/*      $OpenBSD: log.c,v 1.4 2017/04/28 14:52:13 bluhm Exp $   */

/*
 * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
 * Copyright (c) 2017 Alexander Bluhm <bluhm@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 <err.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <time.h>

#include "log.h"
#include "syslogd.h"

static int               verbose;
static int               facility;
static const char       *log_procname;
static char             *debug_ebuf;
static size_t            debug_length;

void
log_init(int n_debug, int fac)
{
        extern char     *__progname;

        verbose = n_debug;
        facility = fac;
        log_procinit(__progname);

        if (debug_ebuf == NULL)
                if ((debug_ebuf = malloc(ERRBUFSIZE)) == NULL)
                        err(1, "allocate debug buffer");
        debug_ebuf[0] = '\0';
        debug_length = 0;

        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)
{
        int      saved_errno = errno;

        vlogmsg(facility|pri, log_procname, fmt, ap);

        errno = saved_errno;
}

void
log_warn(const char *emsg, ...)
{
        char     ebuf[ERRBUFSIZE];
        size_t   l;
        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);
                l = vsnprintf(ebuf, sizeof(ebuf), emsg, ap);
                if (l < sizeof(ebuf))
                        snprintf(ebuf+l, sizeof(ebuf)-l, ": %s",
                            strerror(saved_errno));
                logit(LOG_ERR, "%s", ebuf);
                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(int pri, const char *emsg, ...)
{
        va_list  ap;

        va_start(ap, emsg);
        vlog(pri, emsg, ap);
        va_end(ap);
}

void
log_debug(const char *emsg, ...)
{
        va_list  ap;
        int      saved_errno;

        if (verbose) {
                saved_errno = errno;
                va_start(ap, emsg);
                if (debug_length < ERRBUFSIZE - 1)
                        vsnprintf(debug_ebuf + debug_length,
                            ERRBUFSIZE - debug_length, emsg, ap);
                fprintf(stderr, "%s\n", debug_ebuf);
                fflush(stderr);
                va_end(ap);
                errno = saved_errno;
        }
        debug_ebuf[0] = '\0';
        debug_length = 0;
}

void
log_debugadd(const char *emsg, ...)
{
        size_t   l;
        va_list  ap;
        int      saved_errno;

        if (verbose) {
                saved_errno = errno;
                va_start(ap, emsg);
                if (debug_length < ERRBUFSIZE - 1) {
                        l = vsnprintf(debug_ebuf + debug_length,
                            ERRBUFSIZE - debug_length, emsg, ap);
                        if (l < ERRBUFSIZE - debug_length)
                                debug_length += l;
                        else
                                debug_length = ERRBUFSIZE - 1;
                }
                va_end(ap);
                errno = saved_errno;
        }
}

static void
vfatalc(int error, const char *emsg, va_list ap)
{
        char             ebuf[ERRBUFSIZE];
        const char      *sep;

        if (emsg != NULL) {
                (void)vsnprintf(ebuf, sizeof(ebuf), emsg, ap);
                sep = ": ";
        } else {
                ebuf[0] = '\0';
                sep = "";
        }
        if (error)
                logit(LOG_CRIT, "fatal in %s: %s%s%s",
                    log_procname, ebuf, sep, strerror(error));
        else
                logit(LOG_CRIT, "fatal in %s%s%s", log_procname, sep, ebuf);
}

void
fatal(const char *emsg, ...)
{
        va_list ap;

        va_start(ap, emsg);
        vfatalc(errno, emsg, ap);
        va_end(ap);
        die(0);
}

void
fatalx(const char *emsg, ...)
{
        va_list ap;

        va_start(ap, emsg);
        vfatalc(0, emsg, ap);
        va_end(ap);
        die(0);
}