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
  28 #ifdef HAVE_CONFIG_H
  29 #include "config.h"
  30 #endif
  31
  32 #include <tcpdump-stdinc.h>
  33
  34 #include <stdio.h>
  35 #include <string.h>
  36
  37 #include "interface.h"
  38 #include "addrtoname.h"
  39 #include "extract.h"                    /* must come after interface.h */
  40
  41 #ifndef lint
  42 static const char rcsid[] _U_ =
  43     "@(#) $Header: /tcpdump/master/tcpdump/print-cdp.c,v 1.20 2003-11-15 00:39:17 guy Exp $";
  44 #endif
  45 #define CDP_HEADER_LEN  4
  46
  47 static struct tok cdp_tlv_values[] = {
  48     { 0x01,             "Device-ID"},
  49     { 0x02,             "Address"},
  50     { 0x03,             "Port-ID"},
  51     { 0x04,             "Capability"},
  52     { 0x05,             "Version String"},
  53     { 0x06,             "Platform"},
  54     { 0x07,             "Prefixes"},
  55     { 0x08,             "Protocol-Hello option"},
  56     { 0x09,             "VTP Management Domain"},
  57     { 0x0a,             "Native VLAN ID"},
  58     { 0x0b,             "Duplex"},
  59     { 0x0e,             "ATA-186 VoIP VLAN request"},
  60     { 0x0f,             "ATA-186 VoIP VLAN assignment"},
  61     { 0x10,             "power consumption"},
  62     { 0x11,             "MTU"},
  63     { 0x12,             "AVVID trust bitmap"},
  64     { 0x13,             "AVVID untrusted ports CoS"},
  65     { 0x14,             "System Name"},
  66     { 0x15,             "System Object ID (not decoded)"},
  67     { 0x16,             "Management Addresses"},
  68     { 0x17,             "Physical Location"},
  69     { 0, NULL}
  70 };
  71
  72 static struct tok cdp_capability_values[] = {
  73     { 0x01,             "Router" },
  74     { 0x02,             "Transparent Bridge" },
  75     { 0x04,             "Source Route Bridge" },
  76     { 0x08,             "L2 Switch" },
  77     { 0x10,             "L3 capable" },
  78     { 0x20,             "IGMP snooping" },
  79     { 0x40,             "L1 capable" },
  80     { 0, NULL }
  81 };
  82
  83 static int cdp_print_addr(const u_char *, int);
  84 static int cdp_print_prefixes(const u_char *, int);
  85 static unsigned long cdp_get_number(const u_char *, int);
  86
  87 void
  88 cdp_print(const u_char *pptr, u_int length, u_int caplen)
  89 {
  90         int type, len, i, j;
  91         const u_char *tptr;
  92
  93         if (caplen < CDP_HEADER_LEN) {
  94                 (void)printf("[|cdp]");
  95                 return;
  96         }
  97
  98         tptr = pptr; /* temporary pointer */
  99
 100         if (!TTEST2(*tptr, CDP_HEADER_LEN))
 101                 goto trunc;
 102         printf("CDP v%u, ttl: %us", *tptr, *(tptr+1));
 103         if (vflag)
 104                 printf(", checksum: %u (unverified)", EXTRACT_16BITS(tptr));
 105         tptr += CDP_HEADER_LEN;
 106
 107         while (tptr < (pptr+length)) {
 108
 109                 if (!TTEST2(*tptr, 4)) /* read out Type and Length */
 110                     goto trunc;
 111                 type = EXTRACT_16BITS(tptr);
 112                 len  = EXTRACT_16BITS(tptr+2); /* object length includes the 4 bytes header length */
 113                 tptr += 4;
 114                 len -= 4;
 115
 116                 if (!TTEST2(*tptr, len))
 117                         goto trunc;
 118
 119                 if (vflag || type == 1) { /* in non-verbose mode just print Device-ID */
 120
 121                     if (vflag)
 122                         printf("\n\t%s (0x%02x), length: %u byte%s: ",
 123                                tok2str(cdp_tlv_values,"unknown field type", type),
 124                                type,
 125                                len,
 126                                len>1 ? "s" : ""); /* plural */
 127
 128                     switch (type) {
 129
 130                     case 0x01: /* Device-ID */
 131                         if (!vflag)
 132                             printf(", Device-ID '%.*s'", len, tptr);
 133                         else
 134                             printf("'%.*s'", len, tptr);
 135                         break;
 136                     case 0x02: /* Address */
 137                         if (cdp_print_addr(tptr, len) < 0)
 138                             goto trunc;
 139                         break;
