1 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
2 /* dbus-transport-socket.c Socket subclasses of DBusTransport
3 *
4 * Copyright (C) 2002, 2003, 2004, 2006 Red Hat Inc.
5 *
6 * Licensed under the Academic Free License version 2.1
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 *
22 */
23
24 #include <config.h>
25 #include "dbus-internals.h"
26 #include "dbus-connection-internal.h"
27 #include "dbus-nonce.h"
28 #include "dbus-transport-socket.h"
29 #include "dbus-transport-protected.h"
30 #include "dbus-watch.h"
31 #include "dbus-credentials.h"
32
33 /**
34 * @defgroup DBusTransportSocket DBusTransport implementations for sockets
35 * @ingroup DBusInternals
36 * @brief Implementation details of DBusTransport on sockets
37 *
38 * @{
39 */
40
41 /**
42 * Opaque object representing a socket file descriptor transport.
43 */
44 typedef struct DBusTransportSocket DBusTransportSocket;
45
46 /**
47 * Implementation details of DBusTransportSocket. All members are private.
48 */
49 struct DBusTransportSocket
50 {
51 DBusTransport base; /**< Parent instance */
52 DBusSocket fd; /**< File descriptor. */
53 DBusWatch *read_watch; /**< Watch for readability. */
54 DBusWatch *write_watch; /**< Watch for writability. */
55
56 int max_bytes_read_per_iteration; /**< To avoid blocking too long. */
57 int max_bytes_written_per_iteration; /**< To avoid blocking too long. */
58
59 int message_bytes_written; /**< Number of bytes of current
60 * outgoing message that have
61 * been written.
62 */
63 DBusString encoded_outgoing; /**< Encoded version of current
64 * outgoing message.
65 */
66 DBusString encoded_incoming; /**< Encoded version of current
67 * incoming data.
68 */
69 };
70
71 static void
free_watches(DBusTransport * transport)72 free_watches (DBusTransport *transport)
73 {
74 DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
75
76 _dbus_verbose ("start\n");
77
78 if (socket_transport->read_watch)
79 {
80 if (transport->connection)
81 _dbus_connection_remove_watch_unlocked (transport->connection,
82 socket_transport->read_watch);
83 _dbus_watch_invalidate (socket_transport->read_watch);
84 _dbus_watch_unref (socket_transport->read_watch);
85 socket_transport->read_watch = NULL;
86 }
87
88 if (socket_transport->write_watch)
89 {
90 if (transport->connection)
91 _dbus_connection_remove_watch_unlocked (transport->connection,
92 socket_transport->write_watch);
93 _dbus_watch_invalidate (socket_transport->write_watch);
94 _dbus_watch_unref (socket_transport->write_watch);
95 socket_transport->write_watch = NULL;
96 }
97
98 _dbus_verbose ("end\n");
99 }
100
101 static void
socket_finalize(DBusTransport * transport)102 socket_finalize (DBusTransport *transport)
103 {
104 DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
105
106 _dbus_verbose ("\n");
107
108 free_watches (transport);
109
110 _dbus_string_free (&socket_transport->encoded_outgoing);
111 _dbus_string_free (&socket_transport->encoded_incoming);
112
113 _dbus_transport_finalize_base (transport);
114
115 _dbus_assert (socket_transport->read_watch == NULL);
116 _dbus_assert (socket_transport->write_watch == NULL);
117
118 dbus_free (transport);
119 }
120
121 static void
check_write_watch(DBusTransport * transport)122 check_write_watch (DBusTransport *transport)
123 {
124 DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
125 dbus_bool_t needed;
126
127 if (transport->connection == NULL)
128 return;
129
130 if (transport->disconnected)
131 {
132 _dbus_assert (socket_transport->write_watch == NULL);
133 return;
134 }
135
136 _dbus_transport_ref (transport);
137
138 if (_dbus_transport_try_to_authenticate (transport))
139 needed = _dbus_connection_has_messages_to_send_unlocked (transport->connection);
140 else
141 {
142 if (transport->send_credentials_pending)
143 needed = TRUE;
144 else
145 {
146 DBusAuthState auth_state;
147
148 auth_state = _dbus_auth_do_work (transport->auth);
149
150 /* If we need memory we install the write watch just in case,
151 * if there's no need for it, it will get de-installed
152 * next time we try reading.
153 */
154 if (auth_state == DBUS_AUTH_STATE_HAVE_BYTES_TO_SEND ||
155 auth_state == DBUS_AUTH_STATE_WAITING_FOR_MEMORY)
156 needed = TRUE;
157 else
158 needed = FALSE;
159 }
160 }
161
162 _dbus_verbose ("check_write_watch(): needed = %d on connection %p watch %p fd = %" DBUS_SOCKET_FORMAT " outgoing messages exist %d\n",
163 needed, transport->connection, socket_transport->write_watch,
164 _dbus_socket_printable (socket_transport->fd),
165 _dbus_connection_has_messages_to_send_unlocked (transport->connection));
166
167 _dbus_connection_toggle_watch_unlocked (transport->connection,
168 socket_transport->write_watch,
169 needed);
170
171 _dbus_transport_unref (transport);
172 }
173
174 static void
check_read_watch(DBusTransport * transport)175 check_read_watch (DBusTransport *transport)
176 {
177 DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
178 dbus_bool_t need_read_watch;
179
180 _dbus_verbose ("fd = %" DBUS_SOCKET_FORMAT "\n",
181 _dbus_socket_printable (socket_transport->fd));
182
183 if (transport->connection == NULL)
184 return;
185
186 if (transport->disconnected)
187 {
188 _dbus_assert (socket_transport->read_watch == NULL);
189 return;
190 }
191
192 _dbus_transport_ref (transport);
193
194 if (_dbus_transport_try_to_authenticate (transport))
195 need_read_watch =
196 (_dbus_counter_get_size_value (transport->live_messages) < transport->max_live_messages_size) &&
197 (_dbus_counter_get_unix_fd_value (transport->live_messages) < transport->max_live_messages_unix_fds);
198 else
199 {
200 if (transport->receive_credentials_pending)
201 need_read_watch = TRUE;
202 else
203 {
204 /* The reason to disable need_read_watch when not WAITING_FOR_INPUT
205 * is to avoid spinning on the file descriptor when we're waiting
206 * to write or for some other part of the auth process
207 */
208 DBusAuthState auth_state;
209
210 auth_state = _dbus_auth_do_work (transport->auth);
211
212 /* If we need memory we install the read watch just in case,
213 * if there's no need for it, it will get de-installed
214 * next time we try reading. If we're authenticated we
215 * install it since we normally have it installed while
216 * authenticated.
