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path: root/sysklogd/syslogd.c (plain)
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1/* vi: set sw=4 ts=4: */
2/*
3 * Mini syslogd implementation for busybox
4 *
5 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
6 *
7 * Copyright (C) 2000 by Karl M. Hegbloom <karlheg@debian.org>
8 *
9 * "circular buffer" Copyright (C) 2001 by Gennady Feldman <gfeldman@gena01.com>
10 *
11 * Maintainer: Gennady Feldman <gfeldman@gena01.com> as of Mar 12, 2001
12 *
13 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
14 */
15
16//usage:#define syslogd_trivial_usage
17//usage: "[OPTIONS]"
18//usage:#define syslogd_full_usage "\n\n"
19//usage: "System logging utility\n"
20//usage: IF_NOT_FEATURE_SYSLOGD_CFG(
21//usage: "(this version of syslogd ignores /etc/syslog.conf)\n"
22//usage: )
23//usage: "\n -n Run in foreground"
24//usage: "\n -O FILE Log to FILE (default:/var/log/messages)"
25//usage: "\n -l N Log only messages more urgent than prio N (1-8)"
26//usage: "\n -S Smaller output"
27//usage: IF_FEATURE_ROTATE_LOGFILE(
28//usage: "\n -s SIZE Max size (KB) before rotation (default:200KB, 0=off)"
29//usage: "\n -b N N rotated logs to keep (default:1, max=99, 0=purge)"
30//usage: )
31//usage: IF_FEATURE_REMOTE_LOG(
32//usage: "\n -R HOST[:PORT] Log to HOST:PORT (default PORT:514)"
33//usage: "\n -L Log locally and via network (default is network only if -R)"
34//usage: )
35//usage: IF_FEATURE_SYSLOGD_DUP(
36//usage: "\n -D Drop duplicates"
37//usage: )
38//usage: IF_FEATURE_IPC_SYSLOG(
39/* NB: -Csize shouldn't have space (because size is optional) */
40//usage: "\n -C[size_kb] Log to shared mem buffer (use logread to read it)"
41//usage: )
42//usage: IF_FEATURE_SYSLOGD_CFG(
43//usage: "\n -f FILE Use FILE as config (default:/etc/syslog.conf)"
44//usage: )
45/* //usage: "\n -m MIN Minutes between MARK lines (default:20, 0=off)" */
46//usage: IF_FEATURE_KMSG_SYSLOG(
47//usage: "\n -K Log to kernel printk buffer (use dmesg to read it)"
48//usage: )
49//usage:
50//usage:#define syslogd_example_usage
51//usage: "$ syslogd -R masterlog:514\n"
52//usage: "$ syslogd -R 192.168.1.1:601\n"
53
54/*
55 * Done in syslogd_and_logger.c:
56#include "libbb.h"
57#define SYSLOG_NAMES
58#define SYSLOG_NAMES_CONST
59#include <syslog.h>
60*/
61#ifndef _PATH_LOG
62#define _PATH_LOG "/dev/log"
63#endif
64
65#include <sys/un.h>
66#include <sys/uio.h>
67
68#if ENABLE_FEATURE_REMOTE_LOG
69#include <netinet/in.h>
70#endif
71
72#if ENABLE_FEATURE_IPC_SYSLOG
73#include <sys/ipc.h>
74#include <sys/sem.h>
75#include <sys/shm.h>
76#endif
77
78
79#define DEBUG 0
80
81/* MARK code is not very useful, is bloat, and broken:
82 * can deadlock if alarmed to make MARK while writing to IPC buffer
83 * (semaphores are down but do_mark routine tries to down them again) */
84#undef SYSLOGD_MARK
85
86/* Write locking does not seem to be useful either */
87#undef SYSLOGD_WRLOCK
88
89enum {
90 MAX_READ = CONFIG_FEATURE_SYSLOGD_READ_BUFFER_SIZE,
91 DNS_WAIT_SEC = 2 * 60,
92};
93
94/* Semaphore operation structures */
95struct shbuf_ds {
96 int32_t size; /* size of data - 1 */
97 int32_t tail; /* end of message list */
98 char data[1]; /* data/messages */
99};
100
101#if ENABLE_FEATURE_REMOTE_LOG
102typedef struct {
103 int remoteFD;
104 unsigned last_dns_resolve;
105 len_and_sockaddr *remoteAddr;
106 const char *remoteHostname;
107} remoteHost_t;
108#endif
109
110typedef struct logFile_t {
111 const char *path;
112 int fd;
113#if ENABLE_FEATURE_ROTATE_LOGFILE
114 unsigned size;
115 uint8_t isRegular;
116#endif
117} logFile_t;
118
119#if ENABLE_FEATURE_SYSLOGD_CFG
120typedef struct logRule_t {
121 uint8_t enabled_facility_priomap[LOG_NFACILITIES];
122 struct logFile_t *file;
123 struct logRule_t *next;
124} logRule_t;
125#endif
126
127/* Allows us to have smaller initializer. Ugly. */
128#define GLOBALS \
129 logFile_t logFile; \
130 /* interval between marks in seconds */ \
131 /*int markInterval;*/ \
