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Diffstat (limited to 'src/3rdparty/libdbus/dbus/dbus-connection.c')
| -rw-r--r-- | src/3rdparty/libdbus/dbus/dbus-connection.c | 6451 |
1 files changed, 6451 insertions, 0 deletions
diff --git a/src/3rdparty/libdbus/dbus/dbus-connection.c b/src/3rdparty/libdbus/dbus/dbus-connection.c new file mode 100644 index 00000000..13f5085f --- /dev/null +++ b/src/3rdparty/libdbus/dbus/dbus-connection.c @@ -0,0 +1,6451 @@ +/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */ +/* dbus-connection.c DBusConnection object + * + * Copyright (C) 2002-2006 Red Hat Inc. + * + * SPDX-License-Identifier: AFL-2.1 OR GPL-2.0-or-later + * + * 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 <config.h> +#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-signature.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\n"); } \ + _dbus_rmutex_lock ((connection)->mutex); \ + TOOK_LOCK_CHECK (connection); \ + } while (0) + +#define CONNECTION_UNLOCK(connection) _dbus_connection_unlock (connection) + +#define SLOTS_LOCK(connection) do { \ + _dbus_rmutex_lock ((connection)->slot_mutex); \ + } while (0) + +#define SLOTS_UNLOCK(connection) do { \ + _dbus_rmutex_unlock ((connection)->slot_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: + * <ul> + * <li><b>read</b> means to fill the incoming message queue by reading from the socket</li> + * <li><b>write</b> means to drain the outgoing queue by writing to the socket</li> + * <li><b>dispatch</b> means to drain the incoming queue by invoking application-provided message handlers</li> + * </ul> + * + * 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 <em>very</em> 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 + * + * @{ + */ + +static void +_dbus_connection_trace_ref (DBusConnection *connection, + int old_refcount, + int new_refcount, + const char *why) +{ +#ifdef DBUS_ENABLE_VERBOSE_MODE + static int enabled = -1; + + _dbus_trace_ref ("DBusConnection", connection, old_refcount, new_refcount, + why, "DBUS_CONNECTION_TRACE", &enabled); +#endif +} + +/** + * 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 */ +}; + +#if HAVE_DECL_MSG_NOSIGNAL +static DBusAtomic _dbus_modify_sigpipe = { FALSE }; +#else +static DBusAtomic _dbus_modify_sigpipe = { TRUE }; +#endif + +/** + * Implementation details of DBusConnection. All fields are private. + */ +struct DBusConnection +{ + DBusAtomic refcount; /**< Reference count. */ + + DBusRMutex *mutex; /**< Lock on the entire DBusConnection */ + + DBusCMutex *dispatch_mutex; /**< Protects dispatch_acquired */ + DBusCondVar *dispatch_cond; /**< Notify when dispatch_acquired is available */ + DBusCMutex *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. */ + DBusList *expired_messages; /**< Messages that will be released when we next unlock. */ + + 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. */ + + DBusRMutex *slot_mutex; /**< Lock on slot_list so overall connection lock need not be taken */ + 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. */ + + 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 builtin_filters_enabled : 1; /**< If #TRUE, handle org.freedesktop.DBus.Peer messages automatically, whether they have a bus name or not */ + + 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 + +#if defined(DBUS_ENABLE_CHECKS) || defined(DBUS_ENABLE_ASSERT) + 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 dbus_bool_t _dbus_connection_peek_for_reply_unlocked (DBusConnection *connection, + dbus_uint32_t client_serial); + +static DBusMessageFilter * +_dbus_message_filter_ref (DBusMessageFilter *filter) +{ +#ifdef DBUS_DISABLE_ASSERT + _dbus_atomic_inc (&filter->refcount); +#else + dbus_int32_t old_value; + + old_value = _dbus_atomic_inc (&filter->refcount); + _dbus_assert (old_value > 0); +#endif + + return filter; +} + +static void +_dbus_message_filter_unref (DBusMessageFilter *filter) +{ + dbus_int32_t old_value; + + old_value = _dbus_atomic_dec (&filter->refcount); + _dbus_assert (old_value > 0); + + if (old_value == 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) +{ + DBusList *expired_messages; + DBusList *iter; + + if (TRACE_LOCKS) + { + _dbus_verbose ("UNLOCK\n"); + } + + /* If we had messages that expired (fell off the incoming or outgoing + * queues) while we were locked, actually release them now */ + expired_messages = connection->expired_messages; + connection->expired_messages = NULL; + + RELEASING_LOCK_CHECK (connection); + _dbus_rmutex_unlock (connection->mutex); + + for (iter = _dbus_list_pop_first_link (&expired_messages); + iter != NULL; + iter = _dbus_list_pop_first_link (&expired_messages)) + { + DBusMessage *message = iter->data; + + dbus_message_unref (message); + _dbus_list_free_link (iter); + } +} + +/** + * 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_ENABLE_EMBEDDED_TESTS +/** + * 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 = (DBusMutex *) connection->mutex; + *dispatch_mutex_loc = (DBusMutex *) connection->dispatch_mutex; + *io_path_mutex_loc = (DBusMutex *) 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_peek_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 (%s %s %s %s '%s' reply to %u) added to incoming queue %p, %d incoming\n", + message, + dbus_message_type_to_string (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); + + _dbus_message_trace_ref (message, -1, -1, + "_dbus_conection_queue_received_message_link"); +} + +/** + * 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_message_trace_ref (link->data, -1, -1, + "_dbus_connection_queue_synthesized_message_link"); + + _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_unlocked (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); + + _dbus_list_unlink (&connection->outgoing_messages, + link); + _dbus_list_prepend_link (&connection->expired_messages, link); + + connection->n_outgoing -= 1; + + _dbus_verbose ("Message %p (%s %s %s %s '%s') removed from outgoing queue %p, %d left to send\n", + message, + dbus_message_type_to_string (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); + + /* It's OK that in principle we call the notify function, because for the + * outgoing limit, there isn't one */ + _dbus_message_remove_counter (message, connection->outgoing_counter); + + /* The message will actually be unreffed when we unlock */ +} + +/** 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) +{ + dbus_bool_t retval; + + HAVE_LOCK_CHECK (connection); + + /* The original purpose of protected_change_watch() was to hold a + * ref on the connection while dropping the connection lock, then + * calling out to the app. This was a broken hack that did not + * work, since the connection was in a hosed state (no WatchList + * field) while calling out. + * + * So for now we'll just keep the lock while calling out. This means + * apps are not allowed to call DBusConnection methods inside a + * watch function or they will deadlock. + * + * The "real fix" is to use the _and_unlock() pattern found + * elsewhere in the code, to defer calling out to the app until + * we're about to drop locks and return flow of control to the app + * anyway. + * + * See http://lists.freedesktop.org/archives/dbus/2007-July/thread.html#8144 + */ + + if (connection->watches) + { + if (add_function) + retval = (* add_function) (connection->watches, watch); + else if (remove_function) + { + retval = TRUE; + (* remove_function) (connection->watches, watch); + } + else + { + retval = TRUE; + (* toggle_function) (connection->watches, watch, enabled); + } + 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) +{ + dbus_bool_t retval; + + HAVE_LOCK_CHECK (connection); + + /* The original purpose of protected_change_timeout() was to hold a + * ref on the connection while dropping the connection lock, then + * calling out to the app. This was a broken hack that did not + * work, since the connection was in a hosed state (no TimeoutList + * field) while calling out. + * + * So for now we'll just keep the lock while calling out. This means + * apps are not allowed to call DBusConnection methods inside a + * timeout function or they will deadlock. + * + * The "real fix" is to use the _and_unlock() pattern found + * elsewhere in the code, to defer calling out to the app until + * we're about to drop locks and return flow of control to the app + * anyway. + * + * See http://lists.freedesktop.org/archives/dbus/2007-July/thread.html#8144 + */ + + if (connection->timeouts) + { + if (add_function) + retval = (* add_function) (connection->timeouts, timeout); + else if (remove_function) + { + retval = TRUE; + (* remove_function) (connection->timeouts, timeout); + } + else + { + retval = TRUE; + (* toggle_function) (connection->timeouts, timeout, enabled); + } + 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 ("locking io_path_mutex\n"); + _dbus_cmutex_lock (connection->io_path_mutex); + + _dbus_verbose ("start connection->io_path_acquired = %d timeout = %d\n", + connection->io_path_acquired, timeout_milliseconds); + + we_acquired = FALSE; + + if (connection->io_path_acquired) + { + if (timeout_milliseconds != -1) + { + _dbus_verbose ("waiting %d for IO path to be acquirable\n", + 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 ("waiting for IO path to be acquirable\n"); + _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 ("end connection->io_path_acquired = %d we_acquired = %d\n", + connection->io_path_acquired, we_acquired); + + _dbus_verbose ("unlocking io_path_mutex\n"); + _dbus_cmutex_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 ("locking io_path_mutex\n"); + _dbus_cmutex_lock (connection->io_path_mutex); + + _dbus_assert (connection->io_path_acquired); + + _dbus_verbose ("start connection->io_path_acquired = %d\n", + connection->io_path_acquired); + + connection->io_path_acquired = FALSE; + _dbus_condvar_wake_one (connection->io_path_cond); + + _dbus_verbose ("unlocking io_path_mutex\n"); + _dbus_cmutex_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. + * + * If pending is not NULL then a check is made if the pending call + * is completed after the io path has been required. If the call + * has been completed nothing is done. This must be done since + * the _dbus_connection_acquire_io_path releases the connection + * lock for a while. + * + * Called with connection lock held. + * + * @param connection the connection. + * @param pending the pending call that should be checked or NULL + * @param flags iteration flags. + * @param timeout_milliseconds maximum blocking time, or -1 for no limit. + */ +void +_dbus_connection_do_iteration_unlocked (DBusConnection *connection, + DBusPendingCall *pending, + unsigned int flags, + int