1 /* -*- mode: C; c-file-style: "gnu" -*- */
2 /* dbus-transport.c DBusTransport object (internal to D-BUS implementation)
4 * Copyright (C) 2002, 2003 Red Hat Inc.
6 * Licensed under the Academic Free License version 2.0
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.
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.
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
24 #include "dbus-transport-protected.h"
25 #include "dbus-transport-unix.h"
26 #include "dbus-connection-internal.h"
27 #include "dbus-watch.h"
28 #include "dbus-auth.h"
29 #include "dbus-address.h"
30 #ifdef DBUS_BUILD_TESTS
31 #include "dbus-server-debug-pipe.h"
35 * @defgroup DBusTransport DBusTransport object
36 * @ingroup DBusInternals
37 * @brief "Backend" for a DBusConnection.
39 * Types and functions related to DBusTransport. A transport is an
40 * abstraction that can send and receive data via various kinds of
41 * network connections or other IPC mechanisms.
47 * @typedef DBusTransport
49 * Opaque object representing a way message stream.
50 * DBusTransport abstracts various kinds of actual
51 * transport mechanism, such as different network protocols,
52 * or encryption schemes.
56 live_messages_size_notify (DBusCounter *counter,
59 DBusTransport *transport = user_data;
61 _dbus_transport_ref (transport);
64 _dbus_verbose ("Counter value is now %d\n",
65 (int) _dbus_counter_get_value (counter));
68 /* disable or re-enable the read watch for the transport if
71 if (* transport->vtable->live_messages_changed)
72 (* transport->vtable->live_messages_changed) (transport);
74 _dbus_transport_unref (transport);
78 * Initializes the base class members of DBusTransport.
79 * Chained up to by subclasses in their constructor.
81 * @param transport the transport being created.
82 * @param vtable the subclass vtable.
83 * @param server #TRUE if this transport is on the server side of a connection
84 * @param address the address of the transport
85 * @returns #TRUE on success.
88 _dbus_transport_init_base (DBusTransport *transport,
89 const DBusTransportVTable *vtable,
91 const DBusString *address)
93 DBusMessageLoader *loader;
98 loader = _dbus_message_loader_new ();
103 auth = _dbus_auth_server_new ();
105 auth = _dbus_auth_client_new ();
108 _dbus_message_loader_unref (loader);
112 counter = _dbus_counter_new ();
115 _dbus_auth_unref (auth);
116 _dbus_message_loader_unref (loader);
122 _dbus_assert (address == NULL);
127 _dbus_assert (address != NULL);
129 if (!_dbus_string_copy_data (address, &address_copy))
131 _dbus_counter_unref (counter);
132 _dbus_auth_unref (auth);
133 _dbus_message_loader_unref (loader);
138 transport->refcount = 1;
139 transport->vtable = vtable;
140 transport->loader = loader;
141 transport->auth = auth;
142 transport->live_messages_size = counter;
143 transport->authenticated = FALSE;
144 transport->messages_need_sending = FALSE;
145 transport->disconnected = FALSE;
146 transport->send_credentials_pending = !server;
147 transport->receive_credentials_pending = server;
148 transport->is_server = server;
149 transport->address = address_copy;
151 transport->unix_user_function = NULL;
152 transport->unix_user_data = NULL;
153 transport->free_unix_user_data = NULL;
155 /* Try to default to something that won't totally hose the system,
156 * but doesn't impose too much of a limitation.
158 transport->max_live_messages_size = _DBUS_ONE_MEGABYTE * 63;
160 transport->credentials.pid = -1;
161 transport->credentials.uid = -1;
162 transport->credentials.gid = -1;
164 _dbus_counter_set_notify (transport->live_messages_size,
165 transport->max_live_messages_size,
166 live_messages_size_notify,
169 if (transport->address)
170 _dbus_verbose ("Initialized transport on address %s\n", transport->address);
176 * Finalizes base class members of DBusTransport.
177 * Chained up to from subclass finalizers.
179 * @param transport the transport.
