Implement pipe instruction and handlers.

src/libguac/client-handlers.c

@@ -39,6 +39,7 @@ __guac_instruction_handler_mapping __guac_instruction_handler_map[] = {
    {"disconnect", __guac_handle_disconnect},
    {"size",       __guac_handle_size},
    {"file",       __guac_handle_file},
+   {"pipe",       __guac_handle_pipe},
    {"ack",        __guac_handle_ack},
    {"blob",       __guac_handle_blob},
    {"end",        __guac_handle_end},
@@ -153,6 +154,43 @@ int __guac_handle_file(guac_client* client, guac_instruction* instruction) {
     return 0;
 }
 
+int __guac_handle_pipe(guac_client* client, guac_instruction* instruction) {
+
+    /* Pull corresponding stream */
+    int stream_index = atoi(instruction->argv[0]);
+    guac_stream* stream;
+
+    /* Validate stream index */
+    if (stream_index < 0 || stream_index >= GUAC_CLIENT_MAX_STREAMS) {
+
+        guac_stream dummy_stream;
+        dummy_stream.index = stream_index;
+
+        guac_protocol_send_ack(client->socket, &dummy_stream,
+                "Invalid stream index", GUAC_PROTOCOL_STATUS_INVALID_PARAMETER);
+        return 0;
+    }
+
+    /* Initialize stream */
+    stream = &(client->__input_streams[stream_index]);
+    stream->index = stream_index;
+    stream->data = NULL;
+
+    /* If supported, call handler */
+    if (client->pipe_handler)
+        return client->pipe_handler(
+            client,
+            stream,
+            instruction->argv[1], /* mimetype */
+            instruction->argv[2]  /* name */
+        );
+
+    /* Otherwise, abort */
+    guac_protocol_send_ack(client->socket, stream,
+            "Named pipes unsupported", GUAC_PROTOCOL_STATUS_UNSUPPORTED);
+    return 0;
+}
+
 int __guac_handle_ack(guac_client* client, guac_instruction* instruction) {
 
     guac_stream* stream;

src/libguac/client-handlers.h

@@ -94,6 +94,13 @@ int __guac_handle_clipboard(guac_client* client, guac_instruction* instruction);
  */
 int __guac_handle_file(guac_client* client, guac_instruction* instruction);
 
+/**
+ * Internal initial handler for the pipe instruction. When a pipe instruction
+ * is received, this handler will be called. The client's pipe handler will
+ * be invoked if defined.
+ */
+int __guac_handle_pipe(guac_client* client, guac_instruction* instruction);
+
 /**
  * Internal initial handler for the ack instruction. When a ack instruction
  * is received, this handler will be called. The client's ack handler will

src/libguac/guacamole/client.h

@@ -85,6 +85,12 @@ typedef int guac_client_size_handler(guac_client* client,
 typedef int guac_client_file_handler(guac_client* client, guac_stream* stream,
         char* mimetype, char* filename);
 
+/**
+ * Handler for Guacamole pipe events.
+ */
+typedef int guac_client_pipe_handler(guac_client* client, guac_stream* stream,
+        char* mimetype, char* name);
+
 /**
  * Handler for Guacamole stream blob events.
  */
@@ -402,6 +408,25 @@ struct guac_client {
      */
     guac_client_file_handler* file_handler;
 
+    /**
+     * Handler for pipe events sent by the Guacamole web-client.
+     *
+     * The handler takes a guac_stream which contains the stream index and
+     * will persist through the duration of the transfer, the mimetype of
+     * the data being transferred, and the pipe name.
+     *
+     * Example:
+     * @code
+     *     int pipe_handler(guac_client* client, guac_stream* stream,
+     *             char* mimetype, char* name);
+     *
+     *     int guac_client_init(guac_client* client, int argc, char** argv) {
+     *         client->pipe_handler = pipe_handler;
+     *     }
+     * @endcode
+     */
+    guac_client_pipe_handler* pipe_handler;
+
     /**
      * Handler for ack events sent by the Guacamole web-client.
      *

src/libguac/guacamole/protocol.h

@@ -412,6 +412,21 @@ int guac_protocol_send_audio(guac_socket* socket, const guac_stream* stream,
 int guac_protocol_send_file(guac_socket* socket, const guac_stream* stream,
         const char* mimetype, const char* name);
 
+/**
+ * Sends a pipe instruction over the given guac_socket connection.
+ *
+ * If an error occurs sending the instruction, a non-zero value is
+ * returned, and guac_error is set appropriately.
+ *
+ * @param socket The guac_socket connection to use.
+ * @param stream The stream to use.
+ * @param mimetype The mimetype of the data being sent.
+ * @param name An arbitrary name uniquely identifying this pipe.
+ * @return Zero on success, non-zero on error.
+ */
+int guac_protocol_send_pipe(guac_socket* socket, const guac_stream* stream,
+        const char* mimetype, const char* name);
+
 /**
  * Writes a block of data to the currently in-progress blob which was already
  * created.

src/libguac/protocol.c

@@ -982,6 +982,26 @@ int guac_protocol_send_nop(guac_socket* socket) {
 
 }
 
+int guac_protocol_send_pipe(guac_socket* socket, const guac_stream* stream,
+        const char* mimetype, const char* name) {
+
+    int ret_val;
+
+    guac_socket_instruction_begin(socket);
+    ret_val =
+           guac_socket_write_string(socket, "4.pipe,")
+        || __guac_socket_write_length_int(socket, stream->index)
+        || guac_socket_write_string(socket, ",")
+        || __guac_socket_write_length_string(socket, mimetype)
+        || guac_socket_write_string(socket, ",")
+        || __guac_socket_write_length_string(socket, name)
+        || guac_socket_write_string(socket, ";");
+
+    guac_socket_instruction_end(socket);
+    return ret_val;
+
+}
+
 int guac_protocol_send_png(guac_socket* socket, guac_composite_mode mode,
         const guac_layer* layer, int x, int y, cairo_surface_t* surface) {