GUACAMOLE-1388: Merge ensure RDP-specific resources are cleaned up after channel disconnect.

src/protocols/rdp/channels/cliprdr.c

@@ -546,6 +546,48 @@ static void guac_rdp_cliprdr_channel_connected(rdpContext* context,
 
 }
 
+/**
+ * Callback which disassociates Guacamole from the CliprdrClientContext
+ * instance that was originally allocated by FreeRDP and is about to be
+ * deallocated.
+ *
+ * This function is called whenever a channel disconnects via the PubSub event
+ * system within FreeRDP, but only has any effect if the disconnected channel
+ * is the CLIPRDR channel. This specific callback is registered with the PubSub
+ * system of the relevant rdpContext when guac_rdp_clipboard_load_plugin() is
+ * called.
+ *
+ * @param context
+ *     The rdpContext associated with the active RDP session.
+ *
+ * @param e
+ *     Event-specific arguments, mainly the name of the channel, and a
+ *     reference to the associated plugin loaded for that channel by FreeRDP.
+ */
+static void guac_rdp_cliprdr_channel_disconnected(rdpContext* context,
+        ChannelDisconnectedEventArgs* e) {
+
+    guac_client* client = ((rdp_freerdp_context*) context)->client;
+    guac_rdp_client* rdp_client = (guac_rdp_client*) client->data;
+    guac_rdp_clipboard* clipboard = rdp_client->clipboard;
+
+    /* FreeRDP-specific handlers for CLIPRDR are not assigned, and thus not
+     * callable, until after the relevant guac_rdp_clipboard structure is
+     * allocated and associated with the guac_rdp_client */
+    assert(clipboard != NULL);
+
+    /* Ignore disconnection event if it's not for the CLIPRDR channel */
+    if (strcmp(e->name, CLIPRDR_SVC_CHANNEL_NAME) != 0)
+        return;
+
+    /* Channel is no longer connected */
+    clipboard->cliprdr = NULL;
+
+    guac_client_log(client, GUAC_LOG_DEBUG, "CLIPRDR (clipboard redirection) "
+            "channel disconnected.");
+
+}
+
 guac_rdp_clipboard* guac_rdp_clipboard_alloc(guac_client* client) {
 
     /* Allocate clipboard and underlying storage */
@@ -575,6 +617,10 @@ void guac_rdp_clipboard_load_plugin(guac_rdp_clipboard* clipboard,
     PubSub_SubscribeChannelConnected(context->pubSub,
             (pChannelConnectedEventHandler) guac_rdp_cliprdr_channel_connected);
 
+    /* Clean up any RDP-specific resources when channel is disconnected */
+    PubSub_SubscribeChannelDisconnected(context->pubSub,
+            (pChannelDisconnectedEventHandler) guac_rdp_cliprdr_channel_disconnected);
+
     guac_client_log(clipboard->client, GUAC_LOG_DEBUG, "Support for CLIPRDR "
             "(clipboard redirection) registered. Awaiting channel "
             "connection.");

src/protocols/rdp/channels/disp.c

@@ -96,12 +96,52 @@ static void guac_rdp_disp_channel_connected(rdpContext* context,
 
 }
 
+/**
+ * Callback which disassociates Guacamole from the DispClientContext instance
+ * that was originally allocated by FreeRDP and is about to be deallocated.
+ *
+ * This function is called whenever a channel disconnects via the PubSub event
+ * system within FreeRDP, but only has any effect if the disconnected channel
+ * is the Display Update channel. This specific callback is registered with the
+ * PubSub system of the relevant rdpContext when guac_rdp_disp_load_plugin() is
+ * called.
+ *
+ * @param context
+ *     The rdpContext associated with the active RDP session.
+ *
+ * @param e
+ *     Event-specific arguments, mainly the name of the channel, and a
+ *     reference to the associated plugin loaded for that channel by FreeRDP.
+ */
+static void guac_rdp_disp_channel_disconnected(rdpContext* context,
+        ChannelDisconnectedEventArgs* e) {
+
+    guac_client* client = ((rdp_freerdp_context*) context)->client;
+    guac_rdp_client* rdp_client = (guac_rdp_client*) client->data;
+    guac_rdp_disp* guac_disp = rdp_client->disp;
+
+    /* Ignore disconnection event if it's not for the Display Update channel */
+    if (strcmp(e->name, DISP_DVC_CHANNEL_NAME) != 0)
+        return;
+
+    /* Channel is no longer connected */
+    guac_disp->disp = NULL;
+
+    guac_client_log(client, GUAC_LOG_DEBUG, "Display update channel "
+            "disconnected.");
+
+}
+
 void guac_rdp_disp_load_plugin(rdpContext* context) {
 
