GUAC-556: Add guac_client_abort() function for convenience.

src/libguac/client.c

@@ -231,3 +231,35 @@ void guac_client_stop(guac_client* client) {
     client->state = GUAC_CLIENT_STOPPING;
 }
 
+void vguac_client_abort(guac_client* client, guac_protocol_status status,
+        const char* format, va_list ap) {
+
+    /* Only relevant if client is running */
+    if (client->state == GUAC_CLIENT_RUNNING) {
+
+        /* Log detail of error */
+        vguac_client_log_error(client, format, ap);
+
+        /* Send error immediately, limit information given */
+        guac_protocol_send_error(client->socket, "Aborted. See logs.", status);
+        guac_socket_flush(client->socket);
+
+        /* Stop client */
+        guac_client_stop(client);
+
+    }
+
+}
+
+void guac_client_abort(guac_client* client, guac_protocol_status status,
+        const char* format, ...) {
+
+    va_list args;
+    va_start(args, format);
+
+    vguac_client_abort(client, status, format, args);
+
+    va_end(args);
+
+}
+

src/libguac/guacamole/client.h

@@ -671,6 +671,35 @@ void vguac_client_log_error(guac_client* client, const char* format, va_list ap)
  */
 void guac_client_stop(guac_client* client);
 
+/**
+ * Signals the given client to stop gracefully, while also signalling via the
+ * Guacamole protocol that an error has occurred. Note that this is a completely
+ * cooperative signal, and can be ignored by the client or the hosting
+ * daemon. The message given will be logged to the system logs.
+ *
+ * @param client The proxy client to signal to stop.
+ * @param status The status to send over the Guacamole protocol.
+ * @param format A printf-style format string to log.
+ * @param ... Arguments to use when filling the format string for printing.
+ */
+void guac_client_abort(guac_client* client, guac_protocol_status status,
+        const char* format, ...);
+
+/**
+ * Signals the given client to stop gracefully, while also signalling via the
+ * Guacamole protocol that an error has occurred. Note that this is a completely
+ * cooperative signal, and can be ignored by the client or the hosting
+ * daemon. The message given will be logged to the system logs.
+ *
+ * @param client The proxy client to signal to stop.
+ * @param status The status to send over the Guacamole protocol.
+ * @param format A printf-style format string to log.
+ * @param ap The va_list containing the arguments to be used when filling the
+ *           format string for printing.
+ */
+void vguac_client_abort(guac_client* client, guac_protocol_status status,
+        const char* format, va_list ap);
+
 /**
  * Allocates a new buffer (invisible layer). An arbitrary index is
  * automatically assigned if no existing buffer is available for use.