217 */
218 if (auth_state == DBUS_AUTH_STATE_WAITING_FOR_INPUT ||
219 auth_state == DBUS_AUTH_STATE_WAITING_FOR_MEMORY ||
220 auth_state == DBUS_AUTH_STATE_AUTHENTICATED)
221 need_read_watch = TRUE;
222 else
223 need_read_watch = FALSE;
224 }
225 }
226
227 _dbus_verbose (" setting read watch enabled = %d\n", need_read_watch);
228 _dbus_connection_toggle_watch_unlocked (transport->connection,
229 socket_transport->read_watch,
230 need_read_watch);
231
232 _dbus_transport_unref (transport);
233 }
234
235 static void
do_io_error(DBusTransport * transport)236 do_io_error (DBusTransport *transport)
237 {
238 _dbus_transport_ref (transport);
239 _dbus_transport_disconnect (transport);
240 _dbus_transport_unref (transport);
241 }
242
243 /* return value is whether we successfully read any new data. */
244 static dbus_bool_t
read_data_into_auth(DBusTransport * transport,dbus_bool_t * oom)245 read_data_into_auth (DBusTransport *transport,
246 dbus_bool_t *oom)
247 {
248 DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
249 DBusString *buffer;
250 int bytes_read;
251 int saved_errno;
252
253 *oom = FALSE;
254
255 _dbus_auth_get_buffer (transport->auth, &buffer);
256
257 bytes_read = _dbus_read_socket (socket_transport->fd,
258 buffer, socket_transport->max_bytes_read_per_iteration);
259 saved_errno = _dbus_save_socket_errno ();
260
261 _dbus_auth_return_buffer (transport->auth, buffer);
262
263 if (bytes_read > 0)
264 {
265 _dbus_verbose (" read %d bytes in auth phase\n", bytes_read);
266
267 return TRUE;
268 }
269 else if (bytes_read < 0)
270 {
271 /* EINTR already handled for us */
272
273 if (_dbus_get_is_errno_enomem (saved_errno))
274 {
275 *oom = TRUE;
276 }
277 else if (_dbus_get_is_errno_eagain_or_ewouldblock (saved_errno))
278 ; /* do nothing, just return FALSE below */
279 else
280 {
281 _dbus_verbose ("Error reading from remote app: %s\n",
282 _dbus_strerror (saved_errno));
283 do_io_error (transport);
284 }
285
286 return FALSE;
287 }
288 else
289 {
290 _dbus_assert (bytes_read == 0);
291
292 _dbus_verbose ("Disconnected from remote app\n");
293 do_io_error (transport);
294
295 return FALSE;
296 }
297 }
298
299 /* Return value is whether we successfully wrote any bytes */
300 static dbus_bool_t
write_data_from_auth(DBusTransport * transport)301 write_data_from_auth (DBusTransport *transport)
302 {
303 DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
304 int bytes_written;
305 int saved_errno;
306 const DBusString *buffer;
307
308 if (!_dbus_auth_get_bytes_to_send (transport->auth,
309 &buffer))
310 return FALSE;
311
312 bytes_written = _dbus_write_socket (socket_transport->fd,
313 buffer,
314 0, _dbus_string_get_length (buffer));
315 saved_errno = _dbus_save_socket_errno ();
316
317 if (bytes_written > 0)
318 {
319 _dbus_auth_bytes_sent (transport->auth, bytes_written);
320 return TRUE;
321 }
322 else if (bytes_written < 0)
323 {
324 /* EINTR already handled for us */
325
326 if (_dbus_get_is_errno_eagain_or_ewouldblock (saved_errno))
327 ;
328 else
329 {
330 _dbus_verbose ("Error writing to remote app: %s\n",
331 _dbus_strerror (saved_errno));
332 do_io_error (transport);
333 }
334 }
335
336 return FALSE;
337 }
338
339 /* FALSE on OOM */
340 static dbus_bool_t
exchange_credentials(DBusTransport * transport,dbus_bool_t do_reading,dbus_bool_t do_writing)341 exchange_credentials (DBusTransport *transport,
342 dbus_bool_t do_reading,
343 dbus_bool_t do_writing)
344 {
345 DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
346 DBusError error = DBUS_ERROR_INIT;
347
348 _dbus_verbose ("exchange_credentials: do_reading = %d, do_writing = %d\n",
349 do_reading, do_writing);
350
351 if (do_writing && transport->send_credentials_pending)
352 {
353 if (_dbus_send_credentials_socket (socket_transport->fd,
354 &error))
355 {
356 transport->send_credentials_pending = FALSE;
357 }
358 else
359 {
360 _dbus_verbose ("Failed to write credentials: %s\n", error.message);
361 dbus_error_free (&error);
362 do_io_error (transport);
363 }
364 }
365
366 if (do_reading && transport->receive_credentials_pending)
367 {
368 /* FIXME this can fail due to IO error _or_ OOM, broken
369 * (somewhat tricky to fix since the OOM error can be set after
370 * we already read the credentials byte, so basically we need to
371 * separate reading the byte and storing it in the
372 * transport->credentials). Does not really matter for now
373 * because storing in credentials never actually fails on unix.
