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d6c9574f | 1 | /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
e537352b LP |
2 | |
3 | /*** | |
4 | This file is part of systemd. | |
5 | ||
6 | Copyright 2010 Lennart Poettering | |
7 | ||
8 | systemd is free software; you can redistribute it and/or modify it | |
5430f7f2 LP |
9 | under the terms of the GNU Lesser General Public License as published by |
10 | the Free Software Foundation; either version 2.1 of the License, or | |
e537352b LP |
11 | (at your option) any later version. |
12 | ||
13 | systemd is distributed in the hope that it will be useful, but | |
14 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
5430f7f2 | 16 | Lesser General Public License for more details. |
e537352b | 17 | |
5430f7f2 | 18 | You should have received a copy of the GNU Lesser General Public License |
e537352b LP |
19 | along with systemd; If not, see <http://www.gnu.org/licenses/>. |
20 | ***/ | |
21 | ||
22 | #include <utmpx.h> | |
23 | #include <errno.h> | |
24 | #include <assert.h> | |
25 | #include <string.h> | |
26 | #include <sys/utsname.h> | |
ef2f1067 LP |
27 | #include <fcntl.h> |
28 | #include <unistd.h> | |
0a6f50c0 | 29 | #include <poll.h> |
e537352b LP |
30 | |
31 | #include "macro.h" | |
9eb977db | 32 | #include "path-util.h" |
e537352b LP |
33 | #include "utmp-wtmp.h" |
34 | ||
35 | int utmp_get_runlevel(int *runlevel, int *previous) { | |
b92bea5d | 36 | struct utmpx *found, lookup = { .ut_type = RUN_LVL }; |
e537352b LP |
37 | int r; |
38 | const char *e; | |
39 | ||
40 | assert(runlevel); | |
41 | ||
42 | /* If these values are set in the environment this takes | |
43 | * precedence. Presumably, sysvinit does this to work around a | |
44 | * race condition that would otherwise exist where we'd always | |
45 | * go to disk and hence might read runlevel data that might be | |
46 | * very new and does not apply to the current script being | |
47 | * executed. */ | |
48 | ||
e7fb33ff LP |
49 | e = getenv("RUNLEVEL"); |
50 | if (e && e[0] > 0) { | |
e537352b LP |
51 | *runlevel = e[0]; |
52 | ||
53 | if (previous) { | |
54 | /* $PREVLEVEL seems to be an Upstart thing */ | |
55 | ||
e7fb33ff LP |
56 | e = getenv("PREVLEVEL"); |
57 | if (e && e[0] > 0) | |
e537352b LP |
58 | *previous = e[0]; |
59 | else | |
60 | *previous = 0; | |
61 | } | |
62 | ||
63 | return 0; | |
64 | } | |
65 | ||
66 | if (utmpxname(_PATH_UTMPX) < 0) | |
67 | return -errno; | |
68 | ||
69 | setutxent(); | |
70 | ||
e7fb33ff LP |
71 | found = getutxid(&lookup); |
72 | if (!found) | |
e537352b LP |
73 | r = -errno; |
74 | else { | |
75 | int a, b; | |
76 | ||
77 | a = found->ut_pid & 0xFF; | |
78 | b = (found->ut_pid >> 8) & 0xFF; | |
79 | ||
4dd1de72 ZJS |
80 | *runlevel = a; |
81 | if (previous) | |
82 | *previous = b; | |
83 | ||
84 | r = 0; | |
e537352b LP |
85 | } |
86 | ||
87 | endutxent(); | |
88 | ||
89 | return r; | |
90 | } | |
91 | ||
169c1bda | 92 | static void init_timestamp(struct utmpx *store, usec_t t) { |
e537352b LP |
93 | assert(store); |
94 | ||
871d7de4 LP |
95 | if (t <= 0) |
96 | t = now(CLOCK_REALTIME); | |
e537352b | 97 | |
871d7de4 LP |
98 | store->ut_tv.tv_sec = t / USEC_PER_SEC; |
99 | store->ut_tv.tv_usec = t % USEC_PER_SEC; | |
