D-Bus  1.13.7
dbus-server-unix.c
1 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
2 /* dbus-server-unix.c Server implementation for Unix network protocols.
3  *
4  * Copyright (C) 2002, 2003, 2004 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-unix.h"
27 #include "dbus-server-socket.h"
28 #include "dbus-server-launchd.h"
29 #include "dbus-transport-unix.h"
30 #include "dbus-connection-internal.h"
31 #include "dbus-sysdeps-unix.h"
32 #include "dbus-string.h"
33 
53 DBusServerListenResult
55  DBusServer **server_p,
56  DBusError *error)
57 {
58  const char *method;
59 
60  *server_p = NULL;
61 
62  method = dbus_address_entry_get_method (entry);
63 
64  if (strcmp (method, "unix") == 0)
65  {
66  const char *path = dbus_address_entry_get_value (entry, "path");
67  const char *dir = dbus_address_entry_get_value (entry, "dir");
68  const char *tmpdir = dbus_address_entry_get_value (entry, "tmpdir");
69  const char *abstract = dbus_address_entry_get_value (entry, "abstract");
70  const char *runtime = dbus_address_entry_get_value (entry, "runtime");
71  int mutually_exclusive_modes = 0;
72 
73  mutually_exclusive_modes = (path != NULL) + (tmpdir != NULL) +
74  (abstract != NULL) + (runtime != NULL) + (dir != NULL);
75 
76  if (mutually_exclusive_modes < 1)
77  {
78  _dbus_set_bad_address(error, "unix",
79  "path or tmpdir or abstract or runtime or dir",
80  NULL);
81  return DBUS_SERVER_LISTEN_BAD_ADDRESS;
82  }
83 
84  if (mutually_exclusive_modes > 1)
85  {
87  "cannot specify two of \"path\", \"tmpdir\", \"abstract\", \"runtime\" and \"dir\" at the same time");
88  return DBUS_SERVER_LISTEN_BAD_ADDRESS;
89  }
90 
91  if (runtime != NULL)
92  {
93  DBusString full_path;
94  DBusString filename;
95  const char *runtimedir;
96 
97  if (strcmp (runtime, "yes") != 0)
98  {
100  "if given, the only value allowed for \"runtime\" is \"yes\"");
101  return DBUS_SERVER_LISTEN_BAD_ADDRESS;
102  }
103 
104  runtimedir = _dbus_getenv ("XDG_RUNTIME_DIR");
105 
106  if (runtimedir == NULL)
107  {
108  dbus_set_error (error,
109  DBUS_ERROR_NOT_SUPPORTED, "\"XDG_RUNTIME_DIR\" is not set");
110  return DBUS_SERVER_LISTEN_DID_NOT_CONNECT;
111  }
112 
113  _dbus_string_init_const (&filename, "bus");
114 
115  if (!_dbus_string_init (&full_path))
116  {
117  _DBUS_SET_OOM (error);
118  return DBUS_SERVER_LISTEN_DID_NOT_CONNECT;
119  }
120 
121  if (!_dbus_string_append (&full_path, runtimedir) ||
122  !_dbus_concat_dir_and_file (&full_path, &filename))
123  {
124  _dbus_string_free (&full_path);
125  _DBUS_SET_OOM (error);
126  return DBUS_SERVER_LISTEN_DID_NOT_CONNECT;
127  }
128 
129  /* We can safely use filesystem sockets in the runtime directory,
130  * and they are preferred because they can be bind-mounted between
131  * Linux containers. */
133  _dbus_string_get_const_data (&full_path),
134  FALSE, error);
135 
136  _dbus_string_free (&full_path);
137  }
138  else if (tmpdir != NULL || dir != NULL)
139  {
140  DBusString full_path;
141  DBusString filename;
142  dbus_bool_t use_abstract = FALSE;
143 
144  if (tmpdir != NULL)
145  {
146  dir = tmpdir;
147 
148 #ifdef __linux__
149  /* Use abstract sockets for tmpdir if supported, so that it
150  * never needs to be cleaned up. Use dir instead if you want a
151  * path-based socket. */
152  use_abstract = TRUE;
153 #endif
154  }
155 
156  if (!_dbus_string_init (&full_path))
157  {
159  return DBUS_SERVER_LISTEN_DID_NOT_CONNECT;
160  }
161 
162  if (!_dbus_string_init (&filename))
163  {
164  _dbus_string_free (&full_path);
166  return DBUS_SERVER_LISTEN_DID_NOT_CONNECT;
167  }
168 
169  if (!_dbus_string_append (&filename, "dbus-"))
170  {
171  _dbus_string_free (&full_path);
172  _dbus_string_free (&filename);
174  return DBUS_SERVER_LISTEN_DID_NOT_CONNECT;
175  }
176 
177  if (!_dbus_generate_random_ascii (&filename, 10, error))
178  {
179  _dbus_string_free (&full_path);
180  _dbus_string_free (&filename);
181  return DBUS_SERVER_LISTEN_DID_NOT_CONNECT;
182  }
183 
184  if (!_dbus_string_append (&full_path, dir) ||
185  !_dbus_concat_dir_and_file (&full_path, &filename))
186  {
187  _dbus_string_free (&full_path);
188  _dbus_string_free (&filename);
190  return DBUS_SERVER_LISTEN_DID_NOT_CONNECT;
191  }
192 
