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 /* specification: RFC 827 */
24
25 #ifdef HAVE_CONFIG_H
26 #include <config.h>
27 #endif
28
29 #include "netdissect-stdinc.h"
30
31 #include "netdissect.h"
32 #include "addrtoname.h"
33 #include "extract.h"
34
35 struct egp_packet {
36 nd_uint8_t egp_version;
37 #define EGP_VERSION 2
38 nd_uint8_t egp_type;
39 #define EGPT_ACQUIRE 3
40 #define EGPT_REACH 5
41 #define EGPT_POLL 2
42 #define EGPT_UPDATE 1
43 #define EGPT_ERROR 8
44 nd_uint8_t egp_code;
45 #define EGPC_REQUEST 0
46 #define EGPC_CONFIRM 1
47 #define EGPC_REFUSE 2
48 #define EGPC_CEASE 3
49 #define EGPC_CEASEACK 4
50 #define EGPC_HELLO 0
51 #define EGPC_HEARDU 1
52 nd_uint8_t egp_status;
53 #define EGPS_UNSPEC 0
54 #define EGPS_ACTIVE 1
55 #define EGPS_PASSIVE 2
56 #define EGPS_NORES 3
57 #define EGPS_ADMIN 4
58 #define EGPS_GODOWN 5
59 #define EGPS_PARAM 6
60 #define EGPS_PROTO 7
61 #define EGPS_INDET 0
62 #define EGPS_UP 1
63 #define EGPS_DOWN 2
64 #define EGPS_UNSOL 0x80
65 nd_uint16_t egp_checksum;
66 nd_uint16_t egp_as;
67 nd_uint16_t egp_sequence;
68 union {
69 nd_uint16_t egpu_hello;
70 nd_uint8_t egpu_gws[2];
71 nd_uint16_t egpu_reason;
72 #define EGPR_UNSPEC 0
73 #define EGPR_BADHEAD 1
74 #define EGPR_BADDATA 2
75 #define EGPR_NOREACH 3
76 #define EGPR_XSPOLL 4
77 #define EGPR_NORESP 5
78 #define EGPR_UVERSION 6
79 } egp_handg;
80 #define egp_hello egp_handg.egpu_hello
81 #define egp_intgw egp_handg.egpu_gws[0]
82 #define egp_extgw egp_handg.egpu_gws[1]
83 #define egp_reason egp_handg.egpu_reason
84 union {
85 nd_uint16_t egpu_poll;
86 nd_ipv4 egpu_sourcenet;
87 } egp_pands;
88 #define egp_poll egp_pands.egpu_poll
89 #define egp_sourcenet egp_pands.egpu_sourcenet
90 };
91
92 static const char *egp_acquire_codes[] = {
93 "request",
94 "confirm",
95 "refuse",
96 "cease",
97 "cease_ack"
98 };
99
100 static const char *egp_acquire_status[] = {
101 "unspecified",
102 "active_mode",
103 "passive_mode",
104 "insufficient_resources",
105 "administratively_prohibited",
106 "going_down",
107 "parameter_violation",
108 "protocol_violation"
109 };
110
111 static const char *egp_reach_codes[] = {
112 "hello",
113 "i-h-u"
114 };
115
116 static const char *egp_status_updown[] = {
117 "indeterminate",
118 "up",
119 "down"
120 };
121
122 static const char *egp_reasons[] = {
123 "unspecified",
124 "bad_EGP_header_format",
125 "bad_EGP_data_field_format",
126 "reachability_info_unavailable",
127 "excessive_polling_rate",
128 "no_response",
129 "unsupported_version"
130 };
131
132 static void
egpnr_print(netdissect_options * ndo,const struct egp_packet * egp,u_int length)133 egpnr_print(netdissect_options *ndo,
134 const struct egp_packet *egp, u_int length)
135 {
136 const uint8_t *cp;
137 uint32_t addr;
138 uint32_t net;
139 u_int netlen;
140 u_int gateways, distances, networks;
