/*

 * 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.

 * 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 sccsid[] = "@(#)syslog.c	8.4 (Berkeley) 3/18/94";

#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 <stdio_ext.h>

#include <string.h>

#include <time.h>

#include <unistd.h>

#include <stdlib.h>

#include <libc-lock.h>

#include <signal.h>

#include <locale.h>

#include <stdarg.h>

#include <libio/iolibio.h>

#include <math_ldbl_opt.h>

#include <kernel-features.h>

#define ftell(s) _IO_ftell (s)

static int	LogType = SOCK_DGRAM;	/* type of socket connection */

static int	LogFile = -1;		/* fd for log */

static int	connected;		/* have done connect */

static int	LogStat;		/* status bits, set by openlog() */

static const char *LogTag;		/* 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. */

/* Define the lock.  */

__libc_lock_define_initialized (static, syslog_lock)

static void openlog_internal(const char *, int, int);

static void closelog_internal(void);

#ifndef NO_SIGPIPE

static void sigpipe_handler (int);

#endif

#ifndef send_flags

# define send_flags 0

#endif

struct cleanup_arg

{

  void *buf;

  struct sigaction *oldaction;

};

static void

cancel_handler (void *ptr)

{

#ifndef NO_SIGPIPE

  /* Restore the old signal handler.  */

  struct cleanup_arg *clarg = (struct cleanup_arg *) ptr;

  if (clarg != NULL && clarg->oldaction != NULL)

    __sigaction (SIGPIPE, clarg->oldaction, NULL);

#endif

  /* Free the lock.  */

  __libc_lock_unlock (syslog_lock);

}

/*

 * syslog, vsyslog --

 *	print message on log file; output is intended for syslogd(8).

 */

void

__syslog(int pri, const char *fmt, ...)

{

	va_list ap;

	va_start(ap, fmt);

	__vsyslog_chk(pri, -1, fmt, ap);

	va_end(ap);

}

ldbl_hidden_def (__syslog, syslog)

ldbl_strong_alias (__syslog, syslog)

void

__syslog_chk(int pri, int flag, const char *fmt, ...)

{

	va_list ap;

	va_start(ap, fmt);

	__vsyslog_chk(pri, flag, fmt, ap);

	va_end(ap);

}

void

__vsyslog_chk(int pri, int flag, const char *fmt, va_list ap)

{

	struct tm now_tm;

	time_t now;

	int fd;

	FILE *f;

	char *buf = 0;

	size_t bufsize = 0;

	size_t msgoff;

#ifndef NO_SIGPIPE

 	struct sigaction action, oldaction;

 	int sigpipe;

#endif

	int saved_errno = errno;

	char failbuf[3 * sizeof (pid_t) + sizeof "out of memory []"];

#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) == 0)

		return;

	/* Set default facility if none specified. */

	if ((pri & LOG_FACMASK) == 0)

		pri |= LogFacility;

	/* Build the message in a memory-buffer stream.  */

	f = __open_memstream (&buf, &bufsize);

	if (f == NULL)

	  {

	    /* We cannot get a stream.  There is not much we can do but

	       emitting an error messages.  */

	    char numbuf[3 * sizeof (pid_t)];

	    char *nump;

	    char *endp = __stpcpy (failbuf, "out of memory [");

	    pid_t pid = __getpid ();

	    nump = numbuf + sizeof (numbuf);

	    /* The PID can never be zero.  */

	    do

	      *--nump = '0' + pid % 10;

	    while ((pid /= 10) != 0);

	    endp = __mempcpy (endp, nump, (numbuf + sizeof (numbuf)) - nump);

	    *endp++ = ']';

	    *endp = '\0';

	    buf = failbuf;

	    bufsize = endp - failbuf;

	    msgoff = 0;

	  }

	else

	  {

	    __fsetlocking (f, FSETLOCKING_BYCALLER);

	    fprintf (f, "<%d>", pri);

	    (void) time (&now;;

	    f->_IO_write_ptr += __strftime_l (f->_IO_write_ptr,

					      f->_IO_write_end

					      - f->_IO_write_ptr,

					      "%h %e %T ",

					      __localtime_r (&now, &now_tm),

					      _nl_C_locobj_ptr);

	    msgoff = ftell (f);

	    if (LogTag == NULL)

	      LogTag = __progname;

	    if (LogTag != NULL)

	      __fputs_unlocked (LogTag, f);

	    if (LogStat & LOG_PID)

	      fprintf (f, "[%d]", (int) __getpid ());

	    if (LogTag != NULL)

	      {

		__putc_unlocked (':', f);

		__putc_unlocked (' ', f);

	      }

	    /* Restore errno for %m format.  */

	    __set_errno (saved_errno);

	    /* We have the header.  Print the user's format into the

               buffer.  */

	    if (flag == -1)

	      vfprintf (f, fmt, ap);

	    else

	      __vfprintf_chk (f, flag, fmt, ap);

	    /* Close the memory stream; this will finalize the data

	       into a malloc'd buffer in BUF.  */

	    fclose (f);

	  }

	/* Output to stderr if requested. */

	if (LogStat & LOG_PERROR) {

		struct iovec iov[2];

		struct iovec *v = iov;

		v->iov_base = buf + msgoff;

		v->iov_len = bufsize - msgoff;

		/* Append a newline if necessary.  */

		if (buf[bufsize - 1] != '\n')

