#ifndef lint static char sccsid[] = "@(#)syslogd.c"; #endif not lint /* * syslogd -- log system messages * * This program implements a system log. It takes a series of lines. * Each line may have a priority, signified as "" as * the first characters of the line. If this is * not present, a default priority is used. * * To kill syslogd, send a signal 15 (terminate). A signal 1 (hup) will * cause it to reread its configuration file. * * Defined Constants: * * MAXLINE -- the maximimum line length that can be handled. * NLOGS -- the maximum number of simultaneous log files. * DEFUPRI -- the default priority for user messages * DEFSPRI -- the default priority for kernel messages * */ #define NLOGS 20 /* max number of log files */ #define MAXLINE 1024 /* maximum line length */ #define DEFUPRI (LOG_USER|LOG_NOTICE) #define DEFSPRI (LOG_KERN|LOG_CRIT) #define MARKCOUNT 10 /* ratio of minor to major marks */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include typedef int (*sighand)(); char *LogName = "/dev/log"; char *ConfFile = "/etc/syslog.conf"; char *PidFile = "/etc/syslog.pid"; char ctty[] = "/dev/tty0"; #define FDMASK(fd) (1 << (fd)) /* * defines for BSD compat....I think! */ #define index(a, b) strchr(a, b) #define bzero(a, b) memset(a, '\0', b) #define dprintf if (Debug) printf #define UNAMESZ 8 /* length of a login name */ #define MAXUNAMES 20 /* maximum number of user names */ #define MAXFNAME 200 /* max file pathname length */ #define NOPRI 0x10 /* the "no priority" priority */ #define LOG_MARK (LOG_NFACILITIES << 3) /* mark "facility" */ /* * Flags to logmsg(). */ #define IGN_CONS 0x001 /* don't print on console */ #define SYNC_FILE 0x002 /* do fsync on file after printing */ #define NOCOPY 0x004 /* don't suppress duplicate messages */ #define ADDDATE 0x008 /* add a date to the message */ #define MARK 0x010 /* this message is a mark */ /* * This structure represents the files that will have log * copies printed. */ struct filed { short f_type; /* entry type, see below */ short f_file; /* file descriptor */ time_t f_time; /* time this was last written */ u_char f_pmask[LOG_NFACILITIES+1]; /* priority mask */ union { char f_uname[MAXUNAMES][UNAMESZ+1]; char f_fname[MAXFNAME]; } f_un; }; /* values for f_type */ #define F_UNUSED 0 /* unused entry */ #define F_FILE 1 /* regular file */ #define F_TTY 2 /* terminal */ #define F_CONSOLE 3 /* console terminal */ #define F_FORW 4 /* remote machine */ #define F_USERS 5 /* list of users */ #define F_WALL 6 /* everyone logged on */ /* how often (in seconds) to check for more input */ #define GRANULARITY 10 #define MSG_BSIZE 1024 char *TypeNames[7] = { "UNUSED", "FILE", "TTY", "CONSOLE", "FORW", "USERS", "WALL" }; struct filed Files[NLOGS]; int Debug; /* debug flag */ char LocalHostName[MAXHOSTNAMELEN+1]; /* our hostname */ char *LocalDomain; /* our local domain name */ int InetInuse = 0; /* non-zero if INET sockets are being used */ int LogPort; /* port number for INET connections */ char PrevLine[MAXLINE + 1]; /* copy of last line to supress repeats */ char PrevHost[MAXHOSTNAMELEN+1]; /* previous host */ int PrevFlags; int PrevPri; int PrevCount = 0; /* number of times seen */ int Initialized = 0; /* set when we have initialized ourselves */ int MarkInterval = 20; /* interval between marks in minutes */ int MarkSeq = 0; /* mark sequence number */ int Gran = 0; static int mask = 0; int count; int readfds; extern int errno, sys_nerr; extern char *sys_errlist[]; extern char *ctime(); /* extern char *index(); */ main(argc, argv) int argc; char **argv; { register int i; register char *p; static int funix; int len, nlen, ns, nfds; struct sockaddr afunix, fromunix; int fd; FILE *fp; char *lp, *lpb; char errbuf[100]; char line[MSG_BSIZE + 1]; extern int die(), domark(); while (--argc > 0) { p = *++argv; if (p[0] != '-') usage(); switch (p[1]) { case 'f': /* configuration file */ if (p[2] != '\0') ConfFile = &p[2]; break; case 'd': /* debug */ Debug++; break; case 'p': /* path */ if (p[2] != '\0') LogName = &p[2]; break; case 'm': /* mark interval */ if (p[2] != '\0') MarkInterval = atoi(&p[2]); break; default: usage(); } } if (!Debug) { if (fork()) exit(0); for (i = 0; i < 10; i++) close(i); open("/", 0); dup2(0, 1); dup2(0, 2); untty(); } else #ifdef linux ; #else setlinebuf(stdout); #endif gethostname(LocalHostName, sizeof LocalHostName); if (p = index(LocalHostName, '.')) { *p++ = '\0'; LocalDomain = p; } else LocalDomain = ""; signal(SIGTERM, (void *) die); signal(SIGINT, Debug ? (void *) die : SIG_IGN); signal(SIGQUIT, Debug ? (void *) die : SIG_IGN); unlink(LogName); /* * create system logfile LogName mode 0666 * logerror and die if can't */ funix = socket(AF_UNIX, SOCK_STREAM, 0); if (funix < 0) { logerror("unable to create socket"); die(0); } afunix.sa_family = AF_UNIX; strcpy(afunix.sa_data, LogName); if (bind(funix, &afunix, sizeof(afunix)) < 0) { logerror("can't bind"); die(0); } chmod(LogName, 0666); /* tuck my process id away */ fp = fopen(PidFile, "w"); if (fp != NULL) { fprintf(fp, "%d\n", getpid()); fclose(fp); } dprintf("off & running....\n"); init(); signal(SIGHUP, (void *) init); signal(SIGALRM, (void *) domark); if (listen(funix, 5) < 0) { perror("listen"); exit(1); } alarm(MarkInterval * 60 / MARKCOUNT); for (;;) { errno = 0; /* * Change this so it only reads one line at a time * otherwise if more than BUFSIZ messages are read * we'll get lost---also reading char at a time would * help us catch messages that are being written while * we run .... oh for an atomic flock */ readfds = FDMASK(funix) | mask; errno = 0; nfds = select(20, (fd_set *) &readfds, (fd_set *) NULL, (fd_set *) NULL, (struct timeval *) NULL); count++; if (nfds == 0) continue; if (nfds < 0) { if (errno != EINTR) perror("select"); continue; } if (readfds & (FDMASK(funix) | mask)) { len = sizeof fromunix; if ((i = recvfrom(funix, line, MSG_BSIZE, 0, (struct sockaddr *) &fromunix, &len)) > 0) { line[i]='\0'; printline(LocalHostName, line); } else { if ((errno == EAGAIN) || (errno == 0)) continue; sprintf(errbuf, "recvfrom unix %d: %s", errno, strerror(errno)); logerror(errbuf); } } else { if (errno != EINTR) { logerror("accept failure"); die(0); } } } } usage() { fprintf(stderr, "usage: syslogd [-d] [-mmarkinterval] [-ppath] [-fconffile]\n"); exit(1); } untty() { int