print-sll.c revision 172683 
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#ifndef lint
22static const char rcsid[] _U_ =
23    "@(#) $Header: /tcpdump/master/tcpdump/print-sll.c,v 1.16.2.3 2005/11/13 12:13:00 guy Exp $ (LBL)";
24#endif
25
26#ifdef HAVE_CONFIG_H
27#include "config.h"
28#endif
29
30#include <tcpdump-stdinc.h>
31
32#include <stdio.h>
33#include <string.h>
34#include <pcap.h>
35
36#include "interface.h"
37#include "addrtoname.h"
38#include "ethertype.h"
39#include "extract.h"
40
41#include "ether.h"
42#include "sll.h"
43
44const struct tok sll_pkttype_values[] = {
45    { LINUX_SLL_HOST, "In" },
46    { LINUX_SLL_BROADCAST, "B" },
47    { LINUX_SLL_MULTICAST, "M" },
48    { LINUX_SLL_OTHERHOST, "P" },
49    { LINUX_SLL_OUTGOING, "Out" },
50    { 0, NULL}
51};
52
53static inline void
54sll_print(register const struct sll_header *sllp, u_int length)
55{
56	u_short ether_type;
57
58        printf("%3s ",tok2str(sll_pkttype_values,"?",EXTRACT_16BITS(&sllp->sll_pkttype)));
59
60	/*
61	 * XXX - check the link-layer address type value?
62	 * For now, we just assume 6 means Ethernet.
63	 * XXX - print others as strings of hex?
64	 */
65	if (EXTRACT_16BITS(&sllp->sll_halen) == 6)
66		(void)printf("%s ", etheraddr_string(sllp->sll_addr));
67
68	if (!qflag) {
69		ether_type = EXTRACT_16BITS(&sllp->sll_protocol);
70
71		if (ether_type <= ETHERMTU) {
72			/*
73			 * Not an Ethernet type; what type is it?
74			 */
75			switch (ether_type) {
76
77			case LINUX_SLL_P_802_3:
78				/*
79				 * Ethernet_802.3 IPX frame.
80				 */
81				(void)printf("802.3");
82				break;
83
84			case LINUX_SLL_P_802_2:
85				/*
86				 * 802.2.
87				 */
88				(void)printf("802.3");
89				break;
90
91			default:
92				/*
93				 * What is it?
94				 */
95				(void)printf("ethertype Unknown (0x%04x)",
96				    ether_type);
97				break;
98			}
99		} else {
100			(void)printf("ethertype %s (0x%04x)",
101			    tok2str(ethertype_values, "Unknown", ether_type),
102			    ether_type);
103		}
104		(void)printf(", length %u: ", length);
105	}
106}
107
108/*
109 * This is the top level routine of the printer.  'p' points to the
110 * Linux "cooked capture" header of the packet, 'h->ts' is the timestamp,
111 * 'h->len' is the length of the packet off the wire, and 'h->caplen'
112 * is the number of bytes actually captured.
113 */
114u_int
115sll_if_print(const struct pcap_pkthdr *h, const u_char *p)
116{
117	u_int caplen = h->caplen;
118	u_int length = h->len;
119	register const struct sll_header *sllp;
120	u_short ether_type;
121	u_short extracted_ethertype;
122
123	if (caplen < SLL_HDR_LEN) {
124		/*
125		 * XXX - this "can't happen" because "pcap-linux.c" always
126		 * adds this many bytes of header to every packet in a
127		 * cooked socket capture.
128		 */
129		printf("[|sll]");
130		return (caplen);
131	}
132
133	sllp = (const struct sll_header *)p;
134
135	if (eflag)
136		sll_print(sllp, length);
137
138	/*
139	 * Go past the cooked-mode header.
140	 */
141	length -= SLL_HDR_LEN;
142	caplen -= SLL_HDR_LEN;
143	p += SLL_HDR_LEN;
144
145	ether_type = ntohs(sllp->sll_protocol);
146
147	/*
148	 * Is it (gag) an 802.3 encapsulation, or some non-Ethernet
149	 * packet type?
150	 */
151	if (ether_type <= ETHERMTU) {
152		/*
153		 * Yes - what type is it?
154		 */
155		switch (ether_type) {
156
157		case LINUX_SLL_P_802_3:
158			/*
159			 * Ethernet_802.3 IPX frame.
160			 */
161			ipx_print(p, length);
162			break;
163
164		case LINUX_SLL_P_802_2:
165			/*
166			 * 802.2.
167			 * Try to print the LLC-layer header & higher layers.
168			 */
169			if (llc_print(p, length, caplen, NULL, NULL,
170			    &extracted_ethertype) == 0)
171				goto unknown;	/* unknown LLC type */
172			break;
173
174		default:
175			extracted_ethertype = 0;
176			/*FALLTHROUGH*/
177
178		unknown:
179			/* ether_type not known, print raw packet */
180			if (!eflag)
181				sll_print(sllp, length + SLL_HDR_LEN);
182			if (extracted_ethertype) {
183				printf("(LLC %s) ",
184			       etherproto_string(htons(extracted_ethertype)));
185			}
186			if (!suppress_default_print)
187				default_print(p, caplen);
188			break;
189		}
190	} else if (ether_encap_print(ether_type, p, length, caplen,
191	    &extracted_ethertype) == 0) {
192		/* ether_type not known, print raw packet */
193		if (!eflag)
194			sll_print(sllp, length + SLL_HDR_LEN);
195		if (!suppress_default_print)
196			default_print(p, caplen);
197	}
198
199	return (SLL_HDR_LEN);
200}
201