]>
Commit | Line | Data |
---|---|---|
1 | /* | |
2 | * bootlogd.c Store output from the console during bootup into a file. | |
3 | * The file is usually located on the /var partition, and | |
4 | * gets written (and fsynced) as soon as possible. | |
5 | * | |
6 | * Version: @(#)bootlogd 2.86pre 12-Jan-2004 miquels@cistron.nl | |
7 | * | |
8 | * Bugs: Uses openpty(), only available in glibc. Sorry. | |
9 | * | |
10 | * This file is part of the sysvinit suite, | |
11 | * Copyright (C) 1991-2004 Miquel van Smoorenburg. | |
12 | * | |
13 | * This program is free software; you can redistribute it and/or modify | |
14 | * it under the terms of the GNU General Public License as published by | |
15 | * the Free Software Foundation; either version 2 of the License, or | |
16 | * (at your option) any later version. | |
17 | * | |
18 | * This program is distributed in the hope that it will be useful, | |
19 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
20 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
21 | * GNU General Public License for more details. | |
22 | * | |
23 | * You should have received a copy of the GNU General Public License | |
24 | * along with this program; if not, write to the Free Software | |
25 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
26 | * | |
27 | * *NOTE* *NOTE* *NOTE* | |
28 | * This is a PROOF OF CONCEPT IMPLEMENTATION | |
29 | * | |
30 | * I have bigger plans for Debian, but for now | |
31 | * this has to do ;) | |
32 | * | |
33 | */ | |
34 | ||
35 | #include <sys/types.h> | |
36 | #include <sys/time.h> | |
37 | #include <sys/stat.h> | |
38 | #include <sys/ioctl.h> | |
39 | #include <sys/utsname.h> | |
40 | #include <time.h> | |
41 | #include <stdio.h> | |
42 | #include <errno.h> | |
43 | #include <malloc.h> | |
44 | #include <stdlib.h> | |
45 | #include <unistd.h> | |
46 | #include <string.h> | |
47 | #include <signal.h> | |
48 | #include <getopt.h> | |
49 | #include <dirent.h> | |
50 | #include <fcntl.h> | |
51 | #include <pty.h> | |
52 | #include <ctype.h> | |
53 | #ifdef __linux__ | |
54 | #include <sys/mount.h> | |
55 | #endif | |
56 | ||
57 | char *Version = "@(#) bootlogd 2.86 03-Jun-2004 miquels@cistron.nl"; | |
58 | ||
59 | #define LOGFILE "/var/log/boot" | |
60 | ||
61 | char ringbuf[32768]; | |
62 | char *endptr = ringbuf + sizeof(ringbuf); | |
63 | char *inptr = ringbuf; | |
64 | char *outptr = ringbuf; | |
65 | ||
66 | int got_signal = 0; | |
67 | int didnl = 1; | |
68 | int createlogfile = 0; | |
69 | int syncalot = 0; | |
70 | ||
71 | struct line { | |
72 | char buf[256]; | |
73 | int pos; | |
74 | } line; | |
75 | ||
76 | /* | |
77 | * Console devices as listed on the kernel command line and | |
78 | * the mapping to actual devices in /dev | |
79 | */ | |
80 | struct consdev { | |
81 | char *cmdline; | |
82 | char *dev1; | |
83 | char *dev2; | |
84 | } consdev[] = { | |
85 | { "ttyB", "/dev/ttyB%s", NULL }, | |
86 | { "ttySC", "/dev/ttySC%s", "/dev/ttsc/%s" }, | |
87 | { "ttyS", "/dev/ttyS%s", "/dev/tts/%s" }, | |
88 | { "tty", "/dev/tty%s", "/dev/vc/%s" }, | |
