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 "gasyncresult.h"
  30 #include "giomodule.h"
  31 #include "giomodule-priv.h"
  32 #include "giostream.h"
  33 #include "ginetaddress.h"
  34 #include "ginputstream.h"
  35 #include "glibintl.h"
  36 #include "goutputstream.h"
  37 #include "gproxy.h"
  38 #include "gproxyaddress.h"
  39 #include "gsimpleasyncresult.h"
  40
  41 #define SOCKS4_VERSION            4
  42
  43 #define SOCKS4_CMD_CONNECT        1
  44 #define SOCKS4_CMD_BIND           2
  45
  46 #define SOCKS4_MAX_LEN            255
  47
  48 #define SOCKS4_REP_VERSION        0
  49 #define SOCKS4_REP_GRANTED        90
  50 #define SOCKS4_REP_REJECTED       91
  51 #define SOCKS4_REP_NO_IDENT       92
  52 #define SOCKS4_REP_BAD_IDENT      93
  53
  54 static void g_socks4a_proxy_iface_init (GProxyInterface *proxy_iface);
  55
  56 #define g_socks4a_proxy_get_type _g_socks4a_proxy_get_type
  57 G_DEFINE_TYPE_WITH_CODE (GSocks4aProxy, g_socks4a_proxy, G_TYPE_OBJECT,
  58                          G_IMPLEMENT_INTERFACE (G_TYPE_PROXY,
  59                                                 g_socks4a_proxy_iface_init)
  60                          _g_io_modules_ensure_extension_points_registered ();
  61                          g_io_extension_point_implement (G_PROXY_EXTENSION_POINT_NAME,
  62                                                          g_define_type_id,
  63                                                          "socks4a",
  64                                                          0))
  65
  66 static void
  67 g_socks4a_proxy_finalize (GObject *object)
  68 {
  69   /* must chain up */
  70   G_OBJECT_CLASS (g_socks4a_proxy_parent_class)->finalize (object);
  71 }
  72
  73 static void
  74 g_socks4a_proxy_init (GSocks4aProxy *proxy)
  75 {
  76   proxy->supports_hostname = TRUE;
  77 }
  78
  79 /*                                                             |-> SOCKSv4a only
  80  * +----+----+----+----+----+----+----+----+----+----+....+----+------+....+------+
  81  * | VN | CD | DSTPORT |      DSTIP        | USERID       |NULL| HOST |    | NULL |
  82  * +----+----+----+----+----+----+----+----+----+----+....+----+------+....+------+
  83  *    1    1      2              4           variable       1    variable
  84  */
  85 #define SOCKS4_CONN_MSG_LEN         (9 + SOCKS4_MAX_LEN * 2)
  86 static gint
  87 set_connect_msg (guint8      *msg,
  88                  const gchar *hostname,
  89                  guint16      port,
  90                  const char  *username,
  91                  GError     **error)
  92 {
  93   GInetAddress *addr;
  94   guint len = 0;
  95   gsize addr_len;
  96   gboolean is_ip;
  97   const gchar *ip;
  98
  99   msg[len++] = SOCKS4_VERSION;
 100   msg[len++] = SOCKS4_CMD_CONNECT;
 101
 102     {
 103       guint16 hp = g_htons (port);
 104       memcpy (msg + len, &hp, 2);
 105       len += 2;
 106     }
 107
 108   is_ip = g_hostname_is_ip_address (hostname);
 109
 110   if (is_ip)
 111     ip = hostname;
 112   else
 113     ip = "0.0.0.1";
 114
 115   addr = g_inet_address_new_from_string (ip);
 116   addr_len = g_inet_address_get_native_size (addr);
 117
 118   if (addr_len != 4)
 119     {
 120       g_set_error (error, G_IO_ERROR, G_IO_ERROR_PROXY_FAILED,
 121                   _("SOCKSv4 does not support IPv6 address '%s'"),
 122                   ip);
 123       g_object_unref (addr);
 124       return -1;
 125     }
 126
 127   memcpy (msg + len, g_inet_address_to_bytes (addr), addr_len);
 128   len += addr_len;
 129
 130   g_object_unref (addr);
 131
 132   if (username)
 133     {
 134       gsize user_len = strlen (username);
 135
 136       if (user_len > SOCKS4_MAX_LEN)
 137         {
 138           g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_PROXY_FAILED,
