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 static 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
chdlc_if_print(const struct pcap_pkthdr * h,register const u_char * p)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
chdlc_print(register const u_char * p,u_int length)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
chdlc_slarp_print(const u_char * cp,u_int length)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