summaryrefslogtreecommitdiff
path: root/src/update-utmp/update-utmp.c
blob: 311d686a8cc3e654cca5271985ba5eea355909ce (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/

/***
  This file is part of systemd.

  Copyright 2010 Lennart Poettering

  systemd is free software; you can redistribute it and/or modify it
  under the terms of the GNU Lesser General Public License as published by
  the Free Software Foundation; either version 2.1 of the License, or
  (at your option) any later version.

  systemd is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/

#include <assert.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>

#ifdef HAVE_AUDIT
#include <libaudit.h>
#endif

#include "sd-bus.h"

#include "log.h"
#include "macro.h"
#include "util.h"
#include "special.h"
#include "utmp-wtmp.h"
#include "bus-util.h"
#include "bus-error.h"
#include "unit-name.h"

typedef struct Context {
        sd_bus *bus;
#ifdef HAVE_AUDIT
        int audit_fd;
#endif
} Context;

static usec_t get_startup_time(Context *c) {
        _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
        usec_t t = 0;
        int r;

        assert(c);

        r = sd_bus_get_property_trivial(
                        c->bus,
                        "org.freedesktop.systemd1",
                        "/org/freedesktop/systemd1",
                        "org.freedesktop.systemd1.Manager",
                        "UserspaceTimestamp",
                        &error,
                        't', &t);
        if (r < 0) {
                log_error("Failed to get timestamp: %s", bus_error_message(&error, -r));
                return 0;
        }

        return t;
}

static int get_current_runlevel(Context *c) {
        static const struct {
                const int runlevel;
                const char *special;
        } table[] = {
                /* The first target of this list that is active or has
                 * a job scheduled wins. We prefer runlevels 5 and 3
                 * here over the others, since these are the main
                 * runlevels used on Fedora. It might make sense to
                 * change the order on some distributions. */
                { '5', SPECIAL_RUNLEVEL5_TARGET },
                { '3', SPECIAL_RUNLEVEL3_TARGET },
                { '4', SPECIAL_RUNLEVEL4_TARGET },
                { '2', SPECIAL_RUNLEVEL2_TARGET },
                { '1', SPECIAL_RESCUE_TARGET },
        };

        _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
        int r;
        unsigned i;

        assert(c);

        for (i = 0; i < ELEMENTSOF(table); i++) {
                _cleanup_free_ char *state = NULL, *path = NULL;

                path = unit_dbus_path_from_name(table[i].special);
                if (!path)
                        return log_oom();

                r = sd_bus_get_property_string(
                                c->bus,
                                "org.freedesktop.systemd1",
                                path,
                                "org.freedesktop.systemd1.Unit",
                                "ActiveState",
                                &error,
                                &state);
                if (r < 0) {
                        log_warning("Failed to get state: %s", bus_error_message(&error, -r));
                        return r;
                }

                if (streq(state, "active") || streq(state, "reloading"))
                        return table[i].runlevel;
        }

        return 0;
}

static int on_reboot(Context *c) {
        int r = 0, q;
        usec_t t;

        assert(c);

        /* We finished start-up, so let's write the utmp
         * record and send the audit msg */

#ifdef HAVE_AUDIT
        if (c->audit_fd >= 0)
                if (audit_log_user_comm_message(c->audit_fd, AUDIT_SYSTEM_BOOT, "", "systemd-update-utmp", NULL, NULL, NULL, 1) < 0 &&
                    errno != EPERM) {
                        log_error("Failed to send audit message: %m");
                        r = -errno;
                }
#endif

        /* If this call fails it will return 0, which
         * utmp_put_reboot() will then fix to the current time */
        t = get_startup_time(c);

        q = utmp_put_reboot(t);
        if (q < 0) {
                log_error("Failed to write utmp record: %s", strerror(-q));
                r = q;
        }

        return r;
}

static int on_shutdown(Context *c) {
        int r = 0, q;

        assert(c);