132 /* level of messages to be logged */ \
133 int logLevel; \
134IF_FEATURE_ROTATE_LOGFILE( \
135 /* max size of file before rotation */ \
136 unsigned logFileSize; \
137 /* number of rotated message files */ \
138 unsigned logFileRotate; \
139) \
140IF_FEATURE_IPC_SYSLOG( \
141 int shmid; /* ipc shared memory id */ \
142 int s_semid; /* ipc semaphore id */ \
143 int shm_size; \
144 struct sembuf SMwup[1]; \
145 struct sembuf SMwdn[3]; \
146) \
147IF_FEATURE_SYSLOGD_CFG( \
148 logRule_t *log_rules; \
149) \
150IF_FEATURE_KMSG_SYSLOG( \
151 int kmsgfd; \
152 int primask; \
153)
154
155struct init_globals {
156 GLOBALS
157};
158
159struct globals {
160 GLOBALS
161
162#if ENABLE_FEATURE_REMOTE_LOG
163 llist_t *remoteHosts;
164#endif
165#if ENABLE_FEATURE_IPC_SYSLOG
166 struct shbuf_ds *shbuf;
167#endif
168 time_t last_log_time;
169 /* localhost's name. We print only first 64 chars */
170 char *hostname;
171
172 /* We recv into recvbuf... */
173 char recvbuf[MAX_READ * (1 + ENABLE_FEATURE_SYSLOGD_DUP)];
174 /* ...then copy to parsebuf, escaping control chars */
175 /* (can grow x2 max) */
176 char parsebuf[MAX_READ*2];
177 /* ...then sprintf into printbuf, adding timestamp (15 chars),
178 * host (64), fac.prio (20) to the message */
179 /* (growth by: 15 + 64 + 20 + delims = ~110) */
180 char printbuf[MAX_READ*2 + 128];
181};
182
183static const struct init_globals init_data = {
184 .logFile = {
185 .path = "/var/log/messages",
186 .fd = -1,
187 },
188#ifdef SYSLOGD_MARK
189 .markInterval = 20 * 60,
190#endif
191 .logLevel = 8,
192#if ENABLE_FEATURE_ROTATE_LOGFILE
193 .logFileSize = 200 * 1024,
194 .logFileRotate = 1,
195#endif
196#if ENABLE_FEATURE_IPC_SYSLOG
197 .shmid = -1,
198 .s_semid = -1,
199 .shm_size = ((CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE)*1024), /* default shm size */
200 .SMwup = { {1, -1, IPC_NOWAIT} },
201 .SMwdn = { {0, 0}, {1, 0}, {1, +1} },
202#endif
203};
204
205#define G (*ptr_to_globals)
206#define INIT_G() do { \
207 SET_PTR_TO_GLOBALS(memcpy(xzalloc(sizeof(G)), &init_data, sizeof(init_data))); \
208} while (0)
209
210
211/* Options */
212enum {
213 OPTBIT_mark = 0, // -m
214 OPTBIT_nofork, // -n
215 OPTBIT_outfile, // -O
216 OPTBIT_loglevel, // -l
217 OPTBIT_small, // -S
218 IF_FEATURE_ROTATE_LOGFILE(OPTBIT_filesize ,) // -s
219 IF_FEATURE_ROTATE_LOGFILE(OPTBIT_rotatecnt ,) // -b
220 IF_FEATURE_REMOTE_LOG( OPTBIT_remotelog ,) // -R
221 IF_FEATURE_REMOTE_LOG( OPTBIT_locallog ,) // -L
222 IF_FEATURE_IPC_SYSLOG( OPTBIT_circularlog,) // -C
223 IF_FEATURE_SYSLOGD_DUP( OPTBIT_dup ,) // -D
224 IF_FEATURE_SYSLOGD_CFG( OPTBIT_cfg ,) // -f
225 IF_FEATURE_KMSG_SYSLOG( OPTBIT_kmsg ,) // -K
226
227 OPT_mark = 1 << OPTBIT_mark ,
228 OPT_nofork = 1 << OPTBIT_nofork ,
229 OPT_outfile = 1 << OPTBIT_outfile ,
230 OPT_loglevel = 1 << OPTBIT_loglevel,
231 OPT_small = 1 << OPTBIT_small ,
232 OPT_filesize = IF_FEATURE_ROTATE_LOGFILE((1 << OPTBIT_filesize )) + 0,
233 OPT_rotatecnt = IF_FEATURE_ROTATE_LOGFILE((1 << OPTBIT_rotatecnt )) + 0,
234 OPT_remotelog = IF_FEATURE_REMOTE_LOG( (1 << OPTBIT_remotelog )) + 0,
235 OPT_locallog = IF_FEATURE_REMOTE_LOG( (1 << OPTBIT_locallog )) + 0,
236 OPT_circularlog = IF_FEATURE_IPC_SYSLOG( (1 << OPTBIT_circularlog)) + 0,
237 OPT_dup = IF_FEATURE_SYSLOGD_DUP( (1 << OPTBIT_dup )) + 0,
238 OPT_cfg = IF_FEATURE_SYSLOGD_CFG( (1 << OPTBIT_cfg )) + 0,
239 OPT_kmsg = IF_FEATURE_KMSG_SYSLOG( (1 << OPTBIT_kmsg )) + 0,
240
241};
242#define OPTION_STR "m:nO:l:S" \
243 IF_FEATURE_ROTATE_LOGFILE("s:" ) \
244 IF_FEATURE_ROTATE_LOGFILE("b:" ) \
245 IF_FEATURE_REMOTE_LOG( "R:" ) \
246 IF_FEATURE_REMOTE_LOG( "L" ) \
247 IF_FEATURE_IPC_SYSLOG( "C::") \
248 IF_FEATURE_SYSLOGD_DUP( "D" ) \
249 IF_FEATURE_SYSLOGD_CFG( "f:" ) \
250 IF_FEATURE_KMSG_SYSLOG( "K" )
251#define OPTION_DECL *opt_m, *opt_l \
252 IF_FEATURE_ROTATE_LOGFILE(,*opt_s) \
253 IF_FEATURE_ROTATE_LOGFILE(,*opt_b) \
254 IF_FEATURE_IPC_SYSLOG( ,*opt_C = NULL) \
255 IF_FEATURE_SYSLOGD_CFG( ,*opt_f = NULL)
256#define OPTION_PARAM &opt_m, &(G.logFile.path), &opt_l \
