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 #ifdef HAVE_CONFIG_H
  98 #include <config.h>
  99 #endif
 100
 101 #include "netdissect-stdinc.h"
 102 #include "netdissect.h"
 103
 104 #include "ip.h"
 105 #include "ip6.h"
 106
 107 #include "extract.h"
 108 #include "addrtoname.h"
 109
 110
 111 #define IPv4_AFI                        1
 112 #define IPv6_AFI                        2
 113 #define TYPE_INDEX                      4
 114 #define LISP_MAP_NOTIFY_IBIT_MASK       8
 115 #define LISP_MAP_REGISTER_IBIT_MASK     2
 116
 117 enum {
 118         LISP_MAP_REQUEST = 1,
 119         LISP_MAP_REPLY,
 120         LISP_MAP_REGISTER,
 121         LISP_MAP_NOTIFY,
 122         LISP_ENCAPSULATED_CONTROL_MESSAGE = 8
 123 };
 124
 125 enum {
 126         LISP_AUTH_NONE,
 127         LISP_AUTH_SHA1,
 128         LISP_AUTH_SHA256
 129 };
 130
 131 static const struct tok lisp_type [] = {
 132         { 0, "LISP-Reserved"                    },
 133         { 1, "LISP-Map-Request"                 },
 134         { 2, "LISP-Map-Reply"                   },
 135         { 3, "LISP-Map-Register"                },
 136         { 4, "LISP-Map-Notify"                  },
 137         { 8, "LISP-Encapsulated-Contol-Message" },
 138         { 0, NULL }
 139 };
 140
 141 /*
 142  * P-Bit : Request for Proxy Map-Reply from the MS/MR
 143  * S-Bit : Security Enhancement. ETR is LISP-SEC enabled. draft-ietf-lisp-sec
 144  * I-Bit : 128 bit xTR-ID and 64 bit Site-ID present.
 145  *         xTR-ID and Site-ID help in differentiation of xTRs in multi xTR
 146  *         and multi Site deployment scenarios.
 147  * R-Bit : Built for a Reencapsulating-Tunnel-Router. Used in Traffic
 148  *         Engineering and Service Chaining
 149  */
 150 static const struct tok map_register_hdr_flag[] = {
 151         { 0x08000000, "P-Proxy-Map-Reply"  },
 152         { 0x04000000, "S-LISP-SEC-Capable" },
 153         { 0x02000000, "I-xTR-ID-Present"   },
 154         { 0x01000000, "R-Build-For-RTR"    },
 155         { 0x00000100, "M-Want-Map-Notify"  },
 156         { 0, NULL }
 157 };
 158
 159 static const struct tok map_notify_hdr_flag[] = {
 160         { 0x08000000, "I-xTR-ID-Present"   },
 161         { 0x04000000, "R-Build-For-RTR"    },
 162         { 0, NULL }
 163 };
 164
 165 static const struct tok auth_type[] = {
 166         { LISP_AUTH_NONE,   "None"   },
 167         { LISP_AUTH_SHA1,   "SHA1"   },
 168         { LISP_AUTH_SHA256, "SHA256" },
 169         { 0, NULL}
 170 };
 171
 172 static const struct tok lisp_eid_action[] = {
 173         { 0, "No-Action"        },
 174         { 1, "Natively-Forward" },
 175         { 2, "Send-Map-Request" },
 176         { 3, "Drop"             },
 177         { 0, NULL}
 178 };
 179
 180 static const struct tok lisp_loc_flag[] = {
 181         { 0x0004, "Local-Locator" },
 182         { 0x0002, "RLoc-Probed"   },
 183         { 0x0001, "Reachable"     },
 184         { 0, NULL }
 185 };
 186
 187 typedef struct map_register_hdr {
 188         nd_uint8_t type_and_flag;
 189         nd_uint8_t reserved;
 190         nd_uint8_t reserved_and_flag2;
 191         nd_uint8_t record_count;
 192         nd_uint64_t nonce;
 193         nd_uint16_t key_id;
 194         nd_uint16_t auth_data_len;
 195 } lisp_map_register_hdr;
 196
 197 #define MAP_REGISTER_HDR_LEN sizeof(lisp_map_register_hdr)
 198
 199 typedef struct map_register_eid {
 200         nd_uint32_t ttl;
 201         nd_uint8_t locator_count;
 202         nd_uint8_t eid_prefix_mask_length;
 203         nd_uint8_t act_auth_inc_res;
 204         nd_uint8_t reserved;
 205         nd_uint16_t reserved_and_version;
 206         nd_uint16_t eid_prefix_afi;
 207 } lisp_map_register_eid;
 208
 209 #define MAP_REGISTER_EID_LEN sizeof(lisp_map_register_eid)
 210
 211 typedef struct map_register_loc {
