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24#include <sys/un.h>
25#include <sys/uio.h>
26
27#if ENABLE_FEATURE_REMOTE_LOG
28#include <netinet/in.h>
29#endif
30
31#if ENABLE_FEATURE_IPC_SYSLOG
32#include <sys/ipc.h>
33#include <sys/sem.h>
34#include <sys/shm.h>
35#endif
36
37
38#define DEBUG 0
39
40
41
42
43#undef SYSLOGD_MARK
44
45
46#undef SYSLOGD_WRLOCK
47
48enum {
49 MAX_READ = CONFIG_FEATURE_SYSLOGD_READ_BUFFER_SIZE,
50 DNS_WAIT_SEC = 2 * 60,
51};
52
53
54struct shbuf_ds {
55 int32_t size;
56 int32_t tail;
57 char data[1];
58};
59
60#if ENABLE_FEATURE_REMOTE_LOG
61typedef struct {
62 int remoteFD;
63 unsigned last_dns_resolve;
64 len_and_sockaddr *remoteAddr;
65 const char *remoteHostname;
66} remoteHost_t;
67#endif
68
69
70#define GLOBALS \
71 const char *logFilePath; \
72 int logFD; \
73 \
74 \
75 \
76 int logLevel; \
77IF_FEATURE_ROTATE_LOGFILE( \
78 \
79 unsigned logFileSize; \
80 \
81 unsigned logFileRotate; \
82 unsigned curFileSize; \
83 smallint isRegular; \
84) \
85IF_FEATURE_IPC_SYSLOG( \
86 int shmid; \
87 int s_semid; \
88 int shm_size; \
89 struct sembuf SMwup[1]; \
90 struct sembuf SMwdn[3]; \
91)
92
93struct init_globals {
94 GLOBALS
95};
96
97struct globals {
98 GLOBALS
99
100#if ENABLE_FEATURE_REMOTE_LOG
101 llist_t *remoteHosts;
102#endif
103#if ENABLE_FEATURE_IPC_SYSLOG
104 struct shbuf_ds *shbuf;
105#endif
106 time_t last_log_time;
107
108 char *hostname;
109
110
111 char recvbuf[MAX_READ * (1 + ENABLE_FEATURE_SYSLOGD_DUP)];
112
113
114 char parsebuf[MAX_READ*2];
115
116
117
118 char printbuf[MAX_READ*2 + 128];
119};
120
121static const struct init_globals init_data = {
122 .logFilePath = "/var/log/messages",
123 .logFD = -1,
124#ifdef SYSLOGD_MARK
125 .markInterval = 20 * 60,
126#endif
127 .logLevel = 8,
128#if ENABLE_FEATURE_ROTATE_LOGFILE
129 .logFileSize = 200 * 1024,
130 .logFileRotate = 1,
131#endif
132#if ENABLE_FEATURE_IPC_SYSLOG
133 .shmid = -1,
134 .s_semid = -1,
135 .shm_size = ((CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE)*1024),
136 .SMwup = { {1, -1, IPC_NOWAIT} },
137 .SMwdn = { {0, 0}, {1, 0}, {1, +1} },
138#endif
139};
140
141#define G (*ptr_to_globals)
142#define INIT_G() do { \
143 SET_PTR_TO_GLOBALS(memcpy(xzalloc(sizeof(G)), &init_data, sizeof(init_data))); \
144} while (0)
145
146
147
148enum {
149 OPTBIT_mark = 0,
150 OPTBIT_nofork,
151 OPTBIT_outfile,
152 OPTBIT_loglevel,
153 OPTBIT_small,
154 IF_FEATURE_ROTATE_LOGFILE(OPTBIT_filesize ,)
155 IF_FEATURE_ROTATE_LOGFILE(OPTBIT_rotatecnt ,)
156 IF_FEATURE_REMOTE_LOG( OPTBIT_remotelog ,)
157 IF_FEATURE_REMOTE_LOG( OPTBIT_locallog ,)
158 IF_FEATURE_IPC_SYSLOG( OPTBIT_circularlog,)
