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/*
* Copyright (c) 1995 - 2000 Kungliga Tekniska Högskolan
* (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. 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.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include "roken.h"
#ifdef HAVE_ARPA_NAMESER_H
#include <arpa/nameser.h>
#endif
#ifdef HAVE_RESOLV_H
#include <resolv.h>
#endif
#include "resolve.h"
RCSID("$Id: resolve.c,v 1.26 2000/06/27 01:15:53 assar Exp $");
#if defined(HAVE_RES_SEARCH) && defined(HAVE_DN_EXPAND)
#define DECL(X) {#X, T_##X}
static struct stot{
const char *name;
int type;
}stot[] = {
DECL(A),
DECL(NS),
DECL(CNAME),
DECL(SOA),
DECL(PTR),
DECL(MX),
DECL(TXT),
DECL(AFSDB),
DECL(SIG),
DECL(KEY),
DECL(SRV),
DECL(NAPTR),
{NULL, 0}
};
int _resolve_debug = 0;
int
dns_string_to_type(const char *name)
{
struct stot *p = stot;
for(p = stot; p->name; p++)
if(strcasecmp(name, p->name) == 0)
return p->type;
return -1;
}
const char *
dns_type_to_string(int type)
{
struct stot *p = stot;
for(p = stot; p->name; p++)
if(type == p->type)
return p->name;
return NULL;
}
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;
struct dns_reply *r;
struct resource_record **rr;
r = calloc(1, sizeof(*r));
if (r == NULL)
return NULL;
p = data;
#if 0
/* doesn't work on Crays */
memcpy(&r->h, p, sizeof(HEADER));
p += sizeof(HEADER);
#else
memcpy(&r->h, p, 12); /* XXX this will probably be mostly garbage */
p += 12;
#endif
status = dn_expand(data, data + len, p, host, sizeof(host));
if(status < 0){
dns_free_data(r);
return NULL;
}
r->q.domain = strdup(host);
if(r->q.domain == NULL) {
dns_free_data(r);
return NULL;
}
p += status;
r->q.type = (p[0] << 8 | p[1]);
p += 2;
r->q.class = (p[0] << 8 | p[1]);
p += 2;
rr = &r->head;
while(p < data + len){
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;
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;
*rr = (struct resource_record*)calloc(1,
sizeof(struct resource_record));
if(*rr == NULL) {
dns_free_data(r);
return NULL;
}
(*rr)->domain = strdup(host);
if((*rr)->domain == NULL) {
dns_free_data(r);
return NULL;
}
(*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);
if((*rr)->u.txt == NULL) {
dns_free_data(r);
return NULL;
}
break;
case T_MX:
case T_AFSDB:{
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));
if((*rr)->u.mx == NULL) {
dns_free_data(r);
return NULL;
}
(*rr)->u.mx->preference = (p[0] << 8) | p[1];
strcpy((*rr)->u.mx->domain, host);
break;
}
case T_SRV:{
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));
if((*rr)->u.srv == NULL) {
dns_free_data(r);
return NULL;
}
(*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:{
(*rr)->u.txt = (char*)malloc(size + 1);
if((*rr)->u.txt == NULL) {
dns_free_data(r);
return NULL;
}
strncpy((*rr)->u.txt, (char*)p + 1, *p);
(*rr)->u.txt[*p] = 0;
break;
}
case T_KEY : {
size_t key_len;
key_len = size - 4;
(*rr)->u.key = malloc (sizeof(*(*rr)->u.key) + key_len - 1);
if ((*rr)->u.key == NULL) {
dns_free_data (r);
return NULL;
}
(*rr)->u.key->flags = (p[0] << 8) | p[1];
(*rr)->u.key->protocol = p[2];
(*rr)->u.key->algorithm = p[3];
(*rr)->u.key->key_len = key_len;
memcpy ((*rr)->u.key->key_data, p + 4, key_len);
break;
}
case T_SIG : {
size_t sig_len;
status = dn_expand (data, data + len, p + 18, host, sizeof(host));
if (status < 0) {
dns_free_data (r);
return NULL;
}
sig_len = len - 18 - status;
(*rr)->u.sig = malloc(sizeof(*(*rr)->u.sig)
