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authorEric Dumazet <edumazet@google.com>2012-07-23 09:48:52 +0200
committerDavid S. Miller <davem@davemloft.net>2012-07-23 00:58:46 -0700
commit563d34d05786263893ba4a1042eb9b9374127cf5 (patch)
treee9ce502c1f32bea966c81d5597d0a29eb4b9d244 /include/net/sock.h
parentc3def943c7117d42caaed3478731ea7c3c87190e (diff)
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tcp: dont drop MTU reduction indications
ICMP messages generated in output path if frame length is bigger than mtu are actually lost because socket is owned by user (doing the xmit) One example is the ipgre_tunnel_xmit() calling icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu)); We had a similar case fixed in commit a34a101e1e6 (ipv6: disable GSO on sockets hitting dst_allfrag). Problem of such fix is that it relied on retransmit timers, so short tcp sessions paid a too big latency increase price. This patch uses the tcp_release_cb() infrastructure so that MTU reduction messages (ICMP messages) are not lost, and no extra delay is added in TCP transmits. Reported-by: Maciej Żenczykowski <maze@google.com> Diagnosed-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Nandita Dukkipati <nanditad@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Tore Anderson <tore@fud.no> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net/sock.h')
-rw-r--r--include/net/sock.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/net/sock.h b/include/net/sock.h
index 88de092df50f..e067f8c18f88 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -859,6 +859,7 @@ struct proto {
struct sk_buff *skb);
void (*release_cb)(struct sock *sk);
+ void (*mtu_reduced)(struct sock *sk);
/* Keeping track of sk's, looking them up, and port selection methods. */
void (*hash)(struct sock *sk);