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 #include <string.h>
 104 #include <stdlib.h>
 105
 106 #include "ip.h"
 107 #include "ip6.h"
 108
 109 #include "extract.h"
 110 #include "addrtoname.h"
 111
 112
 113 #define IPv4_AFI                        1
 114 #define IPv6_AFI                        2
 115 #define TYPE_INDEX                      4
 116 #define LISP_MAP_NOTIFY_IBIT_MASK       8
 117 #define LISP_MAP_REGISTER_IBIT_MASK     2
 118
 119 enum {
 120         LISP_MAP_REQUEST = 1,
 121         LISP_MAP_REPLY,
 122         LISP_MAP_REGISTER,
 123         LISP_MAP_NOTIFY,
 124         LISP_ENCAPSULATED_CONTROL_MESSAGE = 8
 125 };
 126
 127 enum {
 128         LISP_AUTH_NONE,
 129         LISP_AUTH_SHA1,
 130         LISP_AUTH_SHA256
 131 };
 132
 133 static const struct tok lisp_type [] = {
 134         { 0, "LISP-Reserved"                    },
 135         { 1, "LISP-Map-Request"                 },
 136         { 2, "LISP-Map-Reply"                   },
 137         { 3, "LISP-Map-Register"                },
 138         { 4, "LISP-Map-Notify"                  },
 139         { 8, "LISP-Encapsulated-Contol-Message" },
 140         { 0, NULL }
 141 };
 142
 143 /*
 144  * P-Bit : Request for Proxy Map-Reply from the MS/MR
 145  * S-Bit : Security Enhancement. ETR is LISP-SEC enabled. draft-ietf-lisp-sec
 146  * I-Bit : 128 bit xTR-ID and 64 bit Site-ID present.
 147  *         xTR-ID and Site-ID help in differentiation of xTRs in multi xTR
 148  *         and multi Site deployment scenarios.
 149  * R-Bit : Built for a Reencapsulating-Tunnel-Router. Used in Traffic
 150  *         Engineering and Service Chaining
 151  */
 152 static const struct tok map_register_hdr_flag[] = {
 153         { 0x08000000, "P-Proxy-Map-Reply"  },
 154         { 0x04000000, "S-LISP-SEC-Capable" },
 155         { 0x02000000, "I-xTR-ID-Present"   },
 156         { 0x01000000, "R-Build-For-RTR"    },
 157         { 0x00000100, "M-Want-Map-Notify"  },
 158         { 0, NULL }
 159 };
 160
 161 static const struct tok map_notify_hdr_flag[] = {
 162         { 0x08000000, "I-xTR-ID-Present"   },
 163         { 0x04000000, "R-Build-For-RTR"    },
 164         { 0, NULL }
 165 };
 166
 167 static const struct tok auth_type[] = {
 168         { LISP_AUTH_NONE,   "None"   },
 169         { LISP_AUTH_SHA1,   "SHA1"   },
 170         { LISP_AUTH_SHA256, "SHA256" },
 171         { 0, NULL}
 172 };
 173
 174 static const struct tok lisp_eid_action[] = {
 175         { 0, "No-Action"        },
 176         { 1, "Natively-Forward" },
 177         { 2, "Send-Map-Request" },
 178         { 3, "Drop"             },
 179         { 0, NULL}
 180 };
 181
 182 static const struct tok lisp_loc_flag[] = {
 183         { 0x0004, "Local-Locator" },
 184         { 0x0002, "RLoc-Probed"   },
 185         { 0x0001, "Reachable"     },
 186         { 0, NULL }
 187 };
 188
 189 typedef struct map_register_hdr {
 190         nd_uint8_t type_and_flag;
 191         nd_uint8_t reserved;
 192         nd_uint8_t reserved_and_flag2;
 193         nd_uint8_t record_count;
 194         nd_uint64_t nonce;
 195         nd_uint16_t key_id;
 196         nd_uint16_t auth_data_len;
 197 } lisp_map_register_hdr;
 198
 199 #define MAP_REGISTER_HDR_LEN sizeof(lisp_map_register_hdr)
 200
 201 typedef struct map_register_eid {
 202         nd_uint32_t ttl;
 203         nd_uint8_t locator_count;
 204         nd_uint8_t eid_prefix_mask_length;
 205         nd_uint8_t act_auth_inc_res;
 206         nd_uint8_t reserved;
 207         nd_uint16_t reserved_and_version;
 208         nd_uint16_t eid_prefix_afi;
 209 } lisp_map_register_eid;
 210
 211 #define MAP_REGISTER_EID_LEN sizeof(lisp_map_register_eid)
 212
 213 typedef struct map_register_loc {
 214         nd_uint8_t priority;
 215         nd_uint8_t weight;
