source: MondoRescue/branches/2.2.9/mindi-busybox/sysklogd/syslogd.c@ 2177

Last change on this file since 2177 was 1765, checked in by Bruno Cornec, 16 years ago

Update to busybox 1.7.2
File size: 15.9 KB
Line 
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 the GPL v2 or later, see the file LICENSE in this tarball.
14 */
15
16#include "libbb.h"
17#include <paths.h>
18#include <sys/un.h>
19
20/* SYSLOG_NAMES defined to pull prioritynames[] and facilitynames[]
21 * from syslog.h. Grrrr - glibc puts those in _rwdata_! :( */
22#define SYSLOG_NAMES
23#define SYSLOG_NAMES_CONST /* uclibc is saner :) */
24#include <sys/syslog.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/* MARK code is not very useful, is bloat, and broken:
41 * can deadlock if alarmed to make MARK while writing to IPC buffer
42 * (semaphores are down but do_mark routine tries to down them again) */
43#undef SYSLOGD_MARK
44
45enum { MAX_READ = 256 };
46
47/* Semaphore operation structures */
48struct shbuf_ds {
49 int32_t size; /* size of data - 1 */
50 int32_t tail; /* end of message list */
51 char data[1]; /* data/messages */
52};
53
54/* Allows us to have smaller initializer. Ugly. */
55#define GLOBALS \
56 const char *logFilePath; \
57 int logFD; \
58 /* interval between marks in seconds */ \
59 /*int markInterval;*/ \
60 /* level of messages to be logged */ \
61 int logLevel; \
62USE_FEATURE_ROTATE_LOGFILE( \
63 /* max size of file before rotation */ \
64 unsigned logFileSize; \
65 /* number of rotated message files */ \
66 unsigned logFileRotate; \
67 unsigned curFileSize; \
68 smallint isRegular; \
69) \
70USE_FEATURE_REMOTE_LOG( \
71 /* udp socket for remote logging */ \
72 int remoteFD; \
73 len_and_sockaddr* remoteAddr; \
74) \
75USE_FEATURE_IPC_SYSLOG( \
76 int shmid; /* ipc shared memory id */ \
77 int s_semid; /* ipc semaphore id */ \
78 int shm_size; \
79 struct sembuf SMwup[1]; \
80 struct sembuf SMwdn[3]; \
81)
82
83struct init_globals {
84 GLOBALS
85};
86
87struct globals {
88 GLOBALS
89#if ENABLE_FEATURE_IPC_SYSLOG
90 struct shbuf_ds *shbuf;
91#endif
92 time_t last_log_time;
93 /* localhost's name */
94 char localHostName[64];
95
96 /* We recv into recvbuf... */
97 char recvbuf[MAX_READ];
98 /* ...then copy to parsebuf, escaping control chars */
99 /* (can grow x2 max) */
100 char parsebuf[MAX_READ*2];
101 /* ...then sprintf into printbuf, adding timestamp (15 chars),
102 * host (64), fac.prio (20) to the message */
103 /* (growth by: 15 + 64 + 20 + delims = ~110) */
104 char printbuf[MAX_READ*2 + 128];
105};