 212         nd_uint8_t priority;
 213         nd_uint8_t weight;
 214         nd_uint8_t m_priority;
 215         nd_uint8_t m_weight;
 216         nd_uint16_t unused_and_flag;
 217         nd_uint16_t locator_afi;
 218 } lisp_map_register_loc;
 219
 220 #define MAP_REGISTER_LOC_LEN sizeof(lisp_map_register_loc)
 221
 222 static uint8_t extract_lisp_type(uint8_t);
 223 static uint8_t is_xtr_data_present(uint8_t, uint8_t);
 224 static void lisp_hdr_flag(netdissect_options *, const lisp_map_register_hdr *);
 225 static void action_flag(netdissect_options *, uint8_t);
 226 static void loc_hdr_flag(netdissect_options *, uint16_t);
 227
 228 void
 229 lisp_print(netdissect_options *ndo, const u_char *bp, u_int length)
 230 {
 231         uint8_t type_and_flag;
 232         uint8_t type;
 233         uint8_t mask_len;
 234         uint8_t loc_count;
 235         uint8_t xtr_present;
 236         uint8_t record_count;
 237         uint16_t key_id;
 238         uint16_t eid_afi;
 239         uint16_t loc_afi;
 240         uint16_t map_version;
 241         uint16_t packet_offset;
 242         uint16_t auth_data_len;
 243         uint32_t ttl;
 244         const u_char *packet_iterator;
 245         const u_char *loc_ip_pointer;
 246         const lisp_map_register_hdr *lisp_hdr;
 247         const lisp_map_register_eid *lisp_eid;
 248         const lisp_map_register_loc *lisp_loc;
 249
 250         ndo->ndo_protocol = "lisp";
 251         /* Check if enough bytes for header are available */
 252         ND_TCHECK_LEN(bp, MAP_REGISTER_HDR_LEN);
 253         lisp_hdr = (const lisp_map_register_hdr *) bp;
 254         lisp_hdr_flag(ndo, lisp_hdr);
 255         /* Supporting only MAP NOTIFY and MAP REGISTER LISP packets */
 256         type_and_flag = GET_U_1(lisp_hdr->type_and_flag);
 257         type = extract_lisp_type(type_and_flag);
 258         if ((type != LISP_MAP_REGISTER) && (type != LISP_MAP_NOTIFY))
 259                 return;
 260
 261         /* Find if the packet contains xTR and Site-ID data */
 262         xtr_present = is_xtr_data_present(type, type_and_flag);
 263
 264         /* Extract the number of EID records present */
 265         auth_data_len = GET_BE_U_2(lisp_hdr->auth_data_len);
 266         packet_iterator = (const u_char *)(lisp_hdr);
 267         packet_offset = MAP_REGISTER_HDR_LEN;
 268         record_count = GET_U_1(lisp_hdr->record_count);
 269
 270         if (ndo->ndo_vflag) {
 271                 key_id = GET_BE_U_2(lisp_hdr->key_id);
 272                 ND_PRINT("\n    %u record(s), ", record_count);
 273                 ND_PRINT("Authentication %s,",
 274                         tok2str(auth_type, "unknown-type", key_id));
 275                 hex_print(ndo, "\n    Authentication-Data: ", packet_iterator +
 276                                                 packet_offset, auth_data_len);
 277         } else {
 278                 ND_PRINT(" %u record(s),", record_count);
 279         }
 280         packet_offset += auth_data_len;
 281
 282         if (record_count == 0)
 283                 goto invalid;
 284
 285         /* Print all the EID records */
 286         while ((length > packet_offset) && (record_count != 0)) {
 287                 record_count--;
 288                 ND_TCHECK_LEN(packet_iterator + packet_offset,
 289                               MAP_REGISTER_EID_LEN);
 290                 ND_PRINT("\n");
 291                 lisp_eid = (const lisp_map_register_eid *)
 292                                 ((const u_char *)lisp_hdr + packet_offset);
 293                 packet_offset += MAP_REGISTER_EID_LEN;
 294                 mask_len = GET_U_1(lisp_eid->eid_prefix_mask_length);
 295                 eid_afi = GET_BE_U_2(lisp_eid->eid_prefix_afi);
 296                 loc_count = GET_U_1(lisp_eid->locator_count);