169c1bda LP |
100 | } |
101 | ||
102 | static void init_entry(struct utmpx *store, usec_t t) { | |
b92bea5d | 103 | struct utsname uts = {}; |
169c1bda LP |
104 | |
105 | assert(store); | |
106 | ||
107 | init_timestamp(store, t); | |
108 | ||
e537352b LP |
109 | if (uname(&uts) >= 0) |
110 | strncpy(store->ut_host, uts.release, sizeof(store->ut_host)); | |
111 | ||
112 | strncpy(store->ut_line, "~", sizeof(store->ut_line)); /* or ~~ ? */ | |
113 | strncpy(store->ut_id, "~~", sizeof(store->ut_id)); | |
114 | } | |
115 | ||
116 | static int write_entry_utmp(const struct utmpx *store) { | |
117 | int r; | |
118 | ||
119 | assert(store); | |
120 | ||
121 | /* utmp is similar to wtmp, but there is only one entry for | |
122 | * each entry type resp. user; i.e. basically a key/value | |
123 | * table. */ | |
124 | ||
125 | if (utmpxname(_PATH_UTMPX) < 0) | |
126 | return -errno; | |
127 | ||
128 | setutxent(); | |
129 | ||
130 | if (!pututxline(store)) | |
131 | r = -errno; | |
132 | else | |
133 | r = 0; | |
134 | ||
135 | endutxent(); | |
136 | ||
137 | return r; | |
138 | } | |
139 | ||
140 | static int write_entry_wtmp(const struct utmpx *store) { | |
141 | assert(store); | |
142 | ||
143 | /* wtmp is a simple append-only file where each entry is | |
863f3ce0 | 144 | simply appended to the end; i.e. basically a log. */ |
e537352b LP |
145 | |
146 | errno = 0; | |
147 | updwtmpx(_PATH_WTMPX, store); | |
148 | return -errno; | |
149 | } | |
150 | ||
4743137a | 151 | static int write_utmp_wtmp(const struct utmpx *store_utmp, const struct utmpx *store_wtmp) { |
e537352b LP |
152 | int r, s; |
153 | ||
4743137a MS |
154 | r = write_entry_utmp(store_utmp); |
155 | s = write_entry_wtmp(store_wtmp); | |
e537352b LP |
156 | |
157 | if (r >= 0) | |
158 | r = s; | |
159 | ||
160 | /* If utmp/wtmp have been disabled, that's a good thing, hence | |
161 | * ignore the errors */ | |
162 | if (r == -ENOENT) | |
163 | r = 0; | |
164 | ||
165 | return r; | |
166 | } | |
167 | ||
4743137a MS |
168 | static int write_entry_both(const struct utmpx *store) { |
169 | return write_utmp_wtmp(store, store); | |
170 | } | |
171 | ||
0ad26e09 | 172 | int utmp_put_shutdown(void) { |
863f3ce0 | 173 | struct utmpx store = {}; |
e537352b | 174 | |
0ad26e09 | 175 | init_entry(&store, 0); |
e537352b LP |
176 | |
177 | store.ut_type = RUN_LVL; | |
178 | strncpy(store.ut_user, "shutdown", sizeof(store.ut_user)); | |
179 | ||
180 | return write_entry_both(&store); | |
181 | } | |
182 | ||
871d7de4 | 183 | int utmp_put_reboot(usec_t t) { |
863f3ce0 | 184 | struct utmpx store = {}; |
e537352b | 185 | |
871d7de4 | 186 | init_entry(&store, t); |
e537352b LP |
187 | |
188 | store.ut_type = BOOT_TIME; | |
55e39f40 | 189 | strncpy(store.ut_user, "reboot", sizeof(store.ut_user)); |
e537352b LP |
190 | |
191 | return write_entry_both(&store); | |
192 | } | |
193 | ||
44a6b1b6 | 194 | _pure_ static const char *sanitize_id(const char *id) { |
169c1bda LP |
195 | size_t l; |
196 | ||
197 | assert(id); | |
198 | l = strlen(id); | |
199 | ||
200 | if (l <= sizeof(((struct utmpx*) NULL)->ut_id)) | |
201 | return id; | |
202 | ||
203 | return id + l - sizeof(((struct utmpx*) NULL)->ut_id); | |
204 | } | |
205 | ||