 140                     case 0x03: /* Port-ID */
 141                         printf("'%.*s'", len, tptr);
 142                         break;
 143                     case 0x04: /* Capabilities */
 144                         printf("(0x%08x): %s",
 145                                EXTRACT_32BITS(tptr),
 146                                bittok2str(cdp_capability_values, "none",EXTRACT_32BITS(tptr)));
 147                         break;
 148                     case 0x05: /* Version */
 149                         printf("\n\t  ");
 150                         for (i=0;i<len;i++) {
 151                             j = *(tptr+i);
 152                             putchar(j);
 153                             if (j == 0x0a) /* lets rework the version string to get a nice identation */
 154                                 printf("\t  ");
 155                         }
 156                         break;
 157                     case 0x06: /* Platform */
 158                         printf("'%.*s'", len, tptr);
 159                         break;
 160                     case 0x07: /* Prefixes */
 161                         if (cdp_print_prefixes(tptr, len) < 0)
 162                             goto trunc;
 163                         break;
 164                     case 0x08: /* Protocol Hello Option - not documented */
 165                         break;
 166                     case 0x09: /* VTP Mgmt Domain  - not documented */
 167                         printf("'%.*s'", len,tptr);
 168                         break;
 169                     case 0x0a: /* Native VLAN ID - not documented */
 170                         printf("%d",EXTRACT_16BITS(tptr));
 171                         break;
 172                     case 0x0b: /* Duplex - not documented */
 173                         printf("%s", *(tptr) ? "full": "half");
 174                         break;
 175
 176                     /* http://www.cisco.com/univercd/cc/td/doc/product/voice/ata/atarn/186rn21m.htm
 177                      * plus more details from other sources
 178                      */
 179                     case 0x0e: /* ATA-186 VoIP VLAN request - incomplete doc. */
 180                         printf("app %d, vlan %d",
 181                                *(tptr), EXTRACT_16BITS(tptr+1));
 182                         break;
 183                     case 0x10: /* ATA-186 VoIP VLAN assignment - incomplete doc. */
 184                         printf("%1.2fW",
 185                                cdp_get_number(tptr, len)/1000.0 );
 186                         break;
 187                     case 0x11: /* MTU - not documented */
 188                         printf("%u bytes", EXTRACT_32BITS(tptr));
 189                         break;
 190                     case 0x12: /* AVVID trust bitmap - not documented */
 191                         printf("0x%02x", *(tptr) );
 192                         break;
 193                     case 0x13: /* AVVID untrusted port CoS - not documented */
 194                         printf("0x%02x", *(tptr));
 195                         break;
 196                     case 0x14: /* System Name - not documented */
 197                         printf("'%.*s'", len, tptr);
 198                         break;
 199                     case 0x16: /* System Object ID - not documented */
 200                         if (cdp_print_addr(tptr, len) < 0)
 201                                 goto trunc;
 202                         break;
 203                     case 0x17: /* Physical Location - not documented */
 204                         printf("0x%02x/%.*s", *(tptr), len - 1, tptr + 1 );
 205                         break;
 206                     default:
 207                         print_unknown_data(tptr,"\n\t  ",len);
 208                         break;
 209                     }
 210                 }
 211                 /* avoid infinite loop */
 212                 if (len == 0)
 213                         break;
 214                 tptr = tptr+len;
 215         }
 216         return;
 217 trunc:
 218         printf("[|cdp]");
 219 }
 220
 221 /*
 222  * Protocol type values.
 223  *
 224  * PT_NLPID means that the protocol type field contains an OSI NLPID.
 225  *
 226  * PT_IEEE_802_2 means that the protocol type field contains an IEEE 802.2
 227  * LLC header that specifies that the payload is for that protocol.