89 | { "hvc", "/dev/hvc%s", "/dev/hvc/%s" }, | |
90 | { NULL, NULL, NULL }, | |
91 | }; | |
92 | ||
93 | /* | |
94 | * Devices to try as console if not found on kernel command line. | |
95 | * Tried from left to right (as opposed to kernel cmdline). | |
96 | */ | |
97 | char *defcons[] = { "tty0", "hvc0", "ttyS0", "ttySC0", "ttyB0", NULL }; | |
98 | ||
99 | /* | |
100 | * Catch signals. | |
101 | */ | |
102 | void handler(int sig) | |
103 | { | |
104 | got_signal = sig; | |
105 | } | |
106 | ||
107 | ||
108 | /* | |
109 | * Scan /dev and find the device name. | |
110 | * Side-effect: directory is changed to /dev | |
111 | * | |
112 | * FIXME: scan subdirectories for devfs support ? | |
113 | */ | |
114 | int findtty(char *res, int rlen, dev_t dev) | |
115 | { | |
116 | DIR *dir; | |
117 | struct dirent *ent; | |
118 | struct stat st; | |
119 | int r = 0; | |
120 | ||
121 | if (chdir("/dev") < 0 || (dir = opendir(".")) == NULL) { | |
122 | perror("bootlogd: /dev"); | |
123 | return -1; | |
124 | } | |
125 | while ((ent = readdir(dir)) != NULL) { | |
126 | if (lstat(ent->d_name, &st) != 0) | |
127 | continue; | |
128 | if (!S_ISCHR(st.st_mode)) | |
129 | continue; | |
130 | if (st.st_rdev == dev) { | |
131 | break; | |
132 | } | |
133 | } | |
134 | if (ent == NULL) { | |
135 | fprintf(stderr, "bootlogd: cannot find console device " | |
136 | "%d:%d in /dev\n", major(dev), minor(dev)); | |
137 | r = -1; | |
138 | } else if (strlen(ent->d_name) + 5 >= rlen) { | |
139 | fprintf(stderr, "bootlogd: console device name too long\n"); | |
140 | r = -1; | |
141 | } else | |
142 | snprintf(res, rlen, "/dev/%s", ent->d_name); | |
143 | closedir(dir); | |
144 | ||
145 | return r; | |
146 | } | |
147 | ||
148 | /* | |
149 | * For some reason, openpty() in glibc sometimes doesn't | |
150 | * work at boot-time. It must be a bug with old-style pty | |
151 | * names, as new-style (/dev/pts) is not available at that | |
152 | * point. So, we find a pty/tty pair ourself if openpty() | |
153 | * fails for whatever reason. | |
154 | */ | |
155 | int findpty(int *master, int *slave, char *name) | |
156 | { | |
157 | char pty[16]; | |
158 | char tty[16]; | |
159 | int i, j; | |
160 | int found; | |
161 | ||
162 | if (openpty(master, slave, name, NULL, NULL) >= 0) | |
163 | return 0; | |
164 | ||
165 | found = 0; | |
166 | ||
167 | for (i = 'p'; i <= 'z'; i++) { | |
168 | for (j = '0'; j <= 'f'; j++) { | |
169 | if (j == '9' + 1) j = 'a'; | |
170 | sprintf(pty, "/dev/pty%c%c", i, j); | |
171 | sprintf(tty, "/dev/tty%c%c", i, j); | |
172 | if ((*master = open(pty, O_RDWR|O_NOCTTY)) >= 0) { | |
173 | *slave = open(tty, O_RDWR|O_NOCTTY); | |
174 | if (*slave >= 0) { | |
175 | found = 1; | |
176 | break; | |
177 | } | |
178 | } | |
179 | } | |
180 | if (found) break; | |
181 | } | |
182 | if (found < 0) return -1; | |
183 | ||
184 | if (name) strcpy(name, tty); | |
185 | ||
186 | return 0; | |
187 | } | |
188 | /* | |
189 | * See if a console taken from the kernel command line maps | |
190 | * to a character device we know about, and if we can open it. | |
191 | */ | |
