GUAC-654: Implement simple telnet client. No screen resize yet.

Makefile.am

@@ -30,6 +30,7 @@ DIST_SUBDIRS =           \
     src/guacd            \
     src/protocols/rdp    \
     src/protocols/ssh    \
+    src/protocols/telnet \
     src/protocols/vnc    \
     tests
 
@@ -51,6 +52,10 @@ if ENABLE_SSH
     SUBDIRS += src/protocols/ssh
 endif
 
+if ENABLE_TELNET
+    SUBDIRS += src/protocols/telnet
+endif
+
 if ENABLE_VNC
     SUBDIRS += src/protocols/vnc
 endif

configure.ac

@@ -609,6 +609,23 @@ AM_CONDITIONAL([ENABLE_SSH_AGENT],
 	   [test "x${have_ssh_agent}"   = "xyes" \
 	      -a "x${enable_ssh_agent}" = "xyes"])
 
+#
+# libtelnet
+#
+
+have_libtelnet=yes
+SSH_LIBS=
+
+AC_CHECK_LIB([telnet], [telnet_init],
+                       [TELNET_LIBS="$TELNET_LIBS -ltelnet"],
+                       [have_libtelnet=no])
+AM_CONDITIONAL([ENABLE_TELNET], [test "x${have_libtelnet}"  = "xyes" \
+                                   -a "x${have_terminal}" = "xyes" \
+                                   -a "x${have_ssl}"      = "xyes"])
+
+AC_SUBST(TELNET_LIBS)
+
+
 AC_CONFIG_FILES([Makefile
                  tests/Makefile
                  src/common/Makefile
@@ -617,11 +634,13 @@ AC_CONFIG_FILES([Makefile
                  src/guacd/Makefile
                  src/protocols/rdp/Makefile
                  src/protocols/ssh/Makefile
+                 src/protocols/telnet/Makefile
                  src/protocols/vnc/Makefile])
 AC_OUTPUT
 
 AM_COND_IF([ENABLE_RDP],    [build_rdp=yes],    [build_rdp=no])
 AM_COND_IF([ENABLE_SSH],    [build_ssh=yes],    [build_ssh=no])
+AM_COND_IF([ENABLE_TELNET], [build_telnet=yes], [build_telnet=no])
 AM_COND_IF([ENABLE_VNC],    [build_vnc=yes],    [build_vnc=no])
 
 AM_COND_IF([ENABLE_INIT], [build_init="${init_dir}"], [build_init=no])
@@ -637,6 +656,7 @@ $PACKAGE_NAME version $PACKAGE_VERSION
      pango ............... ${have_pango}
      libssh2 ............. ${have_libssh2}
      libssl .............. ${have_ssl}
+     libtelnet ........... ${have_libtelnet}
      libVNCServer ........ ${have_libvncserver}
      libvorbis ........... ${have_vorbis}
      libpulse ............ ${have_pulse}
@@ -645,6 +665,7 @@ $PACKAGE_NAME version $PACKAGE_VERSION
 
       RDP ....... ${build_rdp}
       SSH ....... ${build_ssh}
+      Telnet .... ${build_telnet}
       VNC ....... ${build_vnc}
 
    Init scripts: ${build_init}

src/protocols/telnet/.gitignore

@@ -0,0 +1,36 @@
+
+# Object code
+*.o
+*.so
+*.lo
+*.la
+
+# Backup files
+*~
+
+# Release files
+*.tar.gz
+
+# Files currently being edited by vim or vi
+*.swp
+
+# automake/autoconf
+.deps/
+.libs/
+Makefile
+Makefile.in
+aclocal.m4
+autom4te.cache/
+m4/*
+!README
+config.guess
+config.log
+config.status
+config.sub
+configure
+depcomp
+install-sh
+libtool
+ltmain.sh
+missing
+

