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 #ifndef lint 23 static const char rcsid[] _U_ = 24 "@(#) $Header: /tcpdump/master/tcpdump/print-arp.c,v 1.66 2006-03-03 22:53:21 hannes Exp $ (LBL)"; 25 #endif 26 27 #ifdef HAVE_CONFIG_H 28 #include "config.h" 29 #endif 30 31 #include <tcpdump-stdinc.h> 32 33 #include <stdio.h> 34 #include <string.h> 35 36 #include "netdissect.h" 37 #include "addrtoname.h" 38 #include "ether.h" 39 #include "ethertype.h" 40 #include "extract.h" /* must come after interface.h */ 41 42 /* 43 * Address Resolution Protocol. 44 * 45 * See RFC 826 for protocol description. ARP packets are variable 46 * in size; the arphdr structure defines the fixed-length portion. 47 * Protocol type values are the same as those for 10 Mb/s Ethernet. 48 * It is followed by the variable-sized fields ar_sha, arp_spa, 49 * arp_tha and arp_tpa in that order, according to the lengths 50 * specified. Field names used correspond to RFC 826. 51 */ 52 struct arp_pkthdr { 53 u_short ar_hrd; /* format of hardware address */ 54 #define ARPHRD_ETHER 1 /* ethernet hardware format */ 55 #define ARPHRD_IEEE802 6 /* token-ring hardware format */ 56 #define ARPHRD_ARCNET 7 /* arcnet hardware format */ 57 #define ARPHRD_FRELAY 15 /* frame relay hardware format */ 58 #define ARPHRD_ATM2225 19 /* ATM (RFC 2225) */ 59 #define ARPHRD_STRIP 23 /* Ricochet Starmode Radio hardware format */ 60 #define ARPHRD_IEEE1394 24 /* IEEE 1394 (FireWire) hardware format */ 61 u_short ar_pro; /* format of protocol address */ 62 u_char ar_hln; /* length of hardware address */ 63 u_char ar_pln; /* length of protocol address */ 64 u_short ar_op; /* one of: */ 65 #define ARPOP_REQUEST 1 /* request to resolve address */ 66 #define ARPOP_REPLY 2 /* response to previous request */ 67 #define ARPOP_REVREQUEST 3 /* request protocol address given hardware */ 68 #define ARPOP_REVREPLY 4 /* response giving protocol address */ 69 #define ARPOP_INVREQUEST 8 /* request to identify peer */ 70 #define ARPOP_INVREPLY 9 /* response identifying peer */ 71 #define ARPOP_NAK 10 /* NAK - only valif for ATM ARP */ 72 73 /* 74 * The remaining fields are variable in size, 75 * according to the sizes above. 76 */ 77 #ifdef COMMENT_ONLY 78 u_char ar_sha[]; /* sender hardware address */ 79 u_char ar_spa[]; /* sender protocol address */ 80 u_char ar_tha[]; /* target hardware address */ 81 u_char ar_tpa[]; /* target protocol address */ 82 #endif 83 #define ar_sha(ap) (((const u_char *)((ap)+1))+0) 84 #define ar_spa(ap) (((const u_char *)((ap)+1))+ (ap)->ar_hln) 85 #define ar_tha(ap) (((const u_char *)((ap)+1))+ (ap)->ar_hln+(ap)->ar_pln) 86 #define ar_tpa(ap) (((const u_char *)((ap)+1))+2*(ap)->ar_hln+(ap)->ar_pln) 87 }; 88 89 #define ARP_HDRLEN 8 90 91 #define HRD(ap) EXTRACT_16BITS(&(ap)->ar_hrd) 92 #define HRD_LEN(ap) ((ap)->ar_hln) 93 #define PROTO_LEN(ap) ((ap)->ar_pln) 94 #define OP(ap) EXTRACT_16BITS(&(ap)->ar_op) 95 #define PRO(ap) EXTRACT_16BITS(&(ap)->ar_pro) 96 #define SHA(ap) (ar_sha(ap)) 97 #define SPA(ap) (ar_spa(ap)) 98 #define THA(ap) (ar_tha(ap)) 