257 IF_FEATURE_ROTATE_LOGFILE(,&opt_s) \
258 IF_FEATURE_ROTATE_LOGFILE(,&opt_b) \
259 IF_FEATURE_REMOTE_LOG( ,&remoteAddrList) \
260 IF_FEATURE_IPC_SYSLOG( ,&opt_C) \
261 IF_FEATURE_SYSLOGD_CFG( ,&opt_f)
262
263
264#if ENABLE_FEATURE_SYSLOGD_CFG
265static const CODE* find_by_name(char *name, const CODE* c_set)
266{
267 for (; c_set->c_name; c_set++) {
268 if (strcmp(name, c_set->c_name) == 0)
269 return c_set;
270 }
271 return NULL;
272}
273#endif
274static const CODE* find_by_val(int val, const CODE* c_set)
275{
276 for (; c_set->c_name; c_set++) {
277 if (c_set->c_val == val)
278 return c_set;
279 }
280 return NULL;
281}
282
283#if ENABLE_FEATURE_SYSLOGD_CFG
284static void parse_syslogdcfg(const char *file)
285{
286 char *t;
287 logRule_t **pp_rule;
288 /* tok[0] set of selectors */
289 /* tok[1] file name */
290 /* tok[2] has to be NULL */
291 char *tok[3];
292 parser_t *parser;
293
294 parser = config_open2(file ? file : "/etc/syslog.conf",
295 file ? xfopen_for_read : fopen_for_read);
296 if (!parser)
297 /* didn't find default /etc/syslog.conf */
298 /* proceed as if we built busybox without config support */
299 return;
300
301 /* use ptr to ptr to avoid checking whether head was initialized */
302 pp_rule = &G.log_rules;
303 /* iterate through lines of config, skipping comments */
304 while (config_read(parser, tok, 3, 2, "# \t", PARSE_NORMAL | PARSE_MIN_DIE)) {
305 char *cur_selector;
306 logRule_t *cur_rule;
307
308 /* unexpected trailing token? */
309 if (tok[2])
310 goto cfgerr;
311
312 cur_rule = *pp_rule = xzalloc(sizeof(*cur_rule));
313
314 cur_selector = tok[0];
315 /* iterate through selectors: "kern.info;kern.!err;..." */
316 do {
317 const CODE *code;
318 char *next_selector;
319 uint8_t negated_prio; /* "kern.!err" */
320 uint8_t single_prio; /* "kern.=err" */
321 uint32_t facmap; /* bitmap of enabled facilities */
322 uint8_t primap; /* bitmap of enabled priorities */
323 unsigned i;
324
325 next_selector = strchr(cur_selector, ';');
326 if (next_selector)
327 *next_selector++ = '\0';
328
329 t = strchr(cur_selector, '.');
330 if (!t)
331 goto cfgerr;
332 *t++ = '\0'; /* separate facility from priority */
333
334 negated_prio = 0;
335 single_prio = 0;
336 if (*t == '!') {
337 negated_prio = 1;
338 ++t;
339 }
340 if (*t == '=') {
341 single_prio = 1;
342 ++t;
343 }
344
345 /* parse priority */
346 if (*t == '*')
347 primap = 0xff; /* all 8 log levels enabled */
348 else {
349 uint8_t priority;
350 code = find_by_name(t, prioritynames);
351 if (!code)
352 goto cfgerr;
353 primap = 0;
354 priority = code->c_val;
355 if (priority == INTERNAL_NOPRI) {
356 /* ensure we take "enabled_facility_priomap[fac] &= 0" branch below */
357 negated_prio = 1;
358 } else {
359 priority = 1 << priority;
360 do {
361 primap |= priority;
362 if (single_prio)
363 break;
364 priority >>= 1;
365 } while (priority);
366 if (negated_prio)
367 primap = ~primap;
368 }
369 }
370
371 /* parse facility */
372 if (*cur_selector == '*')
373 facmap = (1<<LOG_NFACILITIES) - 1;
374 else {
375 char *next_facility;
376 facmap = 0;
377 t = cur_selector;
378 /* iterate through facilities: "kern,daemon.<priospec>" */
379 do {
380 next_facility = strchr(t, ',');
381 if (next_facility)
382 *next_facility++ = '\0';
383 code = find_by_name(t, facilitynames);
384 if (!code)
385 goto cfgerr;
386 /* "mark" is not a real facility, skip it */
387 if (code->c_val != INTERNAL_MARK)
388 facmap |= 1<<(LOG_FAC(code->c_val));
389 t = next_facility;
390 } while (t);
391 }
392
393 /* merge result with previous selectors */
394 for (i = 0; i < LOG_NFACILITIES; ++i) {
395 if (!(facmap & (1<<i)))
396 continue;
397 if (negated_prio)
398 cur_rule->enabled_facility_priomap[i] &= primap;
399 else
400 cur_rule->enabled_facility_priomap[i] |= primap;
401 }
402
403 cur_selector = next_selector;
404 } while (cur_selector);
405
406 /* check whether current file name was mentioned in previous rules or
407 * as global logfile (G.logFile).
