dist/tcpdump/print-arp.c

   1 /*      $NetBSD$        */
   2
   3 /*
   4  * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that: (1) source code distributions
   9  * retain the above copyright notice and this paragraph in its entirety, (2)
  10  * distributions including binary code include the above copyright notice and
  11  * this paragraph in its entirety in the documentation or other materials
  12  * provided with the distribution, and (3) all advertising materials mentioning
  13  * features or use of this software display the following acknowledgement:
  14  * ``This product includes software developed by the University of California,
  15  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
  16  * the University nor the names of its contributors may be used to endorse
  17  * or promote products derived from this software without specific prior
  18  * written permission.
  19  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
  20  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  21  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  22  */
  23
  24 #include <sys/cdefs.h>
  25 #ifndef lint
  26 #if 0
  27 static const char rcsid[] _U_ =
  28     "@(#) Header: /tcpdump/master/tcpdump/print-arp.c,v 1.64 2004/04/30 16:42:14 mcr Exp (LBL)";
  29 #else
  30 __RCSID("$NetBSD: tcpdump2rcsid.ex,v 1.1 2001/06/25 20:09:58 itojun Exp $");
  31 #endif
  32 #endif
  33
  34 #ifdef HAVE_CONFIG_H
  35 #include "config.h"
  36 #endif
  37
  38 #include <tcpdump-stdinc.h>
  39
  40 #include <stdio.h>
  41 #include <string.h>
  42
  43 #include "netdissect.h"
  44 #include "addrtoname.h"
  45 #include "ether.h"
  46 #include "ethertype.h"
  47 #include "extract.h"                    /* must come after interface.h */
  48
  49 /*
  50  * Address Resolution Protocol.
  51  *
  52  * See RFC 826 for protocol description.  ARP packets are variable
  53  * in size; the arphdr structure defines the fixed-length portion.
  54  * Protocol type values are the same as those for 10 Mb/s Ethernet.
  55  * It is followed by the variable-sized fields ar_sha, arp_spa,
  56  * arp_tha and arp_tpa in that order, according to the lengths
  57  * specified.  Field names used correspond to RFC 826.
  58  */
  59 struct  arp_pkthdr {
  60         u_short ar_hrd;         /* format of hardware address */
  61 #define ARPHRD_ETHER    1       /* ethernet hardware format */
  62 #define ARPHRD_IEEE802  6       /* token-ring hardware format */
  63 #define ARPHRD_ARCNET   7       /* arcnet hardware format */
  64 #define ARPHRD_FRELAY   15      /* frame relay hardware format */
  65 #define ARPHRD_STRIP    23      /* Ricochet Starmode Radio hardware format */
  66 #define ARPHRD_IEEE1394 24      /* IEEE 1394 (FireWire) hardware format */
  67         u_short ar_pro;         /* format of protocol address */
  68         u_char  ar_hln;         /* length of hardware address */
  69         u_char  ar_pln;         /* length of protocol address */
  70         u_short ar_op;          /* one of: */
  71 #define ARPOP_REQUEST   1       /* request to resolve address */
  72 #define ARPOP_REPLY     2       /* response to previous request */
  73 #define ARPOP_REVREQUEST 3      /* request protocol address given hardware */
  74 #define ARPOP_REVREPLY  4       /* response giving protocol address */
  75 #define ARPOP_INVREQUEST 8      /* request to identify peer */
  76 #define ARPOP_INVREPLY  9       /* response identifying peer */
  77 /*
  78  * The remaining fields are variable in size,
  79  * according to the sizes above.
