ipv6: silence log messages for locally generated multicast

This patch fixes minor annoyance during transmission of unsolicited
neighbor advertisements from userspace to multicast addresses (as
far as I can see in RFC, this is allowed and the similar functionality
for IPv4 has been in arping for a long time).

Outgoing multicast packets get reinserted into local processing as if they
are received from the network. The machine thus sees its own NA and fills
the logs with error messages. This patch removes the message if NA has been
generated locally.

Signed-off-by: Jan Sembera <jsembera@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 172438320eec74287b045cd6b784bb3de0b38b0f..d0f54d18e19b92de1407eb9a36fed5344363d01d 100644 (file)
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -912,8 +912,13 @@ static void ndisc_recv_na(struct sk_buff *skb)
                   is invalid, but ndisc specs say nothing
                   about it. It could be misconfiguration, or
                   an smart proxy agent tries to help us :-)
+
+                  We should not print the error if NA has been
+                  received from loopback - it is just our own
+                  unsolicited advertisement.
                 */
-               ND_PRINTK1(KERN_WARNING
+               if (skb->pkt_type != PACKET_LOOPBACK)
+                       ND_PRINTK1(KERN_WARNING
                           "ICMPv6 NA: someone advertises our address on %s!\n",
                           ifp->idev->dev->name);
                in6_ifa_put(ifp);