1 /* 2 * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997 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 22 /* \summary: Address Resolution Protocol (ARP) printer */ 23 24 #ifdef HAVE_CONFIG_H 25 #include <config.h> 26 #endif 27 28 #include "netdissect-stdinc.h" 29 30 #define ND_LONGJMP_FROM_TCHECK 31 #include "netdissect.h" 32 #include "addrtoname.h" 33 #include "ethertype.h" 34 #include "extract.h" 35 36 37 /* 38 * Address Resolution Protocol. 39 * 40 * See RFC 826 for protocol description. ARP packets are variable 41 * in size; the arphdr structure defines the fixed-length portion. 42 * Protocol type values are the same as those for 10 Mb/s Ethernet. 43 * It is followed by the variable-sized fields ar_sha, arp_spa, 44 * arp_tha and arp_tpa in that order, according to the lengths 45 * specified. Field names used correspond to RFC 826. 46 */ 47 struct arp_pkthdr { 48 nd_uint16_t ar_hrd; /* format of hardware address */ 49 #define ARPHRD_ETHER 1 /* ethernet hardware format */ 50 #define ARPHRD_IEEE802 6 /* token-ring hardware format */ 51 #define ARPHRD_ARCNET 7 /* arcnet hardware format */ 52 #define ARPHRD_FRELAY 15 /* frame relay hardware format */ 53 #define ARPHRD_ATM2225 19 /* ATM (RFC 2225) */ 54 #define ARPHRD_STRIP 23 /* Ricochet Starmode Radio hardware format */ 55 #define ARPHRD_IEEE1394 24 /* IEEE 1394 (FireWire) hardware format */ 56 #define ARPHRD_INFINIBAND 32 /* InfiniBand RFC 4391 */ 57 nd_uint16_t ar_pro; /* format of protocol address */ 58 nd_uint8_t ar_hln; /* length of hardware address */ 59 nd_uint8_t ar_pln; /* length of protocol address */ 60 nd_uint16_t ar_op; /* one of: */ 61 #define ARPOP_REQUEST 1 /* request to resolve address */ 62 #define ARPOP_REPLY 2 /* response to previous request */ 63 #define ARPOP_REVREQUEST 3 /* request protocol address given hardware */ 64 #define ARPOP_REVREPLY 4 /* response giving protocol address */ 65 #define ARPOP_INVREQUEST 8 /* request to identify peer */ 66 #define ARPOP_INVREPLY 9 /* response identifying peer */ 67 #define ARPOP_NAK 10 /* NAK - only valid for ATM ARP */ 68 69 /* 70 * The remaining fields are variable in size, 71 * according to the sizes above. 72 */ 73 #ifdef COMMENT_ONLY 74 nd_byte ar_sha[]; /* sender hardware address */ 75 nd_byte ar_spa[]; /* sender protocol address */ 76 nd_byte ar_tha[]; /* target hardware address */ 77 nd_byte ar_tpa[]; /* target protocol address */ 78 #endif 79 #define ar_sha(ap) (((const u_char *)((ap)+1))+ 0) 80 #define ar_spa(ap) (((const u_char *)((ap)+1))+ GET_U_1((ap)->ar_hln)) 81 #define ar_tha(ap) (((const u_char *)((ap)+1))+ GET_U_1((ap)->ar_hln)+GET_U_1((ap)->ar_pln)) 82 #define ar_tpa(ap) (((const u_char *)((ap)+1))+2*GET_U_1((ap)->ar_hln)+GET_U_1((ap)->ar_pln)) 83 }; 84 85 #define ARP_HDRLEN 8 86 87 #define