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 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or
16 * (at your option) any later version.
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
21 * General Public License for more details.
23 * You should have received a copy of the GNU General Public License
24 * along with this program; if not, write to the Free Software
25 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
43 #include <sys/socket.h>
44 #include <sys/types.h>
46 #include <sys/param.h>
50 /* SYSLOG_NAMES defined to pull some extra junk from syslog.h */
52 #include <sys/syslog.h>
55 /* Path for the file where all log messages are written */
56 #define __LOG_FILE "/var/log/messages"
58 /* Path to the unix socket */
59 static char lfile[MAXPATHLEN];
61 static const char *logFilePath = __LOG_FILE;
63 #ifdef CONFIG_FEATURE_ROTATE_LOGFILE
64 /* max size of message file before being rotated */
65 static int logFileSize = 200 * 1024;
67 /* number of rotated message files */
68 static int logFileRotate = 1;
71 /* interval between marks in seconds */
72 static int MarkInterval = 20 * 60;
74 /* localhost's name */
75 static char LocalHostName[64];
77 #ifdef CONFIG_FEATURE_REMOTE_LOG
78 #include <netinet/in.h>
79 /* udp socket for logging to remote host */
80 static int remotefd = -1;
81 static struct sockaddr_in remoteaddr;
83 /* where do we log? */
84 static char *RemoteHost;
86 /* what port to log to? */
87 static int RemotePort = 514;
89 /* To remote log or not to remote log, that is the question. */
90 static int doRemoteLog = FALSE;
91 static int local_logging = FALSE;
94 /* Make loging output smaller. */
95 static bool small = false;
98 #define MAXLINE 1024 /* maximum line length */
101 /* circular buffer variables/structures */
102 #ifdef CONFIG_FEATURE_IPC_SYSLOG
104 #if CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE < 4
105 #error Sorry, you must set the syslogd buffer size to at least 4KB.
106 #error Please check CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE
114 static const long KEY_ID = 0x414e4547; /*"GENA" */
116 // Semaphore operation structures
117 static struct shbuf_ds {
118 int size; // size of data written
119 int head; // start of message list
120 int tail; // end of message list
121 char data[1]; // data/messages
122 } *buf = NULL; // shared memory pointer
124 static struct sembuf SMwup[1] = { {1, -1, IPC_NOWAIT} }; // set SMwup
125 static struct sembuf SMwdn[3] = { {0, 0}, {1, 0}, {1, +1} }; // set SMwdn
127 static int shmid = -1; // ipc shared memory id
128 static int s_semid = -1; // ipc semaphore id
129 static int shm_size = ((CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE)*1024); // default shm size
130 static int circular_logging = FALSE;
133 * sem_up - up()'s a semaphore.
135 static inline void sem_up(int semid)
137 if (semop(semid, SMwup, 1) == -1) {
138 bb_perror_msg_and_die("semop[SMwup]");
143 * sem_down - down()'s a semaphore
145 static inline void sem_down(int semid)
147 if (semop(semid, SMwdn, 3) == -1) {
148 bb_perror_msg_and_die("semop[SMwdn]");
153 static void ipcsyslog_cleanup(void)
155 printf("Exiting Syslogd!\n");
161 shmctl(shmid, IPC_RMID, NULL);
164 semctl(s_semid, 0, IPC_RMID, 0);
168 static void ipcsyslog_init(void)
171 if ((shmid = shmget(KEY_ID, shm_size, IPC_CREAT | 1023)) == -1) {
172 bb_perror_msg_and_die("shmget");
175 if ((buf = shmat(shmid, NULL, 0)) == NULL) {
176 bb_perror_msg_and_die("shmat");
179 buf->size = shm_size - sizeof(*buf);
180 buf->head = buf->tail = 0;
182 // we'll trust the OS to set initial semval to 0 (let's hope)
183 if ((s_semid = semget(KEY_ID, 2, IPC_CREAT | IPC_EXCL | 1023)) == -1) {
184 if (errno == EEXIST) {
185 if ((s_semid = semget(KEY_ID, 2, 0)) == -1) {
186 bb_perror_msg_and_die("semget");
189 bb_perror_msg_and_die("semget");
193 printf("Buffer already allocated just grab the semaphore?");
197 /* write message to buffer */
198 static void circ_message(const char *msg)
200 int l = strlen(msg) + 1; /* count the whole message w/ '\0' included */
205 * Circular Buffer Algorithm:
206 * --------------------------
208 * Start-off w/ empty buffer of specific size SHM_SIZ
209 * Start filling it up w/ messages. I use '\0' as separator to break up messages.
