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
35 static void chdlc_slarp_print(netdissect_options *, const u_char *, u_int);
36
37 static const struct tok chdlc_cast_values[] = {
38 { CHDLC_UNICAST, "unicast" },
39 { CHDLC_BCAST, "bcast" },
40 { 0, NULL}
41 };
42
43
44 /* Standard CHDLC printer */
45 u_int
chdlc_if_print(netdissect_options * ndo,const struct pcap_pkthdr * h,register const u_char * p)46 chdlc_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
58 u_int
chdlc_print(netdissect_options * ndo,register const u_char * p,u_int length)59 chdlc_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 */
115 struct 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
136 static void
chdlc_slarp_print(netdissect_options * ndo,const u_char * cp,u_int length)137 chdlc_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
195 trunc:
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