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Commit | Line | Data |
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53e1b683 | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
e537352b | 2 | |
e537352b | 3 | #include <errno.h> |
07630cea LP |
4 | #include <fcntl.h> |
5 | #include <poll.h> | |
a8fbdf54 TA |
6 | #include <stddef.h> |
7 | #include <stdio.h> | |
8 | #include <stdlib.h> | |
e537352b | 9 | #include <string.h> |
a8fbdf54 | 10 | #include <sys/time.h> |
e537352b | 11 | #include <sys/utsname.h> |
ef2f1067 | 12 | #include <unistd.h> |
07630cea | 13 | #include <utmpx.h> |
e537352b | 14 | |
b5efdb8a | 15 | #include "alloc-util.h" |
3ffd4af2 | 16 | #include "fd-util.h" |
07630cea | 17 | #include "hostname-util.h" |
e537352b | 18 | #include "macro.h" |
9eb977db | 19 | #include "path-util.h" |
07630cea | 20 | #include "string-util.h" |
288a74cc | 21 | #include "terminal-util.h" |
a8fbdf54 | 22 | #include "time-util.h" |
b1d4f8e1 | 23 | #include "user-util.h" |
a8fbdf54 | 24 | #include "util.h" |
958b66ea | 25 | #include "utmp-wtmp.h" |
e537352b LP |
26 | |
27 | int utmp_get_runlevel(int *runlevel, int *previous) { | |
b92bea5d | 28 | struct utmpx *found, lookup = { .ut_type = RUN_LVL }; |
e537352b LP |
29 | int r; |
30 | const char *e; | |
31 | ||
32 | assert(runlevel); | |
33 | ||
34 | /* If these values are set in the environment this takes | |
35 | * precedence. Presumably, sysvinit does this to work around a | |
36 | * race condition that would otherwise exist where we'd always | |
37 | * go to disk and hence might read runlevel data that might be | |
38 | * very new and does not apply to the current script being | |
39 | * executed. */ | |
40 | ||
e7fb33ff LP |
41 | e = getenv("RUNLEVEL"); |
42 | if (e && e[0] > 0) { | |
e537352b LP |
43 | *runlevel = e[0]; |
44 | ||
45 | if (previous) { | |
46 | /* $PREVLEVEL seems to be an Upstart thing */ | |
47 | ||
e7fb33ff LP |
48 | e = getenv("PREVLEVEL"); |
49 | if (e && e[0] > 0) | |
e537352b LP |
50 | *previous = e[0]; |
51 | else | |
52 | *previous = 0; | |
53 | } | |
54 | ||
55 | return 0; | |
56 | } | |
57 | ||
58 | if (utmpxname(_PATH_UTMPX) < 0) | |
59 | return -errno; | |
60 | ||
61 | setutxent(); | |
62 | ||
e7fb33ff LP |
63 | found = getutxid(&lookup); |
64 | if (!found) | |
e537352b LP |
65 | r = -errno; |
66 | else { | |
67 | int a, b; | |
68 | ||
69 | a = found->ut_pid & 0xFF; | |
70 | b = (found->ut_pid >> 8) & 0xFF; | |
71 | ||
4dd1de72 ZJS |
72 | *runlevel = a; |
73 | if (previous) | |
74 | *previous = b; | |
75 | ||
76 | r = 0; | |
e537352b LP |
77 | } |
78 | ||
79 | endutxent(); | |
80 | ||
81 | return r; | |
82 | } | |
83 | ||
169c1bda | 84 | static void init_timestamp(struct utmpx *store, usec_t t) { |
e537352b LP |
85 | assert(store); |
86 | ||
871d7de4 LP |
87 | if (t <= 0) |
88 | t = now(CLOCK_REALTIME); | |
e537352b | 89 | |
871d7de4 LP |
90 | store->ut_tv.tv_sec = t / USEC_PER_SEC; |
91 | store->ut_tv.tv_usec = t % USEC_PER_SEC; | |
169c1bda LP |
92 | } |
93 | ||
94 | static void init_entry(struct utmpx *store, usec_t t) { | |
b92bea5d | 95 | struct utsname uts = {}; |
169c1bda LP |
96 | |
97 | assert(store); | |
98 | ||
99 | init_timestamp(store, t); | |
100 | ||
e537352b LP |
101 | if (uname(&uts) >= 0) |
102 | strncpy(store->ut_host, uts.release, sizeof(store->ut_host)); | |
103 | ||
104 | strncpy(store->ut_line, "~", sizeof(store->ut_line)); /* or ~~ ? */ | |
