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ether.c revision 1.23 
      1 /*	$NetBSD: ether.c,v 1.23 2014/03/29 14:30:16 jakllsch Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1992 Regents of the University of California.
      5  * All rights reserved.
      6  *
      7  * This software was developed by the Computer Systems Engineering group
      8  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
      9  * contributed to Berkeley.
     10  *
     11  * Redistribution and use in source and binary forms, with or without
     12  * modification, are permitted provided that the following conditions
     13  * are met:
     14  * 1. Redistributions of source code must retain the above copyright
     15  *    notice, this list of conditions and the following disclaimer.
     16  * 2. Redistributions in binary form must reproduce the above copyright
     17  *    notice, this list of conditions and the following disclaimer in the
     18  *    documentation and/or other materials provided with the distribution.
     19  * 3. All advertising materials mentioning features or use of this software
     20  *    must display the following acknowledgement:
     21  *	This product includes software developed by the University of
     22  *	California, Lawrence Berkeley Laboratory and its contributors.
     23  * 4. Neither the name of the University nor the names of its contributors
     24  *    may be used to endorse or promote products derived from this software
     25  *    without specific prior written permission.
     26  *
     27  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     37  * SUCH DAMAGE.
     38  *
     39  * @(#) Header: net.c,v 1.9 93/08/06 19:32:15 leres Exp  (LBL)
     40  */
     41 
     42 #include <sys/param.h>
     43 #include <sys/socket.h>
     44 #ifdef _STANDALONE
     45 #include <lib/libkern/libkern.h>
     46 #else
     47 #include <string.h>
     48 #endif
     49 
     50 #include <net/if.h>
     51 #include <net/if_ether.h>
     52 
     53 #include <netinet/in.h>
     54 #include <netinet/in_systm.h>
     55 
     56 #include "stand.h"
     57 #include "net.h"
     58 
     59 /* Caller must leave room for ethernet header in front!! */
     60 ssize_t
     61 sendether(struct iodesc *d, void *pkt, size_t len, u_char *dea, int etype)
     62 {
     63 	ssize_t n;
     64 	struct ether_header *eh;
     65 
     66 #ifdef ETHER_DEBUG
     67  	if (debug)
     68 		printf("sendether: called\n");
     69 #endif
     70 
     71 	eh = (struct ether_header *)pkt - 1;
     72 	len += sizeof(*eh);
     73 
     74 	MACPY(d->myea, eh->ether_shost);		/* by byte */
     75 	MACPY(dea, eh->ether_dhost);			/* by byte */
     76 	eh->ether_type = htons(etype);
     77 
     78 	n = netif_put(d, eh, len);
     79 	if (n == -1 || (size_t)n < sizeof(*eh))
     80 		return -1;
     81 
     82 	n -= sizeof(*eh);
     83 	return n;
     84 }
     85 
     86 /*
     87  * Get a packet of any Ethernet type, with our address or
     88  * the broadcast address.  Save the Ether type in arg 5.
     89  * NOTE: Caller must leave room for the Ether header.
     90  */
     91 ssize_t
     92 readether(struct iodesc *d, void *pkt, size_t len, saseconds_t tleft,
     93 	u_int16_t *etype)
     94 {
     95 	ssize_t n;
     96 	struct ether_header *eh;
     97 
     98 #ifdef ETHER_DEBUG
     99  	if (debug)
    100 		printf("readether: called\n");
    101 #endif
    102 
    103 	eh = (struct ether_header *)pkt - 1;
    104 	len += sizeof(*eh);
    105 
    106 	n = netif_get(d, eh, len, tleft);
    107 	if (n == -1 || (size_t)n < sizeof(*eh))
    108 		return -1;
    109 
    110 	/* Validate Ethernet address. */
    111 	if (memcmp(d->myea, eh->ether_dhost, ETHER_ADDR_LEN) != 0 &&
    112 	    memcmp(bcea, eh->ether_dhost, ETHER_ADDR_LEN) != 0) {
    113 #ifdef ETHER_DEBUG
    114 		if (debug)
    115 			printf("readether: not ours (ea=%s)\n",
    116 			    ether_sprintf(eh->ether_dhost));
    117 #endif
    118 		return -1;
    119 	}
    120 	*etype = ntohs(eh->ether_type);
    121 
    122 	n -= sizeof(*eh);
    123 	return n;
    124 }
    125