external/bsd/dhcp/dist/common/ethernet.c

   1 /*      $NetBSD: ethernet.c,v 1.1.1.2 2014/07/12 11:57:43 spz Exp $     */
   2 /* ethernet.c
   3
   4    Packet assembly code, originally contributed by Archie Cobbs. */
   5
   6 /*
   7  * Copyright (c) 2004,2007,2009,2014 by Internet Systems Consortium, Inc. ("ISC")
   8  * Copyright (c) 1996-2003 by Internet Software Consortium
   9  *
  10  * Permission to use, copy, modify, and distribute this software for any
  11  * purpose with or without fee is hereby granted, provided that the above
  12  * copyright notice and this permission notice appear in all copies.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
  15  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  16  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
  17  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  18  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  19  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  20  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  21  *
  22  *   Internet Systems Consortium, Inc.
  23  *   950 Charter Street
  24  *   Redwood City, CA 94063
  25  *   <info@isc.org>
  26  *   https://www.isc.org/
  27  *
  28  */
  29
  30 #include <sys/cdefs.h>
  31 __RCSID("$NetBSD: ethernet.c,v 1.1.1.2 2014/07/12 11:57:43 spz Exp $");
  32
  33 #include "dhcpd.h"
  34
  35 #if defined (PACKET_ASSEMBLY) || defined (PACKET_DECODING)
  36 #include "includes/netinet/if_ether.h"
  37 #endif /* PACKET_ASSEMBLY || PACKET_DECODING */
  38
  39 #if defined (PACKET_ASSEMBLY)
  40 /* Assemble an hardware header... */
  41
  42 void assemble_ethernet_header (interface, buf, bufix, to)
  43         struct interface_info *interface;
  44         unsigned char *buf;
  45         unsigned *bufix;
  46         struct hardware *to;
  47 {
  48         struct isc_ether_header eh;
  49
  50         if (to && to -> hlen == 7) /* XXX */
  51                 memcpy (eh.ether_dhost, &to -> hbuf [1],
  52                         sizeof eh.ether_dhost);
  53         else
  54                 memset (eh.ether_dhost, 0xff, sizeof (eh.ether_dhost));
  55         if (interface -> hw_address.hlen - 1 == sizeof (eh.ether_shost))
  56                 memcpy (eh.ether_shost, &interface -> hw_address.hbuf [1],
  57                         sizeof (eh.ether_shost));
  58         else
  59                 memset (eh.ether_shost, 0x00, sizeof (eh.ether_shost));
  60
  61         eh.ether_type = htons (ETHERTYPE_IP);
  62
  63         memcpy (&buf [*bufix], &eh, ETHER_HEADER_SIZE);
  64         *bufix += ETHER_HEADER_SIZE;
  65 }
  66 #endif /* PACKET_ASSEMBLY */
  67
  68 #ifdef PACKET_DECODING
  69 /* Decode a hardware header... */
  70
  71 ssize_t decode_ethernet_header (interface, buf, bufix, from)
  72      struct interface_info *interface;
  73      unsigned char *buf;
  74      unsigned bufix;
  75      struct hardware *from;
  76 {
  77   struct isc_ether_header eh;
  78
  79   memcpy (&eh, buf + bufix, ETHER_HEADER_SIZE);
  80
  81 #ifdef USERLAND_FILTER
  82   if (ntohs (eh.ether_type) != ETHERTYPE_IP)
  83           return -1;
  84 #endif
  85   memcpy (&from -> hbuf [1], eh.ether_shost, sizeof (eh.ether_shost));
  86   from -> hbuf [0] = ARPHRD_ETHER;
  87   from -> hlen = (sizeof eh.ether_shost) + 1;
  88
  89   return ETHER_HEADER_SIZE;
  90 }
  91 #endif /* PACKET_DECODING */