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abbbea81 LP |
1 | #ifndef foosddaemonhfoo |
2 | #define foosddaemonhfoo | |
3 | ||
4 | /*** | |
952d1536 KS |
5 | This file is part of systemd. |
6 | ||
7 | Copyright 2013 Lennart Poettering | |
8 | ||
9 | systemd is free software; you can redistribute it and/or modify it | |
10 | under the terms of the GNU Lesser General Public License as published by | |
11 | the Free Software Foundation; either version 2.1 of the License, or | |
12 | (at your option) any later version. | |
13 | ||
14 | systemd is distributed in the hope that it will be useful, but | |
15 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
17 | Lesser General Public License for more details. | |
18 | ||
19 | You should have received a copy of the GNU Lesser General Public License | |
20 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
abbbea81 LP |
21 | ***/ |
22 | ||
7c394faa | 23 | #include <inttypes.h> |
71d35b6b | 24 | #include <sys/types.h> |
7c394faa | 25 | |
0ebee881 | 26 | #include "_sd-common.h" |
8c47c732 | 27 | |
0ebee881 | 28 | _SD_BEGIN_DECLARATIONS; |
40473a70 | 29 | |
0ebee881 | 30 | /* |
40473a70 LP |
31 | The following functionality is provided: |
32 | ||
33 | - Support for logging with log levels on stderr | |
34 | - File descriptor passing for socket-based activation | |
35 | - Daemon startup and status notification | |
36 | - Detection of systemd boots | |
37 | ||
cb07866b | 38 | See sd-daemon(3) for more information. |
40473a70 LP |
39 | */ |
40 | ||
abbbea81 LP |
41 | /* |
42 | Log levels for usage on stderr: | |
43 | ||
f9378423 | 44 | fprintf(stderr, SD_NOTICE "Hello World!\n"); |
abbbea81 LP |
45 | |
46 | This is similar to printk() usage in the kernel. | |
47 | */ | |
abbbea81 LP |
48 | #define SD_EMERG "<0>" /* system is unusable */ |
49 | #define SD_ALERT "<1>" /* action must be taken immediately */ | |
50 | #define SD_CRIT "<2>" /* critical conditions */ | |
51 | #define SD_ERR "<3>" /* error conditions */ | |
52 | #define SD_WARNING "<4>" /* warning conditions */ | |
53 | #define SD_NOTICE "<5>" /* normal but significant condition */ | |
54 | #define SD_INFO "<6>" /* informational */ | |
55 | #define SD_DEBUG "<7>" /* debug-level messages */ | |
56 | ||
57 | /* The first passed file descriptor is fd 3 */ | |
58 | #define SD_LISTEN_FDS_START 3 | |
59 | ||
40473a70 LP |
60 | /* |
61 | Returns how many file descriptors have been passed, or a negative | |
62 | errno code on failure. Optionally, removes the $LISTEN_FDS and | |
63 | $LISTEN_PID file descriptors from the environment (recommended, but | |
64 | problematic in threaded environments). If r is the return value of | |
65 | this function you'll find the file descriptors passed as fds | |
66 | SD_LISTEN_FDS_START to SD_LISTEN_FDS_START+r-1. Returns a negative | |
67 | errno style error code on failure. This function call ensures that | |
68 | the FD_CLOEXEC flag is set for the passed file descriptors, to make | |
69 | sure they are not passed on to child processes. If FD_CLOEXEC shall | |
70 | not be set, the caller needs to unset it after this call for all file | |
71 | descriptors that are used. | |
daaa7e5a LP |
72 | |
73 | See sd_listen_fds(3) for more information. | |
40473a70 | 74 | */ |
b136daf5 | 75 | int sd_listen_fds(int unset_environment); |
40473a70 | 76 | |
8dd4c05b LP |
77 | int sd_listen_fds_with_names(int unset_environment, char ***names); |
78 | ||
40473a70 LP |
79 | /* |
80 | Helper call for identifying a passed file descriptor. Returns 1 if | |
81 | the file descriptor is a FIFO in the file system stored under the | |