210 * This is also very handy since we can do printf on message.
212 * Once the buffer is full we need to get rid of the first message in buffer and
213 * insert the new message. (Note: if the message being added is >1 message then
214 * we will need to "remove" >1 old message from the buffer). The way this is done
216 * When we reach the end of the buffer we set a mark and start from the beginning.
217 * Now what about the beginning and end of the buffer? Well we have the "head"
218 * index/pointer which is the starting point for the messages and we have "tail"
219 * index/pointer which is the ending point for the messages. When we "display" the
220 * messages we start from the beginning and continue until we reach "tail". If we
221 * reach end of buffer, then we just start from the beginning (offset 0). "head" and
222 * "tail" are actually offsets from the beginning of the buffer.
224 * Note: This algorithm uses Linux IPC mechanism w/ shared memory and semaphores to provide
225 * a threasafe way of handling shared memory operations.
227 if ((buf->tail + l) < buf->size) {
228 /* before we append the message we need to check the HEAD so that we won't
229 overwrite any of the message that we still need and adjust HEAD to point
230 to the next message! */
231 if (buf->tail < buf->head) {
232 if ((buf->tail + l) >= buf->head) {
233 /* we need to move the HEAD to point to the next message
234 * Theoretically we have enough room to add the whole message to the
235 * buffer, because of the first outer IF statement, so we don't have
236 * to worry about overflows here!
238 int k = buf->tail + l - buf->head; /* we need to know how many bytes
239 we are overwriting to make
242 memchr(buf->data + buf->head + k, '\0',
243 buf->size - (buf->head + k));
244 if (c != NULL) { /* do a sanity check just in case! */
245 buf->head = c - buf->data + 1; /* we need to convert pointer to
246 offset + skip the '\0' since
247 we need to point to the beginning
248 of the next message */
249 /* Note: HEAD is only used to "retrieve" messages, it's not used
250 when writing messages into our buffer */
251 } else { /* show an error message to know we messed up? */
252 printf("Weird! Can't find the terminator token??? \n");
258 /* in other cases no overflows have been done yet, so we don't care! */
259 /* we should be ok to append the message now */
260 strncpy(buf->data + buf->tail, msg, l); /* append our message */
261 buf->tail += l; /* count full message w/ '\0' terminating char */
263 /* we need to break up the message and "circle" it around */
265 int k = buf->tail + l - buf->size; /* count # of bytes we don't fit */
267 /* We need to move HEAD! This is always the case since we are going
268 * to "circle" the message.
270 c = memchr(buf->data + k, '\0', buf->size - k);
272 if (c != NULL) { /* if we don't have '\0'??? weird!!! */
273 /* move head pointer */
274 buf->head = c - buf->data + 1;
276 /* now write the first part of the message */
277 strncpy(buf->data + buf->tail, msg, l - k - 1);
279 /* ALWAYS terminate end of buffer w/ '\0' */
280 buf->data[buf->size - 1] = '\0';
282 /* now write out the rest of the string to the beginning of the buffer */
283 strcpy(buf->data, &msg[l - k - 1]);
285 /* we need to place the TAIL at the end of the message */
289 ("Weird! Can't find the terminator token from the beginning??? \n");
290 buf->head = buf->tail = 0; /* reset buffer, since it's probably corrupted */
296 #endif /* CONFIG_FEATURE_IPC_SYSLOG */
298 /* Note: There is also a function called "message()" in init.c */
299 /* Print a message to the log file. */
300 static void message(char *fmt, ...) __attribute__ ((format(printf, 1, 2)));
301 static void message(char *fmt, ...)
