1 /* vi: set sw=4 ts=4: */
3 * Mini syslogd implementation for busybox
5 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
7 * Copyright (C) 2000 by Karl M. Hegbloom <karlheg@debian.org>
9 * "circular buffer" Copyright (C) 2001 by Gennady Feldman <gfeldman@gena01.com>
11 * Maintainer: Gennady Feldman <gfeldman@gena01.com> as of Mar 12, 2001
13 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
15 //config:config SYSLOGD
16 //config: bool "syslogd (13 kb)"
19 //config: The syslogd utility is used to record logs of all the
20 //config: significant events that occur on a system. Every
21 //config: message that is logged records the date and time of the
22 //config: event, and will generally also record the name of the
23 //config: application that generated the message. When used in
24 //config: conjunction with klogd, messages from the Linux kernel
25 //config: can also be recorded. This is terribly useful,
26 //config: especially for finding what happened when something goes
27 //config: wrong. And something almost always will go wrong if
28 //config: you wait long enough....
30 //config:config FEATURE_ROTATE_LOGFILE
31 //config: bool "Rotate message files"
33 //config: depends on SYSLOGD
35 //config: This enables syslogd to rotate the message files
36 //config: on his own. No need to use an external rotate script.
38 //config:config FEATURE_REMOTE_LOG
39 //config: bool "Remote Log support"
41 //config: depends on SYSLOGD
43 //config: When you enable this feature, the syslogd utility can
44 //config: be used to send system log messages to another system
45 //config: connected via a network. This allows the remote
46 //config: machine to log all the system messages, which can be
47 //config: terribly useful for reducing the number of serial
48 //config: cables you use. It can also be a very good security
49 //config: measure to prevent system logs from being tampered with
50 //config: by an intruder.
52 //config:config FEATURE_SYSLOGD_DUP
53 //config: bool "Support -D (drop dups) option"
55 //config: depends on SYSLOGD
57 //config: Option -D instructs syslogd to drop consecutive messages
58 //config: which are totally the same.
60 //config:config FEATURE_SYSLOGD_CFG
61 //config: bool "Support syslog.conf"
63 //config: depends on SYSLOGD
65 //config: Supports restricted syslogd config. See docs/syslog.conf.txt
67 //config:config FEATURE_SYSLOGD_PRECISE_TIMESTAMPS
68 //config: bool "Include milliseconds in timestamps"
70 //config: depends on SYSLOGD
72 //config: Includes milliseconds (HH:MM:SS.mmm) in timestamp when
73 //config: timestamps are added.
75 //config:config FEATURE_SYSLOGD_READ_BUFFER_SIZE
76 //config: int "Read buffer size in bytes"
78 //config: range 256 20000
79 //config: depends on SYSLOGD
81 //config: This option sets the size of the syslog read buffer.
82 //config: Actual memory usage increases around five times the
83 //config: change done here.
85 //config:config FEATURE_IPC_SYSLOG
86 //config: bool "Circular Buffer support"
88 //config: depends on SYSLOGD
90 //config: When you enable this feature, the syslogd utility will
91 //config: use a circular buffer to record system log messages.
92 //config: When the buffer is filled it will continue to overwrite
93 //config: the oldest messages. This can be very useful for
94 //config: systems with little or no permanent storage, since
95 //config: otherwise system logs can eventually fill up your
96 //config: entire filesystem, which may cause your system to
97 //config: break badly.
99 //config:config FEATURE_IPC_SYSLOG_BUFFER_SIZE
100 //config: int "Circular buffer size in Kbytes (minimum 4KB)"
102 //config: range 4 2147483647
103 //config: depends on FEATURE_IPC_SYSLOG
105 //config: This option sets the size of the circular buffer
106 //config: used to record system log messages.
108 //config:config FEATURE_KMSG_SYSLOG
109 //config: bool "Linux kernel printk buffer support"
111 //config: depends on SYSLOGD
112 //config: select PLATFORM_LINUX
114 //config: When you enable this feature, the syslogd utility will
115 //config: write system log message to the Linux kernel's printk buffer.
116 //config: This can be used as a smaller alternative to the syslogd IPC
117 //config: support, as klogd and logread aren't needed.
119 //config: NOTICE: Syslog facilities in log entries needs kernel 3.5+.