 297
 298                 if (ndo->ndo_vflag) {
 299                         ttl = GET_BE_U_4(lisp_eid->ttl);
 300                         ND_PRINT("      Record TTL %u,", ttl);
 301                         action_flag(ndo, GET_U_1(lisp_eid->act_auth_inc_res));
 302                         map_version = GET_BE_U_2(lisp_eid->reserved_and_version) & 0x0FFF;
 303                         ND_PRINT(" Map Version: %u,", map_version);
 304                 }
 305
 306                 switch (eid_afi) {
 307                 case IPv4_AFI:
 308                         ND_PRINT(" EID %s/%u,",
 309                                 GET_IPADDR_STRING(packet_iterator + packet_offset),
 310                                 mask_len);
 311                         packet_offset += 4;
 312                         break;
 313                 case IPv6_AFI:
 314                         ND_PRINT(" EID %s/%u,",
 315                                 GET_IP6ADDR_STRING(packet_iterator + packet_offset),
 316                                 mask_len);
 317                         packet_offset += 16;
 318                         break;
 319                 default:
 320                         /*
 321                          * No support for LCAF right now.
 322                          */
 323                         return;
 324                         break;
 325                 }
 326
 327                 ND_PRINT(" %u locator(s)", loc_count);
 328
 329                 while (loc_count != 0) {
 330                         loc_count--;
 331                         ND_TCHECK_LEN(packet_iterator + packet_offset,
 332                                       MAP_REGISTER_LOC_LEN);
 333                         lisp_loc = (const lisp_map_register_loc *) (packet_iterator + packet_offset);
 334                         loc_ip_pointer = (const u_char *) (lisp_loc + 1);
 335                         packet_offset += MAP_REGISTER_LOC_LEN;
 336                         loc_afi = GET_BE_U_2(lisp_loc->locator_afi);
 337
 338                         if (ndo->ndo_vflag)
 339                                 ND_PRINT("\n       ");
 340
 341                         switch (loc_afi) {
 342                         case IPv4_AFI:
 343                                 ND_TCHECK_4(packet_iterator + packet_offset);
 344                                 ND_PRINT(" LOC %s", GET_IPADDR_STRING(loc_ip_pointer));
 345                                 packet_offset += 4;
 346                                 break;
 347                         case IPv6_AFI:
 348                                 ND_TCHECK_16(packet_iterator + packet_offset);
 349                                 ND_PRINT(" LOC %s", GET_IP6ADDR_STRING(loc_ip_pointer));
 350                                 packet_offset += 16;
 351                                 break;
 352                         default:
 353                                 break;
 354                         }
 355                         if (ndo->ndo_vflag) {
 356                                 ND_PRINT("\n          Priority/Weight %u/%u,"
 357                                                 " Multicast Priority/Weight %u/%u,",
 358                                                 GET_U_1(lisp_loc->priority),
 359                                                 GET_U_1(lisp_loc->weight),
 360                                                 GET_U_1(lisp_loc->m_priority),
 361                                                 GET_U_1(lisp_loc->m_weight));
 362                                 loc_hdr_flag(ndo,
 363                                              GET_BE_U_2(lisp_loc->unused_and_flag));
 364                         }
 365                 }
 366         }
 367
 368         /*
 369          * Print xTR and Site ID. Handle the fact that the packet could be invalid.
