[NET] Move DF check to ip_forward
Do fragmentation check in ip_forward, similar to ipv6 forwarding.
Signed-off-by: John Heffner <jheffner@psc.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ip_forward.c b/net/ipv4/ip_forward.c
index 467ebed..61b30d1 100644
--- a/net/ipv4/ip_forward.c
+++ b/net/ipv4/ip_forward.c
@@ -85,6 +85,14 @@
if (opt->is_strictroute && rt->rt_dst != rt->rt_gateway)
goto sr_failed;
+ if (unlikely(skb->len > dst_mtu(&rt->u.dst) &&
+ (ip_hdr(skb)->frag_off & htons(IP_DF))) && !skb->local_df) {
+ IP_INC_STATS(IPSTATS_MIB_FRAGFAILS);
+ icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
+ htonl(dst_mtu(&rt->u.dst)));
+ goto drop;
+ }
+
/* We are about to mangle packet. Copy it! */
if (skb_cow(skb, LL_RESERVED_SPACE(rt->u.dst.dev)+rt->u.dst.header_len))
goto drop;