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 __RCSID("$NetBSD: print-arp.c,v 1.7 2017/01/24 23:29:13 christos Exp $"); 25 #endif 26 27 #ifdef HAVE_CONFIG_H 28 #include "config.h" 29 #endif 30 31 #include <netdissect-stdinc.h> 32 33 #include <string.h> 34 35 #include "netdissect.h" 36 #include "addrtoname.h" 37 #include "ether.h" 38 #include "ethertype.h" 39 #include "extract.h" 40 41 static const char tstr[] = "[|ARP]"; 42 43 /* 44 * Address Resolution Protocol. 45 * 46 * See RFC 826 for protocol description. ARP packets are variable 47 * in size; the arphdr structure defines the fixed-length portion. 48 * Protocol type values are the same as those for 10 Mb/s Ethernet. 49 * It is followed by the variable-sized fields ar_sha, arp_spa, 50 * arp_tha and arp_tpa in that order, according to the lengths 51 * specified. Field names used correspond to RFC 826. 52 */ 53 struct arp_pkthdr { 54 u_short ar_hrd; /* format of hardware address */ 55 #define ARPHRD_ETHER 1 /* ethernet hardware format */ 56 #define ARPHRD_IEEE802 6 /* token-ring hardware format */ 57 #define ARPHRD_ARCNET 7 /* arcnet hardware format */ 58 #define ARPHRD_FRELAY 15 /* frame relay hardware format */ 59 #define ARPHRD_ATM2225 19 /* ATM (RFC 2225) */ 60 #define ARPHRD_STRIP 23 /* Ricochet Starmode Radio hardware format */ 61 #define ARPHRD_IEEE1394 24 /* IEEE 1394 (FireWire) hardware format */ 62 u_short ar_pro; /* format of protocol address */ 63 u_char ar_hln; /* length of hardware address */ 64 u_char ar_pln; /* length of protocol address */ 65 u_short ar_op; /* one of: */ 66 #define ARPOP_REQUEST 1 /* request to resolve address */ 67 #define ARPOP_REPLY 2 /* response to previous request */ 68 #define ARPOP_REVREQUEST 3 /* request protocol address given hardware */ 69 #define ARPOP_REVREPLY 4 /* response giving protocol address */ 70 #define ARPOP_INVREQUEST 8 /* request to identify peer */ 71 #define ARPOP_INVREPLY 9 /* response identifying peer */ 72 #define ARPOP_NAK 10 /* NAK - only valif for ATM ARP */ 73 74 /* 75 * The remaining fields are variable in size, 76 * according to the sizes above. 77 */ 78 #ifdef COMMENT_ONLY 79 u_char ar_sha[]; /* sender hardware address */ 80 u_char ar_spa[]; /* sender protocol address */ 81 u_char ar_tha[]; /* target hardware address */ 82 u_char ar_tpa[]; /* target protocol address */ 83 #endif 84 #define ar_sha(ap) (((const u_char *)((ap)+1))+0) 85 #define ar_spa(ap) (((const u_char *)((ap)+1))+ (ap)->ar_hln) 86 #define ar_tha(ap) (((const u_char *)((ap)+1))+ (ap)->ar_hln+(ap)->ar_pln) 87 #define ar_tpa(ap) (((const u_char *)((ap)+1))+2*(ap)->ar_hln+(ap)->ar_pln) 88 }; 89 90 #define ARP_HDRLEN 8 91 92 #define HRD(ap) EXTRACT_16BITS(&(ap)->ar_hrd) 93 #define HRD_LEN(ap) ((ap)->ar_hln) 94 #define PROTO_LEN(ap) ((ap)->ar_pln) 95 #define OP(ap) EXTRACT_16BITS(&(ap)->ar_op) 96 #define