text: /*
   * Copyright (c) 1983, 1988, 1993
   *	The Regents of the University of California.  All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. All advertising materials mentioning features or use of this software
   *    must display the following acknowledgement:
   *	This product includes software developed by the University of
   *	California, Berkeley and its contributors.
   * 4. Neither the name of the University nor the names of its contributors
   *    may be used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   */
  
  #if defined(LIBC_SCCS) && !defined(lint)
  static char rcsid[] = "$OpenBSD: syslog.c,v 1.8 1998/03/19 00:30:03 millert Exp $";
  #endif /* LIBC_SCCS and not lint */
  
  #include <sys/types.h>
  #include <sys/socket.h>
  #include <sys/syslog.h>
  #include <sys/uio.h>
  #include <sys/un.h>
  #include <netdb.h>
  
  #include <errno.h>
  #include <fcntl.h>
  #include <paths.h>
  #include <stdio.h>
  #include <string.h>
  #include <time.h>
  #include <unistd.h>
  
  #ifdef __STDC__
  #include <stdarg.h>
  #else
  #include <varargs.h>
  #endif
  
  static int	LogFile = -1;		/* fd for log */
  static int	connected;		/* have done connect */
  static int	LogStat = 0;		/* status bits, set by openlog() */
  static const char *LogTag = NULL;	/* string to tag the entry with */
  static int	LogFacility = LOG_USER;	/* default facility code */
  static int	LogMask = 0xff;		/* mask of priorities to be logged */
  extern char	*__progname;		/* Program name, from crt0. */
  
  /*
   * syslog, vsyslog --
   *	print message on log file; output is intended for syslogd(8).
   */
  void
  #ifdef __STDC__
  syslog(int pri, const char *fmt, ...)
  #else
  syslog(pri, fmt, va_alist)
  	int pri;
  	char *fmt;
  	va_dcl
  #endif
  {
  	va_list ap;
  
  #ifdef __STDC__
  	va_start(ap, fmt);
  #else
  	va_start(ap);
  #endif
  	vsyslog(pri, fmt, ap);
  	va_end(ap);
  }
  
  void
  vsyslog(pri, fmt, ap)
  	int pri;
  	register const char *fmt;
  	va_list ap;
  {
  	register int cnt;
  	register char ch, *p, *t;
  	time_t now;
  	int fd, saved_errno;
  #define	TBUF_LEN	2048
  #define	FMT_LEN		1024
  	char *stdp, tbuf[TBUF_LEN], fmt_cpy[FMT_LEN];
  	int tbuf_left, fmt_left, prlen;
  
  #define	INTERNALLOG	LOG_ERR|LOG_CONS|LOG_PERROR|LOG_PID
  	/* Check for invalid bits. */
  	if (pri & ~(LOG_PRIMASK|LOG_FACMASK)) {
  		syslog(INTERNALLOG,
  		    "syslog: unknown facility/priority: %x", pri);
  		pri &= LOG_PRIMASK|LOG_FACMASK;
  	}
  
  	/* Check priority against setlogmask values. */
  	if (!(LOG_MASK(LOG_PRI(pri)) & LogMask))
  		return;
  
  	saved_errno = errno;
  
  	/* Set default facility if none specified. */
  	if ((pri & LOG_FACMASK) == 0)
  		pri |= LogFacility;
  
  	/* Build the message. */
  	
  	/*
   	 * Although it's tempting, we can't ignore the possibility of
  	 * overflowing the buffer when assembling the "fixed" portion
  	 * of the message.  Strftime's "%h" directive expands to the
  	 * locale's abbreviated month name, but if the user has the
  	 * ability to construct to his own locale files, it may be
  	 * arbitrarily long.
  	 */
  	(void)time(&now);
  
  	p = tbuf;  
  	tbuf_left = TBUF_LEN;
  	
  #define	DEC()	\
  	do {					\
  		if (prlen >= tbuf_left)		\
  			prlen = tbuf_left - 1;	\
  		p += prlen;			\
  		tbuf_left -= prlen;		\
  	} while (0)
  
  	prlen = snprintf(p, tbuf_left, "<%d>", pri);
  	DEC();
  
  	prlen = strftime(p, tbuf_left, "%h %e %T ", localtime(&now));
  	DEC();
  
  	if (LogStat & LOG_PERROR)
  		stdp = p;
  	if (LogTag == NULL)
  		LogTag = __progname;
  	if (LogTag != NULL) {
  		prlen = snprintf(p, tbuf_left, "%s", LogTag);
  		DEC();
  	}
  	if (LogStat & LOG_PID) {
  		prlen = snprintf(p, tbuf_left, "[%d]", getpid());
  		DEC();
  	}
  	if (LogTag != NULL) {
  		if (tbuf_left > 1) {
  			*p++ = ':';
  			tbuf_left--;
  		}
  		if (tbuf_left > 1) {
  			*p++ = ' ';
  			tbuf_left--;
  		}
  	}
  
