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