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 #include <sys/cdefs.h> 28 #ifndef lint 29 __RCSID("$NetBSD: print-cdp.c,v 1.6 2015/03/31 21:59:35 christos Exp $"); 30 #endif 31 32 #define NETDISSECT_REWORKED 33 #ifdef HAVE_CONFIG_H 34 #include "config.h" 35 #endif 36 37 #include <tcpdump-stdinc.h> 38 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 #define CDP_HEADER_VERSION_OFFSET 0 50 #define CDP_HEADER_TTL_OFFSET 1 51 #define CDP_HEADER_CHECKSUM_OFFSET 2 52 53 #define CDP_TLV_HEADER_LEN 4 54 #define CDP_TLV_TYPE_OFFSET 0 55 #define CDP_TLV_LEN_OFFSET 2 56 57 static const struct tok cdp_tlv_values[] = { 58 { 0x01, "Device-ID"}, 59 { 0x02, "Address"}, 60 { 0x03, "Port-ID"}, 61 { 0x04, "Capability"}, 62 { 0x05, "Version String"}, 63 { 0x06, "Platform"}, 64 { 0x07, "Prefixes"}, 65 { 0x08, "Protocol-Hello option"}, 66 { 0x09, "VTP Management Domain"}, 67 { 0x0a, "Native VLAN ID"}, 68 { 0x0b, "Duplex"}, 69 { 0x0e, "ATA-186 VoIP VLAN request"}, 70 { 0x0f, "ATA-186 VoIP VLAN assignment"}, 71 { 0x10, "power consumption"}, 72 { 0x11, "MTU"}, 73 { 0x12, "AVVID trust bitmap"}, 74 { 0x13, "AVVID untrusted ports CoS"}, 75 { 0x14, "System Name"}, 76 { 0x15, "System Object ID (not decoded)"}, 77 { 0x16, "Management Addresses"}, 78 { 0x17, "Physical Location"}, 79 { 0, NULL} 80 }; 81 82 static const struct tok cdp_capability_values[] = { 83 { 0x01, "Router" }, 84 { 0x02, "Transparent Bridge" }, 85 { 0x04, "Source Route Bridge" }, 86 { 0x08, "L2 Switch" }, 87 { 0x10, "L3 capable" }, 88 { 0x20, "IGMP snooping" }, 89 { 0x40, "L1 capable" }, 90 { 0, NULL } 91 }; 92 93 static int cdp_print_addr(netdissect_options *, const u_char *, int); 94 static int cdp_print_prefixes(netdissect_options *, const u_char *, int); 95 static unsigned long cdp_get_number(const u_char *, int); 96 97 void 98 cdp_print(netdissect_options *ndo, 99 const u_char *pptr, u_int length, u_int caplen) 100 { 101 int type, len, i, j; 102 const u_char *tptr; 103 104 if (caplen < CDP_HEADER_LEN) { 105 ND_PRINT((ndo, "%s", tstr)); 106 return; 107 } 108 109 tptr = pptr; /* temporary pointer */ 110 111 ND_TCHECK2(*tptr, CDP_HEADER_LEN); 112 ND_PRINT((ndo, "CDPv%u, ttl: %us", *(tptr + CDP_HEADER_VERSION_OFFSET), 113 *(tptr + CDP_HEADER_TTL_OFFSET))); 114 if (ndo->ndo_vflag) 115 ND_PRINT((ndo, ", checksum: 0x%04x (unverified), length %u", EXTRACT_16BITS(tptr+CDP_HEADER_CHECKSUM_OFFSET), length)); 116 tptr += CDP_HEADER_LEN; 117 118 while (tptr < (pptr+length)) { 119 ND_TCHECK2(*tptr, CDP_TLV_HEADER_LEN); /* read out Type and Length */ 120 type = EXTRACT_16BITS(tptr+CDP_TLV_TYPE_OFFSET); 121 len = EXTRACT_16BITS(tptr+CDP_TLV_LEN_OFFSET); /* object length includes the 4 bytes header length */ 122 if (len < CDP_TLV_HEADER_LEN) { 123 if (ndo->ndo_vflag) 124 ND_PRINT((ndo, "\n\t%s (0x%02x), TLV length: %u byte%s (too short)", 125 tok2str(cdp_tlv_values,"unknown field type", type), 126 type, 127 len, 128 PLURAL_SUFFIX(len))); /* plural */ 129 else 130 ND_PRINT((ndo, ", %s TLV length %u too short", 131 tok2str(cdp_tlv_values,"unknown field type", type), 132 len)); 133 break; 134 } 135 tptr += CDP_TLV_HEADER_LEN; 136 len -= CDP_TLV_HEADER_LEN; 137 138 ND_TCHECK2(*tptr, len); 139 140 if (ndo->ndo_vflag || type == 1) { /* in non-verbose mode just print Device-ID */ 141 142 if (ndo->ndo_vflag) 143 ND_PRINT((ndo, "\n\t%s (0x%02x), value length: %u byte%s: ", 144 