192 | int isconsole(char *s, char *res, int rlen) | |
193 | { | |
194 | struct consdev *c; | |
195 | int l, sl, i, fd; | |
196 | char *p, *q; | |
197 | ||
198 | sl = strlen(s); | |
199 | ||
200 | for (c = consdev; c->cmdline; c++) { | |
201 | l = strlen(c->cmdline); | |
202 | if (sl <= l) continue; | |
203 | p = s + l; | |
204 | if (strncmp(s, c->cmdline, l) != 0 || !isdigit(*p)) | |
205 | continue; | |
206 | for (i = 0; i < 2; i++) { | |
207 | snprintf(res, rlen, i ? c->dev1 : c->dev2, p); | |
208 | if ((q = strchr(res, ',')) != NULL) *q = 0; | |
209 | if ((fd = open(res, O_RDONLY|O_NONBLOCK)) >= 0) { | |
210 | close(fd); | |
211 | return 1; | |
212 | } | |
213 | } | |
214 | } | |
215 | return 0; | |
216 | } | |
217 | ||
218 | /* | |
219 | * Find out the _real_ console. Assume that stdin is connected to | |
220 | * the console device (/dev/console). | |
221 | */ | |
222 | int consolename(char *res, int rlen) | |
223 | { | |
224 | #ifdef TIOCGDEV | |
225 | unsigned int kdev; | |
226 | #endif | |
227 | struct stat st, st2; | |
228 | char buf[256]; | |
229 | char *p; | |
230 | int didmount = 0; | |
231 | int n, r; | |
232 | int fd; | |
233 | ||
234 | fstat(0, &st); | |
235 | if (major(st.st_rdev) != 5 || minor(st.st_rdev) != 1) { | |
236 | /* | |
237 | * Old kernel, can find real device easily. | |
238 | */ | |
239 | return findtty(res, rlen, st.st_rdev); | |
240 | } | |
241 | ||
242 | #ifdef TIOCGDEV | |
243 | if (ioctl(0, TIOCGDEV, &kdev) == 0) | |
244 | return findtty(res, rlen, (dev_t)kdev); | |
245 | if (errno != ENOIOCTLCMD) return -1; | |
246 | #endif | |
247 | ||
248 | #ifdef __linux__ | |
249 | /* | |
250 | * Read /proc/cmdline. | |
251 | */ | |
252 | stat("/", &st); | |
253 | if (stat("/proc", &st2) < 0) { | |
254 | perror("bootlogd: /proc"); | |
255 | return -1; | |
256 | } | |
257 | if (st.st_dev == st2.st_dev) { | |
258 | if (mount("proc", "/proc", "proc", 0, NULL) < 0) { | |
259 | perror("bootlogd: mount /proc"); | |
260 | return -1; | |
261 | } | |
262 | didmount = 1; | |
263 | } | |
264 | ||
265 | n = 0; | |
266 | r = -1; | |
267 | if ((fd = open("/proc/cmdline", O_RDONLY)) < 0) { | |
268 | perror("bootlogd: /proc/cmdline"); | |
269 | } else { | |
270 | buf[0] = 0; | |
271 | if ((n = read(fd, buf, sizeof(buf) - 1)) >= 0) | |
272 | r = 0; | |
273 | else | |
274 | perror("bootlogd: /proc/cmdline"); | |
275 | close(fd); | |
276 | } | |
277 | if (didmount) umount("/proc"); | |
278 | ||
279 | if (r < 0) return r; | |
280 | ||
281 | /* | |
282 | * OK, so find console= in /proc/cmdline. | |
283 | * Parse in reverse, opening as we go. | |
284 | */ | |
285 | p = buf + n; | |
286 | *p-- = 0; | |
287 | r = -1; | |
288 | while (p >= buf) { | |
289 | if (*p == ' ' || *p == '\t' || *p == '\r' || *p == '\n') { | |
290 | *p-- = 0; | |
291 | continue; | |
292 | } | |
293 | if (strncmp(p, "console=", 8) == 0 && | |
294 | isconsole(p + 8, res, rlen)) { | |
295 | r = 0; | |
296 | break; | |
297 | } | |
298 | p--; | |
299 | } | |
300 | ||
301 | if (r == 0) return r; | |
302 | #endif | |
303 | ||
304 | /* | |
