print-arp.c revision 190207
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 * $FreeBSD: head/contrib/tcpdump/print-arp.c 190207 2009-03-21 18:30:25Z rpaulo $ 22 */ 23 24#ifndef lint 25static 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#endif 28 29#ifdef HAVE_CONFIG_H 30#include "config.h" 31#endif 32 33#include <tcpdump-stdinc.h> 34 35#include <stdio.h> 36#include <string.h> 37 38#include "netdissect.h" 39#include "addrtoname.h" 40#include "ether.h" 41#include "ethertype.h" 42#include "extract.h" /* must come after interface.h */ 43 44/* 45 * Address Resolution Protocol. 46 * 47 * See RFC 826 for protocol description. ARP packets are variable 48 * in size; the arphdr structure defines the fixed-length portion. 49 * Protocol type values are the same as those for 10 Mb/s Ethernet. 50 * It is followed by the variable-sized fields ar_sha, arp_spa, 51 * arp_tha and arp_tpa in that order, according to the lengths 52 * specified. Field names used correspond to RFC 826. 53 */ 54struct arp_pkthdr { 55 u_short ar_hrd; /* format of hardware address */ 56#define ARPHRD_ETHER 1 /* ethernet hardware format */ 57#define ARPHRD_IEEE802 6 /* token-ring hardware format */ 58#define ARPHRD_ARCNET 7 /* arcnet hardware format */ 59#define ARPHRD_FRELAY 15 /* frame relay hardware format */ 60#define ARPHRD_ATM2225 19 /* ATM (RFC 2225) */ 61#define ARPHRD_STRIP 23 /* Ricochet Starmode Radio hardware format */ 62#define ARPHRD_IEEE1394 24 /* IEEE 1394 (FireWire) hardware format */ 63 u_short ar_pro; /* format of protocol address */ 64 u_char ar_hln; /* length of hardware address */ 65 u_char ar_pln; /* length of protocol address */ 66 u_short ar_op; /* one of: */ 67#define ARPOP_REQUEST 1 /* request to resolve address */ 68#define ARPOP_REPLY 2 /* response to previous request */ 69#define ARPOP_REVREQUEST 3 /* request protocol address given hardware */ 70#define ARPOP_REVREPLY 4 /* response giving protocol address */ 71#define ARPOP_INVREQUEST 8 /* request to identify peer */ 72#define ARPOP_INVREPLY 9 /* response identifying peer */ 73#define ARPOP_NAK 10 /* NAK - only valif for ATM ARP */ 74 75/* 76 * The remaining fields are variable in size, 77 * according to the sizes above. 78 */ 79#ifdef COMMENT_ONLY 80 u_char ar_sha[]; /* sender hardware address */ 81 u_char ar_spa[]; /* sender protocol address */ 82 u_char ar_tha[]; /* target hardware address */ 83 u_char ar_tpa[]; /* target protocol address */ 84#endif 85#define ar_sha(ap) (((const u_char *)((ap)+1))+0) 86#define ar_spa(ap) (((const u_char *)((ap)+1))+ (ap)->ar_hln) 87#define ar_tha(ap) (((const u_char *)((ap)+1))+ (ap)->ar_hln+(ap)->ar_pln) 88#define ar_tpa(ap) (((const u_char *)((ap)+1))+2*(ap)->ar_hln+(ap)->ar_pln) 89}; 90 91#define ARP_HDRLEN 8 92 93#define HRD(ap) EXTRACT_16BITS(&(ap)->ar_hrd) 94#define HRD_LEN(ap) ((ap)->ar_hln) 95#define PROTO_LEN(ap) ((ap)->ar_pln) 96#define OP(ap) EXTRACT_16BITS(&(ap)->ar_op) 97#define PRO(ap) EXTRACT_16BITS(&(ap)->ar_pro) 98#define SHA(ap) (ar_sha(ap)) 99#define SPA(ap) (ar_spa(ap)) 100#define