 216         nd_uint8_t m_priority;
 217         nd_uint8_t m_weight;
 218         nd_uint16_t unused_and_flag;
 219         nd_uint16_t locator_afi;
 220 } lisp_map_register_loc;
 221
 222 #define MAP_REGISTER_LOC_LEN sizeof(lisp_map_register_loc)
 223
 224 static uint8_t extract_lisp_type(uint8_t);
 225 static uint8_t is_xtr_data_present(uint8_t, uint8_t);
 226 static void lisp_hdr_flag(netdissect_options *, const lisp_map_register_hdr *);
 227 static void action_flag(netdissect_options *, uint8_t);
 228 static void loc_hdr_flag(netdissect_options *, uint16_t);
 229
 230 void
 231 lisp_print(netdissect_options *ndo, const u_char *bp, u_int length)
 232 {
 233         uint8_t type_and_flag;
 234         uint8_t type;
 235         uint8_t mask_len;
 236         uint8_t loc_count;
 237         uint8_t xtr_present;
 238         uint8_t record_count;
 239         uint16_t key_id;
 240         uint16_t eid_afi;
 241         uint16_t loc_afi;
 242         uint16_t map_version;
 243         uint16_t packet_offset;
 244         uint16_t auth_data_len;
 245         uint32_t ttl;
 246         const u_char *packet_iterator;
 247         const u_char *loc_ip_pointer;
 248         const lisp_map_register_hdr *lisp_hdr;
 249         const lisp_map_register_eid *lisp_eid;
 250         const lisp_map_register_loc *lisp_loc;
 251
 252         ndo->ndo_protocol = "lisp";
 253         /* Check if enough bytes for header are available */
 254         ND_TCHECK_LEN(bp, MAP_REGISTER_HDR_LEN);
 255         lisp_hdr = (const lisp_map_register_hdr *) bp;
 256         lisp_hdr_flag(ndo, lisp_hdr);
 257         /* Supporting only MAP NOTIFY and MAP REGISTER LISP packets */
 258         type_and_flag = EXTRACT_U_1(lisp_hdr->type_and_flag);
 259         type = extract_lisp_type(type_and_flag);
 260         if ((type != LISP_MAP_REGISTER) && (type != LISP_MAP_NOTIFY))
 261                 return;
 262
 263         /* Find if the packet contains xTR and Site-ID data */
 264         xtr_present = is_xtr_data_present(type, type_and_flag);
 265
 266         /* Extract the number of EID records present */
 267         auth_data_len = EXTRACT_BE_U_2(lisp_hdr->auth_data_len);
 268         packet_iterator = (const u_char *)(lisp_hdr);
 269         packet_offset = MAP_REGISTER_HDR_LEN;
 270         record_count = EXTRACT_U_1(lisp_hdr->record_count);
 271
 272         if (ndo->ndo_vflag) {
 273                 key_id = EXTRACT_BE_U_2(lisp_hdr->key_id);
 274                 ND_PRINT("\n    %u record(s), ", record_count);
 275                 ND_PRINT("Authentication %s,",
 276                         tok2str(auth_type, "unknown-type", key_id));
 277                 hex_print(ndo, "\n    Authentication-Data: ", packet_iterator +
 278                                                 packet_offset, auth_data_len);
 279         } else {
 280                 ND_PRINT(" %u record(s),", record_count);
 281         }
 282         packet_offset += auth_data_len;
 283
 284         if (record_count == 0)
 285                 goto invalid;
 286
 287         /* Print all the EID records */
 288         while ((length > packet_offset) && (record_count--)) {
 289
 290                 ND_TCHECK_LEN(packet_iterator + packet_offset,
 291                               MAP_REGISTER_EID_LEN);
 292                 ND_PRINT("\n");
 293                 lisp_eid = (const lisp_map_register_eid *)
 294                                 ((const u_char *)lisp_hdr + packet_offset);
 295                 packet_offset += MAP_REGISTER_EID_LEN;
 296                 mask_len = EXTRACT_U_1(lisp_eid->eid_prefix_mask_length);
 297                 eid_afi = EXTRACT_BE_U_2(lisp_eid->eid_prefix_afi);
 298                 loc_count = EXTRACT_U_1(lisp_eid->locator_count);
 299
 300                 if (ndo->ndo_vflag) {
