1 /* $OpenBSD: print-isoclns.c,v 1.16 2023/02/28 10:04:50 claudio Exp $ */
2
3 /*
4 * Copyright (c) 1992, 1993, 1994, 1995, 1996
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that: (1) source code distributions
9 * retain the above copyright notice and this paragraph in its entirety, (2)
10 * distributions including binary code include the above copyright notice and
11 * this paragraph in its entirety in the documentation or other materials
12 * provided with the distribution, and (3) all advertising materials mentioning
13 * features or use of this software display the following acknowledgement:
14 * ``This product includes software developed by the University of California,
15 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
16 * the University nor the names of its contributors may be used to endorse
17 * or promote products derived from this software without specific prior
18 * written permission.
19 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
20 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
21 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
22 *
23 * Original code by Matt Thomas, Digital Equipment Corporation
24 */
25
26 #include <sys/types.h>
27 #include <sys/time.h>
28 #include <sys/socket.h>
29
30 #include <net/if.h>
31
32 #include <netinet/in.h>
33 #include <netinet/if_ether.h>
34
35 #include <stdio.h>
36
37 #include "interface.h"
38 #include "addrtoname.h"
39 #include "ethertype.h"
40
41 #define CLNS 129
42 #define ESIS 130
43 #define ISIS 131
44 #define NULLNS 0
45
46 static int osi_cksum(const u_char *, u_int, const u_char *, u_char *, u_char *);
47 static void esis_print(const u_char *, u_int);
48
49 void
isoclns_print(const u_char * p,u_int length,u_int caplen,const u_char * esrc,const u_char * edst)50 isoclns_print(const u_char *p, u_int length, u_int caplen,
51 const u_char *esrc, const u_char *edst)
52 {
53 if (caplen < 1) {
54 printf("[|iso-clns] ");
55 if (!eflag)
56 printf("%s > %s",
57 etheraddr_string(esrc),
58 etheraddr_string(edst));
59 return;
60 }
61
62 switch (*p) {
63
64 case CLNS:
65 /* esis_print(&p, &length); */
66 printf("iso-clns");
67 if (!eflag)
68 printf(" %s > %s",
69 etheraddr_string(esrc),
70 etheraddr_string(edst));
71 break;
72
73 case ESIS:
74 printf("iso-esis");
75 if (!eflag)
76 printf(" %s > %s",
77 etheraddr_string(esrc),
78 etheraddr_string(edst));
79 esis_print(p, length);
80 return;
81
82 case ISIS:
83 printf("iso-isis");
84 if (!eflag)
85 printf(" %s > %s",
86 etheraddr_string(esrc),
87 etheraddr_string(edst));
88 /* isis_print(&p, &length); */
89 printf(" len=%d ", length);
90 if (caplen > 1)
91 default_print(p, caplen);
92 break;
93
94 case NULLNS:
95 printf("iso-nullns");
96 if (!eflag)
97 printf(" %s > %s",
98 etheraddr_string(esrc),
99 etheraddr_string(edst));
100 break;
101
102 default:
103 printf("iso-clns %02x", p[0]);
104 if (!eflag)
105 printf(" %s > %s",
106 etheraddr_string(esrc),
107 etheraddr_string(edst));
108 printf(" len=%d ", length);
109 if (caplen > 1)
110 default_print(p, caplen);
111 break;
112 }
113 }
114
115 #define ESIS_REDIRECT 6
116 #define ESIS_ESH 2
117 #define ESIS_ISH 4
118
119 struct esis_hdr {
120 u_char version;
121 u_char reserved;
122 u_char type;
123 u_char tmo[2];
124 u_char cksum[2];
125 };
126
127 static void
esis_print(const u_char * p,u_int length)128 esis_print(const u_char *p, u_int length)
129 {
130 const u_char *ep;
131 int li = p[1];
132 const struct esis_hdr *eh = (const struct esis_hdr *) &p[2];
133 u_char cksum[2];
134 u_char off[2];
135
136 if (length == 2) {
137 if (qflag)
138 printf(" bad pkt!");
139 else
140 printf(" no header at all!");
141 return;
142 }
143 ep = p + li;
144 if (li > length) {
145 if (qflag)
