/*      $OpenBSD: log.c,v 1.3 2019/03/31 03:53:42 yasuoka 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 <errno.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <time.h>

#include "log.h"

int              log_debug_use_syslog = 0;
static int       log_initialized = 0;
static int       debug = 0;

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

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

        debug = n_debug;

        if (!debug)
                openlog(__progname, LOG_PID | LOG_NDELAY, LOG_DAEMON);

        tzset();
        log_initialized++;
}

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                     fmtbuf[1024];
        time_t                   curr;
        struct tm                tm;
        u_int                    i = 0, j;
        int                      saved_errno = errno;
        static struct {
                int              v;
                const char      *l;
        } syslog_prionames[] = {
#define NV(_l)  { _l, #_l }
                NV(LOG_DEBUG),
                NV(LOG_INFO),
                NV(LOG_NOTICE),
                NV(LOG_WARNING),
                NV(LOG_ERR),
                NV(LOG_ALERT),
                NV(LOG_CRIT),
#undef NV
                { -1, NULL }
        };

        if (log_initialized && !debug) {
                vsyslog(pri, fmt, ap);
                return;
        }
        if (log_initialized) {
                time(&curr);
                localtime_r(&curr, &tm);
                strftime(fmtbuf, sizeof(fmtbuf), "%Y-%m-%d %H:%M:%S:", &tm);
                for (i = 0; syslog_prionames[i].v != -1; i++) {
                        if (syslog_prionames[i].v == LOG_PRI(pri)) {
                                strlcat(fmtbuf, syslog_prionames[i].l + 4,
                                    sizeof(fmtbuf));
                                strlcat(fmtbuf, ": ", sizeof(fmtbuf));
                                break;
                        }
                }
                i = strlen(fmtbuf);
        }
        for (j = 0; i < sizeof(fmtbuf) - 2 && fmt[j] != '\0'; j++) {
                if (fmt[j] == '%' && fmt[j + 1] == 'm') {
                        ++j;
                        fmtbuf[i] = '\0';
                        strlcat(fmtbuf, strerror(saved_errno),
                            sizeof(fmtbuf) - 1);
                        i = strlen(fmtbuf);
                } else
                        fmtbuf[i++] = fmt[j];
        }
        fmtbuf[i++] = '\n';
        fmtbuf[i++] = '\0';

        vfprintf(stderr, fmtbuf, ap);
}


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_WARNING, "%s", strerror(saved_errno));
        else {
                va_start(ap, emsg);

                if (asprintf(&nfmt, "%s: %s", emsg, strerror(saved_errno))
                    == -1) {
                        /* we tried it... */
                        vlog(LOG_WARNING, emsg, ap);
                        logit(LOG_WARNING, "%s", strerror(saved_errno));
                } else {
                        vlog(LOG_WARNING, nfmt, ap);
                        free(nfmt);
                }
                va_end(ap);
        }
}

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

        va_start(ap, emsg);
        vlog(LOG_WARNING, 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 (debug || log_debug_use_syslog) {
                va_start(ap, emsg);
                vlog(LOG_DEBUG, emsg, ap);
                va_end(ap);
        }
}

void
fatal(const char *emsg)
{
        if (emsg == NULL)
                logit(LOG_CRIT, "fatal: %s", strerror(errno));
        else
                if (errno)
                        logit(LOG_CRIT, "fatal: %s: %s",
                            emsg, strerror(errno));
                else
                        logit(LOG_CRIT, "fatal: %s", emsg);

        exit(1);
}

void
fatalx(const char *emsg)
{
        errno = 0;
        fatal(emsg);
}