[ 27/61] tcp: fix incorrect LOCKDROPPEDICMPS counter

Greg Kroah-Hartman
2013-02-12T21:04:59Z

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3.7-stable review patch. If anyone has any objections, please let me know.

------------------

From: Eric Dumazet <edumazet@google.com>

[ Upstream commit b74aa930ef49a3c0d8e4c1987f89decac768fb2c ]

commit 563d34d057 (tcp: dont drop MTU reduction indications)
added an error leading to incorrect accounting of
LINUX_MIB_LOCKDROPPEDICMPS

If socket is owned by the user, we want to increment
this SNMP counter, unless the message is a
(ICMP_DEST_UNREACH,ICMP_FRAG_NEEDED) one.

Reported-by: Maciej ¯enczykowski <maze@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Maciej ¯enczykowski <maze@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/ipv4/tcp_ipv4.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)

--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -380,11 +380,10 @@ void tcp_v4_err(struct sk_buff *icmp_skb
* We do take care of PMTU discovery (RFC1191) special case :
* we can receive locally generated ICMP messages while socket is held.
*/
- if (sock_owned_by_user(sk) &&
- type != ICMP_DEST_UNREACH &&
- code != ICMP_FRAG_NEEDED)
- NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
-
+ if (sock_owned_by_user(sk)) {
+ if (!(type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED))
+ NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
+ }
if (sk->sk_state == TCP_CLOSE)
goto out;