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 (error, G_IO_ERROR, G_IO_ERROR_PROXY_FAILED,
 139                        _("SOCKSv4 implementation limits username to %i characters"),
 140                        SOCKS4_MAX_LEN);
 141           return -1;
 142         }
 143
 144       memcpy (msg + len, username, user_len);
 145       len += user_len;
 146     }
 147
 148   msg[len++] = '\0';
 149
 150   if (!is_ip)
 151     {
 152       gsize host_len = strlen (hostname);
 153
 154       if (host_len > SOCKS4_MAX_LEN)
 155         {
 156           g_set_error (error, G_IO_ERROR, G_IO_ERROR_PROXY_FAILED,
 157                        _("SOCKSv4a implementation limits hostname to %i characters"),
 158                        SOCKS4_MAX_LEN);
 159           return -1;
 160         }
 161
 162       memcpy (msg + len, hostname, host_len);
 163       len += host_len;
 164       msg[len++] = '\0';
 165     }
 166
 167   return len;
 168 }
 169
 170 /*
 171  * +----+----+----+----+----+----+----+----+
 172  * | VN | CD | DSTPORT |      DSTIP        |
 173  * +----+----+----+----+----+----+----+----+
 174  *    1    1      2              4
 175  */
 176 #define SOCKS4_CONN_REP_LEN       8
 177 static gboolean
 178 parse_connect_reply (const guint8 *data, GError **error)
 179 {
 180   if (data[0] != SOCKS4_REP_VERSION)
 181     {
 182       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_PROXY_FAILED,
 183                            _("The server is not a SOCKSv4 proxy server."));
 184       return FALSE;
 185     }
 186
 187   if (data[1] != SOCKS4_REP_GRANTED)
 188     {
 189       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_PROXY_FAILED,
 190                            _("Connection through SOCKSv4 server was rejected"));
 191       return FALSE;
 192     }
 193
 194   return TRUE;
 195 }
 196
 197 static GIOStream *
 198 g_socks4a_proxy_connect (GProxy            *proxy,
 199                          GIOStream         *io_stream,
 200                          GProxyAddress     *proxy_address,
 201                          GCancellable      *cancellable,
 202                          GError           **error)
 203 {
 204   GInputStream *in;
 205   GOutputStream *out;
 206   const gchar *hostname;
 207   guint16 port;
 208   const gchar *username;
 209
 210   hostname = g_proxy_address_get_destination_hostname (proxy_address);
 211   port = g_proxy_address_get_destination_port (proxy_address);
 212   username = g_proxy_address_get_username (proxy_address);
 213
 214   in = g_io_stream_get_input_stream (io_stream);
 215   out = g_io_stream_get_output_stream (io_stream);
 216
 217   /* Send SOCKS4 connection request */
 218     {
 219       guint8 msg[SOCKS4_CONN_MSG_LEN];
 220       gint len;
 221
 222       len = set_connect_msg (msg, hostname, port, username, error);
 223
 224       if (len < 0)
 225         goto error;
 226
 227       if (!g_output_stream_write_all (out, msg, len, NULL,
 228                                       cancellable, error))
 229         goto error;
 230     }
 231
 232   /* Read SOCKS4 response */
 233     {
 234       guint8 data[SOCKS4_CONN_REP_LEN];
 235
 236       if (!g_input_stream_read_all (in, data, SOCKS4_CONN_REP_LEN, NULL,
 237                                     cancellable, error))
 238         goto error;
 239
 240       if (!parse_connect_reply (data, error))
 241         goto error;
 242     }
 243
 244   return g_object_ref (io_stream);
 245
 246 error:
 247   return NULL;
 248 }
 249
 250
 251 typedef struct
 252 {
 253   GSimpleAsyncResult *simple;
 254   GIOStream *io_stream;
 255   GProxyAddress *proxy_address;
 256   GCancellable *cancellable;
 257
 258   /* For connecting */
 259   guint8 *buffer;
 260   gssize length;
 261   gssize offset;
 262
 263 } ConnectAsyncData;
 264
 265 static void connect_msg_write_cb      (GObject          *source,