82 | specified path, 0 otherwise. If path is NULL a path name check will | |
83 | not be done and the call only verifies if the file descriptor | |
84 | refers to a FIFO. Returns a negative errno style error code on | |
85 | failure. | |
daaa7e5a LP |
86 | |
87 | See sd_is_fifo(3) for more information. | |
40473a70 | 88 | */ |
b136daf5 | 89 | int sd_is_fifo(int fd, const char *path); |
40473a70 | 90 | |
4160ec67 WD |
91 | /* |
92 | Helper call for identifying a passed file descriptor. Returns 1 if | |
93 | the file descriptor is a special character device on the file | |
94 | system stored under the specified path, 0 otherwise. | |
95 | If path is NULL a path name check will not be done and the call | |
96 | only verifies if the file descriptor refers to a special character. | |
97 | Returns a negative errno style error code on failure. | |
98 | ||
99 | See sd_is_special(3) for more information. | |
100 | */ | |
101 | int sd_is_special(int fd, const char *path); | |
102 | ||
40473a70 LP |
103 | /* |
104 | Helper call for identifying a passed file descriptor. Returns 1 if | |
105 | the file descriptor is a socket of the specified family (AF_INET, | |
106 | ...) and type (SOCK_DGRAM, SOCK_STREAM, ...), 0 otherwise. If | |
107 | family is 0 a socket family check will not be done. If type is 0 a | |
108 | socket type check will not be done and the call only verifies if | |
109 | the file descriptor refers to a socket. If listening is > 0 it is | |
110 | verified that the socket is in listening mode. (i.e. listen() has | |
111 | been called) If listening is == 0 it is verified that the socket is | |
112 | not in listening mode. If listening is < 0 no listening mode check | |
113 | is done. Returns a negative errno style error code on failure. | |
daaa7e5a LP |
114 | |
115 | See sd_is_socket(3) for more information. | |
40473a70 | 116 | */ |
b136daf5 | 117 | int sd_is_socket(int fd, int family, int type, int listening); |
40473a70 LP |
118 | |
119 | /* | |
120 | Helper call for identifying a passed file descriptor. Returns 1 if | |
121 | the file descriptor is an Internet socket, of the specified family | |
122 | (either AF_INET or AF_INET6) and the specified type (SOCK_DGRAM, | |
123 | SOCK_STREAM, ...), 0 otherwise. If version is 0 a protocol version | |
124 | check is not done. If type is 0 a socket type check will not be | |
125 | done. If port is 0 a socket port check will not be done. The | |
126 | listening flag is used the same way as in sd_is_socket(). Returns a | |
127 | negative errno style error code on failure. | |
daaa7e5a LP |
128 | |
129 | See sd_is_socket_inet(3) for more information. | |
40473a70 | 130 | */ |
b136daf5 | 131 | int sd_is_socket_inet(int fd, int family, int type, int listening, uint16_t port); |
40473a70 LP |
132 | |
133 | /* | |
134 | Helper call for identifying a passed file descriptor. Returns 1 if | |
135 | the file descriptor is an AF_UNIX socket of the specified type | |
136 | (SOCK_DGRAM, SOCK_STREAM, ...) and path, 0 otherwise. If type is 0 | |
137 | a socket type check will not be done. If path is NULL a socket path | |
138 | check will not be done. For normal AF_UNIX sockets set length to | |
139 | 0. For abstract namespace sockets set length to the length of the | |
140 | socket name (including the initial 0 byte), and pass the full | |
141 | socket path in path (including the initial 0 byte). The listening | |
142 | flag is used the same way as in sd_is_socket(). Returns a negative | |
143 | errno style error code on failure. | |
daaa7e5a LP |
