print-sll.c revision 146773 
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 2004/10/28 00:34:29 hannes 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        printf("%3s ",tok2str(sll_pkttype_values,"?",EXTRACT_16BITS(&sllp->sll_pkttype)));
57
58	/*
59	 * XXX - check the link-layer address type value?
60	 * For now, we just assume 6 means Ethernet.
61	 * XXX - print others as strings of hex?
62	 */
63	if (EXTRACT_16BITS(&sllp->sll_halen) == 6)
64		(void)printf("%s ", etheraddr_string(sllp->sll_addr));
65
66	if (!qflag)
67                (void)printf("ethertype %s (0x%04x), length %u: ",
68                         tok2str(ethertype_values,"Unknown", EXTRACT_16BITS(&sllp->sll_protocol)),
69                         EXTRACT_16BITS(&sllp->sll_protocol),
70                         length);
71}
72
73/*
74 * This is the top level routine of the printer.  'p' points to the
75 * Linux "cooked capture" header of the packet, 'h->ts' is the timestamp,
76 * 'h->len' is the length of the packet off the wire, and 'h->caplen'
77 * is the number of bytes actually captured.
78 */
79u_int
80sll_if_print(const struct pcap_pkthdr *h, const u_char *p)
81{
82	u_int caplen = h->caplen;
83	u_int length = h->len;
84	register const struct sll_header *sllp;
85	u_short ether_type;
86	u_short extracted_ethertype;
87
88	if (caplen < SLL_HDR_LEN) {
89		/*
90		 * XXX - this "can't happen" because "pcap-linux.c" always
91		 * adds this many bytes of header to every packet in a
92		 * cooked socket capture.
93		 */
94		printf("[|sll]");
95		return (caplen);
96	}
97
98	sllp = (const struct sll_header *)p;
99
100	if (eflag)
101		sll_print(sllp, length);
102
103	/*
104	 * Go past the cooked-mode header.
105	 */
106	length -= SLL_HDR_LEN;
107	caplen -= SLL_HDR_LEN;
108	p += SLL_HDR_LEN;
109
110	ether_type = ntohs(sllp->sll_protocol);
111
112	/*
113	 * Is it (gag) an 802.3 encapsulation, or some non-Ethernet
114	 * packet type?
115	 */
116	extracted_ethertype = 0;
117	if (ether_type <= ETHERMTU) {
118		/*
119		 * Yes - what type is it?
120		 */
121		switch (ether_type) {
122
123		case LINUX_SLL_P_802_3:
124			/*
125			 * Ethernet_802.3 IPX frame.
126			 */
127			ipx_print(p, length);
128			break;
129
130		case LINUX_SLL_P_802_2:
131			/*
132			 * 802.2.
133			 * Try to print the LLC-layer header & higher layers.
134			 */
135			if (llc_print(p, length, caplen, NULL, NULL,
136			    &extracted_ethertype) == 0)
137				goto unknown;	/* unknown LLC type */
138			break;
139
140		default:
141		unknown:
142			/* ether_type not known, print raw packet */
143			if (!eflag)
144				sll_print(sllp, length + SLL_HDR_LEN);
145			if (extracted_ethertype) {
146				printf("(LLC %s) ",
147			       etherproto_string(htons(extracted_ethertype)));
148			}
149			if (!xflag && !qflag)
150				default_print(p, caplen);
151			break;
152		}
153	} else if (ether_encap_print(ether_type, p, length, caplen,
154	    &extracted_ethertype) == 0) {
155		/* ether_type not known, print raw packet */
156		if (!eflag)
157			sll_print(sllp, length + SLL_HDR_LEN);
158		if (!xflag && !qflag)
159			default_print(p, caplen);
160	}
161
162	return (SLL_HDR_LEN);
163}
164