PRO(ap) EXTRACT_16BITS(&(ap)->ar_pro) 97 #define SHA(ap) (ar_sha(ap)) 98 #define SPA(ap) (ar_spa(ap)) 99 #define THA(ap) (ar_tha(ap)) 100 #define TPA(ap) (ar_tpa(ap)) 101 102 103 static const struct tok arpop_values[] = { 104 { ARPOP_REQUEST, "Request" }, 105 { ARPOP_REPLY, "Reply" }, 106 { ARPOP_REVREQUEST, "Reverse Request" }, 107 { ARPOP_REVREPLY, "Reverse Reply" }, 108 { ARPOP_INVREQUEST, "Inverse Request" }, 109 { ARPOP_INVREPLY, "Inverse Reply" }, 110 { ARPOP_NAK, "NACK Reply" }, 111 { 0, NULL } 112 }; 113 114 static const struct tok arphrd_values[] = { 115 { ARPHRD_ETHER, "Ethernet" }, 116 { ARPHRD_IEEE802, "TokenRing" }, 117 { ARPHRD_ARCNET, "ArcNet" }, 118 { ARPHRD_FRELAY, "FrameRelay" }, 119 { ARPHRD_STRIP, "Strip" }, 120 { ARPHRD_IEEE1394, "IEEE 1394" }, 121 { ARPHRD_ATM2225, "ATM" }, 122 { 0, NULL } 123 }; 124 125 /* 126 * ATM Address Resolution Protocol. 127 * 128 * See RFC 2225 for protocol description. ATMARP packets are similar 129 * to ARP packets, except that there are no length fields for the 130 * protocol address - instead, there are type/length fields for 131 * the ATM number and subaddress - and the hardware addresses consist 132 * of an ATM number and an ATM subaddress. 133 */ 134 struct atmarp_pkthdr { 135 u_short aar_hrd; /* format of hardware address */ 136 u_short aar_pro; /* format of protocol address */ 137 u_char aar_shtl; /* length of source ATM number */ 138 u_char aar_sstl; /* length of source ATM subaddress */ 139 #define ATMARP_IS_E164 0x40 /* bit in type/length for E.164 format */ 140 #define ATMARP_LEN_MASK 0x3F /* length of {sub}address in type/length */ 141 u_short aar_op; /* same as regular ARP */ 142 u_char aar_spln; /* length of source protocol address */ 143 u_char aar_thtl; /* length of target ATM number */ 144 u_char aar_tstl; /* length of target ATM subaddress */ 145 u_char aar_tpln; /* length of target protocol address */ 146 /* 147 * The remaining fields are variable in size, 148 * according to the sizes above. 149 */ 150 #ifdef COMMENT_ONLY 151 u_char aar_sha[]; /* source ATM number */ 152 u_char aar_ssa[]; /* source ATM subaddress */ 153 u_char aar_spa[]; /* sender protocol address */ 154 u_char aar_tha[]; /* target ATM number */ 155 u_char aar_tsa[]; /* target ATM subaddress */ 156 u_char aar_tpa[]; /* target protocol address */ 157 #endif 158 159 #define ATMHRD(ap) EXTRACT_16BITS(&(ap)->aar_hrd) 160 #define ATMSHRD_LEN(ap) ((ap)->aar_shtl & ATMARP_LEN_MASK) 161 #define ATMSSLN(ap) ((ap)->aar_sstl & ATMARP_LEN_MASK) 162 #define ATMSPROTO_LEN(ap) ((ap)->aar_spln) 163 #define ATMOP(ap) EXTRACT_16BITS(&(ap)->aar_op) 164 #define ATMPRO(ap) EXTRACT_16BITS(&(ap)->aar_pro) 165 #define ATMTHRD_LEN(ap) ((ap)->aar_thtl & ATMARP_LEN_MASK) 166 #define ATMTSLN(ap) ((ap)->aar_tstl & ATMARP_LEN_MASK) 167 #define ATMTPROTO_LEN(ap) ((ap)->aar_tpln) 168 #define aar_sha(ap) ((const u_char *)((ap)+1)) 169 #define aar_ssa(ap) (aar_sha(ap) + ATMSHRD_LEN(ap)) 170 #define aar_spa(ap) (aar_ssa(ap) + ATMSSLN(ap)) 171 #define aar_tha(ap) (aar_spa(ap) + ATMSPROTO_LEN(ap)) 172 #define aar_tsa(ap) (aar_tha(ap) + ATMTHRD_LEN(ap)) 173 #define aar_tpa(ap) (aar_tsa(ap) + ATMTSLN(ap)) 174 }; 175 176 #define ATMSHA(ap) (aar_sha(ap)) 177 #define ATMSSA(ap) (aar_ssa(ap)) 178 #define ATMSPA(ap) (aar_spa(ap)) 179 #define ATMTHA(ap) (aar_tha(ap)) 180 #define ATMTSA(ap) (aar_tsa(ap)) 181 #define ATMTPA(ap) (aar_tpa(ap)) 182 183 static u_char ezero[6]; 184 185 static void 186 atmarp_addr_print(netdissect_options *ndo, 187 const u_char *ha, u_int ha_len, const u_char *srca, 188 u_int srca_len) 189 { 190 if (ha_len == 0) 191 ND_PRINT((ndo, "<No address>")); 192 else { 193 ND_PRINT((ndo, "%s", linkaddr_string(ndo, ha, LINKADDR_ATM, ha_len))); 194 if (srca_len != 0) 195 ND_PRINT((ndo, ",%s", 196 linkaddr_string(ndo, srca, LINKADDR_ATM, srca_len))); 197 } 198 } 199 200 static void 201 atmarp_print(netdissect_options *ndo, 202 const u_char *bp, u_int length, u_int caplen) 203 { 204 const struct atmarp_pkthdr *ap; 205 u_short pro, hrd, op; 206 207 ap = (const struct atmarp_pkthdr *)bp; 208 ND_TCHECK(*ap); 209 210 hrd = ATMHRD(ap); 211 pro = ATMPRO(ap); 212 op = ATMOP(ap); 213 214 if (!ND_TTEST2(*aar_tpa(ap), ATMTPROTO_LEN(ap))) { 215 ND_PRINT((ndo, "%s", tstr)); 216 ND_DEFAULTPRINT((const u_char *)ap, length); 217 return; 218 } 219 220 if (!ndo->ndo_eflag) { 221 ND_PRINT((ndo, "ARP, ")); 222 } 223 224 if ((pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) || 225 ATMSPROTO_LEN(ap) != 4 || 226 ATMTPROTO_LEN(ap) != 4 || 227 ndo->ndo_vflag) { 228 ND_PRINT((ndo, "%s, %s (len %u/%u)", 229 tok2str(arphrd_values, "Unknown Hardware (%u)", hrd), 230 tok2str(ethertype_values, "Unknown Protocol (0x%04x)", pro), 231 ATMSPROTO_LEN(ap), 232 ATMTPROTO_LEN(ap))); 233 234 /* don't know know about the address formats */ 235 if (!ndo->ndo_vflag) { 236 goto out; 237 } 238 } 239 240 /* print operation */ 241 ND_PRINT((ndo, "%s%s ", 242 ndo->ndo_vflag ? ", " : "", 243 tok2str(arpop_values, "Unknown (%u)", op))); 244 245 switch (op) { 246 247 case ARPOP_REQUEST: 248 ND_PRINT((ndo, "who-has %s", ipaddr_string(ndo, ATMTPA(ap)))); 249 if (ATMTHRD_LEN(ap) != 0) { 250 ND_PRINT((ndo, " (")); 251 atmarp_addr_print(ndo, ATMTHA(ap), ATMTHRD_LEN(ap), 252 ATMTSA(ap), ATMTSLN(ap)); 253 ND_PRINT((ndo, ")")); 254 } 255 ND_PRINT((ndo, "tell %s", ipaddr_string(ndo, ATMSPA(ap)))); 256 break; 257 258 case ARPOP_REPLY: 259 ND_PRINT((ndo, "%s is-at ", ipaddr_string(ndo, ATMSPA(ap)))); 260 atmarp_addr_print(ndo, ATMSHA(ap), ATMSHRD_LEN(ap), ATMSSA(ap), 261 ATMSSLN(ap)); 262 break; 263 264 case ARPOP_INVREQUEST: 265 ND_PRINT((ndo, "who-is ")); 266 atmarp_addr_print(ndo, ATMTHA(ap), ATMTHRD_LEN(ap), ATMTSA(ap), 