net/ipv6: Increment OUTxxx counters after netfilter hook
authorJeff Barnhill <0xeffeff@gmail.com>
Thu, 5 Apr 2018 21:29:47 +0000 (21:29 +0000)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 12 Apr 2018 10:32:23 +0000 (12:32 +0200)
[ Upstream commit 71a1c915238c970cd9bdd5bf158b1279d6b6d55b ]

At the end of ip6_forward(), IPSTATS_MIB_OUTFORWDATAGRAMS and
IPSTATS_MIB_OUTOCTETS are incremented immediately before the NF_HOOK call
for NFPROTO_IPV6 / NF_INET_FORWARD.  As a result, these counters get
incremented regardless of whether or not the netfilter hook allows the
packet to continue being processed.  This change increments the counters
in ip6_forward_finish() so that it will not happen if the netfilter hook
chooses to terminate the packet, which is similar to how IPv4 works.

Signed-off-by: Jeff Barnhill <0xeffeff@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net/ipv6/ip6_output.c

index 75b8c8a..ffbb816 100644 (file)
@@ -375,6 +375,11 @@ static int ip6_forward_proxy_check(struct sk_buff *skb)
 static inline int ip6_forward_finish(struct net *net, struct sock *sk,
                                     struct sk_buff *skb)
 {
+       struct dst_entry *dst = skb_dst(skb);
+
+       __IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS);
+       __IP6_ADD_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTOCTETS, skb->len);
+
        return dst_output(net, sk, skb);
 }
 
@@ -568,8 +573,6 @@ int ip6_forward(struct sk_buff *skb)
 
        hdr->hop_limit--;
 
-       __IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS);
-       __IP6_ADD_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTOCTETS, skb->len);
        return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD,
                       net, NULL, skb, skb->dev, dst->dev,
                       ip6_forward_finish);