The Tcpdump Group git mirrors - tcpdump/blob - 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 #ifndef lint
  28 static const char rcsid[] _U_ =
  29     "@(#) $Header: /tcpdump/master/tcpdump/print-cdp.c,v 1.25 2004-10-07 14:53:11 hannes Exp $";
  30 #endif
  31
  32 #ifdef HAVE_CONFIG_H
  33 #include "config.h"
  34 #endif
  35
  36 #include <tcpdump-stdinc.h>
  37
  38 #include <stdio.h>
  39 #include <string.h>
  40
  41 #include "interface.h"
  42 #include "addrtoname.h"
  43 #include "extract.h"                    /* must come after interface.h */
  44 #include "nlpid.h"
  45
  46 static const char tstr[] = "[|cdp]";
  47
  48 #define CDP_HEADER_LEN  4
  49
  50 static const struct tok cdp_tlv_values[] = {
  51     { 0x01,             "Device-ID"},
  52     { 0x02,             "Address"},
  53     { 0x03,             "Port-ID"},
  54     { 0x04,             "Capability"},
  55     { 0x05,             "Version String"},
  56     { 0x06,             "Platform"},
  57     { 0x07,             "Prefixes"},
  58     { 0x08,             "Protocol-Hello option"},
  59     { 0x09,             "VTP Management Domain"},
  60     { 0x0a,             "Native VLAN ID"},
  61     { 0x0b,             "Duplex"},
  62     { 0x0e,             "ATA-186 VoIP VLAN request"},
  63     { 0x0f,             "ATA-186 VoIP VLAN assignment"},
  64     { 0x10,             "power consumption"},
  65     { 0x11,             "MTU"},
  66     { 0x12,             "AVVID trust bitmap"},
  67     { 0x13,             "AVVID untrusted ports CoS"},
  68     { 0x14,             "System Name"},
  69     { 0x15,             "System Object ID (not decoded)"},
  70     { 0x16,             "Management Addresses"},
  71     { 0x17,             "Physical Location"},
  72     { 0, NULL}
  73 };
  74
  75 static const struct tok cdp_capability_values[] = {
  76     { 0x01,             "Router" },
  77     { 0x02,             "Transparent Bridge" },
  78     { 0x04,             "Source Route Bridge" },
  79     { 0x08,             "L2 Switch" },
  80     { 0x10,             "L3 capable" },
  81     { 0x20,             "IGMP snooping" },
  82     { 0x40,             "L1 capable" },
  83     { 0, NULL }
  84 };
  85
  86 static int cdp_print_addr(const u_char *, int);
  87 static int cdp_print_prefixes(const u_char *, int);
  88 static unsigned long cdp_get_number(const u_char *, int);
  89
  90 void
  91 cdp_print(const u_char *pptr, u_int length, u_int caplen)
  92 {
  93         int type, len, i, j;
  94         const u_char *tptr;
  95
  96         if (caplen < CDP_HEADER_LEN) {
  97                 printf("%s", tstr);
  98                 return;
  99         }
 100
 101         tptr = pptr; /* temporary pointer */
 102
 103         if (!TTEST2(*tptr, CDP_HEADER_LEN))
 104                 goto trunc;
 105         printf("CDPv%u, ttl: %us", *tptr, *(tptr+1));
 106         if (vflag)
 107                 printf(", checksum: %u (unverified), length %u", EXTRACT_16BITS(tptr), length);
 108         tptr += CDP_HEADER_LEN;
 109
 110         while (tptr < (pptr+length)) {
 111
 112                 if (!TTEST2(*tptr, 4)) /* read out Type and Length */
 113                     goto trunc;
 114                 type = EXTRACT_16BITS(tptr);
 115                 len  = EXTRACT_16BITS(tptr+2); /* object length includes the 4 bytes header length */
 116                 tptr += 4;
 117                 len -= 4;
 118
 119                 if (!TTEST2(*tptr, len))
 120                         goto trunc;
 121
 122                 if (vflag || type == 1) { /* in non-verbose mode just print Device-ID */
 123
 124                     if (vflag)
 125                         printf("\n\t%s (0x%02x), length: %u byte%s: ",
 126                                tok2str(cdp_tlv_values,"unknown field type", type),
 127                                type,
 128                                len,
 129                                PLURAL_SUFFIX(len)); /* plural */
 130
 131                     switch (type) {
 132
 133                     case 0x01: /* Device-ID */
 134                         if (!vflag)
 135                             printf(", Device-ID ");
 136                         printf("'");
 137                         fn_printn(tptr, len, NULL);
 138                         printf("'");
 139                         break;
 140                     case 0x02: /* Address */
 141                         if (cdp_print_addr(tptr, len) < 0)
 142                             goto trunc;
 143                         break;
 144                     case 0x03: /* Port-ID */
 145                         printf("'");
 146                         fn_printn(tptr, len, NULL);
 147                         printf("'");
 148                         break;