  80  */
  81 #ifdef COMMENT_ONLY
  82         u_char  ar_sha[];       /* sender hardware address */
  83         u_char  ar_spa[];       /* sender protocol address */
  84         u_char  ar_tha[];       /* target hardware address */
  85         u_char  ar_tpa[];       /* target protocol address */
  86 #endif
  87 #define ar_sha(ap)      (((const u_char *)((ap)+1))+0)
  88 #define ar_spa(ap)      (((const u_char *)((ap)+1))+  (ap)->ar_hln)
  89 #define ar_tha(ap)      (((const u_char *)((ap)+1))+  (ap)->ar_hln+(ap)->ar_pln)
  90 #define ar_tpa(ap)      (((const u_char *)((ap)+1))+2*(ap)->ar_hln+(ap)->ar_pln)
  91 };
  92
  93 #define ARP_HDRLEN      8
  94
  95 #define HRD(ap) EXTRACT_16BITS(&(ap)->ar_hrd)
  96 #define HLN(ap) ((ap)->ar_hln)
  97 #define PLN(ap) ((ap)->ar_pln)
  98 #define OP(ap)  EXTRACT_16BITS(&(ap)->ar_op)
  99 #define PRO(ap) EXTRACT_16BITS(&(ap)->ar_pro)
 100 #define SHA(ap) (ar_sha(ap))
 101 #define SPA(ap) (ar_spa(ap))
 102 #define THA(ap) (ar_tha(ap))
 103 #define TPA(ap) (ar_tpa(ap))
 104
 105 /*
 106  * ATM Address Resolution Protocol.
 107  *
 108  * See RFC 2225 for protocol description.  ATMARP packets are similar
 109  * to ARP packets, except that there are no length fields for the
 110  * protocol address - instead, there are type/length fields for
 111  * the ATM number and subaddress - and the hardware addresses consist
 112  * of an ATM number and an ATM subaddress.
 113  */
 114 struct  atmarp_pkthdr {
 115         u_short aar_hrd;        /* format of hardware address */
 116 #define ARPHRD_ATM2225  19      /* ATM (RFC 2225) */
 117         u_short aar_pro;        /* format of protocol address */
 118         u_char  aar_shtl;       /* length of source ATM number */
 119         u_char  aar_sstl;       /* length of source ATM subaddress */
 120 #define ATMARP_IS_E164  0x40    /* bit in type/length for E.164 format */
 121 #define ATMARP_LEN_MASK 0x3F    /* length of {sub}address in type/length */
 122         u_short aar_op;         /* same as regular ARP */
 123 #define ATMARPOP_NAK    10      /* NAK */
 124         u_char  aar_spln;       /* length of source protocol address */
 125         u_char  aar_thtl;       /* length of target ATM number */
 126         u_char  aar_tstl;       /* length of target ATM subaddress */
 127         u_char  aar_tpln;       /* length of target protocol address */
 128 /*
 129  * The remaining fields are variable in size,
 130  * according to the sizes above.
 131  */
 132 #ifdef COMMENT_ONLY
 133         u_char  aar_sha[];      /* source ATM number */
 134         u_char  aar_ssa[];      /* source ATM subaddress */
 135         u_char  aar_spa[];      /* sender protocol address */
 136         u_char  aar_tha[];      /* target ATM number */
 137         u_char  aar_tsa[];      /* target ATM subaddress */
 138         u_char  aar_tpa[];      /* target protocol address */
 139 #endif
 140
 141 #define ATMHRD(ap)  EXTRACT_16BITS(&(ap)->aar_hrd)
 142 #define ATMSHLN(ap) ((ap)->aar_shtl & ATMARP_LEN_MASK)
 143 #define ATMSSLN(ap) ((ap)->aar_sstl & ATMARP_LEN_MASK)
 144 #define ATMSPLN(ap) ((ap)->aar_spln)
 145 #define ATMOP(ap)   EXTRACT_16BITS(&(ap)->aar_op)
 146 #define ATMPRO(ap)  EXTRACT_16BITS(&(ap)->aar_pro)
 147 #define ATMTHLN(ap) ((ap)->aar_thtl & ATMARP_LEN_MASK)
 148 #define ATMTSLN(ap) ((ap)->aar_tstl & ATMARP_LEN_MASK)
 149 #define ATMTPLN(ap) ((ap)->aar_tpln)
 150 #define aar_sha(ap)     ((const u_char *)((ap)+1))
 151 #define aar_ssa(ap)     (aar_sha(ap) + ATMSHLN(ap))
 152 #define aar_spa(ap)     (aar_ssa(ap) + ATMSSLN(ap))
 153 #define aar_tha(ap)     (aar_spa(ap) + ATMSPLN(ap))
 154 #define aar_tsa(ap)     (aar_tha(ap) + ATMTHLN(ap))