timeout_milliseconds) +{ + _dbus_verbose ("start\n"); + + 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); + + if ( (pending != NULL) && _dbus_pending_call_get_completed_unlocked(pending)) + { + _dbus_verbose ("pending call completed while acquiring I/O path"); + } + else if ( (pending != NULL) && + _dbus_connection_peek_for_reply_unlocked (connection, + _dbus_pending_call_get_reply_serial_unlocked (pending))) + { + _dbus_verbose ("pending call completed while acquiring I/O path (reply found in queue)"); + } + else + { + _dbus_transport_do_iteration (connection->transport, + flags, timeout_milliseconds); + } + + _dbus_connection_release_io_path (connection); + } + + HAVE_LOCK_CHECK (connection); + + _dbus_verbose ("end\n"); +} + +/** + * 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_rmutex_new_at_location (&connection->mutex); + if (connection->mutex == NULL) + goto error; + + _dbus_cmutex_new_at_location (&connection->io_path_mutex); + if (connection->io_path_mutex == NULL) + goto error; + + _dbus_cmutex_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; + + _dbus_rmutex_new_at_location (&connection->slot_mutex); + if (connection->slot_mutex == 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_atomic_get (&_dbus_modify_sigpipe) != 0) + _dbus_disable_sigpipe (); + + /* initialized to 0: use atomic op to avoid mixing atomic and non-atomic */ + _dbus_atomic_inc (&connection->refcount); + 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->builtin_filters_enabled = TRUE; + connection->route_peer_messages = FALSE; + connection->disconnected_message_arrived = FALSE; + connection->disconnected_message_processed = FALSE; + +#if defined(DBUS_ENABLE_CHECKS) || defined(DBUS_ENABLE_ASSERT) + 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); + + _dbus_connection_trace_ref (connection, 0, 1, "new_for_transport"); + 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_rmutex_free_at_location (&connection->mutex); + _dbus_cmutex_free_at_location (&connection->io_path_mutex); + _dbus_cmutex_free_at_location (&connection->dispatch_mutex); + _dbus_rmutex_free_at_location (&connection->slot_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_int32_t old_refcount; + + _dbus_assert (connection != NULL); + _dbus_assert (connection->generation == _dbus_current_generation); + + HAVE_LOCK_CHECK (connection); + + old_refcount = _dbus_atomic_inc (&connection->refcount); + _dbus_connection_trace_ref (connection, old_refcount, old_refcount + 1, + "ref_unlocked"); + + 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_int32_t old_refcount; + + HAVE_LOCK_CHECK (connection); + + _dbus_assert (connection != NULL); + + old_refcount = _dbus_atomic_dec (&connection->refcount); + + _dbus_connection_trace_ref (connection, old_refcount, old_refcount - 1, + "unref_unlocked"); + + if (old_refcount == 1) + _dbus_connection_last_unref (connection); +} + +/** + * Allocate and return the next non-zero serial number for outgoing messages. + * + * This method is only valid to call from single-threaded code, such as + * the dbus-daemon, or with the connection lock held. + * + * @param connection the connection + * @returns A suitable serial number for the next message to be sent on the connection. + */ +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 ("start\n"); + + CONNECTION_LOCK (connection); + + if (!_dbus_connection_acquire_io_path (connection, 1)) + { + /* another thread is handling the message */ + CONNECTION_UNLOCK (connection); + return TRUE; + } + + 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 ("middle\n"); + + 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 ("end\n"); + + return retval; +} + +/* Protected by _DBUS_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; + + if (!_DBUS_LOCK (shared_connections)) + { + /* We'd have initialized locks before adding anything, so there + * can't be anything there. */ + return; + } + + /* 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); + if (!_DBUS_LOCK (shared_connections)) + _dbus_assert_not_reached ("global locks were already initialized"); + + /* 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); + if (!_DBUS_LOCK (shared_connections)) + _dbus_assert_not_reached ("global locks were already initialized"); + 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; + + if (!_DBUS_LOCK (shared_connections)) + { + /* If it was shared, we'd have initialized global locks when we put + * it in shared_connections. */ + return FALSE; + } + + 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) + { + if (!_DBUS_LOCK (shared_connections)) + return FALSE; + + 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; + } + + if (!_DBUS_LOCK (shared_connections)) + { + dbus_free (guid_in_connection); + dbus_free (guid_key); + return FALSE; + } + + _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; + + if (!