contrib/tcpdump/print-cdp.c

   1 /*
   2  * Copyright (c) 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  * Code by Gert Doering, SpaceNet GmbH, gert@space.net
  22  *
  23  * Reference documentation:
  24  *    http://www.cisco.com/univercd/cc/td/doc/product/lan/trsrb/frames.htm
  25  */
  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 "extract.h"                    /* must come after interface.h */
  39 #include "nlpid.h"
  40
  41 static const char tstr[] = "[|cdp]";
  42
  43 #define CDP_HEADER_LEN             4
  44 #define CDP_HEADER_VERSION_OFFSET  0
  45 #define CDP_HEADER_TTL_OFFSET      1
  46 #define CDP_HEADER_CHECKSUM_OFFSET 2
  47
  48 #define CDP_TLV_HEADER_LEN  4
  49 #define CDP_TLV_TYPE_OFFSET 0
  50 #define CDP_TLV_LEN_OFFSET  2
  51
  52 static const struct tok cdp_tlv_values[] = {
  53     { 0x01,             "Device-ID"},
  54     { 0x02,             "Address"},
  55     { 0x03,             "Port-ID"},
  56     { 0x04,             "Capability"},
  57     { 0x05,             "Version String"},
  58     { 0x06,             "Platform"},
  59     { 0x07,             "Prefixes"},
  60     { 0x08,             "Protocol-Hello option"},
  61     { 0x09,             "VTP Management Domain"},
  62     { 0x0a,             "Native VLAN ID"},
  63     { 0x0b,             "Duplex"},
  64     { 0x0e,             "ATA-186 VoIP VLAN request"},
  65     { 0x0f,             "ATA-186 VoIP VLAN assignment"},
  66     { 0x10,             "power consumption"},
  67     { 0x11,             "MTU"},
  68     { 0x12,             "AVVID trust bitmap"},
  69     { 0x13,             "AVVID untrusted ports CoS"},
  70     { 0x14,             "System Name"},
  71     { 0x15,             "System Object ID (not decoded)"},
  72     { 0x16,             "Management Addresses"},
  73     { 0x17,             "Physical Location"},
  74     { 0, NULL}
  75 };
  76
  77 static const struct tok cdp_capability_values[] = {
  78     { 0x01,             "Router" },
  79     { 0x02,             "Transparent Bridge" },
  80     { 0x04,             "Source Route Bridge" },
  81     { 0x08,             "L2 Switch" },
  82     { 0x10,             "L3 capable" },
  83     { 0x20,             "IGMP snooping" },
  84     { 0x40,             "L1 capable" },
  85     { 0, NULL }
  86 };
  87
  88 static int cdp_print_addr(netdissect_options *, const u_char *, int);
  89 static int cdp_print_prefixes(netdissect_options *, const u_char *, int);
  90 static unsigned long cdp_get_number(const u_char *, int);
  91
  92 void
  93 cdp_print(netdissect_options *ndo,
  94           const u_char *pptr, u_int length, u_int caplen)
  95 {
  96         int type, len, i, j;
  97         const u_char *tptr;
  98
  99         if (caplen < CDP_HEADER_LEN) {
 100                 ND_PRINT((ndo, "%s", tstr));
 101                 return;
 102         }
 103
 104         tptr = pptr; /* temporary pointer */
 105
 106         ND_TCHECK2(*tptr, CDP_HEADER_LEN);
 107         ND_PRINT((ndo, "CDPv%u, ttl: %us", *(tptr + CDP_HEADER_VERSION_OFFSET),
 108                                            *(tptr + CDP_HEADER_TTL_OFFSET)));
 109         if (ndo->ndo_vflag)
 110                 ND_PRINT((ndo, ", checksum: 0x%04x (unverified), length %u", EXTRACT_16BITS(tptr+CDP_HEADER_CHECKSUM_OFFSET), length));
 111         tptr += CDP_HEADER_LEN;
 112
 113         while (tptr < (pptr+length)) {
 114                 ND_TCHECK2(*tptr, CDP_TLV_HEADER_LEN); /* read out Type and Length */
 115                 type = EXTRACT_16BITS(tptr+CDP_TLV_TYPE_OFFSET);
 116                 len  = EXTRACT_16BITS(tptr+CDP_TLV_LEN_OFFSET); /* object length includes the 4 bytes header length */
 117                 if (len < CDP_TLV_HEADER_LEN) {
 118                     if (ndo->ndo_vflag)
