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@cachier.com>
12 * Maintainer: Gennady Feldman <gena01@cachier.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[BUFSIZ];
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[32];
68 #ifdef CONFIG_FEATURE_REMOTE_LOG
69 #include <netinet/in.h>
70 /* udp socket for logging to remote host */
71 static int remotefd = -1;
72 /* where do we log? */
73 static char *RemoteHost;
74 /* what port to log to? */
75 static int RemotePort = 514;
76 /* To remote log or not to remote log, that is the question. */
77 static int doRemoteLog = FALSE;
78 static int local_logging = FALSE;
81 /* circular buffer variables/structures */
82 #ifdef CONFIG_FEATURE_IPC_SYSLOG
84 #if __GNU_LIBRARY__ < 5
85 #error Sorry. Looks like you are using libc5.
86 #error libc5 shm support isnt good enough.
87 #error Please disable CONFIG_FEATURE_IPC_SYSLOG
95 static const long KEY_ID = 0x414e4547; /*"GENA"*/
97 // Semaphore operation structures
98 static struct shbuf_ds {
99 int size; // size of data written
100 int head; // start of message list
101 int tail; // end of message list
102 char data[1]; // data/messages
103 } *buf = NULL; // shared memory pointer
105 static struct sembuf SMwup[1] = {{1, -1, IPC_NOWAIT}}; // set SMwup
106 static struct sembuf SMwdn[3] = {{0, 0}, {1, 0}, {1, +1}}; // set SMwdn
108 static int shmid = -1; // ipc shared memory id
109 static int s_semid = -1; // ipc semaphore id
110 int data_size = 16000; // data size
111 int shm_size = 16000 + sizeof(*buf); // our buffer size
112 static int circular_logging = FALSE;
115 * sem_up - up()'s a semaphore.
117 static inline void sem_up(int semid)
119 if ( semop(semid, SMwup, 1) == -1 )
120 perror_msg_and_die("semop[SMwup]");
124 * sem_down - down()'s a semaphore
126 static inline void sem_down(int semid)
128 if ( semop(semid, SMwdn, 3) == -1 )
129 perror_msg_and_die("semop[SMwdn]");
133 void ipcsyslog_cleanup(void){
134 printf("Exiting Syslogd!\n");
139 shmctl(shmid, IPC_RMID, NULL);
141 semctl(s_semid, 0, IPC_RMID, 0);
144 void ipcsyslog_init(void){
146 if ((shmid = shmget(KEY_ID, shm_size, IPC_CREAT | 1023)) == -1)
147 perror_msg_and_die("shmget");
150 if ((buf = shmat(shmid, NULL, 0)) == NULL)
151 perror_msg_and_die("shmat");
155 buf->head=buf->tail=0;
157 // we'll trust the OS to set initial semval to 0 (let's hope)
158 if ((s_semid = semget(KEY_ID, 2, IPC_CREAT | IPC_EXCL | 1023)) == -1){
159 if (errno == EEXIST){
160 if ((s_semid = semget(KEY_ID, 2, 0)) == -1)
161 perror_msg_and_die("semget");
163 perror_msg_and_die("semget");
166 printf("Buffer already allocated just grab the semaphore?");
170 /* write message to buffer */
171 void circ_message(const char *msg){
172 int l=strlen(msg)+1; /* count the whole message w/ '\0' included */
177 * Circular Buffer Algorithm:
178 * --------------------------
180 * Start-off w/ empty buffer of specific size SHM_SIZ
181 * Start filling it up w/ messages. I use '\0' as separator to break up messages.
182 * This is also very handy since we can do printf on message.
184 * Once the buffer is full we need to get rid of the first message in buffer and
185 * insert the new message. (Note: if the message being added is >1 message then
186 * we will need to "remove" >1 old message from the buffer). The way this is done
188 * When we reach the end of the buffer we set a mark and start from the beginning.
189 * Now what about the beginning and end of the buffer? Well we have the "head"
190 * index/pointer which is the starting point for the messages and we have "tail"
191 * index/pointer which is the ending point for the messages. When we "display" the
192 * messages we start from the beginning and continue until we reach "tail". If we
193 * reach end of buffer, then we just start from the beginning (offset 0). "head" and
194 * "tail" are actually offsets from the beginning of the buffer.