_DBUS_LOCK (shared_connections)) + { + /* If it was shared, we'd have initialized global locks when we put + * it in the table; so it can't be there. */ + return; + } + + 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; + + preallocated->queue_link = _dbus_list_alloc_link (NULL); + if (preallocated->queue_link == NULL) + goto failed_0; + + 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; + + preallocated->queue_link->data = message; + _dbus_list_prepend_link (&connection->outgoing_messages, + preallocated->queue_link); + + /* It's OK that we'll never call the notify function, because for the + * outgoing limit, there isn't one */ + _dbus_message_add_counter_link (message, + preallocated->counter_link); + + dbus_free (preallocated); + preallocated = NULL; + + dbus_message_ref (message); + + connection->n_outgoing += 1; + + _dbus_verbose ("Message %p (%s %s %s %s '%s') for %s added to outgoing queue %p, %d pending to send\n", + message, + dbus_message_type_to_string (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_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, + NULL, + 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 ("middle\n"); + 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) +{ + dbus_int32_t refcount; + + CONNECTION_LOCK (connection); + + refcount = _dbus_atomic_get (&connection->refcount); + /* The caller should have at least one ref */ + _dbus_assert (refcount >= 1); + + if (refcount == 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. + * + * @param 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, + const char *error_name, + const 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; +} + +/* + * Peek the incoming queue to see if we got reply for a specific serial + */ +static dbus_bool_t +_dbus_connection_peek_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_verbose ("%s reply to %d found in queue\n", _DBUS_FUNCTION_NAME, client_serial); + return TRUE; + } + link = _dbus_list_get_next_link (&connection->incoming_messages, link); + } + + return FALSE; +} + +/* 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_pending_call_start_completion_unlocked(pending); + _dbus_connection_detach_pending_call_and_unlock (connection, pending); + + /* Must be called unlocked since it invokes app callback */ + _dbus_pending_call_finish_completion (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 ("checked for reply\n"); + + _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) +{ + dbus_int64_t start_tv_sec; + long start_tv_usec; + dbus_int64_t tv_sec; + long 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); + _dbus_get_monotonic_time (&start_tv_sec, &start_tv_usec); + if (timeout) + { + timeout_milliseconds = dbus_timeout_get_interval (timeout); + + _dbus_verbose ("dbus_connection_send_with_reply_and_block(): will block %d milliseconds for reply serial %u from %" DBUS_INT64_MODIFIER "d 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, + pending, + DBUS_ITERATION_DO_READING | + DBUS_ITERATION_BLOCK, + timeout_milliseconds); + + recheck_status: + + _dbus_verbose ("top of recheck\n"); + + 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\n"); + _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_monotonic_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); + if (error_msg != NULL) + dbus_message_unref (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, + pending, + 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, + pending, + DBUS_ITERATION_DO_READING | + DBUS_ITERATION_BLOCK, + timeout_milliseconds - elapsed_milliseconds); + } + + goto recheck_status; + } + + _dbus_verbose ("dbus_connection_send_with_reply_and_block(): Waited %d 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); +} + +/** + * Return how many file descriptors are pending in the loader + * + * @param connection the connection + */ +int +_dbus_connection_get_pending_fds_count (DBusConnection *connection) +{ + return _dbus_transport_get_pending_fds_count (connection->transport); +} + +/** + * Register a function to be called whenever the number of pending file + * descriptors in the loader change. + * + * @param connection the connection + * @param callback the callback + */ +void +_dbus_connection_set_pending_fds_function (DBusConnection *connection, + DBusPendingFdsChangeFunction callback, + void *data) +{ + _dbus_transport_set_pending_fds_function (connection->transport, + callback, data); +} + +/** @} */ + +/** + * @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_int32_t old_refcount; + + _dbus_return_val_if_fail (connection != NULL, NULL); + _dbus_return_val_if_fail (connection->generation == _dbus_current_generation, NULL); + old_refcount = _dbus_atomic_inc (&connection->refcount); + _dbus_connection_trace_ref (connection, old_refcount, old_refcount + 1, + "ref"); + + 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); + 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 (_dbus_atomic_get (&connection->refcount) == 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_connection_set_windows_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_foreach (&connection->outgoing_messages, + free_outgoing_message, + connection); + _dbus_list_clear (&connection->outgoing_messages); + + _dbus_list_clear_full (&connection->incoming_messages, + (DBusFreeFunction) dbus_message_unref); + + _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_condvar_free_at_location (&connection->dispatch_cond); + _dbus_condvar_free_at_location (&connection->io_path_cond); + + _dbus_cmutex_free_at_location (&connection->io_path_mutex); + _dbus_cmutex_free_at_location (&connection->dispatch_mutex); + + _dbus_rmutex_free_at_location (&connection->slot_mutex); + + _dbus_rmutex_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_int32_t old_refcount; + + _dbus_return_if_fail (connection != NULL); + _dbus_return_if_fail (connection->generation == _dbus_current_generation); + + old_refcount = _dbus_atomic_dec (&connection->refcount); + + _dbus_connection_trace_ref (connection, old_refcount, old_refcount - 1, + "unref"); + + if (old_refcount == 1) + { +#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." : + "Most likely, the application was supposed to call dbus_connection_close(), since this is a private connection."); + 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."); + 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_try_to_authenticate (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_try_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, including invalid or reserved types. + * + * @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_connection_ref_unlocked (connection); + + _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 ("middle\n"); + status = _dbus_connection_get_dispatch_status_unlocked (connection); + + /* Unlocks, and calls out to user code */ + _dbus_connection_update_dispatch_status_and_unlock (connection, status); + dbus_connection_unref (connection); + + 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 #DBUS_TIMEOUT_INFINITE 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 (or + * #DBUS_TIMEOUT_USE_DEFAULT) for default or #DBUS_TIMEOUT_INFINITE 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 (or + * #DBUS_TIMEOUT_USE_DEFAULT) for default or #DBUS_TIMEOUT_INFINITE 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\n"); + HAVE_LOCK_CHECK (connection); + _dbus_connection_do_iteration_unlocked (connection, + NULL, + DBUS_ITERATION_DO_READING | + DBUS_ITERATION_DO_WRITING | + DBUS_ITERATION_BLOCK, + -1); + } + + HAVE_LOCK_CHECK (connection); + _dbus_verbose ("middle\n"); + 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 ("end\n"); +} + +/** + * 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\n"); + dbus_connection_dispatch (connection); + CONNECTION_LOCK (connection); + } + else if (dstatus == DBUS_DISPATCH_NEED_MEMORY) + { + _dbus_verbose ("pausing for memory\n"); + _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\n"); + _dbus_connection_do_iteration_unlocked (connection, + NULL, + 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 ("start\n"); + + /* 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); + + _dbus_message_trace_ref (message, -1, -1, "dbus_connection_borrow_message"); + + /* 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); + + _dbus_message_trace_ref (message, -1, -1, "dbus_connection_return_message"); +} + +/** + * 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); + (void) pop_message; /* unused unless asserting */ + + 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); + _dbus_message_trace_ref (message, -1, -1, + "dbus_connection_steal_borrowed_message"); +} + +/* 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 (%s %s %s %s sig:'%s' serial:%u) removed from incoming queue %p, %d incoming\n", + link->data, + dbus_message_type_to_string (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), + dbus_message_get_serial (link->data), + connection, connection->n_incoming); + + _dbus_message_trace_ref (link->data, -1, -1, + "_dbus_connection_pop_message_link_unlocked"); + + 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 (%s %s %s '%s') put back into queue %p, %d incoming\n", + message_link->data, + dbus_message_type_to_string (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); + + _dbus_message_trace_ref (message_link->data, -1, -1, + "_dbus_connection_putback_message_link_unlocked"); +} + +/** + * 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 ("start\n"); + + /* 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 ("locking dispatch_mutex\n"); + _dbus_cmutex_lock (connection->dispatch_mutex); + + while (connection->dispatch_acquired) + { + _dbus_verbose ("waiting for dispatch to be acquirable\n"); + _dbus_condvar_wait (connection->dispatch_cond, + connection->dispatch_mutex); + } + + _dbus_assert (!connection->dispatch_acquired); + + connection->dispatch_acquired = TRUE; + + _dbus_verbose ("unlocking dispatch_mutex\n"); + _dbus_cmutex_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 ("locking dispatch_mutex\n"); + _dbus_cmutex_lock (connection->dispatch_mutex); + + _dbus_assert (connection->dispatch_acquired); + + connection->dispatch_acquired = FALSE; + _dbus_condvar_wake_one (connection->dispatch_cond); + + _dbus_verbose ("unlocking dispatch_mutex\n"); + _dbus_cmutex_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_unlocked (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\n"); + + /* 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 ("start\n"); + + 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) +{ + dbus_bool_t sent = FALSE; + DBusMessage *ret = NULL; + DBusList *expire_link; + + 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; + } + + if (!dbus_message_has_interface (message, DBUS_INTERFACE_PEER)) + { + return DBUS_HANDLER_RESULT_NOT_YET_HANDLED; + } + + /* Preallocate a linked-list link, so that if we need to dispose of a + * message, we can attach it to the expired list */ + expire_link = _dbus_list_alloc_link (NULL); + + if (!expire_link) + return DBUS_HANDLER_RESULT_NEED_MEMORY; + + if (dbus_message_is_method_call (message, + DBUS_INTERFACE_PEER, + "Ping")) + { + ret = dbus_message_new_method_return (message); + if (ret == NULL) + goto out; + + sent = _dbus_connection_send_unlocked_no_update (connection, ret, NULL); + } + else if (dbus_message_is_method_call (message, + DBUS_INTERFACE_PEER, + "GetMachineId")) + { + DBusString uuid; + DBusError error = DBUS_ERROR_INIT; + + if (!