Modified bbr restart mechanism when dodagid was lost

Instance id is only increased when bbr stop was called by application
meaning it is only used in testing purposes

dodag_root_delete now only removes us from root and allows information
to be retained.

rpl_dodag_was_root added to check if we were root before and ignore
the dodag DIOs and advertisements

Fixed compile problem in bootstrap

Author: Mika Tervonen

source/6LoWPAN/ws/ws_bbr_api.c

@@ -123,7 +123,6 @@ static void ws_bbr_rpl_root_start(uint8_t *dodag_id)
     if (protocol_6lowpan_rpl_root_dodag) {
         rpl_control_delete_dodag_root(protocol_6lowpan_rpl_domain, protocol_6lowpan_rpl_root_dodag);
         protocol_6lowpan_rpl_root_dodag = NULL;
-        current_instance_id++;
     }
 
     protocol_6lowpan_rpl_root_dodag = rpl_control_create_dodag_root(protocol_6lowpan_rpl_domain, current_instance_id, dodag_id, &rpl_conf, rpl_conf.min_hop_rank_increase, RPL_GROUNDED | RPL_MODE_NON_STORING | RPL_DODAG_PREF(0));
@@ -141,7 +140,6 @@ static void ws_bbr_rpl_root_stop(void)
     if (protocol_6lowpan_rpl_root_dodag) {
         rpl_control_delete_dodag_root(protocol_6lowpan_rpl_domain, protocol_6lowpan_rpl_root_dodag);
         protocol_6lowpan_rpl_root_dodag = NULL;
-        current_instance_id++;
     }
     memset(current_local_prefix, 0, 8);
     memset(current_global_prefix, 0, 8);
@@ -610,12 +608,7 @@ void ws_bbr_stop(int8_t interface_id)
     (void)interface_id;
     backbone_interface_id = -1;
 
-    if (!protocol_6lowpan_rpl_domain) {
-        return;
-    }
-
-    rpl_control_delete_dodag_root(protocol_6lowpan_rpl_domain, protocol_6lowpan_rpl_root_dodag);
-    protocol_6lowpan_rpl_root_dodag = NULL;
+    ws_bbr_rpl_root_stop();
     current_instance_id++;
 
 #else

source/6LoWPAN/ws/ws_bootstrap.c

@@ -896,6 +896,7 @@ static void ws_bootstrap_pan_advertisement_analyse_active(struct protocol_interf
      */
 
 #ifdef WISUN_1_0_ERRATA_FIX
+    (void)pan_information;
     // All messages are considered as consistent only Solicit will cause inconsistent
     trickle_consistent_heard(&cur->ws_info->trickle_pan_advertisement);
 #else

source/RPL/rpl_control.c

@@ -495,8 +495,13 @@ rpl_dodag_t *rpl_control_create_dodag_root(rpl_domain_t *domain, uint8_t instanc
 
     rpl_dodag_t *dodag = rpl_lookup_dodag(instance, dodagid);
     if (dodag) {
-        tr_error("Root DODAG already exists");
-        return NULL;
+        if (rpl_dodag_am_root(dodag)) {
+            tr_error("Root DODAG already exists");
+            return NULL;
+        }
+
+        // Delete non root information and recreate dodag
+        rpl_delete_dodag(dodag);
     }
     dodag = rpl_create_dodag(instance, dodagid, g_mop_prf);
     if (!dodag) {
@@ -975,8 +980,9 @@ static buffer_t *rpl_control_dio_handler(protocol_interface_info_entry_t *cur, r
         }
     }
 
-    /* Never listen to nodes in a DODAG we're rooting */
-    if (rpl_dodag_am_root(dodag)) {
+    /* Never listen to nodes in a DODAG we're rooting or were root*/
+    if (rpl_dodag_am_root(dodag) ||
+            rpl_dodag_was_root(dodag)) {
         /* TODO - if version is newer or unordered, increment our version to be higher? */
         /* Old code had this trick - actually, would need to go further. Want to listen first, then use a higher
          * than existing. */