        /* We started shut-down, so let's write the utmp
         * record and send the audit msg */

#ifdef HAVE_AUDIT
        if (c->audit_fd >= 0)
                if (audit_log_user_comm_message(c->audit_fd, AUDIT_SYSTEM_SHUTDOWN, "", "systemd-update-utmp", NULL, NULL, NULL, 1) < 0 &&
                    errno != EPERM) {
                        log_error("Failed to send audit message: %m");
                        r = -errno;
                }
#endif

        q = utmp_put_shutdown();
        if (q < 0) {
                log_error("Failed to write utmp record: %s", strerror(-q));
                r = q;
        }

        return r;
}

static int on_runlevel(Context *c) {
        int r = 0, q, previous, runlevel;

        assert(c);

        /* We finished changing runlevel, so let's write the
         * utmp record and send the audit msg */

        /* First, get last runlevel */
        q = utmp_get_runlevel(&previous, NULL);

        if (q < 0) {
                if (q != -ESRCH && q != -ENOENT) {
                        log_error("Failed to get current runlevel: %s", strerror(-q));
                        return q;
                }

                previous = 0;
        }

        /* Secondly, get new runlevel */
        runlevel = get_current_runlevel(c);

        if (runlevel < 0)
                return runlevel;

        if (previous == runlevel)
                return 0;

#ifdef HAVE_AUDIT
        if (c->audit_fd >= 0) {
                _cleanup_free_ char *s = NULL;

                if (asprintf(&s, "old-level=%c new-level=%c",
                             previous > 0 ? previous : 'N',
                             runlevel > 0 ? runlevel : 'N') < 0)
                        return log_oom();

                if (audit_log_user_comm_message(c->audit_fd, AUDIT_SYSTEM_RUNLEVEL, s, "systemd-update-utmp", NULL, NULL, NULL, 1) < 0 &&
                    errno != EPERM) {
                        log_error("Failed to send audit message: %m");
                        r = -errno;
                }
        }
#endif

        q = utmp_put_runlevel(runlevel, previous);
        if (q < 0 && q != -ESRCH && q != -ENOENT) {
                log_error("Failed to write utmp record: %s", strerror(-q));
                r = q;
        }

        return r;
}

int main(int argc, char *argv[]) {
        Context c = {
#ifdef HAVE_AUDIT
                .audit_fd = -1
#endif
        };
        int r;

        if (getppid() != 1) {
                log_error("This program should be invoked by init only.");
                return EXIT_FAILURE;
        }

        if (argc != 2) {
                log_error("This program requires one argument.");
                return EXIT_FAILURE;
        }

        log_set_target(LOG_TARGET_AUTO);
        log_parse_environment();
        log_open();

        umask(0022);

#ifdef HAVE_AUDIT
        /* If the kernel lacks netlink or audit support,
         * don't worry about it. */
        c.audit_fd = audit_open();
        if (c.audit_fd < 0 && errno != EAFNOSUPPORT && errno != EPROTONOSUPPORT)
                log_error("Failed to connect to audit log: %m");
#endif
        r = bus_open_system_systemd(&c.bus);
        if (r < 0) {
                log_error("Failed to get D-Bus connection: %s", strerror(-r));
                r = -EIO;
                goto finish;
        }

        log_debug("systemd-update-utmp running as pid "PID_FMT, getpid());

        if (streq(argv[1], "reboot"))
                r = on_reboot(&c);
        else if (streq(argv[1], "shutdown"))
                r = on_shutdown(&c);
        else if (streq(argv[1], "runlevel"))
                r = on_runlevel(&c);
        else {
                log_error("Unknown command %s", argv[1]);
                r = -EINVAL;
        }

        log_debug("systemd-update-utmp stopped as pid "PID_FMT, getpid());

finish:
#ifdef HAVE_AUDIT
        if (c.audit_fd >= 0)
                audit_close(c.audit_fd);
#endif

        if (c.bus)
                sd_bus_unref(c.bus);

        return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
}