gio/gsocks4aproxy.c

   1  /* GIO - GLib Input, Output and Streaming Library
   2  *
   3  * Copyright (C) 2010 Collabora, Ltd.
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General
  16  * Public License along with this library; if not, write to the
  17  * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  18  * Boston, MA 02111-1307, USA.
  19  *
  20  * Author: Nicolas Dufresne <nicolas.dufresne@collabora.co.uk>
  21  */
  22
  23 #include "config.h"
  24
  25 #include "gsocks4aproxy.h"
  26
  27 #include <string.h>
  28
  29 #include "giomodule.h"
  30 #include "giomodule-priv.h"
  31 #include "giostream.h"
  32 #include "ginetaddress.h"
  33 #include "ginputstream.h"
  34 #include "glibintl.h"
  35 #include "goutputstream.h"
  36 #include "gproxy.h"
  37 #include "gproxyaddress.h"
  38 #include "gtask.h"
  39
  40 #define SOCKS4_VERSION            4
  41
  42 #define SOCKS4_CMD_CONNECT        1
  43 #define SOCKS4_CMD_BIND           2
  44
  45 #define SOCKS4_MAX_LEN            255
  46
  47 #define SOCKS4_REP_VERSION        0
  48 #define SOCKS4_REP_GRANTED        90
  49 #define SOCKS4_REP_REJECTED       91
  50 #define SOCKS4_REP_NO_IDENT       92
  51 #define SOCKS4_REP_BAD_IDENT      93
  52
  53 static void g_socks4a_proxy_iface_init (GProxyInterface *proxy_iface);
  54
  55 #define g_socks4a_proxy_get_type _g_socks4a_proxy_get_type
  56 G_DEFINE_TYPE_WITH_CODE (GSocks4aProxy, g_socks4a_proxy, G_TYPE_OBJECT,
  57                          G_IMPLEMENT_INTERFACE (G_TYPE_PROXY,
  58                                                 g_socks4a_proxy_iface_init)
  59                          _g_io_modules_ensure_extension_points_registered ();
  60                          g_io_extension_point_implement (G_PROXY_EXTENSION_POINT_NAME,
  61                                                          g_define_type_id,
  62                                                          "socks4a",
  63                                                          0))
  64
  65 static void
  66 g_socks4a_proxy_finalize (GObject *object)
  67 {
  68   /* must chain up */
  69   G_OBJECT_CLASS (g_socks4a_proxy_parent_class)->finalize (object);
  70 }
  71
  72 static void
  73 g_socks4a_proxy_init (GSocks4aProxy *proxy)
  74 {
  75   proxy->supports_hostname = TRUE;
  76 }
  77
  78 /*                                                             |-> SOCKSv4a only
  79  * +----+----+----+----+----+----+----+----+----+----+....+----+------+....+------+
  80  * | VN | CD | DSTPORT |      DSTIP        | USERID       |NULL| HOST |    | NULL |
  81  * +----+----+----+----+----+----+----+----+----+----+....+----+------+....+------+
  82  *    1    1      2              4           variable       1    variable
  83  */
  84 #define SOCKS4_CONN_MSG_LEN         (9 + SOCKS4_MAX_LEN * 2)
  85 static gint
  86 set_connect_msg (guint8      *msg,
  87                  const gchar *hostname,
  88                  guint16      port,
  89                  const char  *username,
  90                  GError     **error)
  91 {
  92   GInetAddress *addr;
  93   guint len = 0;
  94   gsize addr_len;
  95   gboolean is_ip;
  96   const gchar *ip;
  97
  98   msg[len++] = SOCKS4_VERSION;
  99   msg[len++] = SOCKS4_CMD_CONNECT;
 100
 101     {
 102       guint16 hp = g_htons (port);
 103       memcpy (msg + len, &hp, 2);
 104       len += 2;
 105     }
 106
 107   is_ip = g_hostname_is_ip_address (hostname);
 108
 109   if (is_ip)
 110     ip = hostname;
 111   else
 112     ip = "0.0.0.1";
 113
 114   addr = g_inet_address_new_from_string (ip);
 115   addr_len = g_inet_address_get_native_size (addr);
 116
 117   if (addr_len != 4)
 118     {
 119       g_set_error (error, G_IO_ERROR, G_IO_ERROR_PROXY_FAILED,
 120                   _("SOCKSv4 does not support IPv6 address '%s'"),
 121                   ip);
 122       g_object_unref (addr);
 123       return -1;
 124     }
 125
 126   memcpy (msg + len, g_inet_address_to_bytes (addr), addr_len);
 127   len += addr_len;
 128
 129   g_object_unref (addr);
 130
 131   if (username)
 132     {
 133       gsize user_len = strlen (username);
 134
 135       if (user_len > SOCKS4_MAX_LEN)
 136         {
 137           g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_PROXY_FAILED,
 138                                _("Username is too long for SOCKSv4 protocol"));
 139           return -1;
 140         }
 141
 142       memcpy (msg + len, username, user_len);
 143       len += user_len;
 144     }
 145
 146   msg[len++] = '\0';
 147
 148   if (!is_ip)
 149     {
 150       gsize host_len = strlen (hostname);
 151
 152       if (host_len > SOCKS4_MAX_LEN)
 153         {
 154           g_set_error (error, G_IO_ERROR, G_IO_ERROR_PROXY_FAILED,
 155                        _("Hostname '%s' is too long for SOCKSv4 protocol"),
 156                        hostname);
