/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */ /* dbus-connection.c DBusConnection object * * Copyright (C) 2002-2006 Red Hat Inc. * * Licensed under the Academic Free License version 2.1 * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA * */ #include #include "dbus-shared.h" #include "dbus-connection.h" #include "dbus-list.h" #include "dbus-timeout.h" #include "dbus-transport.h" #include "dbus-watch.h" #include "dbus-connection-internal.h" #include "dbus-pending-call-internal.h" #include "dbus-list.h" #include "dbus-hash.h" #include "dbus-message-internal.h" #include "dbus-message-private.h" #include "dbus-threads.h" #include "dbus-protocol.h" #include "dbus-dataslot.h" #include "dbus-string.h" #include "dbus-pending-call.h" #include "dbus-object-tree.h" #include "dbus-threads-internal.h" #include "dbus-bus.h" #include "dbus-marshal-basic.h" #ifdef DBUS_DISABLE_CHECKS #define TOOK_LOCK_CHECK(connection) #define RELEASING_LOCK_CHECK(connection) #define HAVE_LOCK_CHECK(connection) #else #define TOOK_LOCK_CHECK(connection) do { \ _dbus_assert (!(connection)->have_connection_lock); \ (connection)->have_connection_lock = TRUE; \ } while (0) #define RELEASING_LOCK_CHECK(connection) do { \ _dbus_assert ((connection)->have_connection_lock); \ (connection)->have_connection_lock = FALSE; \ } while (0) #define HAVE_LOCK_CHECK(connection) _dbus_assert ((connection)->have_connection_lock) /* A "DO_NOT_HAVE_LOCK_CHECK" is impossible since we need the lock to check the flag */ #endif #define TRACE_LOCKS 1 #define CONNECTION_LOCK(connection) do { \ if (TRACE_LOCKS) { _dbus_verbose (" LOCK: %s\n", _DBUS_FUNCTION_NAME); } \ _dbus_mutex_lock ((connection)->mutex); \ TOOK_LOCK_CHECK (connection); \ } while (0) #define CONNECTION_UNLOCK(connection) do { \ if (TRACE_LOCKS) { _dbus_verbose (" UNLOCK: %s\n", _DBUS_FUNCTION_NAME); } \ RELEASING_LOCK_CHECK (connection); \ _dbus_mutex_unlock ((connection)->mutex); \ } while (0) #define DISPATCH_STATUS_NAME(s) \ ((s) == DBUS_DISPATCH_COMPLETE ? "complete" : \ (s) == DBUS_DISPATCH_DATA_REMAINS ? "data remains" : \ (s) == DBUS_DISPATCH_NEED_MEMORY ? "need memory" : \ "???") /** * @defgroup DBusConnection DBusConnection * @ingroup DBus * @brief Connection to another application * * A DBusConnection represents a connection to another * application. Messages can be sent and received via this connection. * The other application may be a message bus; for convenience, the * function dbus_bus_get() is provided to automatically open a * connection to the well-known message buses. * * In brief a DBusConnection is a message queue associated with some * message transport mechanism such as a socket. The connection * maintains a queue of incoming messages and a queue of outgoing * messages. * * Several functions use the following terms: * * * The function dbus_connection_read_write_dispatch() for example does all * three of these things, offering a simple alternative to a main loop. * * In an application with a main loop, the read/write/dispatch * operations are usually separate. * * The connection provides #DBusWatch and #DBusTimeout objects to * the main loop. These are used to know when reading, writing, or * dispatching should be performed. * * Incoming messages are processed * by calling dbus_connection_dispatch(). dbus_connection_dispatch() * runs any handlers registered for the topmost message in the message * queue, then discards the message, then returns. * * dbus_connection_get_dispatch_status() indicates whether * messages are currently in the queue that need dispatching. * dbus_connection_set_dispatch_status_function() allows * you to set a function to be used to monitor the dispatch status. * * If you're using GLib or Qt add-on libraries for D-Bus, there are * special convenience APIs in those libraries that hide * all the details of dispatch and watch/timeout monitoring. * For example, dbus_connection_setup_with_g_main(). * * If you aren't using these add-on libraries, but want to process * messages asynchronously, you must manually call * dbus_connection_set_dispatch_status_function(), * dbus_connection_set_watch_functions(), * dbus_connection_set_timeout_functions() providing appropriate * functions to integrate the connection with your application's main * loop. This can be tricky to get right; main loops are not simple. * * If you don't need to be asynchronous, you can ignore #DBusWatch, * #DBusTimeout, and dbus_connection_dispatch(). Instead, * dbus_connection_read_write_dispatch() can be used. * * Or, in very simple applications, * dbus_connection_pop_message() may be all you need, allowing you to * avoid setting up any handler functions (see * dbus_connection_add_filter(), * dbus_connection_register_object_path() for more on handlers). * * When you use dbus_connection_send() or one of its variants to send * a message, the message is added to the outgoing queue. It's * actually written to the network later; either in * dbus_watch_handle() invoked by your main loop, or in * dbus_connection_flush() which blocks until it can write out the * entire outgoing queue. The GLib/Qt add-on libraries again * handle the details here for you by setting up watch functions. * * When a connection is disconnected, you are guaranteed to get a * signal "Disconnected" from the interface * #DBUS_INTERFACE_LOCAL, path * #DBUS_PATH_LOCAL. * * You may not drop the last reference to a #DBusConnection * until that connection has been disconnected. * * You may dispatch the unprocessed incoming message queue even if the * connection is disconnected. However, "Disconnected" will always be * the last message in the queue (obviously no messages are received * after disconnection). * * After calling dbus_threads_init(), #DBusConnection has thread * locks and drops them when invoking user callbacks, so in general is * transparently threadsafe. However, #DBusMessage does NOT have * thread locks; you must not send the same message to multiple * #DBusConnection if those connections will be used from different threads, * for example. * * Also, if you dispatch or pop messages from multiple threads, it * may work in the sense that it won't crash, but it's tough to imagine * sane results; it will be completely unpredictable which messages * go to which threads. * * It's recommended to dispatch from a single thread. * * The most useful function to call from multiple threads at once * is dbus_connection_send_with_reply_and_block(). That is, * multiple threads can make method calls at the same time. * * If you aren't using threads, you can use a main loop and * dbus_pending_call_set_notify() to achieve a similar result. */ /** * @defgroup DBusConnectionInternals DBusConnection implementation details * @ingroup DBusInternals * @brief Implementation details of DBusConnection * * @{ */ /** * Internal struct representing a message filter function */ typedef struct DBusMessageFilter DBusMessageFilter; /** * Internal struct representing a message filter function */ struct DBusMessageFilter { DBusAtomic refcount; /**< Reference count */ DBusHandleMessageFunction function; /**< Function to call to filter */ void *user_data; /**< User data for the function */ DBusFreeFunction free_user_data_function; /**< Function to free the user data */ }; /** * Internals of DBusPreallocatedSend */ struct DBusPreallocatedSend { DBusConnection *connection; /**< Connection we'd send the message to */ DBusList *queue_link; /**< Preallocated link in the queue */ DBusList *counter_link; /**< Preallocated link in the resource counter */ }; #ifdef HAVE_DECL_MSG_NOSIGNAL static dbus_bool_t _dbus_modify_sigpipe = FALSE; #else static dbus_bool_t _dbus_modify_sigpipe = TRUE; #endif /** * Implementation details of DBusConnection. All fields are private. */ struct DBusConnection { DBusAtomic refcount; /**< Reference count. */ DBusMutex *mutex; /**< Lock on the entire DBusConnection */ DBusMutex *dispatch_mutex; /**< Protects dispatch_acquired */ DBusCondVar *dispatch_cond; /**< Notify when dispatch_acquired is available */ DBusMutex *io_path_mutex; /**< Protects io_path_acquired */ DBusCondVar *io_path_cond; /**< Notify when io_path_acquired is available */ DBusList *outgoing_messages; /**< Queue of messages we need to send, send the end of the list first. */ DBusList *incoming_messages; /**< Queue of messages we have received, end of the list received most recently. */ DBusMessage *message_borrowed; /**< Filled in if the first incoming message has been borrowed; * dispatch_acquired will be set by the borrower */ int n_outgoing; /**< Length of outgoing queue. */ int n_incoming; /**< Length of incoming queue. */ DBusCounter *outgoing_counter; /**< Counts size of outgoing messages. */ DBusTransport *transport; /**< Object that sends/receives messages over network. */ DBusWatchList *watches; /**< Stores active watches. */ DBusTimeoutList *timeouts; /**< Stores active timeouts. */ DBusList *filter_list; /**< List of filters. */ DBusDataSlotList slot_list; /**< Data stored by allocated integer ID */ DBusHashTable *pending_replies; /**< Hash of message serials to #DBusPendingCall. */ dbus_uint32_t client_serial; /**< Client serial. Increments each time a message is sent */ DBusList *disconnect_message_link; /**< Preallocated list node for queueing the disconnection message */ DBusWakeupMainFunction wakeup_main_function; /**< Function to wake up the mainloop */ void *wakeup_main_data; /**< Application data for wakeup_main_function */ DBusFreeFunction free_wakeup_main_data; /**< free wakeup_main_data */ DBusDispatchStatusFunction dispatch_status_function; /**< Function on dispatch status changes */ void *dispatch_status_data; /**< Application data for dispatch_status_function */ DBusFreeFunction free_dispatch_status_data; /**< free dispatch_status_data */ DBusDispatchStatus last_dispatch_status; /**< The last dispatch status we reported to the application. */ DBusList *link_cache; /**< A cache of linked list links to prevent contention * for the global linked list mempool lock */ DBusObjectTree *objects; /**< Object path handlers registered with this connection */ char *server_guid; /**< GUID of server if we are in shared_connections, #NULL if server GUID is unknown or connection is private */ /* These two MUST be bools and not bitfields, because they are protected by a separate lock * from connection->mutex and all bitfields in a word have to be read/written together. * So you can't have a different lock for different bitfields in the same word. */ dbus_bool_t dispatch_acquired; /**< Someone has dispatch path (can drain incoming queue) */ dbus_bool_t io_path_acquired; /**< Someone has transport io path (can use the transport to read/write messages) */ unsigned int shareable : 1; /**< #TRUE if libdbus owns a reference to the connection and can return it from dbus_connection_open() more than once */ unsigned int exit_on_disconnect : 1; /**< If #TRUE, exit after handling disconnect signal */ unsigned int route_peer_messages : 1; /**< If #TRUE, if org.freedesktop.DBus.Peer messages have a bus name, don't handle them automatically */ unsigned int disconnected_message_arrived : 1; /**< We popped or are dispatching the disconnected message. * if the disconnect_message_link is NULL then we queued it, but * this flag is whether it got to the head of the queue. */ unsigned int disconnected_message_processed : 1; /**< We did our default handling of the disconnected message, * such as closing the connection. */ #ifndef DBUS_DISABLE_CHECKS unsigned int have_connection_lock : 1; /**< Used to check locking */ #endif #ifndef DBUS_DISABLE_CHECKS int generation; /**< _dbus_current_generation that should correspond to this connection */ #endif }; static DBusDispatchStatus _dbus_connection_get_dispatch_status_unlocked (DBusConnection *connection); static void _dbus_connection_update_dispatch_status_and_unlock (DBusConnection *connection, DBusDispatchStatus new_status); static void _dbus_connection_last_unref (DBusConnection *connection); static void _dbus_connection_acquire_dispatch (DBusConnection *connection); static void _dbus_connection_release_dispatch (DBusConnection *connection); static DBusDispatchStatus _dbus_connection_flush_unlocked (DBusConnection *connection); static void _dbus_connection_close_possibly_shared_and_unlock (DBusConnection *connection); static dbus_bool_t _dbus_connection_get_is_connected_unlocked (DBusConnection *connection); static DBusMessageFilter * _dbus_message_filter_ref (DBusMessageFilter *filter) { _dbus_assert (filter->refcount.value > 0); _dbus_atomic_inc (&filter->refcount); return filter; } static void _dbus_message_filter_unref (DBusMessageFilter *filter) { _dbus_assert (filter->refcount.value > 0); if (_dbus_atomic_dec (&filter->refcount) == 1) { if (filter->free_user_data_function) (* filter->free_user_data_function) (filter->user_data); dbus_free (filter); } } /** * Acquires the connection lock. * * @param connection the connection. */ void _dbus_connection_lock (DBusConnection *connection) { CONNECTION_LOCK (connection); } /** * Releases the connection lock. * * @param connection the connection. */ void _dbus_connection_unlock (DBusConnection *connection) { CONNECTION_UNLOCK (connection); } /** * Wakes up the main loop if it is sleeping * Needed if we're e.g. queueing outgoing messages * on a thread while the mainloop sleeps. * * @param connection the connection. */ static void _dbus_connection_wakeup_mainloop (DBusConnection *connection) { if (connection->wakeup_main_function) (*connection->wakeup_main_function) (connection->wakeup_main_data); } #ifdef DBUS_BUILD_TESTS /* For now this function isn't used */ /** * Adds a message to the incoming message queue, returning #FALSE * if there's insufficient memory to queue the message. * Does not take over refcount of the message. * * @param connection the connection. * @param message the message to queue. * @returns #TRUE on success. */ dbus_bool_t _dbus_connection_queue_received_message (DBusConnection *connection, DBusMessage *message) { DBusList *link; link = _dbus_list_alloc_link (message); if (link == NULL) return FALSE; dbus_message_ref (message); _dbus_connection_queue_received_message_link (connection, link); return TRUE; } /** * Gets the locks so we can examine them * * @param connection the connection. * @param mutex_loc return for the location of the main mutex pointer * @param dispatch_mutex_loc return location of the dispatch mutex pointer * @param io_path_mutex_loc return location of the io_path mutex pointer * @param dispatch_cond_loc return location of the dispatch conditional * variable pointer * @param io_path_cond_loc return location of the io_path conditional * variable pointer */ void _dbus_connection_test_get_locks (DBusConnection *connection, DBusMutex **mutex_loc, DBusMutex **dispatch_mutex_loc, DBusMutex **io_path_mutex_loc, DBusCondVar **dispatch_cond_loc, DBusCondVar **io_path_cond_loc) { *mutex_loc = connection->mutex; *dispatch_mutex_loc = connection->dispatch_mutex; *io_path_mutex_loc = connection->io_path_mutex; *dispatch_cond_loc = connection->dispatch_cond; *io_path_cond_loc = connection->io_path_cond; } #endif /** * Adds a message-containing list link to the incoming message queue, * taking ownership of the link and the message's current refcount. * Cannot fail due to lack of memory. * * @param connection the connection. * @param link the message link to queue. */ void _dbus_connection_queue_received_message_link (DBusConnection *connection, DBusList *link) { DBusPendingCall *pending; dbus_uint32_t reply_serial; DBusMessage *message; _dbus_assert (_dbus_transport_get_is_authenticated (connection->transport)); _dbus_list_append_link (&connection->incoming_messages, link); message = link->data; /* If this is a reply we're waiting on, remove timeout for it */ reply_serial = dbus_message_get_reply_serial (message); if (reply_serial != 0) { pending = _dbus_hash_table_lookup_int (connection->pending_replies, reply_serial); if (pending != NULL) { if (_dbus_pending_call_is_timeout_added_unlocked (pending)) _dbus_connection_remove_timeout_unlocked (connection, _dbus_pending_call_get_timeout_unlocked (pending)); _dbus_pending_call_set_timeout_added_unlocked (pending, FALSE); } } connection->n_incoming += 1; _dbus_connection_wakeup_mainloop (connection); _dbus_verbose ("Message %p (%d %s %s %s '%s' reply to %u) added to incoming queue %p, %d incoming\n", message, dbus_message_get_type (message), dbus_message_get_path (message) ? dbus_message_get_path (message) : "no path", dbus_message_get_interface (message) ? dbus_message_get_interface (message) : "no interface", dbus_message_get_member (message) ? dbus_message_get_member (message) : "no member", dbus_message_get_signature (message), dbus_message_get_reply_serial (message), connection, connection->n_incoming);} /** * Adds a link + message to the incoming message queue. * Can't fail. Takes ownership of both link and message. * * @param connection the connection. * @param link the list node and message to queue. * */ void _dbus_connection_queue_synthesized_message_link (DBusConnection *connection, DBusList *link) { HAVE_LOCK_CHECK (connection); _dbus_list_append_link (&connection->incoming_messages, link); connection->n_incoming += 1; _dbus_connection_wakeup_mainloop (connection); _dbus_verbose ("Synthesized message %p added to incoming queue %p, %d incoming\n", link->data, connection, connection->n_incoming); } /** * Checks whether there are messages in the outgoing message queue. * Called with connection lock held. * * @param connection the connection. * @returns #TRUE if the outgoing queue is non-empty. */ dbus_bool_t _dbus_connection_has_messages_to_send_unlocked (DBusConnection *connection) { HAVE_LOCK_CHECK (connection); return connection->outgoing_messages != NULL; } /** * Checks whether there are messages in the outgoing message queue. * Use dbus_connection_flush() to block until all outgoing * messages have been written to the underlying transport * (such as a socket). * * @param connection the connection. * @returns #TRUE if the outgoing queue is non-empty. */ dbus_bool_t dbus_connection_has_messages_to_send (DBusConnection *connection) { dbus_bool_t v; _dbus_return_val_if_fail (connection != NULL, FALSE); CONNECTION_LOCK (connection); v = _dbus_connection_has_messages_to_send_unlocked (connection); CONNECTION_UNLOCK (connection); return v; } /** * Gets the next outgoing message. The message remains in the * queue, and the caller does not own a reference to it. * * @param connection the connection. * @returns the message to be sent. */ DBusMessage* _dbus_connection_get_message_to_send (DBusConnection *connection) { HAVE_LOCK_CHECK (connection); return _dbus_list_get_last (&connection->outgoing_messages); } /** * Notifies the connection that a message has been sent, so the * message can be removed from the outgoing queue. * Called with the connection lock held. * * @param connection the connection. * @param message the message that was sent. */ void _dbus_connection_message_sent (DBusConnection *connection, DBusMessage *message) { DBusList *link; HAVE_LOCK_CHECK (connection); /* This can be called before we even complete authentication, since * it's called on disconnect to clean up the outgoing queue. * It's also called as we successfully send each message. */ link = _dbus_list_get_last_link (&connection->outgoing_messages); _dbus_assert (link != NULL); _dbus_assert (link->data == message); /* Save this link in the link cache */ _dbus_list_unlink (&connection->outgoing_messages, link); _dbus_list_prepend_link (&connection->link_cache, link); connection->n_outgoing -= 1; _dbus_verbose ("Message %p (%d %s %s %s '%s') removed from outgoing queue %p, %d left to send\n", message, dbus_message_get_type (message), dbus_message_get_path (message) ? dbus_message_get_path (message) : "no path", dbus_message_get_interface (message) ? dbus_message_get_interface (message) : "no interface", dbus_message_get_member (message) ? dbus_message_get_member (message) : "no member", dbus_message_get_signature (message), connection, connection->n_outgoing); /* Save this link in the link cache also */ _dbus_message_remove_counter (message, connection->outgoing_counter, &link); _dbus_list_prepend_link (&connection->link_cache, link); dbus_message_unref (message); } /** Function to be called in protected_change_watch() with refcount held */ typedef dbus_bool_t (* DBusWatchAddFunction) (DBusWatchList *list, DBusWatch *watch); /** Function to be called in protected_change_watch() with refcount held */ typedef void (* DBusWatchRemoveFunction) (DBusWatchList *list, DBusWatch *watch); /** Function to be called in protected_change_watch() with refcount held */ typedef void (* DBusWatchToggleFunction) (DBusWatchList *list, DBusWatch *watch, dbus_bool_t enabled); static dbus_bool_t protected_change_watch (DBusConnection *connection, DBusWatch *watch, DBusWatchAddFunction add_function, DBusWatchRemoveFunction remove_function, DBusWatchToggleFunction toggle_function, dbus_bool_t enabled) { DBusWatchList *watches; dbus_bool_t retval; HAVE_LOCK_CHECK (connection); /* This isn't really safe or reasonable; a better pattern is the "do everything, then * drop lock and call out" one; but it has to be propagated up through all callers */ watches = connection->watches; if (watches) { connection->watches = NULL; _dbus_connection_ref_unlocked (connection); CONNECTION_UNLOCK (connection); if (add_function) retval = (* add_function) (watches, watch); else if (remove_function) { retval = TRUE; (* remove_function) (watches, watch); } else { retval = TRUE; (* toggle_function) (watches, watch, enabled); } CONNECTION_LOCK (connection); connection->watches = watches; _dbus_connection_unref_unlocked (connection); return retval; } else return FALSE; } /** * Adds a watch using the connection's DBusAddWatchFunction if * available. Otherwise records the watch to be added when said * function is available. Also re-adds the watch if the * DBusAddWatchFunction changes. May fail due to lack of memory. * Connection lock should be held when calling this. * * @param connection the connection. * @param watch the watch to add. * @returns #TRUE on success. */ dbus_bool_t _dbus_connection_add_watch_unlocked (DBusConnection *connection, DBusWatch *watch) { return