105 | strncpy(store->ut_id, "~~", sizeof(store->ut_id)); | |
106 | } | |
107 | ||
108 | static int write_entry_utmp(const struct utmpx *store) { | |
109 | int r; | |
110 | ||
111 | assert(store); | |
112 | ||
113 | /* utmp is similar to wtmp, but there is only one entry for | |
114 | * each entry type resp. user; i.e. basically a key/value | |
115 | * table. */ | |
116 | ||
117 | if (utmpxname(_PATH_UTMPX) < 0) | |
118 | return -errno; | |
119 | ||
120 | setutxent(); | |
121 | ||
122 | if (!pututxline(store)) | |
123 | r = -errno; | |
124 | else | |
125 | r = 0; | |
126 | ||
127 | endutxent(); | |
128 | ||
129 | return r; | |
130 | } | |
131 | ||
132 | static int write_entry_wtmp(const struct utmpx *store) { | |
133 | assert(store); | |
134 | ||
135 | /* wtmp is a simple append-only file where each entry is | |
863f3ce0 | 136 | simply appended to the end; i.e. basically a log. */ |
e537352b LP |
137 | |
138 | errno = 0; | |
139 | updwtmpx(_PATH_WTMPX, store); | |
140 | return -errno; | |
141 | } | |
142 | ||
4743137a | 143 | static int write_utmp_wtmp(const struct utmpx *store_utmp, const struct utmpx *store_wtmp) { |
e537352b LP |
144 | int r, s; |
145 | ||
4743137a MS |
146 | r = write_entry_utmp(store_utmp); |
147 | s = write_entry_wtmp(store_wtmp); | |
e537352b LP |
148 | |
149 | if (r >= 0) | |
150 | r = s; | |
151 | ||
152 | /* If utmp/wtmp have been disabled, that's a good thing, hence | |
153 | * ignore the errors */ | |
154 | if (r == -ENOENT) | |
155 | r = 0; | |
156 | ||
157 | return r; | |
158 | } | |
159 | ||
4743137a MS |
160 | static int write_entry_both(const struct utmpx *store) { |
161 | return write_utmp_wtmp(store, store); | |
162 | } | |
163 | ||
0ad26e09 | 164 | int utmp_put_shutdown(void) { |
863f3ce0 | 165 | struct utmpx store = {}; |
e537352b | 166 | |
0ad26e09 | 167 | init_entry(&store, 0); |
e537352b LP |
168 | |
169 | store.ut_type = RUN_LVL; | |
170 | strncpy(store.ut_user, "shutdown", sizeof(store.ut_user)); | |
171 | ||
172 | return write_entry_both(&store); | |
173 | } | |
174 | ||
871d7de4 | 175 | int utmp_put_reboot(usec_t t) { |
863f3ce0 | 176 | struct utmpx store = {}; |
e537352b | 177 | |
871d7de4 | 178 | init_entry(&store, t); |
e537352b LP |
179 | |
180 | store.ut_type = BOOT_TIME; | |
55e39f40 | 181 | strncpy(store.ut_user, "reboot", sizeof(store.ut_user)); |
e537352b LP |
182 | |
183 | return write_entry_both(&store); | |
184 | } | |
185 | ||
44a6b1b6 | 186 | _pure_ static const char *sanitize_id(const char *id) { |
169c1bda LP |
187 | size_t l; |
188 | ||
189 | assert(id); | |
190 | l = strlen(id); | |
191 | ||
192 | if (l <= sizeof(((struct utmpx*) NULL)->ut_id)) | |
193 | return id; | |
194 | ||
195 | return id + l - sizeof(((struct utmpx*) NULL)->ut_id); | |
196 | } | |
197 | ||
023a4f67 | 198 | int utmp_put_init_process(const char *id, pid_t pid, pid_t sid, const char *line, int ut_type, const char *user) { |
863f3ce0 TG |
199 | struct utmpx store = { |
200 | .ut_type = INIT_PROCESS, | |
201 | .ut_pid = pid, | |
202 | .ut_session = sid, | |
203 | }; | |
023a4f67 | 204 | int r; |
169c1bda LP |
205 | |
206 | assert(id); | |
207 | ||
0ad26e09 | 208 | init_timestamp(&store, 0); |
169c1bda | 209 | |
863f3ce0 | 210 | /* ut_id needs only be nul-terminated if it is shorter than sizeof(ut_id) */ |
169c1bda LP |
211 | strncpy(store.ut_id, sanitize_id(id), sizeof(store.ut_id)); |
212 | ||