141 u_int intgw, extgw, t_gateways;
142 const char *comma;
143
144 addr = GET_IPV4_TO_NETWORK_ORDER(egp->egp_sourcenet);
145 if (IN_CLASSA(addr)) {
146 net = addr & IN_CLASSA_NET;
147 netlen = 1;
148 } else if (IN_CLASSB(addr)) {
149 net = addr & IN_CLASSB_NET;
150 netlen = 2;
151 } else if (IN_CLASSC(addr)) {
152 net = addr & IN_CLASSC_NET;
153 netlen = 3;
154 } else {
155 net = 0;
156 netlen = 0;
157 }
158 cp = (const uint8_t *)(egp + 1);
159 length -= sizeof(*egp);
160
161 intgw = GET_U_1(egp->egp_intgw);
162 extgw = GET_U_1(egp->egp_extgw);
163 t_gateways = intgw + extgw;
164 for (gateways = 0; gateways < t_gateways; ++gateways) {
165 /* Pickup host part of gateway address */
166 addr = 0;
167 if (length < 4 - netlen)
168 goto trunc;
169 ND_TCHECK_LEN(cp, 4 - netlen);
170 switch (netlen) {
171
172 case 1:
173 addr = GET_U_1(cp);
174 cp++;
175 /* fall through */
176 case 2:
177 addr = (addr << 8) | GET_U_1(cp);
178 cp++;
179 /* fall through */
180 case 3:
181 addr = (addr << 8) | GET_U_1(cp);
182 cp++;
183 break;
184 }
185 addr |= net;
186 length -= 4 - netlen;
187 if (length < 1)
188 goto trunc;
189 distances = GET_U_1(cp);
190 cp++;
191 length--;
192 ND_PRINT(" %s %s ",
193 gateways < intgw ? "int" : "ext",
194 ipaddr_string(ndo, (const u_char *)&addr));
195
196 comma = "";
197 ND_PRINT("(");
198 while (distances != 0) {
199 if (length < 2)
200 goto trunc;
201 ND_PRINT("%sd%u:", comma, GET_U_1(cp));
202 cp++;
203 comma = ", ";
204 networks = GET_U_1(cp);
205 cp++;
206 length -= 2;
207 while (networks != 0) {
208 /* Pickup network number */
209 if (length < 1)
210 goto trunc;
211 addr = ((uint32_t) GET_U_1(cp)) << 24;
212 cp++;
213 length--;
214 if (IN_CLASSB(addr)) {
215 if (length < 1)
216 goto trunc;
217 addr |= ((uint32_t) GET_U_1(cp)) << 16;
218 cp++;
219 length--;
220 } else if (!IN_CLASSA(addr)) {
221 if (length < 2)
222 goto trunc;
223 addr |= ((uint32_t) GET_U_1(cp)) << 16;
224 cp++;
225 addr |= ((uint32_t) GET_U_1(cp)) << 8;
226 cp++;
227 length -= 2;
228 }
229 ND_PRINT(" %s", ipaddr_string(ndo, (const u_char *)&addr));
230 networks--;
231 }
232 distances--;
233 }
234 ND_PRINT(")");
235 }
236 return;
237 trunc:
238 nd_print_trunc(ndo);
239 }
240
241 void
egp_print(netdissect_options * ndo,const uint8_t * bp,u_int length)242 egp_print(netdissect_options *ndo,
243 const uint8_t *bp, u_int length)
244 {
245 const struct egp_packet *egp;
246 u_int version;
247 u_int type;
248 u_int code;
249 u_int status;
250
251 ndo->ndo_protocol = "egp";
252 egp = (const struct egp_packet *)bp;
253 if (length < sizeof(*egp) || !ND_TTEST_SIZE(egp)) {
254 nd_print_trunc(ndo);
255 return;
256 }
257
258 version = GET_U_1(egp->egp_version);
259 if (!ndo->ndo_vflag) {
260 ND_PRINT("EGPv%u, AS %u, seq %u, length %u",
261 version,
262 GET_BE_U_2(egp->egp_as),
263 GET_BE_U_2(egp->egp_sequence),
264 length);
