1/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
2/* dbus-userdb-util.c Would be in dbus-userdb.c, but not used in libdbus
3 *
4 * Copyright (C) 2003, 2004, 2005  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#include <config.h>
24#define DBUS_USERDB_INCLUDES_PRIVATE 1
25#include "dbus-userdb.h"
26#include "dbus-test.h"
27#include "dbus-internals.h"
28#include "dbus-protocol.h"
29#include <string.h>
30
31#if HAVE_SYSTEMD
32#include <systemd/sd-daemon.h>
33#include <systemd/sd-login.h>
34#endif
35
36/**
37 * @addtogroup DBusInternalsUtils
38 * @{
39 */
40
41/**
42 * Checks to see if the UID sent in is the console user
43 *
44 * @param uid UID of person to check
45 * @param error return location for errors
46 * @returns #TRUE if the UID is the same as the console user and there are no errors
47 */
48dbus_bool_t
49_dbus_is_console_user (dbus_uid_t uid,
50		       DBusError *error)
51{
52
53  DBusUserDatabase *db;
54  const DBusUserInfo *info;
55  dbus_bool_t result = FALSE;
56
57#ifdef HAVE_SYSTEMD
58  if (sd_booted () > 0)
59    {
60      int r;
61
62      /* Check whether this user is logged in on at least one physical
63         seat */
64      r = sd_uid_get_seats (uid, 0, NULL);
65      if (r < 0)
66        {
67          dbus_set_error (error, _dbus_error_from_errno (-r),
68                          "Failed to determine seats of user \"" DBUS_UID_FORMAT "\": %s",
69                          uid,
70                          _dbus_strerror (-r));
71          return FALSE;
72        }
73
74      return (r > 0);
75    }
76#endif
77
78#ifdef HAVE_CONSOLE_OWNER_FILE
79
80  DBusString f;
81  DBusStat st;
82
83  if (!_dbus_string_init (&f))
84    {
85      _DBUS_SET_OOM (error);
86      return FALSE;
87    }
88
89  if (!_dbus_string_append(&f, DBUS_CONSOLE_OWNER_FILE))
90    {
91      _dbus_string_free(&f);
92      _DBUS_SET_OOM (error);
93      return FALSE;
94    }
95
96  if (_dbus_stat(&f, &st, NULL) && (st.uid == uid))
97    {
98      _dbus_string_free(&f);
99      return TRUE;
100    }
101
102  _dbus_string_free(&f);
103
104#endif /* HAVE_CONSOLE_OWNER_FILE */
105
106  _dbus_user_database_lock_system ();
107
108  db = _dbus_user_database_get_system ();
109  if (db == NULL)
110    {
111      dbus_set_error (error, DBUS_ERROR_FAILED, "Could not get system database.");
112      _dbus_user_database_unlock_system ();
113      return FALSE;
114    }
115
116  /* TPTD: this should be cache-safe, we've locked the DB and
117    _dbus_user_at_console doesn't pass it on. */
118  info = _dbus_user_database_lookup (db, uid, NULL, error);
119
120  if (info == NULL)
121    {
122      _dbus_user_database_unlock_system ();
123       return FALSE;
124    }
125
126  result = _dbus_user_at_console (info->username, error);
127
128  _dbus_user_database_unlock_system ();
129
130  return result;
131}
132
133/**
134 * Gets user ID given username
135 *
136 * @param username the username
137 * @param uid return location for UID
138 * @returns #TRUE if username existed and we got the UID
139 */
140dbus_bool_t
141_dbus_get_user_id (const DBusString  *username,
142                   dbus_uid_t        *uid)
143{
144  return _dbus_get_user_id_and_primary_group (username, uid, NULL);
145}
146
147/**
148 * Gets group ID given groupname
149 *
150 * @param groupname the groupname
151 * @param gid return location for GID
152 * @returns #TRUE if group name existed and we got the GID
153 */
154dbus_bool_t
155_dbus_get_group_id (const DBusString  *groupname,
156                    dbus_gid_t        *gid)
157{
158  DBusUserDatabase *db;
159  const DBusGroupInfo *info;
160  _dbus_user_database_lock_system ();
161
162  db = _dbus_user_database_get_system ();
163  if (db == NULL)
164    {
165      _dbus_user_database_unlock_system ();
166      return FALSE;
167    }
168
169  if (!_dbus_user_database_get_groupname (db, groupname,
170                                          &info, NULL))
171    {
172      _dbus_user_database_unlock_system ();
173      return FALSE;
174    }
175
176  *gid = info->gid;
177
178  _dbus_user_database_unlock_system ();
179  return TRUE;
180}
181
182/**
183 * Gets user ID and primary group given username
184 *
185 * @param username the username
186 * @param uid_p return location for UID
187 * @param gid_p return location for GID
188 * @returns #TRUE if username existed and we got the UID and GID