121 //applet:IF_SYSLOGD(APPLET(syslogd, BB_DIR_SBIN, BB_SUID_DROP))
123 //kbuild:lib-$(CONFIG_SYSLOGD) += syslogd_and_logger.o
125 //usage:#define syslogd_trivial_usage
127 //usage:#define syslogd_full_usage "\n\n"
128 //usage: "System logging utility\n"
129 //usage: IF_NOT_FEATURE_SYSLOGD_CFG(
130 //usage: "(this version of syslogd ignores /etc/syslog.conf)\n"
132 //usage: "\n -n Run in foreground"
133 //usage: IF_FEATURE_REMOTE_LOG(
134 //usage: "\n -R HOST[:PORT] Log to HOST:PORT (default PORT:514)"
135 //usage: "\n -L Log locally and via network (default is network only if -R)"
137 //usage: IF_FEATURE_IPC_SYSLOG(
138 /* NB: -Csize shouldn't have space (because size is optional) */
139 //usage: "\n -C[size_kb] Log to shared mem buffer (use logread to read it)"
141 //usage: IF_FEATURE_KMSG_SYSLOG(
142 //usage: "\n -K Log to kernel printk buffer (use dmesg to read it)"
144 //usage: "\n -O FILE Log to FILE (default: /var/log/messages, stdout if -)"
145 //usage: IF_FEATURE_ROTATE_LOGFILE(
146 //usage: "\n -s SIZE Max size (KB) before rotation (default 200KB, 0=off)"
147 //usage: "\n -b N N rotated logs to keep (default 1, max 99, 0=purge)"
149 //usage: "\n -l N Log only messages more urgent than prio N (1-8)"
150 //usage: "\n -S Smaller output"
151 //usage: "\n -t Strip client-generated timestamps"
152 //usage: IF_FEATURE_SYSLOGD_DUP(
153 //usage: "\n -D Drop duplicates"
155 //usage: IF_FEATURE_SYSLOGD_CFG(
156 //usage: "\n -f FILE Use FILE as config (default:/etc/syslog.conf)"
158 /* //usage: "\n -m MIN Minutes between MARK lines (default 20, 0=off)" */
160 //usage:#define syslogd_example_usage
161 //usage: "$ syslogd -R masterlog:514\n"
162 //usage: "$ syslogd -R 192.168.1.1:601\n"
165 * Done in syslogd_and_logger.c:
168 #define SYSLOG_NAMES_CONST
172 #define _PATH_LOG "/dev/log"
178 #if ENABLE_FEATURE_REMOTE_LOG
179 #include <netinet/in.h>
182 #if ENABLE_FEATURE_IPC_SYSLOG
191 /* MARK code is not very useful, is bloat, and broken:
192 * can deadlock if alarmed to make MARK while writing to IPC buffer
193 * (semaphores are down but do_mark routine tries to down them again) */
196 /* Write locking does not seem to be useful either */
197 #undef SYSLOGD_WRLOCK
200 MAX_READ = CONFIG_FEATURE_SYSLOGD_READ_BUFFER_SIZE,
201 DNS_WAIT_SEC = 2 * 60,
204 /* Semaphore operation structures */
206 int32_t size; /* size of data - 1 */
207 int32_t tail; /* end of message list */
208 char data[1]; /* data/messages */
211 #if ENABLE_FEATURE_REMOTE_LOG
214 unsigned last_dns_resolve;
215 len_and_sockaddr *remoteAddr;
216 const char *remoteHostname;
220 typedef struct logFile_t {
223 time_t last_log_time;
224 #if ENABLE_FEATURE_ROTATE_LOGFILE
230 #if ENABLE_FEATURE_SYSLOGD_CFG
231 typedef struct logRule_t {
232 uint8_t enabled_facility_priomap[LOG_NFACILITIES];
233 struct logFile_t *file;
234 struct logRule_t *next;
238 /* Allows us to have smaller initializer. Ugly. */
241 /* interval between marks in seconds */ \
242 /*int markInterval;*/ \
243 /* level of messages to be logged */ \
245 IF_FEATURE_ROTATE_LOGFILE( \
246 /* max size of file before rotation */ \
247 unsigned logFileSize; \
248 /* number of rotated message files */ \
249 unsigned logFileRotate; \
251 IF_FEATURE_IPC_SYSLOG( \
252 int shmid; /* ipc shared memory id */ \
253 int s_semid; /* ipc semaphore id */ \
255 struct sembuf SMwup[1]; \
256 struct sembuf SMwdn[3]; \
258 IF_FEATURE_SYSLOGD_CFG( \
259 logRule_t *log_rules; \