408 */
409 if (strcmp(G.logFile.path, tok[1]) == 0) {
410 cur_rule->file = &G.logFile;
411 goto found;
412 }
413 /* temporarily use cur_rule as iterator, but *pp_rule still points
414 * to currently processing rule entry.
415 * NOTE: *pp_rule points to the current (and last in the list) rule.
416 */
417 for (cur_rule = G.log_rules; cur_rule != *pp_rule; cur_rule = cur_rule->next) {
418 if (strcmp(cur_rule->file->path, tok[1]) == 0) {
419 /* found - reuse the same file structure */
420 (*pp_rule)->file = cur_rule->file;
421 cur_rule = *pp_rule;
422 goto found;
423 }
424 }
425 cur_rule->file = xzalloc(sizeof(*cur_rule->file));
426 cur_rule->file->fd = -1;
427 cur_rule->file->path = xstrdup(tok[1]);
428 found:
429 pp_rule = &cur_rule->next;
430 }
431 config_close(parser);
432 return;
433
434 cfgerr:
435 bb_error_msg_and_die("error in '%s' at line %d",
436 file ? file : "/etc/syslog.conf",
437 parser->lineno);
438}
439#endif
440
441/* circular buffer variables/structures */
442#if ENABLE_FEATURE_IPC_SYSLOG
443
444#if CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE < 4
445#error Sorry, you must set the syslogd buffer size to at least 4KB.
446#error Please check CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE
447#endif
448
449/* our shared key (syslogd.c and logread.c must be in sync) */
450enum { KEY_ID = 0x414e4547 }; /* "GENA" */
451
452static void ipcsyslog_cleanup(void)
453{
454 if (G.shmid != -1) {
455 shmdt(G.shbuf);
456 }
457 if (G.shmid != -1) {
458 shmctl(G.shmid, IPC_RMID, NULL);
459 }
460 if (G.s_semid != -1) {
461 semctl(G.s_semid, 0, IPC_RMID, 0);
462 }
463}
464
465static void ipcsyslog_init(void)
466{
467 if (DEBUG)
468 printf("shmget(%x, %d,...)\n", (int)KEY_ID, G.shm_size);
469
470 G.shmid = shmget(KEY_ID, G.shm_size, IPC_CREAT | 0644);
471 if (G.shmid == -1) {
472 bb_perror_msg_and_die("shmget");
473 }
474
475 G.shbuf = shmat(G.shmid, NULL, 0);
476 if (G.shbuf == (void*) -1L) { /* shmat has bizarre error return */
477 bb_perror_msg_and_die("shmat");
478 }
479
480 memset(G.shbuf, 0, G.shm_size);
481 G.shbuf->size = G.shm_size - offsetof(struct shbuf_ds, data) - 1;
482 /*G.shbuf->tail = 0;*/
483
484 /* we'll trust the OS to set initial semval to 0 (let's hope) */
485 G.s_semid = semget(KEY_ID, 2, IPC_CREAT | IPC_EXCL | 1023);
486 if (G.s_semid == -1) {
487 if (errno == EEXIST) {
488 G.s_semid = semget(KEY_ID, 2, 0);
489 if (G.s_semid != -1)
490 return;
491 }
492 bb_perror_msg_and_die("semget");
493 }
494}
495
496/* Write message to shared mem buffer */
497static void log_to_shmem(const char *msg)
498{
499 int old_tail, new_tail;
500 int len;
501
502 if (semop(G.s_semid, G.SMwdn, 3) == -1) {
503 bb_perror_msg_and_die("SMwdn");
504 }
505
506 /* Circular Buffer Algorithm:
507 * --------------------------
508 * tail == position where to store next syslog message.
509 * tail's max value is (shbuf->size - 1)
510 * Last byte of buffer is never used and remains NUL.