HRD(ap) GET_BE_U_2((ap)->ar_hrd) 88 #define HRD_LEN(ap) GET_U_1((ap)->ar_hln) 89 #define PROTO_LEN(ap) GET_U_1((ap)->ar_pln) 90 #define OP(ap) GET_BE_U_2((ap)->ar_op) 91 #define PRO(ap) GET_BE_U_2((ap)->ar_pro) 92 #define SHA(ap) (ar_sha(ap)) 93 #define SPA(ap) (ar_spa(ap)) 94 #define THA(ap) (ar_tha(ap)) 95 #define TPA(ap) (ar_tpa(ap)) 96 97 98 static const struct tok arpop_values[] = { 99 { ARPOP_REQUEST, "Request" }, 100 { ARPOP_REPLY, "Reply" }, 101 { ARPOP_REVREQUEST, "Reverse Request" }, 102 { ARPOP_REVREPLY, "Reverse Reply" }, 103 { ARPOP_INVREQUEST, "Inverse Request" }, 104 { ARPOP_INVREPLY, "Inverse Reply" }, 105 { ARPOP_NAK, "NACK Reply" }, 106 { 0, NULL } 107 }; 108 109 static const struct tok arphrd_values[] = { 110 { ARPHRD_ETHER, "Ethernet" }, 111 { ARPHRD_IEEE802, "TokenRing" }, 112 { ARPHRD_ARCNET, "ArcNet" }, 113 { ARPHRD_FRELAY, "FrameRelay" }, 114 { ARPHRD_STRIP, "Strip" }, 115 { ARPHRD_IEEE1394, "IEEE 1394" }, 116 { ARPHRD_ATM2225, "ATM" }, 117 { ARPHRD_INFINIBAND, "InfiniBand" }, 118 { 0, NULL } 119 }; 120 121 /* 122 * ATM Address Resolution Protocol. 123 * 124 * See RFC 2225 for protocol description. ATMARP packets are similar 125 * to ARP packets, except that there are no length fields for the 126 * protocol address - instead, there are type/length fields for 127 * the ATM number and subaddress - and the hardware addresses consist 128 * of an ATM number and an ATM subaddress. 129 */ 130 struct atmarp_pkthdr { 131 nd_uint16_t aar_hrd; /* format of hardware address */ 132 nd_uint16_t aar_pro; /* format of protocol address */ 133 nd_uint8_t aar_shtl; /* length of source ATM number */ 134 nd_uint8_t aar_sstl; /* length of source ATM subaddress */ 135 #define ATMARP_IS_E164 0x40 /* bit in type/length for E.164 format */ 136 #define ATMARP_LEN_MASK 0x3F /* length of {sub}address in type/length */ 137 nd_uint16_t aar_op; /* same as regular ARP */ 138 nd_uint8_t aar_spln; /* length of source protocol address */ 139 nd_uint8_t aar_thtl; /* length of target ATM number */ 140 nd_uint8_t aar_tstl; /* length of target ATM subaddress */ 141 nd_uint8_t aar_tpln; /* length of target protocol address */ 142 /* 143 * The remaining fields are variable in size, 144 * according to the sizes above. 145 */ 146 #ifdef COMMENT_ONLY 147 nd_byte aar_sha[]; /* source ATM number */ 148 nd_byte aar_ssa[]; /* source ATM subaddress */ 149 nd_byte aar_spa[]; /* sender protocol address */ 150 nd_byte aar_tha[]; /* target ATM number */ 151 nd_byte aar_tsa[]; /* target ATM subaddress */ 152 nd_byte aar_tpa[]; /* target protocol address */ 153 #endif 154 155 #define ATMHRD(ap) GET_BE_U_2((ap)->aar_hrd) 156 #define ATMSHRD_LEN(ap) (GET_U_1((ap)->aar_shtl) & ATMARP_LEN_MASK) 157 #define ATMSSLN(ap) (GET_U_1((ap)->aar_sstl) & ATMARP_LEN_MASK) 158 #define ATMSPROTO_LEN(ap) GET_U_1((ap)->aar_spln) 