1 /* syslogd.c - a system logging utility.
3 * Copyright 2013 Madhur Verma <mad.flexi@gmail.com>
4 * Copyright 2013 Kyungwan Han <asura321@gmail.com>
8 USE_SYSLOGD(NEWTOY(syslogd,">0l#<1>8=8R:b#<0>99=1s#<0=200m#<0>71582787=20O:p:f:a:nSKLD", TOYFLAG_SBIN|TOYFLAG_STAYROOT))
14 usage: syslogd [-a socket] [-O logfile] [-f config file] [-m interval]
15 [-p socket] [-s SIZE] [-b N] [-R HOST] [-l N] [-nSLKD]
17 System logging utility
19 -a Extra unix socket for listen
20 -O FILE Default log file <DEFAULT: /var/log/messages>
21 -f FILE Config file <DEFAULT: /etc/syslog.conf>
22 -p Alternative unix domain socket <DEFAULT : /dev/log>
23 -n Avoid auto-backgrounding.
25 -m MARK interval <DEFAULT: 20 minutes> (RANGE: 0 to 71582787)
26 -R HOST Log to IP or hostname on PORT (default PORT=514/UDP)"
27 -L Log locally and via network (default is network only if -R)"
28 -s SIZE Max size (KB) before rotation (default:200KB, 0=off)
29 -b N rotated logs to keep (default:1, max=99, 0=purge)
30 -K Log to kernel printk buffer (use dmesg to read it)
31 -l N Log only messages more urgent than prio(default:8 max:8 min:1)
39 // UNIX Sockets for listening
43 struct sockaddr_un sdu;
47 // Log file entry to log into.
52 uint8_t level[LOG_NFACILITIES];
54 struct sockaddr_in saddr;
68 struct unsocks *lsocks; // list of listen sockets
69 struct logfile *lfiles; // list of write logfiles
73 // Lookup numerical code from name
74 // Also used in logger
75 int logger_lookup(int where, char *key)
77 CODE *w = ((CODE *[]){facilitynames, prioritynames})[where];
79 for (; w->c_name; w++)
80 if (!strcasecmp(key, w->c_name)) return w->c_val;
85 //search the given name and return its value
86 static char *dec(int val, CODE *clist, char *buf)
88 for (; clist->c_name; clist++)
89 if (val == clist->c_val) return clist->c_name;
90 sprintf(buf, "%u", val);
96 * recurses the logfile list and resolves config
97 * for evry file and updates facilty and log level bits.
99 static int resolve_config(struct logfile *file, char *config)
103 for (tk = strtok(config, "; \0"); tk; tk = strtok(NULL, "; \0")) {
104 char *fac = tk, *lvl;
107 uint8_t set, levval, bits = 0;
109 tk = strchr(fac, '.');
115 char *nfac = strchr(fac, ',');
117 if (nfac) *nfac = '\0';
120 if (fac[1]) return -1;
122 if ((i = logger_lookup(0, fac)) == -1) return -1;
123 facval |= (1 << LOG_FAC(i));
125 if (nfac) fac = nfac + 1;
130 for (tk = "!=*"; *tk; tk++, bits <<= 1) {
136 if (bits & 2) levval = 0xff;
138 if ((i = logger_lookup(1, lvl)) == -1) return -1;
139 levval |= (bits & 4) ? LOG_MASK(i) : LOG_UPTO(i);
140 if (bits & 8) levval = ~levval;
143 for (i = 0, set = levval; set; set >>= 1, i++)
144 if (set & 0x1) file->facility[i] |= ~facval;
145 for (i = 0; i < LOG_NFACILITIES; facval >>= 1, i++)
146 if (facval & 0x1) file->level[i] |= ~levval;
152 // Parse config file and update the log file list.
153 static int parse_config_file(void)
155 struct logfile *file;
157 char *confline, *tk[2];
161 * if -K then open only /dev/kmsg
162 * all other log files are neglected
163 * thus no need to open config either.
