/*  $OpenBSD: log.c,v 1.12 2017/03/21 12:06:55 bluhm Exp $  */

/*

 * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>

 *

 * Permission to use, copy, modify, and distribute this software for any

 * purpose with or without fee is hereby granted, provided that the above

 * copyright notice and this permission notice appear in all copies.

 *

 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES

 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF

 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR

 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES

 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN

 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF

 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

 */

#include <stdio.h>

#include <stdlib.h>

#include <stdarg.h>

#include <string.h>

#include <syslog.h>

#include <errno.h>

#include <time.h>

static int   debug;

static int   verbose;

const char  *log_procname;

void  log_init(int, int);

void  log_procinit(const char *);

void  log_setverbose(int);

int log_getverbose(void);

void  log_warn(const char *, ...)

      __attribute__((__format__ (printf, 1, 2)));

void  log_warnx(const char *, ...)

      __attribute__((__format__ (printf, 1, 2)));

void  log_info(const char *, ...)

      __attribute__((__format__ (printf, 1, 2)));

void  log_debug(const char *, ...)

      __attribute__((__format__ (printf, 1, 2)));

void  logit(int, const char *, ...)

      __attribute__((__format__ (printf, 2, 3)));

void  vlog(int, const char *, va_list)

      __attribute__((__format__ (printf, 2, 0)));

__dead void fatal(const char *, ...)

      __attribute__((__format__ (printf, 1, 2)));

__dead void fatalx(const char *, ...)

      __attribute__((__format__ (printf, 1, 2)));

void

log_init(int n_debug, int facility)

{

  extern char *__progname;

  debug = n_debug;

  verbose = n_debug;

  log_procinit(__progname);

  if (!debug)

    openlog(__progname, LOG_PID | LOG_NDELAY, facility);

  tzset();

}

void

log_procinit(const char *procname)

{

  if (procname != NULL)

    log_procname = procname;

}

void

log_setverbose(int v)

{

  verbose = v;

}

int

log_getverbose(void)

{

  return (verbose);

}

void

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

{

  va_list ap;

  va_start(ap, fmt);

  vlog(pri, fmt, ap);

  va_end(ap);

}

void

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

{

  char  *nfmt;

  int  saved_errno = errno;

  if (debug) {

    /* best effort in out of mem situations */

    if (asprintf(&nfmt, "%s\n", fmt) == -1) {

      vfprintf(stderr, fmt, ap);

      fprintf(stderr, "\n");

    } else {

      vfprintf(stderr, nfmt, ap);

      free(nfmt);

    }

    fflush(stderr);

  } else

    vsyslog(pri, fmt, ap);

  errno = saved_errno;

}

void

log_warn(const char *emsg, ...)

{

  char    *nfmt;

  va_list    ap;

  int    saved_errno = errno;

  /* best effort to even work in out of memory situations */

  if (emsg == NULL)

    logit(LOG_ERR, "%s", strerror(saved_errno));

  else {

    va_start(ap, emsg);

    if (asprintf(&nfmt, "%s: %s", emsg,

        strerror(saved_errno)) == -1) {

      /* we tried it... */

      vlog(LOG_ERR, emsg, ap);

      logit(LOG_ERR, "%s", strerror(saved_errno));

    } else {

      vlog(LOG_ERR, nfmt, ap);

      free(nfmt);

    }

    va_end(ap);

  }

  errno = saved_errno;

}

void

log_warnx(const char *emsg, ...)

{

  va_list  ap;

  va_start(ap, emsg);

  vlog(LOG_ERR, emsg, ap);

  va_end(ap);

}

void

log_info(const char *emsg, ...)

{

  va_list  ap;

  va_start(ap, emsg);

  vlog(LOG_INFO, emsg, ap);

  va_end(ap);

}

void

log_debug(const char *emsg, ...)

{

  va_list  ap;

  if (verbose > 1) {

    va_start(ap, emsg);

    vlog(LOG_DEBUG, emsg, ap);

    va_end(ap);

  }

}

static void

vfatalc(int code, const char *emsg, va_list ap)

{

  static char s[BUFSIZ];

  const char  *sep;

  if (emsg != NULL) {

    (void)vsnprintf(s, sizeof(s), emsg, ap);

    sep = ": ";

  } else {

    s[0] = '\0';

    sep = "";

  }

  if (code)

    logit(LOG_CRIT, "%s: %s%s%s",

        log_procname, s, sep, strerror(code));

  else

    logit(LOG_CRIT, "%s%s%s", log_procname, sep, s);

}

void

fatal(const char *emsg, ...)

{

  va_list ap;

  va_start(ap, emsg);

  vfatalc(errno, emsg, ap);

  va_end(ap);

  exit(1);

}

void

fatalx(const char *emsg, ...)

{

  va_list ap;

  va_start(ap, emsg);

  vfatalc(0, emsg, ap);

  va_end(ap);

  exit(1);

}