protected_change_watch (connection, watch, _dbus_watch_list_add_watch, NULL, NULL, FALSE); } /** * Removes a watch using the connection's DBusRemoveWatchFunction * if available. It's an error to call this function on a watch * that was not previously added. * Connection lock should be held when calling this. * * @param connection the connection. * @param watch the watch to remove. */ void _dbus_connection_remove_watch_unlocked (DBusConnection *connection, DBusWatch *watch) { protected_change_watch (connection, watch, NULL, _dbus_watch_list_remove_watch, NULL, FALSE); } /** * Toggles a watch and notifies app via connection's * DBusWatchToggledFunction if available. It's an error to call this * function on a watch that was not previously added. * Connection lock should be held when calling this. * * @param connection the connection. * @param watch the watch to toggle. * @param enabled whether to enable or disable */ void _dbus_connection_toggle_watch_unlocked (DBusConnection *connection, DBusWatch *watch, dbus_bool_t enabled) { _dbus_assert (watch != NULL); protected_change_watch (connection, watch, NULL, NULL, _dbus_watch_list_toggle_watch, enabled); } /** Function to be called in protected_change_timeout() with refcount held */ typedef dbus_bool_t (* DBusTimeoutAddFunction) (DBusTimeoutList *list, DBusTimeout *timeout); /** Function to be called in protected_change_timeout() with refcount held */ typedef void (* DBusTimeoutRemoveFunction) (DBusTimeoutList *list, DBusTimeout *timeout); /** Function to be called in protected_change_timeout() with refcount held */ typedef void (* DBusTimeoutToggleFunction) (DBusTimeoutList *list, DBusTimeout *timeout, dbus_bool_t enabled); static dbus_bool_t protected_change_timeout (DBusConnection *connection, DBusTimeout *timeout, DBusTimeoutAddFunction add_function, DBusTimeoutRemoveFunction remove_function, DBusTimeoutToggleFunction toggle_function, dbus_bool_t enabled) { DBusTimeoutList *timeouts; dbus_bool_t retval; HAVE_LOCK_CHECK (connection); /* This isn't really safe or reasonable; a better pattern is the "do everything, then * drop lock and call out" one; but it has to be propagated up through all callers */ timeouts = connection->timeouts; if (timeouts) { connection->timeouts = NULL; _dbus_connection_ref_unlocked (connection); CONNECTION_UNLOCK (connection); if (add_function) retval = (* add_function) (timeouts, timeout); else if (remove_function) { retval = TRUE; (* remove_function) (timeouts, timeout); } else { retval = TRUE; (* toggle_function) (timeouts, timeout, enabled); } CONNECTION_LOCK (connection); connection->timeouts = timeouts; _dbus_connection_unref_unlocked (connection); return retval; } else return FALSE; } /** * Adds a timeout using the connection's DBusAddTimeoutFunction if * available. Otherwise records the timeout to be added when said * function is available. Also re-adds the timeout if the * DBusAddTimeoutFunction changes. May fail due to lack of memory. * The timeout will fire repeatedly until removed. * Connection lock should be held when calling this. * * @param connection the connection. * @param timeout the timeout to add. * @returns #TRUE on success. */ dbus_bool_t _dbus_connection_add_timeout_unlocked (DBusConnection *connection, DBusTimeout *timeout) { return protected_change_timeout (connection, timeout, _dbus_timeout_list_add_timeout, NULL, NULL, FALSE); } /** * Removes a timeout using the connection's DBusRemoveTimeoutFunction * if available. It's an error to call this function on a timeout * that was not previously added. * Connection lock should be held when calling this. * * @param connection the connection. * @param timeout the timeout to remove. */ void _dbus_connection_remove_timeout_unlocked (DBusConnection *connection, DBusTimeout *timeout) { protected_change_timeout (connection, timeout, NULL, _dbus_timeout_list_remove_timeout, NULL, FALSE); } /** * Toggles a timeout and notifies app via connection's * DBusTimeoutToggledFunction if available. It's an error to call this * function on a timeout that was not previously added. * Connection lock should be held when calling this. * * @param connection the connection. * @param timeout the timeout to toggle. * @param enabled whether to enable or disable */ void _dbus_connection_toggle_timeout_unlocked (DBusConnection *connection, DBusTimeout *timeout, dbus_bool_t enabled) { protected_change_timeout (connection, timeout, NULL, NULL, _dbus_timeout_list_toggle_timeout, enabled); } static dbus_bool_t _dbus_connection_attach_pending_call_unlocked (DBusConnection *connection, DBusPendingCall *pending) { dbus_uint32_t reply_serial; DBusTimeout *timeout; HAVE_LOCK_CHECK (connection); reply_serial = _dbus_pending_call_get_reply_serial_unlocked (pending); _dbus_assert (reply_serial != 0); timeout = _dbus_pending_call_get_timeout_unlocked (pending); if (timeout) { if (!_dbus_connection_add_timeout_unlocked (connection, timeout)) return FALSE; if (!_dbus_hash_table_insert_int (connection->pending_replies, reply_serial, pending)) { _dbus_connection_remove_timeout_unlocked (connection, timeout); _dbus_pending_call_set_timeout_added_unlocked (pending, FALSE); HAVE_LOCK_CHECK (connection); return FALSE; } _dbus_pending_call_set_timeout_added_unlocked (pending, TRUE); } else { if (!_dbus_hash_table_insert_int (connection->pending_replies, reply_serial, pending)) { HAVE_LOCK_CHECK (connection); return FALSE; } } _dbus_pending_call_ref_unlocked (pending); HAVE_LOCK_CHECK (connection); return TRUE; } static void free_pending_call_on_hash_removal (void *data) { DBusPendingCall *pending; DBusConnection *connection; if (data == NULL) return; pending = data; connection = _dbus_pending_call_get_connection_unlocked (pending); HAVE_LOCK_CHECK (connection); if (_dbus_pending_call_is_timeout_added_unlocked (pending)) { _dbus_connection_remove_timeout_unlocked (connection, _dbus_pending_call_get_timeout_unlocked (pending)); _dbus_pending_call_set_timeout_added_unlocked (pending, FALSE); } /* FIXME 1.0? this is sort of dangerous and undesirable to drop the lock * here, but the pending call finalizer could in principle call out to * application code so we pretty much have to... some larger code reorg * might be needed. */ _dbus_connection_ref_unlocked (connection); _dbus_pending_call_unref_and_unlock (pending); CONNECTION_LOCK (connection); _dbus_connection_unref_unlocked (connection); } static void _dbus_connection_detach_pending_call_unlocked (DBusConnection *connection, DBusPendingCall *pending) { /* This ends up unlocking to call the pending call finalizer, which is unexpected to * say the least. */ _dbus_hash_table_remove_int (connection->pending_replies, _dbus_pending_call_get_reply_serial_unlocked (pending)); } static void _dbus_connection_detach_pending_call_and_unlock (DBusConnection *connection, DBusPendingCall *pending) { /* The idea here is to avoid finalizing the pending call * with the lock held, since there's a destroy notifier * in pending call that goes out to application code. * * There's an extra unlock inside the hash table * "free pending call" function FIXME... */ _dbus_pending_call_ref_unlocked (pending); _dbus_hash_table_remove_int (connection->pending_replies, _dbus_pending_call_get_reply_serial_unlocked (pending)); if (_dbus_pending_call_is_timeout_added_unlocked (pending)) _dbus_connection_remove_timeout_unlocked (connection, _dbus_pending_call_get_timeout_unlocked (pending)); _dbus_pending_call_set_timeout_added_unlocked (pending, FALSE); _dbus_pending_call_unref_and_unlock (pending); } /** * Removes a pending call from the connection, such that * the pending reply will be ignored. May drop the last * reference to the pending call. * * @param connection the connection * @param pending the pending call */ void _dbus_connection_remove_pending_call (DBusConnection *connection, DBusPendingCall *pending) { CONNECTION_LOCK (connection); _dbus_connection_detach_pending_call_and_unlock (connection, pending); } /** * Acquire the transporter I/O path. This must be done before * doing any I/O in the transporter. May sleep and drop the * IO path mutex while waiting for the I/O path. * * @param connection the connection. * @param timeout_milliseconds maximum blocking time, or -1 for no limit. * @returns TRUE if the I/O path was acquired. */ static dbus_bool_t _dbus_connection_acquire_io_path (DBusConnection *connection, int timeout_milliseconds) { dbus_bool_t we_acquired; HAVE_LOCK_CHECK (connection); /* We don't want the connection to vanish */ _dbus_connection_ref_unlocked (connection); /* We will only touch io_path_acquired which is protected by our mutex */ CONNECTION_UNLOCK (connection); _dbus_verbose ("%s locking io_path_mutex\n", _DBUS_FUNCTION_NAME); _dbus_mutex_lock (connection->io_path_mutex); _dbus_verbose ("%s start connection->io_path_acquired = %d timeout = %d\n", _DBUS_FUNCTION_NAME, connection->io_path_acquired, timeout_milliseconds); we_acquired = FALSE; if (connection->io_path_acquired) { if (timeout_milliseconds != -1) { _dbus_verbose ("%s waiting %d for IO path to be acquirable\n", _DBUS_FUNCTION_NAME, timeout_milliseconds); if (!_dbus_condvar_wait_timeout (connection->io_path_cond, connection->io_path_mutex, timeout_milliseconds)) { /* We timed out before anyone signaled. */ /* (writing the loop to handle the !timedout case by * waiting longer if needed is a pain since dbus * wraps pthread_cond_timedwait to take a relative * time instead of absolute, something kind of stupid * on our part. for now it doesn't matter, we will just * end up back here eventually.) */ } } else { while (connection->io_path_acquired) { _dbus_verbose ("%s waiting for IO path to be acquirable\n", _DBUS_FUNCTION_NAME); _dbus_condvar_wait (connection->io_path_cond, connection->io_path_mutex); } } } if (!connection->io_path_acquired) { we_acquired = TRUE; connection->io_path_acquired = TRUE; } _dbus_verbose ("%s end connection->io_path_acquired = %d we_acquired = %d\n", _DBUS_FUNCTION_NAME, connection->io_path_acquired, we_acquired); _dbus_verbose ("%s unlocking io_path_mutex\n", _DBUS_FUNCTION_NAME); _dbus_mutex_unlock (connection->io_path_mutex); CONNECTION_LOCK (connection); HAVE_LOCK_CHECK (connection); _dbus_connection_unref_unlocked (connection); return we_acquired; } /** * Release the I/O path when you're done with it. Only call * after you've acquired the I/O. Wakes up at most one thread * currently waiting to acquire the I/O path. * * @param connection the connection. */ static void _dbus_connection_release_io_path (DBusConnection *connection) { HAVE_LOCK_CHECK (connection); _dbus_verbose ("%s locking io_path_mutex\n", _DBUS_FUNCTION_NAME); _dbus_mutex_lock (connection->io_path_mutex); _dbus_assert (connection->io_path_acquired); _dbus_verbose ("%s start connection->io_path_acquired = %d\n", _DBUS_FUNCTION_NAME, connection->io_path_acquired); connection->io_path_acquired = FALSE; _dbus_condvar_wake_one (connection->io_path_cond); _dbus_verbose ("%s unlocking io_path_mutex\n", _DBUS_FUNCTION_NAME); _dbus_mutex_unlock (connection->io_path_mutex); } /** * Queues incoming messages and sends outgoing messages for this * connection, optionally blocking in the process. Each call to * _dbus_connection_do_iteration_unlocked() will call select() or poll() one * time and then read or write data if possible. * * The purpose of this function is to be able to flush outgoing * messages or queue up incoming messages without returning * control to the application and causing reentrancy weirdness. * * The flags parameter allows you to specify whether to * read incoming messages, write outgoing messages, or both, * and whether to block if no immediate action is possible. * * The timeout_milliseconds parameter does nothing unless the * iteration is blocking. * * If there are no outgoing messages and DBUS_ITERATION_DO_READING * wasn't specified, then it's impossible to block, even if * you specify DBUS_ITERATION_BLOCK; in that case the function * returns immediately. * * Called with connection lock held. * * @param connection the connection. * @param flags iteration flags. * @param timeout_milliseconds maximum blocking time, or -1 for no limit. */ void _dbus_connection_do_iteration_unlocked (DBusConnection *connection, unsigned int flags, int timeout_milliseconds) { _dbus_verbose ("%s start\n", _DBUS_FUNCTION_NAME); HAVE_LOCK_CHECK (connection); if (connection->n_outgoing == 0) flags &= ~DBUS_ITERATION_DO_WRITING; if (_dbus_connection_acquire_io_path (connection, (flags & DBUS_ITERATION_BLOCK) ? timeout_milliseconds : 0)) { HAVE_LOCK_CHECK (connection); _dbus_transport_do_iteration (connection->transport, flags, timeout_milliseconds); _dbus_connection_release_io_path (connection); } HAVE_LOCK_CHECK (connection); _dbus_verbose ("%s end\n", _DBUS_FUNCTION_NAME); } /** * Creates a new connection for the given transport. A transport * represents a message stream that uses some concrete mechanism, such * as UNIX domain sockets. May return #NULL if insufficient * memory exists to create the connection. * * @param transport the transport. * @returns the new connection, or #NULL on failure. */ DBusConnection* _dbus_connection_new_for_transport (DBusTransport *transport) { DBusConnection *connection; DBusWatchList *watch_list; DBusTimeoutList *timeout_list; DBusHashTable *pending_replies; DBusList *disconnect_link; DBusMessage *disconnect_message; DBusCounter *outgoing_counter; DBusObjectTree *objects; watch_list = NULL; connection = NULL; pending_replies = NULL; timeout_list = NULL; disconnect_link = NULL; disconnect_message = NULL; outgoing_counter = NULL; objects = NULL; watch_list = _dbus_watch_list_new (); if (watch_list == NULL) goto error; timeout_list = _dbus_timeout_list_new (); if (timeout_list == NULL) goto error; pending_replies = _dbus_hash_table_new (DBUS_HASH_INT, NULL, (DBusFreeFunction)free_pending_call_on_hash_removal); if (pending_replies == NULL) goto error; connection = dbus_new0 (DBusConnection, 1); if (connection == NULL) goto error; _dbus_mutex_new_at_location (&connection->mutex); if (connection->mutex == NULL) goto error; _dbus_mutex_new_at_location (&connection->io_path_mutex); if (connection->io_path_mutex == NULL) goto error; _dbus_mutex_new_at_location (&connection->dispatch_mutex); if (connection->dispatch_mutex == NULL) goto error; _dbus_condvar_new_at_location (&connection->dispatch_cond); if (connection->dispatch_cond == NULL) goto error; _dbus_condvar_new_at_location (&connection->io_path_cond); if (connection->io_path_cond == NULL) goto error; disconnect_message = dbus_message_new_signal (DBUS_PATH_LOCAL, DBUS_INTERFACE_LOCAL, "Disconnected"); if (disconnect_message == NULL) goto error; disconnect_link = _dbus_list_alloc_link (disconnect_message); if (disconnect_link == NULL) goto error; outgoing_counter = _dbus_counter_new (); if (outgoing_counter == NULL) goto error; objects = _dbus_object_tree_new (connection); if (objects == NULL) goto error; if (_dbus_modify_sigpipe) _dbus_disable_sigpipe (); connection->refcount.value = 1; connection->transport = transport; connection->watches = watch_list; connection->timeouts = timeout_list; connection->pending_replies = pending_replies; connection->outgoing_counter = outgoing_counter; connection->filter_list = NULL; connection->last_dispatch_status = DBUS_DISPATCH_COMPLETE; /* so we're notified first time there's data */ connection->objects = objects; connection->exit_on_disconnect = FALSE; connection->shareable = FALSE; connection->route_peer_messages = FALSE; connection->disconnected_message_arrived = FALSE; connection->disconnected_message_processed = FALSE; #ifndef DBUS_DISABLE_CHECKS connection->generation = _dbus_current_generation; #endif _dbus_data_slot_list_init (&connection->slot_list); connection->client_serial = 1; connection->disconnect_message_link = disconnect_link; CONNECTION_LOCK (connection); if (!_dbus_transport_set_connection (transport, connection)) { CONNECTION_UNLOCK (connection); goto error; } _dbus_transport_ref (transport); CONNECTION_UNLOCK (connection); return connection; error: if (disconnect_message != NULL) dbus_message_unref (disconnect_message); if (disconnect_link != NULL) _dbus_list_free_link (disconnect_link); if (connection != NULL) { _dbus_condvar_free_at_location (&connection->io_path_cond); _dbus_condvar_free_at_location (&connection->dispatch_cond); _dbus_mutex_free_at_location (&connection->mutex); _dbus_mutex_free_at_location (&connection->io_path_mutex); _dbus_mutex_free_at_location (&connection->dispatch_mutex); dbus_free (connection); } if (pending_replies) _dbus_hash_table_unref (pending_replies); if (watch_list) _dbus_watch_list_free (watch_list); if (timeout_list) _dbus_timeout_list_free (timeout_list); if (outgoing_counter) _dbus_counter_unref (outgoing_counter); if (objects) _dbus_object_tree_unref (objects); return NULL; } /** * Increments the reference count of a DBusConnection. * Requires that the caller already holds the connection lock. * * @param connection the connection. * @returns the connection. */ DBusConnection * _dbus_connection_ref_unlocked (DBusConnection *connection) { _dbus_assert (connection != NULL); _dbus_assert (connection->generation == _dbus_current_generation); HAVE_LOCK_CHECK (connection); #ifdef DBUS_HAVE_ATOMIC_INT _dbus_atomic_inc (&connection->refcount); #else _dbus_assert (connection->refcount.value > 0); connection->refcount.value += 1; #endif return connection; } /** * Decrements the reference count of a DBusConnection. * Requires that the caller already holds the connection lock. * * @param connection the connection. */ void _dbus_connection_unref_unlocked (DBusConnection *connection) { dbus_bool_t last_unref; HAVE_LOCK_CHECK (connection); _dbus_assert (connection != NULL); /* The connection lock is better than the global * lock in the atomic increment fallback */ #ifdef DBUS_HAVE_ATOMIC_INT last_unref = (_dbus_atomic_dec (&connection->refcount) == 1); #else _dbus_assert (connection->refcount.value > 0); connection->refcount.value -= 1; last_unref = (connection->refcount.value == 0); #if 0 printf ("unref_unlocked() connection %p count = %d\n", connection, connection->refcount.value); #endif #endif if (last_unref) _dbus_connection_last_unref (connection); } static dbus_uint32_t _dbus_connection_get_next_client_serial (DBusConnection *connection) { dbus_uint32_t serial; serial = connection->client_serial++; if (connection->client_serial == 0) connection->client_serial = 1; return serial; } /** * A callback for use with dbus_watch_new() to create a DBusWatch. * * @todo This is basically a hack - we could delete _dbus_transport_handle_watch() * and the virtual handle_watch in DBusTransport if we got rid of it. * The reason this is some work is threading, see the _dbus_connection_handle_watch() * implementation. * * @param watch the watch. * @param condition the current condition of the file descriptors being watched. * @param data must be a pointer to a #DBusConnection * @returns #FALSE if the IO condition may not have been fully handled due to lack of memory */ dbus_bool_t _dbus_connection_handle_watch (DBusWatch *watch, unsigned int condition, void *data) { DBusConnection *connection; dbus_bool_t retval; DBusDispatchStatus status; connection = data; _dbus_verbose ("%s start\n", _DBUS_FUNCTION_NAME); CONNECTION_LOCK (connection); _dbus_connection_acquire_io_path (connection, -1); HAVE_LOCK_CHECK (connection); retval = _dbus_transport_handle_watch (connection->transport, watch, condition); _dbus_connection_release_io_path (connection); HAVE_LOCK_CHECK (connection); _dbus_verbose ("%s middle\n", _DBUS_FUNCTION_NAME); status = _dbus_connection_get_dispatch_status_unlocked (connection); /* this calls out to user code */ _dbus_connection_update_dispatch_status_and_unlock (connection, status); _dbus_verbose ("%s end\n", _DBUS_FUNCTION_NAME); return retval; } _DBUS_DEFINE_GLOBAL_LOCK (shared_connections); static DBusHashTable *shared_connections = NULL; static DBusList *shared_connections_no_guid = NULL; static void close_connection_on_shutdown (DBusConnection *connection) { DBusMessage *message; dbus_connection_ref (connection); _dbus_connection_close_possibly_shared (connection); /* Churn through to the Disconnected message */ while ((message = dbus_connection_pop_message (connection))) { dbus_message_unref (message); } dbus_connection_unref (connection); } static void shared_connections_shutdown (void *data) { int n_entries; _DBUS_LOCK (shared_connections); /* This is a little bit unpleasant... better ideas? */ while ((n_entries = _dbus_hash_table_get_n_entries (shared_connections)) > 0) { DBusConnection *connection; DBusHashIter iter; _dbus_hash_iter_init (shared_connections, &iter); _dbus_hash_iter_next (&iter); connection = _dbus_hash_iter_get_value (&iter); _DBUS_UNLOCK (shared_connections); close_connection_on_shutdown (connection); _DBUS_LOCK (shared_connections); /* The connection should now be dead and not in our hash ... */ _dbus_assert (_dbus_hash_table_get_n_entries (shared_connections) < n_entries); } _dbus_assert (_dbus_hash_table_get_n_entries (shared_connections) == 0); _dbus_hash_table_unref (shared_connections); shared_connections = NULL; if (shared_connections_no_guid != NULL) { DBusConnection *connection; connection = _dbus_list_pop_first (&shared_connections_no_guid); while (connection != NULL) { _DBUS_UNLOCK (shared_connections); close_connection_on_shutdown (connection); _DBUS_LOCK (shared_connections); connection = _dbus_list_pop_first (&shared_connections_no_guid); } } shared_connections_no_guid = NULL; _DBUS_UNLOCK (shared_connections); } static dbus_bool_t connection_lookup_shared (DBusAddressEntry *entry, DBusConnection **result) { _dbus_verbose ("checking for existing connection\n"); *result = NULL; _DBUS_LOCK (shared_connections); if (shared_connections == NULL) { _dbus_verbose ("creating shared_connections hash table\n"); shared_connections = _dbus_hash_table_new (DBUS_HASH_STRING, dbus_free, NULL); if (shared_connections == NULL) { _DBUS_UNLOCK (shared_connections); return FALSE; } if (!