diff options
Diffstat (limited to 'nameserv.c')
| -rw-r--r-- | nameserv.c | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/nameserv.c b/nameserv.c new file mode 100644 index 0000000..c87aef0 --- /dev/null +++ b/nameserv.c @@ -0,0 +1,211 @@ +/* + 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(); +} + +/* ================================================== */ + |