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path: root/net/ipv4/tcp_metrics.c
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2012-07-23tcp: avoid oops in tcp_metrics and reset tcpm_stampJulian Anastasov1-2/+3
In tcp_tw_remember_stamp we incorrectly checked tw instead of tm, it can lead to oops if the cached entry is not found. tcpm_stamp was not updated in tcpm_check_stamp when tcpm_suck_dst was called, move the update into tcpm_suck_dst, so that we do not call it infinitely on every next cache hit after TCP_METRICS_TIMEOUT. Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20tcp: use hash_32() in tcp_metricsEric Dumazet1-15/+10
Fix a missing roundup_pow_of_two(), since tcpmhash_entries is not guaranteed to be a power of two. Uses hash_32() instead of custom hash. tcpmhash_entries should be an unsigned int. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-19net-tcp: Fast Open client - detecting SYN-data dropsYuchung Cheng1-3/+13
On paths with firewalls dropping SYN with data or experimental TCP options, Fast Open connections will have experience SYN timeout and bad performance. The solution is to track such incidents in the cookie cache and disables Fast Open temporarily. Since only the original SYN includes data and/or Fast Open option, the SYN-ACK has some tell-tale sign (tcp_rcv_fastopen_synack()) to detect such drops. If a path has recurring Fast Open SYN drops, Fast Open is disabled for 2^(recurring_losses) minutes starting from four minutes up to roughly one and half day. sendmsg with MSG_FASTOPEN flag will succeed but it behaves as connect() then write(). Signed-off-by: Yuchung Cheng <ycheng@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-19net-tcp: Fast Open client - cookie cacheYuchung Cheng1-0/+51
With help from Eric Dumazet, add Fast Open metrics in tcp metrics cache. The basic ones are MSS and the cookies. Later patch will cache more to handle unfriendly middleboxes. Signed-off-by: Yuchung Cheng <ycheng@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-18ipv6: add ipv6_addr_hash() helperEric Dumazet1-12/+3
Introduce ipv6_addr_hash() helper doing a XOR on all bits of an IPv6 address, with an optimized x86_64 version. Use it in flow dissector, as suggested by Andrew McGregor, to reduce hash collision probabilities in fq_codel (and other users of flow dissector) Use it in ip6_tunnel.c and use more bit shuffling, as suggested by David Laight, as existing hash was ignoring most of them. Use it in sunrpc and use more bit shuffling, using hash_32(). Use it in net/ipv6/addrconf.c, using hash_32() as well. As a cleanup, use it in net/ipv4/tcp_metrics.c Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Andrew McGregor <andrewmcgr@gmail.com> Cc: Dave Taht <dave.taht@gmail.com> Cc: Tom Herbert <therbert@google.com> Cc: David Laight <David.Laight@ACULAB.COM> Cc: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-11tcp: Fix out of bounds access to tcpm_valsAlexander Duyck1-1/+1
The recent patch "tcp: Maintain dynamic metrics in local cache." introduced an out of bounds access due to what appears to be a typo. I believe this change should resolve the issue by replacing the access to RTAX_CWND with TCP_METRIC_CWND. Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-10tcp: Move timestamps from inetpeer to metrics cache.David S. Miller1-5/+131
With help from Lin Ming. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-10tcp: Maintain dynamic metrics in local cache.David S. Miller1-93/+462
Maintain a local hash table of TCP dynamic metrics blobs. Computed TCP metrics are no longer maintained in the route metrics. The table uses RCU and an extremely simple hash so that it has low latency and low overhead. A simple hash is legitimate because we only make metrics blobs for fully established connections. Some tweaking of the default hash table sizes, metric timeouts, and the hash chain length limit certainly could use some tweaking. But the basic design seems sound. With help from Eric Dumazet and Joe Perches. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-10tcp: Abstract back handling peer aliveness test into helper function.David S. Miller1-0/+10
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-10tcp: Move dynamnic metrics handling into seperate file.David S. Miller1-0/+192
Signed-off-by: David S. Miller <davem@davemloft.net>