 266                                        GAsyncResult     *result,
 267                                        gpointer          user_data);
 268 static void connect_reply_read_cb     (GObject          *source,
 269                                        GAsyncResult     *result,
 270                                        gpointer          user_data);
 271
 272 static void
 273 free_connect_data (ConnectAsyncData *data)
 274 {
 275   if (data->io_stream)
 276     g_object_unref (data->io_stream);
 277
 278   if (data->proxy_address)
 279     g_object_unref (data->proxy_address);
 280
 281   if (data->cancellable)
 282     g_object_unref (data->cancellable);
 283
 284   g_slice_free (ConnectAsyncData, data);
 285 }
 286
 287 static void
 288 complete_async_from_error (ConnectAsyncData *data, GError *error)
 289 {
 290   GSimpleAsyncResult *simple = data->simple;
 291   g_simple_async_result_set_from_error (data->simple,
 292                                         error);
 293   g_error_free (error);
 294   g_simple_async_result_set_op_res_gpointer (simple, NULL, NULL);
 295   g_simple_async_result_complete (simple);
 296   g_object_unref (simple);
 297 }
 298
 299 static void
 300 do_read (GAsyncReadyCallback callback, ConnectAsyncData *data)
 301 {
 302    GInputStream *in;
 303    in = g_io_stream_get_input_stream (data->io_stream);
 304    g_input_stream_read_async (in,
 305                               data->buffer + data->offset,
 306                               data->length - data->offset,
 307                               G_PRIORITY_DEFAULT, data->cancellable,
 308                               callback, data);
 309 }
 310
 311 static void
 312 do_write (GAsyncReadyCallback callback, ConnectAsyncData *data)
 313 {
 314   GOutputStream *out;
 315   out = g_io_stream_get_output_stream (data->io_stream);
 316   g_output_stream_write_async (out,
 317                                data->buffer + data->offset,
 318                                data->length - data->offset,
 319                                G_PRIORITY_DEFAULT, data->cancellable,
 320                                callback, data);
 321 }
 322
 323
 324
 325 static void
 326 g_socks4a_proxy_connect_async (GProxy               *proxy,
 327                                GIOStream            *io_stream,
 328                                GProxyAddress        *proxy_address,
 329                                GCancellable         *cancellable,
 330                                GAsyncReadyCallback   callback,
 331                                gpointer              user_data)
 332 {
 333   GError *error = NULL;
 334   GSimpleAsyncResult *simple;
 335   ConnectAsyncData *data;
 336   const gchar *hostname;
 337   guint16 port;
 338   const gchar *username;
 339
 340   simple = g_simple_async_result_new (G_OBJECT (proxy),
 341                                       callback, user_data,
 342                                       g_socks4a_proxy_connect_async);
 343
 344   data = g_slice_new0 (ConnectAsyncData);
 345
 346   data->simple = simple;
 347   data->io_stream = g_object_ref (io_stream);
 348
 349   if (cancellable)
 350     data->cancellable = g_object_ref (cancellable);
 351
 352   g_simple_async_result_set_op_res_gpointer (simple, data,
 353                                              (GDestroyNotify) free_connect_data);
 354
 355   hostname = g_proxy_address_get_destination_hostname (proxy_address);
 356   port = g_proxy_address_get_destination_port (proxy_address);
 357   username = g_proxy_address_get_username (proxy_address);
 358
 359   data->buffer = g_malloc0 (SOCKS4_CONN_MSG_LEN);
 360   data->length = set_connect_msg (data->buffer,
 361                                   hostname, port, username,
 362                                   &error);
 363   data->offset = 0;
 364
 365   if (data->length < 0)
 366     {
 367       g_simple_async_result_set_from_error (data->simple,