THA(ap) (ar_tha(ap)) 101#define TPA(ap) (ar_tpa(ap)) 102 103 104struct tok arpop_values[] = { 105 { ARPOP_REQUEST, "Request" }, 106 { ARPOP_REPLY, "Reply" }, 107 { ARPOP_REVREQUEST, "Reverse Request" }, 108 { ARPOP_REVREPLY, "Reverse Reply" }, 109 { ARPOP_INVREQUEST, "Inverse Request" }, 110 { ARPOP_INVREPLY, "Inverse Reply" }, 111 { ARPOP_NAK, "NACK Reply" }, 112 { 0, NULL } 113}; 114 115struct tok arphrd_values[] = { 116 { ARPHRD_ETHER, "Ethernet" }, 117 { ARPHRD_IEEE802, "TokenRing" }, 118 { ARPHRD_ARCNET, "ArcNet" }, 119 { ARPHRD_FRELAY, "FrameRelay" }, 120 { ARPHRD_STRIP, "Strip" }, 121 { ARPHRD_IEEE1394, "IEEE 1394" }, 122 { ARPHRD_ATM2225, "ATM" }, 123 { 0, NULL } 124}; 125 126/* 127 * ATM Address Resolution Protocol. 128 * 129 * See RFC 2225 for protocol description. ATMARP packets are similar 130 * to ARP packets, except that there are no length fields for the 131 * protocol address - instead, there are type/length fields for 132 * the ATM number and subaddress - and the hardware addresses consist 133 * of an ATM number and an ATM subaddress. 134 */ 135struct atmarp_pkthdr { 136 u_short aar_hrd; /* format of hardware address */ 137 u_short aar_pro; /* format of protocol address */ 138 u_char aar_shtl; /* length of source ATM number */ 139 u_char aar_sstl; /* length of source ATM subaddress */ 140#define ATMARP_IS_E164 0x40 /* bit in type/length for E.164 format */ 141#define ATMARP_LEN_MASK 0x3F /* length of {sub}address in type/length */ 142 u_short aar_op; /* same as regular ARP */ 143 u_char aar_spln; /* length of source protocol address */ 144 u_char aar_thtl; /* length of target ATM number */ 145 u_char aar_tstl; /* length of target ATM subaddress */ 146 u_char aar_tpln; /* length of target protocol address */ 147/* 148 * The remaining fields are variable in size, 149 * according to the sizes above. 150 */ 151#ifdef COMMENT_ONLY 152 u_char aar_sha[]; /* source ATM number */ 153 u_char aar_ssa[]; /* source ATM subaddress */ 154 u_char aar_spa[]; /* sender protocol address */ 155 u_char aar_tha[]; /* target ATM number */ 156 u_char aar_tsa[]; /* target ATM subaddress */ 157 u_char aar_tpa[]; /* target protocol address */ 158#endif 159 160#define ATMHRD(ap) EXTRACT_16BITS(&(ap)->aar_hrd) 161#define ATMSHRD_LEN(ap) ((ap)->aar_shtl & ATMARP_LEN_MASK) 162#define ATMSSLN(ap) ((ap)->aar_sstl & ATMARP_LEN_MASK) 163#define ATMSPROTO_LEN(ap) ((ap)->aar_spln) 164#define ATMOP(ap) EXTRACT_16BITS(&(ap)->aar_op) 165#define ATMPRO(ap) EXTRACT_16BITS(&(ap)->aar_pro) 166#define ATMTHRD_LEN(ap) ((ap)->aar_thtl & ATMARP_LEN_MASK) 167#define ATMTSLN(ap) ((ap)->aar_tstl & ATMARP_LEN_MASK) 168#define ATMTPROTO_LEN(ap) ((ap)->aar_tpln) 169#define aar_sha(ap) ((const u_char *)((ap)+1)) 170#define aar_ssa(ap) (aar_sha(ap) + ATMSHRD_LEN(ap)) 171#define aar_spa(ap) (aar_ssa(ap) + ATMSSLN(ap)) 172#define aar_tha(ap) (aar_spa(ap) + ATMSPROTO_LEN(ap)) 173#define aar_tsa(ap) (aar_tha(ap) + ATMTHRD_LEN(ap)) 174#define aar_tpa(ap) (aar_tsa(ap) + ATMTSLN(ap)) 175}; 176 177#define ATMSHA(ap) (aar_sha(ap)) 178#define