1 /* -*- mode: C; c-file-style: "gnu" -*- */
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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 *
22 */
23
24 #include "dbus-internals.h"
25 #include "dbus-connection-internal.h"
26 #include "dbus-transport-socket.h"
27 #include "dbus-transport-protected.h"
28 #include "dbus-watch.h"
29
30
31 /**
32 * @defgroup DBusTransportSocket DBusTransport implementations for sockets
33 * @ingroup DBusInternals
34 * @brief Implementation details of DBusTransport on sockets
35 *
36 * @{
37 */
38
39 /**
40 * Opaque object representing a socket file descriptor transport.
41 */
42 typedef struct DBusTransportSocket DBusTransportSocket;
43
44 /**
45 * Implementation details of DBusTransportSocket. All members are private.
46 */
47 struct DBusTransportSocket
48 {
49 DBusTransport base; /**< Parent instance */
50 int fd; /**< File descriptor. */
51 DBusWatch *read_watch; /**< Watch for readability. */
52 DBusWatch *write_watch; /**< Watch for writability. */
53
54 int max_bytes_read_per_iteration; /**< To avoid blocking too long. */
55 int max_bytes_written_per_iteration; /**< To avoid blocking too long. */
56
57 int message_bytes_written; /**< Number of bytes of current
58 * outgoing message that have
59 * been written.
60 */
61 DBusString encoded_outgoing; /**< Encoded version of current
62 * outgoing message.
63 */
64 DBusString encoded_incoming; /**< Encoded version of current
65 * incoming data.
66 */
67 };
68
69 static void
free_watches(DBusTransport * transport)70 free_watches (DBusTransport *transport)
71 {
72 DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
73
74 _dbus_verbose ("%s start\n", _DBUS_FUNCTION_NAME);
75
76 if (socket_transport->read_watch)
77 {
78 if (transport->connection)
79 _dbus_connection_remove_watch_unlocked (transport->connection,
80 socket_transport->read_watch);
81 _dbus_watch_invalidate (socket_transport->read_watch);
82 _dbus_watch_unref (socket_transport->read_watch);
83 socket_transport->read_watch = NULL;
84 }
85
86 if (socket_transport->write_watch)
87 {
88 if (transport->connection)
89 _dbus_connection_remove_watch_unlocked (transport->connection,
90 socket_transport->write_watch);
91 _dbus_watch_invalidate (socket_transport->write_watch);
92 _dbus_watch_unref (socket_transport->write_watch);
93 socket_transport->write_watch = NULL;
94 }
95
96 _dbus_verbose ("%s end\n", _DBUS_FUNCTION_NAME);
97 }
98
99 static void
socket_finalize(DBusTransport * transport)100 socket_finalize (DBusTransport *transport)
101 {
102 DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
103
104 _dbus_verbose ("%s\n", _DBUS_FUNCTION_NAME);
105
106 free_watches (transport);
107
108 _dbus_string_free (&socket_transport->encoded_outgoing);
109 _dbus_string_free (&socket_transport->encoded_incoming);
110
111 _dbus_transport_finalize_base (transport);
112
113 _dbus_assert (socket_transport->read_watch == NULL);
114 _dbus_assert (socket_transport->write_watch == NULL);
115
116 dbus_free (transport);
117 }
118
119 static void
check_write_watch(DBusTransport * transport)120 check_write_watch (DBusTransport *transport)
121 {
122 DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
123 dbus_bool_t needed;
124
125 if (transport->connection == NULL)
126 return;
127
128 if (transport->disconnected)
129 {
130 _dbus_assert (socket_transport->write_watch == NULL);
131 return;
132 }
133
134 _dbus_transport_ref (transport);
135
136 if (_dbus_transport_get_is_authenticated (transport))
137 needed = _dbus_connection_has_messages_to_send_unlocked (transport->connection);
138 else
139 {
140 if (transport->send_credentials_pending)
141 needed = TRUE;
142 else
143 {
144 DBusAuthState auth_state;
145
146 auth_state = _dbus_auth_do_work (transport->auth);
147
148 /* If we need memory we install the write watch just in case,
149 * if there's no need for it, it will get de-installed
150 * next time we try reading.
151 */
152 if (auth_state == DBUS_AUTH_STATE_HAVE_BYTES_TO_SEND ||
153 auth_state == DBUS_AUTH_STATE_WAITING_FOR_MEMORY)
154 needed = TRUE;
155 else
156 needed = FALSE;
157 }
158 }
159
160 _dbus_verbose ("check_write_watch(): needed = %d on connection %p watch %p fd = %d outgoing messages exist %d\n",
161 needed, transport->connection, socket_transport->write_watch,
162 socket_transport->fd,
163 _dbus_connection_has_messages_to_send_unlocked (transport->connection));
164
165 _dbus_connection_toggle_watch_unlocked (transport->connection,
166 socket_transport->write_watch,
167 needed);
168
169 _dbus_transport_unref (transport);
170 }
171
172 static void
check_read_watch(DBusTransport * transport)173 check_read_watch (DBusTransport *transport)
174 {
175 DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
176 dbus_bool_t need_read_watch;
177
178 _dbus_verbose ("%s: fd = %d\n",
179 _DBUS_FUNCTION_NAME, socket_transport->fd);
180
181 if (transport->connection == NULL)
182 return;
183
184 if (transport->disconnected)
185 {
186 _dbus_assert (socket_transport->read_watch == NULL);
187 return;
188 }
189
190 _dbus_transport_ref (transport);
191
192 if (_dbus_transport_get_is_authenticated (transport))
193 need_read_watch =
194 _dbus_counter_get_value (transport->live_messages_size) < transport->max_live_messages_size;
195 else
196 {
197 if (transport->receive_credentials_pending)
198 need_read_watch = TRUE;
199 else
200 {
201 /* The reason to disable need_read_watch when not WAITING_FOR_INPUT
202 * is to avoid spinning on the file descriptor when we're waiting
203 * to write or for some other part of the auth process
204 */
205 DBusAuthState auth_state;
206
207 auth_state = _dbus_auth_do_work (transport->auth);
208
209 /* If we need memory we install the read watch just in case,
210 * if there's no need for it, it will get de-installed
211 * next time we try reading. If we're authenticated we
212 * install it since we normally have it installed while
213 * authenticated.