193  *server_p =
194  _dbus_server_new_for_domain_socket (_dbus_string_get_const_data (&full_path),
195  use_abstract,
196  error);
197 
198  _dbus_string_free (&full_path);
199  _dbus_string_free (&filename);
200  }
201  else
202  {
203  if (path)
204  *server_p = _dbus_server_new_for_domain_socket (path, FALSE, error);
205  else
206  *server_p = _dbus_server_new_for_domain_socket (abstract, TRUE, error);
207  }
208 
209  if (*server_p != NULL)
210  {
211  _DBUS_ASSERT_ERROR_IS_CLEAR(error);
212  return DBUS_SERVER_LISTEN_OK;
213  }
214  else
215  {
216  _DBUS_ASSERT_ERROR_IS_SET(error);
217  return DBUS_SERVER_LISTEN_DID_NOT_CONNECT;
218  }
219  }
220  else if (strcmp (method, "systemd") == 0)
221  {
222  int i, n;
223  DBusSocket *fds;
224  DBusString address;
225 
226  n = _dbus_listen_systemd_sockets (&fds, error);
227  if (n < 0)
228  {
229  _DBUS_ASSERT_ERROR_IS_SET (error);
230  return DBUS_SERVER_LISTEN_DID_NOT_CONNECT;
231  }
232 
233  if (!_dbus_string_init (&address))
234  goto systemd_oom;
235 
236  for (i = 0; i < n; i++)
237  {
238  if (i > 0)
239  {
240  if (!_dbus_string_append (&address, ";"))
241  goto systemd_oom;
242  }
243  if (!_dbus_append_address_from_socket (fds[i], &address, error))
244  goto systemd_err;
245  }
246 
247  *server_p = _dbus_server_new_for_socket (fds, n, &address, NULL, error);
248  if (*server_p == NULL)
249  goto systemd_err;
250 
251  dbus_free (fds);
252  _dbus_string_free (&address);
253 
254  return DBUS_SERVER_LISTEN_OK;
255 
256  systemd_oom:
257  _DBUS_SET_OOM (error);
258  systemd_err:
259  for (i = 0; i < n; i++)
260  {
261  _dbus_close_socket (fds[i], NULL);
262  }
263  dbus_free (fds);
264  _dbus_string_free (&address);
265 
266  return DBUS_SERVER_LISTEN_DID_NOT_CONNECT;
267  }
268 #ifdef DBUS_ENABLE_LAUNCHD
269  else if (strcmp (method, "launchd") == 0)
270  {
271  const char *launchd_env_var = dbus_address_entry_get_value (entry, "env");
272  if (launchd_env_var == NULL)
273  {
274  _dbus_set_bad_address (error, "launchd", "env", NULL);
275  return DBUS_SERVER_LISTEN_DID_NOT_CONNECT;
276  }
277  *server_p = _dbus_server_new_for_launchd (launchd_env_var, error);
278 
279  if (*server_p != NULL)
280  {
281  _DBUS_ASSERT_ERROR_IS_CLEAR(error);
282  return DBUS_SERVER_LISTEN_OK;
283  }
284  else
285  {
286  _DBUS_ASSERT_ERROR_IS_SET(error);
287  return DBUS_SERVER_LISTEN_DID_NOT_CONNECT;
288  }
289  }
290 #endif
291  else
292  {
293  /* If we don't handle the method, we return NULL with the
294  * error unset
295  */
296  _DBUS_ASSERT_ERROR_IS_CLEAR(error);
297  return DBUS_SERVER_LISTEN_NOT_HANDLED;
298  }
299 }
300 
309 DBusServer*
311  dbus_bool_t abstract,
312  DBusError *error)
313 {
314  DBusServer *server;
315  DBusSocket listen_fd;
316  DBusString address;
317  char *path_copy;
318  DBusString path_str;
319 
320  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
321 
322  if (!_dbus_string_init (&address))
323  {
325  return NULL;
326  }
327 
328  _dbus_string_init_const (&path_str, path);
329  if ((abstract &&
330  !_dbus_string_append (&address, "unix:abstract=")) ||
331  (!abstract &&
332  !_dbus_string_append (&address, "unix:path=")) ||
333  !_dbus_address_append_escaped (&address, &path_str))
334  {
336  goto failed_0;
337  }
338 
339  if (abstract)
340  {
341  path_copy = NULL;
342  }
343  else
344  {
345  path_copy = _dbus_strdup (path);
346  if (path_copy == NULL)
347  {
349  goto failed_0;
350  }
351  }
352 
353  listen_fd.fd = _dbus_listen_unix_socket (path, abstract, error);
354 
355  if (listen_fd.fd < 0)
356  {
357  _DBUS_ASSERT_ERROR_IS_SET (error);
358  goto failed_1;
359  }
360 
361  server = _dbus_server_new_for_socket (&listen_fd, 1, &address, 0, error);
362  if (server == NULL)
363  {
364  goto failed_2;
365  }
366 
367  if (path_copy != NULL)
368  _dbus_server_socket_own_filename(server, path_copy);
369 
370  _dbus_string_free (&address);
371 
372  return server;
373 
374  failed_2:
375  _dbus_close_socket (listen_fd, NULL);
376  failed_1:
377  dbus_free (path_copy);
378  failed_0:
379  _dbus_string_free (&address);
380 
381  return NULL;
382 }
383 
dbus_bool_t _dbus_string_append(DBusString *str, const char *buffer)
Appends a nul-terminated C-style string to a DBusString.
