summaryrefslogtreecommitdiff
path: root/daemon/gvfsftpconnection.c
blob: 2db6f51cc9aa260732f33e3fdcdc249e7532a5f3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
/* GIO - GLib Input, Output and Streaming Library
 *
 * Copyright (C) 2009 Benjamin Otte <otte@gnome.org>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General
 * Public License along with this library; if not, write to the
 * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 * Author: Benjamin Otte <otte@gnome.org>
 */

#include <config.h>

#include "gvfsftpconnection.h"

#include <string.h>
#include <glib/gi18n.h>
#include <gio/gnetworking.h>

#include "gvfsbackendftp.h"

/* used for identifying the connection during debugging */
static volatile int debug_id = 0;

struct _GVfsFtpConnection
{
  GSocketClient *       client;                 /* socket client used for opening connections */

  GIOStream *        	commands;               /* ftp command stream */
  GSocketConnection *   connection;             /* original connection */
  GDataInputStream *    commands_in;            /* wrapper around in stream to allow line-wise reading */
  gboolean              waiting_for_reply;           /* TRUE if a command was sent but no reply received yet */

  GSocket *             listen_socket;          /* socket we are listening on for active FTP connections */
  GIOStream *        	data;                   /* ftp data stream or NULL if not in use */

  int                   debug_id;               /* unique id for debugging purposes */
};

static void
enable_keepalive (GSocketConnection *conn)
{
  /* We enable keepalive on the socket, because data connections can be
   * idle for a long time while data is transferred using the data
   * connection. And there are still buggy routers in existance that purge
   * idle connections from time to time.
   * To work around this problem, we set the keep alive flag here. It's the
   * user's responsibility to configure his kernel properly so that the
   * keepalive packets are sent before the buggy router disconnects the
   * TCP connection. If a user asks, a howto is at
   * http://tldp.org/HOWTO/html_single/TCP-Keepalive-HOWTO/
   */
  g_socket_set_keepalive (g_socket_connection_get_socket (conn), TRUE);
}

/* Set TCP_NODELAY on the connection to avoid a bad interaction between Nagle's
 * algorithm and delayed acks when doing a write-write-read. */
static void
enable_nodelay (GSocketConnection *conn)
{
  GError *error = NULL;
  GSocket *socket = g_socket_connection_get_socket (conn);

  if (!g_socket_set_option (socket, IPPROTO_TCP, TCP_NODELAY, TRUE, &error))
    {
      g_warning ("Could not set TCP_NODELAY: %s\n", error->message);
      g_error_free (error);
    }
}

static void
create_input_stream (GVfsFtpConnection *conn)
{
  if (conn->commands_in)
    {
      g_filter_input_stream_set_close_base_stream (G_FILTER_INPUT_STREAM (conn->commands_in), FALSE);
      g_object_unref (conn->commands_in);
    }

  conn->commands_in = G_DATA_INPUT_STREAM (g_data_input_stream_new (g_io_stream_get_input_stream (conn->commands)));
  g_data_input_stream_set_newline_type (conn->commands_in, G_DATA_STREAM_NEWLINE_TYPE_CR_LF);
}

GVfsFtpConnection *
g_vfs_ftp_connection_new (GSocketConnectable *addr,
                          GCancellable *      cancellable,
                          GError **           error)
{
  GVfsFtpConnection *conn;

  g_return_val_if_fail (G_IS_SOCKET_CONNECTABLE (addr), NULL);

  conn = g_slice_new0 (GVfsFtpConnection);
  conn->client = g_socket_client_new ();
  conn->debug_id = g_atomic_int_add (&debug_id, 1);
  conn->commands = G_IO_STREAM (g_socket_client_connect (conn->client,
                                                         addr,
                                                         cancellable,
                                                         error));
  if (conn->commands == NULL)
    {
      g_object_unref (conn->client);
      g_slice_free (GVfsFtpConnection, conn);
      return NULL;
    }

  conn->connection = G_SOCKET_CONNECTION (conn->commands);
  enable_nodelay (conn->connection);
  enable_keepalive (conn->connection);
  create_input_stream (conn);
  /* The first thing that needs to happen is receiving the welcome message */
  conn->waiting_for_reply = TRUE;