		  {

		    ++v;

		    v->iov_base = (char *) "\n";

		    v->iov_len = 1;

		  }

		__libc_cleanup_push (free, buf == failbuf ? NULL : buf);

		/* writev is a cancellation point.  */

		(void)__writev(STDERR_FILENO, iov, v - iov + 1);

		__libc_cleanup_pop (0);

	}

	/* Prepare for multiple users.  We have to take care: open and

	   write are cancellation points.  */

	struct cleanup_arg clarg;

	clarg.buf = buf;

	clarg.oldaction = NULL;

	__libc_cleanup_push (cancel_handler, &clarg);

	__libc_lock_lock (syslog_lock);

#ifndef NO_SIGPIPE

	/* Prepare for a broken connection.  */

 	memset (&action, 0, sizeof (action));

 	action.sa_handler = sigpipe_handler;

 	sigemptyset (&action.sa_mask);

 	sigpipe = __sigaction (SIGPIPE, &action, &oldaction);

	if (sigpipe == 0)

	  clarg.oldaction = &oldaction;

#endif

	/* Get connected, output the message to the local logger. */

	if (!connected)

		openlog_internal(LogTag, LogStat | LOG_NDELAY, 0);

	/* If we have a SOCK_STREAM connection, also send ASCII NUL as

	   a record terminator.  */

	if (LogType == SOCK_STREAM)

	  ++bufsize;

	if (!connected || __send(LogFile, buf, bufsize, send_flags) < 0)

	  {

	    if (connected)

	      {

		/* Try to reopen the syslog connection.  Maybe it went

		   down.  */

		closelog_internal ();

		openlog_internal(LogTag, LogStat | LOG_NDELAY, 0);

	      }

	    if (!connected || __send(LogFile, buf, bufsize, send_flags) < 0)

	      {

		closelog_internal ();	/* attempt re-open next time */

		/*

		 * 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|O_NOCTTY, 0)) >= 0)

		  {

		    __dprintf (fd, "%s\r\n", buf + msgoff);

		    (void)__close(fd);

		  }

	      }

	  }

#ifndef NO_SIGPIPE

	if (sigpipe == 0)

		__sigaction (SIGPIPE, &oldaction, (struct sigaction *) NULL);

#endif

	/* End of critical section.  */

	__libc_cleanup_pop (0);

	__libc_lock_unlock (syslog_lock);

	if (buf != failbuf)

		free (buf);

}

libc_hidden_def (__vsyslog_chk)

void

__vsyslog(int pri, const char *fmt, va_list ap)

{

  __vsyslog_chk (pri, -1, fmt, ap);

}

ldbl_hidden_def (__vsyslog, vsyslog)

ldbl_weak_alias (__vsyslog, vsyslog)

static struct sockaddr_un SyslogAddr;	/* AF_UNIX address of local logger */

static void

openlog_internal(const char *ident, int logstat, int logfac)

{

	if (ident != NULL)

		LogTag = ident;

	LogStat = logstat;

	if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0)

		LogFacility = logfac;

	int retry = 0;

	while (retry < 2) {

		if (LogFile == -1) {

			SyslogAddr.sun_family = AF_UNIX;

			(void)strncpy(SyslogAddr.sun_path, _PATH_LOG,

				      sizeof(SyslogAddr.sun_path));

			if (LogStat & LOG_NDELAY) {

			  LogFile = __socket(AF_UNIX, LogType | SOCK_CLOEXEC, 0);

			  if (LogFile == -1)

			    return;

			}

		}

		if (LogFile != -1 && !connected)

		{

			int old_errno = errno;

			if (__connect(LogFile, &SyslogAddr, sizeof(SyslogAddr))

			    == -1)

			{

				int saved_errno = errno;

				int fd = LogFile;

				LogFile = -1;

				(void)__close(fd);

				__set_errno (old_errno);

				if (saved_errno == EPROTOTYPE)

				{

					/* retry with the other type: */

					LogType = (LogType == SOCK_DGRAM

						   ? SOCK_STREAM : SOCK_DGRAM);

					++retry;

					continue;

				}

			} else

				connected = 1;

		}

		break;

	}

}

void

openlog (const char *ident, int logstat, int logfac)

{

  /* Protect against multiple users and cancellation.  */

  __libc_cleanup_push (cancel_handler, NULL);

  __libc_lock_lock (syslog_lock);

  openlog_internal (ident, logstat, logfac);

  __libc_cleanup_pop (1);

}

#ifndef NO_SIGPIPE

static void

sigpipe_handler (int signo)

{

  closelog_internal ();

}

#endif

static void

closelog_internal (void)

{

  if (!connected)

    return;

  __close (LogFile);

  LogFile = -1;

  connected = 0;

}

void

closelog (void)

{

  /* Protect against multiple users and cancellation.  */

  __libc_cleanup_push (cancel_handler, NULL);

  __libc_lock_lock (syslog_lock);

  closelog_internal ();

  LogTag = NULL;

  LogType = SOCK_DGRAM; /* this is the default */

  /* Free the lock.  */

  __libc_cleanup_pop (1);

}

/* setlogmask -- set the log mask level */

int

setlogmask (int pmask)

{

	int omask;

	omask = LogMask;

	if (pmask != 0)

		LogMask = pmask;

	return (omask);

}