/*
* resolving DNS hostname routine
*
* Copyright (C) 2010 Jeff Layton (jlayton@samba.org)
* Copyright (C) 2010 Igor Druzhinin (jaxbrigs@gmail.com)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* 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, see .
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif /* HAVE_CONFIG_H */
#include
#include
#include
#include
#include
#include "mount.h"
#include "util.h"
#include "resolve_host.h"
/*
* resolve hostname to comma-separated list of address(es)
*/
int resolve_host(const char *host, char *addrstr)
{
int rc;
/* 10 for max width of decimal scopeid */
char tmpbuf[NI_MAXHOST + 1 + 10 + 1];
const char *ipaddr;
size_t len;
struct addrinfo *addrlist, *addr;
struct sockaddr_in *sin;
struct sockaddr_in6 *sin6;
rc = getaddrinfo(host, NULL, NULL, &addrlist);
if (rc != 0)
return EX_USAGE;
addr = addrlist;
while (addr) {
/* skip non-TCP entries */
if (addr->ai_socktype != SOCK_STREAM ||
addr->ai_protocol != IPPROTO_TCP) {
addr = addr->ai_next;
continue;
}
switch (addr->ai_addr->sa_family) {
case AF_INET6:
sin6 = (struct sockaddr_in6 *)addr->ai_addr;
ipaddr = inet_ntop(AF_INET6, &sin6->sin6_addr, tmpbuf,
sizeof(tmpbuf));
if (!ipaddr) {
rc = EX_SYSERR;
goto resolve_host_out;
}
if (sin6->sin6_scope_id) {
len = strnlen(tmpbuf, sizeof(tmpbuf));
ipaddr = tmpbuf + len;
snprintf(tmpbuf, sizeof(tmpbuf) - len, "%%%u",
sin6->sin6_scope_id);
}
break;
case AF_INET:
sin = (struct sockaddr_in *)addr->ai_addr;
ipaddr = inet_ntop(AF_INET, &sin->sin_addr, tmpbuf,
sizeof(tmpbuf));
if (!ipaddr) {
rc = EX_SYSERR;
goto resolve_host_out;
}
break;
default:
addr = addr->ai_next;
continue;
}
if (addr == addrlist)
*addrstr = '\0';
else
strlcat(addrstr, ",", MAX_ADDR_LIST_LEN);
strlcat(addrstr, tmpbuf, MAX_ADDR_LIST_LEN);
addr = addr->ai_next;
}
resolve_host_out:
freeaddrinfo(addrlist);
return rc;
}