106
107static const struct init_globals init_data = {
108 .logFilePath = "/var/log/messages",
109 .logFD = -1,
110#ifdef SYSLOGD_MARK
111 .markInterval = 20 * 60,
112#endif
113 .logLevel = 8,
114#if ENABLE_FEATURE_ROTATE_LOGFILE
115 .logFileSize = 200 * 1024,
116 .logFileRotate = 1,
117#endif
118#if ENABLE_FEATURE_REMOTE_LOG
119 .remoteFD = -1,
120#endif
121#if ENABLE_FEATURE_IPC_SYSLOG
122 .shmid = -1,
123 .s_semid = -1,
124 .shm_size = ((CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE)*1024), // default shm size
125 .SMwup = { {1, -1, IPC_NOWAIT} },
126 .SMwdn = { {0, 0}, {1, 0}, {1, +1} },
127#endif
128};
129
130#define G (*ptr_to_globals)
131
132
133/* Options */
134enum {
135 OPTBIT_mark = 0, // -m
136 OPTBIT_nofork, // -n
137 OPTBIT_outfile, // -O
138 OPTBIT_loglevel, // -l
139 OPTBIT_small, // -S
140 USE_FEATURE_ROTATE_LOGFILE(OPTBIT_filesize ,) // -s
141 USE_FEATURE_ROTATE_LOGFILE(OPTBIT_rotatecnt ,) // -b
142 USE_FEATURE_REMOTE_LOG( OPTBIT_remote ,) // -R
143 USE_FEATURE_REMOTE_LOG( OPTBIT_localtoo ,) // -L
144 USE_FEATURE_IPC_SYSLOG( OPTBIT_circularlog,) // -C
145
146 OPT_mark = 1 << OPTBIT_mark ,
147 OPT_nofork = 1 << OPTBIT_nofork ,
148 OPT_outfile = 1 << OPTBIT_outfile ,
149 OPT_loglevel = 1 << OPTBIT_loglevel,
150 OPT_small = 1 << OPTBIT_small ,
151 OPT_filesize = USE_FEATURE_ROTATE_LOGFILE((1 << OPTBIT_filesize )) + 0,
152 OPT_rotatecnt = USE_FEATURE_ROTATE_LOGFILE((1 << OPTBIT_rotatecnt )) + 0,
153 OPT_remotelog = USE_FEATURE_REMOTE_LOG( (1 << OPTBIT_remote )) + 0,
154 OPT_locallog = USE_FEATURE_REMOTE_LOG( (1 << OPTBIT_localtoo )) + 0,
155 OPT_circularlog = USE_FEATURE_IPC_SYSLOG( (1 << OPTBIT_circularlog)) + 0,
156};
157#define OPTION_STR "m:nO:l:S" \
158 USE_FEATURE_ROTATE_LOGFILE("s:" ) \
159 USE_FEATURE_ROTATE_LOGFILE("b:" ) \
160 USE_FEATURE_REMOTE_LOG( "R:" ) \
161 USE_FEATURE_REMOTE_LOG( "L" ) \
162 USE_FEATURE_IPC_SYSLOG( "C::")
163#define OPTION_DECL *opt_m, *opt_l \
164 USE_FEATURE_ROTATE_LOGFILE(,*opt_s) \
165 USE_FEATURE_ROTATE_LOGFILE(,*opt_b) \
166 USE_FEATURE_REMOTE_LOG( ,*opt_R) \
167 USE_FEATURE_IPC_SYSLOG( ,*opt_C = NULL)
168#define OPTION_PARAM &opt_m, &G.logFilePath, &opt_l \
169 USE_FEATURE_ROTATE_LOGFILE(,&opt_s) \
170 USE_FEATURE_ROTATE_LOGFILE(,&opt_b) \
171 USE_FEATURE_REMOTE_LOG( ,&opt_R) \
172 USE_FEATURE_IPC_SYSLOG( ,&opt_C)
173
174
175/* circular buffer variables/structures */
176#if ENABLE_FEATURE_IPC_SYSLOG
177
178#if CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE < 4
179#error Sorry, you must set the syslogd buffer size to at least 4KB.