165 if (toys.optflags & FLAG_K) {
166 file = xzalloc(sizeof(struct logfile));
167 file->filename = xstrdup("/dev/kmsg");
172 * if -R then add remote host to log list
173 * if -L is not provided all other log
174 * files are neglected thus no need to
175 * open config either so just return.
177 if (toys.optflags & FLAG_R) {
178 file = xzalloc(sizeof(struct logfile));
179 file->filename = xmprintf("@%s",TT.remote_log);
181 if (!(toys.optflags & FLAG_L)) return 0;
184 * Read config file and add logfiles to the list
185 * with their configuration.
187 if (!(fp = fopen(TT.config_file, "r")) && (toys.optflags & FLAG_f))
188 perror_exit("can't open '%s'", TT.config_file);
190 for (linelen = 0; fp;) {
192 len = getline(&confline, &linelen, fp);
195 for (; *confline == ' '; confline++, len--) ;
196 if ((confline[0] == '#') || (confline[0] == '\n')) continue;
198 for (; len && !(*tk[0]==' ' || *tk[0]=='\t'); tk[0]++, len--);
199 for (tk[1] = tk[0]; len && (*tk[1]==' ' || *tk[1]=='\t'); tk[1]++, len--);
200 if (!len || (len == 1 && *tk[1] == '\n')) {
201 error_msg("error in '%s' at line %d", TT.config_file, lineno);
204 else if (*(tk[1] + len - 1) == '\n') *(tk[1] + len - 1) = '\0';
208 while (file && strcmp(file->filename, tk[1])) file = file->next;
210 file = xzalloc(sizeof(struct logfile));
211 file->filename = xstrdup(tk[1]);
212 file->next = TT.lfiles;
215 if (resolve_config(file, confline) == -1) {
216 error_msg("error in '%s' at line %d", TT.config_file, lineno);
223 * Can't open config file or support is not enabled
224 * adding default logfile to the head of list.
227 file = xzalloc(sizeof(struct logfile));
228 file->filename = xstrdup((toys.optflags & FLAG_O) ?
229 TT.logfile : "/var/log/messages"); //DEFLOGFILE
230 file->next = TT.lfiles;
236 // open every log file in list.
237 static void open_logfiles(void)
241 for (tfd = TT.lfiles; tfd; tfd = tfd->next) {
245 if (*tfd->filename == '@') { // network
246 struct addrinfo *info, rp;
248 tmpfile = xstrdup(tfd->filename + 1);
249 if ((p = strchr(tmpfile, ':'))) {
253 port = strtol(++p, &endptr, 10);
254 if (*endptr || endptr == p || port < 0 || port > 65535)
255 error_exit("bad port in %s", tfd->filename);
257 memset(&rp, 0, sizeof(rp));
258 rp.ai_family = AF_INET;
259 rp.ai_socktype = SOCK_DGRAM;
260 rp.ai_protocol = IPPROTO_UDP;
262 if (getaddrinfo(tmpfile, NULL, &rp, &info) || !info)
263 perror_exit("BAD ADDRESS: can't find : %s ", tmpfile);
264 ((struct sockaddr_in*)info->ai_addr)->sin_port = htons(port);
265 memcpy(&tfd->saddr, info->ai_addr, info->ai_addrlen);
268 tfd->logfd = xsocket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
270 } else tfd->logfd = open(tfd->filename, O_CREAT | O_WRONLY | O_APPEND, 0666);
271 if (tfd->logfd < 0) {
272 tfd->filename = "/dev/console";
273 tfd->logfd = open(tfd->filename, O_APPEND);
278 //write to file with rotation
279 static int write_rotate(struct logfile *tf, int len)
283 isreg = (!fstat(tf->logfd, &statf) && S_ISREG(statf.st_mode));
284 size = statf.st_size;
286 if ((toys.optflags & FLAG_s) || (toys.optflags & FLAG_b)) {
287 if (TT.rot_size && isreg && (size + len) > (TT.rot_size*1024)) {
288 if (TT.rot_count) { /* always 0..99 */
289 int i = strlen(tf->filename) + 3 + 1;
292 i = TT.rot_count - 1;
294 sprintf(new_file, "%s.%d", tf->filename, i);
296 sprintf(old_file, "%s.%d", tf->filename, --i);
297 rename(old_file, new_file);
299 rename(tf->filename, new_file);
300 unlink(tf->filename);
302 tf->logfd = open(tf->filename, O_CREAT | O_WRONLY | O_APPEND, 0666);
304 perror_msg("can't open %s", tf->filename);
308 ftruncate(tf->logfd, 0);
311 return write(tf->logfd, toybuf, len);
314 //Parse messege and write to file.