159 IF_FEATURE_SYSLOGD_DUP( OPTBIT_dup ,)
160
161 OPT_mark = 1 << OPTBIT_mark ,
162 OPT_nofork = 1 << OPTBIT_nofork ,
163 OPT_outfile = 1 << OPTBIT_outfile ,
164 OPT_loglevel = 1 << OPTBIT_loglevel,
165 OPT_small = 1 << OPTBIT_small ,
166 OPT_filesize = IF_FEATURE_ROTATE_LOGFILE((1 << OPTBIT_filesize )) + 0,
167 OPT_rotatecnt = IF_FEATURE_ROTATE_LOGFILE((1 << OPTBIT_rotatecnt )) + 0,
168 OPT_remotelog = IF_FEATURE_REMOTE_LOG( (1 << OPTBIT_remotelog )) + 0,
169 OPT_locallog = IF_FEATURE_REMOTE_LOG( (1 << OPTBIT_locallog )) + 0,
170 OPT_circularlog = IF_FEATURE_IPC_SYSLOG( (1 << OPTBIT_circularlog)) + 0,
171 OPT_dup = IF_FEATURE_SYSLOGD_DUP( (1 << OPTBIT_dup )) + 0,
172};
173#define OPTION_STR "m:nO:l:S" \
174 IF_FEATURE_ROTATE_LOGFILE("s:" ) \
175 IF_FEATURE_ROTATE_LOGFILE("b:" ) \
176 IF_FEATURE_REMOTE_LOG( "R:" ) \
177 IF_FEATURE_REMOTE_LOG( "L" ) \
178 IF_FEATURE_IPC_SYSLOG( "C::") \
179 IF_FEATURE_SYSLOGD_DUP( "D" )
180#define OPTION_DECL *opt_m, *opt_l \
181 IF_FEATURE_ROTATE_LOGFILE(,*opt_s) \
182 IF_FEATURE_ROTATE_LOGFILE(,*opt_b) \
183 IF_FEATURE_IPC_SYSLOG( ,*opt_C = NULL)
184#define OPTION_PARAM &opt_m, &G.logFilePath, &opt_l \
185 IF_FEATURE_ROTATE_LOGFILE(,&opt_s) \
186 IF_FEATURE_ROTATE_LOGFILE(,&opt_b) \
187 IF_FEATURE_REMOTE_LOG( ,&remoteAddrList) \
188 IF_FEATURE_IPC_SYSLOG( ,&opt_C)
189
190
191
192#if ENABLE_FEATURE_IPC_SYSLOG
193
194#if CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE < 4
195#error Sorry, you must set the syslogd buffer size to at least 4KB.
196#error Please check CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE
197#endif
198
199
200enum { KEY_ID = 0x414e4547 };
201
202static void ipcsyslog_cleanup(void)
203{
204 if (G.shmid != -1) {
205 shmdt(G.shbuf);
206 }
207 if (G.shmid != -1) {
208 shmctl(G.shmid, IPC_RMID, NULL);
209 }
210 if (G.s_semid != -1) {
211 semctl(G.s_semid, 0, IPC_RMID, 0);
212 }
213}
214
215static void ipcsyslog_init(void)
216{
217 if (DEBUG)
218 printf("shmget(%x, %d,...)\n", (int)KEY_ID, G.shm_size);
219
220 G.shmid = shmget(KEY_ID, G.shm_size, IPC_CREAT | 0644);
221 if (G.shmid == -1) {
222 bb_perror_msg_and_die("shmget");
223 }
224
225 G.shbuf = shmat(G.shmid, NULL, 0);
226 if (G.shbuf == (void*) -1L) {
227 bb_perror_msg_and_die("shmat");
228 }
229
230 memset(G.shbuf, 0, G.shm_size);
231 G.shbuf->size = G.shm_size - offsetof(struct shbuf_ds, data) - 1;
232
233
234
235 G.s_semid = semget(KEY_ID, 2, IPC_CREAT | IPC_EXCL | 1023);
236 if (G.s_semid == -1) {
237 if (errno == EEXIST) {
238 G.s_semid = semget(KEY_ID, 2, 0);
239 if (G.s_semid != -1)
240 return;
241 }
242 bb_perror_msg_and_die("semget");
243 }
244}
245
246
