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[thirdparty/util-linux.git] / sys-utils / dmesg.c
1 /*
2 * dmesg.c -- Print out the contents of the kernel ring buffer
3 *
4 * Copyright (C) 1993 Theodore Ts'o <tytso@athena.mit.edu>
5 * Copyright (C) 2011 Karel Zak <kzak@redhat.com>
6 *
7 * This program comes with ABSOLUTELY NO WARRANTY.
8 */
9 #include <stdio.h>
10 #include <getopt.h>
11 #include <stdlib.h>
12 #include <sys/klog.h>
13 #include <sys/syslog.h>
14 #include <sys/time.h>
15 #include <sys/sysinfo.h>
16 #include <ctype.h>
17 #include <time.h>
18 #include <sys/mman.h>
19 #include <sys/types.h>
20 #include <sys/stat.h>
21 #include <unistd.h>
22 #include <fcntl.h>
23
24 #include "c.h"
25 #include "colors.h"
26 #include "nls.h"
27 #include "strutils.h"
28 #include "xalloc.h"
29 #include "widechar.h"
30 #include "all-io.h"
31 #include "bitops.h"
32 #include "closestream.h"
33 #include "optutils.h"
34 #include "timeutils.h"
35 #include "monotonic.h"
36 #include "mangle.h"
37 #include "pager.h"
38
39 /* Close the log. Currently a NOP. */
40 #define SYSLOG_ACTION_CLOSE 0
41 /* Open the log. Currently a NOP. */
42 #define SYSLOG_ACTION_OPEN 1
43 /* Read from the log. */
44 #define SYSLOG_ACTION_READ 2
45 /* Read all messages remaining in the ring buffer. (allowed for non-root) */
46 #define SYSLOG_ACTION_READ_ALL 3
47 /* Read and clear all messages remaining in the ring buffer */
48 #define SYSLOG_ACTION_READ_CLEAR 4
49 /* Clear ring buffer. */
50 #define SYSLOG_ACTION_CLEAR 5
51 /* Disable printk's to console */
52 #define SYSLOG_ACTION_CONSOLE_OFF 6
53 /* Enable printk's to console */
54 #define SYSLOG_ACTION_CONSOLE_ON 7
55 /* Set level of messages printed to console */
56 #define SYSLOG_ACTION_CONSOLE_LEVEL 8
57 /* Return number of unread characters in the log buffer */
58 #define SYSLOG_ACTION_SIZE_UNREAD 9
59 /* Return size of the log buffer */
60 #define SYSLOG_ACTION_SIZE_BUFFER 10
61
62 /*
63 * Color scheme
64 */
65 struct dmesg_color {
66 const char *scheme; /* name used in termina-colors.d/dmesg.scheme */
67 const char *dflt; /* default color ESC sequence */
68 };
69
70 enum {
71 DMESG_COLOR_SUBSYS,
72 DMESG_COLOR_TIME,
73 DMESG_COLOR_TIMEBREAK,
74 DMESG_COLOR_ALERT,
75 DMESG_COLOR_CRIT,
76 DMESG_COLOR_ERR,
77 DMESG_COLOR_WARN,
78 DMESG_COLOR_SEGFAULT
79 };
80
81 static const struct dmesg_color colors[] =
82 {
83 [DMESG_COLOR_SUBSYS] = { "subsys", UL_COLOR_BROWN },
84 [DMESG_COLOR_TIME] = { "time", UL_COLOR_GREEN },
85 [DMESG_COLOR_TIMEBREAK] = { "timebreak",UL_COLOR_GREEN UL_COLOR_BOLD },
86 [DMESG_COLOR_ALERT] = { "alert", UL_COLOR_REVERSE UL_COLOR_RED },
87 [DMESG_COLOR_CRIT] = { "crit", UL_COLOR_BOLD UL_COLOR_RED },
88 [DMESG_COLOR_ERR] = { "err", UL_COLOR_RED },
89 [DMESG_COLOR_WARN] = { "warn", UL_COLOR_BOLD },
90 [DMESG_COLOR_SEGFAULT] = { "segfault", UL_COLOR_HALFBRIGHT UL_COLOR_RED }
91 };
92
93 #define dmesg_enable_color(_id) \
94 color_scheme_enable(colors[_id].scheme, colors[_id].dflt);
95
96 /*
97 * Priority and facility names
98 */
99 struct dmesg_name {
100 const char *name;
101 const char *help;
102 };
103
104 /*
105 * Priority names -- based on sys/syslog.h
106 */
107 static const struct dmesg_name level_names[] =
108 {
109 [LOG_EMERG] = { "emerg", N_("system is unusable") },
110 [LOG_ALERT] = { "alert", N_("action must be taken immediately") },
111 [LOG_CRIT] = { "crit", N_("critical conditions") },
112 [LOG_ERR] = { "err", N_("error conditions") },
113 [LOG_WARNING] = { "warn", N_("warning conditions") },
114 [LOG_NOTICE] = { "notice",N_("normal but significant condition") },
115 [LOG_INFO] = { "info", N_("informational") },
116 [LOG_DEBUG] = { "debug", N_("debug-level messages") }
117 };
118
119 /*
120 * sys/syslog.h uses (f << 3) for all facility codes.
121 * We want to use the codes as array indexes, so shift back...
122 *
123 * Note that libc LOG_FAC() macro returns the base codes, not the
124 * shifted code :-)
125 */
126 #define FAC_BASE(f) ((f) >> 3)
127
128 static const struct dmesg_name facility_names[] =
129 {
130 [FAC_BASE(LOG_KERN)] = { "kern", N_("kernel messages") },
131 [FAC_BASE(LOG_USER)] = { "user", N_("random user-level messages") },
132 [FAC_BASE(LOG_MAIL)] = { "mail", N_("mail system") },
133 [FAC_BASE(LOG_DAEMON)] = { "daemon", N_("system daemons") },
134 [FAC_BASE(LOG_AUTH)] = { "auth", N_("security/authorization messages") },
135 [FAC_BASE(LOG_SYSLOG)] = { "syslog", N_("messages generated internally by syslogd") },
136 [FAC_BASE(LOG_LPR)] = { "lpr", N_("line printer subsystem") },
137 [FAC_BASE(LOG_NEWS)] = { "news", N_("network news subsystem") },
138 [FAC_BASE(LOG_UUCP)] = { "uucp", N_("UUCP subsystem") },
139 [FAC_BASE(LOG_CRON)] = { "cron", N_("clock daemon") },
140 [FAC_BASE(LOG_AUTHPRIV)] = { "authpriv", N_("security/authorization messages (private)") },
141 [FAC_BASE(LOG_FTP)] = { "ftp", N_("FTP daemon") },
142 };
143
144 /* supported methods to read message buffer
145 */
146 enum {
147 DMESG_METHOD_KMSG, /* read messages from /dev/kmsg (default) */
148 DMESG_METHOD_SYSLOG, /* klogctl() buffer */
149 DMESG_METHOD_MMAP /* mmap file with records (see --file) */
150 };
151
152 enum {
153 DMESG_TIMEFTM_NONE = 0,
154 DMESG_TIMEFTM_CTIME, /* [ctime] */
155 DMESG_TIMEFTM_CTIME_DELTA, /* [ctime <delta>] */
156 DMESG_TIMEFTM_DELTA, /* [<delta>] */
157 DMESG_TIMEFTM_RELTIME, /* [relative] */
158 DMESG_TIMEFTM_TIME, /* [time] */
159 DMESG_TIMEFTM_TIME_DELTA, /* [time <delta>] */
160 DMESG_TIMEFTM_ISO8601 /* 2013-06-13T22:11:00,123456+0100 */
161 };
162 #define is_timefmt(c, f) ((c)->time_fmt == (DMESG_TIMEFTM_ ##f))
163
164 struct dmesg_control {
165 /* bit arrays -- see include/bitops.h */
166 char levels[ARRAY_SIZE(level_names) / NBBY + 1];
167 char facilities[ARRAY_SIZE(facility_names) / NBBY + 1];
168
169 struct timeval lasttime; /* last printed timestamp */
170 struct tm lasttm; /* last localtime */
171 struct timeval boot_time; /* system boot time */
172
173 int action; /* SYSLOG_ACTION_* */
174 int method; /* DMESG_METHOD_* */
175
176 size_t bufsize; /* size of syslog buffer */
177
178 int kmsg; /* /dev/kmsg file descriptor */
179 ssize_t kmsg_first_read;/* initial read() return code */
180 char kmsg_buf[BUFSIZ];/* buffer to read kmsg data */
181
182 /*
183 * For the --file option we mmap whole file. The unnecessary (already
184 * printed) pages are always unmapped. The result is that we have in
185 * memory only the currently used page(s).