374 */
375 if (_dbus_read_credentials_socket (socket_transport->fd,
376 transport->credentials,
377 &error))
378 {
379 transport->receive_credentials_pending = FALSE;
380 }
381 else
382 {
383 _dbus_verbose ("Failed to read credentials %s\n", error.message);
384 dbus_error_free (&error);
385 do_io_error (transport);
386 }
387 }
388
389 if (!(transport->send_credentials_pending ||
390 transport->receive_credentials_pending))
391 {
392 if (!_dbus_auth_set_credentials (transport->auth,
393 transport->credentials))
394 return FALSE;
395 }
396
397 return TRUE;
398 }
399
400 static dbus_bool_t
do_authentication(DBusTransport * transport,dbus_bool_t do_reading,dbus_bool_t do_writing,dbus_bool_t * auth_completed)401 do_authentication (DBusTransport *transport,
402 dbus_bool_t do_reading,
403 dbus_bool_t do_writing,
404 dbus_bool_t *auth_completed)
405 {
406 dbus_bool_t oom;
407 dbus_bool_t orig_auth_state;
408
409 oom = FALSE;
410
411 orig_auth_state = _dbus_transport_try_to_authenticate (transport);
412
413 /* This is essential to avoid the check_write_watch() at the end,
414 * we don't want to add a write watch in do_iteration before
415 * we try writing and get EAGAIN
416 */
417 if (orig_auth_state)
418 {
419 if (auth_completed)
420 *auth_completed = FALSE;
421 return TRUE;
422 }
423
424 _dbus_transport_ref (transport);
425
426 while (!_dbus_transport_try_to_authenticate (transport) &&
427 _dbus_transport_get_is_connected (transport))
428 {
429 if (!exchange_credentials (transport, do_reading, do_writing))
430 {
431 /* OOM */
432 oom = TRUE;
433 goto out;
434 }
435
436 if (transport->send_credentials_pending ||
437 transport->receive_credentials_pending)
438 {
439 _dbus_verbose ("send_credentials_pending = %d receive_credentials_pending = %d\n",
440 transport->send_credentials_pending,
441 transport->receive_credentials_pending);
442 goto out;
443 }
444
445 #define TRANSPORT_SIDE(t) ((t)->is_server ? "server" : "client")
446 switch (_dbus_auth_do_work (transport->auth))
447 {
448 case DBUS_AUTH_STATE_WAITING_FOR_INPUT:
449 _dbus_verbose (" %s auth state: waiting for input\n",
450 TRANSPORT_SIDE (transport));
451 if (!do_reading || !read_data_into_auth (transport, &oom))
452 goto out;
453 break;
454
455 case DBUS_AUTH_STATE_WAITING_FOR_MEMORY:
456 _dbus_verbose (" %s auth state: waiting for memory\n",
457 TRANSPORT_SIDE (transport));
458 oom = TRUE;
459 goto out;
460 break;
461
462 case DBUS_AUTH_STATE_HAVE_BYTES_TO_SEND:
463 _dbus_verbose (" %s auth state: bytes to send\n",
464 TRANSPORT_SIDE (transport));
465 if (!do_writing || !write_data_from_auth (transport))
466 goto out;
467 break;
468
469 case DBUS_AUTH_STATE_NEED_DISCONNECT:
470 _dbus_verbose (" %s auth state: need to disconnect\n",
471 TRANSPORT_SIDE (transport));
472 do_io_error (transport);
473 break;
474
475 case DBUS_AUTH_STATE_AUTHENTICATED:
476 _dbus_verbose (" %s auth state: authenticated\n",
477 TRANSPORT_SIDE (transport));
478 break;
479
480 case DBUS_AUTH_STATE_INVALID:
481 /* fall through */
482 default:
483 _dbus_assert_not_reached ("invalid auth state");
484 }
485 }
486
487 out:
488 if (auth_completed)
489 *auth_completed = (orig_auth_state != _dbus_transport_try_to_authenticate (transport));
490
491 check_read_watch (transport);
492 check_write_watch (transport);
493 _dbus_transport_unref (transport);
494
495 if (oom)
496 return FALSE;
497 else
498 return TRUE;
499 }
500
501 /* returns false on oom */
502 static dbus_bool_t
do_writing(DBusTransport * transport)503 do_writing (DBusTransport *transport)
504 {
505 int total;
506 DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
507 dbus_bool_t oom;
508
509 /* No messages without authentication! */
510 if (!_dbus_transport_try_to_authenticate (transport))
511 {
512 _dbus_verbose ("Not authenticated, not writing anything\n");
513 return TRUE;
514 }
515
516 if (transport->disconnected)
517 {
518 _dbus_verbose ("Not connected, not writing anything\n");
519 return TRUE;
520 }
521
522 #if 1
523 _dbus_verbose ("do_writing(), have_messages = %d, fd = %" DBUS_SOCKET_FORMAT "\n",
524 _dbus_connection_has_messages_to_send_unlocked (transport->connection),
525 _dbus_socket_printable (socket_transport->fd));
526 #endif
527
528 oom = FALSE;
529 total = 0;
530
531 while (!transport->disconnected &&
532 _dbus_connection_has_messages_to_send_unlocked (transport->connection))
533 {
534 int bytes_written;
535 DBusMessage *message;
536 const DBusString *header;
537 const DBusString *body;
538 int header_len, body_len;
539 int total_bytes_to_write;
540 int saved_errno;
541
542 if (total > socket_transport->max_bytes_written_per_iteration)
543 {
544 _dbus_verbose ("%d bytes exceeds %d bytes written per iteration, returning\n",
545 total, socket_transport->max_bytes_written_per_iteration);
546 goto out;
547 }
548
549 message = _dbus_connection_get_message_to_send (transport->connection);
550 _dbus_assert (message != NULL);
551 dbus_message_lock (message);
552
553 #if 0
554 _dbus_verbose ("writing message %p\n", message);
555 #endif
556
557 _dbus_message_get_network_data (message,
558 &header, &body);
559
560 header_len = _dbus_string_get_length (header);
561 body_len = _dbus_string_get_length (body);
562
563 if (_dbus_auth_needs_encoding (transport->auth))
564 {
565 /* Does fd passing even make sense with encoded data? */
566 _dbus_assert(!DBUS_TRANSPORT_CAN_SEND_UNIX_FD(transport));
567
568 if (_dbus_string_get_length (&socket_transport->encoded_outgoing) == 0)
569 {
570 if (!_dbus_auth_encode_data (transport->auth,
571 header, &socket_transport->encoded_outgoing))
572 {
573 oom = TRUE;
574 goto out;
575 }
576
577 if (!_dbus_auth_encode_data (transport->auth,
578 body, &socket_transport->encoded_outgoing))
579 {
580 _dbus_string_set_length (&socket_transport->encoded_outgoing, 0);
581 oom = TRUE;
582 goto out;
583 }
