1/*
2 * Copyright (c) 1991, 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 are permitted
6 * provided that the above copyright notice and this paragraph are
7 * duplicated in all such forms and that any documentation,
8 * advertising materials, and other materials related to such
9 * distribution and use acknowledge that the software was developed
10 * by the University of California, Lawrence Berkeley Laboratory,
11 * Berkeley, CA.  The name of the University may not be used to
12 * endorse or promote products derived from this software without
13 * specific prior written permission.
14 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
16 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
17 *
18 * Initial contribution from Jeff Honig (jch@MITCHELL.CIT.CORNELL.EDU).
19 */
20
21#define NETDISSECT_REWORKED
22#ifdef HAVE_CONFIG_H
23#include "config.h"
24#endif
25
26#include <tcpdump-stdinc.h>
27
28#include "interface.h"
29#include "addrtoname.h"
30#include "extract.h"
31
32struct egp_packet {
33	uint8_t  egp_version;
34#define	EGP_VERSION	2
35	uint8_t  egp_type;
36#define  EGPT_ACQUIRE	3
37#define  EGPT_REACH	5
38#define  EGPT_POLL	2
39#define  EGPT_UPDATE	1
40#define  EGPT_ERROR	8
41	uint8_t  egp_code;
42#define  EGPC_REQUEST	0
43#define  EGPC_CONFIRM	1
44#define  EGPC_REFUSE	2
45#define  EGPC_CEASE	3
46#define  EGPC_CEASEACK	4
47#define  EGPC_HELLO	0
48#define  EGPC_HEARDU	1
49	uint8_t  egp_status;
50#define  EGPS_UNSPEC	0
51#define  EGPS_ACTIVE	1
52#define  EGPS_PASSIVE	2
53#define  EGPS_NORES	3
54#define  EGPS_ADMIN	4
55#define  EGPS_GODOWN	5
56#define  EGPS_PARAM	6
57#define  EGPS_PROTO	7
58#define  EGPS_INDET	0
59#define  EGPS_UP	1
60#define  EGPS_DOWN	2
61#define  EGPS_UNSOL	0x80
62	uint16_t  egp_checksum;
63	uint16_t  egp_as;
64	uint16_t  egp_sequence;
65	union {
66		uint16_t  egpu_hello;
67		uint8_t egpu_gws[2];
68		uint16_t  egpu_reason;
69#define  EGPR_UNSPEC	0
70#define  EGPR_BADHEAD	1
71#define  EGPR_BADDATA	2
72#define  EGPR_NOREACH	3
73#define  EGPR_XSPOLL	4
74#define  EGPR_NORESP	5
75#define  EGPR_UVERSION	6
76	} egp_handg;
77#define  egp_hello  egp_handg.egpu_hello
78#define  egp_intgw  egp_handg.egpu_gws[0]
79#define  egp_extgw  egp_handg.egpu_gws[1]
80#define  egp_reason  egp_handg.egpu_reason
81	union {
82		uint16_t  egpu_poll;
83		uint32_t egpu_sourcenet;
84	} egp_pands;
85#define  egp_poll  egp_pands.egpu_poll
86#define  egp_sourcenet  egp_pands.egpu_sourcenet
87};
88
89static const char *egp_acquire_codes[] = {
90	"request",
91	"confirm",
92	"refuse",
93	"cease",
94	"cease_ack"
95};
96
97static const char *egp_acquire_status[] = {
98	"unspecified",
99	"active_mode",
100	"passive_mode",
101	"insufficient_resources",
102	"administratively_prohibited",
103	"going_down",
104	"parameter_violation",
105	"protocol_violation"
106};
107
108static const char *egp_reach_codes[] = {
109	"hello",
110	"i-h-u"
111};
112
113static const char *egp_status_updown[] = {
114	"indeterminate",
115	"up",
116	"down"
117};
118
119static const char *egp_reasons[] = {
120	"unspecified",
121	"bad_EGP_header_format",