261 IF_FEATURE_KMSG_SYSLOG( \
266 struct init_globals {
273 #if ENABLE_FEATURE_REMOTE_LOG
274 llist_t *remoteHosts;
276 #if ENABLE_FEATURE_IPC_SYSLOG
277 struct shbuf_ds *shbuf;
279 /* localhost's name. We print only first 64 chars */
282 /* We recv into recvbuf... */
283 char recvbuf[MAX_READ * (1 + ENABLE_FEATURE_SYSLOGD_DUP)];
284 /* ...then copy to parsebuf, escaping control chars */
285 /* (can grow x2 max) */
286 char parsebuf[MAX_READ*2];
287 /* ...then sprintf into printbuf, adding timestamp (15 or 19 chars),
288 * host (64), fac.prio (20) to the message */
289 /* (growth by: 15 + 64 + 20 + delims = ~110) */
290 char printbuf[MAX_READ*2 + 128];
293 static const struct init_globals init_data = {
295 .path = "/var/log/messages",
299 .markInterval = 20 * 60,
302 #if ENABLE_FEATURE_ROTATE_LOGFILE
303 .logFileSize = 200 * 1024,
306 #if ENABLE_FEATURE_IPC_SYSLOG
309 .shm_size = ((CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE)*1024), /* default shm size */
310 .SMwup = { {1, -1, IPC_NOWAIT} },
311 .SMwdn = { {0, 0}, {1, 0}, {1, +1} },
315 #define G (*ptr_to_globals)
316 #define INIT_G() do { \
317 SET_PTR_TO_GLOBALS(memcpy(xzalloc(sizeof(G)), &init_data, sizeof(init_data))); \
323 OPTBIT_mark = 0, // -m
325 OPTBIT_outfile, // -O
326 OPTBIT_loglevel, // -l
328 OPTBIT_timestamp, // -t
329 IF_FEATURE_ROTATE_LOGFILE(OPTBIT_filesize ,) // -s
330 IF_FEATURE_ROTATE_LOGFILE(OPTBIT_rotatecnt ,) // -b
331 IF_FEATURE_REMOTE_LOG( OPTBIT_remotelog ,) // -R
332 IF_FEATURE_REMOTE_LOG( OPTBIT_locallog ,) // -L
333 IF_FEATURE_IPC_SYSLOG( OPTBIT_circularlog,) // -C
334 IF_FEATURE_SYSLOGD_DUP( OPTBIT_dup ,) // -D
335 IF_FEATURE_SYSLOGD_CFG( OPTBIT_cfg ,) // -f
336 IF_FEATURE_KMSG_SYSLOG( OPTBIT_kmsg ,) // -K
338 OPT_mark = 1 << OPTBIT_mark ,
339 OPT_nofork = 1 << OPTBIT_nofork ,
340 OPT_outfile = 1 << OPTBIT_outfile ,
341 OPT_loglevel = 1 << OPTBIT_loglevel,
342 OPT_small = 1 << OPTBIT_small ,
343 OPT_timestamp = 1 << OPTBIT_timestamp,
344 OPT_filesize = IF_FEATURE_ROTATE_LOGFILE((1 << OPTBIT_filesize )) + 0,
345 OPT_rotatecnt = IF_FEATURE_ROTATE_LOGFILE((1 << OPTBIT_rotatecnt )) + 0,
346 OPT_remotelog = IF_FEATURE_REMOTE_LOG( (1 << OPTBIT_remotelog )) + 0,
347 OPT_locallog = IF_FEATURE_REMOTE_LOG( (1 << OPTBIT_locallog )) + 0,
348 OPT_circularlog = IF_FEATURE_IPC_SYSLOG( (1 << OPTBIT_circularlog)) + 0,
349 OPT_dup = IF_FEATURE_SYSLOGD_DUP( (1 << OPTBIT_dup )) + 0,
350 OPT_cfg = IF_FEATURE_SYSLOGD_CFG( (1 << OPTBIT_cfg )) + 0,
351 OPT_kmsg = IF_FEATURE_KMSG_SYSLOG( (1 << OPTBIT_kmsg )) + 0,
353 #define OPTION_STR "m:nO:l:St" \
354 IF_FEATURE_ROTATE_LOGFILE("s:" ) \
355 IF_FEATURE_ROTATE_LOGFILE("b:" ) \
356 IF_FEATURE_REMOTE_LOG( "R:*") \
357 IF_FEATURE_REMOTE_LOG( "L" ) \
358 IF_FEATURE_IPC_SYSLOG( "C::") \
359 IF_FEATURE_SYSLOGD_DUP( "D" ) \
360 IF_FEATURE_SYSLOGD_CFG( "f:" ) \
361 IF_FEATURE_KMSG_SYSLOG( "K" )
362 #define OPTION_DECL *opt_m, *opt_l \
363 IF_FEATURE_ROTATE_LOGFILE(,*opt_s) \
364 IF_FEATURE_ROTATE_LOGFILE(,*opt_b) \
365 IF_FEATURE_IPC_SYSLOG( ,*opt_C = NULL) \
366 IF_FEATURE_SYSLOGD_CFG( ,*opt_f = NULL)
367 #define OPTION_PARAM &opt_m, &(G.logFile.path), &opt_l \
368 IF_FEATURE_ROTATE_LOGFILE(,&opt_s) \
369 IF_FEATURE_ROTATE_LOGFILE(,&opt_b) \
370 IF_FEATURE_REMOTE_LOG( ,&remoteAddrList) \
371 IF_FEATURE_IPC_SYSLOG( ,&opt_C) \
372 IF_FEATURE_SYSLOGD_CFG( ,&opt_f)
375 #if ENABLE_FEATURE_SYSLOGD_CFG
376 static const CODE* find_by_name(char *name, const CODE* c_set)
