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/*
** Copyright (C) 2006 Olivier DEMBOUR
** $Id: rr.c,v 1.4.4.4 2010/02/11 16:06:37 dembour Exp $
**
**
** 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 2 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, write to the Free Software
** Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <string.h>
#include <stdio.h>
#include "dns.h"
#include "client.h"
#include "requests.h"
#include "rr.h"
#include "debug.h"
t_rr_functions rr_function[] = {
{ "TXT", TYPE_TXT, 0, &rr_decode_next_reply_encode, 0 /* UNUSED */},
{ "KEY", TYPE_KEY, 0, &rr_decode_next_reply_raw, 0 /* UNUSED */},
{0,0,0,0,0}
/*
{ "A", TYPE_A, 0, &rr_decode_next_reply_encode, 0 },
{ "SIG", TYPE_SIG, 0, &rr_decode_next_reply_raw, 0 },
{ "NS", TYPE_NS, 0, 0, 0},
*/
};
t_rr_functions *get_rr_function_by_type(uint16_t type)
{
int i = 0;
while (rr_function[i].type
&& (rr_function[i].type != type))
i++;
return (rr_function[i].type ? &rr_function[i] : 0);
}
t_rr_functions *get_rr_function_by_name(char *name)
{
int i = 0;
while (rr_function[i].name
&& (strcmp(rr_function[i].name, name)))
i++;
return (rr_function[i].name ? &rr_function[i] : 0);
}
struct rr_hdr *jump_next_reply(t_request *req, char *output, int max_len, int idx, uint8_t is_encode)
{
void *ptr;
uint32_t count;
struct rr_hdr *answer;
struct dns_hdr *hdr;
hdr = (struct dns_hdr *) &(req->req_data);
if (!(ptr = jump_end_query(&(req->req_data), GET_16(&hdr->qdcount), req->len)))
{
fprintf(stderr, "invalid reply\n");
return (0);
}
for (count = GET_16(&hdr->ancount); count ; count--)
{
if (idx + 1 > GET_16(&hdr->ancount))
return (0);
if ((answer = jump_qname(ptr, req->len - (int) ((unsigned long) ptr - (unsigned long) hdr))) == 0)
return (0);
if ((GET_16(&answer->rdlength) + (uint16_t)((unsigned long)answer-(unsigned long)hdr)) > req->len)
return (0);
if ( (JUMP_RR_HDR(answer)[0 + is_encode] - idx) == 'A')
return (answer);
ptr = (void *)(JUMP_RR_HDR(answer) + GET_16(&answer->rdlength));
}
return (0);
}
int rr_decode_next_reply_encode(t_request *req, char *output, int max_len, int idx)
{
struct rr_hdr *reply;
char buffer[MAX_EDNS_LEN - DNS_HDR_SIZE - RR_HDR_SIZE];
if (!(reply = jump_next_reply(req, output, max_len, idx, 1)))
return (0);
if (ENCODED_LEN(DECODED_BASE64_SIZE(strlen(JUMP_RR_HDR(reply)))) > max_len)
{
DPRINTF(1,"Packet seems too big, this part is drop");
return (0);
}
dns_simple_decode_strip_dot(JUMP_RR_HDR(reply), buffer, GET_16(&(reply->rdlength)));
DPRINTF(3, "%s base64 data was = %s (reply len = %d)\n", __FUNCTION__, &buffer[1], GET_16(&(reply->rdlength)));
/* jump idx -> &buffer[1] */
return (base64_decode((unsigned char *)output, &buffer[1]));
}
int rr_decode_next_reply_raw(t_request *req, char *output, int max_len, int idx)
{
struct rr_hdr *reply;
char buffer[MAX_EDNS_LEN - DNS_HDR_SIZE - RR_HDR_SIZE];
if (!(reply = jump_next_reply(req, output, max_len, idx, 0)))
return (0);
memset(buffer, 0, sizeof(buffer));
strncpy(buffer, JUMP_RR_HDR(reply), GET_16(&(reply->rdlength)));
DPRINTF(3, "%s base64 data was = %s (reply len = %d)\n", __FUNCTION__, buffer, GET_16(&(reply->rdlength)));
if (DECODED_BASE64_SIZE(strlen(buffer)) > max_len)
return (0);
/* jump idx -> &buffer[1] */
return (base64_decode((unsigned char *)output, &buffer[1]));
}
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