conncheck: Don't remove elements in the conncheck list while iterating it

priv_limit_conn_check_list_size() would remove elemtns from the conncheck_list
while the calling functions were iterating it. Now instead just mark them as
cancelled. Then later, at the outer function, free all cancelled elements to
prevent the list from growing out of bounds.

1 files changed, 50 insertions, 30 deletions

diff --git a/agent/conncheck.c b/agent/conncheck.c
index 0fcfb16..783a977 100644
--- a/agent/conncheck.c
+++ b/agent/conncheck.c
@@ -1010,6 +1010,27 @@ static void priv_preprocess_conn_check_pending_data (NiceAgent *agent, Stream *s
   }
 }
 
+
+static GSList *prune_cancelled_conn_check (GSList *conncheck_list)
+{
+  GSList *item = conncheck_list;
+
+  while (item) {
+    CandidateCheckPair *pair = item->data;
+    GSList *next = item->next;
+
+    if (pair->state == NICE_CHECK_CANCELLED) {
+      conn_check_free_item (pair);
+      conncheck_list = g_slist_delete_link (conncheck_list, item);
+    }
+
+    item = next;
+  }
+
+  return conncheck_list;
+}
+
+
 /*
  * Handle any processing steps for connectivity checks after
  * remote candidates have been set. This function handles
@@ -1141,6 +1162,9 @@ void conn_check_remote_candidates_set(NiceAgent *agent)
           (GDestroyNotify) incoming_check_free);
       component->incoming_checks = NULL;
     }
+
+    stream->conncheck_list =
+        prune_cancelled_conn_check (stream->conncheck_list);
   }
 }
 
@@ -1149,37 +1173,30 @@ void conn_check_remote_candidates_set(NiceAgent *agent)
  * in ICE spec section 5.7.3 (ID-19). See also 
  * conn_check_add_for_candidate().
  */
-static GSList *priv_limit_conn_check_list_size (GSList *conncheck_list, guint upper_limit)
+static void priv_limit_conn_check_list_size (GSList *conncheck_list, guint upper_limit)
 {
-  guint list_len = g_slist_length (conncheck_list);
-  guint c = 0;
-  GSList *result = conncheck_list;
-
-  if (list_len > upper_limit) {
-    nice_debug ("Agent : Pruning candidates. Conncheck list has %d elements. "
-        "Maximum connchecks allowed : %d", list_len, upper_limit);
-    c = list_len - upper_limit;
-    if (c == list_len) {
-      /* case: delete whole list */
-      g_slist_free_full (conncheck_list, conn_check_free_item);
-      result = NULL;
+  guint valid = 0;
+  guint cancelled = 0;
+  GSList *item = conncheck_list;
+
+  while (item) {
+    CandidateCheckPair *pair = item->data;
+
+    if (pair->state != NICE_CHECK_CANCELLED) {
+      valid++;
+      if (valid > upper_limit) {
+        pair->state = NICE_CHECK_CANCELLED;
+        cancelled++;
+      }
     }
-    else {
-      /* case: remove 'c' items from list end (lowest priority) */
-      GSList *i, *tmp;
-
-      g_assert (c > 0);
-      i = g_slist_nth (conncheck_list, c - 1);
 
-      tmp = i->next;
-      i->next = NULL;
-
-      /* delete the rest of the connectivity check list */
-      g_slist_free_full (tmp, conn_check_free_item);
-    }
+    item = item->next;
   }
 
-  return result;
+  if (cancelled > 0)
+    nice_debug ("Agent : Pruned %d candidates. Conncheck list has %d elements"
+        " left. Maximum connchecks allowed : %d", cancelled, valid,
+        upper_limit);
 }
 
 /*
@@ -1383,8 +1400,7 @@ static void priv_add_new_check_pair (NiceAgent *agent, guint stream_id, Componen
   /* implement the hard upper limit for number of
      checks (see sect 5.7.3 ICE ID-19): */
   if (agent->compatibility == NICE_COMPATIBILITY_RFC5245) {
-    stream->conncheck_list =
-        priv_limit_conn_check_list_size (stream->conncheck_list, agent->max_conn_checks);
+    priv_limit_conn_check_list_size (stream->conncheck_list, agent->max_conn_checks);
   }
 }
 
@@ -2271,8 +2287,8 @@ static CandidateCheckPair *priv_process_response_check_for_peer_reflexive(NiceAg
     p->state = NICE_CHECK_FAILED;
     nice_debug ("Agent %p : pair %p state FAILED", agent, p);
 
-    /* step: add a new discovered pair (see ICE 7.1.2.2.2
-	       "Constructing a Valid Pair" (ID-19)) */
+    /* step: add a new discovered pair (see RFC 5245 7.1.3.2.2
+	       "Constructing a Valid Pair") */
     new_pair = priv_add_peer_reflexive_pair (agent, stream->id, component->id, cand, p);
     nice_debug ("Agent %p : conncheck %p FAILED, %p DISCOVERED.", agent, p, new_pair);
   }
@@ -2412,6 +2428,10 @@ static gboolean priv_map_reply_to_conn_check_request (NiceAgent *agent, Stream *
     }
   }
 
+
+  stream->conncheck_list =
+      prune_cancelled_conn_check (stream->conncheck_list);
+
   return trans_found;
 }