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 #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 45 static const struct tok cdp_tlv_values[] = { 46 { 0x01, "Device-ID"}, 47 { 0x02, "Address"}, 48 { 0x03, "Port-ID"}, 49 { 0x04, "Capability"}, 50 { 0x05, "Version String"}, 51 { 0x06, "Platform"}, 52 { 0x07, "Prefixes"}, 53 { 0x08, "Protocol-Hello option"}, 54 { 0x09, "VTP Management Domain"}, 55 { 0x0a, "Native VLAN ID"}, 56 { 0x0b, "Duplex"}, 57 { 0x0e, "ATA-186 VoIP VLAN request"}, 58 { 0x0f, "ATA-186 VoIP VLAN assignment"}, 59 { 0x10, "power consumption"}, 60 { 0x11, "MTU"}, 61 { 0x12, "AVVID trust bitmap"}, 62 { 0x13, "AVVID untrusted ports CoS"}, 63 { 0x14, "System Name"}, 64 { 0x15, "System Object ID (not decoded)"}, 65 { 0x16, "Management Addresses"}, 66 { 0x17, "Physical Location"}, 67 { 0, NULL} 68 }; 69 70 static const struct tok cdp_capability_values[] = { 71 { 0x01, "Router" }, 72 { 0x02, "Transparent Bridge" }, 73 { 0x04, "Source Route Bridge" }, 74 { 0x08, "L2 Switch" }, 75 { 0x10, "L3 capable" }, 76 { 0x20, "IGMP snooping" }, 77 { 0x40, "L1 capable" }, 78 { 0, NULL } 79 }; 80 81 static int cdp_print_addr(netdissect_options *, const u_char *, int); 82 static int cdp_print_prefixes(netdissect_options *, const u_char *, int); 83 static unsigned long cdp_get_number(const u_char *, int); 84 85 void 86 cdp_print(netdissect_options *ndo, 87 const u_char *pptr, u_int length, u_int caplen) 88 { 89 int type, len, i, j; 90 const u_char *tptr; 91 92 if (caplen < CDP_HEADER_LEN) { 93 ND_PRINT((ndo, "%s", tstr)); 94 return; 95 } 96 97 tptr = pptr; /* temporary pointer */ 98 99 ND_TCHECK2(*tptr, CDP_HEADER_LEN); 100 ND_PRINT((ndo, "CDPv%u, ttl: %us", *tptr, *(tptr + 1))); 101 if (ndo->ndo_vflag) 102 ND_PRINT((ndo, ", checksum: %u (unverified), length %u", EXTRACT_16BITS(tptr), length)); 103 tptr += CDP_HEADER_LEN; 104 105 while (tptr < (pptr+length)) { 106 ND_TCHECK2(*tptr, 4); /* read out Type and Length */ 107 type = EXTRACT_16BITS(tptr); 108 len = EXTRACT_16BITS(tptr+2); /* object length includes the 4 bytes header length */ 109 tptr += 4; 110 len -= 4; 111 112 ND_TCHECK2(*tptr, len); 113 114 if (ndo->ndo_vflag || type == 1) { /* in non-verbose mode just print Device-ID */ 115 116 if (ndo->ndo_vflag) 117 ND_PRINT((ndo, "\n\t%s (0x%02x), length: %u byte%s: ", 118 tok2str(cdp_tlv_values,"unknown field type", type), 119 type, 120 len, 121 PLURAL_SUFFIX(len))); /* plural */ 122 123 switch (type) { 124 125 case 0x01: /* Device-ID */ 126 if (!ndo->ndo_vflag) 127 ND_PRINT((ndo, ", Device-ID ")); 128 ND_PRINT((ndo, "'")); 129 fn_printn(ndo, tptr, len, NULL); 130 ND_PRINT((ndo, "'")); 131 break; 132 case 0x02: /* Address */ 133 if (cdp_print_addr(ndo, tptr, len) < 0) 134 goto trunc; 135 break; 136 case 0x03: /* Port-ID */ 137 ND_PRINT((ndo, "'")); 138 fn_printn(ndo, tptr, len, NULL); 139 ND_PRINT((ndo, "'")); 140 break; 141 case 0x04: /* Capabilities */ 142 ND_PRINT((ndo, "(0x%08x): %s", 143 EXTRACT_32BITS(tptr), 144 bittok2str(cdp_capability_values, "none", EXTRACT_32BITS(tptr)))); 145 break; 146 case 0x05: /* Version */ 147 ND_PRINT((ndo, "\n\t ")); 148 for (i=0;i<len;i++) { 149 j = *(tptr+i); 150 ND_PRINT((ndo, "%c", j)); 151 if (j == 0x0a) /* lets rework the version string to get a nice identation */ 152 ND_PRINT((ndo, "\t ")); 153 } 154 break; 155 case 0x06: /* Platform */ 156 ND_PRINT((ndo, "'")); 157 fn_printn(ndo, tptr, len, NULL); 158 ND_PRINT((ndo, "'")); 159 break; 160 case 0x07: /* Prefixes */ 161 if (cdp_print_prefixes(ndo, 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 ND_PRINT((ndo, "'")); 168 fn_printn(ndo, tptr, len, NULL); 169 ND_PRINT((ndo, "'")); 170 break; 171 case 0x0a: /* Native VLAN ID - not documented */ 172 ND_PRINT((ndo, "%d", EXTRACT_16BITS(tptr))); 173 break; 174 case 0x0b: /* Duplex - not documented */ 175 ND_PRINT((ndo, "%s", *(tptr) ? "full": "half")); 176 break; 177 178 /* http://www.cisco.com/univercd/cc/td/doc/product/voice/ata/atarn/186rn21m.htm 179 * plus more details from other sources 180 */ 181 case 0x0e: /* ATA-186 VoIP VLAN request - incomplete doc. */ 182 ND_PRINT((ndo, "app %d, vlan %d", *(tptr), EXTRACT_16BITS(tptr + 1))); 183 break; 184 case 0x10: /* ATA-186 VoIP VLAN assignment - incomplete doc. */ 185 ND_PRINT((ndo, "%1.2fW", cdp_get_number(tptr, len) / 1000.0)); 186 break; 187 case 0x11: /* MTU - not documented */ 188 ND_PRINT((ndo, "%u bytes", EXTRACT_32BITS(tptr))); 189 break; 190 case 0x12: /* AVVID trust bitmap - not documented */ 191 ND_PRINT((ndo, "0x%02x", *(tptr))); 192 break; 193 case 0x13: /* AVVID untrusted port CoS - not documented */ 194 ND_PRINT((ndo, "0x%02x", *(tptr))); 195 break; 196 case 0x14: /* System Name - not documented */ 197 ND_PRINT((ndo, "'")); 198 fn_printn(ndo, tptr, len, NULL); 199 ND_PRINT((ndo, "'")); 200 break; 201 case 0x16: /* System Object ID - not documented */ 202 if (cdp_print_addr(ndo, tptr, len) < 0) 203 goto trunc; 204 break; 205 case 0x17: /* Physical Location - not documented */ 206 ND_PRINT((ndo, "0x%02x", *(tptr))); 207 if (len > 1) { 208 ND_PRINT((ndo, "/")); 209 fn_printn(ndo, tptr + 1, len - 1, NULL); 210 } 211 break; 212 default: 213 print_unknown_data(ndo, tptr, "\n\t ", len); 214 break; 215 } 216 } 217 /* avoid infinite loop */ 218 if (len == 0) 219 break; 220 tptr = tptr+len; 221 } 222 if (ndo->ndo_vflag < 1) 223 ND_PRINT((ndo, ", length %u", caplen)); 224 225 return; 226 trunc: 227 ND_PRINT((ndo, "%s", tstr)); 228 } 229 230 /* 231 * Protocol type values. 232 * 233 * PT_NLPID means that the protocol type field contains an OSI NLPID. 234 * 235 * PT_IEEE_802_2 means that the protocol type field contains an IEEE 802.2 236 * LLC header that specifies that the payload is for that protocol. 