_dbus_string_init (&uuid)) + goto out; + + if (_dbus_get_local_machine_uuid_encoded (&uuid, &error)) + { + const char *v_STRING; + + ret = dbus_message_new_method_return (message); + + if (ret == NULL) + { + _dbus_string_free (&uuid); + goto out; + } + + 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); + } + } + else if (dbus_error_has_name (&error, DBUS_ERROR_NO_MEMORY)) + { + dbus_error_free (&error); + goto out; + } + else + { + ret = dbus_message_new_error (message, error.name, error.message); + dbus_error_free (&error); + + if (ret == NULL) + goto out; + + sent = _dbus_connection_send_unlocked_no_update (connection, ret, + NULL); + } + + _dbus_string_free (&uuid); + } + else + { + /* 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. + */ + ret = dbus_message_new_error (message, + DBUS_ERROR_UNKNOWN_METHOD, + "Unknown method invoked on org.freedesktop.DBus.Peer interface"); + if (ret == NULL) + goto out; + + sent = _dbus_connection_send_unlocked_no_update (connection, ret, NULL); + } + +out: + if (ret == NULL) + { + _dbus_list_free_link (expire_link); + } + else + { + /* It'll be safe to unref the reply when we unlock */ + expire_link->data = ret; + _dbus_list_prepend_link (&connection->expired_messages, expire_link); + } + + if (!sent) + return DBUS_HANDLER_RESULT_NEED_MEMORY; + + return DBUS_HANDLER_RESULT_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_bool_t found_object; + + _dbus_return_val_if_fail (connection != NULL, DBUS_DISPATCH_COMPLETE); + + _dbus_verbose ("\n"); + + 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 (%s %s %s '%s')\n", + message, + dbus_message_type_to_string (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; + } + + /* If skipping builtin filters, we are probably a monitor. */ + if (connection->builtin_filters_enabled) + { + 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); + dbus_connection_unref (connection); + + return DBUS_DISPATCH_NEED_MEMORY; + } + + for (link = _dbus_list_get_first_link (&filter_list_copy); + link != NULL; + link = _dbus_list_get_next_link (&filter_list_copy, link)) + _dbus_message_filter_ref (link->data); + + /* 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_clear_full (&filter_list_copy, + (DBusFreeFunction) _dbus_message_filter_unref); + + CONNECTION_LOCK (connection); + + if (result == DBUS_HANDLER_RESULT_NEED_MEMORY) + { + _dbus_verbose ("No memory\n"); + 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 (%s %s %s '%s')\n", + message, + dbus_message_type_to_string (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, + &found_object); + + 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; + DBusList *expire_link; + + _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, + found_object ? DBUS_ERROR_UNKNOWN_METHOD : DBUS_ERROR_UNKNOWN_OBJECT, + _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; + } + + expire_link = _dbus_list_alloc_link (reply); + + if (expire_link == NULL) + { + dbus_message_unref (reply); + result = DBUS_HANDLER_RESULT_NEED_MEMORY; + _dbus_verbose ("no memory for error send in dispatch\n"); + goto out; + } + + preallocated = _dbus_connection_preallocate_send_unlocked (connection); + + if (preallocated == NULL) + { + _dbus_list_free_link (expire_link); + /* It's OK that this is finalized, because it hasn't been seen by + * anything that could attach user callbacks */ + 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); + /* reply will be freed when we release the lock */ + _dbus_list_prepend_link (&connection->expired_messages, expire_link); + + result = DBUS_HANDLER_RESULT_HANDLED; + } + + _dbus_verbose (" done dispatching %p (%s %s %s '%s') on connection %p\n", message, + dbus_message_type_to_string (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\n"); + + /* 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); + /* now we don't want to free them */ + message_link = NULL; + message = NULL; + } + else + { + _dbus_verbose (" ... done dispatching\n"); + } + + _dbus_connection_release_dispatch (connection); + HAVE_LOCK_CHECK (connection); + + if (message != NULL) + { + /* We don't want this message to count in maximum message limits when + * computing the dispatch status, below. We have to drop the lock + * temporarily, because finalizing a message can trigger callbacks. + * + * We have a reference to the connection, and we don't use any cached + * pointers to the connection's internals below this point, so it should + * be safe to drop the lock and take it back. */ + CONNECTION_UNLOCK (connection); + dbus_message_unref (message); + CONNECTION_LOCK (connection); + } + + if (message_link != NULL) + _dbus_list_free_link (message_link); + + _dbus_verbose ("before final status update\n"); + 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. + * + * @note The thread lock on DBusConnection is held while + * watch functions are invoked, so inside these functions you + * may not invoke any methods on DBusConnection or it will deadlock. + * See the comments in the code or