1 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
2 /* dbus-transport-unix.c UNIX socket subclasses of DBusTransport
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 
26 #include <stdio.h>
27 
28 #include "dbus-internals.h"
29 #include "dbus-connection-internal.h"
30 #include "dbus-transport-unix.h"
31 #include "dbus-transport-socket.h"
32 #include "dbus-transport-protected.h"
33 #include "dbus-watch.h"
34 #include "dbus-sysdeps-unix.h"
35 #include "dbus-test.h"
36 
37 /**
38  * @defgroup DBusTransportUnix DBusTransport implementations for UNIX
39  * @ingroup  DBusInternals
40  * @brief Implementation details of DBusTransport on UNIX
41  *
42  * @{
43  */
44 
45 /**
46  * Creates a new transport for the given Unix domain socket
47  * path. This creates a client-side of a transport.
48  *
49  * @todo once we add a way to escape paths in a dbus
50  * address, this function needs to do escaping.
51  *
52  * @param path the path to the domain socket.
53  * @param abstract #TRUE to use abstract socket namespace
54  * @param error address where an error can be returned.
55  * @returns a new transport, or #NULL on failure.
56  */
57 DBusTransport*
_dbus_transport_new_for_domain_socket(const char * path,dbus_bool_t abstract,DBusError * error)58 _dbus_transport_new_for_domain_socket (const char     *path,
59                                        dbus_bool_t     abstract,
60                                        DBusError      *error)
61 {
62   int fd;
63   DBusTransport *transport;
64   DBusString address;
65 
66   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
67 
68   if (!_dbus_string_init (&address))
69     {
70       dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
71       return NULL;
72     }
73 
74   fd = -1;
75 
76   if ((abstract &&
77        !_dbus_string_append (&address, "unix:abstract=")) ||
78       (!abstract &&
79        !_dbus_string_append (&address, "unix:path=")) ||
80       !_dbus_string_append (&address, path))
81     {
82       dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
83       goto failed_0;
84     }
85 
86   fd = _dbus_connect_unix_socket (path, abstract, error);
87   if (fd < 0)
88     {
89       _DBUS_ASSERT_ERROR_IS_SET (error);
90       goto failed_0;
91     }
92 
93   _dbus_verbose ("Successfully connected to unix socket %s\n",
94                  path);
95 
96   transport = _dbus_transport_new_for_socket (fd, NULL, &address);
97   if (transport == NULL)
98     {
99       dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
100       goto failed_1;
101     }
102 
103   _dbus_string_free (&address);
104 
105   return transport;
106 
107  failed_1:
108   _dbus_close_socket (fd, NULL);
109  failed_0:
110   _dbus_string_free (&address);
111   return NULL;
112 }
113 
114 /**
115  * Creates a new transport for the given binary and arguments. This
116  * creates a client-side of a transport. The process will be forked
117  * off and executed with stdin/stdout connected to a local AF_UNIX
118  * socket.
119  *
120  * @param path the path to the domain socket.
121  * @param argv Parameters list
122  * @param error address where an error can be returned.
123  * @returns a new transport, or #NULL on failure.
124  */
125 static DBusTransport*
_dbus_transport_new_for_exec(const char * path,char * const argv[],DBusError * error)126 _dbus_transport_new_for_exec (const char     *path,
127                               char *const     argv[],
128                               DBusError      *error)
129 {
130   int fd;
131   DBusTransport *transport;
132   DBusString address;
133   unsigned i;
134   char *escaped;
135 
136   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
137 
138   if (!_dbus_string_init (&address))
139     {
140       dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
141       return NULL;
142     }
143 
144   fd = -1;
145 
146   escaped = dbus_address_escape_value (path);
147   if (!escaped)
148     {
149       dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
150       goto failed;
151     }
152 
153   if (!_dbus_string_append (&address, "unixexec:path=") ||
154       !_dbus_string_append (&address, escaped))
155     {
156       dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
157       dbus_free (escaped);
158       goto failed;
159     }
160 
161   dbus_free (escaped);
162 
163   if (argv)
164     {
165       for (i = 0; argv[i]; i++)
166         {
167           dbus_bool_t success;
168 
169           escaped = dbus_address_escape_value (argv[i]);
170           if (!escaped)
171             {
172               dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
173               goto failed;
174             }
175 
176           success = _dbus_string_append_printf (&address, ",argv%u=%s", i, escaped);
177           dbus_free (escaped);
178 
179           if (!success)
180             {
181               dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
182               goto failed;
183             }
184         }
185     }
186 
187   fd = _dbus_connect_exec (path, argv, error);
188   if (fd < 0)
189     {
190       _DBUS_ASSERT_ERROR_IS_SET (error);
191       goto failed;
192     }
193 
194   _dbus_verbose ("Successfully connected to process %s\n",
195                  path);
196 
197   transport = _dbus_transport_new_for_socket (fd, NULL, &address);
198   if (transport == NULL)
199     {
200       dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
201       goto failed;
202     }
203 
204   _dbus_string_free (&address);
205 
206   return transport;
207 
208  failed:
209   if (fd >= 0)
210     _dbus_close_socket (fd, NULL);
211 
212   _dbus_string_free (&address);
213   return NULL;
214 }
215 
216 /**
217  * Opens platform specific transport types.
