1 /* vi: set sw=4 ts=4: */
3 * Mini syslogd implementation for busybox
5 * Copyright (C) 1999,2000,2001 by Lineo, inc.
6 * Written by Erik Andersen <andersen@lineo.com>, <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 BB_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 BB_FEATURE_IPC_SYSLOG
89 static const long KEY_ID = 0x414e4547; /*"GENA"*/
91 // Semaphore operation structures
92 static struct shbuf_ds {
93 int size; // size of data written
94 int head; // start of message list
95 int tail; // end of message list
96 char data[1]; // data/messages
97 } *buf = NULL; // shared memory pointer
99 static struct sembuf SMwup[1] = {{1, -1, IPC_NOWAIT}}; // set SMwup
100 static struct sembuf SMwdn[3] = {{0, 0}, {1, 0}, {1, +1}}; // set SMwdn
102 static int shmid = -1; // ipc shared memory id
103 static int s_semid = -1; // ipc semaphore id
104 int data_size = 16000; // data size
105 int shm_size = 16000 + sizeof(*buf); // our buffer size
106 static int circular_logging = FALSE;
109 * sem_up - up()'s a semaphore.
111 static inline void sem_up(int semid)
113 if ( semop(semid, SMwup, 1) == -1 )
114 perror_msg_and_die("semop[SMwup]");
118 * sem_down - down()'s a semaphore
120 static inline void sem_down(int semid)
122 if ( semop(semid, SMwdn, 3) == -1 )
123 perror_msg_and_die("semop[SMwdn]");
127 void ipcsyslog_cleanup(void){
128 printf("Exiting Syslogd!\n");
133 shmctl(shmid, IPC_RMID, NULL);
135 semctl(s_semid, 0, IPC_RMID, 0);
138 void ipcsyslog_init(void){
140 if ((shmid = shmget(KEY_ID, shm_size, IPC_CREAT | 1023)) == -1)
141 perror_msg_and_die("shmget");
144 if ((buf = shmat(shmid, NULL, 0)) == NULL)
145 perror_msg_and_die("shmat");
149 buf->head=buf->tail=0;
151 // we'll trust the OS to set initial semval to 0 (let's hope)
152 if ((s_semid = semget(KEY_ID, 2, IPC_CREAT | IPC_EXCL | 1023)) == -1){
153 if (errno == EEXIST){
154 if ((s_semid = semget(KEY_ID, 2, 0)) == -1)
155 perror_msg_and_die("semget");
157 perror_msg_and_die("semget");
162 printf("Buffer already allocated just grab the semaphore?");
166 /* write message to buffer */
167 void circ_message(const char *msg){
168 int l=strlen(msg)+1; /* count the whole message w/ '\0' included */
173 * Circular Buffer Algorithm:
174 * --------------------------
176 * Start-off w/ empty buffer of specific size SHM_SIZ
177 * Start filling it up w/ messages. I use '\0' as separator to break up messages.
178 * This is also very handy since we can do printf on message.
180 * Once the buffer is full we need to get rid of the first message in buffer and
181 * insert the new message. (Note: if the message being added is >1 message then
182 * we will need to "remove" >1 old message from the buffer). The way this is done
184 * When we reach the end of the buffer we set a mark and start from the beginning.
185 * Now what about the beginning and end of the buffer? Well we have the "head"
186 * index/pointer which is the starting point for the messages and we have "tail"
187 * index/pointer which is the ending point for the messages. When we "display" the
188 * messages we start from the beginning and continue until we reach "tail". If we
189 * reach end of buffer, then we just start from the beginning (offset 0). "head" and
190 * "tail" are actually offsets from the beginning of the buffer.
192 * Note: This algorithm uses Linux IPC mechanism w/ shared memory and semaphores to provide
193 * a threasafe way of handling shared memory operations.
