ipv[4|6]: correct dropwatch false positive in local_deliver_finish

I had a report recently of a user trying to use dropwatch to localise some frame
loss, and they were getting false positives.  Turned out they were using a user
space SCTP stack that used raw sockets to grab frames.  When we don't have a
registered protocol for a given packet, we record it as a drop, even if a raw
socket receieves the frame.  We should only record the drop in the event a raw
socket doesnt exist to receive the frames

Tested by the reported successfully

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Reported-by: William Reich <reich@ulticom.com>
Tested-by: William Reich <reich@ulticom.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: William Reich <reich@ulticom.com>
CC: eric.dumazet@gmail.com
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Neil Horman 2013-03-01 07:44:08 +00:00 committed by David S. Miller
parent 9e0aab8649
commit d8c6f4b9b7
2 changed files with 8 additions and 4 deletions

View file

@ -228,9 +228,11 @@ static int ip_local_deliver_finish(struct sk_buff *skb)
icmp_send(skb, ICMP_DEST_UNREACH,
ICMP_PROT_UNREACH, 0);
}
} else
kfree_skb(skb);
} else {
IP_INC_STATS_BH(net, IPSTATS_MIB_INDELIVERS);
kfree_skb(skb);
consume_skb(skb);
}
}
}
out:

View file

@ -241,9 +241,11 @@ resubmit:
icmpv6_send(skb, ICMPV6_PARAMPROB,
ICMPV6_UNK_NEXTHDR, nhoff);
}
} else
kfree_skb(skb);
} else {
IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS);
kfree_skb(skb);
consume_skb(skb);
}
}
rcu_read_unlock();
return 0;