307 fl.l_whence = SEEK_SET;
311 #ifdef CONFIG_FEATURE_IPC_SYSLOG
312 if ((circular_logging == TRUE) && (buf != NULL)) {
315 va_start(arguments, fmt);
316 vsnprintf(b, sizeof(b) - 1, fmt, arguments);
322 if ((fd = device_open(logFilePath,
323 O_WRONLY | O_CREAT | O_NOCTTY | O_APPEND |
326 fcntl(fd, F_SETLKW, &fl);
327 #ifdef CONFIG_FEATURE_ROTATE_LOGFILE
328 if ( logFileSize > 0 ) {
330 int r = fstat(fd, &statf);
331 if( !r && (statf.st_mode & S_IFREG)
332 && (lseek(fd,0,SEEK_END) > logFileSize) ) {
333 if(logFileRotate > 0) {
335 char oldFile[(strlen(logFilePath)+4)], newFile[(strlen(logFilePath)+4)];
336 for(i=logFileRotate-1;i>0;i--) {
337 sprintf(oldFile, "%s.%d", logFilePath, i-1);
338 sprintf(newFile, "%s.%d", logFilePath, i);
339 rename(oldFile, newFile);
341 sprintf(newFile, "%s.%d", logFilePath, 0);
343 fcntl (fd, F_SETLKW, &fl);
345 rename(logFilePath, newFile);
346 fd = device_open (logFilePath,
347 O_WRONLY | O_CREAT | O_NOCTTY | O_APPEND |
350 fcntl (fd, F_SETLKW, &fl);
357 va_start(arguments, fmt);
358 vdprintf(fd, fmt, arguments);
361 fcntl(fd, F_SETLKW, &fl);
364 /* Always send console messages to /dev/console so people will see them. */
365 if ((fd = device_open(_PATH_CONSOLE,
366 O_WRONLY | O_NOCTTY | O_NONBLOCK)) >= 0) {
367 va_start(arguments, fmt);
368 vdprintf(fd, fmt, arguments);
372 fprintf(stderr, "Bummer, can't print: ");
373 va_start(arguments, fmt);
374 vfprintf(stderr, fmt, arguments);
381 #ifdef CONFIG_FEATURE_REMOTE_LOG
382 static void init_RemoteLog(void)
384 memset(&remoteaddr, 0, sizeof(remoteaddr));
385 remotefd = socket(AF_INET, SOCK_DGRAM, 0);
388 bb_error_msg("cannot create socket");
391 remoteaddr.sin_family = AF_INET;
392 remoteaddr.sin_addr = *(struct in_addr *) *(xgethostbyname(RemoteHost))->h_addr_list;
393 remoteaddr.sin_port = htons(RemotePort);
397 static void logMessage(int pri, char *msg)
402 #ifdef CONFIG_FEATURE_REMOTE_LOG
403 static char line[MAXLINE + 1];
408 for (c_fac = facilitynames;
409 c_fac->c_name && !(c_fac->c_val == LOG_FAC(pri) << 3); c_fac++);
410 for (c_pri = prioritynames;
411 c_pri->c_name && !(c_pri->c_val == LOG_PRI(pri)); c_pri++);
412 if (c_fac->c_name == NULL || c_pri->c_name == NULL) {
413 snprintf(res, sizeof(res), "<%d>", pri);
415 snprintf(res, sizeof(res), "%s.%s", c_fac->c_name, c_pri->c_name);
419 if (strlen(msg) < 16 || msg[3] != ' ' || msg[6] != ' ' ||
420 msg[9] != ':' || msg[12] != ':' || msg[15] != ' ') {
422 timestamp = ctime(&now) + 4;
423 timestamp[15] = '\0';
426 timestamp[15] = '\0';
430 /* todo: supress duplicates */
432 #ifdef CONFIG_FEATURE_REMOTE_LOG
433 if (doRemoteLog == TRUE) {
434 /* trying connect the socket */
435 if (-1 == remotefd) {
439 /* if we have a valid socket, send the message */
440 if (-1 != remotefd) {
442 snprintf(line, sizeof(line), "<%d>%s", pri, msg);
445 /* send message to remote logger */
446 if(( -1 == sendto(remotefd, line, strlen(line), 0,
447 (struct sockaddr *) &remoteaddr,
448 sizeof(remoteaddr))) && (errno == EINTR)) {
449 /* sleep now seconds and retry (with now * 2) */
457 if (local_logging == TRUE)
460 /* now spew out the message to wherever it is supposed to go */
462 message("%s %s\n", timestamp, msg);
464 message("%s %s %s %s\n", timestamp, LocalHostName, res, msg);
468 static void quit_signal(int sig)
470 logMessage(LOG_SYSLOG | LOG_INFO, "System log daemon exiting.");
472 #ifdef CONFIG_FEATURE_IPC_SYSLOG
479 static void domark(int sig)
481 if (MarkInterval > 0) {
482 logMessage(LOG_SYSLOG | LOG_INFO, "-- MARK --");
487 /* This must be a #define, since when CONFIG_DEBUG and BUFFERS_GO_IN_BSS are