189 */
190dbus_bool_t
191_dbus_get_user_id_and_primary_group (const DBusString  *username,
192                                     dbus_uid_t        *uid_p,
193                                     dbus_gid_t        *gid_p)
194{
195  DBusUserDatabase *db;
196  const DBusUserInfo *info;
197  _dbus_user_database_lock_system ();
198
199  db = _dbus_user_database_get_system ();
200  if (db == NULL)
201    {
202      _dbus_user_database_unlock_system ();
203      return FALSE;
204    }
205
206  if (!_dbus_user_database_get_username (db, username,
207                                         &info, NULL))
208    {
209      _dbus_user_database_unlock_system ();
210      return FALSE;
211    }
212
213  if (uid_p)
214    *uid_p = info->uid;
215  if (gid_p)
216    *gid_p = info->primary_gid;
217
218  _dbus_user_database_unlock_system ();
219  return TRUE;
220}
221
222/**
223 * Looks up a gid or group name in the user database.  Only one of
224 * name or GID can be provided. There are wrapper functions for this
225 * that are better to use, this one does no locking or anything on the
226 * database and otherwise sort of sucks.
227 *
228 * @param db the database
229 * @param gid the group ID or #DBUS_GID_UNSET
230 * @param groupname group name or #NULL
231 * @param error error to fill in
232 * @returns the entry in the database
233 */
234DBusGroupInfo*
235_dbus_user_database_lookup_group (DBusUserDatabase *db,
236                                  dbus_gid_t        gid,
237                                  const DBusString *groupname,
238                                  DBusError        *error)
239{
240  DBusGroupInfo *info;
241
242  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
243
244   /* See if the group is really a number */
245   if (gid == DBUS_UID_UNSET)
246    {
247      unsigned long n;
248
249      if (_dbus_is_a_number (groupname, &n))
250        gid = n;
251    }
252
253#ifdef DBUS_ENABLE_USERDB_CACHE
254  if (gid != DBUS_GID_UNSET)
255    info = _dbus_hash_table_lookup_uintptr (db->groups, gid);
256  else
257    info = _dbus_hash_table_lookup_string (db->groups_by_name,
258                                           _dbus_string_get_const_data (groupname));
259  if (info)
260    {
261      _dbus_verbose ("Using cache for GID "DBUS_GID_FORMAT" information\n",
262                     info->gid);
263      return info;
264    }
265  else
266#else
267  if (1)
268#endif
269    {
270      if (gid != DBUS_GID_UNSET)
271	_dbus_verbose ("No cache for GID "DBUS_GID_FORMAT"\n",
272		       gid);
273      else
274	_dbus_verbose ("No cache for groupname \"%s\"\n",
275		       _dbus_string_get_const_data (groupname));
276
277      info = dbus_new0 (DBusGroupInfo, 1);
278      if (info == NULL)
279        {
280          dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
281          return NULL;
282        }
283
284      if (gid != DBUS_GID_UNSET)
285        {
286          if (!_dbus_group_info_fill_gid (info, gid, error))
287            {
288              _DBUS_ASSERT_ERROR_IS_SET (error);
289              _dbus_group_info_free_allocated (info);
290              return NULL;
291            }
292        }
293      else
294        {
295          if (!_dbus_group_info_fill (info, groupname, error))
296            {
297              _DBUS_ASSERT_ERROR_IS_SET (error);
298              _dbus_group_info_free_allocated (info);
299              return NULL;
300            }
301        }
302
303      /* don't use these past here */
304      gid = DBUS_GID_UNSET;
305      groupname = NULL;
306
307      if (!_dbus_hash_table_insert_uintptr (db->groups, info->gid, info))
308        {
309          dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
310          _dbus_group_info_free_allocated (info);
311          return NULL;
312        }
313
314
315      if (!_dbus_hash_table_insert_string (db->groups_by_name,
316                                           info->groupname,
317                                           info))
318        {
319          _dbus_hash_table_remove_uintptr (db->groups, info->gid);
320          dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
321          return NULL;
322        }
323
324      return info;
325    }
326}
327
328
329/**
330 * Gets the user information for the given group name,
331 * returned group info should not be freed.