 119                         ND_PRINT((ndo, "\n\t%s (0x%02x), TLV length: %u byte%s (too short)",
 120                                tok2str(cdp_tlv_values,"unknown field type", type),
 121                                type,
 122                                len,
 123                                PLURAL_SUFFIX(len))); /* plural */
 124                     else
 125                         ND_PRINT((ndo, ", %s TLV length %u too short",
 126                                tok2str(cdp_tlv_values,"unknown field type", type),
 127                                len));
 128                     break;
 129                 }
 130                 tptr += CDP_TLV_HEADER_LEN;
 131                 len -= CDP_TLV_HEADER_LEN;
 132
 133                 ND_TCHECK2(*tptr, len);
 134
 135                 if (ndo->ndo_vflag || type == 1) { /* in non-verbose mode just print Device-ID */
 136
 137                     if (ndo->ndo_vflag)
 138                         ND_PRINT((ndo, "\n\t%s (0x%02x), value length: %u byte%s: ",
 139                                tok2str(cdp_tlv_values,"unknown field type", type),
 140                                type,
 141                                len,
 142                                PLURAL_SUFFIX(len))); /* plural */
 143
 144                     switch (type) {
 145
 146                     case 0x01: /* Device-ID */
 147                         if (!ndo->ndo_vflag)
 148                             ND_PRINT((ndo, ", Device-ID "));
 149                         ND_PRINT((ndo, "'"));
 150                         (void)fn_printn(ndo, tptr, len, NULL);
 151                         ND_PRINT((ndo, "'"));
 152                         break;
 153                     case 0x02: /* Address */
 154                         if (cdp_print_addr(ndo, tptr, len) < 0)
 155                             goto trunc;
 156                         break;
 157                     case 0x03: /* Port-ID */
 158                         ND_PRINT((ndo, "'"));
 159                         (void)fn_printn(ndo, tptr, len, NULL);
 160                         ND_PRINT((ndo, "'"));
 161                         break;
 162                     case 0x04: /* Capabilities */
 163                         if (len < 4)
 164                             goto trunc;
 165                         ND_PRINT((ndo, "(0x%08x): %s",
 166                                EXTRACT_32BITS(tptr),
 167                                bittok2str(cdp_capability_values, "none", EXTRACT_32BITS(tptr))));
 168                         break;
 169                     case 0x05: /* Version */
 170                         ND_PRINT((ndo, "\n\t  "));
 171                         for (i=0;i<len;i++) {
 172                             j = *(tptr+i);
 173                             ND_PRINT((ndo, "%c", j));
 174                             if (j == 0x0a) /* lets rework the version string to get a nice indentation */
 175                                 ND_PRINT((ndo, "\t  "));
 176                         }
 177                         break;
 178                     case 0x06: /* Platform */
 179                         ND_PRINT((ndo, "'"));
 180                         (void)fn_printn(ndo, tptr, len, NULL);
 181                         ND_PRINT((ndo, "'"));
 182                         break;
 183                     case 0x07: /* Prefixes */
 184                         if (cdp_print_prefixes(ndo, tptr, len) < 0)
 185                             goto trunc;
 186                         break;
 187                     case 0x08: /* Protocol Hello Option - not documented */
 188                         break;
 189                     case 0x09: /* VTP Mgmt Domain  - CDPv2 */
 190                         ND_PRINT((ndo, "'"));
 191                         (void)fn_printn(ndo, tptr, len, NULL);
 192                         ND_PRINT((ndo, "'"));
