linux/net/ipv4
Yuchung Cheng 6e08d5e3c8 tcp: fix false undo corner cases
The undo code assumes that, upon entering loss recovery, TCP
1) always retransmit something
2) the retransmission never fails locally (e.g., qdisc drop)

so undo_marker is set in tcp_enter_recovery() and undo_retrans is
incremented only when tcp_retransmit_skb() is successful.

When the assumption is broken because TCP's cwnd is too small to
retransmit or the retransmit fails locally. The next (DUP)ACK
would incorrectly revert the cwnd and the congestion state in
tcp_try_undo_dsack() or tcp_may_undo(). Subsequent (DUP)ACKs
may enter the recovery state. The sender repeatedly enter and
(incorrectly) exit recovery states if the retransmits continue to
fail locally while receiving (DUP)ACKs.

The fix is to initialize undo_retrans to -1 and start counting on
the first retransmission. Always increment undo_retrans even if the
retransmissions fail locally because they couldn't cause DSACKs to
undo the cwnd reduction.

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>
2014-07-07 21:40:48 -07:00
..
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next 2014-05-30 17:54:47 -07:00
af_inet.c gre: Call gso_make_checksum 2014-06-04 22:46:38 -07:00
ah4.c ah4: Use the IPsec protocol multiplexer API 2014-02-25 07:04:17 +01:00
arp.c ipv4: arp: update neighbour address when a gratuitous arp is received and arp_accept is set 2014-01-02 00:08:38 -05:00
cipso_ipv4.c ipv4: ERROR: code indent should use tabs where possible 2013-12-26 13:43:21 -05:00
datagram.c ipv4: fix a race in ip4_datagram_release_cb() 2014-06-11 15:39:18 -07:00
devinet.c ipv4: minor spelling fix 2014-05-18 21:10:29 -04:00
esp4.c esp4: Use the IPsec protocol multiplexer API 2014-02-25 07:04:17 +01:00
fib_frontend.c ipv4, fib: pass LOOPBACK_IFINDEX instead of 0 to flowi4_iif 2014-04-16 15:05:11 -04:00
fib_lookup.h ipv4: make fib_detect_death static 2013-12-28 17:01:46 -05:00
fib_rules.c inet: fix NULL pointer Oops in fib(6)_rule_suppress 2013-12-10 17:54:23 -05:00
fib_semantics.c ipv4: fib_semantics: increment fib_info_cnt after fib_info allocation 2014-05-07 17:14:32 -04:00
fib_trie.c net: Revert "fib_trie: use seq_file_net rather than seq->private" 2014-06-04 15:11:41 -07:00
gre_demux.c gre: Call gso_make_checksum 2014-06-04 22:46:38 -07:00
gre_offload.c net: Save software checksum complete 2014-06-11 15:46:13 -07:00
icmp.c ipv4: icmp: Fix pMTU handling for rare case 2014-07-07 17:22:57 -07:00
igmp.c igmp: fix the problem when mc leave group 2014-07-07 21:30:55 -07:00
inet_connection_sock.c ipv4: make ip_local_reserved_ports per netns 2014-05-14 15:31:45 -04:00
inet_diag.c inet_diag: fix inet_diag_dump_icsk() to use correct state for timewait sockets 2014-01-13 22:35:46 -08:00
inet_fragment.c inet: frag: make sure forced eviction removes all frags 2014-03-06 15:28:45 -05:00
inet_hashtables.c net: Use a more standard macro for INET_ADDR_COOKIE 2014-05-14 16:07:23 -04:00
inet_lro.c lro: remove dead code 2013-12-29 16:34:25 -05:00
inet_timewait_sock.c tcp/dccp: remove twchain 2013-10-08 23:19:24 -04:00
inetpeer.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-06-12 14:27:40 -07:00
ip_forward.c net: rename local_df to ignore_df 2014-05-12 14:03:41 -04:00
ip_fragment.c ipv4: fix "conntrack zones" support for defrag user check in ip_expire 2014-05-05 16:02:59 +02:00
ip_gre.c gre: allow changing mac address when device is up 2014-06-10 22:46:42 -07:00
ip_input.c net: Fix memory leak if TPROXY used with TCP early demux 2014-01-27 16:22:11 -08:00
ip_options.c ipv4: Use predefined value for readability 2014-04-28 13:28:43 -04:00
ip_output.c inetpeer: get rid of ip_id_count 2014-06-02 11:00:41 -07:00
ip_sockglue.c ipv4: yet another new IP_MTU_DISCOVER option IP_PMTUDISC_OMIT 2014-02-26 15:51:00 -05:00
ip_tunnel.c ipv4: fix dst race in sk_dst_get() 2014-06-25 17:41:44 -07:00
ip_tunnel_core.c net: Support for multiple checksums with gso 2014-06-04 22:46:38 -07:00
ip_vti.c ip_vti: Fix 'ip tunnel add' with 'key' parameters 2014-06-11 00:30:52 -07:00
ipcomp.c ipcomp4: Use the IPsec protocol multiplexer API 2014-02-25 07:04:17 +01:00
ipconfig.c ipv4: ipconfig.c: add parentheses in an if statement 2014-02-14 00:14:23 -05:00
ipip.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-06-11 16:02:55 -07:00
ipmr.c inetpeer: get rid of ip_id_count 2014-06-02 11:00:41 -07:00