 370          * If the xTR_ID_Present bit is not set, and we still have data to display,
 371          * show it as hex data.
 372          */
 373         if (xtr_present) {
 374                 if (!ND_TTEST_LEN(packet_iterator + packet_offset, 24))
 375                         goto invalid;
 376                 hex_print(ndo, "\n    xTR-ID: ", packet_iterator + packet_offset, 16);
 377                 ND_PRINT("\n    SITE-ID: %" PRIu64,
 378                         GET_BE_U_8(packet_iterator + packet_offset + 16));
 379         } else {
 380                 /* Check if packet isn't over yet */
 381                 if (packet_iterator + packet_offset < ndo->ndo_snapend) {
 382                         hex_print(ndo, "\n    Data: ", packet_iterator + packet_offset,
 383                                 ND_BYTES_AVAILABLE_AFTER(packet_iterator + packet_offset));
 384                 }
 385         }
 386         return;
 387 trunc:
 388         nd_print_trunc(ndo);
 389         return;
 390 invalid:
 391         nd_print_invalid(ndo);
 392 }
 393
 394 static uint8_t
 395 extract_lisp_type(uint8_t lisp_hdr_flags)
 396 {
 397         return (lisp_hdr_flags) >> TYPE_INDEX;
 398 }
 399
 400 static uint8_t
 401 is_xtr_data_present(uint8_t type, uint8_t lisp_hdr_flags)
 402 {
 403         uint8_t xtr_present = 0;
 404
 405         if (type == LISP_MAP_REGISTER)
 406                 xtr_present = (lisp_hdr_flags) & LISP_MAP_REGISTER_IBIT_MASK;
 407         else if (type == LISP_MAP_NOTIFY)
 408                 xtr_present = (lisp_hdr_flags) & LISP_MAP_NOTIFY_IBIT_MASK;
 409
 410         return xtr_present;
 411 }
 412
 413 static void lisp_hdr_flag(netdissect_options *ndo, const lisp_map_register_hdr *lisp_hdr)
 414 {
 415         uint8_t type = extract_lisp_type(GET_U_1(lisp_hdr->type_and_flag));
 416
 417         if (!ndo->ndo_vflag) {
 418                 ND_PRINT("%s,", tok2str(lisp_type, "unknown-type-%u", type));
 419                 return;
 420         } else {
 421                 ND_PRINT("%s,", tok2str(lisp_type, "unknown-type-%u", type));
 422         }
 423
 424         if (type == LISP_MAP_REGISTER) {
 425                 ND_PRINT(" flags [%s],", bittok2str(map_register_hdr_flag,
 426                          "none", GET_BE_U_4(lisp_hdr)));
 427         } else if (type == LISP_MAP_NOTIFY) {
 428                 ND_PRINT(" flags [%s],", bittok2str(map_notify_hdr_flag,
 429                          "none", GET_BE_U_4(lisp_hdr)));
 430         }
 431 }
 432
 433 static void action_flag(netdissect_options *ndo, uint8_t act_auth_inc_res)
 434 {
 435         uint8_t action;
 436         uint8_t authoritative;
 437
 438         authoritative  = ((act_auth_inc_res >> 4) & 1);
 439
 440         if (authoritative)
 441                 ND_PRINT(" Authoritative,");
 442         else
 443                 ND_PRINT(" Non-Authoritative,");
 444
 445         action = act_auth_inc_res >> 5;
 446         ND_PRINT(" %s,", tok2str(lisp_eid_action, "unknown", action));
 447 }
 448
 449 static void loc_hdr_flag(netdissect_options *ndo, uint16_t flag)
 450 {
 451         ND_PRINT(" flags [%s],", bittok2str(lisp_loc_flag, "none", flag));
 452 }
 453