1 /*        $NetBSD: ether.c,v 1.24 2019/03/31 20:08:45 christos 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
sendether(struct iodesc * d,void * pkt,size_t len,u_char * dea,int etype)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("%s: called\n", __func__);
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 -= (ssize_t)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
readether(struct iodesc * d,void * pkt,size_t len,saseconds_t tleft,u_int16_t * etype)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("%s: called\n", __func__);
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("%s: not ours (ea=%s)\n", __func__,
116                                   ether_sprintf(eh->ether_dhost));
117 #endif
118                     return -1;
119           }
120           *etype = ntohs(eh->ether_type);
121 
122           n -= (ssize_t)sizeof(*eh);
123           return n;
124 }
125