378 for (; c_set->c_name; c_set++) {
379 if (strcmp(name, c_set->c_name) == 0)
385 static const CODE* find_by_val(int val, const CODE* c_set)
387 for (; c_set->c_name; c_set++) {
388 if (c_set->c_val == val)
394 #if ENABLE_FEATURE_SYSLOGD_CFG
395 static void parse_syslogdcfg(const char *file)
399 /* tok[0] set of selectors */
400 /* tok[1] file name */
401 /* tok[2] has to be NULL */
405 parser = config_open2(file ? file : "/etc/syslog.conf",
406 file ? xfopen_for_read : fopen_for_read);
408 /* didn't find default /etc/syslog.conf */
409 /* proceed as if we built busybox without config support */
412 /* use ptr to ptr to avoid checking whether head was initialized */
413 pp_rule = &G.log_rules;
414 /* iterate through lines of config, skipping comments */
415 while (config_read(parser, tok, 3, 2, "# \t", PARSE_NORMAL | PARSE_MIN_DIE)) {
419 /* unexpected trailing token? */
423 cur_rule = *pp_rule = xzalloc(sizeof(*cur_rule));
425 cur_selector = tok[0];
426 /* iterate through selectors: "kern.info;kern.!err;..." */
430 uint8_t negated_prio; /* "kern.!err" */
431 uint8_t single_prio; /* "kern.=err" */
432 uint32_t facmap; /* bitmap of enabled facilities */
433 uint8_t primap; /* bitmap of enabled priorities */
436 next_selector = strchr(cur_selector, ';');
438 *next_selector++ = '\0';
440 t = strchr(cur_selector, '.');
443 *t++ = '\0'; /* separate facility from priority */
458 primap = 0xff; /* all 8 log levels enabled */
461 code = find_by_name(t, bb_prioritynames);
465 priority = code->c_val;
466 if (priority == INTERNAL_NOPRI) {
467 /* ensure we take "enabled_facility_priomap[fac] &= 0" branch below */
470 priority = 1 << priority;
483 if (*cur_selector == '*')
484 facmap = (1<<LOG_NFACILITIES) - 1;
489 /* iterate through facilities: "kern,daemon.<priospec>" */
491 next_facility = strchr(t, ',');
493 *next_facility++ = '\0';
494 code = find_by_name(t, bb_facilitynames);
497 /* "mark" is not a real facility, skip it */
498 if (code->c_val != INTERNAL_MARK)
499 facmap |= 1<<(LOG_FAC(code->c_val));
504 /* merge result with previous selectors */
505 for (i = 0; i < LOG_NFACILITIES; ++i) {
506 if (!(facmap & (1<<i)))
509 cur_rule->enabled_facility_priomap[i] &= primap;
511 cur_rule->enabled_facility_priomap[i] |= primap;
514 cur_selector = next_selector;
515 } while (cur_selector);
517 /* check whether current file name was mentioned in previous rules or
518 * as global logfile (G.logFile).
520 if (strcmp(G.logFile.path, tok[1]) == 0) {
521 cur_rule->file = &G.logFile;
524 /* temporarily use cur_rule as iterator, but *pp_rule still points
525 * to currently processing rule entry.
526 * NOTE: *pp_rule points to the current (and last in the list) rule.
528 for (cur_rule = G.log_rules; cur_rule != *pp_rule; cur_rule = cur_rule->next) {
529 if (strcmp(cur_rule->file->path, tok[1]) == 0) {
530 /* found - reuse the same file structure */
531 (*pp_rule)->file = cur_rule->file;
536 cur_rule->file = xzalloc(sizeof(*cur_rule->file));
537 cur_rule->file->fd = -1;
538 cur_rule->file->path = xstrdup(tok[1]);
540 pp_rule = &cur_rule->next;
542 config_close(parser);
546 bb_error_msg_and_die("error in '%s' at line %d",
547 file ? file : "/etc/syslog.conf",
552 /* circular buffer variables/structures */
553 #if ENABLE_FEATURE_IPC_SYSLOG
555 #if CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE < 4
556 #error Sorry, you must set the syslogd buffer size to at least 4KB.
