gtp: do not confirm neighbor when do pmtu update

BugLink: https://bugs.launchpad.net/bugs/1860602
[ Upstream commit 6e9105c73f8d2163d12d5dfd762fd75483ed30f5 ]

When do IPv6 tunnel PMTU update and calls __ip6_rt_update_pmtu() in the end,
we should not call dst_confirm_neigh() as there is no two-way communication.

Although GTP only support ipv4 right now, and __ip_rt_update_pmtu() does not
call dst_confirm_neigh(), we still set it to false to keep consistency with
IPv6 code.

v5: No change.
v4: No change.
v3: Do not remove dst_confirm_neigh, but add a new bool parameter in
    dst_ops.update_pmtu to control whether we should do neighbor confirm.
    Also split the big patch to small ones for each area.
v2: Remove dst_confirm_neigh in __ip6_rt_update_pmtu.

Reviewed-by: Guillaume Nault <gnault@redhat.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c
index 97bce0170c1260d21bb74dbed590d3fd138b3353..d8b2698f7f47a0f65897123d014414494c68a0ae 100644 (file)
--- a/drivers/net/gtp.c
+++ b/drivers/net/gtp.c
@@ -545,7 +545,7 @@ static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev,
                mtu = dst_mtu(&rt->dst);
        }
 
-       rt->dst.ops->update_pmtu(&rt->dst, NULL, skb, mtu, true);
+       rt->dst.ops->update_pmtu(&rt->dst, NULL, skb, mtu, false);
 
        if (!skb_is_gso(skb) && (iph->frag_off & htons(IP_DF)) &&
            mtu < ntohs(iph->tot_len)) {