bridge: br_arp_nd_proxy: set icmp6_router if neigh has NTF_ROUTER

mainline inclusion
from mainline-4.20
commit 7aca011f
category: bugfix
bugzilla: 6062
CVE: NA

-------------------------------------------------

Fixes: ed842fae ("bridge: suppress nd pkts on BR_NEIGH_SUPPRESS ports")
Signed-off-by: NRoopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NKeefe LIU <liuqifa@huawei.com>
Reviewed-by: NWei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

net/bridge/br_arp_nd_proxy.c

@@ -311,7 +311,7 @@ static void br_nd_send(struct net_bridge *br, struct net_bridge_port *p,
 	/* Neighbor Advertisement */
 	memset(na, 0, sizeof(*na) + na_olen);
 	na->icmph.icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT;
-	na->icmph.icmp6_router = 0; /* XXX: should be 1 ? */
+	na->icmph.icmp6_router = (n->flags & NTF_ROUTER) ? 1 : 0;
 	na->icmph.icmp6_override = 1;
 	na->icmph.icmp6_solicited = 1;
 	na->target = ns->target;