http://lists.freedesktop.org/archives/dbus/2007-July/tread.html#8144 + * if you encounter this issue and want to attempt writing a patch. + * + * @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; + + _dbus_return_val_if_fail (connection != NULL, FALSE); + + CONNECTION_LOCK (connection); + + retval = _dbus_watch_list_set_functions (connection->watches, + add_function, remove_function, + toggled_function, + data, free_data_function); + + CONNECTION_UNLOCK (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. + * + * @note The thread lock on DBusConnection is held while + * timeout functions are invoked, so inside these functions you + * may not invoke any methods on DBusConnection or it will deadlock. + * See the comments in the code or http://lists.freedesktop.org/archives/dbus/2007-July/thread.html#8144 + * if you encounter this issue and want to attempt writing a patch. + * + * @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; + + _dbus_return_val_if_fail (connection != NULL, FALSE); + + CONNECTION_LOCK (connection); + + retval = _dbus_timeout_list_set_functions (connection->timeouts, + add_function, remove_function, + toggled_function, + data, free_data_function); + + CONNECTION_UNLOCK (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; + DBusSocket s = DBUS_SOCKET_INIT; + + _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, &s); + + if (retval) + { + *fd = _dbus_socket_get_int (s); + } + + 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_try_to_authenticate (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_try_to_authenticate (connection->transport)) + result = FALSE; + else + result = _dbus_transport_get_unix_process_id (connection->transport, + pid); + + 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 + * @param data_size return location for length of 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_try_to_authenticate (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); +} + +/* Same calling convention as dbus_connection_get_windows_user */ +dbus_bool_t +_dbus_connection_get_linux_security_label (DBusConnection *connection, + char **label_p) +{ + dbus_bool_t result; + + _dbus_assert (connection != NULL); + _dbus_assert (label_p != NULL); + + CONNECTION_LOCK (connection); + + if (!_dbus_transport_try_to_authenticate (connection->transport)) + result = FALSE; + else + result = _dbus_transport_get_linux_security_label (connection->transport, + label_p); +#ifndef __linux__ + _dbus_assert (!result); +#endif + + CONNECTION_UNLOCK (connection); + + return result; +} + +DBusCredentials * +_dbus_connection_get_credentials (DBusConnection *connection) +{ + DBusCredentials *result; + + _dbus_assert (connection != NULL); + + CONNECTION_LOCK (connection); + + if (!_dbus_transport_try_to_authenticate (connection->transport)) + result = NULL; + else + result = _dbus_transport_get_credentials (connection->transport); + + CONNECTION_UNLOCK (connection); + + return result; +} + +/** + * 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_try_to_authenticate (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); +} + +/** + * Enables the builtin filtering of messages. + * + * Currently the only filtering implemented by libdbus and mandated by the spec + * is that of peer messages. + * + * If #TRUE, #DBusConnection automatically handles all messages to the + * org.freedesktop.DBus.Peer interface. For monitors this can break the + * specification if the response is sending a message. + * + * If #FALSE, the result is similar to calling + * dbus_connection_set_route_peer_messages() with argument TRUE, but + * messages with a NULL destination are also dispatched to the + * application instead of being passed to the built-in filters. + * + * If a normal application disables this flag, it can break things badly. So + * only unset this if you are a monitor. + * + * @param connection the connection + * @param value #TRUE to pass through org.freedesktop.DBus.Peer messages + */ +void +dbus_connection_set_builtin_filters_enabled (DBusConnection *connection, + dbus_bool_t value) +{ + _dbus_return_if_fail (connection != NULL); + + CONNECTION_LOCK (connection); + connection->builtin_filters_enabled = 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 = value; + 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; + + _dbus_atomic_inc (&filter->refcount); + + 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", + 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 or subsection in the object + * hierarchy. The given vtable handles messages sent to exactly the + * given path or also for paths bellow that, depending on fallback + * parameter. + * + * @param connection the connection + * @param fallback whether to handle messages also for "subdirectory" + * @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_OBJECT_PATH_IN_USE) is reported + */ +static dbus_bool_t +_dbus_connection_register_object_path (DBusConnection *connection, + dbus_bool_t fallback, + const char *path, + const DBusObjectPathVTable *vtable, + void *user_data, + DBusError *error) +{ + char **decomposed_path; + dbus_bool_t retval; + + if (!