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 #include <sys/cdefs.h> 23 #ifndef lint 24 #if 0 25 static const char rcsid[] _U_ = 26 "@(#) Header: /tcpdump/master/tcpdump/print-arp.c,v 1.66 2006-03-03 22:53:21 hannes Exp (LBL)"; 27 #else 28 __RCSID("$NetBSD: print-arp.c,v 1.2 2010/12/05 05:11:30 christos Exp $"); 29 #endif 30 #endif 31 32 #ifdef HAVE_CONFIG_H 33 #include "config.h" 34 #endif 35 36 #include <tcpdump-stdinc.h> 37 38 #include <stdio.h> 39 #include <string.h> 40 41 #include "netdissect.h" 42 #include "addrtoname.h" 43 #include "ether.h" 44 #include "ethertype.h" 45 #include "extract.h" /* must come after interface.h */ 46 47 /* 48 * Address Resolution Protocol. 49 * 50 * See RFC 826 for protocol description. ARP packets are variable 51 * in size; the arphdr structure defines the fixed-length portion. 52 * Protocol type values are the same as those for 10 Mb/s Ethernet. 53 * It is followed by the variable-sized fields ar_sha, arp_spa, 54 * arp_tha and arp_tpa in that order, according to the lengths 55 * specified. Field names used correspond to RFC 826. 56 */ 57 struct arp_pkthdr { 58 u_short ar_hrd; /* format of hardware address */ 59 #define ARPHRD_ETHER 1 /* ethernet hardware format */ 60 #define ARPHRD_IEEE802 6 /* token-ring hardware format */ 61 #define ARPHRD_ARCNET 7 /* arcnet hardware format */ 62 #define ARPHRD_FRELAY 15 /* frame relay hardware format */ 63 #define ARPHRD_ATM2225 19 /* ATM (RFC 2225) */ 64 #define ARPHRD_STRIP 23 /* Ricochet Starmode Radio hardware format */ 65 #define ARPHRD_IEEE1394 24 /* IEEE 1394 (FireWire) hardware format */ 66 u_short ar_pro; /* format of protocol address */ 67 u_char ar_hln; /* length of hardware address */ 68 u_char ar_pln; /* length of protocol address */ 69 u_short ar_op; /* one of: */ 70 #define ARPOP_REQUEST 1 /* request to resolve address */ 71 #define ARPOP_REPLY 2 /* response to previous request */ 72 #define ARPOP_REVREQUEST 3 /* request protocol address given hardware */ 73 #define ARPOP_REVREPLY 4 /* response giving protocol address */ 74 #define ARPOP_INVREQUEST 8 /* request to identify peer */ 75 #define ARPOP_INVREPLY 9 /* response identifying peer */ 76 #define ARPOP_NAK 10 /* NAK - only valif for ATM ARP */ 77 78 /* 79 * The remaining fields are variable in size, 80 * according to the sizes above. 81 */ 82 #ifdef COMMENT_ONLY 83 u_char ar_sha[]; /* sender hardware address */ 84 u_char ar_spa[]; /* sender protocol address */ 85 u_char ar_tha[]; /* target hardware address */ 86 u_char ar_tpa[]; /* target protocol address */ 87 #endif 88 #define ar_sha(ap) (((const u_char *)((ap)+1))+0) 89 #define ar_spa(ap) (((const u_char *)((ap)+1))+ (ap)->ar_hln) 90 #define ar_tha(ap) (((const u_char *)((ap)+1))+ (ap)->ar_hln+(ap)->ar_pln) 91 #define ar_tpa(ap) (((const u_char *)((ap)+1))+2*(ap)->ar_hln+(ap)->ar_pln) 92 }; 93 94 #define ARP_HDRLEN 8 95 96 #define HRD(ap) EXTRACT_16BITS(&(ap)->ar_hrd) 97 #define HRD_LEN(ap) ((ap)->ar_hln) 98 #define PROTO_LEN(ap) ((ap)->ar_pln) 99 #define OP(ap) EXTRACT_16BITS(&(ap)->ar_op) 100 #define PRO(ap) EXTRACT_16BITS(&(ap)->ar_pro) 