leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
e0f9759f53
linux/net/ipv6
History
Eric Dumazet e0f9759f53 tcp: try to keep packet if SYN_RCV race is lost 
배석진 reported that in some situations, packets for a given 5-tuple
end up being processed by different CPUS.

This involves RPS, and fragmentation.

배석진 is seeing packet drops when a SYN_RECV request socket is
moved into ESTABLISH state. Other states are protected by socket lock.

This is caused by a CPU losing the race, and simply not caring enough.

Since this seems to occur frequently, we can do better and perform
a second lookup.

Note that all needed memory barriers are already in the existing code,
thanks to the spin_lock()/spin_unlock() pair in inet_ehash_insert()
and reqsk_put(). The second lookup must find the new socket,
unless it has already been accepted and closed by another cpu.

Note that the fragmentation could be avoided in the first place by
use of a correct TCP MSS option in the SYN{ACK} packet, but this
does not mean we can not be more robust.

Many thanks to 배석진 for a very detailed analysis.

Reported-by: 배석진 <soukjin.bae@samsung.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-14 14:21:45 -05:00
..
ila rhashtable: Change rhashtable_walk_start to return void 2017-12-11 09:58:38 -05:00
netfilter netfilter: nf_tables: fix flowtable free 2018-02-07 00:58:57 +01:00
addrconf_core.c net: ipv6: Make inet6addr_validator a blocking notifier 2017-10-20 13:15:07 +01:00
addrconf.c net: Convert addrconf_ops 2018-02-13 10:36:09 -05:00
addrlabel.c rtnetlink: ipv6: convert remaining users to rtnl_register_module 2017-12-04 13:35:36 -05:00
af_inet6.c net: make getname() functions return length rather than use int* parameter 2018-02-12 14:15:04 -05:00
ah6.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-11-15 11:56:19 -08:00
anycast.c net: delete /proc THIS_MODULE references 2018-01-16 15:01:33 -05:00
calipso.c net, calipso: convert calipso_doi.refcount from atomic_t to refcount_t 2017-07-04 22:35:16 +01:00
datagram.c net: ipv6: Allow connect to linklocal address from socket bound to vrf 2018-01-08 14:11:18 -05:00
esp6_offload.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-01-23 13:51:56 -05:00
esp6.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-01-17 00:10:42 -05:00
exthdrs_core.c net: ipv6: remove unused code in ipv6_find_hdr() 2017-10-05 21:53:02 -07:00
exthdrs_offload.c
exthdrs.c ipv6: sr: fix TLVs not being copied using setsockopt 2018-01-10 16:03:55 -05:00
fib6_notifier.c net: Add module reference to FIB notifiers 2017-09-01 20:33:42 -07:00
fib6_rules.c net: ipv6: avoid overhead when no custom FIB rules are installed 2017-08-08 21:40:08 -07:00
fou6.c fou: make local function static 2017-05-21 13:42:36 -04:00
icmp.c ipv6: mark expected switch fall-throughs 2017-10-18 14:13:08 +01:00
inet6_connection_sock.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-01-28 10:33:06 -05:00
inet6_hashtables.c inet: Add a 2nd listener hashtable (port+addr) 2017-12-03 10:18:28 -05:00
ip6_checksum.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ip6_fib.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-01-19 22:59:33 -05:00
ip6_flowlabel.c net: delete /proc THIS_MODULE references 2018-01-16 15:01:33 -05:00
ip6_gre.c net: erspan: fix erspan config overwrite 2018-02-06 11:32:49 -05:00
ip6_icmp.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ip6_input.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-04-20 10:35:33 -04:00
ip6_offload.c gso: fix payload length when gso_size is zero 2017-10-08 10:12:15 -07:00
ip6_offload.h
ip6_output.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-01-24 23:44:15 -05:00