tok2str(cdp_tlv_values,"unknown field type", type), 145 type, 146 len, 147 PLURAL_SUFFIX(len))); /* plural */ 148 149 switch (type) { 150 151 case 0x01: /* Device-ID */ 152 if (!ndo->ndo_vflag) 153 ND_PRINT((ndo, ", Device-ID ")); 154 ND_PRINT((ndo, "'")); 155 (void)fn_printn(ndo, tptr, len, NULL); 156 ND_PRINT((ndo, "'")); 157 break; 158 case 0x02: /* Address */ 159 if (cdp_print_addr(ndo, tptr, len) < 0) 160 goto trunc; 161 break; 162 case 0x03: /* Port-ID */ 163 ND_PRINT((ndo, "'")); 164 (void)fn_printn(ndo, tptr, len, NULL); 165 ND_PRINT((ndo, "'")); 166 break; 167 case 0x04: /* Capabilities */ 168 if (len < 4) 169 goto trunc; 170 ND_PRINT((ndo, "(0x%08x): %s", 171 EXTRACT_32BITS(tptr), 172 bittok2str(cdp_capability_values, "none", EXTRACT_32BITS(tptr)))); 173 break; 174 case 0x05: /* Version */ 175 ND_PRINT((ndo, "\n\t ")); 176 for (i=0;i<len;i++) { 177 j = *(tptr+i); 178 ND_PRINT((ndo, "%c", j)); 179 if (j == 0x0a) /* lets rework the version string to get a nice indentation */ 180 ND_PRINT((ndo, "\t ")); 181 } 182 break; 183 case 0x06: /* Platform */ 184 ND_PRINT((ndo, "'")); 185 (void)fn_printn(ndo, tptr, len, NULL); 186 ND_PRINT((ndo, "'")); 187 break; 188 case 0x07: /* Prefixes */ 189 if (cdp_print_prefixes(ndo, tptr, len) < 0) 190 goto trunc; 191 break; 192 case 0x08: /* Protocol Hello Option - not documented */ 193 break; 194 case 0x09: /* VTP Mgmt Domain - CDPv2 */ 195 ND_PRINT((ndo, "'")); 196 (void)fn_printn(ndo, tptr, len, NULL); 197 ND_PRINT((ndo, "'")); 198 break; 199 case 0x0a: /* Native VLAN ID - CDPv2 */ 200 if (len < 2) 201 goto trunc; 202 ND_PRINT((ndo, "%d", EXTRACT_16BITS(tptr))); 203 break; 204 case 0x0b: /* Duplex - CDPv2 */ 205 if (len < 1) 206 goto trunc; 207 ND_PRINT((ndo, "%s", *(tptr) ? "full": "half")); 208 break; 209 210 /* http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cata/186/2_12_m/english/release/notes/186rn21m.html 211 * plus more details from other sources 212 */ 213 case 0x0e: /* ATA-186 VoIP VLAN request - incomplete doc. */ 214 if (len < 3) 215 goto trunc; 216 ND_PRINT((ndo, "app %d, vlan %d", *(tptr), EXTRACT_16BITS(tptr + 1))); 217 break; 218 case 0x10: /* ATA-186 VoIP VLAN assignment - incomplete doc. */ 219 ND_PRINT((ndo, "%1.2fW", cdp_get_number(tptr, len) / 1000.0)); 220 break; 221 case 0x11: /* MTU - not documented */ 222 if (len < 4) 223 goto trunc; 224 ND_PRINT((ndo, "%u bytes", EXTRACT_32BITS(tptr))); 225 break; 226 case 0x12: /* AVVID trust bitmap - not documented */ 227 if (len < 1) 228 goto trunc; 229 ND_PRINT((ndo, "0x%02x", *(tptr))); 230 break; 231 case 0x13: /* AVVID untrusted port CoS - not documented */ 232 if (len < 1) 233 goto trunc; 234 ND_PRINT((ndo, "0x%02x", *(tptr))); 235 break; 236 case 0x14: /* System Name - not documented */ 237 ND_PRINT((ndo, "'")); 238 (void)fn_printn(ndo, tptr, len, NULL); 239 ND_PRINT((ndo, "'")); 240 break; 241 case 0x16: /* System Object ID - not documented */ 242 if (cdp_print_addr(ndo, tptr, len) < 0) 243 goto trunc; 244 break; 245 case 0x17: /* Physical Location - not documented */ 246 if (len < 1) 247 goto trunc; 248 ND_PRINT((ndo, "0x%02x", *(tptr))); 249 if (len > 1) { 250 ND_PRINT((ndo, "/")); 251 (void)fn_printn(ndo, tptr + 1, len - 1, NULL); 252 } 253 break; 254 default: 255 print_unknown_data(ndo, tptr, "\n\t ", len); 256 break; 257 } 258 } 259 tptr = tptr+len; 260 } 261 if (ndo->ndo_vflag < 1) 262 ND_PRINT((ndo, ", length %u", caplen)); 263 264 return; 265 trunc: 266 ND_PRINT((ndo, "%s", tstr)); 267 } 268 269 /* 270 * Protocol type values. 