The Tcpdump Group git mirrors - tcpdump/blob - print-lisp.c

   1 /*
   2  * Copyright (c) 2015 Ritesh Ranjan (r.ranjan789@gmail.com)
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. The name of the author may not be used to endorse or promote products
  14  *    derived from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  18  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  19  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
  20  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  21  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  22  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  24  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  25  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  26  * POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 /* \summary: - Locator/Identifier Separation Protocol (LISP) printer */
  30
  31 /*
  32  * specification: RFC 6830
  33  *
  34  *
  35  * The Map-Register message format is:
  36  *
  37  *       0                   1                   2                   3
  38  *       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  39  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  40  *      |Type=3 |P|S|I|R|      Reserved               |M| Record Count  |
  41  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  42  *      |                         Nonce . . .                           |
  43  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  44  *      |                         . . . Nonce                           |
  45  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  46  *      |            Key ID             |  Authentication Data Length   |
  47  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  48  *      ~                     Authentication Data                       ~
  49  *  +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  50  *  |   |                          Record TTL                           |
  51  *  |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  52  *  R   | Locator Count | EID mask-len  | ACT |A|      Reserved         |
  53  *  e   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  54  *  c   | Rsvd  |  Map-Version Number   |        EID-Prefix-AFI         |
  55  *  o   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  56  *  r   |                          EID-Prefix                           |
  57  *  d   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  58  *  |  /|    Priority   |    Weight     |  M Priority   |   M Weight    |
  59  *  | L +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  60  *  | o |        Unused Flags     |L|p|R|           Loc-AFI             |
  61  *  | c +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  62  *  |  \|                             Locator                           |
  63  *  +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  64  *
  65  *
  66  * The Map-Notify message format is:
  67  *
  68  *       0                   1                   2                   3
  69  *       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  70  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  71  *      |Type=4 |I|R|          Reserved                 | Record Count  |
  72  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  73  *      |                         Nonce . . .                           |
  74  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  75  *      |                         . . . Nonce                           |
  76  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  77  *      |            Key ID             |  Authentication Data Length   |
  78  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  79  *      ~                     Authentication Data                       ~
  80  *  +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  81  *  |   |                          Record TTL                           |
  82  *  |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  83  *  R   | Locator Count | EID mask-len  | ACT |A|      Reserved         |
  84  *  e   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  85  *  c   | Rsvd  |  Map-Version Number   |         EID-Prefix-AFI        |
  86  *  o   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  87  *  r   |                          EID-Prefix                           |
  88  *  d   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  89  *  |  /|    Priority   |    Weight     |  M Priority   |   M Weight    |
  90  *  | L +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  91  *  | o |        Unused Flags     |L|p|R|           Loc-AFI             |
  92  *  | c +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  93  *  |  \|                             Locator                           |
  94  *  +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  95  */
  96
  97 #include <config.h>
  98
  99 #include "netdissect-stdinc.h"
 100 #include "netdissect.h"
 101
 102 #include "ip.h"
 103 #include "ip6.h"
 104
 105 #include "extract.h"
 106 #include "addrtoname.h"
 107
 108
 109 #define IPv4_AFI                        1
 110 #define IPv6_AFI                        2
 111 #define TYPE_INDEX                      4
 112 #define LISP_MAP_NOTIFY_IBIT_MASK       8
 113 #define LISP_MAP_REGISTER_IBIT_MASK     2
 114
 115 enum {
 116         LISP_MAP_REQUEST = 1,
 117         LISP_MAP_REPLY,
 118         LISP_MAP_REGISTER,
 119         LISP_MAP_NOTIFY,
 120         LISP_ENCAPSULATED_CONTROL_MESSAGE = 8
 121 };
 122
 123 enum {
 124         LISP_AUTH_NONE,
 125         LISP_AUTH_SHA1,
 126         LISP_AUTH_SHA256
 127 };
 128
 129 static const struct tok lisp_type [] = {
 130         { 0, "LISP-Reserved"                     },
 131         { 1, "LISP-Map-Request"                  },
 132         { 2, "LISP-Map-Reply"                    },
 133         { 3, "LISP-Map-Register"                 },
 134         { 4, "LISP-Map-Notify"                   },
 135         { 8, "LISP-Encapsulated-Control-Message" },
 136         { 0, NULL }
 137 };
 138
 139 /*
 140  * P-Bit : Request for Proxy Map-Reply from the MS/MR
 141  * S-Bit : Security Enhancement. ETR is LISP-SEC enabled. draft-ietf-lisp-sec
 142  * I-Bit : 128 bit xTR-ID and 64 bit Site-ID present.
 143  *         xTR-ID and Site-ID help in differentiation of xTRs in multi xTR
 144  *         and multi Site deployment scenarios.