182 _dbus_transport_finalize_base (DBusTransport *transport)
184 if (!transport->disconnected)
185 _dbus_transport_disconnect (transport);
187 if (transport->free_unix_user_data != NULL)
188 (* transport->free_unix_user_data) (transport->unix_user_data);
190 _dbus_message_loader_unref (transport->loader);
191 _dbus_auth_unref (transport->auth);
192 _dbus_counter_set_notify (transport->live_messages_size,
194 _dbus_counter_unref (transport->live_messages_size);
195 dbus_free (transport->address);
199 * Opens a new transport for the given address. (This opens a
200 * client-side-of-the-connection transport.)
202 * @todo error messages on bad address could really be better.
203 * DBusResultCode is a bit limiting here.
205 * @param address the address.
206 * @param error location to store reason for failure.
207 * @returns new transport of #NULL on failure.
210 _dbus_transport_open (const char *address,
213 DBusTransport *transport;
214 DBusAddressEntry **entries;
216 DBusError first_error;
218 const char *address_problem_type;
219 const char *address_problem_field;
220 const char *address_problem_other;
222 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
224 if (!dbus_parse_address (address, &entries, &len, error))
227 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
230 address_problem_type = NULL;
231 address_problem_field = NULL;
232 address_problem_other = NULL;
234 dbus_error_init (&tmp_error);
235 dbus_error_init (&first_error);
236 for (i = 0; i < len; i++)
240 method = dbus_address_entry_get_method (entries[i]);
242 if (strcmp (method, "unix") == 0)
244 const char *path = dbus_address_entry_get_value (entries[i], "path");
245 const char *tmpdir = dbus_address_entry_get_value (entries[i], "tmpdir");
246 const char *abstract = dbus_address_entry_get_value (entries[i], "abstract");
250 address_problem_other = "cannot use the \"tmpdir\" option for an address to connect to, only in an address to listen on";
254 if (path == NULL && abstract == NULL)
256 address_problem_type = "unix";
257 address_problem_field = "path or abstract";
261 if (path != NULL && abstract != NULL)
263 address_problem_other = "can't specify both \"path\" and \"abstract\" options in an address";
268 transport = _dbus_transport_new_for_domain_socket (path, FALSE,
271 transport = _dbus_transport_new_for_domain_socket (abstract, TRUE,
274 else if (strcmp (method, "tcp") == 0)
276 const char *host = dbus_address_entry_get_value (entries[i], "host");
277 const char *port = dbus_address_entry_get_value (entries[i], "port");
284 address_problem_type = "tcp";
285 address_problem_field = "port";
289 _dbus_string_init_const (&str, port);
290 sresult = _dbus_string_parse_int (&str, 0, &lport, NULL);
291 _dbus_string_free (&str);
293 if (sresult == FALSE || lport <= 0 || lport > 65535)
295 address_problem_other = "Port is not an integer between 0 and 65535";
299 transport = _dbus_transport_new_for_tcp_socket (host, lport, &tmp_error);
301 #ifdef DBUS_BUILD_TESTS
302 else if (strcmp (method, "debug-pipe") == 0)
304 const char *name = dbus_address_entry_get_value (entries[i], "name");
308 address_problem_type = "debug-pipe";
309 address_problem_field = "name";
313 transport = _dbus_transport_debug_pipe_new (name, &tmp_error);
318 address_problem_other = "Unknown address type (examples of valid types are \"unix\" and \"tcp\")";
325 _DBUS_ASSERT_ERROR_IS_SET (&tmp_error);
328 dbus_move_error (&tmp_error, &first_error);
330 dbus_error_free (&tmp_error);
333 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
334 _DBUS_ASSERT_ERROR_IS_CLEAR (&tmp_error);
336 if (transport == NULL)
338 _DBUS_ASSERT_ERROR_IS_SET (&first_error);
339 dbus_move_error (&first_error, error);
343 dbus_error_free (&first_error);
346 dbus_address_entries_free (entries);
350 dbus_address_entries_free (entries);
352 if (address_problem_type != NULL)
353 dbus_set_error (error, DBUS_ERROR_BAD_ADDRESS,
354 "Address of type %s was missing argument %s",
355 address_problem_type, address_problem_field);
357 dbus_set_error (error, DBUS_ERROR_BAD_ADDRESS,
358 "Could not parse address: %s",
359 address_problem_other);
365 * Increments the reference count for the transport.