180#error Please check CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE
181#endif
182
183/* our shared key */
184#define KEY_ID ((long)0x414e4547) /* "GENA" */
185
186static void ipcsyslog_cleanup(void)
187{
188 if (G.shmid != -1) {
189 shmdt(G.shbuf);
190 }
191 if (G.shmid != -1) {
192 shmctl(G.shmid, IPC_RMID, NULL);
193 }
194 if (G.s_semid != -1) {
195 semctl(G.s_semid, 0, IPC_RMID, 0);
196 }
197}
198
199static void ipcsyslog_init(void)
200{
201 if (DEBUG)
202 printf("shmget(%lx, %d,...)\n", KEY_ID, G.shm_size);
203
204 G.shmid = shmget(KEY_ID, G.shm_size, IPC_CREAT | 0644);
205 if (G.shmid == -1) {
206 bb_perror_msg_and_die("shmget");
207 }
208
209 G.shbuf = shmat(G.shmid, NULL, 0);
210 if (!G.shbuf) {
211 bb_perror_msg_and_die("shmat");
212 }
213
214 memset(G.shbuf, 0, G.shm_size);
215 G.shbuf->size = G.shm_size - offsetof(struct shbuf_ds, data) - 1;
216 /*G.shbuf->tail = 0;*/
217
218 // we'll trust the OS to set initial semval to 0 (let's hope)
219 G.s_semid = semget(KEY_ID, 2, IPC_CREAT | IPC_EXCL | 1023);
220 if (G.s_semid == -1) {
221 if (errno == EEXIST) {
222 G.s_semid = semget(KEY_ID, 2, 0);
223 if (G.s_semid != -1)
224 return;
225 }
226 bb_perror_msg_and_die("semget");
227 }
228}
229
230/* Write message to shared mem buffer */
231static void log_to_shmem(const char *msg, int len)
232{
233 int old_tail, new_tail;
234
235 if (semop(G.s_semid, G.SMwdn, 3) == -1) {
236 bb_perror_msg_and_die("SMwdn");
237 }
238
239 /* Circular Buffer Algorithm:
240 * --------------------------
241 * tail == position where to store next syslog message.
242 * tail's max value is (shbuf->size - 1)
243 * Last byte of buffer is never used and remains NUL.
244 */
245 len++; /* length with NUL included */
246 again:
247 old_tail = G.shbuf->tail;
248 new_tail = old_tail + len;
249 if (new_tail < G.shbuf->size) {
250 /* store message, set new tail */
251 memcpy(G.shbuf->data + old_tail, msg, len);
252 G.shbuf->tail = new_tail;
253 } else {
254 /* k == available buffer space ahead of old tail */
255 int k = G.shbuf->size - old_tail;
256 /* copy what fits to the end of buffer, and repeat */
257 memcpy(G.shbuf->data + old_tail, msg, k);
258 msg += k;
259 len -= k;
260 G.shbuf->tail = 0;
261 goto again;
262 }
263 if (semop(G.s_semid, G.SMwup, 1) == -1) {
264 bb_perror_msg_and_die("SMwup");
265 }
266 if (DEBUG)
267 printf("tail:%d\n", G.shbuf->tail);
268}
269#else
270void ipcsyslog_cleanup(void);
271void ipcsyslog_init(void);
272void log_to_shmem(const char *msg);
273#endif /* FEATURE_IPC_SYSLOG */
274
275
276/* Print a message to the log file. */
277static void log_locally(char *msg)
278{
279 struct flock fl;
280 int len = strlen(msg);
281
282#if ENABLE_FEATURE_IPC_SYSLOG
283 if ((option_mask32 & OPT_circularlog) && G.shbuf) {
284 log_to_shmem(msg, len);
285 return;
286 }
287#endif
288 if (G.logFD >= 0) {
289 time_t cur;
290 time(&cur);
291 if (G.last_log_time != cur) {
292 G.last_log_time = cur; /* reopen log file every second */
293 close(G.logFD);
294 goto reopen;
