net: rpl: Do not run IPv6 DAD for global addresses

When CONFIG_NET_RPL enabled, do not run DAD (duplicate address
detection) for global addresses. In RPL mesh network global addresses
for nodes are determined by prefix from Border Router. DAD is not
necessary in this case.

Signed-off-by: Ravi kumar Veeramally <[email protected]>

Author: rveerama1

subsys/net/ip/net_if.c

@@ -677,6 +677,27 @@ static inline void net_if_addr_init(struct net_if_addr *ifaddr,
 	}
 }
 
+static inline struct in6_addr *check_global_addr(struct net_if *iface)
+{
+	int i;
+
+	for (i = 0; i < NET_IF_MAX_IPV6_ADDR; i++) {
+		if (!iface->ipv6.unicast[i].is_used ||
+		    (iface->ipv6.unicast[i].addr_state != NET_ADDR_TENTATIVE &&
+		     iface->ipv6.unicast[i].addr_state != NET_ADDR_PREFERRED) ||
+		    iface->ipv6.unicast[i].address.family != AF_INET6) {
+			continue;
+		}
+
+		if (!net_is_ipv6_ll_addr(
+			    &iface->ipv6.unicast[i].address.in6_addr)) {
+			return &iface->ipv6.unicast[i].address.in6_addr;
+		}
+	}
+
+	return NULL;
+}
+
 struct net_if_addr *net_if_ipv6_addr_add(struct net_if *iface,
 					 struct in6_addr *addr,
 					 enum net_addr_type addr_type,
@@ -691,6 +712,9 @@ struct net_if_addr *net_if_ipv6_addr_add(struct net_if *iface,
 	}
 
 	for (i = 0; i < NET_IF_MAX_IPV6_ADDR; i++) {
+#if defined(CONFIG_NET_RPL)
+		struct in6_addr *global;
+#endif
 		if (iface->ipv6.unicast[i].is_used) {
 			continue;
 		}
@@ -711,9 +735,18 @@ struct net_if_addr *net_if_ipv6_addr_add(struct net_if *iface,
 		 * net_ipv6_mcast_join() checks if we have already joined.
 		 */
 		join_mcast_allnodes(iface);
-		join_mcast_solicit_node(iface, &iface->ipv6.unicast[i].address.in6_addr);
+		join_mcast_solicit_node(iface,
+				&iface->ipv6.unicast[i].address.in6_addr);
 
+#if defined(CONFIG_NET_RPL)
+		/* Do not send DAD for global addresses */
+		global = check_global_addr(iface);
+		if (!net_ipv6_addr_cmp(global, addr)) {
+			net_if_ipv6_start_dad(iface, &iface->ipv6.unicast[i]);
+		}
+#else
 		net_if_ipv6_start_dad(iface, &iface->ipv6.unicast[i]);
+#endif
 
 		net_mgmt_event_notify(NET_EVENT_IPV6_ADDR_ADD, iface);
 
@@ -1266,27 +1299,6 @@ struct in6_addr *net_if_ipv6_get_ll_addr(enum net_addr_state state,
 	return NULL;
 }
 
-static inline struct in6_addr *check_global_addr(struct net_if *iface)
-{
-	int i;
-
-	for (i = 0; i < NET_IF_MAX_IPV6_ADDR; i++) {
-		if (!iface->ipv6.unicast[i].is_used ||
-		    (iface->ipv6.unicast[i].addr_state != NET_ADDR_TENTATIVE &&
-		     iface->ipv6.unicast[i].addr_state != NET_ADDR_PREFERRED) ||
-		    iface->ipv6.unicast[i].address.family != AF_INET6) {
-			continue;
-		}
-
-		if (!net_is_ipv6_ll_addr(
-			    &iface->ipv6.unicast[i].address.in6_addr)) {
-			return &iface->ipv6.unicast[i].address.in6_addr;
-		}
-	}
-
-	return NULL;
-}
-
 struct in6_addr *net_if_ipv6_get_global_addr(struct net_if **iface)
 {
 	struct net_if *tmp;