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Diffstat (limited to '')
| -rw-r--r-- | nameserv.c | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/nameserv.c b/nameserv.c new file mode 100644 index 0000000..9f7e648 --- /dev/null +++ b/nameserv.c @@ -0,0 +1,166 @@ +/* + 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) +{ + struct addrinfo hints, *res, *ai; + int i, result; + IPAddr ip; + + max_addrs = MIN(max_addrs, DNS_MAX_ADDRESSES); + + for (i = 0; i < max_addrs; i++) + ip_addrs[i].family = IPADDR_UNSPEC; + + /* Avoid calling getaddrinfo() if the name is an IP address */ + if (UTI_StringToIP(name, &ip)) { + if (address_family != IPADDR_UNSPEC && ip.family != address_family) + return DNS_Failure; + if (max_addrs >= 1) + ip_addrs[0] = ip; + return DNS_Success; + } + + 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 + } + } + + freeaddrinfo(res); + + return !max_addrs || ip_addrs[0].family != IPADDR_UNSPEC ? DNS_Success : DNS_Failure; +} + +/* ================================================== */ + +int +DNS_IPAddress2Name(IPAddr *ip_addr, char *name, int len) +{ + char *result = NULL; +#ifdef FEAT_IPV6 + struct sockaddr_in6 saddr; +#else + struct sockaddr_in saddr; +#endif + 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 *)&saddr, sizeof (saddr)); + if (!getnameinfo((struct sockaddr *)&saddr, slen, hbuf, sizeof (hbuf), NULL, 0, 0)) + result = hbuf; + + 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(); +} + +/* ================================================== */ + |