[thirdparty/dhcp.git] / common / ethernet.c

/* ethernet.c

   Packet assembly code, originally contributed by Archie Cobbs. */

/*
 * Copyright (c) 2004-2017 by Internet Systems Consortium, Inc. ("ISC")
 * Copyright (c) 1996-2003 by Internet Software Consortium
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 *   Internet Systems Consortium, Inc.
 *   950 Charter Street
 *   Redwood City, CA 94063
 *   <info@isc.org>
 *   https://www.isc.org/
 *
 */

#include "dhcpd.h"

#if defined (PACKET_ASSEMBLY) || defined (PACKET_DECODING)
#include "includes/netinet/if_ether.h"
#endif /* PACKET_ASSEMBLY || PACKET_DECODING */

#if defined (PACKET_ASSEMBLY)
/* Assemble an hardware header... */

void assemble_ethernet_header (interface, buf, bufix, to)
	struct interface_info *interface;
	unsigned char *buf;
	unsigned *bufix;
	struct hardware *to;
{
	struct isc_ether_header eh;

	if (to && to -> hlen == 7) /* XXX */
		memcpy (eh.ether_dhost, &to -> hbuf [1],
			sizeof eh.ether_dhost);
	else
		memset (eh.ether_dhost, 0xff, sizeof (eh.ether_dhost));
	if (interface -> hw_address.hlen - 1 == sizeof (eh.ether_shost))
		memcpy (eh.ether_shost, &interface -> hw_address.hbuf [1],
			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;
}
#endif /* PACKET_ASSEMBLY */

#ifdef PACKET_DECODING
/* Decode a hardware header... */

ssize_t decode_ethernet_header (interface, buf, bufix, from)
     struct interface_info *interface;
     unsigned char *buf;
     unsigned bufix;
     struct hardware *from;
{
  struct isc_ether_header eh;

  memcpy (&eh, buf + bufix, ETHER_HEADER_SIZE);

#ifdef USERLAND_FILTER
  if (ntohs (eh.ether_type) != ETHERTYPE_IP)
	  return -1;
#endif
  memcpy (&from -> hbuf [1], eh.ether_shost, sizeof (eh.ether_shost));
  from -> hbuf [0] = ARPHRD_ETHER;
  from -> hlen = (sizeof eh.ether_shost) + 1;

  return ETHER_HEADER_SIZE;
}
#endif /* PACKET_DECODING */
Commit	Line	Data
a770670e	1	/* ethernet.c
0c699a23 TL	2
	3	Packet assembly code, originally contributed by Archie Cobbs. */
	4
	5	/*
7512d88b	6	* Copyright (c) 2004-2017 by Internet Systems Consortium, Inc. ("ISC")
98311e4b	7	* Copyright (c) 1996-2003 by Internet Software Consortium
0c699a23	8	*
7512d88b TM	9	* This Source Code Form is subject to the terms of the Mozilla Public
	10	* License, v. 2.0. If a copy of the MPL was not distributed with this
	11	* file, You can obtain one at http://mozilla.org/MPL/2.0/.
0c699a23	12	*
98311e4b DH	13	* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
	14	* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
	15	* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
	16	* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
	17	* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
	18	* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
	19	* OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
0c699a23	20	*
98311e4b DH	21	* Internet Systems Consortium, Inc.
	22	* 950 Charter Street
	23	* Redwood City, CA 94063
	24	* <info@isc.org>
2c85ac9b	25	* https://www.isc.org/
49733f31	26	*
0c699a23 TL	27	*/
0c699a23 TL	28
0c699a23 TL	29	#include "dhcpd.h"
	30
	31	#if defined (PACKET_ASSEMBLY) \|\| defined (PACKET_DECODING)
	32	#include "includes/netinet/if_ether.h"
	33	#endif /* PACKET_ASSEMBLY \|\| PACKET_DECODING */
	34
	35	#if defined (PACKET_ASSEMBLY)
	36	/* Assemble an hardware header... */
0c699a23 TL	37
	38	void assemble_ethernet_header (interface, buf, bufix, to)
	39	struct interface_info *interface;
	40	unsigned char *buf;
b1b7b521	41	unsigned *bufix;
0c699a23 TL	42	struct hardware *to;
0c699a23 TL	43	{
d758ad8c	44	struct isc_ether_header eh;
0c699a23	45
31730f17 TL	46	if (to && to -> hlen == 7) /* XXX */
	47	memcpy (eh.ether_dhost, &to -> hbuf [1],
	48	sizeof eh.ether_dhost);
0c699a23 TL	49	else
0c699a23 TL	50	memset (eh.ether_dhost, 0xff, sizeof (eh.ether_dhost));
31730f17 TL	51	if (interface -> hw_address.hlen - 1 == sizeof (eh.ether_shost))
31730f17 TL	52	memcpy (eh.ether_shost, &interface -> hw_address.hbuf [1],
0c699a23 TL	53	sizeof (eh.ether_shost));
	54	else
	55	memset (eh.ether_shost, 0x00, sizeof (eh.ether_shost));
	56
0c699a23	57	eh.ether_type = htons (ETHERTYPE_IP);
0c699a23	58
98c83345 TL	59	memcpy (&buf [*bufix], &eh, ETHER_HEADER_SIZE);
98c83345 TL	60	*bufix += ETHER_HEADER_SIZE;
0c699a23 TL	61	}
	62	#endif /* PACKET_ASSEMBLY */
	63
	64	#ifdef PACKET_DECODING
	65	/* Decode a hardware header... */
	66
	67	ssize_t decode_ethernet_header (interface, buf, bufix, from)
	68	struct interface_info *interface;
	69	unsigned char *buf;
b1b7b521	70	unsigned bufix;
0c699a23 TL	71	struct hardware *from;
0c699a23 TL	72	{
d758ad8c	73	struct isc_ether_header eh;
0c699a23	74
98c83345	75	memcpy (&eh, buf + bufix, ETHER_HEADER_SIZE);
0c699a23 TL	76
	77	#ifdef USERLAND_FILTER
	78	if (ntohs (eh.ether_type) != ETHERTYPE_IP)
	79	return -1;
	80	#endif
31730f17 TL	81	memcpy (&from -> hbuf [1], eh.ether_shost, sizeof (eh.ether_shost));
	82	from -> hbuf [0] = ARPHRD_ETHER;
	83	from -> hlen = (sizeof eh.ether_shost) + 1;
0c699a23	84
31730f17	85	return ETHER_HEADER_SIZE;
0c699a23 TL	86	}
0c699a23 TL	87	#endif /* PACKET_DECODING */