conncheck: enable retransmit flag after nominated pair reordering

When an existing peer-reflexive remote candidate is updated to a server
reflexive one, due to the late reception of remove candidates, this
update has several consequences on the conncheck list:

 - pair foundations and priorities must be recomputed
 - the highest nominated pair may have changed too
 - this is not strictly required, but some pairs that had *a lower*
   priority than the previously peer-reflexive nominated pair, had
   their retransmit flag set to false, for this reason. These pairs may
   now have *a higher* priority than the newly promoted nominated pair,
   and it is fair in that case to turn their retransmit flag back to
   true.

diff --git a/agent/agent.c b/agent/agent.c
index 3bb59bd..ef13b68 100644 (file)
--- a/agent/agent.c
+++ b/agent/agent.c
@@ -3692,6 +3692,7 @@ static gboolean priv_add_remote_candidate (
           "priority nominated pair %p.", agent, pair);
       conn_check_update_selected_pair (agent, component, pair);
     }
+    conn_check_update_retransmit_flag (agent, stream_id, component_id);
   }
   else {
     /* case 2: add a new candidate */

diff --git a/agent/conncheck.c b/agent/conncheck.c
index a4f6982..ad71d62 100644 (file)
--- a/agent/conncheck.c
+++ b/agent/conncheck.c
@@ -2216,6 +2216,38 @@ conn_check_update_selected_pair (NiceAgent *agent, NiceComponent *component,
 }
 
 /*
+ * Update the retransmit flag of pairs with higher priority than
+ * the first nominated pair
+ */
+void
+conn_check_update_retransmit_flag (NiceAgent *agent, guint stream_id,
+    guint component_id)
+{
+  NiceStream *stream;
+  NiceComponent *component;
+  CandidateCheckPair *pair;
+  GSList *i;
+
+  if (agent_find_component (agent, stream_id, component_id, &stream,
+      &component)) {
+
+    for (i = stream->conncheck_list; i; i = i->next) {
+      pair = i->data;
+      if (pair->component_id != component_id)
+        continue;
+      if (pair->nominated)
+        break;
+      if (pair->state == NICE_CHECK_IN_PROGRESS && !pair->retransmit &&
+          pair->stun_transactions) {
+        pair->retransmit = TRUE;
+        nice_debug ("Agent %p : pair %p will be retransmitted.", agent, pair);
+      }
+    }
+  }
+  return;
+}
+
+/*
  * Updates the check list state.
  *
  * Implements parts of the algorithm described in 

diff --git a/agent/conncheck.h b/agent/conncheck.h
index 55f97a3..ce8ff93 100644 (file)
--- a/agent/conncheck.h
+++ b/agent/conncheck.h
@@ -121,6 +121,8 @@ conn_check_prune_socket (NiceAgent *agent, NiceStream *stream, NiceComponent *co
 void recalculate_pair_priorities (NiceAgent *agent);
 void conn_check_update_selected_pair (NiceAgent *agent,
     NiceComponent *component, CandidateCheckPair *pair);
+void conn_check_update_retransmit_flag (NiceAgent *agent, guint stream_id,
+    guint component_id);
 
 
 #endif /*_NICE_CONNCHECK_H */