On Fri, Mar 18, 2016 at 2:26 PM, Wei Wang <tracyw...@gmail.com> wrote:
> I don't think ip6_sk_update_pmtu() is a good place to put it as all it
> does is to call ip6_update_pmtu(). And ip6_update_pmtu() does the
> route lookup and call __ip6_rt_update_pmtu.
> We can put it in ip6_update_pmtu(). But that still means we need to
> pass sk to ip6_update_pmtu() and I don't think it makes any difference
> compared to the current fix.
>
Well, your patch touches all the callers of ip6_update_pmtu() , if you just
fix ip6_sk_update_pmtu() as I suggested, you only need to change one
function, ideally. And the ipv4 code is there, although I am not sure, it
looks like we can just mimic the logic here:
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index ed44663..b88c2ff 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1417,8 +1417,28 @@ EXPORT_SYMBOL_GPL(ip6_update_pmtu);
void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu)
{
- ip6_update_pmtu(skb, sock_net(sk), mtu,
- sk->sk_bound_dev_if, sk->sk_mark);
+ const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
+ struct net *net = sock_net(sk);
+ struct dst_entry *dst;
+ struct flowi6 fl6;
+
+ bh_lock_sock(sk);
+
+ memset(&fl6, 0, sizeof(fl6));
+ fl6.flowi6_oif = sk->sk_bound_dev_if;
+ fl6.flowi6_mark = sk->sk_mark ? : IP6_REPLY_MARK(net, skb->mark);
+ fl6.daddr = iph->daddr;
+ fl6.saddr = iph->saddr;
+ fl6.flowlabel = ip6_flowinfo(iph);
+
+ dst = ip6_route_output(net, NULL, &fl6);
+ if (!dst->error)
+ __ip6_rt_update_pmtu(dst, NULL, iph, ntohl(mtu));
+
+ sk_dst_set(sk, &rt->dst);
+ bh_unlock_sock(sk);
+
+ dst_release(dst);
}
Please don't judge me on the code, it could still miss a lot of things,
but it can show my idea...