367 * @param transport the transport.
368 * @returns the transport.
371 _dbus_transport_ref (DBusTransport *transport)
373 _dbus_assert (transport->refcount > 0);
375 transport->refcount += 1;
381 * Decrements the reference count for the transport.
382 * Disconnects and finalizes the transport if
383 * the reference count reaches zero.
385 * @param transport the transport.
388 _dbus_transport_unref (DBusTransport *transport)
390 _dbus_assert (transport != NULL);
391 _dbus_assert (transport->refcount > 0);
393 transport->refcount -= 1;
394 if (transport->refcount == 0)
396 _dbus_assert (transport->vtable->finalize != NULL);
398 (* transport->vtable->finalize) (transport);
403 * Closes our end of the connection to a remote application. Further
404 * attempts to use this transport will fail. Only the first call to
405 * _dbus_transport_disconnect() will have an effect.
407 * @param transport the transport.
411 _dbus_transport_disconnect (DBusTransport *transport)
413 _dbus_assert (transport->vtable->disconnect != NULL);
415 if (transport->disconnected)
418 (* transport->vtable->disconnect) (transport);
420 transport->disconnected = TRUE;
424 * Returns #TRUE if the transport has not been disconnected.
425 * Disconnection can result from _dbus_transport_disconnect()
426 * or because the server drops its end of the connection.
428 * @param transport the transport.
429 * @returns whether we're connected
432 _dbus_transport_get_is_connected (DBusTransport *transport)
434 return !transport->disconnected;
438 * Returns #TRUE if we have been authenticated. Will return #TRUE
439 * even if the transport is disconnected.
441 * @todo needs to drop connection->mutex when calling the unix_user_function
443 * @param transport the transport
444 * @returns whether we're authenticated
447 _dbus_transport_get_is_authenticated (DBusTransport *transport)
449 if (transport->authenticated)
453 dbus_bool_t maybe_authenticated;
455 if (transport->disconnected)
458 maybe_authenticated =
459 (!(transport->send_credentials_pending ||
460 transport->receive_credentials_pending));
462 if (maybe_authenticated)
464 switch (_dbus_auth_do_work (transport->auth))
466 case DBUS_AUTH_STATE_AUTHENTICATED:
467 /* leave as maybe_authenticated */
470 maybe_authenticated = FALSE;
474 /* If we've authenticated as some identity, check that the auth
475 * identity is the same as our own identity. In the future, we
476 * may have API allowing applications to specify how this is
477 * done, for example they may allow connection as any identity,
478 * but then impose restrictions on certain identities.
479 * Or they may give certain identities extra privileges.
482 if (maybe_authenticated && transport->is_server)
484 DBusCredentials auth_identity;
486 _dbus_auth_get_identity (transport->auth, &auth_identity);
488 if (transport->unix_user_function != NULL)
490 /* FIXME we hold the connection lock here and should drop it */
491 if (!(* transport->unix_user_function) (transport->connection,
493 transport->unix_user_data))
495 _dbus_verbose ("Client UID "DBUS_UID_FORMAT
496 " was rejected, disconnecting\n",
498 _dbus_transport_disconnect (transport);
503 _dbus_verbose ("Client UID "DBUS_UID_FORMAT" authorized\n", auth_identity.uid);
508 DBusCredentials our_identity;
510 _dbus_credentials_from_current_process (&our_identity);
512 if (!_dbus_credentials_match (&our_identity,
515 _dbus_verbose ("Client authorized as UID "DBUS_UID_FORMAT
516 " but our UID is "DBUS_UID_FORMAT", disconnecting\n",
517 auth_identity.uid, our_identity.uid);
518 _dbus_transport_disconnect (transport);
523 _dbus_verbose ("Client authorized as UID "DBUS_UID_FORMAT
524 " matching our UID "DBUS_UID_FORMAT"\n",
525 auth_identity.uid, our_identity.uid);
530 transport->authenticated = maybe_authenticated;
532 return transport->authenticated;
537 * Gets the address of a transport. It will be
538 * #NULL for a server-side transport.
