ip6: fix iface output for multicast destination

The returned nexthop for a multicast route lookup doesn't have a defined iface. Yet, this nexthop is valid, and we can rely on the iface defined by the parent node to select the output iface. Signed-off-by: Christophe Fontaine <[email protected]>
DPDK · Jan 15, 2025 · 78f1bb6 · 78f1bb6
1 parent 39dd3a3
commit 78f1bb6
Showing 1 changed file with 6 additions and 1 deletion.
diff --git a/modules/ip6/datapath/ip6_output.c b/modules/ip6/datapath/ip6_output.c
@@ -57,7 +57,12 @@ ip6_output_process(struct rte_graph *graph, struct rte_node *node, void **objs,
 			edge = DEST_UNREACH;
 			goto next;
 		}
-		iface = iface_from_id(nh->iface_id);
+
+		// For multicast destination, nh->iface will be NULL
+		if (rte_ipv6_addr_is_mcast(&ip->dst_addr))
+			iface = mbuf_data(mbuf)->iface;
+		else
+			iface = iface_from_id(nh->iface_id);
 		if (iface == NULL) {
 			edge = ERROR;
 			goto next;