 368                                             error);
 369       g_error_free (error);
 370       g_simple_async_result_set_op_res_gpointer (simple, NULL, NULL);
 371       g_simple_async_result_complete_in_idle (simple);
 372       g_object_unref (simple);
 373     }
 374   else
 375     {
 376       do_write (connect_msg_write_cb, data);
 377     }
 378 }
 379
 380 static void
 381 connect_msg_write_cb (GObject      *source,
 382                       GAsyncResult *result,
 383                       gpointer      user_data)
 384 {
 385   GError *error = NULL;
 386   ConnectAsyncData *data = user_data;
 387   gssize written;
 388
 389   written = g_output_stream_write_finish (G_OUTPUT_STREAM (source),
 390                                           result, &error);
 391
 392   if (written < 0)
 393     {
 394       complete_async_from_error (data, error);
 395       return;
 396     }
 397
 398   data->offset += written;
 399
 400   if (data->offset == data->length)
 401     {
 402       g_free (data->buffer);
 403
 404       data->buffer = g_malloc0 (SOCKS4_CONN_REP_LEN);
 405       data->length = SOCKS4_CONN_REP_LEN;
 406       data->offset = 0;
 407
 408       do_read (connect_reply_read_cb, data);
 409     }
 410   else
 411     {
 412       do_write (connect_msg_write_cb, data);
 413     }
 414 }
 415
 416 static void
 417 connect_reply_read_cb (GObject       *source,
 418                        GAsyncResult  *result,
 419                        gpointer       user_data)
 420 {
 421   GError *error = NULL;
 422   ConnectAsyncData *data = user_data;
 423   gssize read;
 424
 425   read = g_input_stream_read_finish (G_INPUT_STREAM (source),
 426                                      result, &error);
 427
 428   if (read < 0)
 429     {
 430       complete_async_from_error (data, error);
 431       return;
 432     }
 433
 434   data->offset += read;
 435
 436   if (data->offset == data->length)
 437     {
 438       if (!parse_connect_reply (data->buffer, &error))
 439         {
 440           complete_async_from_error (data, error);
 441         }
 442       else
 443         {
 444           GSimpleAsyncResult *simple = data->simple;
 445           g_simple_async_result_complete (simple);
 446           g_object_unref (simple);
 447         }
 448     }
 449   else
 450     {
 451       do_read (connect_reply_read_cb, data);
 452     }
 453 }
 454
 455 static GIOStream *g_socks4a_proxy_connect_finish (GProxy       *proxy,
 456                                                   GAsyncResult *result,
 457                                                   GError      **error);
 458
 459 static GIOStream *
 460 g_socks4a_proxy_connect_finish (GProxy       *proxy,
 461                                 GAsyncResult *result,
 462                                 GError      **error)
 463 {
 464   GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
 465   ConnectAsyncData *data = g_simple_async_result_get_op_res_gpointer (simple);
 466
 467   if (g_simple_async_result_propagate_error (simple, error))
 468     return NULL;
 469
 470   return g_object_ref (data->io_stream);
 471 }
 472
 473 static gboolean
 474 g_socks4a_proxy_supports_hostname (GProxy *proxy)
 475 {
 476   return G_SOCKS4A_PROXY (proxy)->supports_hostname;
 477 }
 478
 479 static void
 480 g_socks4a_proxy_class_init (GSocks4aProxyClass *class)
 481 {
 482   GObjectClass *object_class;
 483
 484   object_class = (GObjectClass *) class;
 485   object_class->finalize = g_socks4a_proxy_finalize;
 486 }
 487
 488 static void
 489 g_socks4a_proxy_iface_init (GProxyInterface *proxy_iface)
 490 {
 491   proxy_iface->connect  = g_socks4a_proxy_connect;
 492   proxy_iface->connect_async = g_socks4a_proxy_connect_async;
 493   proxy_iface->connect_finish = g_socks4a_proxy_connect_finish;
 494   proxy_iface->supports_hostname = g_socks4a_proxy_supports_hostname;
 495 }