218  *
219  * @param entry the address entry to try opening
220  * @param transport_p return location for the opened transport
221  * @param error error to be set
222  * @returns result of the attempt
223  */
224 DBusTransportOpenResult
_dbus_transport_open_platform_specific(DBusAddressEntry * entry,DBusTransport ** transport_p,DBusError * error)225 _dbus_transport_open_platform_specific (DBusAddressEntry  *entry,
226                                         DBusTransport    **transport_p,
227                                         DBusError         *error)
228 {
229   const char *method;
230 
231   method = dbus_address_entry_get_method (entry);
232   _dbus_assert (method != NULL);
233 
234   if (strcmp (method, "unix") == 0)
235     {
236       const char *path = dbus_address_entry_get_value (entry, "path");
237       const char *tmpdir = dbus_address_entry_get_value (entry, "tmpdir");
238       const char *abstract = dbus_address_entry_get_value (entry, "abstract");
239 
240       if (tmpdir != NULL)
241         {
242           _dbus_set_bad_address (error, NULL, NULL,
243                                  "cannot use the \"tmpdir\" option for an address to connect to, only in an address to listen on");
244           return DBUS_TRANSPORT_OPEN_BAD_ADDRESS;
245         }
246 
247       if (path == NULL && abstract == NULL)
248         {
249           _dbus_set_bad_address (error, "unix",
250                                  "path or abstract",
251                                  NULL);
252           return DBUS_TRANSPORT_OPEN_BAD_ADDRESS;
253         }
254 
255       if (path != NULL && abstract != NULL)
256         {
257           _dbus_set_bad_address (error, NULL, NULL,
258                                  "can't specify both \"path\" and \"abstract\" options in an address");
259           return DBUS_TRANSPORT_OPEN_BAD_ADDRESS;
260         }
261 
262       if (path)
263         *transport_p = _dbus_transport_new_for_domain_socket (path, FALSE,
264                                                            error);
265       else
266         *transport_p = _dbus_transport_new_for_domain_socket (abstract, TRUE,
267                                                            error);
268       if (*transport_p == NULL)
269         {
270           _DBUS_ASSERT_ERROR_IS_SET (error);
271           return DBUS_TRANSPORT_OPEN_DID_NOT_CONNECT;
272         }
273       else
274         {
275           _DBUS_ASSERT_ERROR_IS_CLEAR (error);
276           return DBUS_TRANSPORT_OPEN_OK;
277         }
278     }
279   else if (strcmp (method, "unixexec") == 0)
280     {
281       const char *path;
282       unsigned i;
283       char **argv;
284 
285       path = dbus_address_entry_get_value (entry, "path");
286       if (path == NULL)
287         {
288           _dbus_set_bad_address (error, NULL, NULL,
289                                  "No process path specified");
290           return DBUS_TRANSPORT_OPEN_BAD_ADDRESS;
291         }
292 
293       /* First count argv arguments */
294       for (i = 1; ; i++)
295         {
296           char t[4+20+1]; /* "argv" plus space for a formatted base 10 64bit integer, plus NUL */
297 
298           snprintf (t, sizeof(t), "argv%u", i);
299 
300           if (!dbus_address_entry_get_value (entry, t))
301             break;
302         }
303 
304       /* Allocate string array */
305       argv = dbus_new0 (char*, i+1);
306       if (!argv)
307         {
308           dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
309           return DBUS_TRANSPORT_OPEN_DID_NOT_CONNECT;
310         }
311 
312       /* Fill in string array */
313       for (i = 0; ; i++)
314         {
315           char t[4+20+1];
316           const char *p;
317 
318           snprintf (t, sizeof(t), "argv%u", i);
319 
