/*-
 * SPDX-License-Identifier: (BSD-2-Clause AND Beerware)
 *
 * Copyright (c) 2005-2006 The FreeBSD Project
 * All rights reserved.
 *
 * Author: Victor Cruceru <soc-victor@freebsd.org>
 *
 * Redistribution of this software and documentation 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 or documentation 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.
 *
 * This C file contains code developed by Poul-Henning Kamp under the
 * following license:
 *
 * FreeBSD: src/sbin/mdconfig/mdconfig.c,v 1.33.2.1 2004/09/14 03:32:21 jmg Exp
 * ----------------------------------------------------------------------------
 * "THE BEER-WARE LICENSE" (Revision 42):
 * <phk@FreeBSD.ORG> wrote this file.  As long as you retain this notice you
 * can do whatever you want with this stuff. If we meet some day, and you think
 * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
 * ----------------------------------------------------------------------------
 */

/*
 * Host Resources MIB implementation for bsnmpd.
 */

#include <paths.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>

#include "hostres_snmp.h"
#include "hostres_oid.h"
#include "hostres_tree.h"

/* Internal id got after we'll register this module with the agent */
static u_int host_registration_id = 0;

/* This our hostres module */
static struct lmodule *hostres_module;

/* See the generated file hostres_oid.h */
static const struct asn_oid oid_host = OIDX_host;

/* descriptor to access kernel memory */
kvm_t *hr_kd;

/*
 * HOST RESOURCES mib module finalization hook.
 * Returns 0 on success, < 0 on error
 */
static int
hostres_fini(void)
{

        if (hr_kd != NULL)
                (void)kvm_close(hr_kd);

        fini_storage_tbl();
        fini_fs_tbl();
        fini_processor_tbl();
        fini_disk_storage_tbl();
        fini_device_tbl();
        fini_partition_tbl();
        fini_network_tbl();
        fini_printer_tbl();

        fini_swrun_tbl();
        fini_swins_tbl();

        fini_scalars();

        if (host_registration_id > 0)
                or_unregister(host_registration_id);

        HRDBG("done.");
        return (0);
}

/*
 * HOST RESOURCES mib module initialization hook.
 * Returns 0 on success, < 0 on error
 */
static int
hostres_init(struct lmodule *mod, int argc __unused, char *argv[] __unused)
{

        hostres_module = mod;

        /*
         * NOTE: order of these calls is important here!
         */
        if ((hr_kd = kvm_open(NULL, _PATH_DEVNULL, NULL, O_RDONLY,
            "kvm_open")) == NULL) {
                syslog(LOG_ERR, "kvm_open failed: %m ");
                return (-1);
        }

        /*
         * The order is relevant here, because some table depend on each other.
         */
        init_device_tbl();

        /* populates partition table too */
        if (init_disk_storage_tbl()) {
                hostres_fini();
                return (-1);
        }
        init_processor_tbl();
        init_printer_tbl();

        /*
         * populate storage and FS tables. Must be done after device
         * initialisation because the FS refresh code calls into the
         * partition refresh code.
         */
        init_storage_tbl();


        /* also the hrSWRunPerfTable's support is initialized here */
        init_swrun_tbl();
        init_swins_tbl();

        HRDBG("done.");

        return (0);
}

/*
 * HOST RESOURCES mib module start operation
 * returns nothing
 */
static void
hostres_start(void)
{

        host_registration_id = or_register(&oid_host,
            "The MIB module for Host Resource MIB (RFC 2790).",
            hostres_module);

        start_device_tbl(hostres_module);
        start_processor_tbl(hostres_module);
        start_network_tbl();

        HRDBG("done.");
}

/* this identifies the HOST RESOURCES mib module */
const struct snmp_module config = {
        "This module implements the host resource mib (rfc 2790)",
        hostres_init,
        hostres_fini,
        NULL,                   /* idle function, do not use it */
        NULL,
        NULL,
        hostres_start,
        NULL,              /* proxy a PDU */
        hostres_ctree,    /* see the generated hostres_tree.h */
        hostres_CTREE_SIZE,     /* see the generated hostres_tree.h */
        NULL
};

/**
 * Make an SNMP DateAndTime from a struct tm. This should be in the library.
 */
int
make_date_time(u_char *str, const struct tm *tm, u_int decisecs)
{

        str[0] = (u_char)((tm->tm_year + 1900) >> 8);
        str[1] = (u_char)(tm->tm_year + 1900);
        str[2] = tm->tm_mon + 1;
        str[3] = tm->tm_mday;
        str[4] = tm->tm_hour;
        str[5] = tm->tm_min;
        str[6] = tm->tm_sec;
        str[7] = decisecs;
        if (tm->tm_gmtoff < 0)
                str[8] = '-';
        else
                str[8] = '+';

        str[9] = (u_char)(labs(tm->tm_gmtoff) / 3600);
        str[10] = (u_char)((labs(tm->tm_gmtoff) % 3600) / 60);

        return (11);
}