_dbus_register_shutdown_func (shared_connections_shutdown, NULL)) { _dbus_hash_table_unref (shared_connections); shared_connections = NULL; _DBUS_UNLOCK (shared_connections); return FALSE; } _dbus_verbose (" successfully created shared_connections\n"); _DBUS_UNLOCK (shared_connections); return TRUE; /* no point looking up in the hash we just made */ } else { const char *guid; guid = dbus_address_entry_get_value (entry, "guid"); if (guid != NULL) { DBusConnection *connection; connection = _dbus_hash_table_lookup_string (shared_connections, guid); if (connection) { /* The DBusConnection can't be finalized without taking * the shared_connections lock to remove it from the * hash. So it's safe to ref the connection here. * However, it may be disconnected if the Disconnected * message hasn't been processed yet, in which case we * want to pretend it isn't in the hash and avoid * returning it. * * The idea is to avoid ever returning a disconnected connection * from dbus_connection_open(). We could just synchronously * drop our shared ref to the connection on connection disconnect, * and then assert here that the connection is connected, but * that causes reentrancy headaches. */ CONNECTION_LOCK (connection); if (_dbus_connection_get_is_connected_unlocked (connection)) { _dbus_connection_ref_unlocked (connection); *result = connection; _dbus_verbose ("looked up existing connection to server guid %s\n", guid); } else { _dbus_verbose ("looked up existing connection to server guid %s but it was disconnected so ignoring it\n", guid); } CONNECTION_UNLOCK (connection); } } _DBUS_UNLOCK (shared_connections); return TRUE; } } static dbus_bool_t connection_record_shared_unlocked (DBusConnection *connection, const char *guid) { char *guid_key; char *guid_in_connection; HAVE_LOCK_CHECK (connection); _dbus_assert (connection->server_guid == NULL); _dbus_assert (connection->shareable); /* get a hard ref on this connection, even if * we won't in fact store it in the hash, we still * need to hold a ref on it until it's disconnected. */ _dbus_connection_ref_unlocked (connection); if (guid == NULL) { _DBUS_LOCK (shared_connections); if (!_dbus_list_prepend (&shared_connections_no_guid, connection)) { _DBUS_UNLOCK (shared_connections); return FALSE; } _DBUS_UNLOCK (shared_connections); return TRUE; /* don't store in the hash */ } /* A separate copy of the key is required in the hash table, because * we don't have a lock on the connection when we are doing a hash * lookup. */ guid_key = _dbus_strdup (guid); if (guid_key == NULL) return FALSE; guid_in_connection = _dbus_strdup (guid); if (guid_in_connection == NULL) { dbus_free (guid_key); return FALSE; } _DBUS_LOCK (shared_connections); _dbus_assert (shared_connections != NULL); if (!_dbus_hash_table_insert_string (shared_connections, guid_key, connection)) { dbus_free (guid_key); dbus_free (guid_in_connection); _DBUS_UNLOCK (shared_connections); return FALSE; } connection->server_guid = guid_in_connection; _dbus_verbose ("stored connection to %s to be shared\n", connection->server_guid); _DBUS_UNLOCK (shared_connections); _dbus_assert (connection->server_guid != NULL); return TRUE; } static void connection_forget_shared_unlocked (DBusConnection *connection) { HAVE_LOCK_CHECK (connection); if (!connection->shareable) return; _DBUS_LOCK (shared_connections); if (connection->server_guid != NULL) { _dbus_verbose ("dropping connection to %s out of the shared table\n", connection->server_guid); if (!_dbus_hash_table_remove_string (shared_connections, connection->server_guid)) _dbus_assert_not_reached ("connection was not in the shared table"); dbus_free (connection->server_guid); connection->server_guid = NULL; } else { _dbus_list_remove (&shared_connections_no_guid, connection); } _DBUS_UNLOCK (shared_connections); /* remove our reference held on all shareable connections */ _dbus_connection_unref_unlocked (connection); } static DBusConnection* connection_try_from_address_entry (DBusAddressEntry *entry, DBusError *error) { DBusTransport *transport; DBusConnection *connection; transport = _dbus_transport_open (entry, error); if (transport == NULL) { _DBUS_ASSERT_ERROR_IS_SET (error); return NULL; } connection = _dbus_connection_new_for_transport (transport); _dbus_transport_unref (transport); if (connection == NULL) { _DBUS_SET_OOM (error); return NULL; } #ifndef DBUS_DISABLE_CHECKS _dbus_assert (!connection->have_connection_lock); #endif return connection; } /* * If the shared parameter is true, then any existing connection will * be used (and if a new connection is created, it will be available * for use by others). If the shared parameter is false, a new * connection will always be created, and the new connection will * never be returned to other callers. * * @param address the address * @param shared whether the connection is shared or private * @param error error return * @returns the connection or #NULL on error */ static DBusConnection* _dbus_connection_open_internal (const char *address, dbus_bool_t shared, DBusError *error) { DBusConnection *connection; DBusAddressEntry **entries; DBusError tmp_error = DBUS_ERROR_INIT; DBusError first_error = DBUS_ERROR_INIT; int len, i; _DBUS_ASSERT_ERROR_IS_CLEAR (error); _dbus_verbose ("opening %s connection to: %s\n", shared ? "shared" : "private", address); if (!dbus_parse_address (address, &entries, &len, error)) return NULL; _DBUS_ASSERT_ERROR_IS_CLEAR (error); connection = NULL; for (i = 0; i < len; i++) { if (shared) { if (!connection_lookup_shared (entries[i], &connection)) _DBUS_SET_OOM (&tmp_error); } if (connection == NULL) { connection = connection_try_from_address_entry (entries[i], &tmp_error); if (connection != NULL && shared) { const char *guid; connection->shareable = TRUE; /* guid may be NULL */ guid = dbus_address_entry_get_value (entries[i], "guid"); CONNECTION_LOCK (connection); if (!connection_record_shared_unlocked (connection, guid)) { _DBUS_SET_OOM (&tmp_error); _dbus_connection_close_possibly_shared_and_unlock (connection); dbus_connection_unref (connection); connection = NULL; } else CONNECTION_UNLOCK (connection); } } if (connection) break; _DBUS_ASSERT_ERROR_IS_SET (&tmp_error); if (i == 0) dbus_move_error (&tmp_error, &first_error); else dbus_error_free (&tmp_error); } _DBUS_ASSERT_ERROR_IS_CLEAR (error); _DBUS_ASSERT_ERROR_IS_CLEAR (&tmp_error); if (connection == NULL) { _DBUS_ASSERT_ERROR_IS_SET (&first_error); dbus_move_error (&first_error, error); } else dbus_error_free (&first_error); dbus_address_entries_free (entries); return connection; } /** * Closes a shared OR private connection, while dbus_connection_close() can * only be used on private connections. Should only be called by the * dbus code that owns the connection - an owner must be known, * the open/close state is like malloc/free, not like ref/unref. * * @param connection the connection */ void _dbus_connection_close_possibly_shared (DBusConnection *connection) { _dbus_assert (connection != NULL); _dbus_assert (connection->generation == _dbus_current_generation); CONNECTION_LOCK (connection); _dbus_connection_close_possibly_shared_and_unlock (connection); } static DBusPreallocatedSend* _dbus_connection_preallocate_send_unlocked (DBusConnection *connection) { DBusPreallocatedSend *preallocated; HAVE_LOCK_CHECK (connection); _dbus_assert (connection != NULL); preallocated = dbus_new (DBusPreallocatedSend, 1); if (preallocated == NULL) return NULL; if (connection->link_cache != NULL) { preallocated->queue_link = _dbus_list_pop_first_link (&connection->link_cache); preallocated->queue_link->data = NULL; } else { preallocated->queue_link = _dbus_list_alloc_link (NULL); if (preallocated->queue_link == NULL) goto failed_0; } if (connection->link_cache != NULL) { preallocated->counter_link = _dbus_list_pop_first_link (&connection->link_cache); preallocated->counter_link->data = connection->outgoing_counter; } else { preallocated->counter_link = _dbus_list_alloc_link (connection->outgoing_counter); if (preallocated->counter_link == NULL) goto failed_1; } _dbus_counter_ref (preallocated->counter_link->data); preallocated->connection = connection; return preallocated; failed_1: _dbus_list_free_link (preallocated->queue_link); failed_0: dbus_free (preallocated); return NULL; } /* Called with lock held, does not update dispatch status */ static void _dbus_connection_send_preallocated_unlocked_no_update (DBusConnection *connection, DBusPreallocatedSend *preallocated, DBusMessage *message, dbus_uint32_t *client_serial) { dbus_uint32_t serial; const char *sig; preallocated->queue_link->data = message; _dbus_list_prepend_link (&connection->outgoing_messages, preallocated->queue_link); _dbus_message_add_counter_link (message, preallocated->counter_link); dbus_free (preallocated); preallocated = NULL; dbus_message_ref (message); connection->n_outgoing += 1; sig = dbus_message_get_signature (message); _dbus_verbose ("Message %p (%d %s %s %s '%s') for %s added to outgoing queue %p, %d pending to send\n", message, dbus_message_get_type (message), dbus_message_get_path (message) ? dbus_message_get_path (message) : "no path", dbus_message_get_interface (message) ? dbus_message_get_interface (message) : "no interface", dbus_message_get_member (message) ? dbus_message_get_member (message) : "no member", sig, dbus_message_get_destination (message) ? dbus_message_get_destination (message) : "null", connection, connection->n_outgoing); if (dbus_message_get_serial (message) == 0) { serial = _dbus_connection_get_next_client_serial (connection); dbus_message_set_serial (message, serial); if (client_serial) *client_serial = serial; } else { if (client_serial) *client_serial = dbus_message_get_serial (message); } _dbus_verbose ("Message %p serial is %u\n", message, dbus_message_get_serial (message)); dbus_message_lock (message); /* Now we need to run an iteration to hopefully just write the messages * out immediately, and otherwise get them queued up */ _dbus_connection_do_iteration_unlocked (connection, DBUS_ITERATION_DO_WRITING, -1); /* If stuff is still queued up, be sure we wake up the main loop */ if (connection->n_outgoing > 0) _dbus_connection_wakeup_mainloop (connection); } static void _dbus_connection_send_preallocated_and_unlock (DBusConnection *connection, DBusPreallocatedSend *preallocated, DBusMessage *message, dbus_uint32_t *client_serial) { DBusDispatchStatus status; HAVE_LOCK_CHECK (connection); _dbus_connection_send_preallocated_unlocked_no_update (connection, preallocated, message, client_serial); _dbus_verbose ("%s middle\n", _DBUS_FUNCTION_NAME); status = _dbus_connection_get_dispatch_status_unlocked (connection); /* this calls out to user code */ _dbus_connection_update_dispatch_status_and_unlock (connection, status); } /** * Like dbus_connection_send(), but assumes the connection * is already locked on function entry, and unlocks before returning. * * @param connection the connection * @param message the message to send * @param client_serial return location for client serial of sent message * @returns #FALSE on out-of-memory */ dbus_bool_t _dbus_connection_send_and_unlock (DBusConnection *connection, DBusMessage *message, dbus_uint32_t *client_serial) { DBusPreallocatedSend *preallocated; _dbus_assert (connection != NULL); _dbus_assert (message != NULL); preallocated = _dbus_connection_preallocate_send_unlocked (connection); if (preallocated == NULL) { CONNECTION_UNLOCK (connection); return FALSE; } _dbus_connection_send_preallocated_and_unlock (connection, preallocated, message, client_serial); return TRUE; } /** * Used internally to handle the semantics of dbus_server_set_new_connection_function(). * If the new connection function does not ref the connection, we want to close it. * * A bit of a hack, probably the new connection function should have returned a value * for whether to close, or should have had to close the connection itself if it * didn't want it. * * But, this works OK as long as the new connection function doesn't do anything * crazy like keep the connection around without ref'ing it. * * We have to lock the connection across refcount check and close in case * the new connection function spawns a thread that closes and unrefs. * In that case, if the app thread * closes and unrefs first, we'll harmlessly close again; if the app thread * still has the ref, we'll close and then the app will close harmlessly. * If the app unrefs without closing, the app is broken since if the * app refs from the new connection function it is supposed to also close. * * If we didn't atomically check the refcount and close with the lock held * though, we could screw this up. * * @param connection the connection */ void _dbus_connection_close_if_only_one_ref (DBusConnection *connection) { CONNECTION_LOCK (connection); _dbus_assert (connection->refcount.value > 0); if (connection->refcount.value == 1) _dbus_connection_close_possibly_shared_and_unlock (connection); else CONNECTION_UNLOCK (connection); } /** * When a function that blocks has been called with a timeout, and we * run out of memory, the time to wait for memory is based on the * timeout. If the caller was willing to block a long time we wait a * relatively long time for memory, if they were only willing to block * briefly then we retry for memory at a rapid rate. * * @timeout_milliseconds the timeout requested for blocking */ static void _dbus_memory_pause_based_on_timeout (int timeout_milliseconds) { if (timeout_milliseconds == -1) _dbus_sleep_milliseconds (1000); else if (timeout_milliseconds < 100) ; /* just busy loop */ else if (timeout_milliseconds <= 1000) _dbus_sleep_milliseconds (timeout_milliseconds / 3); else _dbus_sleep_milliseconds (1000); } static DBusMessage * generate_local_error_message (dbus_uint32_t serial, char *error_name, char *error_msg) { DBusMessage *message; message = dbus_message_new (DBUS_MESSAGE_TYPE_ERROR); if (!message) goto out; if (!dbus_message_set_error_name (message, error_name)) { dbus_message_unref (message); message = NULL; goto out; } dbus_message_set_no_reply (message, TRUE); if (!dbus_message_set_reply_serial (message, serial)) { dbus_message_unref (message); message = NULL; goto out; } if (error_msg != NULL) { DBusMessageIter iter; dbus_message_iter_init_append (message, &iter); if (!dbus_message_iter_append_basic (&iter, DBUS_TYPE_STRING, &error_msg)) { dbus_message_unref (message); message = NULL; goto out; } } out: return message; } /* This is slightly strange since we can pop a message here without * the dispatch lock. */ static DBusMessage* check_for_reply_unlocked (DBusConnection *connection, dbus_uint32_t client_serial) { DBusList *link; HAVE_LOCK_CHECK (connection); link = _dbus_list_get_first_link (&connection->incoming_messages); while (link != NULL) { DBusMessage *reply = link->data; if (dbus_message_get_reply_serial (reply) == client_serial) { _dbus_list_remove_link (&connection->incoming_messages, link); connection->n_incoming -= 1; return reply; } link = _dbus_list_get_next_link (&connection->incoming_messages, link); } return NULL; } static void connection_timeout_and_complete_all_pending_calls_unlocked (DBusConnection *connection) { /* We can't iterate over the hash in the normal way since we'll be * dropping the lock for each item. So we restart the * iter each time as we drain the hash table. */ while (_dbus_hash_table_get_n_entries (connection->pending_replies) > 0) { DBusPendingCall *pending; DBusHashIter iter; _dbus_hash_iter_init (connection->pending_replies, &iter); _dbus_hash_iter_next (&iter); pending = _dbus_hash_iter_get_value (&iter); _dbus_pending_call_ref_unlocked (pending); _dbus_pending_call_queue_timeout_error_unlocked (pending, connection); if (_dbus_pending_call_is_timeout_added_unlocked (pending)) _dbus_connection_remove_timeout_unlocked (connection, _dbus_pending_call_get_timeout_unlocked (pending)); _dbus_pending_call_set_timeout_added_unlocked (pending, FALSE); _dbus_hash_iter_remove_entry (&iter); _dbus_pending_call_unref_and_unlock (pending); CONNECTION_LOCK (connection); } HAVE_LOCK_CHECK (connection); } static void complete_pending_call_and_unlock (DBusConnection *connection, DBusPendingCall *pending, DBusMessage *message) { _dbus_pending_call_set_reply_unlocked (pending, message); _dbus_pending_call_ref_unlocked (pending); /* in case there's no app with a ref held */ _dbus_connection_detach_pending_call_and_unlock (connection, pending); /* Must be called unlocked since it invokes app callback */ _dbus_pending_call_complete (pending); dbus_pending_call_unref (pending); } static dbus_bool_t check_for_reply_and_update_dispatch_unlocked (DBusConnection *connection, DBusPendingCall *pending) { DBusMessage *reply; DBusDispatchStatus status; reply = check_for_reply_unlocked (connection, _dbus_pending_call_get_reply_serial_unlocked (pending)); if (reply != NULL) { _dbus_verbose ("%s checked for reply\n", _DBUS_FUNCTION_NAME); _dbus_verbose ("dbus_connection_send_with_reply_and_block(): got reply\n"); complete_pending_call_and_unlock (connection, pending, reply); dbus_message_unref (reply); CONNECTION_LOCK (connection); status = _dbus_connection_get_dispatch_status_unlocked (connection); _dbus_connection_update_dispatch_status_and_unlock (connection, status); dbus_pending_call_unref (pending); return TRUE; } return FALSE; } /** * Blocks until a pending call times out or gets a reply. * * Does not re-enter the main loop or run filter/path-registered * callbacks. The reply to the message will not be seen by * filter callbacks. * * Returns immediately if pending call already got a reply. * * @todo could use performance improvements (it keeps scanning * the whole message queue for example) * * @param pending the pending call we block for a reply on */ void _dbus_connection_block_pending_call (DBusPendingCall *pending) { long start_tv_sec, start_tv_usec; long tv_sec, tv_usec; DBusDispatchStatus status; DBusConnection *connection; dbus_uint32_t client_serial; DBusTimeout *timeout; int timeout_milliseconds, elapsed_milliseconds; _dbus_assert (pending != NULL); if (dbus_pending_call_get_completed (pending)) return; dbus_pending_call_ref (pending); /* necessary because the call could be canceled */ connection = _dbus_pending_call_get_connection_and_lock (pending); /* Flush message queue - note, can affect dispatch status */ _dbus_connection_flush_unlocked (connection); client_serial = _dbus_pending_call_get_reply_serial_unlocked (pending); /* note that timeout_milliseconds is limited to a smallish value * in _dbus_pending_call_new() so overflows aren't possible * below */ timeout = _dbus_pending_call_get_timeout_unlocked (pending); if (timeout) { timeout_milliseconds = dbus_timeout_get_interval (timeout); _dbus_get_current_time (&start_tv_sec, &start_tv_usec); _dbus_verbose ("dbus_connection_send_with_reply_and_block(): will block %d milliseconds for reply serial %u from %ld sec %ld usec\n", timeout_milliseconds, client_serial, start_tv_sec, start_tv_usec); } else { timeout_milliseconds = -1; _dbus_verbose ("dbus_connection_send_with_reply_and_block(): will block for reply serial %u\n", client_serial); } /* check to see if we already got the data off the socket */ /* from another blocked pending call */ if (check_for_reply_and_update_dispatch_unlocked (connection, pending)) return; /* Now we wait... */ /* always block at least once as we know we don't have the reply yet */ _dbus_connection_do_iteration_unlocked (connection, DBUS_ITERATION_DO_READING | DBUS_ITERATION_BLOCK, timeout_milliseconds); recheck_status: _dbus_verbose ("%s top of recheck\n", _DBUS_FUNCTION_NAME); HAVE_LOCK_CHECK (connection); /* queue messages and get status */ status = _dbus_connection_get_dispatch_status_unlocked (connection); /* the get_completed() is in case a dispatch() while we were blocking * got the reply instead of us. */ if (_dbus_pending_call_get_completed_unlocked (pending)) { _dbus_verbose ("Pending call completed by dispatch in %s\n", _DBUS_FUNCTION_NAME); _dbus_connection_update_dispatch_status_and_unlock (connection, status); dbus_pending_call_unref (pending); return; } if (status == DBUS_DISPATCH_DATA_REMAINS) { if (check_for_reply_and_update_dispatch_unlocked (connection, pending)) return; } _dbus_get_current_time (&tv_sec, &tv_usec); elapsed_milliseconds = (tv_sec - start_tv_sec) * 1000 + (tv_usec - start_tv_usec) / 1000; if (!_dbus_connection_get_is_connected_unlocked (connection)) { DBusMessage *error_msg; error_msg = generate_local_error_message (client_serial, DBUS_ERROR_DISCONNECTED, "Connection was disconnected before a reply was received"); /* on OOM error_msg is set to NULL */ complete_pending_call_and_unlock (connection, pending, error_msg); dbus_pending_call_unref (pending); return; } else if (connection->disconnect_message_link == NULL) _dbus_verbose ("dbus_connection_send_with_reply_and_block(): disconnected\n"); else if (timeout == NULL) { if (status == DBUS_DISPATCH_NEED_MEMORY) { /* Try sleeping a bit, as we aren't sure we need to block for reading, * we may already have a reply in the buffer and just can't process * it. */ _dbus_verbose ("dbus_connection_send_with_reply_and_block() waiting for more memory\n"); _dbus_memory_pause_based_on_timeout (timeout_milliseconds - elapsed_milliseconds); } else { /* block again, we don't have the reply buffered yet. */ _dbus_connection_do_iteration_unlocked (connection, DBUS_ITERATION_DO_READING | DBUS_ITERATION_BLOCK, timeout_milliseconds - elapsed_milliseconds); } goto recheck_status; } else if (tv_sec < start_tv_sec) _dbus_verbose ("dbus_connection_send_with_reply_and_block(): clock set backward\n"); else if (elapsed_milliseconds < timeout_milliseconds) { _dbus_verbose ("dbus_connection_send_with_reply_and_block(): %d milliseconds remain\n", timeout_milliseconds - elapsed_milliseconds); if (status == DBUS_DISPATCH_NEED_MEMORY) { /* Try sleeping a bit, as we aren't sure we need to block for reading, * we may already have a reply in the buffer and just can't process * it. */ _dbus_verbose ("dbus_connection_send_with_reply_and_block() waiting for more memory\n"); _dbus_memory_pause_based_on_timeout (timeout_milliseconds - elapsed_milliseconds); } else { /* block again, we don't have the reply buffered yet. */ _dbus_connection_do_iteration_unlocked (connection, DBUS_ITERATION_DO_READING | DBUS_ITERATION_BLOCK, timeout_milliseconds - elapsed_milliseconds); } goto recheck_status; } _dbus_verbose ("dbus_connection_send_with_reply_and_block(): Waited %ld milliseconds and got no reply\n", elapsed_milliseconds); _dbus_assert (!