320           p = dbus_address_entry_get_value (entry, t);
321           if (!p)
322             {
323               if (i == 0)
324                 /* If argv0 isn't specified, fill in the path instead */
325                 p = path;
326               else
327                 break;
328             }
329 
330           argv[i] = _dbus_strdup (p);
331           if (!argv[i])
332             {
333               dbus_free_string_array (argv);
334               dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
335               return DBUS_TRANSPORT_OPEN_DID_NOT_CONNECT;
336             }
337         }
338 
339       *transport_p = _dbus_transport_new_for_exec (path, argv, error);
340       dbus_free_string_array (argv);
341 
342       if (*transport_p == NULL)
343         {
344           _DBUS_ASSERT_ERROR_IS_SET (error);
345           return DBUS_TRANSPORT_OPEN_DID_NOT_CONNECT;
346         }
347       else
348         {
349           _DBUS_ASSERT_ERROR_IS_CLEAR (error);
350           return DBUS_TRANSPORT_OPEN_OK;
351         }
352     }
353 #ifdef DBUS_ENABLE_LAUNCHD
354   else if (strcmp (method, "launchd") == 0)
355     {
356       DBusError tmp_error = DBUS_ERROR_INIT;
357       const char *launchd_env_var = dbus_address_entry_get_value (entry, "env");
358       const char *launchd_socket;
359       DBusString socket_path;
360       dbus_bool_t valid_socket;
361 
362       if (!_dbus_string_init (&socket_path))
363         {
364           _DBUS_SET_OOM (error);
365           return FALSE;
366         }
367 
368       if (launchd_env_var == NULL)
369         {
370           _dbus_set_bad_address (error, "launchd", "env", NULL);
371           return DBUS_TRANSPORT_OPEN_BAD_ADDRESS;
372         }
373 
374       valid_socket = _dbus_lookup_launchd_socket (&socket_path, launchd_env_var, error);
375 
376       if (dbus_error_is_set(error))
377         {
378           _dbus_string_free(&socket_path);
379           return DBUS_TRANSPORT_OPEN_DID_NOT_CONNECT;
380         }
381 
382       if (!valid_socket)
383         {
384           dbus_set_error(&tmp_error, DBUS_ERROR_BAD_ADDRESS,
385                          "launchd's env var %s does not exist", launchd_env_var);
386           dbus_error_free(error);
387           dbus_move_error(&tmp_error, error);
388           return DBUS_TRANSPORT_OPEN_DID_NOT_CONNECT;
389         }
390 
391       launchd_socket = _dbus_string_get_const_data(&socket_path);
392       *transport_p = _dbus_transport_new_for_domain_socket (launchd_socket, FALSE, error);
393 
394       if (*transport_p == NULL)
395         {
396           _DBUS_ASSERT_ERROR_IS_SET (error);
397           return DBUS_TRANSPORT_OPEN_DID_NOT_CONNECT;
398         }
399       else
400         {
401           _DBUS_ASSERT_ERROR_IS_CLEAR (error);
402           return DBUS_TRANSPORT_OPEN_OK;
403         }
404     }
405 #endif
406   else
407     {
408       _DBUS_ASSERT_ERROR_IS_CLEAR (error);
409       return DBUS_TRANSPORT_OPEN_NOT_HANDLED;
410     }
411 }
412 
413 /** @} */
414 
415 #ifdef DBUS_BUILD_TESTS
416 
417 dbus_bool_t
_dbus_transport_unix_test(void)418 _dbus_transport_unix_test (void)
419 {
420   DBusConnection *c;
421   DBusError error;
422   dbus_bool_t ret;
423   const char *address;
424 
425   dbus_error_init (&error);
426 
427   c = dbus_connection_open ("unixexec:argv0=false,argv1=foobar,path=/bin/false", &error);
428   _dbus_assert (c != NULL);
429   _dbus_assert (!dbus_error_is_set (&error));
430 
431   address = _dbus_connection_get_address (c);
432   _dbus_assert (address != NULL);
433 
434   /* Let's see if the address got parsed, reordered and formatted correctly */
435   ret = strcmp (address, "unixexec:path=/bin/false,argv0=false,argv1=foobar") == 0;
436 
437   dbus_connection_unref (c);
438 
439   return ret;
440 }
441 
442 #endif
443