0ad26e09 | 206 | int utmp_put_init_process(const char *id, pid_t pid, pid_t sid, const char *line) { |
863f3ce0 TG |
207 | struct utmpx store = { |
208 | .ut_type = INIT_PROCESS, | |
209 | .ut_pid = pid, | |
210 | .ut_session = sid, | |
211 | }; | |
169c1bda LP |
212 | |
213 | assert(id); | |
214 | ||
0ad26e09 | 215 | init_timestamp(&store, 0); |
169c1bda | 216 | |
863f3ce0 | 217 | /* ut_id needs only be nul-terminated if it is shorter than sizeof(ut_id) */ |
169c1bda LP |
218 | strncpy(store.ut_id, sanitize_id(id), sizeof(store.ut_id)); |
219 | ||
220 | if (line) | |
2b6bf07d | 221 | strncpy(store.ut_line, basename(line), sizeof(store.ut_line)); |
169c1bda LP |
222 | |
223 | return write_entry_both(&store); | |
224 | } | |
225 | ||
226 | int utmp_put_dead_process(const char *id, pid_t pid, int code, int status) { | |
863f3ce0 TG |
227 | struct utmpx lookup = { |
228 | .ut_type = INIT_PROCESS /* looks for DEAD_PROCESS, LOGIN_PROCESS, USER_PROCESS, too */ | |
229 | }, store, store_wtmp, *found; | |
169c1bda LP |
230 | |
231 | assert(id); | |
232 | ||
233 | setutxent(); | |
234 | ||
863f3ce0 | 235 | /* ut_id needs only be nul-terminated if it is shorter than sizeof(ut_id) */ |
169c1bda LP |
236 | strncpy(lookup.ut_id, sanitize_id(id), sizeof(lookup.ut_id)); |
237 | ||
e7fb33ff LP |
238 | found = getutxid(&lookup); |
239 | if (!found) | |
169c1bda LP |
240 | return 0; |
241 | ||
242 | if (found->ut_pid != pid) | |
243 | return 0; | |
244 | ||
fa4ad7ce | 245 | memcpy(&store, found, sizeof(store)); |
169c1bda LP |
246 | store.ut_type = DEAD_PROCESS; |
247 | store.ut_exit.e_termination = code; | |
248 | store.ut_exit.e_exit = status; | |
249 | ||
250 | zero(store.ut_user); | |
251 | zero(store.ut_host); | |
252 | zero(store.ut_tv); | |
253 | ||
4743137a MS |
254 | memcpy(&store_wtmp, &store, sizeof(store_wtmp)); |
255 | /* wtmp wants the current time */ | |
256 | init_timestamp(&store_wtmp, 0); | |
257 | ||
258 | return write_utmp_wtmp(&store, &store_wtmp); | |
169c1bda LP |
259 | } |
260 | ||
261 | ||
0ad26e09 | 262 | int utmp_put_runlevel(int runlevel, int previous) { |
863f3ce0 | 263 | struct utmpx store = {}; |
e537352b LP |
264 | int r; |
265 | ||
266 | assert(runlevel > 0); | |
267 | ||
268 | if (previous <= 0) { | |
269 | /* Find the old runlevel automatically */ | |
270 | ||
e7fb33ff LP |
271 | r = utmp_get_runlevel(&previous, NULL); |
272 | if (r < 0) { | |
d7fc909d LP |
273 | if (r != -ESRCH) |
274 | return r; | |
275 | ||
276 | previous = 0; | |
277 | } | |
e537352b LP |
278 | } |
279 | ||
4927fcae LP |
280 | if (previous == runlevel) |
281 | return 0; | |
282 | ||
0ad26e09 | 283 | init_entry(&store, 0); |
e537352b LP |
284 | |
285 | store.ut_type = RUN_LVL; | |
286 | store.ut_pid = (runlevel & 0xFF) | ((previous & 0xFF) << 8); | |
287 | strncpy(store.ut_user, "runlevel", sizeof(store.ut_user)); | |
288 | ||
289 | return write_entry_both(&store); | |
290 | } | |
ef2f1067 LP |
291 | |
292 | #define TIMEOUT_MSEC 50 | |
293 | ||
294 | static int write_to_terminal(const char *tty, const char *message) { | |
7fd1b19b | 295 | _cleanup_close_ int fd = -1; |
ef2f1067 LP |
296 | const char *p; |
297 | size_t left; | |
298 | usec_t end; | |
299 | ||
300 | assert(tty); | |
301 | assert(message); | |
302 | ||
e62d8c39 ZJS |
