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#define NETDISSECT_REWORKED
23#ifdef HAVE_CONFIG_H
24#include "config.h"
25#endif
26
27#include <tcpdump-stdinc.h>
28
29#include "interface.h"
30#include "addrtoname.h"
31#include "ethertype.h"
32#include "extract.h"
33#include "chdlc.h"
34
35static void chdlc_slarp_print(netdissect_options *, const u_char *, u_int);
36
37static const struct tok chdlc_cast_values[] = {
38    { CHDLC_UNICAST, "unicast" },
39    { CHDLC_BCAST, "bcast" },
40    { 0, NULL}
41};
42
43
44/* Standard CHDLC printer */
45u_int
46chdlc_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, register const u_char *p)
47{
48	register u_int length = h->len;
49	register u_int caplen = h->caplen;
50
51	if (caplen < CHDLC_HDRLEN) {
52		ND_PRINT((ndo, "[|chdlc]"));
53		return (caplen);
54	}
55        return (chdlc_print(ndo, p,length));
56}
57
58u_int
59chdlc_print(netdissect_options *ndo, register const u_char *p, u_int length)
60{
61	u_int proto;
62
63	proto = EXTRACT_16BITS(&p[2]);
64	if (ndo->ndo_eflag) {
65                ND_PRINT((ndo, "%s, ethertype %s (0x%04x), length %u: ",
66                       tok2str(chdlc_cast_values, "0x%02x", p[0]),
67                       tok2str(ethertype_values, "Unknown", proto),
68                       proto,
69                       length));
70	}
71
72	length -= CHDLC_HDRLEN;
73	p += CHDLC_HDRLEN;
74
75	switch (proto) {
76	case ETHERTYPE_IP:
77		ip_print(ndo, p, length);
78		break;
79	case ETHERTYPE_IPV6:
80		ip6_print(ndo, p, length);
81		break;
82	case CHDLC_TYPE_SLARP:
83		chdlc_slarp_print(ndo, p, length);
84		break;
85#if 0
86	case CHDLC_TYPE_CDP:
87		chdlc_cdp_print(p, length);
88		break;
89#endif
90        case ETHERTYPE_MPLS:
91        case ETHERTYPE_MPLS_MULTI:
92                mpls_print(ndo, p, length);
93		break;
94        case ETHERTYPE_ISO:
95                /* is the fudge byte set ? lets verify by spotting ISO headers */
96                if (*(p+1) == 0x81 ||
97                    *(p+1) == 0x82 ||
98                    *(p+1) == 0x83)
99                    isoclns_print(ndo, p + 1, length - 1, length - 1);
100                else
101                    isoclns_print(ndo, p, length, length);
102                break;
103	default:
104                if (!ndo->ndo_eflag)
105                        ND_PRINT((ndo, "unknown CHDLC protocol (0x%04x)", proto));
106                break;
107	}
108
109	return (CHDLC_HDRLEN);
110}
111
112/*
113 * The fixed-length portion of a SLARP packet.
114 */
115struct cisco_slarp {
116	uint8_t code[4];
117#define SLARP_REQUEST	0
118#define SLARP_REPLY	1
119#define SLARP_KEEPALIVE	2
120	union {
121		struct {
122			uint8_t addr[4];
123			uint8_t mask[4];
124		} addr;
125		struct {
126			uint8_t myseq[4];
127			uint8_t yourseq[4];
128			uint8_t rel[2];
129		} keep;
130	} un;
131};
132
133#define SLARP_MIN_LEN	14
134#define SLARP_MAX_LEN	18
135
136static void
137chdlc_slarp_print(netdissect_options *ndo, const u_char *cp, u_int length)
138{
139	const struct cisco_slarp *slarp;
140        u_int sec,min,hrs,days;
141
142	ND_PRINT((ndo, "SLARP (length: %u), ",length));
143	if (length < SLARP_MIN_LEN)
144		goto trunc;
145
146	slarp = (const struct cisco_slarp *)cp;
147	ND_TCHECK2(*slarp, SLARP_MIN_LEN);
148	switch (EXTRACT_32BITS(&slarp->code)) {
149	case SLARP_REQUEST:
150		ND_PRINT((ndo, "request"));
151		/*
152		 * At least according to William "Chops" Westfield's
153		 * message in
154		 *
155		 *	http://www.nethelp.no/net/cisco-hdlc.txt
156		 *
157		 * the address and mask aren't used in requests -
158		 * they're just zero.
159		 */
160		break;
161	case SLARP_REPLY:
162		ND_PRINT((ndo, "reply %s/%s",
163			ipaddr_string(ndo, &slarp->un.addr.addr),
164			ipaddr_string(ndo, &slarp->un.addr.mask)));
165		break;
166	case SLARP_KEEPALIVE:
167		ND_PRINT((ndo, "keepalive: mineseen=0x%08x, yourseen=0x%08x, reliability=0x%04x",
168                       EXTRACT_32BITS(&slarp->un.keep.myseq),
169                       EXTRACT_32BITS(&slarp->un.keep.yourseq),
170                       EXTRACT_16BITS(&slarp->un.keep.rel)));
171
172                if (length >= SLARP_MAX_LEN) { /* uptime-stamp is optional */
173                        cp += SLARP_MIN_LEN;
174                        ND_TCHECK2(*cp, 4);
175                        sec = EXTRACT_32BITS(cp) / 1000;
176                        min = sec / 60; sec -= min * 60;
177                        hrs = min / 60; min -= hrs * 60;
178                        days = hrs / 24; hrs -= days * 24;
179                        ND_PRINT((ndo, ", link uptime=%ud%uh%um%us",days,hrs,min,sec));
180                }
181		break;
182	default:
183		ND_PRINT((ndo, "0x%02x unknown", EXTRACT_32BITS(&slarp->code)));
184                if (ndo->ndo_vflag <= 1)
185                    print_unknown_data(ndo,cp+4,"\n\t",length-4);
186		break;
187	}
188
189	if (SLARP_MAX_LEN < length && ndo->ndo_vflag)
190		ND_PRINT((ndo, ", (trailing junk: %d bytes)", length - SLARP_MAX_LEN));
191        if (ndo->ndo_vflag > 1)
192            print_unknown_data(ndo,cp+4,"\n\t",length-4);
193	return;
194
195trunc:
196	ND_PRINT((ndo, "[|slarp]"));
197}
198
199
200/*
201 * Local Variables:
202 * c-style: whitesmith
203 * c-basic-offset: 8
204 * End:
205 */
206