xref: /openbsd/sys/lib/libsa/ether.c (revision 73471bf0)
1 /*	$OpenBSD: ether.c,v 1.10 2014/11/19 20:28:56 miod Exp $	*/
2 /*	$NetBSD: ether.c,v 1.8 1996/10/13 02:29:00 christos Exp $	*/
3 
4 /*
5  * Copyright (c) 1992 Regents of the University of California.
6  * All rights reserved.
7  *
8  * This software was developed by the Computer Systems Engineering group
9  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
10  * contributed to Berkeley.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. All advertising materials mentioning features or use of this software
21  *    must display the following acknowledgement:
22  *	This product includes software developed by the University of
23  *	California, Lawrence Berkeley Laboratory and its contributors.
24  * 4. Neither the name of the University nor the names of its contributors
25  *    may be used to endorse or promote products derived from this software
26  *    without specific prior written permission.
27  *
28  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38  * SUCH DAMAGE.
39  *
40  * @(#) Header: net.c,v 1.9 93/08/06 19:32:15 leres Exp  (LBL)
41  */
42 
43 #include <sys/param.h>
44 #include <sys/socket.h>
45 
46 #include <net/if.h>
47 
48 #include <netinet/in.h>
49 #include <netinet/if_ether.h>
50 #include <netinet/ip.h>
51 
52 #include "stand.h"
53 #include "net.h"
54 #include "netif.h"
55 
56 /* Caller must leave room for ethernet header in front!! */
57 ssize_t
58 sendether(struct iodesc *d, void *pkt, size_t len, u_char *dea, int etype)
59 {
60 	ssize_t n;
61 	struct ether_header *eh;
62 
63 #ifdef ETHER_DEBUG
64 	if (debug)
65 		printf("sendether: called\n");
66 #endif
67 
68 	eh = (struct ether_header *)pkt - 1;
69 	len += sizeof(*eh);
70 
71 	MACPY(d->myea, eh->ether_shost);		/* by byte */
72 	MACPY(dea, eh->ether_dhost);			/* by byte */
73 	eh->ether_type = htons(etype);
74 
75 	n = netif_put(d, eh, len);
76 	if (n < 0 || (size_t)n < sizeof(*eh))
77 		return (-1);
78 
79 	n -= sizeof(*eh);
80 	return (n);
81 }
82 
83 /*
84  * Get a packet of any Ethernet type, with our address or
85  * the broadcast address.  Save the Ether type in arg 5.
86  * NOTE: Caller must leave room for the Ether header.
87  */
88 ssize_t
89 readether(struct iodesc *d, void *pkt, size_t len, time_t tleft,
90     u_int16_t *etype)
91 {
92 	ssize_t n;
93 	struct ether_header *eh;
94 
95 #ifdef ETHER_DEBUG
96 	if (debug)
97 		printf("readether: called\n");
98 #endif
99 
100 	eh = (struct ether_header *)pkt - 1;
101 	len += sizeof(*eh);
102 
103 	n = netif_get(d, eh, len, tleft);
104 	if (n < 0 || (size_t)n < sizeof(*eh))
105 		return (-1);
106 
107 	/* Validate Ethernet address. */
108 	if (bcmp(d->myea, eh->ether_dhost, 6) != 0 &&
109 	    bcmp(bcea, eh->ether_dhost, 6) != 0) {
110 #ifdef ETHER_DEBUG
111 		if (debug)
112 			printf("readether: not ours (ea=%s)\n",
113 			    ether_sprintf(eh->ether_dhost));
114 #endif
115 		return (-1);
116 	}
117 	*etype = ntohs(eh->ether_type);
118 
119 	n -= sizeof(*eh);
120 	return (n);
121 }
122 
123 /*
124  * Convert Ethernet address to printable (loggable) representation.
125  */
126 static const char digits[] = "0123456789abcdef";
127 const char *
128 ether_sprintf(const u_char *ap)
129 {
130 	int i;
131 	static char etherbuf[18];
132 	char *cp = etherbuf;
133 
134 	for (i = 0; i < 6; i++) {
135 		*cp++ = digits[*ap >> 4];
136 		*cp++ = digits[*ap++ & 0xf];
137 		*cp++ = ':';
138 	}
139 	*--cp = 0;
140 	return (etherbuf);
141 }
142