summaryrefslogtreecommitdiffstats
path: root/usr.sbin/tcpdump/print-null.c
blob: a42b3599a861690d9cce1c972413c51d10733219 (plain) (blame)
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
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
/*	$OpenBSD: print-null.c,v 1.23 2018/10/22 16:12:45 kn Exp $	*/

/*
 * Copyright (c) 1991, 1993, 1994, 1995, 1996, 1997
 *	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.
 */

#include <sys/time.h>
#include <sys/socket.h>
#include <sys/file.h>
#include <sys/ioctl.h>

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

#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/ip6.h>
#include <netinet/if_ether.h>
#include <netinet/ip_var.h>
#include <netinet/udp.h>
#include <netinet/udp_var.h>
#include <netinet/tcp.h>

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

#include "interface.h"
#include "addrtoname.h"

#ifndef AF_NS
#define AF_NS		6		/* XEROX NS protocols */
#endif

/*
 * The DLT_NULL packet header is 4 bytes long. It contains a host
 * order 32 bit integer that specifies the family, e.g. AF_INET
 */
#define	NULL_HDRLEN 4

static void
null_print(const u_char *p, const struct ip *ip, u_int length)
{
	u_int family;

	memcpy((char *)&family, (char *)p, sizeof(family));

	if (nflag && family != AF_LINK) {
		/* XXX just dump the header */
		return;
	}
	switch (family) {

	case AF_INET:
		printf("ip: ");
		break;

	case AF_INET6:
		printf("ip6: ");
		break;

	case AF_NS:
		printf("ns: ");
		break;

#ifdef __OpenBSD__
	case AF_LINK:
		ether_print(p + NULL_HDRLEN, length);
		break;
#endif
	case AF_MPLS:
		printf("mpls: ");
		break;

	default:
		printf("AF %d: ", family);
		break;
	}
}

void
loop_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
{
	*(u_int *)p = ntohl(*(u_int *)p);

	null_if_print(user, h, p);
}

void
null_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
{
	u_int length = h->len;
	u_int caplen = h->caplen;
	u_int family = *(u_int *)p;

#ifdef __OpenBSD__
	struct ether_header *ep;
	u_short ether_type;
	extern u_short extracted_ethertype;
#endif

	ts_print(&h->ts);

	/*
	 * Some printers want to get back at the link level addresses,
	 * and/or check that they're not walking off the end of the packet.
	 * Rather than pass them all the way down, we set these globals.
	 */
	packetp = p;
	snapend = p + caplen;

	length -= NULL_HDRLEN;

	if (eflag)
		null_print(p, (struct ip *)(p + NULL_HDRLEN), length);

	switch (family) {
	case AF_INET:
		ip_print(p + NULL_HDRLEN, length);
		break;

	case AF_INET6:
		ip6_print(p + NULL_HDRLEN, length);
		break;

	case AF_MPLS:
		mpls_print(p + NULL_HDRLEN, length);
		break;

#ifdef __OpenBSD__
	case AF_LINK:
		if (caplen < sizeof(struct ether_header) + NULL_HDRLEN) {
			printf("[|ether]");
			goto out;
		}

		length -= sizeof(struct ether_header);
		caplen -= sizeof(struct ether_header);
		ep = (struct ether_header *)(p + NULL_HDRLEN);
		p += NULL_HDRLEN + sizeof(struct ether_header);
		packetp += sizeof(struct ether_header);
		ether_type = ntohs(ep->ether_type);

		extracted_ethertype = 0;
		if (ether_type <= ETHERMTU) {
			/* Try to print the LLC-layer header & higher layers */
			if (llc_print(p, length, caplen, ESRC(ep),
			    EDST(ep)) == 0) {
				/* ether_type not known, print raw packet */
				if (!eflag)
					ether_print((u_char *)ep, length);
				if (extracted_ethertype) {
					printf("(LLC %s) ",
					       etherproto_string(htons(extracted_ethertype)));
				}
				if (!xflag && !qflag)
					default_print(p, caplen - NULL_HDRLEN);
			}
		} else if (ether_encap_print(ether_type, p, length,
		           caplen) == 0) {
			/* ether_type not known, print raw packet */
			if (!eflag)
				ether_print((u_char *)ep, length +
				    sizeof(*ep));
			if (!xflag && !qflag)
				default_print(p, caplen - NULL_HDRLEN);
		}
		break;
#endif /* __OpenBSD__ */
	}

	if (xflag)
		default_print((const u_char *)(packetp + NULL_HDRLEN),
		    caplen - NULL_HDRLEN);
 out:
	putchar('\n');
}