/* -*- mode: C; c-file-style: "gnu" -*- */ /* connection.c Client connections * * Copyright (C) 2003 Red Hat, Inc. * * Licensed under the Academic Free License version 2.1 * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * */ #include "connection.h" #include "dispatch.h" #include "policy.h" #include "services.h" #include "utils.h" #include "signals.h" #include "expirelist.h" #include "selinux.h" #include #include #include static void bus_connection_remove_transactions (DBusConnection *connection); typedef struct { BusExpireItem expire_item; DBusConnection *will_get_reply; DBusConnection *will_send_reply; dbus_uint32_t reply_serial; } BusPendingReply; struct BusConnections { int refcount; DBusList *completed; /**< List of all completed connections */ int n_completed; /**< Length of completed list */ DBusList *incomplete; /**< List of all not-yet-active connections */ int n_incomplete; /**< Length of incomplete list */ BusContext *context; DBusHashTable *completed_by_user; /**< Number of completed connections for each UID */ DBusTimeout *expire_timeout; /**< Timeout for expiring incomplete connections. */ int stamp; /**< Incrementing number */ BusExpireList *pending_replies; /**< List of pending replies */ }; static dbus_int32_t connection_data_slot = -1; typedef struct { BusConnections *connections; DBusList *link_in_connection_list; DBusConnection *connection; DBusList *services_owned; int n_services_owned; DBusList *match_rules; int n_match_rules; char *name; DBusList *transaction_messages; /**< Stuff we need to send as part of a transaction */ DBusMessage *oom_message; DBusPreallocatedSend *oom_preallocated; BusClientPolicy *policy; BusSELinuxID *selinux_id; long connection_tv_sec; /**< Time when we connected (seconds component) */ long connection_tv_usec; /**< Time when we connected (microsec component) */ int stamp; /**< connections->stamp last time we were traversed */ } BusConnectionData; static dbus_bool_t bus_pending_reply_expired (BusExpireList *list, DBusList *link, void *data); static void bus_connection_drop_pending_replies (BusConnections *connections, DBusConnection *connection); static dbus_bool_t expire_incomplete_timeout (void *data); #define BUS_CONNECTION_DATA(connection) (dbus_connection_get_data ((connection), connection_data_slot)) static DBusLoop* connection_get_loop (DBusConnection *connection) { BusConnectionData *d; d = BUS_CONNECTION_DATA (connection); return bus_context_get_loop (d->connections->context); } static int get_connections_for_uid (BusConnections *connections, dbus_uid_t uid) { void *val; int current_count; /* val is NULL is 0 when it isn't in the hash yet */ val = _dbus_hash_table_lookup_ulong (connections->completed_by_user, uid); current_count = _DBUS_POINTER_TO_INT (val); return current_count; } static dbus_bool_t adjust_connections_for_uid (BusConnections *connections, dbus_uid_t uid, int adjustment) { int current_count; current_count = get_connections_for_uid (connections, uid); _dbus_verbose ("Adjusting connection count for UID " DBUS_UID_FORMAT ": was %d adjustment %d making %d\n", uid, current_count, adjustment, current_count + adjustment); _dbus_assert (current_count >= 0); current_count += adjustment; _dbus_assert (current_count >= 0); if (current_count == 0) { _dbus_hash_table_remove_ulong (connections->completed_by_user, uid); return TRUE; } else { dbus_bool_t retval; retval = _dbus_hash_table_insert_ulong (connections->completed_by_user, uid, _DBUS_INT_TO_POINTER (current_count)); /* only positive adjustment can fail as otherwise * a hash entry should already exist */ _dbus_assert (adjustment > 0 || (adjustment <= 0 && retval)); return retval; } } void bus_connection_disconnected (DBusConnection *connection) { BusConnectionData *d; BusService *service; BusMatchmaker *matchmaker; d = BUS_CONNECTION_DATA (connection); _dbus_assert (d != NULL); _dbus_verbose ("%s disconnected, dropping all service ownership and releasing\n", d->name ? d->name : "(inactive)"); /* Delete our match rules */ if (d->n_match_rules > 0) { matchmaker = bus_context_get_matchmaker (d->connections->context); bus_matchmaker_disconnected (matchmaker, connection); } /* Drop any service ownership. FIXME Unfortunately, this requires * memory allocation and there doesn't seem to be a good way to * handle it other than sleeping; we can't "fail" the operation of * disconnecting a client, and preallocating a broadcast "service is * now gone" message for every client-service pair seems kind of * involved. Probably we need to do that though. */ while ((service = _dbus_list_get_last (&d->services_owned))) { BusTransaction *transaction; DBusError error; retry: dbus_error_init (&error); while ((transaction = bus_transaction_new (d->connections->context)) == NULL) _dbus_wait_for_memory (); if (!bus_service_remove_owner (service, connection, transaction, &error)) { _DBUS_ASSERT_ERROR_IS_SET (&error); if (dbus_error_has_name (&error, DBUS_ERROR_NO_MEMORY)) { dbus_error_free (&error); bus_transaction_cancel_and_free (transaction); _dbus_wait_for_memory (); goto retry; } else { _dbus_verbose ("Failed to remove service owner: %s %s\n", error.name, error.message); _dbus_assert_not_reached ("Removing service owner failed for non-memory-related reason"); } } bus_transaction_execute_and_free (transaction); } bus_dispatch_remove_connection (connection); /* no more watching */ if (!dbus_connection_set_watch_functions (connection, NULL, NULL, NULL, connection, NULL)) _dbus_assert_not_reached ("setting watch functions to NULL failed"); if (!dbus_connection_set_timeout_functions (connection, NULL, NULL, NULL, connection, NULL)) _dbus_assert_not_reached ("setting timeout functions to NULL failed"); dbus_connection_set_unix_user_function (connection, NULL, NULL, NULL); dbus_connection_set_dispatch_status_function (connection, NULL, NULL, NULL); bus_connection_remove_transactions (connection); if (d->link_in_connection_list != NULL) { if (d->name != NULL) { unsigned long uid; _dbus_list_remove_link (&d->connections->completed, d->link_in_connection_list); d->link_in_connection_list = NULL; d->connections->n_completed -= 1; if (dbus_connection_get_unix_user (connection, &uid)) { if (!adjust_connections_for_uid (d->connections, uid, -1)) _dbus_assert_not_reached ("adjusting downward should never fail"); } } else { _dbus_list_remove_link (&d->connections->incomplete, d->link_in_connection_list); d->link_in_connection_list = NULL; d->connections->n_incomplete -= 1; } _dbus_assert (d->connections->n_incomplete >= 0); _dbus_assert (d->connections->n_completed >= 0); } bus_connection_drop_pending_replies (d->connections, connection); /* frees "d" as side effect */ dbus_connection_set_data (connection, connection_data_slot, NULL, NULL); dbus_connection_unref (connection); } static dbus_bool_t connection_watch_callback (DBusWatch *watch, unsigned int condition, void *data) { /* FIXME this can be done in dbus-mainloop.c * if the code in activation.c for the babysitter * watch handler is fixed. */ #if 0 _dbus_verbose ("Calling handle_watch\n"); #endif return dbus_watch_handle (watch, condition); } static dbus_bool_t add_connection_watch (DBusWatch *watch, void *data) { DBusConnection *connection = data; return _dbus_loop_add_watch (connection_get_loop (connection), watch, connection_watch_callback, connection, NULL); } static void remove_connection_watch (DBusWatch *watch, void *data) { DBusConnection *connection = data; _dbus_loop_remove_watch (connection_get_loop (connection), watch, connection_watch_callback, connection); } static void connection_timeout_callback (DBusTimeout *timeout, void *data) { /* DBusConnection *connection = data; */ /* can return FALSE on OOM but we just let it fire again later */ dbus_timeout_handle (timeout); } static dbus_bool_t add_connection_timeout (DBusTimeout *timeout, void *data) { DBusConnection *connection = data; return _dbus_loop_add_timeout (connection_get_loop (connection), timeout, connection_timeout_callback, connection, NULL); } static void remove_connection_timeout (DBusTimeout *timeout, void *data) { DBusConnection *connection = data; _dbus_loop_remove_timeout (connection_get_loop (connection), timeout, connection_timeout_callback, connection); } static void dispatch_status_function (DBusConnection *connection, DBusDispatchStatus new_status, void *data) { DBusLoop *loop = data; if (new_status != DBUS_DISPATCH_COMPLETE) { while (!_dbus_loop_queue_dispatch (loop, connection)) _dbus_wait_for_memory (); } } static dbus_bool_t allow_user_function (DBusConnection *connection, unsigned long uid, void *data) { BusConnectionData *d; d = BUS_CONNECTION_DATA (connection); _dbus_assert (d != NULL); return bus_context_allow_user (d->connections->context, uid); } static void free_connection_data (void *data) { BusConnectionData *d = data; /* services_owned should be NULL since we should be disconnected */ _dbus_assert (d->services_owned == NULL); _dbus_assert (d->n_services_owned == 0); /* similarly */ _dbus_assert (d->transaction_messages == NULL); if (d->oom_preallocated) dbus_connection_free_preallocated_send (d->connection, d->oom_preallocated); if (d->oom_message) dbus_message_unref (d->oom_message); if (d->policy) bus_client_policy_unref (d->policy); if (d->selinux_id) bus_selinux_id_unref (d->selinux_id); dbus_free (d->name); dbus_free (d); } static void call_timeout_callback (DBusTimeout *timeout, void *data) { /* can return FALSE on OOM but we just let it fire again later */ dbus_timeout_handle (timeout); } BusConnections* bus_connections_new (BusContext *context) { BusConnections *connections; if (!dbus_connection_allocate_data_slot (&connection_data_slot)) goto failed_0; connections = dbus_new0 (BusConnections, 1); if (connections == NULL) goto failed_1; connections->completed_by_user = _dbus_hash_table_new (DBUS_HASH_ULONG, NULL, NULL); if (connections->completed_by_user == NULL) goto failed_2; connections->expire_timeout = _dbus_timeout_new (100, /* irrelevant */ expire_incomplete_timeout, connections, NULL); if (connections->expire_timeout == NULL) goto failed_3; _dbus_timeout_set_enabled (connections->expire_timeout, FALSE); connections->pending_replies = bus_expire_list_new (bus_context_get_loop (context), bus_context_get_reply_timeout (context), bus_pending_reply_expired, connections); if (connections->pending_replies == NULL) goto failed_4; if (!_dbus_loop_add_timeout (bus_context_get_loop (context), connections->expire_timeout, call_timeout_callback, NULL, NULL)) goto failed_5; connections->refcount = 1; connections->context = context; return connections; failed_5: bus_expire_list_free (connections->pending_replies); failed_4: _dbus_timeout_unref (connections->expire_timeout); failed_3: _dbus_hash_table_unref (connections->completed_by_user); failed_2: dbus_free (connections); failed_1: dbus_connection_free_data_slot (&connection_data_slot); failed_0: return NULL; } BusConnections * bus_connections_ref (BusConnections *connections) { _dbus_assert (connections->refcount > 0); connections->refcount += 1; return connections; } void bus_connections_unref (BusConnections *connections) { _dbus_assert (connections->refcount > 0); connections->refcount -= 1; if (connections->refcount == 0) { /* drop all incomplete */ while (connections->incomplete != NULL) { DBusConnection *connection; connection = connections->incomplete->data; dbus_connection_ref (connection); dbus_connection_close (connection); bus_connection_disconnected (connection); dbus_connection_unref (connection); } _dbus_assert (connections->n_incomplete == 0); /* drop all real connections */ while (connections->completed != NULL) { DBusConnection *connection; connection = connections->completed->data; dbus_connection_ref (connection); dbus_connection_close (connection); bus_connection_disconnected (connection); dbus_connection_unref (connection); } _dbus_assert (connections->n_completed == 0); bus_expire_list_free (connections->pending_replies); _dbus_loop_remove_timeout (bus_context_get_loop (connections->context), connections->expire_timeout, call_timeout_callback, NULL); _dbus_timeout_unref (connections->expire_timeout); _dbus_hash_table_unref (connections->completed_by_user); dbus_free (connections); dbus_connection_free_data_slot (&connection_data_slot); } } dbus_bool_t bus_connections_setup_connection (BusConnections *connections, DBusConnection *connection) { BusConnectionData *d; dbus_bool_t retval; DBusError error; d = dbus_new0 (BusConnectionData, 1); if (d == NULL) return FALSE; d->connections = connections; d->connection = connection; _dbus_get_current_time (&d->connection_tv_sec, &d->connection_tv_usec); _dbus_assert (connection_data_slot >= 0); if (!dbus_connection_set_data (connection, connection_data_slot, d, free_connection_data)) { dbus_free (d); return FALSE; } retval = FALSE; dbus_error_init (&error); d->selinux_id = bus_selinux_init_connection_id (connection, &error); if (dbus_error_is_set (&error)) { /* This is a bit bogus because we pretend all errors * are OOM; this is done because we know that in bus.c * an OOM error disconnects the connection, which is * the same thing we want on any other error. */ dbus_error_free (&error); goto out; } if (!dbus_connection_set_watch_functions (connection, add_connection_watch, remove_connection_watch, NULL, connection, NULL)) goto out; if (!dbus_connection_set_timeout_functions (connection, add_connection_timeout, remove_connection_timeout, NULL, connection, NULL)) goto out; dbus_connection_set_unix_user_function (connection, allow_user_function, NULL, NULL); dbus_connection_set_dispatch_status_function (connection, dispatch_status_function, bus_context_get_loop (connections->context), NULL); d->link_in_connection_list = _dbus_list_alloc_link (connection); if (d->link_in_connection_list == NULL) goto out; /* Setup the connection with the dispatcher */ if (!bus_dispatch_add_connection (connection)) goto out; if (dbus_connection_get_dispatch_status (connection) != DBUS_DISPATCH_COMPLETE) { if (!_dbus_loop_queue_dispatch (bus_context_get_loop (connections->context), connection)) { bus_dispatch_remove_connection (connection); goto out; } } _dbus_list_append_link (&connections->incomplete, d->link_in_connection_list); connections->n_incomplete += 1; dbus_connection_ref (connection); /* Note that we might disconnect ourselves here, but it only takes * effect on return to the main loop. We call this to free up * expired connections if possible, and to queue the timeout for our * own expiration. */ bus_connections_expire_incomplete (connections); /* And we might also disconnect ourselves here, but again it * only takes effect on return to main loop. */ if (connections->n_incomplete > bus_context_get_max_incomplete_connections (connections->context)) { _dbus_verbose ("Number of incomplete connections exceeds max, dropping oldest one\n"); _dbus_assert (connections->incomplete != NULL); /* Disconnect the oldest unauthenticated connection. FIXME * would it be more secure to drop a *random* connection? This * algorithm seems to mean that if someone can create new * connections quickly enough, they can keep anyone else from * completing authentication. But random may or may not really * help with that, a more elaborate solution might be required. */ dbus_connection_close (connections->incomplete->data); } retval = TRUE; out: if (!retval) { if (d->selinux_id) bus_selinux_id_unref (d->selinux_id); d->selinux_id = NULL; if (!dbus_connection_set_watch_functions (connection, NULL, NULL, NULL, connection, NULL)) _dbus_assert_not_reached ("setting watch functions to NULL failed"); if (!dbus_connection_set_timeout_functions (connection, NULL, NULL, NULL, connection, NULL)) _dbus_assert_not_reached ("setting timeout functions to NULL failed"); dbus_connection_set_unix_user_function (connection, NULL, NULL, NULL); dbus_connection_set_dispatch_status_function (connection, NULL, NULL, NULL); if (d->link_in_connection_list != NULL) { _dbus_assert (d->link_in_connection_list->next == NULL); _dbus_assert (d->link_in_connection_list->prev == NULL); _dbus_list_free_link (d->link_in_connection_list); d->link_in_connection_list = NULL; } if (!dbus_connection_set_data (connection, connection_data_slot, NULL, NULL)) _dbus_assert_not_reached ("failed to set connection data to null"); /* "d" has now been freed */ } return retval; } void bus_connections_expire_incomplete (BusConnections *connections) { int next_interval; next_interval = -1; if (connections->incomplete != NULL) { long tv_sec, tv_usec; DBusList *link; int auth_timeout; _dbus_get_current_time (&tv_sec, &tv_usec); auth_timeout = bus_context_get_auth_timeout (connections->context); link = _dbus_list_get_first_link (&connections->incomplete); while (link != NULL) { DBusList *next = _dbus_list_get_next_link (&connections->incomplete, link); DBusConnection *connection; BusConnectionData *d; double elapsed; connection = link->data; d = BUS_CONNECTION_DATA (connection); _dbus_assert (d != NULL); elapsed = ELAPSED_MILLISECONDS_SINCE (d->connection_tv_sec, d->connection_tv_usec, tv_sec, tv_usec); if (elapsed >= (double) auth_timeout) { _dbus_verbose ("Timing out authentication for connection %p\n", connection); dbus_connection_close (connection); } else { /* We can end the loop, since the connections are in oldest-first order */ next_interval = ((double)auth_timeout) - elapsed; _dbus_verbose ("Connection %p authentication expires in %d milliseconds\n", connection, next_interval); break; } link = next; } } bus_expire_timeout_set_interval (connections->expire_timeout, next_interval); } static dbus_bool_t expire_incomplete_timeout (void *data) { BusConnections *connections = data; _dbus_verbose ("Running %s\n", _DBUS_FUNCTION_NAME); /* note that this may remove the timeout */ bus_connections_expire_incomplete (connections); return TRUE; } dbus_bool_t bus_connection_get_groups (DBusConnection *connection, unsigned long **groups, int *n_groups, DBusError *error) { BusConnectionData *d; unsigned long uid; DBusUserDatabase *user_database; d = BUS_CONNECTION_DATA (connection); _dbus_assert (d != NULL); user_database = bus_context_get_user_database (d->connections->context); *groups = NULL; *n_groups = 0; if (dbus_connection_get_unix_user (connection, &uid)) { if (!