101 #define SHA(ap) (ar_sha(ap)) 102 #define SPA(ap) (ar_spa(ap)) 103 #define THA(ap) (ar_tha(ap)) 104 #define TPA(ap) (ar_tpa(ap)) 105 106 107 struct tok arpop_values[] = { 108 { ARPOP_REQUEST, "Request" }, 109 { ARPOP_REPLY, "Reply" }, 110 { ARPOP_REVREQUEST, "Reverse Request" }, 111 { ARPOP_REVREPLY, "Reverse Reply" }, 112 { ARPOP_INVREQUEST, "Inverse Request" }, 113 { ARPOP_INVREPLY, "Inverse Reply" }, 114 { ARPOP_NAK, "NACK Reply" }, 115 { 0, NULL } 116 }; 117 118 struct tok arphrd_values[] = { 119 { ARPHRD_ETHER, "Ethernet" }, 120 { ARPHRD_IEEE802, "TokenRing" }, 121 { ARPHRD_ARCNET, "ArcNet" }, 122 { ARPHRD_FRELAY, "FrameRelay" }, 123 { ARPHRD_STRIP, "Strip" }, 124 { ARPHRD_IEEE1394, "IEEE 1394" }, 125 { ARPHRD_ATM2225, "ATM" }, 126 { 0, NULL } 127 }; 128 129 /* 130 * ATM Address Resolution Protocol. 131 * 132 * See RFC 2225 for protocol description. ATMARP packets are similar 133 * to ARP packets, except that there are no length fields for the 134 * protocol address - instead, there are type/length fields for 135 * the ATM number and subaddress - and the hardware addresses consist 136 * of an ATM number and an ATM subaddress. 137 */ 138 struct atmarp_pkthdr { 139 u_short aar_hrd; /* format of hardware address */ 140 u_short aar_pro; /* format of protocol address */ 141 u_char aar_shtl; /* length of source ATM number */ 142 u_char aar_sstl; /* length of source ATM subaddress */ 143 #define ATMARP_IS_E164 0x40 /* bit in type/length for E.164 format */ 144 #define ATMARP_LEN_MASK 0x3F /* length of {sub}address in type/length */ 145 u_short aar_op; /* same as regular ARP */ 146 u_char aar_spln; /* length of source protocol address */ 147 u_char aar_thtl; /* length of target ATM number */ 148 u_char aar_tstl; /* length of target ATM subaddress */ 149 u_char aar_tpln; /* length of target protocol address */ 150 /* 151 * The remaining fields are variable in size, 152 * according to the sizes above. 153 */ 154 #ifdef COMMENT_ONLY 155 u_char aar_sha[]; /* source ATM number */ 156 u_char aar_ssa[]; /* source ATM subaddress */ 157 u_char aar_spa[]; /* sender protocol address */ 158 u_char aar_tha[]; /* target ATM number */ 159 u_char aar_tsa[]; /* target ATM subaddress */ 160 u_char aar_tpa[]; /* target protocol address */ 161 #endif 162 163 #define ATMHRD(ap) EXTRACT_16BITS(&(ap)->aar_hrd) 164 #define ATMSHRD_LEN(ap) ((ap)->aar_shtl & ATMARP_LEN_MASK) 165 #define ATMSSLN(ap) ((ap)->aar_sstl & ATMARP_LEN_MASK) 166 #define ATMSPROTO_LEN(ap) ((ap)->aar_spln) 167 #define ATMOP(ap) EXTRACT_16BITS(&(ap)->aar_op) 168 #define ATMPRO(ap) EXTRACT_16BITS(&(ap)->aar_pro) 169 #define ATMTHRD_LEN(ap) ((ap)->aar_thtl & ATMARP_LEN_MASK) 170 #define ATMTSLN(ap) ((ap)->aar_tstl & ATMARP_LEN_MASK) 171 #define ATMTPROTO_LEN(ap) ((ap)->aar_tpln) 172 #define aar_sha(ap) ((const u_char *)((ap)+1)) 173 #define aar_ssa(ap) (aar_sha(ap) + ATMSHRD_LEN(ap)) 174 #define aar_spa(ap) (aar_ssa(ap) + ATMSSLN(ap)) 175 #define aar_tha(ap) (aar_spa(ap) + ATMSPROTO_LEN(ap)) 176 #define aar_tsa(ap) (aar_tha(ap) + ATMTHRD_LEN(ap)) 177 #define aar_tpa(ap) (aar_tsa(ap) + ATMTSLN(ap)) 