99 #define TPA(ap) (ar_tpa(ap)) 100 101 102 struct tok arpop_values[] = { 103 { ARPOP_REQUEST, "Request" }, 104 { ARPOP_REPLY, "Reply" }, 105 { ARPOP_REVREQUEST, "Reverse Request" }, 106 { ARPOP_REVREPLY, "Reverse Reply" }, 107 { ARPOP_INVREQUEST, "Inverse Request" }, 108 { ARPOP_INVREPLY, "Inverse Reply" }, 109 { ARPOP_NAK, "NACK Reply" }, 110 { 0, NULL } 111 }; 112 113 struct tok arphrd_values[] = { 114 { ARPHRD_ETHER, "Ethernet" }, 115 { ARPHRD_IEEE802, "TokenRing" }, 116 { ARPHRD_ARCNET, "ArcNet" }, 117 { ARPHRD_FRELAY, "FrameRelay" }, 118 { ARPHRD_STRIP, "Strip" }, 119 { ARPHRD_IEEE1394, "IEEE 1394" }, 120 { ARPHRD_ATM2225, "ATM" }, 121 { 0, NULL } 122 }; 123 124 /* 125 * ATM Address Resolution Protocol. 126 * 127 * See RFC 2225 for protocol description. ATMARP packets are similar 128 * to ARP packets, except that there are no length fields for the 129 * protocol address - instead, there are type/length fields for 130 * the ATM number and subaddress - and the hardware addresses consist 131 * of an ATM number and an ATM subaddress. 132 */ 133 struct atmarp_pkthdr { 134 u_short aar_hrd; /* format of hardware address */ 135 u_short aar_pro; /* format of protocol address */ 136 u_char aar_shtl; /* length of source ATM number */ 137 u_char aar_sstl; /* length of source ATM subaddress */ 138 #define ATMARP_IS_E164 0x40 /* bit in type/length for E.164 format */ 139 #define ATMARP_LEN_MASK 0x3F /* length of {sub}address in type/length */ 140 u_short aar_op; /* same as regular ARP */ 141 u_char aar_spln; /* length of source protocol address */ 142 u_char aar_thtl; /* length of target ATM number */ 143 u_char aar_tstl; /* length of target ATM subaddress */ 144 u_char aar_tpln; /* length of target protocol address */ 145 /* 146 * The remaining fields are variable in size, 147 * according to the sizes above. 148 */ 149 #ifdef COMMENT_ONLY 150 u_char aar_sha[]; /* source ATM number */ 151 u_char aar_ssa[]; /* source ATM subaddress */ 152 u_char aar_spa[]; /* sender protocol address */ 153 u_char aar_tha[]; /* target ATM number */ 154 u_char aar_tsa[]; /* target ATM subaddress */ 155 u_char aar_tpa[]; /* target protocol address */ 156 #endif 157 158 #define ATMHRD(ap) EXTRACT_16BITS(&(ap)->aar_hrd) 159 #define ATMSHRD_LEN(ap) ((ap)->aar_shtl & ATMARP_LEN_MASK) 160 #define ATMSSLN(ap) ((ap)->aar_sstl & ATMARP_LEN_MASK) 161 #define ATMSPROTO_LEN(ap) ((ap)->aar_spln) 162 #define ATMOP(ap) EXTRACT_16BITS(&(ap)->aar_op) 163 #define ATMPRO(ap) EXTRACT_16BITS(&(ap)->aar_pro) 164 #define ATMTHRD_LEN(ap) ((ap)->aar_thtl & ATMARP_LEN_MASK) 165 #define ATMTSLN(ap) ((ap)->aar_tstl & ATMARP_LEN_MASK) 166 #define ATMTPROTO_LEN(ap) ((ap)->aar_tpln) 167 #define aar_sha(ap) ((const u_char *)((ap)+1)) 168 #define aar_ssa(ap) (aar_sha(ap) + ATMSHRD_LEN(ap)) 169 #define aar_spa(ap) (aar_ssa(ap) + ATMSSLN(ap)) 170 #define aar_tha(ap) (aar_spa(ap) + ATMSPROTO_LEN(ap)) 171 #define aar_tsa(ap) (aar_tha(ap) + ATMTHRD_LEN(ap)) 172 #define aar_tpa(ap) (aar_tsa(ap) + ATMTSLN(ap)) 173 }; 174 175 #define ATMSHA(ap) (aar_sha(ap)) 176 #define