Merge pull request #103 from glyptodon/terminal-pipe-streams

GUAC-1452: Implement OSC sequence for redirecting output to pipe streams

bin/guacctl

@@ -1,6 +1,6 @@
 #!/bin/sh
 #
-# Copyright (C) 2013 Glyptodon LLC
+# Copyright (C) 2016 Glyptodon LLC
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the "Software"), to deal
@@ -25,20 +25,25 @@
 # guacctl
 # -------
 #
-# Utility for sending Guacamole-specific console codes for controlling the SSH
+# Utility for sending Guacamole-specific console codes for controlling a
-# session, such as:
+# terminal session, such as:
 #
-#     * Downloading files
+#     * Downloading files (SSH only)
-#     * Setting the destination directory for uploads
+#     * Setting the destination directory for uploads (SSH only)
+#     * Redirecting output to a named pipe stream (SSH or telnet)
 #
 # This script may also be run as "guacget", in which case the script accepts
 # no options and assumes anything given on the commandline is a file to be
 # downloaded.
 #
 
-
+##
-# Given the name of a file, which may be a relative path, produce the full,
+## Given the name of a file, which may be a relative path, produce the full,
-# real, non-relative path for that same file.
+## real, non-relative path for that same file.
+##
+## @param FILENAME
+##     The name of the file to produce the full path of.
+##
 fullpath() {
     FILENAME="$1"
     DIR=`dirname "$FILENAME"`
@@ -46,44 +51,98 @@ fullpath() {
     (cd "$DIR" && echo "$PWD/$FILE")
 }
 
-# Sends the Guacamole-specific console code for initiating a download.
+##
+## Sends the Guacamole-specific console code for initiating a download.
+##
+## @param FILENAME
+##     The full path of the file to download.
+##
 send_download_file() {
     FILENAME="$1"
     printf "\033]482200;%s\007" "$FILENAME"
 }
 
-# Sends the Guacamole-specific console code for setting the upload directory.
+##
+## Sends the Guacamole-specific console code for setting the upload directory.
+##
+## @param FILENAME
+##     The full path to the directory which should receive uploads.
+##
 send_set_directory() {
     FILENAME="$1"
     printf "\033]482201;%s\007" "$FILENAME"
 }
 
-# Prints the given error text to STDERR.
+##
+## Sends the Guacamole-specific console code for redirecting output to a named
+## pipe stream (instead of the terminal emulator)
+##
+## @param NAME
+##     The name of the pipe stream to open.
+##
+send_open_pipe_stream() {
+    NAME="$1"
+    printf "\033]482202;%s\007" "$NAME"
+}
+
+##
+## Sends the Guacamole-specific console code for redirecting output back to the
+## terminal emulator
+##
+send_close_pipe_stream() {
+    printf "\033]482203;\007"
+}
+
+##
+## Prints the given error text to STDERR.
+##
+## @param ...
+##     The text to print as an error message.
+##
 error() {
     echo "$NAME:" "$@" >&2
 }
 
-# Prints usage documentation for this script.
+##
+## Prints usage documentation for this script.
+##
 usage() {
     cat >&2 <<END
-guacctl 0.8.0, Guacamole SSH session control utility.
+guacctl 0.9.9, Guacamole terminal session control utility.
-Usage: guacctl [OPTION] [FILE]...
+Usage: guacctl [OPTION] [FILE or NAME]...
 
     -d, --download         download each of the files listed.
     -s, --set-directory    set the destination directory for future uploaded 
                            files.
+    -o, --open-pipe        redirect output to a new pipe stream with the given
+                           name.
+    -c, --close-pipe       close any existing pipe stream and redirect output
+                           back to the terminal emulator.
 END
 }
 
-# Initiates a download for each of the specified files
+##
+## Initiates a download for each of the specified files.
+##
+## @param ...
+##     The name of each file that should be downloaded, as originally
+##     provided to guacctl.
+##
 download_files() {
 
+    #
     # Validate arguments
+    #
+
     if [ $# -lt 1 ]; then
         error "No files specified."
         return;
     fi
 
+    #
+    # Send download code for each file given
+    #
+
     for FILENAME in "$@"; do
         if [ -e "$FILENAME" ]; then
             send_download_file "`fullpath "$FILENAME"`"
@@ -94,10 +153,18 @@ download_files() {
 
