1/*
2 * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that: (1) source code distributions
7 * retain the above copyright notice and this paragraph in its entirety, (2)
8 * distributions including binary code include the above copyright notice and
9 * this paragraph in its entirety in the documentation or other materials
10 * provided with the distribution, and (3) all advertising materials mentioning
11 * features or use of this software display the following acknowledgement:
12 * ``This product includes software developed by the University of California,
13 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
14 * the University nor the names of its contributors may be used to endorse
15 * or promote products derived from this software without specific prior
16 * written permission.
17 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
18 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
20 *
21 * $FreeBSD: head/contrib/tcpdump/print-arp.c 56896 2000-01-30 01:05:24Z fenner $
22 */
23
24#ifndef lint
25static const char rcsid[] =
26 "@(#) $Header: /tcpdump/master/tcpdump/print-arp.c,v 1.44 1999/11/21 09:36:48 fenner Exp $ (LBL)";
27#endif
28
29#ifdef HAVE_CONFIG_H
30#include "config.h"
31#endif
32
33#include <sys/param.h>
34#include <sys/time.h>
35#include <sys/socket.h>
36
37#if __STDC__
38struct mbuf;
39struct rtentry;
40#endif
41#include <net/if.h>
42#include <net/if_var.h>
43
44#include <netinet/in.h>
45#include <netinet/if_ether.h>
46
47#ifdef HAVE_MEMORY_H
48#include <memory.h>
49#endif
50#include <stdio.h>
51#include <string.h>
52
53#include "interface.h"
54#include "addrtoname.h"
55#include "ethertype.h"
56#include "extract.h" /* must come after interface.h */
57
58/* Compatibility */
59#ifndef REVARP_REQUEST
60#define REVARP_REQUEST 3
61#endif
62#ifndef REVARP_REPLY
63#define REVARP_REPLY 4
64#endif
65
66static u_char ezero[6];
67
68void
69arp_print(register const u_char *bp, u_int length, u_int caplen)
70{
71 register const struct ether_arp *ap;
72 register const struct ether_header *eh;
73 register u_short pro, hrd, op;
74
75 ap = (struct ether_arp *)bp;
76 if ((u_char *)(ap + 1) > snapend) {
77 printf("[|arp]");
78 return;
79 }
80 if (length < sizeof(struct ether_arp)) {
81 (void)printf("truncated-arp");
82 default_print((u_char *)ap, length);
83 return;
84 }
85
86 pro = EXTRACT_16BITS(&ap->arp_pro);
87 hrd = EXTRACT_16BITS(&ap->arp_hrd);
88 op = EXTRACT_16BITS(&ap->arp_op);
89
90 if ((pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL)
91 || ap->arp_hln != sizeof(SHA(ap))
92 || ap->arp_pln != sizeof(SPA(ap))) {
93 (void)printf("arp-#%d for proto #%d (%d) hardware #%d (%d)",
94 op, pro, ap->arp_pln,
95 hrd, ap->arp_hln);
96 return;
97 }
98 if (pro == ETHERTYPE_TRAIL)
99 (void)printf("trailer-");
100 eh = (struct ether_header *)packetp;
101 switch (op) {
102
103 case ARPOP_REQUEST:
104 (void)printf("arp who-has %s", ipaddr_string(TPA(ap)));
105 if (memcmp((char *)ezero, (char *)THA(ap), 6) != 0)
106 (void)printf(" (%s)", etheraddr_string(THA(ap)));
107 (void)printf(" tell %s", ipaddr_string(SPA(ap)));
108 if (memcmp((char *)ESRC(eh), (char *)SHA(ap), 6) != 0)
109 (void)printf(" (%s)", etheraddr_string(SHA(ap)));
110 break;
111
112 case ARPOP_REPLY:
113 (void)printf("arp reply %s", ipaddr_string(SPA(ap)));
114 if (memcmp((char *)ESRC(eh), (char *)SHA(ap), 6) != 0)
115 (void)printf(" (%s)", etheraddr_string(SHA(ap)));
116 (void)printf(" is-at %s", etheraddr_string(SHA(ap)));
117 if (memcmp((char *)EDST(eh), (char *)THA(ap), 6) != 0)
118 (void)printf(" (%s)", etheraddr_string(THA(ap)));
119 break;
120
121 case REVARP_REQUEST:
122 (void)printf("rarp who-is %s tell %s",
123 etheraddr_string(THA(ap)),
124 etheraddr_string(SHA(ap)));
125 break;
126
127 case REVARP_REPLY:
128 (void)printf("rarp reply %s at %s",
129 etheraddr_string(THA(ap)),
130 ipaddr_string(TPA(ap)));
131 break;
132
133 default:
134 (void)printf("arp-#%d", op);
135 default_print((u_char *)ap, caplen);
136 return;
137 }
138 if (hrd != ARPHRD_ETHER)
139 printf(" hardware #%d", hrd);
140}