186 */
187 char *filename;
188 char *mmap_buff;
189 size_t pagesize;
190 unsigned int time_fmt; /* time format */
191
192 unsigned int follow:1, /* wait for new messages */
193 raw:1, /* raw mode */
194 fltr_lev:1, /* filter out by levels[] */
195 fltr_fac:1, /* filter out by facilities[] */
196 decode:1, /* use "facility: level: " prefix */
197 pager:1, /* pipe output into a pager */
198 color:1, /* colorize messages */
199 force_prefix:1; /* force timestamp and decode prefix
200 on each line */
201 int indent; /* due to timestamps if newline */
202 };
203
204 struct dmesg_record {
205 const char *mesg;
206 size_t mesg_size;
207
208 int level;
209 int facility;
210 struct timeval tv;
211
212 const char *next; /* buffer with next unparsed record */
213 size_t next_size; /* size of the next buffer */
214 };
215
216 #define INIT_DMESG_RECORD(_r) do { \
217 (_r)->mesg = NULL; \
218 (_r)->mesg_size = 0; \
219 (_r)->facility = -1; \
220 (_r)->level = -1; \
221 (_r)->tv.tv_sec = 0; \
222 (_r)->tv.tv_usec = 0; \
223 } while (0)
224
225 static int read_kmsg(struct dmesg_control *ctl);
226
227 static int set_level_color(int log_level, const char *mesg, size_t mesgsz)
228 {
229 int id = -1;
230
231 switch (log_level) {
232 case LOG_ALERT:
233 id = DMESG_COLOR_ALERT;
234 break;
235 case LOG_CRIT:
236 id = DMESG_COLOR_CRIT;
237 break;
238 case LOG_ERR:
239 id = DMESG_COLOR_ERR;
240 break;
241 case LOG_WARNING:
242 id = DMESG_COLOR_WARN;
243 break;
244 default:
245 break;
246 }
247
248 /* well, sometimes the messages contains important keywords, but in
249 * non-warning/error messages
250 */
251 if (id < 0 && memmem(mesg, mesgsz, "segfault at", 11))
252 id = DMESG_COLOR_SEGFAULT;
253
254 if (id >= 0)
255 dmesg_enable_color(id);
256
257 return id >= 0 ? 0 : -1;
258 }
259
260 static void __attribute__((__noreturn__)) usage(void)
261 {
262 FILE *out = stdout;
263 size_t i;
264
265 fputs(USAGE_HEADER, out);
266 fprintf(out, _(" %s [options]\n"), program_invocation_short_name);
267
268 fputs(USAGE_SEPARATOR, out);
269 fputs(_("Display or control the kernel ring buffer.\n"), out);
270
271 fputs(USAGE_OPTIONS, out);
272 fputs(_(" -C, --clear clear the kernel ring buffer\n"), out);
273 fputs(_(" -c, --read-clear read and clear all messages\n"), out);
274 fputs(_(" -D, --console-off disable printing messages to console\n"), out);
275 fputs(_(" -E, --console-on enable printing messages to console\n"), out);
276 fputs(_(" -F, --file <file> use the file instead of the kernel log buffer\n"), out);
277 fputs(_(" -f, --facility <list> restrict output to defined facilities\n"), out);
278 fputs(_(" -H, --human human readable output\n"), out);
279 fputs(_(" -k, --kernel display kernel messages\n"), out);
280 fputs(_(" -L, --color[=<when>] colorize messages (auto, always or never)\n"), out);
281 fprintf(out,
282 " %s\n", USAGE_COLORS_DEFAULT);
283 fputs(_(" -l, --level <list> restrict output to defined levels\n"), out);
284 fputs(_(" -n, --console-level <level> set level of messages printed to console\n"), out);
285 fputs(_(" -P, --nopager do not pipe output into a pager\n"), out);
286 fputs(_(" -p, --force-prefix force timestamp output on each line of multi-line messages\n"), out);
287 fputs(_(" -r, --raw print the raw message buffer\n"), out);
288 fputs(_(" -S, --syslog force to use syslog(2) rather than /dev/kmsg\n"), out);
289 fputs(_(" -s, --buffer-size <size> buffer size to query the kernel ring buffer\n"), out);
290 fputs(_(" -u, --userspace display userspace messages\n"), out);
291 fputs(_(" -w, --follow wait for new messages\n"), out);
292 fputs(_(" -x, --decode decode facility and level to readable string\n"), out);
293 fputs(_(" -d, --show-delta show time delta between printed messages\n"), out);
294 fputs(_(" -e, --reltime show local time and time delta in readable format\n"), out);
295 fputs(_(" -T, --ctime show human-readable timestamp (may be inaccurate!)\n"), out);
296 fputs(_(" -t, --notime don't show any timestamp with messages\n"), out);
297 fputs(_(" --time-format <format> show timestamp using the given format:\n"
298 " [delta|reltime|ctime|notime|iso]\n"
299 "Suspending/resume will make ctime and iso timestamps inaccurate.\n"), out);
300 fputs(USAGE_SEPARATOR, out);
301 printf(USAGE_HELP_OPTIONS(29));
302 fputs(_("\nSupported log facilities:\n"), out);
303 for (i = 0; i < ARRAY_SIZE(level_names); i++)
304 fprintf(out, " %7s - %s\n",
305 facility_names[i].name,
306 _(facility_names[i].help));
307
308 fputs(_("\nSupported log levels (priorities):\n"), out);
309 for (i = 0; i < ARRAY_SIZE(level_names); i++)
310 fprintf(out, " %7s - %s\n",
311 level_names[i].name,
312 _(level_names[i].help));
313
314 printf(USAGE_MAN_TAIL("dmesg(1)"));
315 exit(EXIT_SUCCESS);
316 }
317
318 /*
319 * LEVEL ::= <number> | <name>
320 * <number> ::= @len is set: number in range <0..N>, where N < ARRAY_SIZE(level_names)
321 * ::= @len not set: number in range <1..N>, where N <= ARRAY_SIZE(level_names)
322 * <name> ::= case-insensitive text
323 *
324 * Note that @len argument is not set when parsing "-n <level>" command line
325 * option. The console_level is interpreted as "log level less than the value".