540 * @param transport the transport
541 * @returns transport's address
544 _dbus_transport_get_address (DBusTransport *transport)
546 return transport->address;
550 * Handles a watch by reading data, writing data, or disconnecting
551 * the transport, as appropriate for the given condition.
553 * @param transport the transport.
554 * @param watch the watch.
555 * @param condition the current state of the watched file descriptor.
556 * @returns #FALSE if not enough memory to fully handle the watch
559 _dbus_transport_handle_watch (DBusTransport *transport,
561 unsigned int condition)
565 _dbus_assert (transport->vtable->handle_watch != NULL);
567 if (transport->disconnected)
570 if (dbus_watch_get_fd (watch) < 0)
572 _dbus_warn ("Tried to handle an invalidated watch; this watch should have been removed\n");
576 _dbus_watch_sanitize_condition (watch, &condition);
578 _dbus_transport_ref (transport);
579 _dbus_watch_ref (watch);
580 retval = (* transport->vtable->handle_watch) (transport, watch, condition);
581 _dbus_watch_unref (watch);
582 _dbus_transport_unref (transport);
588 * Sets the connection using this transport. Allows the transport
589 * to add watches to the connection, queue incoming messages,
590 * and pull outgoing messages.
592 * @param transport the transport.
593 * @param connection the connection.
594 * @returns #FALSE if not enough memory
597 _dbus_transport_set_connection (DBusTransport *transport,
598 DBusConnection *connection)
600 _dbus_assert (transport->vtable->connection_set != NULL);
601 _dbus_assert (transport->connection == NULL);
603 transport->connection = connection;
605 _dbus_transport_ref (transport);
606 if (!(* transport->vtable->connection_set) (transport))
607 transport->connection = NULL;
608 _dbus_transport_unref (transport);
610 return transport->connection != NULL;
614 * Notifies the transport when the outgoing message queue goes from
615 * empty to non-empty or vice versa. Typically causes the transport to
616 * add or remove its DBUS_WATCH_WRITABLE watch.
618 * @param transport the transport.
619 * @param queue_length the length of the outgoing message queue.
623 _dbus_transport_messages_pending (DBusTransport *transport,
626 _dbus_assert (transport->vtable->messages_pending != NULL);
628 if (transport->disconnected)
631 transport->messages_need_sending = queue_length > 0;
633 _dbus_transport_ref (transport);
634 (* transport->vtable->messages_pending) (transport,
636 _dbus_transport_unref (transport);
640 * Get the UNIX file descriptor, if any.
642 * @param transport the transport
643 * @param fd_p pointer to fill in with the descriptor
644 * @returns #TRUE if a descriptor was available
647 _dbus_transport_get_unix_fd (DBusTransport *transport,
652 if (transport->vtable->get_unix_fd == NULL)
655 if (transport->disconnected)
658 _dbus_transport_ref (transport);
660 retval = (* transport->vtable->get_unix_fd) (transport,
663 _dbus_transport_unref (transport);
669 * Performs a single poll()/select() on the transport's file
670 * descriptors and then reads/writes data as appropriate,
671 * queueing incoming messages and sending outgoing messages.
672 * This is the backend for _dbus_connection_do_iteration().
673 * See _dbus_connection_do_iteration() for full details.
675 * @param transport the transport.
676 * @param flags indicates whether to read or write, and whether to block.
677 * @param timeout_milliseconds if blocking, timeout or -1 for no timeout.
