1/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
2/* dbus-misc.c  A few assorted public functions that don't fit elsewhere
3 *
4 * Copyright (C) 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-misc.h"
26#include "dbus-internals.h"
27#include "dbus-string.h"
28
29/**
30 * @defgroup DBusMisc Miscellaneous
31 * @ingroup  DBus
32 * @brief Miscellaneous API that doesn't cleanly fit anywhere else
33 *
34 * @{
35 */
36
37/**
38 * Obtains the machine UUID of the machine this process is running on.
39 *
40 * The returned string must be freed with dbus_free().
41 *
42 * This UUID is guaranteed to remain the same until the next reboot
43 * (unless the sysadmin foolishly changes it and screws themselves).
44 * It will usually remain the same across reboots also, but hardware
45 * configuration changes or rebuilding the machine could break that.
46 *
47 * The idea is that two processes with the same machine ID should be
48 * able to use shared memory, UNIX domain sockets, process IDs, and other
49 * features of the OS that require both processes to be running
50 * on the same OS kernel instance.
51 *
52 * The machine ID can also be used to create unique per-machine
53 * instances. For example, you could use it in bus names or
54 * X selection names.
55 *
56 * The machine ID is preferred over the machine hostname, because
57 * the hostname is frequently set to "localhost.localdomain" and
58 * may also change at runtime.
59 *
60 * You can get the machine ID of a remote application by invoking the
61 * method GetMachineId from interface org.freedesktop.DBus.Peer.
62 *
63 * If the remote application has the same machine ID as the one
64 * returned by this function, then the remote application is on the
65 * same machine as your application.
66 *
67 * The UUID is not a UUID in the sense of RFC4122; the details
68 * are explained in the D-Bus specification.
69 *
70 * @returns a 32-byte-long hex-encoded UUID string, or #NULL if insufficient memory
71 */
72char*
73dbus_get_local_machine_id (void)
74{
75  DBusString uuid;
76  char *s;
77
78  s = NULL;
79
80  if (!_dbus_string_init (&uuid))
81    return NULL;
82
83  if (!_dbus_get_local_machine_uuid_encoded (&uuid) ||
84      !_dbus_string_steal_data (&uuid, &s))
85    {
86      _dbus_string_free (&uuid);
87      return NULL;
88    }
89  else
90    {
91      _dbus_string_free (&uuid);
92      return s;
93    }
94
95}
96
97/**
98 * @def DBUS_MAJOR_VERSION
99 *
100 * The COMPILE TIME major version of libdbus, that is, the "X" in "X.Y.Z",
101 * as an integer literal. Consider carefully whether to use this or the
102 * runtime version from dbus_get_version().
103 */
104
105/**
106 * @def DBUS_MINOR_VERSION
107 *
108 * The COMPILE TIME minor version of libdbus, that is, the "Y" in "X.Y.Z",
109 * as an integer literal. Consider carefully whether to use this or the
110 * runtime version from dbus_get_version().
111 */
112
113/**
114 * @def DBUS_MICRO_VERSION
115 *
116 * The COMPILE TIME micro version of libdbus, that is, the "Z" in "X.Y.Z",
117 * as an integer literal. Consider carefully whether to use this or the
118 * runtime version from dbus_get_version().
119 */
120
121/**
122 * @def DBUS_VERSION
123 *
124 * The COMPILE TIME version of libdbus, as a single integer that has 0 in the most
125 * significant byte, the major version in the next most significant byte,
126 * the minor version in the third most significant, and the micro version in the
127 * least significant byte. This means two DBUS_VERSION can be compared to see
128 * which is higher.
129 *
130 * Consider carefully whether to use this or the runtime version from
131 * dbus_get_version().
132 */
133
134/**
135 * @def DBUS_VERSION_STRING
136 *
137 * The COMPILE TIME version of libdbus, as a string "X.Y.Z".
138 *
139 * Consider carefully whether to use this or the runtime version from
140 * dbus_get_version().
141 */
142
143/**
144 * Gets the DYNAMICALLY LINKED version of libdbus. Alternatively, there
145 * are macros #DBUS_MAJOR_VERSION, #DBUS_MINOR_VERSION, #DBUS_MICRO_VERSION,
146 * and #DBUS_VERSION which allow you to test the VERSION YOU ARE COMPILED AGAINST.
147 * In other words, you can get either the runtime or the compile-time version.
148 * Think carefully about which of these you want in a given case.
