[PATCH 4.19 103/114] sit: do not confirm neighbor when do pmtu update

From: Greg Kroah-Hartman
Date: Thu Jan 02 2020 - 17:23:35 EST

From: Hangbin Liu <liuhangbin@xxxxxxxxx>

[ Upstream commit 4d42df46d6372ece4cb4279870b46c2ea7304a47 ]

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.

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@xxxxxxxxxx>
Acked-by: David Ahern <dsahern@xxxxxxxxx>
Signed-off-by: Hangbin Liu <liuhangbin@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
net/ipv6/sit.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -943,7 +943,7 @@ static netdev_tx_t ipip6_tunnel_xmit(str

if (tunnel->parms.iph.daddr)
- skb_dst_update_pmtu(skb, mtu);
+ skb_dst_update_pmtu_no_confirm(skb, mtu);

if (skb->len > mtu && !skb_is_gso(skb)) {
icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);