ATMSSA(ap) (aar_ssa(ap)) 179#define ATMSPA(ap) (aar_spa(ap)) 180#define ATMTHA(ap) (aar_tha(ap)) 181#define ATMTSA(ap) (aar_tsa(ap)) 182#define ATMTPA(ap) (aar_tpa(ap)) 183 184static u_char ezero[6]; 185 186static void 187atmarp_addr_print(netdissect_options *ndo, 188 const u_char *ha, u_int ha_len, const u_char *srca, 189 u_int srca_len) 190{ 191 if (ha_len == 0) 192 ND_PRINT((ndo, "<No address>")); 193 else { 194 ND_PRINT((ndo, "%s", linkaddr_string(ha, LINKADDR_ATM, ha_len))); 195 if (srca_len != 0) 196 ND_PRINT((ndo, ",%s", 197 linkaddr_string(srca, LINKADDR_ATM, srca_len))); 198 } 199} 200 201static void 202atmarp_print(netdissect_options *ndo, 203 const u_char *bp, u_int length, u_int caplen) 204{ 205 const struct atmarp_pkthdr *ap; 206 u_short pro, hrd, op; 207 208 ap = (const struct atmarp_pkthdr *)bp; 209 ND_TCHECK(*ap); 210 211 hrd = ATMHRD(ap); 212 pro = ATMPRO(ap); 213 op = ATMOP(ap); 214 215 if (!ND_TTEST2(*aar_tpa(ap), ATMTPROTO_LEN(ap))) { 216 ND_PRINT((ndo, "[|ARP]")); 217 ND_DEFAULTPRINT((const u_char *)ap, length); 218 return; 219 } 220 221 if (!ndo->ndo_eflag) { 222 ND_PRINT((ndo, "ARP, ")); 223 } 224 225 if ((pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) || 226 ATMSPROTO_LEN(ap) != 4 || 227 ATMTPROTO_LEN(ap) != 4 || 228 ndo->ndo_vflag) { 229 ND_PRINT((ndo, "%s, %s (len %u/%u)", 230 tok2str(arphrd_values, "Unknown Hardware (%u)", hrd), 231 tok2str(ethertype_values, "Unknown Protocol (0x%04x)", pro), 232 ATMSPROTO_LEN(ap), 233 ATMTPROTO_LEN(ap))); 234 235 /* don't know know about the address formats */ 236 if (!ndo->ndo_vflag) { 237 goto out; 238 } 239 } 240 241 /* print operation */ 242 printf("%s%s ", 243 ndo->ndo_vflag ? ", " : "", 244 tok2str(arpop_values, "Unknown (%u)", op)); 245 246 switch (op) { 247 248 case ARPOP_REQUEST: 249 ND_PRINT((ndo, "who-has %s", ipaddr_string(ATMTPA(ap)))); 250 if (ATMTHRD_LEN(ap) != 0) { 251 ND_PRINT((ndo, " (")); 252 atmarp_addr_print(ndo, ATMTHA(ap), ATMTHRD_LEN(ap), 253 ATMTSA(ap), ATMTSLN(ap)); 254 ND_PRINT((ndo, ")")); 255 } 256 ND_PRINT((ndo, "tell %s", ipaddr_string(ATMSPA(ap)))); 257 break; 258 259 case ARPOP_REPLY: 260 ND_PRINT((ndo, "%s is-at ", ipaddr_string(ATMSPA(ap)))); 261 atmarp_addr_print(ndo, ATMSHA(ap), ATMSHRD_LEN(ap), ATMSSA(ap), 262 ATMSSLN(ap)); 263 break; 264 265 case ARPOP_INVREQUEST: 266 ND_PRINT((ndo, "who-is ")); 267 atmarp_addr_print(ndo, ATMTHA(ap), ATMTHRD_LEN(ap), ATMTSA(ap), 268 ATMTSLN(ap)); 269 ND_PRINT((ndo, " tell ")); 270 atmarp_addr_print(ndo, ATMSHA(ap), ATMSHRD_LEN(ap), ATMSSA(ap), 271 ATMSSLN(ap)); 272 break; 273 274 case ARPOP_INVREPLY: 275 atmarp_addr_print(ndo, ATMSHA(ap), ATMSHRD_LEN(ap), ATMSSA(ap), 276 ATMSSLN(ap)); 277 ND_PRINT((ndo, "at %s", ipaddr_string(ATMSPA(ap)))); 278 break; 279 280 case ARPOP_NAK: 281 ND_PRINT((ndo, "for %s", ipaddr_string(ATMSPA(ap)))); 282 break; 283 284 default: 285 ND_DEFAULTPRINT((const u_char *)ap, caplen); 286 return; 287 } 288 289 out: 290 ND_PRINT((ndo, ", length %u", length)); 291 return; 292 293trunc: 294 ND_PRINT((ndo, "[|ARP]")); 295} 296 297void 