326 *
327 * For example "dmesg -n 8" or "dmesg -n debug" enables debug console log
328 * level by klogctl(SYSLOG_ACTION_CONSOLE_LEVEL, NULL, 8). The @str argument
329 * has to be parsed to number in range <1..8>.
330 */
331 static int parse_level(const char *str, size_t len)
332 {
333 int offset = 0;
334
335 if (!str)
336 return -1;
337 if (!len) {
338 len = strlen(str);
339 offset = 1;
340 }
341 errno = 0;
342
343 if (isdigit(*str)) {
344 char *end = NULL;
345 long x = strtol(str, &end, 10) - offset;
346
347 if (!errno && end && end > str && (size_t) (end - str) == len &&
348 x >= 0 && (size_t) x < ARRAY_SIZE(level_names))
349 return x + offset;
350 } else {
351 size_t i;
352
353 for (i = 0; i < ARRAY_SIZE(level_names); i++) {
354 const char *n = level_names[i].name;
355
356 if (strncasecmp(str, n, len) == 0 && *(n + len) == '\0')
357 return i + offset;
358 }
359 }
360
361 if (errno)
362 err(EXIT_FAILURE, _("failed to parse level '%s'"), str);
363
364 errx(EXIT_FAILURE, _("unknown level '%s'"), str);
365 return -1;
366 }
367
368 /*
369 * FACILITY ::= <number> | <name>
370 * <number> ::= number in range <0..N>, where N < ARRAY_SIZE(facility_names)
371 * <name> ::= case-insensitive text
372 */
373 static int parse_facility(const char *str, size_t len)
374 {
375 if (!str)
376 return -1;
377 if (!len)
378 len = strlen(str);
379 errno = 0;
380
381 if (isdigit(*str)) {
382 char *end = NULL;
383 long x = strtol(str, &end, 10);
384
385 if (!errno && end && end > str && (size_t) (end - str) == len &&
386 x >= 0 && (size_t) x < ARRAY_SIZE(facility_names))
387 return x;
388 } else {
389 size_t i;
390
391 for (i = 0; i < ARRAY_SIZE(facility_names); i++) {
392 const char *n = facility_names[i].name;
393
394 if (strncasecmp(str, n, len) == 0 && *(n + len) == '\0')
395 return i;
396 }
397 }
398
399 if (errno)
400 err(EXIT_FAILURE, _("failed to parse facility '%s'"), str);
401
402 errx(EXIT_FAILURE, _("unknown facility '%s'"), str);
403 return -1;
404 }
405
406 /*
407 * Parses numerical prefix used for all messages in kernel ring buffer.
408 *
409 * Priorities/facilities are encoded into a single 32-bit quantity, where the
410 * bottom 3 bits are the priority (0-7) and the top 28 bits are the facility
411 * (0-big number).
412 *
413 * Note that the number has to end with '>' or ',' char.
414 */
415 static const char *parse_faclev(const char *str, int *fac, int *lev)
416 {
417 long num;
418 char *end = NULL;
419
420 if (!str)
421 return str;
422
423 errno = 0;
424 num = strtol(str, &end, 10);
425
426 if (!errno && end && end > str) {
427 *fac = LOG_FAC(num);
428 *lev = LOG_PRI(num);
429
430 if (*lev < 0 || (size_t) *lev > ARRAY_SIZE(level_names))
431 *lev = -1;
432 if (*fac < 0 || (size_t) *fac > ARRAY_SIZE(facility_names))
433 *fac = -1;
434 return end + 1; /* skip '<' or ',' */
435 }
436
437 return str;
438 }
439
440 /*
441 * Parses timestamp from syslog message prefix, expected format:
442 *
443 * seconds.microseconds]
444 *
445 * the ']' is the timestamp field terminator.
446 */
447 static const char *parse_syslog_timestamp(const char *str0, struct timeval *tv)
448 {
449 const char *str = str0;
450 char *end = NULL;
451
452 if (!str0)
453 return str0;
454
455 errno = 0;
456 tv->tv_sec = strtol(str, &end, 10);
457
458 if (!errno && end && *end == '.' && *(end + 1)) {
459 str = end + 1;
460 end = NULL;
461 tv->tv_usec = strtol(str, &end, 10);
462 }
463 if (errno || !end || end == str || *end != ']')
464 return str0;
465
466 return end + 1; /* skip ']' */
467 }
468
469 /*
470 * Parses timestamp from /dev/kmsg, expected formats:
471 *
472 * microseconds,
473 * microseconds;
474 *
475 * the ',' is fields separators and ';' items terminator (for the last item)
476 */
477 static const char *parse_kmsg_timestamp(const char *str0, struct timeval *tv)
478 {
479 const char *str = str0;
480 char *end = NULL;
481 uint64_t usec;
482
483 if (!str0)
484 return str0;
485
486 errno = 0;
487 usec = strtoumax(str, &end, 10);
488
489 if (!errno && end && (*end == ';' || *end == ',')) {
490 tv->tv_usec = usec % 1000000;
491 tv->tv_sec = usec / 1000000;
492 } else
493 return str0;
494
495 return end + 1; /* skip separator */
496 }
497
498
499 static double time_diff(struct timeval *a, struct timeval *b)
500 {
501 return (a->tv_sec - b->tv_sec) + (a->tv_usec - b->tv_usec) / 1E6;
502 }
503
504 static int get_syslog_buffer_size(void)
505 {
506 int n = klogctl(SYSLOG_ACTION_SIZE_BUFFER, NULL, 0);
507
508 return n > 0 ? n : 0;
509 }
510
511 /*
512 * Reads messages from regular file by mmap
513 */
514 static ssize_t mmap_file_buffer(struct dmesg_control *ctl, char **buf)
515 {
516 struct stat st;
517 int fd;
518
519 if (!ctl->filename)
520 return -1;
521
522 fd = open(ctl->filename, O_RDONLY);
523 if (fd < 0)
524 err(EXIT_FAILURE, _("cannot open %s"), ctl->filename);
525 if (fstat(fd, &st))
526 err(EXIT_FAILURE, _("stat of %s failed"), ctl->filename);
527
528 *buf = mmap(NULL, st.st_size, PROT_READ, MAP_SHARED, fd, 0);
529 if (*buf == MAP_FAILED)
530 err(EXIT_FAILURE, _("cannot mmap: %s"), ctl->filename);
531 ctl->mmap_buff = *buf;
532 ctl->pagesize = getpagesize();
533 close(fd);
534
535 return st.st_size;
536 }
537
538 /*
539 * Reads messages from kernel ring buffer by klogctl()
540 */
541 static ssize_t read_syslog_buffer(struct dmesg_control *ctl, char **buf)
542 {
543 size_t sz;
544 int rc = -1;
545
546 if (ctl->bufsize) {
547 sz = ctl->bufsize + 8;
548 *buf = xmalloc(sz * sizeof(char));
549 rc = klogctl(ctl->action, *buf, sz);
550 } else {