_dbus_decompose_path (path, strlen (path), &decomposed_path, NULL)) + return FALSE; + + CONNECTION_LOCK (connection); + + retval = _dbus_object_tree_register (connection->objects, + fallback, + (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. + * + * @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_OBJECT_PATH_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) +{ + _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); + + return _dbus_connection_register_object_path (connection, FALSE, path, vtable, user_data, error); +} + +/** + * 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 an error (#DBUS_ERROR_NO_MEMORY or + * #DBUS_ERROR_OBJECT_PATH_IN_USE) ocurred + */ +dbus_bool_t +dbus_connection_register_object_path (DBusConnection *connection, + const char *path, + const DBusObjectPathVTable *vtable, + void *user_data) +{ + 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); + + retval = _dbus_connection_register_object_path (connection, FALSE, path, vtable, user_data, &error); + + if (dbus_error_has_name (&error, DBUS_ERROR_OBJECT_PATH_IN_USE)) + { + _dbus_warn ("%s", 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_OBJECT_PATH_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) +{ + _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); + + return _dbus_connection_register_object_path (connection, TRUE, path, vtable, user_data, error); +} + +/** + * 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 an error (#DBUS_ERROR_NO_MEMORY or + * #DBUS_ERROR_OBJECT_PATH_IN_USE) occured + */ +dbus_bool_t +dbus_connection_register_fallback (DBusConnection *connection, + const char *path, + const DBusObjectPathVTable *vtable, + void *user_data) +{ + 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); + + retval = _dbus_connection_register_object_path (connection, TRUE, path, vtable, user_data, &error); + + if (dbus_error_has_name (&error, DBUS_ERROR_OBJECT_PATH_IN_USE)) + { + _dbus_warn ("%s", 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_DATA_SLOT_ALLOCATOR_INIT (_DBUS_LOCK_NAME (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, + 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(). + * + * @note This function does not take the + * main thread lock on DBusConnection, which allows it to be + * used from inside watch and timeout functions. (See the + * note in docs for dbus_connection_set_watch_functions().) + * A side effect of this is that you need to know there's + * a reference held on the connection while invoking + * dbus_connection_set_data(), or the connection could be + * finalized during dbus_connection_set_data(). + * + * @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); + + SLOTS_LOCK (connection); + + retval = _dbus_data_slot_list_set (&slot_allocator, + &connection->slot_list, + slot, data, free_data_func, + &old_free_func, &old_data); + + SLOTS_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). + * + * @note This function does not take the + * main thread lock on DBusConnection, which allows it to be + * used from inside watch and timeout functions. (See the + * note in docs for dbus_connection_set_watch_functions().) + * A side effect of this is that you need to know there's + * a reference held on the connection while invoking + * dbus_connection_get_data(), or the connection could be + * finalized during dbus_connection_get_data(). + * + * @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); + _dbus_return_val_if_fail (slot >= 0, NULL); + + SLOTS_LOCK (connection); + + res = _dbus_data_slot_list_get (&slot_allocator, + &connection->slot_list, + slot); + + SLOTS_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) +{ + if (will_modify_sigpipe) + _dbus_atomic_set_nonzero (&_dbus_modify_sigpipe); + else + _dbus_atomic_set_zero (&_dbus_modify_sigpipe); +} + +/** + * 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 n 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 n 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; +} + +#ifdef DBUS_ENABLE_STATS +void +_dbus_connection_get_stats (DBusConnection *connection, + dbus_uint32_t *in_messages, + dbus_uint32_t *in_bytes, + dbus_uint32_t *in_fds, + dbus_uint32_t *in_peak_bytes, + dbus_uint32_t *in_peak_fds, + dbus_uint32_t *out_messages, + dbus_uint32_t *out_bytes, + dbus_uint32_t *out_fds, + dbus_uint32_t *out_peak_bytes, + dbus_uint32_t *out_peak_fds) +{ + CONNECTION_LOCK (connection); + + if (in_messages != NULL) + *in_messages = connection->n_incoming; + + _dbus_transport_get_stats (connection->transport, + in_bytes, in_fds, in_peak_bytes, in_peak_fds); + + if (out_messages != NULL) + *out_messages = connection->n_outgoing; + + if (out_bytes != NULL) + *out_bytes = _dbus_counter_get_size_value (connection->outgoing_counter); + + if (out_fds != NULL) + *out_fds = _dbus_counter_get_unix_fd_value (connection->outgoing_counter); + + if (out_peak_bytes != NULL) + *out_peak_bytes = _dbus_counter_get_peak_size_value (connection->outgoing_counter); + + if (out_peak_fds != NULL) + *out_peak_fds = _dbus_counter_get_peak_unix_fd_value (connection->outgoing_counter); + + CONNECTION_UNLOCK (connection); +} +#endif /* DBUS_ENABLE_STATS */ + +/** + * 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; +} + +#ifdef DBUS_ENABLE_EMBEDDED_TESTS +/** + * Returns the address of the transport object of this connection + * + * @param connection the connection + * @returns the address string + */ +const char* +_dbus_connection_get_address (DBusConnection *connection) +{ + return _dbus_transport_get_address (connection->transport); +} +#endif + +/** @} */ |