/* -*- mode: C; c-file-style: "gnu" -*- */ /* dbus-transport.c DBusTransport object (internal to D-BUS implementation) * * Copyright (C) 2002, 2003 Red Hat Inc. * * Licensed under the Academic Free License version 1.2 * * 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 "dbus-transport-protected.h" #include "dbus-transport-unix.h" #include "dbus-connection-internal.h" #include "dbus-watch.h" #include "dbus-auth.h" #include "dbus-address.h" #ifdef DBUS_BUILD_TESTS #include "dbus-transport-debug.h" #endif /** * @defgroup DBusTransport DBusTransport object * @ingroup DBusInternals * @brief "Backend" for a DBusConnection. * * Types and functions related to DBusTransport. A transport is an * abstraction that can send and receive data via various kinds of * network connections or other IPC mechanisms. * * @{ */ /** * @typedef DBusTransport * * Opaque object representing a way message stream. * DBusTransport abstracts various kinds of actual * transport mechanism, such as different network protocols, * or encryption schemes. */ static void live_messages_size_notify (DBusCounter *counter, void *user_data) { DBusTransport *transport = user_data; _dbus_transport_ref (transport); #if 0 _dbus_verbose ("Counter value is now %d\n", (int) _dbus_counter_get_value (counter)); #endif /* disable or re-enable the read watch for the transport if * required. */ if (* transport->vtable->live_messages_changed) (* transport->vtable->live_messages_changed) (transport); _dbus_transport_unref (transport); } /** * Initializes the base class members of DBusTransport. * Chained up to by subclasses in their constructor. * * @param transport the transport being created. * @param vtable the subclass vtable. * @param server #TRUE if this transport is on the server side of a connection * @returns #TRUE on success. */ dbus_bool_t _dbus_transport_init_base (DBusTransport *transport, const DBusTransportVTable *vtable, dbus_bool_t server) { DBusMessageLoader *loader; DBusAuth *auth; DBusCounter *counter; loader = _dbus_message_loader_new (); if (loader == NULL) return FALSE; if (server) auth = _dbus_auth_server_new (); else auth = _dbus_auth_client_new (); if (auth == NULL) { _dbus_message_loader_unref (loader); return FALSE; } counter = _dbus_counter_new (); if (counter == NULL) { _dbus_auth_unref (auth); _dbus_message_loader_unref (loader); return FALSE; } transport->refcount = 1; transport->vtable = vtable; transport->loader = loader; transport->auth = auth; transport->live_messages_size = counter; transport->authenticated = FALSE; transport->messages_need_sending = FALSE; transport->disconnected = FALSE; transport->send_credentials_pending = !server; transport->receive_credentials_pending = server; transport->is_server = server; /* Try to default to something that won't totally hose the system, * but doesn't impose too much of a limitation. */ transport->max_live_messages_size = _DBUS_ONE_MEGABYTE * 63; transport->credentials.pid = -1; transport->credentials.uid = -1; transport->credentials.gid = -1; _dbus_counter_set_notify (transport->live_messages_size, transport->max_live_messages_size, live_messages_size_notify, transport); return TRUE; } /** * Finalizes base class members of DBusTransport. * Chained up to from subclass finalizers. * * @param transport the transport. */ void _dbus_transport_finalize_base (DBusTransport *transport) { if (!transport->disconnected) _dbus_transport_disconnect (transport); _dbus_message_loader_unref (transport->loader); _dbus_auth_unref (transport->auth); _dbus_counter_set_notify (transport->live_messages_size, 0, NULL, NULL); _dbus_counter_unref (transport->live_messages_size); } /** * Opens a new transport for the given address. (This opens a * client-side-of-the-connection transport.) * * @todo error messages on bad address could really be better. * DBusResultCode is a bit limiting here. * * @param address the address. * @param result location to store reason for failure. * @returns new transport of #NULL on failure. */ DBusTransport* _dbus_transport_open (const char *address, DBusResultCode *result) { DBusTransport *transport; DBusAddressEntry **entries; int len, i; if (!dbus_parse_address (address, &entries, &len, result)) return NULL; transport = NULL; for (i = 0; i < len; i++) { const char *method = dbus_address_entry_get_method (entries[i]); if (strcmp (method, "unix") == 0) { const char *path = dbus_address_entry_get_value (entries[i], "path"); if (path == NULL) goto bad_address; transport = _dbus_transport_new_for_domain_socket (path, FALSE, result); } else if (strcmp (method, "tcp") == 0) { const char *host = dbus_address_entry_get_value (entries[i], "host"); const char *port = dbus_address_entry_get_value (entries[i], "port"); DBusString str; long lport; dbus_bool_t sresult; if (port == NULL) goto bad_address; _dbus_string_init_const (&str, port); sresult = _dbus_string_parse_int (&str, 0, &lport, NULL); _dbus_string_free (&str); if (sresult == FALSE || lport <= 0 || lport > 65535) goto bad_address; transport = _dbus_transport_new_for_tcp_socket (host, lport, FALSE, result); } else if (strcmp (method, "tcp") == 0) { const char *path = dbus_address_entry_get_value (entries[i], "path"); if (path == NULL) goto bad_address; transport = _dbus_transport_new_for_domain_socket (path, FALSE, result); } #ifdef DBUS_BUILD_TESTS else if (strcmp (method, "debug") == 0) { const char *name = dbus_address_entry_get_value (entries[i], "name"); if (name == NULL) goto bad_address; transport = _dbus_transport_debug_client_new (name, result); } #endif else goto bad_address; if (transport) break; } dbus_address_entries_free (entries); return transport; bad_address: dbus_address_entries_free (entries); dbus_set_result (result, DBUS_RESULT_BAD_ADDRESS); return NULL; } /** * Increments the reference count for the transport. * * @param transport the transport. */ void _dbus_transport_ref (DBusTransport *transport) { transport->refcount += 1; } /** * Decrements the reference count for the transport. * Disconnects and finalizes the transport if * the reference count reaches zero. * * @param transport the transport. */ void _dbus_transport_unref (DBusTransport *transport) { _dbus_assert (transport != NULL); _dbus_assert (transport->refcount > 0); transport->refcount -= 1; if (transport->refcount == 0) { _dbus_assert (transport->vtable->finalize != NULL); (* transport->vtable->finalize) (transport); } } /** * Closes our end of the connection to a remote application. Further * attempts to use this transport will fail. Only the first call to * _dbus_transport_disconnect() will have an effect. * * @param transport the transport. * */ void _dbus_transport_disconnect (DBusTransport *transport) { _dbus_assert (transport->vtable->disconnect != NULL); if (transport->disconnected) return; _dbus_transport_ref (transport); (* transport->vtable->disconnect) (transport); transport->disconnected = TRUE; _dbus_connection_notify_disconnected (transport->connection); _dbus_transport_unref (transport); } /** * Returns #TRUE if the transport has not been disconnected. * Disconnection can result from _dbus_transport_disconnect() * or because the server drops its end of the connection. * * @param transport the transport. * @returns whether we're connected */ dbus_bool_t _dbus_transport_get_is_connected (DBusTransport *transport) { return !transport->disconnected; } /** * Returns #TRUE if we have been authenticated. Will return #TRUE * even if the transport is disconnected. * * @param transport the transport * @returns whether we're authenticated */ dbus_bool_t _dbus_transport_get_is_authenticated (DBusTransport *transport) { if (transport->authenticated) return TRUE; else { if (transport->disconnected) return FALSE; transport->authenticated = (!(transport->send_credentials_pending || transport->receive_credentials_pending)) && _dbus_auth_do_work (transport->auth) == DBUS_AUTH_STATE_AUTHENTICATED; /* If we've authenticated as some identity, check that the auth * identity is the same as our own identity. In the future, we * may have API allowing applications to specify how this is * done, for example they may allow connection as any identity, * but then impose restrictions on certain identities. * Or they may give certain identities extra privileges. */ if (transport->authenticated && transport->is_server) { DBusCredentials auth_identity; DBusCredentials our_identity; _dbus_credentials_from_current_process (&our_identity); _dbus_auth_get_identity (transport->auth, &auth_identity); if (!