 145  * R-Bit : Built for a Reencapsulating-Tunnel-Router. Used in Traffic
 146  *         Engineering and Service Chaining
 147  */
 148 static const struct tok map_register_hdr_flag[] = {
 149         { 0x08000000, "P-Proxy-Map-Reply"  },
 150         { 0x04000000, "S-LISP-SEC-Capable" },
 151         { 0x02000000, "I-xTR-ID-Present"   },
 152         { 0x01000000, "R-Build-For-RTR"    },
 153         { 0x00000100, "M-Want-Map-Notify"  },
 154         { 0, NULL }
 155 };
 156
 157 static const struct tok map_notify_hdr_flag[] = {
 158         { 0x08000000, "I-xTR-ID-Present"   },
 159         { 0x04000000, "R-Build-For-RTR"    },
 160         { 0, NULL }
 161 };
 162
 163 static const struct tok auth_type[] = {
 164         { LISP_AUTH_NONE,   "None"   },
 165         { LISP_AUTH_SHA1,   "SHA1"   },
 166         { LISP_AUTH_SHA256, "SHA256" },
 167         { 0, NULL}
 168 };
 169
 170 static const struct tok lisp_eid_action[] = {
 171         { 0, "No-Action"        },
 172         { 1, "Natively-Forward" },
 173         { 2, "Send-Map-Request" },
 174         { 3, "Drop"             },
 175         { 0, NULL}
 176 };
 177
 178 static const struct tok lisp_loc_flag[] = {
 179         { 0x0004, "Local-Locator" },
 180         { 0x0002, "RLoc-Probed"   },
 181         { 0x0001, "Reachable"     },
 182         { 0, NULL }
 183 };
 184
 185 typedef struct map_register_hdr {
 186         nd_uint8_t type_and_flag;
 187         nd_uint8_t reserved;
 188         nd_uint8_t reserved_and_flag2;
 189         nd_uint8_t record_count;
 190         nd_uint64_t nonce;
 191         nd_uint16_t key_id;
 192         nd_uint16_t auth_data_len;
 193 } lisp_map_register_hdr;
 194
 195 #define MAP_REGISTER_HDR_LEN sizeof(lisp_map_register_hdr)
 196
 197 typedef struct map_register_eid {
 198         nd_uint32_t ttl;
 199         nd_uint8_t locator_count;
 200         nd_uint8_t eid_prefix_mask_length;
 201         nd_uint8_t act_auth_inc_res;
 202         nd_uint8_t reserved;
 203         nd_uint16_t reserved_and_version;
 204         nd_uint16_t eid_prefix_afi;
 205 } lisp_map_register_eid;
 206
 207 #define MAP_REGISTER_EID_LEN sizeof(lisp_map_register_eid)
 208
 209 typedef struct map_register_loc {
 210         nd_uint8_t priority;
 211         nd_uint8_t weight;
 212         nd_uint8_t m_priority;
 213         nd_uint8_t m_weight;
 214         nd_uint16_t unused_and_flag;
 215         nd_uint16_t locator_afi;
 216 } lisp_map_register_loc;
 217
 218 #define MAP_REGISTER_LOC_LEN sizeof(lisp_map_register_loc)
 219
 220 static uint8_t extract_lisp_type(uint8_t);
 221 static uint8_t is_xtr_data_present(uint8_t, uint8_t);
 222 static void lisp_hdr_flag(netdissect_options *, const lisp_map_register_hdr *);
 223 static void action_flag(netdissect_options *, uint8_t);
 224 static void loc_hdr_flag(netdissect_options *, uint16_t);
 225
 226 void
 227 lisp_print(netdissect_options *ndo, const u_char *bp, u_int length)
 228 {
 229         uint8_t type_and_flag;
 230         uint8_t type;
 231         uint8_t mask_len;
 232         uint8_t loc_count;
 233         uint8_t xtr_present;
 234         uint8_t record_count;
 235         uint16_t key_id;
 236         uint16_t eid_afi;
 237         uint16_t loc_afi;
 238         uint16_t map_version;
 239         uint16_t packet_offset;
 240         uint16_t auth_data_len;
 241         uint32_t ttl;
 242         const u_char *packet_iterator;
 243         const u_char *loc_ip_pointer;
 244         const lisp_map_register_hdr *lisp_hdr;
 245         const lisp_map_register_eid *lisp_eid;
 246         const lisp_map_register_loc *lisp_loc;
 247
 248         ndo->ndo_protocol = "lisp";
 249         /* Check if enough bytes for header are available */
 250         ND_TCHECK_LEN(bp, MAP_REGISTER_HDR_LEN);
 251         lisp_hdr = (const lisp_map_register_hdr *) bp;
 252         lisp_hdr_flag(ndo, lisp_hdr);
 253         /* Supporting only MAP NOTIFY and MAP REGISTER LISP packets */
 254         type_and_flag = GET_U_1(lisp_hdr->type_and_flag);
 255         type = extract_lisp_type(type_and_flag);
 256         if ((type != LISP_MAP_REGISTER) && (type != LISP_MAP_NOTIFY))
 257                 return;
 258
 259         /* Find if the packet contains xTR and Site-ID data */
 260         xtr_present = is_xtr_data_present(type, type_and_flag);
 261
 262         /* Extract the number of EID records present */
 263         auth_data_len = GET_BE_U_2(lisp_hdr->auth_data_len);
 264         packet_iterator = (const u_char *)(lisp_hdr);
 265         packet_offset = MAP_REGISTER_HDR_LEN;
 266         record_count = GET_U_1(lisp_hdr->record_count);
 267
 268         if (ndo->ndo_vflag) {
 269                 key_id = GET_BE_U_2(lisp_hdr->key_id);
 270                 ND_PRINT("\n    %u record(s), ", record_count);
 271                 ND_PRINT("Authentication %s,",
 272                         tok2str(auth_type, "unknown-type", key_id));