584 }
585
586 total_bytes_to_write = _dbus_string_get_length (&socket_transport->encoded_outgoing);
587
588 #if 0
589 _dbus_verbose ("encoded message is %d bytes\n",
590 total_bytes_to_write);
591 #endif
592
593 bytes_written =
594 _dbus_write_socket (socket_transport->fd,
595 &socket_transport->encoded_outgoing,
596 socket_transport->message_bytes_written,
597 total_bytes_to_write - socket_transport->message_bytes_written);
598 saved_errno = _dbus_save_socket_errno ();
599 }
600 else
601 {
602 total_bytes_to_write = header_len + body_len;
603
604 #if 0
605 _dbus_verbose ("message is %d bytes\n",
606 total_bytes_to_write);
607 #endif
608
609 #ifdef HAVE_UNIX_FD_PASSING
610 if (socket_transport->message_bytes_written <= 0 && DBUS_TRANSPORT_CAN_SEND_UNIX_FD(transport))
611 {
612 /* Send the fds along with the first byte of the message */
613 const int *unix_fds;
614 unsigned n;
615
616 _dbus_message_get_unix_fds(message, &unix_fds, &n);
617
618 bytes_written =
619 _dbus_write_socket_with_unix_fds_two (socket_transport->fd,
620 header,
621 socket_transport->message_bytes_written,
622 header_len - socket_transport->message_bytes_written,
623 body,
624 0, body_len,
625 unix_fds,
626 n);
627 saved_errno = _dbus_save_socket_errno ();
628
629 if (bytes_written > 0 && n > 0)
630 _dbus_verbose("Wrote %i unix fds\n", n);
631 }
632 else
633 #endif
634 {
635 if (socket_transport->message_bytes_written < header_len)
636 {
637 bytes_written =
638 _dbus_write_socket_two (socket_transport->fd,
639 header,
640 socket_transport->message_bytes_written,
641 header_len - socket_transport->message_bytes_written,
642 body,
643 0, body_len);
644 }
645 else
646 {
647 bytes_written =
648 _dbus_write_socket (socket_transport->fd,
649 body,
650 (socket_transport->message_bytes_written - header_len),
651 body_len -
652 (socket_transport->message_bytes_written - header_len));
653 }
654
655 saved_errno = _dbus_save_socket_errno ();
656 }
657 }
658
659 if (bytes_written < 0)
660 {
661 /* EINTR already handled for us */
662
663 /* If the other end closed the socket with close() or shutdown(), we
664 * receive EPIPE here but we must not close the socket yet: there
665 * might still be some data to read. See:
666 * http://lists.freedesktop.org/archives/dbus/2008-March/009526.html
667 */
668
669 if (_dbus_get_is_errno_eagain_or_ewouldblock (saved_errno) || _dbus_get_is_errno_epipe (saved_errno))
670 goto out;
671
672 /* Since Linux commit 25888e (from 2.6.37-rc4, Nov 2010), sendmsg()
673 * on Unix sockets returns -1 errno=ETOOMANYREFS when the passfd
674 * mechanism (SCM_RIGHTS) is used recursively with a recursion level
675 * of maximum 4. The kernel does not have an API to check whether
676 * the passed fds can be forwarded and it can change asynchronously.
677 * See:
678 * https://bugs.freedesktop.org/show_bug.cgi?id=80163
679 */
680
681 else if (_dbus_get_is_errno_etoomanyrefs (saved_errno))
682 {
683 /* We only send fds in the first byte of the message.
684 * ETOOMANYREFS cannot happen after.
685 */
686 _dbus_assert (socket_transport->message_bytes_written == 0);
687
688 _dbus_verbose (" discard message of %d bytes due to ETOOMANYREFS\n",
689 total_bytes_to_write);
690
691 socket_transport->message_bytes_written = 0;
692 _dbus_string_set_length (&socket_transport->encoded_outgoing, 0);
693 _dbus_string_compact (&socket_transport->encoded_outgoing, 2048);
694
695 /* The message was not actually sent but it needs to be removed
696 * from the outgoing queue
697 */
698 _dbus_connection_message_sent_unlocked (transport->connection,
699 message);
700 }
701 else
702 {
703 _dbus_verbose ("Error writing to remote app: %s\n",
704 _dbus_strerror (saved_errno));
705 do_io_error (transport);
706 goto out;
707 }
708 }
709 else
710 {
711 _dbus_verbose (" wrote %d bytes of %d\n", bytes_written,
712 total_bytes_to_write);
713
714 total += bytes_written;
715 socket_transport->message_bytes_written += bytes_written;
716
717 _dbus_assert (socket_transport->message_bytes_written <=
718 total_bytes_to_write);
719
720 if (socket_transport->message_bytes_written == total_bytes_to_write)
721 {
722 socket_transport->message_bytes_written = 0;
723 _dbus_string_set_length (&socket_transport->encoded_outgoing, 0);
724 _dbus_string_compact (&socket_transport->encoded_outgoing, 2048);
725
726 _dbus_connection_message_sent_unlocked (transport->connection,
727 message);
728 }
729 }
730 }
731
732 out:
733 if (oom)
734 return FALSE;
735 else
736 return TRUE;
737 }
738
739 /* returns false on out-of-memory */
740 static dbus_bool_t
do_reading(DBusTransport * transport)741 do_reading (DBusTransport *transport)
742 {
743 DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
744 DBusString *buffer;
745 int bytes_read;
746 int total;
747 dbus_bool_t oom;
748 int saved_errno;
749
750 _dbus_verbose ("fd = %" DBUS_SOCKET_FORMAT "\n",
751 _dbus_socket_printable (socket_transport->fd));
752
753 /* No messages without authentication! */
754 if (!_dbus_transport_try_to_authenticate (transport))
755 return TRUE;
756
757 oom = FALSE;
758
759 total = 0;
760
761 again:
762
763 /* See if we've exceeded max messages and need to disable reading */
764 check_read_watch (transport);
765
766 if (total > socket_transport->max_bytes_read_per_iteration)
767 {
768 _dbus_verbose ("%d bytes exceeds %d bytes read per iteration, returning\n",
769 total, socket_transport->max_bytes_read_per_iteration);
770 goto out;
771 }
772
773 _dbus_assert (socket_transport->read_watch != NULL ||
774 transport->disconnected);
775
776 if (transport->disconnected)
777 goto out;
778
779 if (!dbus_watch_get_enabled (socket_transport->read_watch))
780 return TRUE;
781
782 if (_dbus_auth_needs_decoding (transport->auth))
783 {
784 /* Does fd passing even make sense with encoded data? */
785 _dbus_assert(!DBUS_TRANSPORT_CAN_SEND_UNIX_FD(transport));
