Hello, On Tue, 28 Aug 2012, Jesper Dangaard Brouer wrote: > On Mon, 2012-08-27 at 18:20 +0300, Julian Anastasov wrote: > > > > > @@ -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) && > > I guess: > ntohs(old_iph->payload_len) + sizeof(struct ipv6hdr) > Is the same as: > skb->len I think so. You can think of this in different way: all transmitters are called from same place, there is no difference in the packets we see. When we can use __mtu_check_toobig_v6 for other methods relying on skb->len being correct, we can do the same for tunnels, only that tunnels have lower MTU, that is the only difference. > > > - !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? > > To Julian, is the extra sizeof(struct ipv6hdr) addition to > frag_max_size, wrong? (as the mtu is already reduced) Yes, sizeof(struct ipv6hdr) is needed only together with payload_len because payload_len does not include the first header. > If above statements hold, I think we can simply use > __mtu_check_toobig_v6() also for the tunnel case :-) Yep > --Jesper Regards -- Julian Anastasov <ja@xxxxxx> -- To unsubscribe from this list: send the line "unsubscribe lvs-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html