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 /*
  30  * netdissect printer for LISP - Locator/Identifier Separation Protocol
  31  * RFC 6830
  32  *
  33  *
  34  * The Map-Register message format is:
  35  *
  36  *       0                   1                   2                   3
  37  *       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
  38  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  39  *      |Type=3 |P|S|I|R|      Reserved               |M| Record Count  |
  40  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  41  *      |                         Nonce . . .                           |
  42  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  43  *      |                         . . . Nonce                           |
  44  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  45  *      |            Key ID             |  Authentication Data Length   |
  46  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  47  *      ~                     Authentication Data                       ~
  48  *  +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  49  *  |   |                          Record TTL                           |
  50  *  |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  51  *  R   | Locator Count | EID mask-len  | ACT |A|      Reserved         |
  52  *  e   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  53  *  c   | Rsvd  |  Map-Version Number   |        EID-Prefix-AFI         |
  54  *  o   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  55  *  r   |                          EID-Prefix                           |
  56  *  d   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  57  *  |  /|    Priority   |    Weight     |  M Priority   |   M Weight    |
  58  *  | L +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  59  *  | o |        Unused Flags     |L|p|R|           Loc-AFI             |
  60  *  | c +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  61  *  |  \|                             Locator                           |
  62  *  +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  63  *
  64  *
  65  * The Map-Notify message format is:
  66  *
  67  *       0                   1                   2                   3
  68  *       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
  69  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  70  *      |Type=4 |I|R|          Reserved                 | Record Count  |
  71  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  72  *      |                         Nonce . . .                           |
  73  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  74  *      |                         . . . Nonce                           |
  75  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  76  *      |            Key ID             |  Authentication Data Length   |
  77  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  78  *      ~                     Authentication Data                       ~
  79  *  +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  80  *  |   |                          Record TTL                           |
  81  *  |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  82  *  R   | Locator Count | EID mask-len  | ACT |A|      Reserved         |
  83  *  e   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  84  *  c   | Rsvd  |  Map-Version Number   |         EID-Prefix-AFI        |
  85  *  o   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  86  *  r   |                          EID-Prefix                           |
  87  *  d   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  88  *  |  /|    Priority   |    Weight     |  M Priority   |   M Weight    |
  89  *  | L +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  90  *  | o |        Unused Flags     |L|p|R|           Loc-AFI             |
  91  *  | c +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  92  *  |  \|                             Locator                           |
  93  *  +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  94  */
  95
  96 #ifdef HAVE_CONFIG_H
  97 #include "config.h"
  98 #endif
  99
 100 #include <netdissect-stdinc.h>
 101 #include <netdissect.h>
 102 #include <string.h>
 103 #include <stdlib.h>
 104
 105 #include "ip.h"
 106 #include "ip6.h"
 107
 108 #include "extract.h"
 109 #include "addrtoname.h"
 110
 111 static const char tstr[] = " [|LISP]";
 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_uint8_t reserved_version_hi;
 208         nd_uint8_t version_low;