786
787 if (_dbus_string_get_length (&socket_transport->encoded_incoming) > 0)
788 bytes_read = _dbus_string_get_length (&socket_transport->encoded_incoming);
789 else
790 bytes_read = _dbus_read_socket (socket_transport->fd,
791 &socket_transport->encoded_incoming,
792 socket_transport->max_bytes_read_per_iteration);
793
794 saved_errno = _dbus_save_socket_errno ();
795
796 _dbus_assert (_dbus_string_get_length (&socket_transport->encoded_incoming) ==
797 bytes_read);
798
799 if (bytes_read > 0)
800 {
801 _dbus_message_loader_get_buffer (transport->loader,
802 &buffer,
803 NULL,
804 NULL);
805
806 if (!_dbus_auth_decode_data (transport->auth,
807 &socket_transport->encoded_incoming,
808 buffer))
809 {
810 _dbus_verbose ("Out of memory decoding incoming data\n");
811 _dbus_message_loader_return_buffer (transport->loader,
812 buffer);
813
814 oom = TRUE;
815 goto out;
816 }
817
818 _dbus_message_loader_return_buffer (transport->loader,
819 buffer);
820
821 _dbus_string_set_length (&socket_transport->encoded_incoming, 0);
822 _dbus_string_compact (&socket_transport->encoded_incoming, 2048);
823 }
824 }
825 else
826 {
827 int max_to_read = DBUS_MAXIMUM_MESSAGE_LENGTH;
828 dbus_bool_t may_read_unix_fds = TRUE;
829
830 _dbus_message_loader_get_buffer (transport->loader,
831 &buffer,
832 &max_to_read,
833 &may_read_unix_fds);
834
835 if (max_to_read > socket_transport->max_bytes_read_per_iteration)
836 max_to_read = socket_transport->max_bytes_read_per_iteration;
837
838 #ifdef HAVE_UNIX_FD_PASSING
839 if (DBUS_TRANSPORT_CAN_SEND_UNIX_FD(transport) && may_read_unix_fds)
840 {
841 int *fds;
842 unsigned int n_fds;
843
844 if (!_dbus_message_loader_get_unix_fds(transport->loader, &fds, &n_fds))
845 {
846 _dbus_verbose ("Out of memory reading file descriptors\n");
847 _dbus_message_loader_return_buffer (transport->loader, buffer);
848 oom = TRUE;
849 goto out;
850 }
851
852 bytes_read = _dbus_read_socket_with_unix_fds(socket_transport->fd,
853 buffer,
854 max_to_read,
855 fds, &n_fds);
856 saved_errno = _dbus_save_socket_errno ();
857
858 if (bytes_read >= 0 && n_fds > 0)
859 _dbus_verbose("Read %i unix fds\n", n_fds);
860
861 _dbus_message_loader_return_unix_fds(transport->loader, fds, bytes_read < 0 ? 0 : n_fds);
862 }
863 else
864 #endif
865 {
866 bytes_read = _dbus_read_socket (socket_transport->fd,
867 buffer, max_to_read);
868 saved_errno = _dbus_save_socket_errno ();
869 }
870
871 _dbus_message_loader_return_buffer (transport->loader,
872 buffer);
873 }
874
875 if (bytes_read < 0)
876 {
877 /* EINTR already handled for us */
878
879 if (_dbus_get_is_errno_enomem (saved_errno))
880 {
881 _dbus_verbose ("Out of memory in read()/do_reading()\n");
882 oom = TRUE;
883 goto out;
884 }
885 else if (_dbus_get_is_errno_eagain_or_ewouldblock (saved_errno))
886 goto out;
887 else
888 {
889 _dbus_verbose ("Error reading from remote app: %s\n",
890 _dbus_strerror (saved_errno));
891 do_io_error (transport);
892 goto out;
893 }
894 }
895 else if (bytes_read == 0)
896 {
897 _dbus_verbose ("Disconnected from remote app\n");
898 do_io_error (transport);
899 goto out;
900 }
901 else
902 {
903 _dbus_verbose (" read %d bytes\n", bytes_read);
904
905 total += bytes_read;
906
907 if (!_dbus_transport_queue_messages (transport))
908 {
909 oom = TRUE;
910 _dbus_verbose (" out of memory when queueing messages we just read in the transport\n");
911 goto out;
912 }
913
914 /* Try reading more data until we get EAGAIN and return, or
915 * exceed max bytes per iteration. If in blocking mode of
916 * course we'll block instead of returning.
917 */
918 goto again;
919 }
920
921 out:
922 if (oom)
923 return FALSE;
924 else
925 return TRUE;
926 }
927
928 static dbus_bool_t
unix_error_with_read_to_come(DBusTransport * itransport,DBusWatch * watch,unsigned int flags)929 unix_error_with_read_to_come (DBusTransport *itransport,
930 DBusWatch *watch,
931 unsigned int flags)
932 {
933 DBusTransportSocket *transport = (DBusTransportSocket *) itransport;
934
935 if (!(flags & DBUS_WATCH_HANGUP || flags & DBUS_WATCH_ERROR))
936 return FALSE;
937
938 /* If we have a read watch enabled ...
939 we -might have data incoming ... => handle the HANGUP there */
940 if (watch != transport->read_watch &&
941 _dbus_watch_get_enabled (transport->read_watch))
942 return FALSE;
943
944 return TRUE;
945 }
946
947 static dbus_bool_t
socket_handle_watch(DBusTransport * transport,DBusWatch * watch,unsigned int flags)948 socket_handle_watch (DBusTransport *transport,
949 DBusWatch *watch,
950 unsigned int flags)
951 {
952 DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
953
954 _dbus_assert (watch == socket_transport->read_watch ||
955 watch == socket_transport->write_watch);
956 _dbus_assert (watch != NULL);
957
958 /* If we hit an error here on a write watch, don't disconnect the transport yet because data can
959 * still be in the buffer and do_reading may need several iteration to read
960 * it all (because of its max_bytes_read_per_iteration limit).
961 */
962 if (!(flags & DBUS_WATCH_READABLE) && unix_error_with_read_to_come (transport, watch, flags))
963 {
964 _dbus_verbose ("Hang up or error on watch\n");
965 _dbus_transport_disconnect (transport);
966 return TRUE;
967 }
968
969 if (watch == socket_transport->read_watch &&
970 (flags & DBUS_WATCH_READABLE))
971 {
972 dbus_bool_t auth_finished;
973 #if 1
974 _dbus_verbose ("handling read watch %p flags = %x\n",
975 watch, flags);
976 #endif
977 if (!do_authentication (transport, TRUE, FALSE, &auth_finished))
978 return FALSE;
979
980 /* We don't want to do a read immediately following
981 * a successful authentication. This is so we
982 * have a chance to propagate the authentication
983 * state further up. Specifically, we need to
984 * process any pending data from the auth object.
