GUAC-1389: Ensure users that join after a SVC has connected are alerted to its existence.

src/protocols/rdp/guac_svc/svc_service.c

@@ -97,8 +97,9 @@ void guac_svc_process_connect(rdpSvcPlugin* plugin) {
 
     /* Create pipe */
     svc->output_pipe = guac_client_alloc_stream(svc->client);
-    guac_protocol_send_pipe(svc->client->socket, svc->output_pipe,
-            "application/octet-stream", svc->name);
+
+    /* Notify of pipe's existence */
+    guac_rdp_svc_send_pipe(svc->client->socket, svc);
 
     /* Log connection to static channel */
     guac_client_log(svc->client, GUAC_LOG_INFO,

src/protocols/rdp/rdp_svc.c

@@ -65,6 +65,32 @@ void guac_rdp_free_svc(guac_rdp_svc* svc) {
     free(svc);
 }
 
+void guac_rdp_svc_send_pipe(guac_socket* socket, guac_rdp_svc* svc) {
+
+    /* Send pipe instruction for the SVC's output stream */
+    guac_protocol_send_pipe(socket, svc->output_pipe,
+            "application/octet-stream", svc->name);
+
+}
+
+void guac_rdp_svc_send_pipes(guac_user* user) {
+
+    guac_client* client = user->client;
+    guac_rdp_client* rdp_client = (guac_rdp_client*) client->data;
+
+    guac_common_list_lock(rdp_client->available_svc);
+
+    /* Send pipe for each allocated SVC's output stream */
+    guac_common_list_element* current = rdp_client->available_svc->head;
+    while (current != NULL) {
+        guac_rdp_svc_send_pipe(user->socket, (guac_rdp_svc*) current->data);
+        current = current->next;
+    }
+
+    guac_common_list_unlock(rdp_client->available_svc);
+
+}
+
 void guac_rdp_add_svc(guac_client* client, guac_rdp_svc* svc) {
 
     guac_rdp_client* rdp_client = (guac_rdp_client*) client->data;

src/protocols/rdp/rdp_svc.h

@@ -79,6 +79,31 @@ guac_rdp_svc* guac_rdp_alloc_svc(guac_client* client, char* name);
  */
 void guac_rdp_free_svc(guac_rdp_svc* svc);
 
+/**
+ * Sends the "pipe" instruction describing the given static virtual channel
+ * along the given socket. This pipe instruction will relate the SVC's
+ * underlying output stream with the SVC's name and the mimetype
+ * "application/octet-stream".
+ *
+ * @param socket
+ *     The socket along which the "pipe" instruction should be sent.
+ *
+ * @param svc
+ *     The static virtual channel that the "pipe" instruction should describe.
+ */
+void guac_rdp_svc_send_pipe(guac_socket* socket, guac_rdp_svc* svc);
+
+/**
+ * Sends the "pipe" instructions describing all static virtual channels
+ * available to the given user along that user's socket. Each pipe instruction
+ * will relate the associated SVC's underlying output stream with the SVC's
+ * name and the mimetype "application/octet-stream".
+ *
+ * @param user
+ *     The user to send the "pipe" instructions to.
+ */
+void guac_rdp_svc_send_pipes(guac_user* user);
+
 /**
  * Add the given SVC to the list of all available SVCs.
  *

src/protocols/rdp/user.c

@@ -28,6 +28,7 @@
 #include "rdp.h"
 #include "rdp_settings.h"
 #include "rdp_stream.h"
+#include "rdp_svc.h"
 
 #ifdef ENABLE_COMMON_SSH
 #include "sftp.h"
@@ -76,6 +77,9 @@ int guac_rdp_user_join_handler(guac_user* user, int argc, char** argv) {
         if (rdp_client->audio)
             guac_audio_stream_add_user(rdp_client->audio, user);
 
+        /* Bring user up to date with any registered static channels */
+        guac_rdp_svc_send_pipes(user);
+
         /* Synchronize with current display */
         guac_common_display_dup(rdp_client->display, user, user->socket);
         guac_socket_flush(user->socket);