i; if (!Debug) { #ifdef linux setpgrp(); #endif i = open("/dev/tty", O_RDWR); if (i >= 0) { #ifndef linux ioctl(i, (int) TIOCNOTTY, (char *)0); #endif linux close(i); } } } /* * Take a raw input line, decode the message, and print the message * on the appropriate log files. */ printline(hname, msg) char *hname; char *msg; { register char *p, *q; register int c; char line[MAXLINE + 1]; int pri; /* test for special codes */ pri = DEFUPRI; p = msg; if (*p == '<') { pri = 0; while (isdigit(*++p)) pri = 10 * pri + (*p - '0'); if (*p == '>') ++p; if (pri <= 0 || pri >= (LOG_NFACILITIES << 3)) pri = DEFUPRI; } /* don't allow users to log kernel messages */ if ((pri & LOG_PRIMASK) == LOG_KERN) pri |= LOG_USER; q = line; while ((c = *p++ & 0177) != '\0' && c != '\n' && q < &line[sizeof(line) - 1]) { if (iscntrl(c)) { *q++ = '^'; *q++ = c ^ 0100; } else *q++ = c; } *q = '\0'; logmsg(pri, line, hname, 0); } /* * Log a message to the appropriate log files, users, etc. based on * the priority. */ logmsg(pri, msg, from, flags) int pri; char *msg, *from; int flags; { register struct filed *f; register int l; int fac, prilev; time_t now; int omask; sighand s1, s2; struct iovec iov[6]; register struct iovec *v = iov; char line[MAXLINE + 1]; dprintf("logmsg: pri %o, flags %x, from %s, msg %s\n", pri, flags, from, msg); s1 = signal(SIGHUP, SIG_IGN); s2 = signal(SIGALRM, SIG_IGN); /* * Check to see if msg looks non-standard. */ if (strlen(msg) < 16 || msg[3] != ' ' || msg[6] != ' ' || msg[9] != ':' || msg[12] != ':' || msg[15] != ' ') flags |= ADDDATE; if (!(flags & NOCOPY)) { if (flags & (ADDDATE|MARK)) flushmsg(); else if (!strcmp(msg + 16, PrevLine + 16)) { /* we found a match, update the time */ strncpy(PrevLine, msg, 15); PrevCount++; signal(SIGHUP, (void *) s1); signal(SIGALRM, (void *) s2); return; } else { /* new line, save it */ flushmsg(); strcpy(PrevLine, msg); strcpy(PrevHost, from); PrevFlags = flags; PrevPri = pri; } } time(&now); if (flags & ADDDATE) v->iov_base = ctime(&now) + 4; else v->iov_base = msg; v->iov_len = 15; v++; v->iov_base = " "; v->iov_len = 1; v++; v->iov_base = from; v->iov_len = strlen(v->iov_base); v++; v->iov_base = " "; v->iov_len = 1; v++; if (flags & ADDDATE) v->iov_base = msg; else v->iov_base = msg + 16; v->iov_len = strlen(v->iov_base); v++; /* extract facility and priority level */ fac = (pri & LOG_FACMASK) >> 3; if (flags & MARK) fac = LOG_NFACILITIES; prilev = pri & LOG_PRIMASK; /* log the message to the particular outputs */ if (!Initialized) { int cfd = open(ctty, O_WRONLY); if (cfd >= 0) { v->iov_base = "\r\n"; v->iov_len = 2; writev(cfd, iov, 6); close(cfd); } untty(); signal(SIGHUP, (void *) s1); signal(SIGALRM, (void *) s2); return; } for (f = Files; f < &Files[NLOGS]; f++) { /* skip messages that are incorrect priority */ if (f->f_pmask[fac] < prilev || f->f_pmask[fac] == NOPRI) continue; /* don't output marks to recently written files */ if ((flags & MARK) && (now - f->f_time) < (MarkInterval * 60 / 2)) continue; dprintf("Logging to %s", TypeNames[f->f_type]); f->f_time = now; switch (f->f_type) { case F_UNUSED: dprintf("\n"); break; case F_FORW: dprintf("Forward (unsupported)\n"); break; case F_CONSOLE: if (flags & IGN_CONS) { dprintf(" (ignored)\n"); break; } case F_TTY: case F_FILE: dprintf(" %s\n", f->f_un.f_fname); if (f->f_type != F_FILE) { v->iov_base = "\r\n"; v->iov_len = 2; } else { v->iov_base = "\n"; v->iov_len = 1; } if (writev(f->f_file, iov, 6) < 0) { int e = errno; close(f->f_file); /* * Check for EBADF on TTY's due to vhangup() XXX */ if (e == EBADF && f->f_type != F_FILE) { f->f_file = open(f->f_un.f_fname, O_WRONLY|O_APPEND); if (f->f_file < 0) { f->f_type = F_UNUSED; logerror(f->f_un.f_fname); } } else { f->f_type = F_UNUSED; errno = e; logerror(f->f_un.f_fname); } } else if (flags & SYNC_FILE) #ifndef linux fsync(f->f_file); #else sync(); #endif break; case F_USERS: case F_WALL: dprintf("\n"); v->iov_base = "\r\n"; v->iov_len = 2; wallmsg(f, iov); break; } } signal(SIGHUP, (void *) s1); signal(SIGALRM, (void *) s2); } /* * WALLMSG -- Write a message to the world at large * * Write the specified message to either the entire * world, or a list of approved users. */ wallmsg(f, iov) register struct filed *f; struct iovec *iov; { register char *p; register int i; int ttyf, len, pid, wstat, xpid; FILE *uf; static int reenter = 0; struct utmp ut; time_t now; char greetings[200]; if (reenter++) return; /* open the user login file */ if ((uf = fopen("/etc/utmp", "r")) == NULL) { logerror("/etc/utmp"); reenter = 0; return; } time(&now); sprintf(greetings, "\r\n\7Message from syslogd@%s at %.24s ...\r\n", iov[2].iov_base, ctime(&now)); len = strlen(greetings); /* scan the user login file */ xpid = 0; while (fread((char *) &ut, sizeof ut, 1, uf) == 1) { /* is this slot used? */ if (ut.ut_name[0] == '\0') continue; /* should we send the message to this user? */ if (f->f_type == F_USERS) { for (i = 0; i < MAXUNAMES; i++) { if (!f->f_un.f_uname[i][0]) { i = MAXUNAMES; break; } if (strncmp(f->f_un.f_uname[i], ut.ut_name, UNAMESZ) == 0) break; } if (i >= MAXUNAMES) continue; } /* compute the device name */ p = "/dev/12345678"; strncpy(&p[5], ut.ut_line, UNAMESZ); /* * Might as well instead of using nonblocking I/O * and doing notty(). */ pid = fork(); /* if (pid != 0) { while ((xpid = wait(&wstat)) != pid) { if (xpid == -1) break; } } else */ if (pid == 0) { if (f->f_type == F_WALL) { iov[0].iov_base = greetings; iov[0].iov_len = len; iov[1].iov_len = 0; } signal(SIGALRM, SIG_DFL); alarm(30); /* open the terminal */ ttyf = open(p, O_WRONLY); if (ttyf >= 0) writev(ttyf, iov, 6); exit(0); } } /* close the user login file */ fclose(uf); while ((xpid = wait(&wstat)) != -1) ; reenter = 0; } domark() { int pri; if ((++MarkSeq % MARKCOUNT) == 0) logmsg(LOG_INFO, "-- MARK --", LocalHostName, ADDDATE|MARK); else flushmsg(); signal(SIGALRM, (void *) domark); alarm(MarkInterval * 60 / MARKCOUNT); } flushmsg() { if (PrevCount == 0) return; if (PrevCount > 1) sprintf(PrevLine+16, "last message repeated %d times", PrevCount); PrevCount = 0; logmsg(PrevPri, PrevLine, PrevHost, PrevFlags|NOCOPY); PrevLine[0] = '\0'; } /* * Print syslogd errors some place. */ logerror(type) char *type; { char buf[100]; if (errno == 0) sprintf(buf, "syslogd: %s", type); else