214 */
215 if (auth_state == DBUS_AUTH_STATE_WAITING_FOR_INPUT ||
216 auth_state == DBUS_AUTH_STATE_WAITING_FOR_MEMORY ||
217 auth_state == DBUS_AUTH_STATE_AUTHENTICATED)
218 need_read_watch = TRUE;
219 else
220 need_read_watch = FALSE;
221 }
222 }
223
224 _dbus_verbose (" setting read watch enabled = %d\n", need_read_watch);
225 _dbus_connection_toggle_watch_unlocked (transport->connection,
226 socket_transport->read_watch,
227 need_read_watch);
228
229 _dbus_transport_unref (transport);
230 }
231
232 static void
do_io_error(DBusTransport * transport)233 do_io_error (DBusTransport *transport)
234 {
235 _dbus_transport_ref (transport);
236 _dbus_transport_disconnect (transport);
237 _dbus_transport_unref (transport);
238 }
239
240 /* return value is whether we successfully read any new data. */
241 static dbus_bool_t
read_data_into_auth(DBusTransport * transport,dbus_bool_t * oom)242 read_data_into_auth (DBusTransport *transport,
243 dbus_bool_t *oom)
244 {
245 DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
246 DBusString *buffer;
247 int bytes_read;
248
249 *oom = FALSE;
250
251 _dbus_auth_get_buffer (transport->auth, &buffer);
252
253 bytes_read = _dbus_read_socket (socket_transport->fd,
254 buffer, socket_transport->max_bytes_read_per_iteration);
255
256 _dbus_auth_return_buffer (transport->auth, buffer,
257 bytes_read > 0 ? bytes_read : 0);
258
259 if (bytes_read > 0)
260 {
261 _dbus_verbose (" read %d bytes in auth phase\n", bytes_read);
262
263 return TRUE;
264 }
265 else if (bytes_read < 0)
266 {
267 /* EINTR already handled for us */
268
269 if (errno == ENOMEM)
270 {
271 *oom = TRUE;
272 }
273 else if (errno == EAGAIN ||
274 errno == EWOULDBLOCK)
275 ; /* do nothing, just return FALSE below */
276 else
277 {
278 _dbus_verbose ("Error reading from remote app: %s\n",
279 _dbus_strerror (errno));
280 do_io_error (transport);
281 }
282
283 return FALSE;
284 }
285 else
286 {
287 _dbus_assert (bytes_read == 0);
288
289 _dbus_verbose ("Disconnected from remote app\n");
290 do_io_error (transport);
291
292 return FALSE;
293 }
294 }
295
296 /* Return value is whether we successfully wrote any bytes */
297 static dbus_bool_t
write_data_from_auth(DBusTransport * transport)298 write_data_from_auth (DBusTransport *transport)
299 {
300 DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
301 int bytes_written;
302 const DBusString *buffer;
303
304 if (!_dbus_auth_get_bytes_to_send (transport->auth,
305 &buffer))
306 return FALSE;
307
308 bytes_written = _dbus_write_socket (socket_transport->fd,
309 buffer,
310 0, _dbus_string_get_length (buffer));
311
312 if (bytes_written > 0)
313 {
314 _dbus_auth_bytes_sent (transport->auth, bytes_written);
315 return TRUE;
316 }
317 else if (bytes_written < 0)
318 {
319 /* EINTR already handled for us */
320
321 if (errno == EAGAIN ||
322 errno == EWOULDBLOCK)
323 ;
324 else
325 {
326 _dbus_verbose ("Error writing to remote app: %s\n",
327 _dbus_strerror (errno));
328 do_io_error (transport);
329 }
330 }
331
332 return FALSE;
333 }
334
335 static void
exchange_credentials(DBusTransport * transport,dbus_bool_t do_reading,dbus_bool_t do_writing)336 exchange_credentials (DBusTransport *transport,
337 dbus_bool_t do_reading,
338 dbus_bool_t do_writing)
339 {
340 DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
341 DBusError error;
342
343 _dbus_verbose ("exchange_credentials: do_reading = %d, do_writing = %d\n",
344 do_reading, do_writing);
345
346 dbus_error_init (&error);
347 if (do_writing && transport->send_credentials_pending)
348 {
349 if (_dbus_send_credentials_unix_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 if (_dbus_read_credentials_unix_socket (socket_transport->fd,
365 &transport->credentials,
366 &error))
367 {
368 transport->receive_credentials_pending = FALSE;
369 }
370 else
371 {
372 _dbus_verbose ("Failed to read credentials %s\n", error.message);
373 dbus_error_free (&error);
374 do_io_error (transport);
375 }
376 }
377
378 if (!(transport->send_credentials_pending ||
379 transport->receive_credentials_pending))
380 {
381 _dbus_auth_set_credentials (transport->auth,