303 | fd = open(tty, O_WRONLY|O_NDELAY|O_NOCTTY|O_CLOEXEC); |
304 | if (fd < 0 || !isatty(fd)) | |
ef2f1067 LP |
305 | return -errno; |
306 | ||
ef2f1067 LP |
307 | p = message; |
308 | left = strlen(message); | |
309 | ||
310 | end = now(CLOCK_MONOTONIC) + TIMEOUT_MSEC*USEC_PER_MSEC; | |
311 | ||
312 | while (left > 0) { | |
313 | ssize_t n; | |
b92bea5d ZJS |
314 | struct pollfd pollfd = { |
315 | .fd = fd, | |
316 | .events = POLLOUT, | |
317 | }; | |
ef2f1067 LP |
318 | usec_t t; |
319 | int k; | |
320 | ||
321 | t = now(CLOCK_MONOTONIC); | |
322 | ||
e62d8c39 ZJS |
323 | if (t >= end) |
324 | return -ETIME; | |
ef2f1067 | 325 | |
e62d8c39 ZJS |
326 | k = poll(&pollfd, 1, (end - t) / USEC_PER_MSEC); |
327 | if (k < 0) | |
ef2f1067 LP |
328 | return -errno; |
329 | ||
e62d8c39 ZJS |
330 | if (k == 0) |
331 | return -ETIME; | |
ef2f1067 | 332 | |
e62d8c39 ZJS |
333 | n = write(fd, p, left); |
334 | if (n < 0) { | |
ef2f1067 LP |
335 | if (errno == EAGAIN) |
336 | continue; | |
337 | ||
e62d8c39 | 338 | return -errno; |
ef2f1067 LP |
339 | } |
340 | ||
341 | assert((size_t) n <= left); | |
342 | ||
343 | p += n; | |
344 | left -= n; | |
345 | } | |
346 | ||
e62d8c39 | 347 | return 0; |
ef2f1067 LP |
348 | } |
349 | ||
9003d9b0 | 350 | int utmp_wall(const char *message, const char *username, bool (*match_tty)(const char *tty)) { |
e7fb33ff | 351 | _cleanup_free_ char *text = NULL, *hn = NULL, *un = NULL, *tty = NULL; |
11620592 | 352 | char date[FORMAT_TIMESTAMP_MAX]; |
e7fb33ff | 353 | struct utmpx *u; |
ef2f1067 | 354 | int r; |
ef2f1067 | 355 | |
e7fb33ff | 356 | hn = gethostname_malloc(); |
9003d9b0 | 357 | if (!hn) |
e7fb33ff | 358 | return -ENOMEM; |
9003d9b0 ST |
359 | if (!username) { |
360 | un = getlogname_malloc(); | |
361 | if (!un) | |
362 | return -ENOMEM; | |
363 | } | |
ef2f1067 | 364 | |
fc116c6a | 365 | getttyname_harder(STDIN_FILENO, &tty); |
ef2f1067 LP |
366 | |
367 | if (asprintf(&text, | |
368 | "\a\r\n" | |
11620592 | 369 | "Broadcast message from %s@%s%s%s (%s):\r\n\r\n" |
ef2f1067 | 370 | "%s\r\n\r\n", |
9003d9b0 | 371 | un ?: username, hn, |
11620592 LP |
372 | tty ? " on " : "", strempty(tty), |
373 | format_timestamp(date, sizeof(date), now(CLOCK_REALTIME)), | |
e7fb33ff LP |
374 | message) < 0) |
375 | return -ENOMEM; | |
ef2f1067 LP |
376 | |
377 | setutxent(); | |
378 | ||
379 | r = 0; | |
380 | ||
381 | while ((u = getutxent())) { | |
e7fb33ff | 382 | _cleanup_free_ char *buf = NULL; |
ef2f1067 | 383 | const char *path; |
e7fb33ff | 384 | int q; |
ef2f1067 LP |
385 | |
386 | if (u->ut_type != USER_PROCESS || u->ut_user[0] == 0) | |
387 | continue; | |
388 | ||
26888876 | 389 | /* this access is fine, because strlen("/dev/") << 32 (UT_LINESIZE) */ |
ef2f1067 LP |
390 | if (path_startswith(u->ut_line, "/dev/")) |
391 | path = u->ut_line; | |
392 | else { | |
e7fb33ff LP |
393 | if (asprintf(&buf, "/dev/%.*s", (int) sizeof(u->ut_line), u->ut_line) < 0) |
394 | return -ENOMEM; | |
ef2f1067 LP |
395 | |
396 | path = buf; | |
397 | } | |
398 | ||
e7fb33ff LP |
399 | if (!match_tty || match_tty(path)) { |
400 | q = write_to_terminal(path, text); | |
401 | if (q < 0) | |
7af53310 | 402 | r = q; |
e7fb33ff | 403 | } |
ef2f1067 LP |
404 | } |
405 | ||
ef2f1067 LP |
406 | return r; |
407 | } |