_dbus_pending_call_get_completed_unlocked (pending)); /* unlock and call user code */ complete_pending_call_and_unlock (connection, pending, NULL); /* update user code on dispatch status */ CONNECTION_LOCK (connection); status = _dbus_connection_get_dispatch_status_unlocked (connection); _dbus_connection_update_dispatch_status_and_unlock (connection, status); dbus_pending_call_unref (pending); } /** @} */ /** * @addtogroup DBusConnection * * @{ */ /** * Gets a connection to a remote address. If a connection to the given * address already exists, returns the existing connection with its * reference count incremented. Otherwise, returns a new connection * and saves the new connection for possible re-use if a future call * to dbus_connection_open() asks to connect to the same server. * * Use dbus_connection_open_private() to get a dedicated connection * not shared with other callers of dbus_connection_open(). * * If the open fails, the function returns #NULL, and provides a * reason for the failure in the error parameter. Pass #NULL for the * error parameter if you aren't interested in the reason for * failure. * * Because this connection is shared, no user of the connection * may call dbus_connection_close(). However, when you are done with the * connection you should call dbus_connection_unref(). * * @note Prefer dbus_connection_open() to dbus_connection_open_private() * unless you have good reason; connections are expensive enough * that it's wasteful to create lots of connections to the same * server. * * @param address the address. * @param error address where an error can be returned. * @returns new connection, or #NULL on failure. */ DBusConnection* dbus_connection_open (const char *address, DBusError *error) { DBusConnection *connection; _dbus_return_val_if_fail (address != NULL, NULL); _dbus_return_val_if_error_is_set (error, NULL); connection = _dbus_connection_open_internal (address, TRUE, error); return connection; } /** * Opens a new, dedicated connection to a remote address. Unlike * dbus_connection_open(), always creates a new connection. * This connection will not be saved or recycled by libdbus. * * If the open fails, the function returns #NULL, and provides a * reason for the failure in the error parameter. Pass #NULL for the * error parameter if you aren't interested in the reason for * failure. * * When you are done with this connection, you must * dbus_connection_close() to disconnect it, * and dbus_connection_unref() to free the connection object. * * (The dbus_connection_close() can be skipped if the * connection is already known to be disconnected, for example * if you are inside a handler for the Disconnected signal.) * * @note Prefer dbus_connection_open() to dbus_connection_open_private() * unless you have good reason; connections are expensive enough * that it's wasteful to create lots of connections to the same * server. * * @param address the address. * @param error address where an error can be returned. * @returns new connection, or #NULL on failure. */ DBusConnection* dbus_connection_open_private (const char *address, DBusError *error) { DBusConnection *connection; _dbus_return_val_if_fail (address != NULL, NULL); _dbus_return_val_if_error_is_set (error, NULL); connection = _dbus_connection_open_internal (address, FALSE, error); return connection; } /** * Increments the reference count of a DBusConnection. * * @param connection the connection. * @returns the connection. */ DBusConnection * dbus_connection_ref (DBusConnection *connection) { _dbus_return_val_if_fail (connection != NULL, NULL); _dbus_return_val_if_fail (connection->generation == _dbus_current_generation, NULL); /* The connection lock is better than the global * lock in the atomic increment fallback */ #ifdef DBUS_HAVE_ATOMIC_INT _dbus_atomic_inc (&connection->refcount); #else CONNECTION_LOCK (connection); _dbus_assert (connection->refcount.value > 0); connection->refcount.value += 1; CONNECTION_UNLOCK (connection); #endif return connection; } static void free_outgoing_message (void *element, void *data) { DBusMessage *message = element; DBusConnection *connection = data; _dbus_message_remove_counter (message, connection->outgoing_counter, NULL); dbus_message_unref (message); } /* This is run without the mutex held, but after the last reference * to the connection has been dropped we should have no thread-related * problems */ static void _dbus_connection_last_unref (DBusConnection *connection) { DBusList *link; _dbus_verbose ("Finalizing connection %p\n", connection); _dbus_assert (connection->refcount.value == 0); /* You have to disconnect the connection before unref:ing it. Otherwise * you won't get the disconnected message. */ _dbus_assert (!_dbus_transport_get_is_connected (connection->transport)); _dbus_assert (connection->server_guid == NULL); /* ---- We're going to call various application callbacks here, hope it doesn't break anything... */ _dbus_object_tree_free_all_unlocked (connection->objects); dbus_connection_set_dispatch_status_function (connection, NULL, NULL, NULL); dbus_connection_set_wakeup_main_function (connection, NULL, NULL, NULL); dbus_connection_set_unix_user_function (connection, NULL, NULL, NULL); _dbus_watch_list_free (connection->watches); connection->watches = NULL; _dbus_timeout_list_free (connection->timeouts); connection->timeouts = NULL; _dbus_data_slot_list_free (&connection->slot_list); link = _dbus_list_get_first_link (&connection->filter_list); while (link != NULL) { DBusMessageFilter *filter = link->data; DBusList *next = _dbus_list_get_next_link (&connection->filter_list, link); filter->function = NULL; _dbus_message_filter_unref (filter); /* calls app callback */ link->data = NULL; link = next; } _dbus_list_clear (&connection->filter_list); /* ---- Done with stuff that invokes application callbacks */ _dbus_object_tree_unref (connection->objects); _dbus_hash_table_unref (connection->pending_replies); connection->pending_replies = NULL; _dbus_list_clear (&connection->filter_list); _dbus_list_foreach (&connection->outgoing_messages, free_outgoing_message, connection); _dbus_list_clear (&connection->outgoing_messages); _dbus_list_foreach (&connection->incoming_messages, (DBusForeachFunction) dbus_message_unref, NULL); _dbus_list_clear (&connection->incoming_messages); _dbus_counter_unref (connection->outgoing_counter); _dbus_transport_unref (connection->transport); if (connection->disconnect_message_link) { DBusMessage *message = connection->disconnect_message_link->data; dbus_message_unref (message); _dbus_list_free_link (connection->disconnect_message_link); } _dbus_list_clear (&connection->link_cache); _dbus_condvar_free_at_location (&connection->dispatch_cond); _dbus_condvar_free_at_location (&connection->io_path_cond); _dbus_mutex_free_at_location (&connection->io_path_mutex); _dbus_mutex_free_at_location (&connection->dispatch_mutex); _dbus_mutex_free_at_location (&connection->mutex); dbus_free (connection); } /** * Decrements the reference count of a DBusConnection, and finalizes * it if the count reaches zero. * * Note: it is a bug to drop the last reference to a connection that * is still connected. * * For shared connections, libdbus will own a reference * as long as the connection is connected, so you can know that either * you don't have the last reference, or it's OK to drop the last reference. * Most connections are shared. dbus_connection_open() and dbus_bus_get() * return shared connections. * * For private connections, the creator of the connection must arrange for * dbus_connection_close() to be called prior to dropping the last reference. * Private connections come from dbus_connection_open_private() or dbus_bus_get_private(). * * @param connection the connection. */ void dbus_connection_unref (DBusConnection *connection) { dbus_bool_t last_unref; _dbus_return_if_fail (connection != NULL); _dbus_return_if_fail (connection->generation == _dbus_current_generation); /* The connection lock is better than the global * lock in the atomic increment fallback */ #ifdef DBUS_HAVE_ATOMIC_INT last_unref = (_dbus_atomic_dec (&connection->refcount) == 1); #else CONNECTION_LOCK (connection); _dbus_assert (connection->refcount.value > 0); connection->refcount.value -= 1; last_unref = (connection->refcount.value == 0); #if 0 printf ("unref() connection %p count = %d\n", connection, connection->refcount.value); #endif CONNECTION_UNLOCK (connection); #endif if (last_unref) { #ifndef DBUS_DISABLE_CHECKS if (_dbus_transport_get_is_connected (connection->transport)) { _dbus_warn_check_failed ("The last reference on a connection was dropped without closing the connection. This is a bug in an application. See dbus_connection_unref() documentation for details.\n%s", connection->shareable ? "Most likely, the application called unref() too many times and removed a reference belonging to libdbus, since this is a shared connection.\n" : "Most likely, the application was supposed to call dbus_connection_close(), since this is a private connection.\n"); return; } #endif _dbus_connection_last_unref (connection); } } /* * Note that the transport can disconnect itself (other end drops us) * and in that case this function never runs. So this function must * not do anything more than disconnect the transport and update the * dispatch status. * * If the transport self-disconnects, then we assume someone will * dispatch the connection to cause the dispatch status update. */ static void _dbus_connection_close_possibly_shared_and_unlock (DBusConnection *connection) { DBusDispatchStatus status; HAVE_LOCK_CHECK (connection); _dbus_verbose ("Disconnecting %p\n", connection); /* We need to ref because update_dispatch_status_and_unlock will unref * the connection if it was shared and libdbus was the only remaining * refcount holder. */ _dbus_connection_ref_unlocked (connection); _dbus_transport_disconnect (connection->transport); /* This has the side effect of queuing the disconnect message link * (unless we don't have enough memory, possibly, so don't assert it). * After the disconnect message link is queued, dbus_bus_get/dbus_connection_open * should never again return the newly-disconnected connection. * * However, we only unref the shared connection and exit_on_disconnect when * the disconnect message reaches the head of the message queue, * NOT when it's first queued. */ status = _dbus_connection_get_dispatch_status_unlocked (connection); /* This calls out to user code */ _dbus_connection_update_dispatch_status_and_unlock (connection, status); /* Could also call out to user code */ dbus_connection_unref (connection); } /** * Closes a private connection, so no further data can be sent or received. * This disconnects the transport (such as a socket) underlying the * connection. * * Attempts to send messages after closing a connection are safe, but will result in * error replies generated locally in libdbus. * * This function does not affect the connection's reference count. It's * safe to close a connection more than once; all calls after the * first do nothing. It's impossible to "reopen" a connection, a * new connection must be created. This function may result in a call * to the DBusDispatchStatusFunction set with * dbus_connection_set_dispatch_status_function(), as the disconnect * message it generates needs to be dispatched. * * If a connection is dropped by the remote application, it will * close itself. * * You must close a connection prior to releasing the last reference to * the connection. If you dbus_connection_unref() for the last time * without closing the connection, the results are undefined; it * is a bug in your program and libdbus will try to print a warning. * * You may not close a shared connection. Connections created with * dbus_connection_open() or dbus_bus_get() are shared. * These connections are owned by libdbus, and applications should * only unref them, never close them. Applications can know it is * safe to unref these connections because libdbus will be holding a * reference as long as the connection is open. Thus, either the * connection is closed and it is OK to drop the last reference, * or the connection is open and the app knows it does not have the * last reference. * * Connections created with dbus_connection_open_private() or * dbus_bus_get_private() are not kept track of or referenced by * libdbus. The creator of these connections is responsible for * calling dbus_connection_close() prior to releasing the last * reference, if the connection is not already disconnected. * * @param connection the private (unshared) connection to close */ void dbus_connection_close (DBusConnection *connection) { _dbus_return_if_fail (connection != NULL); _dbus_return_if_fail (connection->generation == _dbus_current_generation); CONNECTION_LOCK (connection); #ifndef DBUS_DISABLE_CHECKS if (connection->shareable) { CONNECTION_UNLOCK (connection); _dbus_warn_check_failed ("Applications must not close shared connections - see dbus_connection_close() docs. This is a bug in the application.\n"); return; } #endif _dbus_connection_close_possibly_shared_and_unlock (connection); } static dbus_bool_t _dbus_connection_get_is_connected_unlocked (DBusConnection *connection) { HAVE_LOCK_CHECK (connection); return _dbus_transport_get_is_connected (connection->transport); } /** * Gets whether the connection is currently open. A connection may * become disconnected when the remote application closes its end, or * exits; a connection may also be disconnected with * dbus_connection_close(). * * There are not separate states for "closed" and "disconnected," the two * terms are synonymous. This function should really be called * get_is_open() but for historical reasons is not. * * @param connection the connection. * @returns #TRUE if the connection is still alive. */ dbus_bool_t dbus_connection_get_is_connected (DBusConnection *connection) { dbus_bool_t res; _dbus_return_val_if_fail (connection != NULL, FALSE); CONNECTION_LOCK (connection); res = _dbus_connection_get_is_connected_unlocked (connection); CONNECTION_UNLOCK (connection); return res; } /** * Gets whether the connection was authenticated. (Note that * if the connection was authenticated then disconnected, * this function still returns #TRUE) * * @param connection the connection * @returns #TRUE if the connection was ever authenticated */ dbus_bool_t dbus_connection_get_is_authenticated (DBusConnection *connection) { dbus_bool_t res; _dbus_return_val_if_fail (connection != NULL, FALSE); CONNECTION_LOCK (connection); res = _dbus_transport_get_is_authenticated (connection->transport); CONNECTION_UNLOCK (connection); return res; } /** * Gets whether the connection is not authenticated as a specific * user. If the connection is not authenticated, this function * returns #TRUE, and if it is authenticated but as an anonymous user, * it returns #TRUE. If it is authenticated as a specific user, then * this returns #FALSE. (Note that if the connection was authenticated * as anonymous then disconnected, this function still returns #TRUE.) * * If the connection is not anonymous, you can use * dbus_connection_get_unix_user() and * dbus_connection_get_windows_user() to see who it's authorized as. * * If you want to prevent non-anonymous authorization, use * dbus_server_set_auth_mechanisms() to remove the mechanisms that * allow proving user identity (i.e. only allow the ANONYMOUS * mechanism). * * @param connection the connection * @returns #TRUE if not authenticated or authenticated as anonymous */ dbus_bool_t dbus_connection_get_is_anonymous (DBusConnection *connection) { dbus_bool_t res; _dbus_return_val_if_fail (connection != NULL, FALSE); CONNECTION_LOCK (connection); res = _dbus_transport_get_is_anonymous (connection->transport); CONNECTION_UNLOCK (connection); return res; } /** * Gets the ID of the server address we are authenticated to, if this * connection is on the client side. If the connection is on the * server side, this will always return #NULL - use dbus_server_get_id() * to get the ID of your own server, if you are the server side. * * If a client-side connection is not authenticated yet, the ID may be * available if it was included in the server address, but may not be * available. The only way to be sure the server ID is available * is to wait for authentication to complete. * * In general, each mode of connecting to a given server will have * its own ID. So for example, if the session bus daemon is listening * on UNIX domain sockets and on TCP, then each of those modalities * will have its own server ID. * * If you want an ID that identifies an entire session bus, look at * dbus_bus_get_id() instead (which is just a convenience wrapper * around the org.freedesktop.DBus.GetId method invoked on the bus). * * You can also get a machine ID; see dbus_get_local_machine_id() to * get the machine you are on. There isn't a convenience wrapper, but * you can invoke org.freedesktop.DBus.Peer.GetMachineId on any peer * to get the machine ID on the other end. * * The D-Bus specification describes the server ID and other IDs in a * bit more detail. * * @param connection the connection * @returns the server ID or #NULL if no memory or the connection is server-side */ char* dbus_connection_get_server_id (DBusConnection *connection) { char *id; _dbus_return_val_if_fail (connection != NULL, NULL); CONNECTION_LOCK (connection); id = _dbus_strdup (_dbus_transport_get_server_id (connection->transport)); CONNECTION_UNLOCK (connection); return id; } /** * Tests whether a certain type can be send via the connection. This * will always return TRUE for all types, with the exception of * DBUS_TYPE_UNIX_FD. The function will return TRUE for * DBUS_TYPE_UNIX_FD only on systems that know Unix file descriptors * and can send them via the chosen transport and when the remote side * supports this. * * This function can be used to do runtime checking for types that * might be unknown to the specific D-Bus client implementation * version, i.e. it will return FALSE for all types this * implementation does not know. * * @param connection the connection * @param type the type to check * @returns TRUE if the type may be send via the connection */ dbus_bool_t dbus_connection_can_send_type(DBusConnection *connection, int type) { _dbus_return_val_if_fail (connection != NULL, FALSE); if (!_dbus_type_is_valid(type)) return FALSE; if (type != DBUS_TYPE_UNIX_FD) return TRUE; #ifdef HAVE_UNIX_FD_PASSING { dbus_bool_t b; CONNECTION_LOCK(connection); b = _dbus_transport_can_pass_unix_fd(connection->transport); CONNECTION_UNLOCK(connection); return b; } #endif return FALSE; } /** * Set whether _exit() should be called when the connection receives a * disconnect signal. The call to _exit() comes after any handlers for * the disconnect signal run; handlers can cancel the exit by calling * this function. * * By default, exit_on_disconnect is #FALSE; but for message bus * connections returned from dbus_bus_get() it will be toggled on * by default. * * @param connection the connection * @param exit_on_disconnect #TRUE if _exit() should be called after a disconnect signal */ void dbus_connection_set_exit_on_disconnect (DBusConnection *connection, dbus_bool_t exit_on_disconnect) { _dbus_return_if_fail (connection != NULL); CONNECTION_LOCK (connection); connection->exit_on_disconnect = exit_on_disconnect != FALSE; CONNECTION_UNLOCK (connection); } /** * Preallocates resources needed to send a message, allowing the message * to be sent without the possibility of memory allocation failure. * Allows apps to create a future guarantee that they can send * a message regardless of memory shortages. * * @param connection the connection we're preallocating for. * @returns the preallocated resources, or #NULL */ DBusPreallocatedSend* dbus_connection_preallocate_send (DBusConnection *connection) { DBusPreallocatedSend *preallocated; _dbus_return_val_if_fail (connection != NULL, NULL); CONNECTION_LOCK (connection); preallocated = _dbus_connection_preallocate_send_unlocked (connection); CONNECTION_UNLOCK (connection); return preallocated; } /** * Frees preallocated message-sending resources from * dbus_connection_preallocate_send(). Should only * be called if the preallocated resources are not used * to send a message. * * @param connection the connection * @param preallocated the resources */ void dbus_connection_free_preallocated_send (DBusConnection *connection, DBusPreallocatedSend *preallocated) { _dbus_return_if_fail (connection != NULL); _dbus_return_if_fail (preallocated != NULL); _dbus_return_if_fail (connection == preallocated->connection); _dbus_list_free_link (preallocated->queue_link); _dbus_counter_unref (preallocated->counter_link->data); _dbus_list_free_link (preallocated->counter_link); dbus_free (preallocated); } /** * Sends a message using preallocated resources. This function cannot fail. * It works identically to dbus_connection_send() in other respects. * Preallocated resources comes from dbus_connection_preallocate_send(). * This function "consumes" the preallocated resources, they need not * be freed separately. * * @param connection the connection * @param preallocated the preallocated resources * @param message the message to send * @param client_serial return location for client serial assigned to the message */ void dbus_connection_send_preallocated (DBusConnection *connection, DBusPreallocatedSend *preallocated, DBusMessage *message, dbus_uint32_t *client_serial) { _dbus_return_if_fail (connection != NULL); _dbus_return_if_fail (preallocated != NULL); _dbus_return_if_fail (message != NULL); _dbus_return_if_fail (preallocated->connection == connection); _dbus_return_if_fail (dbus_message_get_type (message) != DBUS_MESSAGE_TYPE_METHOD_CALL || dbus_message_get_member (message) != NULL); _dbus_return_if_fail (dbus_message_get_type (message) != DBUS_MESSAGE_TYPE_SIGNAL || (dbus_message_get_interface (message) != NULL && dbus_message_get_member (message) != NULL)); CONNECTION_LOCK (connection); #ifdef HAVE_UNIX_FD_PASSING if (!