src/protocols/telnet/Makefile.am

@@ -0,0 +1,44 @@
+#
+# Copyright (C) 2014 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
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+#
+
+AUTOMAKE_OPTIONS = foreign
+
+ACLOCAL_AMFLAGS = -I m4
+
+lib_LTLIBRARIES = libguac-client-telnet.la
+
+libguac_client_telnet_la_SOURCES = \
+    client.c                       \
+    clipboard.c                    \
+    guac_handlers.c                \
+    telnet_client.c
+
+noinst_HEADERS =                \
+    client.h                    \
+    clipboard.h                 \
+    guac_handlers.h             \
+    telnet_client.h
+
+libguac_client_telnet_la_CFLAGS = -Werror -Wall -Iinclude @LIBGUAC_INCLUDE@ @TERMINAL_INCLUDE@
+libguac_client_telnet_la_LIBADD = @LIBGUAC_LTLIB@ @TERMINAL_LTLIB@
+libguac_client_telnet_la_LDFLAGS = -version-info 0:0:0 @TELNET_LIBS@ @PTHREAD_LIBS@
+

src/protocols/telnet/client.c

@@ -0,0 +1,150 @@
+/*
+ * Copyright (C) 2013 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
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "config.h"
+
+#include "client.h"
+#include "clipboard.h"
+#include "guac_handlers.h"
+#include "telnet_client.h"
+#include "terminal.h"
+
+#include <pthread.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <guacamole/client.h>
+#include <guacamole/protocol.h>
+#include <guacamole/socket.h>
+
+#define GUAC_TELNET_DEFAULT_FONT_NAME "monospace" 
+#define GUAC_TELNET_DEFAULT_FONT_SIZE 12
+#define GUAC_TELNET_DEFAULT_PORT      "23"
+
+/* Client plugin arguments */
+const char* GUAC_CLIENT_ARGS[] = {
+    "hostname",
+    "port",
+    "font-name",
+    "font-size",
+    NULL
+};
+
+enum __TELNET_ARGS_IDX {
+
+    /**
+     * The hostname to connect to. Required.
+     */
+    IDX_HOSTNAME,
+
+    /**
+     * The port to connect to. Optional.
+     */
+    IDX_PORT,
+
+    /**
+     * The name of the font to use within the terminal.
+     */
+    IDX_FONT_NAME,
+
+    /**
+     * The size of the font to use within the terminal, in points.
+     */
+    IDX_FONT_SIZE,
+
+    TELNET_ARGS_COUNT
+};
+
+int guac_client_init(guac_client* client, int argc, char** argv) {
+
+    guac_socket* socket = client->socket;
+
+    telnet_client_data* client_data = malloc(sizeof(telnet_client_data));
+
+    /* Init client data */
+    client->data = client_data;
+    client_data->telnet = NULL;
+    client_data->socket_fd = -1;
+
+    if (argc != TELNET_ARGS_COUNT) {
+        guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR, "Wrong number of arguments");
+        return -1;
+    }
+
+    /* Read parameters */
+    strcpy(client_data->hostname,  argv[IDX_HOSTNAME]);
+
+    /* Read port */
+    if (argv[IDX_PORT][0] != 0)
+        strcpy(client_data->port, argv[IDX_PORT]);
+    else
+        strcpy(client_data->port, GUAC_TELNET_DEFAULT_PORT);
+
+    /* Read font name */
+    if (argv[IDX_FONT_NAME][0] != 0)
+        strcpy(client_data->font_name, argv[IDX_FONT_NAME]);
+    else
+        strcpy(client_data->font_name, GUAC_TELNET_DEFAULT_FONT_NAME );
+
+    /* Read font size */
+    if (argv[IDX_FONT_SIZE][0] != 0)
+        client_data->font_size = atoi(argv[IDX_FONT_SIZE]);
+    else
+        client_data->font_size = GUAC_TELNET_DEFAULT_FONT_SIZE;
+
+    /* Create terminal */
+    client_data->term = guac_terminal_create(client,
+            client_data->font_name, client_data->font_size,
+            client->info.optimal_resolution,
+            client->info.optimal_width, client->info.optimal_height);
+
+    /* Fail if terminal init failed */
+    if (client_data->term == NULL) {
+        guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR, "Terminal initialization failed");
+        return -1;
+    }
+
+    /* Send initial name */
+    guac_protocol_send_name(socket, client_data->hostname);
+
+    guac_socket_flush(socket);
+
+    /* Set basic handlers */
+    client->handle_messages   = telnet_guac_client_handle_messages;
+    client->key_handler       = telnet_guac_client_key_handler;
+    client->mouse_handler     = telnet_guac_client_mouse_handler;
+    client->size_handler      = telnet_guac_client_size_handler;
+    client->free_handler      = telnet_guac_client_free_handler;
+    client->clipboard_handler = guac_telnet_clipboard_handler;
+
+    /* Start client thread */
+    if (pthread_create(&(client_data->client_thread), NULL, telnet_client_thread, (void*) client)) {
+        guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR, "Unable to start telnet client thread");
+        return -1;
+    }
+
+    /* Success */
+    return 0;
+
+}
+