_dbus_user_database_get_groups (user_database, uid, groups, n_groups, error)) { _DBUS_ASSERT_ERROR_IS_SET (error); _dbus_verbose ("Did not get any groups for UID %lu\n", uid); return FALSE; } else { _dbus_verbose ("Got %d groups for UID %lu\n", *n_groups, uid); return TRUE; } } else return TRUE; /* successfully got 0 groups */ } dbus_bool_t bus_connection_is_in_group (DBusConnection *connection, unsigned long gid) { int i; unsigned long *group_ids; int n_group_ids; if (!bus_connection_get_groups (connection, &group_ids, &n_group_ids, NULL)) return FALSE; i = 0; while (i < n_group_ids) { if (group_ids[i] == gid) { dbus_free (group_ids); return TRUE; } ++i; } dbus_free (group_ids); return FALSE; } BusClientPolicy* bus_connection_get_policy (DBusConnection *connection) { BusConnectionData *d; d = BUS_CONNECTION_DATA (connection); _dbus_assert (d != NULL); _dbus_assert (d->policy != NULL); return d->policy; } static dbus_bool_t foreach_active (BusConnections *connections, BusConnectionForeachFunction function, void *data) { DBusList *link; link = _dbus_list_get_first_link (&connections->completed); while (link != NULL) { DBusConnection *connection = link->data; DBusList *next = _dbus_list_get_next_link (&connections->completed, link); if (!(* function) (connection, data)) return FALSE; link = next; } return TRUE; } static dbus_bool_t foreach_inactive (BusConnections *connections, BusConnectionForeachFunction function, void *data) { DBusList *link; link = _dbus_list_get_first_link (&connections->incomplete); while (link != NULL) { DBusConnection *connection = link->data; DBusList *next = _dbus_list_get_next_link (&connections->incomplete, link); if (!(* function) (connection, data)) return FALSE; link = next; } return TRUE; } /** * Calls function on each active connection; if the function returns * #FALSE, stops iterating. Active connections are authenticated * and have sent a Hello message. * * @param connections the connections object * @param function the function * @param data data to pass to it as a second arg */ void bus_connections_foreach_active (BusConnections *connections, BusConnectionForeachFunction function, void *data) { foreach_active (connections, function, data); } /** * Calls function on each connection; if the function returns * #FALSE, stops iterating. * * @param connections the connections object * @param function the function * @param data data to pass to it as a second arg */ void bus_connections_foreach (BusConnections *connections, BusConnectionForeachFunction function, void *data) { if (!foreach_active (connections, function, data)) return; foreach_inactive (connections, function, data); } BusContext* bus_connections_get_context (BusConnections *connections) { return connections->context; } /* * This is used to avoid covering the same connection twice when * traversing connections. Note that it assumes we will * bus_connection_mark_stamp() each connection at least once per * INT_MAX increments of the global stamp, or wraparound would break * things. */ void bus_connections_increment_stamp (BusConnections *connections) { connections->stamp += 1; } /* Mark connection with current stamp, return TRUE if it * didn't already have that stamp */ dbus_bool_t bus_connection_mark_stamp (DBusConnection *connection) { BusConnectionData *d; d = BUS_CONNECTION_DATA (connection); _dbus_assert (d != NULL); if (d->stamp == d->connections->stamp) return FALSE; else { d->stamp = d->connections->stamp; return TRUE; } } BusContext* bus_connection_get_context (DBusConnection *connection) { BusConnectionData *d; d = BUS_CONNECTION_DATA (connection); _dbus_assert (d != NULL); return d->connections->context; } BusConnections* bus_connection_get_connections (DBusConnection *connection) { BusConnectionData *d; d = BUS_CONNECTION_DATA (connection); _dbus_assert (d != NULL); return d->connections; } BusRegistry* bus_connection_get_registry (DBusConnection *connection) { BusConnectionData *d; d = BUS_CONNECTION_DATA (connection); _dbus_assert (d != NULL); return bus_context_get_registry (d->connections->context); } BusActivation* bus_connection_get_activation (DBusConnection *connection) { BusConnectionData *d; d = BUS_CONNECTION_DATA (connection); _dbus_assert (d != NULL); return bus_context_get_activation (d->connections->context); } BusMatchmaker* bus_connection_get_matchmaker (DBusConnection *connection) { BusConnectionData *d; d = BUS_CONNECTION_DATA (connection); _dbus_assert (d != NULL); return bus_context_get_matchmaker (d->connections->context); } BusSELinuxID* bus_connection_get_selinux_id (DBusConnection *connection) { BusConnectionData *d; d = BUS_CONNECTION_DATA (connection); _dbus_assert (d != NULL); return d->selinux_id; } /** * Checks whether the connection is registered with the message bus. * * @param connection the connection * @returns #TRUE if we're an active message bus participant */ dbus_bool_t bus_connection_is_active (DBusConnection *connection) { BusConnectionData *d; d = BUS_CONNECTION_DATA (connection); return d != NULL && d->name != NULL; } dbus_bool_t bus_connection_preallocate_oom_error (DBusConnection *connection) { DBusMessage *message; DBusPreallocatedSend *preallocated; BusConnectionData *d; d = BUS_CONNECTION_DATA (connection); _dbus_assert (d != NULL); if (d->oom_preallocated != NULL) return TRUE; preallocated = dbus_connection_preallocate_send (connection); if (preallocated == NULL) return FALSE; message = dbus_message_new (DBUS_MESSAGE_TYPE_ERROR); if (message == NULL) { dbus_connection_free_preallocated_send (connection, preallocated); return FALSE; } /* d->name may be NULL, but that is OK */ if (!dbus_message_set_error_name (message, DBUS_ERROR_NO_MEMORY) || !dbus_message_set_destination (message, d->name) || !dbus_message_set_sender (message, DBUS_SERVICE_DBUS)) { dbus_connection_free_preallocated_send (connection, preallocated); dbus_message_unref (message); return