source/RPL/rpl_structures.h

@@ -87,6 +87,7 @@ struct rpl_dodag {
     rpl_dodag_conf_t config;                        /* Configuration from DIO */
     uint8_t info_version;                           /* Version for g_mop_prf and config */
     bool root: 1;                                   /* We are the root of this DODAG */
+    bool was_root: 1;                               /* If we have ever been a root in this DODAG */
     bool leaf: 1;                                   /* We are a leaf in this DODAG (by policy) */
     bool have_config: 1;                            /* We have the config */
     bool used: 1;                                   /* We have ever been a member of this DODAG? */

source/RPL/rpl_upward.c

@@ -638,6 +638,7 @@ rpl_dodag_t *rpl_create_dodag(rpl_instance_t *instance, const uint8_t *dodagid,
     memcpy(dodag->id, dodagid, 16);
     dodag->leaf = false;
     dodag->root = false;
+    dodag->was_root = false;
     dodag->have_config = false;
     dodag->used = false;
     dodag->g_mop_prf = g_mop_prf;
@@ -678,15 +679,9 @@ void rpl_delete_dodag_root(rpl_dodag_t *dodag)
 {
     // This should trigger immediate poison
     rpl_instance_set_dodag_version(dodag->instance, NULL, RPL_RANK_INFINITE);
-    // Deleting DODAG is not ideal - we will just pick up adverts from our
-    // former children, and recreate, possibly violating the MaxRankIncrease.
-    // Should retain DODAG version info and just unset root flag, which will
-    // limit what happens when we hear adverts.
-    // Problem is rpl_control_create_dodag_root which can't handle the
-    // case where DODAG already exists. This would always be a problem if
-    // we'd heard adverts in between delete and create, but would be an instant
-    // problem without this delete. Need to fix.
-    rpl_delete_dodag(dodag);
+    // Retain DODAG version info and just unset root flag
+    // We have was_root still set which will drop adverts for this dodag.
+    dodag->root = false;
 }
 
 /* Convert RPL configuration to generic trickle parameters. Returns true if
@@ -792,6 +787,7 @@ void rpl_dodag_set_root(rpl_dodag_t *dodag, bool root)
         dodag->root = root;
         if (root) {
             rpl_instance_remove_parents(dodag->instance);
+            dodag->was_root = true;
         } else {
             rpl_instance_run_parent_selection(dodag->instance);
         }
@@ -803,6 +799,11 @@ bool rpl_dodag_am_root(const rpl_dodag_t *dodag)
 {
     return dodag->root;
 }
+
+bool rpl_dodag_was_root(const rpl_dodag_t *dodag)
+{
+    return dodag->was_root;
+}
 #endif
 
 void rpl_dodag_set_leaf(rpl_dodag_t *dodag, bool leaf)
@@ -1381,7 +1382,8 @@ void rpl_instance_run_parent_selection(rpl_instance_t *instance)
         return;
     }
 
-    if (instance->current_dodag_version && instance->current_dodag_version->dodag->root) {
+    if (instance->current_dodag_version &&
+            (instance->current_dodag_version->dodag->root || instance->current_dodag_version->dodag->was_root)) {
         return;
     }
 

source/RPL/rpl_upward.h

@@ -97,8 +97,10 @@ uint8_t rpl_dodag_mop(const rpl_dodag_t *dodag);
 void rpl_dodag_set_root(rpl_dodag_t *dodag, bool root);
 #ifdef HAVE_RPL_ROOT
 bool rpl_dodag_am_root(const rpl_dodag_t *dodag);
+bool rpl_dodag_was_root(const rpl_dodag_t *dodag);
 #else
 #define rpl_dodag_am_root(dodag) false
+#define rpl_dodag_was_root(dodag) false
 #endif
 uint8_t rpl_dodag_get_version_number_as_root(const rpl_dodag_t *dodag);
 void rpl_dodag_set_version_number_as_root(rpl_dodag_t *dodag, uint8_t number);

test/nanostack/unittest/stub/rpl_upward_stub.c

@@ -308,6 +308,12 @@ void rpl_dodag_set_root(rpl_dodag_t *dodag, bool root)
 
 bool rpl_dodag_am_root(const rpl_dodag_t *dodag)
 {
+    return true;
+}
+
+bool rpl_dodag_was_root(const rpl_dodag_t *dodag)
+{
+    return true;
 }
 
 void rpl_dodag_set_leaf(rpl_dodag_t *dodag, bool leaf)