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 (at) 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 } 406
