1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
2
3 #include <errno.h>
4 #include <getopt.h>
5 #include <stdio.h>
6 #include <stdlib.h>
7 #include <unistd.h>
8
9 #include "sd-daemon.h"
10
11 #include "alloc-util.h"
12 #include "env-util.h"
13 #include "format-util.h"
14 #include "log.h"
15 #include "main-func.h"
16 #include "parse-util.h"
17 #include "pretty-print.h"
18 #include "string-util.h"
19 #include "strv.h"
20 #include "terminal-util.h"
21 #include "time-util.h"
22 #include "user-util.h"
23 #include "util.h"
24
25 static bool arg_ready = false;
26 static pid_t arg_pid = 0;
27 static const char *arg_status = NULL;
28 static bool arg_booted = false;
29 static uid_t arg_uid = UID_INVALID;
30 static gid_t arg_gid = GID_INVALID;
31 static bool arg_no_block = false;
32
help(void)33 static int help(void) {
34 _cleanup_free_ char *link = NULL;
35 int r;
36
37 r = terminal_urlify_man("systemd-notify", "1", &link);
38 if (r < 0)
39 return log_oom();
40
41 printf("%s [OPTIONS...] [VARIABLE=VALUE...]\n"
42 "\n%sNotify the init system about service status updates.%s\n\n"
43 " -h --help Show this help\n"
44 " --version Show package version\n"
45 " --ready Inform the init system about service start-up completion\n"
46 " --pid[=PID] Set main PID of daemon\n"
47 " --uid=USER Set user to send from\n"
48 " --status=TEXT Set status text\n"
49 " --booted Check if the system was booted up with systemd\n"
50 " --no-block Do not wait until operation finished\n"
51 "\nSee the %s for details.\n",
52 program_invocation_short_name,
53 ansi_highlight(),
54 ansi_normal(),
55 link);
56
57 return 0;
58 }
59
manager_pid(void)60 static pid_t manager_pid(void) {
61 const char *e;
62 pid_t pid;
63 int r;
64
65 /* If we run as a service managed by systemd --user the $MANAGERPID environment variable points to
66 * the service manager's PID. */
67 e = getenv("MANAGERPID");
68 if (!e)
69 return 0;
70
71 r = parse_pid(e, &pid);
72 if (r < 0) {
73 log_warning_errno(r, "$MANAGERPID is set to an invalid PID, ignoring: %s", e);
74 return 0;
75 }
76
77 return pid;
78 }
79
parse_argv(int argc,char * argv[])80 static int parse_argv(int argc, char *argv[]) {
81
82 enum {
83 ARG_READY = 0x100,
84 ARG_VERSION,
85 ARG_PID,
86 ARG_STATUS,
87 ARG_BOOTED,
88 ARG_UID,
89 ARG_NO_BLOCK
90 };
91
92 static const struct option options[] = {
93 { "help", no_argument, NULL, 'h' },
94 { "version", no_argument, NULL, ARG_VERSION },
95 { "ready", no_argument, NULL, ARG_READY },
96 { "pid", optional_argument, NULL, ARG_PID },
97 { "status", required_argument, NULL, ARG_STATUS },
98 { "booted", no_argument, NULL, ARG_BOOTED },
99 { "uid", required_argument, NULL, ARG_UID },
100 { "no-block", no_argument, NULL, ARG_NO_BLOCK },
101 {}
102 };
103
104 int c, r;
105
106 assert(argc >= 0);
107 assert(argv);
108
109 while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0) {
110
111 switch (c) {
112
113 case 'h':
114 return help();
115
116 case ARG_VERSION:
117 return version();
118
119 case ARG_READY:
120 arg_ready = true;
121 break;
122
123 case ARG_PID:
124 if (isempty(optarg) || streq(optarg, "auto")) {
125 arg_pid = getppid();
126
127 if (arg_pid <= 1 ||
128 arg_pid == manager_pid()) /* Don't send from PID 1 or the service
129 * manager's PID (which might be distinct from
130 * 1, if we are a --user instance), that'd just
131 * be confusing for the service manager */
132 arg_pid = getpid();
133 } else if (streq(optarg, "parent"))
134 arg_pid = getppid();
135 else if (streq(optarg, "self"))
136 arg_pid = getpid();
137 else {
138 r = parse_pid(optarg, &arg_pid);
139 if (r < 0)
140 return log_error_errno(r, "Failed to parse PID %s.", optarg);
141 }
142
143 break;
144
145 case ARG_STATUS:
146 arg_status = optarg;
147 break;