+ strlen(host) + sig_len);
if ((*rr)->u.sig == NULL) {
dns_free_data (r);
return NULL;
}
(*rr)->u.sig->type = (p[0] << 8) | p[1];
(*rr)->u.sig->algorithm = p[2];
(*rr)->u.sig->labels = p[3];
(*rr)->u.sig->orig_ttl = (p[4] << 24) | (p[5] << 16)
| (p[6] << 8) | p[7];
(*rr)->u.sig->sig_expiration = (p[8] << 24) | (p[9] << 16)
| (p[10] << 8) | p[11];
(*rr)->u.sig->sig_inception = (p[12] << 24) | (p[13] << 16)
| (p[14] << 8) | p[15];
(*rr)->u.sig->key_tag = (p[16] << 8) | p[17];
(*rr)->u.sig->sig_len = sig_len;
memcpy ((*rr)->u.sig->sig_data, p + 18 + status, sig_len);
(*rr)->u.sig->signer = &(*rr)->u.sig->sig_data[sig_len];
strcpy((*rr)->u.sig->signer, host);
break;
}
case T_CERT : {
size_t cert_len;
cert_len = size - 5;
(*rr)->u.cert = malloc (sizeof(*(*rr)->u.cert) + cert_len - 1);
if ((*rr)->u.cert == NULL) {
dns_free_data (r);
return NULL;
}
(*rr)->u.cert->type = (p[0] << 8) | p[1];
(*rr)->u.cert->tag = (p[2] << 8) | p[3];
(*rr)->u.cert->algorithm = p[4];
(*rr)->u.cert->cert_len = cert_len;
memcpy ((*rr)->u.cert->cert_data, p + 5, cert_len);
break;
}
default:
(*rr)->u.data = (unsigned char*)malloc(size);
if(size != 0 && (*rr)->u.data == NULL) {
dns_free_data(r);
return NULL;
}
memcpy((*rr)->u.data, p, size);
}
p += size;
rr = &(*rr)->next;
}
*rr = NULL;
return r;
}
static struct dns_reply *
dns_lookup_int(const char *domain, int rr_class, int rr_type)
{
unsigned char reply[1024];
int len;
struct dns_reply *r = NULL;
u_long old_options = 0;
if (_resolve_debug) {
old_options = _res.options;
_res.options |= RES_DEBUG;
fprintf(stderr, "dns_lookup(%s, %d, %s)\n", domain,
rr_class, dns_type_to_string(rr_type));
}
len = res_search(domain, rr_class, rr_type, reply, sizeof(reply));
if (_resolve_debug) {
_res.options = old_options;
fprintf(stderr, "dns_lookup(%s, %d, %s) --> %d\n",
domain, rr_class, dns_type_to_string(rr_type), len);
}
if (len >= 0)
r = parse_reply(reply, len);
return r;
}
struct dns_reply *
dns_lookup(const char *domain, const char *type_name)
{
int type;
type = dns_string_to_type(type_name);
if(type == -1) {
if(_resolve_debug)
fprintf(stderr, "dns_lookup: unknown resource type: `%s'\n",
type_name);
return NULL;
}
return dns_lookup_int(domain, C_IN, type);
}
#else /* NOT 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, dns_type_to_string(rr->type), rr->ttl);
switch(rr->type){
case T_NS:
case T_CNAME:
case T_PTR:
printf("%s\n", (char*)rr->u.data);
break;
case T_A:
printf("%s\n", inet_ntoa(*rr->u.a));
break;
case T_MX:
case T_AFSDB:{
printf("%d %s\n", rr->u.mx->preference, rr->u.mx->domain);
break;
}
case T_SRV:{
struct srv_record *srv = rr->u.srv;
printf("%d %d %d %s\n", srv->priority, srv->weight,
srv->port, srv->target);
break;
}
case T_TXT: {
printf("%s\n", rr->u.txt);
break;
}
case T_SIG : {
struct sig_record *sig = rr->u.sig;
const char *type_string = dns_type_to_string (sig->type);
printf ("type %u (%s), algorithm %u, labels %u, orig_ttl %u, sig_expiration %u, sig_inception %u, key_tag %u, signer %s\n",
sig->type, type_string ? type_string : "",
sig->algorithm, sig->labels, sig->orig_ttl,
sig->sig_expiration, sig->sig_inception, sig->key_tag,
sig->signer);
break;
}
case T_KEY : {
struct key_record *key = rr->u.key;
printf ("flags %u, protocol %u, algorithm %u\n",
key->flags, key->protocol, key->algorithm);
break;
}
default:
printf("\n");
break;
}
}
return 0;
}
#endif
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