382 &transport->credentials);
383 }
384 }
385
386 static dbus_bool_t
do_authentication(DBusTransport * transport,dbus_bool_t do_reading,dbus_bool_t do_writing,dbus_bool_t * auth_completed)387 do_authentication (DBusTransport *transport,
388 dbus_bool_t do_reading,
389 dbus_bool_t do_writing,
390 dbus_bool_t *auth_completed)
391 {
392 dbus_bool_t oom;
393 dbus_bool_t orig_auth_state;
394
395 oom = FALSE;
396
397 orig_auth_state = _dbus_transport_get_is_authenticated (transport);
398
399 /* This is essential to avoid the check_write_watch() at the end,
400 * we don't want to add a write watch in do_iteration before
401 * we try writing and get EAGAIN
402 */
403 if (orig_auth_state)
404 {
405 if (auth_completed)
406 *auth_completed = FALSE;
407 return TRUE;
408 }
409
410 _dbus_transport_ref (transport);
411
412 while (!_dbus_transport_get_is_authenticated (transport) &&
413 _dbus_transport_get_is_connected (transport))
414 {
415 exchange_credentials (transport, do_reading, do_writing);
416
417 if (transport->send_credentials_pending ||
418 transport->receive_credentials_pending)
419 {
420 _dbus_verbose ("send_credentials_pending = %d receive_credentials_pending = %d\n",
421 transport->send_credentials_pending,
422 transport->receive_credentials_pending);
423 goto out;
424 }
425
426 #define TRANSPORT_SIDE(t) ((t)->is_server ? "server" : "client")
427 switch (_dbus_auth_do_work (transport->auth))
428 {
429 case DBUS_AUTH_STATE_WAITING_FOR_INPUT:
430 _dbus_verbose (" %s auth state: waiting for input\n",
431 TRANSPORT_SIDE (transport));
432 if (!do_reading || !read_data_into_auth (transport, &oom))
433 goto out;
434 break;
435
436 case DBUS_AUTH_STATE_WAITING_FOR_MEMORY:
437 _dbus_verbose (" %s auth state: waiting for memory\n",
438 TRANSPORT_SIDE (transport));
439 oom = TRUE;
440 goto out;
441 break;
442
443 case DBUS_AUTH_STATE_HAVE_BYTES_TO_SEND:
444 _dbus_verbose (" %s auth state: bytes to send\n",
445 TRANSPORT_SIDE (transport));
446 if (!do_writing || !write_data_from_auth (transport))
447 goto out;
448 break;
449
450 case DBUS_AUTH_STATE_NEED_DISCONNECT:
451 _dbus_verbose (" %s auth state: need to disconnect\n",
452 TRANSPORT_SIDE (transport));
453 do_io_error (transport);
454 break;
455
456 case DBUS_AUTH_STATE_AUTHENTICATED:
457 _dbus_verbose (" %s auth state: authenticated\n",
458 TRANSPORT_SIDE (transport));
459 break;
460 }
461 }
462
463 out:
464 if (auth_completed)
465 *auth_completed = (orig_auth_state != _dbus_transport_get_is_authenticated (transport));
466
467 check_read_watch (transport);
468 check_write_watch (transport);
469 _dbus_transport_unref (transport);
470
471 if (oom)
472 return FALSE;
473 else
474 return TRUE;
475 }
476
477 /* returns false on oom */
478 static dbus_bool_t
do_writing(DBusTransport * transport)479 do_writing (DBusTransport *transport)
480 {
481 int total;
482 DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
483 dbus_bool_t oom;
484
485 /* No messages without authentication! */
486 if (!_dbus_transport_get_is_authenticated (transport))
487 {
488 _dbus_verbose ("Not authenticated, not writing anything\n");
489 return TRUE;
490 }
491
492 if (transport->disconnected)
493 {
494 _dbus_verbose ("Not connected, not writing anything\n");
495 return TRUE;
496 }
497
498 #if 1
499 _dbus_verbose ("do_writing(), have_messages = %d, fd = %d\n",
500 _dbus_connection_has_messages_to_send_unlocked (transport->connection),
501 socket_transport->fd);
502 #endif
503
504 oom = FALSE;
505 total = 0;
506
507 while (!transport->disconnected &&
508 _dbus_connection_has_messages_to_send_unlocked (transport->connection))
509 {
510 int bytes_written;
511 DBusMessage *message;
512 const DBusString *header;
513 const DBusString *body;
514 int header_len, body_len;
515 int total_bytes_to_write;
516
517 if (total > socket_transport->max_bytes_written_per_iteration)
518 {
519 _dbus_verbose ("%d bytes exceeds %d bytes written per iteration, returning\n",
520 total, socket_transport->max_bytes_written_per_iteration);
521 goto out;
522 }
523
524 message = _dbus_connection_get_message_to_send (transport->connection);