 157           return -1;
 158         }
 159
 160       memcpy (msg + len, hostname, host_len);
 161       len += host_len;
 162       msg[len++] = '\0';
 163     }
 164
 165   return len;
 166 }
 167
 168 /*
 169  * +----+----+----+----+----+----+----+----+
 170  * | VN | CD | DSTPORT |      DSTIP        |
 171  * +----+----+----+----+----+----+----+----+
 172  *    1    1      2              4
 173  */
 174 #define SOCKS4_CONN_REP_LEN       8
 175 static gboolean
 176 parse_connect_reply (const guint8 *data, GError **error)
 177 {
 178   if (data[0] != SOCKS4_REP_VERSION)
 179     {
 180       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_PROXY_FAILED,
 181                            _("The server is not a SOCKSv4 proxy server."));
 182       return FALSE;
 183     }
 184
 185   if (data[1] != SOCKS4_REP_GRANTED)
 186     {
 187       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_PROXY_FAILED,
 188                            _("Connection through SOCKSv4 server was rejected"));
 189       return FALSE;
 190     }
 191
 192   return TRUE;
 193 }
 194
 195 static GIOStream *
 196 g_socks4a_proxy_connect (GProxy            *proxy,
 197                          GIOStream         *io_stream,
 198                          GProxyAddress     *proxy_address,
 199                          GCancellable      *cancellable,
 200                          GError           **error)
 201 {
 202   GInputStream *in;
 203   GOutputStream *out;
 204   const gchar *hostname;
 205   guint16 port;
 206   const gchar *username;
 207
 208   hostname = g_proxy_address_get_destination_hostname (proxy_address);
 209   port = g_proxy_address_get_destination_port (proxy_address);
 210   username = g_proxy_address_get_username (proxy_address);
 211
 212   in = g_io_stream_get_input_stream (io_stream);
 213   out = g_io_stream_get_output_stream (io_stream);
 214
 215   /* Send SOCKS4 connection request */
 216     {
 217       guint8 msg[SOCKS4_CONN_MSG_LEN];
 218       gint len;
 219
 220       len = set_connect_msg (msg, hostname, port, username, error);
 221
 222       if (len < 0)
 223         goto error;
 224
 225       if (!g_output_stream_write_all (out, msg, len, NULL,
 226                                       cancellable, error))
 227         goto error;
 228     }
 229
 230   /* Read SOCKS4 response */
 231     {
 232       guint8 data[SOCKS4_CONN_REP_LEN];
 233
 234       if (!g_input_stream_read_all (in, data, SOCKS4_CONN_REP_LEN, NULL,
 235                                     cancellable, error))
 236         goto error;
 237
 238       if (!parse_connect_reply (data, error))
 239         goto error;
 240     }
 241
 242   return g_object_ref (io_stream);
 243
 244 error:
 245   return NULL;
 246 }
 247
 248
 249 typedef struct
 250 {
 251   GIOStream *io_stream;
 252
 253   /* For connecting */
 254   guint8 *buffer;
 255   gssize length;
 256   gssize offset;
 257
 258 } ConnectAsyncData;
 259
 260 static void connect_msg_write_cb      (GObject          *source,
 261                                        GAsyncResult     *result,
 262                                        gpointer          user_data);
 263 static void connect_reply_read_cb     (GObject          *source,
 264                                        GAsyncResult     *result,
 265                                        gpointer          user_data);
 266
 267 static void
 268 free_connect_data (ConnectAsyncData *data)
 269 {
 270   g_object_unref (data->io_stream);
 271   g_slice_free (ConnectAsyncData, data);
 272 }
 273
 274 static void
 275 do_read (GAsyncReadyCallback callback, GTask *task, ConnectAsyncData *data)
 276 {
 277    GInputStream *in;
 278    in = g_io_stream_get_input_stream (data->io_stream);
 279    g_input_stream_read_async (in,
 280                               data->buffer + data->offset,
 281                               data->length - data->offset,
 282                               g_task_get_priority (task),
 283                               g_task_get_cancellable (task),
 284                               callback, task);
 285 }
 286
 287 static void
 288 do_write (GAsyncReadyCallback callback, GTask *task, ConnectAsyncData *data)
 289 {
 290   GOutputStream *out;
 291   out = g_io_stream_get_output_stream (data->io_stream);
 292   g_output_stream_write_async (out,
 293                                data->buffer + data->offset,
 294                                data->length - data->offset,
 295                                g_task_get_priority (task),
 296                                g_task_get_cancellable (task),
 297                                callback, task);
 298 }
 299
 300
 301
 302 static void
 303 g_socks4a_proxy_connect_async (GProxy               *proxy,
 304                                GIOStream            *io_stream,
 305                                GProxyAddress        *proxy_address,