305 | * Okay, no console on the command line - | |
306 | * guess the default console. | |
307 | */ | |
308 | for (n = 0; defcons[n]; n++) | |
309 | if (isconsole(defcons[n], res, rlen)) | |
310 | return 0; | |
311 | ||
312 | fprintf(stderr, "bootlogd: cannot deduce real console device\n"); | |
313 | ||
314 | return -1; | |
315 | } | |
316 | ||
317 | ||
318 | /* | |
319 | * Write data and make sure it's on disk. | |
320 | */ | |
321 | void writelog(FILE *fp, unsigned char *ptr, int len) | |
322 | { | |
323 | time_t t; | |
324 | char *s; | |
325 | char tmp[8]; | |
326 | int olen = len; | |
327 | int dosync = 0; | |
328 | int tlen; | |
329 | ||
330 | while (len > 0) { | |
331 | tmp[0] = 0; | |
332 | if (didnl) { | |
333 | time(&t); | |
334 | s = ctime(&t); | |
335 | fprintf(fp, "%.24s: ", s); | |
336 | didnl = 0; | |
337 | } | |
338 | switch (*ptr) { | |
339 | case 27: /* ESC */ | |
340 | strcpy(tmp, "^["); | |
341 | break; | |
342 | case '\r': | |
343 | line.pos = 0; | |
344 | break; | |
345 | case 8: /* ^H */ | |
346 | if (line.pos > 0) line.pos--; | |
347 | break; | |
348 | case '\n': | |
349 | didnl = 1; | |
350 | dosync = syncalot; | |
351 | break; | |
352 | case '\t': | |
353 | line.pos += (line.pos / 8 + 1) * 8; | |
354 | if (line.pos >= sizeof(line.buf)) | |
355 | line.pos = sizeof(line.buf) - 1; | |
356 | break; | |
357 | case 32 ... 127: | |
358 | case 161 ... 255: | |
359 | tmp[0] = *ptr; | |
360 | tmp[1] = 0; | |
361 | break; | |
362 | default: | |
363 | sprintf(tmp, "\\%03o", *ptr); | |
364 | break; | |
365 | } | |
366 | ptr++; | |
367 | len--; | |
368 | ||
369 | tlen = strlen(tmp); | |
370 | if (tlen && (line.pos + tlen < sizeof(line.buf))) { | |
371 | memcpy(line.buf + line.pos, tmp, tlen); | |
372 | line.pos += tlen; | |
373 | } | |
374 | if (didnl) { | |
375 | fprintf(fp, "%s\n", line.buf); | |
376 | memset(&line, 0, sizeof(line)); | |
377 | } | |
378 | } | |
379 | ||
380 | if (dosync) { | |
381 | fflush(fp); | |
382 | fdatasync(fileno(fp)); | |
383 | } | |
384 | ||
385 | outptr += olen; | |
386 | if (outptr >= endptr) | |
387 | outptr = ringbuf; | |
388 | ||
389 | } | |
390 | ||
391 | ||
392 | /* | |
393 | * Print usage message and exit. | |
394 | */ | |
395 | void usage(void) | |
396 | { | |
397 | fprintf(stderr, "Usage: bootlogd [-v] [-r] [-d] [-s] [-c] [-p pidfile] [-l logfile]\n"); | |
398 | exit(1); | |
399 | } | |
400 | ||
401 | int open_nb(char *buf) | |
402 | { | |
403 | int fd, n; | |
404 | ||
405 | if ((fd = open(buf, O_WRONLY|O_NONBLOCK|O_NOCTTY)) < 0) | |
406 | return -1; | |
407 | n = fcntl(fd, F_GETFL); | |
408 | n &= ~(O_NONBLOCK); | |
409 | fcntl(fd, F_SETFL, n); | |
410 | ||
411 | return fd; | |
412 | } | |
413 | ||
414 | /* | |
415 | * We got a write error on the real console. If its an EIO, | |
416 | * somebody hung up our filedescriptor, so try to re-open it. | |
417 | */ | |
418 | int write_err(int pts, int realfd, char *realcons, int e) | |
419 | { | |
420 | int fd; | |
421 | ||
422 | if (e != EIO) { | |
423 | werr: | |
424 | close(pts); | |
425 | fprintf(stderr, "bootlogd: writing to console: %s\n", | |