_dbus_transport_can_pass_unix_fd(connection->transport) && message->n_unix_fds > 0) { /* Refuse to send fds on a connection that cannot handle them. Unfortunately we cannot return a proper error here, so the best we can is just return. */ CONNECTION_UNLOCK (connection); return; } #endif _dbus_connection_send_preallocated_and_unlock (connection, preallocated, message, client_serial); } static dbus_bool_t _dbus_connection_send_unlocked_no_update (DBusConnection *connection, DBusMessage *message, dbus_uint32_t *client_serial) { DBusPreallocatedSend *preallocated; _dbus_assert (connection != NULL); _dbus_assert (message != NULL); preallocated = _dbus_connection_preallocate_send_unlocked (connection); if (preallocated == NULL) return FALSE; _dbus_connection_send_preallocated_unlocked_no_update (connection, preallocated, message, client_serial); return TRUE; } /** * Adds a message to the outgoing message queue. Does not block to * write the message to the network; that happens asynchronously. To * force the message to be written, call dbus_connection_flush() however * it is not necessary to call dbus_connection_flush() by hand; the * message will be sent the next time the main loop is run. * dbus_connection_flush() should only be used, for example, if * the application was expected to exit before running the main loop. * * Because this only queues the message, the only reason it can * fail is lack of memory. Even if the connection is disconnected, * no error will be returned. If the function fails due to lack of memory, * it returns #FALSE. The function will never fail for other reasons; even * if the connection is disconnected, you can queue an outgoing message, * though obviously it won't be sent. * * The message serial is used by the remote application to send a * reply; see dbus_message_get_serial() or the D-Bus specification. * * dbus_message_unref() can be called as soon as this method returns * as the message queue will hold its own ref until the message is sent. * * @param connection the connection. * @param message the message to write. * @param serial return location for message serial, or #NULL if you don't care * @returns #TRUE on success. */ dbus_bool_t dbus_connection_send (DBusConnection *connection, DBusMessage *message, dbus_uint32_t *serial) { _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (message != NULL, FALSE); CONNECTION_LOCK (connection); #ifdef HAVE_UNIX_FD_PASSING if (!_dbus_transport_can_pass_unix_fd(connection->transport) && message->n_unix_fds > 0) { /* Refuse to send fds on a connection that cannot handle them. Unfortunately we cannot return a proper error here, so the best we can is just return. */ CONNECTION_UNLOCK (connection); return FALSE; } #endif return _dbus_connection_send_and_unlock (connection, message, serial); } static dbus_bool_t reply_handler_timeout (void *data) { DBusConnection *connection; DBusDispatchStatus status; DBusPendingCall *pending = data; connection = _dbus_pending_call_get_connection_and_lock (pending); _dbus_pending_call_queue_timeout_error_unlocked (pending, connection); _dbus_connection_remove_timeout_unlocked (connection, _dbus_pending_call_get_timeout_unlocked (pending)); _dbus_pending_call_set_timeout_added_unlocked (pending, FALSE); _dbus_verbose ("%s middle\n", _DBUS_FUNCTION_NAME); status = _dbus_connection_get_dispatch_status_unlocked (connection); /* Unlocks, and calls out to user code */ _dbus_connection_update_dispatch_status_and_unlock (connection, status); return TRUE; } /** * Queues a message to send, as with dbus_connection_send(), * but also returns a #DBusPendingCall used to receive a reply to the * message. If no reply is received in the given timeout_milliseconds, * this function expires the pending reply and generates a synthetic * error reply (generated in-process, not by the remote application) * indicating that a timeout occurred. * * A #DBusPendingCall will see a reply message before any filters or * registered object path handlers. See dbus_connection_dispatch() for * details on when handlers are run. * * A #DBusPendingCall will always see exactly one reply message, * unless it's cancelled with dbus_pending_call_cancel(). * * If #NULL is passed for the pending_return, the #DBusPendingCall * will still be generated internally, and used to track * the message reply timeout. This means a timeout error will * occur if no reply arrives, unlike with dbus_connection_send(). * * If -1 is passed for the timeout, a sane default timeout is used. -1 * is typically the best value for the timeout for this reason, unless * you want a very short or very long timeout. If INT_MAX is passed for * the timeout, no timeout will be set and the call will block forever. * * @warning if the connection is disconnected or you try to send Unix * file descriptors on a connection that does not support them, the * #DBusPendingCall will be set to #NULL, so be careful with this. * * @param connection the connection * @param message the message to send * @param pending_return return location for a #DBusPendingCall * object, or #NULL if connection is disconnected or when you try to * send Unix file descriptors on a connection that does not support * them. * @param timeout_milliseconds timeout in milliseconds, -1 for default or INT_MAX for no timeout * @returns #FALSE if no memory, #TRUE otherwise. * */ dbus_bool_t dbus_connection_send_with_reply (DBusConnection *connection, DBusMessage *message, DBusPendingCall **pending_return, int timeout_milliseconds) { DBusPendingCall *pending; dbus_int32_t serial = -1; DBusDispatchStatus status; _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (message != NULL, FALSE); _dbus_return_val_if_fail (timeout_milliseconds >= 0 || timeout_milliseconds == -1, FALSE); if (pending_return) *pending_return = NULL; CONNECTION_LOCK (connection); #ifdef HAVE_UNIX_FD_PASSING if (!_dbus_transport_can_pass_unix_fd(connection->transport) && message->n_unix_fds > 0) { /* Refuse to send fds on a connection that cannot handle them. Unfortunately we cannot return a proper error here, so the best we can do is return TRUE but leave *pending_return as NULL. */ CONNECTION_UNLOCK (connection); return TRUE; } #endif if (!_dbus_connection_get_is_connected_unlocked (connection)) { CONNECTION_UNLOCK (connection); return TRUE; } pending = _dbus_pending_call_new_unlocked (connection, timeout_milliseconds, reply_handler_timeout); if (pending == NULL) { CONNECTION_UNLOCK (connection); return FALSE; } /* Assign a serial to the message */ serial = dbus_message_get_serial (message); if (serial == 0) { serial = _dbus_connection_get_next_client_serial (connection); dbus_message_set_serial (message, serial); } if (!_dbus_pending_call_set_timeout_error_unlocked (pending, message, serial)) goto error; /* Insert the serial in the pending replies hash; * hash takes a refcount on DBusPendingCall. * Also, add the timeout. */ if (!_dbus_connection_attach_pending_call_unlocked (connection, pending)) goto error; if (!_dbus_connection_send_unlocked_no_update (connection, message, NULL)) { _dbus_connection_detach_pending_call_and_unlock (connection, pending); goto error_unlocked; } if (pending_return) *pending_return = pending; /* hand off refcount */ else { _dbus_connection_detach_pending_call_unlocked (connection, pending); /* we still have a ref to the pending call in this case, we unref * after unlocking, below */ } status = _dbus_connection_get_dispatch_status_unlocked (connection); /* this calls out to user code */ _dbus_connection_update_dispatch_status_and_unlock (connection, status); if (pending_return == NULL) dbus_pending_call_unref (pending); return TRUE; error: CONNECTION_UNLOCK (connection); error_unlocked: dbus_pending_call_unref (pending); return FALSE; } /** * Sends a message and blocks a certain time period while waiting for * a reply. This function does not reenter the main loop, * i.e. messages other than the reply are queued up but not * processed. This function is used to invoke method calls on a * remote object. * * If a normal reply is received, it is returned, and removed from the * incoming message queue. If it is not received, #NULL is returned * and the error is set to #DBUS_ERROR_NO_REPLY. If an error reply is * received, it is converted to a #DBusError and returned as an error, * then the reply message is deleted and #NULL is returned. If * something else goes wrong, result is set to whatever is * appropriate, such as #DBUS_ERROR_NO_MEMORY or * #DBUS_ERROR_DISCONNECTED. * * @warning While this function blocks the calling thread will not be * processing the incoming message queue. This means you can end up * deadlocked if the application you're talking to needs you to reply * to a method. To solve this, either avoid the situation, block in a * separate thread from the main connection-dispatching thread, or use * dbus_pending_call_set_notify() to avoid blocking. * * @param connection the connection * @param message the message to send * @param timeout_milliseconds timeout in milliseconds, -1 for default or INT_MAX for no timeout. * @param error return location for error message * @returns the message that is the reply or #NULL with an error code if the * function fails. */ DBusMessage* dbus_connection_send_with_reply_and_block (DBusConnection *connection, DBusMessage *message, int timeout_milliseconds, DBusError *error) { DBusMessage *reply; DBusPendingCall *pending; _dbus_return_val_if_fail (connection != NULL, NULL); _dbus_return_val_if_fail (message != NULL, NULL); _dbus_return_val_if_fail (timeout_milliseconds >= 0 || timeout_milliseconds == -1, NULL); _dbus_return_val_if_error_is_set (error, NULL); #ifdef HAVE_UNIX_FD_PASSING CONNECTION_LOCK (connection); if (!_dbus_transport_can_pass_unix_fd(connection->transport) && message->n_unix_fds > 0) { CONNECTION_UNLOCK (connection); dbus_set_error(error, DBUS_ERROR_FAILED, "Cannot send file descriptors on this connection."); return NULL; } CONNECTION_UNLOCK (connection); #endif if (!dbus_connection_send_with_reply (connection, message, &pending, timeout_milliseconds)) { _DBUS_SET_OOM (error); return NULL; } if (pending == NULL) { dbus_set_error (error, DBUS_ERROR_DISCONNECTED, "Connection is closed"); return NULL; } dbus_pending_call_block (pending); reply = dbus_pending_call_steal_reply (pending); dbus_pending_call_unref (pending); /* call_complete_and_unlock() called from pending_call_block() should * always fill this in. */ _dbus_assert (reply != NULL); if (dbus_set_error_from_message (error, reply)) { dbus_message_unref (reply); return NULL; } else return reply; } /** * Blocks until the outgoing message queue is empty. * Assumes connection lock already held. * * If you call this, you MUST call update_dispatch_status afterword... * * @param connection the connection. */ static DBusDispatchStatus _dbus_connection_flush_unlocked (DBusConnection *connection) { /* We have to specify DBUS_ITERATION_DO_READING here because * otherwise we could have two apps deadlock if they are both doing * a flush(), and the kernel buffers fill up. This could change the * dispatch status. */ DBusDispatchStatus status; HAVE_LOCK_CHECK (connection); while (connection->n_outgoing > 0 && _dbus_connection_get_is_connected_unlocked (connection)) { _dbus_verbose ("doing iteration in %s\n", _DBUS_FUNCTION_NAME); HAVE_LOCK_CHECK (connection); _dbus_connection_do_iteration_unlocked (connection, DBUS_ITERATION_DO_READING | DBUS_ITERATION_DO_WRITING | DBUS_ITERATION_BLOCK, -1); } HAVE_LOCK_CHECK (connection); _dbus_verbose ("%s middle\n", _DBUS_FUNCTION_NAME); status = _dbus_connection_get_dispatch_status_unlocked (connection); HAVE_LOCK_CHECK (connection); return status; } /** * Blocks until the outgoing message queue is empty. * * @param connection the connection. */ void dbus_connection_flush (DBusConnection *connection) { /* We have to specify DBUS_ITERATION_DO_READING here because * otherwise we could have two apps deadlock if they are both doing * a flush(), and the kernel buffers fill up. This could change the * dispatch status. */ DBusDispatchStatus status; _dbus_return_if_fail (connection != NULL); CONNECTION_LOCK (connection); status = _dbus_connection_flush_unlocked (connection); HAVE_LOCK_CHECK (connection); /* Unlocks and calls out to user code */ _dbus_connection_update_dispatch_status_and_unlock (connection, status); _dbus_verbose ("%s end\n", _DBUS_FUNCTION_NAME); } /** * This function implements dbus_connection_read_write_dispatch() and * dbus_connection_read_write() (they pass a different value for the * dispatch parameter). * * @param connection the connection * @param timeout_milliseconds max time to block or -1 for infinite * @param dispatch dispatch new messages or leave them on the incoming queue * @returns #TRUE if the disconnect message has not been processed */ static dbus_bool_t _dbus_connection_read_write_dispatch (DBusConnection *connection, int timeout_milliseconds, dbus_bool_t dispatch) { DBusDispatchStatus dstatus; dbus_bool_t progress_possible; /* Need to grab a ref here in case we're a private connection and * the user drops the last ref in a handler we call; see bug * https://bugs.freedesktop.org/show_bug.cgi?id=15635 */ dbus_connection_ref (connection); dstatus = dbus_connection_get_dispatch_status (connection); if (dispatch && dstatus == DBUS_DISPATCH_DATA_REMAINS) { _dbus_verbose ("doing dispatch in %s\n", _DBUS_FUNCTION_NAME); dbus_connection_dispatch (connection); CONNECTION_LOCK (connection); } else if (dstatus == DBUS_DISPATCH_NEED_MEMORY) { _dbus_verbose ("pausing for memory in %s\n", _DBUS_FUNCTION_NAME); _dbus_memory_pause_based_on_timeout (timeout_milliseconds); CONNECTION_LOCK (connection); } else { CONNECTION_LOCK (connection); if (_dbus_connection_get_is_connected_unlocked (connection)) { _dbus_verbose ("doing iteration in %s\n", _DBUS_FUNCTION_NAME); _dbus_connection_do_iteration_unlocked (connection, DBUS_ITERATION_DO_READING | DBUS_ITERATION_DO_WRITING | DBUS_ITERATION_BLOCK, timeout_milliseconds); } } HAVE_LOCK_CHECK (connection); /* If we can dispatch, we can make progress until the Disconnected message * has been processed; if we can only read/write, we can make progress * as long as the transport is open. */ if (dispatch) progress_possible = connection->n_incoming != 0 || connection->disconnect_message_link != NULL; else progress_possible = _dbus_connection_get_is_connected_unlocked (connection); CONNECTION_UNLOCK (connection); dbus_connection_unref (connection); return progress_possible; /* TRUE if we can make more progress */ } /** * This function is intended for use with applications that don't want * to write a main loop and deal with #DBusWatch and #DBusTimeout. An * example usage would be: * * @code * while (dbus_connection_read_write_dispatch (connection, -1)) * ; // empty loop body * @endcode * * In this usage you would normally have set up a filter function to look * at each message as it is dispatched. The loop terminates when the last * message from the connection (the disconnected signal) is processed. * * If there are messages to dispatch, this function will * dbus_connection_dispatch() once, and return. If there are no * messages to dispatch, this function will block until it can read or * write, then read or write, then return. * * The way to think of this function is that it either makes some sort * of progress, or it blocks. Note that, while it is blocked on I/O, it * cannot be interrupted (even by other threads), which makes this function * unsuitable for applications that do more than just react to received * messages. * * The return value indicates whether the disconnect message has been * processed, NOT whether the connection is connected. This is * important because even after disconnecting, you want to process any * messages you received prior to the disconnect. * * @param connection the connection * @param timeout_milliseconds max time to block or -1 for infinite * @returns #TRUE if the disconnect message has not been processed */ dbus_bool_t dbus_connection_read_write_dispatch (DBusConnection *connection, int timeout_milliseconds) { _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (timeout_milliseconds >= 0 || timeout_milliseconds == -1, FALSE); return _dbus_connection_read_write_dispatch(connection, timeout_milliseconds, TRUE); } /** * This function is intended for use with applications that don't want to * write a main loop and deal with #DBusWatch and #DBusTimeout. See also * dbus_connection_read_write_dispatch(). * * As long as the connection is open, this function will block until it can * read or write, then read or write, then return #TRUE. * * If the connection is closed, the function returns #FALSE. * * The return value indicates whether reading or writing is still * possible, i.e. whether the connection is connected. * * Note that even after disconnection, messages may remain in the * incoming queue that need to be * processed. dbus_connection_read_write_dispatch() dispatches * incoming messages for you; with dbus_connection_read_write() you * have to arrange to drain the incoming queue yourself. * * @param connection the connection * @param timeout_milliseconds max time to block or -1 for infinite * @returns #TRUE if still connected */ dbus_bool_t dbus_connection_read_write (DBusConnection *connection, int timeout_milliseconds) { _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (timeout_milliseconds >= 0 || timeout_milliseconds == -1, FALSE); return _dbus_connection_read_write_dispatch(connection, timeout_milliseconds, FALSE); } /* We need to call this anytime we pop the head of the queue, and then * update_dispatch_status_and_unlock needs to be called afterward * which will "process" the disconnected message and set * disconnected_message_processed. */ static void check_disconnected_message_arrived_unlocked (DBusConnection *connection, DBusMessage *head_of_queue) { HAVE_LOCK_CHECK (connection); /* checking that the link is NULL is an optimization to avoid the is_signal call */ if (connection->disconnect_message_link == NULL && dbus_message_is_signal (head_of_queue, DBUS_INTERFACE_LOCAL, "Disconnected")) { connection->disconnected_message_arrived = TRUE; } } /** * Returns the first-received message from the incoming message queue, * leaving it in the queue. If the queue is empty, returns #NULL. * * The caller does not own a reference to the returned message, and * must either return it using dbus_connection_return_message() or * keep it after calling dbus_connection_steal_borrowed_message(). No * one can get at the message while its borrowed, so return it as * quickly as possible and don't keep a reference to it after * returning it. If you need to keep the message, make a copy of it. * * dbus_connection_dispatch() will block if called while a borrowed * message is outstanding; only one piece of code can be playing with * the incoming queue at a time. This function will block if called * during a dbus_connection_dispatch(). * * @param connection the connection. * @returns next message in the incoming queue. */ DBusMessage* dbus_connection_borrow_message (DBusConnection *connection) { DBusDispatchStatus status; DBusMessage *message; _dbus_return_val_if_fail (connection != NULL, NULL); _dbus_verbose ("%s start\n", _DBUS_FUNCTION_NAME); /* this is called for the side effect that it queues * up any messages from the transport */ status = dbus_connection_get_dispatch_status (connection); if (status != DBUS_DISPATCH_DATA_REMAINS) return NULL; CONNECTION_LOCK (connection); _dbus_connection_acquire_dispatch (connection); /* While a message is outstanding, the dispatch lock is held */ _dbus_assert (connection->message_borrowed == NULL); connection->message_borrowed = _dbus_list_get_first (&connection->incoming_messages); message = connection->message_borrowed; check_disconnected_message_arrived_unlocked (connection, message); /* Note that we KEEP the dispatch lock until the message is returned */ if (message == NULL) _dbus_connection_release_dispatch (connection); CONNECTION_UNLOCK (connection); /* We don't update dispatch status until it's returned or stolen */ return message; } /** * Used to return a message after peeking at it using * dbus_connection_borrow_message(). Only called if * message from dbus_connection_borrow_message() was non-#NULL. * * @param connection the connection * @param message the message from dbus_connection_borrow_message() */ void dbus_connection_return_message (DBusConnection *connection, DBusMessage *message) { DBusDispatchStatus status; _dbus_return_if_fail (connection != NULL); _dbus_return_if_fail (message != NULL); _dbus_return_if_fail (message == connection->message_borrowed); _dbus_return_if_fail (connection->dispatch_acquired); CONNECTION_LOCK (connection); _dbus_assert (message == connection->message_borrowed); connection->message_borrowed = NULL; _dbus_connection_release_dispatch (connection); status = _dbus_connection_get_dispatch_status_unlocked (connection); _dbus_connection_update_dispatch_status_and_unlock (connection, status); } /** * Used to keep a message after peeking at it using * dbus_connection_borrow_message(). Before using this function, see * the caveats/warnings in the documentation for * dbus_connection_pop_message(). * * @param connection the connection * @param message the message from dbus_connection_borrow_message() */ void dbus_connection_steal_borrowed_message (DBusConnection *connection, DBusMessage *message) { DBusMessage *pop_message; DBusDispatchStatus status; _dbus_return_if_fail (connection != NULL); _dbus_return_if_fail (message != NULL); _dbus_return_if_fail (message == connection->message_borrowed); _dbus_return_if_fail (connection->dispatch_acquired); CONNECTION_LOCK (connection); _dbus_assert (message == connection->message_borrowed); pop_message = _dbus_list_pop_first (&connection->incoming_messages); _dbus_assert (message == pop_message); connection->n_incoming -= 1; _dbus_verbose ("Incoming message %p stolen from queue, %d incoming\n", message, connection->n_incoming); connection->message_borrowed = NULL; _dbus_connection_release_dispatch (connection); status = _dbus_connection_get_dispatch_status_unlocked (connection); _dbus_connection_update_dispatch_status_and_unlock (connection, status); } /* See dbus_connection_pop_message, but requires the caller to own * the lock before calling. May drop the lock while running. */ static DBusList* _dbus_connection_pop_message_link_unlocked (DBusConnection *connection) { HAVE_LOCK_CHECK (connection); _dbus_assert (connection->message_borrowed == NULL); if (connection->n_incoming > 0) { DBusList *link; link = _dbus_list_pop_first_link (&connection->incoming_messages); connection->n_incoming -= 1; _dbus_verbose ("Message %p (%d %s %s %s '%s') removed from incoming queue %p, %d incoming\n", link->data, dbus_message_get_type (link->data), dbus_message_get_path (link->data) ? dbus_message_get_path (link->data) : "no path", dbus_message_get_interface (link->data) ? dbus_message_get_interface (link->data) : "no interface", dbus_message_get_member (link->data) ? dbus_message_get_member (link->data) : "no member", dbus_message_get_signature (link->data), connection, connection->n_incoming); check_disconnected_message_arrived_unlocked (connection, link->data); return link; } else return NULL; } /* See dbus_connection_pop_message, but requires the caller to own * the lock before calling. May drop the lock while running. */ static DBusMessage* _dbus_connection_pop_message_unlocked (DBusConnection *connection) { DBusList *link; HAVE_LOCK_CHECK (connection); link = _dbus_connection_pop_message_link_unlocked (connection); if (link != NULL) { DBusMessage *message; message = link->data; _dbus_list_free_link (link); return message; } else return NULL; } static void _dbus_connection_putback_message_link_unlocked (DBusConnection *connection, DBusList *message_link) { HAVE_LOCK_CHECK (connection); _dbus_assert (message_link != NULL); /* You can't borrow a message while a link is outstanding */ _dbus_assert (connection->message_borrowed == NULL); /* We had to have the dispatch lock across the pop/putback */ _dbus_assert (connection->dispatch_acquired); _dbus_list_prepend_link (&connection->incoming_messages, message_link); connection->n_incoming += 1; _dbus_verbose ("Message %p (%d %s %s '%s') put back into queue %p, %d incoming\n", message_link->data, dbus_message_get_type (message_link->data), dbus_message_get_interface (message_link->data) ? dbus_message_get_interface (message_link->data) : "no interface", dbus_message_get_member (message_link->data) ? dbus_message_get_member (message_link->data) : "no member", dbus_message_get_signature (message_link->data), connection, connection->n_incoming); } /** * Returns the first-received message from the incoming message queue, * removing it from the queue. The caller owns a reference to the * returned message. If the queue is empty, returns #NULL. * * This function bypasses any message handlers that are registered, * and so using it is usually wrong. Instead, let the main loop invoke * dbus_connection_dispatch(). Popping messages manually is only * useful in very simple programs that don't share a #DBusConnection * with any libraries or other modules. * * There is a lock that covers all ways of accessing the incoming message * queue, so dbus_connection_dispatch(), dbus_connection_pop_message(), * dbus_connection_borrow_message(), etc. will all block while one of the others * in the group is running. * * @param connection the connection. * @returns next message in the incoming queue. */ DBusMessage* dbus_connection_pop_message (DBusConnection *connection) { DBusMessage *message; DBusDispatchStatus status; _dbus_verbose ("%s start\n", _DBUS_FUNCTION_NAME); /* this is called for the side effect that it queues * up any messages from the transport */ status = dbus_connection_get_dispatch_status (connection); if (status != DBUS_DISPATCH_DATA_REMAINS) return NULL; CONNECTION_LOCK (connection); _dbus_connection_acquire_dispatch (connection); HAVE_LOCK_CHECK (connection); message = _dbus_connection_pop_message_unlocked (connection); _dbus_verbose ("Returning popped message %p\n", message); _dbus_connection_release_dispatch (connection); status = _dbus_connection_get_dispatch_status_unlocked (connection); _dbus_connection_update_dispatch_status_and_unlock (connection, status); return message; } /** * Acquire the dispatcher. This is a separate lock so the main * connection lock can be dropped to call out to application dispatch * handlers. * * @param connection the connection. */ static void _dbus_connection_acquire_dispatch (DBusConnection *connection) { HAVE_LOCK_CHECK (connection); _dbus_connection_ref_unlocked (connection); CONNECTION_UNLOCK (connection); _dbus_verbose ("%s locking dispatch_mutex\n", _DBUS_FUNCTION_NAME); _dbus_mutex_lock (connection->dispatch_mutex); while (connection->dispatch_acquired) { _dbus_verbose ("%s waiting for dispatch to be acquirable\n", _DBUS_FUNCTION_NAME); _dbus_condvar_wait (connection->dispatch_cond, connection->dispatch_mutex); } _dbus_assert (!connection->dispatch_acquired); connection->dispatch_acquired = TRUE; _dbus_verbose ("%s unlocking dispatch_mutex\n", _DBUS_FUNCTION_NAME); _dbus_mutex_unlock (connection->dispatch_mutex); CONNECTION_LOCK (connection); _dbus_connection_unref_unlocked (connection); } /** * Release the dispatcher when you're done with it. Only call * after you've acquired the dispatcher. Wakes up at most one * thread currently waiting to acquire the dispatcher. * * @param connection the connection. */ static void _dbus_connection_release_dispatch (DBusConnection *connection) { HAVE_LOCK_CHECK (connection); _dbus_verbose ("%s locking dispatch_mutex\n", _DBUS_FUNCTION_NAME); _dbus_mutex_lock (connection->dispatch_mutex); _dbus_assert (connection->dispatch_acquired); connection->dispatch_acquired = FALSE; _dbus_condvar_wake_one (connection->dispatch_cond); _dbus_verbose ("%s unlocking dispatch_mutex\n", _DBUS_FUNCTION_NAME); _dbus_mutex_unlock (connection->dispatch_mutex); } static void _dbus_connection_failed_pop (DBusConnection *connection, DBusList *message_link) { _dbus_list_prepend_link (&connection->incoming_messages, message_link); connection->n_incoming += 1; } /* Note this may be called multiple times since we don't track whether we already did it */ static void notify_disconnected_unlocked (DBusConnection *connection) { HAVE_LOCK_CHECK (connection); /* Set the weakref in dbus-bus.c to NULL, so nobody will get a disconnected * connection from dbus_bus_get(). We make the same guarantee for * dbus_connection_open() but in a different way since we don't want to * unref right here; we instead check for connectedness before returning * the connection from the hash. */ _dbus_bus_notify_shared_connection_disconnected_unlocked (connection); /* Dump the outgoing queue, we aren't going to be able to * send it now, and we'd like accessors like * dbus_connection_get_outgoing_size() to be accurate. */ if (connection->n_outgoing > 0) { DBusList *link; _dbus_verbose ("Dropping %d outgoing messages since we're disconnected\n", connection->n_outgoing); while ((link = _dbus_list_get_last_link (&connection->outgoing_messages))) { _dbus_connection_message_sent (connection, link->data); } } } /* Note this may be called multiple times since we don't track whether we already did it */ static DBusDispatchStatus notify_disconnected_and_dispatch_complete_unlocked (DBusConnection *connection) { HAVE_LOCK_CHECK (connection); if (connection->disconnect_message_link != NULL) { _dbus_verbose ("Sending disconnect message from %s\n", _DBUS_FUNCTION_NAME); /* If we have pending calls, queue their timeouts - we want the Disconnected * to be the last message, after these timeouts. */ connection_timeout_and_complete_all_pending_calls_unlocked (connection); /* We haven't sent the disconnect message already, * and all real messages have been queued up. */ _dbus_connection_queue_synthesized_message_link (connection, connection->disconnect_message_link); connection->disconnect_message_link = NULL; return DBUS_DISPATCH_DATA_REMAINS; } return DBUS_DISPATCH_COMPLETE; } static DBusDispatchStatus _dbus_connection_get_dispatch_status_unlocked (DBusConnection *connection) { HAVE_LOCK_CHECK (connection); if (connection->n_incoming > 0) return DBUS_DISPATCH_DATA_REMAINS; else if (!_dbus_transport_queue_messages (connection->transport)) return DBUS_DISPATCH_NEED_MEMORY; else { DBusDispatchStatus status; dbus_bool_t is_connected; status = _dbus_transport_get_dispatch_status (connection->transport); is_connected = _dbus_transport_get_is_connected (connection->transport); _dbus_verbose ("dispatch status = %s is_connected = %d\n", DISPATCH_STATUS_NAME (status), is_connected); if (!is_connected) { /* It's possible this would be better done by having an explicit * notification from _dbus_transport_disconnect() that would * synchronously do this, instead of waiting for the next dispatch * status check. However, probably not good to change until it causes * a problem. */ notify_disconnected_unlocked (connection); /* I'm not sure this is needed; the idea is that we want to * queue the Disconnected only after we've read all the * messages, but if we're disconnected maybe we are guaranteed * to have read them all ? */ if (status == DBUS_DISPATCH_COMPLETE) status = notify_disconnected_and_dispatch_complete_unlocked (connection); } if (status != DBUS_DISPATCH_COMPLETE) return status; else if (connection->n_incoming > 0) return DBUS_DISPATCH_DATA_REMAINS; else return DBUS_DISPATCH_COMPLETE; } } static void _dbus_connection_update_dispatch_status_and_unlock (DBusConnection *connection, DBusDispatchStatus new_status) { dbus_bool_t changed; DBusDispatchStatusFunction function; void *data; HAVE_LOCK_CHECK (connection); _dbus_connection_ref_unlocked (connection); changed = new_status != connection->last_dispatch_status; connection->last_dispatch_status = new_status; function = connection->dispatch_status_function; data = connection->dispatch_status_data; if (connection->disconnected_message_arrived && !connection->disconnected_message_processed) { connection->disconnected_message_processed = TRUE; /* this does an unref, but we have a ref * so we should not run the finalizer here * inside the lock. */ connection_forget_shared_unlocked (connection); if (connection->exit_on_disconnect) { CONNECTION_UNLOCK (connection); _dbus_verbose ("Exiting on Disconnected signal\n"); _dbus_exit (1); _dbus_assert_not_reached ("Call to exit() returned"); } } /* We drop the lock */ CONNECTION_UNLOCK (connection); if (changed && function) { _dbus_verbose ("Notifying of change to dispatch status of %p now %d (%s)\n", connection, new_status, DISPATCH_STATUS_NAME (new_status)); (* function) (connection, new_status, data); } dbus_connection_unref (connection); } /** * Gets the current state of the incoming message queue. * #DBUS_DISPATCH_DATA_REMAINS indicates that the message queue * may contain messages. #DBUS_DISPATCH_COMPLETE indicates that the * incoming queue is empty. #DBUS_DISPATCH_NEED_MEMORY indicates that * there could be data, but we can't know for sure without more * memory. * * To process the incoming message queue, use dbus_connection_dispatch() * or (in rare cases) dbus_connection_pop_message(). * * Note, #DBUS_DISPATCH_DATA_REMAINS really means that either we * have messages in the queue, or we have raw bytes buffered up * that need to be parsed. When these bytes are parsed, they * may not add up to an entire message. Thus, it's possible * to see a status of #DBUS_DISPATCH_DATA_REMAINS but not * have a message yet. * * In particular this happens on initial connection, because all sorts * of authentication protocol stuff has to be parsed before the * first message arrives. * * @param connection the connection. * @returns current dispatch status */ DBusDispatchStatus dbus_connection_get_dispatch_status (DBusConnection *connection) { DBusDispatchStatus status; _dbus_return_val_if_fail (connection != NULL, DBUS_DISPATCH_COMPLETE); _dbus_verbose ("%s start\n", _DBUS_FUNCTION_NAME); CONNECTION_LOCK (connection); status = _dbus_connection_get_dispatch_status_unlocked (connection); CONNECTION_UNLOCK (connection); return status; } /** * Filter funtion for handling the Peer standard interface. */ static DBusHandlerResult _dbus_connection_peer_filter_unlocked_no_update (DBusConnection *connection, DBusMessage *message) { if (connection->route_peer_messages && dbus_message_get_destination (message) != NULL) { /* This means we're letting the bus route this message */ return DBUS_HANDLER_RESULT_NOT_YET_HANDLED; } else if (dbus_message_is_method_call (message, DBUS_INTERFACE_PEER, "Ping")) { DBusMessage *ret; dbus_bool_t sent; ret = dbus_message_new_method_return (message); if (ret == NULL) return DBUS_HANDLER_RESULT_NEED_MEMORY; sent = _dbus_connection_send_unlocked_no_update (connection, ret, NULL); dbus_message_unref (ret); if (!sent) return DBUS_HANDLER_RESULT_NEED_MEMORY; return DBUS_HANDLER_RESULT_HANDLED; } else if (dbus_message_is_method_call (message, DBUS_INTERFACE_PEER, "GetMachineId")) { DBusMessage *ret; dbus_bool_t sent; DBusString uuid; ret = dbus_message_new_method_return (message); if (ret == NULL) return DBUS_HANDLER_RESULT_NEED_MEMORY; sent = FALSE; _dbus_string_init (&uuid); if (_dbus_get_local_machine_uuid_encoded (&uuid)) { const char *v_STRING = _dbus_string_get_const_data (&uuid); if (dbus_message_append_args (ret, DBUS_TYPE_STRING, &v_STRING, DBUS_TYPE_INVALID)) { sent = _dbus_connection_send_unlocked_no_update (connection, ret, NULL); } } _dbus_string_free (&uuid); dbus_message_unref (ret); if (!sent) return DBUS_HANDLER_RESULT_NEED_MEMORY; return DBUS_HANDLER_RESULT_HANDLED; } else if (dbus_message_has_interface (message, DBUS_INTERFACE_PEER)) { /* We need to bounce anything else with this interface, otherwise apps * could start extending the interface and when we added extensions * here to DBusConnection we'd break those apps. */ DBusMessage *ret; dbus_bool_t sent; ret = dbus_message_new_error (message, DBUS_ERROR_UNKNOWN_METHOD, "Unknown method invoked on org.freedesktop.DBus.Peer interface"); if (ret == NULL) return DBUS_HANDLER_RESULT_NEED_MEMORY; sent = _dbus_connection_send_unlocked_no_update (connection, ret, NULL); dbus_message_unref (ret); if (!sent) return DBUS_HANDLER_RESULT_NEED_MEMORY; return DBUS_HANDLER_RESULT_HANDLED; } else { return DBUS_HANDLER_RESULT_NOT_YET_HANDLED; } } /** * Processes all builtin filter functions * * If the spec specifies a standard interface * they should be processed from this method **/ static DBusHandlerResult _dbus_connection_run_builtin_filters_unlocked_no_update (DBusConnection *connection, DBusMessage *message) { /* We just run one filter for now but have the option to run more if the spec calls for it in the future */ return _dbus_connection_peer_filter_unlocked_no_update (connection, message); } /** * Processes any incoming data. * * If there's incoming raw data that has not yet been parsed, it is * parsed, which may or may not result in adding messages to the * incoming queue. * * The incoming data buffer is filled when the connection reads from * its underlying transport (such as a socket). Reading usually * happens in dbus_watch_handle() or dbus_connection_read_write(). * * If there are complete messages in the incoming queue, * dbus_connection_dispatch() removes one message from the queue and * processes it. Processing has three steps. * * First, any method replies are passed to #DBusPendingCall or * dbus_connection_send_with_reply_and_block() in order to * complete the pending method call. * * Second, any filters registered with dbus_connection_add_filter() * are run. If any filter returns #DBUS_HANDLER_RESULT_HANDLED * then processing stops after that filter. * * Third, if the message is a method call it is forwarded to * any registered object path handlers added with * dbus_connection_register_object_path() or * dbus_connection_register_fallback(). * * A single call to dbus_connection_dispatch() will process at most * one message; it will not clear the entire message queue. * * Be careful about calling dbus_connection_dispatch() from inside a * message handler, i.e. calling dbus_connection_dispatch() * recursively. If threads have been initialized with a recursive * mutex function, then this will not deadlock; however, it can * certainly confuse your application. * * @todo some FIXME in here about handling DBUS_HANDLER_RESULT_NEED_MEMORY * * @param connection the connection * @returns dispatch status, see dbus_connection_get_dispatch_status() */ DBusDispatchStatus dbus_connection_dispatch (DBusConnection *connection) { DBusMessage *message; DBusList *link, *filter_list_copy, *message_link; DBusHandlerResult result; DBusPendingCall *pending; dbus_int32_t reply_serial; DBusDispatchStatus status; _dbus_return_val_if_fail (connection != NULL, DBUS_DISPATCH_COMPLETE); _dbus_verbose ("%s\n", _DBUS_FUNCTION_NAME); CONNECTION_LOCK (connection); status = _dbus_connection_get_dispatch_status_unlocked (connection); if (status != DBUS_DISPATCH_DATA_REMAINS) { /* unlocks and calls out to user code */ _dbus_connection_update_dispatch_status_and_unlock (connection, status); return status; } /* We need to ref the connection since the callback could potentially * drop the last ref to it */ _dbus_connection_ref_unlocked (connection); _dbus_connection_acquire_dispatch (connection); HAVE_LOCK_CHECK (connection); message_link = _dbus_connection_pop_message_link_unlocked (connection); if (message_link == NULL) { /* another thread dispatched our stuff */ _dbus_verbose ("another thread dispatched message (during acquire_dispatch above)\n"); _dbus_connection_release_dispatch (connection); status = _dbus_connection_get_dispatch_status_unlocked (connection); _dbus_connection_update_dispatch_status_and_unlock (connection, status); dbus_connection_unref (connection); return status; } message = message_link->data; _dbus_verbose (" dispatching message %p (%d %s %s '%s')\n", message, dbus_message_get_type (message), dbus_message_get_interface (message) ? dbus_message_get_interface (message) : "no interface", dbus_message_get_member (message) ? dbus_message_get_member (message) : "no member", dbus_message_get_signature (message)); result = DBUS_HANDLER_RESULT_NOT_YET_HANDLED; /* Pending call handling must be first, because if you do * dbus_connection_send_with_reply_and_block() or * dbus_pending_call_block() then no handlers/filters will be run on * the reply. We want consistent semantics in the case where we * dbus_connection_dispatch() the reply. */ reply_serial = dbus_message_get_reply_serial (message); pending = _dbus_hash_table_lookup_int (connection->pending_replies, reply_serial); if (pending) { _dbus_verbose ("Dispatching a pending reply\n"); complete_pending_call_and_unlock (connection, pending, message); pending = NULL; /* it's probably unref'd */ CONNECTION_LOCK (connection); _dbus_verbose ("pending call completed in dispatch\n"); result = DBUS_HANDLER_RESULT_HANDLED; goto out; } result = _dbus_connection_run_builtin_filters_unlocked_no_update (connection, message); if (result != DBUS_HANDLER_RESULT_NOT_YET_HANDLED) goto out; if (!_dbus_list_copy (&connection->filter_list, &filter_list_copy)) { _dbus_connection_release_dispatch (connection); HAVE_LOCK_CHECK (connection); _dbus_connection_failed_pop (connection, message_link); /* unlocks and calls user code */ _dbus_connection_update_dispatch_status_and_unlock (connection, DBUS_DISPATCH_NEED_MEMORY); if (pending) dbus_pending_call_unref (pending); dbus_connection_unref (connection); return DBUS_DISPATCH_NEED_MEMORY; } _dbus_list_foreach (&filter_list_copy, (DBusForeachFunction)_dbus_message_filter_ref, NULL); /* We're still protected from dispatch() reentrancy here * since we acquired the dispatcher */ CONNECTION_UNLOCK (connection); link = _dbus_list_get_first_link (&filter_list_copy); while (link != NULL) { DBusMessageFilter *filter = link->data; DBusList *next = _dbus_list_get_next_link (&filter_list_copy, link); if (filter->function == NULL) { _dbus_verbose (" filter was removed in a callback function\n"); link = next; continue; } _dbus_verbose (" running filter on message %p\n", message); result = (* filter->function) (connection, message, filter->user_data); if (result != DBUS_HANDLER_RESULT_NOT_YET_HANDLED) break; link = next; } _dbus_list_foreach (&filter_list_copy, (DBusForeachFunction)_dbus_message_filter_unref, NULL); _dbus_list_clear (&filter_list_copy); CONNECTION_LOCK (connection); if (result == DBUS_HANDLER_RESULT_NEED_MEMORY) { _dbus_verbose ("No memory in %s\n", _DBUS_FUNCTION_NAME); goto out; } else if (result == DBUS_HANDLER_RESULT_HANDLED) { _dbus_verbose ("filter handled message in dispatch\n"); goto out; } /* We're still protected from dispatch() reentrancy here * since we acquired the dispatcher */ _dbus_verbose (" running object path dispatch on message %p (%d %s %s '%s')\n", message, dbus_message_get_type (message), dbus_message_get_interface (message) ? dbus_message_get_interface (message) : "no interface", dbus_message_get_member (message) ? dbus_message_get_member (message) : "no member", dbus_message_get_signature (message)); HAVE_LOCK_CHECK (connection); result = _dbus_object_tree_dispatch_and_unlock (connection->objects, message); CONNECTION_LOCK (connection); if (result != DBUS_HANDLER_RESULT_NOT_YET_HANDLED) { _dbus_verbose ("object tree handled message in dispatch\n"); goto out; } if (dbus_message_get_type (message) == DBUS_MESSAGE_TYPE_METHOD_CALL) { DBusMessage *reply; DBusString str; DBusPreallocatedSend *preallocated; _dbus_verbose (" sending error %s\n", DBUS_ERROR_UNKNOWN_METHOD); if (!_dbus_string_init (&str)) { result = DBUS_HANDLER_RESULT_NEED_MEMORY; _dbus_verbose ("no memory for error string in dispatch\n"); goto out; } if (!