 228  */
 229 #define PT_NLPID                1       /* OSI NLPID */
 230 #define PT_IEEE_802_2           2       /* IEEE 802.2 LLC header */
 231
 232 static int
 233 cdp_print_addr(const u_char * p, int l)
 234 {
 235         int pt, pl, al, num;
 236         const u_char *endp = p + l;
 237 #ifdef INET6
 238         static u_char prot_ipv6[] = {
 239                 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00, 0x86, 0xdd
 240         };
 241 #endif
 242
 243         num = EXTRACT_32BITS(p);
 244         p += 4;
 245
 246         while (p < endp && num >= 0) {
 247                 if (p + 2 > endp)
 248                         goto trunc;
 249                 pt = p[0];              /* type of "protocol" field */
 250                 pl = p[1];              /* length of "protocol" field */
 251                 p += 2;
 252
 253                 if (p + pl + 2 > endp)
 254                         goto trunc;
 255                 al = EXTRACT_16BITS(&p[pl]);    /* address length */
 256
 257                 if (pt == PT_NLPID && pl == 1 && *p == 0xcc && al == 4) {
 258                         /*
 259                          * IPv4: protocol type = NLPID, protocol length = 1
 260                          * (1-byte NLPID), protocol = 0xcc (NLPID for IPv4),
 261                          * address length = 4
 262                          */
 263                         p += 3;
 264
 265                         if (p + 4 > endp)
 266                                 goto trunc;
 267                         printf("IPv4 (%u) %s",
 268                                num,
 269                                ipaddr_string(p));
 270                         p += 4;
 271                 }
 272 #ifdef INET6
 273                 else if (pt == PT_IEEE_802_2 && pl == 8 &&
 274                     memcmp(p, prot_ipv6, 8) == 0 && al == 16) {
 275                         /*
 276                          * IPv6: protocol type = IEEE 802.2 header,
 277                          * protocol length = 8 (size of LLC+SNAP header),
 278                          * protocol = LLC+SNAP header with the IPv6
 279                          * Ethertype, address length = 16
 280                          */
 281                         p += 10;
 282                         if (p + al > endp)
 283                                 goto trunc;
 284
 285                         printf("IPv6 (%u) %s",
 286                                num,
 287                                ip6addr_string(p));
 288                         p += al;
 289                 }
 290 #endif
 291                 else {
 292                         /*
 293                          * Generic case: just print raw data
 294                          */
 295                         if (p + pl > endp)
 296                                 goto trunc;
 297                         printf("pt=0x%02x, pl=%d, pb=", *(p - 2), pl);
 298                         while (pl-- > 0)
 299                                 printf(" %02x", *p++);
 300                         if (p + 2 > endp)
 301                                 goto trunc;
 302                         al = (*p << 8) + *(p + 1);
 303                         printf(", al=%d, a=", al);
 304                         p += 2;
 305                         if (p + al > endp)
 306                                 goto trunc;
 307                         while (al-- > 0)
 308                                 printf(" %02x", *p++);
 309                 }
 310                 num--;
 311                 if (num)
 312                         printf(" ");
 313         }
 314
 315         return 0;
 316
 317 trunc:
 318         return -1;
 319 }
 320
 321
 322 static int
 323 cdp_print_prefixes(const u_char * p, int l)
 324 {
 325         if (l % 5)
 326                 goto trunc;
 327
 328         printf(" IPv4 Prefixes (%d):", l / 5);
 329
 330         while (l > 0) {
 331                 printf(" %u.%u.%u.%u/%u", p[0], p[1], p[2], p[3], p[4]);
 332                 l -= 5;
 333                 p += 5;
 334         }
 335
 336         return 0;
 337
 338 trunc:
 339         return -1;
 340 }
 341
 342 /* read in a <n>-byte number, MSB first
 343  * (of course this can handle max sizeof(long))
 344  */
 345 static unsigned long cdp_get_number(const u_char * p, int l)
 346 {
 347     unsigned long res=0;
 348     while( l>0 )
 349     {
 350         res = (res<<8) + *p;
 351         p++; l--;
 352     }
 353     return res;
 354 }