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authorEric Dumazet <edumazet@google.com>2015-10-02 11:43:32 -0700
committerDavid S. Miller <davem@davemloft.net>2015-10-03 04:32:41 -0700
commit079096f103faca2dd87342cca6f23d4b34da8871 (patch)
treefa3fb0fdc064f1611c464384e70a7a402179808f /net/ipv4/syncookies.c
parent2feda34192a379f8b35a7c6c5826b2f23e884f32 (diff)
tcp/dccp: install syn_recv requests into ehash table
In this patch, we insert request sockets into TCP/DCCP regular ehash table (where ESTABLISHED and TIMEWAIT sockets are) instead of using the per listener hash table. ACK packets find SYN_RECV pseudo sockets without having to find and lock the listener. In nominal conditions, this halves pressure on listener lock. Note that this will allow for SO_REUSEPORT refinements, so that we can select a listener using cpu/numa affinities instead of the prior 'consistent hash', since only SYN packets will apply this selection logic. We will shrink listen_sock in the following patch to ease code review. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Ying Cai <ycai@google.com> Cc: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/syncookies.c')
-rw-r--r--net/ipv4/syncookies.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
index 6b97b5f6457c..729ceb5f63c6 100644
--- a/net/ipv4/syncookies.c
+++ b/net/ipv4/syncookies.c
@@ -284,6 +284,10 @@ bool cookie_ecn_ok(const struct tcp_options_received *tcp_opt,
}
EXPORT_SYMBOL(cookie_ecn_ok);
+/* On input, sk is a listener.
+ * Output is listener if incoming packet would not create a child
+ * NULL if memory could not be allocated.
+ */
struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
{
struct ip_options *opt = &TCP_SKB_CB(skb)->header.h4.opt;