/* vim:ts=8:sts=8:sw=4:noai:noexpandtab
*
* portable function to return the nodes IP address.
*
* Copyright (c) 2006-2010 Miru Limited.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <errno.h>
#ifndef _WIN32
# include <netdb.h>
#endif
#include <impl/i18n.h>
#include <impl/framework.h>
//#define GETNODEADDR_DEBUG
/* globals */
static const char* pgm_family_string (const sa_family_t);
/* return node primary address on multi-address family interfaces.
*
* returns TRUE on success, returns FALSE on failure.
*/
bool
pgm_if_getnodeaddr (
const sa_family_t family, /* requested address family, AF_INET, AF_INET6, or AF_UNSPEC */
struct sockaddr* restrict addr,
const socklen_t cnt, /* size of address pointed to by addr */
pgm_error_t** restrict error
)
{
pgm_return_val_if_fail (AF_INET == family || AF_INET6 == family || AF_UNSPEC == family, FALSE);
pgm_return_val_if_fail (NULL != addr, FALSE);
if (AF_INET == family || AF_UNSPEC == family)
pgm_return_val_if_fail (cnt >= sizeof(struct sockaddr_in), FALSE);
else
pgm_return_val_if_fail (cnt >= sizeof(struct sockaddr_in6), FALSE);
pgm_debug ("pgm_if_getnodeaddr (family:%s addr:%p cnt:%d error:%p)",
pgm_family_string (family), (const void*)addr, cnt, (const void*)error);
char hostname[NI_MAXHOST + 1];
struct hostent* he;
if (0 != gethostname (hostname, sizeof(hostname))) {
pgm_set_error (error,
PGM_ERROR_DOMAIN_IF,
pgm_error_from_errno (errno),
_("Resolving hostname: %s"),
#ifndef _WIN32
strerror (errno)
#else
pgm_wsastrerror (WSAGetLastError())
#endif
);
return FALSE;
}
addr->sa_family = family;
struct addrinfo hints = {
.ai_family = family,
.ai_socktype = SOCK_STREAM, /* not really */
.ai_protocol = IPPROTO_TCP, /* not really */
.ai_flags = AI_ADDRCONFIG,
}, *res;
int e = getaddrinfo (hostname, NULL, &hints, &res);
if (0 == e) {
const socklen_t addrlen = res->ai_addrlen;
memcpy (addr, res->ai_addr, addrlen);
freeaddrinfo (res);
return TRUE;
} else if (EAI_NONAME != e) {
pgm_set_error (error,
PGM_ERROR_DOMAIN_IF,
pgm_error_from_eai_errno (e, errno),
_("Resolving hostname address: %s"),
gai_strerror (e));
return FALSE;
} else if (AF_UNSPEC == family) {
pgm_set_error (error,
PGM_ERROR_DOMAIN_IF,
PGM_ERROR_NONAME,
_("Resolving hostname address family."));
return FALSE;
}
/* Common case a dual stack host has incorrect IPv6 configuration, i.e.
* hostname is only IPv4 and despite one or more IPv6 addresses. Workaround
* for this case is to resolve the IPv4 hostname, find the matching interface
* and from that interface find an active IPv6 address taking global scope as
* preference over link scoped addresses.
*/
he = gethostbyname (hostname);
if (NULL == he) {
pgm_set_error (error,
PGM_ERROR_DOMAIN_IF,
pgm_error_from_h_errno (h_errno),
#ifndef _WIN32
_("Resolving IPv4 hostname address: %s"),
hstrerror (h_errno)
#else
_("Resolving IPv4 hostname address: %s"),
pgm_wsastrerror (WSAGetLastError())
#endif
);
return FALSE;
}
struct pgm_ifaddrs_t *ifap, *ifa, *ifa6;
if (!pgm_getifaddrs (&ifap, error)) {
pgm_prefix_error (error,
_("Enumerating network interfaces: "));
return FALSE;
}
/* hunt for IPv4 interface */
for (ifa = ifap; ifa; ifa = ifa->ifa_next)
{
if (NULL == ifa->ifa_addr ||
AF_INET != ifa->ifa_addr->sa_family)
continue;
if (((struct sockaddr_in *)ifa->ifa_addr)->sin_addr.s_addr == ((struct in_addr*)(he->h_addr_list[0]))->s_addr)
{
goto ipv4_found;
}
}
pgm_freeifaddrs (ifap);
pgm_set_error (error,
PGM_ERROR_DOMAIN_IF,
PGM_ERROR_NONET,
_("Discovering primary IPv4 network interface."));
return FALSE;
ipv4_found:
/* hunt for IPv6 interface */
for (ifa6 = ifap; ifa6; ifa6 = ifa6->ifa_next)
{
if (AF_INET6 != ifa6->ifa_addr->sa_family)
continue;
if (0 == strcmp (ifa->ifa_name, ifa6->ifa_name))
{
goto ipv6_found;
}
}
pgm_freeifaddrs (ifap);
pgm_set_error (error,
PGM_ERROR_DOMAIN_IF,
PGM_ERROR_NONET,
_("Discovering primary IPv6 network interface."));
return FALSE;
ipv6_found:
memcpy (addr, ifa6->ifa_addr, pgm_sockaddr_len (ifa6->ifa_addr));
pgm_freeifaddrs (ifap);
return TRUE;
}
static
const char*
pgm_family_string (
const sa_family_t family
)
{
const char* c;
switch (family) {
case AF_UNSPEC: c = "AF_UNSPEC"; break;
case AF_INET: c = "AF_INET"; break;
case AF_INET6: c = "AF_INET6"; break;
default: c = "(unknown)"; break;
}
return c;
}
/* eof */