Kconfig net: neighbour: Remove CONFIG_ARPD 2013-09-03 21:41:43 -04:00
Makefile xfrm4: Add IPsec protocol multiplexer 2014-02-25 07:04:16 +01:00
netfilter.c netfilter: remove double colon 2014-02-19 11:41:25 +01:00
ping.c ping: move ping_group_range out of CONFIG_SYSCTL 2014-05-08 22:50:47 -04:00
proc.c net: clean up snmp stats code 2014-05-07 16:06:05 -04:00
protocol.c net: remove outdated comment for ipv4 and ipv6 protocol handler 2013-11-28 18:47:51 -05:00
raw.c inetpeer: get rid of ip_id_count 2014-06-02 11:00:41 -07:00
route.c ipv4: irq safe sk_dst_[re]set() and ipv4_sk_update_pmtu() fix 2014-06-30 23:40:58 -07:00
syncookies.c net: support marking accepting TCP sockets 2014-05-13 18:35:09 -04:00
sysctl_net_ipv4.c ipv4: make ip_local_reserved_ports per netns 2014-05-14 15:31:45 -04:00
tcp.c tcp: Fix divide by zero when pushing during tcp-repair 2014-07-02 18:21:03 -07:00
tcp_bic.c tcp: remove in_flight parameter from cong_avoid() methods 2014-05-03 19:23:07 -04:00
tcp_cong.c tcp: remove in_flight parameter from cong_avoid() methods 2014-05-03 19:23:07 -04:00
tcp_cubic.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-05-12 13:19:14 -04:00
tcp_diag.c inet_diag: Rename inet_diag_req into inet_diag_req_v2 2012-01-11 12:56:06 -08:00
tcp_fastopen.c tcp: remove unnecessary tcp_sk assignment. 2014-06-16 21:35:00 -07:00
tcp_highspeed.c tcp: remove in_flight parameter from cong_avoid() methods 2014-05-03 19:23:07 -04:00
tcp_htcp.c tcp: remove in_flight parameter from cong_avoid() methods 2014-05-03 19:23:07 -04:00
tcp_hybla.c tcp: remove in_flight parameter from cong_avoid() methods 2014-05-03 19:23:07 -04:00
tcp_illinois.c tcp: remove in_flight parameter from cong_avoid() methods 2014-05-03 19:23:07 -04:00
tcp_input.c tcp: fix false undo corner cases 2014-07-07 21:40:48 -07:00
tcp_ipv4.c net: support marking accepting TCP sockets 2014-05-13 18:35:09 -04:00
tcp_lp.c tcp: remove in_flight parameter from cong_avoid() methods 2014-05-03 19:23:07 -04:00
tcp_memcontrol.c cgroup: replace cftype->trigger() with cftype->write() 2014-05-13 12:16:21 -04:00
tcp_metrics.c net: use the new API kvfree() 2014-06-05 00:49:51 -07:00
tcp_minisocks.c tcp: use tcp_v4_send_synack on first SYN-ACK 2014-05-13 17:53:02 -04:00
tcp_offload.c gre: Call gso_make_checksum 2014-06-04 22:46:38 -07:00
tcp_output.c tcp: fix false undo corner cases 2014-07-07 21:40:48 -07:00
tcp_probe.c tcp: switch rtt estimations to usec resolution 2014-02-26 17:08:40 -05:00
tcp_scalable.c tcp: remove in_flight parameter from cong_avoid() methods 2014-05-03 19:23:07 -04:00
tcp_timer.c tcp: snmp stats for Fast Open, SYN rtx, and data pkts 2014-03-03 15:58:03 -05:00
tcp_vegas.c tcp: remove in_flight parameter from cong_avoid() methods 2014-05-03 19:23:07 -04:00
tcp_vegas.h net: ipv4/ipv6: Remove extern from function prototypes 2013-10-19 19:12:11 -04:00
tcp_veno.c tcp: remove in_flight parameter from cong_avoid() methods 2014-05-03 19:23:07 -04:00
tcp_westwood.c tcp: remove unused min_cwnd member of tcp_congestion_ops 2014-02-13 18:22:34 -05:00
tcp_yeah.c tcp: remove in_flight parameter from cong_avoid() methods 2014-05-03 19:23:07 -04:00
tunnel4.c net: Convert printks to pr_<level> 2012-03-11 23:42:51 -07:00
udp.c udp: Add MIB counters for rcvbuferrors 2014-06-27 00:20:55 -07:00
udp_diag.c netlink: rename ssk to sk in struct netlink_skb_params 2013-04-19 14:57:56 -04:00
udp_impl.h net: ipv4/ipv6: Remove extern from function prototypes 2013-10-19 19:12:11 -04:00
udp_offload.c net: Add skb_gro_postpull_rcsum to udp and vxlan 2014-06-11 15:46:13 -07:00
udplite.c net: Eliminate no_check from protosw 2014-05-23 16:28:53 -04:00
xfrm4_input.c xfrm4: Add IPsec protocol multiplexer 2014-02-25 07:04:16 +01:00
xfrm4_mode_beet.c ipv4: ERROR: code indent should use tabs where possible 2013-12-26 13:43:21 -05:00
xfrm4_mode_transport.c
xfrm4_mode_tunnel.c inetpeer: get rid of ip_id_count 2014-06-02 11:00:41 -07:00
xfrm4_output.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-05-24 00:32:30 -04:00
xfrm4_policy.c xfrm: Introduce xfrm_input_afinfo to access the the callbacks properly 2014-03-14 07:28:07 +01:00
xfrm4_protocol.c xfrm4: Properly handle unsupported protocols 2014-04-29 08:41:12 +02:00
xfrm4_state.c inet: make no_pmtu_disc per namespace and kill ipv4_config 2013-12-18 16:58:20 -05:00
xfrm4_tunnel.c sit: add IPv4 over IPv4 support 2013-05-31 17:19:05 -07:00