 }
 
-# Changes the upload path for future uploads to the given directory
+##
+## Changes the upload path for future uploads to the given directory.
+##
+## @param ...
+##     The name of the directory to use for uploads, as provided to guacctl.
+##
 set_directory() {
 
+    #
     # Validate arguments
+    #
+
     if [ $# -lt 1 ]; then
         error "No destination directory specified."
         return;
@@ -108,6 +175,10 @@ set_directory() {
         return;
     fi
 
+    #
+    # Send code for setting the upload directory
+    #
+
     FILENAME="$1"
     if [ -d "$FILENAME" ]; then
         send_set_directory "`fullpath "$FILENAME"`"
@@ -117,20 +188,128 @@ set_directory() {
 
 }
 
-# Get script name
+##
-NAME=`basename "$0"`
+## Opens a new pipe stream having the given name and redirects terminal output
+## to that stream.
+##
+## @param ...
+##     The name of the pipe stream to open, as provided to guacctl.
+##
+open_pipe_stream() {
 
-# Parse options
+    #
-if [ "x$NAME" = "xguacget" ]; then
+    # Validate arguments
-    download_files "$@"
+    #
-elif [ "x$1" = "x--download" -o "x$1" = "x-d" ]; then
+
-    shift
+    if [ $# -lt 1 ]; then
-    download_files "$@"
+        error "No pipe name specified."
-elif [ "x$1" = "x--set-directory" -o "x$1" = "x-s" ]; then
+        return;
-    shift
-    set_directory "$@"
-else
-    usage
-    exit 1
     fi
 
+    if [ $# -gt 1 ]; then
+        error "Only one pipe name may be given."
+        return;
+    fi
+
+    #
+    # Send code for opening the named pipe stream
+    #
+
+    NAME="$1"
+    send_open_pipe_stream "$NAME"
+
+}
+
+##
+## Closes the currently-open pipe stream and redirects terminal output back to
+## the terminal emulator
+##
+## @param ...
+##     The arguments provided to guacctl, which should be empty.
+##
+close_pipe_stream() {
+
+    #
+    # Validate arguments
+    #
+
+    if [ $# -gt 0 ]; then
+        error "Closing an open pipe stream does not require any arguments."
+        return;
+    fi
+
+    #
+    # Send code for closing the currently-open named pipe stream
+    #
+
+    send_close_pipe_stream
+
+}
+
+#
+# Get script name
+#
+
+NAME=`basename "$0"`
+
+#
+# Handle downloads directly if invoked as "guacget"
+#
+
+if [ "x$NAME" = "xguacget" ]; then
+    download_files "$@"
+    exit 0;
+fi
+
+#
+# Parse options
+#
+
+case "$1" in
+
+    #
+    # Download files
+    #
+
+    "--download"|"-d")
+        shift
+        download_files "$@"
+        ;;
+
+    #
+    # Set upload directory
+    #
+
+    "--set-directory"|"-s")
+        shift
+        set_directory "$@"
+        ;;
+
+    #
+    # Redirect to pipe
+    #
+
+    "--open-pipe"|"-o")
+        shift
+        open_pipe_stream "$@"
+        ;;
+
+    #
+    # Redirect back to terminal
+    #
+
+    "--close-pipe"|"-c")
+        shift
+        close_pipe_stream "$@"
+        ;;
+
+    #
+    # Show usage info if options are invalid
+    #
+
+    *)
+        usage
+        exit 1
+        ;;
+esac
+

src/terminal/terminal.c

@@ -326,6 +326,9 @@ guac_terminal* guac_terminal_create(guac_client* client,
         return NULL;
     }
 
+    /* Init pipe stream (output to display by default) */
+    term->pipe_stream = NULL;
+
     /* Init terminal lock */
     pthread_mutex_init(&(term->lock), NULL);
 
@@ -369,6 +372,9 @@ guac_terminal* guac_terminal_create(guac_client* client,
 
 void guac_terminal_free(guac_terminal* term) {
 
+    /* Close and flush any open pipe stream */
+    guac_terminal_pipe_stream_close(term);
+
     /* Close terminal output pipe */
     close(term->stdout_pipe_fd[1]);
     close(term->stdout_pipe_fd[0]);
@@ -1728,3 +1734,80 @@ int guac_terminal_next_tab(guac_terminal* term, int column) {
     return tabstop;
 }
 