  return conn;
}

static void
g_vfs_ftp_connection_stop_listening (GVfsFtpConnection *conn)
{
  if (conn->listen_socket)
    {
      g_object_unref (conn->listen_socket);
      conn->listen_socket = NULL;
    }
}

void
g_vfs_ftp_connection_free (GVfsFtpConnection *conn)
{
  g_return_if_fail (conn != NULL);

  g_vfs_ftp_connection_stop_listening (conn);
  g_vfs_ftp_connection_close_data_connection (conn);

  g_object_unref (conn->commands_in);
  g_object_unref (conn->commands);
  g_object_unref (conn->client);
  g_slice_free (GVfsFtpConnection, conn);
}

gboolean
g_vfs_ftp_connection_send (GVfsFtpConnection *conn,
                           const char *       command,
                           int                len,
                           GCancellable *     cancellable,
                           GError **          error)
{
  g_return_val_if_fail (conn != NULL, FALSE);
  g_return_val_if_fail (!conn->waiting_for_reply, FALSE);
  g_return_val_if_fail (command != NULL, FALSE);
  g_return_val_if_fail (len >= -1, FALSE);
  if (len < 0)
    len = strlen (command);
  g_return_val_if_fail (command[len-2] == '\r' && command[len-1] == '\n', FALSE);

  if (g_str_has_prefix (command, "PASS"))
    g_debug ("--%2d ->  PASS ***\r\n", conn->debug_id);
  else
    g_debug ("--%2d ->  %s", conn->debug_id, command);

  conn->waiting_for_reply = TRUE;
  return g_output_stream_write_all (g_io_stream_get_output_stream (conn->commands),
                                    command,
                                    len,
                                    NULL,
                                    cancellable,
                                    error);
}

guint
g_vfs_ftp_connection_receive (GVfsFtpConnection *conn,
                              char ***           reply,
                              GCancellable *     cancellable,
                              GError **          error)
{
  char *line;
  enum {
    FIRST_LINE,
    MULTILINE,
    DONE
  } reply_state = FIRST_LINE;
  GPtrArray *lines;
  guint response = 0;

  g_return_val_if_fail (conn != NULL, 0);
  g_return_val_if_fail (conn->waiting_for_reply, 0);

  if (reply)
    lines = g_ptr_array_new_with_free_func (g_free);
  else
    lines = NULL;

  while (reply_state != DONE)
    {
      line = g_data_input_stream_read_line (conn->commands_in, NULL, cancellable, error);
      if (line == NULL)
        {
          if (error && *error == NULL)
            g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_CLOSED,
                                 _("Unexpected end of stream"));

          goto fail;
        }

      g_debug ("<-%2d --  %s\r\n", conn->debug_id, line);
      if (lines)
        g_ptr_array_add (lines, line);

      if (reply_state == FIRST_LINE)
        {
          if (line[0] <= '0' || line[0] > '5' ||
              line[1] < '0' || line[1] > '9' ||
              line[2] < '0' || line[2] > '9')
            {
              g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_FAILED,
        			   _("Invalid reply"));
              goto fail;
            }
          response = 100 * (line[0] - '0') +
        	      10 * (line[1] - '0') +
        	 	   (line[2] - '0');
          if (line[3] == ' ')
            reply_state = DONE;
          else if (line[3] == '-')
            reply_state = MULTILINE;
          else
            {
              g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_FAILED,
        			   _("Invalid reply"));
              goto fail;
            }
        }
      else
        {
          if (line[0] - '0' == response / 100 &&
              line[1] - '0' == (response / 10) % 10 &&
              line[2] - '0' == response % 10 &&
              line[3] == ' ')
            reply_state = DONE;
        }
      if (!lines)
        g_free (line);
    }

  if (lines)
    {
      g_ptr_array_add (lines, NULL);
      *reply = (char **) g_ptr_array_free (lines, FALSE);
    }