985 */
986 if (!auth_finished)
987 {
988 if (!do_reading (transport))
989 {
990 _dbus_verbose ("no memory to read\n");
991 return FALSE;
992 }
993 }
994 else
995 {
996 _dbus_verbose ("Not reading anything since we just completed the authentication\n");
997 }
998 }
999 else if (watch == socket_transport->write_watch &&
1000 (flags & DBUS_WATCH_WRITABLE))
1001 {
1002 #if 1
1003 _dbus_verbose ("handling write watch, have_outgoing_messages = %d\n",
1004 _dbus_connection_has_messages_to_send_unlocked (transport->connection));
1005 #endif
1006 if (!do_authentication (transport, FALSE, TRUE, NULL))
1007 return FALSE;
1008
1009 if (!do_writing (transport))
1010 {
1011 _dbus_verbose ("no memory to write\n");
1012 return FALSE;
1013 }
1014
1015 /* See if we still need the write watch */
1016 check_write_watch (transport);
1017 }
1018 #ifdef DBUS_ENABLE_VERBOSE_MODE
1019 else
1020 {
1021 if (watch == socket_transport->read_watch)
1022 _dbus_verbose ("asked to handle read watch with non-read condition 0x%x\n",
1023 flags);
1024 else if (watch == socket_transport->write_watch)
1025 _dbus_verbose ("asked to handle write watch with non-write condition 0x%x\n",
1026 flags);
1027 else
1028 _dbus_verbose ("asked to handle watch %p on fd %" DBUS_SOCKET_FORMAT " that we don't recognize\n",
1029 watch, _dbus_socket_printable (_dbus_watch_get_socket (watch)));
1030 }
1031 #endif /* DBUS_ENABLE_VERBOSE_MODE */
1032
1033 return TRUE;
1034 }
1035
1036 static void
socket_disconnect(DBusTransport * transport)1037 socket_disconnect (DBusTransport *transport)
1038 {
1039 DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
1040
1041 _dbus_verbose ("\n");
1042
1043 free_watches (transport);
1044
1045 _dbus_close_socket (socket_transport->fd, NULL);
1046 _dbus_socket_invalidate (&socket_transport->fd);
1047 }
1048
1049 static dbus_bool_t
socket_connection_set(DBusTransport * transport)1050 socket_connection_set (DBusTransport *transport)
1051 {
1052 DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
1053
1054 _dbus_watch_set_handler (socket_transport->write_watch,
1055 _dbus_connection_handle_watch,
1056 transport->connection, NULL);
1057
1058 _dbus_watch_set_handler (socket_transport->read_watch,
1059 _dbus_connection_handle_watch,
1060 transport->connection, NULL);
1061
1062 if (!_dbus_connection_add_watch_unlocked (transport->connection,
1063 socket_transport->write_watch))
1064 return FALSE;
1065
1066 if (!_dbus_connection_add_watch_unlocked (transport->connection,
1067 socket_transport->read_watch))
1068 {
1069 _dbus_connection_remove_watch_unlocked (transport->connection,
1070 socket_transport->write_watch);
1071 return FALSE;
1072 }
1073
1074 check_read_watch (transport);
1075 check_write_watch (transport);
1076
1077 return TRUE;
1078 }
1079
1080 /**
1081 * @todo We need to have a way to wake up the select sleep if
1082 * a new iteration request comes in with a flag (read/write) that
1083 * we're not currently serving. Otherwise a call that just reads
1084 * could block a write call forever (if there are no incoming
1085 * messages).
1086 */
1087 static void
socket_do_iteration(DBusTransport * transport,unsigned int flags,int timeout_milliseconds)1088 socket_do_iteration (DBusTransport *transport,
1089 unsigned int flags,
1090 int timeout_milliseconds)
1091 {
1092 DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
1093 DBusPollFD poll_fd;
1094 int poll_res;
1095 int poll_timeout;
1096
1097 _dbus_verbose (" iteration flags = %s%s timeout = %d read_watch = %p write_watch = %p fd = %" DBUS_SOCKET_FORMAT "\n",
1098 flags & DBUS_ITERATION_DO_READING ? "read" : "",
1099 flags & DBUS_ITERATION_DO_WRITING ? "write" : "",
1100 timeout_milliseconds,
1101 socket_transport->read_watch,
1102 socket_transport->write_watch,
1103 _dbus_socket_printable (socket_transport->fd));
1104
1105 /* the passed in DO_READING/DO_WRITING flags indicate whether to
1106 * read/write messages, but regardless of those we may need to block
1107 * for reading/writing to do auth. But if we do reading for auth,
1108 * we don't want to read any messages yet if not given DO_READING.
1109 */
1110
1111 poll_fd.fd = _dbus_socket_get_pollable (socket_transport->fd);
1112 poll_fd.events = 0;
1113
1114 if (_dbus_transport_try_to_authenticate (transport))
1115 {
1116 /* This is kind of a hack; if we have stuff to write, then try
1117 * to avoid the poll. This is probably about a 5% speedup on an
1118 * echo client/server.
1119 *
1120 * If both reading and writing were requested, we want to avoid this
1121 * since it could have funky effects:
1122 * - both ends spinning waiting for the other one to read
1123 * data so they can finish writing
1124 * - prioritizing all writing ahead of reading
1125 */
1126 if ((flags & DBUS_ITERATION_DO_WRITING) &&
1127 !(flags & (DBUS_ITERATION_DO_READING | DBUS_ITERATION_BLOCK)) &&
1128 !transport->disconnected &&
1129 _dbus_connection_has_messages_to_send_unlocked (transport->connection))
1130 {
1131 do_writing (transport);
1132
1133 if (transport->disconnected ||
1134 !_dbus_connection_has_messages_to_send_unlocked (transport->connection))
1135 goto out;
1136 }
1137
1138 /* If we get here, we decided to do the poll() after all */
1139 _dbus_assert (socket_transport->read_watch);
1140 if (flags & DBUS_ITERATION_DO_READING)
1141 poll_fd.events |= _DBUS_POLLIN;
1142
1143 _dbus_assert (socket_transport->write_watch);
1144 if (flags & DBUS_ITERATION_DO_WRITING)
1145 poll_fd.events |= _DBUS_POLLOUT;
1146 }
1147 else
1148 {
1149 DBusAuthState auth_state;
1150
1151 auth_state = _dbus_auth_do_work (transport->auth);
1152
1153 if (transport->receive_credentials_pending ||
1154 auth_state == DBUS_AUTH_STATE_WAITING_FOR_INPUT)
1155 poll_fd.events |= _DBUS_POLLIN;
1156
1157 if (transport->send_credentials_pending ||
1158 auth_state == DBUS_AUTH_STATE_HAVE_BYTES_TO_SEND)
1159 poll_fd.events |= _DBUS_POLLOUT;
1160 }
1161
1162 if (poll_fd.events)
1163 {
1164 int saved_errno;
1165
1166 if (flags & DBUS_ITERATION_BLOCK)
1167 poll_timeout = timeout_milliseconds;
1168 else
1169 poll_timeout = 0;
1170
1171 /* For blocking selects we drop the connection lock here
1172 * to avoid blocking out connection access during a potentially
1173 * indefinite blocking call. The io path is still protected
1174 * by the io_path_cond condvar, so we won't reenter this.