144 | |
145 | See sd_is_socket_unix(3) for more information. | |
40473a70 | 146 | */ |
b136daf5 | 147 | int sd_is_socket_unix(int fd, int type, int listening, const char *path, size_t length); |
40473a70 | 148 | |
916abb21 LP |
149 | /* |
150 | Helper call for identifying a passed file descriptor. Returns 1 if | |
151 | the file descriptor is a POSIX Message Queue of the specified name, | |
152 | 0 otherwise. If path is NULL a message queue name check is not | |
153 | done. Returns a negative errno style error code on failure. | |
09812eb7 LP |
154 | |
155 | See sd_is_mq(3) for more information. | |
916abb21 | 156 | */ |
b136daf5 | 157 | int sd_is_mq(int fd, const char *path); |
916abb21 | 158 | |
40473a70 | 159 | /* |
f9378423 | 160 | Informs systemd about changed daemon state. This takes a number of |
96d4ce01 | 161 | newline separated environment-style variable assignments in a |
f9378423 | 162 | string. The following variables are known: |
40473a70 LP |
163 | |
164 | READY=1 Tells systemd that daemon startup is finished (only | |
165 | relevant for services of Type=notify). The passed | |
166 | argument is a boolean "1" or "0". Since there is | |
35b8ca3a | 167 | little value in signaling non-readiness the only |
40473a70 LP |
168 | value daemons should send is "READY=1". |
169 | ||
170 | STATUS=... Passes a single-line status string back to systemd | |
4a6970c5 | 171 | that describes the daemon state. This is free-form |
40473a70 LP |
172 | and can be used for various purposes: general state |
173 | feedback, fsck-like programs could pass completion | |
174 | percentages and failing programs could pass a human | |
175 | readable error message. Example: "STATUS=Completed | |
176 | 66% of file system check..." | |
177 | ||
178 | ERRNO=... If a daemon fails, the errno-style error code, | |
179 | formatted as string. Example: "ERRNO=2" for ENOENT. | |
180 | ||
181 | BUSERROR=... If a daemon fails, the D-Bus error-style error | |
182 | code. Example: "BUSERROR=org.freedesktop.DBus.Error.TimedOut" | |
183 | ||
184 | MAINPID=... The main pid of a daemon, in case systemd did not | |
185 | fork off the process itself. Example: "MAINPID=4711" | |
186 | ||
a6927d7f MO |
187 | WATCHDOG=1 Tells systemd to update the watchdog timestamp. |
188 | Services using this feature should do this in | |
189 | regular intervals. A watchdog framework can use the | |
09812eb7 LP |
190 | timestamps to detect failed services. Also see |
191 | sd_watchdog_enabled() below. | |
a6927d7f | 192 | |
a354329f LP |
193 | FDSTORE=1 Store the file descriptors passed along with the |
194 | message in the per-service file descriptor store, | |
195 | and pass them to the main process again on next | |
196 | invocation. This variable is only supported with | |
197 | sd_pid_notify_with_fds(). | |
198 | ||
2787d83c M |
199 | WATCHDOG_USEC=... |
200 | Reset watchdog_usec value during runtime. | |
201 | To reset watchdog_usec value, start the service again. | |
202 | Example: "WATCHDOG_USEC=20000000" | |
203 | ||
f9378423 | 204 | Daemons can choose to send additional variables. However, it is |
35b8ca3a | 205 | recommended to prefix variable names not listed above with X_. |
40473a70 LP |
206 | |
207 | Returns a negative errno-style error code on failure. Returns > 0 | |
208 | if systemd could be notified, 0 if it couldn't possibly because | |
209 | systemd is not running. | |
210 | ||
211 | Example: When a daemon finished starting up, it could issue this | |
212 | call to notify systemd about it: | |
213 | ||
214 | sd_notify(0, "READY=1"); | |
215 | ||