511 */
512 len = strlen(msg) + 1; /* length with NUL included */
513 again:
514 old_tail = G.shbuf->tail;
515 new_tail = old_tail + len;
516 if (new_tail < G.shbuf->size) {
517 /* store message, set new tail */
518 memcpy(G.shbuf->data + old_tail, msg, len);
519 G.shbuf->tail = new_tail;
520 } else {
521 /* k == available buffer space ahead of old tail */
522 int k = G.shbuf->size - old_tail;
523 /* copy what fits to the end of buffer, and repeat */
524 memcpy(G.shbuf->data + old_tail, msg, k);
525 msg += k;
526 len -= k;
527 G.shbuf->tail = 0;
528 goto again;
529 }
530 if (semop(G.s_semid, G.SMwup, 1) == -1) {
531 bb_perror_msg_and_die("SMwup");
532 }
533 if (DEBUG)
534 printf("tail:%d\n", G.shbuf->tail);
535}
536#else
537static void ipcsyslog_cleanup(void) {}
538static void ipcsyslog_init(void) {}
539void log_to_shmem(const char *msg);
540#endif /* FEATURE_IPC_SYSLOG */
541
542#if ENABLE_FEATURE_KMSG_SYSLOG
543static void kmsg_init(void)
544{
545 G.kmsgfd = xopen("/dev/kmsg", O_WRONLY);
546
547 /*
548 * kernel < 3.5 expects single char printk KERN_* priority prefix,
549 * from 3.5 onwards the full syslog facility/priority format is supported
550 */
551 if (get_linux_version_code() < KERNEL_VERSION(3,5,0))
552 G.primask = LOG_PRIMASK;
553 else
554 G.primask = -1;
555}
556
557static void kmsg_cleanup(void)
558{
559 if (ENABLE_FEATURE_CLEAN_UP)
560 close(G.kmsgfd);
561}
562
563/* Write message to /dev/kmsg */
564static void log_to_kmsg(int pri, const char *msg)
565{
566 /*
567 * kernel < 3.5 expects single char printk KERN_* priority prefix,
568 * from 3.5 onwards the full syslog facility/priority format is supported
569 */
570 pri &= G.primask;
571
572 write(G.kmsgfd, G.printbuf, sprintf(G.printbuf, "<%d>%s\n", pri, msg));
573}
574#else
575static void kmsg_init(void) {}
576static void kmsg_cleanup(void) {}
577static void log_to_kmsg(int pri UNUSED_PARAM, const char *msg UNUSED_PARAM) {}
578#endif /* FEATURE_KMSG_SYSLOG */
579
580/* Print a message to the log file. */
581static void log_locally(time_t now, char *msg, logFile_t *log_file)
582{
583#ifdef SYSLOGD_WRLOCK
584 struct flock fl;
585#endif
586 int len = strlen(msg);
587
588 if (log_file->fd >= 0) {
589 /* Reopen log file every second. This allows admin
590 * to delete the file and not worry about restarting us.
591 * This costs almost nothing since it happens
592 * _at most_ once a second.
593 */
594 if (!now)
595 now = time(NULL);
596 if (G.last_log_time != now) {
597 G.last_log_time = now;
598 close(log_file->fd);
599 goto reopen;
600 }
601 } else {
602 reopen:
603 log_file->fd = open(log_file->path, O_WRONLY | O_CREAT
604 | O_NOCTTY | O_APPEND | O_NONBLOCK,
605 0666);
606 if (log_file->fd < 0) {
607 /* cannot open logfile? - print to /dev/console then */
608 int fd = device_open(DEV_CONSOLE, O_WRONLY | O_NOCTTY | O_NONBLOCK);
609 if (fd < 0)
610 fd = 2; /* then stderr, dammit */
611 full_write(fd, msg, len);
612 if (fd != 2)
613 close(fd);
614 return;
615 }
616#if ENABLE_FEATURE_ROTATE_LOGFILE
617 {
618 struct stat statf;
619 log_file->isRegular = (fstat(log_file->fd, &statf) == 0 && S_ISREG(statf.st_mode));
620 /* bug (mostly harmless): can wrap around if file > 4gb */
621 log_file->size = statf.st_size;
622 }
623#endif
624 }
625
626#ifdef SYSLOGD_WRLOCK
627 fl.l_whence = SEEK_SET;
628 fl.l_start = 0;
629 fl.l_len = 1;
630 fl.l_type = F_WRLCK;
631 fcntl(log_file->fd, F_SETLKW, &fl);
632#endif
633
634#if ENABLE_FEATURE_ROTATE_LOGFILE
635 if (G.logFileSize && log_file->isRegular && log_file->size > G.logFileSize) {
636 if (G.logFileRotate) { /* always 0..99 */
637 int i = strlen(log_file->path) + 3 + 1;
638 char oldFile[i];
639 char newFile[i];
640 i = G.logFileRotate - 1;
641 /* rename: f.8 -> f.9; f.7 -> f.8; ... */
642 while (1) {
643 sprintf(newFile, "%s.%d", log_file->path, i);
644 if (i == 0) break;
645 sprintf(oldFile, "%s.%d", log_file->path, --i);
646 /* ignore errors - file might be missing */
647 rename(oldFile, newFile);
648 }
649 /* newFile == "f.0" now */
650 rename(log_file->path, newFile);
651 /* Incredibly, if F and F.0 are hardlinks, POSIX
652 * _demands_ that rename returns 0 but does not
653 * remove F!!!
654 * (hardlinked F/F.0 pair was observed after
655 * power failure during rename()).