551 sz = 16392;
552 while (1) {
553 *buf = xmalloc(sz * sizeof(char));
554 rc = klogctl(SYSLOG_ACTION_READ_ALL, *buf, sz);
555 if (rc < 0)
556 break;
557 if ((size_t) rc != sz || sz > (1 << 28))
558 break;
559 free(*buf);
560 *buf = NULL;
561 sz *= 4;
562 }
563
564 if (rc > 0 && ctl->action == SYSLOG_ACTION_READ_CLEAR)
565 rc = klogctl(SYSLOG_ACTION_READ_CLEAR, *buf, sz);
566 }
567
568 return rc;
569 }
570
571 /*
572 * Top level function to read messages
573 */
574 static ssize_t read_buffer(struct dmesg_control *ctl, char **buf)
575 {
576 ssize_t n = -1;
577
578 switch (ctl->method) {
579 case DMESG_METHOD_MMAP:
580 n = mmap_file_buffer(ctl, buf);
581 break;
582 case DMESG_METHOD_SYSLOG:
583 if (!ctl->bufsize)
584 ctl->bufsize = get_syslog_buffer_size();
585
586 n = read_syslog_buffer(ctl, buf);
587 break;
588 case DMESG_METHOD_KMSG:
589 /*
590 * Since kernel 3.5.0
591 */
592 n = read_kmsg(ctl);
593 if (n == 0 && ctl->action == SYSLOG_ACTION_READ_CLEAR)
594 n = klogctl(SYSLOG_ACTION_CLEAR, NULL, 0);
595 break;
596 default:
597 abort(); /* impossible method -> drop core */
598 }
599
600 return n;
601 }
602
603 static int fwrite_hex(const char *buf, size_t size, FILE *out)
604 {
605 size_t i;
606
607 for (i = 0; i < size; i++) {
608 int rc = fprintf(out, "\\x%02hhx", buf[i]);
609 if (rc < 0)
610 return rc;
611 }
612 return 0;
613 }
614
615 /*
616 * Prints to 'out' and non-printable chars are replaced with \x<hex> sequences.
617 */
618 static void safe_fwrite(const char *buf, size_t size, int indent, FILE *out)
619 {
620 size_t i;
621 #ifdef HAVE_WIDECHAR
622 mbstate_t s;
623 memset(&s, 0, sizeof (s));
624 #endif
625 for (i = 0; i < size; i++) {
626 const char *p = buf + i;
627 int rc, hex = 0;
628 size_t len;
629
630 #ifdef HAVE_WIDECHAR
631 wchar_t wc;
632 len = mbrtowc(&wc, p, size - i, &s);
633
634 if (len == 0) /* L'\0' */
635 return;
636
637 if (len == (size_t)-1 || len == (size_t)-2) { /* invalid sequence */
638 memset(&s, 0, sizeof (s));
639 len = hex = 1;
640 } else if (len > 1 && !iswprint(wc)) { /* non-printable multibyte */
641 hex = 1;
642 }
643 i += len - 1;
644 #else
645 len = 1;
646 if (!isprint((unsigned char) *p) &&
647 !isspace((unsigned char) *p)) /* non-printable */
648 hex = 1;
649 #endif
650 if (hex)
651 rc = fwrite_hex(p, len, out);
652 else if (*p == '\n' && *(p + 1) && indent) {
653 rc = fwrite(p, 1, len, out) != len;
654 if (fprintf(out, "%*s", indent, "") != indent)
655 rc |= 1;
656 }
657 else
658 rc = fwrite(p, 1, len, out) != len;
659 if (rc != 0) {
660 if (errno != EPIPE)
661 err(EXIT_FAILURE, _("write failed"));
662 exit(EXIT_SUCCESS);
663 }
664 }
665 }
666
667 static const char *skip_item(const char *begin, const char *end, const char *sep)
668 {
669 while (begin < end) {
670 int c = *begin++;
671
672 if (c == '\0' || strchr(sep, c))
673 break;
674 }
675
676 return begin;
677 }
678
679 /*
680 * Parses one record from syslog(2) buffer
681 */
682 static int get_next_syslog_record(struct dmesg_control *ctl,
683 struct dmesg_record *rec)
684 {
685 size_t i;
686 const char *begin = NULL;
687
688 if (ctl->method != DMESG_METHOD_MMAP &&
689 ctl->method != DMESG_METHOD_SYSLOG)
690 return -1;
691
692 if (!rec->next || !rec->next_size)
693 return 1;
694
695 INIT_DMESG_RECORD(rec);
696
697 /*
698 * Unmap already printed file data from memory
699 */
700 if (ctl->mmap_buff && (size_t) (rec->next - ctl->mmap_buff) > ctl->pagesize) {
701 void *x = ctl->mmap_buff;
702
703 ctl->mmap_buff += ctl->pagesize;
704 munmap(x, ctl->pagesize);
705 }
706
707 for (i = 0; i < rec->next_size; i++) {
708 const char *p = rec->next + i;
709 const char *end = NULL;
710
711 if (!begin)
712 begin = p;
713 if (i + 1 == rec->next_size) {
714 end = p + 1;
715 i++;
716 } else if (*p == '\n' && *(p + 1) == '<')
717 end = p;
718
719 if (begin && !*begin)
720 begin = NULL; /* zero(s) at the end of the buffer? */
721 if (!begin || !end)
722 continue;
723 if (end <= begin)
724 continue; /* error or empty line? */
725
726 if (*begin == '<') {
727 if (ctl->fltr_lev || ctl->fltr_fac || ctl->decode || ctl->color)
728 begin = parse_faclev(begin + 1, &rec->facility,
729 &rec->level);
730 else
731 begin = skip_item(begin, end, ">");
732 }
733
734 if (*begin == '[' && (*(begin + 1) == ' ' ||
735 isdigit(*(begin + 1)))) {
736
737 if (!is_timefmt(ctl, NONE))
738 begin = parse_syslog_timestamp(begin + 1, &rec->tv);
739 else
740 begin = skip_item(begin, end, "]");
741
742 if (begin < end && *begin == ' ')
743 begin++;
744 }
745
746 rec->mesg = begin;
747 rec->mesg_size = end - begin;
748
749 /* Don't count \n from the last message to the message size */
750 if (*end != '\n' && *(end - 1) == '\n')
751 rec->mesg_size--;
752
753 rec->next_size -= end - rec->next;
754 rec->next = rec->next_size > 0 ? end + 1 : NULL;
755 if (rec->next_size > 0)
756 rec->next_size--;
757
758 return 0;
759 }
760
761 return 1;
762 }
763
764 static int accept_record(struct dmesg_control *ctl, struct dmesg_record *rec)
765 {
766 if (ctl->fltr_lev && (rec->facility < 0 ||
767 !isset(ctl->levels, rec->level)))
768 return 0;
769
770 if (ctl->fltr_fac && (rec->facility < 0 ||
771 !isset(ctl->facilities, rec->facility)))
772 return 0;
773
774 return 1;
775 }
776
777 static void raw_print(struct dmesg_control *ctl, const char *buf, size_t size)
778 {
779 int lastc = '\n';
780
781 if (!ctl->mmap_buff) {
782 /*
783 * Print whole ring buffer
784 */
785 safe_fwrite(buf, size, 0, stdout);
786 lastc = buf[size - 1];
787 } else {
788 /*
789 * Print file in small chunks to save memory
