dhcp-eth.c

this is sample about DHCP-agent

/* $Header: /cvsroot/dhcp-agent/dhcp-agent/src/dhcp-eth.c,v 1.4 2002/12/27 02:53:45 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.
 *
 * 
 * Ethernet object.
 * 
 */

#define MODULE_NAME "dhcp-eth"

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

#include "dhcp-align.h"

eth_obj *eth_create(void)
{
    eth_obj *eth;

    eth = xmalloc(sizeof(eth_obj));
    return eth;
}

void eth_destroy(eth_obj * eth)
{
    xfree(eth);
    return;
}

eth_addr_t eth_get_src_addr(eth_obj * eth)
{
    return (eth->header.eth_src);
}

eth_addr_t eth_get_dst_addr(eth_obj * eth)
{
    return (eth->header.eth_dst);
}

uint16_t eth_get_type(eth_obj * eth)
{
    return (ntohs(eth->header.eth_type));
}

void eth_set_src_addr(eth_obj * eth, eth_addr_t addr)
{
    memcpy(&eth->header.eth_src.data, &addr.data, ETH_ADDR_LEN);
    return;
}

void eth_set_dst_addr(eth_obj * eth, eth_addr_t addr)
{
    memcpy(&eth->header.eth_dst.data, &addr.data, ETH_ADDR_LEN);
    return;
}

void eth_set_type(eth_obj * eth, uint16_t type)
{
    eth->header.eth_type = htons(type);
    return;
}

int eth_read_packet_image(eth_obj * eth, const unsigned char *packet, int len)
{
    if(len < ETH_HDR_LEN)
        return -1;

    align_eth(packet, &eth->header);

    return 0;
}

void eth_write_packet_image(eth_obj * eth, unsigned char *packet)
{
    /* Structures may have padding
     * so copy out each member individually. */

    memcpy(packet, &eth->header.eth_dst.data, ETH_ADDR_LEN);
    packet += ETH_ADDR_LEN;

    memcpy(packet, &eth->header.eth_src.data, ETH_ADDR_LEN);
    packet += ETH_ADDR_LEN;

    memcpy(packet, &eth->header.eth_type, 2);

    return;
}