Re: [PATCH 2/2] ipvs: Extend MTU check to account for IPv6 NAT defrag ch

To: Julian Anastasov <ja@xxxxxx>
Subject: Re: [PATCH 2/2] ipvs: Extend MTU check to account for IPv6 NAT defrag changes
Cc: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>, netdev@xxxxxxxxxxxxxxx, lvs-devel@xxxxxxxxxxxxxxx, Simon Horman <horms@xxxxxxxxxxxx>, Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>, Hans Schillstrom <hans@xxxxxxxxxxxxxxx>, Wensong Zhang <wensong@xxxxxxxxxxxx>, netfilter-devel@xxxxxxxxxxxxxxx
From: Patrick McHardy <kaber@xxxxxxxxx>
Date: Tue, 28 Aug 2012 10:22:05 +0200 (MEST)
On Mon, 27 Aug 2012, Julian Anastasov wrote:


On Mon, 27 Aug 2012, Jesper Dangaard Brouer wrote:

This patch is necessary, to make IPVS work, after Patrick McHardys
IPv6 NAT defragmentation changes.

Signed-off-by: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>

I would appriciate, if someone (e.g. Julian) double check the tunnel mode code.



 net/netfilter/ipvs/ip_vs_xmit.c |   16 +++++++++++++---
 1 files changed, 13 insertions(+), 3 deletions(-)

@@ -956,8 +963,11 @@ ip_vs_tunnel_xmit_v6(struct sk_buff *skb, struct 
ip_vs_conn *cp,
                skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);

        /* MTU checking: Special for tunnel mode */
-       if (mtu < ntohs(old_iph->payload_len) + sizeof(struct ipv6hdr) &&
-           !skb_is_gso(skb)) {
+       if ((!IP6CB(skb)->frag_max_size &&
+            (mtu < ntohs(old_iph->payload_len) + sizeof(struct ipv6hdr) &&
+             !skb_is_gso(skb)))
+           || IP6CB(skb)->frag_max_size + sizeof(struct ipv6hdr) > mtu) {

        mtu is already reduced with the new outer header size,
may be we can just call __mtu_check_toobig_v6 with mtu?

                if (!skb->dev) {
                        struct net *net = dev_net(skb_dst(skb)->dev);

        All other changes in patch 1 and 2 look ok and
I'll ack them next time.

I'd like to take the final patches through my nat-ipv6 tree in order
to avoid temporary regressions. Please let me know when they're ready
for applying.
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