print-chdlc.c revision 162017 
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 1.32.2.8 2005/08/23 10:29:42 hannes 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
52	if (caplen < CHDLC_HDRLEN) {
53		printf("[|chdlc]");
54		return (caplen);
55	}
56        return (chdlc_print(p,length));
57}
58
59u_int
60chdlc_print(register const u_char *p, u_int length) {
61	u_int proto;
62	const struct ip *ip;
63
64	proto = EXTRACT_16BITS(&p[2]);
65	if (eflag) {
66		switch (p[0]) {
67		case CHDLC_UNICAST:
68			printf("unicast ");
69			break;
70		case CHDLC_BCAST:
71			printf("bcast ");
72			break;
73		default:
74			printf("0x%02x ", p[0]);
75			break;
76		}
77		printf("%d %04x: ", length, proto);
78	}
79
80	length -= CHDLC_HDRLEN;
81	ip = (const struct ip *)(p + CHDLC_HDRLEN);
82	switch (proto) {
83	case ETHERTYPE_IP:
84		ip_print(gndo, (const u_char *)ip, length);
85		break;
86#ifdef INET6
87	case ETHERTYPE_IPV6:
88		ip6_print((const u_char *)ip, length);
89		break;
90#endif
91	case CHDLC_TYPE_SLARP:
92		chdlc_slarp_print((const u_char *)ip, length);
93		break;
94#if 0
95	case CHDLC_TYPE_CDP:
96		chdlc_cdp_print((const u_char *)ip, length);
97		break;
98#endif
99        case ETHERTYPE_MPLS:
100        case ETHERTYPE_MPLS_MULTI:
101                mpls_print((const u_char *)(ip), length);
102		break;
103        case ETHERTYPE_ISO:
104                /* is the fudge byte set ? lets verify by spotting ISO headers */
105                if (*(p+CHDLC_HDRLEN+1) == 0x81 ||
106                    *(p+CHDLC_HDRLEN+1) == 0x82 ||
107                    *(p+CHDLC_HDRLEN+1) == 0x83)
108                    isoclns_print(p+CHDLC_HDRLEN+1, length-1, length-1);
109                else
110                    isoclns_print(p+CHDLC_HDRLEN, length, length);
111                break;
112	default:
113                printf("unknown CHDLC protocol (0x%04x)", proto);
114                break;
115	}
116
117	return (CHDLC_HDRLEN);
118}
119
120/*
121 * The fixed-length portion of a SLARP packet.
122 */
123struct cisco_slarp {
124	u_int8_t code[4];
125#define SLARP_REQUEST	0
126#define SLARP_REPLY	1
127#define SLARP_KEEPALIVE	2
128	union {
129		struct {
130			u_int8_t addr[4];
131			u_int8_t mask[4];
132		} addr;
133		struct {
134			u_int8_t myseq[4];
135			u_int8_t yourseq[4];
136			u_int8_t rel[2];
137		} keep;
138	} un;
139};
140
141#define SLARP_MIN_LEN	14
142#define SLARP_MAX_LEN	18
143
144static void
145chdlc_slarp_print(const u_char *cp, u_int length)
146{
147	const struct cisco_slarp *slarp;
148        u_int sec,min,hrs,days;
149
150        printf("SLARP (length: %u), ",length);
151	if (length < SLARP_MIN_LEN)
152		goto trunc;
153
154	slarp = (const struct cisco_slarp *)cp;
155	TCHECK2(*slarp, SLARP_MIN_LEN);
156	switch (EXTRACT_32BITS(&slarp->code)) {
157	case SLARP_REQUEST:
158		printf("request");
159		/*
160		 * At least according to William "Chops" Westfield's
161		 * message in
162		 *
163		 *	http://www.nethelp.no/net/cisco-hdlc.txt
164		 *
165		 * the address and mask aren't used in requests -
166		 * they're just zero.
167		 */
168		break;
169	case SLARP_REPLY:
170		printf("reply %s/%s",
171			ipaddr_string(&slarp->un.addr.addr),
172			ipaddr_string(&slarp->un.addr.mask));
173		break;
174	case SLARP_KEEPALIVE:
175		printf("keepalive: mineseen=0x%08x, yourseen=0x%08x, reliability=0x%04x",
176                       EXTRACT_32BITS(&slarp->un.keep.myseq),
177                       EXTRACT_32BITS(&slarp->un.keep.yourseq),
178                       EXTRACT_16BITS(&slarp->un.keep.rel));
179
180                if (length >= SLARP_MAX_LEN) { /* uptime-stamp is optional */
181                        cp += SLARP_MIN_LEN;
182                        if (!TTEST2(*cp, 4))
183                                goto trunc;
184                        sec = EXTRACT_32BITS(cp) / 1000;
185                        min = sec / 60; sec -= min * 60;
186                        hrs = min / 60; min -= hrs * 60;
187                        days = hrs / 24; hrs -= days * 24;
188                        printf(", link uptime=%ud%uh%um%us",days,hrs,min,sec);
189                }
190		break;
191	default:
192		printf("0x%02x unknown", EXTRACT_32BITS(&slarp->code));
193                if (vflag <= 1)
194                    print_unknown_data(cp+4,"\n\t",length-4);
195		break;
196	}
197
198	if (SLARP_MAX_LEN < length && vflag)
199		printf(", (trailing junk: %d bytes)", length - SLARP_MAX_LEN);
200        if (vflag > 1)
201            print_unknown_data(cp+4,"\n\t",length-4);
202	return;
203
204trunc:
205	printf("[|slarp]");
206}
207
208
209/*
210 * Local Variables:
211 * c-style: whitesmith
212 * c-basic-offset: 8
213 * End:
214 */
215