changes for more priorities & added LOG_ODELAY to delay open.

[unix-history] / usr / src / lib / libc / gen / syslog.c

#ifndef lint
static char sccsid[] = "@(#)syslog.c    4.6 (Berkeley) %G%";
#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 <sys/types.h>
#include <sys/socket.h>
#include <sys/file.h>
#include <syslog.h>
#include <netdb.h>

#define MAXLINE 1024                    /* max message size */
#define NULL    0                       /* manifest */

#define mask(p) (1 << (p))
#define IMPORTANT (mask(KERN_EMERG)|mask(KERN_ALERT)|mask(KERN_ERR)|mask(KERN_FAIL)\
       |mask(KERN_RECOV)|mask(KERN_INFO)|mask(LOG_EMERG)|mask(LOG_ALERT)\
       |mask(LOG_CRIT)|mask(LOG_ERR)|mask(LOG_FAIL))

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 = 0xffffffff;   /* mask of priorities 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 <= 0 || pri >= 32 || (mask(pri) & LogMask) == 0)
               return;
       if (LogFile < 0)
               openlog(LogTag, LogStat & ~LOG_ODELAY, 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 (!(LogStat & LOG_CONS) && !(mask(pri) & IMPORTANT))
               return;
       pid = fork();
       if (pid == -1)
               return;
       if (pid == 0) {
               LogFile = open(ctty, O_RDWR);
               strcat(o, "\r");
               write(LogFile, outline, c+1);
               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 = logmask;
       if (LogFile >= 0)
               return;
       SyslogAddr.sa_family = AF_UNIX;
       strncpy(SyslogAddr.sa_data, logname, sizeof SyslogAddr.sa_data);
       if (!(LogStat & LOG_ODELAY)) {
               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(pmask)
       int pmask;
{
       int omask;

       omask = LogMask;
       if (pmask != 0)
               LogMask = pmask;
       return (omask);
}