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
|
/* SPDX-License-Identifier: LGPL-2.1+ */
/***
This file is part of systemd.
Copyright 2014 Kay Sievers, 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 "sd-daemon.h"
#include "sd-event.h"
#include "capability-util.h"
#include "clock-util.h"
#include "fd-util.h"
#include "fs-util.h"
#include "mkdir.h"
#include "network-util.h"
#include "process-util.h"
#include "signal-util.h"
#include "timesyncd-conf.h"
#include "timesyncd-manager.h"
#include "user-util.h"
static int load_clock_timestamp(uid_t uid, gid_t gid) {
_cleanup_close_ int fd = -1;
usec_t min = TIME_EPOCH * USEC_PER_SEC;
usec_t ct;
int r;
/* Let's try to make sure that the clock is always
* monotonically increasing, by saving the clock whenever we
* have a new NTP time, or when we shut down, and restoring it
* when we start again. This is particularly helpful on
* systems lacking a battery backed RTC. We also will adjust
* the time to at least the build time of systemd. */
fd = open("/var/lib/systemd/timesync/clock", O_RDWR|O_CLOEXEC, 0644);
if (fd >= 0) {
struct stat st;
usec_t stamp;
/* check if the recorded time is later than the compiled-in one */
r = fstat(fd, &st);
if (r >= 0) {
stamp = timespec_load(&st.st_mtim);
if (stamp > min)
min = stamp;
}
if (geteuid() == 0) {
/* Try to fix the access mode, so that we can still
touch the file after dropping priviliges */
r = fchmod(fd, 0644);
if (r < 0)
return log_error_errno(errno, "Failed to change file access mode: %m");
r = fchown(fd, uid, gid);
return log_error_errno(errno, "Failed to change file owner: %m");
}
} else {
r = mkdir_safe_label("/var/lib/systemd/timesync", 0755, uid, gid, true);
if (r < 0)
return log_error_errno(r, "Failed to create state directory: %m");
/* create stamp file with the compiled-in date */
(void) touch_file("/var/lib/systemd/timesync/clock", false, min, uid, gid, 0644);
}
ct = now(CLOCK_REALTIME);
if (ct < min) {
struct timespec ts;
char date[FORMAT_TIMESTAMP_MAX];
log_info("System clock time unset or jumped backwards, restoring from recorded timestamp: %s",
format_timestamp(date, sizeof(date), min));
if (clock_settime(CLOCK_REALTIME, timespec_store(&ts, min)) < 0)
log_error_errno(errno, "Failed to restore system clock: %m");
}
return 0;
}
int main(int argc, char *argv[]) {
_cleanup_(manager_freep) Manager *m = NULL;
const char *user = "systemd-timesync";
uid_t uid;
gid_t gid;
int r;
log_set_target(LOG_TARGET_AUTO);
log_set_facility(LOG_CRON);
log_parse_environment();
log_open();
umask(0022);
if (argc != 1) {
log_error("This program does not take arguments.");
r = -EINVAL;
goto finish;
}
r = get_user_creds(&user, &uid, &gid, NULL, NULL);
if (r < 0) {
log_error_errno(r, "Cannot resolve user name %s: %m", user);
goto finish;
}
r = load_clock_timestamp(uid, gid);
if (r < 0)
goto finish;
/* Drop privileges, but only if we have been started as root. If we are not running as root we assume all
* privileges are already dropped. */
if (geteuid() == 0) {
r = drop_privileges(uid, gid, (1ULL << CAP_SYS_TIME));
if (r < 0)
goto finish;
}
assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGTERM, SIGINT, -1) >= 0);
r = manager_new(&m);
if (r < 0) {
log_error_errno(r, "Failed to allocate manager: %m");
goto finish;
}
if (clock_is_localtime(NULL) > 0) {
log_info("The system is configured to read the RTC time in the local time zone. "
"This mode can not be fully supported. All system time to RTC updates are disabled.");
m->rtc_local_time = true;
}
r = manager_parse_config_file(m);
if (r < 0)
log_warning_errno(r, "Failed to parse configuration file: %m");
r = manager_parse_fallback_string(m, NTP_SERVERS);
if (r < 0) {
log_error_errno(r, "Failed to parse fallback server strings: %m");
goto finish;
}
log_debug("systemd-timesyncd running as pid " PID_FMT, getpid_cached());
sd_notify(false,
"READY=1\n"
"STATUS=Daemon is running");
if (network_is_online()) {
r = manager_connect(m);
if (r < 0)
goto finish;
}
r = sd_event_loop(m->event);
if (r < 0) {
log_error_errno(r, "Failed to run event loop: %m");
goto finish;
}
/* if we got an authoritative time, store it in the file system */
if (m->sync)
(void) touch("/var/lib/systemd/timesync/clock");
sd_event_get_exit_code(m->event, &r);
finish:
sd_notify(false,
"STOPPING=1\n"
"STATUS=Shutting down...");
return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
}
|
GitWeb