external/bsd/tcpdump/dist/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 #include <sys/cdefs.h>
  23 #ifndef lint
  24 __RCSID("$NetBSD: print-arp.c,v 1.6 2015/03/31 21:59:35 christos Exp $");
  25 #endif
  26
  27 #define NETDISSECT_REWORKED
  28 #ifdef HAVE_CONFIG_H
  29 #include "config.h"
  30 #endif
  31
  32 #include <tcpdump-stdinc.h>
  33
  34 #include <string.h>
  35
  36 #include "interface.h"
  37 #include "addrtoname.h"
  38 #include "ether.h"
  39 #include "ethertype.h"
  40 #include "extract.h"                    /* must come after interface.h */
  41
  42 static const char tstr[] = "[|ARP]";
  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  */
  54 struct  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
 104 static const struct 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
 115 static const struct 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  */
 135 struct  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
 184 static u_char ezero[6];
 185
 186 static void
 187 atmarp_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(ndo, ha, LINKADDR_ATM, ha_len)));
 195                 if (srca_len != 0)
 196                         ND_PRINT((ndo, ",%s",
 197                                   linkaddr_string(ndo, srca, LINKADDR_ATM, srca_len)));
 198         }
 199 }
 200
 201 static void
 202 atmarp_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, "%s", tstr));
 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         ND_PRINT((ndo, "%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(ndo, 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(ndo, ATMSPA(ap))));
 257                 break;
 258
 259         case ARPOP_REPLY:
 260                 ND_PRINT((ndo, "%s is-at ", ipaddr_string(ndo, 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(ndo, ATMSPA(ap))));
 278                 break;
 279
 280         case ARPOP_NAK:
 281                 ND_PRINT((ndo, "for %s", ipaddr_string(ndo, 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
 293 trunc:
 294         ND_PRINT((ndo, "%s", tstr));
 295 }
 296
 297 void
 298 arp_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(ndo, ) 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             break;
 324         default:
 325             linkaddr = LINKADDR_ETHER;
 326             break;
 327         }
 328
 329         if (!ND_TTEST2(*ar_tpa(ap), PROTO_LEN(ap))) {
 330                 ND_PRINT((ndo, "%s", tstr));
 331                 ND_DEFAULTPRINT((const u_char *)ap, length);
 332                 return;
 333         }
 334
 335         if (!ndo->ndo_eflag) {
 336             ND_PRINT((ndo, "ARP, "));
 337         }
 338
 339         /* print hardware type/len and proto type/len */
 340         if ((pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) ||
 341             PROTO_LEN(ap) != 4 ||
 342             HRD_LEN(ap) == 0 ||
 343             ndo->ndo_vflag) {
 344             ND_PRINT((ndo, "%s (len %u), %s (len %u)",
 345                       tok2str(arphrd_values, "Unknown Hardware (%u)", hrd),
 346                       HRD_LEN(ap),
 347                       tok2str(ethertype_values, "Unknown Protocol (0x%04x)", pro),
 348                       PROTO_LEN(ap)));
 349
 350             /* don't know know about the address formats */
 351             if (!ndo->ndo_vflag) {
 352                 goto out;
 353             }
 354         }
 355
 356         /* print operation */
 357         ND_PRINT((ndo, "%s%s ",
 358                ndo->ndo_vflag ? ", " : "",
 359                tok2str(arpop_values, "Unknown (%u)", op)));
 360
 361         switch (op) {
 362
 363         case ARPOP_REQUEST:
 364                 ND_PRINT((ndo, "who-has %s", ipaddr_string(ndo, TPA(ap))));
 365                 if (memcmp((const char *)ezero, (const char *)THA(ap), HRD_LEN(ap)) != 0)
 366                         ND_PRINT((ndo, " (%s)",
 367                                   linkaddr_string(ndo, THA(ap), linkaddr, HRD_LEN(ap))));
 368                 ND_PRINT((ndo, " tell %s", ipaddr_string(ndo, SPA(ap))));
 369                 break;
 370
 371         case ARPOP_REPLY:
 372                 ND_PRINT((ndo, "%s is-at %s",
 373                           ipaddr_string(ndo, SPA(ap)),
 374                           linkaddr_string(ndo, SHA(ap), linkaddr, HRD_LEN(ap))));
 375                 break;
 376
 377         case ARPOP_REVREQUEST:
 378                 ND_PRINT((ndo, "who-is %s tell %s",
 379                           linkaddr_string(ndo, THA(ap), linkaddr, HRD_LEN(ap)),
 380                           linkaddr_string(ndo, SHA(ap), linkaddr, HRD_LEN(ap))));
 381                 break;
 382
 383         case ARPOP_REVREPLY:
 384                 ND_PRINT((ndo, "%s at %s",
 385                           linkaddr_string(ndo, THA(ap), linkaddr, HRD_LEN(ap)),
 386                           ipaddr_string(ndo, TPA(ap))));
 387                 break;
 388
 389         case ARPOP_INVREQUEST:
 390                 ND_PRINT((ndo, "who-is %s tell %s",
 391                           linkaddr_string(ndo, THA(ap), linkaddr, HRD_LEN(ap)),
 392                           linkaddr_string(ndo, SHA(ap), linkaddr, HRD_LEN(ap))));
 393                 break;
 394
 395         case ARPOP_INVREPLY:
 396                 ND_PRINT((ndo,"%s at %s",
 397                           linkaddr_string(ndo, SHA(ap), linkaddr, HRD_LEN(ap)),
 398                           ipaddr_string(ndo, SPA(ap))));
 399                 break;
 400
 401         default:
 402                 ND_DEFAULTPRINT((const u_char *)ap, caplen);
 403                 return;
 404         }
 405
 406  out:
 407         ND_PRINT((ndo, ", length %u", length));
 408
 409         return;
 410 trunc:
 411         ND_PRINT((ndo, "%s", tstr));
 412 }
 413
 414 /*
 415  * Local Variables:
 416  * c-style: bsd
 417  * End:
 418  */
 419