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Annotation of embedaddon/dhcp/common/ethernet.c, revision 1.1.1.1

1.1       misho       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 */