216 | See sd_notifyf() for more complete examples. | |
daaa7e5a LP |
217 | |
218 | See sd_notify(3) for more information. | |
40473a70 | 219 | */ |
b136daf5 | 220 | int sd_notify(int unset_environment, const char *state); |
40473a70 LP |
221 | |
222 | /* | |
223 | Similar to sd_notify() but takes a format string. | |
224 | ||
225 | Example 1: A daemon could send the following after initialization: | |
226 | ||
227 | sd_notifyf(0, "READY=1\n" | |
228 | "STATUS=Processing requests...\n" | |
229 | "MAINPID=%lu", | |
230 | (unsigned long) getpid()); | |
231 | ||
232 | Example 2: A daemon could send the following shortly before | |
233 | exiting, on failure: | |
234 | ||
235 | sd_notifyf(0, "STATUS=Failed to start up: %s\n" | |
236 | "ERRNO=%i", | |
237 | strerror(errno), | |
238 | errno); | |
daaa7e5a LP |
239 | |
240 | See sd_notifyf(3) for more information. | |
40473a70 | 241 | */ |
0ebee881 | 242 | int sd_notifyf(int unset_environment, const char *format, ...) _sd_printf_(2,3); |
40473a70 | 243 | |
be8f4e9e LP |
244 | /* |
245 | Similar to sd_notify(), but send the message on behalf of another | |
246 | process, if the appropriate permissions are available. | |
247 | */ | |
248 | int sd_pid_notify(pid_t pid, int unset_environment, const char *state); | |
249 | ||
250 | /* | |
251 | Similar to sd_notifyf(), but send the message on behalf of another | |
252 | process, if the appropriate permissions are available. | |
253 | */ | |
254 | int sd_pid_notifyf(pid_t pid, int unset_environment, const char *format, ...) _sd_printf_(3,4); | |
255 | ||
a354329f LP |
256 | /* |
257 | Similar to sd_pid_notify(), but also passes the specified fd array | |
258 | to the service manager for storage. This is particularly useful for | |
259 | FDSTORE=1 messages. | |
260 | */ | |
261 | int sd_pid_notify_with_fds(pid_t pid, int unset_environment, const char *state, const int *fds, unsigned n_fds); | |
262 | ||
40473a70 LP |
263 | /* |
264 | Returns > 0 if the system was booted with systemd. Returns < 0 on | |
265 | error. Returns 0 if the system was not booted with systemd. Note | |
266 | that all of the functions above handle non-systemd boots just | |
267 | fine. You should NOT protect them with a call to this function. Also | |
268 | note that this function checks whether the system, not the user | |
269 | session is controlled by systemd. However the functions above work | |
af2d49f7 | 270 | for both user and system services. |
daaa7e5a LP |
271 | |
272 | See sd_booted(3) for more information. | |
40473a70 | 273 | */ |
b136daf5 | 274 | int sd_booted(void); |
8c47c732 | 275 | |
09812eb7 LP |
276 | /* |
277 | Returns > 0 if the service manager expects watchdog keep-alive | |
278 | events to be sent regularly via sd_notify(0, "WATCHDOG=1"). Returns | |
279 | 0 if it does not expect this. If the usec argument is non-NULL | |
280 | returns the watchdog timeout in µs after which the service manager | |
281 | will act on a process that has not sent a watchdog keep alive | |
282 | message. This function is useful to implement services that | |
283 | recognize automatically if they are being run under supervision of | |
284 | systemd with WatchdogSec= set. It is recommended for clients to | |
285 | generate keep-alive pings via sd_notify(0, "WATCHDOG=1") every half | |
286 | of the returned time. | |
287 | ||
288 | See sd_watchdog_enabled(3) for more information. | |
289 | */ | |
290 | int sd_watchdog_enabled(int unset_environment, uint64_t *usec); | |
291 | ||
0ebee881 | 292 | _SD_END_DECLARATIONS; |
8c47c732 | 293 | |
abbbea81 | 294 | #endif |