148
149 case ARG_BOOTED:
150 arg_booted = true;
151 break;
152
153 case ARG_UID: {
154 const char *u = optarg;
155
156 r = get_user_creds(&u, &arg_uid, &arg_gid, NULL, NULL, 0);
157 if (r == -ESRCH) /* If the user doesn't exist, then accept it anyway as numeric */
158 r = parse_uid(u, &arg_uid);
159 if (r < 0)
160 return log_error_errno(r, "Can't resolve user %s: %m", optarg);
161
162 break;
163 }
164
165 case ARG_NO_BLOCK:
166 arg_no_block = true;
167 break;
168
169 case '?':
170 return -EINVAL;
171
172 default:
173 assert_not_reached();
174 }
175 }
176
177 if (optind >= argc &&
178 !arg_ready &&
179 !arg_status &&
180 !arg_pid &&
181 !arg_booted) {
182 help();
183 return -EINVAL;
184 }
185
186 return 1;
187 }
188
run(int argc,char * argv[])189 static int run(int argc, char* argv[]) {
190 _cleanup_free_ char *status = NULL, *cpid = NULL, *n = NULL;
191 _cleanup_strv_free_ char **final_env = NULL;
192 char* our_env[4];
193 unsigned i = 0;
194 pid_t source_pid;
195 int r;
196
197 log_show_color(true);
198 log_parse_environment();
199 log_open();
200
201 r = parse_argv(argc, argv);
202 if (r <= 0)
203 return r;
204
205 if (arg_booted) {
206 r = sd_booted();
207 if (r < 0)
208 log_debug_errno(r, "Failed to determine whether we are booted with systemd, assuming we aren't: %m");
209 else
210 log_debug("The system %s booted with systemd.", r ? "was" : "was not");
211
212 return r <= 0;
213 }
214
215 if (arg_ready)
216 our_env[i++] = (char*) "READY=1";
217
218 if (arg_status) {
219 status = strjoin("STATUS=", arg_status);
220 if (!status)
221 return log_oom();
222
223 our_env[i++] = status;
224 }
225
226 if (arg_pid > 0) {
227 if (asprintf(&cpid, "MAINPID="PID_FMT, arg_pid) < 0)
228 return log_oom();
229
230 our_env[i++] = cpid;
231 }
232
233 our_env[i++] = NULL;
234
235 final_env = strv_env_merge(our_env, argv + optind);
236 if (!final_env)
237 return log_oom();
238
239 if (strv_isempty(final_env))
240 return 0;
241
242 n = strv_join(final_env, "\n");
243 if (!n)
244 return log_oom();
245
246 /* If this is requested change to the requested UID/GID. Note that we only change the real UID here, and leave
247 the effective UID in effect (which is 0 for this to work). That's because we want the privileges to fake the
248 ucred data, and sd_pid_notify() uses the real UID for filling in ucred. */
249
250 if (arg_gid != GID_INVALID &&
251 setregid(arg_gid, GID_INVALID) < 0)
252 return log_error_errno(errno, "Failed to change GID: %m");
253
254 if (arg_uid != UID_INVALID &&
255 setreuid(arg_uid, UID_INVALID) < 0)
256 return log_error_errno(errno, "Failed to change UID: %m");
257
258 if (arg_pid > 0)
259 source_pid = arg_pid;
260 else {
261 /* Pretend the message originates from our parent, given that we are typically called from a
262 * shell script, i.e. we are not the main process of a service but only a child of it. */
263 source_pid = getppid();
264 if (source_pid <= 1 ||
265 source_pid == manager_pid()) /* safety check: don't claim we'd send anything from PID 1
266 * or the service manager itself */
267 source_pid = 0;
268 }
269 r = sd_pid_notify(source_pid, false, n);
270 if (r < 0)
271 return log_error_errno(r, "Failed to notify init system: %m");
272 if (r == 0)
273 return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
274 "No status data could be sent: $NOTIFY_SOCKET was not set");
275
276 if (!arg_no_block) {
277 r = sd_notify_barrier(0, 5 * USEC_PER_SEC);
278 if (r < 0)
279 return log_error_errno(r, "Failed to invoke barrier: %m");
280 if (r == 0)
281 return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
282 "No status data could be sent: $NOTIFY_SOCKET was not set");
283 }
284
285 return 0;
286 }
287
288 DEFINE_MAIN_FUNCTION_WITH_POSITIVE_FAILURE(run);
289