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/* \summary: Cisco HDLC printer */
23
24#ifdef HAVE_CONFIG_H
25#include "config.h"
26#endif
27
28#include <netdissect-stdinc.h>
29
30#include "netdissect.h"
31#include "addrtoname.h"
32#include "ethertype.h"
33#include "extract.h"
34#include "chdlc.h"
35
36static void chdlc_slarp_print(netdissect_options *, const u_char *, u_int);
37
38static const struct tok chdlc_cast_values[] = {
39    { CHDLC_UNICAST, "unicast" },
40    { CHDLC_BCAST, "bcast" },
41    { 0, NULL}
42};
43
44
45/* Standard CHDLC printer */
46u_int
47chdlc_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, register const u_char *p)
48{
49	return chdlc_print(ndo, p, h->len);
50}
51
52u_int
53chdlc_print(netdissect_options *ndo, register const u_char *p, u_int length)
54{
55	u_int proto;
56	const u_char *bp = p;
57
58	if (length < CHDLC_HDRLEN)
59		goto trunc;
60	ND_TCHECK2(*p, CHDLC_HDRLEN);
61	proto = EXTRACT_16BITS(&p[2]);
62	if (ndo->ndo_eflag) {
63                ND_PRINT((ndo, "%s, ethertype %s (0x%04x), length %u: ",
64                       tok2str(chdlc_cast_values, "0x%02x", p[0]),
65                       tok2str(ethertype_values, "Unknown", proto),
66                       proto,
67                       length));
68	}
69
70	length -= CHDLC_HDRLEN;
71	p += CHDLC_HDRLEN;
72
73	switch (proto) {
74	case ETHERTYPE_IP:
75		ip_print(ndo, p, length);
76		break;
77	case ETHERTYPE_IPV6:
78		ip6_print(ndo, p, length);
79		break;
80	case CHDLC_TYPE_SLARP:
81		chdlc_slarp_print(ndo, p, length);
82		break;
83#if 0
84	case CHDLC_TYPE_CDP:
85		chdlc_cdp_print(p, length);
86		break;
87#endif
88        case ETHERTYPE_MPLS:
89        case ETHERTYPE_MPLS_MULTI:
90                mpls_print(ndo, p, length);
91		break;
92        case ETHERTYPE_ISO:
93                /* is the fudge byte set ? lets verify by spotting ISO headers */
94                if (length < 2)
95                    goto trunc;
96                ND_TCHECK_16BITS(p);
97                if (*(p+1) == 0x81 ||
98                    *(p+1) == 0x82 ||
99                    *(p+1) == 0x83)
100                    isoclns_print(ndo, p + 1, length - 1);
101                else
102                    isoclns_print(ndo, p, length);
103                break;
104	default:
105                if (!ndo->ndo_eflag)
106                        ND_PRINT((ndo, "unknown CHDLC protocol (0x%04x)", proto));
107                break;
108	}
109
110	return (CHDLC_HDRLEN);
111
112trunc:
113	ND_PRINT((ndo, "[|chdlc]"));
114	return ndo->ndo_snapend - bp;
115}
116
117/*
118 * The fixed-length portion of a SLARP packet.
119 */
120struct cisco_slarp {
121	uint8_t code[4];
122#define SLARP_REQUEST	0
123#define SLARP_REPLY	1
124#define SLARP_KEEPALIVE	2
125	union {
126		struct {
127			uint8_t addr[4];
128			uint8_t mask[4];
129		} addr;
130		struct {
131			uint8_t myseq[4];
132			uint8_t yourseq[4];
133			uint8_t rel[2];
134		} keep;
135	} un;
136};
137
138#define SLARP_MIN_LEN	14
139#define SLARP_MAX_LEN	18
140
141static void
142chdlc_slarp_print(netdissect_options *ndo, const u_char *cp, u_int length)
143{
144	const struct cisco_slarp *slarp;
145        u_int sec,min,hrs,days;
146
147	ND_PRINT((ndo, "SLARP (length: %u), ",length));
148	if (length < SLARP_MIN_LEN)
149		goto trunc;
150
151	slarp = (const struct cisco_slarp *)cp;
152	ND_TCHECK2(*slarp, SLARP_MIN_LEN);
153	switch (EXTRACT_32BITS(&slarp->code)) {
154	case SLARP_REQUEST:
155		ND_PRINT((ndo, "request"));
156		/*
157		 * At least according to William "Chops" Westfield's
158		 * message in
159		 *
160		 *	http://www.nethelp.no/net/cisco-hdlc.txt
161		 *
162		 * the address and mask aren't used in requests -
163		 * they're just zero.
164		 */
165		break;
166	case SLARP_REPLY:
167		ND_PRINT((ndo, "reply %s/%s",
168			ipaddr_string(ndo, &slarp->un.addr.addr),
169			ipaddr_string(ndo, &slarp->un.addr.mask)));
170		break;
171	case SLARP_KEEPALIVE:
172		ND_PRINT((ndo, "keepalive: mineseen=0x%08x, yourseen=0x%08x, reliability=0x%04x",
173                       EXTRACT_32BITS(&slarp->un.keep.myseq),
174                       EXTRACT_32BITS(&slarp->un.keep.yourseq),
175                       EXTRACT_16BITS(&slarp->un.keep.rel)));
176
177                if (length >= SLARP_MAX_LEN) { /* uptime-stamp is optional */
178                        cp += SLARP_MIN_LEN;
179                        ND_TCHECK2(*cp, 4);
180                        sec = EXTRACT_32BITS(cp) / 1000;
181                        min = sec / 60; sec -= min * 60;
182                        hrs = min / 60; min -= hrs * 60;
183                        days = hrs / 24; hrs -= days * 24;
184                        ND_PRINT((ndo, ", link uptime=%ud%uh%um%us",days,hrs,min,sec));
185                }
186		break;
187	default:
188		ND_PRINT((ndo, "0x%02x unknown", EXTRACT_32BITS(&slarp->code)));
189                if (ndo->ndo_vflag <= 1)
190                    print_unknown_data(ndo,cp+4,"\n\t",length-4);
191		break;
192	}
193
194	if (SLARP_MAX_LEN < length && ndo->ndo_vflag)
195		ND_PRINT((ndo, ", (trailing junk: %d bytes)", length - SLARP_MAX_LEN));
196        if (ndo->ndo_vflag > 1)
197            print_unknown_data(ndo,cp+4,"\n\t",length-4);
198	return;
199
200trunc:
201	ND_PRINT((ndo, "[|slarp]"));
202}
203
204
205/*
206 * Local Variables:
207 * c-style: whitesmith
208 * c-basic-offset: 8
209 * End:
210 */
211