 306                                GCancellable         *cancellable,
 307                                GAsyncReadyCallback   callback,
 308                                gpointer              user_data)
 309 {
 310   GError *error = NULL;
 311   GTask *task;
 312   ConnectAsyncData *data;
 313   const gchar *hostname;
 314   guint16 port;
 315   const gchar *username;
 316
 317   data = g_slice_new0 (ConnectAsyncData);
 318   data->io_stream = g_object_ref (io_stream);
 319
 320   task = g_task_new (proxy, cancellable, callback, user_data);
 321   g_task_set_task_data (task, data, (GDestroyNotify) free_connect_data);
 322
 323   hostname = g_proxy_address_get_destination_hostname (proxy_address);
 324   port = g_proxy_address_get_destination_port (proxy_address);
 325   username = g_proxy_address_get_username (proxy_address);
 326
 327   data->buffer = g_malloc0 (SOCKS4_CONN_MSG_LEN);
 328   data->length = set_connect_msg (data->buffer,
 329                                   hostname, port, username,
 330                                   &error);
 331   data->offset = 0;
 332
 333   if (data->length < 0)
 334     {
 335       g_task_return_error (task, error);
 336       g_object_unref (task);
 337     }
 338   else
 339     {
 340       do_write (connect_msg_write_cb, task, data);
 341     }
 342 }
 343
 344 static void
 345 connect_msg_write_cb (GObject      *source,
 346                       GAsyncResult *result,
 347                       gpointer      user_data)
 348 {
 349   GTask *task = user_data;
 350   ConnectAsyncData *data = g_task_get_task_data (task);
 351   GError *error = NULL;
 352   gssize written;
 353
 354   written = g_output_stream_write_finish (G_OUTPUT_STREAM (source),
 355                                           result, &error);
 356
 357   if (written < 0)
 358     {
 359       g_task_return_error (task, error);
 360       g_object_unref (task);
 361       return;
 362     }
 363
 364   data->offset += written;
 365
 366   if (data->offset == data->length)
 367     {
 368       g_free (data->buffer);
 369
 370       data->buffer = g_malloc0 (SOCKS4_CONN_REP_LEN);
 371       data->length = SOCKS4_CONN_REP_LEN;
 372       data->offset = 0;
 373
 374       do_read (connect_reply_read_cb, task, data);
 375     }
 376   else
 377     {
 378       do_write (connect_msg_write_cb, task, data);
 379     }
 380 }
 381
 382 static void
 383 connect_reply_read_cb (GObject       *source,
 384                        GAsyncResult  *result,
 385                        gpointer       user_data)
 386 {
 387   GTask *task = user_data;
 388   ConnectAsyncData *data = g_task_get_task_data (task);
 389   GError *error = NULL;
 390   gssize read;
 391
 392   read = g_input_stream_read_finish (G_INPUT_STREAM (source),
 393                                      result, &error);
 394
 395   if (read < 0)
 396     {
 397       g_task_return_error (task, error);
 398       g_object_unref (task);
 399       return;
 400     }
 401
 402   data->offset += read;
 403
 404   if (data->offset == data->length)
 405     {
 406       if (!parse_connect_reply (data->buffer, &error))
 407         {
 408           g_task_return_error (task, error);
 409           g_object_unref (task);
 410           return;
 411         }
 412       else
 413         {
 414           g_task_return_pointer (task, g_object_ref (data->io_stream), g_object_unref);
 415           g_object_unref (task);
 416           return;
 417         }
 418     }
 419   else
 420     {
 421       do_read (connect_reply_read_cb, task, data);
 422     }
 423 }
 424
 425 static GIOStream *g_socks4a_proxy_connect_finish (GProxy       *proxy,
 426                                                   GAsyncResult *result,
 427                                                   GError      **error);
 428
 429 static GIOStream *
 430 g_socks4a_proxy_connect_finish (GProxy       *proxy,
 431                                 GAsyncResult *result,
 432                                 GError      **error)
 433 {
 434   return g_task_propagate_pointer (G_TASK (result), error);
 435 }
 436
 437 static gboolean
 438 g_socks4a_proxy_supports_hostname (GProxy *proxy)
 439 {
 440   return G_SOCKS4A_PROXY (proxy)->supports_hostname;
 441 }
 442
 443 static void
 444 g_socks4a_proxy_class_init (GSocks4aProxyClass *class)
 445 {
 446   GObjectClass *object_class;
 447
 448   object_class = (GObjectClass *) class;
 449   object_class->finalize = g_socks4a_proxy_finalize;
 450 }
 451
 452 static void
 453 g_socks4a_proxy_iface_init (GProxyInterface *proxy_iface)
 454 {
 455   proxy_iface->connect  = g_socks4a_proxy_connect;
 456   proxy_iface->connect_async = g_socks4a_proxy_connect_async;
 457   proxy_iface->connect_finish = g_socks4a_proxy_connect_finish;
 458   proxy_iface->supports_hostname = g_socks4a_proxy_supports_hostname;
 459 }