lib.c

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/*
 * Copyright (C) 2004, 2005, 2007, 2009, 2013, 2014  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 1999-2001  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and/or 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 ISC DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS.  IN NO EVENT SHALL ISC 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.
 */

/* $Id: lib.c,v 1.19 2009/09/03 00:12:23 each Exp $ */

/*! \file */

#include <config.h>

#include <stddef.h>

#include <isc/hash.h>
#include <isc/mem.h>
#include <isc/msgcat.h>
#include <isc/mutex.h>
#include <isc/once.h>
#include <isc/util.h>

#include <dns/db.h>
#include <dns/ecdb.h>
#include <dns/lib.h>
#include <dns/result.h>

#include <dst/dst.h>


/***
 *** Globals
 ***/

LIBDNS_EXTERNAL_DATA unsigned int                       dns_pps = 0U;
LIBDNS_EXTERNAL_DATA isc_msgcat_t *                     dns_msgcat = NULL;


/***
 *** Private
 ***/

static isc_once_t               msgcat_once = ISC_ONCE_INIT;


/***
 *** Functions
 ***/

static void
open_msgcat(void) {
        isc_msgcat_open("libdns.cat", &dns_msgcat);
}

void
dns_lib_initmsgcat(void) {

        /*
         * Initialize the DNS library's message catalog, dns_msgcat, if it
         * has not already been initialized.
         */

        RUNTIME_CHECK(isc_once_do(&msgcat_once, open_msgcat) == ISC_R_SUCCESS);
}

static isc_once_t init_once = ISC_ONCE_INIT;
static isc_mem_t *dns_g_mctx = NULL;
static dns_dbimplementation_t *dbimp = NULL;
static isc_boolean_t initialize_done = ISC_FALSE;
static isc_mutex_t reflock;
static unsigned int references = 0;

static void
initialize(void) {
        isc_result_t result;

        REQUIRE(initialize_done == ISC_FALSE);

        result = isc_mem_create(0, 0, &dns_g_mctx);
        if (result != ISC_R_SUCCESS)
                return;
        dns_result_register();
        result = dns_ecdb_register(dns_g_mctx, &dbimp);
        if (result != ISC_R_SUCCESS)
                goto cleanup_mctx;
        result = isc_hash_create(dns_g_mctx, NULL, DNS_NAME_MAXWIRE);
        if (result != ISC_R_SUCCESS)
                goto cleanup_db;

        result = dst_lib_init(dns_g_mctx, NULL, 0);
        if (result != ISC_R_SUCCESS)
                goto cleanup_hash;

        result = isc_mutex_init(&reflock);
        if (result != ISC_R_SUCCESS)
                goto cleanup_dst;

        initialize_done = ISC_TRUE;
        return;

  cleanup_dst:
        dst_lib_destroy();
  cleanup_hash:
        isc_hash_destroy();
  cleanup_db:
        if (dbimp != NULL)
                dns_ecdb_unregister(&dbimp);
  cleanup_mctx:
        if (dns_g_mctx != NULL)
                isc_mem_detach(&dns_g_mctx);
}

isc_result_t
dns_lib_init(void) {
        isc_result_t result;

        /*
         * Since this routine is expected to be used by a normal application,
         * it should be better to return an error, instead of an emergency
         * abort, on any failure.
         */
        result = isc_once_do(&init_once, initialize);
        if (result != ISC_R_SUCCESS)
                return (result);

        if (!initialize_done)
                return (ISC_R_FAILURE);

        LOCK(&reflock);
        references++;
        UNLOCK(&reflock);

        return (ISC_R_SUCCESS);
}

void
dns_lib_shutdown(void) {
        isc_boolean_t cleanup_ok = ISC_FALSE;

        LOCK(&reflock);
        if (--references == 0)
                cleanup_ok = ISC_TRUE;
        UNLOCK(&reflock);

        if (!cleanup_ok)
                return;

        dst_lib_destroy();
        isc_hash_destroy();
        if (dbimp != NULL)
                dns_ecdb_unregister(&dbimp);
        if (dns_g_mctx != NULL)
                isc_mem_detach(&dns_g_mctx);
}

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