656 * Ensure old file is gone:
657 */
658 unlink(log_file->path);
659#ifdef SYSLOGD_WRLOCK
660 fl.l_type = F_UNLCK;
661 fcntl(log_file->fd, F_SETLKW, &fl);
662#endif
663 close(log_file->fd);
664 goto reopen;
665 }
666 ftruncate(log_file->fd, 0);
667 }
668 log_file->size +=
669#endif
670 full_write(log_file->fd, msg, len);
671#ifdef SYSLOGD_WRLOCK
672 fl.l_type = F_UNLCK;
673 fcntl(log_file->fd, F_SETLKW, &fl);
674#endif
675}
676
677static void parse_fac_prio_20(int pri, char *res20)
678{
679 const CODE *c_pri, *c_fac;
680
681 c_fac = find_by_val(LOG_FAC(pri) << 3, facilitynames);
682 if (c_fac) {
683 c_pri = find_by_val(LOG_PRI(pri), prioritynames);
684 if (c_pri) {
685 snprintf(res20, 20, "%s.%s", c_fac->c_name, c_pri->c_name);
686 return;
687 }
688 }
689 snprintf(res20, 20, "<%d>", pri);
690}
691
692/* len parameter is used only for "is there a timestamp?" check.
693 * NB: some callers cheat and supply len==0 when they know
694 * that there is no timestamp, short-circuiting the test. */
695static void timestamp_and_log(int pri, char *msg, int len)
696{
697 char *timestamp;
698 time_t now;
699
700 /* Jan 18 00:11:22 msg... */
701 /* 01234567890123456 */
702 if (len < 16 || msg[3] != ' ' || msg[6] != ' '
703 || msg[9] != ':' || msg[12] != ':' || msg[15] != ' '
704 ) {
705 time(&now);
706 timestamp = ctime(&now) + 4; /* skip day of week */
707 } else {
708 now = 0;
709 timestamp = msg;
710 msg += 16;
711 }
712 timestamp[15] = '\0';
713
714 if (option_mask32 & OPT_kmsg) {
715 log_to_kmsg(pri, msg);
716 return;
717 }
718
719 if (option_mask32 & OPT_small)
720 sprintf(G.printbuf, "%s %s\n", timestamp, msg);
721 else {
722 char res[20];
723 parse_fac_prio_20(pri, res);
724 sprintf(G.printbuf, "%s %.64s %s %s\n", timestamp, G.hostname, res, msg);
725 }
726
727 /* Log message locally (to file or shared mem) */
728#if ENABLE_FEATURE_SYSLOGD_CFG
729 {
730 bool match = 0;
731 logRule_t *rule;
732 uint8_t facility = LOG_FAC(pri);
733 uint8_t prio_bit = 1 << LOG_PRI(pri);
734
735 for (rule = G.log_rules; rule; rule = rule->next) {
736 if (rule->enabled_facility_priomap[facility] & prio_bit) {
737 log_locally(now, G.printbuf, rule->file);
738 match = 1;
739 }
740 }
741 if (match)
742 return;
743 }
744#endif
745 if (LOG_PRI(pri) < G.logLevel) {
746#if ENABLE_FEATURE_IPC_SYSLOG
747 if ((option_mask32 & OPT_circularlog) && G.shbuf) {
748 log_to_shmem(G.printbuf);
749 return;
750 }
751#endif
752 log_locally(now, G.printbuf, &G.logFile);
753 }
754}
755
756static void timestamp_and_log_internal(const char *msg)
757{
758 /* -L, or no -R */
759 if (ENABLE_FEATURE_REMOTE_LOG && !(option_mask32 & OPT_locallog))
760 return;
761 timestamp_and_log(LOG_SYSLOG | LOG_INFO, (char*)msg, 0);
762}
763
764/* tmpbuf[len] is a NUL byte (set by caller), but there can be other,
765 * embedded NULs. Split messages on each of these NULs, parse prio,
766 * escape control chars and log each locally. */
767static void split_escape_and_log(char *tmpbuf, int len)
768{
769 char *p = tmpbuf;
770
771 tmpbuf += len;
772 while (p < tmpbuf) {
773 char c;
774 char *q = G.parsebuf;
775 int pri = (LOG_USER | LOG_NOTICE);
776
777 if (*p == '<') {
778 /* Parse the magic priority number */
779 pri = bb_strtou(p + 1, &p, 10);
780 if (*p == '>')
781 p++;
782 if (pri & ~(LOG_FACMASK | LOG_PRIMASK))
783 pri = (LOG_USER | LOG_NOTICE);
784 }
785
786 while ((c = *p++)) {
787 if (c == '\n')
788 c = ' ';
789 if (!(c & ~0x1f) && c != '\t') {
790 *q++ = '^';
791 c += '@'; /* ^@, ^A, ^B... */
792 }
793 *q++ = c;
794 }
795 *q = '\0';
796
797 /* Now log it */
798 timestamp_and_log(pri, G.parsebuf, q - G.parsebuf);
799 }
800}
801
802#ifdef SYSLOGD_MARK
803static void do_mark(int sig)
804{
805 if (G.markInterval) {
806 timestamp_and_log_internal("-- MARK --");
807 alarm(G.markInterval);
808 }
809}
810#endif
811
812/* Don't inline: prevent struct sockaddr_un to take up space on stack
813 * permanently */
