print-ether.c revision 98527 
119914Swollman/*
250476Speter * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000
31558Srgrimes *	The Regents of the University of California.  All rights reserved.
41558Srgrimes *
525451Speter * Redistribution and use in source and binary forms, with or without
625451Speter * modification, are permitted provided that: (1) source code distributions
725451Speter * retain the above copyright notice and this paragraph in its entirety, (2)
825451Speter * distributions including binary code include the above copyright notice and
925451Speter * this paragraph in its entirety in the documentation or other materials
1054624Sshin * provided with the distribution, and (3) all advertising materials mentioning
1125451Speter * features or use of this software display the following acknowledgement:
1244764Swpaul * ``This product includes software developed by the University of California,
1344764Swpaul * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
1444764Swpaul * the University nor the names of its contributors may be used to endorse
1544764Swpaul * or promote products derived from this software without specific prior
161855Swollman * written permission.
1719914Swollman * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
1819914Swollman * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
1919914Swollman * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
2044764Swpaul *
211558Srgrimes * $FreeBSD: head/contrib/tcpdump/print-ether.c 98527 2002-06-21 00:49:02Z fenner $
221558Srgrimes */
23#ifndef lint
24static const char rcsid[] =
25    "@(#) $Header: /tcpdump/master/tcpdump/print-ether.c,v 1.65 2001/07/04 22:03:14 fenner Exp $ (LBL)";
26#endif
27
28#ifdef HAVE_CONFIG_H
29#include "config.h"
30#endif
31
32#include <sys/param.h>
33#include <sys/time.h>
34#include <sys/socket.h>
35
36struct mbuf;
37struct rtentry;
38
39#include <netinet/in.h>
40
41#include <stdio.h>
42#include <pcap.h>
43
44#include "interface.h"
45#include "addrtoname.h"
46#include "ethertype.h"
47
48#include "ether.h"
49
50const u_char *packetp;
51const u_char *snapend;
52
53static inline void
54ether_print(register const u_char *bp, u_int length)
55{
56	register const struct ether_header *ep;
57
58	ep = (const struct ether_header *)bp;
59	if (qflag)
60		(void)printf("%s %s %d: ",
61			     etheraddr_string(ESRC(ep)),
62			     etheraddr_string(EDST(ep)),
63			     length);
64	else
65		(void)printf("%s %s %s %d: ",
66			     etheraddr_string(ESRC(ep)),
67			     etheraddr_string(EDST(ep)),
68			     etherproto_string(ep->ether_type),
69			     length);
70}
71
72/*
73 * This is the top level routine of the printer.  'p' is the points
74 * to the ether header of the packet, 'h->tv' is the timestamp,
75 * 'h->length' is the length of the packet off the wire, and 'h->caplen'
76 * is the number of bytes actually captured.
77 */
78void
79ether_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
80{
81	u_int caplen = h->caplen;
82	u_int length = h->len;
83	struct ether_header *ep;
84	u_short ether_type;
85	u_short extracted_ethertype;
86
87	++infodelay;
88	ts_print(&h->ts);
89
90	if (caplen < ETHER_HDRLEN) {
91		printf("[|ether]");
92		goto out;
93	}
94
95	if (eflag)
96		ether_print(p, length);
97
98	/*
99	 * Some printers want to get back at the ethernet addresses,
100	 * and/or check that they're not walking off the end of the packet.
101	 * Rather than pass them all the way down, we set these globals.
102	 */
103	packetp = p;
104	snapend = p + caplen;
105
106	length -= ETHER_HDRLEN;
107	caplen -= ETHER_HDRLEN;
108	ep = (struct ether_header *)p;
109	p += ETHER_HDRLEN;
110
111	ether_type = ntohs(ep->ether_type);
112
113	/*
114	 * Is it (gag) an 802.3 encapsulation?