122	"bad_EGP_data_field_format",
123	"reachability_info_unavailable",
124	"excessive_polling_rate",
125	"no_response",
126	"unsupported_version"
127};
128
129static void
130egpnrprint(netdissect_options *ndo,
131           register const struct egp_packet *egp)
132{
133	register const uint8_t *cp;
134	uint32_t addr;
135	register uint32_t net;
136	register u_int netlen;
137	int gateways, distances, networks;
138	int t_gateways;
139	const char *comma;
140
141	addr = egp->egp_sourcenet;
142	if (IN_CLASSA(addr)) {
143		net = addr & IN_CLASSA_NET;
144		netlen = 1;
145	} else if (IN_CLASSB(addr)) {
146		net = addr & IN_CLASSB_NET;
147		netlen = 2;
148	} else if (IN_CLASSC(addr)) {
149		net = addr & IN_CLASSC_NET;
150		netlen = 3;
151	} else {
152		net = 0;
153		netlen = 0;
154	}
155	cp = (uint8_t *)(egp + 1);
156
157	t_gateways = egp->egp_intgw + egp->egp_extgw;
158	for (gateways = 0; gateways < t_gateways; ++gateways) {
159		/* Pickup host part of gateway address */
160		addr = 0;
161		ND_TCHECK2(cp[0], 4 - netlen);
162		switch (netlen) {
163
164		case 1:
165			addr = *cp++;
166			/* fall through */
167		case 2:
168			addr = (addr << 8) | *cp++;
169			/* fall through */
170		case 3:
171			addr = (addr << 8) | *cp++;
172		}
173		addr |= net;
174		ND_TCHECK2(cp[0], 1);
175		distances = *cp++;
176		ND_PRINT((ndo, " %s %s ",
177		       gateways < (int)egp->egp_intgw ? "int" : "ext",
178		       ipaddr_string(ndo, &addr)));
179
180		comma = "";
181		ND_PRINT((ndo, "("));
182		while (--distances >= 0) {
183			ND_TCHECK2(cp[0], 2);
184			ND_PRINT((ndo, "%sd%d:", comma, (int)*cp++));
185			comma = ", ";
186			networks = *cp++;
187			while (--networks >= 0) {
188				/* Pickup network number */
189				ND_TCHECK2(cp[0], 1);
190				addr = (uint32_t)*cp++ << 24;
191				if (IN_CLASSB(addr)) {
192					ND_TCHECK2(cp[0], 1);
193					addr |= (uint32_t)*cp++ << 16;
194				} else if (!IN_CLASSA(addr)) {
195					ND_TCHECK2(cp[0], 2);
196					addr |= (uint32_t)*cp++ << 16;
197					addr |= (uint32_t)*cp++ << 8;
198				}
199				ND_PRINT((ndo, " %s", ipaddr_string(ndo, &addr)));
200			}
201		}
202		ND_PRINT((ndo, ")"));
203	}
204	return;
205trunc:
206	ND_PRINT((ndo, "[|]"));
207}
208
209void
210egp_print(netdissect_options *ndo,
211          register const uint8_t *bp, register u_int length)
212{
213	register const struct egp_packet *egp;
214	register int status;
215	register int code;
216	register int type;
217
218	egp = (struct egp_packet *)bp;
219        if (!ND_TTEST2(*egp, length)) {
220		ND_PRINT((ndo, "[|egp]"));
221		return;
222	}
223
224        if (!ndo->ndo_vflag) {
225            ND_PRINT((ndo, "EGPv%u, AS %u, seq %u, length %u",
226                   egp->egp_version,
227                   EXTRACT_16BITS(&egp->egp_as),
228                   EXTRACT_16BITS(&egp->egp_sequence),
229                   length));
230            return;
231        } else
232            ND_PRINT((ndo, "EGPv%u, length %u",
233                   egp->egp_version,
234                   length));
235
236	if (egp->egp_version != EGP_VERSION) {
