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 /* \summary: Exterior Gateway Protocol (EGP) printer */
22
23 #ifdef HAVE_CONFIG_H
24 #include "config.h"
25 #endif
26
27 #include <netdissect-stdinc.h>
28
29 #include "netdissect.h"
30 #include "addrtoname.h"
31 #include "extract.h"
32
33 struct egp_packet {
34 uint8_t egp_version;
35 #define EGP_VERSION 2
36 uint8_t egp_type;
37 #define EGPT_ACQUIRE 3
38 #define EGPT_REACH 5
39 #define EGPT_POLL 2
40 #define EGPT_UPDATE 1
41 #define EGPT_ERROR 8
42 uint8_t egp_code;
43 #define EGPC_REQUEST 0
44 #define EGPC_CONFIRM 1
45 #define EGPC_REFUSE 2
46 #define EGPC_CEASE 3
47 #define EGPC_CEASEACK 4
48 #define EGPC_HELLO 0
49 #define EGPC_HEARDU 1
50 uint8_t egp_status;
51 #define EGPS_UNSPEC 0
52 #define EGPS_ACTIVE 1
53 #define EGPS_PASSIVE 2
54 #define EGPS_NORES 3
55 #define EGPS_ADMIN 4
56 #define EGPS_GODOWN 5
57 #define EGPS_PARAM 6
58 #define EGPS_PROTO 7
59 #define EGPS_INDET 0
60 #define EGPS_UP 1
61 #define EGPS_DOWN 2
62 #define EGPS_UNSOL 0x80
63 uint16_t egp_checksum;
64 uint16_t egp_as;
65 uint16_t egp_sequence;
66 union {
67 uint16_t egpu_hello;
68 uint8_t egpu_gws[2];
69 uint16_t egpu_reason;
70 #define EGPR_UNSPEC 0
71 #define EGPR_BADHEAD 1
72 #define EGPR_BADDATA 2
73 #define EGPR_NOREACH 3
74 #define EGPR_XSPOLL 4
75 #define EGPR_NORESP 5
76 #define EGPR_UVERSION 6
77 } egp_handg;
78 #define egp_hello egp_handg.egpu_hello
79 #define egp_intgw egp_handg.egpu_gws[0]
80 #define egp_extgw egp_handg.egpu_gws[1]
81 #define egp_reason egp_handg.egpu_reason
82 union {
83 uint16_t egpu_poll;
84 uint32_t egpu_sourcenet;
85 } egp_pands;
86 #define egp_poll egp_pands.egpu_poll
87 #define egp_sourcenet egp_pands.egpu_sourcenet
88 };
89
90 static const char *egp_acquire_codes[] = {
91 "request",
92 "confirm",
93 "refuse",
94 "cease",
95 "cease_ack"
96 };
97
98 static const char *egp_acquire_status[] = {
99 "unspecified",
100 "active_mode",
101 "passive_mode",
102 "insufficient_resources",
103 "administratively_prohibited",
104 "going_down",
105 "parameter_violation",
106 "protocol_violation"
107 };
108
109 static const char *egp_reach_codes[] = {
110 "hello",
111 "i-h-u"
112 };
113
114 static const char *egp_status_updown[] = {
115 "indeterminate",
116 "up",
117 "down"
118 };
119
120 static const char *egp_reasons[] = {
121 "unspecified",
122 "bad_EGP_header_format",
123 "bad_EGP_data_field_format",
124 "reachability_info_unavailable",
125 "excessive_polling_rate",
126 "no_response",
127 "unsupported_version"
128 };
129
130 static void
egpnrprint(netdissect_options * ndo,register const struct egp_packet * egp,u_int length)131 egpnrprint(netdissect_options *ndo,
132 register const struct egp_packet *egp, u_int length)
133 {
134 register const uint8_t *cp;
135 uint32_t addr;
136 register uint32_t net;
137 register u_int netlen;
138 int gateways, distances, networks;
