1 /* vi: set sw=4 ts=4: */
3 * Mini syslogd implementation for busybox
5 * Copyright (C) 1999,2000 by Lineo, inc. and Erik Andersen
6 * Copyright (C) 1999,2000,2001 by Erik Andersen <andersee@debian.org>
8 * Copyright (C) 2000 by Karl M. Hegbloom <karlheg@debian.org>
10 * "circular buffer" Copyright (C) 2001 by Gennady Feldman <gfeldman@gena01.com>
12 * Maintainer: Gennady Feldman <gfeldman@gena01.com> as of Mar 12, 2001
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
22 * General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, write to the Free Software
26 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
42 #include <sys/socket.h>
43 #include <sys/types.h>
45 #include <sys/param.h>
49 /* SYSLOG_NAMES defined to pull some extra junk from syslog.h */
51 #include <sys/syslog.h>
54 /* Path for the file where all log messages are written */
55 #define __LOG_FILE "/var/log/messages"
57 /* Path to the unix socket */
58 static char lfile[MAXPATHLEN];
60 static char *logFilePath = __LOG_FILE;
62 /* interval between marks in seconds */
63 static int MarkInterval = 20 * 60;
65 /* localhost's name */
66 static char LocalHostName[64];
68 #ifdef CONFIG_FEATURE_REMOTE_LOG
69 #include <netinet/in.h>
70 /* udp socket for logging to remote host */
71 static int remotefd = -1;
73 /* where do we log? */
74 static char *RemoteHost;
76 /* what port to log to? */
77 static int RemotePort = 514;
79 /* To remote log or not to remote log, that is the question. */
80 static int doRemoteLog = FALSE;
81 static int local_logging = FALSE;
85 #define MAXLINE 1024 /* maximum line length */
88 /* circular buffer variables/structures */
89 #ifdef CONFIG_FEATURE_IPC_SYSLOG
90 #if __GNU_LIBRARY__ < 5
91 #error Sorry. Looks like you are using libc5.
92 #error libc5 shm support isnt good enough.
93 #error Please disable CONFIG_FEATURE_IPC_SYSLOG
101 static const long KEY_ID = 0x414e4547; /*"GENA" */
103 // Semaphore operation structures
104 static struct shbuf_ds {
105 int size; // size of data written
106 int head; // start of message list
107 int tail; // end of message list
108 char data[1]; // data/messages
109 } *buf = NULL; // shared memory pointer
111 static struct sembuf SMwup[1] = { {1, -1, IPC_NOWAIT} }; // set SMwup
112 static struct sembuf SMwdn[3] = { {0, 0}, {1, 0}, {1, +1} }; // set SMwdn
114 static int shmid = -1; // ipc shared memory id
115 static int s_semid = -1; // ipc semaphore id
116 int data_size = 16000; // data size
117 int shm_size = 16000 + sizeof(*buf); // our buffer size
118 static int circular_logging = FALSE;
121 * sem_up - up()'s a semaphore.
123 static inline void sem_up(int semid)
125 if (semop(semid, SMwup, 1) == -1) {
126 bb_perror_msg_and_die("semop[SMwup]");
131 * sem_down - down()'s a semaphore
133 static inline void sem_down(int semid)
135 if (semop(semid, SMwdn, 3) == -1) {
136 bb_perror_msg_and_die("semop[SMwdn]");
141 void ipcsyslog_cleanup(void)
143 printf("Exiting Syslogd!\n");
149 shmctl(shmid, IPC_RMID, NULL);
152 semctl(s_semid, 0, IPC_RMID, 0);
156 void ipcsyslog_init(void)
159 if ((shmid = shmget(KEY_ID, shm_size, IPC_CREAT | 1023)) == -1) {
160 bb_perror_msg_and_die("shmget");
163 if ((buf = shmat(shmid, NULL, 0)) == NULL) {
164 bb_perror_msg_and_die("shmat");
167 buf->size = data_size;
168 buf->head = buf->tail = 0;
170 // we'll trust the OS to set initial semval to 0 (let's hope)
171 if ((s_semid = semget(KEY_ID, 2, IPC_CREAT | IPC_EXCL | 1023)) == -1) {
172 if (errno == EEXIST) {
173 if ((s_semid = semget(KEY_ID, 2, 0)) == -1) {
174 bb_perror_msg_and_die("semget");
177 bb_perror_msg_and_die("semget");
181 printf("Buffer already allocated just grab the semaphore?");
185 /* write message to buffer */
186 void circ_message(const char *msg)
188 int l = strlen(msg) + 1; /* count the whole message w/ '\0' included */
193 * Circular Buffer Algorithm:
194 * --------------------------
196 * Start-off w/ empty buffer of specific size SHM_SIZ
197 * Start filling it up w/ messages. I use '\0' as separator to break up messages.
