dhcp-route.c

this is sample about DHCP-agent

/* $Header: /cvsroot/dhcp-agent/dhcp-agent/src/dhcp-route.c,v 1.4 2003/06/08 22:14:16 actmodern Exp $
 *
 * Copyright 2002 Thamer Alharbash <[e-mail]>
 * 
 * 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. The names of the authors may not be used to endorse or promote
 * products derived from this software without specific prior
 * written permission.
 * 
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 * Routing manipulation:
 *
 * Here we can add/delete routes, and lookup routes.  We return
 * mac addresses so packets can be sent out to the right MAC
 * address.
 * 
 */

#define MODULE_NAME "dhcp-route"

#include "dhcp-local.h"
#include "dhcp-libutil.h"
#include "dhcp-librawnet.h"

int route_find(rawnet_t *net, int retries, int timeout, ip_addr_t addr, eth_addr_t *dest_mac)
{
    route_t *rt;
    struct route_entry entry;

    rt = route_open();
    if(rt == NULL) {
        ERROR_MESSAGE("could not get route handler.");
        return -1;
    }

    memset(&entry.route_dst, 0, sizeof(entry.route_dst));
    memset(&entry.route_gw, 0, sizeof(entry.route_gw));

    entry.route_dst.addr_type = ADDR_TYPE_IP;
    entry.route_dst.addr_bits = 0;
    entry.route_dst.addr_ip = addr;

    if(route_get(rt, &entry)) {
        /* not in routing table. do an arp for it then. */
        return (arp_discover_hardware_address(net, retries, timeout, entry.route_dst.addr_ip, dest_mac));
    }

    route_close(rt);

    /* arp for gateway address. */
    return (arp_discover_hardware_address(net, retries, timeout, entry.route_gw.addr_ip, dest_mac));
}