net: use dst_confirm_neigh for UDP, RAW, ICMP, L2TP

When same struct dst_entry can be used for many different
neighbours we can not use it for pending confirmations.

The datagram protocols can use MSG_CONFIRM to confirm the
neighbour. When used with MSG_PROBE we do not reach the
code where neighbour is confirmed, so we have to do the
same slow lookup by using the dst_confirm_neigh() helper.
When MSG_PROBE is not used, ip_append_data/ip6_append_data
will set the skb flag dst_pending_confirm.

Reported-by: YueHaibing <yuehaibing@huawei.com>
Fixes: 5110effee8fd ("net: Do delayed neigh confirmation.")
Fixes: f2bb4bedf35d ("ipv4: Cache output routes in fib_info nexthops.")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 0 deletions

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 14d99fbf102e..d299040613a0 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1145,6 +1145,9 @@ static inline int ip6_ufo_append_data(struct sock *sk,
                 skb->protocol = htons(ETH_P_IPV6);
                 skb->csum = 0;
 
+                if (flags & MSG_CONFIRM)
+                        skb_set_dst_pending_confirm(skb, 1);
+
                 __skb_queue_tail(queue, skb);
         } else if (skb_is_gso(skb)) {
                 goto append;
@@ -1517,6 +1520,9 @@ alloc_new_skb:
                         exthdrlen = 0;
                         dst_exthdrlen = 0;
 
+                        if ((flags & MSG_CONFIRM) && !skb_prev)
+                                skb_set_dst_pending_confirm(skb, 1);
+
                         /*
                          * Put the packet on the pending queue
                          */