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 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 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