xref: /freebsd/contrib/tcpdump/print-chdlc.c (revision 3e0efd2ec4fcb4cd68fb8ccf8aea6fc6151c454b)
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
23 static const char rcsid[] _U_ =
24     "@(#) $Header: /tcpdump/master/tcpdump/print-chdlc.c,v 1.43 2005-11-29 08:56:19 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 
43 static void chdlc_slarp_print(const u_char *, u_int);
44 
45 const struct tok chdlc_cast_values[] = {
46     { CHDLC_UNICAST, "unicast" },
47     { CHDLC_BCAST, "bcast" },
48     { 0, NULL}
49 };
50 
51 
52 /* Standard CHDLC printer */
53 u_int
54 chdlc_if_print(const struct pcap_pkthdr *h, register const u_char *p)
55 {
56 	register u_int length = h->len;
57 	register u_int caplen = h->caplen;
58 
59 	if (caplen < CHDLC_HDRLEN) {
60 		printf("[|chdlc]");
61 		return (caplen);
62 	}
63         return (chdlc_print(p,length));
64 }
65 
66 u_int
67 chdlc_print(register const u_char *p, u_int length) {
68 	u_int proto;
69 
70 	proto = EXTRACT_16BITS(&p[2]);
71 	if (eflag) {
72                 printf("%s, ethertype %s (0x%04x), length %u: ",
73                        tok2str(chdlc_cast_values, "0x%02x", p[0]),
74                        tok2str(ethertype_values, "Unknown", proto),
75                        proto,
76                        length);
77 	}
78 
79 	length -= CHDLC_HDRLEN;
80 	p += CHDLC_HDRLEN;
81 
82 	switch (proto) {
83 	case ETHERTYPE_IP:
84 		ip_print(gndo, p, length);
85 		break;
86 #ifdef INET6
87 	case ETHERTYPE_IPV6:
88 		ip6_print(gndo, p, length);
89 		break;
90 #endif
91 	case CHDLC_TYPE_SLARP:
92 		chdlc_slarp_print(p, length);
93 		break;
94 #if 0
95 	case CHDLC_TYPE_CDP:
96 		chdlc_cdp_print(p, length);
97 		break;
98 #endif
99         case ETHERTYPE_MPLS:
100         case ETHERTYPE_MPLS_MULTI:
101                 mpls_print(p, length);
102 		break;
103         case ETHERTYPE_ISO:
104                 /* is the fudge byte set ? lets verify by spotting ISO headers */
105                 if (*(p+1) == 0x81 ||
106                     *(p+1) == 0x82 ||
107                     *(p+1) == 0x83)
108                     isoclns_print(p+1, length-1, length-1);
109                 else
110                     isoclns_print(p, length, length);
111                 break;
112 	default:
113                 if (!eflag)
114                         printf("unknown CHDLC protocol (0x%04x)", proto);
115                 break;
116 	}
117 
118 	return (CHDLC_HDRLEN);
119 }
120 
121 /*
122  * The fixed-length portion of a SLARP packet.
123  */
124 struct cisco_slarp {
125 	u_int8_t code[4];
126 #define SLARP_REQUEST	0
127 #define SLARP_REPLY	1
128 #define SLARP_KEEPALIVE	2
129 	union {
130 		struct {
131 			u_int8_t addr[4];
132 			u_int8_t mask[4];
133 		} addr;
134 		struct {
135 			u_int8_t myseq[4];
136 			u_int8_t yourseq[4];
137 			u_int8_t rel[2];
138 		} keep;
139 	} un;
140 };
141 
142 #define SLARP_MIN_LEN	14
143 #define SLARP_MAX_LEN	18
144 
145 static void
146 chdlc_slarp_print(const u_char *cp, u_int length)
147 {
148 	const struct cisco_slarp *slarp;
149         u_int sec,min,hrs,days;
150 
151         printf("SLARP (length: %u), ",length);
152 	if (length < SLARP_MIN_LEN)
153 		goto trunc;
154 
155 	slarp = (const struct cisco_slarp *)cp;
156 	TCHECK2(*slarp, SLARP_MIN_LEN);
157 	switch (EXTRACT_32BITS(&slarp->code)) {
158 	case SLARP_REQUEST:
159 		printf("request");
160 		/*
161 		 * At least according to William "Chops" Westfield's
162 		 * message in
163 		 *
164 		 *	http://www.nethelp.no/net/cisco-hdlc.txt
165 		 *
166 		 * the address and mask aren't used in requests -
167 		 * they're just zero.
168 		 */
169 		break;
170 	case SLARP_REPLY:
171 		printf("reply %s/%s",
172 			ipaddr_string(&slarp->un.addr.addr),
173 			ipaddr_string(&slarp->un.addr.mask));
174 		break;
175 	case SLARP_KEEPALIVE:
176 		printf("keepalive: mineseen=0x%08x, yourseen=0x%08x, reliability=0x%04x",
177                        EXTRACT_32BITS(&slarp->un.keep.myseq),
178                        EXTRACT_32BITS(&slarp->un.keep.yourseq),
179                        EXTRACT_16BITS(&slarp->un.keep.rel));
180 
181                 if (length >= SLARP_MAX_LEN) { /* uptime-stamp is optional */
182                         cp += SLARP_MIN_LEN;
183                         if (!TTEST2(*cp, 4))
184                                 goto trunc;
185                         sec = EXTRACT_32BITS(cp) / 1000;
186                         min = sec / 60; sec -= min * 60;
187                         hrs = min / 60; min -= hrs * 60;
188                         days = hrs / 24; hrs -= days * 24;
189                         printf(", link uptime=%ud%uh%um%us",days,hrs,min,sec);
190                 }
191 		break;
192 	default:
193 		printf("0x%02x unknown", EXTRACT_32BITS(&slarp->code));
194                 if (vflag <= 1)
195                     print_unknown_data(cp+4,"\n\t",length-4);
196 		break;
197 	}
198 
199 	if (SLARP_MAX_LEN < length && vflag)
200 		printf(", (trailing junk: %d bytes)", length - SLARP_MAX_LEN);
201         if (vflag > 1)
202             print_unknown_data(cp+4,"\n\t",length-4);
203 	return;
204 
205 trunc:
206 	printf("[|slarp]");
207 }
208 
209 
210 /*
211  * Local Variables:
212  * c-style: whitesmith
213  * c-basic-offset: 8
214  * End:
215  */
216