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