zebra: Ignore RTM_GETNEIGH messages from the linux kernel

The linux kernel will occassionally send RTM_GETNEIGH when
it expects user space to help in resolution of an ARP entry.
See linux kernel commit:

commit 3e25c65ed085b361cc91a8f02e028f1158c9f255
Author: Tim Gardner <tim.gardner@canonical.com>
Date:   Thu Aug 29 06:38:47 2013 -0600

    net: neighbour: Remove CONFIG_ARPD

Since we don't care about this, let's just safely ignore this
message for the moment.  I imagine in the future we might
care when we implement neighbor managment in the system.

Reported By: Stefan Priebe <s.priebe@profihost.ag>
Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>

diff --git a/zebra/kernel_netlink.c b/zebra/kernel_netlink.c
index 23f1a3bf86ca61a5cbca8a26735dade8f6f7a1ff..ed749089a4f422a50938ff17cae65f41e7a4e940 100644 (file)
--- a/zebra/kernel_netlink.c
+++ b/zebra/kernel_netlink.c
@@ -290,6 +290,18 @@ static int netlink_information_fetch(struct nlmsghdr *h, ns_id_t ns_id,
                return netlink_neigh_change(h, ns_id);
        case RTM_DELNEIGH:
                return netlink_neigh_change(h, ns_id);
+       case RTM_GETNEIGH:
+               /*
+                * Kernel in some situations when it expects
+                * user space to resolve arp entries, we will
+                * receive this notification.  As we don't
+                * need this notification and as that
+                * we don't want to spam the log file with
+                * below messages, just ignore.
+                */
+               if (IS_ZEBRA_DEBUG_KERNEL)
+                       zlog_debug("Received RTM_GETNEIGH, ignoring");
+               break;
        case RTM_NEWRULE:
                return netlink_rule_change(h, ns_id, startup);
        case RTM_DELRULE: