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 1.64 2004/04/30 16:42:14 mcr 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_STRIP 23 /* Ricochet Starmode Radio hardware format */ 59 #define ARPHRD_IEEE1394 24 /* IEEE 1394 (FireWire) hardware format */ 60 u_short ar_pro; /* format of protocol address */ 61 u_char ar_hln; /* length of hardware address */ 62 u_char ar_pln; /* length of protocol address */ 63 u_short ar_op; /* one of: */ 64 #define ARPOP_REQUEST 1 /* request to resolve address */ 65 #define ARPOP_REPLY 2 /* response to previous request */ 66 #define ARPOP_REVREQUEST 3 /* request protocol address given hardware */ 67 #define ARPOP_REVREPLY 4 /* response giving protocol address */ 68 #define ARPOP_INVREQUEST 8 /* request to identify peer */ 69 #define ARPOP_INVREPLY 9 /* response identifying peer */ 70 /* 71 * The remaining fields are variable in size, 72 * according to the sizes above. 73 */ 74 #ifdef COMMENT_ONLY 75 u_char ar_sha[]; /* sender hardware address */ 76 u_char ar_spa[]; /* sender protocol address */ 77 u_char ar_tha[]; /* target hardware address */ 78 u_char ar_tpa[]; /* target protocol address */ 79 #endif 80 #define ar_sha(ap) (((const u_char *)((ap)+1))+0) 81 #define ar_spa(ap) (((const u_char *)((ap)+1))+ (ap)->ar_hln) 82 #define ar_tha(ap) (((const u_char *)((ap)+1))+ (ap)->ar_hln+(ap)->ar_pln) 83 #define ar_tpa(ap) (((const u_char *)((ap)+1))+2*(ap)->ar_hln+(ap)->ar_pln) 84 }; 85 86 #define ARP_HDRLEN 8 87 88 #define HRD(ap) EXTRACT_16BITS(&(ap)->ar_hrd) 89 #define HLN(ap) ((ap)->ar_hln) 90 #define PLN(ap) ((ap)->ar_pln) 91 #define OP(ap) EXTRACT_16BITS(&(ap)->ar_op) 92 #define PRO(ap) EXTRACT_16BITS(&(ap)->ar_pro) 93 #define SHA(ap) (ar_sha(ap)) 94 #define SPA(ap) (ar_spa(ap)) 95 #define THA(ap) (ar_tha(ap)) 96 #define TPA(ap) (ar_tpa(ap)) 97 98 /* 99 * ATM Address Resolution Protocol. 100 * 101 * See RFC 2225 for protocol description. ATMARP packets are similar 102 * to ARP packets, except that there are no length fields for the 103 * protocol address - instead, there are type/length fields for 104 * the ATM number and subaddress - and the hardware addresses consist 105 * of an ATM number and an ATM subaddress. 106 */ 107 struct atmarp_pkthdr { 108 u_short aar_hrd; /* format of hardware address */ 109 #define ARPHRD_ATM2225 19 /* ATM (RFC 2225) */ 110 u_short aar_pro; /* format of protocol address */ 111 u_char aar_shtl; /* length of source ATM number */ 112 u_char aar_sstl; /* length of source ATM subaddress */ 113 #define ATMARP_IS_E164 0x40 /* bit in type/length for E.164 format */ 114 #define ATMARP_LEN_MASK 0x3F /* length of {sub}address in type/length */ 115 u_short aar_op; /* same as regular ARP */ 116 #define ATMARPOP_NAK 10 /* NAK */ 117 u_char aar_spln; /* length of source protocol address */ 118 u_char aar_thtl; /* length of target ATM number */ 119 u_char aar_tstl; /* length of target ATM subaddress */ 120 u_char aar_tpln; /* length of target protocol address */ 121 /* 122 * The remaining fields are variable in size, 123 * according to the sizes above. 124 */ 125 #ifdef COMMENT_ONLY 126 u_char aar_sha[]; /* source ATM number */ 127 u_char aar_ssa[]; /* source ATM subaddress */ 128 u_char aar_spa[]; /* sender protocol address */ 129 u_char aar_tha[]; /* target ATM number */ 130 u_char aar_tsa[]; /* target ATM subaddress */ 131 u_char aar_tpa[]; /* target protocol address */ 132 #endif 133 134 #define ATMHRD(ap) EXTRACT_16BITS(&(ap)->aar_hrd) 135 #define ATMSHLN(ap) ((ap)->aar_shtl & ATMARP_LEN_MASK) 136 #define ATMSSLN(ap) ((ap)->aar_sstl & ATMARP_LEN_MASK) 137 #define ATMSPLN(ap) ((ap)->aar_spln) 138 #define ATMOP(ap) EXTRACT_16BITS(&(ap)->aar_op) 139 #define ATMPRO(ap) EXTRACT_16BITS(&(ap)->aar_pro) 140 #define ATMTHLN(ap) ((ap)->aar_thtl & ATMARP_LEN_MASK) 141 #define ATMTSLN(ap) ((ap)->aar_tstl & ATMARP_LEN_MASK) 142 #define ATMTPLN(ap) ((ap)->aar_tpln) 143 #define aar_sha(ap) ((const u_char *)((ap)+1)) 144 #define aar_ssa(ap) (aar_sha(ap) + ATMSHLN(ap)) 145 #define aar_spa(ap) (aar_ssa(ap) + ATMSSLN(ap)) 146 #define aar_tha(ap) (aar_spa(ap) + ATMSPLN(ap)) 147 #define aar_tsa(ap) (aar_tha(ap) + ATMTHLN(ap)) 148 #define aar_tpa(ap) (aar_tsa(ap) + ATMTSLN(ap)) 149 }; 150 151 #define ATMSHA(ap) (aar_sha(ap)) 152 #define ATMSSA(ap) (aar_ssa(ap)) 153 #define ATMSPA(ap) (aar_spa(ap)) 154 #define ATMTHA(ap) (aar_tha(ap)) 155 #define ATMTSA(ap) (aar_tsa(ap)) 156 #define ATMTPA(ap) (aar_tpa(ap)) 157 158 static u_char ezero[6]; 159 160 static void 161 atmarp_addr_print(netdissect_options *ndo, 162 const u_char *ha, u_int ha_len, const u_char *srca, 163 u_int srca_len) 164 { 165 if (ha_len == 0) 166 ND_PRINT((ndo, "<No address>")); 167 else { 168 ND_PRINT((ndo, "%s", linkaddr_string(ha, ha_len))); 169 if (srca_len != 0) 170 ND_PRINT((ndo, ",%s", 171 linkaddr_string(srca, srca_len))); 172 } 173 } 174 175 static void 176 atmarp_print(netdissect_options *ndo, 177 const u_char *bp, u_int length, u_int caplen) 178 { 179 const struct atmarp_pkthdr *ap; 180 u_short pro, hrd, op; 181 182 ap = (const struct atmarp_pkthdr *)bp; 183 ND_TCHECK(*ap); 184 185 hrd = ATMHRD(ap); 186 pro = ATMPRO(ap); 187 op = ATMOP(ap); 188 189 if (!ND_TTEST2(*aar_tpa(ap), ATMTPLN(ap))) { 190 ND_PRINT((ndo, "truncated-atmarp")); 191 ND_DEFAULTPRINT((const u_char *)ap, length); 192 return; 193 } 194 195 if ((pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) || 196 ATMSPLN(ap) != 4 || ATMTPLN(ap) != 4) { 197 ND_PRINT((ndo, "atmarp-#%d for proto #%d (%d/%d) hardware #%d", 198 op, pro, ATMSPLN(ap), ATMTPLN(ap), hrd)); 199 return; 200 } 201 if (pro == ETHERTYPE_TRAIL) 202 ND_PRINT((ndo, "trailer-")); 203 switch (op) { 204 205 case ARPOP_REQUEST: 206 ND_PRINT((ndo, "arp who-has %s", ipaddr_string(ATMTPA(ap)))); 207 if (ATMTHLN(ap) != 0) { 208 ND_PRINT((ndo, " (")); 209 atmarp_addr_print(ndo, ATMTHA(ap), ATMTHLN(ap), 210 ATMTSA(ap), ATMTSLN(ap)); 211 ND_PRINT((ndo, ")")); 212 } 213 ND_PRINT((ndo, " tell %s", ipaddr_string(ATMSPA(ap)))); 214 break; 215 216 case ARPOP_REPLY: 217 ND_PRINT((ndo, "arp reply %s", ipaddr_string(ATMSPA(ap)))); 218 ND_PRINT((ndo, " is-at ")); 219 atmarp_addr_print(ndo, ATMSHA(ap), ATMSHLN(ap), ATMSSA(ap), 220 ATMSSLN(ap)); 221 break; 222 223 case ARPOP_INVREQUEST: 224 ND_PRINT((ndo, "invarp who-is ")); 225 atmarp_addr_print(ndo, ATMTHA(ap), ATMTHLN(ap), ATMTSA(ap), 226 ATMTSLN(ap)); 227 ND_PRINT((ndo, " tell ")); 228 atmarp_addr_print(ndo, ATMSHA(ap), ATMSHLN(ap), ATMSSA(ap), 229 ATMSSLN(ap)); 230 break; 231 232 case ARPOP_INVREPLY: 233 ND_PRINT((ndo, "invarp reply ")); 234 atmarp_addr_print(ndo, ATMSHA(ap), ATMSHLN(ap), ATMSSA(ap), 235 ATMSSLN(ap)); 236 ND_PRINT((ndo, " at %s", ipaddr_string(ATMSPA(ap)))); 237 break; 238 239 case ATMARPOP_NAK: 240 ND_PRINT((ndo, "nak reply for %s", 241 ipaddr_string(ATMSPA(ap)))); 242 break; 243 244 default: 245 ND_PRINT((ndo, "atmarp-#%d", op)); 246 ND_DEFAULTPRINT((const u_char *)ap, caplen); 247 return; 248 } 249 return; 250 trunc: 251 ND_PRINT((ndo, "[|atmarp]")); 252 } 253 254 void 255 arp_print(netdissect_options *ndo, 256 const u_char *bp, u_int length, u_int caplen) 257 { 258 const struct arp_pkthdr *ap; 259 u_short pro, hrd, op; 260 261 ap = (const struct arp_pkthdr *)bp; 262 ND_TCHECK(*ap); 263 hrd = HRD(ap); 264 if (hrd == ARPHRD_ATM2225) { 265 atmarp_print(ndo, bp, length, caplen); 266 return; 267 } 268 pro = PRO(ap); 269 op = OP(ap); 270 271 if (!ND_TTEST2(*ar_tpa(ap), PLN(ap))) { 272 ND_PRINT((ndo, "truncated-arp")); 273 ND_DEFAULTPRINT((const u_char *)ap, length); 274 return; 275 } 276 277 if ((pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) || 278 PLN(ap) != 4 || HLN(ap) == 0) { 279 ND_PRINT((ndo, "arp-#%d for proto #%d (%d) hardware #%d (%d)", 280 op, pro, PLN(ap), hrd, HLN(ap))); 281 return; 282 } 283 if (pro == ETHERTYPE_TRAIL) 284 ND_PRINT((ndo, "trailer-")); 285 switch (op) { 286 287 case ARPOP_REQUEST: 288 ND_PRINT((ndo, "arp who-has %s", ipaddr_string(TPA(ap)))); 289 if (memcmp((const char *)ezero, (const char *)THA(ap), HLN(ap)) != 0) 290 ND_PRINT((ndo, " (%s)", 291 linkaddr_string(THA(ap), HLN(ap)))); 292 ND_PRINT((ndo, " tell %s", ipaddr_string(SPA(ap)))); 293 break; 294 295 case ARPOP_REPLY: 296 ND_PRINT((ndo, "arp reply %s", ipaddr_string(SPA(ap)))); 297 ND_PRINT((ndo, " is-at %s", linkaddr_string(SHA(ap), HLN(ap)))); 298 break; 299 300 case ARPOP_REVREQUEST: 301 ND_PRINT((ndo, "rarp who-is %s tell %s", 302 linkaddr_string(THA(ap), HLN(ap)), 303 linkaddr_string(SHA(ap), HLN(ap)))); 304 break; 305 306 case ARPOP_REVREPLY: 307 ND_PRINT((ndo, "rarp reply %s at %s", 308 linkaddr_string(THA(ap), HLN(ap)), 309 ipaddr_string(TPA(ap)))); 310 break; 311 312 case ARPOP_INVREQUEST: 313 ND_PRINT((ndo, "invarp who-is %s tell %s", 314 linkaddr_string(THA(ap), HLN(ap)), 315 linkaddr_string(SHA(ap), HLN(ap)))); 316 break; 317 318 case ARPOP_INVREPLY: 319 ND_PRINT((ndo,"invarp reply %s at %s", 320 linkaddr_string(THA(ap), HLN(ap)), 321 ipaddr_string(TPA(ap)))); 322 break; 323 324 default: 325 ND_PRINT((ndo, "arp-#%d", op)); 326 ND_DEFAULTPRINT((const u_char *)ap, caplen); 327 return; 328 } 329 if (hrd != ARPHRD_ETHER) 330 ND_PRINT((ndo, " hardware #%d", hrd)); 331 return; 332 trunc: 333 ND_PRINT((ndo, "[|arp]")); 334 } 335 336 /* 337 * Local Variables: 338 * c-style: bsd 339 * End: 340 */ 341 342