  	/* 
  	 * We wouldn't need this mess if printf handled %m, or if 
  	 * strerror() had been invented before syslog().
  	 */
  	for (t = fmt_cpy, fmt_left = FMT_LEN; (ch = *fmt); ++fmt) {
  		if (ch == '%' && fmt[1] == 'm') {
  			++fmt;
  			prlen = snprintf(t, fmt_left, "%s",
  			    strerror(saved_errno));
  			if (prlen >= fmt_left)
  				prlen = fmt_left - 1;
  			t += prlen;
  			fmt_left -= prlen;
  		} else {
  			if (fmt_left > 1) {
  				*t++ = ch;
  				fmt_left--;
  			}
  		}
  	}
  	*t = '\0';
  
  	prlen = vsnprintf(p, tbuf_left, fmt_cpy, ap);
  	DEC();
  	cnt = p - tbuf;
  
  	/* Output to stderr if requested. */
  	if (LogStat & LOG_PERROR) {
  		struct iovec iov[2];
  
  		iov[0].iov_base = stdp;
  		iov[0].iov_len = cnt - (stdp - tbuf);
  		iov[1].iov_base = "\n";
  		iov[1].iov_len = 1;
  		(void)writev(STDERR_FILENO, iov, 2);
  	}
  
  	/* Get connected, output the message to the local logger. */
  	if (!connected)
  		openlog(LogTag, LogStat | LOG_NDELAY, 0);
  	if (send(LogFile, tbuf, cnt, 0) >= 0)
  		return;
  
  	/*
  	 * Output the message to the console; don't worry about blocking,
  	 * if console blocks everything will.  Make sure the error reported
  	 * is the one from the syslogd failure.
  	 */
  	if (LogStat & LOG_CONS &&
  	    (fd = open(_PATH_CONSOLE, O_WRONLY, 0)) >= 0) {
  		struct iovec iov[2];
  		
  		p = strchr(tbuf, '>') + 1;
  		iov[0].iov_base = p;
  		iov[0].iov_len = cnt - (p - tbuf);
  		iov[1].iov_base = "\r\n";
  		iov[1].iov_len = 2;
  		(void)writev(fd, iov, 2);
  		(void)close(fd);
  	}
  }
  
  static struct sockaddr_un SyslogAddr;	/* AF_UNIX address of local logger */
  
  void
  openlog(ident, logstat, logfac)
  	const char *ident;
  	int logstat, logfac;
  {
  	if (ident != NULL)
  		LogTag = ident;
  	LogStat = logstat;
  	if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0)
  		LogFacility = logfac;
  
  	if (LogFile == -1) {
  		memset(&SyslogAddr, '\0', sizeof(SyslogAddr));
  		SyslogAddr.sun_len = sizeof(SyslogAddr);
  		SyslogAddr.sun_family = AF_UNIX;
  		(void)strncpy(SyslogAddr.sun_path, _PATH_LOG,
  		    sizeof(SyslogAddr.sun_path) - 1);
  		SyslogAddr.sun_path[sizeof(SyslogAddr.sun_path) - 1] = '\0';
  		if (LogStat & LOG_NDELAY) {
  			if ((LogFile = socket(AF_UNIX, SOCK_DGRAM, 0)) == -1)
  				return;
  			(void)fcntl(LogFile, F_SETFD, 1);
  		}
  	}
  	if (LogFile != -1 && !connected) {
  		if (connect(LogFile, (struct sockaddr *)&SyslogAddr,
  			sizeof(SyslogAddr)) == -1) {
  			(void)close(LogFile);
  			LogFile = -1;
  		} else
  			connected = 1;
  	}
  }
  
  void
  closelog()
  {
  	(void)close(LogFile);
  	LogFile = -1;
  	connected = 0;
  }
  
  /* setlogmask -- set the log mask level */
  int
  setlogmask(pmask)
  	int pmask;
  {
  	int omask;
  
  	omask = LogMask;
  	if (pmask != 0)
  		LogMask = pmask;
  	return (omask);
  }
  