FALSE; } /* set reply serial to placeholder value just so space is already allocated * for it. */ if (!dbus_message_set_reply_serial (message, 14)) { dbus_connection_free_preallocated_send (connection, preallocated); dbus_message_unref (message); return FALSE; } d->oom_message = message; d->oom_preallocated = preallocated; return TRUE; } void bus_connection_send_oom_error (DBusConnection *connection, DBusMessage *in_reply_to) { BusConnectionData *d; d = BUS_CONNECTION_DATA (connection); _dbus_assert (d != NULL); _dbus_assert (d->oom_message != NULL); /* should always succeed since we set it to a placeholder earlier */ if (!dbus_message_set_reply_serial (d->oom_message, dbus_message_get_serial (in_reply_to))) _dbus_assert_not_reached ("Failed to set reply serial for preallocated oom message"); _dbus_assert (dbus_message_get_sender (d->oom_message) != NULL); dbus_connection_send_preallocated (connection, d->oom_preallocated, d->oom_message, NULL); dbus_message_unref (d->oom_message); d->oom_message = NULL; d->oom_preallocated = NULL; } void bus_connection_add_match_rule_link (DBusConnection *connection, DBusList *link) { BusConnectionData *d; d = BUS_CONNECTION_DATA (connection); _dbus_assert (d != NULL); _dbus_list_append_link (&d->match_rules, link); d->n_match_rules += 1; } dbus_bool_t bus_connection_add_match_rule (DBusConnection *connection, BusMatchRule *rule) { DBusList *link; link = _dbus_list_alloc_link (rule); if (link == NULL) return FALSE; bus_connection_add_match_rule_link (connection, link); return TRUE; } void bus_connection_remove_match_rule (DBusConnection *connection, BusMatchRule *rule) { BusConnectionData *d; d = BUS_CONNECTION_DATA (connection); _dbus_assert (d != NULL); _dbus_list_remove_last (&d->match_rules, rule); d->n_match_rules -= 1; _dbus_assert (d->n_match_rules >= 0); } int bus_connection_get_n_match_rules (DBusConnection *connection) { BusConnectionData *d; d = BUS_CONNECTION_DATA (connection); _dbus_assert (d != NULL); return d->n_match_rules; } void bus_connection_add_owned_service_link (DBusConnection *connection, DBusList *link) { BusConnectionData *d; d = BUS_CONNECTION_DATA (connection); _dbus_assert (d != NULL); _dbus_list_append_link (&d->services_owned, link); d->n_services_owned += 1; } dbus_bool_t bus_connection_add_owned_service (DBusConnection *connection, BusService *service) { DBusList *link; link = _dbus_list_alloc_link (service); if (link == NULL) return FALSE; bus_connection_add_owned_service_link (connection, link); return TRUE; } void bus_connection_remove_owned_service (DBusConnection *connection, BusService *service) { BusConnectionData *d; d = BUS_CONNECTION_DATA (connection); _dbus_assert (d != NULL); _dbus_list_remove_last (&d->services_owned, service); d->n_services_owned -= 1; _dbus_assert (d->n_services_owned >= 0); } int bus_connection_get_n_services_owned (DBusConnection *connection) { BusConnectionData *d; d = BUS_CONNECTION_DATA (connection); _dbus_assert (d != NULL); return d->n_services_owned; } dbus_bool_t bus_connection_complete (DBusConnection *connection, const DBusString *name, DBusError *error) { BusConnectionData *d; unsigned long uid; d = BUS_CONNECTION_DATA (connection); _dbus_assert (d != NULL); _dbus_assert (d->name == NULL); _dbus_assert (d->policy == NULL); _dbus_assert (!bus_connection_is_active (connection)); if (!_dbus_string_copy_data (name, &d->name)) { BUS_SET_OOM (error); return FALSE; } _dbus_assert (d->name != NULL); _dbus_verbose ("Name %s assigned to %p\n", d->name, connection); d->policy = bus_context_create_client_policy (d->connections->context, connection, error); /* we may have a NULL policy on OOM or error getting list of * groups for a user. In the latter case we don't handle it so * well currently, as it will just keep failing over and over. */ if (d->policy == NULL) { _dbus_verbose ("Failed to create security policy for connection %p\n", connection); _DBUS_ASSERT_ERROR_IS_SET (error); dbus_free (d->name); d->name = NULL; return FALSE; } if (dbus_connection_get_unix_user (connection, &uid)) { if (!adjust_connections_for_uid (d->connections, uid, 1)) { BUS_SET_OOM (error); dbus_free (d->name); d->name = NULL; return FALSE; } } /* Now the connection is active, move it between lists */ _dbus_list_unlink (&d->connections->incomplete, d->link_in_connection_list); d->connections->n_incomplete -= 1; _dbus_list_append_link (&d->connections->completed, d->link_in_connection_list); d->connections->n_completed += 1; _dbus_assert (d->connections->n_incomplete >= 0); _dbus_assert (d->connections->n_completed > 0); /* See if we can remove the timeout */ bus_connections_expire_incomplete (d->connections); _dbus_assert (bus_connection_is_active (connection)); return TRUE; } const char * bus_connection_get_name (DBusConnection *connection) { BusConnectionData *d; d = BUS_CONNECTION_DATA (connection); _dbus_assert (d != NULL); return d->name; } /** * Check whether completing the passed-in connection would * exceed limits, and if so set error and return #FALSE */ dbus_bool_t bus_connections_check_limits (BusConnections *connections, DBusConnection *requesting_completion, DBusError *error) { BusConnectionData *d; unsigned long uid; d = BUS_CONNECTION_DATA (requesting_completion); _dbus_assert (d != NULL); _dbus_assert (d->name == NULL); if (connections->n_completed >= bus_context_get_max_completed_connections (connections->context)) { dbus_set_error (error, DBUS_ERROR_LIMITS_EXCEEDED, "The maximum number of active connections has been reached"); return FALSE; } if (dbus_connection_get_unix_user (requesting_completion, &uid)) { if (get_connections_for_uid (connections, uid) >= bus_context_get_max_connections_per_user (connections->context)) { dbus_set_error (error, DBUS_ERROR_LIMITS_EXCEEDED, "The maximum number of active connections for UID %lu has been reached", uid); return FALSE; } } return TRUE; } static void bus_pending_reply_free (BusPendingReply *pending) { _dbus_verbose ("Freeing pending reply %p, replier %p receiver %p serial %u\n", pending, pending->will_send_reply, pending->will_get_reply, pending->reply_serial); dbus_free (pending); } static dbus_bool_t bus_pending_reply_send_no_reply (BusConnections *connections, BusTransaction *transaction, BusPendingReply *pending) { DBusMessage *message; DBusMessageIter iter; dbus_bool_t retval; const char *errmsg; retval = FALSE; message = dbus_message_new (DBUS_MESSAGE_TYPE_ERROR); if (message == NULL) return FALSE; dbus_message_set_no_reply (message, TRUE); if (!dbus_message_set_reply_serial (message, pending->reply_serial)) goto out; if (!dbus_message_set_error_name (message, DBUS_ERROR_NO_REPLY)) goto out; errmsg = "Message did not receive a reply (timeout by message bus)"; dbus_message_iter_init_append (message, &iter); if (!dbus_message_iter_append_basic (&iter, DBUS_TYPE_STRING, &errmsg)) goto out; if (!bus_transaction_send_from_driver (transaction, pending->will_get_reply, message)) goto out; retval = TRUE; out: dbus_message_unref (message); return retval; } static dbus_bool_t bus_pending_reply_expired (BusExpireList *list, DBusList *link, void *data) { BusPendingReply *pending = link->data; BusConnections *connections = data; BusTransaction *transaction; /* No reply is forthcoming. So nuke it if we can. If not, * leave it in the list to try expiring again later when we * get more memory. */ _dbus_verbose ("Expiring pending reply %p, replier %p receiver %p serial %u\n", pending, pending->will_send_reply, pending->will_get_reply, pending->reply_serial); transaction = bus_transaction_new (connections->context); if (transaction == NULL) return FALSE; if (!bus_pending_reply_send_no_reply (connections, transaction, pending)) { bus_transaction_cancel_and_free (transaction); return FALSE; } _dbus_list_remove_link (&connections->pending_replies->items, link); bus_pending_reply_free (pending); bus_transaction_execute_and_free (transaction); return TRUE; } static void bus_connection_drop_pending_replies (BusConnections *connections, DBusConnection *connection) { /* The DBusConnection is almost 100% finalized here, so you can't * do anything with it except check for pointer equality */ DBusList *link; _dbus_verbose ("Dropping pending replies that involve connection %p\n", connection); link = _dbus_list_get_first_link (&connections->pending_replies->items); while (link != NULL) { DBusList *next; BusPendingReply *pending; next = _dbus_list_get_next_link (&connections->pending_replies->items, link); pending = link->data; if (pending->will_get_reply == connection) { /* We don't need to track this pending reply anymore */ _dbus_verbose ("Dropping pending reply %p, replier %p receiver %p serial %u\n", pending, pending->will_send_reply, pending->will_get_reply, pending->reply_serial); _dbus_list_remove_link (&connections->pending_replies->items, link); bus_pending_reply_free (pending); } else if (pending->will_send_reply == connection) { /* The reply isn't going to be sent, so set things * up so it will be expired right away */ _dbus_verbose ("Will expire pending reply %p, replier %p receiver %p serial %u\n", pending, pending->will_send_reply, pending->will_get_reply, pending->reply_serial); pending->will_send_reply = NULL; pending->expire_item.added_tv_sec = 0; pending->expire_item.added_tv_usec = 0; bus_expire_timeout_set_interval (connections->pending_replies->timeout, 0); } link = next; } } typedef struct { BusPendingReply *pending; BusConnections *connections; } CancelPendingReplyData; static void cancel_pending_reply (void *data) { CancelPendingReplyData *d = data; _dbus_verbose ("%s: d = %p\n", _DBUS_FUNCTION_NAME, d); if (!_dbus_list_remove (&d->connections->pending_replies->items, d->pending)) _dbus_assert_not_reached ("pending reply did not exist to be cancelled"); bus_pending_reply_free (d->pending); /* since it's been cancelled */ } static void cancel_pending_reply_data_free (void *data) { CancelPendingReplyData *d = data; _dbus_verbose ("%s: d = %p\n", _DBUS_FUNCTION_NAME, d); /* d->pending should be either freed or still * in the list of pending replies (owned by someone * else) */ dbus_free (d); } /* * Record that a reply is allowed; return TRUE on success. */ dbus_bool_t bus_connections_expect_reply (BusConnections *connections, BusTransaction *transaction, DBusConnection *will_get_reply, DBusConnection *will_send_reply, DBusMessage *reply_to_this, DBusError *error) { BusPendingReply *pending; dbus_uint32_t reply_serial; DBusList *link; CancelPendingReplyData *cprd; int count; _dbus_assert (will_get_reply != NULL); _dbus_assert (will_send_reply != NULL); _dbus_assert (reply_to_this != NULL); if (dbus_message_get_no_reply (reply_to_this)) return TRUE; /* we won't allow a reply, since client doesn't care for one. */ reply_serial = dbus_message_get_serial (reply_to_this); link = _dbus_list_get_first_link (&connections->pending_replies->items); count = 0; while (link != NULL) { pending = link->data; if (pending->reply_serial == reply_serial && pending->will_get_reply == will_get_reply && pending->will_send_reply == will_send_reply) { dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED, "Message has the same reply serial as a currently-outstanding existing method call"); return FALSE; } link = _dbus_list_get_next_link (&connections->pending_replies->items, link); ++count; } if (count >= bus_context_get_max_replies_per_connection (connections->context)) { dbus_set_error (error, DBUS_ERROR_LIMITS_EXCEEDED, "The maximum number of pending replies per connection has been reached"); return FALSE; } pending = dbus_new0 (BusPendingReply, 1); if (pending == NULL) { BUS_SET_OOM (error); return FALSE; } #ifdef DBUS_ENABLE_VERBOSE_MODE /* so we can see a not-yet-added pending reply */ pending->expire_item.added_tv_sec = 1; pending->expire_item.added_tv_usec = 1; #endif pending->will_get_reply = will_get_reply; pending->will_send_reply = will_send_reply; pending->reply_serial = reply_serial; cprd = dbus_new0 (CancelPendingReplyData, 1); if (cprd == NULL) { BUS_SET_OOM (error); bus_pending_reply_free (pending); return FALSE; } if (!