1 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
2 /* dbus-server-socket.c Server implementation for sockets
3 *
4 * Copyright (C) 2002, 2003, 2004, 2006 Red Hat Inc.
5 *
6 * Licensed under the Academic Free License version 2.1
7 *
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.
12 *
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.
17 *
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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 *
22 */
23
24 #include <config.h>
25 #include "dbus-internals.h"
26 #include "dbus-server-socket.h"
27 #include "dbus-transport-socket.h"
28 #include "dbus-connection-internal.h"
29 #include "dbus-memory.h"
30 #include "dbus-nonce.h"
31 #include "dbus-string.h"
32
33 /**
34 * @defgroup DBusServerSocket DBusServer implementations for SOCKET
35 * @ingroup DBusInternals
36 * @brief Implementation details of DBusServer on SOCKET
37 *
38 * @{
39 */
40 /**
41 *
42 * Opaque object representing a Socket server implementation.
43 */
44 typedef struct DBusServerSocket DBusServerSocket;
45
46 /**
47 * Implementation details of DBusServerSocket. All members
48 * are private.
49 */
50 struct DBusServerSocket
51 {
52 DBusServer base; /**< Parent class members. */
53 int n_fds; /**< Number of active file handles */
54 int *fds; /**< File descriptor or -1 if disconnected. */
55 DBusWatch **watch; /**< File descriptor watch. */
56 char *socket_name; /**< Name of domain socket, to unlink if appropriate */
57 DBusNonceFile *noncefile; /**< Nonce file used to authenticate clients */
58 };
59
60 static void
socket_finalize(DBusServer * server)61 socket_finalize (DBusServer *server)
62 {
63 DBusServerSocket *socket_server = (DBusServerSocket*) server;
64 int i;
65
66 _dbus_server_finalize_base (server);
67
68 for (i = 0 ; i < socket_server->n_fds ; i++)
69 if (socket_server->watch[i])
70 {
71 _dbus_watch_unref (socket_server->watch[i]);
72 socket_server->watch[i] = NULL;
73 }
74
75 dbus_free (socket_server->fds);
76 dbus_free (socket_server->watch);
77 dbus_free (socket_server->socket_name);
78 if (socket_server->noncefile)
79 _dbus_noncefile_delete (socket_server->noncefile, NULL);
80 dbus_free (socket_server->noncefile);
81 dbus_free (server);
82 }
83
84 /* Return value is just for memory, not other failures. */
85 static dbus_bool_t
handle_new_client_fd_and_unlock(DBusServer * server,int client_fd)86 handle_new_client_fd_and_unlock (DBusServer *server,
87 int client_fd)
88 {
89 DBusConnection *connection;
90 DBusTransport *transport;
91 DBusNewConnectionFunction new_connection_function;
92 DBusServerSocket* socket_server;
93 void *new_connection_data;
94
95 socket_server = (DBusServerSocket*)server;
96 _dbus_verbose ("Creating new client connection with fd %d\n", client_fd);
97
98 HAVE_LOCK_CHECK (server);
99
100 if (!_dbus_set_fd_nonblocking (client_fd, NULL))
101 {
102 SERVER_UNLOCK (server);
103 return TRUE;
104 }
105
106 transport = _dbus_transport_new_for_socket (client_fd, &server->guid_hex, FALSE);
107 if (transport == NULL)
108 {
109 _dbus_close_socket (client_fd, NULL);
110 SERVER_UNLOCK (server);
111 return FALSE;
112 }
113
114 if (!_dbus_transport_set_auth_mechanisms (transport,
115 (const char **) server->auth_mechanisms))
116 {
117 _dbus_transport_unref (transport);
118 SERVER_UNLOCK (server);
119 return FALSE;
120 }
121
122 /* note that client_fd is now owned by the transport, and will be
123 * closed on transport disconnection/finalization
124 */
125
126 connection = _dbus_connection_new_for_transport (transport);
127 _dbus_transport_unref (transport);
128 transport = NULL; /* now under the connection lock */
129
130 if (connection == NULL)
131 {
132 SERVER_UNLOCK (server);
133 return FALSE;
134 }
135
136 /* See if someone wants to handle this new connection, self-referencing
137 * for paranoia.