 273                 hex_print(ndo, "\n    Authentication-Data: ", packet_iterator +
 274                                                 packet_offset, auth_data_len);
 275         } else {
 276                 ND_PRINT(" %u record(s),", record_count);
 277         }
 278         packet_offset += auth_data_len;
 279
 280         if (record_count == 0)
 281                 goto invalid;
 282
 283         /* Print all the EID records */
 284         while ((length > packet_offset) && (record_count != 0)) {
 285                 record_count--;
 286                 ND_TCHECK_LEN(packet_iterator + packet_offset,
 287                               MAP_REGISTER_EID_LEN);
 288                 ND_PRINT("\n");
 289                 lisp_eid = (const lisp_map_register_eid *)
 290                                 ((const u_char *)lisp_hdr + packet_offset);
 291                 packet_offset += MAP_REGISTER_EID_LEN;
 292                 mask_len = GET_U_1(lisp_eid->eid_prefix_mask_length);
 293                 eid_afi = GET_BE_U_2(lisp_eid->eid_prefix_afi);
 294                 loc_count = GET_U_1(lisp_eid->locator_count);
 295
 296                 if (ndo->ndo_vflag) {
 297                         ttl = GET_BE_U_4(lisp_eid->ttl);
 298                         ND_PRINT("      Record TTL %u,", ttl);
 299                         action_flag(ndo, GET_U_1(lisp_eid->act_auth_inc_res));
 300                         map_version = GET_BE_U_2(lisp_eid->reserved_and_version) & 0x0FFF;
 301                         ND_PRINT(" Map Version: %u,", map_version);
 302                 }
 303
 304                 switch (eid_afi) {
 305                 case IPv4_AFI:
 306                         ND_PRINT(" EID %s/%u,",
 307                                 GET_IPADDR_STRING(packet_iterator + packet_offset),
 308                                 mask_len);
 309                         packet_offset += 4;
 310                         break;
 311                 case IPv6_AFI:
 312                         ND_PRINT(" EID %s/%u,",
 313                                 GET_IP6ADDR_STRING(packet_iterator + packet_offset),
 314                                 mask_len);
 315                         packet_offset += 16;
 316                         break;
 317                 default:
 318                         /*
 319                          * No support for LCAF right now.
 320                          */
 321                         return;
 322                         break;
 323                 }
 324
 325                 ND_PRINT(" %u locator(s)", loc_count);
 326
 327                 while (loc_count != 0) {
 328                         loc_count--;
 329                         ND_TCHECK_LEN(packet_iterator + packet_offset,
 330                                       MAP_REGISTER_LOC_LEN);
 331                         lisp_loc = (const lisp_map_register_loc *) (packet_iterator + packet_offset);
 332                         loc_ip_pointer = (const u_char *) (lisp_loc + 1);
 333                         packet_offset += MAP_REGISTER_LOC_LEN;
 334                         loc_afi = GET_BE_U_2(lisp_loc->locator_afi);
 335
 336                         if (ndo->ndo_vflag)
 337                                 ND_PRINT("\n       ");
 338
 339                         switch (loc_afi) {
 340                         case IPv4_AFI:
 341                                 ND_TCHECK_4(packet_iterator + packet_offset);
 342                                 ND_PRINT(" LOC %s", GET_IPADDR_STRING(loc_ip_pointer));
 343                                 packet_offset += 4;
 344                                 break;
 345                         case IPv6_AFI:
 346                                 ND_TCHECK_16(packet_iterator + packet_offset);
 347                                 ND_PRINT(" LOC %s", GET_IP6ADDR_STRING(loc_ip_pointer));
 348                                 packet_offset += 16;
 349                                 break;
 350                         default:
 351                                 break;
 352                         }
 353                         if (ndo->ndo_vflag) {
 354                                 ND_PRINT("\n          Priority/Weight %u/%u,"
 355                                                 " Multicast Priority/Weight %u/%u,",
 356                                                 GET_U_1(lisp_loc->priority),
 357                                                 GET_U_1(lisp_loc->weight),
 358                                                 GET_U_1(lisp_loc->m_priority),
 359                                                 GET_U_1(lisp_loc->m_weight));
 360                                 loc_hdr_flag(ndo,
 361                                              GET_BE_U_2(lisp_loc->unused_and_flag));
 362                         }
 363                 }
 364         }
 365
 366         /*
 367          * Print xTR and Site ID. Handle the fact that the packet could be invalid.
 368          * If the xTR_ID_Present bit is not set, and we still have data to display,
 369          * show it as hex data.
 370          */
 371         if (xtr_present) {
 372                 if (!ND_TTEST_LEN(packet_iterator + packet_offset, 24))
 373                         goto invalid;
 374                 hex_print(ndo, "\n    xTR-ID: ", packet_iterator + packet_offset, 16);
 375                 ND_PRINT("\n    SITE-ID: %" PRIu64,
 376                         GET_BE_U_8(packet_iterator + packet_offset + 16));
 377         } else {
 378                 /* Check if packet isn't over yet */
 379                 if (packet_iterator + packet_offset < ndo->ndo_snapend) {
 380                         hex_print(ndo, "\n    Data: ", packet_iterator + packet_offset,
 381                                 ND_BYTES_AVAILABLE_AFTER(packet_iterator + packet_offset));
 382                 }
 383         }
 384         return;
 385 trunc:
 386         nd_print_trunc(ndo);
 387         return;
 388 invalid:
 389         nd_print_invalid(ndo);
 390 }
 391
 392 static uint8_t
 393 extract_lisp_type(uint8_t lisp_hdr_flags)
 394 {
 395         return (lisp_hdr_flags) >> TYPE_INDEX;
 396 }
 397
 398 static uint8_t
 399 is_xtr_data_present(uint8_t type, uint8_t lisp_hdr_flags)
 400 {
 401         uint8_t xtr_present = 0;
 402
 403         if (type == LISP_MAP_REGISTER)
 404                 xtr_present = (lisp_hdr_flags) & LISP_MAP_REGISTER_IBIT_MASK;
 405         else if (type == LISP_MAP_NOTIFY)
 406                 xtr_present = (lisp_hdr_flags) & LISP_MAP_NOTIFY_IBIT_MASK;
 407
 408         return xtr_present;
 409 }
 410
 411 static void lisp_hdr_flag(netdissect_options *ndo, const lisp_map_register_hdr *lisp_hdr)
 412 {
 413         uint8_t type = extract_lisp_type(GET_U_1(lisp_hdr->type_and_flag));
 414
 415         if (!ndo->ndo_vflag) {
 416                 ND_PRINT("%s,", tok2str(lisp_type, "unknown-type-%u", type));
 417                 return;
 418         } else {
 419                 ND_PRINT("%s,", tok2str(lisp_type, "unknown-type-%u", type));
 420         }
 421
 422         if (type == LISP_MAP_REGISTER) {
 423                 ND_PRINT(" flags [%s],", bittok2str(map_register_hdr_flag,
 424                          "none", GET_BE_U_4(lisp_hdr)));
 425         } else if (type == LISP_MAP_NOTIFY) {
 426                 ND_PRINT(" flags [%s],", bittok2str(map_notify_hdr_flag,
 427                          "none", GET_BE_U_4(lisp_hdr)));
 428         }
 429 }
 430
 431 static void action_flag(netdissect_options *ndo, uint8_t act_auth_inc_res)
 432 {
 433         uint8_t action;
 434         uint8_t authoritative;
 435
 436         authoritative  = ((act_auth_inc_res >> 4) & 1);
 437
 438         if (authoritative)
 439                 ND_PRINT(" Authoritative,");
 440         else
 441                 ND_PRINT(" Non-Authoritative,");
 442
 443         action = act_auth_inc_res >> 5;
 444         ND_PRINT(" %s,", tok2str(lisp_eid_action, "unknown", action));
 445 }
 446
 447 static void loc_hdr_flag(netdissect_options *ndo, uint16_t flag)
 448 {
 449         ND_PRINT(" flags [%s],", bittok2str(lisp_loc_flag, "none", flag));
 450 }
 451