+void guac_terminal_pipe_stream_open(guac_terminal* term, const char* name) {
+
+    guac_client* client = term->client;
+    guac_socket* socket = client->socket;
+
+    /* Close existing stream, if any */
+    guac_terminal_pipe_stream_close(term);
+
+    /* Allocate and assign new pipe stream */
+    term->pipe_stream = guac_client_alloc_stream(client);
+    term->pipe_buffer_length = 0;
+
+    /* Open new pipe stream */
+    guac_protocol_send_pipe(socket, term->pipe_stream, "text/plain", name);
+
+    /* Log redirect at debug level */
+    guac_client_log(client, GUAC_LOG_DEBUG,
+            "Terminal output now redirected to pipe '%s'.", name);
+
+}
+
+void guac_terminal_pipe_stream_write(guac_terminal* term, char c) {
+
+    /* Append byte to buffer only if pipe is open */
+    if (term->pipe_stream != NULL) {
+
+        /* Flush buffer if no space is available */
+        if (term->pipe_buffer_length == sizeof(term->pipe_buffer))
+            guac_terminal_pipe_stream_flush(term);
+
+        /* Append single byte to buffer */
+        term->pipe_buffer[term->pipe_buffer_length++] = c;
+
+    }
+
+}
+
+void guac_terminal_pipe_stream_flush(guac_terminal* term) {
+
+    guac_client* client = term->client;
+    guac_socket* socket = client->socket;
+    guac_stream* pipe_stream = term->pipe_stream;
+
+    /* Write blob if data exists in buffer */
+    if (pipe_stream != NULL && term->pipe_buffer_length > 0) {
+        guac_protocol_send_blob(socket, pipe_stream,
+                term->pipe_buffer, term->pipe_buffer_length);
+        term->pipe_buffer_length = 0;
+    }
+
+}
+
+void guac_terminal_pipe_stream_close(guac_terminal* term) {
+
+    guac_client* client = term->client;
+    guac_socket* socket = client->socket;
+    guac_stream* pipe_stream = term->pipe_stream;
+
+    /* Close any existing pipe */
+    if (pipe_stream != NULL) {
+
+        /* Write end of stream */
+        guac_terminal_pipe_stream_flush(term);
+        guac_protocol_send_end(socket, pipe_stream);
+
+        /* Destroy stream */
+        guac_client_free_stream(client, pipe_stream);
+        term->pipe_stream = NULL;
+
+        /* Log redirect at debug level */
+        guac_client_log(client, GUAC_LOG_DEBUG,
+                "Terminal output now redirected to display.");
+
+    }
+
+}
+

src/terminal/terminal.h

@@ -149,6 +149,26 @@ struct guac_terminal {
      */
     int stdin_pipe_fd[2];
 
+    /**
+     * The currently-open pipe stream to which all terminal output should be
+     * written, if any. If no pipe stream is open, terminal output will be
+     * written to the terminal display, and this value will be NULL.
+     */
+    guac_stream* pipe_stream;
+
+    /**
+     * Buffer of data pending write to the pipe_stream. Data within this buffer
+     * will be flushed to the pipe_stream when either (1) the buffer is full
+     * and another character needs to be written or (2) the pipe_stream is
+     * closed.
+     */
+    char pipe_buffer[6048];
+
+    /**
+     * The number of bytes currently stored within the pipe_buffer.
+     */
+    int pipe_buffer_length;
+
     /**
      * Graphical representation of the current scroll state.
      */
@@ -656,5 +676,58 @@ void guac_terminal_clear_tabs(guac_terminal* term);
  */
 int guac_terminal_next_tab(guac_terminal* term, int column);
 