138 */
139 new_connection_function = server->new_connection_function;
140 new_connection_data = server->new_connection_data;
141
142 _dbus_server_ref_unlocked (server);
143 SERVER_UNLOCK (server);
144
145 if (new_connection_function)
146 {
147 (* new_connection_function) (server, connection,
148 new_connection_data);
149 }
150 dbus_server_unref (server);
151
152 /* If no one grabbed a reference, the connection will die. */
153 _dbus_connection_close_if_only_one_ref (connection);
154 dbus_connection_unref (connection);
155
156 return TRUE;
157 }
158
159 static dbus_bool_t
socket_handle_watch(DBusWatch * watch,unsigned int flags,void * data)160 socket_handle_watch (DBusWatch *watch,
161 unsigned int flags,
162 void *data)
163 {
164 DBusServer *server = data;
165 DBusServerSocket *socket_server = data;
166
167 #ifndef DBUS_DISABLE_ASSERT
168 int i;
169 dbus_bool_t found = FALSE;
170 #endif
171
172 SERVER_LOCK (server);
173
174 #ifndef DBUS_DISABLE_ASSERT
175 for (i = 0 ; i < socket_server->n_fds ; i++)
176 {
177 if (socket_server->watch[i] == watch)
178 found = TRUE;
179 }
180 _dbus_assert (found);
181 #endif
182
183 _dbus_verbose ("Handling client connection, flags 0x%x\n", flags);
184
185 if (flags & DBUS_WATCH_READABLE)
186 {
187 int client_fd;
188 int listen_fd;
189
190 listen_fd = dbus_watch_get_socket (watch);
191
192 if (socket_server->noncefile)
193 client_fd = _dbus_accept_with_noncefile (listen_fd, socket_server->noncefile);
194 else
195 client_fd = _dbus_accept (listen_fd);
196
197 if (client_fd < 0)
198 {
199 /* EINTR handled for us */
200
201 if (_dbus_get_is_errno_eagain_or_ewouldblock ())
202 _dbus_verbose ("No client available to accept after all\n");
203 else
204 _dbus_verbose ("Failed to accept a client connection: %s\n",
205 _dbus_strerror_from_errno ());
206
207 SERVER_UNLOCK (server);
208 }
209 else
210 {
211 if (!handle_new_client_fd_and_unlock (server, client_fd))
212 _dbus_verbose ("Rejected client connection due to lack of memory\n");
213 }
214 }
215
216 if (flags & DBUS_WATCH_ERROR)
217 _dbus_verbose ("Error on server listening socket\n");
218
219 if (flags & DBUS_WATCH_HANGUP)
220 _dbus_verbose ("Hangup on server listening socket\n");
221
222 return TRUE;
223 }
224
225 static void
socket_disconnect(DBusServer * server)226 socket_disconnect (DBusServer *server)
227 {
228 DBusServerSocket *socket_server = (DBusServerSocket*) server;
229 int i;
230
231 HAVE_LOCK_CHECK (server);
232
233 for (i = 0 ; i < socket_server->n_fds ; i++)
234 {
235 if (socket_server->watch[i])
236 {
237 _dbus_server_remove_watch (server,
238 socket_server->watch[i]);
239 _dbus_watch_unref (socket_server->watch[i]);
240 socket_server->watch[i] = NULL;
241 }
242
243 _dbus_close_socket (socket_server->fds[i], NULL);
244 socket_server->fds[i] = -1;
245 }
246
247 if (socket_server->socket_name != NULL)
248 {
249 DBusString tmp;
250 _dbus_string_init_const (&tmp, socket_server->socket_name);
251 _dbus_delete_file (&tmp, NULL);
252 }
253
254 HAVE_LOCK_CHECK (server);
255 }
256
257 static const DBusServerVTable socket_vtable = {
258 socket_finalize,
259 socket_disconnect
260 };
261
262 /**
263 * Creates a new server listening on the given file descriptor. The
264 * file descriptor should be nonblocking (use
265 * _dbus_set_fd_nonblocking() to make it so). The file descriptor
266 * should be listening for connections, that is, listen() should have
267 * been successfully invoked on it. The server will use accept() to
268 * accept new client connections.
269 *
270 * @param fds list of file descriptors.
271 * @param n_fds number of file descriptors
272 * @param address the server's address
273 * @param use_nonce whether to create and use a nonce for authentication
274 * @returns the new server, or #NULL if no memory.