247static void log_to_shmem(const char *msg, int len)
248{
249 int old_tail, new_tail;
250
251 if (semop(G.s_semid, G.SMwdn, 3) == -1) {
252 bb_perror_msg_and_die("SMwdn");
253 }
254
255
256
257
258
259
260
261 len++;
262 again:
263 old_tail = G.shbuf->tail;
264 new_tail = old_tail + len;
265 if (new_tail < G.shbuf->size) {
266
267 memcpy(G.shbuf->data + old_tail, msg, len);
268 G.shbuf->tail = new_tail;
269 } else {
270
271 int k = G.shbuf->size - old_tail;
272
273 memcpy(G.shbuf->data + old_tail, msg, k);
274 msg += k;
275 len -= k;
276 G.shbuf->tail = 0;
277 goto again;
278 }
279 if (semop(G.s_semid, G.SMwup, 1) == -1) {
280 bb_perror_msg_and_die("SMwup");
281 }
282 if (DEBUG)
283 printf("tail:%d\n", G.shbuf->tail);
284}
285#else
286void ipcsyslog_cleanup(void);
287void ipcsyslog_init(void);
288void log_to_shmem(const char *msg);
289#endif
290
291
292
293static void log_locally(time_t now, char *msg)
294{
295#ifdef SYSLOGD_WRLOCK
296 struct flock fl;
297#endif
298 int len = strlen(msg);
299
300#if ENABLE_FEATURE_IPC_SYSLOG
301 if ((option_mask32 & OPT_circularlog) && G.shbuf) {
302 log_to_shmem(msg, len);
303 return;
304 }
305#endif
306 if (G.logFD >= 0) {
307
308
309
310
311
312 if (!now)
313 now = time(NULL);
314 if (G.last_log_time != now) {
315 G.last_log_time = now;
316 close(G.logFD);
317 goto reopen;
318 }
319 } else {
320 reopen:
321 G.logFD = open(G.logFilePath, O_WRONLY | O_CREAT
322 | O_NOCTTY | O_APPEND | O_NONBLOCK,
323 0666);
324 if (G.logFD < 0) {
325
326 int fd = device_open(DEV_CONSOLE, O_WRONLY | O_NOCTTY | O_NONBLOCK);
327 if (fd < 0)
328 fd = 2;
329 full_write(fd, msg, len);
330 if (fd != 2)
331 close(fd);
332 return;
333 }
334#if ENABLE_FEATURE_ROTATE_LOGFILE
335 {
336 struct stat statf;
337 G.isRegular = (fstat(G.logFD, &statf) == 0 && S_ISREG(statf.st_mode));
338
339 G.curFileSize = statf.st_size;
340 }
341#endif
342 }
343
344#ifdef SYSLOGD_WRLOCK
345 fl.l_whence = SEEK_SET;
346 fl.l_start = 0;
347 fl.l_len = 1;
348 fl.l_type = F_WRLCK;
349 fcntl(G.logFD, F_SETLKW, &fl);
350#endif
351
352#if ENABLE_FEATURE_ROTATE_LOGFILE
353 if (G.logFileSize && G.isRegular && G.curFileSize > G.logFileSize) {
354 if (G.logFileRotate) {
355 int i = strlen(G.logFilePath) + 3 + 1;
356 char oldFile[i];
357 char newFile[i];
358 i = G.logFileRotate - 1;
359
360 while (1) {
361 sprintf(newFile, "%s.%d", G.logFilePath, i);
362 if (i == 0) break;
363 sprintf(oldFile, "%s.%d", G.logFilePath, --i);
364
365 rename(oldFile, newFile);
366 }
367
368 rename(G.logFilePath, newFile);
369#ifdef SYSLOGD_WRLOCK
370 fl.l_type = F_UNLCK;
371 fcntl(G.logFD, F_SETLKW, &fl);
372#endif
373 close(G.logFD);
374 goto reopen;