315 static void logmsg(char *msg, int len)
318 char *p, *ts, *lvlstr, *facstr;
321 struct logfile *tf = TT.lfiles;
324 int olen = len, fac, lvl;
326 if (*msg == '<') { // Extract the priority no.
327 pri = (int) strtoul(msg + 1, &p, 10);
328 if (*p == '>') msg = p + 1;
330 /* Jan 18 00:11:22 msg...
333 if (len < 16 || msg[3] != ' ' || msg[6] != ' ' || msg[9] != ':'
334 || msg[12] != ':' || msg[15] != ' ') {
336 ts = ctime(&now) + 4; /* skip day of week */
346 if (toys.optflags & FLAG_K) len = sprintf(toybuf, "<%d> %s\n", pri, msg);
348 char facbuf[12], pribuf[12];
350 facstr = dec(pri & LOG_FACMASK, facilitynames, facbuf);
351 lvlstr = dec(LOG_PRI(pri), prioritynames, pribuf);
354 if (!uname(&uts)) p = uts.nodename;
355 if (toys.optflags & FLAG_S) len = sprintf(toybuf, "%s %s\n", ts, msg);
356 else len = sprintf(toybuf, "%s %s %s.%s %s\n", ts, p, facstr, lvlstr, msg);
358 if (lvl >= TT.log_prio) return;
360 for (; tf; tf = tf->next) {
362 if (!((tf->facility[lvl] & (1 << fac)) || (tf->level[fac] & (1<<lvl)))) {
363 int wlen, isNetwork = *tf->filename == '@';
365 wlen = sendto(tf->logfd, omsg, olen, 0, (struct sockaddr*)&tf->saddr, sizeof(tf->saddr));
366 else wlen = write_rotate(tf, len);
367 if (wlen < 0) perror_msg("write failed file : %s ", tf->filename + isNetwork);
374 * closes all read and write fds
375 * and frees all nodes and lists
377 static void cleanup(void)
380 struct unsocks *fnode = TT.lsocks;
382 if (fnode->sd >= 0) {
386 TT.lsocks = fnode->next;
391 struct logfile *fnode = TT.lfiles;
393 free(fnode->filename);
394 if (fnode->logfd >= 0) close(fnode->logfd);
395 TT.lfiles = fnode->next;
400 static void signal_handler(int sig)
402 unsigned char ch = sig;
403 if (write(TT.sigfd[1], &ch, 1) != 1) error_msg("can't send signal");
406 void syslogd_main(void)
409 int nfds, retval, last_len=0;
411 fd_set rfds; // fds for reading
412 char *temp, *buffer = (toybuf +2048), *last_buf = (toybuf + 3072); //these two buffs are of 1K each
414 if ((toys.optflags & FLAG_p) && (strlen(TT.unix_socket) > 108))
415 error_exit("Socket path should not be more than 108");
417 TT.config_file = (toys.optflags & FLAG_f) ?
418 TT.config_file : "/etc/syslog.conf"; //DEFCONFFILE
420 tsd = xzalloc(sizeof(struct unsocks));
422 tsd->path = (toys.optflags & FLAG_p) ? TT.unix_socket : "/dev/log"; // DEFLOGSOCK
425 if (toys.optflags & FLAG_a) {
426 for (temp = strtok(TT.socket, ":"); temp; temp = strtok(NULL, ":")) {
427 if (strlen(temp) > 107) temp[108] = '\0';
428 tsd = xzalloc(sizeof(struct unsocks));
430 tsd->next = TT.lsocks;
435 * initializes unsock_t structure
436 * and opens socket for reading
437 * and adds to global lsock list.
