108 lines
3.8 KiB
C
108 lines
3.8 KiB
C
/* ethernet.c
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Packet assembly code, originally contributed by Archie Cobbs. */
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/*
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* Copyright (c) 1996-2000 Internet Software Consortium.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of The Internet Software Consortium nor the names
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* of its contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
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* CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
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* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
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* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* This software has been written for the Internet Software Consortium
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* by Ted Lemon in cooperation with Vixie Enterprises and Nominum, Inc.
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* To learn more about the Internet Software Consortium, see
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* ``http://www.isc.org/''. To learn more about Vixie Enterprises,
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* see ``http://www.vix.com''. To learn more about Nominum, Inc., see
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* ``http://www.nominum.com''.
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*/
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#ifndef lint
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static char copyright[] =
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"$Id: ethernet.c,v 1.1.1.1 2001/08/03 11:35:32 drochner Exp $ Copyright (c) 1996-2000 The Internet Software Consortium. All rights reserved.\n";
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#endif /* not lint */
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#include "dhcpd.h"
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#if defined (PACKET_ASSEMBLY) || defined (PACKET_DECODING)
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#include "includes/netinet/if_ether.h"
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#endif /* PACKET_ASSEMBLY || PACKET_DECODING */
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#if defined (PACKET_ASSEMBLY)
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/* Assemble an hardware header... */
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void assemble_ethernet_header (interface, buf, bufix, to)
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struct interface_info *interface;
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unsigned char *buf;
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unsigned *bufix;
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struct hardware *to;
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{
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struct isc_ether_header eh;
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if (to && to -> hlen == 7) /* XXX */
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memcpy (eh.ether_dhost, &to -> hbuf [1],
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sizeof eh.ether_dhost);
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else
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memset (eh.ether_dhost, 0xff, sizeof (eh.ether_dhost));
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if (interface -> hw_address.hlen - 1 == sizeof (eh.ether_shost))
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memcpy (eh.ether_shost, &interface -> hw_address.hbuf [1],
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sizeof (eh.ether_shost));
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else
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memset (eh.ether_shost, 0x00, sizeof (eh.ether_shost));
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eh.ether_type = htons (ETHERTYPE_IP);
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memcpy (&buf [*bufix], &eh, ETHER_HEADER_SIZE);
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*bufix += ETHER_HEADER_SIZE;
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}
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#endif /* PACKET_ASSEMBLY */
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#ifdef PACKET_DECODING
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/* Decode a hardware header... */
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ssize_t decode_ethernet_header (interface, buf, bufix, from)
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struct interface_info *interface;
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unsigned char *buf;
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unsigned bufix;
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struct hardware *from;
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{
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struct isc_ether_header eh;
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memcpy (&eh, buf + bufix, ETHER_HEADER_SIZE);
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#ifdef USERLAND_FILTER
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if (ntohs (eh.ether_type) != ETHERTYPE_IP)
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return -1;
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#endif
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memcpy (&from -> hbuf [1], eh.ether_shost, sizeof (eh.ether_shost));
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from -> hbuf [0] = ARPHRD_ETHER;
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from -> hlen = (sizeof eh.ether_shost) + 1;
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return ETHER_HEADER_SIZE;
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}
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#endif /* PACKET_DECODING */
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