if ((unsigned) errno > sys_nerr) sprintf(buf, "syslogd: %s: error %d", type, errno); else sprintf(buf, "syslogd: %s: %s", type, sys_errlist[errno]); errno = 0; dprintf("%s\n", buf); logmsg(LOG_SYSLOG|LOG_ERR, buf, LocalHostName, ADDDATE); } die(sig) { char buf[100]; if (sig) { dprintf("syslogd: going down on signal %d\n", sig); flushmsg(); sprintf(buf, "going down on signal %d", sig); logerror(buf); } unlink(LogName); exit(0); } /* * INIT -- Initialize syslogd from configuration table */ init() { register int i; register FILE *cf; register struct filed *f; register char *p; char cline[BUFSIZ]; dprintf("init\n"); /* flush any pending output */ flushmsg(); /* * Close all open log files. */ for (f = Files; f < &Files[NLOGS]; f++) { if (f->f_type == F_FILE || f->f_type == F_TTY) close(f->f_file); f->f_type = F_UNUSED; } /* open the configuration file */ if ((cf = fopen(ConfFile, "r")) == NULL) { dprintf("cannot open %s\n", ConfFile); cfline("*.ERR\t/dev/tty0", &Files[0]); cfline("*.PANIC\t*", &Files[1]); return; } /* * Foreach line in the conf table, open that file. */ f = Files; while (fgets(cline, sizeof cline, cf) != NULL && f < &Files[NLOGS]) { /* check for end-of-section */ if (cline[0] == '\n' || cline[0] == '#') continue; /* strip off newline character */ p = index(cline, '\n'); if (p) *p = '\0'; cfline(cline, f++); } /* close the configuration file */ fclose(cf); Initialized = 1; if (Debug) { for (f = Files; f < &Files[NLOGS]; f++) { for (i = 0; i <= LOG_NFACILITIES; i++) if (f->f_pmask[i] == NOPRI) printf("X "); else printf("%d ", f->f_pmask[i]); printf("%s: ", TypeNames[f->f_type]); switch (f->f_type) { case F_FILE: case F_TTY: case F_CONSOLE: printf("%s", f->f_un.f_fname); break; case F_FORW: break; case F_USERS: for (i = 0; i < MAXUNAMES && *f->f_un.f_uname[i]; i++) printf("%s, ", f->f_un.f_uname[i]); break; } printf("\n"); } } logmsg(LOG_SYSLOG|LOG_INFO, "syslogd: restart", LocalHostName, ADDDATE); dprintf("syslogd: restarted\n"); } /* * Crack a configuration file line */ struct code { char *c_name; int c_val; }; struct code PriNames[] = { "panic", LOG_EMERG, "emerg", LOG_EMERG, "alert", LOG_ALERT, "crit", LOG_CRIT, "err", LOG_ERR, "error", LOG_ERR, "warn", LOG_WARNING, "warning", LOG_WARNING, "notice", LOG_NOTICE, "info", LOG_INFO, "debug", LOG_DEBUG, "none", NOPRI, NULL, -1 }; struct code FacNames[] = { "kern", LOG_KERN, "user", LOG_USER, "mail", LOG_MAIL, "daemon", LOG_DAEMON, "auth", LOG_AUTH, "security", LOG_AUTH, "mark", LOG_MARK, "syslog", LOG_SYSLOG, "lpr", LOG_LPR, "local0", LOG_LOCAL0, "local1", LOG_LOCAL1, "local2", LOG_LOCAL2, "local3", LOG_LOCAL3, "local4", LOG_LOCAL4, "local5", LOG_LOCAL5, "local6", LOG_LOCAL6, "local7", LOG_LOCAL7, NULL, -1 }; cfline(line, f) char *line; register struct filed *f; { register char *p; register char *q; register int i; char *bp; int pri; struct hostent *hp; char buf[MAXLINE]; dprintf("cfline(%s)\n", line); /* clear out file entry */ bzero((char *) f, sizeof *f); for (i = 0; i <= LOG_NFACILITIES; i++) f->f_pmask[i] = NOPRI; /* scan through the list of selectors */ for (p = line; *p && *p != '\t';) { /* find the end of this facility name