375 }
376 ftruncate(G.logFD, 0);
377 }
378 G.curFileSize +=
379#endif
380 full_write(G.logFD, msg, len);
381#ifdef SYSLOGD_WRLOCK
382 fl.l_type = F_UNLCK;
383 fcntl(G.logFD, F_SETLKW, &fl);
384#endif
385}
386
387static void parse_fac_prio_20(int pri, char *res20)
388{
389 const CODE *c_pri, *c_fac;
390
391 if (pri != 0) {
392 c_fac = facilitynames;
393 while (c_fac->c_name) {
394 if (c_fac->c_val != (LOG_FAC(pri) << 3)) {
395 c_fac++;
396 continue;
397 }
398
399 c_pri = prioritynames;
400 while (c_pri->c_name) {
401 if (c_pri->c_val != LOG_PRI(pri)) {
402 c_pri++;
403 continue;
404 }
405 snprintf(res20, 20, "%s.%s",
406 c_fac->c_name, c_pri->c_name);
407 return;
408 }
409
410 break;
411 }
412 snprintf(res20, 20, "<%d>", pri);
413 }
414}
415
416
417
418
419static void timestamp_and_log(int pri, char *msg, int len)
420{
421 char *timestamp;
422 time_t now;
423
424
425
426 if (len < 16 || msg[3] != ' ' || msg[6] != ' '
427 || msg[9] != ':' || msg[12] != ':' || msg[15] != ' '
428 ) {
429 time(&now);
430 timestamp = ctime(&now) + 4;
431 } else {
432 now = 0;
433 timestamp = msg;
434 msg += 16;
435 }
436 timestamp[15] = '\0';
437
438 if (option_mask32 & OPT_small)
439 sprintf(G.printbuf, "%s %s\n", timestamp, msg);
440 else {
441 char res[20];
442 parse_fac_prio_20(pri, res);
443 sprintf(G.printbuf, "%s %.64s %s %s\n", timestamp, G.hostname, res, msg);
444 }
445
446
447 log_locally(now, G.printbuf);
448}
449
450static void timestamp_and_log_internal(const char *msg)
451{
452
453 if (ENABLE_FEATURE_REMOTE_LOG && !(option_mask32 & OPT_locallog))
454 return;
455 timestamp_and_log(LOG_SYSLOG | LOG_INFO, (char*)msg, 0);
456}
457
458
459
460
461static void split_escape_and_log(char *tmpbuf, int len)
462{
463 char *p = tmpbuf;
464
465 tmpbuf += len;
466 while (p < tmpbuf) {
467 char c;
468 char *q = G.parsebuf;
469 int pri = (LOG_USER | LOG_NOTICE);
470
471 if (*p == '<') {
472
473 pri = bb_strtou(p + 1, &p, 10);
474 if (*p == '>')
475 p++;
476 if (pri & ~(LOG_FACMASK | LOG_PRIMASK))
477 pri = (LOG_USER | LOG_NOTICE);
478 }
479
480 while ((c = *p++)) {
481 if (c == '\n')
482 c = ' ';
483 if (!(c & ~0x1f) && c != '\t') {
484 *q++ = '^';
485 c += '@';
486 }
487 *q++ = c;
488 }
489 *q = '\0';
490
491
492 if (LOG_PRI(pri) < G.logLevel)
493 timestamp_and_log(pri, G.parsebuf, q - G.parsebuf);
494 }
495}
496
497#ifdef SYSLOGD_MARK
498static void do_mark(int sig)
499{
500 if (G.markInterval) {
501 timestamp_and_log_internal("-- MARK --");
502 alarm(G.markInterval);
503 }
504}
505#endif
506
507
508
509static NOINLINE int create_socket(void)
510{
511 struct sockaddr_un sunx;
512 int sock_fd;
513 char *dev_log_name;
514