 301                         ttl = EXTRACT_BE_U_4(lisp_eid->ttl);
 302                         ND_PRINT("      Record TTL %u,", ttl);
 303                         action_flag(ndo, EXTRACT_U_1(lisp_eid->act_auth_inc_res));
 304                         map_version = EXTRACT_BE_U_2(lisp_eid->reserved_and_version) & 0x0FFF;
 305                         ND_PRINT(" Map Version: %u,", map_version);
 306                 }
 307
 308                 switch (eid_afi) {
 309                 case IPv4_AFI:
 310                         ND_TCHECK_4(packet_iterator + packet_offset);
 311                         ND_PRINT(" EID %s/%u,", ipaddr_string(ndo,
 312                                 packet_iterator + packet_offset), mask_len);
 313                         packet_offset += 4;
 314                         break;
 315                 case IPv6_AFI:
 316                         ND_TCHECK_16(packet_iterator + packet_offset);
 317                         ND_PRINT(" EID %s/%u,", ip6addr_string(ndo,
 318                                 packet_iterator + packet_offset), mask_len);
 319                         packet_offset += 16;
 320                         break;
 321                 default:
 322                         /*
 323                          * No support for LCAF right now.
 324                          */
 325                         return;
 326                         break;
 327                 }
 328
 329                 ND_PRINT(" %u locator(s)", loc_count);
 330
 331                 while (loc_count--) {
 332                         ND_TCHECK_LEN(packet_iterator + packet_offset,
 333                                       MAP_REGISTER_LOC_LEN);
 334                         lisp_loc = (const lisp_map_register_loc *) (packet_iterator + packet_offset);
 335                         loc_ip_pointer = (const u_char *) (lisp_loc + 1);
 336                         packet_offset += MAP_REGISTER_LOC_LEN;
 337                         loc_afi = EXTRACT_BE_U_2(lisp_loc->locator_afi);
 338
 339                         if (ndo->ndo_vflag)
 340                                 ND_PRINT("\n       ");
 341
 342                         switch (loc_afi) {
 343                         case IPv4_AFI:
 344                                 ND_TCHECK_4(packet_iterator + packet_offset);
 345                                 ND_PRINT(" LOC %s", ipaddr_string(ndo, loc_ip_pointer));
 346                                 packet_offset += 4;
 347                                 break;
 348                         case IPv6_AFI:
 349                                 ND_TCHECK_16(packet_iterator + packet_offset);
 350                                 ND_PRINT(" LOC %s", ip6addr_string(ndo, loc_ip_pointer));
 351                                 packet_offset += 16;
 352                                 break;
 353                         default:
 354                                 break;
 355                         }
 356                         if (ndo->ndo_vflag) {
 357                                 ND_PRINT("\n          Priority/Weight %u/%u,"
 358                                                 " Multicast Priority/Weight %u/%u,",
 359                                                 EXTRACT_U_1(lisp_loc->priority),
 360                                                 EXTRACT_U_1(lisp_loc->weight),
 361                                                 EXTRACT_U_1(lisp_loc->m_priority),
 362                                                 EXTRACT_U_1(lisp_loc->m_weight));
 363                                 loc_hdr_flag(ndo,
 364                                              EXTRACT_BE_U_2(lisp_loc->unused_and_flag));
 365                         }
 366                 }
 367         }
 368
 369         /*
 370          * Print xTR and Site ID. Handle the fact that the packet could be invalid.
