From eddc9ec53be2ecdbf4efe0efd4a83052594f0ac0 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Fri, 20 Apr 2007 22:47:35 -0700 Subject: [SK_BUFF]: Introduce ip_hdr(), remove skb->nh.iph Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: David S. Miller --- net/ipv4/ip_forward.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net/ipv4/ip_forward.c') diff --git a/net/ipv4/ip_forward.c b/net/ipv4/ip_forward.c index 369e721c4bab..467ebedb99ba 100644 --- a/net/ipv4/ip_forward.c +++ b/net/ipv4/ip_forward.c @@ -74,7 +74,7 @@ int ip_forward(struct sk_buff *skb) * 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)) @@ -88,7 +88,7 @@ int ip_forward(struct sk_buff *skb) /* 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); -- cgit v1.2.2 From 9af3912ec9e30509b76cb376abb65a4d8af27df3 Mon Sep 17 00:00:00 2001 From: John Heffner Date: Sun, 25 Mar 2007 23:32:29 -0700 Subject: [NET] Move DF check to ip_forward Do fragmentation check in ip_forward, similar to ipv6 forwarding. Signed-off-by: John Heffner Signed-off-by: David S. Miller --- net/ipv4/ip_forward.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'net/ipv4/ip_forward.c') diff --git a/net/ipv4/ip_forward.c b/net/ipv4/ip_forward.c index 467ebedb99ba..61b30d100676 100644 --- a/net/ipv4/ip_forward.c +++ b/net/ipv4/ip_forward.c @@ -85,6 +85,14 @@ 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; -- cgit v1.2.2 From 35fc92a9deee0da6e35fdc3150bb134e58f2fd63 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Mon, 26 Mar 2007 23:22:20 -0700 Subject: [NET]: Allow forwarding of ip_summed except CHECKSUM_COMPLETE Right now Xen has a horrible hack that lets it forward packets with partial checksums. One of the reasons that CHECKSUM_PARTIAL and CHECKSUM_COMPLETE were added is so that we can get rid of this hack (where it creates two extra bits in the skbuff to essentially mirror ip_summed without being destroyed by the forwarding code). I had forgotten that I've already gone through all the deivce drivers last time around to make sure that they're looking at ip_summed == CHECKSUM_PARTIAL rather than ip_summed != 0 on transmit. In any case, I've now done that again so it should definitely be safe. Unfortunately nobody has yet added any code to update CHECKSUM_COMPLETE values on forward so we I'm setting that to CHECKSUM_NONE. This should be safe to remove for bridging but I'd like to check that code path first. So here is the patch that lets us get rid of the hack by preserving ip_summed (mostly) on forwarded packets. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- net/ipv4/ip_forward.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/ipv4/ip_forward.c') diff --git a/net/ipv4/ip_forward.c b/net/ipv4/ip_forward.c index 61b30d100676..9cb04df0054b 100644 --- a/net/ipv4/ip_forward.c +++ b/net/ipv4/ip_forward.c @@ -67,7 +67,7 @@ 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 -- cgit v1.2.2