Merge pull request #300 from cetic/rpl-nopath-dao

RPL No-Path DAOs

core/net/rpl/rpl-icmp6.c

@@ -655,7 +655,7 @@ dao_input(void)
 
   if(lifetime == RPL_ZERO_LIFETIME) {
     /* No-Path DAO received; invoke the route purging routine. */
-    if(rep != NULL && rep->state.saved_lifetime == 0 && rep->length == prefixlen) {
+    if(rep != NULL && rep->state.saved_lifetime == 0 && rep->length == prefixlen && uip_ipaddr_cmp(&rep->nexthop, &dao_sender_addr)) {
       PRINTF("RPL: Setting expiration timer for prefix ");
       PRINT6ADDR(&prefix);
       PRINTF("\n");
@@ -707,27 +707,36 @@ dao_input(void)
 }
 /*---------------------------------------------------------------------------*/
 void
-dao_output(rpl_parent_t *n, uint8_t lifetime)
+dao_output(rpl_parent_t *parent, uint8_t lifetime)
 {
-  rpl_dag_t *dag;
-  rpl_instance_t *instance;
-  unsigned char *buffer;
-  uint8_t prefixlen;
-  uip_ipaddr_t prefix;
-  int pos;
-
   /* Destination Advertisement Object */
+  uip_ipaddr_t prefix;
 
   if(get_global_addr(&prefix) == 0) {
     PRINTF("RPL: No global address set for this node - suppressing DAO\n");
     return;
   }
 
-  dag = n->dag;
+  /* Sending a DAO with own prefix as target */
+  dao_output_target(parent, &prefix, lifetime);
+}
+/*---------------------------------------------------------------------------*/
+void
+dao_output_target(rpl_parent_t *parent, uip_ipaddr_t *prefix, uint8_t lifetime)
+{
+  rpl_dag_t *dag;
+  rpl_instance_t *instance;
+  unsigned char *buffer;
+  uint8_t prefixlen;
+  int pos;
+
+  /* Destination Advertisement Object */
+
+  dag = parent->dag;
   instance = dag->instance;
 
 #ifdef RPL_DEBUG_DAO_OUTPUT
-  RPL_DEBUG_DAO_OUTPUT(n);
+  RPL_DEBUG_DAO_OUTPUT(parent);
 #endif
 
   buffer = UIP_ICMP_PAYLOAD;
@@ -752,12 +761,12 @@ dao_output(rpl_parent_t *n, uint8_t lifetime)
 #endif /* RPL_DAO_SPECIFY_DAG */
 
   /* create target subopt */
-  prefixlen = sizeof(prefix) * CHAR_BIT;
+  prefixlen = sizeof(*prefix) * CHAR_BIT;
   buffer[pos++] = RPL_OPTION_TARGET;
   buffer[pos++] = 2 + ((prefixlen + 7) / CHAR_BIT);
   buffer[pos++] = 0; /* reserved */
   buffer[pos++] = prefixlen;
-  memcpy(buffer + pos, &prefix, (prefixlen + 7) / CHAR_BIT);
+  memcpy(buffer + pos, prefix, (prefixlen + 7) / CHAR_BIT);
   pos += ((prefixlen + 7) / CHAR_BIT);
 
   /* Create a transit information sub-option. */
@@ -769,12 +778,12 @@ dao_output(rpl_parent_t *n, uint8_t lifetime)
   buffer[pos++] = lifetime;
 
   PRINTF("RPL: Sending DAO with prefix ");
-  PRINT6ADDR(&prefix);
+  PRINT6ADDR(prefix);
   PRINTF(" to ");
-  PRINT6ADDR(&n->addr);
+  PRINT6ADDR(&parent->addr);
   PRINTF("\n");
 
-  uip_icmp6_send(&n->addr, ICMP6_RPL, RPL_CODE_DAO, pos);
+  uip_icmp6_send(&parent->addr, ICMP6_RPL, RPL_CODE_DAO, pos);
 }
 /*---------------------------------------------------------------------------*/
 static void

core/net/rpl/rpl-private.h

@@ -270,6 +270,7 @@ extern rpl_instance_t *default_instance;
 void dis_output(uip_ipaddr_t *addr);
 void dio_output(rpl_instance_t *, uip_ipaddr_t *uc_addr);
 void dao_output(rpl_parent_t *, uint8_t lifetime);
+void dao_output_target(rpl_parent_t *, uip_ipaddr_t *, uint8_t lifetime);
 void dao_ack_output(rpl_instance_t *, uip_ipaddr_t *, uint8_t);
 
 /* RPL logic functions. */

core/net/rpl/rpl.c

@@ -63,6 +63,8 @@ void
 rpl_purge_routes(void)
 {
   uip_ds6_route_t *r;
+  uip_ipaddr_t prefix;
+  rpl_dag_t *dag;
 
   /* First pass, decrement lifetime */
   r = uip_ds6_route_list_head();
@@ -86,8 +88,20 @@ rpl_purge_routes(void)
     if(r->state.lifetime < 1) {
       /* Routes with lifetime == 1 have only just been decremented from 2 to 1,
        * thus we want to keep them. Hence < and not <= */
+      uip_ipaddr_copy(&prefix, &r->ipaddr);
       uip_ds6_route_rm(r);
       r = uip_ds6_route_list_head();
+      PRINTF("No more routes to ");
+      PRINT6ADDR(&prefix);
+      dag = default_instance->current_dag;
+      /* Propagate this information with a No-Path DAO to preferred parent if we are not a RPL Root */
+      if(dag->rank != ROOT_RANK(default_instance)) {
+        PRINTF(" -> generate No-Path DAO\n");
+        dao_output_target(dag->preferred_parent, &prefix, RPL_ZERO_LIFETIME);
+        /* Don't schedule more than 1 No-Path DAO, let next iteration handle that */
+        return;
+      }
+      PRINTF("\n");
     } else {
       r = list_item_next(r);
     }