271 * 272 * PT_NLPID means that the protocol type field contains an OSI NLPID. 273 * 274 * PT_IEEE_802_2 means that the protocol type field contains an IEEE 802.2 275 * LLC header that specifies that the payload is for that protocol. 276 */ 277 #define PT_NLPID 1 /* OSI NLPID */ 278 #define PT_IEEE_802_2 2 /* IEEE 802.2 LLC header */ 279 280 static int 281 cdp_print_addr(netdissect_options *ndo, 282 const u_char * p, int l) 283 { 284 int pt, pl, al, num; 285 const u_char *endp = p + l; 286 #ifdef INET6 287 static const u_char prot_ipv6[] = { 288 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00, 0x86, 0xdd 289 }; 290 #endif 291 292 ND_TCHECK2(*p, 4); 293 if (p + 4 > endp) 294 goto trunc; 295 num = EXTRACT_32BITS(p); 296 p += 4; 297 298 while (p < endp && num >= 0) { 299 ND_TCHECK2(*p, 2); 300 if (p + 2 > endp) 301 goto trunc; 302 pt = p[0]; /* type of "protocol" field */ 303 pl = p[1]; /* length of "protocol" field */ 304 p += 2; 305 306 ND_TCHECK2(p[pl], 2); 307 if (p + pl + 2 > endp) 308 goto trunc; 309 al = EXTRACT_16BITS(&p[pl]); /* address length */ 310 311 if (pt == PT_NLPID && pl == 1 && *p == NLPID_IP && al == 4) { 312 /* 313 * IPv4: protocol type = NLPID, protocol length = 1 314 * (1-byte NLPID), protocol = 0xcc (NLPID for IPv4), 315 * address length = 4 316 */ 317 p += 3; 318 319 ND_TCHECK2(*p, 4); 320 if (p + 4 > endp) 321 goto trunc; 322 ND_PRINT((ndo, "IPv4 (%u) %s", num, ipaddr_string(ndo, p))); 323 p += 4; 324 } 325 #ifdef INET6 326 else if (pt == PT_IEEE_802_2 && pl == 8 && 327 memcmp(p, prot_ipv6, 8) == 0 && al == 16) { 328 /* 329 * IPv6: protocol type = IEEE 802.2 header, 330 * protocol length = 8 (size of LLC+SNAP header), 331 * protocol = LLC+SNAP header with the IPv6 332 * Ethertype, address length = 16 333 */ 334 p += 10; 335 ND_TCHECK2(*p, al); 336 if (p + al > endp) 337 goto trunc; 338 339 ND_PRINT((ndo, "IPv6 (%u) %s", num, ip6addr_string(ndo, p))); 340 p += al; 341 } 342 #endif 343 else { 344 /* 345 * Generic case: just print raw data 346 */ 347 ND_TCHECK2(*p, pl); 348 if (p + pl > endp) 349 goto trunc; 350 ND_PRINT((ndo, "pt=0x%02x, pl=%d, pb=", *(p - 2), pl)); 351 while (pl-- > 0) 352 ND_PRINT((ndo, " %02x", *p++)); 353 ND_TCHECK2(*p, 2); 354 if (p + 2 > endp) 355 goto trunc; 356 al = (*p << 8) + *(p + 1); 357 ND_PRINT((ndo, ", al=%d, a=", al)); 358 p += 2; 359 ND_TCHECK2(*p, al); 360 if (p + al > endp) 361 goto trunc; 362 while (al-- > 0) 363 ND_PRINT((ndo, " %02x", *p++)); 364 } 365 num--; 366 if (num) 367 ND_PRINT((ndo, " ")); 368 } 369 370 return 0; 371 372 trunc: 373 return -1; 374 } 375 376 377 static int 378 cdp_print_prefixes(netdissect_options *ndo, 379 const u_char * p, int l) 380 { 381 if (l % 5) 382 goto trunc; 383 384 ND_PRINT((ndo, " IPv4 Prefixes (%d):", l / 5)); 385 386 while (l > 0) { 387 ND_PRINT((ndo, " %u.%u.%u.%u/%u", p[0], p[1], p[2], p[3], p[4])); 388 l -= 5; 389 p += 5; 390 } 391 392 return 0; 393 394 trunc: 395 return -1; 396 } 397 398 /* read in a <n>-byte number, MSB first 399 * (of course this can handle max sizeof(long)) 400 */ 401 static unsigned long cdp_get_number(const u_char * p, int l) 402 { 403 unsigned long res=0; 404 while( l>0 ) 405 { 406 res = (res<<8) + *p; 407 p++; l--; 408 } 409 return res; 410 } 411