198 * This is also very handy since we can do printf on message.
200 * Once the buffer is full we need to get rid of the first message in buffer and
201 * insert the new message. (Note: if the message being added is >1 message then
202 * we will need to "remove" >1 old message from the buffer). The way this is done
204 * When we reach the end of the buffer we set a mark and start from the beginning.
205 * Now what about the beginning and end of the buffer? Well we have the "head"
206 * index/pointer which is the starting point for the messages and we have "tail"
207 * index/pointer which is the ending point for the messages. When we "display" the
208 * messages we start from the beginning and continue until we reach "tail". If we
209 * reach end of buffer, then we just start from the beginning (offset 0). "head" and
210 * "tail" are actually offsets from the beginning of the buffer.
212 * Note: This algorithm uses Linux IPC mechanism w/ shared memory and semaphores to provide
213 * a threasafe way of handling shared memory operations.
215 if ((buf->tail + l) < buf->size) {
216 /* before we append the message we need to check the HEAD so that we won't
217 overwrite any of the message that we still need and adjust HEAD to point
218 to the next message! */
219 if (buf->tail < buf->head) {
220 if ((buf->tail + l) >= buf->head) {
221 /* we need to move the HEAD to point to the next message
222 * Theoretically we have enough room to add the whole message to the
223 * buffer, because of the first outer IF statement, so we don't have
224 * to worry about overflows here!
226 int k = buf->tail + l - buf->head; /* we need to know how many bytes
227 we are overwriting to make
230 memchr(buf->data + buf->head + k, '\0',
231 buf->size - (buf->head + k));
232 if (c != NULL) { /* do a sanity check just in case! */
233 buf->head = c - buf->data + 1; /* we need to convert pointer to
234 offset + skip the '\0' since
235 we need to point to the beginning
236 of the next message */
237 /* Note: HEAD is only used to "retrieve" messages, it's not used
238 when writing messages into our buffer */
239 } else { /* show an error message to know we messed up? */
240 printf("Weird! Can't find the terminator token??? \n");
246 /* in other cases no overflows have been done yet, so we don't care! */
247 /* we should be ok to append the message now */
248 strncpy(buf->data + buf->tail, msg, l); /* append our message */
249 buf->tail += l; /* count full message w/ '\0' terminating char */
251 /* we need to break up the message and "circle" it around */
253 int k = buf->tail + l - buf->size; /* count # of bytes we don't fit */
255 /* We need to move HEAD! This is always the case since we are going
256 * to "circle" the message.
258 c = memchr(buf->data + k, '\0', buf->size - k);
260 if (c != NULL) { /* if we don't have '\0'??? weird!!! */
261 /* move head pointer */
262 buf->head = c - buf->data + 1;
264 /* now write the first part of the message */
265 strncpy(buf->data + buf->tail, msg, l - k - 1);
267 /* ALWAYS terminate end of buffer w/ '\0' */
268 buf->data[buf->size - 1] = '\0';
270 /* now write out the rest of the string to the beginning of the buffer */
271 strcpy(buf->data, &msg[l - k - 1]);
273 /* we need to place the TAIL at the end of the message */
277 ("Weird! Can't find the terminator token from the beginning??? \n");
278 buf->head = buf->tail = 0; /* reset buffer, since it's probably corrupted */
284 #endif /* CONFIG_FEATURE_IPC_SYSLOG */
286 /* Note: There is also a function called "message()" in init.c */
287 /* Print a message to the log file. */
288 static void message(char *fmt, ...) __attribute__ ((format(printf, 1, 2)));
289 static void message(char *fmt, ...)
