1 /* -*- mode: C; c-file-style: "gnu" -*- */
2 /* dbus-transport.c DBusTransport object (internal to D-BUS implementation)
4 * Copyright (C) 2002 Red Hat Inc.
6 * Licensed under the Academic Free License version 1.2
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24 #include "dbus-transport-protected.h"
25 #include "dbus-transport-unix.h"
26 #include "dbus-connection-internal.h"
27 #include "dbus-watch.h"
28 #include "dbus-auth.h"
31 * @defgroup DBusTransport DBusTransport object
32 * @ingroup DBusInternals
33 * @brief "Backend" for a DBusConnection.
35 * Types and functions related to DBusTransport. A transport is an
36 * abstraction that can send and receive data via various kinds of
37 * network connections or other IPC mechanisms.
43 * @typedef DBusTransport
45 * Opaque object representing a way message stream.
46 * DBusTransport abstracts various kinds of actual
47 * transport mechanism, such as different network protocols,
48 * or encryption schemes.
52 * Refs a transport and associated connection for reentrancy.
54 * @todo this macro reflects a design mistake, which is that the
55 * transport has a pointer to its connection. Ownership should move in
56 * only one direction; the connection should push/pull from the
57 * transport, rather than vice versa. Then the connection would take
58 * care of referencing itself when needed.
60 #define DBUS_TRANSPORT_HOLD_REF(t) \
61 _dbus_transport_ref (t); if ((t)->connection) dbus_connection_ref ((t)->connection)
64 * Inverse of DBUS_TRANSPORT_HOLD_REF().
66 #define DBUS_TRANSPORT_RELEASE_REF(t) \
67 if ((t)->connection) dbus_connection_unref ((t)->connection); _dbus_transport_unref (t)
71 * Initializes the base class members of DBusTransport.
72 * Chained up to by subclasses in their constructor.
74 * @param transport the transport being created.
75 * @param vtable the subclass vtable.
76 * @param server #TRUE if this transport is on the server side of a connection
77 * @returns #TRUE on success.
80 _dbus_transport_init_base (DBusTransport *transport,
81 const DBusTransportVTable *vtable,
84 DBusMessageLoader *loader;
87 loader = _dbus_message_loader_new ();
92 auth = _dbus_auth_server_new ();
94 auth = _dbus_auth_client_new ();
97 _dbus_message_loader_unref (loader);
101 transport->refcount = 1;
102 transport->vtable = vtable;
103 transport->loader = loader;
104 transport->auth = auth;
105 transport->authenticated = FALSE;
106 transport->messages_need_sending = FALSE;
107 transport->disconnected = FALSE;
108 transport->send_credentials_pending = !server;
109 transport->receive_credentials_pending = server;
110 transport->is_server = server;
112 transport->credentials.pid = -1;
113 transport->credentials.uid = -1;
114 transport->credentials.gid = -1;
120 * Finalizes base class members of DBusTransport.
121 * Chained up to from subclass finalizers.
123 * @param transport the transport.
126 _dbus_transport_finalize_base (DBusTransport *transport)
128 if (!transport->disconnected)
129 _dbus_transport_disconnect (transport);
131 _dbus_message_loader_unref (transport->loader);
132 _dbus_auth_unref (transport->auth);
136 * Opens a new transport for the given address. (This opens a
137 * client-side-of-the-connection transport.)
139 * @todo right now the address is just a Unix domain socket path.
141 * @param address the address.
142 * @param result location to store reason for failure.
143 * @returns new transport of #NULL on failure.
146 _dbus_transport_open (const char *address,
147 DBusResultCode *result)
149 DBusTransport *transport;
151 /* FIXME parse the address - whatever format
152 * we decide addresses are in - and find the
153 * appropriate transport.
156 /* Pretend it's just a unix domain socket name for now */
157 transport = _dbus_transport_new_for_domain_socket (address,
165 * Increments the reference count for the transport.
167 * @param transport the transport.
170 _dbus_transport_ref (DBusTransport *transport)
172 transport->refcount += 1;
176 * Decrements the reference count for the transport.
177 * Disconnects and finalizes the transport if
178 * the reference count reaches zero.
180 * @param transport the transport.
183 _dbus_transport_unref (DBusTransport *transport)
185 _dbus_assert (transport != NULL);
186 _dbus_assert (transport->refcount > 0);
188 transport->refcount -= 1;
189 if (transport->refcount == 0)
191 _dbus_assert (transport->vtable->finalize != NULL);
193 (* transport->vtable->finalize) (transport);
198 * Closes our end of the connection to a remote application. Further
199 * attempts to use this transport will fail. Only the first call to
200 * _dbus_transport_disconnect() will have an effect.
202 * @param transport the transport.
206 _dbus_transport_disconnect (DBusTransport *transport)
208 _dbus_assert (transport->vtable->disconnect != NULL);
210 if (transport->disconnected)
213 DBUS_TRANSPORT_HOLD_REF (transport);
214 (* transport->vtable->disconnect) (transport);
216 transport->disconnected = TRUE;
218 _dbus_connection_transport_error (transport->connection,
219 DBUS_RESULT_DISCONNECTED);
221 DBUS_TRANSPORT_RELEASE_REF (transport);
225 * Returns #TRUE if the transport has not been disconnected.
226 * Disconnection can result from _dbus_transport_disconnect()
227 * or because the server drops its end of the connection.
