contrib/tcpdump/print-arp.c

   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