  /* 1xx commands are intermediate commands and require a further
   * message from the server to complete
   */
  if (response >= 200)
    conn->waiting_for_reply = FALSE;

  return response;

fail:
  if (lines)
    g_ptr_array_free (lines, TRUE);
  else
    g_free (line);
  return 0;
}

GSocketAddress *
g_vfs_ftp_connection_get_address (GVfsFtpConnection *conn, GError **error)
{
  g_return_val_if_fail (conn != NULL, NULL);

  return g_socket_connection_get_remote_address (conn->connection, error);
}

/**
 * g_vfs_ftp_connection_data_connection_enable_tls:
 * @conn: a connection with an active control connection
 * @server_identity: address of the server used to verify the certificate
 * @cb: callback called if there's a verification error
 * @user_data: user data passed to @cb
 * @cancellable: cancellable to interrupt wait
 * @error: %NULL or location to take a potential error
 *
 * Tries to enable TLS on the given @connection's data connection. If setting
 * up TLS fails, %FALSE will be returned and @error will be set.
 *
 * Returns: %TRUE on success, %FALSE otherwise.
 **/
gboolean
g_vfs_ftp_connection_data_connection_enable_tls (GVfsFtpConnection  *conn,
                                                 GSocketConnectable *server_identity,
                                                 CertificateCallback cb,
                                                 gpointer            user_data,
                                                 GCancellable *      cancellable,
                                                 GError **           error)
{
  GIOStream *secure;

  g_return_val_if_fail (conn != NULL, FALSE);
  g_return_val_if_fail (conn->commands != NULL, FALSE);

  secure = g_tls_client_connection_new (conn->data,
                                        server_identity,
                                        error);
  if (secure == NULL)
    return FALSE;

  g_object_unref (conn->data);
  conn->data = secure;

  g_tls_client_connection_copy_session_state (G_TLS_CLIENT_CONNECTION (secure),
                                              G_TLS_CLIENT_CONNECTION (conn->commands));

  g_signal_connect (secure, "accept-certificate", G_CALLBACK (cb), user_data);

  if (!g_tls_connection_handshake (G_TLS_CONNECTION (secure),
                                   cancellable,
                                   error))
    {
      /* Close here to be sure it won't get used anymore */
      g_io_stream_close (secure, cancellable, NULL);
      return FALSE;
    }

  return TRUE;
}

gboolean
g_vfs_ftp_connection_open_data_connection (GVfsFtpConnection *conn,
                                           GSocketAddress *   addr,
                                           GCancellable *     cancellable,
                                           GError **          error)
{
  g_return_val_if_fail (conn != NULL, FALSE);
  g_return_val_if_fail (conn->data == NULL, FALSE);

  g_vfs_ftp_connection_stop_listening (conn);

  conn->data = G_IO_STREAM (g_socket_client_connect (conn->client,
                                                     G_SOCKET_CONNECTABLE (addr),
                                                     cancellable,
                                                     error));
  if (conn->data)
    enable_nodelay (G_SOCKET_CONNECTION (conn->data));

  return conn->data != NULL;
}

/**
 * g_vfs_ftp_connection_listen_data_connection:
 * @conn: a connection
 * @error: %NULL or location to take potential errors
 *
 * Initiates a listening socket that the FTP server can connect to. To accept 
 * connections and initialize data transfers, use 
 * g_vfs_ftp_connection_accept_data_connection().
 * This function supports what is known as "active FTP", while
 * g_vfs_ftp_connection_open_data_connection() is to be used for "passive FTP".
 *
 * Returns: the actual address the socket is listening on or %NULL on error
 **/
GSocketAddress *
g_vfs_ftp_connection_listen_data_connection (GVfsFtpConnection *conn,
                                             GError **          error)
{
  GSocketAddress *local, *addr;

  g_return_val_if_fail (conn != NULL, NULL);
  g_return_val_if_fail (conn->data == NULL, NULL);

  g_vfs_ftp_connection_stop_listening (conn);

  local = g_socket_connection_get_local_address (conn->connection, error);
  if (local == NULL)
    return NULL;

  conn->listen_socket = g_socket_new (g_socket_address_get_family (local),
                                      G_SOCKET_TYPE_STREAM,
                                      G_SOCKET_PROTOCOL_TCP,
                                      error);
  if (conn->listen_socket == NULL)
    return NULL;