     /* Subscribe to and handle channel connected events */
     PubSub_SubscribeChannelConnected(context->pubSub,
         (pChannelConnectedEventHandler) guac_rdp_disp_channel_connected);
 
+    /* Subscribe to and handle channel disconnected events */
+    PubSub_SubscribeChannelDisconnected(context->pubSub,
+            (pChannelDisconnectedEventHandler) guac_rdp_disp_channel_disconnected);
+
     /* Add "disp" channel */
     guac_freerdp_dynamic_channel_collection_add(context->settings, "disp", NULL);
 

src/protocols/rdp/channels/rdpei.c

@@ -94,12 +94,51 @@ static void guac_rdp_rdpei_channel_connected(rdpContext* context,
 
 }
 
+/**
+ * Callback which disassociates Guacamole from the RdpeiClientContext instance
+ * that was originally allocated by FreeRDP and is about to be deallocated.
+ *
+ * This function is called whenever a channel disconnects via the PubSub event
+ * system within FreeRDP, but only has any effect if the disconnected channel
+ * is the RDPEI channel. This specific callback is registered with the PubSub
+ * system of the relevant rdpContext when guac_rdp_rdpei_load_plugin() is
+ * called.
+ *
+ * @param context
+ *     The rdpContext associated with the active RDP session.
+ *
+ * @param e
+ *     Event-specific arguments, mainly the name of the channel, and a
+ *     reference to the associated plugin loaded for that channel by FreeRDP.
+ */
+static void guac_rdp_rdpei_channel_disconnected(rdpContext* context,
+        ChannelDisconnectedEventArgs* e) {
+
+    guac_client* client = ((rdp_freerdp_context*) context)->client;
+    guac_rdp_client* rdp_client = (guac_rdp_client*) client->data;
+    guac_rdp_rdpei* guac_rdpei = rdp_client->rdpei;
+
+    /* Ignore disconnection event if it's not for the RDPEI channel */
+    if (strcmp(e->name, RDPEI_DVC_CHANNEL_NAME) != 0)
+        return;
+
+    /* Channel is no longer connected */
+    guac_rdpei->rdpei = NULL;
+
+    guac_client_log(client, GUAC_LOG_DEBUG, "RDPDI channel disconnected.");
+
+}
+
 void guac_rdp_rdpei_load_plugin(rdpContext* context) {
 
     /* Subscribe to and handle channel connected events */
     PubSub_SubscribeChannelConnected(context->pubSub,
         (pChannelConnectedEventHandler) guac_rdp_rdpei_channel_connected);
 
+    /* Subscribe to and handle channel disconnected events */
+    PubSub_SubscribeChannelDisconnected(context->pubSub,
+            (pChannelDisconnectedEventHandler) guac_rdp_rdpei_channel_disconnected);
+
     /* Add "rdpei" channel */
     guac_freerdp_dynamic_channel_collection_add(context->settings, "rdpei", NULL);
 

src/protocols/rdp/rdp.c

@@ -471,18 +471,6 @@ static int guac_rdp_handle_connection(guac_client* client) {
 
     pthread_rwlock_wrlock(&(rdp_client->lock));
 
-    /* Set up screen recording, if requested */
-    if (settings->recording_path != NULL) {
-        rdp_client->recording = guac_common_recording_create(client,
-                settings->recording_path,
-                settings->recording_name,
-                settings->create_recording_path,
-                !settings->recording_exclude_output,
-                !settings->recording_exclude_mouse,
-                !settings->recording_exclude_touch,
-                settings->recording_include_keys);
-    }
-
     /* Create display */
     rdp_client->display = guac_common_display_alloc(client,
             rdp_client->settings->width,
@@ -816,6 +804,18 @@ void* guac_rdp_client_thread(void* data) {
     }
 #endif
 
+    /* Set up screen recording, if requested */
+    if (settings->recording_path != NULL) {
+        rdp_client->recording = guac_common_recording_create(client,
+                settings->recording_path,
+                settings->recording_name,
+                settings->create_recording_path,
+                !settings->recording_exclude_output,
+                !settings->recording_exclude_mouse,
+                !settings->recording_exclude_touch,
+                settings->recording_include_keys);
+    }
+
     /* Continue handling connections until error or client disconnect */
     while (client->state == GUAC_CLIENT_RUNNING) {
         if (guac_rdp_handle_connection(client))