265 return;
266 } else
267 ND_PRINT("EGPv%u, length %u",
268 version,
269 length);
270
271 if (version != EGP_VERSION) {
272 ND_PRINT("[version %u]", version);
273 return;
274 }
275
276 type = GET_U_1(egp->egp_type);
277 code = GET_U_1(egp->egp_code);
278 status = GET_U_1(egp->egp_status);
279
280 switch (type) {
281 case EGPT_ACQUIRE:
282 ND_PRINT(" acquire");
283 switch (code) {
284 case EGPC_REQUEST:
285 case EGPC_CONFIRM:
286 ND_PRINT(" %s", egp_acquire_codes[code]);
287 switch (status) {
288 case EGPS_UNSPEC:
289 case EGPS_ACTIVE:
290 case EGPS_PASSIVE:
291 ND_PRINT(" %s", egp_acquire_status[status]);
292 break;
293
294 default:
295 ND_PRINT(" [status %u]", status);
296 break;
297 }
298 ND_PRINT(" hello:%u poll:%u",
299 GET_BE_U_2(egp->egp_hello),
300 GET_BE_U_2(egp->egp_poll));
301 break;
302
303 case EGPC_REFUSE:
304 case EGPC_CEASE:
305 case EGPC_CEASEACK:
306 ND_PRINT(" %s", egp_acquire_codes[code]);
307 switch (status ) {
308 case EGPS_UNSPEC:
309 case EGPS_NORES:
310 case EGPS_ADMIN:
311 case EGPS_GODOWN:
312 case EGPS_PARAM:
313 case EGPS_PROTO:
314 ND_PRINT(" %s", egp_acquire_status[status]);
315 break;
316
317 default:
318 ND_PRINT("[status %u]", status);
319 break;
320 }
321 break;
322
323 default:
324 ND_PRINT("[code %u]", code);
325 break;
326 }
327 break;
328
329 case EGPT_REACH:
330 switch (code) {
331
332 case EGPC_HELLO:
333 case EGPC_HEARDU:
334 ND_PRINT(" %s", egp_reach_codes[code]);
335 if (status <= EGPS_DOWN)
336 ND_PRINT(" state:%s", egp_status_updown[status]);
337 else
338 ND_PRINT(" [status %u]", status);
339 break;
340
341 default:
342 ND_PRINT("[reach code %u]", code);
343 break;
344 }
345 break;
346
347 case EGPT_POLL:
348 ND_PRINT(" poll");
349 if (status <= EGPS_DOWN)
350 ND_PRINT(" state:%s", egp_status_updown[status]);
351 else
352 ND_PRINT(" [status %u]", status);
353 ND_PRINT(" net:%s", GET_IPADDR_STRING(egp->egp_sourcenet));
354 break;
355
356 case EGPT_UPDATE:
357 ND_PRINT(" update");
358 if (status & EGPS_UNSOL) {
359 status &= ~EGPS_UNSOL;
360 ND_PRINT(" unsolicited");
361 }
362 if (status <= EGPS_DOWN)
363 ND_PRINT(" state:%s", egp_status_updown[status]);
364 else
365 ND_PRINT(" [status %u]", status);
366 ND_PRINT(" %s int %u ext %u",
367 GET_IPADDR_STRING(egp->egp_sourcenet),
368 GET_U_1(egp->egp_intgw),
369 GET_U_1(egp->egp_extgw));
370 if (ndo->ndo_vflag)
371 egpnr_print(ndo, egp, length);
372 break;
373
374 case EGPT_ERROR:
375 ND_PRINT(" error");
376 if (status <= EGPS_DOWN)
377 ND_PRINT(" state:%s", egp_status_updown[status]);
378 else
379 ND_PRINT(" [status %u]", status);
380
381 if (GET_BE_U_2(egp->egp_reason) <= EGPR_UVERSION)
382 ND_PRINT(" %s",
383 egp_reasons[GET_BE_U_2(egp->egp_reason)]);
384 else
385 ND_PRINT(" [reason %u]", GET_BE_U_2(egp->egp_reason));
386 break;
387
388 default:
389 ND_PRINT("[type %u]", type);
390 break;
391 }
392 }
393