159 #define ATMOP(ap) GET_BE_U_2((ap)->aar_op) 160 #define ATMPRO(ap) GET_BE_U_2((ap)->aar_pro) 161 #define ATMTHRD_LEN(ap) (GET_U_1((ap)->aar_thtl) & ATMARP_LEN_MASK) 162 #define ATMTSLN(ap) (GET_U_1((ap)->aar_tstl) & ATMARP_LEN_MASK) 163 #define ATMTPROTO_LEN(ap) GET_U_1((ap)->aar_tpln) 164 #define aar_sha(ap) ((const u_char *)((ap)+1)) 165 #define aar_ssa(ap) (aar_sha(ap) + ATMSHRD_LEN(ap)) 166 #define aar_spa(ap) (aar_ssa(ap) + ATMSSLN(ap)) 167 #define aar_tha(ap) (aar_spa(ap) + ATMSPROTO_LEN(ap)) 168 #define aar_tsa(ap) (aar_tha(ap) + ATMTHRD_LEN(ap)) 169 #define aar_tpa(ap) (aar_tsa(ap) + ATMTSLN(ap)) 170 }; 171 172 #define ATMSHA(ap) (aar_sha(ap)) 173 #define ATMSSA(ap) (aar_ssa(ap)) 174 #define ATMSPA(ap) (aar_spa(ap)) 175 #define ATMTHA(ap) (aar_tha(ap)) 176 #define ATMTSA(ap) (aar_tsa(ap)) 177 #define ATMTPA(ap) (aar_tpa(ap)) 178 179 static int 180 isnonzero(netdissect_options *ndo, const u_char *a, size_t len) 181 { 182 while (len > 0) { 183 if (GET_U_1(a) != 0) 184 return (1); 185 a++; 186 len--; 187 } 188 return (0); 189 } 190 191 static void 192 tpaddr_print_ip(netdissect_options *ndo, 193 const struct arp_pkthdr *ap, u_short pro) 194 { 195 if (pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) 196 ND_PRINT("<wrong proto type>"); 197 else if (PROTO_LEN(ap) != 4) 198 ND_PRINT("<wrong len>"); 199 else 200 ND_PRINT("%s", GET_IPADDR_STRING(TPA(ap))); 201 } 202 203 static void 204 spaddr_print_ip(netdissect_options *ndo, 205 const struct arp_pkthdr *ap, u_short pro) 206 { 207 if (pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) 208 ND_PRINT("<wrong proto type>"); 209 else if (PROTO_LEN(ap) != 4) 210 ND_PRINT("<wrong len>"); 211 else 212 ND_PRINT("%s", GET_IPADDR_STRING(SPA(ap))); 213 } 214 215 static void 216 atmarp_addr_print(netdissect_options *ndo, 217 const u_char *ha, u_int ha_len, const u_char *srca, 218 u_int srca_len) 219 { 220 if (ha_len == 0) 221 ND_PRINT("<No address>"); 222 else { 223 ND_PRINT("%s", GET_LINKADDR_STRING(ha, LINKADDR_ATM, ha_len)); 224 if (srca_len != 0) 225 ND_PRINT(",%s", 226 GET_LINKADDR_STRING(srca, LINKADDR_ATM, srca_len)); 227 } 228 } 229 230 static void 231 atmarp_tpaddr_print(netdissect_options *ndo, 232 const struct atmarp_pkthdr *ap, u_short pro) 233 { 234 if (pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) 235 ND_PRINT("<wrong proto type>"); 236 else if (ATMTPROTO_LEN(ap) != 4) 237 ND_PRINT("<wrong tplen>"); 238 else 239 ND_PRINT("%s", GET_IPADDR_STRING(ATMTPA(ap))); 240 } 241 242 static void 243 atmarp_spaddr_print(netdissect_options *ndo, 244 const struct atmarp_pkthdr *ap, u_short pro) 245 { 246 if (pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) 247 ND_PRINT("<wrong proto type>"); 248 else if (ATMSPROTO_LEN(ap) != 4) 249 ND_PRINT("<wrong splen>"); 250 else 251 