275 *
276 */
277 DBusServer*
_dbus_server_new_for_socket(int * fds,int n_fds,const DBusString * address,DBusNonceFile * noncefile)278 _dbus_server_new_for_socket (int *fds,
279 int n_fds,
280 const DBusString *address,
281 DBusNonceFile *noncefile)
282 {
283 DBusServerSocket *socket_server;
284 DBusServer *server;
285 int i;
286
287 socket_server = dbus_new0 (DBusServerSocket, 1);
288 if (socket_server == NULL)
289 return NULL;
290
291 socket_server->noncefile = noncefile;
292
293 socket_server->fds = dbus_new (int, n_fds);
294 if (!socket_server->fds)
295 goto failed_0;
296
297 socket_server->watch = dbus_new0 (DBusWatch *, n_fds);
298 if (!socket_server->watch)
299 goto failed_1;
300
301 for (i = 0 ; i < n_fds ; i++)
302 {
303 DBusWatch *watch;
304
305 watch = _dbus_watch_new (fds[i],
306 DBUS_WATCH_READABLE,
307 TRUE,
308 socket_handle_watch, socket_server,
309 NULL);
310 if (watch == NULL)
311 goto failed_2;
312
313 socket_server->n_fds++;
314 socket_server->fds[i] = fds[i];
315 socket_server->watch[i] = watch;
316 }
317
318 if (!_dbus_server_init_base (&socket_server->base,
319 &socket_vtable, address))
320 goto failed_2;
321
322 server = (DBusServer*)socket_server;
323
324 SERVER_LOCK (server);
325
326 for (i = 0 ; i < n_fds ; i++)
327 {
328 if (!_dbus_server_add_watch (&socket_server->base,
329 socket_server->watch[i]))
330 {
331 int j;
332 for (j = 0 ; j < i ; j++)
333 _dbus_server_remove_watch (server,
334 socket_server->watch[j]);
335
336 SERVER_UNLOCK (server);
337 _dbus_server_finalize_base (&socket_server->base);
338 goto failed_2;
339 }
340 }
341
342 SERVER_UNLOCK (server);
343
344 return (DBusServer*) socket_server;
345
346 failed_3:
347 if (socket_server->noncefile)
348 {
349 _dbus_noncefile_delete (socket_server->noncefile, NULL);
350 dbus_free (socket_server->noncefile );
351 }
352 failed_2:
353 for (i = 0 ; i < n_fds ; i++)
354 {
355 if (socket_server->watch[i] != NULL)
356 {
357 _dbus_watch_unref (socket_server->watch[i]);
358 socket_server->watch[i] = NULL;
359 }
360 }
361 dbus_free (socket_server->watch);
362
363 failed_1:
364 dbus_free (socket_server->fds);
365
366 failed_0:
367 dbus_free (socket_server);
368 return NULL;
369 }
370
371 /**
372 * Creates a new server listening on TCP.
373 * If host is NULL, it will default to localhost.
374 * If bind is NULL, it will default to the value for the host
375 * parameter, and if that is NULL, then localhost
376 * If bind is a hostname, it will be resolved and will listen
377 * on all returned addresses.
378 * If family is NULL, hostname resolution will try all address
379 * families, otherwise it can be ipv4 or ipv6 to restrict the
380 * addresses considered.
381 *
382 * @param host the hostname to report for the listen address
383 * @param bind the hostname to listen on
384 * @param port the port to listen on or 0 to let the OS choose
385 * @param family
386 * @param error location to store reason for failure.
387 * @param use_nonce whether to use a nonce for low-level authentication (nonce-tcp transport) or not (tcp transport)
388 * @returns the new server, or #NULL on failure.
389 */
390 DBusServer*
_dbus_server_new_for_tcp_socket(const char * host,const char * bind,const char * port,const char * family,DBusError * error,dbus_bool_t use_nonce)391 _dbus_server_new_for_tcp_socket (const char *host,
392 const char *bind,
393 const char *port,
394 const char *family,
395 DBusError *error,
396 dbus_bool_t use_nonce)
397 {
398 DBusServer *server;
399 int *listen_fds = NULL;
400 int nlisten_fds = 0, i;
401 DBusString address;
402 DBusString host_str;
403 DBusString port_str;
404 DBusNonceFile *noncefile;
405
406 _DBUS_ASSERT_ERROR_IS_CLEAR (error);
407
408 noncefile = NULL;
409
410 if (!_dbus_string_init (&address))
411 {
412 dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
413 return NULL;
414 }
415
416 if (!_dbus_string_init (&port_str))
417 {
418 dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
419 goto failed_0;
420 }
421
422 if (host == NULL)
423 host = "localhost";
424
425 if (port == NULL)
426 port = "0";
427
428 if (bind == NULL)