src/protocols/telnet/client.h

@@ -0,0 +1,83 @@
+/*
+ * Copyright (C) 2013 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
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+
+#ifndef _TELNET_GUAC_CLIENT_H
+#define _TELNET_GUAC_CLIENT_H
+
+#include "config.h"
+
+#include "terminal.h"
+
+#include <pthread.h>
+#include <libtelnet.h>
+
+/**
+ * Telnet-specific client data.
+ */
+typedef struct telnet_client_data {
+
+    /**
+     * The hostname of the telnet server to connect to.
+     */
+    char hostname[1024];
+
+    /**
+     * The port of the telnet server to connect to.
+     */
+    char port[64];
+
+    /**
+     * The name of the font to use for display rendering.
+     */
+    char font_name[1024];
+
+    /**
+     * The size of the font to use, in points.
+     */
+    int font_size;
+
+    /**
+     * The telnet client thread.
+     */
+    pthread_t client_thread;
+
+    /**
+     * The file descriptor of the socket connected to the telnet server,
+     * or -1 if no connection has been established.
+     */
+    int socket_fd;
+
+    /**
+     * Telnet connection, used by the telnet client thread.
+     */
+    telnet_t* telnet;
+
+    /**
+     * The terminal which will render all output from the telnet client.
+     */
+    guac_terminal* term;
+   
+} telnet_client_data;
+
+#endif
+

src/protocols/telnet/clipboard.c

@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2014 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
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "config.h"
+#include "client.h"
+#include "clipboard.h"
+
+int guac_telnet_clipboard_handler(guac_client* client, guac_stream* stream,
+        char* mimetype) {
+
+    /* Clear clipboard and prepare for new data */
+    telnet_client_data* client_data = (telnet_client_data*) client->data;
+    guac_terminal_clipboard_reset(client_data->term, mimetype);
+
+    /* Set handlers for clipboard stream */
+    stream->blob_handler = guac_telnet_clipboard_blob_handler;
+    stream->end_handler = guac_telnet_clipboard_end_handler;
+
+    return 0;
+}
+
+int guac_telnet_clipboard_blob_handler(guac_client* client, guac_stream* stream,
+        void* data, int length) {
+
+    /* Append new data */
+    telnet_client_data* client_data = (telnet_client_data*) client->data;
+    guac_terminal_clipboard_append(client_data->term, data, length);
+
+    return 0;
+}
+
+int guac_telnet_clipboard_end_handler(guac_client* client, guac_stream* stream) {
+
+    /* Nothing to do - clipboard is implemented within client */
+
+    return 0;
+}
+