213 | if (line) | |
2b6bf07d | 214 | strncpy(store.ut_line, basename(line), sizeof(store.ut_line)); |
169c1bda | 215 | |
023a4f67 LP |
216 | r = write_entry_both(&store); |
217 | if (r < 0) | |
218 | return r; | |
219 | ||
3742095b | 220 | if (IN_SET(ut_type, LOGIN_PROCESS, USER_PROCESS)) { |
023a4f67 LP |
221 | store.ut_type = LOGIN_PROCESS; |
222 | r = write_entry_both(&store); | |
223 | if (r < 0) | |
224 | return r; | |
225 | } | |
226 | ||
227 | if (ut_type == USER_PROCESS) { | |
228 | store.ut_type = USER_PROCESS; | |
229 | strncpy(store.ut_user, user, sizeof(store.ut_user)-1); | |
230 | r = write_entry_both(&store); | |
231 | if (r < 0) | |
232 | return r; | |
233 | } | |
234 | ||
235 | return 0; | |
169c1bda LP |
236 | } |
237 | ||
238 | int utmp_put_dead_process(const char *id, pid_t pid, int code, int status) { | |
863f3ce0 TG |
239 | struct utmpx lookup = { |
240 | .ut_type = INIT_PROCESS /* looks for DEAD_PROCESS, LOGIN_PROCESS, USER_PROCESS, too */ | |
241 | }, store, store_wtmp, *found; | |
169c1bda LP |
242 | |
243 | assert(id); | |
244 | ||
245 | setutxent(); | |
246 | ||
863f3ce0 | 247 | /* ut_id needs only be nul-terminated if it is shorter than sizeof(ut_id) */ |
169c1bda LP |
248 | strncpy(lookup.ut_id, sanitize_id(id), sizeof(lookup.ut_id)); |
249 | ||
e7fb33ff LP |
250 | found = getutxid(&lookup); |
251 | if (!found) | |
169c1bda LP |
252 | return 0; |
253 | ||
254 | if (found->ut_pid != pid) | |
255 | return 0; | |
256 | ||
fa4ad7ce | 257 | memcpy(&store, found, sizeof(store)); |
169c1bda LP |
258 | store.ut_type = DEAD_PROCESS; |
259 | store.ut_exit.e_termination = code; | |
260 | store.ut_exit.e_exit = status; | |
261 | ||
262 | zero(store.ut_user); | |
263 | zero(store.ut_host); | |
264 | zero(store.ut_tv); | |
265 | ||
4743137a MS |
266 | memcpy(&store_wtmp, &store, sizeof(store_wtmp)); |
267 | /* wtmp wants the current time */ | |
268 | init_timestamp(&store_wtmp, 0); | |
269 | ||
270 | return write_utmp_wtmp(&store, &store_wtmp); | |
169c1bda LP |
271 | } |
272 | ||
0ad26e09 | 273 | int utmp_put_runlevel(int runlevel, int previous) { |
863f3ce0 | 274 | struct utmpx store = {}; |
e537352b LP |
275 | int r; |
276 | ||
277 | assert(runlevel > 0); | |
278 | ||
279 | if (previous <= 0) { | |
280 | /* Find the old runlevel automatically */ | |
281 | ||
e7fb33ff LP |
282 | r = utmp_get_runlevel(&previous, NULL); |
283 | if (r < 0) { | |
d7fc909d LP |
284 | if (r != -ESRCH) |
285 | return r; | |
286 | ||
287 | previous = 0; | |
288 | } | |
e537352b LP |
289 | } |
290 | ||
4927fcae LP |
291 | if (previous == runlevel) |
292 | return 0; | |
293 | ||
0ad26e09 | 294 | init_entry(&store, 0); |
e537352b LP |
295 | |
296 | store.ut_type = RUN_LVL; | |
297 | store.ut_pid = (runlevel & 0xFF) | ((previous & 0xFF) << 8); | |
298 | strncpy(store.ut_user, "runlevel", sizeof(store.ut_user)); | |
299 | ||
300 | return write_entry_both(&store); | |
301 | } | |
ef2f1067 LP |
302 | |
303 | #define TIMEOUT_MSEC 50 | |
304 | ||
305 | static int write_to_terminal(const char *tty, const char *message) { | |
7fd1b19b | 306 | _cleanup_close_ int fd = -1; |
ef2f1067 LP |
307 | const char *p; |
308 | size_t left; | |
309 | usec_t end; | |
310 | ||
311 | assert(tty); | |
312 | assert(message); | |
313 | ||
db4a47e9 | 314 | fd = open(tty, O_WRONLY|O_NONBLOCK|O_NOCTTY|O_CLOEXEC); |
e62d8c39 | 315 | if (fd < 0 || !isatty(fd)) |
ef2f1067 LP |