_dbus_credentials_match (&our_identity, &auth_identity)) { _dbus_verbose ("Client authorized as UID %d but our UID is %d, disconnecting\n", auth_identity.uid, our_identity.uid); _dbus_transport_disconnect (transport); return FALSE; } else { _dbus_verbose ("Client authorized as UID %d matching our UID %d\n", auth_identity.uid, our_identity.uid); } } return transport->authenticated; } } /** * Handles a watch by reading data, writing data, or disconnecting * the transport, as appropriate for the given condition. * * @param transport the transport. * @param watch the watch. * @param condition the current state of the watched file descriptor. */ void _dbus_transport_handle_watch (DBusTransport *transport, DBusWatch *watch, unsigned int condition) { _dbus_assert (transport->vtable->handle_watch != NULL); if (transport->disconnected) return; if (dbus_watch_get_fd (watch) < 0) { _dbus_warn ("Tried to handle an invalidated watch; this watch should have been removed\n"); return; } _dbus_watch_sanitize_condition (watch, &condition); _dbus_transport_ref (transport); _dbus_watch_ref (watch); (* transport->vtable->handle_watch) (transport, watch, condition); _dbus_watch_unref (watch); _dbus_transport_unref (transport); } /** * Sets the connection using this transport. Allows the transport * to add watches to the connection, queue incoming messages, * and pull outgoing messages. * * @param transport the transport. * @param connection the connection. */ void _dbus_transport_set_connection (DBusTransport *transport, DBusConnection *connection) { _dbus_assert (transport->vtable->connection_set != NULL); _dbus_assert (transport->connection == NULL); transport->connection = connection; _dbus_transport_ref (transport); (* transport->vtable->connection_set) (transport); _dbus_transport_unref (transport); } /** * Notifies the transport when the outgoing message queue goes from * empty to non-empty or vice versa. Typically causes the transport to * add or remove its DBUS_WATCH_WRITABLE watch. * * @param transport the transport. * @param queue_length the length of the outgoing message queue. * */ void _dbus_transport_messages_pending (DBusTransport *transport, int queue_length) { _dbus_assert (transport->vtable->messages_pending != NULL); if (transport->disconnected) return; transport->messages_need_sending = queue_length > 0; _dbus_transport_ref (transport); (* transport->vtable->messages_pending) (transport, queue_length); _dbus_transport_unref (transport); } /** * Performs a single poll()/select() on the transport's file * descriptors and then reads/writes data as appropriate, * queueing incoming messages and sending outgoing messages. * This is the backend for _dbus_connection_do_iteration(). * See _dbus_connection_do_iteration() for full details. * * @param transport the transport. * @param flags indicates whether to read or write, and whether to block. * @param timeout_milliseconds if blocking, timeout or -1 for no timeout. */ void _dbus_transport_do_iteration (DBusTransport *transport, unsigned int flags, int timeout_milliseconds) { _dbus_assert (transport->vtable->do_iteration != NULL); _dbus_verbose ("Transport iteration flags 0x%x timeout %d connected = %d\n", flags, timeout_milliseconds, !transport->disconnected); if ((flags & (DBUS_ITERATION_DO_WRITING | DBUS_ITERATION_DO_READING)) == 0) return; /* Nothing to do */ if (transport->disconnected) return; _dbus_transport_ref (transport); (* transport->vtable->do_iteration) (transport, flags, timeout_milliseconds); _dbus_transport_unref (transport); } /** * See dbus_connection_set_max_message_size(). * * @param transport the transport * @param size the max size of a single message */ void _dbus_transport_set_max_message_size (DBusTransport *transport, long size) { _dbus_message_loader_set_max_message_size (transport->loader, size); } /** * See dbus_connection_get_max_message_size(). * * @param transport the transport * @returns max message size */ long _dbus_transport_get_max_message_size (DBusTransport *transport) { return _dbus_message_loader_get_max_message_size (transport->loader); } /** * See dbus_connection_set_max_live_messages_size(). * * @param transport the transport * @param size the max size of all incoming messages */ void _dbus_transport_set_max_live_messages_size (DBusTransport *transport, long size) { transport->max_live_messages_size = size; _dbus_counter_set_notify (transport->live_messages_size, transport->max_live_messages_size, live_messages_size_notify, transport); } /** * See dbus_connection_get_max_live_messages_size(). * * @param transport the transport * @returns max bytes for all live messages */ long _dbus_transport_get_max_live_messages_size (DBusTransport *transport) { return transport->max_live_messages_size; } /** @} */