429 bind = host;
430 else if (strcmp (bind, "*") == 0)
431 bind = NULL;
432
433 nlisten_fds =_dbus_listen_tcp_socket (bind, port, family,
434 &port_str,
435 &listen_fds, error);
436 if (nlisten_fds <= 0)
437 {
438 _DBUS_ASSERT_ERROR_IS_SET(error);
439 goto failed_1;
440 }
441
442 _dbus_string_init_const (&host_str, host);
443 if (!_dbus_string_append (&address, use_nonce ? "nonce-tcp:host=" : "tcp:host=") ||
444 !_dbus_address_append_escaped (&address, &host_str) ||
445 !_dbus_string_append (&address, ",port=") ||
446 !_dbus_string_append (&address, _dbus_string_get_const_data(&port_str)))
447 {
448 dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
449 goto failed_2;
450 }
451 if (family &&
452 (!_dbus_string_append (&address, ",family=") ||
453 !_dbus_string_append (&address, family)))
454 {
455 dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
456 goto failed_2;
457 }
458
459 if (use_nonce)
460 {
461 noncefile = dbus_new0 (DBusNonceFile, 1);
462 if (noncefile == NULL)
463 {
464 goto failed_2;
465 }
466
467 if (!_dbus_noncefile_create (noncefile, NULL))
468 goto failed_2;
469
470 if (!_dbus_string_append (&address, ",noncefile=") ||
471 !_dbus_address_append_escaped (&address, _dbus_noncefile_get_path (noncefile)))
472 {
473 goto failed_2;
474 }
475
476 }
477
478 server = _dbus_server_new_for_socket (listen_fds, nlisten_fds, &address, noncefile);
479 if (server == NULL)
480 {
481 dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
482 goto failed_2;
483 }
484
485 _dbus_string_free (&port_str);
486 _dbus_string_free (&address);
487 dbus_free(listen_fds);
488
489 return server;
490
491 failed_2:
492 for (i = 0 ; i < nlisten_fds ; i++)
493 _dbus_close_socket (listen_fds[i], NULL);
494 dbus_free(listen_fds);
495
496 failed_1:
497 _dbus_string_free (&port_str);
498
499 failed_0:
500 _dbus_string_free (&address);
501
502 return NULL;
503 }
504
505 /**
506 * Tries to interpret the address entry for various socket-related
507 * addresses (well, currently only tcp and nonce-tcp).
508 *
509 * Sets error if the result is not OK.
510 *
511 * @param entry an address entry
512 * @param server_p a new DBusServer, or #NULL on failure.
513 * @param error location to store rationale for failure on bad address
514 * @returns the outcome
515 *
516 */
517 DBusServerListenResult
_dbus_server_listen_socket(DBusAddressEntry * entry,DBusServer ** server_p,DBusError * error)518 _dbus_server_listen_socket (DBusAddressEntry *entry,
519 DBusServer **server_p,
520 DBusError *error)
521 {
522 const char *method;
523
524 *server_p = NULL;
525
526 method = dbus_address_entry_get_method (entry);
527
528 if (strcmp (method, "tcp") == 0 || strcmp (method, "nonce-tcp") == 0)
529 {
530 const char *host;
531 const char *port;
532 const char *bind;
533 const char *family;
534
535 host = dbus_address_entry_get_value (entry, "host");
536 bind = dbus_address_entry_get_value (entry, "bind");
537 port = dbus_address_entry_get_value (entry, "port");
538 family = dbus_address_entry_get_value (entry, "family");
539
540 *server_p = _dbus_server_new_for_tcp_socket (host, bind, port,
541 family, error, strcmp (method, "nonce-tcp") == 0 ? TRUE : FALSE);
542
543 if (*server_p)
544 {
545 _DBUS_ASSERT_ERROR_IS_CLEAR(error);
546 return DBUS_SERVER_LISTEN_OK;
547 }
548 else
549 {
550 _DBUS_ASSERT_ERROR_IS_SET(error);
551 return DBUS_SERVER_LISTEN_DID_NOT_CONNECT;
552 }
553 }
554 else
555 {
556 _DBUS_ASSERT_ERROR_IS_CLEAR(error);
557 return DBUS_SERVER_LISTEN_NOT_HANDLED;
558 }
559 }
560
561 /**
562 * This is a bad hack since it's really unix domain socket
563 * specific. Also, the function weirdly adopts ownership
564 * of the passed-in string.
565 *
566 * @param server a socket server
567 * @param filename socket filename to report/delete
568 *
569 */
570 void
_dbus_server_socket_own_filename(DBusServer * server,char * filename)571 _dbus_server_socket_own_filename (DBusServer *server,
572 char *filename)
573 {
574 DBusServerSocket *socket_server = (DBusServerSocket*) server;
575
576 socket_server->socket_name = filename;
577 }
578
579
580 /** @} */
581
582