237		ND_PRINT((ndo, "[version %d]", egp->egp_version));
238		return;
239	}
240
241	type = egp->egp_type;
242	code = egp->egp_code;
243	status = egp->egp_status;
244
245	switch (type) {
246	case EGPT_ACQUIRE:
247		ND_PRINT((ndo, " acquire"));
248		switch (code) {
249		case EGPC_REQUEST:
250		case EGPC_CONFIRM:
251			ND_PRINT((ndo, " %s", egp_acquire_codes[code]));
252			switch (status) {
253			case EGPS_UNSPEC:
254			case EGPS_ACTIVE:
255			case EGPS_PASSIVE:
256				ND_PRINT((ndo, " %s", egp_acquire_status[status]));
257				break;
258
259			default:
260				ND_PRINT((ndo, " [status %d]", status));
261				break;
262			}
263			ND_PRINT((ndo, " hello:%d poll:%d",
264			       EXTRACT_16BITS(&egp->egp_hello),
265			       EXTRACT_16BITS(&egp->egp_poll)));
266			break;
267
268		case EGPC_REFUSE:
269		case EGPC_CEASE:
270		case EGPC_CEASEACK:
271			ND_PRINT((ndo, " %s", egp_acquire_codes[code]));
272			switch (status ) {
273			case EGPS_UNSPEC:
274			case EGPS_NORES:
275			case EGPS_ADMIN:
276			case EGPS_GODOWN:
277			case EGPS_PARAM:
278			case EGPS_PROTO:
279				ND_PRINT((ndo, " %s", egp_acquire_status[status]));
280				break;
281
282			default:
283				ND_PRINT((ndo, "[status %d]", status));
284				break;
285			}
286			break;
287
288		default:
289			ND_PRINT((ndo, "[code %d]", code));
290			break;
291		}
292		break;
293
294	case EGPT_REACH:
295		switch (code) {
296
297		case EGPC_HELLO:
298		case EGPC_HEARDU:
299			ND_PRINT((ndo, " %s", egp_reach_codes[code]));
300			if (status <= EGPS_DOWN)
301				ND_PRINT((ndo, " state:%s", egp_status_updown[status]));
302			else
303				ND_PRINT((ndo, " [status %d]", status));
304			break;
305
306		default:
307			ND_PRINT((ndo, "[reach code %d]", code));
308			break;
309		}
310		break;
311
312	case EGPT_POLL:
313		ND_PRINT((ndo, " poll"));
314		if (egp->egp_status <= EGPS_DOWN)
315			ND_PRINT((ndo, " state:%s", egp_status_updown[status]));
316		else
317			ND_PRINT((ndo, " [status %d]", status));
318		ND_PRINT((ndo, " net:%s", ipaddr_string(ndo, &egp->egp_sourcenet)));
319		break;
320
321	case EGPT_UPDATE:
322		ND_PRINT((ndo, " update"));
323		if (status & EGPS_UNSOL) {
324			status &= ~EGPS_UNSOL;
325			ND_PRINT((ndo, " unsolicited"));
326		}
327		if (status <= EGPS_DOWN)
328			ND_PRINT((ndo, " state:%s", egp_status_updown[status]));
329		else
330			ND_PRINT((ndo, " [status %d]", status));
331		ND_PRINT((ndo, " %s int %d ext %d",
332		       ipaddr_string(ndo, &egp->egp_sourcenet),
333		       egp->egp_intgw,
334		       egp->egp_extgw));
335		if (ndo->ndo_vflag)
336			egpnrprint(ndo, egp);
337		break;
338
339	case EGPT_ERROR:
340		ND_PRINT((ndo, " error"));
341		if (status <= EGPS_DOWN)
342			ND_PRINT((ndo, " state:%s", egp_status_updown[status]));
343		else
344			ND_PRINT((ndo, " [status %d]", status));
345
346		if (EXTRACT_16BITS(&egp->egp_reason) <= EGPR_UVERSION)
347			ND_PRINT((ndo, " %s", egp_reasons[EXTRACT_16BITS(&egp->egp_reason)]));
348		else
349			ND_PRINT((ndo, " [reason %d]", EXTRACT_16BITS(&egp->egp_reason)));
350		break;
351
352	default:
353		ND_PRINT((ndo, "[type %d]", type));
354		break;
355	}
356}
357