525 _dbus_assert (message != NULL);
526 _dbus_message_lock (message);
527
528 #if 0
529 _dbus_verbose ("writing message %p\n", message);
530 #endif
531
532 _dbus_message_get_network_data (message,
533 &header, &body);
534
535 header_len = _dbus_string_get_length (header);
536 body_len = _dbus_string_get_length (body);
537
538 if (_dbus_auth_needs_encoding (transport->auth))
539 {
540 if (_dbus_string_get_length (&socket_transport->encoded_outgoing) == 0)
541 {
542 if (!_dbus_auth_encode_data (transport->auth,
543 header, &socket_transport->encoded_outgoing))
544 {
545 oom = TRUE;
546 goto out;
547 }
548
549 if (!_dbus_auth_encode_data (transport->auth,
550 body, &socket_transport->encoded_outgoing))
551 {
552 _dbus_string_set_length (&socket_transport->encoded_outgoing, 0);
553 oom = TRUE;
554 goto out;
555 }
556 }
557
558 total_bytes_to_write = _dbus_string_get_length (&socket_transport->encoded_outgoing);
559
560 #if 0
561 _dbus_verbose ("encoded message is %d bytes\n",
562 total_bytes_to_write);
563 #endif
564
565 bytes_written =
566 _dbus_write_socket (socket_transport->fd,
567 &socket_transport->encoded_outgoing,
568 socket_transport->message_bytes_written,
569 total_bytes_to_write - socket_transport->message_bytes_written);
570 }
571 else
572 {
573 total_bytes_to_write = header_len + body_len;
574
575 #if 0
576 _dbus_verbose ("message is %d bytes\n",
577 total_bytes_to_write);
578 #endif
579
580 if (socket_transport->message_bytes_written < header_len)
581 {
582 bytes_written =
583 _dbus_write_socket_two (socket_transport->fd,
584 header,
585 socket_transport->message_bytes_written,
586 header_len - socket_transport->message_bytes_written,
587 body,
588 0, body_len);
589 }
590 else
591 {
592 bytes_written =
593 _dbus_write_socket (socket_transport->fd,
594 body,
595 (socket_transport->message_bytes_written - header_len),
596 body_len -
597 (socket_transport->message_bytes_written - header_len));
598 }
599 }
600
601 if (bytes_written < 0)
602 {
603 /* EINTR already handled for us */
604
605 if (errno == EAGAIN ||
606 errno == EWOULDBLOCK)
607 goto out;
608 else
609 {
610 _dbus_verbose ("Error writing to remote app: %s\n",
611 _dbus_strerror (errno));
612 do_io_error (transport);
613 goto out;
614 }
615 }
616 else
617 {
618 _dbus_verbose (" wrote %d bytes of %d\n", bytes_written,
619 total_bytes_to_write);
620
621 total += bytes_written;
622 socket_transport->message_bytes_written += bytes_written;
623
624 _dbus_assert (socket_transport->message_bytes_written <=
625 total_bytes_to_write);
626
627 if (socket_transport->message_bytes_written == total_bytes_to_write)
628 {
629 socket_transport->message_bytes_written = 0;
630 _dbus_string_set_length (&socket_transport->encoded_outgoing, 0);
631
632 _dbus_connection_message_sent (transport->connection,
633 message);
634 }
635 }
636 }
637
638 out:
639 if (oom)
640 return FALSE;
641 else
642 return TRUE;
643 }
644
645 /* returns false on out-of-memory */
646 static dbus_bool_t
do_reading(DBusTransport * transport)647 do_reading (DBusTransport *transport)
648 {
649 DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
650 DBusString *buffer;
651 int bytes_read;
652 int total;
653 dbus_bool_t oom;
654
655 _dbus_verbose ("%s: fd = %d\n", _DBUS_FUNCTION_NAME,
656 socket_transport->fd);
657
658 /* No messages without authentication! */
659 if (!_dbus_transport_get_is_authenticated (transport))
660 return TRUE;
661
662 oom = FALSE;
663
664 total = 0;
665
666 again:
667
668 /* See if we've exceeded max messages and need to disable reading */
669 check_read_watch (transport);
670
671 if (total > socket_transport->max_bytes_read_per_iteration)
672 {
673 _dbus_verbose ("%d bytes exceeds %d bytes read per iteration, returning\n",
674 total, socket_transport->max_bytes_read_per_iteration);
675 goto out;
676 }
677
678 _dbus_assert (socket_transport->read_watch != NULL ||
679 transport->disconnected);
680
681 if (transport->disconnected)
682 goto out;
683
684 if (!dbus_watch_get_enabled (socket_transport->read_watch))
685 return TRUE;
686
687 if (_dbus_auth_needs_decoding (transport->auth))