488 * enabled, we otherwise get a "storage size isn't constant error. */
489 static int serveConnection(char *tmpbuf, int n_read)
493 while (p < tmpbuf + n_read) {
495 int pri = (LOG_USER | LOG_NOTICE);
497 char line[MAXLINE + 1];
501 while ((c = *p) && q < &line[sizeof(line) - 1]) {
502 if (c == '<' && num_lt == 0) {
503 /* Parse the magic priority number. */
506 while (isdigit(*(++p))) {
507 pri = 10 * pri + (*p - '0');
509 if (pri & ~(LOG_FACMASK | LOG_PRIMASK)) {
510 pri = (LOG_USER | LOG_NOTICE);
512 } else if (c == '\n') {
514 } else if (iscntrl(c) && (c < 0177)) {
525 logMessage(pri, line);
530 static void doSyslogd(void) __attribute__ ((noreturn));
531 static void doSyslogd(void)
533 struct sockaddr_un sunx;
534 socklen_t addrLength;
539 /* Set up signal handlers. */
540 signal(SIGINT, quit_signal);
541 signal(SIGTERM, quit_signal);
542 signal(SIGQUIT, quit_signal);
543 signal(SIGHUP, SIG_IGN);
544 signal(SIGCHLD, SIG_IGN);
546 signal(SIGCLD, SIG_IGN);
548 signal(SIGALRM, domark);
551 /* Create the syslog file so realpath() can work. */
552 if (realpath(_PATH_LOG, lfile) != NULL) {
556 memset(&sunx, 0, sizeof(sunx));
557 sunx.sun_family = AF_UNIX;
558 strncpy(sunx.sun_path, lfile, sizeof(sunx.sun_path));
559 if ((sock_fd = socket(AF_UNIX, SOCK_DGRAM, 0)) < 0) {
560 bb_perror_msg_and_die("Couldn't get file descriptor for socket "
564 addrLength = sizeof(sunx.sun_family) + strlen(sunx.sun_path);
565 if (bind(sock_fd, (struct sockaddr *) &sunx, addrLength) < 0) {
566 bb_perror_msg_and_die("Could not connect to socket " _PATH_LOG);
569 if (chmod(lfile, 0666) < 0) {
570 bb_perror_msg_and_die("Could not set permission on " _PATH_LOG);
572 #ifdef CONFIG_FEATURE_IPC_SYSLOG
573 if (circular_logging == TRUE) {
578 #ifdef CONFIG_FEATURE_REMOTE_LOG
579 if (doRemoteLog == TRUE) {
584 logMessage(LOG_SYSLOG | LOG_INFO, "syslogd started: " BB_BANNER);
589 FD_SET(sock_fd, &fds);
591 if (select(sock_fd + 1, &fds, NULL, NULL, NULL) < 0) {
592 if (errno == EINTR) {
593 /* alarm may have happened. */
596 bb_perror_msg_and_die("select error");
599 if (FD_ISSET(sock_fd, &fds)) {
602 # define TMP_BUF_SZ BUFSIZ
604 # define TMP_BUF_SZ MAXLINE
606 #define tmpbuf bb_common_bufsiz1
608 if ((i = recv(sock_fd, tmpbuf, TMP_BUF_SZ, 0)) > 0) {
610 serveConnection(tmpbuf, i);
612 bb_perror_msg_and_die("UNIX socket error");
615 } /* for main loop */
618 extern int syslogd_main(int argc, char **argv)
626 /* do normal option parsing */
627 while ((opt = getopt(argc, argv, "m:nO:s:Sb:R:LC::")) > 0) {
630 MarkInterval = atoi(optarg) * 60;
636 logFilePath = optarg;
638 #ifdef CONFIG_FEATURE_ROTATE_LOGFILE
640 logFileSize = atoi(optarg) * 1024;
643 logFileRotate = atoi(optarg);
644 if( logFileRotate > 99 ) logFileRotate = 99;
647 #ifdef CONFIG_FEATURE_REMOTE_LOG
649 RemoteHost = bb_xstrdup(optarg);
650 if ((p = strchr(RemoteHost, ':'))) {
651 RemotePort = atoi(p + 1);
657 local_logging = TRUE;
660 #ifdef CONFIG_FEATURE_IPC_SYSLOG
663 int buf_size = atoi(optarg);
665 shm_size = buf_size * 1024;
668 circular_logging = TRUE;
679 #ifdef CONFIG_FEATURE_REMOTE_LOG
680 /* If they have not specified remote logging, then log locally */
681 if (doRemoteLog == FALSE)
682 local_logging = TRUE;
686 /* Store away localhost's name before the fork */
687 gethostname(LocalHostName, sizeof(LocalHostName));
688 if ((p = strchr(LocalHostName, '.'))) {
694 if (doFork == TRUE) {
695 #if defined(__uClinux__)
696 vfork_daemon_rexec(0, 1, argc, argv, "-n");
697 #else /* __uClinux__ */
699 bb_perror_msg_and_die("daemon");
700 #endif /* __uClinux__ */
709 c-file-style: "linux"