196 * Note: This algorithm uses Linux IPC mechanism w/ shared memory and semaphores to provide
197 * a threasafe way of handling shared memory operations.
199 if ( (buf->tail + l) < buf->size ){
200 /* before we append the message we need to check the HEAD so that we won't
201 overwrite any of the message that we still need and adjust HEAD to point
202 to the next message! */
203 if ( buf->tail < buf->head){
204 if ( (buf->tail + l) >= buf->head ){
205 /* we need to move the HEAD to point to the next message
206 * Theoretically we have enough room to add the whole message to the
207 * buffer, because of the first outer IF statement, so we don't have
208 * to worry about overflows here!
210 int k= buf->tail + l - buf->head; /* we need to know how many bytes
211 we are overwriting to make
213 char *c=memchr(buf->data+buf->head + k,'\0',buf->size - (buf->head + k));
214 if (c != NULL) {/* do a sanity check just in case! */
215 buf->head = c - buf->data + 1; /* we need to convert pointer to
216 offset + skip the '\0' since
217 we need to point to the beginning
218 of the next message */
219 /* Note: HEAD is only used to "retrieve" messages, it's not used
220 when writing messages into our buffer */
221 }else{ /* show an error message to know we messed up? */
222 printf("Weird! Can't find the terminator token??? \n");
226 } /* in other cases no overflows have been done yet, so we don't care! */
228 /* we should be ok to append the message now */
229 strncpy(buf->data + buf->tail,msg,l); /* append our message */
230 buf->tail+=l; /* count full message w/ '\0' terminating char */
232 /* we need to break up the message and "circle" it around */
234 int k=buf->tail + l - buf->size; /* count # of bytes we don't fit */
236 /* We need to move HEAD! This is always the case since we are going
237 * to "circle" the message.
239 c=memchr(buf->data + k ,'\0', buf->size - k);
241 if (c != NULL) /* if we don't have '\0'??? weird!!! */{
242 /* move head pointer*/
243 buf->head=c-buf->data+1;
245 /* now write the first part of the message */
246 strncpy(buf->data + buf->tail, msg, l - k - 1);
248 /* ALWAYS terminate end of buffer w/ '\0' */
249 buf->data[buf->size-1]='\0';
251 /* now write out the rest of the string to the beginning of the buffer */
252 strcpy(buf->data, &msg[l-k-1]);
254 /* we need to place the TAIL at the end of the message */
257 printf("Weird! Can't find the terminator token from the beginning??? \n");
258 buf->head = buf->tail = 0; /* reset buffer, since it's probably corrupted */
265 /* Note: There is also a function called "message()" in init.c */
266 /* Print a message to the log file. */
267 static void message (char *fmt, ...) __attribute__ ((format (printf, 1, 2)));
268 static void message (char *fmt, ...)