1175 */
1176 if (flags & DBUS_ITERATION_BLOCK)
1177 {
1178 _dbus_verbose ("unlock pre poll\n");
1179 _dbus_connection_unlock (transport->connection);
1180 }
1181
1182 again:
1183 poll_res = _dbus_poll (&poll_fd, 1, poll_timeout);
1184 saved_errno = _dbus_save_socket_errno ();
1185
1186 if (poll_res < 0 && _dbus_get_is_errno_eintr (saved_errno))
1187 goto again;
1188
1189 if (flags & DBUS_ITERATION_BLOCK)
1190 {
1191 _dbus_verbose ("lock post poll\n");
1192 _dbus_connection_lock (transport->connection);
1193 }
1194
1195 if (poll_res >= 0)
1196 {
1197 if (poll_res == 0)
1198 poll_fd.revents = 0; /* some concern that posix does not guarantee this;
1199 * valgrind flags it as an error. though it probably
1200 * is guaranteed on linux at least.
1201 */
1202
1203 if (poll_fd.revents & _DBUS_POLLERR)
1204 do_io_error (transport);
1205 else
1206 {
1207 dbus_bool_t need_read = (poll_fd.revents & _DBUS_POLLIN) > 0;
1208 dbus_bool_t need_write = (poll_fd.revents & _DBUS_POLLOUT) > 0;
1209 dbus_bool_t authentication_completed;
1210
1211 _dbus_verbose ("in iteration, need_read=%d need_write=%d\n",
1212 need_read, need_write);
1213 do_authentication (transport, need_read, need_write,
1214 &authentication_completed);
1215
1216 /* See comment in socket_handle_watch. */
1217 if (authentication_completed)
1218 goto out;
1219
1220 if (need_read && (flags & DBUS_ITERATION_DO_READING))
1221 do_reading (transport);
1222 if (need_write && (flags & DBUS_ITERATION_DO_WRITING))
1223 do_writing (transport);
1224 }
1225 }
1226 else
1227 {
1228 _dbus_verbose ("Error from _dbus_poll(): %s\n",
1229 _dbus_strerror (saved_errno));
1230 }
1231 }
1232
1233
1234 out:
1235 /* We need to install the write watch only if we did not
1236 * successfully write everything. Note we need to be careful that we
1237 * don't call check_write_watch *before* do_writing, since it's
1238 * inefficient to add the write watch, and we can avoid it most of
1239 * the time since we can write immediately.
1240 *
1241 * However, we MUST always call check_write_watch(); DBusConnection code
1242 * relies on the fact that running an iteration will notice that
1243 * messages are pending.
1244 */
1245 check_write_watch (transport);
1246
1247 _dbus_verbose (" ... leaving do_iteration()\n");
1248 }
1249
1250 static void
socket_live_messages_changed(DBusTransport * transport)1251 socket_live_messages_changed (DBusTransport *transport)
1252 {
1253 /* See if we should look for incoming messages again */
1254 check_read_watch (transport);
1255 }
1256
1257
1258 static dbus_bool_t
socket_get_socket_fd(DBusTransport * transport,DBusSocket * fd_p)1259 socket_get_socket_fd (DBusTransport *transport,
1260 DBusSocket *fd_p)
1261 {
1262 DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
1263
1264 *fd_p = socket_transport->fd;
1265
1266 return TRUE;
1267 }
1268
1269 static const DBusTransportVTable socket_vtable = {
1270 socket_finalize,
1271 socket_handle_watch,
1272 socket_disconnect,
1273 socket_connection_set,
1274 socket_do_iteration,
1275 socket_live_messages_changed,
1276 socket_get_socket_fd
1277 };
1278
1279 /**
1280 * Creates a new transport for the given socket file descriptor. The file
1281 * descriptor must be nonblocking (use _dbus_set_fd_nonblocking() to
1282 * make it so). This function is shared by various transports that
1283 * boil down to a full duplex file descriptor.
1284 *
1285 * @param fd the file descriptor.
1286 * @param server_guid non-#NULL if this transport is on the server side of a connection
1287 * @param address the transport's address
1288 * @returns the new transport, or #NULL if no memory.
