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 */
72 char*
dbus_get_local_machine_id(void)73 dbus_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 */
160 void
dbus_get_version(int * major_version_p,int * minor_version_p,int * micro_version_p)161 dbus_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
184 dbus_bool_t
_dbus_misc_test(void)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, µ);
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