557 #error Please check CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE
560 /* our shared key (syslogd.c and logread.c must be in sync) */
561 enum { KEY_ID = 0x414e4547 }; /* "GENA" */
563 static void ipcsyslog_cleanup(void)
569 shmctl(G.shmid, IPC_RMID, NULL);
571 if (G.s_semid != -1) {
572 semctl(G.s_semid, 0, IPC_RMID, 0);
576 static void ipcsyslog_init(void)
579 printf("shmget(%x, %d,...)\n", (int)KEY_ID, G.shm_size);
581 G.shmid = shmget(KEY_ID, G.shm_size, IPC_CREAT | 0644);
583 bb_simple_perror_msg_and_die("shmget");
586 G.shbuf = shmat(G.shmid, NULL, 0);
587 if (G.shbuf == (void*) -1L) { /* shmat has bizarre error return */
588 bb_simple_perror_msg_and_die("shmat");
591 memset(G.shbuf, 0, G.shm_size);
592 G.shbuf->size = G.shm_size - offsetof(struct shbuf_ds, data) - 1;
593 /*G.shbuf->tail = 0;*/
595 /* we'll trust the OS to set initial semval to 0 (let's hope) */
596 G.s_semid = semget(KEY_ID, 2, IPC_CREAT | IPC_EXCL | 1023);
597 if (G.s_semid == -1) {
598 if (errno == EEXIST) {
599 G.s_semid = semget(KEY_ID, 2, 0);
603 bb_simple_perror_msg_and_die("semget");
607 /* Write message to shared mem buffer */
608 static void log_to_shmem(const char *msg)
610 int old_tail, new_tail;
613 if (semop(G.s_semid, G.SMwdn, 3) == -1) {
614 bb_simple_perror_msg_and_die("SMwdn");
617 /* Circular Buffer Algorithm:
618 * --------------------------
619 * tail == position where to store next syslog message.
620 * tail's max value is (shbuf->size - 1)
621 * Last byte of buffer is never used and remains NUL.
623 len = strlen(msg) + 1; /* length with NUL included */
625 old_tail = G.shbuf->tail;
626 new_tail = old_tail + len;
627 if (new_tail < G.shbuf->size) {
628 /* store message, set new tail */
629 memcpy(G.shbuf->data + old_tail, msg, len);
630 G.shbuf->tail = new_tail;
632 /* k == available buffer space ahead of old tail */
633 int k = G.shbuf->size - old_tail;
634 /* copy what fits to the end of buffer, and repeat */
635 memcpy(G.shbuf->data + old_tail, msg, k);
641 if (semop(G.s_semid, G.SMwup, 1) == -1) {
642 bb_simple_perror_msg_and_die("SMwup");
645 printf("tail:%d\n", G.shbuf->tail);
648 static void ipcsyslog_cleanup(void) {}
649 static void ipcsyslog_init(void) {}
650 void log_to_shmem(const char *msg);
651 #endif /* FEATURE_IPC_SYSLOG */
653 #if ENABLE_FEATURE_KMSG_SYSLOG
654 static void kmsg_init(void)
656 G.kmsgfd = xopen("/dev/kmsg", O_WRONLY);
659 * kernel < 3.5 expects single char printk KERN_* priority prefix,
660 * from 3.5 onwards the full syslog facility/priority format is supported
662 if (get_linux_version_code() < KERNEL_VERSION(3,5,0))
663 G.primask = LOG_PRIMASK;
668 static void kmsg_cleanup(void)
670 if (ENABLE_FEATURE_CLEAN_UP)
674 /* Write message to /dev/kmsg */
675 static void log_to_kmsg(int pri, const char *msg)
678 * kernel < 3.5 expects single char printk KERN_* priority prefix,
679 * from 3.5 onwards the full syslog facility/priority format is supported
683 full_write(G.kmsgfd, G.printbuf, sprintf(G.printbuf, "<%d>%s\n", pri, msg));
686 static void kmsg_init(void) {}
687 static void kmsg_cleanup(void) {}
688 static void log_to_kmsg(int pri UNUSED_PARAM, const char *msg UNUSED_PARAM) {}
689 #endif /* FEATURE_KMSG_SYSLOG */
691 /* Print a message to the log file. */
692 static void log_locally(time_t now, char *msg, logFile_t *log_file)
694 #ifdef SYSLOGD_WRLOCK
697 int len = strlen(msg);
699 /* fd can't be 0 (we connect fd 0 to /dev/log socket) */
700 /* fd is 1 if "-O -" is in use */
701 if (log_file->fd > 1) {
702 /* Reopen log files every second. This allows admin
703 * to delete the files and not worry about restarting us.
704 * This costs almost nothing since it happens
705 * _at most_ once a second for each file, and happens
706 * only when each file is actually written.