 155 #define aar_tpa(ap)     (aar_tsa(ap) + ATMTSLN(ap))
 156 };
 157
 158 #define ATMSHA(ap) (aar_sha(ap))
 159 #define ATMSSA(ap) (aar_ssa(ap))
 160 #define ATMSPA(ap) (aar_spa(ap))
 161 #define ATMTHA(ap) (aar_tha(ap))
 162 #define ATMTSA(ap) (aar_tsa(ap))
 163 #define ATMTPA(ap) (aar_tpa(ap))
 164
 165 static u_char ezero[6];
 166
 167 static void
 168 atmarp_addr_print(netdissect_options *ndo,
 169                   const u_char *ha, u_int ha_len, const u_char *srca,
 170     u_int srca_len)
 171 {
 172         if (ha_len == 0)
 173                 ND_PRINT((ndo, "<No address>"));
 174         else {
 175                 ND_PRINT((ndo, "%s", linkaddr_string(ha, ha_len)));
 176                 if (srca_len != 0)
 177                         ND_PRINT((ndo, ",%s",
 178                                   linkaddr_string(srca, srca_len)));
 179         }
 180 }
 181
 182 static void
 183 atmarp_print(netdissect_options *ndo,
 184              const u_char *bp, u_int length, u_int caplen)
 185 {
 186         const struct atmarp_pkthdr *ap;
 187         u_short pro, hrd, op;
 188
 189         ap = (const struct atmarp_pkthdr *)bp;
 190         ND_TCHECK(*ap);
 191
 192         hrd = ATMHRD(ap);
 193         pro = ATMPRO(ap);
 194         op = ATMOP(ap);
 195
 196         if (!ND_TTEST2(*aar_tpa(ap), ATMTPLN(ap))) {
 197                 ND_PRINT((ndo, "truncated-atmarp"));
 198                 ND_DEFAULTPRINT((const u_char *)ap, length);
 199                 return;
 200         }
 201
 202         if ((pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) ||
 203             ATMSPLN(ap) != 4 || ATMTPLN(ap) != 4) {
 204                 ND_PRINT((ndo, "atmarp-#%d for proto #%d (%d/%d) hardware #%d",
 205                           op, pro, ATMSPLN(ap), ATMTPLN(ap), hrd));
 206                 return;
 207         }
 208         if (pro == ETHERTYPE_TRAIL)
 209                 ND_PRINT((ndo, "trailer-"));
 210         switch (op) {
 211
 212         case ARPOP_REQUEST:
 213                 ND_PRINT((ndo, "arp who-has %s", ipaddr_string(ATMTPA(ap))));
 214                 if (ATMTHLN(ap) != 0) {
 215                         ND_PRINT((ndo, " ("));
 216                         atmarp_addr_print(ndo, ATMTHA(ap), ATMTHLN(ap),
 217                             ATMTSA(ap), ATMTSLN(ap));
 218                         ND_PRINT((ndo, ")"));
 219                 }
 220                 ND_PRINT((ndo, " tell %s", ipaddr_string(ATMSPA(ap))));
 221                 break;
 222
 223         case ARPOP_REPLY:
 224                 ND_PRINT((ndo, "arp reply %s", ipaddr_string(ATMSPA(ap))));
 225                 ND_PRINT((ndo, " is-at "));
 226                 atmarp_addr_print(ndo, ATMSHA(ap), ATMSHLN(ap), ATMSSA(ap),
 227                     ATMSSLN(ap));
 228                 break;
 229
 230         case ARPOP_INVREQUEST:
 231                 ND_PRINT((ndo, "invarp who-is "));
 232                 atmarp_addr_print(ndo, ATMTHA(ap), ATMTHLN(ap), ATMTSA(ap),
 233                     ATMTSLN(ap));
 234                 ND_PRINT((ndo, " tell "));
 235                 atmarp_addr_print(ndo, ATMSHA(ap), ATMSHLN(ap), ATMSSA(ap),
 236                     ATMSSLN(ap));
 237                 break;
 238
 239         case ARPOP_INVREPLY:
 240                 ND_PRINT((ndo, "invarp reply "));
 241                 atmarp_addr_print(ndo, ATMSHA(ap), ATMSHLN(ap), ATMSSA(ap),
 242                     ATMSSLN(ap));
 243                 ND_PRINT((ndo, " at %s", ipaddr_string(ATMSPA(ap))));
 244                 break;
 245
 246         case ATMARPOP_NAK:
 247                 ND_PRINT((ndo, "nak reply for %s",