139 int t_gateways;
140 const char *comma;
141
142 addr = egp->egp_sourcenet;
143 if (IN_CLASSA(addr)) {
144 net = addr & IN_CLASSA_NET;
145 netlen = 1;
146 } else if (IN_CLASSB(addr)) {
147 net = addr & IN_CLASSB_NET;
148 netlen = 2;
149 } else if (IN_CLASSC(addr)) {
150 net = addr & IN_CLASSC_NET;
151 netlen = 3;
152 } else {
153 net = 0;
154 netlen = 0;
155 }
156 cp = (const uint8_t *)(egp + 1);
157 length -= sizeof(*egp);
158
159 t_gateways = egp->egp_intgw + egp->egp_extgw;
160 for (gateways = 0; gateways < t_gateways; ++gateways) {
161 /* Pickup host part of gateway address */
162 addr = 0;
163 if (length < 4 - netlen)
164 goto trunc;
165 ND_TCHECK2(cp[0], 4 - netlen);
166 switch (netlen) {
167
168 case 1:
169 addr = *cp++;
170 /* fall through */
171 case 2:
172 addr = (addr << 8) | *cp++;
173 /* fall through */
174 case 3:
175 addr = (addr << 8) | *cp++;
176 }
177 addr |= net;
178 length -= 4 - netlen;
179 if (length < 1)
180 goto trunc;
181 ND_TCHECK2(cp[0], 1);
182 distances = *cp++;
183 length--;
184 ND_PRINT((ndo, " %s %s ",
185 gateways < (int)egp->egp_intgw ? "int" : "ext",
186 ipaddr_string(ndo, &addr)));
187
188 comma = "";
189 ND_PRINT((ndo, "("));
190 while (--distances >= 0) {
191 if (length < 2)
192 goto trunc;
193 ND_TCHECK2(cp[0], 2);
194 ND_PRINT((ndo, "%sd%d:", comma, (int)*cp++));
195 comma = ", ";
196 networks = *cp++;
197 length -= 2;
198 while (--networks >= 0) {
199 /* Pickup network number */
200 if (length < 1)
201 goto trunc;
202 ND_TCHECK2(cp[0], 1);
203 addr = (uint32_t)*cp++ << 24;
204 length--;
205 if (IN_CLASSB(addr)) {
206 if (length < 1)
207 goto trunc;
208 ND_TCHECK2(cp[0], 1);
209 addr |= (uint32_t)*cp++ << 16;
210 length--;
211 } else if (!IN_CLASSA(addr)) {
212 if (length < 2)
213 goto trunc;
214 ND_TCHECK2(cp[0], 2);
215 addr |= (uint32_t)*cp++ << 16;
216 addr |= (uint32_t)*cp++ << 8;
217 length -= 2;
218 }
219 ND_PRINT((ndo, " %s", ipaddr_string(ndo, &addr)));
220 }
221 }
222 ND_PRINT((ndo, ")"));
223 }
224 return;
225 trunc:
226 ND_PRINT((ndo, "[|]"));
227 }
228
229 void
egp_print(netdissect_options * ndo,register const uint8_t * bp,register u_int length)230 egp_print(netdissect_options *ndo,
231 register const uint8_t *bp, register u_int length)
232 {
233 register const struct egp_packet *egp;
234 register int status;
235 register int code;
236 register int type;
237
238 egp = (const struct egp_packet *)bp;
239 if (length < sizeof(*egp) || !ND_TTEST(*egp)) {
240 ND_PRINT((ndo, "[|egp]"));
241 return;
242 }
243
244 if (!ndo->ndo_vflag) {
245 ND_PRINT((ndo, "EGPv%u, AS %u, seq %u, length %u",
246 egp->egp_version,
247 EXTRACT_16BITS(&egp->egp_as),
248 EXTRACT_16BITS(&egp->egp_sequence),
249 length));
250 return;
251 } else
252 ND_PRINT((ndo, "EGPv%u, length %u",
253 egp->egp_version,
254 length));
255
256 if (egp->egp_version != EGP_VERSION) {
257 ND_PRINT((ndo, "[version %d]", egp->egp_version));
