/*-
 * Copyright (c) 2003 Andrey Simonenko
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 */

#include "config.h"

#ifndef lint
static const char rcsid[] ATTR_UNUSED =
  "@(#)$Id: ipastat_log.c,v 1.1.4.3 2006/04/09 20:55:56 simon Exp $";
#endif /* !lint */

#include <errno.h>
#include <stdarg.h>
#include <stdio.h>
#include <string.h>

#include "ipa_mod.h"

#include "ipastat_log.h"

/*
 * logmsg() and mod_logmsg() save errno on enter and restore errno
 * on exit, to allow external function to check value of errno, changed
 * by some function, which caused error.
 */

static int can_log = 1;				/* If non-zero then can send logs. */

static const char *const priomsg[] = {		/* IPA_LOG_xxx -> Message */
	"", "W: ", "E: "
};

/* vlogmsgx() or something like this. */
void		(*xvlogmsgx)(int, const char *, va_list);

long		mypid;				/* PID of current process. */

const char	*log_ident;			/* -i <log-ident> */

#ifdef WITH_PTHREAD
# define STRERRBUF_SIZE		128	/* Size of buffer for strerror_r(). */
#endif

/*
 * If a module decides to close and open log, then simply disallow
 * it to output anything to the log, since there is limited knowledge
 * what is stderr.
 */
void
open_close_log(void)
{
	can_log = 0;
}

/*
 * vprintf-like function, do not output message for errno.
 */
void
vlogmsgx(int priority, const char *format, va_list ap)
{
	fprintf(stderr, "%s[%ld]: %s", log_ident, mypid, priomsg[priority]);
	vfprintf(stderr, format, ap);
	fprintf(stderr, "\n");
}

/*
 * Output the program name and a message.
 */
void
logmsgx(int priority, const char *format, ...)
{
	if (can_log) {
		va_list ap;

		va_start(ap, format);
		vlogmsgx(priority, format, ap);
		va_end(ap);
	}
}

/*
 * vprintf-like function, also output message for errno.
 */
void
vlogmsg(int priority, const char *format, va_list ap)
{
	int	errno_save;
#ifdef WITH_PTHREAD
	char	strerrbuf[STRERRBUF_SIZE];
#endif

	errno_save = errno;	/* Save errno. */

	fprintf(stderr, "%s[%ld]: %s", log_ident, mypid, priomsg[priority]);
	vfprintf(stderr, format, ap);
	if (errno_save != 0) {
#ifdef WITH_PTHREAD
		if (strerror_r(errno_save, strerrbuf, sizeof strerrbuf) == 0)
			fprintf(stderr, ": %s", strerrbuf);
		else
			fprintf(stderr, ": error code %d", errno_save);
#else
		fprintf(stderr, ": %s", strerror(errno_save));
#endif
	}
	fprintf(stderr, "\n");

	errno = errno_save;	/* Restore errno. */
}

/*
 * printf-like function, also output message for errno.
 */
void
logmsg(int priority, const char *format, ...)
{
	if (can_log) {
		int	errno_save;
		va_list	ap;

		errno_save = errno;	/* Save errno. */

		va_start(ap, format);
		vlogmsg(priority, format, ap);
		va_end(ap);

		errno = errno_save;	/* Restore errno. */
	}
}

/*
 * Call xvlomsgx() which is a pointer to some vlogmsgx-like function.
 */
void
xlogmsgx(int priority, const char *format, ...)
{
	va_list ap;

	va_start(ap, format);
	xvlogmsgx(priority, format, ap);
	va_end(ap);
}

/*
 * This function is called by modules to output their
 * log messages.
 */
void
mod_logmsg(const char *mod_name, int priority, int code, const char *format,
    va_list ap)
{
	if (can_log) {
		int	errno_save;
#ifdef WITH_PTHREAD
		char	strerrbuf[STRERRBUF_SIZE];
#endif

		errno_save = errno;	/* Save errno. */

		fprintf(stderr, "%s[%ld]: MOD %s: %s", log_ident, mypid,
		    mod_name, priomsg[priority]);
		vfprintf(stderr, format, ap);
		if (code != 0) {
#ifdef WITH_PTHREAD
			if (strerror_r(errno_save, strerrbuf, sizeof strerrbuf) == 0)
				fprintf(stderr, ": %s", strerrbuf);
			else
				fprintf(stderr, ": error code %d", errno_save);
#else
			fprintf(stderr, ": %s", strerror(code));
#endif
		}
		fprintf(stderr, "\n");

		errno = errno_save;	/* Restore errno. */
	}
}

/*
 * Wrapper for log function from memfunc.c.
 */
void
mvlogmsgx_wrapper(const char *format, va_list ap)
{
	/*
	 * Since mxxx functions log messages when errors
	 * occurred, we simply use fix log priority here.
	 */
	vlogmsgx(IPA_LOG_ERR, format, ap);
}