229 * @param transport the transport.
230 * @returns whether we're connected
233 _dbus_transport_get_is_connected (DBusTransport *transport)
235 return !transport->disconnected;
239 * Returns #TRUE if we have been authenticated. Will return #TRUE
240 * even if the transport is disconnected.
242 * @param transport the transport
243 * @returns whether we're authenticated
246 _dbus_transport_get_is_authenticated (DBusTransport *transport)
248 if (transport->authenticated)
252 if (transport->disconnected)
255 transport->authenticated =
256 (!(transport->send_credentials_pending ||
257 transport->receive_credentials_pending)) &&
258 _dbus_auth_do_work (transport->auth) == DBUS_AUTH_STATE_AUTHENTICATED;
260 /* If we've authenticated as some identity, check that the auth
261 * identity is the same as our own identity. In the future, we
262 * may have API allowing applications to specify how this is
263 * done, for example they may allow connection as any identity,
264 * but then impose restrictions on certain identities.
265 * Or they may give certain identities extra privileges.
268 if (transport->authenticated && transport->is_server)
270 DBusCredentials auth_identity;
271 DBusCredentials our_identity;
273 _dbus_credentials_from_current_process (&our_identity);
274 _dbus_auth_get_identity (transport->auth, &auth_identity);
276 if (!_dbus_credentials_match (&our_identity,
279 _dbus_verbose ("Client authorized as UID %d but our UID is %d, disconnecting\n",
280 auth_identity.uid, our_identity.uid);
281 _dbus_transport_disconnect (transport);
286 _dbus_verbose ("Client authorized as UID %d matching our UID %d\n",
287 auth_identity.uid, our_identity.uid);
291 return transport->authenticated;
296 * Handles a watch by reading data, writing data, or disconnecting
297 * the transport, as appropriate for the given condition.
299 * @param transport the transport.
300 * @param watch the watch.
301 * @param condition the current state of the watched file descriptor.
304 _dbus_transport_handle_watch (DBusTransport *transport,
306 unsigned int condition)
308 _dbus_assert (transport->vtable->handle_watch != NULL);
310 if (transport->disconnected)
312 _dbus_connection_transport_error (transport->connection,
313 DBUS_RESULT_DISCONNECTED);
317 if (dbus_watch_get_fd (watch) < 0)
319 _dbus_warn ("Tried to handle an invalidated watch; this watch should have been removed\n");
323 _dbus_watch_sanitize_condition (watch, &condition);
325 DBUS_TRANSPORT_HOLD_REF (transport);
326 _dbus_watch_ref (watch);
327 (* transport->vtable->handle_watch) (transport, watch, condition);
328 _dbus_watch_unref (watch);
329 DBUS_TRANSPORT_RELEASE_REF (transport);
333 * Sets the connection using this transport. Allows the transport
334 * to add watches to the connection, queue incoming messages,
335 * and pull outgoing messages.
337 * @param transport the transport.
338 * @param connection the connection.
341 _dbus_transport_set_connection (DBusTransport *transport,
342 DBusConnection *connection)
344 _dbus_assert (transport->vtable->connection_set != NULL);
345 _dbus_assert (transport->connection == NULL);
347 transport->connection = connection;
349 DBUS_TRANSPORT_HOLD_REF (transport);
350 (* transport->vtable->connection_set) (transport);
351 DBUS_TRANSPORT_RELEASE_REF (transport);
355 * Notifies the transport when the outgoing message queue goes from
356 * empty to non-empty or vice versa. Typically causes the transport to
357 * add or remove its DBUS_WATCH_WRITABLE watch.
359 * @param transport the transport.
360 * @param queue_length the length of the outgoing message queue.
364 _dbus_transport_messages_pending (DBusTransport *transport,
367 _dbus_assert (transport->vtable->messages_pending != NULL);
369 if (transport->disconnected)
371 _dbus_connection_transport_error (transport->connection,
372 DBUS_RESULT_DISCONNECTED);
376 transport->messages_need_sending = queue_length > 0;
378 DBUS_TRANSPORT_HOLD_REF (transport);
379 (* transport->vtable->messages_pending) (transport,
381 DBUS_TRANSPORT_RELEASE_REF (transport);
385 * Performs a single poll()/select() on the transport's file
386 * descriptors and then reads/writes data as appropriate,
387 * queueing incoming messages and sending outgoing messages.
388 * This is the backend for _dbus_connection_do_iteration().
389 * See _dbus_connection_do_iteration() for full details.
391 * @param transport the transport.
392 * @param flags indicates whether to read or write, and whether to block.
393 * @param timeout_milliseconds if blocking, timeout or -1 for no timeout.
396 _dbus_transport_do_iteration (DBusTransport *transport,
398 int timeout_milliseconds)
400 _dbus_assert (transport->vtable->do_iteration != NULL);
402 if ((flags & (DBUS_ITERATION_DO_WRITING |
403 DBUS_ITERATION_DO_READING)) == 0)
404 return; /* Nothing to do */
406 if (transport->disconnected)
408 _dbus_connection_transport_error (transport->connection,
409 DBUS_RESULT_DISCONNECTED);
413 DBUS_TRANSPORT_HOLD_REF (transport);
414 (* transport->vtable->do_iteration) (transport, flags,
415 timeout_milliseconds);
416 DBUS_TRANSPORT_RELEASE_REF (transport);