linux/net/ipv4
Willy Tarreau 3979ad7e82 net/tcp-fastopen: make connect()'s return case more consistent with non-TFO
Without TFO, any subsequent connect() call after a successful one returns
-1 EISCONN. The last API update ensured that __inet_stream_connect() can
return -1 EINPROGRESS in response to sendmsg() when TFO is in use to
indicate that the connection is now in progress. Unfortunately since this
function is used both for connect() and sendmsg(), it has the undesired
side effect of making connect() now return -1 EINPROGRESS as well after
a successful call, while at the same time poll() returns POLLOUT. This
can confuse some applications which happen to call connect() and to
check for -1 EISCONN to ensure the connection is usable, and for which
EINPROGRESS indicates a need to poll, causing a loop.

This problem was encountered in haproxy where a call to connect() is
precisely used in certain cases to confirm a connection's readiness.
While arguably haproxy's behaviour should be improved here, it seems
important to aim at a more robust behaviour when the goal of the new
API is to make it easier to implement TFO in existing applications.

This patch simply ensures that we preserve the same semantics as in
the non-TFO case on the connect() syscall when using TFO, while still
returning -1 EINPROGRESS on sendmsg(). For this we simply tell
__inet_stream_connect() whether we're doing a regular connect() or in
fact connecting for a sendmsg() call.