src/protocols/telnet/clipboard.h

@@ -0,0 +1,49 @@
+/*
+ * Copyright (C) 2014 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
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef _GUAC_TELNET_CLIPBOARD_H
+#define _GUAC_TELNET_CLIPBOARD_H
+
+#include "config.h"
+
+#include <guacamole/client.h>
+#include <guacamole/stream.h>
+
+/**
+ * Handler for inbound clipboard data.
+ */
+int guac_telnet_clipboard_handler(guac_client* client, guac_stream* stream,
+        char* mimetype);
+
+/**
+ * Handler for stream data related to clipboard.
+ */
+int guac_telnet_clipboard_blob_handler(guac_client* client, guac_stream* stream,
+        void* data, int length);
+
+/**
+ * Handler for end-of-stream related to clipboard.
+ */
+int guac_telnet_clipboard_end_handler(guac_client* client, guac_stream* stream);
+
+#endif
+

src/protocols/telnet/guac_handlers.c

@@ -0,0 +1,111 @@
+/*
+ * Copyright (C) 2013 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
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "config.h"
+
+#include "client.h"
+#include "guac_handlers.h"
+#include "terminal.h"
+
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/select.h>
+#include <sys/stat.h>
+
+#include <cairo/cairo.h>
+#include <guacamole/socket.h>
+#include <guacamole/protocol.h>
+#include <guacamole/client.h>
+#include <libtelnet.h>
+#include <pango/pangocairo.h>
+
+int telnet_guac_client_handle_messages(guac_client* client) {
+
+    telnet_client_data* client_data = (telnet_client_data*) client->data;
+    return guac_terminal_render_frame(client_data->term);
+
+}
+
+int telnet_guac_client_mouse_handler(guac_client* client, int x, int y, int mask) {
+
+    telnet_client_data* client_data = (telnet_client_data*) client->data;
+    guac_terminal* term = client_data->term;
+
+    /* Send mouse event */
+    guac_terminal_send_mouse(term, x, y, mask);
+    return 0;
+
+}
+
+int telnet_guac_client_key_handler(guac_client* client, int keysym, int pressed) {
+
+    telnet_client_data* client_data = (telnet_client_data*) client->data;
+    guac_terminal* term = client_data->term;
+
+    /* Send key */
+    guac_terminal_send_key(term, keysym, pressed);
+    return 0;
+
+}
+
+int telnet_guac_client_size_handler(guac_client* client, int width, int height) {
+
+    /* STUB */
+
+#if 0
+    /* Get terminal */
+    telnet_client_data* guac_client_data = (telnet_client_data*) client->data;
+    guac_terminal* terminal = guac_client_data->term;
+
+    /* Resize terminal */
+    guac_terminal_resize(terminal, width, height);
+
+    /* Update SSH pty size if connected */
+    if (guac_client_data->term_channel != NULL)
+        libssh2_channel_request_pty_size(guac_client_data->term_channel,
+                terminal->term_width, terminal->term_height);
+#endif
+
+    return 0;
+}
+
+int telnet_guac_client_free_handler(guac_client* client) {
+
+    telnet_client_data* guac_client_data = (telnet_client_data*) client->data;
+
+    /* Close telnet connection */
+    if (guac_client_data->socket_fd != -1)
+        close(guac_client_data->socket_fd);
+
+    /* Wait for and free telnet session, if connected */
+    if (guac_client_data->telnet != NULL) {
+        pthread_join(guac_client_data->client_thread, NULL);
+        telnet_free(guac_client_data->telnet);
+    }
+
+    guac_terminal_free(guac_client_data->term);
+    free(client->data);
+
+    return 0;
+}
+

src/protocols/telnet/guac_handlers.h

@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2014 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
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+
+#ifndef _TELNET_GUAC_HANDLERS_H
+#define _TELNET_GUAC_HANDLERS_H
+
+#include "config.h"
+
+#include <guacamole/client.h>
+
+int telnet_guac_client_handle_messages(guac_client* client);
+int telnet_guac_client_key_handler(guac_client* client, int keysym, int pressed);
+int telnet_guac_client_mouse_handler(guac_client* client, int x, int y, int mask);
+int telnet_guac_client_size_handler(guac_client* client, int width, int height);
+int telnet_guac_client_free_handler(guac_client* client);
+
+#endif
+