298arp_print(netdissect_options *ndo, 299 const u_char *bp, u_int length, u_int caplen) 300{ 301 const struct arp_pkthdr *ap; 302 u_short pro, hrd, op, linkaddr; 303 304 ap = (const struct arp_pkthdr *)bp; 305 ND_TCHECK(*ap); 306 307 hrd = HRD(ap); 308 pro = PRO(ap); 309 op = OP(ap); 310 311 312 /* if its ATM then call the ATM ARP printer 313 for Frame-relay ARP most of the fields 314 are similar to Ethernet so overload the Ethernet Printer 315 and set the linkaddr type for linkaddr_string() accordingly */ 316 317 switch(hrd) { 318 case ARPHRD_ATM2225: 319 atmarp_print(ndo, bp, length, caplen); 320 return; 321 case ARPHRD_FRELAY: 322 linkaddr = LINKADDR_FRELAY; 323 default: 324 linkaddr = LINKADDR_ETHER; 325 break; 326 } 327 328 if (!ND_TTEST2(*ar_tpa(ap), PROTO_LEN(ap))) { 329 ND_PRINT((ndo, "[|ARP]")); 330 ND_DEFAULTPRINT((const u_char *)ap, length); 331 return; 332 } 333 334 if (!ndo->ndo_eflag) { 335 ND_PRINT((ndo, "ARP, ")); 336 } 337 338 /* print hardware type/len and proto type/len */ 339 if ((pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) || 340 PROTO_LEN(ap) != 4 || 341 HRD_LEN(ap) == 0 || 342 ndo->ndo_vflag) { 343 ND_PRINT((ndo, "%s (len %u), %s (len %u)", 344 tok2str(arphrd_values, "Unknown Hardware (%u)", hrd), 345 HRD_LEN(ap), 346 tok2str(ethertype_values, "Unknown Protocol (0x%04x)", pro), 347 PROTO_LEN(ap))); 348 349 /* don't know know about the address formats */ 350 if (!ndo->ndo_vflag) { 351 goto out; 352 } 353 } 354 355 /* print operation */ 356 printf("%s%s ", 357 ndo->ndo_vflag ? ", " : "", 358 tok2str(arpop_values, "Unknown (%u)", op)); 359 360 switch (op) { 361 362 case ARPOP_REQUEST: 363 ND_PRINT((ndo, "who-has %s", ipaddr_string(TPA(ap)))); 364 if (memcmp((const char *)ezero, (const char *)THA(ap), HRD_LEN(ap)) != 0) 365 ND_PRINT((ndo, " (%s)", 366 linkaddr_string(THA(ap), linkaddr, HRD_LEN(ap)))); 367 ND_PRINT((ndo, " tell %s", ipaddr_string(SPA(ap)))); 368 break; 369 370 case ARPOP_REPLY: 371 ND_PRINT((ndo, "%s is-at %s", 372 ipaddr_string(SPA(ap)), 373 linkaddr_string(SHA(ap), linkaddr, HRD_LEN(ap)))); 374 break; 375 376 case ARPOP_REVREQUEST: 377 ND_PRINT((ndo, "who-is %s tell %s", 378 linkaddr_string(THA(ap), linkaddr, HRD_LEN(ap)), 379 linkaddr_string(SHA(ap), linkaddr, HRD_LEN(ap)))); 380 break; 381 382 case ARPOP_REVREPLY: 383 ND_PRINT((ndo, "%s at %s", 384 linkaddr_string(THA(ap), linkaddr, HRD_LEN(ap)), 385 ipaddr_string(TPA(ap)))); 386 break; 387 388 case ARPOP_INVREQUEST: 389 ND_PRINT((ndo, "who-is %s tell %s", 390 linkaddr_string(THA(ap), linkaddr, HRD_LEN(ap)), 391 linkaddr_string(SHA(ap), linkaddr, HRD_LEN(ap)))); 392 break; 393 394 case ARPOP_INVREPLY: 395 ND_PRINT((ndo,"%s at %s", 396 linkaddr_string(THA(ap), linkaddr, HRD_LEN(ap)), 397 ipaddr_string(TPA(ap)))); 398 break; 399 400 default: 401 ND_DEFAULTPRINT((const u_char *)ap, caplen); 402 return; 403 } 404 405 out: 406 ND_PRINT((ndo, ", length %u", length)); 407 408 return; 409trunc: 410 ND_PRINT((ndo, "[|ARP]")); 411} 412 413/* 414 * Local Variables: 415 * c-style: bsd 416 * End: 417 */ 418 419