print-chdlc.c revision 75115 
1/* maybe it should be merged into print-ppp.c */
2/*
3 * Copyright (c) 1990, 1991, 1993, 1994, 1995, 1996, 1997
4 *	The Regents of the University of California.  All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that: (1) source code distributions
8 * retain the above copyright notice and this paragraph in its entirety, (2)
9 * distributions including binary code include the above copyright notice and
10 * this paragraph in its entirety in the documentation or other materials
11 * provided with the distribution, and (3) all advertising materials mentioning
12 * features or use of this software display the following acknowledgement:
13 * ``This product includes software developed by the University of California,
14 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
15 * the University nor the names of its contributors may be used to endorse
16 * or promote products derived from this software without specific prior
17 * written permission.
18 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
19 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
20 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
21 */
22
23#ifndef lint
24static const char rcsid[] =
25    "@(#) $Header: /tcpdump/master/tcpdump/print-chdlc.c,v 1.11 2000/10/09 01:53:19 guy Exp $ (LBL)";
26#endif
27
28#ifdef HAVE_CONFIG_H
29#include "config.h"
30#endif
31
32#include <sys/param.h>
33#include <sys/time.h>
34
35#include <netinet/in.h>
36
37#include <ctype.h>
38#include <netdb.h>
39#include <pcap.h>
40#include <stdio.h>
41
42#include "interface.h"
43#include "addrtoname.h"
44#include "ethertype.h"
45#include "ppp.h"
46#include "chdlc.h"
47
48static void chdlc_slarp_print(const u_char *, u_int);
49
50/* Standard CHDLC printer */
51void
52chdlc_if_print(u_char *user, const struct pcap_pkthdr *h,
53	     register const u_char *p)
54{
55	register u_int length = h->len;
56	register u_int caplen = h->caplen;
57	const struct ip *ip;
58	u_int proto;
59
60	ts_print(&h->ts);
61
62	if (caplen < CHDLC_HDRLEN) {
63		printf("[|chdlc]");
64		goto out;
65	}
66
67	/*
68	 * Some printers want to get back at the link level addresses,
69	 * and/or check that they're not walking off the end of the packet.
70	 * Rather than pass them all the way down, we set these globals.
71	 */
72	proto = ntohs(*(u_short *)&p[2]);
73	packetp = p;
74	snapend = p + caplen;
75
76	if (eflag) {
77		switch (p[0]) {
78		case CHDLC_UNICAST:
79			printf("unicast ");
80			break;
81		case CHDLC_BCAST:
82			printf("bcast ");
83			break;
84		default:
85			printf("0x%02x ", p[0]);
86			break;
87		}
88		printf("%d %04x: ", length, proto);
89	}
90
91	length -= CHDLC_HDRLEN;
92	ip = (struct ip *)(p + CHDLC_HDRLEN);
93	switch (proto) {
94	case ETHERTYPE_IP:
95		ip_print((const u_char *)ip, length);
96		break;
97#ifdef INET6
98	case ETHERTYPE_IPV6:
99		ip6_print((const u_char *)ip, length);
100		break;
101#endif
102	case CHDLC_TYPE_SLARP:
103		chdlc_slarp_print((const u_char *)ip, length);
104		break;
105#if 0
106	case CHDLC_TYPE_CDP:
107		chdlc_cdp_print((const u_char *)ip, length);
108		break;
109#endif
110	}
111	if (xflag)
112		default_print((const u_char *)ip, caplen - CHDLC_HDRLEN);
113out:
114	putchar('\n');
115}
116
117struct cisco_slarp {
118	u_int32_t code;
119#define SLARP_REQUEST	0
120#define SLARP_REPLY	1
121#define SLARP_KEEPALIVE	2
122	union {
123		struct {
124			struct in_addr addr;
125			struct in_addr mask;
126			u_int16_t unused[3];
127		} addr;
128		struct {
129			u_int32_t myseq;
130			u_int32_t yourseq;
131			u_int16_t rel;
132			u_int16_t t1;
133			u_int16_t t2;
134		} keep;
135	} un;
136};
137
138#define SLARP_LEN	18
139
140static void
141chdlc_slarp_print(const u_char *cp, u_int length)
142{
143	struct cisco_slarp *slarp;
144
145	if (length < SLARP_LEN) {
146		printf("[|slarp]");
147		return;
148	}
149
150	slarp = (struct cisco_slarp *)cp;
151	switch (ntohl(slarp->code)) {
152	case SLARP_REQUEST:
153		printf("slarp-request");
154		break;
155	case SLARP_REPLY:
156		printf("slarp-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("slarp-keepalive my=0x%x your=0x%x ",
162			(u_int32_t)ntohl(slarp->un.keep.myseq),
163			(u_int32_t)ntohl(slarp->un.keep.yourseq));
164		printf("reliability=0x%04x t1=%d.%d",
165			ntohs(slarp->un.keep.rel), ntohs(slarp->un.keep.t1),
166			ntohs(slarp->un.keep.t2));
167		break;
168	default:
169		printf("slarp-0x%x unknown", (u_int32_t)ntohl(slarp->code));
170		break;
171	}
172
173	if (SLARP_LEN < length && vflag)
174		printf("(trailing junk: %d bytes)", length - SLARP_LEN);
175}
176