 139                                _("Username is too long for SOCKSv4 protocol"));
 140           return -1;
 141         }
 142
 143       memcpy (msg + len, username, user_len);
 144       len += user_len;
 145     }
 146
 147   msg[len++] = '\0';
 148
 149   if (!is_ip)
 150     {
 151       gsize host_len = strlen (hostname);
 152
 153       if (host_len > SOCKS4_MAX_LEN)
 154         {
 155           g_set_error (error, G_IO_ERROR, G_IO_ERROR_PROXY_FAILED,
 156                        _("Hostname '%s' is too long for SOCKSv4 protocol"),
 157                        hostname);
 158           return -1;
 159         }
 160
 161       memcpy (msg + len, hostname, host_len);
 162       len += host_len;
 163       msg[len++] = '\0';
 164     }
 165
 166   return len;
 167 }
 168
 169 /*
 170  * +----+----+----+----+----+----+----+----+
 171  * | VN | CD | DSTPORT |      DSTIP        |
 172  * +----+----+----+----+----+----+----+----+
 173  *    1    1      2              4
 174  */
 175 #define SOCKS4_CONN_REP_LEN       8
 176 static gboolean
 177 parse_connect_reply (const guint8 *data, GError **error)
 178 {
 179   if (data[0] != SOCKS4_REP_VERSION)
 180     {
 181       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_PROXY_FAILED,
 182                            _("The server is not a SOCKSv4 proxy server."));
 183       return FALSE;
 184     }
 185
 186   if (data[1] != SOCKS4_REP_GRANTED)
 187     {
 188       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_PROXY_FAILED,
 189                            _("Connection through SOCKSv4 server was rejected"));
 190       return FALSE;
 191     }
 192
 193   return TRUE;
 194 }
 195
 196 static GIOStream *
 197 g_socks4a_proxy_connect (GProxy            *proxy,
 198                          GIOStream         *io_stream,
 199                          GProxyAddress     *proxy_address,
 200                          GCancellable      *cancellable,
 201                          GError           **error)
 202 {
 203   GInputStream *in;
 204   GOutputStream *out;
 205   const gchar *hostname;
 206   guint16 port;
 207   const gchar *username;
 208
 209   hostname = g_proxy_address_get_destination_hostname (proxy_address);
 210   port = g_proxy_address_get_destination_port (proxy_address);
 211   username = g_proxy_address_get_username (proxy_address);
 212
 213   in = g_io_stream_get_input_stream (io_stream);
 214   out = g_io_stream_get_output_stream (io_stream);
 215
 216   /* Send SOCKS4 connection request */
 217     {
 218       guint8 msg[SOCKS4_CONN_MSG_LEN];
 219       gint len;
 220
 221       len = set_connect_msg (msg, hostname, port, username, error);
 222
 223       if (len < 0)
 224         goto error;
 225
 226       if (!g_output_stream_write_all (out, msg, len, NULL,
 227                                       cancellable, error))
 228         goto error;
 229     }
 230
 231   /* Read SOCKS4 response */
 232     {
 233       guint8 data[SOCKS4_CONN_REP_LEN];
 234
 235       if (!g_input_stream_read_all (in, data, SOCKS4_CONN_REP_LEN, NULL,
 236                                     cancellable, error))
 237         goto error;
 238
 239       if (!parse_connect_reply (data, error))
 240         goto error;
 241     }
 242
 243   return g_object_ref (io_stream);
 244
 245 error:
 246   return NULL;
 247 }
 248
 249
 250 typedef struct
 251 {
 252   GSimpleAsyncResult *simple;
 253   GIOStream *io_stream;
 254   GProxyAddress *proxy_address;
 255   GCancellable *cancellable;
 256
 257   /* For connecting */
 258   guint8 *buffer;
 259   gssize length;
 260   gssize offset;
 261
 262 } ConnectAsyncData;
 263
 264 static void connect_msg_write_cb      (GObject          *source,
 265                                        GAsyncResult     *result,