790 */
791 while (size) {
792 size_t sz = size > ctl->pagesize ? ctl->pagesize : size;
793 char *x = ctl->mmap_buff;
794
795 safe_fwrite(x, sz, 0, stdout);
796 lastc = x[sz - 1];
797 size -= sz;
798 ctl->mmap_buff += sz;
799 munmap(x, sz);
800 }
801 }
802
803 if (lastc != '\n')
804 putchar('\n');
805 }
806
807 static struct tm *record_localtime(struct dmesg_control *ctl,
808 struct dmesg_record *rec,
809 struct tm *tm)
810 {
811 time_t t = ctl->boot_time.tv_sec + rec->tv.tv_sec;
812 return localtime_r(&t, tm);
813 }
814
815 static char *record_ctime(struct dmesg_control *ctl,
816 struct dmesg_record *rec,
817 char *buf, size_t bufsiz)
818 {
819 struct tm tm;
820
821 record_localtime(ctl, rec, &tm);
822
823 if (strftime(buf, bufsiz, "%a %b %e %H:%M:%S %Y", &tm) == 0)
824 *buf = '\0';
825 return buf;
826 }
827
828 static char *short_ctime(struct tm *tm, char *buf, size_t bufsiz)
829 {
830 if (strftime(buf, bufsiz, "%b%e %H:%M", tm) == 0)
831 *buf = '\0';
832 return buf;
833 }
834
835 static char *iso_8601_time(struct dmesg_control *ctl, struct dmesg_record *rec,
836 char *buf, size_t bufsz)
837 {
838 struct timeval tv = {
839 .tv_sec = ctl->boot_time.tv_sec + rec->tv.tv_sec,
840 .tv_usec = rec->tv.tv_usec
841 };
842
843 if (strtimeval_iso(&tv, ISO_TIMESTAMP_COMMA_T, buf, bufsz) != 0)
844 return NULL;
845
846 return buf;
847 }
848
849 static double record_count_delta(struct dmesg_control *ctl,
850 struct dmesg_record *rec)
851 {
852 double delta = 0;
853
854 if (timerisset(&ctl->lasttime))
855 delta = time_diff(&rec->tv, &ctl->lasttime);
856
857 ctl->lasttime = rec->tv;
858 return delta;
859 }
860
861 static const char *get_subsys_delimiter(const char *mesg, size_t mesg_size)
862 {
863 const char *p = mesg;
864 size_t sz = mesg_size;
865
866 while (sz > 0) {
867 const char *d = strnchr(p, sz, ':');
868 if (!d)
869 return NULL;
870 sz -= d - p + 1;
871 if (sz) {
872 if (isblank(*(d + 1)))
873 return d;
874 p = d + 1;
875 }
876 }
877 return NULL;
878 }
879
880 static void print_record(struct dmesg_control *ctl,
881 struct dmesg_record *rec)
882 {
883 char buf[128];
884 char fpbuf[32] = "\0";
885 char tsbuf[64] = "\0";
886 size_t mesg_size;
887 int timebreak = 0;
888 char *mesg_copy = NULL;
889 const char *line = NULL;
890
891 if (!accept_record(ctl, rec))
892 return;
893
894 if (!rec->mesg_size) {
895 putchar('\n');
896 return;
897 }
898
899 /*
900 * Compose syslog(2) compatible raw output -- used for /dev/kmsg for
901 * backward compatibility with syslog(2) buffers only
902 */
903 if (ctl->raw) {
904 ctl->indent = snprintf(tsbuf, sizeof(tsbuf),
905 "<%d>[%5ld.%06ld] ",
906 LOG_MAKEPRI(rec->facility, rec->level),
907 (long) rec->tv.tv_sec,
908 (long) rec->tv.tv_usec);
909 goto mesg_output;
910 }
911
912 /* Store decode information (facility & priority level) in a buffer */
913 if (ctl->decode &&
914 (rec->level > -1) && (rec->level < (int) ARRAY_SIZE(level_names)) &&
915 (rec->facility > -1) &&
916 (rec->facility < (int) ARRAY_SIZE(facility_names)))
917 snprintf(fpbuf, sizeof(fpbuf), "%-6s:%-6s: ",
918 facility_names[rec->facility].name,
919 level_names[rec->level].name);
920
921 /* Store the timestamp in a buffer */
922 switch (ctl->time_fmt) {
923 double delta;
924 struct tm cur;
925 case DMESG_TIMEFTM_NONE:
926 ctl->indent = 0;
927 break;
928 case DMESG_TIMEFTM_CTIME:
929 ctl->indent = snprintf(tsbuf, sizeof(tsbuf), "[%s] ",
930 record_ctime(ctl, rec, buf, sizeof(buf)));
931 break;
932 case DMESG_TIMEFTM_CTIME_DELTA:
933 ctl->indent = snprintf(tsbuf, sizeof(tsbuf), "[%s <%12.06f>] ",
934 record_ctime(ctl, rec, buf, sizeof(buf)),
935 record_count_delta(ctl, rec));
936 break;
937 case DMESG_TIMEFTM_DELTA:
938 ctl->indent = snprintf(tsbuf, sizeof(tsbuf), "[<%12.06f>] ",
939 record_count_delta(ctl, rec));
940 break;
941 case DMESG_TIMEFTM_RELTIME:
942 record_localtime(ctl, rec, &cur);
943 delta = record_count_delta(ctl, rec);
944 if (cur.tm_min != ctl->lasttm.tm_min ||
945 cur.tm_hour != ctl->lasttm.tm_hour ||
946 cur.tm_yday != ctl->lasttm.tm_yday) {
947 timebreak = 1;
948 ctl->indent = snprintf(tsbuf, sizeof(tsbuf), "[%s] ",
949 short_ctime(&cur, buf,
950 sizeof(buf)));
951 } else {
952 if (delta < 10)
953 ctl->indent = snprintf(tsbuf, sizeof(tsbuf),
954 "[ %+8.06f] ", delta);
955 else
956 ctl->indent = snprintf(tsbuf, sizeof(tsbuf),
957 "[ %+9.06f] ", delta);
958 }
959 ctl->lasttm = cur;
960 break;
961 case DMESG_TIMEFTM_TIME:
962 ctl->indent = snprintf(tsbuf, sizeof(tsbuf), "[%5ld.%06ld] ",
963 (long)rec->tv.tv_sec,
964 (long)rec->tv.tv_usec);
965 break;
966 case DMESG_TIMEFTM_TIME_DELTA:
967 ctl->indent = snprintf(tsbuf, sizeof(tsbuf), "[%5ld.%06ld <%12.06f>] ",
968 (long)rec->tv.tv_sec,
969 (long)rec->tv.tv_usec,
970 record_count_delta(ctl, rec));
971 break;
972 case DMESG_TIMEFTM_ISO8601:
973 ctl->indent = snprintf(tsbuf, sizeof(tsbuf), "%s ",
974 iso_8601_time(ctl, rec, buf,
975 sizeof(buf)));
976 break;
977 default:
978 abort();
979 }
980
981 ctl->indent += strlen(fpbuf);
982
983 full_output:
984 /* Output the decode information */
985 if (*fpbuf)
986 fputs(fpbuf, stdout);
987
988 /* Output the timestamp buffer */
989 if (*tsbuf) {
990 /* Colorize the timestamp */
991 if (ctl->color)
992 dmesg_enable_color(timebreak ? DMESG_COLOR_TIMEBREAK :
993 DMESG_COLOR_TIME);
994 if (ctl->time_fmt != DMESG_TIMEFTM_RELTIME) {
995 fputs(tsbuf, stdout);
996 } else {
997 /*
998 * For relative timestamping, the first line's
999 * timestamp is the offset and all other lines will
1000 * report an offset of 0.000000.