195 if ( (buf->tail + l) < buf->size ){
196 /* before we append the message we need to check the HEAD so that we won't
197 overwrite any of the message that we still need and adjust HEAD to point
198 to the next message! */
199 if ( buf->tail < buf->head){
200 if ( (buf->tail + l) >= buf->head ){
201 /* we need to move the HEAD to point to the next message
202 * Theoretically we have enough room to add the whole message to the
203 * buffer, because of the first outer IF statement, so we don't have
204 * to worry about overflows here!
206 int k= buf->tail + l - buf->head; /* we need to know how many bytes
207 we are overwriting to make
209 char *c=memchr(buf->data+buf->head + k,'\0',buf->size - (buf->head + k));
210 if (c != NULL) {/* do a sanity check just in case! */
211 buf->head = c - buf->data + 1; /* we need to convert pointer to
212 offset + skip the '\0' since
213 we need to point to the beginning
214 of the next message */
215 /* Note: HEAD is only used to "retrieve" messages, it's not used
216 when writing messages into our buffer */
217 }else{ /* show an error message to know we messed up? */
218 printf("Weird! Can't find the terminator token??? \n");
222 } /* in other cases no overflows have been done yet, so we don't care! */
224 /* we should be ok to append the message now */
225 strncpy(buf->data + buf->tail,msg,l); /* append our message */
226 buf->tail+=l; /* count full message w/ '\0' terminating char */
228 /* we need to break up the message and "circle" it around */
230 int k=buf->tail + l - buf->size; /* count # of bytes we don't fit */
232 /* We need to move HEAD! This is always the case since we are going
233 * to "circle" the message.
235 c=memchr(buf->data + k ,'\0', buf->size - k);
237 if (c != NULL) /* if we don't have '\0'??? weird!!! */{
238 /* move head pointer*/
239 buf->head=c-buf->data+1;
241 /* now write the first part of the message */
242 strncpy(buf->data + buf->tail, msg, l - k - 1);
244 /* ALWAYS terminate end of buffer w/ '\0' */
245 buf->data[buf->size-1]='\0';
247 /* now write out the rest of the string to the beginning of the buffer */
248 strcpy(buf->data, &msg[l-k-1]);
250 /* we need to place the TAIL at the end of the message */
253 printf("Weird! Can't find the terminator token from the beginning??? \n");
254 buf->head = buf->tail = 0; /* reset buffer, since it's probably corrupted */
261 /* Note: There is also a function called "message()" in init.c */
262 /* Print a message to the log file. */
263 static void message (char *fmt, ...) __attribute__ ((format (printf, 1, 2)));
264 static void message (char *fmt, ...)
270 fl.l_whence = SEEK_SET;
274 #ifdef BB_FEATURE_IPC_SYSLOG
275 if ((circular_logging == TRUE) && (buf != NULL)){
277 va_start (arguments, fmt);
278 vsprintf (b, fmt, arguments);
284 if ((fd = device_open (logFilePath,
285 O_WRONLY | O_CREAT | O_NOCTTY | O_APPEND |
288 fcntl (fd, F_SETLKW, &fl);
289 va_start (arguments, fmt);
290 vdprintf (fd, fmt, arguments);
293 fcntl (fd, F_SETLKW, &fl);
296 /* Always send console messages to /dev/console so people will see them. */
297 if ((fd = device_open (_PATH_CONSOLE,
298 O_WRONLY | O_NOCTTY | O_NONBLOCK)) >= 0) {
