/*
 * Copyright (C) 2014 Stephen Leake <stephen_leake@stephe-leake.org>
 * Copyright (C) 2001-2004 Peter J Jones (pjones@pmade.org)
 * All Rights Reserved
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name of the Author nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS''
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 * PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR
 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/** @file
 * This file contains the implementation of the resolve_hostname function
 * using the gethostbyname system call.
**/

// common header
#include "common.h"

// Netxx includes
#include "resolve.h"
#include "types.h"
#include "sockaddr.h"

// standard includes
#include <cstring>

//####################################################################
void Netxx::resolve_hostname (const char *hostname, port_type port, bool use_ipv6, std::vector<Peer> &addrs)
{
    { // first try to see if this address is already an IPv4 address
        SockAddr saddr(AF_INET, port);
        sockaddr_in *sai = reinterpret_cast<sockaddr_in*>(saddr.get_sa());;

        if (inet_pton(AF_INET, hostname, &(sai->sin_addr)) == 1) {
            addrs.push_back(Peer(hostname, port, sai, saddr.get_sa_size()));
            return;
        }
    }

#ifndef NETXX_NO_INET6
    if (use_ipv6) { // now try to see if this address is already an IPv6 address
        SockAddr saddr(AF_INET6, port);
        sockaddr_in6 *sai6 = reinterpret_cast<sockaddr_in6*>(saddr.get_sa());

        if (inet_pton(AF_INET6, hostname, &(sai6->sin6_addr)) == 1) {
            addrs.push_back(Peer(hostname, port, sai6, saddr.get_sa_size()));
            return;
        }
    }
#else
    (void)use_ipv6;
#endif

    /*
     * if we got this far then the address must really be a hostname so
     * we are going to have to call gethostbyname and either pull it out
     * of the hosts file or go to DNS. And don't forget NIS and WINS and
     * ...
     */
    hostent *he; // WARNING not MT safe
    if ( (he = gethostbyname(hostname)) == 0) {
        std::string error("name resolution failure for "); error += hostname;
// HACK: Winsock uses a totally different error reporting mechanism.
#if defined(_WIN32) || defined(_WIN64)
        error += ": "; error += str_error(get_last_error());
#else
        error += ": "; error += hstrerror(h_errno);
#endif
        throw NetworkException(error);
    }

    for (char **ii = he->h_addr_list; *ii != 0; ++ii) {
        switch (he->h_addrtype) {
            case AF_INET:
            {
                SockAddr saddr(AF_INET, port);
                sockaddr_in *sai = reinterpret_cast<sockaddr_in*>(saddr.get_sa());
                std::memcpy(&(sai->sin_addr), *ii, sizeof(sai->sin_addr));
                addrs.push_back(Peer(he->h_name, port, sai, saddr.get_sa_size()));
            }
            break;

#ifndef NETXX_NO_INET6
            case AF_INET6:
            {
                SockAddr saddr(AF_INET6, port);
                sockaddr_in6 *sai6 = reinterpret_cast<sockaddr_in6*>(saddr.get_sa());
                std::memcpy(&(sai6->sin6_addr), *ii, sizeof(sai6->sin6_addr));
                addrs.push_back(Peer(he->h_name, port, sai6, saddr.get_sa_size()));
            }
            break;
#endif
        }
    }
}
//####################################################################