1001 */
1002 if (!line)
1003 fputs(tsbuf, stdout);
1004 else
1005 printf("[ +0.000000] ");
1006 }
1007 if (ctl->color)
1008 color_disable();
1009 }
1010
1011 mesg_output:
1012 /*
1013 * A kernel message may contain several lines of output, separated
1014 * by '\n'. If the timestamp and decode outputs are forced then each
1015 * line of the message must be displayed with that information.
1016 */
1017 if (ctl->force_prefix) {
1018 if (!line) {
1019 mesg_copy = strdup(rec->mesg);
1020 line = strtok(mesg_copy, "\n");
1021 mesg_size = strlen(line);
1022 }
1023 } else {
1024 line = rec->mesg;
1025 mesg_size = rec->mesg_size;
1026 }
1027
1028 /* Colorize kernel message output */
1029 if (ctl->color) {
1030 /* Subsystem prefix */
1031 const char *subsys = get_subsys_delimiter(line, mesg_size);
1032 int has_color = 0;
1033
1034 if (subsys) {
1035 dmesg_enable_color(DMESG_COLOR_SUBSYS);
1036 safe_fwrite(line, subsys - line, ctl->indent, stdout);
1037 color_disable();
1038
1039 mesg_size -= subsys - line;
1040 line = subsys;
1041 }
1042 /* Error, alert .. etc. colors */
1043 has_color = set_level_color(rec->level, line, mesg_size) == 0;
1044 safe_fwrite(line, mesg_size, ctl->indent, stdout);
1045 if (has_color)
1046 color_disable();
1047 } else
1048 safe_fwrite(line, mesg_size, ctl->indent, stdout);
1049
1050 /* Get the next line */
1051 if (ctl->force_prefix) {
1052 line = strtok(NULL, "\n");
1053 if (line && *line) {
1054 putchar('\n');
1055 mesg_size = strlen(line);
1056 goto full_output;
1057 }
1058 free(mesg_copy);
1059 }
1060
1061 putchar('\n');
1062 }
1063
1064 /*
1065 * Prints the 'buf' kernel ring buffer; the messages are filtered out according
1066 * to 'levels' and 'facilities' bitarrays.
1067 */
1068 static void print_buffer(struct dmesg_control *ctl,
1069 const char *buf, size_t size)
1070 {
1071 struct dmesg_record rec = { .next = buf, .next_size = size };
1072
1073 if (ctl->raw) {
1074 raw_print(ctl, buf, size);
1075 return;
1076 }
1077
1078 while (get_next_syslog_record(ctl, &rec) == 0)
1079 print_record(ctl, &rec);
1080 }
1081
1082 static ssize_t read_kmsg_one(struct dmesg_control *ctl)
1083 {
1084 ssize_t size;
1085
1086 /* kmsg returns EPIPE if record was modified while reading */
1087 do {
1088 size = read(ctl->kmsg, ctl->kmsg_buf,
1089 sizeof(ctl->kmsg_buf) - 1);
1090 } while (size < 0 && errno == EPIPE);
1091
1092 return size;
1093 }
1094
1095 static int init_kmsg(struct dmesg_control *ctl)
1096 {
1097 int mode = O_RDONLY;
1098
1099 if (!ctl->follow)
1100 mode |= O_NONBLOCK;
1101 else
1102 setlinebuf(stdout);
1103
1104 ctl->kmsg = open("/dev/kmsg", mode);
1105 if (ctl->kmsg < 0)
1106 return -1;
1107
1108 /*
1109 * Seek after the last record available at the time
1110 * the last SYSLOG_ACTION_CLEAR was issued.
1111 *
1112 * ... otherwise SYSLOG_ACTION_CLEAR will have no effect for kmsg.
1113 */
1114 lseek(ctl->kmsg, 0, SEEK_DATA);
1115
1116 /*
1117 * Old kernels (<3.5) allow to successfully open /dev/kmsg for
1118 * read-only, but read() returns -EINVAL :-(((
1119 *
1120 * Let's try to read the first record. The record is later processed in
1121 * read_kmsg().
1122 */
1123 ctl->kmsg_first_read = read_kmsg_one(ctl);
1124 if (ctl->kmsg_first_read < 0) {
1125 close(ctl->kmsg);
1126 ctl->kmsg = -1;
1127 return -1;
1128 }
1129
1130 return 0;
1131 }
1132
1133 /*
1134 * /dev/kmsg record format:
1135 *
1136 * faclev,seqnum,timestamp[optional, ...];message\n
1137 * TAGNAME=value
1138 * ...
1139 *
1140 * - fields are separated by ','
1141 * - last field is terminated by ';'
1142 *
1143 */
1144 #define LAST_KMSG_FIELD(s) (!s || !*s || *(s - 1) == ';')
1145
1146 static int parse_kmsg_record(struct dmesg_control *ctl,
1147 struct dmesg_record *rec,
1148 char *buf,
1149 size_t sz)
1150 {
1151 const char *p = buf, *end;
1152
1153 if (sz == 0 || !buf || !*buf)
1154 return -1;
1155
1156 end = buf + (sz - 1);
1157 INIT_DMESG_RECORD(rec);
1158
1159 while (p < end && isspace(*p))
1160 p++;
1161
1162 /* A) priority and facility */
1163 if (ctl->fltr_lev || ctl->fltr_fac || ctl->decode ||
1164 ctl->raw || ctl->color)
1165 p = parse_faclev(p, &rec->facility, &rec->level);
1166 else
1167 p = skip_item(p, end, ",");
1168 if (LAST_KMSG_FIELD(p))
1169 goto mesg;
1170
1171 /* B) sequence number */
1172 p = skip_item(p, end, ",;");
1173 if (LAST_KMSG_FIELD(p))
1174 goto mesg;
1175
1176 /* C) timestamp */
1177 if (is_timefmt(ctl, NONE))
1178 p = skip_item(p, end, ",;");
1179 else
1180 p = parse_kmsg_timestamp(p, &rec->tv);
1181 if (LAST_KMSG_FIELD(p))
1182 goto mesg;
1183
1184 /* D) optional fields (ignore) */
1185 p = skip_item(p, end, ";");
1186
1187 mesg:
1188 /* E) message text */
1189 rec->mesg = p;
1190 p = skip_item(p, end, "\n");
1191 if (!p)
1192 return -1;
1193
1194 /* The message text is terminated by \n, but it's possible that the
1195 * message contains another stuff behind this linebreak; in this case
1196 * the previous skip_item() returns pointer to the stuff behind \n.