 193                         break;
 194                     case 0x0a: /* Native VLAN ID - CDPv2 */
 195                         if (len < 2)
 196                             goto trunc;
 197                         ND_PRINT((ndo, "%d", EXTRACT_16BITS(tptr)));
 198                         break;
 199                     case 0x0b: /* Duplex - CDPv2 */
 200                         if (len < 1)
 201                             goto trunc;
 202                         ND_PRINT((ndo, "%s", *(tptr) ? "full": "half"));
 203                         break;
 204
 205                     /* http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cata/186/2_12_m/english/release/notes/186rn21m.html
 206                      * plus more details from other sources
 207                      */
 208                     case 0x0e: /* ATA-186 VoIP VLAN request - incomplete doc. */
 209                         if (len < 3)
 210                             goto trunc;
 211                         ND_PRINT((ndo, "app %d, vlan %d", *(tptr), EXTRACT_16BITS(tptr + 1)));
 212                         break;
 213                     case 0x10: /* ATA-186 VoIP VLAN assignment - incomplete doc. */
 214                         ND_PRINT((ndo, "%1.2fW", cdp_get_number(tptr, len) / 1000.0));
 215                         break;
 216                     case 0x11: /* MTU - not documented */
 217                         if (len < 4)
 218                             goto trunc;
 219                         ND_PRINT((ndo, "%u bytes", EXTRACT_32BITS(tptr)));
 220                         break;
 221                     case 0x12: /* AVVID trust bitmap - not documented */
 222                         if (len < 1)
 223                             goto trunc;
 224                         ND_PRINT((ndo, "0x%02x", *(tptr)));
 225                         break;
 226                     case 0x13: /* AVVID untrusted port CoS - not documented */
 227                         if (len < 1)
 228                             goto trunc;
 229                         ND_PRINT((ndo, "0x%02x", *(tptr)));
 230                         break;
 231                     case 0x14: /* System Name - not documented */
 232                         ND_PRINT((ndo, "'"));
 233                         (void)fn_printn(ndo, tptr, len, NULL);
 234                         ND_PRINT((ndo, "'"));
 235                         break;
 236                     case 0x16: /* System Object ID - not documented */
 237                         if (cdp_print_addr(ndo, tptr, len) < 0)
 238                                 goto trunc;
 239                         break;
 240                     case 0x17: /* Physical Location - not documented */
 241                         if (len < 1)
 242                             goto trunc;
 243                         ND_PRINT((ndo, "0x%02x", *(tptr)));
 244                         if (len > 1) {
 245                                 ND_PRINT((ndo, "/"));
 246                                 (void)fn_printn(ndo, tptr + 1, len - 1, NULL);
 247                         }
 248                         break;
 249                     default:
 250                         print_unknown_data(ndo, tptr, "\n\t  ", len);
 251                         break;
 252                     }
 253                 }
 254                 tptr = tptr+len;
 255         }
 256         if (ndo->ndo_vflag < 1)
 257             ND_PRINT((ndo, ", length %u", caplen));
 258
 259         return;
 260 trunc:
 261         ND_PRINT((ndo, "%s", tstr));
 262 }
 263
 264 /*
 265  * Protocol type values.
 266  *
 267  * PT_NLPID means that the protocol type field contains an OSI NLPID.
 268  *
 269  * PT_IEEE_802_2 means that the protocol type field contains an IEEE 802.2
 270  * LLC header that specifies that the payload is for that protocol.
