Merge pull request #3853 from OlegHahm/6lowpan_nd_router_fixes

6lowpan nd router fixes

sys/include/net/gnrc/ndp.h

@@ -41,14 +41,24 @@
 extern "C" {
 #endif
 
-#define GNRC_NDP_MSG_RTR_TIMEOUT        (0x0210)    /**< Message type for router timeouts */
+/** Message type for router timeouts */
-#define GNRC_NDP_MSG_ADDR_TIMEOUT       (0x0211)    /**< Message type for address timeouts */
+#define GNRC_NDP_MSG_RTR_TIMEOUT                (0x0210)
-#define GNRC_NDP_MSG_NBR_SOL_RETRANS    (0x0212)    /**< Message type for multicast
+/** Message type for address timeouts */
-                                                     *   neighbor solicitation retransmissions */
+#define GNRC_NDP_MSG_ADDR_TIMEOUT               (0x0211)
-#define GNRC_NDP_MSG_RTR_ADV_RETRANS    (0x0213)    /**< Message type for periodic router advertisements */
+/** Message type for multicast neighbor solicitation retransmissions */
-#define GNRC_NDP_MSG_RTR_ADV_DELAY      (0x0214)    /**< Message type for delayed router advertisements */
+#define GNRC_NDP_MSG_NBR_SOL_RETRANS            (0x0212)
-#define GNRC_NDP_MSG_RTR_SOL_RETRANS    (0x0215)    /**< Message type for periodic router solicitations */
+/** Message type for periodic router advertisements */
-#define GNRC_NDP_MSG_NC_STATE_TIMEOUT   (0x0216)    /**< Message type for neighbor cache state timeouts */
+#define GNRC_NDP_MSG_RTR_ADV_RETRANS            (0x0213)
+/** Message type for delayed router advertisements */
+#define GNRC_NDP_MSG_RTR_ADV_DELAY              (0x0214)
+/** Message type for delayed router advertisements in a 6LoWPAN
+ * 6LoWPAN needs a special handling, because router advertisements are only
+ * sent after a short randomized delay, but not periodically. */
+#define GNRC_NDP_MSG_RTR_ADV_SIXLOWPAN_DELAY    (0x0215)
+/** Message type for periodic router solicitations */
+#define GNRC_NDP_MSG_RTR_SOL_RETRANS            (0x0216)
+/** Message type for neighbor cache state timeouts */
+#define GNRC_NDP_MSG_NC_STATE_TIMEOUT           (0x0217)
 
 /**
  * @name    Host constants

sys/net/gnrc/network_layer/ipv6/gnrc_ipv6.c

@@ -255,6 +255,12 @@ static void *_event_loop(void *args)
                 DEBUG("ipv6: address registration timeout received\n");
                 gnrc_sixlowpan_nd_router_gc_nc((gnrc_ipv6_nc_t *)msg.content.ptr);
                 break;
+            case GNRC_NDP_MSG_RTR_ADV_SIXLOWPAN_DELAY:
+                DEBUG("ipv6: Delayed router advertisement event received\n");
+                gnrc_ipv6_nc_t *nc_entry = (gnrc_ipv6_nc_t *)msg.content.ptr;
+                gnrc_ndp_internal_send_rtr_adv(nc_entry->iface, NULL,
+                                               &(nc_entry->ipv6_addr), false);
+                break;
 #endif
             default:
                 break;

sys/net/gnrc/network_layer/ndp/gnrc_ndp.c

@@ -414,6 +414,17 @@ void gnrc_ndp_rtr_sol_handle(kernel_pid_t iface, gnrc_pktsnip_t *pkt,
 #endif
             delay = timex_set(0, genrand_uint32_range(0, ms));
             vtimer_remove(&if_entry->rtr_adv_timer);
+#ifdef MODULE_GNRC_SIXLOWPAN_ND_ROUTER
+            /* in case of a 6LBR we have to check if the interface is actually
+             * the 6lo interface */
+            if (if_entry->flags & GNRC_IPV6_NETIF_FLAGS_SIXLOWPAN) {
+                gnrc_ipv6_nc_t *nc_entry = gnrc_ipv6_nc_get(iface, &ipv6->src);
+                if (nc_entry != NULL) {
+                    vtimer_set_msg(&if_entry->rtr_adv_timer, delay, gnrc_ipv6_pid,
+                            GNRC_NDP_MSG_RTR_ADV_SIXLOWPAN_DELAY, nc_entry);
+                }
+            }
+#elif defined(MODULE_GNRC_NDP_ROUTER) || defined(MODULE_GNRC_SIXLOWPAN_ND_BORDER_ROUTER)
             if (ipv6_addr_is_unspecified(&ipv6->src)) {
                 /* either multicast, if source unspecified */
                 vtimer_set_msg(&if_entry->rtr_adv_timer, delay, gnrc_ipv6_pid,
@@ -427,6 +438,7 @@ void gnrc_ndp_rtr_sol_handle(kernel_pid_t iface, gnrc_pktsnip_t *pkt,
                 vtimer_set_msg(&if_entry->rtr_adv_timer, delay, gnrc_ipv6_pid,
                                GNRC_NDP_MSG_RTR_ADV_DELAY, nc_entry);
             }
+#endif
         }
     }
     /* otherwise ignore silently */

sys/net/gnrc/network_layer/ndp/internal/gnrc_ndp_internal.c

@@ -462,8 +462,10 @@ void gnrc_ndp_internal_send_rtr_adv(kernel_pid_t iface, ipv6_addr_t *src, ipv6_a
         pkt = hdr;
     }
     if (src == NULL) {
+        mutex_unlock(&ipv6_iface->mutex);
         /* get address from source selection algorithm */
         src = gnrc_ipv6_netif_find_best_src_addr(iface, dst);
+        mutex_lock(&ipv6_iface->mutex);
     }
     /* add SL2A for source address */
     if (src != NULL) {

sys/net/gnrc/network_layer/sixlowpan/nd/gnrc_sixlowpan_nd.c

@@ -160,9 +160,16 @@ kernel_pid_t gnrc_sixlowpan_nd_next_hop_l2addr(uint8_t *l2addr, uint8_t *l2addr_
 #ifdef MODULE_GNRC_SIXLOWPAN_ND_ROUTER
     /* next hop determination: https://tools.ietf.org/html/rfc6775#section-6.5.4 */
     nc_entry = gnrc_ipv6_nc_get(iface, dst);
-    if ((nc_entry != NULL) && (gnrc_ipv6_nc_get_type(nc_entry) == GNRC_IPV6_NC_TYPE_REGISTERED)) {
+    /* if NCE found */
+    if (nc_entry != NULL) {
+        gnrc_ipv6_netif_t *ipv6_if = gnrc_ipv6_netif_get(nc_entry->iface);
+        /* and interface is not 6LoWPAN */
+        if (!(ipv6_if->flags & GNRC_IPV6_NETIF_FLAGS_SIXLOWPAN) ||
+                /* or entry is registered */
+                (gnrc_ipv6_nc_get_type(nc_entry) == GNRC_IPV6_NC_TYPE_REGISTERED)) {
         next_hop = dst;
         }
+    }
 #endif
     /* next hop determination according to: https://tools.ietf.org/html/rfc6775#section-5.6 */
     if ((next_hop == NULL) && ipv6_addr_is_link_local(dst)) {   /* prefix is "on-link" */