nhrp: fix race condition

	where null lladdr recieved from zebra before nhrp next hop
	is installed.

Signed-off-by: Lou Berger <lberger@labn.net>
(cherry picked from commit 5d9ebe61815814804fac39597578c57e6420a69c)

diff --git a/nhrpd/netlink_arp.c b/nhrpd/netlink_arp.c
index cd7fb7aed496120f215718232fe225b5611f141d..c1f518bf5040ae84422b0dbb66f1ae1cfa43ac92 100644 (file)
--- a/nhrpd/netlink_arp.c
+++ b/nhrpd/netlink_arp.c
@@ -188,6 +188,11 @@ int nhrp_neighbor_operation(ZAPI_CALLBACK_ARGS)
                               "Netlink: update binding for %pSU dev %s from c %pSU peer.vc.nbma %pSU to lladdr %pSU",
                               &addr, ifp->name, &c->cur.remote_nbma_natoa,
                               &c->cur.peer->vc->remote.nbma, &lladdr);
+
+                       if (lladdr.sa.sa_family == AF_UNSPEC)
+                               /* nothing from zebra, so use nhrp peer */
+                               lladdr = c->cur.peer->vc->remote.nbma;
+
                        /* In case of shortcuts, nbma is given by lladdr, not
                         * vc->remote.nbma.
                         */