274 fl.l_whence = SEEK_SET;
278 #ifdef CONFIG_FEATURE_IPC_SYSLOG
279 if ((circular_logging) && (buf != NULL)){
281 va_start (arguments, fmt);
282 vsprintf (b, fmt, arguments);
288 if ((fd = device_open (logFilePath,
289 O_WRONLY | O_CREAT | O_NOCTTY | O_APPEND |
292 fcntl (fd, F_SETLKW, &fl);
293 va_start (arguments, fmt);
294 vdprintf (fd, fmt, arguments);
297 fcntl (fd, F_SETLKW, &fl);
300 /* Always send console messages to /dev/console so people will see them. */
301 if ((fd = device_open (_PATH_CONSOLE,
302 O_WRONLY | O_NOCTTY | O_NONBLOCK)) >= 0) {
303 va_start (arguments, fmt);
304 vdprintf (fd, fmt, arguments);
308 fprintf (stderr, "Bummer, can't print: ");
309 va_start (arguments, fmt);
310 vfprintf (stderr, fmt, arguments);
317 static void logMessage (int pri, char *msg)
321 static char res[20] = "";
325 for (c_fac = facilitynames;
326 c_fac->c_name && !(c_fac->c_val == LOG_FAC(pri) << 3); c_fac++);
327 for (c_pri = prioritynames;
328 c_pri->c_name && !(c_pri->c_val == LOG_PRI(pri)); c_pri++);
329 if (c_fac->c_name == NULL || c_pri->c_name == NULL)
330 snprintf(res, sizeof(res), "<%d>", pri);
332 snprintf(res, sizeof(res), "%s.%s", c_fac->c_name, c_pri->c_name);
335 if (strlen(msg) < 16 || msg[3] != ' ' || msg[6] != ' ' ||
336 msg[9] != ':' || msg[12] != ':' || msg[15] != ' ') {
338 timestamp = ctime(&now) + 4;
339 timestamp[15] = '\0';
342 timestamp[15] = '\0';
346 /* todo: supress duplicates */
348 #ifdef CONFIG_FEATURE_REMOTE_LOG
349 /* send message to remote logger */
350 if ( -1 != remotefd){
351 static const int IOV_COUNT = 2;
352 struct iovec iov[IOV_COUNT];
353 struct iovec *v = iov;
355 memset(&res, 0, sizeof(res));
356 snprintf(res, sizeof(res), "<%d>", pri);
358 v->iov_len = strlen(res);
362 v->iov_len = strlen(msg);
364 if ( -1 == writev(remotefd,iov, IOV_COUNT)){
365 error_msg_and_die("syslogd: cannot write to remote file handle on "
366 "%s:%d",RemoteHost,RemotePort);
371 /* now spew out the message to wherever it is supposed to go */
372 message("%s %s %s %s\n", timestamp, LocalHostName, res, msg);
377 static void quit_signal(int sig)
379 logMessage(LOG_SYSLOG | LOG_INFO, "System log daemon exiting.");
381 #ifdef CONFIG_FEATURE_IPC_SYSLOG
388 static void domark(int sig)
390 if (MarkInterval > 0) {
391 logMessage(LOG_SYSLOG | LOG_INFO, "-- MARK --");
396 /* This must be a #define, since when DODEBUG and BUFFERS_GO_IN_BSS are
397 * enabled, we otherwise get a "storage size isn't constant error. */
399 static int serveConnection (int conn)
401 RESERVE_CONFIG_BUFFER(tmpbuf, BUFSIZE + 1);
405 n_read = read (conn, tmpbuf, BUFSIZE );
407 while (p < tmpbuf + n_read) {
409 int pri = (LOG_USER | LOG_NOTICE);
410 char line[ BUFSIZE + 1 ];
415 tmpbuf[ n_read - 1 ] = '\0';
417 while (p && (c = *p) && q < &line[ sizeof (line) - 1 ]) {
419 /* Parse the magic priority number. */
421 while (isdigit (*(++p))) {
422 pri = 10 * pri + (*p - '0');
424 if (pri & ~(LOG_FACMASK | LOG_PRIMASK)){
425 pri = (LOG_USER | LOG_NOTICE);
427 } else if (c == '\n') {
429 } else if (iscntrl (c) && (c < 0177)) {
440 logMessage (pri, line);
442 RELEASE_CONFIG_BUFFER (tmpbuf);
447 #ifdef CONFIG_FEATURE_REMOTE_LOG
448 static void init_RemoteLog (void){
450 struct sockaddr_in remoteaddr;
451 struct hostent *hostinfo;
452 int len = sizeof(remoteaddr);
454 memset(&remoteaddr, 0, len);
456 remotefd = socket(AF_INET, SOCK_DGRAM, 0);
459 error_msg_and_die("syslogd: cannot create socket");
