print-chdlc.c revision 127668 
1/*
2 * Copyright (c) 1990, 1991, 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
22#ifndef lint
23static const char rcsid[] _U_ =
24    "@(#) $Header: /tcpdump/master/tcpdump/print-chdlc.c,v 1.28.2.3 2004/03/24 00:46:03 guy Exp $ (LBL)";
25#endif
26
27#ifdef HAVE_CONFIG_H
28#include "config.h"
29#endif
30
31#include <tcpdump-stdinc.h>
32
33#include <pcap.h>
34#include <stdio.h>
35
36#include "interface.h"
37#include "addrtoname.h"
38#include "ethertype.h"
39#include "extract.h"
40#include "ppp.h"
41#include "chdlc.h"
42
43static void chdlc_slarp_print(const u_char *, u_int);
44
45/* Standard CHDLC printer */
46u_int
47chdlc_if_print(const struct pcap_pkthdr *h, register const u_char *p)
48{
49	register u_int length = h->len;
50	register u_int caplen = h->caplen;
51	const struct ip *ip;
52	u_int proto;
53
54	if (caplen < CHDLC_HDRLEN) {
55		printf("[|chdlc]");
56		return (caplen);
57	}
58
59	proto = EXTRACT_16BITS(&p[2]);
60	if (eflag) {
61		switch (p[0]) {
62		case CHDLC_UNICAST:
63			printf("unicast ");
64			break;
65		case CHDLC_BCAST:
66			printf("bcast ");
67			break;
68		default:
69			printf("0x%02x ", p[0]);
70			break;
71		}
72		printf("%d %04x: ", length, proto);
73	}
74
75	length -= CHDLC_HDRLEN;
76	ip = (const struct ip *)(p + CHDLC_HDRLEN);
77	switch (proto) {
78	case ETHERTYPE_IP:
79		ip_print((const u_char *)ip, length);
80		break;
81#ifdef INET6
82	case ETHERTYPE_IPV6:
83		ip6_print((const u_char *)ip, length);
84		break;
85#endif
86	case CHDLC_TYPE_SLARP:
87		chdlc_slarp_print((const u_char *)ip, length);
88		break;
89#if 0
90	case CHDLC_TYPE_CDP:
91		chdlc_cdp_print((const u_char *)ip, length);
92		break;
93#endif
94        case ETHERTYPE_MPLS:
95        case ETHERTYPE_MPLS_MULTI:
96                mpls_print((const u_char *)(ip), length);
97		break;
98        case ETHERTYPE_ISO:
99                /* is the fudge byte set ? lets verify by spotting ISO headers */
100                if (*(p+CHDLC_HDRLEN+1) == 0x81 ||
101                    *(p+CHDLC_HDRLEN+1) == 0x82 ||
102                    *(p+CHDLC_HDRLEN+1) == 0x83)
103                    isoclns_print(p+CHDLC_HDRLEN+1, length-1, length-1);
104                else
105                    isoclns_print(p+CHDLC_HDRLEN, length, length);
106                break;
107	default:
108                printf("unknown CHDLC protocol (0x%04x)", proto);
109                break;
110	}
111
112	return (CHDLC_HDRLEN);
113}
114
115struct cisco_slarp {
116	u_int32_t code;
117#define SLARP_REQUEST	0
118#define SLARP_REPLY	1
119#define SLARP_KEEPALIVE	2
120	union {
121		struct {
122			struct in_addr addr;
123			struct in_addr mask;
124			u_int16_t unused[3];
125		} addr;
126		struct {
127			u_int32_t myseq;
128			u_int32_t yourseq;
129			u_int16_t rel;
130			u_int16_t t1;
131			u_int16_t t2;
132		} keep;
133	} un;
134};
135
136#define SLARP_LEN	18
137
138static void
139chdlc_slarp_print(const u_char *cp, u_int length)
140{
141	const struct cisco_slarp *slarp;
142
143	if (length < SLARP_LEN)
144		goto trunc;
145
146	slarp = (const struct cisco_slarp *)cp;
147	TCHECK(*slarp);
148        printf("SLARP (length: %u), ",length);
149	switch (EXTRACT_32BITS(&slarp->code)) {
150	case SLARP_REQUEST:
151		printf("request");
152                /* ok we do not know it - but lets at least dump it */
153                print_unknown_data(cp+4,"\n\t",length-4);
154		break;
155	case SLARP_REPLY:
156		printf("reply %s/%s",
157			ipaddr_string(&slarp->un.addr.addr),
158			ipaddr_string(&slarp->un.addr.mask));
159		break;
160	case SLARP_KEEPALIVE:
161		printf("keepalive: mineseen=0x%08x, yourseen=0x%08x",
162			EXTRACT_32BITS(&slarp->un.keep.myseq),
163			EXTRACT_32BITS(&slarp->un.keep.yourseq));
164		printf(", reliability=0x%04x, t1=%d.%d",
165			EXTRACT_16BITS(&slarp->un.keep.rel),
166			EXTRACT_16BITS(&slarp->un.keep.t1),
167			EXTRACT_16BITS(&slarp->un.keep.t2));
168		break;
169	default:
170		printf("0x%02x unknown", EXTRACT_32BITS(&slarp->code));
171                if (vflag <= 1)
172                    print_unknown_data(cp+4,"\n\t",length-4);
173		break;
174	}
175
176	if (SLARP_LEN < length && vflag)
177		printf(", (trailing junk: %d bytes)", length - SLARP_LEN);
178        if (vflag > 1)
179            print_unknown_data(cp+4,"\n\t",length-4);
180	return;
181
182trunc:
183	printf("[|slarp]");
184}
185