src/protocols/telnet/telnet_client.c

@@ -0,0 +1,258 @@
+/*
+ * Copyright (C) 2013 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
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "config.h"
+
+#include "client.h"
+#include "guac_handlers.h"
+
+#include <errno.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/select.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <libtelnet.h>
+#include <guacamole/client.h>
+#include <guacamole/protocol.h>
+#include <guacamole/socket.h>
+
+static const telnet_telopt_t __telnet_options[] = {
+    { TELNET_TELOPT_ECHO,      TELNET_WONT, TELNET_DONT },
+    { TELNET_TELOPT_TTYPE,     TELNET_WILL, TELNET_DONT },
+    { TELNET_TELOPT_COMPRESS2, TELNET_WONT, TELNET_DO   },
+    { TELNET_TELOPT_MSSP,      TELNET_WONT, TELNET_DO   },
+    { -1, 0, 0 }
+};
+
+static int __write_all(int fd, const char* buffer, int size) {
+
+    int remaining = size;
+    while (remaining > 0) {
+
+        /* Attempt to write data */
+        int ret_val = write(fd, buffer, remaining);
+        if (ret_val <= 0)
+            return -1;
+
+        /* If successful, contine with what data remains (if any) */
+        remaining -= ret_val;
+        buffer += ret_val;
+
+    }
+
+    return size;
+
+}
+
+static void __guac_telnet_event_handler(telnet_t* telnet, telnet_event_t* event, void* data) {
+
+    guac_client* client = (guac_client*) data;
+    telnet_client_data* client_data = (telnet_client_data*) client->data;
+
+    switch (event->type) {
+
+        /* User input received */
+        case TELNET_EV_DATA:
+            guac_terminal_write_stdout(client_data->term, event->data.buffer, event->data.size);
+            break;
+
+        /* Data destined for remote end */
+        case TELNET_EV_SEND:
+            if (__write_all(client_data->socket_fd, event->data.buffer, event->data.size) != event->data.size)
+                guac_client_stop(client);
+            break;
+
+        /* Terminal type request */
+        case TELNET_EV_TTYPE:
+            if (event->ttype.cmd == TELNET_TTYPE_SEND)
+                telnet_ttype_is(client_data->telnet, "linux");
+            break;
+
+        /* Connection warnings */
+        case TELNET_EV_WARNING:
+            guac_client_log_info(client, "%s", event->error.msg);
+            break;
+
+        /* Connection errors */
+        case TELNET_EV_ERROR:
+            guac_client_abort(client, GUAC_PROTOCOL_STATUS_UPSTREAM_ERROR,
+                    "Telnet connection closing with error: %s", event->error.msg);
+            break;
+
+        /* Ignore other events */
+        default:
+            break;
+
+    }
+
+}
+
+void* telnet_input_thread(void* data) {
+
+    guac_client* client = (guac_client*) data;
+    telnet_client_data* client_data = (telnet_client_data*) client->data;
+
+    char buffer[8192];
+    int bytes_read;
+
+    /* Write all data read */
+    while ((bytes_read = guac_terminal_read_stdin(client_data->term, buffer, sizeof(buffer))) > 0)
+        telnet_send(client_data->telnet, buffer, bytes_read);
+
+    return NULL;
+
+}
+
+static telnet_t* __guac_telnet_create_session(guac_client* client) {
+
+    int retval;
+
+    int fd;
+    struct addrinfo* addresses;
+    struct addrinfo* current_address;
+
+    char connected_address[1024];
+    char connected_port[64];
+
+    telnet_client_data* client_data = (telnet_client_data*) client->data;
+
+    struct addrinfo hints = {
+        .ai_family   = AF_UNSPEC,
+        .ai_socktype = SOCK_STREAM,
+        .ai_protocol = IPPROTO_TCP
+    };
+
+    /* Get socket */
+    fd = socket(AF_INET, SOCK_STREAM, 0);
+
+    /* Get addresses connection */
+    if ((retval = getaddrinfo(client_data->hostname, client_data->port,
+                    &hints, &addresses))) {
