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/*
chronyd/chronyc - Programs for keeping computer clocks accurate.
**********************************************************************
* Copyright (C) Richard P. Curnow 1997-2003
* Copyright (C) Miroslav Lichvar 2009-2011
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2 of the GNU General Public License as
* published by the Free Software Foundation.
*
* 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.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
**********************************************************************
=======================================================================
Functions to do name to IP address conversion
*/
#include "config.h"
#include "sysincl.h"
#include <netdb.h>
#include <resolv.h>
#include "nameserv.h"
#include "socket.h"
#include "util.h"
/* ================================================== */
static int address_family = IPADDR_UNSPEC;
void
DNS_SetAddressFamily(int family)
{
address_family = family;
}
DNS_Status
DNS_Name2IPAddress(const char *name, IPAddr *ip_addrs, int max_addrs)
{
#ifdef HAVE_GETADDRINFO
struct addrinfo hints, *res, *ai;
int i, result;
max_addrs = MIN(max_addrs, DNS_MAX_ADDRESSES);
memset(&hints, 0, sizeof (hints));
switch (address_family) {
case IPADDR_INET4:
hints.ai_family = AF_INET;
break;
#ifdef FEAT_IPV6
case IPADDR_INET6:
hints.ai_family = AF_INET6;
break;
#endif
default:
hints.ai_family = AF_UNSPEC;
}
hints.ai_socktype = SOCK_DGRAM;
result = getaddrinfo(name, NULL, &hints, &res);
if (result) {
#ifdef FORCE_DNSRETRY
return DNS_TryAgain;
#else
return result == EAI_AGAIN ? DNS_TryAgain : DNS_Failure;
#endif
}
for (ai = res, i = 0; i < max_addrs && ai != NULL; ai = ai->ai_next) {
switch (ai->ai_family) {
case AF_INET:
if (address_family != IPADDR_UNSPEC && address_family != IPADDR_INET4)
continue;
ip_addrs[i].family = IPADDR_INET4;
ip_addrs[i].addr.in4 = ntohl(((struct sockaddr_in *)ai->ai_addr)->sin_addr.s_addr);
i++;
break;
#ifdef FEAT_IPV6
case AF_INET6:
if (address_family != IPADDR_UNSPEC && address_family != IPADDR_INET6)
continue;
/* Don't return an address that would lose a scope ID */
if (((struct sockaddr_in6 *)ai->ai_addr)->sin6_scope_id != 0)
continue;
ip_addrs[i].family = IPADDR_INET6;
memcpy(&ip_addrs[i].addr.in6, &((struct sockaddr_in6 *)ai->ai_addr)->sin6_addr.s6_addr,
sizeof (ip_addrs->addr.in6));
i++;
break;
#endif
}
}
for (; i < max_addrs; i++)
ip_addrs[i].family = IPADDR_UNSPEC;
freeaddrinfo(res);
return !max_addrs || ip_addrs[0].family != IPADDR_UNSPEC ? DNS_Success : DNS_Failure;
#else
struct hostent *host;
int i;
if (address_family != IPADDR_UNSPEC && address_family != IPADDR_INET4)
return DNS_Failure;
max_addrs = MIN(max_addrs, DNS_MAX_ADDRESSES);
host = gethostbyname(name);
if (host == NULL) {
if (h_errno == TRY_AGAIN)
return DNS_TryAgain;
} else {
if (host->h_addrtype != AF_INET || !host->h_addr_list[0])
return DNS_Failure;
for (i = 0; host->h_addr_list[i] && i < max_addrs; i++) {
ip_addrs[i].family = IPADDR_INET4;
ip_addrs[i].addr.in4 = ntohl(*(uint32_t *)host->h_addr_list[i]);
}
for (; i < max_addrs; i++)
ip_addrs[i].family = IPADDR_UNSPEC;
return DNS_Success;
}
#ifdef FORCE_DNSRETRY
return DNS_TryAgain;
#else
return DNS_Failure;
#endif
#endif
}
/* ================================================== */
int
DNS_IPAddress2Name(IPAddr *ip_addr, char *name, int len)
{
char *result = NULL;
#ifdef FEAT_IPV6
struct sockaddr_in6 in6;
IPSockAddr ip_saddr;
socklen_t slen;
char hbuf[NI_MAXHOST];
ip_saddr.ip_addr = *ip_addr;
ip_saddr.port = 0;
slen = SCK_IPSockAddrToSockaddr(&ip_saddr, (struct sockaddr *)&in6, sizeof (in6));
if (!getnameinfo((struct sockaddr *)&in6, slen, hbuf, sizeof (hbuf), NULL, 0, 0))
result = hbuf;
#else
struct hostent *host;
uint32_t addr;
switch (ip_addr->family) {
case IPADDR_INET4:
addr = htonl(ip_addr->addr.in4);
host = gethostbyaddr((const char *) &addr, sizeof (ip_addr), AF_INET);
break;
#ifdef FEAT_IPV6
case IPADDR_INET6:
host = gethostbyaddr((const void *) ip_addr->addr.in6, sizeof (ip_addr->addr.in6), AF_INET6);
break;
#endif
default:
host = NULL;
}
if (host)
result = host->h_name;
#endif
if (result == NULL)
result = UTI_IPToString(ip_addr);
if (snprintf(name, len, "%s", result) >= len)
return 0;
return 1;
}
/* ================================================== */
void
DNS_Reload(void)
{
res_init();
}
/* ================================================== */
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