diff options
Diffstat (limited to 'common/ethernet.c')
| -rw-r--r-- | common/ethernet.c | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/common/ethernet.c b/common/ethernet.c new file mode 100644 index 0000000..7b8a22c --- /dev/null +++ b/common/ethernet.c @@ -0,0 +1,93 @@ +/* ethernet.c + + Packet assembly code, originally contributed by Archie Cobbs. */ + +/* + * Copyright (c) 2004,2007,2009 by Internet Systems Consortium, Inc. ("ISC") + * Copyright (c) 1996-2003 by Internet Software Consortium + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * 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/ + * + * This software has been written for Internet Systems Consortium + * by Ted Lemon in cooperation with Vixie Enterprises and Nominum, Inc. + * To learn more about Internet Systems Consortium, see + * ``https://www.isc.org/''. To learn more about Vixie Enterprises, + * see ``http://www.vix.com''. To learn more about Nominum, Inc., see + * ``http://www.nominum.com''. + */ + +#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 */ |