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path: root/net/ipv4/tcp_metrics.c
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2013-11-19genetlink: only pass array to genl_register_family_with_ops()Johannes Berg
As suggested by David Miller, make genl_register_family_with_ops() a macro and pass only the array, evaluating ARRAY_SIZE() in the macro, this is a little safer. The openvswitch has some indirection, assing ops/n_ops directly in that code. This might ultimately just assign the pointers in the family initializations, saving the struct genl_family_and_ops and code (once mcast groups are handled differently.) Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-11-14genetlink: make all genl_ops users constJohannes Berg
Now that genl_ops are no longer modified in place when registering, they can be made const. This patch was done mostly with spatch: @@ identifier ops; @@ +const struct genl_ops ops[] = { ... }; (except the struct thing in net/openvswitch/datapath.c) Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-11-14net-tcp: fix panic in tcp_fastopen_cache_set()Eric Dumazet
We had some reports of crashes using TCP fastopen, and Dave Jones gave a nice stack trace pointing to the error. Issue is that tcp_get_metrics() should not be called with a NULL dst Fixes: 1fe4c481ba637 ("net-tcp: Fast Open client - cookie cache") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dave Jones <davej@redhat.com> Cc: Yuchung Cheng <ycheng@google.com> Acked-by: Yuchung Cheng <ycheng@google.com> Tested-by: Dave Jones <davej@fedoraproject.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-29tcp: temporarily disable Fast Open on SYN timeoutYuchung Cheng
Fast Open currently has a fall back feature to address SYN-data being dropped but it requires the middle-box to pass on regular SYN retry after SYN-data. This is implemented in commit aab487435 ("net-tcp: Fast Open client - detecting SYN-data drops") However some NAT boxes will drop all subsequent packets after first SYN-data and blackholes the entire connections. An example is in commit 356d7d8 "netfilter: nf_conntrack: fix tcp_in_window for Fast Open". The sender should note such incidents and fall back to use the regular TCP handshake on subsequent attempts temporarily as well: after the second SYN timeouts the original Fast Open SYN is most likely lost. When such an event recurs Fast Open is disabled based on the number of recurrences exponentially. Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-10inet: includes a sock_common in request_sockEric Dumazet
TCP listener refactoring, part 5 : We want to be able to insert request sockets (SYN_RECV) into main ehash table instead of the per listener hash table to allow RCU lookups and remove listener lock contention. This patch includes the needed struct sock_common in front of struct request_sock This means there is no more inet6_request_sock IPv6 specific structure. Following inet_request_sock fields were renamed as they became macros to reference fields from struct sock_common. Prefix ir_ was chosen to avoid name collisions. loc_port -> ir_loc_port loc_addr -> ir_loc_addr rmt_addr -> ir_rmt_addr rmt_port -> ir_rmt_port iif -> ir_iif Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-09net: fix build errors if ipv6 is disabledEric Dumazet
CONFIG_IPV6=n is still a valid choice ;) It appears we can remove dead code. Reported-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-09ipv6: make lookups simpler and fasterEric Dumazet
TCP listener refactoring, part 4 : To speed up inet lookups, we moved IPv4 addresses from inet to struct sock_common Now is time to do the same for IPv6, because it permits us to have fast lookups for all kind of sockets, including upcoming SYN_RECV. Getting IPv6 addresses in TCP lookups currently requires two extra cache lines, plus a dereference (and memory stall). inet6_sk(sk) does the dereference of inet_sk(__sk)->pinet6 This patch is way bigger than its IPv4 counter part, because for IPv4, we could add aliases (inet_daddr, inet_rcv_saddr), while on IPv6, it's not doable easily. inet6_sk(sk)->daddr becomes sk->sk_v6_daddr inet6_sk(sk)->rcv_saddr becomes sk->sk_v6_rcv_saddr And timewait socket also have tw->tw_v6_daddr & tw->tw_v6_rcv_saddr at the same offset. We get rid of INET6_TW_MATCH() as INET6_MATCH() is now the generic macro. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-17tcp: fix RTO calculated from cached RTTNeal Cardwell
Commit 1b7fdd2ab5852 ("tcp: do not use cached RTT for RTT estimation") did not correctly account for the fact that crtt is the RTT shifted left 3 bits. Fix the calculation to consistently reflect this fact. Signed-off-by: Neal Cardwell <ncardwell@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Yuchung Cheng <ycheng@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Acked-By: Yuchung Cheng <ycheng@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-04tcp: better comments for RTO initiallizationYuchung Cheng
