xref: /openbsd-src/usr.sbin/tcpdump/print-isoclns.c (revision 62a742911104f98b9185b2c6b6007d9b1c36396c) 
1 /*
2  * Copyright (c) 1992, 1993, 1994, 1995, 1996
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  * Original code by Matt Thomas, Digital Equipment Corporation
22  */
23 
24 #ifndef lint
25 static const char rcsid[] =
26     "@(#) $Header: /home/cvs/src/usr.sbin/tcpdump/print-isoclns.c,v 1.6 1997/07/25 20:12:25 mickey Exp $ (LBL)";
27 #endif
28 
29 #include <sys/types.h>
30 #include <sys/time.h>
31 #include <sys/socket.h>
32 
33 #ifdef __STDC__
34 struct mbuf;
35 struct rtentry;
36 #endif
37 #include <net/if.h>
38 
39 #include <netinet/in.h>
40 #include <netinet/if_ether.h>
41 
42 #include <stdio.h>
43 
44 #include "interface.h"
45 #include "addrtoname.h"
46 #include "ethertype.h"
47 
48 #define	CLNS	129
49 #define	ESIS	130
50 #define	ISIS	131
51 #define	NULLNS	0
52 
53 static int osi_cksum(const u_char *, u_int, const u_char *, u_char *, u_char *);
54 static void esis_print(const u_char *, u_int);
55 
56 void
57 isoclns_print(const u_char *p, u_int length, u_int caplen,
58 	      const u_char *esrc, const u_char *edst)
59 {
60 	if (caplen < 1) {
61 		printf("[|iso-clns] ");
62 		if (!eflag)
63 			printf("%s > %s",
64 			       etheraddr_string(esrc),
65 			       etheraddr_string(edst));
66 		return;
67 	}
68 
69 	switch (*p) {
70 
71 	case CLNS:
72 		/* esis_print(&p, &length); */
73 		printf("iso-clns");
74 		if (!eflag)
75 			(void)printf(" %s > %s",
76 				     etheraddr_string(esrc),
77 				     etheraddr_string(edst));
78 		break;
79 
80 	case ESIS:
81 		printf("iso-esis");
82 		if (!eflag)
83 			(void)printf(" %s > %s",
84 				     etheraddr_string(esrc),
85 				     etheraddr_string(edst));
86 		esis_print(p, length);
87 		return;
88 
89 	case ISIS:
90 		printf("iso-isis");
91 		if (!eflag)
92 			(void)printf(" %s > %s",
93 				     etheraddr_string(esrc),
94 				     etheraddr_string(edst));
95 		/* isis_print(&p, &length); */
96 		(void)printf(" len=%d ", length);
97 		if (caplen > 1)
98 			default_print_unaligned(p, caplen);
99 		break;
100 
101 	case NULLNS:
102 		printf("iso-nullns");
103 		if (!eflag)
104 			(void)printf(" %s > %s",
105 				     etheraddr_string(esrc),
106 				     etheraddr_string(edst));
107 		break;
108 
109 	default:
110 		printf("iso-clns %02x", p[0]);
111 		if (!eflag)
112 			(void)printf(" %s > %s",
113 				     etheraddr_string(esrc),
114 				     etheraddr_string(edst));
115 		(void)printf(" len=%d ", length);
116 		if (caplen > 1)
117 			default_print_unaligned(p, caplen);
118 		break;
119 	}
120 }
121 
122 #define	ESIS_REDIRECT	6
123 #define	ESIS_ESH	2
124 #define	ESIS_ISH	4
125 
126 struct esis_hdr {
127 	u_char version;
128 	u_char reserved;
129 	u_char type;
130 	u_char tmo[2];
131 	u_char cksum[2];
132 };
133 
134 static void
135 esis_print(const u_char *p, u_int length)
136 {
137 	const u_char *ep;
138 	int li = p[1];
139 	const struct esis_hdr *eh = (const struct esis_hdr *) &p[2];
140 	u_char cksum[2];
141 	u_char off[2];
142 
143 	if (length == 2) {
144 		if (qflag)
145 			printf(" bad pkt!");
146 		else
147 			printf(" no header at all!");
148 		return;
149 	}
150 	ep = p + li;
151 	if (li > length) {
152 		if (qflag)
153 			printf(" bad pkt!");
154 		else
155 			printf(" LI(%d) > PDU size (%d)!", li, length);
156 		return;
157 	}
158 	if (li < sizeof(struct esis_hdr) + 2) {
159 		if (qflag)
