#ifndef lint static char sccsid[] = "@(#)syslog.c 4.4 (Berkeley) 08/16/84"; #endif /* * SYSLOG -- print message on log file * * This routine looks a lot like printf, except that it * outputs to the log file instead of the standard output. * Also: * adds a timestamp, * prints the module name in front of the message, * has some other formatting types (or will sometime), * adds a newline on the end of the message. * * The output of this routine is intended to be read by /etc/syslogd. * * Author: Eric Allman * Modified to use UNIX domain IPC by Ralph Campbell */ #include #include #include #include #include #define MAXLINE 1024 /* max message size */ #define NULL 0 /* manifest */ static char logname[] = "/dev/log"; static char ctty[] = "/dev/console"; static int LogFile = -1; /* fd for log */ static int LogStat = 0; /* status bits, set by openlog() */ static char *LogTag = NULL; /* string to tag the entry with */ static int LogMask = LOG_DEBUG; /* lowest priority to be logged */ static struct sockaddr SyslogAddr; extern int errno, sys_nerr; extern char *sys_errlist[]; syslog(pri, fmt, p0, p1, p2, p3, p4) int pri; char *fmt; { char buf[MAXLINE + 1], outline[MAXLINE + 1]; register char *b, *f, *o; register int c; long now; int pid, olderrno = errno; /* see if we should just throw out this message */ if (pri < LOG_ALERT || pri > LogMask) return; if (LogFile < 0) openlog(NULL, 0, 0); o = outline; sprintf(o, "<%d>", pri); o += strlen(o); if (LogTag) { strcpy(o, LogTag); o += strlen(o); } if (LogStat & LOG_PID) { sprintf(o, "[%d]", getpid()); o += strlen(o); } time(&now); sprintf(o, ": %.15s-- ", ctime(&now) + 4); o += strlen(o); b = buf; f = fmt; while ((c = *f++) != '\0' && c != '\n' && b < &buf[MAXLINE]) { if (c != '%') { *b++ = c; continue; } if ((c = *f++) != 'm') { *b++ = '%'; *b++ = c; continue; } if ((unsigned)olderrno > sys_nerr) sprintf(b, "error %d", olderrno); else strcpy(b, sys_errlist[olderrno]); b += strlen(b); } *b++ = '\n'; *b = '\0'; sprintf(o, buf, p0, p1, p2, p3, p4); c = strlen(outline); if (c > MAXLINE) c = MAXLINE; if (sendto(LogFile, outline, c, 0, &SyslogAddr, sizeof SyslogAddr) >= 0) return; if (pri > LOG_CRIT) return; pid = fork(); if (pid == -1) return; if (pid == 0) { LogFile = open(ctty, O_RDWR); write(LogFile, outline, c); close(LogFile); exit(0); } while ((c = wait((int *)0)) > 0 && c != pid) ; } /* * OPENLOG -- open system log */ openlog(ident, logstat, logmask) char *ident; int logstat, logmask; { LogTag = (ident != NULL) ? ident : "syslog"; LogStat = logstat; if (logmask > 0 && logmask <= LOG_DEBUG) LogMask = logmask; if (LogFile >= 0) return; SyslogAddr.sa_family = AF_UNIX; strncpy(SyslogAddr.sa_data, logname, sizeof SyslogAddr.sa_data); LogFile = socket(AF_UNIX, SOCK_DGRAM, 0); fcntl(LogFile, F_SETFD, 1); } /* * CLOSELOG -- close the system log */ closelog() { (void) close(LogFile); LogFile = -1; } /* * SETLOGMASK -- set the log mask level */ setlogmask(pri) int pri; { int opri; opri = LogMask; if (pri > 0 && pri <= LOG_DEBUG) LogMask = pri; return (opri); }