Commit 1b7fdd2ab585("tcp: do not use cached RTT for RTT estimation") removes important comments on how RTO is initialized and updated. Hopefully this patch puts those information back. Signed-off-by: Yuchung Cheng <ycheng@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-30tcp: do not use cached RTT for RTT estimationYuchung Cheng
RTT cached in the TCP metrics are valuable for the initial timeout because SYN RTT usually does not account for serialization delays on low BW path. However using it to seed the RTT estimator maybe disruptive because other components (e.g., pacing) require the smooth RTT to be obtained from actual connection. The solution is to use the higher cached RTT to set the first RTO conservatively like tcp_rtt_estimator(), but avoid seeding the other RTT estimator variables such as srtt. It is also a good idea to keep RTO conservative to obtain the first RTT sample, and the performance is insured by TCP loss probe if SYN RTT is available. To keep the seeding formula consistent across SYN RTT and cached RTT, the rttvar is twice the cached RTT instead of cached RTTVAR value. The reason is because cached variation may be too small (near min RTO) which defeats the purpose of being conservative on first RTO. However the metrics still keep the RTT variations as they might be useful for user applications (through ip). Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Tested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-05tcp: do not expire TCP fastopen cookiesEric Dumazet
TCP metric cache expires entries after one hour. This probably make sense for TCP RTT/RTTVAR/CWND, but not for TCP fastopen cookies. Its better to try previous cookie. If it appears to be obsolete, server will send us new cookie anyway. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-16tcp: handle tcp_net_metrics_init() order-5 memory allocation failuresEric Dumazet
order-5 allocations can fail with current kernels, we should try vmalloc() as well. Reported-by: Julien Tinnes <jln@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-01tcp: Fix double sizeof in new tcp_metrics codeJulian Anastasov
Fix double sizeof when parsing IPv6 address from user space because it breaks get/del by specific IPv6 address. Problem noticed by David Binderman: https://bugzilla.kernel.org/show_bug.cgi?id=49171 Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-09-10netlink: Rename pid to portid to avoid confusionEric W. Biederman
It is a frequent mistake to confuse the netlink port identifier with a process identifier. Try to reduce this confusion by renaming fields that hold port identifiers portid instead of pid. I have carefully avoided changing the structures exported to userspace to avoid changing the userspace API. I have successfully built an allyesconfig kernel with this change. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-09-05tcp: add generic netlink support for tcp_metricsJulian Anastasov
Add support for genl "tcp_metrics". No locking is changed, only that now we can unlink and delete entries after grace period. We implement get/del for single entry and dump to support show/flush filtering in user space. Del without address attribute causes flush for all addresses, sadly under genl_mutex. v2: - remove rcu_assign_pointer as suggested by Eric Dumazet, it is not needed because there are no other writes under lock - move the flushing code in tcp_metrics_flush_all v3: - remove synchronize_rcu on flush as suggested by Eric Dumazet Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-09tcp: must free metrics at net dismantleEric Dumazet
We currently leak all tcp metrics at struct net dismantle time. tcp_net_metrics_exit() frees the hash table, we must first iterate it to free all metrics. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-23tcp: avoid oops in tcp_metrics and reset tcpm_stampJulian Anastasov
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 Dumazet
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 Cheng
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 Cheng
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 Dumazet
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 Duyck
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. Miller
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. Miller
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. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-10tcp: Move dynamnic metrics handling into seperate file.David S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>