316 | return -errno; |
317 | ||
ef2f1067 LP |
318 | p = message; |
319 | left = strlen(message); | |
320 | ||
321 | end = now(CLOCK_MONOTONIC) + TIMEOUT_MSEC*USEC_PER_MSEC; | |
322 | ||
323 | while (left > 0) { | |
324 | ssize_t n; | |
b92bea5d ZJS |
325 | struct pollfd pollfd = { |
326 | .fd = fd, | |
327 | .events = POLLOUT, | |
328 | }; | |
ef2f1067 LP |
329 | usec_t t; |
330 | int k; | |
331 | ||
332 | t = now(CLOCK_MONOTONIC); | |
333 | ||
e62d8c39 ZJS |
334 | if (t >= end) |
335 | return -ETIME; | |
ef2f1067 | 336 | |
e62d8c39 ZJS |
337 | k = poll(&pollfd, 1, (end - t) / USEC_PER_MSEC); |
338 | if (k < 0) | |
ef2f1067 LP |
339 | return -errno; |
340 | ||
e62d8c39 ZJS |
341 | if (k == 0) |
342 | return -ETIME; | |
ef2f1067 | 343 | |
e62d8c39 ZJS |
344 | n = write(fd, p, left); |
345 | if (n < 0) { | |
ef2f1067 LP |
346 | if (errno == EAGAIN) |
347 | continue; | |
348 | ||
e62d8c39 | 349 | return -errno; |
ef2f1067 LP |
350 | } |
351 | ||
352 | assert((size_t) n <= left); | |
353 | ||
354 | p += n; | |
355 | left -= n; | |
356 | } | |
357 | ||
e62d8c39 | 358 | return 0; |
ef2f1067 LP |
359 | } |
360 | ||
99f710dd DM |
361 | int utmp_wall( |
362 | const char *message, | |
363 | const char *username, | |
364 | const char *origin_tty, | |
365 | bool (*match_tty)(const char *tty, void *userdata), | |
366 | void *userdata) { | |
367 | ||
368 | _cleanup_free_ char *text = NULL, *hn = NULL, *un = NULL, *stdin_tty = NULL; | |
11620592 | 369 | char date[FORMAT_TIMESTAMP_MAX]; |
e7fb33ff | 370 | struct utmpx *u; |
ef2f1067 | 371 | int r; |
ef2f1067 | 372 | |
e7fb33ff | 373 | hn = gethostname_malloc(); |
9003d9b0 | 374 | if (!hn) |
e7fb33ff | 375 | return -ENOMEM; |
9003d9b0 ST |
376 | if (!username) { |
377 | un = getlogname_malloc(); | |
378 | if (!un) | |
379 | return -ENOMEM; | |
380 | } | |
ef2f1067 | 381 | |
99f710dd DM |
382 | if (!origin_tty) { |
383 | getttyname_harder(STDIN_FILENO, &stdin_tty); | |
384 | origin_tty = stdin_tty; | |
385 | } | |
ef2f1067 LP |
386 | |
387 | if (asprintf(&text, | |
388 | "\a\r\n" | |
11620592 | 389 | "Broadcast message from %s@%s%s%s (%s):\r\n\r\n" |
ef2f1067 | 390 | "%s\r\n\r\n", |
9003d9b0 | 391 | un ?: username, hn, |
99f710dd | 392 | origin_tty ? " on " : "", strempty(origin_tty), |
11620592 | 393 | format_timestamp(date, sizeof(date), now(CLOCK_REALTIME)), |
e7fb33ff LP |
394 | message) < 0) |
395 | return -ENOMEM; | |
ef2f1067 LP |
396 | |
397 | setutxent(); | |
398 | ||
399 | r = 0; | |
400 | ||
401 | while ((u = getutxent())) { | |
e7fb33ff | 402 | _cleanup_free_ char *buf = NULL; |
ef2f1067 | 403 | const char *path; |
e7fb33ff | 404 | int q; |
ef2f1067 LP |
405 | |
406 | if (u->ut_type != USER_PROCESS || u->ut_user[0] == 0) | |
407 | continue; | |
408 | ||
fbd0b64f | 409 | /* this access is fine, because STRLEN("/dev/") << 32 (UT_LINESIZE) */ |
ef2f1067 LP |
410 | if (path_startswith(u->ut_line, "/dev/")) |
411 | path = u->ut_line; | |
412 | else { | |
e7fb33ff LP |
413 | if (asprintf(&buf, "/dev/%.*s", (int) sizeof(u->ut_line), u->ut_line) < 0) |
414 | return -ENOMEM; | |
ef2f1067 LP |
415 | |
416 | path = buf; | |
417 | } | |
418 | ||
99f710dd | 419 | if (!match_tty || match_tty(path, userdata)) { |
e7fb33ff LP |
420 | q = write_to_terminal(path, text); |
421 | if (q < 0) | |
7af53310 | 422 | r = q; |
e7fb33ff | 423 | } |
ef2f1067 LP |
424 | } |
425 | ||
ef2f1067 LP |
426 | return r; |
427 | } |