299 va_start (arguments, fmt);
300 vdprintf (fd, fmt, arguments);
304 fprintf (stderr, "Bummer, can't print: ");
305 va_start (arguments, fmt);
306 vfprintf (stderr, fmt, arguments);
313 static void logMessage (int pri, char *msg)
317 static char res[20] = "";
321 for (c_fac = facilitynames;
322 c_fac->c_name && !(c_fac->c_val == LOG_FAC(pri) << 3); c_fac++);
323 for (c_pri = prioritynames;
324 c_pri->c_name && !(c_pri->c_val == LOG_PRI(pri)); c_pri++);
325 if (c_fac->c_name == NULL || c_pri->c_name == NULL)
326 snprintf(res, sizeof(res), "<%d>", pri);
328 snprintf(res, sizeof(res), "%s.%s", c_fac->c_name, c_pri->c_name);
331 if (strlen(msg) < 16 || msg[3] != ' ' || msg[6] != ' ' ||
332 msg[9] != ':' || msg[12] != ':' || msg[15] != ' ') {
334 timestamp = ctime(&now) + 4;
335 timestamp[15] = '\0';
338 timestamp[15] = '\0';
342 /* todo: supress duplicates */
344 #ifdef BB_FEATURE_REMOTE_LOG
345 /* send message to remote logger */
346 if ( -1 != remotefd){
347 static const int IOV_COUNT = 2;
348 struct iovec iov[IOV_COUNT];
349 struct iovec *v = iov;
351 bzero(&res, sizeof(res));
352 snprintf(res, sizeof(res), "<%d>", pri);
354 v->iov_len = strlen(res);
358 v->iov_len = strlen(msg);
360 if ( -1 == writev(remotefd,iov, IOV_COUNT)){
361 error_msg_and_die("syslogd: cannot write to remote file handle on"
362 "%s:%d",RemoteHost,RemotePort);
365 if (local_logging == TRUE)
367 /* now spew out the message to wherever it is supposed to go */
368 message("%s %s %s %s\n", timestamp, LocalHostName, res, msg);
373 static void quit_signal(int sig)
375 logMessage(0, "System log daemon exiting.");
377 #ifdef BB_FEATURE_IPC_SYSLOG
384 static void domark(int sig)
386 if (MarkInterval > 0) {
387 logMessage(LOG_SYSLOG | LOG_INFO, "-- MARK --");
392 static const int BUFSIZE = 1023;
393 static int serveConnection (int conn)
395 RESERVE_BB_BUFFER(tmpbuf, BUFSIZE + 1);
398 n_read = read (conn, tmpbuf, BUFSIZE );
402 int pri = (LOG_USER | LOG_NOTICE);
403 char line[ BUFSIZE + 1 ];
406 char *p = tmpbuf, *q = line;
408 tmpbuf[ n_read - 1 ] = '\0';
410 while (p && (c = *p) && q < &line[ sizeof (line) - 1 ]) {
412 /* Parse the magic priority number. */
414 while (isdigit (*(++p))) {
415 pri = 10 * pri + (*p - '0');
417 if (pri & ~(LOG_FACMASK | LOG_PRIMASK)){
418 pri = (LOG_USER | LOG_NOTICE);
420 } else if (c == '\n') {
422 } else if (iscntrl (c) && (c < 0177)) {
432 logMessage (pri, line);
438 #ifdef BB_FEATURE_REMOTE_LOG
439 static void init_RemoteLog (void){
441 struct sockaddr_in remoteaddr;
442 struct hostent *hostinfo;
443 int len = sizeof(remoteaddr);
445 bzero(&remoteaddr, len);
447 remotefd = socket(AF_INET, SOCK_DGRAM, 0);
450 error_msg_and_die("syslogd: cannot create socket");
453 hostinfo = (struct hostent *) gethostbyname(RemoteHost);
456 error_msg_and_die("syslogd: cannot resolve remote host name [%s]", RemoteHost);
459 remoteaddr.sin_family = AF_INET;
460 remoteaddr.sin_addr = *(struct in_addr *) *hostinfo->h_addr_list;
461 remoteaddr.sin_port = htons(RemotePort);
464 Since we are using UDP sockets, connect just sets the default host and port
465 for future operations
