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authorEric Dumazet <eric.dumazet@gmail.com>2010-03-07 23:21:57 +0000
committerDavid S. Miller <davem@davemloft.net>2010-03-08 10:45:27 -0800
commit6cce09f87a04797fae5b947ef2626c14a78f0b49 (patch)
treea1d7638f9571a29db9bc5c5d8e0baee19597d59e /net/ipv4
parent4045635318538d3ddd2007720412fdc4b08f6a62 (diff)
downloadlinux-6cce09f87a04797fae5b947ef2626c14a78f0b49.tar.bz2
tcp: Add SNMP counters for backlog and min_ttl drops
Commit 6b03a53a (tcp: use limited socket backlog) added the possibility of dropping frames when backlog queue is full. Commit d218d111 (tcp: Generalized TTL Security Mechanism) added the possibility of dropping frames when TTL is under a given limit. This patch adds new SNMP MIB entries, named TCPBacklogDrop and TCPMinTTLDrop, published in /proc/net/netstat in TcpExt: line netstat -s | egrep "TCPBacklogDrop|TCPMinTTLDrop" TCPBacklogDrop: 0 TCPMinTTLDrop: 0 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
-rw-r--r--net/ipv4/proc.c2
-rw-r--r--net/ipv4/tcp_ipv4.c7
2 files changed, 7 insertions, 2 deletions
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 242ed2307370..4f1f337f4337 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -249,6 +249,8 @@ static const struct snmp_mib snmp4_net_list[] = {
SNMP_MIB_ITEM("TCPSackShifted", LINUX_MIB_SACKSHIFTED),
SNMP_MIB_ITEM("TCPSackMerged", LINUX_MIB_SACKMERGED),
SNMP_MIB_ITEM("TCPSackShiftFallback", LINUX_MIB_SACKSHIFTFALLBACK),
+ SNMP_MIB_ITEM("TCPBacklogDrop", LINUX_MIB_TCPBACKLOGDROP),
+ SNMP_MIB_ITEM("TCPMinTTLDrop", LINUX_MIB_TCPMINTTLDROP),
SNMP_MIB_SENTINEL
};
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 1915f7dc30e6..8d51d39ad1bb 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1651,8 +1651,10 @@ int tcp_v4_rcv(struct sk_buff *skb)
if (!sk)
goto no_tcp_socket;
- if (iph->ttl < inet_sk(sk)->min_ttl)
+ if (unlikely(iph->ttl < inet_sk(sk)->min_ttl)) {
+ NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
goto discard_and_relse;
+ }
process:
if (sk->sk_state == TCP_TIME_WAIT)
@@ -1682,8 +1684,9 @@ process:
if (!tcp_prequeue(sk, skb))
ret = tcp_v4_do_rcv(sk, skb);
}
- } else if (sk_add_backlog(sk, skb)) {
+ } else if (unlikely(sk_add_backlog(sk, skb))) {
bh_unlock_sock(sk);
+ NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
goto discard_and_relse;
}
bh_unlock_sock(sk);