688 {
689 if (_dbus_string_get_length (&socket_transport->encoded_incoming) > 0)
690 bytes_read = _dbus_string_get_length (&socket_transport->encoded_incoming);
691 else
692 bytes_read = _dbus_read_socket (socket_transport->fd,
693 &socket_transport->encoded_incoming,
694 socket_transport->max_bytes_read_per_iteration);
695
696 _dbus_assert (_dbus_string_get_length (&socket_transport->encoded_incoming) ==
697 bytes_read);
698
699 if (bytes_read > 0)
700 {
701 int orig_len;
702
703 _dbus_message_loader_get_buffer (transport->loader,
704 &buffer);
705
706 orig_len = _dbus_string_get_length (buffer);
707
708 if (!_dbus_auth_decode_data (transport->auth,
709 &socket_transport->encoded_incoming,
710 buffer))
711 {
712 _dbus_verbose ("Out of memory decoding incoming data\n");
713 oom = TRUE;
714 goto out;
715 }
716
717 _dbus_message_loader_return_buffer (transport->loader,
718 buffer,
719 _dbus_string_get_length (buffer) - orig_len);
720
721 _dbus_string_set_length (&socket_transport->encoded_incoming, 0);
722 }
723 }
724 else
725 {
726 _dbus_message_loader_get_buffer (transport->loader,
727 &buffer);
728
729 bytes_read = _dbus_read_socket (socket_transport->fd,
730 buffer, socket_transport->max_bytes_read_per_iteration);
731
732 _dbus_message_loader_return_buffer (transport->loader,
733 buffer,
734 bytes_read < 0 ? 0 : bytes_read);
735 }
736
737 if (bytes_read < 0)
738 {
739 /* EINTR already handled for us */
740
741 if (errno == ENOMEM)
742 {
743 _dbus_verbose ("Out of memory in read()/do_reading()\n");
744 oom = TRUE;
745 goto out;
746 }
747 else if (errno == EAGAIN ||
748 errno == EWOULDBLOCK)
749 goto out;
750 else
751 {
752 _dbus_verbose ("Error reading from remote app: %s\n",
753 _dbus_strerror (errno));
754 do_io_error (transport);
755 goto out;
756 }
757 }
758 else if (bytes_read == 0)
759 {
760 _dbus_verbose ("Disconnected from remote app\n");
761 do_io_error (transport);
762 goto out;
763 }
764 else
765 {
766 _dbus_verbose (" read %d bytes\n", bytes_read);
767
768 total += bytes_read;
769
770 if (!_dbus_transport_queue_messages (transport))
771 {
772 oom = TRUE;
773 _dbus_verbose (" out of memory when queueing messages we just read in the transport\n");
774 goto out;
775 }
776
777 /* Try reading more data until we get EAGAIN and return, or
778 * exceed max bytes per iteration. If in blocking mode of
779 * course we'll block instead of returning.
780 */
781 goto again;
782 }
783
784 out:
785 if (oom)
786 return FALSE;
787 else
788 return TRUE;
789 }
790
791 static dbus_bool_t
socket_handle_watch(DBusTransport * transport,DBusWatch * watch,unsigned int flags)792 socket_handle_watch (DBusTransport *transport,
793 DBusWatch *watch,
794 unsigned int flags)
795 {
796 DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
797
798 _dbus_assert (watch == socket_transport->read_watch ||
799 watch == socket_transport->write_watch);
800 _dbus_assert (watch != NULL);
801
802 /* Disconnect in case of an error. In case of hangup do not
803 * disconnect the transport because data can still be in the buffer
804 * and do_reading may need several iteration to read it all (because
805 * of its max_bytes_read_per_iteration limit). The condition where
806 * flags == HANGUP (without READABLE) probably never happen in fact.
807 */
808 if ((flags & DBUS_WATCH_ERROR) ||
809 ((flags & DBUS_WATCH_HANGUP) && !(flags & DBUS_WATCH_READABLE)))
810 {
811 _dbus_verbose ("Hang up or error on watch\n");
812 _dbus_transport_disconnect (transport);
813 return TRUE;
814 }
815
816 if (watch == socket_transport->read_watch &&
817 (flags & DBUS_WATCH_READABLE))
818 {
819 dbus_bool_t auth_finished;
820 #if 1
821 _dbus_verbose ("handling read watch %p flags = %x\n",
822 watch, flags);
823 #endif
824 if (!do_authentication (transport, TRUE, FALSE, &auth_finished))
825 return FALSE;
826
827 /* We don't want to do a read immediately following
828 * a successful authentication. This is so we
829 * have a chance to propagate the authentication
830 * state further up. Specifically, we need to
831 * process any pending data from the auth object.
