4.3BSD - /usr/src/lib/libc/gen/syslog.c

   1: /*
   2:  * Copyright (c) 1983 Regents of the University of California.
   3:  * All rights reserved.  The Berkeley software License Agreement
   4:  * specifies the terms and conditions for redistribution.
   5:  */
   6: 
   7: #if defined(LIBC_SCCS) && !defined(lint)
   8: static char sccsid[] = "@(#)syslog.c	5.9 (Berkeley) 5/7/86";
   9: #endif LIBC_SCCS and not lint
  10: 
  11: /*
  12:  * SYSLOG -- print message on log file
  13:  *
  14:  * This routine looks a lot like printf, except that it
  15:  * outputs to the log file instead of the standard output.
  16:  * Also:
  17:  *	adds a timestamp,
  18:  *	prints the module name in front of the message,
  19:  *	has some other formatting types (or will sometime),
  20:  *	adds a newline on the end of the message.
  21:  *
  22:  * The output of this routine is intended to be read by /etc/syslogd.
  23:  *
  24:  * Author: Eric Allman
  25:  * Modified to use UNIX domain IPC by Ralph Campbell
  26:  */
  27: 
  28: #include <sys/types.h>
  29: #include <sys/socket.h>
  30: #include <sys/file.h>
  31: #include <sys/signal.h>
  32: #include <sys/syslog.h>
  33: #include <netdb.h>
  34: #include <strings.h>
  35: 
  36: #define MAXLINE 1024            /* max message size */
  37: #define NULL    0           /* manifest */
  38: 
  39: #define PRIMASK(p)  (1 << ((p) & LOG_PRIMASK))
  40: #define PRIFAC(p)   (((p) & LOG_FACMASK) >> 3)
  41: #define IMPORTANT   LOG_ERR
  42: 
  43: static char logname[] = "/dev/log";
  44: static char ctty[] = "/dev/console";
  45: 
  46: static int  LogFile = -1;       /* fd for log */
  47: static int  LogStat = 0;        /* status bits, set by openlog() */
  48: static char *LogTag = "syslog"; /* string to tag the entry with */
  49: static int  LogMask = 0xff;     /* mask of priorities to be logged */
  50: static int  LogFacility = LOG_USER; /* default facility code */
  51: 
  52: static struct sockaddr SyslogAddr;  /* AF_UNIX address of local logger */
  53: 
  54: extern  int errno, sys_nerr;
  55: extern  char *sys_errlist[];
  56: 
  57: syslog(pri, fmt, p0, p1, p2, p3, p4)
  58:     int pri;
  59:     char *fmt;
  60: {
  61:     char buf[MAXLINE + 1], outline[MAXLINE + 1];
  62:     register char *b, *f, *o;
  63:     register int c;
  64:     long now;
  65:     int pid, olderrno = errno;
  66: 
  67:     /* see if we should just throw out this message */
  68:     if (pri <= 0 || PRIFAC(pri) >= LOG_NFACILITIES || (PRIMASK(pri) & LogMask) == 0)
  69:         return;
  70:     if (LogFile < 0)
  71:         openlog(LogTag, LogStat | LOG_NDELAY, 0);
  72: 
  73:     /* set default facility if none specified */
  74:     if ((pri & LOG_FACMASK) == 0)
  75:         pri |= LogFacility;
  76: 
  77:     /* build the message */
  78:     o = outline;
  79:     sprintf(o, "<%d>", pri);
  80:     o += strlen(o);
  81:     time(&now);
  82:     sprintf(o, "%.15s ", ctime(&now) + 4);
  83:     o += strlen(o);
  84:     if (LogTag) {
  85:         strcpy(o, LogTag);
  86:         o += strlen(o);
  87:     }
  88:     if (LogStat & LOG_PID) {
  89:         sprintf(o, "[%d]", getpid());
  90:         o += strlen(o);
  91:     }
  92:     if (LogTag) {
  93:         strcpy(o, ": ");
  94:         o += 2;
  95:     }
  96: 
  97:     b = buf;
  98:     f = fmt;
  99:     while ((c = *f++) != '\0' && c != '\n' && b < &buf[MAXLINE]) {
 100:         if (c != '%') {
 101:             *b++ = c;
 102:             continue;
 103:         }
 104:         if ((c = *f++) != 'm') {
 105:             *b++ = '%';
 106:             *b++ = c;
 107:             continue;
 108:         }
 109:         if ((unsigned)olderrno > sys_nerr)
 110:             sprintf(b, "error %d", olderrno);
 111:         else
 112:             strcpy(b, sys_errlist[olderrno]);
 113:         b += strlen(b);
 114:     }
 115:     *b++ = '\n';
 116:     *b = '\0';
 117:     sprintf(o, buf, p0, p1, p2, p3, p4);
 118:     c = strlen(outline);
 119:     if (c > MAXLINE)
 120:         c = MAXLINE;
 121: 
 122:     /* output the message to the local logger */
 123:     if (sendto(LogFile, outline, c, 0, &SyslogAddr, sizeof SyslogAddr) >= 0)
 124:         return;
 125:     if (!(LogStat & LOG_CONS))
 126:         return;
 127: 
 128:     /* output the message to the console */
 129:     pid = vfork();
 130:     if (pid == -1)
 131:         return;
 132:     if (pid == 0) {
 133:         int fd;
 134: 
 135:         signal(SIGALRM, SIG_DFL);
 136:         sigsetmask(sigblock(0) & ~sigmask(SIGALRM));
 137:         alarm(5);
 138:         fd = open(ctty, O_WRONLY);
 139:         alarm(0);
 140:         strcat(o, "\r");
 141:         o = index(outline, '>') + 1;
 142:         write(fd, o, c + 1 - (o - outline));
 143:         close(fd);
 144:         _exit(0);
 145:     }
 146:     if (!(LogStat & LOG_NOWAIT))
 147:         while ((c = wait((int *)0)) > 0 && c != pid)
 148:             ;
 149: }
 150: 
 151: /*
 152:  * OPENLOG -- open system log
 153:  */
 154: 
 155: openlog(ident, logstat, logfac)
 156:     char *ident;
 157:     int logstat, logfac;
 158: {
 159:     if (ident != NULL)
 160:         LogTag = ident;
 161:     LogStat = logstat;
 162:     if (logfac != 0)
 163:         LogFacility = logfac & LOG_FACMASK;
 164:     if (LogFile >= 0)
 165:         return;
 166:     SyslogAddr.sa_family = AF_UNIX;
 167:     strncpy(SyslogAddr.sa_data, logname, sizeof SyslogAddr.sa_data);
 168:     if (LogStat & LOG_NDELAY) {
 169:         LogFile = socket(AF_UNIX, SOCK_DGRAM, 0);
 170:         fcntl(LogFile, F_SETFD, 1);
 171:     }
 172: }
 173: 
 174: /*
 175:  * CLOSELOG -- close the system log
 176:  */
 177: 
 178: closelog()
 179: {
 180: 
 181:     (void) close(LogFile);
 182:     LogFile = -1;
 183: }
 184: 
 185: /*
 186:  * SETLOGMASK -- set the log mask level
 187:  */
 188: setlogmask(pmask)
 189:     int pmask;
 190: {
 191:     int omask;
 192: 
 193:     omask = LogMask;
 194:     if (pmask != 0)
 195:         LogMask = pmask;
 196:     return (omask);
 197: }

Defined functions

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Defined macros