component: Replace agent pointer with weak reference

This should make it safer.

agent/agent.c

@@ -1625,12 +1625,18 @@ static void
 pseudo_tcp_socket_opened (PseudoTcpSocket *sock, gpointer user_data)
 {
   NiceComponent *component = user_data;
-  NiceAgent *agent = component->agent;
+  NiceAgent *agent;
+
+  agent = g_weak_ref_get (&component->agent_ref);
+  if (agent == NULL)
+    return;
 
   nice_debug ("Agent %p: s%d:%d pseudo Tcp socket Opened", agent,
       component->stream_id, component->id);
 
   agent_signal_socket_writable (agent, component);
+
+  g_object_unref (agent);
 }
 
 /* Will attempt to queue all @n_messages into the pseudo-TCP transmission
@@ -1784,17 +1790,18 @@ static void
 pseudo_tcp_socket_readable (PseudoTcpSocket *sock, gpointer user_data)
 {
   NiceComponent *component = user_data;
-  NiceAgent *agent = component->agent;
+  NiceAgent *agent;
   gboolean has_io_callback;
   NiceStream *stream = NULL;
   guint stream_id = component->stream_id;
   guint component_id = component->id;
 
-  g_object_ref (agent);
+  agent = g_weak_ref_get (&component->agent_ref);
+  if (agent == NULL)
+    return;
 
   if (!agent_find_component (agent, stream_id, component_id,
           &stream, &component)) {
-    g_object_unref (agent);
     goto out;
   }
 
@@ -1850,7 +1857,7 @@ pseudo_tcp_socket_readable (PseudoTcpSocket *sock, gpointer user_data)
         break;
       }
 
-      nice_component_emit_io_callback (component, buf, len);
+      nice_component_emit_io_callback (agent, component, buf, len);
 
       if (!agent_find_component (agent, stream_id, component_id,
               &stream, &component)) {
@@ -1915,12 +1922,18 @@ static void
 pseudo_tcp_socket_writable (PseudoTcpSocket *sock, gpointer user_data)
 {
   NiceComponent *component = user_data;
-  NiceAgent *agent = component->agent;
+  NiceAgent *agent;
+
+  agent = g_weak_ref_get (&component->agent_ref);
+  if (agent == NULL)
+    return;
 
   nice_debug_verbose ("Agent %p: s%d:%d pseudo Tcp socket writable", agent,
       component->stream_id, component->id);
 
   agent_signal_socket_writable (agent, component);
+
+  g_object_unref (agent);
 }
 
 static void
@@ -1928,12 +1941,18 @@ pseudo_tcp_socket_closed (PseudoTcpSocket *sock, guint32 err,
     gpointer user_data)
 {
   NiceComponent *component = user_data;
-  NiceAgent *agent = component->agent;
+  NiceAgent *agent;
+
+  agent = g_weak_ref_get (&component->agent_ref);
+  if (agent == NULL)
+    return;
 
   nice_debug ("Agent %p: s%d:%d pseudo Tcp socket closed. "
       "Calling priv_pseudo_tcp_error().",  agent, component->stream_id,
       component->id);
   priv_pseudo_tcp_error (agent, component);
+
+  g_object_unref (agent);
 }
 
 
@@ -1942,6 +1961,11 @@ pseudo_tcp_socket_write_packet (PseudoTcpSocket *psocket,
     const gchar *buffer, guint32 len, gpointer user_data)
 {
   NiceComponent *component = user_data;
+  NiceAgent *agent;
+
+  agent = g_weak_ref_get (&component->agent_ref);
+  if (agent == NULL)
+    return WR_FAIL;
 
   if (component->selected_pair.local != NULL) {
     NiceSocket *sock;
@@ -1956,7 +1980,7 @@ pseudo_tcp_socket_write_packet (PseudoTcpSocket *psocket,
 
       nice_debug_verbose (
           "Agent %p : s%d:%d: sending %d bytes on socket %p (FD %d) to [%s]:%d",
-          component->agent, component->stream_id, component->id, len,
+          agent, component->stream_id, component->id, len,
           sock->fileno, g_socket_get_fd (sock->fileno), tmpbuf,
           nice_address_get_port (addr));
     }
@@ -1968,13 +1992,16 @@ pseudo_tcp_socket_write_packet (PseudoTcpSocket *psocket,
      * its transmission rate and, hopefully, the usage of system resources
      * which caused the EWOULDBLOCK in the first place. */
     if (nice_socket_send (sock, addr, len, buffer) >= 0) {
+      g_object_unref (agent);
       return WR_SUCCESS;
     }
   } else {
     nice_debug ("%s: WARNING: Failed to send pseudo-TCP packet from agent %p "
-        "as no pair has been selected yet.", G_STRFUNC, component->agent);
+        "as no pair has been selected yet.", G_STRFUNC, agent);
   }
 