+/**
+ * Opens a new pipe stream, redirecting all output from the given terminal to
+ * that pipe stream. If a pipe stream is already open, that pipe stream will
+ * be flushed and closed prior to opening the new pipe stream.
+ *
+ * @param term
+ *     The terminal which should redirect output to a new pipe stream having
+ *     the given name.
+ *
+ * @param name
+ *     The name of the pipe stream to open.
+ */
+void guac_terminal_pipe_stream_open(guac_terminal* term, const char* name);
+
+/**
+ * Writes a single byte of data to the pipe stream currently open and
+ * associated with the given terminal. The pipe stream must already have been
+ * opened via guac_terminal_pipe_stream_open(). If no pipe stream is currently
+ * open, this function has no effect. Data written through this function may
+ * be buffered.
+ *
+ * @param term
+ *     The terminal whose currently-open pipe stream should be written to.
+ *
+ * @param c
+ *     The byte of data to write to the pipe stream.
+ */
+void guac_terminal_pipe_stream_write(guac_terminal* term, char c);
+
+/**
+ * Flushes any data currently buffered for the currently-open pipe stream
+ * associated with the given terminal. The pipe stream must already have been
+ * opened via guac_terminal_pipe_stream_open(). If no pipe stream is currently
+ * open or no data is in the buffer, this function has no effect.
+ *
+ * @param term
+ *     The terminal whose pipe stream buffer should be flushed.
+ */
+void guac_terminal_pipe_stream_flush(guac_terminal* term);
+
+/**
+ * Closes the currently-open pipe stream associated with the given terminal,
+ * redirecting all output back to the terminal display.  Any data currently
+ * buffered for output to the pipe stream will be flushed prior to closure. The
+ * pipe stream must already have been opened via
+ * guac_terminal_pipe_stream_open(). If no pipe stream is currently open, this
+ * function has no effect.
+ *
+ * @param term
+ *     The terminal whose currently-open pipe stream should be closed.
+ */
+void guac_terminal_pipe_stream_close(guac_terminal* term);
+
 #endif
 

src/terminal/terminal_handlers.c

@@ -28,6 +28,8 @@
 #include "types.h"
 
 #include <guacamole/client.h>
+#include <guacamole/protocol.h>
+#include <guacamole/socket.h>
 
 #include <stdbool.h>
 #include <stdlib.h>
@@ -57,6 +59,12 @@ int guac_terminal_echo(guac_terminal* term, unsigned char c) {
 
     const int* char_mapping = term->char_mapping[term->active_char_set];
 
+    /* Echo to pipe stream if open and not starting an ESC sequence */
+    if (term->pipe_stream != NULL && c != 0x1B) {
+        guac_terminal_pipe_stream_write(term, c);
+        return 0;
+    }
+
     /* If using non-Unicode mapping, just map straight bytes */
     if (char_mapping != NULL) {
         codepoint = c;
@@ -936,6 +944,52 @@ int guac_terminal_download(guac_terminal* term, unsigned char c) {
 
 }
 
+int guac_terminal_open_pipe_stream(guac_terminal* term, unsigned char c) {
+
+    static char stream_name[2048];
+    static int length = 0;
+
+    /* Open pipe on ECMA-48 ST (String Terminator) */
+    if (c == 0x9C || c == 0x5C || c == 0x07) {
+
+        /* End stream name string */
+        stream_name[length++] = '\0';
+        length = 0;
+
+        /* Open new pipe stream */
+        guac_terminal_pipe_stream_open(term, stream_name);
+
+        /* Return to echo mode */
+        term->char_handler = guac_terminal_echo;
+
+    }
+
+    /* Otherwise, store character within stream name */
+    else if (length < sizeof(stream_name)-1)
+        stream_name[length++] = c;
+
+    return 0;
+
+}
+
+int guac_terminal_close_pipe_stream(guac_terminal* term, unsigned char c) {
+
+    /* Handle closure on ECMA-48 ST (String Terminator) */
+    if (c == 0x9C || c == 0x5C || c == 0x07) {
+
+        /* Close any existing pipe */
+        guac_terminal_pipe_stream_close(term);
+
+        /* Return to echo mode */
+        term->char_handler = guac_terminal_echo;
+
+    }
+
+    /* Ignore all other characters */
+    return 0;
+
+}
+
 int guac_terminal_osc(guac_terminal* term, unsigned char c) {
 
     static int operation = 0;
@@ -955,6 +1009,14 @@ int guac_terminal_osc(guac_terminal* term, unsigned char c) {
         else if (operation == 482201)
             term->char_handler = guac_terminal_set_directory;
 
+        /* Open and redirect output to pipe stream OSC */
+        else if (operation == 482202)
+            term->char_handler = guac_terminal_open_pipe_stream;
+
+        /* Close pipe stream OSC */
+        else if (operation == 482203)
+            term->char_handler = guac_terminal_close_pipe_stream;
+
         /* Reset parameter for next OSC */
         operation = 0;
 

src/terminal/terminal_handlers.h

@@ -28,14 +28,140 @@
 
 #include "terminal.h"
 