680 _dbus_transport_do_iteration (DBusTransport *transport,
682 int timeout_milliseconds)
684 _dbus_assert (transport->vtable->do_iteration != NULL);
686 _dbus_verbose ("Transport iteration flags 0x%x timeout %d connected = %d\n",
687 flags, timeout_milliseconds, !transport->disconnected);
689 if ((flags & (DBUS_ITERATION_DO_WRITING |
690 DBUS_ITERATION_DO_READING)) == 0)
691 return; /* Nothing to do */
693 if (transport->disconnected)
696 _dbus_transport_ref (transport);
697 (* transport->vtable->do_iteration) (transport, flags,
698 timeout_milliseconds);
699 _dbus_transport_unref (transport);
703 recover_unused_bytes (DBusTransport *transport)
705 if (_dbus_auth_needs_decoding (transport->auth))
707 DBusString plaintext;
708 const DBusString *encoded;
712 if (!_dbus_string_init (&plaintext))
715 _dbus_auth_get_unused_bytes (transport->auth,
718 if (!_dbus_auth_decode_data (transport->auth,
719 encoded, &plaintext))
721 _dbus_string_free (&plaintext);
725 _dbus_message_loader_get_buffer (transport->loader,
728 orig_len = _dbus_string_get_length (buffer);
730 if (!_dbus_string_move (&plaintext, 0, buffer,
733 _dbus_string_free (&plaintext);
737 _dbus_verbose (" %d unused bytes sent to message loader\n",
738 _dbus_string_get_length (buffer) -
741 _dbus_message_loader_return_buffer (transport->loader,
743 _dbus_string_get_length (buffer) -
746 _dbus_auth_delete_unused_bytes (transport->auth);
748 _dbus_string_free (&plaintext);
752 const DBusString *bytes;
755 dbus_bool_t succeeded;
757 _dbus_message_loader_get_buffer (transport->loader,
760 orig_len = _dbus_string_get_length (buffer);
762 _dbus_auth_get_unused_bytes (transport->auth,
766 if (!_dbus_string_copy (bytes, 0, buffer, _dbus_string_get_length (buffer)))
769 _dbus_verbose (" %d unused bytes sent to message loader\n",
770 _dbus_string_get_length (buffer) -
773 _dbus_message_loader_return_buffer (transport->loader,
775 _dbus_string_get_length (buffer) -
779 _dbus_auth_delete_unused_bytes (transport->auth);
787 _dbus_verbose ("Not enough memory to transfer unused bytes from auth conversation\n");
792 * Reports our current dispatch status (whether there's buffered
793 * data to be queued as messages, or not, or we need memory).
795 * @param transport the transport
796 * @returns current status
799 _dbus_transport_get_dispatch_status (DBusTransport *transport)
801 if (_dbus_counter_get_value (transport->live_messages_size) >= transport->max_live_messages_size)
802 return DBUS_DISPATCH_COMPLETE; /* complete for now */
804 if (!_dbus_transport_get_is_authenticated (transport))
806 if (_dbus_auth_do_work (transport->auth) ==
807 DBUS_AUTH_STATE_WAITING_FOR_MEMORY)
808 return DBUS_DISPATCH_NEED_MEMORY;
809 else if (!_dbus_transport_get_is_authenticated (transport))
810 return DBUS_DISPATCH_COMPLETE;
813 if (!transport->unused_bytes_recovered &&
814 !recover_unused_bytes (transport))
815 return DBUS_DISPATCH_NEED_MEMORY;
817 transport->unused_bytes_recovered = TRUE;
819 if (!_dbus_message_loader_queue_messages (transport->loader))
820 return DBUS_DISPATCH_NEED_MEMORY;
822 if (_dbus_message_loader_peek_message (transport->loader) != NULL)
823 return DBUS_DISPATCH_DATA_REMAINS;
825 return DBUS_DISPATCH_COMPLETE;
829 * Processes data we've read while handling a watch, potentially
830 * converting some of it to messages and queueing those messages on
833 * @param transport the transport
834 * @returns #TRUE if we had enough memory to queue all messages
837 _dbus_transport_queue_messages (DBusTransport *transport)
839 DBusDispatchStatus status;
842 _dbus_verbose ("_dbus_transport_queue_messages()\n");
845 /* Queue any messages */
846 while ((status = _dbus_transport_get_dispatch_status (transport)) == DBUS_DISPATCH_DATA_REMAINS)
848 DBusMessage *message;
851 link = _dbus_message_loader_pop_message_link (transport->loader);
852 _dbus_assert (link != NULL);
854 message = link->data;
856 _dbus_verbose ("queueing received message %p\n", message);
858 if (!_dbus_message_add_size_counter (message, transport->live_messages_size))
860 _dbus_message_loader_putback_message_link (transport->loader,
862 status = DBUS_DISPATCH_NEED_MEMORY;
867 /* pass ownership of link and message ref to connection */
868 _dbus_connection_queue_received_message_link (transport->connection,
873 if (_dbus_message_loader_get_is_corrupted (transport->loader))
875 _dbus_verbose ("Corrupted message stream, disconnecting\n");
876 _dbus_transport_disconnect (transport);
879 return status != DBUS_DISPATCH_NEED_MEMORY;
883 * See dbus_connection_set_max_message_size().