+  g_object_unref (agent);
+
   return WR_FAIL;
 }
 
@@ -2032,7 +2059,11 @@ void
 _tcp_sock_is_writable (NiceSocket *sock, gpointer user_data)
 {
   NiceComponent *component = user_data;
-  NiceAgent *agent = component->agent;
+  NiceAgent *agent;
+
+  agent = g_weak_ref_get (&component->agent_ref);
+  if (agent == NULL)
+    return;
 
   agent_lock (agent);
 
@@ -2049,6 +2080,8 @@ _tcp_sock_is_writable (NiceSocket *sock, gpointer user_data)
   agent_signal_socket_writable (agent, component);
 
   agent_unlock_and_emit (agent);
+
+  g_object_unref (agent);
 }
 
 static const gchar *
@@ -3216,7 +3249,7 @@ nice_agent_remove_stream (
 
   /* Remove the stream and signal its removal. */
   agent->streams = g_slist_remove (agent->streams, stream);
-  nice_stream_close (stream);
+  nice_stream_close (agent, stream);
 
   if (!agent->streams)
     priv_remove_keepalive_timer (agent);
@@ -5073,7 +5106,7 @@ nice_agent_dispose (GObject *object)
     {
       NiceStream *s = i->data;
 
-      nice_stream_close (s);
+      nice_stream_close (agent, s);
       g_object_unref (s);
     }
 
@@ -5133,7 +5166,10 @@ component_io_cb (GSocket *gsocket, GIOCondition condition, gpointer user_data)
   gboolean remove_source = FALSE;
 
   component = socket_source->component;
-  agent = component->agent;
+
+  agent = g_weak_ref_get (&component->agent_ref);
+  if (agent == NULL)
+    return G_SOURCE_REMOVE;
 
   agent_lock (agent);
 
@@ -5143,6 +5179,7 @@ component_io_cb (GSocket *gsocket, GIOCondition condition, gpointer user_data)
     nice_debug ("%s: stream %d destroyed", G_STRFUNC, component->stream_id);
 
     agent_unlock (agent);
+    g_object_unref (agent);
     return G_SOURCE_REMOVE;
   }
 
@@ -5151,11 +5188,10 @@ component_io_cb (GSocket *gsocket, GIOCondition condition, gpointer user_data)
     nice_debug ("%s: source %p destroyed", G_STRFUNC, g_main_current_source ());
 
     agent_unlock (agent);
+    g_object_unref (agent);
     return G_SOURCE_REMOVE;
   }
 
-  g_object_ref (agent);
-
   /* Remove disconnected sockets when we get a HUP */
   if (condition & G_IO_HUP) {
     nice_debug ("Agent %p: NiceSocket %p has received HUP", agent,
@@ -5279,7 +5315,8 @@ component_io_cb (GSocket *gsocket, GIOCondition condition, gpointer user_data)
             " bytes", G_STRFUNC, agent, local_message.length);
 
         if (local_message.length > 0) {
-          nice_component_emit_io_callback (component, local_buf, local_message.length);
+          nice_component_emit_io_callback (agent, component, local_buf,
+              local_message.length);
         }
       }
 
@@ -5466,7 +5503,7 @@ nice_agent_set_selected_pair (
       NICE_COMPONENT_STATE_READY);
 
   /* step: set the selected pair */
-  nice_component_update_selected_pair (component, &pair);
+  nice_component_update_selected_pair (agent, component, &pair);
   agent_signal_new_selected_pair (agent, stream_id, component_id,
       pair.local, pair.remote);
 

agent/component.h

@@ -199,8 +199,7 @@ struct _NiceComponent {
                                                 recv_messages */
   GError **recv_buf_error;          /* error information about failed reads */
 
-  NiceAgent *agent;  /* unowned, immutable: can be accessed without holding the
-                      * agent lock */
+  GWeakRef agent_ref;
   guint stream_id;
 