515 memset(&sunx, 0, sizeof(sunx));
516 sunx.sun_family = AF_UNIX;
517
518
519
520 strcpy(sunx.sun_path, "/dev/log");
521 dev_log_name = xmalloc_follow_symlinks("/dev/log");
522 if (dev_log_name) {
523 safe_strncpy(sunx.sun_path, dev_log_name, sizeof(sunx.sun_path));
524 free(dev_log_name);
525 }
526 unlink(sunx.sun_path);
527
528 sock_fd = xsocket(AF_UNIX, SOCK_DGRAM, 0);
529 xbind(sock_fd, (struct sockaddr *) &sunx, sizeof(sunx));
530 chmod("/dev/log", 0666);
531
532 return sock_fd;
533}
534
535#if ENABLE_FEATURE_REMOTE_LOG
536static int try_to_resolve_remote(remoteHost_t *rh)
537{
538 if (!rh->remoteAddr) {
539 unsigned now = monotonic_sec();
540
541
542 if ((now - rh->last_dns_resolve) < DNS_WAIT_SEC)
543 return -1;
544 rh->last_dns_resolve = now;
545 rh->remoteAddr = host2sockaddr(rh->remoteHostname, 514);
546 if (!rh->remoteAddr)
547 return -1;
548 }
549 return xsocket(rh->remoteAddr->u.sa.sa_family, SOCK_DGRAM, 0);
550}
551#endif
552
553static void do_syslogd(void) NORETURN;
554static void do_syslogd(void)
555{
556 int sock_fd;
557#if ENABLE_FEATURE_REMOTE_LOG
558 llist_t *item;
559#endif
560#if ENABLE_FEATURE_SYSLOGD_DUP
561 int last_sz = -1;
562 char *last_buf;
563 char *recvbuf = G.recvbuf;
564#else
565#define recvbuf (G.recvbuf)
566#endif
567
568
569 signal_no_SA_RESTART_empty_mask(SIGTERM, record_signo);
570 signal_no_SA_RESTART_empty_mask(SIGINT, record_signo);
571
572 signal(SIGHUP, SIG_IGN);
573#ifdef SYSLOGD_MARK
574 signal(SIGALRM, do_mark);
575 alarm(G.markInterval);
576#endif
577 sock_fd = create_socket();
578
579 if (ENABLE_FEATURE_IPC_SYSLOG && (option_mask32 & OPT_circularlog)) {
580 ipcsyslog_init();
581 }
582
583 timestamp_and_log_internal("syslogd started: BusyBox v" BB_VER);
584
585 while (!bb_got_signal) {
586 ssize_t sz;
587
588#if ENABLE_FEATURE_SYSLOGD_DUP
589 last_buf = recvbuf;
590 if (recvbuf == G.recvbuf)
591 recvbuf = G.recvbuf + MAX_READ;
592 else
593 recvbuf = G.recvbuf;
594#endif
595 read_again:
596 sz = read(sock_fd, recvbuf, MAX_READ - 1);
597 if (sz < 0) {
598 if (!bb_got_signal)
599 bb_perror_msg("read from /dev/log");
600 break;
601 }
602
603
604 while (1) {
605 if (sz == 0)
606 goto read_again;
607
608
609
610
611
612
613
614 if (recvbuf[sz-1] != '\0' && recvbuf[sz-1] != '\n')
615 break;
616 sz--;
617 }
618#if ENABLE_FEATURE_SYSLOGD_DUP
619 if ((option_mask32 & OPT_dup) && (sz == last_sz))
620 if (memcmp(last_buf, recvbuf, sz) == 0)
621 continue;
622 last_sz = sz;
623#endif
624#if ENABLE_FEATURE_REMOTE_LOG
625
626
627 recvbuf[sz] = '\n';
628
629
630
631 for (item = G.remoteHosts; item != NULL; item = item->link) {
632 remoteHost_t *rh = (remoteHost_t *)item->data;
