contrib/tcpdump-3.9/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 1.64 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