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Diffstat (limited to 'net/ipv4/ip_forward.c')
-rw-r--r--net/ipv4/ip_forward.c14
1 files changed, 11 insertions, 3 deletions
diff --git a/net/ipv4/ip_forward.c b/net/ipv4/ip_forward.c
index 369e721c4bab..9cb04df0054b 100644
--- a/net/ipv4/ip_forward.c
+++ b/net/ipv4/ip_forward.c
@@ -67,14 +67,14 @@ int ip_forward(struct sk_buff *skb)
if (skb->pkt_type != PACKET_HOST)
goto drop;
- skb->ip_summed = CHECKSUM_NONE;
+ skb_forward_csum(skb);
/*
* According to the RFC, we must first decrease the TTL field. If
* that reaches zero, we must reply an ICMP control message telling
* that the packet's lifetime expired.
*/
- if (skb->nh.iph->ttl <= 1)
+ if (ip_hdr(skb)->ttl <= 1)
goto too_many_hops;
if (!xfrm4_route_forward(skb))
@@ -85,10 +85,18 @@ int ip_forward(struct sk_buff *skb)
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;
- iph = skb->nh.iph;
+ iph = ip_hdr(skb);
/* Decrease ttl after skb cow done */
ip_decrease_ttl(iph);