295 }
296 } else {
297 reopen:
298 G.logFD = device_open(G.logFilePath, O_WRONLY | O_CREAT
299 | O_NOCTTY | O_APPEND | O_NONBLOCK);
300 if (G.logFD < 0) {
301 /* cannot open logfile? - print to /dev/console then */
302 int fd = device_open(_PATH_CONSOLE, O_WRONLY | O_NOCTTY | O_NONBLOCK);
303 if (fd < 0)
304 fd = 2; /* then stderr, dammit */
305 full_write(fd, msg, len);
306 if (fd != 2)
307 close(fd);
308 return;
309 }
310#if ENABLE_FEATURE_ROTATE_LOGFILE
311 {
312 struct stat statf;
313 G.isRegular = (fstat(G.logFD, &statf) == 0 && S_ISREG(statf.st_mode));
314 /* bug (mostly harmless): can wrap around if file > 4gb */
315 G.curFileSize = statf.st_size;
316 }
317#endif
318 }
319
320 fl.l_whence = SEEK_SET;
321 fl.l_start = 0;
322 fl.l_len = 1;
323 fl.l_type = F_WRLCK;
324 fcntl(G.logFD, F_SETLKW, &fl);
325
326#if ENABLE_FEATURE_ROTATE_LOGFILE
327 if (G.logFileSize && G.isRegular && G.curFileSize > G.logFileSize) {
328 if (G.logFileRotate) { /* always 0..99 */
329 int i = strlen(G.logFilePath) + 3 + 1;
330 char oldFile[i];
331 char newFile[i];
332 i = G.logFileRotate - 1;
333 /* rename: f.8 -> f.9; f.7 -> f.8; ... */
334 while (1) {
335 sprintf(newFile, "%s.%d", G.logFilePath, i);
336 if (i == 0) break;
337 sprintf(oldFile, "%s.%d", G.logFilePath, --i);
338 rename(oldFile, newFile);
339 }
340 /* newFile == "f.0" now */
341 rename(G.logFilePath, newFile);
342 fl.l_type = F_UNLCK;
343 fcntl(G.logFD, F_SETLKW, &fl);
344 close(G.logFD);
345 goto reopen;
346 }
347 ftruncate(G.logFD, 0);
348 }
349 G.curFileSize +=
350#endif
351 full_write(G.logFD, msg, len);
352 fl.l_type = F_UNLCK;
353 fcntl(G.logFD, F_SETLKW, &fl);
354}
355
356static void parse_fac_prio_20(int pri, char *res20)
357{
358 const CODE *c_pri, *c_fac;
359
360 if (pri != 0) {
361 c_fac = facilitynames;
362 while (c_fac->c_name) {
363 if (c_fac->c_val != (LOG_FAC(pri) << 3)) {
364 c_fac++; continue;
365 }
366 /* facility is found, look for prio */
367 c_pri = prioritynames;
368 while (c_pri->c_name) {
369 if (c_pri->c_val != LOG_PRI(pri)) {
370 c_pri++; continue;
371 }
372 snprintf(res20, 20, "%s.%s",
373 c_fac->c_name, c_pri->c_name);
374 return;
375 }
376 /* prio not found, bail out */
377 break;
378 }
379 snprintf(res20, 20, "<%d>", pri);
380 }
381}
382
383/* len parameter is used only for "is there a timestamp?" check.
384 * NB: some callers cheat and supply 0 when they know
385 * that there is no timestamp, short-cutting the test. */
386static void timestamp_and_log(int pri, char *msg, int len)
387{
388 char *timestamp;
389
390 if (len < 16 || msg[3] != ' ' || msg[6] != ' '
391 || msg[9] != ':' || msg[12] != ':' || msg[15] != ' '
392 ) {
393 time_t now;
394 time(&now);
395 timestamp = ctime(&now) + 4;
396 } else {
397 timestamp = msg;
398 msg += 16;
399 }
400 timestamp[15] = '\0';
401
402 /* Log message locally (to file or shared mem) */
403 if (!ENABLE_FEATURE_REMOTE_LOG || (option_mask32 & OPT_locallog)) {
404 if (LOG_PRI(pri) < G.logLevel) {
405 if (option_mask32 & OPT_small)