_dbus_string_append_printf (&str, "Method \"%s\" with signature \"%s\" on interface \"%s\" doesn't exist\n", dbus_message_get_member (message), dbus_message_get_signature (message), dbus_message_get_interface (message))) { _dbus_string_free (&str); result = DBUS_HANDLER_RESULT_NEED_MEMORY; _dbus_verbose ("no memory for error string in dispatch\n"); goto out; } reply = dbus_message_new_error (message, DBUS_ERROR_UNKNOWN_METHOD, _dbus_string_get_const_data (&str)); _dbus_string_free (&str); if (reply == NULL) { result = DBUS_HANDLER_RESULT_NEED_MEMORY; _dbus_verbose ("no memory for error reply in dispatch\n"); goto out; } preallocated = _dbus_connection_preallocate_send_unlocked (connection); if (preallocated == NULL) { dbus_message_unref (reply); result = DBUS_HANDLER_RESULT_NEED_MEMORY; _dbus_verbose ("no memory for error send in dispatch\n"); goto out; } _dbus_connection_send_preallocated_unlocked_no_update (connection, preallocated, reply, NULL); dbus_message_unref (reply); result = DBUS_HANDLER_RESULT_HANDLED; } _dbus_verbose (" done dispatching %p (%d %s %s '%s') on connection %p\n", message, dbus_message_get_type (message), dbus_message_get_interface (message) ? dbus_message_get_interface (message) : "no interface", dbus_message_get_member (message) ? dbus_message_get_member (message) : "no member", dbus_message_get_signature (message), connection); out: if (result == DBUS_HANDLER_RESULT_NEED_MEMORY) { _dbus_verbose ("out of memory in %s\n", _DBUS_FUNCTION_NAME); /* Put message back, and we'll start over. * Yes this means handlers must be idempotent if they * don't return HANDLED; c'est la vie. */ _dbus_connection_putback_message_link_unlocked (connection, message_link); } else { _dbus_verbose (" ... done dispatching in %s\n", _DBUS_FUNCTION_NAME); _dbus_list_free_link (message_link); dbus_message_unref (message); /* don't want the message to count in max message limits * in computing dispatch status below */ } _dbus_connection_release_dispatch (connection); HAVE_LOCK_CHECK (connection); _dbus_verbose ("%s before final status update\n", _DBUS_FUNCTION_NAME); status = _dbus_connection_get_dispatch_status_unlocked (connection); /* unlocks and calls user code */ _dbus_connection_update_dispatch_status_and_unlock (connection, status); dbus_connection_unref (connection); return status; } /** * Sets the watch functions for the connection. These functions are * responsible for making the application's main loop aware of file * descriptors that need to be monitored for events, using select() or * poll(). When using Qt, typically the DBusAddWatchFunction would * create a QSocketNotifier. When using GLib, the DBusAddWatchFunction * could call g_io_add_watch(), or could be used as part of a more * elaborate GSource. Note that when a watch is added, it may * not be enabled. * * The DBusWatchToggledFunction notifies the application that the * watch has been enabled or disabled. Call dbus_watch_get_enabled() * to check this. A disabled watch should have no effect, and enabled * watch should be added to the main loop. This feature is used * instead of simply adding/removing the watch because * enabling/disabling can be done without memory allocation. The * toggled function may be NULL if a main loop re-queries * dbus_watch_get_enabled() every time anyway. * * The DBusWatch can be queried for the file descriptor to watch using * dbus_watch_get_unix_fd() or dbus_watch_get_socket(), and for the * events to watch for using dbus_watch_get_flags(). The flags * returned by dbus_watch_get_flags() will only contain * DBUS_WATCH_READABLE and DBUS_WATCH_WRITABLE, never * DBUS_WATCH_HANGUP or DBUS_WATCH_ERROR; all watches implicitly * include a watch for hangups, errors, and other exceptional * conditions. * * Once a file descriptor becomes readable or writable, or an exception * occurs, dbus_watch_handle() should be called to * notify the connection of the file descriptor's condition. * * dbus_watch_handle() cannot be called during the * DBusAddWatchFunction, as the connection will not be ready to handle * that watch yet. * * It is not allowed to reference a DBusWatch after it has been passed * to remove_function. * * If #FALSE is returned due to lack of memory, the failure may be due * to a #FALSE return from the new add_function. If so, the * add_function may have been called successfully one or more times, * but the remove_function will also have been called to remove any * successful adds. i.e. if #FALSE is returned the net result * should be that dbus_connection_set_watch_functions() has no effect, * but the add_function and remove_function may have been called. * * @todo We need to drop the lock when we call the * add/remove/toggled functions which can be a side effect * of setting the watch functions. * * @param connection the connection. * @param add_function function to begin monitoring a new descriptor. * @param remove_function function to stop monitoring a descriptor. * @param toggled_function function to notify of enable/disable * @param data data to pass to add_function and remove_function. * @param free_data_function function to be called to free the data. * @returns #FALSE on failure (no memory) */ dbus_bool_t dbus_connection_set_watch_functions (DBusConnection *connection, DBusAddWatchFunction add_function, DBusRemoveWatchFunction remove_function, DBusWatchToggledFunction toggled_function, void *data, DBusFreeFunction free_data_function) { dbus_bool_t retval; DBusWatchList *watches; _dbus_return_val_if_fail (connection != NULL, FALSE); CONNECTION_LOCK (connection); #ifndef DBUS_DISABLE_CHECKS if (connection->watches == NULL) { _dbus_warn_check_failed ("Re-entrant call to %s is not allowed\n", _DBUS_FUNCTION_NAME); return FALSE; } #endif /* ref connection for slightly better reentrancy */ _dbus_connection_ref_unlocked (connection); /* This can call back into user code, and we need to drop the * connection lock when it does. This is kind of a lame * way to do it. */ watches = connection->watches; connection->watches = NULL; CONNECTION_UNLOCK (connection); retval = _dbus_watch_list_set_functions (watches, add_function, remove_function, toggled_function, data, free_data_function); CONNECTION_LOCK (connection); connection->watches = watches; CONNECTION_UNLOCK (connection); /* drop our paranoid refcount */ dbus_connection_unref (connection); return retval; } /** * Sets the timeout functions for the connection. These functions are * responsible for making the application's main loop aware of timeouts. * When using Qt, typically the DBusAddTimeoutFunction would create a * QTimer. When using GLib, the DBusAddTimeoutFunction would call * g_timeout_add. * * The DBusTimeoutToggledFunction notifies the application that the * timeout has been enabled or disabled. Call * dbus_timeout_get_enabled() to check this. A disabled timeout should * have no effect, and enabled timeout should be added to the main * loop. This feature is used instead of simply adding/removing the * timeout because enabling/disabling can be done without memory * allocation. With Qt, QTimer::start() and QTimer::stop() can be used * to enable and disable. The toggled function may be NULL if a main * loop re-queries dbus_timeout_get_enabled() every time anyway. * Whenever a timeout is toggled, its interval may change. * * The DBusTimeout can be queried for the timer interval using * dbus_timeout_get_interval(). dbus_timeout_handle() should be called * repeatedly, each time the interval elapses, starting after it has * elapsed once. The timeout stops firing when it is removed with the * given remove_function. The timer interval may change whenever the * timeout is added, removed, or toggled. * * @param connection the connection. * @param add_function function to add a timeout. * @param remove_function function to remove a timeout. * @param toggled_function function to notify of enable/disable * @param data data to pass to add_function and remove_function. * @param free_data_function function to be called to free the data. * @returns #FALSE on failure (no memory) */ dbus_bool_t dbus_connection_set_timeout_functions (DBusConnection *connection, DBusAddTimeoutFunction add_function, DBusRemoveTimeoutFunction remove_function, DBusTimeoutToggledFunction toggled_function, void *data, DBusFreeFunction free_data_function) { dbus_bool_t retval; DBusTimeoutList *timeouts; _dbus_return_val_if_fail (connection != NULL, FALSE); CONNECTION_LOCK (connection); #ifndef DBUS_DISABLE_CHECKS if (connection->timeouts == NULL) { _dbus_warn_check_failed ("Re-entrant call to %s is not allowed\n", _DBUS_FUNCTION_NAME); return FALSE; } #endif /* ref connection for slightly better reentrancy */ _dbus_connection_ref_unlocked (connection); timeouts = connection->timeouts; connection->timeouts = NULL; CONNECTION_UNLOCK (connection); retval = _dbus_timeout_list_set_functions (timeouts, add_function, remove_function, toggled_function, data, free_data_function); CONNECTION_LOCK (connection); connection->timeouts = timeouts; CONNECTION_UNLOCK (connection); /* drop our paranoid refcount */ dbus_connection_unref (connection); return retval; } /** * Sets the mainloop wakeup function for the connection. This function * is responsible for waking up the main loop (if its sleeping in * another thread) when some some change has happened to the * connection that the mainloop needs to reconsider (e.g. a message * has been queued for writing). When using Qt, this typically * results in a call to QEventLoop::wakeUp(). When using GLib, it * would call g_main_context_wakeup(). * * @param connection the connection. * @param wakeup_main_function function to wake up the mainloop * @param data data to pass wakeup_main_function * @param free_data_function function to be called to free the data. */ void dbus_connection_set_wakeup_main_function (DBusConnection *connection, DBusWakeupMainFunction wakeup_main_function, void *data, DBusFreeFunction free_data_function) { void *old_data; DBusFreeFunction old_free_data; _dbus_return_if_fail (connection != NULL); CONNECTION_LOCK (connection); old_data = connection->wakeup_main_data; old_free_data = connection->free_wakeup_main_data; connection->wakeup_main_function = wakeup_main_function; connection->wakeup_main_data = data; connection->free_wakeup_main_data = free_data_function; CONNECTION_UNLOCK (connection); /* Callback outside the lock */ if (old_free_data) (*old_free_data) (old_data); } /** * Set a function to be invoked when the dispatch status changes. * If the dispatch status is #DBUS_DISPATCH_DATA_REMAINS, then * dbus_connection_dispatch() needs to be called to process incoming * messages. However, dbus_connection_dispatch() MUST NOT BE CALLED * from inside the DBusDispatchStatusFunction. Indeed, almost * any reentrancy in this function is a bad idea. Instead, * the DBusDispatchStatusFunction should simply save an indication * that messages should be dispatched later, when the main loop * is re-entered. * * If you don't set a dispatch status function, you have to be sure to * dispatch on every iteration of your main loop, especially if * dbus_watch_handle() or dbus_timeout_handle() were called. * * @param connection the connection * @param function function to call on dispatch status changes * @param data data for function * @param free_data_function free the function data */ void dbus_connection_set_dispatch_status_function (DBusConnection *connection, DBusDispatchStatusFunction function, void *data, DBusFreeFunction free_data_function) { void *old_data; DBusFreeFunction old_free_data; _dbus_return_if_fail (connection != NULL); CONNECTION_LOCK (connection); old_data = connection->dispatch_status_data; old_free_data = connection->free_dispatch_status_data; connection->dispatch_status_function = function; connection->dispatch_status_data = data; connection->free_dispatch_status_data = free_data_function; CONNECTION_UNLOCK (connection); /* Callback outside the lock */ if (old_free_data) (*old_free_data) (old_data); } /** * Get the UNIX file descriptor of the connection, if any. This can * be used for SELinux access control checks with getpeercon() for * example. DO NOT read or write to the file descriptor, or try to * select() on it; use DBusWatch for main loop integration. Not all * connections will have a file descriptor. So for adding descriptors * to the main loop, use dbus_watch_get_unix_fd() and so forth. * * If the connection is socket-based, you can also use * dbus_connection_get_socket(), which will work on Windows too. * This function always fails on Windows. * * Right now the returned descriptor is always a socket, but * that is not guaranteed. * * @param connection the connection * @param fd return location for the file descriptor. * @returns #TRUE if fd is successfully obtained. */ dbus_bool_t dbus_connection_get_unix_fd (DBusConnection *connection, int *fd) { _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (connection->transport != NULL, FALSE); #ifdef DBUS_WIN /* FIXME do this on a lower level */ return FALSE; #endif return dbus_connection_get_socket(connection, fd); } /** * Gets the underlying Windows or UNIX socket file descriptor * of the connection, if any. DO NOT read or write to the file descriptor, or try to * select() on it; use DBusWatch for main loop integration. Not all * connections will have a socket. So for adding descriptors * to the main loop, use dbus_watch_get_socket() and so forth. * * If the connection is not socket-based, this function will return FALSE, * even if the connection does have a file descriptor of some kind. * i.e. this function always returns specifically a socket file descriptor. * * @param connection the connection * @param fd return location for the file descriptor. * @returns #TRUE if fd is successfully obtained. */ dbus_bool_t dbus_connection_get_socket(DBusConnection *connection, int *fd) { dbus_bool_t retval; _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (connection->transport != NULL, FALSE); CONNECTION_LOCK (connection); retval = _dbus_transport_get_socket_fd (connection->transport, fd); CONNECTION_UNLOCK (connection); return retval; } /** * Gets the UNIX user ID of the connection if known. Returns #TRUE if * the uid is filled in. Always returns #FALSE on non-UNIX platforms * for now, though in theory someone could hook Windows to NIS or * something. Always returns #FALSE prior to authenticating the * connection. * * The UID is only read by servers from clients; clients can't usually * get the UID of servers, because servers do not authenticate to * clients. The returned UID is the UID the connection authenticated * as. * * The message bus is a server and the apps connecting to the bus * are clients. * * You can ask the bus to tell you the UID of another connection though * if you like; this is done with dbus_bus_get_unix_user(). * * @param connection the connection * @param uid return location for the user ID * @returns #TRUE if uid is filled in with a valid user ID */ dbus_bool_t dbus_connection_get_unix_user (DBusConnection *connection, unsigned long *uid) { dbus_bool_t result; _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (uid != NULL, FALSE); CONNECTION_LOCK (connection); if (!_dbus_transport_get_is_authenticated (connection->transport)) result = FALSE; else result = _dbus_transport_get_unix_user (connection->transport, uid); #ifdef DBUS_WIN _dbus_assert (!result); #endif CONNECTION_UNLOCK (connection); return result; } /** * Gets the process ID of the connection if any. * Returns #TRUE if the pid is filled in. * Always returns #FALSE prior to authenticating the * connection. * * @param connection the connection * @param pid return location for the process ID * @returns #TRUE if uid is filled in with a valid process ID */ dbus_bool_t dbus_connection_get_unix_process_id (DBusConnection *connection, unsigned long *pid) { dbus_bool_t result; _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (pid != NULL, FALSE); CONNECTION_LOCK (connection); if (!_dbus_transport_get_is_authenticated (connection->transport)) result = FALSE; else result = _dbus_transport_get_unix_process_id (connection->transport, pid); #ifdef DBUS_WIN _dbus_assert (!result); #endif CONNECTION_UNLOCK (connection); return result; } /** * Gets the ADT audit data of the connection if any. * Returns #TRUE if the structure pointer is returned. * Always returns #FALSE prior to authenticating the * connection. * * @param connection the connection * @param data return location for audit data * @returns #TRUE if audit data is filled in with a valid ucred pointer */ dbus_bool_t dbus_connection_get_adt_audit_session_data (DBusConnection *connection, void **data, dbus_int32_t *data_size) { dbus_bool_t result; _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (data != NULL, FALSE); _dbus_return_val_if_fail (data_size != NULL, FALSE); CONNECTION_LOCK (connection); if (!_dbus_transport_get_is_authenticated (connection->transport)) result = FALSE; else result = _dbus_transport_get_adt_audit_session_data (connection->transport, data, data_size); CONNECTION_UNLOCK (connection); return result; } /** * Sets a predicate function used to determine whether a given user ID * is allowed to connect. When an incoming connection has * authenticated with a particular user ID, this function is called; * if it returns #TRUE, the connection is allowed to proceed, * otherwise the connection is disconnected. * * If the function is set to #NULL (as it is by default), then * only the same UID as the server process will be allowed to * connect. Also, root is always allowed to connect. * * On Windows, the function will be set and its free_data_function will * be invoked when the connection is freed or a new function is set. * However, the function will never be called, because there are * no UNIX user ids to pass to it, or at least none of the existing * auth protocols would allow authenticating as a UNIX user on Windows. * * @param connection the connection * @param function the predicate * @param data data to pass to the predicate * @param free_data_function function to free the data */ void dbus_connection_set_unix_user_function (DBusConnection *connection, DBusAllowUnixUserFunction function, void *data, DBusFreeFunction free_data_function) { void *old_data = NULL; DBusFreeFunction old_free_function = NULL; _dbus_return_if_fail (connection != NULL); CONNECTION_LOCK (connection); _dbus_transport_set_unix_user_function (connection->transport, function, data, free_data_function, &old_data, &old_free_function); CONNECTION_UNLOCK (connection); if (old_free_function != NULL) (* old_free_function) (old_data); } /** * Gets the Windows user SID of the connection if known. Returns * #TRUE if the ID is filled in. Always returns #FALSE on non-Windows * platforms for now, though in theory someone could hook UNIX to * Active Directory or something. Always returns #FALSE prior to * authenticating the connection. * * The user is only read by servers from clients; clients can't usually * get the user of servers, because servers do not authenticate to * clients. The returned user is the user the connection authenticated * as. * * The message bus is a server and the apps connecting to the bus * are clients. * * The returned user string has to be freed with dbus_free(). * * The return value indicates whether the user SID is available; * if it's available but we don't have the memory to copy it, * then the return value is #TRUE and #NULL is given as the SID. * * @todo We would like to be able to say "You can ask the bus to tell * you the user of another connection though if you like; this is done * with dbus_bus_get_windows_user()." But this has to be implemented * in bus/driver.c and dbus/dbus-bus.c, and is pointless anyway * since on Windows we only use the session bus for now. * * @param connection the connection * @param windows_sid_p return location for an allocated copy of the user ID, or #NULL if no memory * @returns #TRUE if user is available (returned value may be #NULL anyway if no memory) */ dbus_bool_t dbus_connection_get_windows_user (DBusConnection *connection, char **windows_sid_p) { dbus_bool_t result; _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (windows_sid_p != NULL, FALSE); CONNECTION_LOCK (connection); if (!_dbus_transport_get_is_authenticated (connection->transport)) result = FALSE; else result = _dbus_transport_get_windows_user (connection->transport, windows_sid_p); #ifdef DBUS_UNIX _dbus_assert (!result); #endif CONNECTION_UNLOCK (connection); return result; } /** * Sets a predicate function used to determine whether a given user ID * is allowed to connect. When an incoming connection has * authenticated with a particular user ID, this function is called; * if it returns #TRUE, the connection is allowed to proceed, * otherwise the connection is disconnected. * * If the function is set to #NULL (as it is by default), then * only the same user owning the server process will be allowed to * connect. * * On UNIX, the function will be set and its free_data_function will * be invoked when the connection is freed or a new function is set. * However, the function will never be called, because there is no * way right now to authenticate as a Windows user on UNIX. * * @param connection the connection * @param function the predicate * @param data data to pass to the predicate * @param free_data_function function to free the data */ void dbus_connection_set_windows_user_function (DBusConnection *connection, DBusAllowWindowsUserFunction function, void *data, DBusFreeFunction free_data_function) { void *old_data = NULL; DBusFreeFunction old_free_function = NULL; _dbus_return_if_fail (connection != NULL); CONNECTION_LOCK (connection); _dbus_transport_set_windows_user_function (connection->transport, function, data, free_data_function, &old_data, &old_free_function); CONNECTION_UNLOCK (connection); if (old_free_function != NULL) (* old_free_function) (old_data); } /** * This function must be called on the server side of a connection when the * connection is first seen in the #DBusNewConnectionFunction. If set to * #TRUE (the default is #FALSE), then the connection can proceed even if * the client does not authenticate as some user identity, i.e. clients * can connect anonymously. * * This setting interacts with the available authorization mechanisms * (see dbus_server_set_auth_mechanisms()). Namely, an auth mechanism * such as ANONYMOUS that supports anonymous auth must be included in * the list of available mechanisms for anonymous login to work. * * This setting also changes the default rule for connections * authorized as a user; normally, if a connection authorizes as * a user identity, it is permitted if the user identity is * root or the user identity matches the user identity of the server * process. If anonymous connections are allowed, however, * then any user identity is allowed. * * You can override the rules for connections authorized as a * user identity with dbus_connection_set_unix_user_function() * and dbus_connection_set_windows_user_function(). * * @param connection the connection * @param value whether to allow authentication as an anonymous user */ void dbus_connection_set_allow_anonymous (DBusConnection *connection, dbus_bool_t value) { _dbus_return_if_fail (connection != NULL); CONNECTION_LOCK (connection); _dbus_transport_set_allow_anonymous (connection->transport, value); CONNECTION_UNLOCK (connection); } /** * * Normally #DBusConnection automatically handles all messages to the * org.freedesktop.DBus.Peer interface. However, the message bus wants * to be able to route methods on that interface through the bus and * to other applications. If routing peer messages is enabled, then * messages with the org.freedesktop.DBus.Peer interface that also * have a bus destination name set will not be automatically * handled by the #DBusConnection and instead will be dispatched * normally to the application. * * If a normal application sets this flag, it can break things badly. * So don't set this unless you are the message bus. * * @param connection the connection * @param value #TRUE to pass through org.freedesktop.DBus.Peer messages with a bus name set */ void dbus_connection_set_route_peer_messages (DBusConnection *connection, dbus_bool_t value) { _dbus_return_if_fail (connection != NULL); CONNECTION_LOCK (connection); connection->route_peer_messages = TRUE; CONNECTION_UNLOCK (connection); } /** * Adds a message filter. Filters are handlers that are run on all * incoming messages, prior to the objects registered with * dbus_connection_register_object_path(). Filters are run in the * order that they were added. The same handler can be added as a * filter more than once, in which case it will be run more than once. * Filters added during a filter callback won't be run on the message * being processed. * * @todo we don't run filters on messages while blocking without * entering the main loop, since filters are run as part of * dbus_connection_dispatch(). This is probably a feature, as filters * could create arbitrary reentrancy. But kind of sucks if you're * trying to filter METHOD_RETURN for some reason. * * @param connection the connection * @param function function to handle messages * @param user_data user data to pass to the function * @param free_data_function function to use for freeing user data * @returns #TRUE on success, #FALSE if not enough memory. */ dbus_bool_t dbus_connection_add_filter (DBusConnection *connection, DBusHandleMessageFunction function, void *user_data, DBusFreeFunction free_data_function) { DBusMessageFilter *filter; _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (function != NULL, FALSE); filter = dbus_new0 (DBusMessageFilter, 1); if (filter == NULL) return FALSE; filter->refcount.value = 1; CONNECTION_LOCK (connection); if (!