115	 */
116	extracted_ethertype = 0;
117	if (ether_type <= ETHERMTU) {
118		/* Try to print the LLC-layer header & higher layers */
119		if (llc_print(p, length, caplen, ESRC(ep), EDST(ep),
120		    &extracted_ethertype) == 0) {
121			/* ether_type not known, print raw packet */
122			if (!eflag)
123				ether_print((u_char *)ep, length + ETHER_HDRLEN);
124			if (extracted_ethertype) {
125				printf("(LLC %s) ",
126			       etherproto_string(htons(extracted_ethertype)));
127			}
128			if (!xflag && !qflag)
129				default_print(p, caplen);
130		}
131	} else if (ether_encap_print(ether_type, p, length, caplen,
132	    &extracted_ethertype) == 0) {
133		/* ether_type not known, print raw packet */
134		if (!eflag)
135			ether_print((u_char *)ep, length + ETHER_HDRLEN);
136		if (!xflag && !qflag)
137			default_print(p, caplen);
138	}
139	if (xflag)
140		default_print(p, caplen);
141 out:
142	putchar('\n');
143	--infodelay;
144	if (infoprint)
145		info(0);
146}
147
148/*
149 * Prints the packet encapsulated in an Ethernet data segment
150 * (or an equivalent encapsulation), given the Ethernet type code.
151 *
152 * Returns non-zero if it can do so, zero if the ethertype is unknown.
153 *
154 * The Ethernet type code is passed through a pointer; if it was
155 * ETHERTYPE_8021Q, it gets updated to be the Ethernet type of
156 * the 802.1Q payload, for the benefit of lower layers that might
157 * want to know what it is.
158 */
159
160int
161ether_encap_print(u_short ethertype, const u_char *p,
162    u_int length, u_int caplen, u_short *extracted_ethertype)
163{
164 recurse:
165	*extracted_ethertype = ethertype;
166
167	switch (ethertype) {
168
169	case ETHERTYPE_IP:
170		ip_print(p, length);
171		return (1);
172
173#ifdef INET6
174	case ETHERTYPE_IPV6:
175		ip6_print(p, length);
176		return (1);
177#endif /*INET6*/
178
179	case ETHERTYPE_ARP:
180	case ETHERTYPE_REVARP:
181		arp_print(p, length, caplen);
182		return (1);
183
184	case ETHERTYPE_DN:
185		decnet_print(p, length, caplen);
186		return (1);
187
188	case ETHERTYPE_ATALK:
189		if (vflag)
190			fputs("et1 ", stdout);
191		atalk_print(p, length);
192		return (1);
193
194	case ETHERTYPE_AARP:
195		aarp_print(p, length);
196		return (1);
197
198	case ETHERTYPE_IPX:
199		ipx_print(p, length);
200		return (1);
201
202	case ETHERTYPE_8021Q:
203		printf("802.1Q vlan#%d P%d%s ",
204		       ntohs(*(u_int16_t *)p) & 0xfff,
205		       ntohs(*(u_int16_t *)p) >> 13,
206		       (ntohs(*(u_int16_t *)p) & 0x1000) ? " CFI" : "");
207		ethertype = ntohs(*(u_int16_t *)(p + 2));
208		p += 4;
209		length -= 4;
210		caplen -= 4;
211		if (ethertype > ETHERMTU)
212			goto recurse;
213
214		*extracted_ethertype = 0;
215
216		if (llc_print(p, length, caplen, p - 18, p - 12,
217		    extracted_ethertype) == 0) {
218			/* ether_type not known, print raw packet */
219			if (!eflag)
220				ether_print(p - 18, length + 4);
221			if (*extracted_ethertype) {
222				printf("(LLC %s) ",
223			       etherproto_string(htons(*extracted_ethertype)));
224			}
225			if (!xflag && !qflag)
226				default_print(p - 18, caplen + 4);
227		}
228		return (1);
229
230	case ETHERTYPE_PPPOED:
231	case ETHERTYPE_PPPOES:
232	case ETHERTYPE_PPPOED2:
233	case ETHERTYPE_PPPOES2:
234		pppoe_print(p, length);
235 		return (1);
236
237	case ETHERTYPE_PPP:
238		printf("ppp");
239		if (length) {
240			printf(": ");
241			ppp_print(p, length);
242		}
243		return (1);
244
245	case ETHERTYPE_MPLS:
246	case ETHERTYPE_MPLS_MULTI:
247		mpls_print(p, length);
248		return (1);
249
250	case ETHERTYPE_LAT:
251	case ETHERTYPE_SCA:
252	case ETHERTYPE_MOPRC:
253	case ETHERTYPE_MOPDL:
254		/* default_print for now */
255	default:
256		return (0);
257	}
258}
259