237 */ 238 #define PT_NLPID 1 /* OSI NLPID */ 239 #define PT_IEEE_802_2 2 /* IEEE 802.2 LLC header */ 240 241 static int 242 cdp_print_addr(netdissect_options *ndo, 243 const u_char * p, int l) 244 { 245 int pt, pl, al, num; 246 const u_char *endp = p + l; 247 #ifdef INET6 248 static const u_char prot_ipv6[] = { 249 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00, 0x86, 0xdd 250 }; 251 #endif 252 253 ND_TCHECK2(*p, 2); 254 num = EXTRACT_32BITS(p); 255 p += 4; 256 257 while (p < endp && num >= 0) { 258 ND_TCHECK2(*p, 2); 259 if (p + 2 > endp) 260 goto trunc; 261 pt = p[0]; /* type of "protocol" field */ 262 pl = p[1]; /* length of "protocol" field */ 263 p += 2; 264 265 ND_TCHECK2(p[pl], 2); 266 if (p + pl + 2 > endp) 267 goto trunc; 268 al = EXTRACT_16BITS(&p[pl]); /* address length */ 269 270 if (pt == PT_NLPID && pl == 1 && *p == NLPID_IP && al == 4) { 271 /* 272 * IPv4: protocol type = NLPID, protocol length = 1 273 * (1-byte NLPID), protocol = 0xcc (NLPID for IPv4), 274 * address length = 4 275 */ 276 p += 3; 277 278 ND_TCHECK2(*p, 4); 279 if (p + 4 > endp) 280 goto trunc; 281 ND_PRINT((ndo, "IPv4 (%u) %s", num, ipaddr_string(ndo, p))); 282 p += 4; 283 } 284 #ifdef INET6 285 else if (pt == PT_IEEE_802_2 && pl == 8 && 286 memcmp(p, prot_ipv6, 8) == 0 && al == 16) { 287 /* 288 * IPv6: protocol type = IEEE 802.2 header, 289 * protocol length = 8 (size of LLC+SNAP header), 290 * protocol = LLC+SNAP header with the IPv6 291 * Ethertype, address length = 16 292 */ 293 p += 10; 294 ND_TCHECK2(*p, al); 295 if (p + al > endp) 296 goto trunc; 297 298 ND_PRINT((ndo, "IPv6 (%u) %s", num, ip6addr_string(ndo, p))); 299 p += al; 300 } 301 #endif 302 else { 303 /* 304 * Generic case: just print raw data 305 */ 306 ND_TCHECK2(*p, pl); 307 if (p + pl > endp) 308 goto trunc; 309 ND_PRINT((ndo, "pt=0x%02x, pl=%d, pb=", *(p - 2), pl)); 310 while (pl-- > 0) 311 ND_PRINT((ndo, " %02x", *p++)); 312 ND_TCHECK2(*p, 2); 313 if (p + 2 > endp) 314 goto trunc; 315 al = (*p << 8) + *(p + 1); 316 ND_PRINT((ndo, ", al=%d, a=", al)); 317 p += 2; 318 ND_TCHECK2(*p, al); 319 if (p + al > endp) 320 goto trunc; 321 while (al-- > 0) 322 ND_PRINT((ndo, " %02x", *p++)); 323 } 324 num--; 325 if (num) 326 ND_PRINT((ndo, " ")); 327 } 328 329 return 0; 330 331 trunc: 332 return -1; 333 } 334 335 336 static int 337 cdp_print_prefixes(netdissect_options *ndo, 338 const u_char * p, int l) 339 { 340 if (l % 5) 341 goto trunc; 342 343 ND_PRINT((ndo, " IPv4 Prefixes (%d):", l / 5)); 344 345 while (l > 0) { 346 ND_PRINT((ndo, " %u.%u.%u.%u/%u", p[0], p[1], p[2], p[3], p[4])); 347 l -= 5; 348 p += 5; 349 } 350 351 return 0; 352 353 trunc: 354 return -1; 355 } 356 357 /* read in a <n>-byte number, MSB first 358 * (of course this can handle max sizeof(long)) 359 */ 360 static unsigned long cdp_get_number(const u_char * p, int l) 361 { 362 unsigned long res=0; 363 while( l>0 ) 364 { 365 res = (res<<8) + *p; 366 p++; l--; 367 } 368 return res; 369 } 370