814static NOINLINE int create_socket(void)
815{
816 struct sockaddr_un sunx;
817 int sock_fd;
818 char *dev_log_name;
819
820#if ENABLE_FEATURE_SYSTEMD
821 if (sd_listen_fds() == 1)
822 return SD_LISTEN_FDS_START;
823#endif
824
825 memset(&sunx, 0, sizeof(sunx));
826 sunx.sun_family = AF_UNIX;
827
828 /* Unlink old /dev/log or object it points to. */
829 /* (if it exists, bind will fail) */
830 strcpy(sunx.sun_path, _PATH_LOG);
831 dev_log_name = xmalloc_follow_symlinks(_PATH_LOG);
832 if (dev_log_name) {
833 safe_strncpy(sunx.sun_path, dev_log_name, sizeof(sunx.sun_path));
834 free(dev_log_name);
835 }
836 unlink(sunx.sun_path);
837
838 sock_fd = xsocket(AF_UNIX, SOCK_DGRAM, 0);
839 xbind(sock_fd, (struct sockaddr *) &sunx, sizeof(sunx));
840 chmod(_PATH_LOG, 0666);
841
842 return sock_fd;
843}
844
845#if ENABLE_FEATURE_REMOTE_LOG
846static int try_to_resolve_remote(remoteHost_t *rh)
847{
848 if (!rh->remoteAddr) {
849 unsigned now = monotonic_sec();
850
851 /* Don't resolve name too often - DNS timeouts can be big */
852 if ((now - rh->last_dns_resolve) < DNS_WAIT_SEC)
853 return -1;
854 rh->last_dns_resolve = now;
855 rh->remoteAddr = host2sockaddr(rh->remoteHostname, 514);
856 if (!rh->remoteAddr)
857 return -1;
858 }
859 return xsocket(rh->remoteAddr->u.sa.sa_family, SOCK_DGRAM, 0);
860}
861#endif
862
863static void do_syslogd(void) NORETURN;
864static void do_syslogd(void)
865{
866 int sock_fd;
867#if ENABLE_FEATURE_REMOTE_LOG
868 llist_t *item;
869#endif
870#if ENABLE_FEATURE_SYSLOGD_DUP
871 int last_sz = -1;
872 char *last_buf;
873 char *recvbuf = G.recvbuf;
874#else
875#define recvbuf (G.recvbuf)
876#endif
877
878 /* Set up signal handlers (so that they interrupt read()) */
879 signal_no_SA_RESTART_empty_mask(SIGTERM, record_signo);
880 signal_no_SA_RESTART_empty_mask(SIGINT, record_signo);
881 //signal_no_SA_RESTART_empty_mask(SIGQUIT, record_signo);
882 signal(SIGHUP, SIG_IGN);
883#ifdef SYSLOGD_MARK
884 signal(SIGALRM, do_mark);
885 alarm(G.markInterval);
886#endif
887 sock_fd = create_socket();
888
889 if (option_mask32 & OPT_circularlog)
890 ipcsyslog_init();
891
892 if (option_mask32 & OPT_kmsg)
893 kmsg_init();
894
895 timestamp_and_log_internal("syslogd started: BusyBox v" BB_VER);
896
897 while (!bb_got_signal) {
898 ssize_t sz;
899
900#if ENABLE_FEATURE_SYSLOGD_DUP
901 last_buf = recvbuf;
902 if (recvbuf == G.recvbuf)
903 recvbuf = G.recvbuf + MAX_READ;
904 else
905 recvbuf = G.recvbuf;
906#endif
907 read_again:
908 sz = read(sock_fd, recvbuf, MAX_READ - 1);
909 if (sz < 0) {
910 if (!bb_got_signal)
911 bb_perror_msg("read from %s", _PATH_LOG);
912 break;
913 }
914
915 /* Drop trailing '\n' and NULs (typically there is one NUL) */
916 while (1) {
917 if (sz == 0)
918 goto read_again;
919 /* man 3 syslog says: "A trailing newline is added when needed".
920 * However, neither glibc nor uclibc do this:
921 * syslog(prio, "test") sends "test\0" to /dev/log,
922 * syslog(prio, "test\n") sends "test\n\0".
923 * IOW: newline is passed verbatim!
924 * I take it to mean that it's syslogd's job
925 * to make those look identical in the log files. */
926 if (recvbuf[sz-1] != '\0' && recvbuf[sz-1] != '\n')
927 break;
928 sz--;
929 }
930#if ENABLE_FEATURE_SYSLOGD_DUP
931 if ((option_mask32 & OPT_dup) && (sz == last_sz))
932 if (memcmp(last_buf, recvbuf, sz) == 0)
933 continue;
934 last_sz = sz;
935#endif
936#if ENABLE_FEATURE_REMOTE_LOG
937 /* Stock syslogd sends it '\n'-terminated
938 * over network, mimic that */
939 recvbuf[sz] = '\n';
940
941 /* We are not modifying log messages in any way before send */
942 /* Remote site cannot trust _us_ anyway and need to do validation again */
943 for (item = G.remoteHosts; item != NULL; item = item->link) {
944 remoteHost_t *rh = (remoteHost_t *)item->data;
945
946 if (rh->remoteFD == -1) {
947 rh->remoteFD = try_to_resolve_remote(rh);
948 if (rh->remoteFD == -1)
949 continue;
950 }
951
952 /* Send message to remote logger.
