/* Copyright (c) 2004 Michael Bushkov <bushman@rsu.ru> */
/*
* Copyright (c) 1995, 1996, 1997 Kungliga Tekniska Hvgskolan (Royal Institute of Technology, Stockholm, Sweden). All rights reserved.
*
* Redistribution 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 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.
*
* 3. All advertising materials mentioning features or use of this software must display the following acknowledgement: This product includes software developed by the Kungliga Tekniska Hvgskolan and its contributors.
*
* 4. Neither the name of the Institute nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE 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 INSTITUTE 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.
*/
#include "config.h"
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <string.h>
#ifdef HAVE_STRINGS_H
#include <strings.h>
#endif
#include <resolv.h>
#include "resolve.h"
/*static char rcsId[] = "$Id: resolve.c,v 1.1.1.1 2004/05/06 07:26:16 bushman Exp $";*/
#if defined(HAVE_RES_SEARCH) && defined(HAVE_DN_EXPAND)
#define DECL(X) {#X, T_##X}
#include "bsdtss.h"
struct lookupd_stot {
char *name;
int type;
};
#define STOTRET_INIT(number,X) stotret[number].name=#X; stotret[number].type=T_##X;
struct lookupd_stot *
__stot_init()
{
struct lookupd_stot *stotret = malloc(sizeof(struct lookupd_stot) * 8);
STOTRET_INIT(0, A)
STOTRET_INIT(1, NS)
STOTRET_INIT(2, CNAME)
STOTRET_INIT(3, PTR)
STOTRET_INIT(4, MX)
STOTRET_INIT(5, TXT)
STOTRET_INIT(6, AFSDB)
STOTRET_INIT(7, SRV)
stotret[8].name = NULL;
stotret[8].type = 0;
return stotret;
}
DECLARE_TSS_WITH_INIT(stot, struct lookupd_stot *, __stot_init);
#define stot GET_TSS(stot)
void
_resolve_init_tss_keys()
{
INIT_TSS_KEY(stot);
}
/*
* static struct lookupd_stot { char *name; int type; } stot[] = { DECL (A), DECL (NS), DECL (CNAME), DECL (PTR), DECL (MX), DECL (TXT), DECL (AFSDB), DECL (SRV), { NULL, 0} };
*/
static int
string_to_type(const char *name)
{
struct lookupd_stot *p = stot;
for (p = stot; p->name; p++)
if (strcasecmp(name, p->name) == 0)
return p->type;
return -1;
}
#if 0
static char *
type_to_string(int type)
{
struct lookupd_stot *p = stot;
for (p = stot; p->name; p++)
if (type == p->type)
return p->name;
return NULL;
}
#endif
void
dns_free_data(struct dns_reply * r)
{
struct resource_record *rr;
if (r->q.domain)
free(r->q.domain);
for (rr = r->head; rr;) {
struct resource_record *tmp = rr;
if (rr->domain)
free(rr->domain);
if (rr->u.data)
free(rr->u.data);
rr = rr->next;
free(tmp);
}
free(r);
}
static struct dns_reply *
parse_reply(unsigned char *data, int len)
{
unsigned char *p;
char host[128];
int status;
int query, response;
struct dns_reply *r;
struct resource_record **rr;
r = (struct dns_reply *) malloc(sizeof(struct dns_reply));
#ifdef NeXT
bzero(r, sizeof(struct dns_reply));
#else
memset(r, 0, sizeof(struct dns_reply));
#endif
r->q.domain = NULL;
p = data;
#ifdef NeXT
bcopy(p, &r->h, sizeof(HEADER));
#else
memcpy(&r->h, p, sizeof(HEADER));
#endif
p += sizeof(HEADER);
for (query = 0; query < ntohs(r->h.qdcount); query++) {
status = dn_expand(data, data + len, p, host, sizeof(host));
if (status < 0) {
dns_free_data(r);
return NULL;
}
p += status;
if (p + 4 > data + len) {
dns_free_data(r);
return NULL;
}
if (r->q.domain == NULL) {
r->q.domain = strdup(host);
r->q.type = (p[0] << 8 | p[1]);
r->q.class = (p[2] << 8 | p[3]);
}
p += 4;
}
rr = &r->head;
for (response = 0; (response < ntohs(r->h.ancount)) && (p < data + len); response++) {
unsigned int type, class, ttl, size;
status = dn_expand(data, data + len, p, host, sizeof(host));