885 * @param transport the transport
886 * @param size the max size of a single message
889 _dbus_transport_set_max_message_size (DBusTransport *transport,
892 _dbus_message_loader_set_max_message_size (transport->loader, size);
896 * See dbus_connection_get_max_message_size().
898 * @param transport the transport
899 * @returns max message size
902 _dbus_transport_get_max_message_size (DBusTransport *transport)
904 return _dbus_message_loader_get_max_message_size (transport->loader);
908 * See dbus_connection_set_max_received_size().
910 * @param transport the transport
911 * @param size the max size of all incoming messages
914 _dbus_transport_set_max_received_size (DBusTransport *transport,
917 transport->max_live_messages_size = size;
918 _dbus_counter_set_notify (transport->live_messages_size,
919 transport->max_live_messages_size,
920 live_messages_size_notify,
926 * See dbus_connection_get_max_received_size().
928 * @param transport the transport
929 * @returns max bytes for all live messages
932 _dbus_transport_get_max_received_size (DBusTransport *transport)
934 return transport->max_live_messages_size;
938 * See dbus_connection_get_unix_user().
940 * @param transport the transport
941 * @param uid return location for the user ID
942 * @returns #TRUE if uid is filled in with a valid user ID
945 _dbus_transport_get_unix_user (DBusTransport *transport,
948 DBusCredentials auth_identity;
950 *uid = _DBUS_INT_MAX; /* better than some root or system user in
951 * case of bugs in the caller. Caller should
952 * never use this value on purpose, however.
955 if (!transport->authenticated)
958 _dbus_auth_get_identity (transport->auth, &auth_identity);
960 if (auth_identity.uid != DBUS_UID_UNSET)
962 *uid = auth_identity.uid;
970 * See dbus_connection_get_unix_process_id().
972 * @param transport the transport
973 * @param pid return location for the process ID
974 * @returns #TRUE if uid is filled in with a valid process ID
977 _dbus_transport_get_unix_process_id (DBusTransport *transport,
980 DBusCredentials auth_identity;
982 *pid = DBUS_PID_UNSET; /* Caller should never use this value on purpose,
983 * but we set it to a safe number, INT_MAX,
984 * just to root out possible bugs in bad callers.
987 if (!transport->authenticated)
990 _dbus_auth_get_identity (transport->auth, &auth_identity);
992 if (auth_identity.pid != DBUS_PID_UNSET)
994 *pid = auth_identity.pid;
1002 * See dbus_connection_set_unix_user_function().
1004 * @param transport the transport
1005 * @param function the predicate
1006 * @param data data to pass to the predicate
1007 * @param free_data_function function to free the data
1008 * @param old_data the old user data to be freed
1009 * @param old_free_data_function old free data function to free it with
1012 _dbus_transport_set_unix_user_function (DBusTransport *transport,
1013 DBusAllowUnixUserFunction function,
1015 DBusFreeFunction free_data_function,
1017 DBusFreeFunction *old_free_data_function)
1019 *old_data = transport->unix_user_data;
1020 *old_free_data_function = transport->free_unix_user_data;
1022 transport->unix_user_function = function;
1023 transport->unix_user_data = data;
1024 transport->free_unix_user_data = free_data_function;
1028 * Sets the SASL authentication mechanisms supported by this transport.
1030 * @param transport the transport
1031 * @param mechanisms the #NULL-terminated array of mechanisms
1033 * @returns #FALSE if no memory
1036 _dbus_transport_set_auth_mechanisms (DBusTransport *transport,
1037 const char **mechanisms)
1039 return _dbus_auth_set_mechanisms (transport->auth, mechanisms);