hostres_snmp.c

/*-
 * SPDX-License-Identifier: (BSD-2-Clause AND Beerware)
 *
 * Copyright (c) 2005-2006 The FreeBSD Project
 * All rights reserved.
 *
 * Author: Victor Cruceru <[email protected]>
 *
 * 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):
 * <[email protected]> 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);
}