1197 * Let's notmalize all these sitations and make sure we always point to
1198 * the \n.
1199 *
1200 * Note that the next unhexmangle_to_buffer() will replace \n by \0.
1201 */
1202 if (*p && *p != '\n')
1203 p--;
1204
1205 /*
1206 * Kernel escapes non-printable characters, unfortunately kernel
1207 * definition of "non-printable" is too strict. On UTF8 console we can
1208 * print many chars, so let's decode from kernel.
1209 */
1210 rec->mesg_size = unhexmangle_to_buffer(rec->mesg,
1211 (char *) rec->mesg, p - rec->mesg + 1);
1212
1213 rec->mesg_size--; /* don't count \0 */
1214
1215 /* F) message tags (ignore) */
1216
1217 return 0;
1218 }
1219
1220 /*
1221 * Note that each read() call for /dev/kmsg returns always one record. It means
1222 * that we don't have to read whole message buffer before the records parsing.
1223 *
1224 * So this function does not compose one huge buffer (like read_syslog_buffer())
1225 * and print_buffer() is unnecessary. All is done in this function.
1226 *
1227 * Returns 0 on success, -1 on error.
1228 */
1229 static int read_kmsg(struct dmesg_control *ctl)
1230 {
1231 struct dmesg_record rec;
1232 ssize_t sz;
1233
1234 if (ctl->method != DMESG_METHOD_KMSG || ctl->kmsg < 0)
1235 return -1;
1236
1237 /*
1238 * The very first read() call is done in kmsg_init() where we test
1239 * /dev/kmsg usability. The return code from the initial read() is
1240 * stored in ctl->kmsg_first_read;
1241 */
1242 sz = ctl->kmsg_first_read;
1243
1244 while (sz > 0) {
1245 *(ctl->kmsg_buf + sz) = '\0'; /* for debug messages */
1246
1247 if (parse_kmsg_record(ctl, &rec,
1248 ctl->kmsg_buf, (size_t) sz) == 0)
1249 print_record(ctl, &rec);
1250
1251 sz = read_kmsg_one(ctl);
1252 }
1253
1254 return 0;
1255 }
1256
1257 static int which_time_format(const char *s)
1258 {
1259 if (!strcmp(s, "notime"))
1260 return DMESG_TIMEFTM_NONE;
1261 if (!strcmp(s, "ctime"))
1262 return DMESG_TIMEFTM_CTIME;
1263 if (!strcmp(s, "delta"))
1264 return DMESG_TIMEFTM_DELTA;
1265 if (!strcmp(s, "reltime"))
1266 return DMESG_TIMEFTM_RELTIME;
1267 if (!strcmp(s, "iso"))
1268 return DMESG_TIMEFTM_ISO8601;
1269 errx(EXIT_FAILURE, _("unknown time format: %s"), s);
1270 }
1271
1272 #ifdef TEST_DMESG
1273 static inline int dmesg_get_boot_time(struct timeval *tv)
1274 {
1275 char *str = getenv("DMESG_TEST_BOOTIME");
1276 uintmax_t sec, usec;
1277
1278 if (str && sscanf(str, "%ju.%ju", &sec, &usec) == 2) {
1279 tv->tv_sec = sec;
1280 tv->tv_usec = usec;
1281 return tv->tv_sec >= 0 && tv->tv_usec >= 0 ? 0 : -EINVAL;
1282 }
1283
1284 return get_boot_time(tv);
1285 }
1286 #else
1287 # define dmesg_get_boot_time get_boot_time
1288 #endif
1289
1290 int main(int argc, char *argv[])
1291 {
1292 char *buf = NULL;
1293 int c, nopager = 0;
1294 int console_level = 0;
1295 int klog_rc = 0;
1296 int delta = 0;
1297 ssize_t n;
1298 static struct dmesg_control ctl = {
1299 .filename = NULL,
1300 .action = SYSLOG_ACTION_READ_ALL,
1301 .method = DMESG_METHOD_KMSG,
1302 .kmsg = -1,
1303 .time_fmt = DMESG_TIMEFTM_TIME,
1304 .indent = 0,
1305 };
1306 int colormode = UL_COLORMODE_UNDEF;
1307 enum {
1308 OPT_TIME_FORMAT = CHAR_MAX + 1,
1309 };
1310
1311 static const struct option longopts[] = {
1312 { "buffer-size", required_argument, NULL, 's' },
1313 { "clear", no_argument, NULL, 'C' },
1314 { "color", optional_argument, NULL, 'L' },
1315 { "console-level", required_argument, NULL, 'n' },
1316 { "console-off", no_argument, NULL, 'D' },
1317 { "console-on", no_argument, NULL, 'E' },
1318 { "decode", no_argument, NULL, 'x' },
1319 { "file", required_argument, NULL, 'F' },
1320 { "facility", required_argument, NULL, 'f' },
1321 { "follow", no_argument, NULL, 'w' },
1322 { "human", no_argument, NULL, 'H' },
1323 { "help", no_argument, NULL, 'h' },
1324 { "kernel", no_argument, NULL, 'k' },
1325 { "level", required_argument, NULL, 'l' },
1326 { "syslog", no_argument, NULL, 'S' },
1327 { "raw", no_argument, NULL, 'r' },
1328 { "read-clear", no_argument, NULL, 'c' },
1329 { "reltime", no_argument, NULL, 'e' },
1330 { "show-delta", no_argument, NULL, 'd' },
1331 { "ctime", no_argument, NULL, 'T' },
1332 { "notime", no_argument, NULL, 't' },
1333 { "nopager", no_argument, NULL, 'P' },
1334 { "userspace", no_argument, NULL, 'u' },
1335 { "version", no_argument, NULL, 'V' },
1336 { "time-format", required_argument, NULL, OPT_TIME_FORMAT },
1337 { "force-prefix", no_argument, NULL, 'p' },
1338 { NULL, 0, NULL, 0 }
1339 };
1340
1341 static const ul_excl_t excl[] = { /* rows and cols in ASCII order */
1342 { 'C','D','E','c','n','r' }, /* clear,off,on,read-clear,level,raw*/
1343 { 'H','r' }, /* human, raw */
1344 { 'L','r' }, /* color, raw */
1345 { 'S','w' }, /* syslog,follow */
1346 { 'T','r' }, /* ctime, raw */
1347 { 'd','r' }, /* delta, raw */
1348 { 'e','r' }, /* reltime, raw */
1349 { 'r','x' }, /* raw, decode */
1350 { 'r','t' }, /* notime, raw */
1351 { 0 }
1352 };
1353 int excl_st[ARRAY_SIZE(excl)] = UL_EXCL_STATUS_INIT;