146 printf(" bad pkt!");
147 else
148 printf(" LI(%d) > PDU size (%d)!", li, length);
149 return;
150 }
151 if (li < sizeof(struct esis_hdr) + 2) {
152 if (qflag)
153 printf(" bad pkt!");
154 else {
155 printf(" too short for esis header %d:", li);
156 while (--length != 0)
157 printf("%02X", *p++);
158 }
159 return;
160 }
161 switch (eh->type & 0x1f) {
162
163 case ESIS_REDIRECT:
164 printf(" redirect");
165 break;
166
167 case ESIS_ESH:
168 printf(" esh");
169 break;
170
171 case ESIS_ISH:
172 printf(" ish");
173 break;
174
175 default:
176 printf(" type %d", eh->type & 0x1f);
177 break;
178 }
179 off[0] = eh->cksum[0];
180 off[1] = eh->cksum[1];
181 if (vflag && osi_cksum(p, li, eh->cksum, cksum, off)) {
182 printf(" bad cksum (got %02x%02x want %02x%02x)",
183 eh->cksum[1], eh->cksum[0], cksum[1], cksum[0]);
184 return;
185 }
186 if (eh->version != 1) {
187 printf(" unsupported version %d", eh->version);
188 return;
189 }
190 p += sizeof(*eh) + 2;
191 li -= sizeof(*eh) + 2; /* protoid * li */
192
193 switch (eh->type & 0x1f) {
194 case ESIS_REDIRECT: {
195 const u_char *dst, *snpa, *is;
196
197 dst = p; p += *p + 1;
198 if (p > snapend)
199 return;
200 printf(" %s", isonsap_string(dst));
201 snpa = p; p += *p + 1;
202 is = p; p += *p + 1;
203 if (p > snapend)
204 return;
205 if (p > ep) {
206 printf(" [bad li]");
207 return;
208 }
209 if (is[0] == 0)
210 printf(" > %s", etheraddr_string(&snpa[1]));
211 else
212 printf(" > %s", isonsap_string(is));
213 li = ep - p;
214 break;
215 }
216 case ESIS_ESH: {
217 const u_char *nsap;
218 int i, nnsaps;
219
220 nnsaps = *p++;
221
222 /* print NSAPs */
223 for (i = 0; i < nnsaps; i++) {
224 nsap = p;
225 p += *p + 1;
226 if (p > ep) {
227 printf(" [bad li]");
228 return;
229 }
230 if (p > snapend)
231 return;
232 printf(" nsap %s", isonsap_string(nsap));
233 }
234 li = ep - p;
235 break;
236 }
237 case ESIS_ISH: {
238 const u_char *is;
239
240 is = p; p += *p + 1;
241 if (p > ep) {
242 printf(" [bad li]");
243 return;
244 }
245 if (p > snapend)
246 return;
247 printf(" net %s", isonsap_string(is));
248 li = ep - p;
249 break;
250 }
251
252 default:
253 printf(" len=%d", length);
254 if (length && p < snapend) {
255 length = snapend - p;
256 default_print(p, length);
257 }
258 return;
259 }
260 if (vflag)
261 while (p < ep && li) {
262 int op, opli;
263 const u_char *q;
264
265 if (snapend - p < 2)
266 return;
267 if (li < 2) {
268 printf(" bad opts/li");
269 return;
270 }
271 op = *p++;
272 opli = *p++;
273 li -= 2;
274 if (opli > li) {
275 printf(" opt (%d) too long", op);
276 return;
277 }
278 li -= opli;
279 q = p;
280 p += opli;
281 if (snapend < p)
282 return;
283 if (op == 198 && opli == 2) {
284 printf(" tmo=%d", q[0] * 256 + q[1]);
285 continue;
286 }
287 printf (" %d:<", op);
288 while (--opli >= 0)
289 printf("%02x", *q++);
290 printf (">");
291 }
292 }
293
294 static int
osi_cksum(const u_char * p,u_int len,const u_char * toff,u_char * cksum,u_char * off)295 osi_cksum(const u_char *p, u_int len,
296 const u_char *toff, u_char *cksum, u_char *off)
297 {
298 const u_char *ep;
299 int c0, c1;
300 int n;
301
302 if ((cksum[0] = off[0]) == 0 && (cksum[1] = off[1]) == 0)
303 return 0;
304
305 n = toff - p + 1;
306 c0 = c1 = 0;
307 ep = p + len;
308 for (; p < toff; p++) {
309 c0 = (c0 + *p);
310 c1 += c0;
311 }
312
313 /* skip cksum bytes */
314 p += 2;
315 c1 += c0; c1 += c0;
316
317 for (; p < ep; p++) {
318 c0 = (c0 + *p);
319 c1 += c0;
320 }
321
322 c1 = (((c0 * (len - n)) - c1) % 255);
323 cksum[0] = (u_char) ((c1 < 0) ? c1 + 255 : c1);
324 c1 = (-(int) (c1 + c0)) % 255;
325 cksum[1] = (u_char) (c1 < 0 ? c1 + 255 : c1);
326
327 return (off[0] != cksum[0] || off[1] != cksum[1]);
328 }
329