Cc: Wei Wang <weiwan@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-25 14:12:21 -05:00
..
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf 2017-01-05 11:49:57 -05:00
af_inet.c net/tcp-fastopen: make connect()'s return case more consistent with non-TFO 2017-01-25 14:12:21 -05:00
ah4.c
arp.c
cipso_ipv4.c Merge branch 'stable-4.8' of git://git.infradead.org/users/pcmoore/selinux into next 2016-07-07 10:15:34 +10:00
datagram.c
devinet.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
esp4.c esp4: Fix integrity verification when ESN are used 2016-11-30 11:09:39 +01:00
fib_frontend.c ipv4: Do not allow MAIN to be alias for new LOCAL w/ custom rules 2017-01-03 09:38:34 -05:00
fib_lookup.h
fib_rules.c switchdev: remove FIB offload infrastructure 2016-09-28 04:48:00 -04:00
fib_semantics.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-01-17 15:19:37 -05:00
fib_trie.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
fou.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-10-30 12:42:58 -04:00
gre_demux.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-06-30 05:03:36 -04:00
gre_offload.c net: add recursion limit to GRO 2016-10-20 14:32:22 -04:00
icmp.c net: for rate-limited ICMP replies save one atomic operation 2017-01-09 15:49:12 -05:00
igmp.c igmp: Make igmp group member RFC 3376 compliant 2017-01-02 13:01:03 -05:00
inet_connection_sock.c inet: don't use sk_v6_rcv_saddr directly 2017-01-20 14:35:51 -05:00
inet_diag.c tcp: remove early retransmit 2017-01-13 22:37:16 -05:00
inet_fragment.c
inet_hashtables.c inet: kill smallest_size and smallest_port 2017-01-18 13:04:29 -05:00
inet_timewait_sock.c ipv4: Namespaceify tcp_tw_recycle and tcp_max_tw_buckets knob 2016-12-29 11:38:31 -05:00
inetpeer.c
ip_forward.c ipv4: allow local fragmentation in ip_finish_output_gso() 2016-11-03 16:10:26 -04:00
ip_fragment.c
ip_gre.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
ip_input.c net: VRF: Pass original iif to ip_route_input() 2016-09-16 04:24:07 -04:00
ip_options.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
ip_output.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
ip_sockglue.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-01-05 11:03:07 -05:00
ip_tunnel_core.c net: make ndo_get_stats64 a void function 2017-01-08 17:51:44 -05:00
ip_tunnel.c netns: make struct pernet_operations::id unsigned int 2016-11-18 10:59:15 -05:00
ip_vti.c netns: make struct pernet_operations::id unsigned int 2016-11-18 10:59:15 -05:00
ipcomp.c
ipconfig.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
ipip.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
ipmr.c ipmr: improve hash scalability 2017-01-12 16:48:26 -05:00
Kconfig Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-03 12:29:53 -05:00
Makefile net: ip, diag -- Add diag interface for raw sockets 2016-10-23 19:35:24 -04:00
netfilter.c netfilter: Update ip_route_me_harder to consider L3 domain 2016-11-24 12:44:36 +01:00
ping.c net: ping: Use right format specifier to avoid type casting 2017-01-17 15:25:55 -05:00
proc.c net: remove bh disabling around percpu_counter accesses 2017-01-20 11:27:22 -05:00
protocol.c
raw_diag.c net: ip, raw_diag -- Use jump for exiting from nested loop 2016-11-03 15:25:26 -04:00
raw.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
route.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-01-17 15:19:37 -05:00
syncookies.c syncookies: use SipHash in place of SHA1 2017-01-09 13:58:57 -05:00
sysctl_net_ipv4.c Introduce a sysctl that modifies the value of PROT_SOCK. 2017-01-24 12:10:51 -05:00
tcp_bbr.c tcp_bbr: add a state transition diagram and accompanying comment 2016-10-29 17:12:43 -04:00
tcp_bic.c
tcp_cdg.c tcp: cdg: rename struct minmax in tcp_cdg.c to avoid a naming conflict 2016-09-21 00:22:59 -04:00
tcp_cong.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-11-22 13:27:16 -05:00
tcp_cubic.c
tcp_dctcp.c Revert "dctcp: update cwnd on congestion event" 2016-12-06 11:34:24 -05:00
tcp_diag.c net: diag: Fix refcnt leak in error path destroying socket 2016-08-23 23:11:36 -07:00
tcp_fastopen.c net/tcp-fastopen: Add new API support 2017-01-25 14:04:38 -05:00
tcp_highspeed.c tcp: add cwnd_undo functions to various tcp cc algorithms 2016-11-21 13:20:17 -05:00
tcp_htcp.c
tcp_hybla.c tcp: make undo_cwnd mandatory for congestion modules 2016-11-21 13:20:17 -05:00
tcp_illinois.c tcp: add cwnd_undo functions to various tcp cc algorithms 2016-11-21 13:20:17 -05:00
tcp_input.c tcp: reduce skb overhead in selected places 2017-01-25 13:13:31 -05:00
tcp_ipv4.c net/tcp-fastopen: Add new API support 2017-01-25 14:04:38 -05:00
tcp_lp.c tcp: make undo_cwnd mandatory for congestion modules 2016-11-21 13:20:17 -05:00
tcp_metrics.c tcp: remove early retransmit 2017-01-13 22:37:16 -05:00
tcp_minisocks.c tcp: remove early retransmit 2017-01-13 22:37:16 -05:00
tcp_nv.c
tcp_offload.c gso: Support partial splitting at the frag_list pointer 2016-09-19 20:59:34 -04:00
tcp_output.c net/tcp-fastopen: refactor cookie check logic 2017-01-25 14:04:38 -05:00
tcp_probe.c
tcp_rate.c tcp: export data delivery rate 2016-09-21 00:23:00 -04:00
tcp_recovery.c tcp: enable RACK loss detection to trigger recovery 2017-01-13 22:37:16 -05:00
tcp_scalable.c tcp: add cwnd_undo functions to various tcp cc algorithms 2016-11-21 13:20:17 -05:00
tcp_timer.c tcp: remove early retransmit 2017-01-13 22:37:16 -05:00
tcp_vegas.c tcp: make undo_cwnd mandatory for congestion modules 2016-11-21 13:20:17 -05:00
tcp_vegas.h
tcp_veno.c tcp: add cwnd_undo functions to various tcp cc algorithms 2016-11-21 13:20:17 -05:00
tcp_westwood.c tcp: make undo_cwnd mandatory for congestion modules 2016-11-21 13:20:17 -05:00
tcp_yeah.c tcp: add cwnd_undo functions to various tcp cc algorithms 2016-11-21 13:20:17 -05:00
tcp.c net/tcp-fastopen: make connect()'s return case more consistent with non-TFO 2017-01-25 14:12:21 -05:00
tunnel4.c tunnels: correct conditional build of MPLS and IPv6 2016-07-11 13:27:06 -07:00
udp_diag.c net: inet: diag: expose the socket mark to privileged processes. 2016-09-08 16:13:09 -07:00
udp_impl.h udplite: call proper backlog handlers 2016-11-24 15:32:14 -05:00
udp_offload.c net: add recursion limit to GRO 2016-10-20 14:32:22 -04:00
udp_tunnel.c net: Remove deprecated tunnel specific UDP offload functions 2016-06-17 20:23:32 -07:00
udp.c inet: collapse ipv4/v6 rcv_saddr_equal functions into one 2017-01-18 13:04:28 -05:00
udplite.c udplite: call proper backlog handlers 2016-11-24 15:32:14 -05:00
xfrm4_input.c
xfrm4_mode_beet.c
xfrm4_mode_transport.c
xfrm4_mode_tunnel.c
xfrm4_output.c
xfrm4_policy.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-09-12 15:52:44 -07:00
xfrm4_protocol.c
xfrm4_state.c
xfrm4_tunnel.c