icmp: Account for ICMP out errors

When ip_append() fails because of socket limit or memory shortage,
increment ICMP_MIB_OUTERRORS counter, so that "netstat -s" can report
these errors.

LANG=C netstat -s | grep "ICMP messages failed"
    0 ICMP messages failed

For IPV6, implement ICMP6_MIB_OUTERRORS counter as well.

# grep Icmp6OutErrors /proc/net/dev_snmp6/*
/proc/net/dev_snmp6/eth0:Icmp6OutErrors                   	0
/proc/net/dev_snmp6/lo:Icmp6OutErrors                   	0

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 2 deletions

diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 4b4c2bcd15db..d2aa7438c523 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -330,9 +330,10 @@ static void icmp_push_reply(struct icmp_bxm *icmp_param,
         if (ip_append_data(sk, icmp_glue_bits, icmp_param,
                            icmp_param->data_len+icmp_param->head_len,
                            icmp_param->head_len,
-                           ipc, rt, MSG_DONTWAIT) < 0)
+                           ipc, rt, MSG_DONTWAIT) < 0) {
+                ICMP_INC_STATS_BH(sock_net(sk), ICMP_MIB_OUTERRORS);
                 ip_flush_pending_frames(sk);
-        else if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) {
+        } else if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) {
                 struct icmphdr *icmph = icmp_hdr(skb);
                 __wsum csum = 0;
                 struct sk_buff *skb1;