+        guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR, "Error parsing given address or port: %s",
+                gai_strerror(retval));
+        return NULL;
+
+    }
+
+    /* Attempt connection to each address until success */
+    current_address = addresses;
+    while (current_address != NULL) {
+
+        int retval;
+
+        /* Resolve hostname */
+        if ((retval = getnameinfo(current_address->ai_addr,
+                current_address->ai_addrlen,
+                connected_address, sizeof(connected_address),
+                connected_port, sizeof(connected_port),
+                NI_NUMERICHOST | NI_NUMERICSERV)))
+            guac_client_log_info(client, "Unable to resolve host: %s", gai_strerror(retval));
+
+        /* Connect */
+        if (connect(fd, current_address->ai_addr,
+                        current_address->ai_addrlen) == 0) {
+
+            guac_client_log_info(client, "Successfully connected to "
+                    "host %s, port %s", connected_address, connected_port);
+
+            /* Done if successful connect */
+            break;
+
+        }
+
+        /* Otherwise log information regarding bind failure */
+        else
+            guac_client_log_info(client, "Unable to connect to "
+                    "host %s, port %s: %s",
+                    connected_address, connected_port, strerror(errno));
+
+        current_address = current_address->ai_next;
+
+    }
+
+    /* If unable to connect to anything, fail */
+    if (current_address == NULL) {
+        guac_client_abort(client, GUAC_PROTOCOL_STATUS_UPSTREAM_ERROR, "Unable to connect to any addresses.");
+        return NULL;
+    }
+
+    /* Free addrinfo */
+    freeaddrinfo(addresses);
+
+    /* Open telnet session */
+    telnet_t* telnet = telnet_init(__telnet_options, __guac_telnet_event_handler, 0, client);
+    if (telnet == NULL) {
+        guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR, "Telnet client allocation failed.");
+        return NULL;
+    }
+
+    /* Save file descriptor */
+    client_data->socket_fd = fd;
+
+    return telnet;
+
+}
+
+void* telnet_client_thread(void* data) {
+
+    guac_client* client = (guac_client*) data;
+    telnet_client_data* client_data = (telnet_client_data*) client->data;
+
+    pthread_t input_thread;
+    char buffer[8192];
+    int bytes_read;
+
+    /* Open telnet session */
+    client_data->telnet = __guac_telnet_create_session(client);
+    if (client_data->telnet == NULL) {
+        /* Already aborted within __guac_telnet_create_session() */
+        return NULL;
+    }
+
+    /* Logged in */
+    guac_client_log_info(client, "Telnet connection successful.");
+
+    /* Start input thread */
+    if (pthread_create(&(input_thread), NULL, telnet_input_thread, (void*) client)) {
+        guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR, "Unable to start input thread");
+        return NULL;
+    }
+
+    /* While data available, write to terminal */
+    while ((bytes_read = read(client_data->socket_fd, buffer, sizeof(buffer))) > 0)
+        telnet_recv(client_data->telnet, buffer, bytes_read);
+
+    /* Kill client and Wait for input thread to die */
+    guac_client_stop(client);
+    pthread_join(input_thread, NULL);
+
+    guac_client_log_info(client, "Telnet connection ended.");
+    return NULL;
+
+}
+

src/protocols/telnet/telnet_client.h

@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2013 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
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+
+#ifndef __TELNET_CLIENT_H
+#define __TELNET_CLIENT_H
+
+#include "config.h"
+
+#include <guacamole/client.h>
+
+/**
+ * Main telnet client thread, handling transfer of telnet output to STDOUT.
+ */
+void* telnet_client_thread(void* data);
+
+#endif
+