1354
1355 setlocale(LC_ALL, "");
1356 bindtextdomain(PACKAGE, LOCALEDIR);
1357 textdomain(PACKAGE);
1358 atexit(close_stdout);
1359
1360 while ((c = getopt_long(argc, argv, "CcDdEeF:f:HhkL::l:n:iPprSs:TtuVwx",
1361 longopts, NULL)) != -1) {
1362
1363 err_exclusive_options(c, longopts, excl, excl_st);
1364
1365 switch (c) {
1366 case 'C':
1367 ctl.action = SYSLOG_ACTION_CLEAR;
1368 break;
1369 case 'c':
1370 ctl.action = SYSLOG_ACTION_READ_CLEAR;
1371 break;
1372 case 'D':
1373 ctl.action = SYSLOG_ACTION_CONSOLE_OFF;
1374 break;
1375 case 'd':
1376 delta = 1;
1377 break;
1378 case 'E':
1379 ctl.action = SYSLOG_ACTION_CONSOLE_ON;
1380 break;
1381 case 'e':
1382 ctl.time_fmt = DMESG_TIMEFTM_RELTIME;
1383 break;
1384 case 'F':
1385 ctl.filename = optarg;
1386 ctl.method = DMESG_METHOD_MMAP;
1387 break;
1388 case 'f':
1389 ctl.fltr_fac = 1;
1390 if (string_to_bitarray(optarg,
1391 ctl.facilities, parse_facility) < 0)
1392 return EXIT_FAILURE;
1393 break;
1394 case 'H':
1395 ctl.time_fmt = DMESG_TIMEFTM_RELTIME;
1396 colormode = UL_COLORMODE_AUTO;
1397 ctl.pager = 1;
1398 break;
1399 case 'h':
1400 usage();
1401 break;
1402 case 'k':
1403 ctl.fltr_fac = 1;
1404 setbit(ctl.facilities, FAC_BASE(LOG_KERN));
1405 break;
1406 case 'L':
1407 colormode = UL_COLORMODE_AUTO;
1408 if (optarg)
1409 colormode = colormode_or_err(optarg,
1410 _("unsupported color mode"));
1411 break;
1412 case 'l':
1413 ctl.fltr_lev= 1;
1414 if (string_to_bitarray(optarg,
1415 ctl.levels, parse_level) < 0)
1416 return EXIT_FAILURE;
1417 break;
1418 case 'n':
1419 ctl.action = SYSLOG_ACTION_CONSOLE_LEVEL;
1420 console_level = parse_level(optarg, 0);
1421 break;
1422 case 'P':
1423 nopager = 1;
1424 break;
1425 case 'p':
1426 ctl.force_prefix = 1;
1427 break;
1428 case 'r':
1429 ctl.raw = 1;
1430 break;
1431 case 'S':
1432 ctl.method = DMESG_METHOD_SYSLOG;
1433 break;
1434 case 's':
1435 ctl.bufsize = strtou32_or_err(optarg,
1436 _("invalid buffer size argument"));
1437 if (ctl.bufsize < 4096)
1438 ctl.bufsize = 4096;
1439 break;
1440 case 'T':
1441 ctl.time_fmt = DMESG_TIMEFTM_CTIME;
1442 break;
1443 case 't':
1444 ctl.time_fmt = DMESG_TIMEFTM_NONE;
1445 break;
1446 case 'u':
1447 ctl.fltr_fac = 1;
1448 for (n = 1; (size_t) n < ARRAY_SIZE(facility_names); n++)
1449 setbit(ctl.facilities, n);
1450 break;
1451 case 'V':
1452 printf(UTIL_LINUX_VERSION);
1453 return EXIT_SUCCESS;
1454 case 'w':
1455 ctl.follow = 1;
1456 break;
1457 case 'x':
1458 ctl.decode = 1;
1459 break;
1460 case OPT_TIME_FORMAT:
1461 ctl.time_fmt = which_time_format(optarg);
1462 break;
1463 default:
1464 errtryhelp(EXIT_FAILURE);
1465 }
1466 }
1467
1468 if (argc != optind) {
1469 warnx(_("bad usage"));
1470 errtryhelp(EXIT_FAILURE);
1471 }
1472
1473 if ((is_timefmt(&ctl, RELTIME) ||
1474 is_timefmt(&ctl, CTIME) ||
1475 is_timefmt(&ctl, ISO8601))
1476 && dmesg_get_boot_time(&ctl.boot_time) != 0)
1477 ctl.time_fmt = DMESG_TIMEFTM_NONE;
1478
1479 if (delta)
1480 switch (ctl.time_fmt) {
1481 case DMESG_TIMEFTM_CTIME:
1482 ctl.time_fmt = DMESG_TIMEFTM_CTIME_DELTA;
1483 break;
1484 case DMESG_TIMEFTM_TIME:
1485 ctl.time_fmt = DMESG_TIMEFTM_TIME_DELTA;
1486 break;
1487 case DMESG_TIMEFTM_ISO8601:
1488 warnx(_("--show-delta is ignored when used together with iso8601 time format"));
1489 break;
1490 default:
1491 ctl.time_fmt = DMESG_TIMEFTM_DELTA;
1492 }
1493
1494
1495 ctl.color = colors_init(colormode, "dmesg") ? 1 : 0;
1496 if (ctl.follow)
1497 nopager = 1;
1498 ctl.pager = nopager ? 0 : ctl.pager;
1499 if (ctl.pager)
1500 pager_redirect();
1501
1502 switch (ctl.action) {
1503 case SYSLOG_ACTION_READ_ALL:
1504 case SYSLOG_ACTION_READ_CLEAR:
1505 if (ctl.method == DMESG_METHOD_KMSG && init_kmsg(&ctl) != 0)
1506 ctl.method = DMESG_METHOD_SYSLOG;
1507
1508 if (ctl.raw
1509 && ctl.method != DMESG_METHOD_KMSG
1510 && (ctl.fltr_lev || ctl.fltr_fac))
1511 errx(EXIT_FAILURE, _("--raw can be used together with --level or "
1512 "--facility only when reading messages from /dev/kmsg"));
1513
1514 /* only kmsg supports multi-line messages */
1515 if (ctl.force_prefix && ctl.method != DMESG_METHOD_KMSG)
1516 ctl.force_prefix = 0;
1517
1518 if (ctl.pager)
1519 pager_redirect();
1520 n = read_buffer(&ctl, &buf);
1521 if (n > 0)
1522 print_buffer(&ctl, buf, n);
1523 if (!ctl.mmap_buff)
1524 free(buf);
1525 if (n < 0)
1526 err(EXIT_FAILURE, _("read kernel buffer failed"));
1527 if (ctl.kmsg >= 0)
1528 close(ctl.kmsg);
1529 break;
1530 case SYSLOG_ACTION_CLEAR:
1531 case SYSLOG_ACTION_CONSOLE_OFF:
1532 case SYSLOG_ACTION_CONSOLE_ON:
1533 klog_rc = klogctl(ctl.action, NULL, 0);
1534 break;
1535 case SYSLOG_ACTION_CONSOLE_LEVEL:
1536 klog_rc = klogctl(ctl.action, NULL, console_level);
1537 break;
1538 default:
1539 errx(EXIT_FAILURE, _("unsupported command"));
1540 break;
1541 }
1542
1543
1544 if (klog_rc)
1545 err(EXIT_FAILURE, _("klogctl failed"));
1546
1547 return EXIT_SUCCESS;
1548 }
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