832 */
833 if (!auth_finished)
834 {
835 if (!do_reading (transport))
836 {
837 _dbus_verbose ("no memory to read\n");
838 return FALSE;
839 }
840 }
841 else
842 {
843 _dbus_verbose ("Not reading anything since we just completed the authentication\n");
844 }
845 }
846 else if (watch == socket_transport->write_watch &&
847 (flags & DBUS_WATCH_WRITABLE))
848 {
849 #if 1
850 _dbus_verbose ("handling write watch, have_outgoing_messages = %d\n",
851 _dbus_connection_has_messages_to_send_unlocked (transport->connection));
852 #endif
853 if (!do_authentication (transport, FALSE, TRUE, NULL))
854 return FALSE;
855
856 if (!do_writing (transport))
857 {
858 _dbus_verbose ("no memory to write\n");
859 return FALSE;
860 }
861
862 /* See if we still need the write watch */
863 check_write_watch (transport);
864 }
865 #ifdef DBUS_ENABLE_VERBOSE_MODE
866 else
867 {
868 if (watch == socket_transport->read_watch)
869 _dbus_verbose ("asked to handle read watch with non-read condition 0x%x\n",
870 flags);
871 else if (watch == socket_transport->write_watch)
872 _dbus_verbose ("asked to handle write watch with non-write condition 0x%x\n",
873 flags);
874 else
875 _dbus_verbose ("asked to handle watch %p on fd %d that we don't recognize\n",
876 watch, dbus_watch_get_fd (watch));
877 }
878 #endif /* DBUS_ENABLE_VERBOSE_MODE */
879
880 return TRUE;
881 }
882
883 static void
socket_disconnect(DBusTransport * transport)884 socket_disconnect (DBusTransport *transport)
885 {
886 DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
887
888 _dbus_verbose ("%s\n", _DBUS_FUNCTION_NAME);
889
890 free_watches (transport);
891
892 _dbus_close_socket (socket_transport->fd, NULL);
893 socket_transport->fd = -1;
894 }
895
896 static dbus_bool_t
socket_connection_set(DBusTransport * transport)897 socket_connection_set (DBusTransport *transport)
898 {
899 DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
900
901 _dbus_watch_set_handler (socket_transport->write_watch,
902 _dbus_connection_handle_watch,
903 transport->connection, NULL);
904
905 _dbus_watch_set_handler (socket_transport->read_watch,
906 _dbus_connection_handle_watch,
907 transport->connection, NULL);
908
909 if (!_dbus_connection_add_watch_unlocked (transport->connection,
910 socket_transport->write_watch))
911 return FALSE;
912
913 if (!_dbus_connection_add_watch_unlocked (transport->connection,
914 socket_transport->read_watch))
915 {
916 _dbus_connection_remove_watch_unlocked (transport->connection,
917 socket_transport->write_watch);
918 return FALSE;
919 }
920
921 check_read_watch (transport);
922 check_write_watch (transport);
923
924 return TRUE;
925 }
926
927 /**
928 * @todo We need to have a way to wake up the select sleep if
929 * a new iteration request comes in with a flag (read/write) that
930 * we're not currently serving. Otherwise a call that just reads
931 * could block a write call forever (if there are no incoming
932 * messages).
933 */
934 static void
socket_do_iteration(DBusTransport * transport,unsigned int flags,int timeout_milliseconds)935 socket_do_iteration (DBusTransport *transport,
936 unsigned int flags,
937 int timeout_milliseconds)
938 {
939 DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
940 DBusPollFD poll_fd;
941 int poll_res;
942 int poll_timeout;
943
944 _dbus_verbose (" iteration flags = %s%s timeout = %d read_watch = %p write_watch = %p fd = %d\n",
945 flags & DBUS_ITERATION_DO_READING ? "read" : "",
946 flags & DBUS_ITERATION_DO_WRITING ? "write" : "",
947 timeout_milliseconds,
948 socket_transport->read_watch,
949 socket_transport->write_watch,
950 socket_transport->fd);
951
952 /* the passed in DO_READING/DO_WRITING flags indicate whether to
953 * read/write messages, but regardless of those we may need to block
954 * for reading/writing to do auth. But if we do reading for auth,
955 * we don't want to read any messages yet if not given DO_READING.
956 */
957
958 poll_fd.fd = socket_transport->fd;
959 poll_fd.events = 0;
960
961 if (_dbus_transport_get_is_authenticated (transport))
962 {
963 /* This is kind of a hack; if we have stuff to write, then try
964 * to avoid the poll. This is probably about a 5% speedup on an
965 * echo client/server.
966 *
967 * If both reading and writing were requested, we want to avoid this
968 * since it could have funky effects:
969 * - both ends spinning waiting for the other one to read
970 * data so they can finish writing
971 * - prioritizing all writing ahead of reading
972 */
973 if ((flags & DBUS_ITERATION_DO_WRITING) &&
974 !(flags & (DBUS_ITERATION_DO_READING | DBUS_ITERATION_BLOCK)) &&
975 !transport->disconnected &&
976 _dbus_connection_has_messages_to_send_unlocked (transport->connection))
977 {
978 do_writing (transport);
979
980 if (transport->disconnected ||
981 !_dbus_connection_has_messages_to_send_unlocked (transport->connection))
982 goto out;
983 }
984
985 /* If we get here, we decided to do the poll() after all */
986 _dbus_assert (socket_transport->read_watch);
987 if (flags & DBUS_ITERATION_DO_READING)
988 poll_fd.events |= _DBUS_POLLIN;
989
990 _dbus_assert (socket_transport->write_watch);
991 if (flags & DBUS_ITERATION_DO_WRITING)
992 poll_fd.events |= _DBUS_POLLOUT;
993 }
994 else
995 {
996 DBusAuthState auth_state;
997
998 auth_state = _dbus_auth_do_work (transport->auth);
999
1000 if (transport->receive_credentials_pending ||
1001 auth_state == DBUS_AUTH_STATE_WAITING_FOR_INPUT)
1002 poll_fd.events |= _DBUS_POLLIN;
1003
1004 if (transport->send_credentials_pending ||
1005 auth_state == DBUS_AUTH_STATE_HAVE_BYTES_TO_SEND)
1006 poll_fd.events |= _DBUS_POLLOUT;
1007 }
1008
1009 if (poll_fd.events)
1010 {
1011 if (flags & DBUS_ITERATION_BLOCK)
1012 poll_timeout = timeout_milliseconds;
1013 else
1014 poll_timeout = 0;
1015
1016 /* For blocking selects we drop the connection lock here
1017 * to avoid blocking out connection access during a potentially
1018 * indefinite blocking call. The io path is still protected
1019 * by the io_path_cond condvar, so we won't reenter this.