178 }; 179 180 #define ATMSHA(ap) (aar_sha(ap)) 181 #define ATMSSA(ap) (aar_ssa(ap)) 182 #define ATMSPA(ap) (aar_spa(ap)) 183 #define ATMTHA(ap) (aar_tha(ap)) 184 #define ATMTSA(ap) (aar_tsa(ap)) 185 #define ATMTPA(ap) (aar_tpa(ap)) 186 187 static u_char ezero[6]; 188 189 static void 190 atmarp_addr_print(netdissect_options *ndo, 191 const u_char *ha, u_int ha_len, const u_char *srca, 192 u_int srca_len) 193 { 194 if (ha_len == 0) 195 ND_PRINT((ndo, "<No address>")); 196 else { 197 ND_PRINT((ndo, "%s", linkaddr_string(ha, LINKADDR_ATM, ha_len))); 198 if (srca_len != 0) 199 ND_PRINT((ndo, ",%s", 200 linkaddr_string(srca, LINKADDR_ATM, srca_len))); 201 } 202 } 203 204 static void 205 atmarp_print(netdissect_options *ndo, 206 const u_char *bp, u_int length, u_int caplen) 207 { 208 const struct atmarp_pkthdr *ap; 209 u_short pro, hrd, op; 210 211 ap = (const struct atmarp_pkthdr *)bp; 212 ND_TCHECK(*ap); 213 214 hrd = ATMHRD(ap); 215 pro = ATMPRO(ap); 216 op = ATMOP(ap); 217 218 if (!ND_TTEST2(*aar_tpa(ap), ATMTPROTO_LEN(ap))) { 219 ND_PRINT((ndo, "[|ARP]")); 220 ND_DEFAULTPRINT((const u_char *)ap, length); 221 return; 222 } 223 224 if (!ndo->ndo_eflag) { 225 ND_PRINT((ndo, "ARP, ")); 226 } 227 228 if ((pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) || 229 ATMSPROTO_LEN(ap) != 4 || 230 ATMTPROTO_LEN(ap) != 4 || 231 ndo->ndo_vflag) { 232 ND_PRINT((ndo, "%s, %s (len %u/%u)", 233 tok2str(arphrd_values, "Unknown Hardware (%u)", hrd), 234 tok2str(ethertype_values, "Unknown Protocol (0x%04x)", pro), 235 ATMSPROTO_LEN(ap), 236 ATMTPROTO_LEN(ap))); 237 238 /* don't know know about the address formats */ 239 if (!ndo->ndo_vflag) { 240 goto out; 241 } 242 } 243 244 /* print operation */ 245 printf("%s%s ", 246 ndo->ndo_vflag ? ", " : "", 247 tok2str(arpop_values, "Unknown (%u)", op)); 248 249 switch (op) { 250 251 case ARPOP_REQUEST: 252 ND_PRINT((ndo, "who-has %s", ipaddr_string(ATMTPA(ap)))); 253 if (ATMTHRD_LEN(ap) != 0) { 254 ND_PRINT((ndo, " (")); 255 atmarp_addr_print(ndo, ATMTHA(ap), ATMTHRD_LEN(ap), 256 ATMTSA(ap), ATMTSLN(ap)); 257 ND_PRINT((ndo, ")")); 258 } 259 ND_PRINT((ndo, "tell %s", ipaddr_string(ATMSPA(ap)))); 260 break; 261 262 case ARPOP_REPLY: 263 ND_PRINT((ndo, "%s is-at ", ipaddr_string(ATMSPA(ap)))); 264 atmarp_addr_print(ndo, ATMSHA(ap), ATMSHRD_LEN(ap), ATMSSA(ap), 265 ATMSSLN(ap)); 266 break; 267 268 case ARPOP_INVREQUEST: 269 ND_PRINT((ndo, "who-is ")); 270 atmarp_addr_print(ndo, ATMTHA(ap), ATMTHRD_LEN(ap), ATMTSA(ap), 271 ATMTSLN(ap)); 272 ND_PRINT((ndo, " tell ")); 273 atmarp_addr_print(ndo, ATMSHA(ap), ATMSHRD_LEN(ap), ATMSSA(ap), 274 ATMSSLN(ap)); 275 break; 276 277 case ARPOP_INVREPLY: 278 atmarp_addr_print(ndo, ATMSHA(ap), ATMSHRD_LEN(ap), ATMSSA(ap), 279 ATMSSLN(ap)); 280 ND_PRINT((ndo, "at %s", ipaddr_string(ATMSPA(ap)))); 281 break; 282 283 case ARPOP_NAK: 284 ND_PRINT((ndo, "for %s", ipaddr_string(ATMSPA(ap)))); 285 break; 286 287 default: 288 ND_DEFAULTPRINT((const u_char *)ap, caplen); 289 return; 290 } 291 292 out: 293 ND_PRINT((ndo, ", length %u", length)); 294 return; 295 296 trunc: 297 