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/* $Id$ */
/* Copyright 2005 Dominick Meglio
*
* Permission to use, copy, modify, and distribute this
* software and its documentation for any purpose and without
* fee is hereby granted, provided that the above copyright
* notice appear in all copies and that both that copyright
* notice and this permission notice appear in supporting
* documentation, and that the name of M.I.T. not be used in
* advertising or publicity pertaining to distribution of the
* software without specific, written prior permission.
* M.I.T. makes no representations about the suitability of
* this software for any purpose. It is provided "as is"
* without express or implied warranty.
*/
#include "setup.h"
#if defined(WIN32) && !defined(WATT32)
#include "nameser.h"
#else
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#ifdef HAVE_ARPA_NAMESER_H
#include <arpa/nameser.h>
#endif
#ifdef HAVE_ARPA_NAMESER_COMPAT_H
#include <arpa/nameser_compat.h>
#endif
#endif
#include <stdlib.h>
#include <string.h>
#include "ares.h"
#include "ares_dns.h"
#include "inet_net_pton.h"
#include "ares_private.h"
int ares_parse_aaaa_reply(const unsigned char *abuf, int alen,
struct hostent **host)
{
unsigned int qdcount, ancount;
int status, i, rr_type, rr_class, rr_len, naddrs;
int naliases;
long len;
const unsigned char *aptr;
char *hostname, *rr_name, *rr_data, **aliases;
struct in6_addr *addrs;
struct hostent *hostent;
/* Set *host to NULL for all failure cases. */
*host = NULL;
/* Give up if abuf doesn't have room for a header. */
if (alen < HFIXEDSZ)
return ARES_EBADRESP;
/* Fetch the question and answer count from the header. */
qdcount = DNS_HEADER_QDCOUNT(abuf);
ancount = DNS_HEADER_ANCOUNT(abuf);
if (qdcount != 1)
return ARES_EBADRESP;
/* Expand the name from the question, and skip past the question. */
aptr = abuf + HFIXEDSZ;
status = ares_expand_name(aptr, abuf, alen, &hostname, &len);
if (status != ARES_SUCCESS)
return status;
if (aptr + len + QFIXEDSZ > abuf + alen)
{
free(hostname);
return ARES_EBADRESP;
}
aptr += len + QFIXEDSZ;
/* Allocate addresses and aliases; ancount gives an upper bound for both. */
addrs = malloc(ancount * sizeof(struct in6_addr));
if (!addrs)
{
free(hostname);
return ARES_ENOMEM;
}
aliases = malloc((ancount + 1) * sizeof(char *));
if (!aliases)
{
free(hostname);
free(addrs);
return ARES_ENOMEM;
}
naddrs = 0;
naliases = 0;
/* Examine each answer resource record (RR) in turn. */
for (i = 0; i < (int)ancount; i++)
{
/* Decode the RR up to the data field. */
status = ares_expand_name(aptr, abuf, alen, &rr_name, &len);
if (status != ARES_SUCCESS)
break;
aptr += len;
if (aptr + RRFIXEDSZ > abuf + alen)
{
status = ARES_EBADRESP;
break;
}
rr_type = DNS_RR_TYPE(aptr);
rr_class = DNS_RR_CLASS(aptr);
rr_len = DNS_RR_LEN(aptr);
aptr += RRFIXEDSZ;
if (rr_class == C_IN && rr_type == T_AAAA
&& rr_len == sizeof(struct in6_addr)
&& strcasecmp(rr_name, hostname) == 0)
{
memcpy(&addrs[naddrs], aptr, sizeof(struct in6_addr));
naddrs++;
status = ARES_SUCCESS;
}
if (rr_class == C_IN && rr_type == T_CNAME)
{
/* Record the RR name as an alias. */
aliases[naliases] = rr_name;
naliases++;
/* Decode the RR data and replace the hostname with it. */
status = ares_expand_name(aptr, abuf, alen, &rr_data, &len);
if (status != ARES_SUCCESS)
break;
free(hostname);
hostname = rr_data;
}
else
free(rr_name);
aptr += rr_len;
if (aptr > abuf + alen)
{
status = ARES_EBADRESP;
break;
}
}
if (status == ARES_SUCCESS && naddrs == 0)
status = ARES_ENODATA;
if (status == ARES_SUCCESS)
{
/* We got our answer. Allocate memory to build the host entry. */
aliases[naliases] = NULL;
hostent = malloc(sizeof(struct hostent));
if (hostent)
{
hostent->h_addr_list = malloc((naddrs + 1) * sizeof(char *));
if (hostent->h_addr_list)
{
/* Fill in the hostent and return successfully. */
hostent->h_name = hostname;
hostent->h_aliases = aliases;
hostent->h_addrtype = AF_INET6;
hostent->h_length = sizeof(struct in6_addr);
for (i = 0; i < naddrs; i++)
hostent->h_addr_list[i] = (char *) &addrs[i];
hostent->h_addr_list[naddrs] = NULL;
*host = hostent;
return ARES_SUCCESS;
}
free(hostent);
}
status = ARES_ENOMEM;
}
for (i = 0; i < naliases; i++)
free(aliases[i]);
free(aliases);
free(addrs);
free(hostname);
return status;
}
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