1020 */
1021 if (flags & DBUS_ITERATION_BLOCK)
1022 {
1023 _dbus_verbose ("unlock %s pre poll\n", _DBUS_FUNCTION_NAME);
1024 _dbus_connection_unlock (transport->connection);
1025 }
1026
1027 again:
1028 poll_res = _dbus_poll (&poll_fd, 1, poll_timeout);
1029
1030 if (poll_res < 0 && errno == EINTR)
1031 goto again;
1032
1033 if (flags & DBUS_ITERATION_BLOCK)
1034 {
1035 _dbus_verbose ("lock %s post poll\n", _DBUS_FUNCTION_NAME);
1036 _dbus_connection_lock (transport->connection);
1037 }
1038
1039 if (poll_res >= 0)
1040 {
1041 if (poll_res == 0)
1042 poll_fd.revents = 0; /* some concern that posix does not guarantee this;
1043 * valgrind flags it as an error. though it probably
1044 * is guaranteed on linux at least.
1045 */
1046
1047 if (poll_fd.revents & _DBUS_POLLERR)
1048 do_io_error (transport);
1049 else
1050 {
1051 dbus_bool_t need_read = (poll_fd.revents & _DBUS_POLLIN) > 0;
1052 dbus_bool_t need_write = (poll_fd.revents & _DBUS_POLLOUT) > 0;
1053 dbus_bool_t authentication_completed;
1054
1055 _dbus_verbose ("in iteration, need_read=%d need_write=%d\n",
1056 need_read, need_write);
1057 do_authentication (transport, need_read, need_write,
1058 &authentication_completed);
1059
1060 /* See comment in socket_handle_watch. */
1061 if (authentication_completed)
1062 goto out;
1063
1064 if (need_read && (flags & DBUS_ITERATION_DO_READING))
1065 do_reading (transport);
1066 if (need_write && (flags & DBUS_ITERATION_DO_WRITING))
1067 do_writing (transport);
1068 }
1069 }
1070 else
1071 {
1072 _dbus_verbose ("Error from _dbus_poll(): %s\n",
1073 _dbus_strerror (errno));
1074 }
1075 }
1076
1077
1078 out:
1079 /* We need to install the write watch only if we did not
1080 * successfully write everything. Note we need to be careful that we
1081 * don't call check_write_watch *before* do_writing, since it's
1082 * inefficient to add the write watch, and we can avoid it most of
1083 * the time since we can write immediately.
1084 *
1085 * However, we MUST always call check_write_watch(); DBusConnection code
1086 * relies on the fact that running an iteration will notice that
1087 * messages are pending.
1088 */
1089 check_write_watch (transport);
1090
1091 _dbus_verbose (" ... leaving do_iteration()\n");
1092 }
1093
1094 static void
socket_live_messages_changed(DBusTransport * transport)1095 socket_live_messages_changed (DBusTransport *transport)
1096 {
1097 /* See if we should look for incoming messages again */
1098 check_read_watch (transport);
1099 }
1100
1101
1102 static dbus_bool_t
socket_get_socket_fd(DBusTransport * transport,int * fd_p)1103 socket_get_socket_fd (DBusTransport *transport,
1104 int *fd_p)
1105 {
1106 DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
1107
1108 *fd_p = socket_transport->fd;
1109
1110 return TRUE;
1111 }
1112
1113 static const DBusTransportVTable socket_vtable = {
1114 socket_finalize,
1115 socket_handle_watch,
1116 socket_disconnect,
1117 socket_connection_set,
1118 socket_do_iteration,
1119 socket_live_messages_changed,
1120 socket_get_socket_fd
1121 };
1122
1123 /**
1124 * Creates a new transport for the given socket file descriptor. The file
1125 * descriptor must be nonblocking (use _dbus_set_fd_nonblocking() to
1126 * make it so). This function is shared by various transports that
1127 * boil down to a full duplex file descriptor.
1128 *
1129 * @param fd the file descriptor.
1130 * @param server_guid non-#NULL if this transport is on the server side of a connection
1131 * @param address the transport's address
1132 * @returns the new transport, or #NULL if no memory.
1133 */
1134 DBusTransport*
_dbus_transport_new_for_socket(int fd,const DBusString * server_guid,const DBusString * address)1135 _dbus_transport_new_for_socket (int fd,
1136 const DBusString *server_guid,
1137 const DBusString *address)
1138 {
1139 DBusTransportSocket *socket_transport;
1140
1141 socket_transport = dbus_new0 (DBusTransportSocket, 1);
1142 if (socket_transport == NULL)
1143 return NULL;
1144
1145 if (!_dbus_string_init (&socket_transport->encoded_outgoing))
1146 goto failed_0;
1147
1148 if (!_dbus_string_init (&socket_transport->encoded_incoming))
1149 goto failed_1;
1150
1151 socket_transport->write_watch = _dbus_watch_new (fd,
1152 DBUS_WATCH_WRITABLE,
1153 FALSE,
1154 NULL, NULL, NULL);
1155 if (socket_transport->write_watch == NULL)
1156 goto failed_2;
1157
1158 socket_transport->read_watch = _dbus_watch_new (fd,
1159 DBUS_WATCH_READABLE,
1160 FALSE,
1161 NULL, NULL, NULL);
1162 if (socket_transport->read_watch == NULL)
1163 goto failed_3;
1164
1165 if (!_dbus_transport_init_base (&socket_transport->base,
1166 &socket_vtable,
1167 server_guid, address))
1168 goto failed_4;
1169
1170 socket_transport->fd = fd;
1171 socket_transport->message_bytes_written = 0;
1172
1173 /* These values should probably be tunable or something. */
1174 socket_transport->max_bytes_read_per_iteration = 2048;
1175 socket_transport->max_bytes_written_per_iteration = 2048;
1176
1177 return (DBusTransport*) socket_transport;
1178
1179 failed_4:
1180 _dbus_watch_unref (socket_transport->read_watch);
1181 failed_3:
1182 _dbus_watch_unref (socket_transport->write_watch);
1183 failed_2:
1184 _dbus_string_free (&socket_transport->encoded_incoming);
1185 failed_1:
1186 _dbus_string_free (&socket_transport->encoded_outgoing);
1187 failed_0:
1188 dbus_free (socket_transport);
1189 return NULL;
1190 }
1191
1192 /**
1193 * Creates a new transport for the given hostname and port.