ND_PRINT("%s", GET_IPADDR_STRING(ATMSPA(ap))); 252 } 253 254 static void 255 atmarp_print(netdissect_options *ndo, 256 const u_char *bp, u_int length, u_int caplen) 257 { 258 const struct atmarp_pkthdr *ap; 259 u_short pro, hrd, op; 260 261 ap = (const struct atmarp_pkthdr *)bp; 262 ND_TCHECK_SIZE(ap); 263 264 hrd = ATMHRD(ap); 265 pro = ATMPRO(ap); 266 op = ATMOP(ap); 267 268 ND_TCHECK_LEN(ATMTPA(ap), ATMTPROTO_LEN(ap)); 269 270 if (!ndo->ndo_eflag) { 271 ND_PRINT("ARP, "); 272 } 273 274 if ((pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) || 275 ATMSPROTO_LEN(ap) != 4 || 276 ATMTPROTO_LEN(ap) != 4 || 277 ndo->ndo_vflag) { 278 ND_PRINT("%s, %s (len %u/%u)", 279 tok2str(arphrd_values, "Unknown Hardware (%u)", hrd), 280 tok2str(ethertype_values, "Unknown Protocol (0x%04x)", pro), 281 ATMSPROTO_LEN(ap), 282 ATMTPROTO_LEN(ap)); 283 284 /* don't know about the address formats */ 285 if (!ndo->ndo_vflag) { 286 goto out; 287 } 288 } 289 290 /* print operation */ 291 ND_PRINT("%s%s ", 292 ndo->ndo_vflag ? ", " : "", 293 tok2str(arpop_values, "Unknown (%u)", op)); 294 295 switch (op) { 296 297 case ARPOP_REQUEST: 298 ND_PRINT("who-has "); 299 atmarp_tpaddr_print(ndo, ap, pro); 300 if (ATMTHRD_LEN(ap) != 0) { 301 ND_PRINT(" ("); 302 atmarp_addr_print(ndo, ATMTHA(ap), ATMTHRD_LEN(ap), 303 ATMTSA(ap), ATMTSLN(ap)); 304 ND_PRINT(")"); 305 } 306 ND_PRINT(" tell "); 307 atmarp_spaddr_print(ndo, ap, pro); 308 break; 309 310 case ARPOP_REPLY: 311 atmarp_spaddr_print(ndo, ap, pro); 312 ND_PRINT(" is-at "); 313 atmarp_addr_print(ndo, ATMSHA(ap), ATMSHRD_LEN(ap), ATMSSA(ap), 314 ATMSSLN(ap)); 315 break; 316 317 case ARPOP_INVREQUEST: 318 ND_PRINT("who-is "); 319 atmarp_addr_print(ndo, ATMTHA(ap), ATMTHRD_LEN(ap), ATMTSA(ap), 320 ATMTSLN(ap)); 321 ND_PRINT(" tell "); 322 atmarp_addr_print(ndo, ATMSHA(ap), ATMSHRD_LEN(ap), ATMSSA(ap), 323 ATMSSLN(ap)); 324 break; 325 326 case ARPOP_INVREPLY: 327 atmarp_addr_print(ndo, ATMSHA(ap), ATMSHRD_LEN(ap), ATMSSA(ap), 328 ATMSSLN(ap)); 329 ND_PRINT("at "); 330 atmarp_spaddr_print(ndo, ap, pro); 331 break; 332 333 case ARPOP_NAK: 334 ND_PRINT("for "); 335 atmarp_spaddr_print(ndo, ap, pro); 336 break; 337 338 default: 339 ND_DEFAULTPRINT((const u_char *)ap, caplen); 340 return; 341 } 342 343 out: 344 ND_PRINT(", length %u", length); 345 } 346 347 void 348 arp_print(netdissect_options *ndo, 349 const u_char *bp, u_int length, u_int caplen) 350 { 351 const struct arp_pkthdr *ap; 352 u_short pro, hrd, op, linkaddr; 353 354 ndo->ndo_protocol = "arp"; 355 ap = (const struct arp_pkthdr *)bp; 356 ND_TCHECK_SIZE(ap); 357 358 hrd = HRD(ap); 359 pro = PRO(ap); 360 op = OP(ap); 361 362 363 /* if its ATM then call the ATM ARP printer 364 for Frame-relay ARP most of the fields 365 are similar to Ethernet so overload the Ethernet Printer 366 