summaryrefslogtreecommitdiff
path: root/usr.sbin/tcpdump/print-arp.c
blob: 677e59de0c3b83f1bb4fde9d0309182fca06754c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
/*
 * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that: (1) source code distributions
 * retain the above copyright notice and this paragraph in its entirety, (2)
 * distributions including binary code include the above copyright notice and
 * this paragraph in its entirety in the documentation or other materials
 * provided with the distribution, and (3) all advertising materials mentioning
 * features or use of this software display the following acknowledgement:
 * ``This product includes software developed by the University of California,
 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
 * the University nor the names of its contributors may be used to endorse
 * or promote products derived from this software without specific prior
 * written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#ifndef lint
static const char rcsid[] =
    "@(#) $Header: /cvs/OpenBSD/src/usr.sbin/tcpdump/print-arp.c,v 1.5 1996/12/12 16:22:43 bitblt Exp $ (LBL)";
#endif

#include <sys/param.h>
#include <sys/time.h>
#include <sys/socket.h>

#if __STDC__
struct mbuf;
struct rtentry;
#endif
#include <net/if.h>

#include <netinet/in.h>
#include <netinet/if_ether.h>

#include <stdio.h>
#include <string.h>

#include "interface.h"
#include "addrtoname.h"
#include "ethertype.h"
#include "extract.h"			/* must come after interface.h */

/* Compatibility */
#ifndef REVARP_REQUEST
#define REVARP_REQUEST		3
#endif
#ifndef REVARP_REPLY
#define REVARP_REPLY		4
#endif

static u_char ezero[6];

void
arp_print(register const u_char *bp, u_int length, u_int caplen)
{
	register const struct ether_arp *ap;
	register const struct ether_header *eh;
	register u_short pro, hrd, op;

	ap = (struct ether_arp *)bp;
	if ((u_char *)(ap + 1) > snapend) {
		printf("[|arp]");
		return;
	}
	if (length < sizeof(struct ether_arp)) {
		(void)printf("truncated-arp");
		default_print((u_char *)ap, length);
		return;
	}

	pro = EXTRACT_16BITS(&ap->arp_pro);
	hrd = EXTRACT_16BITS(&ap->arp_hrd);
	op = EXTRACT_16BITS(&ap->arp_op);

	if ((pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL)
	    || ap->arp_hln != sizeof(SHA(ap))
	    || ap->arp_pln != sizeof(SPA(ap))) {
		(void)printf("arp-#%d for proto #%d (%d) hardware #%d (%d)",
				op, pro, ap->arp_pln,
				hrd, ap->arp_hln);
		return;
	}
	if (pro == ETHERTYPE_TRAIL)
		(void)printf("trailer-");
	eh = (struct ether_header *)packetp;
	switch (op) {

	case ARPOP_REQUEST:
		(void)printf("arp who-has %s", ipaddr_string(TPA(ap)));
		if (memcmp((char *)ezero, (char *)THA(ap), 6) != 0)
			(void)printf(" (%s)", etheraddr_string(THA(ap)));
		(void)printf(" tell %s", ipaddr_string(SPA(ap)));
		if (memcmp((char *)ESRC(eh), (char *)SHA(ap), 6) != 0)
			(void)printf(" (%s)", etheraddr_string(SHA(ap)));
		break;

	case ARPOP_REPLY:
		(void)printf("arp reply %s", ipaddr_string(SPA(ap)));
		if (memcmp((char *)ESRC(eh), (char *)SHA(ap), 6) != 0)
			(void)printf(" (%s)", etheraddr_string(SHA(ap)));
		(void)printf(" is-at %s", etheraddr_string(SHA(ap)));
		if (memcmp((char *)EDST(eh), (char *)THA(ap), 6) != 0)
			(void)printf(" (%s)", etheraddr_string(THA(ap)));
		break;

	case REVARP_REQUEST:
		(void)printf("rarp who-is %s tell %s",
			etheraddr_string(THA(ap)),
			etheraddr_string(SHA(ap)));
		break;

	case REVARP_REPLY:
		(void)printf("rarp reply %s at %s",
			etheraddr_string(THA(ap)),
			ipaddr_string(TPA(ap)));
		break;

	default:
		(void)printf("arp-#%d", op);
		default_print((u_char *)ap, caplen);
		return;
	}
	if (hrd != ARPHRD_ETHER)
		printf(" hardware #%d", hrd);
}