  g_assert (G_IS_INET_SOCKET_ADDRESS (local));
  addr = g_inet_socket_address_new (g_inet_socket_address_get_address (G_INET_SOCKET_ADDRESS (local)), 0);
  g_object_unref (local);

  if (!g_socket_bind (conn->listen_socket, addr, TRUE, error) ||
      !g_socket_listen (conn->listen_socket, error) ||
      !(local = g_socket_get_local_address (conn->listen_socket, error)))
    {
      g_object_unref (addr);
      g_vfs_ftp_connection_stop_listening (conn);
      return NULL;
    }

  g_object_unref (addr);
  return local;
}

static void
cancel_timer_cb (GCancellable *orig, GCancellable *to_cancel)
{
  g_cancellable_cancel (to_cancel);
}

static gboolean
cancel_cancellable (gpointer cancellable)
{
  g_cancellable_cancel (cancellable);
  return FALSE;
}

/**
 * g_vfs_ftp_connection_accept_data_connection:
 * @conn: a listening connection
 * @cancellable: cancellable to interrupt wait
 * @error: %NULL or location to take a potential error
 *
 * Opens a data connection for @conn by accepting an incoming connection on the
 * address it is listening on via g_vfs_ftp_connection_listen_data_connection(),
 * which must have been called prior to this function.
 * If this function succeeds, a data connection will have been opened, and calls
 * to g_vfs_ftp_connection_get_data_stream() will work.
 *
 * Returns: %TRUE if a connection was successfully acquired
 **/
gboolean
g_vfs_ftp_connection_accept_data_connection (GVfsFtpConnection *conn,
                                             GCancellable *     cancellable,
                                             GError **          error)
{
  GSocket *accepted;
  GCancellable *timer;
  gulong cancel_cb_id;
  GIOCondition condition;

  g_return_val_if_fail (conn != NULL, FALSE);
  g_return_val_if_fail (conn->data == NULL, FALSE);
  g_return_val_if_fail (G_IS_SOCKET (conn->listen_socket), FALSE);

  timer = g_cancellable_new ();
  cancel_cb_id = g_cancellable_connect (cancellable, 
                                        G_CALLBACK (cancel_timer_cb),
                                        timer,
                                        NULL);
  g_object_ref (timer);
  g_timeout_add_seconds_full (G_PRIORITY_DEFAULT,
                              G_VFS_FTP_TIMEOUT_IN_SECONDS,
                              cancel_cancellable,
                              timer,
                              g_object_unref);

  condition = g_socket_condition_wait (conn->listen_socket, G_IO_IN, timer, error);

  g_cancellable_disconnect (cancellable, cancel_cb_id);
  g_object_unref (timer);

  if ((condition & G_IO_IN) == 0)
    {
      if (g_cancellable_is_cancelled (timer) &&
          !g_cancellable_is_cancelled (cancellable))
        {
          g_clear_error (error);
          g_set_error_literal (error, 
                               G_IO_ERROR, G_IO_ERROR_HOST_NOT_FOUND,
                               _("Failed to create active FTP connection. "
                                 "Maybe your router does not support this?"));
        }
      else if (error && *error == NULL)
        {
          g_set_error_literal (error, 
                               G_IO_ERROR, G_IO_ERROR_HOST_NOT_FOUND,
                               _("Failed to create active FTP connection."));
        }
      return FALSE;
    }

  accepted = g_socket_accept (conn->listen_socket, cancellable, error);
  if (accepted == NULL)
    return FALSE;

  conn->data = G_IO_STREAM (g_socket_connection_factory_create_connection (accepted));
  g_object_unref (accepted);
  enable_nodelay (G_SOCKET_CONNECTION (conn->data));
  return TRUE;
}

void
g_vfs_ftp_connection_close_data_connection (GVfsFtpConnection *conn)
{
  g_return_if_fail (conn != NULL);

  if (conn->data == NULL)
    return;

