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, 5 insertions, 1 deletions

diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c
index ea89073c8247..f174e76e6505 100644
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -654,6 +654,9 @@ static int rawv6_send_hdrinc(struct sock *sk, struct msghdr *msg, int length,
 
         skb->ip_summed = CHECKSUM_NONE;
 
+        if (flags & MSG_CONFIRM)
+                skb_set_dst_pending_confirm(skb, 1);
+
         skb->transport_header = skb->network_header;
         err = memcpy_from_msg(iph, msg, length);
         if (err)
@@ -934,7 +937,8 @@ out:
         txopt_put(opt_to_free);
         return err < 0 ? err : len;
 do_confirm:
-        dst_confirm(dst);
+        if (msg->msg_flags & MSG_PROBE)
+                dst_confirm_neigh(dst, &fl6.daddr);
         if (!(msg->msg_flags & MSG_PROBE) || len)
                 goto back_from_confirm;
         err = 0;