 271  */
 272 #define PT_NLPID                1       /* OSI NLPID */
 273 #define PT_IEEE_802_2           2       /* IEEE 802.2 LLC header */
 274
 275 static int
 276 cdp_print_addr(netdissect_options *ndo,
 277                const u_char * p, int l)
 278 {
 279         int pt, pl, al, num;
 280         const u_char *endp = p + l;
 281 #ifdef INET6
 282         static const u_char prot_ipv6[] = {
 283                 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00, 0x86, 0xdd
 284         };
 285 #endif
 286
 287         ND_TCHECK2(*p, 4);
 288         if (p + 4 > endp)
 289                 goto trunc;
 290         num = EXTRACT_32BITS(p);
 291         p += 4;
 292
 293         while (p < endp && num >= 0) {
 294                 ND_TCHECK2(*p, 2);
 295                 if (p + 2 > endp)
 296                         goto trunc;
 297                 pt = p[0];              /* type of "protocol" field */
 298                 pl = p[1];              /* length of "protocol" field */
 299                 p += 2;
 300
 301                 ND_TCHECK2(p[pl], 2);
 302                 if (p + pl + 2 > endp)
 303                         goto trunc;
 304                 al = EXTRACT_16BITS(&p[pl]);    /* address length */
 305
 306                 if (pt == PT_NLPID && pl == 1 && *p == NLPID_IP && al == 4) {
 307                         /*
 308                          * IPv4: protocol type = NLPID, protocol length = 1
 309                          * (1-byte NLPID), protocol = 0xcc (NLPID for IPv4),
 310                          * address length = 4
 311                          */
 312                         p += 3;
 313
 314                         ND_TCHECK2(*p, 4);
 315                         if (p + 4 > endp)
 316                                 goto trunc;
 317                         ND_PRINT((ndo, "IPv4 (%u) %s", num, ipaddr_string(ndo, p)));
 318                         p += 4;
 319                 }
 320 #ifdef INET6
 321                 else if (pt == PT_IEEE_802_2 && pl == 8 &&
 322                     memcmp(p, prot_ipv6, 8) == 0 && al == 16) {
 323                         /*
 324                          * IPv6: protocol type = IEEE 802.2 header,
 325                          * protocol length = 8 (size of LLC+SNAP header),
 326                          * protocol = LLC+SNAP header with the IPv6
 327                          * Ethertype, address length = 16
 328                          */
 329                         p += 10;
 330                         ND_TCHECK2(*p, al);
 331                         if (p + al > endp)
 332                                 goto trunc;
 333
 334                         ND_PRINT((ndo, "IPv6 (%u) %s", num, ip6addr_string(ndo, p)));
 335                         p += al;
 336                 }
 337 #endif
 338                 else {
 339                         /*
 340                          * Generic case: just print raw data
 341                          */
 342                         ND_TCHECK2(*p, pl);
 343                         if (p + pl > endp)
 344                                 goto trunc;
 345                         ND_PRINT((ndo, "pt=0x%02x, pl=%d, pb=", *(p - 2), pl));
 346                         while (pl-- > 0)
 347                                 ND_PRINT((ndo, " %02x", *p++));
 348                         ND_TCHECK2(*p, 2);
 349                         if (p + 2 > endp)
 350                                 goto trunc;
 351                         al = (*p << 8) + *(p + 1);
 352                         ND_PRINT((ndo, ", al=%d, a=", al));
 353                         p += 2;
 354                         ND_TCHECK2(*p, al);
 355                         if (p + al > endp)
 356                                 goto trunc;
 357                         while (al-- > 0)
 358                                 ND_PRINT((ndo, " %02x", *p++));
 359                 }
 360                 num--;
 361                 if (num)
 362                         ND_PRINT((ndo, " "));
 363         }
 364
 365         return 0;
 366
 367 trunc:
 368         return -1;
 369 }
 370
 371
 372 static int
 373 cdp_print_prefixes(netdissect_options *ndo,
 374                    const u_char * p, int l)
 375 {
 376         if (l % 5)
 377                 goto trunc;
 378
 379         ND_PRINT((ndo, " IPv4 Prefixes (%d):", l / 5));
 380
 381         while (l > 0) {
 382                 ND_PRINT((ndo, " %u.%u.%u.%u/%u", p[0], p[1], p[2], p[3], p[4]));
 383                 l -= 5;
 384                 p += 5;
 385         }
 386
 387         return 0;
 388
 389 trunc:
 390         return -1;
 391 }
 392
 393 /* read in a <n>-byte number, MSB first
 394  * (of course this can handle max sizeof(long))
 395  */
 396 static unsigned long cdp_get_number(const u_char * p, int l)
 397 {
 398     unsigned long res=0;
 399     while( l>0 )
 400     {
 401         res = (res<<8) + *p;
 402         p++; l--;
 403     }
 404     return res;
 405 }