332 *
333 * @param db user database
334 * @param groupname the group name
335 * @param info return location for const ref to group info
336 * @param error error location
337 * @returns #FALSE if error is set
338 */
339dbus_bool_t
340_dbus_user_database_get_groupname (DBusUserDatabase     *db,
341                                   const DBusString     *groupname,
342                                   const DBusGroupInfo **info,
343                                   DBusError            *error)
344{
345  *info = _dbus_user_database_lookup_group (db, DBUS_GID_UNSET, groupname, error);
346  return *info != NULL;
347}
348
349/**
350 * Gets the user information for the given GID,
351 * returned group info should not be freed.
352 *
353 * @param db user database
354 * @param gid the group ID
355 * @param info return location for const ref to group info
356 * @param error error location
357 * @returns #FALSE if error is set
358 */
359dbus_bool_t
360_dbus_user_database_get_gid (DBusUserDatabase     *db,
361                             dbus_gid_t            gid,
362                             const DBusGroupInfo **info,
363                             DBusError            *error)
364{
365  *info = _dbus_user_database_lookup_group (db, gid, NULL, error);
366  return *info != NULL;
367}
368
369
370/**
371 * Gets all groups  corresponding to the given UID. Returns #FALSE
372 * if no memory, or user isn't known, but always initializes
373 * group_ids to a NULL array.
374 *
375 * @param uid the UID
376 * @param group_ids return location for array of group IDs
377 * @param n_group_ids return location for length of returned array
378 * @returns #TRUE if the UID existed and we got some credentials
379 */
380dbus_bool_t
381_dbus_groups_from_uid (dbus_uid_t         uid,
382                       dbus_gid_t       **group_ids,
383                       int               *n_group_ids)
384{
385  DBusUserDatabase *db;
386  const DBusUserInfo *info;
387  *group_ids = NULL;
388  *n_group_ids = 0;
389
390  _dbus_user_database_lock_system ();
391
392  db = _dbus_user_database_get_system ();
393  if (db == NULL)
394    {
395      _dbus_user_database_unlock_system ();
396      return FALSE;
397    }
398
399  if (!_dbus_user_database_get_uid (db, uid,
400                                    &info, NULL))
401    {
402      _dbus_user_database_unlock_system ();
403      return FALSE;
404    }
405
406  _dbus_assert (info->uid == uid);
407
408  if (info->n_group_ids > 0)
409    {
410      *group_ids = dbus_new (dbus_gid_t, info->n_group_ids);
411      if (*group_ids == NULL)
412        {
413	  _dbus_user_database_unlock_system ();
414          return FALSE;
415        }
416
417      *n_group_ids = info->n_group_ids;
418
419      memcpy (*group_ids, info->group_ids, info->n_group_ids * sizeof (dbus_gid_t));
420    }
421
422  _dbus_user_database_unlock_system ();
423  return TRUE;
424}
425/** @} */
426
427#ifdef DBUS_BUILD_TESTS
428#include <stdio.h>
429
430/**
431 * Unit test for dbus-userdb.c.
432 *
433 * @returns #TRUE on success.
434 */
435dbus_bool_t
436_dbus_userdb_test (const char *test_data_dir)
437{
438  const DBusString *username;
439  const DBusString *homedir;
440  dbus_uid_t uid;
441  unsigned long *group_ids;
442  int n_group_ids, i;
443  DBusError error;
444
445  if (!_dbus_username_from_current_process (&username))
446    _dbus_assert_not_reached ("didn't get username");
447
448  if (!_dbus_homedir_from_current_process (&homedir))
449    _dbus_assert_not_reached ("didn't get homedir");
450
451  if (!_dbus_get_user_id (username, &uid))
452    _dbus_assert_not_reached ("didn't get uid");
453
454  if (!_dbus_groups_from_uid (uid, &group_ids, &n_group_ids))
455    _dbus_assert_not_reached ("didn't get groups");
456
457  printf ("    Current user: %s homedir: %s gids:",
458          _dbus_string_get_const_data (username),
459          _dbus_string_get_const_data (homedir));
460
461  for (i=0; i<n_group_ids; i++)
462      printf(" %ld", group_ids[i]);
463
464  printf ("\n");
465
466  dbus_error_init (&error);
467  printf ("Is Console user: %i\n",
468          _dbus_is_console_user (uid, &error));
469  printf ("Invocation was OK: %s\n", error.message ? error.message : "yes");
470  dbus_error_free (&error);
471  printf ("Is Console user 4711: %i\n",
472          _dbus_is_console_user (4711, &error));
473  printf ("Invocation was OK: %s\n", error.message ? error.message : "yes");
474  dbus_error_free (&error);
475
476  dbus_free (group_ids);
477
478  return TRUE;
479}
480#endif /* DBUS_BUILD_TESTS */
481