267 ATMTSLN(ap)); 268 ND_PRINT((ndo, " tell ")); 269 atmarp_addr_print(ndo, ATMSHA(ap), ATMSHRD_LEN(ap), ATMSSA(ap), 270 ATMSSLN(ap)); 271 break; 272 273 case ARPOP_INVREPLY: 274 atmarp_addr_print(ndo, ATMSHA(ap), ATMSHRD_LEN(ap), ATMSSA(ap), 275 ATMSSLN(ap)); 276 ND_PRINT((ndo, "at %s", ipaddr_string(ndo, ATMSPA(ap)))); 277 break; 278 279 case ARPOP_NAK: 280 ND_PRINT((ndo, "for %s", ipaddr_string(ndo, ATMSPA(ap)))); 281 break; 282 283 default: 284 ND_DEFAULTPRINT((const u_char *)ap, caplen); 285 return; 286 } 287 288 out: 289 ND_PRINT((ndo, ", length %u", length)); 290 return; 291 292 trunc: 293 ND_PRINT((ndo, "%s", tstr)); 294 } 295 296 void 297 arp_print(netdissect_options *ndo, 298 const u_char *bp, u_int length, u_int caplen) 299 { 300 const struct arp_pkthdr *ap; 301 u_short pro, hrd, op, linkaddr; 302 303 ap = (const struct arp_pkthdr *)bp; 304 ND_TCHECK(*ap); 305 306 hrd = HRD(ap); 307 pro = PRO(ap); 308 op = OP(ap); 309 310 311 /* if its ATM then call the ATM ARP printer 312 for Frame-relay ARP most of the fields 313 are similar to Ethernet so overload the Ethernet Printer 314 and set the linkaddr type for linkaddr_string(ndo, ) accordingly */ 315 316 switch(hrd) { 317 case ARPHRD_ATM2225: 318 atmarp_print(ndo, bp, length, caplen); 319 return; 320 case ARPHRD_FRELAY: 321 linkaddr = LINKADDR_FRELAY; 322 break; 323 default: 324 linkaddr = LINKADDR_ETHER; 325 break; 326 } 327 328 if (!ND_TTEST2(*ar_tpa(ap), PROTO_LEN(ap))) { 329 ND_PRINT((ndo, "%s", tstr)); 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 ND_PRINT((ndo, "%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(ndo, TPA(ap)))); 364 if (memcmp((const char *)ezero, (const char *)THA(ap), HRD_LEN(ap)) != 0) 365 ND_PRINT((ndo, " (%s)", 366 linkaddr_string(ndo, THA(ap), linkaddr, HRD_LEN(ap)))); 367 ND_PRINT((ndo, " tell %s", ipaddr_string(ndo, SPA(ap)))); 368 break; 369 370 case ARPOP_REPLY: 371 ND_PRINT((ndo, "%s is-at %s", 372 ipaddr_string(ndo, SPA(ap)), 373 linkaddr_string(ndo, 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(ndo, THA(ap), linkaddr, HRD_LEN(ap)), 379 linkaddr_string(ndo, SHA(ap), linkaddr, HRD_LEN(ap)))); 380 break; 381 382 case ARPOP_REVREPLY: 383 ND_PRINT((ndo, "%s at %s", 384 linkaddr_string(ndo, THA(ap), linkaddr, HRD_LEN(ap)), 385 ipaddr_string(ndo, TPA(ap)))); 386 break; 387 388 case ARPOP_INVREQUEST: 389 ND_PRINT((ndo, "who-is %s tell %s", 390 linkaddr_string(ndo, THA(ap), linkaddr, HRD_LEN(ap)), 391 linkaddr_string(ndo, SHA(ap), linkaddr, HRD_LEN(ap)))); 392 break; 393 394 case ARPOP_INVREPLY: 395 ND_PRINT((ndo,"%s at %s", 396 linkaddr_string(ndo, SHA(ap), linkaddr, HRD_LEN(ap)), 397 ipaddr_string(ndo, SPA(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; 409 trunc: 410 ND_PRINT((ndo, "%s", tstr)); 411 } 412 413 /* 414 * Local Variables: 415 * c-style: bsd 416 * End: 417 */ 418 419