295 fl.l_whence = SEEK_SET;
299 #ifdef CONFIG_FEATURE_IPC_SYSLOG
300 if ((circular_logging == TRUE) && (buf != NULL)) {
303 va_start(arguments, fmt);
304 vsnprintf(b, sizeof(b) - 1, fmt, arguments);
311 device_open(logFilePath,
312 O_WRONLY | O_CREAT | O_NOCTTY | O_APPEND |
315 fcntl(fd, F_SETLKW, &fl);
316 va_start(arguments, fmt);
317 vdprintf(fd, fmt, arguments);
320 fcntl(fd, F_SETLKW, &fl);
323 /* Always send console messages to /dev/console so people will see them. */
325 device_open(_PATH_CONSOLE,
326 O_WRONLY | O_NOCTTY | O_NONBLOCK)) >= 0) {
327 va_start(arguments, fmt);
328 vdprintf(fd, fmt, arguments);
332 fprintf(stderr, "Bummer, can't print: ");
333 va_start(arguments, fmt);
334 vfprintf(stderr, fmt, arguments);
341 static void logMessage(int pri, char *msg)
345 static char res[20] = "";
349 for (c_fac = facilitynames;
350 c_fac->c_name && !(c_fac->c_val == LOG_FAC(pri) << 3); c_fac++);
351 for (c_pri = prioritynames;
352 c_pri->c_name && !(c_pri->c_val == LOG_PRI(pri)); c_pri++);
353 if (c_fac->c_name == NULL || c_pri->c_name == NULL) {
354 snprintf(res, sizeof(res), "<%d>", pri);
356 snprintf(res, sizeof(res), "%s.%s", c_fac->c_name, c_pri->c_name);
360 if (strlen(msg) < 16 || msg[3] != ' ' || msg[6] != ' ' ||
361 msg[9] != ':' || msg[12] != ':' || msg[15] != ' ') {
363 timestamp = ctime(&now) + 4;
364 timestamp[15] = '\0';
367 timestamp[15] = '\0';
371 /* todo: supress duplicates */
373 #ifdef CONFIG_FEATURE_REMOTE_LOG
374 /* send message to remote logger */
375 if (-1 != remotefd) {
376 static const int IOV_COUNT = 2;
377 struct iovec iov[IOV_COUNT];
378 struct iovec *v = iov;
380 memset(&res, 0, sizeof(res));
381 snprintf(res, sizeof(res), "<%d>", pri);
383 v->iov_len = strlen(res);
387 v->iov_len = strlen(msg);
389 if ((-1 == writev(remotefd, iov, IOV_COUNT)) && (errno == EINTR)) {
393 if (local_logging == TRUE)
395 /* now spew out the message to wherever it is supposed to go */
396 message("%s %s %s %s\n", timestamp, LocalHostName, res, msg);
399 static void quit_signal(int sig)
401 logMessage(LOG_SYSLOG | LOG_INFO, "System log daemon exiting.");
403 #ifdef CONFIG_FEATURE_IPC_SYSLOG
410 static void domark(int sig)
412 if (MarkInterval > 0) {
413 logMessage(LOG_SYSLOG | LOG_INFO, "-- MARK --");
418 /* This must be a #define, since when DODEBUG and BUFFERS_GO_IN_BSS are
419 * enabled, we otherwise get a "storage size isn't constant error. */
420 static int serveConnection(char *tmpbuf, int n_read)
424 while (p < tmpbuf + n_read) {
426 int pri = (LOG_USER | LOG_NOTICE);
428 char line[MAXLINE + 1];
432 while ((c = *p) && q < &line[sizeof(line) - 1]) {
433 if (c == '<' && num_lt == 0) {
434 /* Parse the magic priority number. */
437 while (isdigit(*(++p))) {
438 pri = 10 * pri + (*p - '0');
440 if (pri & ~(LOG_FACMASK | LOG_PRIMASK)){
441 pri = (LOG_USER | LOG_NOTICE);
442 } else if (c == '\n') {
444 } else if (iscntrl(c) && (c < 0177)) {
455 logMessage(pri, line);
461 #ifdef CONFIG_FEATURE_REMOTE_LOG
462 static void init_RemoteLog(void)
465 struct sockaddr_in remoteaddr;
466 struct hostent *hostinfo;
467 int len = sizeof(remoteaddr);
469 memset(&remoteaddr, 0, len);
471 remotefd = socket(AF_INET, SOCK_DGRAM, 0);
474 bb_error_msg_and_die("cannot create socket");