149 *
150 * The libdbus full version number is "MAJOR.MINOR.MICRO" where the
151 * MINOR changes if API is added, and the MICRO changes with each
152 * release of a MAJOR.MINOR series.  The MINOR is an odd number for
153 * development releases and an even number for stable releases.
154 *
155 * @param major_version_p pointer to return the major version, or #NULL
156 * @param minor_version_p pointer to return the minor version, or #NULL
157 * @param micro_version_p pointer to return the micro version, or #NULL
158 *
159 */
160void
161dbus_get_version (int *major_version_p,
162                  int *minor_version_p,
163                  int *micro_version_p)
164{
165  if (major_version_p)
166    *major_version_p = DBUS_MAJOR_VERSION;
167  if (minor_version_p)
168    *minor_version_p = DBUS_MINOR_VERSION;
169  if (micro_version_p)
170    *micro_version_p = DBUS_MICRO_VERSION;
171}
172
173
174/** @} */ /* End of public API */
175
176#ifdef DBUS_BUILD_TESTS
177
178#ifndef DOXYGEN_SHOULD_SKIP_THIS
179
180#include "dbus-test.h"
181#include <stdlib.h>
182
183
184dbus_bool_t
185_dbus_misc_test (void)
186{
187  int major, minor, micro;
188  DBusString str;
189
190  /* make sure we don't crash on NULL */
191  dbus_get_version (NULL, NULL, NULL);
192
193  /* Now verify that all the compile-time version stuff
194   * is right and matches the runtime. These tests
195   * are mostly intended to catch various kinds of
196   * typo (mixing up major and minor, that sort of thing).
197   */
198  dbus_get_version (&major, &minor, &micro);
199
200  _dbus_assert (major == DBUS_MAJOR_VERSION);
201  _dbus_assert (minor == DBUS_MINOR_VERSION);
202  _dbus_assert (micro == DBUS_MICRO_VERSION);
203
204#define MAKE_VERSION(x, y, z) (((x) << 16) | ((y) << 8) | (z))
205
206  /* check that MAKE_VERSION works and produces the intended ordering */
207  _dbus_assert (MAKE_VERSION (1, 0, 0) > MAKE_VERSION (0, 0, 0));
208  _dbus_assert (MAKE_VERSION (1, 1, 0) > MAKE_VERSION (1, 0, 0));
209  _dbus_assert (MAKE_VERSION (1, 1, 1) > MAKE_VERSION (1, 1, 0));
210
211  _dbus_assert (MAKE_VERSION (2, 0, 0) > MAKE_VERSION (1, 1, 1));
212  _dbus_assert (MAKE_VERSION (2, 1, 0) > MAKE_VERSION (1, 1, 1));
213  _dbus_assert (MAKE_VERSION (2, 1, 1) > MAKE_VERSION (1, 1, 1));
214
215  /* check DBUS_VERSION */
216  _dbus_assert (MAKE_VERSION (major, minor, micro) == DBUS_VERSION);
217
218  /* check that ordering works with DBUS_VERSION */
219  _dbus_assert (MAKE_VERSION (major - 1, minor, micro) < DBUS_VERSION);
220  _dbus_assert (MAKE_VERSION (major, minor - 1, micro) < DBUS_VERSION);
221  _dbus_assert (MAKE_VERSION (major, minor, micro - 1) < DBUS_VERSION);
222
223  _dbus_assert (MAKE_VERSION (major + 1, minor, micro) > DBUS_VERSION);
224  _dbus_assert (MAKE_VERSION (major, minor + 1, micro) > DBUS_VERSION);
225  _dbus_assert (MAKE_VERSION (major, minor, micro + 1) > DBUS_VERSION);
226
227  /* Check DBUS_VERSION_STRING */
228
229  if (!_dbus_string_init (&str))
230    _dbus_assert_not_reached ("no memory");
231
232  if (!(_dbus_string_append_int (&str, major) &&
233        _dbus_string_append_byte (&str, '.') &&
234        _dbus_string_append_int (&str, minor) &&
235        _dbus_string_append_byte (&str, '.') &&
236        _dbus_string_append_int (&str, micro)))
237    _dbus_assert_not_reached ("no memory");
238
239  _dbus_assert (_dbus_string_equal_c_str (&str, DBUS_VERSION_STRING));
240
241  _dbus_string_free (&str);
242
243  return TRUE;
244}
245
246#endif /* !DOXYGEN_SHOULD_SKIP_THIS */
247
248#endif
249