1289 */
1290 DBusTransport*
_dbus_transport_new_for_socket(DBusSocket fd,const DBusString * server_guid,const DBusString * address)1291 _dbus_transport_new_for_socket (DBusSocket fd,
1292 const DBusString *server_guid,
1293 const DBusString *address)
1294 {
1295 DBusTransportSocket *socket_transport;
1296
1297 socket_transport = dbus_new0 (DBusTransportSocket, 1);
1298 if (socket_transport == NULL)
1299 return NULL;
1300
1301 if (!_dbus_string_init (&socket_transport->encoded_outgoing))
1302 goto failed_0;
1303
1304 if (!_dbus_string_init (&socket_transport->encoded_incoming))
1305 goto failed_1;
1306
1307 socket_transport->write_watch = _dbus_watch_new (_dbus_socket_get_pollable (fd),
1308 DBUS_WATCH_WRITABLE,
1309 FALSE,
1310 NULL, NULL, NULL);
1311 if (socket_transport->write_watch == NULL)
1312 goto failed_2;
1313
1314 socket_transport->read_watch = _dbus_watch_new (_dbus_socket_get_pollable (fd),
1315 DBUS_WATCH_READABLE,
1316 FALSE,
1317 NULL, NULL, NULL);
1318 if (socket_transport->read_watch == NULL)
1319 goto failed_3;
1320
1321 if (!_dbus_transport_init_base (&socket_transport->base,
1322 &socket_vtable,
1323 server_guid, address))
1324 goto failed_4;
1325
1326 #ifdef HAVE_UNIX_FD_PASSING
1327 _dbus_auth_set_unix_fd_possible(socket_transport->base.auth, _dbus_socket_can_pass_unix_fd(fd));
1328 #endif
1329
1330 socket_transport->fd = fd;
1331 socket_transport->message_bytes_written = 0;
1332
1333 /* These values should probably be tunable or something. */
1334 socket_transport->max_bytes_read_per_iteration = 2048;
1335 socket_transport->max_bytes_written_per_iteration = 2048;
1336
1337 return (DBusTransport*) socket_transport;
1338
1339 failed_4:
1340 _dbus_watch_invalidate (socket_transport->read_watch);
1341 _dbus_watch_unref (socket_transport->read_watch);
1342 failed_3:
1343 _dbus_watch_invalidate (socket_transport->write_watch);
1344 _dbus_watch_unref (socket_transport->write_watch);
1345 failed_2:
1346 _dbus_string_free (&socket_transport->encoded_incoming);
1347 failed_1:
1348 _dbus_string_free (&socket_transport->encoded_outgoing);
1349 failed_0:
1350 dbus_free (socket_transport);
1351 return NULL;
1352 }
1353
1354 /**
1355 * Creates a new transport for the given hostname and port.
1356 * If host is NULL, it will default to localhost
1357 *
1358 * @param host the host to connect to
1359 * @param port the port to connect to
1360 * @param family the address family to connect to
1361 * @param noncefile path to nonce file
1362 * @param error location to store reason for failure.
1363 * @returns a new transport, or #NULL on failure.
1364 */
1365 DBusTransport*
_dbus_transport_new_for_tcp_socket(const char * host,const char * port,const char * family,const char * noncefile,DBusError * error)1366 _dbus_transport_new_for_tcp_socket (const char *host,
1367 const char *port,
1368 const char *family,
1369 const char *noncefile,
1370 DBusError *error)
1371 {
1372 DBusSocket fd;
1373 DBusTransport *transport;
1374 DBusString address;
1375
1376 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
1377
1378 if (!_dbus_string_init (&address))
1379 {
1380 dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
1381 return NULL;
1382 }
1383
1384 if (host == NULL)
1385 host = "localhost";
1386
1387 if (!_dbus_string_append (&address, noncefile ? "nonce-tcp:" : "tcp:"))
1388 goto error;
1389
1390 if (!_dbus_string_append (&address, "host=") ||
1391 !_dbus_string_append (&address, host))
1392 goto error;
1393
1394 if (!_dbus_string_append (&address, ",port=") ||
1395 !_dbus_string_append (&address, port))
1396 goto error;
1397
1398 if (family != NULL &&
1399 (!_dbus_string_append (&address, ",family=") ||
1400 !_dbus_string_append (&address, family)))
1401 goto error;
1402
1403 if (noncefile != NULL &&
1404 (!_dbus_string_append (&address, ",noncefile=") ||
1405 !_dbus_string_append (&address, noncefile)))
1406 goto error;
1407
1408 fd = _dbus_connect_tcp_socket_with_nonce (host, port, family, noncefile, error);
1409 if (!_dbus_socket_is_valid (fd))
1410 {
1411 _DBUS_ASSERT_ERROR_IS_SET (error);
1412 _dbus_string_free (&address);
1413 return NULL;
1414 }
1415
1416 _dbus_verbose ("Successfully connected to tcp socket %s:%s\n",
1417 host, port);
1418
1419 transport = _dbus_transport_new_for_socket (fd, NULL, &address);
1420 _dbus_string_free (&address);
1421 if (transport == NULL)
1422 {
1423 dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
1424 _dbus_close_socket (fd, NULL);
1425 _dbus_socket_invalidate (&fd);
1426 }
1427
1428 return transport;
1429
1430 error:
1431 _dbus_string_free (&address);
1432 dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
1433 return NULL;
1434 }
1435
1436 /**
1437 * Opens a TCP socket transport.
1438 *
1439 * @param entry the address entry to try opening as a tcp transport.
1440 * @param transport_p return location for the opened transport
1441 * @param error error to be set
1442 * @returns result of the attempt
1443 */
1444 DBusTransportOpenResult
_dbus_transport_open_socket(DBusAddressEntry * entry,DBusTransport ** transport_p,DBusError * error)1445 _dbus_transport_open_socket(DBusAddressEntry *entry,
1446 DBusTransport **transport_p,
1447 DBusError *error)
1448 {
1449 const char *method;
1450 dbus_bool_t isTcp;
1451 dbus_bool_t isNonceTcp;
1452
1453 method = dbus_address_entry_get_method (entry);
1454 _dbus_assert (method != NULL);
1455
1456 isTcp = strcmp (method, "tcp") == 0;
1457 isNonceTcp = strcmp (method, "nonce-tcp") == 0;
1458
1459 if (isTcp || isNonceTcp)
1460 {
1461 const char *host = dbus_address_entry_get_value (entry, "host");
1462 const char *port = dbus_address_entry_get_value (entry, "port");
1463 const char *family = dbus_address_entry_get_value (entry, "family");
1464 const char *noncefile = dbus_address_entry_get_value (entry, "noncefile");
1465
1466 if ((isNonceTcp == TRUE) != (noncefile != NULL)) {
1467 _dbus_set_bad_address (error, method, "noncefile", NULL);
1468 return DBUS_TRANSPORT_OPEN_BAD_ADDRESS;
1469 }
1470
1471 if (port == NULL)
1472 {
1473 _dbus_set_bad_address (error, method, "port", NULL);
1474 return DBUS_TRANSPORT_OPEN_BAD_ADDRESS;
1475 }
1476
1477 *transport_p = _dbus_transport_new_for_tcp_socket (host, port, family, noncefile, error);
1478 if (*transport_p == NULL)
1479 {
1480 _DBUS_ASSERT_ERROR_IS_SET (error);
1481 return DBUS_TRANSPORT_OPEN_DID_NOT_CONNECT;
1482 }
1483 else
1484 {
1485 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
1486 return DBUS_TRANSPORT_OPEN_OK;
1487 }
1488 }
1489 else
1490 {
1491 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
1492 return DBUS_TRANSPORT_OPEN_NOT_HANDLED;
1493 }
1494 }
1495
1496 /** @} */
1497
1498