440 for (tsd = TT.lsocks; tsd; tsd = tsd->next) {
441 tsd->sdu.sun_family = AF_UNIX;
442 strcpy(tsd->sdu.sun_path, tsd->path);
443 tsd->sd = socket(AF_UNIX, SOCK_DGRAM, 0);
445 perror_msg("OPEN SOCKS : failed");
448 unlink(tsd->sdu.sun_path);
449 if (bind(tsd->sd, (struct sockaddr *) &tsd->sdu, sizeof(tsd->sdu))) {
450 perror_msg("BIND SOCKS : failed sock : %s", tsd->sdu.sun_path);
454 chmod(tsd->path, 0777);
458 error_msg("Can't open single socket for listenning.");
465 fcntl(TT.sigfd[1] , F_SETFD, FD_CLOEXEC);
466 fcntl(TT.sigfd[0] , F_SETFD, FD_CLOEXEC);
467 int flags = fcntl(TT.sigfd[1], F_GETFL);
468 fcntl(TT.sigfd[1], F_SETFL, flags | O_NONBLOCK);
469 signal(SIGHUP, signal_handler);
470 signal(SIGTERM, signal_handler);
471 signal(SIGINT, signal_handler);
472 signal(SIGQUIT, signal_handler);
474 if (parse_config_file() == -1) goto clean_and_exit;
476 if (!(toys.optflags & FLAG_n)) {
478 //don't daemonize again if SIGHUP received.
479 toys.optflags |= FLAG_n;
483 logmsg("<46>Toybox: syslogd started", 27); //27 : the length of message
485 // Add opened socks to rfds for select()
487 for (tsd = TT.lsocks; tsd; tsd = tsd->next) FD_SET(tsd->sd, &rfds);
488 FD_SET(TT.sigfd[0], &rfds);
490 tv.tv_sec = TT.interval*60;
492 retval = select(TT.sigfd[0] + 1, &rfds, NULL, NULL, (TT.interval)?&tv:NULL);
494 if (errno != EINTR) perror_msg("Error in select ");
496 else if (!retval) logmsg("<46>-- MARK --", 14);
497 else if (FD_ISSET(TT.sigfd[0], &rfds)) { /* May be a signal */
500 if (read(TT.sigfd[0], &sig, 1) != 1) {
501 error_msg("signal read failed.\n");
505 case SIGTERM: /* FALLTHROUGH */
506 case SIGINT: /* FALLTHROUGH */
508 logmsg("<46>syslogd exiting", 19);
509 if (CFG_TOYBOX_FREE ) cleanup();
510 signal(sig, SIG_DFL);
514 sigprocmask(SIG_UNBLOCK, &ss, NULL);
516 _exit(1); /* Should not reach it */
519 logmsg("<46>syslogd exiting", 19);
520 cleanup(); //cleanup is done, as we restart syslog.
524 } else { /* Some activity on listen sockets. */
525 for (tsd = TT.lsocks; tsd; tsd = tsd->next) {
527 if (FD_ISSET(sd, &rfds)) {
528 int len = read(sd, buffer, 1023); //buffer is of 1K, hence readingonly 1023 bytes, 1 for NUL
531 if((toys.optflags & FLAG_D) && (len == last_len))
532 if (!memcmp(last_buf, buffer, len)) break;
534 memcpy(last_buf, buffer, len);
544 logmsg("<46>syslogd exiting", 19);
545 if (CFG_TOYBOX_FREE ) cleanup();