 149                     case 0x04: /* Capabilities */
 150                         printf("(0x%08x): %s",
 151                                EXTRACT_32BITS(tptr),
 152                                bittok2str(cdp_capability_values, "none",EXTRACT_32BITS(tptr)));
 153                         break;
 154                     case 0x05: /* Version */
 155                         printf("\n\t  ");
 156                         for (i=0;i<len;i++) {
 157                             j = *(tptr+i);
 158                             putchar(j);
 159                             if (j == 0x0a) /* lets rework the version string to get a nice identation */
 160                                 printf("\t  ");
 161                         }
 162                         break;
 163                     case 0x06: /* Platform */
 164                         printf("'");
 165                         fn_printn(tptr, len, NULL);
 166                         printf("'");
 167                         break;
 168                     case 0x07: /* Prefixes */
 169                         if (cdp_print_prefixes(tptr, len) < 0)
 170                             goto trunc;
 171                         break;
 172                     case 0x08: /* Protocol Hello Option - not documented */
 173                         break;
 174                     case 0x09: /* VTP Mgmt Domain  - not documented */
 175                         printf("'");
 176                         fn_printn(tptr, len, NULL);
 177                         printf("'");
 178                         break;
 179                     case 0x0a: /* Native VLAN ID - not documented */
 180                         printf("%d",EXTRACT_16BITS(tptr));
 181                         break;
 182                     case 0x0b: /* Duplex - not documented */
 183                         printf("%s", *(tptr) ? "full": "half");
 184                         break;
 185
 186                     /* http://www.cisco.com/univercd/cc/td/doc/product/voice/ata/atarn/186rn21m.htm
 187                      * plus more details from other sources
 188                      */
 189                     case 0x0e: /* ATA-186 VoIP VLAN request - incomplete doc. */
 190                         printf("app %d, vlan %d",
 191                                *(tptr), EXTRACT_16BITS(tptr+1));
 192                         break;
 193                     case 0x10: /* ATA-186 VoIP VLAN assignment - incomplete doc. */
 194                         printf("%1.2fW",
 195                                cdp_get_number(tptr, len)/1000.0 );
 196                         break;
 197                     case 0x11: /* MTU - not documented */
 198                         printf("%u bytes", EXTRACT_32BITS(tptr));
 199                         break;
 200                     case 0x12: /* AVVID trust bitmap - not documented */
 201                         printf("0x%02x", *(tptr) );
 202                         break;
 203                     case 0x13: /* AVVID untrusted port CoS - not documented */
 204                         printf("0x%02x", *(tptr));
 205                         break;
 206                     case 0x14: /* System Name - not documented */
 207                         printf("'");
 208                         fn_printn(tptr, len, NULL);
 209                         printf("'");
 210                         break;
 211                     case 0x16: /* System Object ID - not documented */
 212                         if (cdp_print_addr(tptr, len) < 0)
 213                                 goto trunc;
 214                         break;
 215                     case 0x17: /* Physical Location - not documented */
 216                         printf("0x%02x", *(tptr));
 217                         if (len > 1) {
 218                                 printf("/");
 219                                 fn_printn(tptr + 1, len - 1, NULL);
 220                         }
 221                         break;
 222                     default:
 223                         print_unknown_data(tptr,"\n\t  ",len);
 224                         break;
 225                     }
 226                 }
 227                 /* avoid infinite loop */
 228                 if (len == 0)
 229                         break;
 230                 tptr = tptr+len;
 231         }
 232         if (vflag < 1)
 233             printf(", length %u",caplen);
 234
 235         return;
 236 trunc:
 237         printf("%s", tstr);
 238 }
 239
 240 /*
 241  * Protocol type values.
 242  *
 243  * PT_NLPID means that the protocol type field contains an OSI NLPID.
 244  *
 245  * PT_IEEE_802_2 means that the protocol type field contains an IEEE 802.2
 246  * LLC header that specifies that the payload is for that protocol.
