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dhcp 4.1 r7

    1: /* ethernet.c
    2: 
    3:    Packet assembly code, originally contributed by Archie Cobbs. */
    4: 
    5: /*
    6:  * Copyright (c) 2004,2007,2009 by Internet Systems Consortium, Inc. ("ISC")
    7:  * Copyright (c) 1996-2003 by Internet Software Consortium
    8:  *
    9:  * Permission to use, copy, modify, and distribute this software for any
   10:  * purpose with or without fee is hereby granted, provided that the above
   11:  * copyright notice and this permission notice appear in all copies.
   12:  *
   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.
   20:  *
   21:  *   Internet Systems Consortium, Inc.
   22:  *   950 Charter Street
   23:  *   Redwood City, CA 94063
   24:  *   <info@isc.org>
   25:  *   https://www.isc.org/
   26:  *
   27:  * This software has been written for Internet Systems Consortium
   28:  * by Ted Lemon in cooperation with Vixie Enterprises and Nominum, Inc.
   29:  * To learn more about Internet Systems Consortium, see
   30:  * ``https://www.isc.org/''.  To learn more about Vixie Enterprises,
   31:  * see ``http://www.vix.com''.   To learn more about Nominum, Inc., see
   32:  * ``http://www.nominum.com''.
   33:  */
   34: 
   35: #include "dhcpd.h"
   36: 
   37: #if defined (PACKET_ASSEMBLY) || defined (PACKET_DECODING)
   38: #include "includes/netinet/if_ether.h"
   39: #endif /* PACKET_ASSEMBLY || PACKET_DECODING */
   40: 
   41: #if defined (PACKET_ASSEMBLY)
   42: /* Assemble an hardware header... */
   43: 
   44: void assemble_ethernet_header (interface, buf, bufix, to)
   45: 	struct interface_info *interface;
   46: 	unsigned char *buf;
   47: 	unsigned *bufix;
   48: 	struct hardware *to;
   49: {
   50: 	struct isc_ether_header eh;
   51: 
   52: 	if (to && to -> hlen == 7) /* XXX */
   53: 		memcpy (eh.ether_dhost, &to -> hbuf [1],
   54: 			sizeof eh.ether_dhost);
   55: 	else
   56: 		memset (eh.ether_dhost, 0xff, sizeof (eh.ether_dhost));
   57: 	if (interface -> hw_address.hlen - 1 == sizeof (eh.ether_shost))
   58: 		memcpy (eh.ether_shost, &interface -> hw_address.hbuf [1],
   59: 			sizeof (eh.ether_shost));
   60: 	else
   61: 		memset (eh.ether_shost, 0x00, sizeof (eh.ether_shost));
   62: 
   63: 	eh.ether_type = htons (ETHERTYPE_IP);
   64: 
   65: 	memcpy (&buf [*bufix], &eh, ETHER_HEADER_SIZE);
   66: 	*bufix += ETHER_HEADER_SIZE;
   67: }
   68: #endif /* PACKET_ASSEMBLY */
   69: 
   70: #ifdef PACKET_DECODING
   71: /* Decode a hardware header... */
   72: 
   73: ssize_t decode_ethernet_header (interface, buf, bufix, from)
   74:      struct interface_info *interface;
   75:      unsigned char *buf;
   76:      unsigned bufix;
   77:      struct hardware *from;
   78: {
   79:   struct isc_ether_header eh;
   80: 
   81:   memcpy (&eh, buf + bufix, ETHER_HEADER_SIZE);
   82: 
   83: #ifdef USERLAND_FILTER
   84:   if (ntohs (eh.ether_type) != ETHERTYPE_IP)
   85: 	  return -1;
   86: #endif
   87:   memcpy (&from -> hbuf [1], eh.ether_shost, sizeof (eh.ether_shost));
   88:   from -> hbuf [0] = ARPHRD_ETHER;
   89:   from -> hlen = (sizeof eh.ether_shost) + 1;
   90: 
   91:   return ETHER_HEADER_SIZE;
   92: }
   93: #endif /* PACKET_DECODING */