160 			printf(" bad pkt!");
161 		else {
162 			printf(" too short for esis header %d:", li);
163 			while (--length >= 0)
164 				printf("%02X", *p++);
165 		}
166 		return;
167 	}
168 	switch (eh->type & 0x1f) {
169 
170 	case ESIS_REDIRECT:
171 		printf(" redirect");
172 		break;
173 
174 	case ESIS_ESH:
175 		printf(" esh");
176 		break;
177 
178 	case ESIS_ISH:
179 		printf(" ish");
180 		break;
181 
182 	default:
183 		printf(" type %d", eh->type & 0x1f);
184 		break;
185 	}
186 	off[0] = eh->cksum[0];
187 	off[1] = eh->cksum[1];
188 	if (vflag && osi_cksum(p, li, eh->cksum, cksum, off)) {
189 		printf(" bad cksum (got %02x%02x want %02x%02x)",
190 		       eh->cksum[1], eh->cksum[0], cksum[1], cksum[0]);
191 		return;
192 	}
193 	if (eh->version != 1) {
194 		printf(" unsupported version %d", eh->version);
195 		return;
196 	}
197 	p += sizeof(*eh) + 2;
198 	li -= sizeof(*eh) + 2;	/* protoid * li */
199 
200 	switch (eh->type & 0x1f) {
201 	case ESIS_REDIRECT: {
202 		const u_char *dst, *snpa, *is;
203 
204 		dst = p; p += *p + 1;
205 		if (p > snapend)
206 			return;
207 		printf(" %s", isonsap_string(dst));
208 		snpa = p; p += *p + 1;
209 		is = p;   p += *p + 1;
210 		if (p > snapend)
211 			return;
212 		if (p > ep) {
213 			printf(" [bad li]");
214 			return;
215 		}
216 		if (is[0] == 0)
217 			printf(" > %s", etheraddr_string(&snpa[1]));
218 		else
219 			printf(" > %s", isonsap_string(is));
220 		li = ep - p;
221 		break;
222 	}
223 #if 0
224 	case ESIS_ESH:
225 		printf(" esh");
226 		break;
227 #endif
228 	case ESIS_ISH: {
229 		const u_char *is;
230 
231 		is = p; p += *p + 1;
232 		if (p > ep) {
233 			printf(" [bad li]");
234 			return;
235 		}
236 		if (p > snapend)
237 			return;
238 		printf(" %s", isonsap_string(is));
239 		li = ep - p;
240 		break;
241 	}
242 
243 	default:
244 		(void)printf(" len=%d", length);
245 		if (length && p < snapend) {
246 			length = snapend - p;
247 			default_print(p, length);
248 		}
249 		return;
250 	}
251 	if (vflag)
252 		while (p < ep && li) {
253 			int op, opli;
254 			const u_char *q;
255 
256 			if (snapend - p < 2)
257 				return;
258 			if (li < 2) {
259 				printf(" bad opts/li");
260 				return;
261 			}
262 			op = *p++;
263 			opli = *p++;
264 			li -= 2;
265 			if (opli > li) {
266 				printf(" opt (%d) too long", op);
267 				return;
268 			}
269 			li -= opli;
270 			q = p;
271 			p += opli;
272 			if (snapend < p)
273 				return;
274 			if (op == 198 && opli == 2) {
275 				printf(" tmo=%d", q[0] * 256 + q[1]);
276 				continue;
277 			}
278 			printf (" %d:<", op);
279 			while (--opli >= 0)
280 				printf("%02x", *q++);
281 			printf (">");
282 		}
283 }
284 
285 static int
286 osi_cksum(register const u_char *p, register u_int len,
287 	  const u_char *toff, u_char *cksum, u_char *off)
288 {
289 	int x, y, f = (len - ((toff - p) + 1));
290 	int32_t c0 = 0, c1 = 0;
291 
292 	if ((cksum[0] = off[0]) == 0 && (cksum[1] = off[1]) == 0)
293 		return 0;
294 
295 	off[0] = off[1] = 0;
296 	while (--len >= 0) {
297 		c0 += *p++;
298 		c1 += c0;
299 		c0 %= 255;
300 		c1 %= 255;
301 	}
302 	x = (c0 * f - c1);
303 	if (x < 0)
304 		x = 255 - (-x % 255);
305 	else
306 		x %= 255;
307 	y = -1 * (x + c0);
308 	if (y < 0)
309 		y = 255 - (-y % 255);
310 	else
311 		y %= 255;
312 
313 	off[0] = x;
314 	off[1] = y;
315 
316 	return (off[0] != cksum[0] || off[1] != cksum[1]);
317 }
318