1 #ifndef lint 2 static char SccsId[] = "@(#)syslog.c 4.3 (Berkeley) 05/04/84"; 3 #endif 4 5 /* 6 * SYSLOG -- print message on log file 7 * 8 * This routine looks a lot like printf, except that it 9 * outputs to the log file instead of the standard output. 10 * Also: 11 * adds a timestamp, 12 * prints the module name in front of the message, 13 * has some other formatting types (or will sometime), 14 * adds a newline on the end of the message. 15 * 16 * The output of this routine is intended to be read by /etc/syslogd. 17 */ 18 19 #include <sys/types.h> 20 #include <sys/socket.h> 21 #include <sys/file.h> 22 #include <syslog.h> 23 #include <netdb.h> 24 25 #define MAXLINE 1024 /* max message size */ 26 #define NULL 0 /* manifest */ 27 28 static char logname[] = "/dev/log"; 29 static char ctty[] = "/dev/console"; 30 31 static int LogFile = -1; /* fd for log */ 32 static int LogStat = 0; /* status bits, set by openlog() */ 33 static char *LogTag = NULL; /* string to tag the entry with */ 34 static int LogMask = LOG_DEBUG; /* lowest priority to be logged */ 35 36 static struct sockaddr SyslogAddr; 37 38 extern int errno, sys_nerr; 39 extern char *sys_errlist[]; 40 41 syslog(pri, fmt, p0, p1, p2, p3, p4) 42 int pri; 43 char *fmt; 44 { 45 char buf[MAXLINE + 1], outline[MAXLINE + 1]; 46 register char *b, *f, *o; 47 register int c; 48 long now; 49 int pid; 50 51 /* see if we should just throw out this message */ 52 if (pri > LogMask) 53 return; 54 if (LogFile < 0) 55 openlog(NULL, 0, 0); 56 o = outline; 57 if (pri > 0) { 58 sprintf(o, "<%d>", pri); 59 o += strlen(o); 60 } 61 if (LogTag) { 62 strcpy(o, LogTag); 63 o += strlen(o); 64 } 65 if (LogStat & LOG_PID) { 66 sprintf(o, " (%d)", getpid()); 67 o += strlen(o); 68 } 69 time(&now); 70 sprintf(o, " %.15s -- ", ctime(&now) + 4); 71 o += strlen(o); 72 73 b = buf; 74 f = fmt; 75 while ((c = *f++) != '\0' && c != '\n' && b < &buf[MAXLINE]) { 76 if (c != '%') { 77 *b++ = c; 78 continue; 79 } 80 if ((c = *f++) != 'm') { 81 *b++ = '%'; 82 *b++ = c; 83 continue; 84 } 85 if ((unsigned)errno > sys_nerr) 86 sprintf(b, "error %d", errno); 87 else 88 strcpy(b, sys_errlist[errno]); 89 b += strlen(b); 90 } 91 *b++ = '\n'; 92 *b = '\0'; 93 sprintf(o, buf, p0, p1, p2, p3, p4); 94 c = strlen(outline); 95 if (c > MAXLINE) 96 c = MAXLINE; 97 if (sendto(LogFile, outline, c, 0, &SyslogAddr, sizeof SyslogAddr) >= 0) 98 return; 99 if (pri > LOG_CRIT) 100 return; 101 pid = fork(); 102 if (pid == -1) 103 return; 104 if (pid == 0) { 105 LogFile = open(ctty, O_RDWR); 106 write(LogFile, outline, c); 107 close(LogFile); 108 exit(0); 109 } 110 while (wait((int *)0) != pid) 111 ; 112 } 113 114 /* 115 * OPENLOG -- open system log 116 */ 117 openlog(ident, logstat, logmask) 118 char *ident; 119 int logstat, logmask; 120 { 121 122 LogTag = ident; 123 LogStat = logstat; 124 if (logmask > 0 && logmask <= LOG_DEBUG) 125 LogMask = logmask; 126 if (LogFile >= 0) 127 return; 128 SyslogAddr.sa_family = AF_UNIX; 129 strncpy(SyslogAddr.sa_data, logname, sizeof SyslogAddr.sa_data); 130 LogFile = socket(AF_UNIX, SOCK_DGRAM, 0); 131 fcntl(LogFile, F_SETFD, 1); 132 } 133 134 /* 135 * CLOSELOG -- close the system log 136 */ 137 closelog() 138 { 139 140 (void) close(LogFile); 141 LogFile = -1; 142 } 143 144 /* 145 * SETLOGMASK -- set the log mask level 146 */ 147 setlogmask(pri) 148 int pri; 149 { 150 int opri; 151 152 opri = LogMask; 153 LogMask = pri; 154 return (opri); 155 } 156