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/* libanode: the Anode C reference implementation
* Copyright (C) 2009-2010 Adam Ierymenko <adam.ierymenko@gmail.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <resolv.h>
#include <netdb.h>
#include "dns_txt.h"
#ifndef C_IN
#define C_IN ns_c_in
#endif
#ifndef T_TXT
#define T_TXT ns_t_txt
#endif
static volatile int Anode_resolver_initialized = 0;
int Anode_sync_resolve_txt(const char *host,char *txt,unsigned int txt_len)
{
unsigned char answer[16384],*pptr,*end;
char name[16384];
int len,explen,i;
if (!Anode_resolver_initialized) {
Anode_resolver_initialized = 1;
res_init();
}
/* Do not taunt happy fun ball. */
len = res_search(host,C_IN,T_TXT,answer,sizeof(answer));
if (len > 12) {
pptr = answer + 12;
end = answer + len;
explen = dn_expand(answer,end,pptr,name,sizeof(name));
if (explen > 0) {
pptr += explen;
if ((pptr + 2) >= end) return 2;
if (ntohs(*((uint16_t *)pptr)) == T_TXT) {
pptr += 4;
if (pptr >= end) return 2;
explen = dn_expand(answer,end,pptr,name,sizeof(name));
if (explen > 0) {
pptr += explen;
if ((pptr + 2) >= end) return 2;
if (ntohs(*((uint16_t *)pptr)) == T_TXT) {
pptr += 10;
if (pptr >= end) return 2;
len = *(pptr++);
if (len <= 0) return 2;
if ((pptr + len) > end) return 2;
if (txt_len < (len + 1))
return 4;
else {
for(i=0;i<len;++i)
txt[i] = pptr[i];
txt[len] = (char)0;
return 0;
}
}
}
}
}
}
return 1;
}
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