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
|
/* SPDX-License-Identifier: LGPL-2.1+ */
#include "sd-daemon.h"
#include "sd-event.h"
#include "capability-util.h"
#include "clock-util.h"
#include "daemon-util.h"
#include "fd-util.h"
#include "fs-util.h"
#include "main-func.h"
#include "mkdir.h"
#include "network-util.h"
#include "process-util.h"
#include "signal-util.h"
#include "timesyncd-bus.h"
#include "timesyncd-conf.h"
#include "timesyncd-manager.h"
#include "user-util.h"
#define STATE_DIR "/var/lib/systemd/timesync"
#define CLOCK_FILE STATE_DIR "/clock"
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(CLOCK_FILE, 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_and_chown(fd, 0644, uid, gid);
if (r < 0)
log_warning_errno(r, "Failed to chmod or chown %s, ignoring: %m", CLOCK_FILE);
}
} else {
r = mkdir_safe_label(STATE_DIR, 0755, uid, gid,
MKDIR_FOLLOW_SYMLINK | MKDIR_WARN_MODE);
if (r < 0) {
log_debug_errno(r, "Failed to create state directory, ignoring: %m");
goto settime;
}
/* create stamp file with the compiled-in date */
r = touch_file(CLOCK_FILE, false, min, uid, gid, 0644);
if (r < 0)
log_debug_errno(r, "Failed to create %s, ignoring: %m", CLOCK_FILE);
}
settime:
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, ignoring: %m");
}
return 0;
}
static int run(int argc, char *argv[]) {
_cleanup_(notify_on_cleanup) const char *notify_message = NULL;
_cleanup_(manager_freep) Manager *m = NULL;
const char *user = "systemd-timesync";
uid_t uid, uid_current;
gid_t gid;
int r;
log_set_facility(LOG_CRON);
log_setup_service();
umask(0022);
if (argc != 1)
return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "This program does not take arguments.");
uid = uid_current = geteuid();
gid = getegid();
if (uid_current == 0) {
r = get_user_creds(&user, &uid, &gid, NULL, NULL, 0);
if (r < 0)
return log_error_errno(r, "Cannot resolve user name %s: %m", user);
}
r = load_clock_timestamp(uid, gid);
if (r < 0)
return r;
/* 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 (uid_current == 0) {
r = drop_privileges(uid, gid, (1ULL << CAP_SYS_TIME));
if (r < 0)
return log_error_errno(r, "Failed to drop privileges: %m");
}
assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGTERM, SIGINT, -1) >= 0);
r = manager_new(&m);
if (r < 0)
return log_error_errno(r, "Failed to allocate manager: %m");
r = manager_connect_bus(m);
if (r < 0)
return log_error_errno(r, "Could not connect to bus: %m");
if (clock_is_localtime(NULL) > 0) {
log_info("The system is configured to read the RTC time in the local time zone. "
"This mode cannot 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)
return log_error_errno(r, "Failed to parse fallback server strings: %m");
log_debug("systemd-timesyncd running as pid " PID_FMT, getpid_cached());
notify_message = notify_start("READY=1\n"
"STATUS=Daemon is running",
NOTIFY_STOPPING);
if (network_is_online()) {
r = manager_connect(m);
if (r < 0)
return r;
}
r = sd_event_loop(m->event);
if (r < 0)
return log_error_errno(r, "Failed to run event loop: %m");
/* if we got an authoritative time, store it in the file system */
if (m->sync) {
r = touch(CLOCK_FILE);
if (r < 0)
log_debug_errno(r, "Failed to touch %s, ignoring: %m", CLOCK_FILE);
}
(void) sd_event_get_exit_code(m->event, &r);
return r;
}
DEFINE_MAIN_FUNCTION(run);
|