710 if (log_file->last_log_time != now) {
711 log_file->last_log_time = now;
716 else if (log_file->fd == 1) {
717 /* We are logging to stdout: do nothing */
720 if (LONE_DASH(log_file->path)) {
722 /* log_file->isRegular = 0; - already is */
725 log_file->fd = open(log_file->path, O_WRONLY | O_CREAT
726 | O_NOCTTY | O_APPEND | O_NONBLOCK,
728 if (log_file->fd < 0) {
729 /* cannot open logfile? - print to /dev/console then */
730 int fd = device_open(DEV_CONSOLE, O_WRONLY | O_NOCTTY | O_NONBLOCK);
732 fd = 2; /* then stderr, dammit */
733 full_write(fd, msg, len);
738 #if ENABLE_FEATURE_ROTATE_LOGFILE
741 log_file->isRegular = (fstat(log_file->fd, &statf) == 0 && S_ISREG(statf.st_mode));
742 /* bug (mostly harmless): can wrap around if file > 4gb */
743 log_file->size = statf.st_size;
749 #ifdef SYSLOGD_WRLOCK
750 fl.l_whence = SEEK_SET;
754 fcntl(log_file->fd, F_SETLKW, &fl);
757 #if ENABLE_FEATURE_ROTATE_LOGFILE
758 if (G.logFileSize && log_file->isRegular && log_file->size > G.logFileSize) {
759 if (G.logFileRotate) { /* always 0..99 */
760 int i = strlen(log_file->path) + 3 + 1;
763 i = G.logFileRotate - 1;
764 /* rename: f.8 -> f.9; f.7 -> f.8; ... */
766 sprintf(newFile, "%s.%d", log_file->path, i);
768 sprintf(oldFile, "%s.%d", log_file->path, --i);
769 /* ignore errors - file might be missing */
770 rename(oldFile, newFile);
772 /* newFile == "f.0" now */
773 rename(log_file->path, newFile);
776 /* We may or may not have just renamed the file away;
777 * if we didn't rename because we aren't keeping any backlog,
778 * then it's time to clobber the file. If we did rename it...,
779 * incredibly, if F and F.0 are hardlinks, POSIX _demands_
780 * that rename returns 0 but does not remove F!!!
781 * (hardlinked F/F.0 pair was observed after
782 * power failure during rename()).
783 * So ensure old file is gone in any case:
785 unlink(log_file->path);
786 #ifdef SYSLOGD_WRLOCK
788 fcntl(log_file->fd, F_SETLKW, &fl);
793 /* TODO: what to do on write errors ("disk full")? */
794 len = full_write(log_file->fd, msg, len);
796 log_file->size += len;
798 full_write(log_file->fd, msg, len);
801 #ifdef SYSLOGD_WRLOCK
803 fcntl(log_file->fd, F_SETLKW, &fl);
807 static void parse_fac_prio_20(int pri, char *res20)
809 const CODE *c_pri, *c_fac;
811 c_fac = find_by_val(LOG_FAC(pri) << 3, bb_facilitynames);
813 c_pri = find_by_val(LOG_PRI(pri), bb_prioritynames);
815 snprintf(res20, 20, "%s.%s", c_fac->c_name, c_pri->c_name);
819 snprintf(res20, 20, "<%d>", pri);
822 /* len parameter is used only for "is there a timestamp?" check.
823 * NB: some callers cheat and supply len==0 when they know
824 * that there is no timestamp, short-circuiting the test. */
825 static void timestamp_and_log(int pri, char *msg, int len)
827 char *timestamp = NULL;
830 /* Jan 18 00:11:22 msg... */
831 /* 01234567890123456 */
832 if (len >= 16 && msg[3] == ' ' && msg[6] == ' '
833 && msg[9] == ':' && msg[12] == ':' && msg[15] == ' '
835 if (!(option_mask32 & OPT_timestamp)) {
836 /* use message timestamp */
843 #if ENABLE_FEATURE_SYSLOGD_PRECISE_TIMESTAMPS
846 gettimeofday(&tv, NULL);
848 timestamp = ctime(&now) + 4; /* skip day of week */
849 /* overwrite year by milliseconds, zero terminate */
850 sprintf(timestamp + 15, ".%03u", (unsigned)tv.tv_usec / 1000u);
852 timestamp[15] = '\0';
857 timestamp = ctime(&now) + 4; /* skip day of week */
859 timestamp[15] = '\0';
862 if (option_mask32 & OPT_kmsg) {
863 log_to_kmsg(pri, msg);
867 if (option_mask32 & OPT_small)
868 sprintf(G.printbuf, "%s %s\n", timestamp, msg);
871 parse_fac_prio_20(pri, res);
872 sprintf(G.printbuf, "%s %.64s %s %s\n", timestamp, G.hostname, res, msg);
875 /* Log message locally (to file or shared mem) */
876 #if ENABLE_FEATURE_SYSLOGD_CFG