467 if ( 0 != (connect(remotefd, (struct sockaddr *) &remoteaddr, len))){
468 error_msg_and_die("syslogd: cannot connect to remote host %s:%d", RemoteHost, RemotePort);
474 static void doSyslogd (void) __attribute__ ((noreturn));
475 static void doSyslogd (void)
477 struct sockaddr_un sunx;
478 socklen_t addrLength;
484 /* Set up signal handlers. */
485 signal (SIGINT, quit_signal);
486 signal (SIGTERM, quit_signal);
487 signal (SIGQUIT, quit_signal);
488 signal (SIGHUP, SIG_IGN);
489 signal (SIGCHLD, SIG_IGN);
491 signal (SIGCLD, SIG_IGN);
493 signal (SIGALRM, domark);
494 alarm (MarkInterval);
496 /* Create the syslog file so realpath() can work. */
497 close (open (_PATH_LOG, O_RDWR | O_CREAT, 0644));
498 if (realpath (_PATH_LOG, lfile) == NULL)
499 perror_msg_and_die ("Could not resolve path to " _PATH_LOG);
503 memset (&sunx, 0, sizeof (sunx));
504 sunx.sun_family = AF_UNIX;
505 strncpy (sunx.sun_path, lfile, sizeof (sunx.sun_path));
506 if ((sock_fd = socket (AF_UNIX, SOCK_STREAM, 0)) < 0)
507 perror_msg_and_die ("Couldn't obtain descriptor for socket " _PATH_LOG);
509 addrLength = sizeof (sunx.sun_family) + strlen (sunx.sun_path);
510 if ((bind (sock_fd, (struct sockaddr *) &sunx, addrLength)) || (listen (sock_fd, 5)))
511 perror_msg_and_die ("Could not connect to socket " _PATH_LOG);
513 if (chmod (lfile, 0666) < 0)
514 perror_msg_and_die ("Could not set permission on " _PATH_LOG);
517 FD_SET (sock_fd, &fds);
519 #ifdef BB_FEATURE_IPC_SYSLOG
520 if (circular_logging == TRUE ){
525 #ifdef BB_FEATURE_REMOTE_LOG
526 if (doRemoteLog == TRUE){
531 logMessage (0, "syslogd started: BusyBox v" BB_VER " (" BB_BT ")");
539 memcpy (&readfds, &fds, sizeof (fds));
541 if ((n_ready = select (FD_SETSIZE, &readfds, NULL, NULL, NULL)) < 0) {
542 if (errno == EINTR) continue; /* alarm may have happened. */
543 perror_msg_and_die ("select error");
546 for (fd = 0; (n_ready > 0) && (fd < FD_SETSIZE); fd++) {
547 if (FD_ISSET (fd, &readfds)) {
554 //printf("New Connection request.\n");
555 if ((conn = accept (sock_fd, (struct sockaddr *) &sunx, &addrLength)) < 0) {
556 perror_msg_and_die ("accept error");
560 //printf("conn: %i, set_size: %i\n",conn,FD_SETSIZE);
562 //printf("Serving connection: %i\n",fd);
563 if ( serveConnection(fd) <= 0 ) {
567 } /* fd == sock_fd */
570 } /* for main loop */
573 extern int syslogd_main(int argc, char **argv)
580 /* do normal option parsing */
581 while ((opt = getopt(argc, argv, "m:nO:R:LC")) > 0) {
584 MarkInterval = atoi(optarg) * 60;
590 logFilePath = strdup(optarg);
592 #ifdef BB_FEATURE_REMOTE_LOG
594 RemoteHost = strdup(optarg);
595 if ( (p = strchr(RemoteHost, ':'))){
596 RemotePort = atoi(p+1);
602 local_logging = TRUE;
605 #ifdef BB_FEATURE_IPC_SYSLOG
607 circular_logging = TRUE;
615 #ifdef BB_FEATURE_REMOTE_LOG
616 /* If they have not specified remote logging, then log locally */
617 if (doRemoteLog == FALSE)
618 local_logging = TRUE;
622 /* Store away localhost's name before the fork */
623 gethostname(LocalHostName, sizeof(LocalHostName));
624 if ((p = strchr(LocalHostName, '.'))) {
630 if (doFork == TRUE) {
631 if (daemon(0, 1) < 0)
632 perror_msg_and_die("daemon");
641 c-file-style: "linux"