406 sprintf(G.printbuf, "%s %s\n", timestamp, msg);
407 else {
408 char res[20];
409 parse_fac_prio_20(pri, res);
410 sprintf(G.printbuf, "%s %s %s %s\n", timestamp, G.localHostName, res, msg);
411 }
412 log_locally(G.printbuf);
413 }
414 }
415}
416
417static void split_escape_and_log(char *tmpbuf, int len)
418{
419 char *p = tmpbuf;
420
421 tmpbuf += len;
422 while (p < tmpbuf) {
423 char c;
424 char *q = G.parsebuf;
425 int pri = (LOG_USER | LOG_NOTICE);
426
427 if (*p == '<') {
428 /* Parse the magic priority number */
429 pri = bb_strtou(p + 1, &p, 10);
430 if (*p == '>') p++;
431 if (pri & ~(LOG_FACMASK | LOG_PRIMASK)) {
432 pri = (LOG_USER | LOG_NOTICE);
433 }
434 }
435
436 while ((c = *p++)) {
437 if (c == '\n')
438 c = ' ';
439 if (!(c & ~0x1f) && c != '\t') {
440 *q++ = '^';
441 c += '@'; /* ^@, ^A, ^B... */
442 }
443 *q++ = c;
444 }
445 *q = '\0';
446 /* Now log it */
447 timestamp_and_log(pri, G.parsebuf, q - G.parsebuf);
448 }
449}
450
451static void quit_signal(int sig)
452{
453 timestamp_and_log(LOG_SYSLOG | LOG_INFO, (char*)"syslogd exiting", 0);
454 puts("syslogd exiting");
455 if (ENABLE_FEATURE_IPC_SYSLOG)
456 ipcsyslog_cleanup();
457 exit(1);
458}
459
460#ifdef SYSLOGD_MARK
461static void do_mark(int sig)
462{
463 if (G.markInterval) {
464 timestamp_and_log(LOG_SYSLOG | LOG_INFO, (char*)"-- MARK --", 0);
465 alarm(G.markInterval);
466 }
467}
468#endif
469
470static void do_syslogd(void) ATTRIBUTE_NORETURN;
471static void do_syslogd(void)
472{
473 struct sockaddr_un sunx;
474 int sock_fd;
475 fd_set fds;
476 char *dev_log_name;
477
478 /* Set up signal handlers */
479 signal(SIGINT, quit_signal);
480 signal(SIGTERM, quit_signal);
481 signal(SIGQUIT, quit_signal);
482 signal(SIGHUP, SIG_IGN);
483 signal(SIGCHLD, SIG_IGN);
484#ifdef SIGCLD
485 signal(SIGCLD, SIG_IGN);
486#endif
487#ifdef SYSLOGD_MARK
488 signal(SIGALRM, do_mark);
489 alarm(G.markInterval);
490#endif
491 remove_pidfile("/var/run/syslogd.pid");
492
493 memset(&sunx, 0, sizeof(sunx));
494 sunx.sun_family = AF_UNIX;
495 strcpy(sunx.sun_path, "/dev/log");
496
497 /* Unlink old /dev/log or object it points to. */
498 /* (if it exists, bind will fail) */
499 logmode = LOGMODE_NONE;
500 dev_log_name = xmalloc_readlink_or_warn("/dev/log");
501 logmode = LOGMODE_STDIO;
502 if (dev_log_name) {
503 int fd = xopen(".", O_NONBLOCK);
504 xchdir("/dev");
505 /* we do not check whether this is a link also */
506 unlink(dev_log_name);
507 fchdir(fd);
508 close(fd);
509 safe_strncpy(sunx.sun_path, dev_log_name, sizeof(sunx.sun_path));
510 free(dev_log_name);
511 } else {
512 unlink("/dev/log");
513 }
514
515 sock_fd = xsocket(AF_UNIX, SOCK_DGRAM, 0);
516 xbind(sock_fd, (struct sockaddr *) &sunx, sizeof(sunx));
517
518 if (chmod("/dev/log", 0666) < 0) {
519 bb_perror_msg_and_die("cannot set permission on /dev/log");
520 }
521 if (ENABLE_FEATURE_IPC_SYSLOG && (option_mask32 & OPT_circularlog)) {
522 ipcsyslog_init();
523 }
524
525 timestamp_and_log(LOG_SYSLOG | LOG_INFO,
526 (char*)"syslogd started: BusyBox v" BB_VER, 0);
