renegade-project/linux-next
2
0
Fork 0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-20 19:23:57 +08:00
Code
f12dd75959
linux-next/net/ipv4
History
Yuchung Cheng fcc2202a9d tcp: fix undo spurious SYNACK in passive Fast Open 
Commit 794200d662 ("tcp: undo cwnd on Fast Open spurious SYNACK
retransmit") may cause tcp_fastretrans_alert() to warn about pending
retransmission in Open state. This is triggered when the Fast Open
server both sends data and has spurious SYNACK retransmission during
the handshake, and the data packets were lost or reordered.

The root cause is a bit complicated:

(1) Upon receiving SYN-data: a full socket is created with
    snd_una = ISN + 1 by tcp_create_openreq_child()

(2) On SYNACK timeout the server/sender enters CA_Loss state.

(3) Upon receiving the final ACK to complete the handshake, sender
    does not mark FLAG_SND_UNA_ADVANCED since (1)

    Sender then calls tcp_process_loss since state is CA_loss by (2)

(4) tcp_process_loss() does not invoke undo operations but instead
    mark REXMIT_LOST to force retransmission

(5) tcp_rcv_synrecv_state_fastopen() calls tcp_try_undo_loss(). It
    changes state to CA_Open but has positive tp->retrans_out

(6) Next ACK triggers the WARN_ON in tcp_fastretrans_alert()

The step that goes wrong is (4) where the undo operation should
have been invoked because the ACK successfully acknowledged the
SYN sequence. This fixes that by specifically checking undo
when the SYN-ACK sequence is acknowledged. Then after
tcp_process_loss() the state would be further adjusted based
in tcp_fastretrans_alert() to avoid triggering the warning in (6).

Fixes: 794200d662 ("tcp: undo cwnd on Fast Open spurious SYNACK retransmit")
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-09 20:04:11 -07:00
..
bpfilter SPDX update for 5.2-rc2, round 1 2019-05-21 12:33:38 -07:00
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf 2019-05-23 14:45:36 -07:00
af_inet.c SPDX update for 5.2-rc3, round 1 2019-05-31 08:34:32 -07:00
ah4.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
arp.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
cipso_ipv4.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00
datagram.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
devinet.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
esp4_offload.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-05-02 22:14:21 -04:00
esp4.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
fib_frontend.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
fib_lookup.h ipv4: Add fib_nh_common to fib_result 2019-04-03 21:50:20 -07:00
fib_notifier.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fib_rules.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
fib_semantics.c net: ipv4: fib_semantics: fix uninitialized variable 2019-06-09 12:47:30 -07:00
fib_trie.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
fou.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
gre_demux.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
gre_offload.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
icmp.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
igmp.c SPDX update for 5.2-rc3, round 1 2019-05-31 08:34:32 -07:00
inet_connection_sock.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
inet_diag.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
inet_fragment.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
inet_hashtables.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
inet_timewait_sock.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
inetpeer.c net: ipv4: use a dedicated counter for icmp_v4 redirect packets 2019-02-08 21:50:15 -08:00
ip_forward.c ipv4: Prepare rtable for IPv6 gateway 2019-04-08 15:22:40 -07:00
ip_fragment.c net: remove unused struct inet_frag_queue.fragments field 2019-02-26 08:27:05 -08:00
ip_gre.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
ip_input.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
ip_options.c vrf: check accept_source_route on the original netdevice 2019-04-01 10:44:58 -07:00
ip_output.c net: correct zerocopy refcnt with udp MSG_MORE 2019-05-30 15:54:04 -07:00
ip_sockglue.c ip_sockglue: Fix missing-check bug in ip_ra_control() 2019-05-25 11:00:50 -07:00
ip_tunnel_core.c netlink: make validation more configurable for future strictness 2019-04-27 17:07:21 -04:00
ip_tunnel.c iptunnel: NULL pointer deref for ip_md_tunnel_xmit 2019-03-06 10:43:06 -08:00
ip_vti.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
ipcomp.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
ipconfig.c ipconfig: add carrier_timeout kernel parameter 2019-02-01 15:24:13 -08:00
ipip.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
ipmr_base.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-05-07 17:22:09 -07:00
ipmr.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile xfrm: make xfrm modes builtin 2019-04-08 09:15:17 +02:00
metrics.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
netfilter.c netfilter: ipv4: remove useless export_symbol 2019-01-28 11:32:58 +01:00
netlink.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
ping.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
proc.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
protocol.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
raw_diag.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
raw.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
route.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-06-07 09:29:14 -07:00
syncookies.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
sysctl_net_ipv4.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-04-25 23:52:29 -04:00
tcp_bbr.c tcp_bbr: adapt cwnd based on ack aggregation estimation 2019-01-24 22:27:27 -08:00
tcp_bic.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
tcp_bpf.c bpf, tcp: correctly handle DONT_WAIT flags and timeo == 0 2019-05-16 01:36:13 +02:00
tcp_cdg.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
tcp_cong.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
tcp_cubic.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
tcp_dctcp.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
tcp_dctcp.h tcp: refactor DCTCP ECN ACK handling 2018-10-10 22:26:00 -07:00
tcp_diag.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
tcp_fastopen.c tcp: pause Fast Open globally after third consecutive timeout 2017-12-13 15:51:12 -05:00
tcp_highspeed.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
tcp_htcp.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
tcp_hybla.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
tcp_illinois.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
tcp_input.c tcp: fix undo spurious SYNACK in passive Fast Open 2019-06-09 20:04:11 -07:00
tcp_ipv4.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
tcp_lp.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
tcp_metrics.c tcp: refactor setting the initial congestion window 2019-05-01 11:47:54 -04:00
tcp_minisocks.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
tcp_nv.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
tcp_offload.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
tcp_output.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
tcp_rate.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
tcp_recovery.c tcp: introduce tcp_skb_timestamp_us() helper 2018-09-21 19:37:59 -07:00
tcp_scalable.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
tcp_timer.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
tcp_ulp.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
tcp_vegas.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
tcp_vegas.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
tcp_veno.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
tcp_westwood.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
tcp_yeah.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
tcp.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
tunnel4.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
udp_diag.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
udp_impl.h udp: add missing rehash callback to udplite 2019-01-17 15:01:08 -08:00
udp_offload.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
udp_tunnel.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
udp.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 2019-06-07 14:46:47 -07:00
udplite.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
xfrm4_input.c xfrm: reset transport header back to network header after all input transforms ahave been applied 2018-09-04 10:26:30 +02:00
xfrm4_output.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
xfrm4_policy.c Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next 2019-04-30 09:26:13 -04:00
xfrm4_protocol.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
xfrm4_state.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xfrm4_tunnel.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00