477 hostinfo = xgethostbyname(RemoteHost);
479 remoteaddr.sin_family = AF_INET;
480 remoteaddr.sin_addr = *(struct in_addr *) *hostinfo->h_addr_list;
481 remoteaddr.sin_port = htons(RemotePort);
483 /* Since we are using UDP sockets, connect just sets the default host and port
484 * for future operations
486 if (0 != (connect(remotefd, (struct sockaddr *) &remoteaddr, len))) {
487 bb_error_msg_and_die("cannot connect to remote host %s:%d", RemoteHost,
494 static void doSyslogd(void) __attribute__ ((noreturn));
495 static void doSyslogd(void)
497 struct sockaddr_un sunx;
498 socklen_t addrLength;
503 /* Set up signal handlers. */
504 signal(SIGINT, quit_signal);
505 signal(SIGTERM, quit_signal);
506 signal(SIGQUIT, quit_signal);
507 signal(SIGHUP, SIG_IGN);
508 signal(SIGCHLD, SIG_IGN);
510 signal(SIGCLD, SIG_IGN);
512 signal(SIGALRM, domark);
515 /* Create the syslog file so realpath() can work. */
516 if (realpath(_PATH_LOG, lfile) != NULL) {
520 memset(&sunx, 0, sizeof(sunx));
521 sunx.sun_family = AF_UNIX;
522 strncpy(sunx.sun_path, lfile, sizeof(sunx.sun_path));
523 if ((sock_fd = socket(AF_UNIX, SOCK_DGRAM, 0)) < 0) {
524 bb_perror_msg_and_die("Couldn't get file descriptor for socket "
528 addrLength = sizeof(sunx.sun_family) + strlen(sunx.sun_path);
529 if (bind(sock_fd, (struct sockaddr *) &sunx, addrLength) < 0) {
530 bb_perror_msg_and_die("Could not connect to socket " _PATH_LOG);
533 if (chmod(lfile, 0666) < 0) {
534 bb_perror_msg_and_die("Could not set permission on " _PATH_LOG);
536 #ifdef CONFIG_FEATURE_IPC_SYSLOG
537 if (circular_logging == TRUE) {
542 #ifdef CONFIG_FEATURE_REMOTE_LOG
543 if (doRemoteLog == TRUE) {
548 logMessage(LOG_SYSLOG | LOG_INFO, "syslogd started: " BB_BANNER);
553 FD_SET(sock_fd, &fds);
555 if (select(sock_fd + 1, &fds, NULL, NULL, NULL) < 0) {
556 if (errno == EINTR) {
557 /* alarm may have happened. */
560 bb_perror_msg_and_die("select error");
563 if (FD_ISSET(sock_fd, &fds)) {
566 RESERVE_CONFIG_BUFFER(tmpbuf, MAXLINE + 1);
568 memset(tmpbuf, '\0', MAXLINE + 1);
569 if ((i = recv(sock_fd, tmpbuf, MAXLINE, 0)) > 0) {
570 serveConnection(tmpbuf, i);
572 bb_perror_msg_and_die("UNIX socket error");
574 RELEASE_CONFIG_BUFFER(tmpbuf);
576 } /* for main loop */
579 extern int syslogd_main(int argc, char **argv)
583 #if ! defined(__uClinux__)
589 /* do normal option parsing */
590 while ((opt = getopt(argc, argv, "m:nO:R:LC")) > 0) {
593 MarkInterval = atoi(optarg) * 60;
595 #if ! defined(__uClinux__)
601 logFilePath = bb_xstrdup(optarg);
603 #ifdef CONFIG_FEATURE_REMOTE_LOG
605 RemoteHost = bb_xstrdup(optarg);
606 if ((p = strchr(RemoteHost, ':'))) {
607 RemotePort = atoi(p + 1);
613 local_logging = TRUE;
616 #ifdef CONFIG_FEATURE_IPC_SYSLOG
618 circular_logging = TRUE;
626 #ifdef CONFIG_FEATURE_REMOTE_LOG
627 /* If they have not specified remote logging, then log locally */
628 if (doRemoteLog == FALSE)
629 local_logging = TRUE;
633 /* Store away localhost's name before the fork */
634 gethostname(LocalHostName, sizeof(LocalHostName));
635 if ((p = strchr(LocalHostName, '.'))) {
641 #if ! defined(__uClinux__)
642 if ((doFork == TRUE) && (daemon(0, 1) < 0)) {
643 bb_perror_msg_and_die("daemon");
653 c-file-style: "linux"