462 hostinfo = xgethostbyname(RemoteHost);
464 remoteaddr.sin_family = AF_INET;
465 remoteaddr.sin_addr = *(struct in_addr *) *hostinfo->h_addr_list;
466 remoteaddr.sin_port = htons(RemotePort);
469 Since we are using UDP sockets, connect just sets the default host and port
470 for future operations
472 if ( 0 != (connect(remotefd, (struct sockaddr *) &remoteaddr, len))){
473 error_msg_and_die("syslogd: cannot connect to remote host %s:%d", RemoteHost, RemotePort);
479 static void doSyslogd (void) __attribute__ ((noreturn));
480 static void doSyslogd (void)
482 struct sockaddr_un sunx;
483 socklen_t addrLength;
489 /* Set up signal handlers. */
490 signal (SIGINT, quit_signal);
491 signal (SIGTERM, quit_signal);
492 signal (SIGQUIT, quit_signal);
493 signal (SIGHUP, SIG_IGN);
494 signal (SIGCHLD, SIG_IGN);
496 signal (SIGCLD, SIG_IGN);
498 signal (SIGALRM, domark);
499 alarm (MarkInterval);
501 /* Create the syslog file so realpath() can work. */
502 if (realpath (_PATH_LOG, lfile) != NULL)
505 memset (&sunx, 0, sizeof (sunx));
506 sunx.sun_family = AF_UNIX;
507 strncpy (sunx.sun_path, lfile, sizeof (sunx.sun_path));
508 if ((sock_fd = socket (AF_UNIX, SOCK_STREAM, 0)) < 0)
509 perror_msg_and_die ("Couldn't get file descriptor for socket " _PATH_LOG);
511 addrLength = sizeof (sunx.sun_family) + strlen (sunx.sun_path);
512 if ((bind (sock_fd, (struct sockaddr *) &sunx, addrLength)) || (listen (sock_fd, 5)))
513 perror_msg_and_die ("Could not connect to socket " _PATH_LOG);
515 if (chmod (lfile, 0666) < 0)
516 perror_msg_and_die ("Could not set permission on " _PATH_LOG);
519 FD_SET (sock_fd, &fds);
521 #ifdef CONFIG_FEATURE_IPC_SYSLOG
522 if (circular_logging ){
527 #ifdef CONFIG_FEATURE_REMOTE_LOG
533 logMessage (LOG_SYSLOG | LOG_INFO, "syslogd started: " BB_BANNER);
541 memcpy (&readfds, &fds, sizeof (fds));
543 if ((n_ready = select (FD_SETSIZE, &readfds, NULL, NULL, NULL)) < 0) {
544 if (errno == EINTR) continue; /* alarm may have happened. */
545 perror_msg_and_die ("select error");
548 for (fd = 0; (n_ready > 0) && (fd < FD_SETSIZE); fd++) {
549 if (FD_ISSET (fd, &readfds)) {
556 //printf("New Connection request.\n");
557 if ((conn = accept (sock_fd, (struct sockaddr *) &sunx, &addrLength)) < 0) {
558 perror_msg_and_die ("accept error");
562 //printf("conn: %i, set_size: %i\n",conn,FD_SETSIZE);
564 //printf("Serving connection: %i\n",fd);
565 if ( serveConnection(fd) <= 0 ) {
569 } /* fd == sock_fd */
572 } /* for main loop */
575 extern int syslogd_main(int argc, char **argv)
582 /* do normal option parsing */
583 while ((opt = getopt(argc, argv, "m:nO:R:LC")) > 0) {
586 MarkInterval = atoi(optarg) * 60;
592 logFilePath = xstrdup(optarg);
594 #ifdef CONFIG_FEATURE_REMOTE_LOG
596 RemoteHost = xstrdup(optarg);
597 if ( (p = strchr(RemoteHost, ':'))){
598 RemotePort = atoi(p+1);
604 local_logging = TRUE;
607 #ifdef CONFIG_FEATURE_IPC_SYSLOG
609 circular_logging = TRUE;
617 #ifdef CONFIG_FEATURE_REMOTE_LOG
618 /* If they have not specified remote logging, then log locally */
620 local_logging = TRUE;
624 /* Store away localhost's name before the fork */
625 gethostname(LocalHostName, sizeof(LocalHostName));
626 if ((p = strchr(LocalHostName, '.'))) {
633 #if !defined(__UCLIBC__) || defined(__UCLIBC_HAS_MMU__)
634 if (daemon(0, 1) < 0)
635 perror_msg_and_die("daemon");
637 error_msg_and_die("daemon not supported");
647 c-file-style: "linux"