880 uint8_t facility = LOG_FAC(pri);
881 uint8_t prio_bit = 1 << LOG_PRI(pri);
883 for (rule = G.log_rules; rule; rule = rule->next) {
884 if (rule->enabled_facility_priomap[facility] & prio_bit) {
885 log_locally(now, G.printbuf, rule->file);
893 if (LOG_PRI(pri) < G.logLevel) {
894 #if ENABLE_FEATURE_IPC_SYSLOG
895 if ((option_mask32 & OPT_circularlog) && G.shbuf) {
896 log_to_shmem(G.printbuf);
900 log_locally(now, G.printbuf, &G.logFile);
904 static void timestamp_and_log_internal(const char *msg)
907 if (ENABLE_FEATURE_REMOTE_LOG && !(option_mask32 & OPT_locallog))
909 timestamp_and_log(LOG_SYSLOG | LOG_INFO, (char*)msg, 0);
912 /* tmpbuf[len] is a NUL byte (set by caller), but there can be other,
913 * embedded NULs. Split messages on each of these NULs, parse prio,
914 * escape control chars and log each locally. */
915 static void split_escape_and_log(char *tmpbuf, int len)
922 char *q = G.parsebuf;
923 int pri = (LOG_USER | LOG_NOTICE);
926 /* Parse the magic priority number */
927 pri = bb_strtou(p + 1, &p, 10);
930 if (pri & ~(LOG_FACMASK | LOG_PRIMASK))
931 pri = (LOG_USER | LOG_NOTICE);
937 if (!(c & ~0x1f) && c != '\t') {
939 c += '@'; /* ^@, ^A, ^B... */
946 timestamp_and_log(pri, G.parsebuf, q - G.parsebuf);
951 static void do_mark(int sig)
953 if (G.markInterval) {
954 timestamp_and_log_internal("-- MARK --");
955 alarm(G.markInterval);
960 /* Don't inline: prevent struct sockaddr_un to take up space on stack
962 static NOINLINE int create_socket(void)
964 struct sockaddr_un sunx;
968 memset(&sunx, 0, sizeof(sunx));
969 sunx.sun_family = AF_UNIX;
971 /* Unlink old /dev/log or object it points to. */
972 /* (if it exists, bind will fail) */
973 strcpy(sunx.sun_path, _PATH_LOG);
974 dev_log_name = xmalloc_follow_symlinks(_PATH_LOG);
976 safe_strncpy(sunx.sun_path, dev_log_name, sizeof(sunx.sun_path));
979 unlink(sunx.sun_path);
981 sock_fd = xsocket(AF_UNIX, SOCK_DGRAM, 0);
982 xbind(sock_fd, (struct sockaddr *) &sunx, sizeof(sunx));
983 chmod(_PATH_LOG, 0666);
988 #if ENABLE_FEATURE_REMOTE_LOG
989 static int try_to_resolve_remote(remoteHost_t *rh)
991 if (!rh->remoteAddr) {
992 unsigned now = monotonic_sec();
994 /* Don't resolve name too often - DNS timeouts can be big */
995 if ((now - rh->last_dns_resolve) < DNS_WAIT_SEC)
997 rh->last_dns_resolve = now;
998 rh->remoteAddr = host2sockaddr(rh->remoteHostname, 514);
1002 return xsocket(rh->remoteAddr->u.sa.sa_family, SOCK_DGRAM, 0);
1006 static void do_syslogd(void) NORETURN;
1007 static void do_syslogd(void)
1009 #if ENABLE_FEATURE_REMOTE_LOG
1012 #if ENABLE_FEATURE_SYSLOGD_DUP
1015 char *recvbuf = G.recvbuf;
1017 #define recvbuf (G.recvbuf)
1020 /* Set up signal handlers (so that they interrupt read()) */
1021 signal_no_SA_RESTART_empty_mask(SIGTERM, record_signo);
1022 signal_no_SA_RESTART_empty_mask(SIGINT, record_signo);
1023 //signal_no_SA_RESTART_empty_mask(SIGQUIT, record_signo);
1024 signal(SIGHUP, SIG_IGN);
1026 signal(SIGALRM, do_mark);
1027 alarm(G.markInterval);
1029 xmove_fd(create_socket(), STDIN_FILENO);
1031 if (option_mask32 & OPT_circularlog)
1034 if (option_mask32 & OPT_kmsg)
1037 timestamp_and_log_internal("syslogd started: BusyBox v" BB_VER);
1039 while (!bb_got_signal) {
1042 #if ENABLE_FEATURE_SYSLOGD_DUP
1044 if (recvbuf == G.recvbuf)
1045 recvbuf = G.recvbuf + MAX_READ;
1047 recvbuf = G.recvbuf;
1050 sz = read(STDIN_FILENO, recvbuf, MAX_READ - 1);
1053 bb_perror_msg("read from %s", _PATH_LOG);
1057 /* Drop trailing '\n' and NULs (typically there is one NUL) */
1061 /* man 3 syslog says: "A trailing newline is added when needed".
1062 * However, neither glibc nor uclibc do this:
1063 * syslog(prio, "test") sends "test\0" to /dev/log,
1064 * syslog(prio, "test\n") sends "test\n\0".