953 * On some errors, close and set remoteFD to -1
954 * so that DNS resolution is retried.
955 */
956 if (sendto(rh->remoteFD, recvbuf, sz+1,
957 MSG_DONTWAIT | MSG_NOSIGNAL,
958 &(rh->remoteAddr->u.sa), rh->remoteAddr->len) == -1
959 ) {
960 switch (errno) {
961 case ECONNRESET:
962 case ENOTCONN: /* paranoia */
963 case EPIPE:
964 close(rh->remoteFD);
965 rh->remoteFD = -1;
966 free(rh->remoteAddr);
967 rh->remoteAddr = NULL;
968 }
969 }
970 }
971#endif
972 if (!ENABLE_FEATURE_REMOTE_LOG || (option_mask32 & OPT_locallog)) {
973 recvbuf[sz] = '\0'; /* ensure it *is* NUL terminated */
974 split_escape_and_log(recvbuf, sz);
975 }
976 } /* while (!bb_got_signal) */
977
978 timestamp_and_log_internal("syslogd exiting");
979 puts("syslogd exiting");
980 remove_pidfile(CONFIG_PID_FILE_PATH "/syslogd.pid");
981 ipcsyslog_cleanup();
982 if (option_mask32 & OPT_kmsg)
983 kmsg_cleanup();
984 kill_myself_with_sig(bb_got_signal);
985#undef recvbuf
986}
987
988int syslogd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
989int syslogd_main(int argc UNUSED_PARAM, char **argv)
990{
991 int opts;
992 char OPTION_DECL;
993#if ENABLE_FEATURE_REMOTE_LOG
994 llist_t *remoteAddrList = NULL;
995#endif
996
997 INIT_G();
998
999 /* No non-option params, -R can occur multiple times */
1000 opt_complementary = "=0" IF_FEATURE_REMOTE_LOG(":R::");
1001 opts = getopt32(argv, OPTION_STR, OPTION_PARAM);
1002#if ENABLE_FEATURE_REMOTE_LOG
1003 while (remoteAddrList) {
1004 remoteHost_t *rh = xzalloc(sizeof(*rh));
1005 rh->remoteHostname = llist_pop(&remoteAddrList);
1006 rh->remoteFD = -1;
1007 rh->last_dns_resolve = monotonic_sec() - DNS_WAIT_SEC - 1;
1008 llist_add_to(&G.remoteHosts, rh);
1009 }
1010#endif
1011
1012#ifdef SYSLOGD_MARK
1013 if (opts & OPT_mark) // -m
1014 G.markInterval = xatou_range(opt_m, 0, INT_MAX/60) * 60;
1015#endif
1016 //if (opts & OPT_nofork) // -n
1017 //if (opts & OPT_outfile) // -O
1018 if (opts & OPT_loglevel) // -l
1019 G.logLevel = xatou_range(opt_l, 1, 8);
1020 //if (opts & OPT_small) // -S
1021#if ENABLE_FEATURE_ROTATE_LOGFILE
1022 if (opts & OPT_filesize) // -s
1023 G.logFileSize = xatou_range(opt_s, 0, INT_MAX/1024) * 1024;
1024 if (opts & OPT_rotatecnt) // -b
1025 G.logFileRotate = xatou_range(opt_b, 0, 99);
1026#endif
1027#if ENABLE_FEATURE_IPC_SYSLOG
1028 if (opt_C) // -Cn
1029 G.shm_size = xatoul_range(opt_C, 4, INT_MAX/1024) * 1024;
1030#endif
1031 /* If they have not specified remote logging, then log locally */
1032 if (ENABLE_FEATURE_REMOTE_LOG && !(opts & OPT_remotelog)) // -R
1033 option_mask32 |= OPT_locallog;
1034#if ENABLE_FEATURE_SYSLOGD_CFG
1035 parse_syslogdcfg(opt_f);
1036#endif
1037
1038 /* Store away localhost's name before the fork */
1039 G.hostname = safe_gethostname();
1040 *strchrnul(G.hostname, '.') = '\0';
1041
1042 if (!(opts & OPT_nofork)) {
1043 bb_daemonize_or_rexec(DAEMON_CHDIR_ROOT, argv);
1044 }
1045
1046 //umask(0); - why??
1047 write_pidfile(CONFIG_PID_FILE_PATH "/syslogd.pid");
1048
1049 do_syslogd();
1050 /* return EXIT_SUCCESS; */
1051}
1052
1053/* Clean up. Needed because we are included from syslogd_and_logger.c */
1054#undef DEBUG
1055#undef SYSLOGD_MARK
1056#undef SYSLOGD_WRLOCK
1057#undef G
1058#undef GLOBALS
1059#undef INIT_G
1060#undef OPTION_STR
1061#undef OPTION_DECL
1062#undef OPTION_PARAM
1063
generated by cgit at 2024-05-16 01:17:06 (GMT)