sk.__sk_common.skc_num
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__be32 inet_saddr;
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__s16 uc_ttl;
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__u16 cmsg_flags;
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__be16 inet_sport;
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__u16 inet_id;
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struct ip_options_rcu __rcu *inet_opt;
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int rx_dst_ifindex;
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__u8 tos;
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__u8 min_ttl;
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__u8 mc_ttl;
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__u8 pmtudisc;
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__u8 recverr:1,
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is_icsk:1,
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freebind:1,
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hdrincl:1,
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mc_loop:1,
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transparent:1,
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mc_all:1,
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nodefrag:1;
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__u8 bind_address_no_port:1,
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defer_connect:1; /* Indicates that fastopen_connect is set
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* and cookie exists so we defer connect
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* until first data frame is written
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*/
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__u8 rcv_tos;
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__u8 convert_csum;
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int uc_index;
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int mc_index;
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__be32 mc_addr;
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struct ip_mc_socklist __rcu *mc_list;
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struct inet_cork_full cork;
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};
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#define IPCORK_OPT 1 /* ip-options has been held in ipcork.opt */
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#define IPCORK_ALLFRAG 2 /* always fragment (for ipv6 for now) */
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/* cmsg flags for inet */
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#define IP_CMSG_PKTINFO BIT(0)
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#define IP_CMSG_TTL BIT(1)
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#define IP_CMSG_TOS BIT(2)
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#define IP_CMSG_RECVOPTS BIT(3)
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#define IP_CMSG_RETOPTS BIT(4)
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#define IP_CMSG_PASSSEC BIT(5)
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#define IP_CMSG_ORIGDSTADDR BIT(6)
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#define IP_CMSG_CHECKSUM BIT(7)
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#define IP_CMSG_RECVFRAGSIZE BIT(8)
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/**
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* sk_to_full_sk - Access to a full socket
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* @sk: pointer to a socket
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*
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* SYNACK messages might be attached to request sockets.
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* Some places want to reach the listener in this case.
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*/
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static inline struct sock *sk_to_full_sk(struct sock *sk)
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{
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#ifdef CONFIG_INET
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if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
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sk = inet_reqsk(sk)->rsk_listener;
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#endif
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return sk;
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}
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/* sk_to_full_sk() variant with a const argument */
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static inline const struct sock *sk_const_to_full_sk(const struct sock *sk)
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{
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#ifdef CONFIG_INET
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if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
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sk = ((const struct request_sock *)sk)->rsk_listener;
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#endif
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return sk;
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}
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static inline struct sock *skb_to_full_sk(const struct sk_buff *skb)
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{
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return sk_to_full_sk(skb->sk);
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}
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static inline struct inet_sock *inet_sk(const struct sock *sk)
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{
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return (struct inet_sock *)sk;
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}
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static inline void __inet_sk_copy_descendant(struct sock *sk_to,
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const struct sock *sk_from,
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const int ancestor_size)
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{
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memcpy(inet_sk(sk_to) + 1, inet_sk(sk_from) + 1,
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sk_from->sk_prot->obj_size - ancestor_size);
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}
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#if !(IS_ENABLED(CONFIG_IPV6))
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static inline void inet_sk_copy_descendant(struct sock *sk_to,
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const struct sock *sk_from)
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{
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__inet_sk_copy_descendant(sk_to, sk_from, sizeof(struct inet_sock));
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}
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#endif
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int inet_sk_rebuild_header(struct sock *sk);
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static inline unsigned int __inet_ehashfn(const __be32 laddr,
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const __u16 lport,
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const __be32 faddr,
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const __be16 fport,
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u32 initval)
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{
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return jhash_3words((__force __u32) laddr,
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(__force __u32) faddr,
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((__u32) lport) << 16 | (__force __u32)fport,
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initval);
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}
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struct request_sock *inet_reqsk_alloc(const struct request_sock_ops *ops,
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struct sock *sk_listener,
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bool attach_listener);
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static inline __u8 inet_sk_flowi_flags(const struct sock *sk)
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{
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__u8 flags = 0;
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if (inet_sk(sk)->transparent || inet_sk(sk)->hdrincl)
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flags |= FLOWI_FLAG_ANYSRC;
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return flags;
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}
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static inline void inet_inc_convert_csum(struct sock *sk)
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{
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inet_sk(sk)->convert_csum++;
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}
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static inline void inet_dec_convert_csum(struct sock *sk)
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{
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if (inet_sk(sk)->convert_csum > 0)
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inet_sk(sk)->convert_csum--;
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}
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static inline bool inet_get_convert_csum(struct sock *sk)
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{
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return !!inet_sk(sk)->convert_csum;
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}
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#endif /* _INET_SOCK_H */
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