633
634 if (rh->remoteFD == -1) {
635 rh->remoteFD = try_to_resolve_remote(rh);
636 if (rh->remoteFD == -1)
637 continue;
638 }
639
640
641
642
643
644 if (sendto(rh->remoteFD, recvbuf, sz+1,
645 MSG_DONTWAIT | MSG_NOSIGNAL,
646 &(rh->remoteAddr->u.sa), rh->remoteAddr->len) == -1
647 ) {
648 switch (errno) {
649 case ECONNRESET:
650 case ENOTCONN:
651 case EPIPE:
652 close(rh->remoteFD);
653 rh->remoteFD = -1;
654 free(rh->remoteAddr);
655 rh->remoteAddr = NULL;
656 }
657 }
658 }
659#endif
660 if (!ENABLE_FEATURE_REMOTE_LOG || (option_mask32 & OPT_locallog)) {
661 recvbuf[sz] = '\0';
662 split_escape_and_log(recvbuf, sz);
663 }
664 }
665
666 timestamp_and_log_internal("syslogd exiting");
667 puts("syslogd exiting");
668 if (ENABLE_FEATURE_IPC_SYSLOG)
669 ipcsyslog_cleanup();
670 kill_myself_with_sig(bb_got_signal);
671#undef recvbuf
672}
673
674int syslogd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
675int syslogd_main(int argc UNUSED_PARAM, char **argv)
676{
677 int opts;
678 char OPTION_DECL;
679#if ENABLE_FEATURE_REMOTE_LOG
680 llist_t *remoteAddrList = NULL;
681#endif
682
683 INIT_G();
684
685
686 opt_complementary = "=0" IF_FEATURE_REMOTE_LOG(":R::");
687 opts = getopt32(argv, OPTION_STR, OPTION_PARAM);
688#if ENABLE_FEATURE_REMOTE_LOG
689 while (remoteAddrList) {
690 remoteHost_t *rh = xzalloc(sizeof(*rh));
691 rh->remoteHostname = llist_pop(&remoteAddrList);
692 rh->remoteFD = -1;
693 rh->last_dns_resolve = monotonic_sec() - DNS_WAIT_SEC - 1;
694 llist_add_to(&G.remoteHosts, rh);
695 }
696#endif
697
698#ifdef SYSLOGD_MARK
699 if (opts & OPT_mark)
700 G.markInterval = xatou_range(opt_m, 0, INT_MAX/60) * 60;
701#endif
702
703
704 if (opts & OPT_loglevel)
705 G.logLevel = xatou_range(opt_l, 1, 8);
706
707#if ENABLE_FEATURE_ROTATE_LOGFILE
708 if (opts & OPT_filesize)
709 G.logFileSize = xatou_range(opt_s, 0, INT_MAX/1024) * 1024;
710 if (opts & OPT_rotatecnt)
711 G.logFileRotate = xatou_range(opt_b, 0, 99);
712#endif
713#if ENABLE_FEATURE_IPC_SYSLOG
714 if (opt_C)
715 G.shm_size = xatoul_range(opt_C, 4, INT_MAX/1024) * 1024;
716#endif
717
718
719 if (ENABLE_FEATURE_REMOTE_LOG && !(opts & OPT_remotelog))
720 option_mask32 |= OPT_locallog;
721
722
723 G.hostname = safe_gethostname();
724 *strchrnul(G.hostname, '.') = '\0';
725
726 if (!(opts & OPT_nofork)) {
727 bb_daemonize_or_rexec(DAEMON_CHDIR_ROOT, argv);
728 }
729
730 write_pidfile("/var/run/syslogd.pid");
731 do_syslogd();
732
733}
734
735
736#undef DEBUG
737#undef SYSLOGD_MARK
738#undef SYSLOGD_WRLOCK
739#undef G
740#undef GLOBALS
741#undef INIT_G
742#undef OPTION_STR
743#undef OPTION_DECL
744#undef OPTION_PARAM
745