* Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")

/* $NetBSD: dns.c,v 1.1.1.2 2012/09/09 16:07:57 christos Exp $ */

/*
* Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
* Copyright (c) 1996-1999 by Internet Software Consortium.
*
* 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 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.
*/

#if defined(LIBC_SCCS) && !defined(lint)
static const char rcsid[] = "Id: dns.c,v 1.5 2006/03/09 23:57:56 marka Exp ";
#endif

/*! \file
* \brief
* dns.c --- this is the top-level accessor function for the dns
*/

#include "port_before.h"

#include <stdlib.h>
#include <string.h>
#include <errno.h>

#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <resolv.h>

#include <resolv.h>

#include <isc/memcluster.h>
#include <irs.h>

#include "port_after.h"

#include "irs_p.h"
#include "hesiod.h"
#include "dns_p.h"

/* forward */

static void dns_close(struct irs_acc *);
static struct __res_state * dns_res_get(struct irs_acc *);
static void dns_res_set(struct irs_acc *, struct __res_state *,
void (*)(void *));

/* public */

struct irs_acc *
irs_dns_acc(const char *options) {
struct irs_acc *acc;
struct dns_p *dns;

UNUSED(options);

if (!(acc = memget(sizeof *acc))) {
errno = ENOMEM;
return (NULL);
}
memset(acc, 0x5e, sizeof *acc);
if (!(dns = memget(sizeof *dns))) {
errno = ENOMEM;
memput(acc, sizeof *acc);
return (NULL);
}
memset(dns, 0x5e, sizeof *dns);
dns->res = NULL;
dns->free_res = NULL;
if (hesiod_init(&dns->hes_ctx) < 0) {
/*
* We allow the dns accessor class to initialize
* despite hesiod failing to initialize correctly,
* since dns host queries don't depend on hesiod.
*/
dns->hes_ctx = NULL;
}
acc->private = dns;
#ifdef WANT_IRS_GR
acc->gr_map = irs_dns_gr;
#else
acc->gr_map = NULL;
#endif
#ifdef WANT_IRS_PW
acc->pw_map = irs_dns_pw;
#else
acc->pw_map = NULL;
#endif
acc->sv_map = irs_dns_sv;
acc->pr_map = irs_dns_pr;
acc->ho_map = irs_dns_ho;
acc->nw_map = irs_dns_nw;
acc->ng_map = irs_nul_ng;
acc->res_get = dns_res_get;
acc->res_set = dns_res_set;
acc->close = dns_close;
return (acc);
}

/* methods */
static struct __res_state *
dns_res_get(struct irs_acc *this) {
struct dns_p *dns = (struct dns_p *)this->private;

if (dns->res == NULL) {
struct __res_state *res;
res = (struct __res_state *)malloc(sizeof *res);
if (res == NULL)
return (NULL);
memset(res, 0, sizeof *res);
dns_res_set(this, res, free);
}

if ((dns->res->options & RES_INIT) == 0U &&
res_ninit(dns->res) < 0)
return (NULL);

return (dns->res);
}

static void
dns_res_set(struct irs_acc *this, struct __res_state *res,
void (*free_res)(void *)) {
struct dns_p *dns = (struct dns_p *)this->private;

if (dns->res && dns->free_res) {
res_nclose(dns->res);
(*dns->free_res)(dns->res);
}
dns->res = res;
dns->free_res = free_res;
}

static void
dns_close(struct irs_acc *this) {
struct dns_p *dns;

dns = (struct dns_p *)this->private;
if (dns->res && dns->free_res)
(*dns->free_res)(dns->res);
if (dns->hes_ctx)
hesiod_end(dns->hes_ctx);
memput(dns, sizeof *dns);
memput(this, sizeof *this);
}