+/**
+ * The default mode of the terminal. This character handler simply echoes
+ * received characters to the terminal display, entering other terminal modes
+ * if control characters are received.
+ *
+ * @param term
+ *     The terminal that received the given character of data.
+ *
+ * @param c
+ *     The character that was received by the given terminal.
+ */
 int guac_terminal_echo(guac_terminal* term, unsigned char c);
+
+/**
+ * Handles any characters which follow an ANSI ESC (0x1B) character.
+ *
+ * @param term
+ *     The terminal that received the given character of data.
+ *
+ * @param c
+ *     The character that was received by the given terminal.
+ */
 int guac_terminal_escape(guac_terminal* term, unsigned char c);
+
+/**
+ * Selects the G0 character mapping from the provided character mapping
+ * specifier (such as B, 0, U, or K).
+ *
+ * @param term
+ *     The terminal that received the given character of data.
+ *
+ * @param c
+ *     The character that was received by the given terminal.
+ */
 int guac_terminal_g0_charset(guac_terminal* term, unsigned char c);
+
+/**
+ * Selects the G1 character mapping from the provided character mapping
+ * specifier (such as B, 0, U, or K).
+ *
+ * @param term
+ *     The terminal that received the given character of data.
+ *
+ * @param c
+ *     The character that was received by the given terminal.
+ */
 int guac_terminal_g1_charset(guac_terminal* term, unsigned char c);
+
+/**
+ * Handles characters within a CSI sequence. CSI sequences are most often
+ * introduced with "ESC [".
+ *
+ * @param term
+ *     The terminal that received the given character of data.
+ *
+ * @param c
+ *     The character that was received by the given terminal.
+ */
 int guac_terminal_csi(guac_terminal* term, unsigned char c);
+
+/**
+ * Parses the remainder of the download initiation OSC specific to the
+ * Guacamole terminal emulator. A download will be initiated for the specified
+ * file once the OSC sequence is complete.
+ *
+ * @param term
+ *     The terminal that received the given character of data.
+ *
+ * @param c
+ *     The character that was received by the given terminal.
+ */
 int guac_terminal_download(guac_terminal* term, unsigned char c);
+
+/**
+ * Parses the remainder of the set directory OSC specific to the Guacamole
+ * terminal emulator. The upload directory will be set to the specified path
+ * once the OSC sequence is complete.
+ *
+ * @param term
+ *     The terminal that received the given character of data.
+ *
+ * @param c
+ *     The character that was received by the given terminal.
+ */
 int guac_terminal_set_directory(guac_terminal* term, unsigned char c);
+
+/**
+ * Parses the remainder of the open pipe OSC specific to the
+ * Guacamole terminal emulator. Terminal output will be redirected to a new
+ * named pipe having the given name once the OSC sequence is complete.
+ *
+ * @param term
+ *     The terminal that received the given character of data.
+ *
+ * @param c
+ *     The character that was received by the given terminal.
+ */
+int guac_terminal_open_pipe_stream(guac_terminal* term, unsigned char c);
+
+/**
+ * Parses the remainder of the close pipe OSC specific to the Guacamole
+ * terminal emulator. Terminal output will be redirected back to the terminal
+ * display and any open named pipe will be closed once the OSC sequence is
+ * complete.
+ *
+ * @param term
+ *     The terminal that received the given character of data.
+ *
+ * @param c
+ *     The character that was received by the given terminal.
+ */
+int guac_terminal_close_pipe_stream(guac_terminal* term, unsigned char c);
+
+/**
+ * Handles the remaining characters of an Operating System Code (OSC) sequence,
+ * typically initiated with "ESC ]".
+ *
+ * @param term
+ *     The terminal that received the given character of data.
+ *
+ * @param c
+ *     The character that was received by the given terminal.
+ */
 int guac_terminal_osc(guac_terminal* term, unsigned char c);
+
+/**
+ * Handles terminal control function sequences initiated with "ESC #".
+ *
+ * @param term
+ *     The terminal that received the given character of data.
+ *
+ * @param c
+ *     The character that was received by the given terminal.
+ */
 int guac_terminal_ctrl_func(guac_terminal* term, unsigned char c);
 
 #endif