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/* Copyright 1998 by the Massachusetts Institute of Technology.
* Copyright (C) 2019 by Andrew Selivanov
*
* 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 "ares_setup.h"
#ifdef HAVE_NETINET_IN_H
# include <netinet/in.h>
#endif
#ifdef HAVE_NETDB_H
# include <netdb.h>
#endif
#ifdef HAVE_ARPA_INET_H
# include <arpa/inet.h>
#endif
#ifdef HAVE_ARPA_NAMESER_H
# include <arpa/nameser.h>
#else
# include "nameser.h"
#endif
#ifdef HAVE_ARPA_NAMESER_COMPAT_H
# include <arpa/nameser_compat.h>
#endif
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif
#ifdef HAVE_LIMITS_H
# include <limits.h>
#endif
#include "ares.h"
#include "ares_dns.h"
#include "ares_private.h"
int ares_parse_a_reply(const unsigned char *abuf, int alen,
struct hostent **host,
struct ares_addrttl *addrttls, int *naddrttls)
{
struct ares_addrinfo ai;
struct ares_addrinfo_node *next;
struct ares_addrinfo_cname *next_cname;
char **aliases = NULL;
char *question_hostname = NULL;
struct hostent *hostent = NULL;
struct in_addr *addrs = NULL;
int naliases = 0, naddrs = 0, alias = 0, i;
int cname_ttl = INT_MAX;
int status;
memset(&ai, 0, sizeof(ai));
status = ares__parse_into_addrinfo2(abuf, alen, &question_hostname, &ai);
if (status != ARES_SUCCESS)
{
ares_free(question_hostname);
if (naddrttls)
{
*naddrttls = 0;
}
return status;
}
hostent = ares_malloc(sizeof(struct hostent));
if (!hostent)
{
goto enomem;
}
next = ai.nodes;
while (next)
{
if (next->ai_family == AF_INET)
{
++naddrs;
}
next = next->ai_next;
}
next_cname = ai.cnames;
while (next_cname)
{
if(next_cname->alias)
++naliases;
next_cname = next_cname->next;
}
aliases = ares_malloc((naliases + 1) * sizeof(char *));
if (!aliases)
{
goto enomem;
}
if (naliases)
{
next_cname = ai.cnames;
while (next_cname)
{
if(next_cname->alias)
aliases[alias++] = strdup(next_cname->alias);
if(next_cname->ttl < cname_ttl)
cname_ttl = next_cname->ttl;
next_cname = next_cname->next;
}
}
aliases[alias] = NULL;
hostent->h_addr_list = ares_malloc((naddrs + 1) * sizeof(char *));
if (!hostent->h_addr_list)
{
goto enomem;
}
for (i = 0; i < naddrs + 1; ++i)
{
hostent->h_addr_list[i] = NULL;
}
if (ai.cnames)
{
hostent->h_name = strdup(ai.cnames->name);
ares_free(question_hostname);
}
else
{
hostent->h_name = question_hostname;
}
hostent->h_aliases = aliases;
hostent->h_addrtype = AF_INET;
hostent->h_length = sizeof(struct in_addr);
if (naddrs)
{
addrs = ares_malloc(naddrs * sizeof(struct in_addr));
if (!addrs)
{
goto enomem;
}
i = 0;
next = ai.nodes;
while (next)
{
if (next->ai_family == AF_INET)
{
hostent->h_addr_list[i] = (char *)&addrs[i];
memcpy(hostent->h_addr_list[i],
&(CARES_INADDR_CAST(struct sockaddr_in *, next->ai_addr)->sin_addr),
sizeof(struct in_addr));
if (naddrttls && i < *naddrttls)
{
if (next->ai_ttl > cname_ttl)
addrttls[i].ttl = cname_ttl;
else
addrttls[i].ttl = next->ai_ttl;
memcpy(&addrttls[i].ipaddr,
&(CARES_INADDR_CAST(struct sockaddr_in *, next->ai_addr)->sin_addr),
sizeof(struct in_addr));
}
++i;
}
next = next->ai_next;
}
if (i == 0)
{
ares_free(addrs);
}
}
if (host)
{
*host = hostent;
}
else
{
ares_free_hostent(hostent);
}
if (naddrttls)
{
/* Truncated to at most *naddrttls entries */
*naddrttls = (naddrs > *naddrttls)?*naddrttls:naddrs;
}
ares__freeaddrinfo_cnames(ai.cnames);
ares__freeaddrinfo_nodes(ai.nodes);
return ARES_SUCCESS;
enomem:
ares_free(aliases);
ares_free(hostent);
ares__freeaddrinfo_cnames(ai.cnames);
ares__freeaddrinfo_nodes(ai.nodes);
ares_free(question_hostname);
return ARES_ENOMEM;
}
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