527
528 for (;;) {
529 FD_ZERO(&fds);
530 FD_SET(sock_fd, &fds);
531
532 if (select(sock_fd + 1, &fds, NULL, NULL, NULL) < 0) {
533 if (errno == EINTR) {
534 /* alarm may have happened */
535 continue;
536 }
537 bb_perror_msg_and_die("select");
538 }
539
540 if (FD_ISSET(sock_fd, &fds)) {
541 int i;
542 i = recv(sock_fd, G.recvbuf, MAX_READ - 1, 0);
543 if (i <= 0)
544 bb_perror_msg_and_die("UNIX socket error");
545 /* TODO: maybe suppress duplicates? */
546#if ENABLE_FEATURE_REMOTE_LOG
547 /* We are not modifying log messages in any way before send */
548 /* Remote site cannot trust _us_ anyway and need to do validation again */
549 if (G.remoteAddr) {
550 if (-1 == G.remoteFD) {
551 G.remoteFD = socket(G.remoteAddr->sa.sa_family, SOCK_DGRAM, 0);
552 }
553 if (-1 != G.remoteFD) {
554 /* send message to remote logger, ignore possible error */
555 sendto(G.remoteFD, G.recvbuf, i, MSG_DONTWAIT,
556 &G.remoteAddr->sa, G.remoteAddr->len);
557 }
558 }
559#endif
560 G.recvbuf[i] = '\0';
561 split_escape_and_log(G.recvbuf, i);
562 } /* FD_ISSET() */
563 } /* for */
564}
565
566int syslogd_main(int argc, char **argv);
567int syslogd_main(int argc, char **argv)
568{
569 char OPTION_DECL;
570 char *p;
571
572 PTR_TO_GLOBALS = memcpy(xzalloc(sizeof(G)), &init_data, sizeof(init_data));
573
574 /* do normal option parsing */
575 opt_complementary = "=0"; /* no non-option params */
576 getopt32(argv, OPTION_STR, OPTION_PARAM);
577#ifdef SYSLOGD_MARK
578 if (option_mask32 & OPT_mark) // -m
579 G.markInterval = xatou_range(opt_m, 0, INT_MAX/60) * 60;
580#endif
581 //if (option_mask32 & OPT_nofork) // -n
582 //if (option_mask32 & OPT_outfile) // -O
583 if (option_mask32 & OPT_loglevel) // -l
584 G.logLevel = xatou_range(opt_l, 1, 8);
585 //if (option_mask32 & OPT_small) // -S
586#if ENABLE_FEATURE_ROTATE_LOGFILE
587 if (option_mask32 & OPT_filesize) // -s
588 G.logFileSize = xatou_range(opt_s, 0, INT_MAX/1024) * 1024;
589 if (option_mask32 & OPT_rotatecnt) // -b
590 G.logFileRotate = xatou_range(opt_b, 0, 99);
591#endif
592#if ENABLE_FEATURE_REMOTE_LOG
593 if (option_mask32 & OPT_remotelog) { // -R
594 G.remoteAddr = xhost2sockaddr(opt_R, 514);
595 }
596 //if (option_mask32 & OPT_locallog) // -L
597#endif
598#if ENABLE_FEATURE_IPC_SYSLOG
599 if (opt_C) // -Cn
600 G.shm_size = xatoul_range(opt_C, 4, INT_MAX/1024) * 1024;
601#endif
602
603 /* If they have not specified remote logging, then log locally */
604 if (ENABLE_FEATURE_REMOTE_LOG && !(option_mask32 & OPT_remotelog))
605 option_mask32 |= OPT_locallog;
606
607 /* Store away localhost's name before the fork */
608 gethostname(G.localHostName, sizeof(G.localHostName));
609 p = strchr(G.localHostName, '.');
610 if (p) {
611 *p = '\0';
612 }
613
614 if (!(option_mask32 & OPT_nofork)) {
615 bb_daemonize_or_rexec(DAEMON_CHDIR_ROOT, argv);
616 }
617 umask(0);
618 write_pidfile("/var/run/syslogd.pid");
619 do_syslogd();
620 /* return EXIT_SUCCESS; */
621}
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