ATMSSA(ap) (aar_ssa(ap)) 177 #define ATMSPA(ap) (aar_spa(ap)) 178 #define ATMTHA(ap) (aar_tha(ap)) 179 #define ATMTSA(ap) (aar_tsa(ap)) 180 #define ATMTPA(ap) (aar_tpa(ap)) 181 182 static u_char ezero[6]; 183 184 static void 185 atmarp_addr_print(netdissect_options *ndo, 186 const u_char *ha, u_int ha_len, const u_char *srca, 187 u_int srca_len) 188 { 189 if (ha_len == 0) 190 ND_PRINT((ndo, "<No address>")); 191 else { 192 ND_PRINT((ndo, "%s", linkaddr_string(ha, LINKADDR_ATM, ha_len))); 193 if (srca_len != 0) 194 ND_PRINT((ndo, ",%s", 195 linkaddr_string(srca, LINKADDR_ATM, srca_len))); 196 } 197 } 198 199 static void 200 atmarp_print(netdissect_options *ndo, 201 const u_char *bp, u_int length, u_int caplen) 202 { 203 const struct atmarp_pkthdr *ap; 204 u_short pro, hrd, op; 205 206 ap = (const struct atmarp_pkthdr *)bp; 207 ND_TCHECK(*ap); 208 209 hrd = ATMHRD(ap); 210 pro = ATMPRO(ap); 211 op = ATMOP(ap); 212 213 if (!ND_TTEST2(*aar_tpa(ap), ATMTPROTO_LEN(ap))) { 214 ND_PRINT((ndo, "[|ARP]")); 215 ND_DEFAULTPRINT((const u_char *)ap, length); 216 return; 217 } 218 219 if (!ndo->ndo_eflag) { 220 ND_PRINT((ndo, "ARP, ")); 221 } 222 223 if ((pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) || 224 ATMSPROTO_LEN(ap) != 4 || 225 ATMTPROTO_LEN(ap) != 4 || 226 ndo->ndo_vflag) { 227 ND_PRINT((ndo, "%s, %s (len %u/%u)", 228 tok2str(arphrd_values, "Unknown Hardware (%u)", hrd), 229 tok2str(ethertype_values, "Unknown Protocol (0x%04x)", pro), 230 ATMSPROTO_LEN(ap), 231 ATMTPROTO_LEN(ap))); 232 233 /* don't know know about the address formats */ 234 if (!ndo->ndo_vflag) { 235 goto out; 236 } 237 } 238 239 /* print operation */ 240 printf("%s%s ", 241 ndo->ndo_vflag ? ", " : "", 242 tok2str(arpop_values, "Unknown (%u)", op)); 243 244 switch (op) { 245 246 case ARPOP_REQUEST: 247 ND_PRINT((ndo, "who-has %s", ipaddr_string(ATMTPA(ap)))); 248 if (ATMTHRD_LEN(ap) != 0) { 249 ND_PRINT((ndo, " (")); 250 atmarp_addr_print(ndo, ATMTHA(ap), ATMTHRD_LEN(ap), 251 ATMTSA(ap), ATMTSLN(ap)); 252 ND_PRINT((ndo, ")")); 253 } 254 ND_PRINT((ndo, "tell %s", ipaddr_string(ATMSPA(ap)))); 255 break; 256 257 case ARPOP_REPLY: 258 ND_PRINT((ndo, "%s is-at ", ipaddr_string(ATMSPA(ap)))); 259 atmarp_addr_print(ndo, ATMSHA(ap), ATMSHRD_LEN(ap), ATMSSA(ap), 260 ATMSSLN(ap)); 261 break; 262 263 case ARPOP_INVREQUEST: 264 ND_PRINT((ndo, "who-is ")); 265 atmarp_addr_print(ndo, ATMTHA(ap), ATMTHRD_LEN(ap), ATMTSA(ap), 266 ATMTSLN(ap)); 267 ND_PRINT((ndo, " tell ")); 268 atmarp_addr_print(ndo, ATMSHA(ap), ATMSHRD_LEN(ap), ATMSSA(ap), 269 ATMSSLN(ap)); 270 break; 271 272 case ARPOP_INVREPLY: 273 atmarp_addr_print(ndo, ATMSHA(ap), ATMSHRD_LEN(ap), ATMSSA(ap), 274 ATMSSLN(ap)); 275 ND_PRINT((ndo, "at %s", ipaddr_string(ATMSPA(ap)))); 276 break; 277 278 case ARPOP_NAK: 279 ND_PRINT((ndo, "for %s", ipaddr_string(ATMSPA(ap)))); 280 break; 281 282 default: 283 ND_DEFAULTPRINT((const u_char *)ap, caplen); 284 return; 285 } 286 287 out: 288 ND_PRINT((ndo, ", length %u", length)); 289 return; 290 291 trunc: 292 ND_PRINT((ndo, "[|ARP]")); 293 } 294 295 void 296 