 266                                        gpointer          user_data);
 267 static void connect_reply_read_cb     (GObject          *source,
 268                                        GAsyncResult     *result,
 269                                        gpointer          user_data);
 270
 271 static void
 272 free_connect_data (ConnectAsyncData *data)
 273 {
 274   if (data->io_stream)
 275     g_object_unref (data->io_stream);
 276
 277   if (data->proxy_address)
 278     g_object_unref (data->proxy_address);
 279
 280   if (data->cancellable)
 281     g_object_unref (data->cancellable);
 282
 283   g_slice_free (ConnectAsyncData, data);
 284 }
 285
 286 static void
 287 complete_async_from_error (ConnectAsyncData *data, GError *error)
 288 {
 289   GSimpleAsyncResult *simple = data->simple;
 290   g_simple_async_result_take_error (data->simple, error);
 291   g_simple_async_result_set_op_res_gpointer (simple, NULL, NULL);
 292   g_simple_async_result_complete (simple);
 293   g_object_unref (simple);
 294 }
 295
 296 static void
 297 do_read (GAsyncReadyCallback callback, ConnectAsyncData *data)
 298 {
 299    GInputStream *in;
 300    in = g_io_stream_get_input_stream (data->io_stream);
 301    g_input_stream_read_async (in,
 302                               data->buffer + data->offset,
 303                               data->length - data->offset,
 304                               G_PRIORITY_DEFAULT, data->cancellable,
 305                               callback, data);
 306 }
 307
 308 static void
 309 do_write (GAsyncReadyCallback callback, ConnectAsyncData *data)
 310 {
 311   GOutputStream *out;
 312   out = g_io_stream_get_output_stream (data->io_stream);
 313   g_output_stream_write_async (out,
 314                                data->buffer + data->offset,
 315                                data->length - data->offset,
 316                                G_PRIORITY_DEFAULT, data->cancellable,
 317                                callback, data);
 318 }
 319
 320
 321
 322 static void
 323 g_socks4a_proxy_connect_async (GProxy               *proxy,
 324                                GIOStream            *io_stream,
 325                                GProxyAddress        *proxy_address,
 326                                GCancellable         *cancellable,
 327                                GAsyncReadyCallback   callback,
 328                                gpointer              user_data)
 329 {
 330   GError *error = NULL;
 331   GSimpleAsyncResult *simple;
 332   ConnectAsyncData *data;
 333   const gchar *hostname;
 334   guint16 port;
 335   const gchar *username;
 336
 337   simple = g_simple_async_result_new (G_OBJECT (proxy),
 338                                       callback, user_data,
 339                                       g_socks4a_proxy_connect_async);
 340
 341   data = g_slice_new0 (ConnectAsyncData);
 342
 343   data->simple = simple;
 344   data->io_stream = g_object_ref (io_stream);
 345
 346   if (cancellable)
 347     data->cancellable = g_object_ref (cancellable);
 348
 349   g_simple_async_result_set_op_res_gpointer (simple, data,
 350                                              (GDestroyNotify) free_connect_data);
 351
 352   hostname = g_proxy_address_get_destination_hostname (proxy_address);
 353   port = g_proxy_address_get_destination_port (proxy_address);
 354   username = g_proxy_address_get_username (proxy_address);
 355
 356   data->buffer = g_malloc0 (SOCKS4_CONN_MSG_LEN);
 357   data->length = set_connect_msg (data->buffer,
 358                                   hostname, port, username,
 359                                   &error);
 360   data->offset = 0;
 361
 362   if (data->length < 0)
 363     {
 364       g_simple_async_result_take_error (data->simple, error);