 247  */
 248 #define PT_NLPID                1       /* OSI NLPID */
 249 #define PT_IEEE_802_2           2       /* IEEE 802.2 LLC header */
 250
 251 static int
 252 cdp_print_addr(const u_char * p, int l)
 253 {
 254         int pt, pl, al, num;
 255         const u_char *endp = p + l;
 256 #ifdef INET6
 257         static const u_char prot_ipv6[] = {
 258                 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00, 0x86, 0xdd
 259         };
 260 #endif
 261
 262         TCHECK2(*p, 2);
 263         num = EXTRACT_32BITS(p);
 264         p += 4;
 265
 266         while (p < endp && num >= 0) {
 267                 TCHECK2(*p, 2);
 268                 if (p + 2 > endp)
 269                         goto trunc;
 270                 pt = p[0];              /* type of "protocol" field */
 271                 pl = p[1];              /* length of "protocol" field */
 272                 p += 2;
 273
 274                 TCHECK2(p[pl], 2);
 275                 if (p + pl + 2 > endp)
 276                         goto trunc;
 277                 al = EXTRACT_16BITS(&p[pl]);    /* address length */
 278
 279                 if (pt == PT_NLPID && pl == 1 && *p == NLPID_IP && al == 4) {
 280                         /*
 281                          * IPv4: protocol type = NLPID, protocol length = 1
 282                          * (1-byte NLPID), protocol = 0xcc (NLPID for IPv4),
 283                          * address length = 4
 284                          */
 285                         p += 3;
 286
 287                         TCHECK2(*p, 4);
 288                         if (p + 4 > endp)
 289                                 goto trunc;
 290                         printf("IPv4 (%u) %s",
 291                                num,
 292                                ipaddr_string(p));
 293                         p += 4;
 294                 }
 295 #ifdef INET6
 296                 else if (pt == PT_IEEE_802_2 && pl == 8 &&
 297                     memcmp(p, prot_ipv6, 8) == 0 && al == 16) {
 298                         /*
 299                          * IPv6: protocol type = IEEE 802.2 header,
 300                          * protocol length = 8 (size of LLC+SNAP header),
 301                          * protocol = LLC+SNAP header with the IPv6
 302                          * Ethertype, address length = 16
 303                          */
 304                         p += 10;
 305                         TCHECK2(*p, al);
 306                         if (p + al > endp)
 307                                 goto trunc;
 308
 309                         printf("IPv6 (%u) %s",
 310                                num,
 311                                ip6addr_string(p));
 312                         p += al;
 313                 }
 314 #endif
 315                 else {
 316                         /*
 317                          * Generic case: just print raw data
 318                          */
 319                         TCHECK2(*p, pl);
 320                         if (p + pl > endp)
 321                                 goto trunc;
 322                         printf("pt=0x%02x, pl=%d, pb=", *(p - 2), pl);
 323                         while (pl-- > 0)
 324                                 printf(" %02x", *p++);
 325                         TCHECK2(*p, 2);
 326                         if (p + 2 > endp)
 327                                 goto trunc;
 328                         al = (*p << 8) + *(p + 1);
 329                         printf(", al=%d, a=", al);
 330                         p += 2;
 331                         TCHECK2(*p, al);
 332                         if (p + al > endp)
 333                                 goto trunc;
 334                         while (al-- > 0)
 335                                 printf(" %02x", *p++);
 336                 }
 337                 num--;
 338                 if (num)
 339                         printf(" ");
 340         }
 341
 342         return 0;
 343
 344 trunc:
 345         return -1;
 346 }
 347
 348
 349 static int
 350 cdp_print_prefixes(const u_char * p, int l)
 351 {
 352         if (l % 5)
 353                 goto trunc;
 354
 355         printf(" IPv4 Prefixes (%d):", l / 5);
 356
 357         while (l > 0) {
 358                 printf(" %u.%u.%u.%u/%u", p[0], p[1], p[2], p[3], p[4]);
 359                 l -= 5;
 360                 p += 5;
 361         }
 362
 363         return 0;
 364
 365 trunc:
 366         return -1;
 367 }
 368
 369 /* read in a <n>-byte number, MSB first
 370  * (of course this can handle max sizeof(long))
 371  */
 372 static unsigned long cdp_get_number(const u_char * p, int l)
 373 {
 374     unsigned long res=0;
 375     while( l>0 )
 376     {
 377         res = (res<<8) + *p;
 378         p++; l--;
 379     }
 380     return res;
 381 }