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/* $OpenBSD: ethernet.c,v 1.4 2004/02/07 13:26:35 henning Exp $ */
/* Packet assembly code, originally contributed by Archie Cobbs. */
/*
* Copyright (c) 1995, 1996 The Internet Software Consortium.
* 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 Internet Software Consortium 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 INTERNET SOFTWARE CONSORTIUM 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 INTERNET SOFTWARE CONSORTIUM 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.
*
* This software has been written for the Internet Software Consortium
* by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
* Enterprises. To learn more about the Internet Software Consortium,
* see ``http://www.vix.com/isc''. To learn more about Vixie
* Enterprises, see ``http://www.vix.com''.
*/
#include "dhcpd.h"
#include <netinet/if_ether.h>
#define ETHER_HEADER_SIZE (ETHER_ADDR_LEN * 2 + sizeof(u_int16_t))
/* Assemble a hardware header... */
/* XXX: currently only supports ethernet; doesn't check for other types. */
void
assemble_ethernet_header(struct interface_info *interface, unsigned char *buf,
int *bufix, struct hardware *to)
{
struct ether_header eh;
if (to != NULL && to->hlen == 6) /* XXX */
memcpy(eh.ether_dhost, to->haddr, sizeof(eh.ether_dhost));
else
memset(eh.ether_dhost, 0xff, sizeof(eh.ether_dhost));
if (interface->hw_address.hlen == sizeof(eh.ether_shost))
memcpy(eh.ether_shost, interface->hw_address.haddr,
sizeof(eh.ether_shost));
else
memset(eh.ether_shost, 0x00, sizeof(eh.ether_shost));
eh.ether_type = htons(ETHERTYPE_IP);
memcpy(&buf[*bufix], &eh, ETHER_HEADER_SIZE);
*bufix += ETHER_HEADER_SIZE;
}
/* Decode a hardware header... */
ssize_t
decode_ethernet_header(struct interface_info *interface, unsigned char *buf,
int bufix, struct hardware *from)
{
struct ether_header eh;
memcpy(&eh, buf + bufix, ETHER_HEADER_SIZE);
memcpy(from->haddr, eh.ether_shost, sizeof(eh.ether_shost));
from->htype = ARPHRD_ETHER;
from->hlen = sizeof(eh.ether_shost);
return (sizeof(eh));
}
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