 371          * If the xTR_ID_Present bit is not set, and we still have data to display,
 372          * show it as hex data.
 373          */
 374         if (xtr_present) {
 375                 if (!ND_TTEST_LEN(packet_iterator + packet_offset, 24))
 376                         goto invalid;
 377                 hex_print_with_offset(ndo, "\n    xTR-ID: ", packet_iterator + packet_offset, 16, 0);
 378                 ND_PRINT("\n    SITE-ID: %" PRIu64,
 379                         EXTRACT_BE_U_8(packet_iterator + packet_offset + 16));
 380         } else {
 381                 /* Check if packet isn't over yet */
 382                 if (packet_iterator + packet_offset < ndo->ndo_snapend) {
 383                         hex_print_with_offset(ndo, "\n    Data: ", packet_iterator + packet_offset,
 384                                 (ndo->ndo_snapend - (packet_iterator + packet_offset)), 0);
 385                 }
 386         }
 387         return;
 388 trunc:
 389         nd_print_trunc(ndo);
 390         return;
 391 invalid:
 392         ND_PRINT("%s", istr);
 393         return;
 394 }
 395
 396 static uint8_t
 397 extract_lisp_type(uint8_t lisp_hdr_flags)
 398 {
 399         return (lisp_hdr_flags) >> TYPE_INDEX;
 400 }
 401
 402 static uint8_t
 403 is_xtr_data_present(uint8_t type, uint8_t lisp_hdr_flags)
 404 {
 405         uint8_t xtr_present = 0;
 406
 407         if (type == LISP_MAP_REGISTER)
 408                 xtr_present = (lisp_hdr_flags) & LISP_MAP_REGISTER_IBIT_MASK;
 409         else if (type == LISP_MAP_NOTIFY)
 410                 xtr_present = (lisp_hdr_flags) & LISP_MAP_NOTIFY_IBIT_MASK;
 411
 412         return xtr_present;
 413 }
 414
 415 static void lisp_hdr_flag(netdissect_options *ndo, const lisp_map_register_hdr *lisp_hdr)
 416 {
 417         uint8_t type = extract_lisp_type(EXTRACT_U_1(lisp_hdr->type_and_flag));
 418
 419         if (!ndo->ndo_vflag) {
 420                 ND_PRINT("%s,", tok2str(lisp_type, "unknown-type-%u", type));
 421                 return;
 422         } else {
 423                 ND_PRINT("%s,", tok2str(lisp_type, "unknown-type-%u", type));
 424         }
 425
 426         if (type == LISP_MAP_REGISTER) {
 427                 ND_PRINT(" flags [%s],", bittok2str(map_register_hdr_flag,
 428                          "none", EXTRACT_BE_U_4(lisp_hdr)));
 429         } else if (type == LISP_MAP_NOTIFY) {
 430                 ND_PRINT(" flags [%s],", bittok2str(map_notify_hdr_flag,
 431                          "none", EXTRACT_BE_U_4(lisp_hdr)));
 432         }
 433
 434         return;
 435 }
 436
 437 static void action_flag(netdissect_options *ndo, uint8_t act_auth_inc_res)
 438 {
 439         uint8_t action;
 440         uint8_t authoritative;
 441
 442         authoritative  = ((act_auth_inc_res >> 4) & 1);
 443
 444         if (authoritative)
 445                 ND_PRINT(" Authoritative,");
 446         else
 447                 ND_PRINT(" Non-Authoritative,");
 448
 449         action = act_auth_inc_res >> 5;
 450         ND_PRINT(" %s,", tok2str(lisp_eid_action, "unknown", action));
 451 }
 452
 453 static void loc_hdr_flag(netdissect_options *ndo, uint16_t flag)
 454 {
 455         ND_PRINT(" flags [%s],", bittok2str(lisp_loc_flag, "none", flag));
 456 }
 457