_dbus_list_prepend (&connections->pending_replies->items, pending)) { BUS_SET_OOM (error); dbus_free (cprd); bus_pending_reply_free (pending); return FALSE; } if (!bus_transaction_add_cancel_hook (transaction, cancel_pending_reply, cprd, cancel_pending_reply_data_free)) { BUS_SET_OOM (error); _dbus_list_remove (&connections->pending_replies->items, pending); dbus_free (cprd); bus_pending_reply_free (pending); return FALSE; } cprd->pending = pending; cprd->connections = connections; _dbus_get_current_time (&pending->expire_item.added_tv_sec, &pending->expire_item.added_tv_usec); _dbus_verbose ("Added pending reply %p, replier %p receiver %p serial %u\n", pending, pending->will_send_reply, pending->will_get_reply, pending->reply_serial); return TRUE; } typedef struct { DBusList *link; BusConnections *connections; } CheckPendingReplyData; static void cancel_check_pending_reply (void *data) { CheckPendingReplyData *d = data; _dbus_verbose ("%s: d = %p\n", _DBUS_FUNCTION_NAME, d); _dbus_list_prepend_link (&d->connections->pending_replies->items, d->link); d->link = NULL; } static void check_pending_reply_data_free (void *data) { CheckPendingReplyData *d = data; _dbus_verbose ("%s: d = %p\n", _DBUS_FUNCTION_NAME, d); if (d->link != NULL) { BusPendingReply *pending = d->link->data; _dbus_assert (_dbus_list_find_last (&d->connections->pending_replies->items, pending) == NULL); bus_pending_reply_free (pending); _dbus_list_free_link (d->link); } dbus_free (d); } /* * Check whether a reply is allowed, remove BusPendingReply * if so, return TRUE if so. */ dbus_bool_t bus_connections_check_reply (BusConnections *connections, BusTransaction *transaction, DBusConnection *sending_reply, DBusConnection *receiving_reply, DBusMessage *reply, DBusError *error) { CheckPendingReplyData *cprd; DBusList *link; dbus_uint32_t reply_serial; _dbus_assert (sending_reply != NULL); _dbus_assert (receiving_reply != NULL); reply_serial = dbus_message_get_reply_serial (reply); link = _dbus_list_get_first_link (&connections->pending_replies->items); while (link != NULL) { BusPendingReply *pending = link->data; if (pending->reply_serial == reply_serial && pending->will_get_reply == receiving_reply && pending->will_send_reply == sending_reply) { _dbus_verbose ("Found pending reply with serial %u\n", reply_serial); break; } link = _dbus_list_get_next_link (&connections->pending_replies->items, link); } if (link == NULL) { _dbus_verbose ("No pending reply expected\n"); return FALSE; } cprd = dbus_new0 (CheckPendingReplyData, 1); if (cprd == NULL) { BUS_SET_OOM (error); return FALSE; } if (!bus_transaction_add_cancel_hook (transaction, cancel_check_pending_reply, cprd, check_pending_reply_data_free)) { BUS_SET_OOM (error); dbus_free (cprd); return FALSE; } cprd->link = link; cprd->connections = connections; _dbus_list_unlink (&connections->pending_replies->items, link); _dbus_assert (_dbus_list_find_last (&connections->pending_replies->items, link->data) == NULL); return TRUE; } /* * Transactions * * Note that this is fairly fragile; in particular, don't try to use * one transaction across any main loop iterations. */ typedef struct { BusTransaction *transaction; DBusMessage *message; DBusPreallocatedSend *preallocated; } MessageToSend; typedef struct { BusTransactionCancelFunction cancel_function; DBusFreeFunction free_data_function; void *data; } CancelHook; struct BusTransaction { DBusList *connections; BusContext *context; DBusList *cancel_hooks; }; static void message_to_send_free (DBusConnection *connection, MessageToSend *to_send) { if (to_send->message) dbus_message_unref (to_send->message); if (to_send->preallocated) dbus_connection_free_preallocated_send (connection, to_send->preallocated); dbus_free (to_send); } static void cancel_hook_cancel (void *element, void *data) { CancelHook *ch = element; _dbus_verbose ("Running transaction cancel hook\n"); if (ch->cancel_function) (* ch->cancel_function) (ch->data); } static void cancel_hook_free (void *element, void *data) { CancelHook *ch = element; if (ch->free_data_function) (* ch->free_data_function) (ch->data); dbus_free (ch); } static void free_cancel_hooks (BusTransaction *transaction) { _dbus_list_foreach (&transaction->cancel_hooks, cancel_hook_free, NULL); _dbus_list_clear (&transaction->cancel_hooks); } BusTransaction* bus_transaction_new (BusContext *context) { BusTransaction *transaction; transaction = dbus_new0 (BusTransaction, 1); if (transaction == NULL) return NULL; transaction->context = context; return transaction; } BusContext* bus_transaction_get_context (BusTransaction *transaction) { return transaction->context; } BusConnections* bus_transaction_get_connections (BusTransaction *transaction) { return bus_context_get_connections (transaction->context); } dbus_bool_t bus_transaction_send_from_driver (BusTransaction *transaction, DBusConnection *connection, DBusMessage *message) { /* We have to set the sender to the driver, and have * to check security policy since it was not done in * dispatch.c */ _dbus_verbose ("Sending %s %s %s from driver\n", 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_error_name (message) ? dbus_message_get_error_name (message) : "(no error name)"); if (!dbus_message_set_sender (message, DBUS_SERVICE_DBUS)) return FALSE; if (bus_connection_is_active (connection)) { if (!dbus_message_set_destination (message, bus_connection_get_name (connection))) return FALSE; } /* bus driver never wants a reply */ dbus_message_set_no_reply (message, TRUE); /* If security policy doesn't allow the message, we silently * eat it; the driver doesn't care about getting a reply. */ if (!bus_context_check_security_policy (bus_transaction_get_context (transaction), transaction, NULL, connection, connection, message, NULL)) return TRUE; return bus_transaction_send (transaction, connection, message); } dbus_bool_t bus_transaction_send (BusTransaction *transaction, DBusConnection *connection, DBusMessage *message) { MessageToSend *to_send; BusConnectionData *d; DBusList *link; _dbus_verbose (" trying