ip6_tunnel.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-01-29 10:15:51 -05:00
ip6_udp_tunnel.c ip6_udp_tunnel: remove unused IPCB related codes 2016-11-02 15:18:36 -04:00
ip6_vti.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-01-29 10:15:51 -05:00
ip6mr.c ip6mr: fix stale iterator 2018-01-31 10:26:30 -05:00
ipcomp6.c net: inet: Support UID-based routing in IP protocols. 2016-11-04 14:45:23 -04:00
ipv6_sockglue.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf 2018-02-01 14:41:46 -05:00
Kconfig ipv6: sr: add helper functions for seg6local 2017-08-25 17:10:24 -07:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mcast_snoop.c
mcast.c build_bug.h: remove BUILD_BUG_ON_NULL() 2018-02-06 18:32:46 -08:00
mip6.c ktime: Get rid of ktime_equal() 2016-12-25 17:21:23 +01:00
ndisc.c net: ipv6: send unsolicited NA after DAD 2018-01-29 14:18:38 -05:00
netfilter.c netfilter: remove struct nf_afinfo and its helper functions 2018-01-08 18:11:02 +01:00
output_core.c net: accept UFO datagrams from tuntap and packet 2017-11-24 01:37:35 +09:00
ping.c net/ipv6: Convert icmpv6_push_pending_frames to void 2017-10-06 09:52:31 -07:00
proc.c net: delete /proc THIS_MODULE references 2018-01-16 15:01:33 -05:00
protocol.c net: Add sysctl to toggle early demux for tcp and udp 2017-03-24 13:17:07 -07:00
raw.c Currently, hardened usercopy performs dynamic bounds checking on slab 2018-02-03 16:25:42 -08:00
reassembly.c inet: frags: Convert timers to use timer_setup() 2017-10-18 12:39:55 +01:00
route.c net/ipv6: onlink nexthop checks should default to main table 2018-02-07 21:52:42 -05:00
seg6_hmac.c ipv6: sr: Use ARRAY_SIZE macro 2017-09-01 18:35:23 -07:00
seg6_iptunnel.c ipv6: sr: add support for encapsulation of L2 frames 2017-08-25 17:10:23 -07:00
seg6_local.c ipv6: use ARRAY_SIZE for array sizing calculation on array seg6_action_table 2018-01-09 11:40:46 -05:00
seg6.c rhashtable: Change rhashtable_walk_start to return void 2017-12-11 09:58:38 -05:00
sit.c net: don't call update_pmtu unconditionally 2018-01-25 16:27:34 -05:00
syncookies.c tcp: Namespace-ify sysctl_tcp_workaround_signed_windows 2017-10-28 19:24:38 +09:00
sysctl_net_ipv6.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
tcp_ipv6.c tcp: try to keep packet if SYN_RCV race is lost 2018-02-14 14:21:45 -05:00
tcpv6_offload.c gso: validate gso_type in GSO handlers 2018-01-22 16:01:30 -05:00
tunnel6.c
udp_impl.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
udp_offload.c gso: validate gso_type in GSO handlers 2018-01-22 16:01:30 -05:00
udp.c net: delete /proc THIS_MODULE references 2018-01-16 15:01:33 -05:00
udplite.c net: delete /proc THIS_MODULE references 2018-01-16 15:01:33 -05:00
xfrm6_input.c xfrm: Reinject transport-mode packets through tasklet 2017-12-19 08:23:21 +01:00
xfrm6_mode_beet.c networking: make skb_pull & friends return void pointers 2017-06-16 11:48:39 -04:00
xfrm6_mode_ro.c ipv6: xfrm: Handle errors reported by xfrm6_find_1stfragopt() 2017-06-02 13:57:27 -04:00
xfrm6_mode_transport.c ipv6: xfrm: Handle errors reported by xfrm6_find_1stfragopt() 2017-06-02 13:57:27 -04:00
xfrm6_mode_tunnel.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-01-24 23:44:15 -05:00
xfrm6_output.c xfrm: Add an IPsec hardware offloading API 2017-04-14 10:06:10 +02:00
xfrm6_policy.c net: Create and use new helper xfrm_dst_child(). 2017-11-30 09:54:25 -05:00
xfrm6_protocol.c xfrm: input: constify xfrm_input_afinfo 2017-02-09 10:22:17 +01:00
xfrm6_state.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xfrm6_tunnel.c xfrm6_tunnel: exit_net cleanup check added 2017-11-14 15:46:17 +09:00