1065 * IOW: newline is passed verbatim!
1066 * I take it to mean that it's syslogd's job
1067 * to make those look identical in the log files. */
1068 if (recvbuf[sz-1] != '\0' && recvbuf[sz-1] != '\n')
1072 #if ENABLE_FEATURE_SYSLOGD_DUP
1073 if ((option_mask32 & OPT_dup) && (sz == last_sz))
1074 if (memcmp(last_buf, recvbuf, sz) == 0)
1078 #if ENABLE_FEATURE_REMOTE_LOG
1079 /* Stock syslogd sends it '\n'-terminated
1080 * over network, mimic that */
1083 /* We are not modifying log messages in any way before send */
1084 /* Remote site cannot trust _us_ anyway and need to do validation again */
1085 for (item = G.remoteHosts; item != NULL; item = item->link) {
1086 remoteHost_t *rh = (remoteHost_t *)item->data;
1088 if (rh->remoteFD == -1) {
1089 rh->remoteFD = try_to_resolve_remote(rh);
1090 if (rh->remoteFD == -1)
1094 /* Send message to remote logger.
1095 * On some errors, close and set remoteFD to -1
1096 * so that DNS resolution is retried.
1098 if (sendto(rh->remoteFD, recvbuf, sz+1,
1099 MSG_DONTWAIT | MSG_NOSIGNAL,
1100 &(rh->remoteAddr->u.sa), rh->remoteAddr->len) == -1
1104 case ENOTCONN: /* paranoia */
1106 close(rh->remoteFD);
1108 free(rh->remoteAddr);
1109 rh->remoteAddr = NULL;
1114 if (!ENABLE_FEATURE_REMOTE_LOG || (option_mask32 & OPT_locallog)) {
1115 recvbuf[sz] = '\0'; /* ensure it *is* NUL terminated */
1116 split_escape_and_log(recvbuf, sz);
1118 } /* while (!bb_got_signal) */
1120 timestamp_and_log_internal("syslogd exiting");
1121 remove_pidfile_std_path_and_ext("syslogd");
1122 ipcsyslog_cleanup();
1123 if (option_mask32 & OPT_kmsg)
1125 kill_myself_with_sig(bb_got_signal);
1129 int syslogd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1130 int syslogd_main(int argc UNUSED_PARAM, char **argv)
1134 #if ENABLE_FEATURE_REMOTE_LOG
1135 llist_t *remoteAddrList = NULL;
1140 /* No non-option params */
1141 opts = getopt32(argv, "^"OPTION_STR"\0""=0", OPTION_PARAM);
1142 #if ENABLE_FEATURE_REMOTE_LOG
1143 while (remoteAddrList) {
1144 remoteHost_t *rh = xzalloc(sizeof(*rh));
1145 rh->remoteHostname = llist_pop(&remoteAddrList);
1147 rh->last_dns_resolve = monotonic_sec() - DNS_WAIT_SEC - 1;
1148 llist_add_to(&G.remoteHosts, rh);
1153 if (opts & OPT_mark) // -m
1154 G.markInterval = xatou_range(opt_m, 0, INT_MAX/60) * 60;
1156 //if (opts & OPT_nofork) // -n
1157 //if (opts & OPT_outfile) // -O
1158 if (opts & OPT_loglevel) // -l
1159 G.logLevel = xatou_range(opt_l, 1, 8);
1160 //if (opts & OPT_small) // -S
1161 #if ENABLE_FEATURE_ROTATE_LOGFILE
1162 if (opts & OPT_filesize) // -s
1163 G.logFileSize = xatou_range(opt_s, 0, INT_MAX/1024) * 1024;
1164 if (opts & OPT_rotatecnt) // -b
1165 G.logFileRotate = xatou_range(opt_b, 0, 99);
1167 #if ENABLE_FEATURE_IPC_SYSLOG
1169 G.shm_size = xatoul_range(opt_C, 4, INT_MAX/1024) * 1024;
1171 /* If they have not specified remote logging, then log locally */
1172 if (ENABLE_FEATURE_REMOTE_LOG && !(opts & OPT_remotelog)) // -R
1173 option_mask32 |= OPT_locallog;
1174 #if ENABLE_FEATURE_SYSLOGD_CFG
1175 parse_syslogdcfg(opt_f);
1178 /* Store away localhost's name before the fork */
1179 G.hostname = safe_gethostname();
1180 *strchrnul(G.hostname, '.') = '\0';
1182 if (!(opts & OPT_nofork)) {
1183 bb_daemonize_or_rexec(DAEMON_CHDIR_ROOT, argv);
1187 write_pidfile_std_path_and_ext("syslogd");
1190 /* return EXIT_SUCCESS; */
1193 /* Clean up. Needed because we are included from syslogd_and_logger.c */
1196 #undef SYSLOGD_WRLOCK