From 41063e9dd11956f2d285e12e4342e1d232ba0ea2 Mon Sep 17 00:00:00 2001 From: David S. Miller Date: Tue, 19 Jun 2012 21:22:05 -0700 Subject: ipv4: Early TCP socket demux. Input packet processing for local sockets involves two major demuxes. One for the route and one for the socket. But we can optimize this down to one demux for certain kinds of local sockets. Currently we only do this for established TCP sockets, but it could at least in theory be expanded to other kinds of connections. If a TCP socket is established then it's identity is fully specified. This means that whatever input route was used during the three-way handshake must work equally well for the rest of the connection since the keys will not change. Once we move to established state, we cache the receive packet's input route to use later. Like the existing cached route in sk->sk_dst_cache used for output packets, we have to check for route invalidations using dst->obsolete and dst->ops->check(). Early demux occurs outside of a socket locked section, so when a route invalidation occurs we defer the fixup of sk->sk_rx_dst until we are actually inside of established state packet processing and thus have the socket locked. Signed-off-by: David S. Miller --- net/core/sock.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'net/core') diff --git a/net/core/sock.c b/net/core/sock.c index 9e5b71fda6ec..929bdcc2383b 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1465,6 +1465,11 @@ void sock_rfree(struct sk_buff *skb) } EXPORT_SYMBOL(sock_rfree); +void sock_edemux(struct sk_buff *skb) +{ + sock_put(skb->sk); +} +EXPORT_SYMBOL(sock_edemux); int sock_i_uid(struct sock *sk) { -- cgit v1.2.3-55-g7522