  g_object_unref (conn->data);
  conn->data = NULL;
}

/**
 * g_vfs_ftp_connection_get_debug_id:
 * @conn: the connection
 *
 * Gets an ID that uniquely identifies this connection. Intended for use in 
 * debug print statements.
 *
 * Returns: the ID to use for referring to this connection in debug messages
 **/
guint
g_vfs_ftp_connection_get_debug_id (GVfsFtpConnection *conn)
{
  g_return_val_if_fail (conn != NULL, 0);

  return conn->debug_id;
}

/**
 * g_vfs_ftp_connection_get_data_stream:
 * @conn: a connection
 *
 * Gets the data stream in use by @conn. It is an error to call this function
 * when no data stream exists. Be sure to check the return value of
 * g_vfs_ftp_connection_open_data_connection().
 *
 * Returns: the data stream of @conn
 **/
GIOStream *
g_vfs_ftp_connection_get_data_stream (GVfsFtpConnection *conn)
{
  g_return_val_if_fail (conn != NULL, NULL);
  g_return_val_if_fail (conn->data != NULL, NULL);

  return conn->data;
}

/**
 * g_vfs_ftp_connection_is_usable:
 * @conn: a connection
 *
 * Checks if this connection can be used to send new commands. For
 * example, if the connection is in the process of a command sequence or
 * if the connection was closed, this is not possible and this function 
 * will return %FALSE.
 *
 * Returns: %TRUE if the connection is still usable
 **/
gboolean
g_vfs_ftp_connection_is_usable (GVfsFtpConnection *conn)
{
  GIOCondition cond;

  g_return_val_if_fail (conn != NULL, FALSE);

  if (conn->waiting_for_reply)
    return FALSE;

  cond = G_IO_ERR | G_IO_HUP | G_IO_IN;
  cond = g_socket_condition_check (g_socket_connection_get_socket (conn->connection), cond);
  if (cond)
    {
      g_debug ("##%2d ##  connection unusuable: %s%s%s\r\n", conn->debug_id,
                                                             cond & G_IO_IN ? "IN " : "",
                                                             cond & G_IO_HUP ? "HUP " : "",
                                                             cond & G_IO_ERR ? "ERR " : "");
      return FALSE;
    }

  return TRUE;
}

/**
 * g_vfs_ftp_connection_enable_tls:
 * @conn: a connection without an active data connection
 * @server_identity: address of the server used to verify the certificate
 * @cb: callback called if there's a verification error
 * @user_data: user data passed to @cb
 * @cancellable: cancellable to interrupt wait
 * @error: %NULL or location to take a potential error
 *
 * Tries to enable TLS on the given @connection. If setting up TLS fails,
 * %FALSE will be returned and @error will be set. When this function fails,
 * you need to check if the connection is still usable. It might have been
 * closed.
 *
 * Returns: %TRUE on success, %FALSE otherwise.
 **/
gboolean
g_vfs_ftp_connection_enable_tls (GVfsFtpConnection * conn,
                                 GSocketConnectable *server_identity,
                                 CertificateCallback cb,
                                 gpointer            user_data,
                                 GCancellable *      cancellable,
                                 GError **           error)
{
  GIOStream *secure;

  g_return_val_if_fail (conn != NULL, FALSE);
  g_return_val_if_fail (conn->data == NULL, FALSE);
  g_return_val_if_fail (!conn->waiting_for_reply, FALSE);
  g_return_val_if_fail (g_buffered_input_stream_get_available (G_BUFFERED_INPUT_STREAM (conn->commands_in)) == 0, FALSE);

  secure = g_tls_client_connection_new (conn->commands,
                                        server_identity,
                                        error);
  if (secure == NULL)
    return FALSE;

  g_object_unref (conn->commands);
  conn->commands = secure;
  create_input_stream (conn);

  g_signal_connect (secure, "accept-certificate", G_CALLBACK (cb), user_data);

  if (!g_tls_connection_handshake (G_TLS_CONNECTION (secure),
                                   cancellable,
                                   error))
    {
      /* Close here to be sure it won't get used anymore */
      g_io_stream_close (secure, cancellable, NULL);
      return FALSE;
    }

  return TRUE;
}