1194 *
1195 * @param host the host to connect to
1196 * @param port the port to connect to
1197 * @param error location to store reason for failure.
1198 * @returns a new transport, or #NULL on failure.
1199 */
1200 DBusTransport*
_dbus_transport_new_for_tcp_socket(const char * host,dbus_int32_t port,DBusError * error)1201 _dbus_transport_new_for_tcp_socket (const char *host,
1202 dbus_int32_t port,
1203 DBusError *error)
1204 {
1205 int fd;
1206 DBusTransport *transport;
1207 DBusString address;
1208
1209 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
1210
1211 if (!_dbus_string_init (&address))
1212 {
1213 dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
1214 return NULL;
1215 }
1216
1217 if (!_dbus_string_append (&address, "tcp:"))
1218 goto error;
1219
1220 if (host != NULL &&
1221 (!_dbus_string_append (&address, "host=") ||
1222 !_dbus_string_append (&address, host)))
1223 goto error;
1224
1225 if (!_dbus_string_append (&address, ",port=") ||
1226 !_dbus_string_append_int (&address, port))
1227 goto error;
1228
1229 fd = _dbus_connect_tcp_socket (host, port, error);
1230 if (fd < 0)
1231 {
1232 _DBUS_ASSERT_ERROR_IS_SET (error);
1233 _dbus_string_free (&address);
1234 return NULL;
1235 }
1236
1237 _dbus_fd_set_close_on_exec (fd);
1238
1239 _dbus_verbose ("Successfully connected to tcp socket %s:%d\n",
1240 host, port);
1241
1242 transport = _dbus_transport_new_for_socket (fd, NULL, &address);
1243 if (transport == NULL)
1244 {
1245 dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
1246 _dbus_close_socket (fd, NULL);
1247 _dbus_string_free (&address);
1248 fd = -1;
1249 }
1250
1251 _dbus_string_free (&address);
1252
1253 return transport;
1254
1255 error:
1256 _dbus_string_free (&address);
1257 dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
1258 return NULL;
1259 }
1260
1261 /**
1262 * Opens a TCP socket transport.
1263 *
1264 * @param entry the address entry to try opening as a tcp transport.
1265 * @param transport_p return location for the opened transport
1266 * @param error error to be set
1267 * @returns result of the attempt
1268 */
1269 DBusTransportOpenResult
_dbus_transport_open_socket(DBusAddressEntry * entry,DBusTransport ** transport_p,DBusError * error)1270 _dbus_transport_open_socket(DBusAddressEntry *entry,
1271 DBusTransport **transport_p,
1272 DBusError *error)
1273 {
1274 const char *method;
1275
1276 method = dbus_address_entry_get_method (entry);
1277 _dbus_assert (method != NULL);
1278
1279 if (strcmp (method, "tcp") == 0)
1280 {
1281 const char *host = dbus_address_entry_get_value (entry, "host");
1282 const char *port = dbus_address_entry_get_value (entry, "port");
1283 DBusString str;
1284 long lport;
1285 dbus_bool_t sresult;
1286
1287 if (port == NULL)
1288 {
1289 _dbus_set_bad_address (error, "tcp", "port", NULL);
1290 return DBUS_TRANSPORT_OPEN_BAD_ADDRESS;
1291 }
1292
1293 _dbus_string_init_const (&str, port);
1294 sresult = _dbus_string_parse_int (&str, 0, &lport, NULL);
1295 _dbus_string_free (&str);
1296
1297 if (sresult == FALSE || lport <= 0 || lport > 65535)
1298 {
1299 _dbus_set_bad_address (error, NULL, NULL,
1300 "Port is not an integer between 0 and 65535");
1301 return DBUS_TRANSPORT_OPEN_BAD_ADDRESS;
1302 }
1303
1304 *transport_p = _dbus_transport_new_for_tcp_socket (host, lport, error);
1305 if (*transport_p == NULL)
1306 {
1307 _DBUS_ASSERT_ERROR_IS_SET (error);
1308 return DBUS_TRANSPORT_OPEN_DID_NOT_CONNECT;
1309 }
1310 else
1311 {
1312 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
1313 return DBUS_TRANSPORT_OPEN_OK;
1314 }
1315 }
1316 else
1317 {
1318 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
1319 return DBUS_TRANSPORT_OPEN_NOT_HANDLED;
1320 }
1321 }
1322
1323 /** @} */
1324
1325