   StunAgent stun_agent; /* This stun agent is used to validate all stun requests */
@@ -236,7 +235,7 @@ NiceComponent *
 nice_component_new (guint component_id, NiceAgent *agent, NiceStream *stream);
 
 void
-nice_component_close (NiceComponent *component);
+nice_component_close (NiceAgent *agent, NiceComponent *component);
 
 gboolean
 nice_component_find_pair (NiceComponent *component, NiceAgent *agent,
@@ -246,7 +245,7 @@ void
 nice_component_restart (NiceComponent *component);
 
 void
-nice_component_update_selected_pair (NiceComponent *component,
+nice_component_update_selected_pair (NiceAgent *agent, NiceComponent *component,
     const CandidatePair *pair);
 
 NiceCandidate *
@@ -284,7 +283,7 @@ nice_component_set_io_callback (NiceComponent *component,
     NiceInputMessage *recv_messages, guint n_recv_messages,
     GError **error);
 void
-nice_component_emit_io_callback (NiceComponent *component,
+nice_component_emit_io_callback (NiceAgent *agent, NiceComponent *component,
     const guint8 *buf, gsize buf_len);
 gboolean
 nice_component_has_io_callback (NiceComponent *component);
@@ -303,7 +302,7 @@ void
 turn_server_unref (TurnServer *turn);
 
 void
-nice_component_add_valid_candidate (NiceComponent *component,
+nice_component_add_valid_candidate (NiceAgent *agent, NiceComponent *component,
     const NiceCandidate *candidate);
 
 gboolean

agent/conncheck.c

@@ -1732,7 +1732,7 @@ static gboolean priv_update_selected_pair (NiceAgent *agent, NiceComponent *comp
     cpair.priority = pair->priority;
     /* cpair.keepalive is not used by nice_component_update_selected_pair() */
 
-    nice_component_update_selected_pair (component, &cpair);
+    nice_component_update_selected_pair (agent, component, &cpair);
 
     priv_conn_keepalive_tick_unlocked (agent);
 
@@ -3041,7 +3041,7 @@ static CandidateCheckPair *priv_process_response_check_for_reflexive(NiceAgent *
     SET_PAIR_STATE (agent, p, NICE_CHECK_SUCCEEDED);
     priv_remove_pair_from_triggered_check_queue (agent, p);
     priv_free_all_stun_transactions (p, component);
-    nice_component_add_valid_candidate (component, remote_candidate);
+    nice_component_add_valid_candidate (agent, component, remote_candidate);
   }
   else {
     if (!local_cand) {
@@ -3079,7 +3079,7 @@ static CandidateCheckPair *priv_process_response_check_for_reflexive(NiceAgent *
   }
 
   if (new_pair && new_pair->valid)
-    nice_component_add_valid_candidate (component, remote_candidate);
+    nice_component_add_valid_candidate (agent, component, remote_candidate);
 
 
   return new_pair;
@@ -3165,7 +3165,7 @@ static gboolean priv_map_reply_to_conn_check_request (NiceAgent *agent, NiceStre
           nice_debug ("Agent %p : Mapped address not found", agent);
           SET_PAIR_STATE (agent, p, NICE_CHECK_SUCCEEDED);
           p->valid = TRUE;
-          nice_component_add_valid_candidate (component, p->remote);
+          nice_component_add_valid_candidate (agent, component, p->remote);
         } else
           ok_pair = priv_process_response_check_for_reflexive (agent,
               stream, component, p, sockptr, &sockaddr.addr,
@@ -4203,7 +4203,7 @@ gboolean conn_check_handle_inbound_stun (NiceAgent *agent, NiceStream *stream,
         }
       }
 
-      nice_component_add_valid_candidate (component, remote_candidate);
+      nice_component_add_valid_candidate (agent, component, remote_candidate);
 
       priv_reply_to_conn_check (agent, stream, component, local_candidate,
           remote_candidate, from, nicesock, rbuf_len, &msg, use_candidate);

agent/stream.c

@@ -81,13 +81,13 @@ nice_stream_new (guint stream_id, guint n_components, NiceAgent *agent)
 }
 
 void
-nice_stream_close (NiceStream *stream)
+nice_stream_close (NiceAgent *agent, NiceStream *stream)
 {
   GSList *i;
 
   for (i = stream->components; i; i = i->next) {
     NiceComponent *component = i->data;
-    nice_component_close (component);
+    nice_component_close (agent, component);
   }
 }
 

agent/stream.h

@@ -101,7 +101,7 @@ NiceStream *
 nice_stream_new (guint stream_id, guint n_components, NiceAgent *agent);
 
 void
-nice_stream_close (NiceStream *stream);
+nice_stream_close (NiceAgent *agent, NiceStream *stream);
 
 NiceComponent *
 nice_stream_find_component_by_id (NiceStream *stream, guint id);