 248                           ipaddr_string(ATMSPA(ap))));
 249                 break;
 250
 251         default:
 252                 ND_PRINT((ndo, "atmarp-#%d", op));
 253                 ND_DEFAULTPRINT((const u_char *)ap, caplen);
 254                 return;
 255         }
 256         return;
 257 trunc:
 258         ND_PRINT((ndo, "[|atmarp]"));
 259 }
 260
 261 void
 262 arp_print(netdissect_options *ndo,
 263           const u_char *bp, u_int length, u_int caplen)
 264 {
 265         const struct arp_pkthdr *ap;
 266         u_short pro, hrd, op;
 267
 268         ap = (const struct arp_pkthdr *)bp;
 269         ND_TCHECK(*ap);
 270         hrd = HRD(ap);
 271         if (hrd == ARPHRD_ATM2225) {
 272                 atmarp_print(ndo, bp, length, caplen);
 273                 return;
 274         }
 275         pro = PRO(ap);
 276         op = OP(ap);
 277
 278         if (!ND_TTEST2(*ar_tpa(ap), PLN(ap))) {
 279                 ND_PRINT((ndo, "truncated-arp"));
 280                 ND_DEFAULTPRINT((const u_char *)ap, length);
 281                 return;
 282         }
 283
 284         if ((pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) ||
 285             PLN(ap) != 4 || HLN(ap) == 0) {
 286                 ND_PRINT((ndo, "arp-#%d for proto #%d (%d) hardware #%d (%d)",
 287                           op, pro, PLN(ap), hrd, HLN(ap)));
 288                 return;
 289         }
 290         if (pro == ETHERTYPE_TRAIL)
 291                 ND_PRINT((ndo, "trailer-"));
 292         switch (op) {
 293
 294         case ARPOP_REQUEST:
 295                 ND_PRINT((ndo, "arp who-has %s", ipaddr_string(TPA(ap))));
 296                 if (memcmp((const char *)ezero, (const char *)THA(ap), HLN(ap)) != 0)
 297                         ND_PRINT((ndo, " (%s)",
 298                                   linkaddr_string(THA(ap), HLN(ap))));
 299                 ND_PRINT((ndo, " tell %s", ipaddr_string(SPA(ap))));
 300                 break;
 301
 302         case ARPOP_REPLY:
 303                 ND_PRINT((ndo, "arp reply %s", ipaddr_string(SPA(ap))));
 304                 ND_PRINT((ndo, " is-at %s", linkaddr_string(SHA(ap), HLN(ap))));
 305                 break;
 306
 307         case ARPOP_REVREQUEST:
 308                 ND_PRINT((ndo, "rarp who-is %s tell %s",
 309                           linkaddr_string(THA(ap), HLN(ap)),
 310                           linkaddr_string(SHA(ap), HLN(ap))));
 311                 break;
 312
 313         case ARPOP_REVREPLY:
 314                 ND_PRINT((ndo, "rarp reply %s at %s",
 315                           linkaddr_string(THA(ap), HLN(ap)),
 316                           ipaddr_string(TPA(ap))));
 317                 break;
 318
 319         case ARPOP_INVREQUEST:
 320                 ND_PRINT((ndo, "invarp who-is %s tell %s",
 321                           linkaddr_string(THA(ap), HLN(ap)),
 322                           linkaddr_string(SHA(ap), HLN(ap))));
 323                 break;
 324
 325         case ARPOP_INVREPLY:
 326                 ND_PRINT((ndo,"invarp reply %s at %s",
 327                           linkaddr_string(THA(ap), HLN(ap)),
 328                           ipaddr_string(TPA(ap))));
 329                 break;
 330
 331         default:
 332                 ND_PRINT((ndo, "arp-#%d", op));
 333                 ND_DEFAULTPRINT((const u_char *)ap, caplen);
 334                 return;
 335         }
 336         if (hrd != ARPHRD_ETHER)
 337                 ND_PRINT((ndo, " hardware #%d", hrd));
 338         return;
 339 trunc:
 340         ND_PRINT((ndo, "[|arp]"));
 341 }
 342
 343 /*
 344  * Local Variables:
 345  * c-style: bsd
 346  * End:
 347  */
 348