if (status < 0) {
dns_free_data(r);
return NULL;
}
p += status;
if (p + 10 > data + len) {
dns_free_data(r);
return NULL;
}
type = (p[0] << 8) | p[1];
p += 2;
class = (p[0] << 8) | p[1];
p += 2;
ttl = (p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3];
p += 4;
size = (p[0] << 8) | p[1];
p += 2;
if (p + size > data + len) {
dns_free_data(r);
return NULL;
}
*rr = (struct resource_record *) calloc(1,
sizeof(struct
resource_record));
(*rr)->domain = strdup(host);
(*rr)->type = type;
(*rr)->class = class;
(*rr)->ttl = ttl;
(*rr)->size = size;
switch (type) {
case T_NS:
case T_CNAME:
case T_PTR:
status = dn_expand(data, data + len, p, host, sizeof(host));
if (status < 0) {
dns_free_data(r);
return NULL;
}
(*rr)->u.txt = strdup(host);
break;
case T_MX:
case T_AFSDB:
{
if (p + 2 > data + len) {
dns_free_data(r);
return NULL;
}
status = dn_expand(data, data + len, p + 2, host, sizeof(host));
if (status < 0) {
dns_free_data(r);
return NULL;
}
(*rr)->u.mx =
(struct mx_record *) malloc(sizeof(struct mx_record) +
strlen(host));
(*rr)->u.mx->preference = (p[0] << 8) | p[1];
strcpy((*rr)->u.mx->domain, host);
break;
}
case T_SRV:
{
if (p + 6 > data + len) {
dns_free_data(r);
return NULL;
}
status = dn_expand(data, data + len, p + 6, host, sizeof(host));
if (status < 0) {
dns_free_data(r);
return NULL;
}
(*rr)->u.srv =
(struct srv_record *) malloc(sizeof(struct srv_record) +
strlen(host));
(*rr)->u.srv->priority = (p[0] << 8) | p[1];
(*rr)->u.srv->weight = (p[2] << 8) | p[3];
(*rr)->u.srv->port = (p[4] << 8) | p[5];
strcpy((*rr)->u.srv->target, host);
break;
}
case T_TXT:
{
if (p + *p > data + len) {
dns_free_data(r);
return NULL;
}
(*rr)->u.txt = (char *)malloc(size + 1);
strncpy((*rr)->u.txt, (char *)p + 1, *p);
(*rr)->u.txt[*p] = 0;
break;
}
default:
(*rr)->u.data = (unsigned char *)malloc(size);
#ifdef NeXT
bcopy(p, (*rr)->u.data, size);
#else
memcpy((*rr)->u.data, p, size);
#endif
}
p += size;
rr = &(*rr)->next;
}
*rr = NULL;
return r;
}
struct dns_reply *
dns_lookup(const char *domain, const char *type_name)
{
unsigned char *reply = NULL;
int len, rlen;
int type;
struct dns_reply *r = NULL;
type = string_to_type(type_name);
rlen = 1024;
reply = malloc(rlen);
do {
len = res_search(domain, C_IN, type, reply, rlen);
if ((len == -1) || (len < rlen)) {
break;
}
reply = realloc(reply, len + 1024);
rlen = len + 1024;
}
while (1);
if (len >= 0)
r = parse_reply(reply, len);
free(reply);
return r;
}
#else /* defined(HAVE_RES_SEARCH) && defined(HAVE_DN_EXPAND) */
struct dns_reply *
dns_lookup(const char *domain, const char *type_name)
{
return NULL;
}
void
dns_free_data(struct dns_reply * r)
{
}
#endif
#ifdef TEST
int
main(int argc, char **argv)
{
struct dns_reply *r;
struct resource_record *rr;
r = dns_lookup(argv[1], argv[2]);
if (r == NULL) {
printf("No reply.\n");
return 1;
}
for (rr = r->head; rr; rr = rr->next) {
printf("%s %s %d ", rr->domain, type_to_string(rr->type), rr->ttl);
switch (rr->type) {
case T_NS:
printf("%s\n", (char *)rr->data);
break;
case T_A:
printf("%d.%d.%d.%d\n",
((unsigned char *)rr->data)[0],
((unsigned char *)rr->data)[1],
((unsigned char *)rr->data)[2],
((unsigned char *)rr->data)[3]);
break;
case T_MX:
case T_AFSDB:
{
struct mx_record *mx = (struct mx_record *) rr->data;
printf("%d %s\n", mx->preference, mx->domain);
break;
}
case T_SRV:
{
struct srv_record *srv = (struct srv_record *) rr->data;
printf("%d %d %d %s\n", srv->priority, srv->weight,
srv->port, srv->target);
break;
}
default:
printf("\n");
break;
}
}
return 0;
}
#endif
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