ND_PRINT((ndo, "[|ARP]")); 298 } 299 300 void 301 arp_print(netdissect_options *ndo, 302 const u_char *bp, u_int length, u_int caplen) 303 { 304 const struct arp_pkthdr *ap; 305 u_short pro, hrd, op, linkaddr; 306 307 ap = (const struct arp_pkthdr *)bp; 308 ND_TCHECK(*ap); 309 310 hrd = HRD(ap); 311 pro = PRO(ap); 312 op = OP(ap); 313 314 315 /* if its ATM then call the ATM ARP printer 316 for Frame-relay ARP most of the fields 317 are similar to Ethernet so overload the Ethernet Printer 318 and set the linkaddr type for linkaddr_string() accordingly */ 319 320 switch(hrd) { 321 case ARPHRD_ATM2225: 322 atmarp_print(ndo, bp, length, caplen); 323 return; 324 case ARPHRD_FRELAY: 325 linkaddr = LINKADDR_FRELAY; 326 default: 327 linkaddr = LINKADDR_ETHER; 328 break; 329 } 330 331 if (!ND_TTEST2(*ar_tpa(ap), PROTO_LEN(ap))) { 332 ND_PRINT((ndo, "[|ARP]")); 333 ND_DEFAULTPRINT((const u_char *)ap, length); 334 return; 335 } 336 337 if (!ndo->ndo_eflag) { 338 ND_PRINT((ndo, "ARP, ")); 339 } 340 341 /* print hardware type/len and proto type/len */ 342 if ((pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) || 343 PROTO_LEN(ap) != 4 || 344 HRD_LEN(ap) == 0 || 345 ndo->ndo_vflag) { 346 ND_PRINT((ndo, "%s (len %u), %s (len %u)", 347 tok2str(arphrd_values, "Unknown Hardware (%u)", hrd), 348 HRD_LEN(ap), 349 tok2str(ethertype_values, "Unknown Protocol (0x%04x)", pro), 350 PROTO_LEN(ap))); 351 352 /* don't know know about the address formats */ 353 if (!ndo->ndo_vflag) { 354 goto out; 355 } 356 } 357 358 /* print operation */ 359 printf("%s%s ", 360 ndo->ndo_vflag ? ", " : "", 361 tok2str(arpop_values, "Unknown (%u)", op)); 362 363 switch (op) { 364 365 case ARPOP_REQUEST: 366 ND_PRINT((ndo, "who-has %s", ipaddr_string(TPA(ap)))); 367 if (memcmp((const char *)ezero, (const char *)THA(ap), HRD_LEN(ap)) != 0) 368 ND_PRINT((ndo, " (%s)", 369 linkaddr_string(THA(ap), linkaddr, HRD_LEN(ap)))); 370 ND_PRINT((ndo, " tell %s", ipaddr_string(SPA(ap)))); 371 break; 372 373 case ARPOP_REPLY: 374 ND_PRINT((ndo, "%s is-at %s", 375 ipaddr_string(SPA(ap)), 376 linkaddr_string(SHA(ap), linkaddr, HRD_LEN(ap)))); 377 break; 378 379 case ARPOP_REVREQUEST: 380 ND_PRINT((ndo, "who-is %s tell %s", 381 linkaddr_string(THA(ap), linkaddr, HRD_LEN(ap)), 382 linkaddr_string(SHA(ap), linkaddr, HRD_LEN(ap)))); 383 break; 384 385 case ARPOP_REVREPLY: 386 ND_PRINT((ndo, "%s at %s", 387 linkaddr_string(THA(ap), linkaddr, HRD_LEN(ap)), 388 ipaddr_string(TPA(ap)))); 389 break; 390 391 case ARPOP_INVREQUEST: 392 ND_PRINT((ndo, "who-is %s tell %s", 393 linkaddr_string(THA(ap), linkaddr, HRD_LEN(ap)), 394 linkaddr_string(SHA(ap), linkaddr, HRD_LEN(ap)))); 395 break; 396 397 case ARPOP_INVREPLY: 398 ND_PRINT((ndo,"%s at %s", 399 linkaddr_string(THA(ap), linkaddr, HRD_LEN(ap)), 400 ipaddr_string(TPA(ap)))); 401 break; 402 403 default: 404 ND_DEFAULTPRINT((const u_char *)ap, caplen); 405 return; 406 } 407 408 out: 409 ND_PRINT((ndo, ", length %u", length)); 410 411 return; 412 trunc: 413 ND_PRINT((ndo, "[|ARP]")); 414 } 415 416 /* 417 * Local Variables: 418 * c-style: bsd 419 * End: 420 */ 421 422