arp_print(netdissect_options *ndo, 297 const u_char *bp, u_int length, u_int caplen) 298 { 299 const struct arp_pkthdr *ap; 300 u_short pro, hrd, op, linkaddr; 301 302 ap = (const struct arp_pkthdr *)bp; 303 ND_TCHECK(*ap); 304 305 hrd = HRD(ap); 306 pro = PRO(ap); 307 op = OP(ap); 308 309 310 /* if its ATM then call the ATM ARP printer 311 for Frame-relay ARP most of the fields 312 are similar to Ethernet so overload the Ethernet Printer 313 and set the linkaddr type for linkaddr_string() accordingly */ 314 315 switch(hrd) { 316 case ARPHRD_ATM2225: 317 atmarp_print(ndo, bp, length, caplen); 318 return; 319 case ARPHRD_FRELAY: 320 linkaddr = LINKADDR_FRELAY; 321 break; 322 default: 323 linkaddr = LINKADDR_ETHER; 324 break; 325 } 326 327 if (!ND_TTEST2(*ar_tpa(ap), PROTO_LEN(ap))) { 328 ND_PRINT((ndo, "[|ARP]")); 329 ND_DEFAULTPRINT((const u_char *)ap, length); 330 return; 331 } 332 333 if (!ndo->ndo_eflag) { 334 ND_PRINT((ndo, "ARP, ")); 335 } 336 337 /* print hardware type/len and proto type/len */ 338 if ((pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) || 339 PROTO_LEN(ap) != 4 || 340 HRD_LEN(ap) == 0 || 341 ndo->ndo_vflag) { 342 ND_PRINT((ndo, "%s (len %u), %s (len %u)", 343 tok2str(arphrd_values, "Unknown Hardware (%u)", hrd), 344 HRD_LEN(ap), 345 tok2str(ethertype_values, "Unknown Protocol (0x%04x)", pro), 346 PROTO_LEN(ap))); 347 348 /* don't know know about the address formats */ 349 if (!ndo->ndo_vflag) { 350 goto out; 351 } 352 } 353 354 /* print operation */ 355 printf("%s%s ", 356 ndo->ndo_vflag ? ", " : "", 357 tok2str(arpop_values, "Unknown (%u)", op)); 358 359 switch (op) { 360 361 case ARPOP_REQUEST: 362 ND_PRINT((ndo, "who-has %s", ipaddr_string(TPA(ap)))); 363 if (memcmp((const char *)ezero, (const char *)THA(ap), HRD_LEN(ap)) != 0) 364 ND_PRINT((ndo, " (%s)", 365 linkaddr_string(THA(ap), linkaddr, HRD_LEN(ap)))); 366 ND_PRINT((ndo, " tell %s", ipaddr_string(SPA(ap)))); 367 break; 368 369 case ARPOP_REPLY: 370 ND_PRINT((ndo, "%s is-at %s", 371 ipaddr_string(SPA(ap)), 372 linkaddr_string(SHA(ap), linkaddr, HRD_LEN(ap)))); 373 break; 374 375 case ARPOP_REVREQUEST: 376 ND_PRINT((ndo, "who-is %s tell %s", 377 linkaddr_string(THA(ap), linkaddr, HRD_LEN(ap)), 378 linkaddr_string(SHA(ap), linkaddr, HRD_LEN(ap)))); 379 break; 380 381 case ARPOP_REVREPLY: 382 ND_PRINT((ndo, "%s at %s", 383 linkaddr_string(THA(ap), linkaddr, HRD_LEN(ap)), 384 ipaddr_string(TPA(ap)))); 385 break; 386 387 case ARPOP_INVREQUEST: 388 ND_PRINT((ndo, "who-is %s tell %s", 389 linkaddr_string(THA(ap), linkaddr, HRD_LEN(ap)), 390 linkaddr_string(SHA(ap), linkaddr, HRD_LEN(ap)))); 391 break; 392 393 case ARPOP_INVREPLY: 394 ND_PRINT((ndo,"%s at %s", 395 linkaddr_string(THA(ap), linkaddr, HRD_LEN(ap)), 396 ipaddr_string(TPA(ap)))); 397 break; 398 399 default: 400 ND_DEFAULTPRINT((const u_char *)ap, caplen); 401 return; 402 } 403 404 out: 405 ND_PRINT((ndo, ", length %u", length)); 406 407 return; 408 trunc: 409 ND_PRINT((ndo, "[|ARP]")); 410 } 411 412 /* 413 * Local Variables: 414 * c-style: bsd 415 * End: 416 */ 417 418