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>

2 files changed, 3 insertions, 0 deletions

diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
index eb9abe24bdf0..a00c18aa6c8d 100644
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -482,6 +482,7 @@ route_done:
                               np->tclass, NULL, &fl, (struct rt6_info*)dst,
                               MSG_DONTWAIT);
         if (err) {
+                ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTMSGS);
                 ip6_flush_pending_frames(sk);
                 goto out_put;
         }
@@ -562,6 +563,7 @@ static void icmpv6_echo_reply(struct sk_buff *skb)
                                 (struct rt6_info*)dst, MSG_DONTWAIT);
 
         if (err) {
+                ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTMSGS);
                 ip6_flush_pending_frames(sk);
                 goto out_put;
         }
diff --git a/net/ipv6/proc.c b/net/ipv6/proc.c
index 58344c0fbd13..458eabfbe130 100644
--- a/net/ipv6/proc.c
+++ b/net/ipv6/proc.c
@@ -97,6 +97,7 @@ static const struct snmp_mib snmp6_icmp6_list[] = {
         SNMP_MIB_ITEM("Icmp6InMsgs", ICMP6_MIB_INMSGS),
         SNMP_MIB_ITEM("Icmp6InErrors", ICMP6_MIB_INERRORS),
         SNMP_MIB_ITEM("Icmp6OutMsgs", ICMP6_MIB_OUTMSGS),
+        SNMP_MIB_ITEM("Icmp6OutErrors", ICMP6_MIB_OUTERRORS),
         SNMP_MIB_SENTINEL
 };