426 | strerror(e)); | |
427 | return -1; | |
428 | } | |
429 | close(realfd); | |
430 | if ((fd = open_nb(realcons)) < 0) | |
431 | goto werr; | |
432 | ||
433 | return fd; | |
434 | } | |
435 | ||
436 | int main(int argc, char **argv) | |
437 | { | |
438 | FILE *fp; | |
439 | struct timeval tv; | |
440 | fd_set fds; | |
441 | char buf[1024]; | |
442 | char realcons[1024]; | |
443 | char *p; | |
444 | char *logfile; | |
445 | char *pidfile; | |
446 | int rotate; | |
447 | int dontfork; | |
448 | int ptm, pts; | |
449 | int realfd; | |
450 | int n, m, i; | |
451 | int todo; | |
452 | ||
453 | fp = NULL; | |
454 | logfile = LOGFILE; | |
455 | pidfile = NULL; | |
456 | rotate = 0; | |
457 | dontfork = 0; | |
458 | ||
459 | while ((i = getopt(argc, argv, "cdsl:p:rv")) != EOF) switch(i) { | |
460 | case 'l': | |
461 | logfile = optarg; | |
462 | break; | |
463 | case 'r': | |
464 | rotate = 1; | |
465 | break; | |
466 | case 'v': | |
467 | printf("%s\n", Version); | |
468 | exit(0); | |
469 | break; | |
470 | case 'p': | |
471 | pidfile = optarg; | |
472 | break; | |
473 | case 'c': | |
474 | createlogfile = 1; | |
475 | break; | |
476 | case 'd': | |
477 | dontfork = 1; | |
478 | break; | |
479 | case 's': | |
480 | syncalot = 1; | |
481 | break; | |
482 | default: | |
483 | usage(); | |
484 | break; | |
485 | } | |
486 | if (optind < argc) usage(); | |
487 | ||
488 | signal(SIGTERM, handler); | |
489 | signal(SIGQUIT, handler); | |
490 | signal(SIGINT, handler); | |
491 | signal(SIGTTIN, SIG_IGN); | |
492 | signal(SIGTTOU, SIG_IGN); | |
493 | signal(SIGTSTP, SIG_IGN); | |
494 | ||
495 | /* | |
496 | * Open console device directly. | |
497 | */ | |
498 | if (consolename(realcons, sizeof(realcons)) < 0) | |
499 | return 1; | |
500 | ||
501 | if (strcmp(realcons, "/dev/tty0") == 0) | |
502 | strcpy(realcons, "/dev/tty1"); | |
503 | if (strcmp(realcons, "/dev/vc/0") == 0) | |
504 | strcpy(realcons, "/dev/vc/1"); | |
505 | ||
506 | if ((realfd = open_nb(realcons)) < 0) { | |
507 | fprintf(stderr, "bootlogd: %s: %s\n", buf, strerror(errno)); | |
508 | return 1; | |
509 | } | |
510 | ||
511 | /* | |
512 | * Grab a pty, and redirect console messages to it. | |
513 | */ | |
514 | ptm = -1; | |
515 | pts = -1; | |
516 | buf[0] = 0; | |
517 | if (findpty(&ptm, &pts, buf) < 0) { | |
518 | fprintf(stderr, | |
519 | "bootlogd: cannot allocate pseudo tty: %s\n", | |
520 | strerror(errno)); | |
521 | return 1; | |
522 | } | |
523 | ||
524 | (void)ioctl(0, TIOCCONS, NULL); | |
525 | #if 1 | |
526 | /* Work around bug in 2.1/2.2 kernels. Fixed in 2.2.13 and 2.3.18 */ | |
527 | if ((n = open("/dev/tty0", O_RDWR)) >= 0) { | |
528 | (void)ioctl(n, TIOCCONS, NULL); | |
529 | close(n); | |
530 | } | |
531 | #endif | |
532 | if (ioctl(pts, TIOCCONS, NULL) < 0) { | |
533 | fprintf(stderr, "bootlogd: ioctl(%s, TIOCCONS): %s\n", | |
534 | buf, strerror(errno)); | |
535 | return 1; | |
536 | } | |
537 | ||
538 | /* | |
539 | * Fork and write pidfile if needed. | |
540 | */ | |
541 | if (!dontfork) { | |
542 | pid_t child_pid = fork(); | |
543 | switch (child_pid) { | |