_dbus_list_append (&connection->filter_list, filter)) { _dbus_message_filter_unref (filter); CONNECTION_UNLOCK (connection); return FALSE; } /* Fill in filter after all memory allocated, * so we don't run the free_user_data_function * if the add_filter() fails */ filter->function = function; filter->user_data = user_data; filter->free_user_data_function = free_data_function; CONNECTION_UNLOCK (connection); return TRUE; } /** * Removes a previously-added message filter. It is a programming * error to call this function for a handler that has not been added * as a filter. If the given handler was added more than once, only * one instance of it will be removed (the most recently-added * instance). * * @param connection the connection * @param function the handler to remove * @param user_data user data for the handler to remove * */ void dbus_connection_remove_filter (DBusConnection *connection, DBusHandleMessageFunction function, void *user_data) { DBusList *link; DBusMessageFilter *filter; _dbus_return_if_fail (connection != NULL); _dbus_return_if_fail (function != NULL); CONNECTION_LOCK (connection); filter = NULL; link = _dbus_list_get_last_link (&connection->filter_list); while (link != NULL) { filter = link->data; if (filter->function == function && filter->user_data == user_data) { _dbus_list_remove_link (&connection->filter_list, link); filter->function = NULL; break; } link = _dbus_list_get_prev_link (&connection->filter_list, link); filter = NULL; } CONNECTION_UNLOCK (connection); #ifndef DBUS_DISABLE_CHECKS if (filter == NULL) { _dbus_warn_check_failed ("Attempt to remove filter function %p user data %p, but no such filter has been added\n", function, user_data); return; } #endif /* Call application code */ if (filter->free_user_data_function) (* filter->free_user_data_function) (filter->user_data); filter->free_user_data_function = NULL; filter->user_data = NULL; _dbus_message_filter_unref (filter); } /** * Registers a handler for a given path in the object hierarchy. * The given vtable handles messages sent to exactly the given path. * * @param connection the connection * @param path a '/' delimited string of path elements * @param vtable the virtual table * @param user_data data to pass to functions in the vtable * @param error address where an error can be returned * @returns #FALSE if an error (#DBUS_ERROR_NO_MEMORY or * #DBUS_ERROR_ADDRESS_IN_USE) is reported */ dbus_bool_t dbus_connection_try_register_object_path (DBusConnection *connection, const char *path, const DBusObjectPathVTable *vtable, void *user_data, DBusError *error) { char **decomposed_path; dbus_bool_t retval; _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (path != NULL, FALSE); _dbus_return_val_if_fail (path[0] == '/', FALSE); _dbus_return_val_if_fail (vtable != NULL, FALSE); if (!_dbus_decompose_path (path, strlen (path), &decomposed_path, NULL)) return FALSE; CONNECTION_LOCK (connection); retval = _dbus_object_tree_register (connection->objects, FALSE, (const char **) decomposed_path, vtable, user_data, error); CONNECTION_UNLOCK (connection); dbus_free_string_array (decomposed_path); return retval; } /** * Registers a handler for a given path in the object hierarchy. * The given vtable handles messages sent to exactly the given path. * * It is a bug to call this function for object paths which already * have a handler. Use dbus_connection_try_register_object_path() if this * might be the case. * * @param connection the connection * @param path a '/' delimited string of path elements * @param vtable the virtual table * @param user_data data to pass to functions in the vtable * @returns #FALSE if not enough memory */ dbus_bool_t dbus_connection_register_object_path (DBusConnection *connection, const char *path, const DBusObjectPathVTable *vtable, void *user_data) { char **decomposed_path; dbus_bool_t retval; DBusError error = DBUS_ERROR_INIT; _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (path != NULL, FALSE); _dbus_return_val_if_fail (path[0] == '/', FALSE); _dbus_return_val_if_fail (vtable != NULL, FALSE); if (!_dbus_decompose_path (path, strlen (path), &decomposed_path, NULL)) return FALSE; CONNECTION_LOCK (connection); retval = _dbus_object_tree_register (connection->objects, FALSE, (const char **) decomposed_path, vtable, user_data, &error); CONNECTION_UNLOCK (connection); dbus_free_string_array (decomposed_path); if (dbus_error_has_name (&error, DBUS_ERROR_ADDRESS_IN_USE)) { _dbus_warn ("%s\n", error.message); dbus_error_free (&error); return FALSE; } return retval; } /** * Registers a fallback handler for a given subsection of the object * hierarchy. The given vtable handles messages at or below the given * path. You can use this to establish a default message handling * policy for a whole "subdirectory." * * @param connection the connection * @param path a '/' delimited string of path elements * @param vtable the virtual table * @param user_data data to pass to functions in the vtable * @param error address where an error can be returned * @returns #FALSE if an error (#DBUS_ERROR_NO_MEMORY or * #DBUS_ERROR_ADDRESS_IN_USE) is reported */ dbus_bool_t dbus_connection_try_register_fallback (DBusConnection *connection, const char *path, const DBusObjectPathVTable *vtable, void *user_data, DBusError *error) { char **decomposed_path; dbus_bool_t retval; _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (path != NULL, FALSE); _dbus_return_val_if_fail (path[0] == '/', FALSE); _dbus_return_val_if_fail (vtable != NULL, FALSE); if (!_dbus_decompose_path (path, strlen (path), &decomposed_path, NULL)) return FALSE; CONNECTION_LOCK (connection); retval = _dbus_object_tree_register (connection->objects, TRUE, (const char **) decomposed_path, vtable, user_data, error); CONNECTION_UNLOCK (connection); dbus_free_string_array (decomposed_path); return retval; } /** * Registers a fallback handler for a given subsection of the object * hierarchy. The given vtable handles messages at or below the given * path. You can use this to establish a default message handling * policy for a whole "subdirectory." * * It is a bug to call this function for object paths which already * have a handler. Use dbus_connection_try_register_fallback() if this * might be the case. * * @param connection the connection * @param path a '/' delimited string of path elements * @param vtable the virtual table * @param user_data data to pass to functions in the vtable * @returns #FALSE if not enough memory */ dbus_bool_t dbus_connection_register_fallback (DBusConnection *connection, const char *path, const DBusObjectPathVTable *vtable, void *user_data) { char **decomposed_path; dbus_bool_t retval; DBusError error = DBUS_ERROR_INIT; _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (path != NULL, FALSE); _dbus_return_val_if_fail (path[0] == '/', FALSE); _dbus_return_val_if_fail (vtable != NULL, FALSE); if (!_dbus_decompose_path (path, strlen (path), &decomposed_path, NULL)) return FALSE; CONNECTION_LOCK (connection); retval = _dbus_object_tree_register (connection->objects, TRUE, (const char **) decomposed_path, vtable, user_data, &error); CONNECTION_UNLOCK (connection); dbus_free_string_array (decomposed_path); if (dbus_error_has_name (&error, DBUS_ERROR_ADDRESS_IN_USE)) { _dbus_warn ("%s\n", error.message); dbus_error_free (&error); return FALSE; } return retval; } /** * Unregisters the handler registered with exactly the given path. * It's a bug to call this function for a path that isn't registered. * Can unregister both fallback paths and object paths. * * @param connection the connection * @param path a '/' delimited string of path elements * @returns #FALSE if not enough memory */ dbus_bool_t dbus_connection_unregister_object_path (DBusConnection *connection, const char *path) { char **decomposed_path; _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (path != NULL, FALSE); _dbus_return_val_if_fail (path[0] == '/', FALSE); if (!_dbus_decompose_path (path, strlen (path), &decomposed_path, NULL)) return FALSE; CONNECTION_LOCK (connection); _dbus_object_tree_unregister_and_unlock (connection->objects, (const char **) decomposed_path); dbus_free_string_array (decomposed_path); return TRUE; } /** * Gets the user data passed to dbus_connection_register_object_path() * or dbus_connection_register_fallback(). If nothing was registered * at this path, the data is filled in with #NULL. * * @param connection the connection * @param path the path you registered with * @param data_p location to store the user data, or #NULL * @returns #FALSE if not enough memory */ dbus_bool_t dbus_connection_get_object_path_data (DBusConnection *connection, const char *path, void **data_p) { char **decomposed_path; _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (path != NULL, FALSE); _dbus_return_val_if_fail (data_p != NULL, FALSE); *data_p = NULL; if (!_dbus_decompose_path (path, strlen (path), &decomposed_path, NULL)) return FALSE; CONNECTION_LOCK (connection); *data_p = _dbus_object_tree_get_user_data_unlocked (connection->objects, (const char**) decomposed_path); CONNECTION_UNLOCK (connection); dbus_free_string_array (decomposed_path); return TRUE; } /** * Lists the registered fallback handlers and object path handlers at * the given parent_path. The returned array should be freed with * dbus_free_string_array(). * * @param connection the connection * @param parent_path the path to list the child handlers of * @param child_entries returns #NULL-terminated array of children * @returns #FALSE if no memory to allocate the child entries */ dbus_bool_t dbus_connection_list_registered (DBusConnection *connection, const char *parent_path, char ***child_entries) { char **decomposed_path; dbus_bool_t retval; _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (parent_path != NULL, FALSE); _dbus_return_val_if_fail (parent_path[0] == '/', FALSE); _dbus_return_val_if_fail (child_entries != NULL, FALSE); if (!_dbus_decompose_path (parent_path, strlen (parent_path), &decomposed_path, NULL)) return FALSE; CONNECTION_LOCK (connection); retval = _dbus_object_tree_list_registered_and_unlock (connection->objects, (const char **) decomposed_path, child_entries); dbus_free_string_array (decomposed_path); return retval; } static DBusDataSlotAllocator slot_allocator; _DBUS_DEFINE_GLOBAL_LOCK (connection_slots); /** * Allocates an integer ID to be used for storing application-specific * data on any DBusConnection. The allocated ID may then be used * with dbus_connection_set_data() and dbus_connection_get_data(). * The passed-in slot must be initialized to -1, and is filled in * with the slot ID. If the passed-in slot is not -1, it's assumed * to be already allocated, and its refcount is incremented. * * The allocated slot is global, i.e. all DBusConnection objects will * have a slot with the given integer ID reserved. * * @param slot_p address of a global variable storing the slot * @returns #FALSE on failure (no memory) */ dbus_bool_t dbus_connection_allocate_data_slot (dbus_int32_t *slot_p) { return _dbus_data_slot_allocator_alloc (&slot_allocator, &_DBUS_LOCK_NAME (connection_slots), slot_p); } /** * Deallocates a global ID for connection data slots. * dbus_connection_get_data() and dbus_connection_set_data() may no * longer be used with this slot. Existing data stored on existing * DBusConnection objects will be freed when the connection is * finalized, but may not be retrieved (and may only be replaced if * someone else reallocates the slot). When the refcount on the * passed-in slot reaches 0, it is set to -1. * * @param slot_p address storing the slot to deallocate */ void dbus_connection_free_data_slot (dbus_int32_t *slot_p) { _dbus_return_if_fail (*slot_p >= 0); _dbus_data_slot_allocator_free (&slot_allocator, slot_p); } /** * Stores a pointer on a DBusConnection, along * with an optional function to be used for freeing * the data when the data is set again, or when * the connection is finalized. The slot number * must have been allocated with dbus_connection_allocate_data_slot(). * * @param connection the connection * @param slot the slot number * @param data the data to store * @param free_data_func finalizer function for the data * @returns #TRUE if there was enough memory to store the data */ dbus_bool_t dbus_connection_set_data (DBusConnection *connection, dbus_int32_t slot, void *data, DBusFreeFunction free_data_func) { DBusFreeFunction old_free_func; void *old_data; dbus_bool_t retval; _dbus_return_val_if_fail (connection != NULL, FALSE); _dbus_return_val_if_fail (slot >= 0, FALSE); CONNECTION_LOCK (connection); retval = _dbus_data_slot_list_set (&slot_allocator, &connection->slot_list, slot, data, free_data_func, &old_free_func, &old_data); CONNECTION_UNLOCK (connection); if (retval) { /* Do the actual free outside the connection lock */ if (old_free_func) (* old_free_func) (old_data); } return retval; } /** * Retrieves data previously set with dbus_connection_set_data(). * The slot must still be allocated (must not have been freed). * * @param connection the connection * @param slot the slot to get data from * @returns the data, or #NULL if not found */ void* dbus_connection_get_data (DBusConnection *connection, dbus_int32_t slot) { void *res; _dbus_return_val_if_fail (connection != NULL, NULL); CONNECTION_LOCK (connection); res = _dbus_data_slot_list_get (&slot_allocator, &connection->slot_list, slot); CONNECTION_UNLOCK (connection); return res; } /** * This function sets a global flag for whether dbus_connection_new() * will set SIGPIPE behavior to SIG_IGN. * * @param will_modify_sigpipe #TRUE to allow sigpipe to be set to SIG_IGN */ void dbus_connection_set_change_sigpipe (dbus_bool_t will_modify_sigpipe) { _dbus_modify_sigpipe = will_modify_sigpipe != FALSE; } /** * Specifies the maximum size message this connection is allowed to * receive. Larger messages will result in disconnecting the * connection. * * @param connection a #DBusConnection * @param size maximum message size the connection can receive, in bytes */ void dbus_connection_set_max_message_size (DBusConnection *connection, long size) { _dbus_return_if_fail (connection != NULL); CONNECTION_LOCK (connection); _dbus_transport_set_max_message_size (connection->transport, size); CONNECTION_UNLOCK (connection); } /** * Gets the value set by dbus_connection_set_max_message_size(). * * @param connection the connection * @returns the max size of a single message */ long dbus_connection_get_max_message_size (DBusConnection *connection) { long res; _dbus_return_val_if_fail (connection != NULL, 0); CONNECTION_LOCK (connection); res = _dbus_transport_get_max_message_size (connection->transport); CONNECTION_UNLOCK (connection); return res; } /** * Specifies the maximum number of unix fds a message on this * connection is allowed to receive. Messages with more unix fds will * result in disconnecting the connection. * * @param connection a #DBusConnection * @param size maximum message unix fds the connection can receive */ void dbus_connection_set_max_message_unix_fds (DBusConnection *connection, long n) { _dbus_return_if_fail (connection != NULL); CONNECTION_LOCK (connection); _dbus_transport_set_max_message_unix_fds (connection->transport, n); CONNECTION_UNLOCK (connection); } /** * Gets the value set by dbus_connection_set_max_message_unix_fds(). * * @param connection the connection * @returns the max numer of unix fds of a single message */ long dbus_connection_get_max_message_unix_fds (DBusConnection *connection) { long res; _dbus_return_val_if_fail (connection != NULL, 0); CONNECTION_LOCK (connection); res = _dbus_transport_get_max_message_unix_fds (connection->transport); CONNECTION_UNLOCK (connection); return res; } /** * Sets the maximum total number of bytes that can be used for all messages * received on this connection. Messages count toward the maximum until * they are finalized. When the maximum is reached, the connection will * not read more data until some messages are finalized. * * The semantics of the maximum are: if outstanding messages are * already above the maximum, additional messages will not be read. * The semantics are not: if the next message would cause us to exceed * the maximum, we don't read it. The reason is that we don't know the * size of a message until after we read it. * * Thus, the max live messages size can actually be exceeded * by up to the maximum size of a single message. * * Also, if we read say 1024 bytes off the wire in a single read(), * and that contains a half-dozen small messages, we may exceed the * size max by that amount. But this should be inconsequential. * * This does imply that we can't call read() with a buffer larger * than we're willing to exceed this limit by. * * @param connection the connection * @param size the maximum size in bytes of all outstanding messages */ void dbus_connection_set_max_received_size (DBusConnection *connection, long size) { _dbus_return_if_fail (connection != NULL); CONNECTION_LOCK (connection); _dbus_transport_set_max_received_size (connection->transport, size); CONNECTION_UNLOCK (connection); } /** * Gets the value set by dbus_connection_set_max_received_size(). * * @param connection the connection * @returns the max size of all live messages */ long dbus_connection_get_max_received_size (DBusConnection *connection) { long res; _dbus_return_val_if_fail (connection != NULL, 0); CONNECTION_LOCK (connection); res = _dbus_transport_get_max_received_size (connection->transport); CONNECTION_UNLOCK (connection); return res; } /** * Sets the maximum total number of unix fds that can be used for all messages * received on this connection. Messages count toward the maximum until * they are finalized. When the maximum is reached, the connection will * not read more data until some messages are finalized. * * The semantics are analogous to those of dbus_connection_set_max_received_size(). * * @param connection the connection * @param size the maximum size in bytes of all outstanding messages */ void dbus_connection_set_max_received_unix_fds (DBusConnection *connection, long n) { _dbus_return_if_fail (connection != NULL); CONNECTION_LOCK (connection); _dbus_transport_set_max_received_unix_fds (connection->transport, n); CONNECTION_UNLOCK (connection); } /** * Gets the value set by dbus_connection_set_max_received_unix_fds(). * * @param connection the connection * @returns the max unix fds of all live messages */ long dbus_connection_get_max_received_unix_fds (DBusConnection *connection) { long res; _dbus_return_val_if_fail (connection != NULL, 0); CONNECTION_LOCK (connection); res = _dbus_transport_get_max_received_unix_fds (connection->transport); CONNECTION_UNLOCK (connection); return res; } /** * Gets the approximate size in bytes of all messages in the outgoing * message queue. The size is approximate in that you shouldn't use * it to decide how many bytes to read off the network or anything * of that nature, as optimizations may choose to tell small white lies * to avoid performance overhead. * * @param connection the connection * @returns the number of bytes that have been queued up but not sent */ long dbus_connection_get_outgoing_size (DBusConnection *connection) { long res; _dbus_return_val_if_fail (connection != NULL, 0); CONNECTION_LOCK (connection); res = _dbus_counter_get_size_value (connection->outgoing_counter); CONNECTION_UNLOCK (connection); return res; } /** * Gets the approximate number of uni fds of all messages in the * outgoing message queue. * * @param connection the connection * @returns the number of unix fds that have been queued up but not sent */ long dbus_connection_get_outgoing_unix_fds (DBusConnection *connection) { long res; _dbus_return_val_if_fail (connection != NULL, 0); CONNECTION_LOCK (connection); res = _dbus_counter_get_unix_fd_value (connection->outgoing_counter); CONNECTION_UNLOCK (connection); return res; } /** @} */