list */ for (q = p; *q && *q != '\t' && *q++ != '.'; ) continue; /* collect priority name */ for (bp = buf; *q && !index("\t,;", *q); ) *bp++ = *q++; *bp = '\0'; /* skip cruft */ while (index(", ;", *q)) q++; /* decode priority name */ pri = decode(buf, PriNames); if (pri < 0) { char xbuf[200]; sprintf(xbuf, "unknown priority name \"%s\"", buf); logerror(xbuf); return; } /* scan facilities */ while (*p && !index("\t.;", *p)) { int i; for (bp = buf; *p && !index("\t,;.", *p); ) *bp++ = *p++; *bp = '\0'; if (*buf == '*') for (i = 0; i < LOG_NFACILITIES; i++) f->f_pmask[i] = pri; else { i = decode(buf, FacNames); if (i < 0) { char xbuf[200]; sprintf(xbuf, "unknown facility name \"%s\"", buf); logerror(xbuf); return; } f->f_pmask[i >> 3] = pri; } while (*p == ',' || *p == ' ') p++; } p = q; } /* skip to action part */ while (*p == '\t') p++; fprintf(stderr, "syslogd: cfline on %s\n", p); switch (*p) { case '@': if (!InetInuse) break; strcpy(f->f_un.f_uname, ++p); f->f_type = F_FORW; break; case '/': strcpy(f->f_un.f_fname, p); if ((f->f_file = open(p, O_WRONLY|O_APPEND)) < 0) { logerror(p); break; } if (isatty(f->f_file)) { f->f_type = F_TTY; untty(); } else f->f_type = F_FILE; if (strcmp(p, ctty) == 0) f->f_type = F_CONSOLE; break; case '*': f->f_type = F_WALL; break; default: for (i = 0; i < MAXUNAMES && *p; i++) { for (q = p; *q && *q != ','; ) q++; strncpy(f->f_un.f_uname[i], p, UNAMESZ); if ((q - p) > UNAMESZ) f->f_un.f_uname[i][UNAMESZ] = '\0'; else f->f_un.f_uname[i][q - p] = '\0'; while (*q == ',' || *q == ' ') q++; p = q; } f->f_type = F_USERS; break; } } /* * Decode a symbolic name to a numeric value */ decode(name, codetab) char *name; struct code *codetab; { register struct code *c; register char *p; char buf[40]; if (isdigit(*name)) return (atoi(name)); strcpy(buf, name); for (p = buf; *p; p++) if (isupper(*p)) *p = tolower(*p); for (c = codetab; c->c_name; c++) if (!strcmp(buf, c->c_name)) return (c->c_val); return (-1); } readline(fd, s, size) int fd; char *s; int size; { int c, i, j; static long cur_pos; struct stat st; fstat(fd, &st); if (cur_pos < st.st_size) { i = 0; j = 0; do { j = read(fd, &c, 1); *s++ = c; i++; } while (j > 0 && c != '\n'); cur_pos = lseek(fd, 0L, 1); return(i); } return(0); } int recvfrom(s, buf, buflen, flags, sock, socklen) int s, buflen, flags; char *buf; struct sockaddr *sock; int *socklen; { int i, fd, nfds, cc; long newmask; /* check for dead connections */ /* I think this is done below now */ /* check for data on current connections and return */ if (mask | FDMASK(s)) { newmask = mask | FDMASK(s); nfds = select(20, (fd_set *) &newmask, (fd_set *) NULL, (fd_set *) NULL, (struct timeval *) NULL); fd = 0; while (nfds > 0) { /* accept new connection and read data */ if (newmask & FDMASK(s)) { listen(s, 5); fd = accept(s, sock, socklen); if (fd < 0) { return -1; } mask |= FDMASK(fd); fcntl(fd, F_SETFL, O_NONBLOCK); cc = read(fd, buf, buflen); return(cc); } else { while (!(newmask & 1)) { newmask = newmask >> 1; fd++; } cc = read(fd, buf, buflen); if (cc <= 0) { mask ^= FDMASK(fd); newmask = newmask >> 1; close(fd); fd++; nfds--; } else { return(cc); } } } } }