to add %s interface=%s member=%s error=%s to transaction%s\n", dbus_message_get_type (message) == DBUS_MESSAGE_TYPE_ERROR ? "error" : dbus_message_get_reply_serial (message) != 0 ? "reply" : "message", dbus_message_get_interface (message) ? dbus_message_get_interface (message) : "(unset)", dbus_message_get_member (message) ? dbus_message_get_member (message) : "(unset)", dbus_message_get_error_name (message) ? dbus_message_get_error_name (message) : "(unset)", dbus_connection_get_is_connected (connection) ? "" : " (disconnected)"); _dbus_assert (dbus_message_get_sender (message) != NULL); if (!dbus_connection_get_is_connected (connection)) return TRUE; /* silently ignore disconnected connections */ d = BUS_CONNECTION_DATA (connection); _dbus_assert (d != NULL); to_send = dbus_new (MessageToSend, 1); if (to_send == NULL) { return FALSE; } to_send->preallocated = dbus_connection_preallocate_send (connection); if (to_send->preallocated == NULL) { dbus_free (to_send); return FALSE; } dbus_message_ref (message); to_send->message = message; to_send->transaction = transaction; _dbus_verbose ("about to prepend message\n"); if (!_dbus_list_prepend (&d->transaction_messages, to_send)) { message_to_send_free (connection, to_send); return FALSE; } _dbus_verbose ("prepended message\n"); /* See if we already had this connection in the list * for this transaction. If we have a pending message, * then we should already be in transaction->connections */ link = _dbus_list_get_first_link (&d->transaction_messages); _dbus_assert (link->data == to_send); link = _dbus_list_get_next_link (&d->transaction_messages, link); while (link != NULL) { MessageToSend *m = link->data; DBusList *next = _dbus_list_get_next_link (&d->transaction_messages, link); if (m->transaction == transaction) break; link = next; } if (link == NULL) { if (!_dbus_list_prepend (&transaction->connections, connection)) { _dbus_list_remove (&d->transaction_messages, to_send); message_to_send_free (connection, to_send); return FALSE; } } return TRUE; } static void connection_cancel_transaction (DBusConnection *connection, BusTransaction *transaction) { DBusList *link; BusConnectionData *d; d = BUS_CONNECTION_DATA (connection); _dbus_assert (d != NULL); link = _dbus_list_get_first_link (&d->transaction_messages); while (link != NULL) { MessageToSend *m = link->data; DBusList *next = _dbus_list_get_next_link (&d->transaction_messages, link); if (m->transaction == transaction) { _dbus_list_remove_link (&d->transaction_messages, link); message_to_send_free (connection, m); } link = next; } } void bus_transaction_cancel_and_free (BusTransaction *transaction) { DBusConnection *connection; _dbus_verbose ("TRANSACTION: cancelled\n"); while ((connection = _dbus_list_pop_first (&transaction->connections))) connection_cancel_transaction (connection, transaction); _dbus_assert (transaction->connections == NULL); _dbus_list_foreach (&transaction->cancel_hooks, cancel_hook_cancel, NULL); free_cancel_hooks (transaction); dbus_free (transaction); } static void connection_execute_transaction (DBusConnection *connection, BusTransaction *transaction) { DBusList *link; BusConnectionData *d; d = BUS_CONNECTION_DATA (connection); _dbus_assert (d != NULL); /* Send the queue in order (FIFO) */ link = _dbus_list_get_last_link (&d->transaction_messages); while (link != NULL) { MessageToSend *m = link->data; DBusList *prev = _dbus_list_get_prev_link (&d->transaction_messages, link); if (m->transaction == transaction) { _dbus_list_remove_link (&d->transaction_messages, link); _dbus_assert (dbus_message_get_sender (m->message) != NULL); dbus_connection_send_preallocated (connection, m->preallocated, m->message, NULL); m->preallocated = NULL; /* so we don't double-free it */ message_to_send_free (connection, m); } link = prev; } } void bus_transaction_execute_and_free (BusTransaction *transaction) { /* For each connection in transaction->connections * send the messages */ DBusConnection *connection; _dbus_verbose ("TRANSACTION: executing\n"); while ((connection = _dbus_list_pop_first (&transaction->connections))) connection_execute_transaction (connection, transaction); _dbus_assert (transaction->connections == NULL); free_cancel_hooks (transaction); dbus_free (transaction); } static void bus_connection_remove_transactions (DBusConnection *connection) { MessageToSend *to_send; BusConnectionData *d; d = BUS_CONNECTION_DATA (connection); _dbus_assert (d != NULL); while ((to_send = _dbus_list_get_first (&d->transaction_messages))) { /* only has an effect for the first MessageToSend listing this transaction */ _dbus_list_remove (&to_send->transaction->connections, connection); _dbus_list_remove (&d->transaction_messages, to_send); message_to_send_free (connection, to_send); } } /** * Converts the DBusError to a message reply */ dbus_bool_t bus_transaction_send_error_reply (BusTransaction *transaction, DBusConnection *connection, const DBusError *error, DBusMessage *in_reply_to) { DBusMessage *reply; _dbus_assert (error != NULL); _DBUS_ASSERT_ERROR_IS_SET (error); _dbus_verbose ("Sending error reply %s \"%s\"\n", error->name, error->message); reply = dbus_message_new_error (in_reply_to, error->name, error->message); if (reply == NULL) return FALSE; if (!bus_transaction_send_from_driver (transaction, connection, reply)) { dbus_message_unref (reply); return FALSE; } dbus_message_unref (reply); return TRUE; } dbus_bool_t bus_transaction_add_cancel_hook (BusTransaction *transaction, BusTransactionCancelFunction cancel_function, void *data, DBusFreeFunction free_data_function) { CancelHook *ch; ch = dbus_new (CancelHook, 1); if (ch == NULL) return FALSE; _dbus_verbose (" adding cancel hook function = %p data = %p\n", cancel_function, data); ch->cancel_function = cancel_function; ch->data = data; ch->free_data_function = free_data_function; /* It's important that the hooks get run in reverse order that they * were added */ if (!_dbus_list_prepend (&transaction->cancel_hooks, ch)) { dbus_free (ch); return FALSE; } return TRUE; }