258 return;
259 }
260
261 type = egp->egp_type;
262 code = egp->egp_code;
263 status = egp->egp_status;
264
265 switch (type) {
266 case EGPT_ACQUIRE:
267 ND_PRINT((ndo, " acquire"));
268 switch (code) {
269 case EGPC_REQUEST:
270 case EGPC_CONFIRM:
271 ND_PRINT((ndo, " %s", egp_acquire_codes[code]));
272 switch (status) {
273 case EGPS_UNSPEC:
274 case EGPS_ACTIVE:
275 case EGPS_PASSIVE:
276 ND_PRINT((ndo, " %s", egp_acquire_status[status]));
277 break;
278
279 default:
280 ND_PRINT((ndo, " [status %d]", status));
281 break;
282 }
283 ND_PRINT((ndo, " hello:%d poll:%d",
284 EXTRACT_16BITS(&egp->egp_hello),
285 EXTRACT_16BITS(&egp->egp_poll)));
286 break;
287
288 case EGPC_REFUSE:
289 case EGPC_CEASE:
290 case EGPC_CEASEACK:
291 ND_PRINT((ndo, " %s", egp_acquire_codes[code]));
292 switch (status ) {
293 case EGPS_UNSPEC:
294 case EGPS_NORES:
295 case EGPS_ADMIN:
296 case EGPS_GODOWN:
297 case EGPS_PARAM:
298 case EGPS_PROTO:
299 ND_PRINT((ndo, " %s", egp_acquire_status[status]));
300 break;
301
302 default:
303 ND_PRINT((ndo, "[status %d]", status));
304 break;
305 }
306 break;
307
308 default:
309 ND_PRINT((ndo, "[code %d]", code));
310 break;
311 }
312 break;
313
314 case EGPT_REACH:
315 switch (code) {
316
317 case EGPC_HELLO:
318 case EGPC_HEARDU:
319 ND_PRINT((ndo, " %s", egp_reach_codes[code]));
320 if (status <= EGPS_DOWN)
321 ND_PRINT((ndo, " state:%s", egp_status_updown[status]));
322 else
323 ND_PRINT((ndo, " [status %d]", status));
324 break;
325
326 default:
327 ND_PRINT((ndo, "[reach code %d]", code));
328 break;
329 }
330 break;
331
332 case EGPT_POLL:
333 ND_PRINT((ndo, " poll"));
334 if (egp->egp_status <= EGPS_DOWN)
335 ND_PRINT((ndo, " state:%s", egp_status_updown[status]));
336 else
337 ND_PRINT((ndo, " [status %d]", status));
338 ND_PRINT((ndo, " net:%s", ipaddr_string(ndo, &egp->egp_sourcenet)));
339 break;
340
341 case EGPT_UPDATE:
342 ND_PRINT((ndo, " update"));
343 if (status & EGPS_UNSOL) {
344 status &= ~EGPS_UNSOL;
345 ND_PRINT((ndo, " unsolicited"));
346 }
347 if (status <= EGPS_DOWN)
348 ND_PRINT((ndo, " state:%s", egp_status_updown[status]));
349 else
350 ND_PRINT((ndo, " [status %d]", status));
351 ND_PRINT((ndo, " %s int %d ext %d",
352 ipaddr_string(ndo, &egp->egp_sourcenet),
353 egp->egp_intgw,
354 egp->egp_extgw));
355 if (ndo->ndo_vflag)
356 egpnrprint(ndo, egp, length);
357 break;
358
359 case EGPT_ERROR:
360 ND_PRINT((ndo, " error"));
361 if (status <= EGPS_DOWN)
362 ND_PRINT((ndo, " state:%s", egp_status_updown[status]));
363 else
364 ND_PRINT((ndo, " [status %d]", status));
365
366 if (EXTRACT_16BITS(&egp->egp_reason) <= EGPR_UVERSION)
367 ND_PRINT((ndo, " %s", egp_reasons[EXTRACT_16BITS(&egp->egp_reason)]));
368 else
369 ND_PRINT((ndo, " [reason %d]", EXTRACT_16BITS(&egp->egp_reason)));
370 break;
371
372 default:
373 ND_PRINT((ndo, "[type %d]", type));
374 break;
375 }
376 }
377