and set the linkaddr type for GET_LINKADDR_STRING() accordingly */ 367 368 switch(hrd) { 369 case ARPHRD_ATM2225: 370 atmarp_print(ndo, bp, length, caplen); 371 return; 372 case ARPHRD_FRELAY: 373 linkaddr = LINKADDR_FRELAY; 374 break; 375 default: 376 linkaddr = LINKADDR_ETHER; 377 break; 378 } 379 380 ND_TCHECK_LEN(TPA(ap), PROTO_LEN(ap)); 381 382 if (!ndo->ndo_eflag) { 383 ND_PRINT("ARP, "); 384 } 385 386 /* print hardware type/len and proto type/len */ 387 if ((pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) || 388 PROTO_LEN(ap) != 4 || 389 HRD_LEN(ap) == 0 || 390 ndo->ndo_vflag) { 391 ND_PRINT("%s (len %u), %s (len %u)", 392 tok2str(arphrd_values, "Unknown Hardware (%u)", hrd), 393 HRD_LEN(ap), 394 tok2str(ethertype_values, "Unknown Protocol (0x%04x)", pro), 395 PROTO_LEN(ap)); 396 397 /* don't know about the address formats */ 398 if (!ndo->ndo_vflag) { 399 goto out; 400 } 401 } 402 403 /* print operation */ 404 ND_PRINT("%s%s ", 405 ndo->ndo_vflag ? ", " : "", 406 tok2str(arpop_values, "Unknown (%u)", op)); 407 408 switch (op) { 409 410 case ARPOP_REQUEST: 411 ND_PRINT("who-has "); 412 tpaddr_print_ip(ndo, ap, pro); 413 if (isnonzero(ndo, (const u_char *)THA(ap), HRD_LEN(ap))) 414 ND_PRINT(" (%s)", 415 GET_LINKADDR_STRING(THA(ap), linkaddr, HRD_LEN(ap))); 416 ND_PRINT(" tell "); 417 spaddr_print_ip(ndo, ap, pro); 418 break; 419 420 case ARPOP_REPLY: 421 spaddr_print_ip(ndo, ap, pro); 422 ND_PRINT(" is-at %s", 423 GET_LINKADDR_STRING(SHA(ap), linkaddr, HRD_LEN(ap))); 424 break; 425 426 case ARPOP_REVREQUEST: 427 /* 428 * XXX - GET_LINKADDR_STRING() may return a pointer to 429 * a static buffer, so we only have one call to it per 430 * ND_PRINT() call. 431 * 432 * This should be done in a cleaner fashion. 433 */ 434 ND_PRINT("who-is %s", 435 GET_LINKADDR_STRING(THA(ap), linkaddr, HRD_LEN(ap))); 436 ND_PRINT(" tell %s", 437 GET_LINKADDR_STRING(SHA(ap), linkaddr, HRD_LEN(ap))); 438 break; 439 440 case ARPOP_REVREPLY: 441 ND_PRINT("%s at ", 442 GET_LINKADDR_STRING(THA(ap), linkaddr, HRD_LEN(ap))); 443 tpaddr_print_ip(ndo, ap, pro); 444 break; 445 446 case ARPOP_INVREQUEST: 447 /* 448 * XXX - GET_LINKADDR_STRING() may return a pointer to 449 * a static buffer, so we only have one call to it per 450 * ND_PRINT() call. 451 * 452 * This should be done in a cleaner fashion. 453 */ 454 ND_PRINT("who-is %s", 455 GET_LINKADDR_STRING(THA(ap), linkaddr, HRD_LEN(ap))); 456 ND_PRINT(" tell %s", 457 GET_LINKADDR_STRING(SHA(ap), linkaddr, HRD_LEN(ap))); 458 break; 459 460 case ARPOP_INVREPLY: 461 ND_PRINT("%s at ", 462 GET_LINKADDR_STRING(SHA(ap), linkaddr, HRD_LEN(ap))); 463 spaddr_print_ip(ndo, ap, pro); 464 break; 465 466 default: 467 ND_DEFAULTPRINT((const u_char *)ap, caplen); 468 return; 469 } 470 471 out: 472 ND_PRINT(", length %u", length); 473 } 474