Definition: dbus-string.c:952
#define NULL
A null pointer, defined appropriately for C or C++.
void dbus_free(void *memory)
Frees a block of memory previously allocated by dbus_malloc() or dbus_malloc0().
Definition: dbus-memory.c:703
DBusServer * _dbus_server_new_for_launchd(const char *launchd_env_var, DBusError *error)
Creates a new server from launchd.
#define DBUS_ERROR_NOT_SUPPORTED
Requested operation isn&#39;t supported (like ENOSYS on UNIX).
Internals of DBusServer object.
dbus_bool_t _dbus_append_address_from_socket(DBusSocket fd, DBusString *address, DBusError *error)
Read the address from the socket and append it to the string.
const char * dbus_address_entry_get_method(DBusAddressEntry *entry)
Returns the method string of an address entry.
Definition: dbus-address.c:228
dbus_bool_t _dbus_concat_dir_and_file(DBusString *dir, const DBusString *next_component)
Appends the given filename to the given directory.
dbus_bool_t _dbus_string_init(DBusString *str)
Initializes a string.
Definition: dbus-string.c:175
DBusServerListenResult _dbus_server_listen_platform_specific(DBusAddressEntry *entry, DBusServer **server_p, DBusError *error)
Tries to interpret the address entry in a platform-specific way, creating a platform-specific server ...
dbus_bool_t _dbus_close_socket(DBusSocket fd, DBusError *error)
Closes a socket.
DBusServer * _dbus_server_new_for_socket(DBusSocket *fds, int n_fds, const DBusString *address, DBusNonceFile *noncefile, DBusError *error)
Creates a new server listening on the given file descriptor.
Socket interface.
Definition: dbus-sysdeps.h:178
const char * dbus_address_entry_get_value(DBusAddressEntry *entry, const char *key)
Returns a value from a key of an entry.
Definition: dbus-address.c:245
dbus_uint32_t dbus_bool_t
A boolean, valid values are TRUE and FALSE.
Definition: dbus-types.h:35
void _dbus_string_init_const(DBusString *str, const char *value)
Initializes a constant string.
Definition: dbus-string.c:190
dbus_bool_t _dbus_generate_random_ascii(DBusString *str, int n_bytes, DBusError *error)
Generates the given number of random bytes, where the bytes are chosen from the alphanumeric ASCII su...
Definition: dbus-sysdeps.c:559
void _dbus_server_socket_own_filename(DBusServer *server, char *filename)
This is a bad hack since it&#39;s really unix domain socket specific.
int _dbus_listen_systemd_sockets(DBusSocket **fds, DBusError *error)
Acquires one or more sockets passed in from systemd.
Internals of DBusAddressEntry.
Definition: dbus-address.c:44
void _dbus_set_bad_address(DBusError *error, const char *address_problem_type, const char *address_problem_field, const char *address_problem_other)
Sets DBUS_ERROR_BAD_ADDRESS.
Definition: dbus-address.c:66
Object representing an exception.
Definition: dbus-errors.h:48
dbus_bool_t _dbus_address_append_escaped(DBusString *escaped, const DBusString *unescaped)
Appends an escaped version of one string to another string, using the D-Bus address escaping mechanis...
Definition: dbus-address.c:105
void dbus_set_error(DBusError *error, const char *name, const char *format,...)
Assigns an error name and message to a DBusError.
Definition: dbus-errors.c:354
void _dbus_string_free(DBusString *str)
Frees a string created by _dbus_string_init(), and fills it with the same contents as #_DBUS_STRING_I...
Definition: dbus-string.c:264
#define TRUE
Expands to "1".
DBusServer * _dbus_server_new_for_domain_socket(const char *path, dbus_bool_t abstract, DBusError *error)
Creates a new server listening on the given Unix domain socket.
#define DBUS_ERROR_NO_MEMORY
There was not enough memory to complete an operation.
#define FALSE
Expands to "0".
char * _dbus_strdup(const char *str)
Duplicates a string.
const char * _dbus_getenv(const char *varname)
Wrapper for getenv().
Definition: dbus-sysdeps.c:195
int _dbus_listen_unix_socket(const char *path, dbus_bool_t abstract, DBusError *error)
Creates a socket and binds it to the given path, then listens on the socket.