544 | case -1: /* I am parent and the attempt to create a child failed */ | |
545 | fprintf(stderr, "bootlogd: fork failed: %s\n", | |
546 | strerror(errno)); | |
547 | exit(1); | |
548 | break; | |
549 | case 0: /* I am the child */ | |
550 | break; | |
551 | default: /* I am parent and got child's pid */ | |
552 | exit(0); | |
553 | break; | |
554 | } | |
555 | setsid(); | |
556 | } | |
557 | if (pidfile) { | |
558 | unlink(pidfile); | |
559 | if ((fp = fopen(pidfile, "w")) != NULL) { | |
560 | fprintf(fp, "%d\n", (int)getpid()); | |
561 | fclose(fp); | |
562 | } | |
563 | fp = NULL; | |
564 | } | |
565 | ||
566 | /* | |
567 | * Read the console messages from the pty, and write | |
568 | * to the real console and the logfile. | |
569 | */ | |
570 | while (!got_signal) { | |
571 | ||
572 | /* | |
573 | * We timeout after 5 seconds if we still need to | |
574 | * open the logfile. There might be buffered messages | |
575 | * we want to write. | |
576 | */ | |
577 | tv.tv_sec = 0; | |
578 | tv.tv_usec = 500000; | |
579 | FD_ZERO(&fds); | |
580 | FD_SET(ptm, &fds); | |
581 | if (select(ptm + 1, &fds, NULL, NULL, &tv) == 1) { | |
582 | /* | |
583 | * See how much space there is left, read. | |
584 | */ | |
585 | if ((n = read(ptm, inptr, endptr - inptr)) >= 0) { | |
586 | /* | |
587 | * Write data (in chunks if needed) | |
588 | * to the real output device. | |
589 | */ | |
590 | m = n; | |
591 | p = inptr; | |
592 | while (m > 0) { | |
593 | i = write(realfd, p, m); | |
594 | if (i >= 0) { | |
595 | m -= i; | |
596 | p += i; | |
597 | continue; | |
598 | } | |
599 | /* | |
600 | * Handle EIO (somebody hung | |
601 | * up our filedescriptor) | |
602 | */ | |
603 | realfd = write_err(pts, realfd, | |
604 | realcons, errno); | |
605 | if (realfd >= 0) continue; | |
606 | got_signal = 1; /* Not really */ | |
607 | break; | |
608 | } | |
609 | ||
610 | /* | |
611 | * Increment buffer position. Handle | |
612 | * wraps, and also drag output pointer | |
613 | * along if we cross it. | |
614 | */ | |
615 | inptr += n; | |
616 | if (inptr - n < outptr && inptr > outptr) | |
617 | outptr = inptr; | |
618 | if (inptr >= endptr) | |
619 | inptr = ringbuf; | |
620 | if (outptr >= endptr) | |
621 | outptr = ringbuf; | |
622 | } | |
623 | } | |
624 | ||
625 | /* | |
626 | * Perhaps we need to open the logfile. | |
627 | */ | |
628 | if (fp == NULL && access(logfile, F_OK) == 0) { | |
629 | if (rotate) { | |
630 | snprintf(buf, sizeof(buf), "%s~", logfile); | |
631 | rename(logfile, buf); | |
632 | } | |
633 | fp = fopen(logfile, "a"); | |
634 | } | |
635 | if (fp == NULL && createlogfile) | |
636 | fp = fopen(logfile, "a"); | |
637 | ||
638 | if (inptr >= outptr) | |
639 | todo = inptr - outptr; | |
640 | else | |
641 | todo = endptr - outptr; | |
642 | if (fp && todo) | |
643 | writelog(fp, outptr, todo); | |
644 | } | |
645 | ||
646 | if (fp) { | |
647 | if (!didnl) fputc('\n', fp); | |
648 | fclose(fp); | |
649 | } | |
650 | ||
651 | close(pts); | |
652 | close(ptm); | |
653 | close(realfd); | |
654 | ||
655 | return 0; | |
656 | } | |
657 |