 365       g_simple_async_result_set_op_res_gpointer (simple, NULL, NULL);
 366       g_simple_async_result_complete_in_idle (simple);
 367       g_object_unref (simple);
 368     }
 369   else
 370     {
 371       do_write (connect_msg_write_cb, data);
 372     }
 373 }
 374
 375 static void
 376 connect_msg_write_cb (GObject      *source,
 377                       GAsyncResult *result,
 378                       gpointer      user_data)
 379 {
 380   GError *error = NULL;
 381   ConnectAsyncData *data = user_data;
 382   gssize written;
 383
 384   written = g_output_stream_write_finish (G_OUTPUT_STREAM (source),
 385                                           result, &error);
 386
 387   if (written < 0)
 388     {
 389       complete_async_from_error (data, error);
 390       return;
 391     }
 392
 393   data->offset += written;
 394
 395   if (data->offset == data->length)
 396     {
 397       g_free (data->buffer);
 398
 399       data->buffer = g_malloc0 (SOCKS4_CONN_REP_LEN);
 400       data->length = SOCKS4_CONN_REP_LEN;
 401       data->offset = 0;
 402
 403       do_read (connect_reply_read_cb, data);
 404     }
 405   else
 406     {
 407       do_write (connect_msg_write_cb, data);
 408     }
 409 }
 410
 411 static void
 412 connect_reply_read_cb (GObject       *source,
 413                        GAsyncResult  *result,
 414                        gpointer       user_data)
 415 {
 416   GError *error = NULL;
 417   ConnectAsyncData *data = user_data;
 418   gssize read;
 419
 420   read = g_input_stream_read_finish (G_INPUT_STREAM (source),
 421                                      result, &error);
 422
 423   if (read < 0)
 424     {
 425       complete_async_from_error (data, error);
 426       return;
 427     }
 428
 429   data->offset += read;
 430
 431   if (data->offset == data->length)
 432     {
 433       if (!parse_connect_reply (data->buffer, &error))
 434         {
 435           complete_async_from_error (data, error);
 436         }
 437       else
 438         {
 439           GSimpleAsyncResult *simple = data->simple;
 440           g_simple_async_result_complete (simple);
 441           g_object_unref (simple);
 442         }
 443     }
 444   else
 445     {
 446       do_read (connect_reply_read_cb, data);
 447     }
 448 }
 449
 450 static GIOStream *g_socks4a_proxy_connect_finish (GProxy       *proxy,
 451                                                   GAsyncResult *result,
 452                                                   GError      **error);
 453
 454 static GIOStream *
 455 g_socks4a_proxy_connect_finish (GProxy       *proxy,
 456                                 GAsyncResult *result,
 457                                 GError      **error)
 458 {
 459   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
 460   ConnectAsyncData *data = g_simple_async_result_get_op_res_gpointer (simple);
 461
 462   if (g_simple_async_result_propagate_error (simple, error))
 463     return NULL;
 464
 465   return g_object_ref (data->io_stream);
 466 }
 467
 468 static gboolean
 469 g_socks4a_proxy_supports_hostname (GProxy *proxy)
 470 {
 471   return G_SOCKS4A_PROXY (proxy)->supports_hostname;
 472 }
 473
 474 static void
 475 g_socks4a_proxy_class_init (GSocks4aProxyClass *class)
 476 {
 477   GObjectClass *object_class;
 478
 479   object_class = (GObjectClass *) class;
 480   object_class->finalize = g_socks4a_proxy_finalize;
 481 }
 482
 483 static void
 484 g_socks4a_proxy_iface_init (GProxyInterface *proxy_iface)
 485 {
 486   proxy_iface->connect  = g_socks4a_proxy_connect;
 487   proxy_iface->connect_async = g_socks4a_proxy_connect_async;
 488   proxy_iface->connect_finish = g_socks4a_proxy_connect_finish;
 489   proxy_iface->supports_hostname = g_socks4a_proxy_supports_hostname;
 490 }