 209         nd_uint16_t eid_prefix_afi;
 210 } lisp_map_register_eid;
 211
 212 #define MAP_REGISTER_EID_LEN sizeof(lisp_map_register_eid)
 213
 214 typedef struct map_register_loc {
 215         nd_uint8_t priority;
 216         nd_uint8_t weight;
 217         nd_uint8_t m_priority;
 218         nd_uint8_t m_weight;
 219         nd_uint16_t unused_and_flag;
 220         nd_uint16_t locator_afi;
 221 } lisp_map_register_loc;
 222
 223 #define MAP_REGISTER_LOC_LEN sizeof(lisp_map_register_loc)
 224
 225 static inline uint8_t extract_lisp_type(uint8_t);
 226 static inline uint8_t is_xtr_data_present(uint8_t , uint8_t);
 227 static void lisp_hdr_flag(netdissect_options *, const lisp_map_register_hdr *);
 228 static void action_flag(netdissect_options *, uint8_t);
 229 static void loc_hdr_flag(netdissect_options *, uint16_t);
 230
 231 void lisp_print(netdissect_options *ndo, const u_char *bp, u_int length)
 232 {
 233         uint8_t type;
 234         uint8_t mask_len;
 235         uint8_t loc_count;
 236         uint8_t xtr_present;
 237         uint8_t record_count;
 238         uint16_t key_id;
 239         uint16_t eid_afi;
 240         uint16_t loc_afi;
 241         uint16_t map_version;
 242         uint16_t packet_offset;
 243         uint16_t auth_data_len;
 244         uint32_t ttl;
 245         const u_char *packet_iterator;
 246         const u_char *loc_ip_pointer;
 247         const lisp_map_register_hdr *lisp_hdr;
 248         const lisp_map_register_eid *lisp_eid;
 249         const lisp_map_register_loc *lisp_loc;
 250
 251         /* Check if enough bytes for header are available */
 252         ND_TCHECK2(*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 = extract_lisp_type(lisp_hdr->type_and_flag);
 257         if ((type != LISP_MAP_REGISTER) && (type != LISP_MAP_NOTIFY))
 258                 return;
 259
 260         /* Find if the packet contains xTR and Site-ID data */
 261         xtr_present = is_xtr_data_present(type, lisp_hdr->type_and_flag);
 262
 263         /* Extract the number of EID records present */
 264         auth_data_len = EXTRACT_16BITS(&lisp_hdr->auth_data_len);
 265         packet_iterator = (const u_char *)(lisp_hdr);
 266         packet_offset = MAP_REGISTER_HDR_LEN;
 267         record_count = lisp_hdr->record_count;
 268
 269         if (ndo->ndo_vflag) {
 270                 key_id = EXTRACT_16BITS(&lisp_hdr->key_id);
 271                 ND_PRINT((ndo, "\n    %u record(s), ", record_count));
 272                 ND_PRINT((ndo, "Authentication %s,",
 273                         tok2str(auth_type, "unknown-type", key_id)));
 274                 hex_print(ndo, "\n    Authentication-Data: ", packet_iterator +
 275                                                 packet_offset, auth_data_len);
 276         } else {
 277                 ND_PRINT((ndo, " %u record(s),", record_count));
 278         }
 279         packet_offset += auth_data_len;
 280
 281         if (record_count == 0)
 282                 goto invalid;
 283
 284         /* Print all the EID records */
 285         while ((length > packet_offset) && (record_count--)) {
 286
 287                 ND_TCHECK2(*(packet_iterator + packet_offset), MAP_REGISTER_EID_LEN);
 288                 ND_PRINT((ndo, "\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 = lisp_eid->eid_prefix_mask_length;
 293                 eid_afi = EXTRACT_16BITS(&lisp_eid->eid_prefix_afi);
 294                 loc_count = lisp_eid->locator_count;
 295
 296                 if (ndo->ndo_vflag) {
 297                         ttl = EXTRACT_32BITS(&lisp_eid->ttl);
 298                         ND_PRINT((ndo, "      Record TTL %u,", ttl));
 299                         action_flag(ndo, lisp_eid->act_auth_inc_res);
 300                         map_version = (((lisp_eid->reserved_version_hi) & 15 ) * 255) +
 301                                         lisp_eid->version_low;
 302                         ND_PRINT((ndo, " Map Version: %u,", map_version));
 303                 }
 304
 305                 switch (eid_afi) {
 306                 case IPv4_AFI:
 307                         ND_TCHECK2(*(packet_iterator + packet_offset), 4);
 308                         ND_PRINT((ndo, " EID %s/%u,", ipaddr_string(ndo,
 309                                 packet_iterator + packet_offset), mask_len));
 310                         packet_offset += 4;
 311                         break;
 312                 case IPv6_AFI:
 313                         ND_TCHECK2(*(packet_iterator + packet_offset), 16);
 314                         ND_PRINT((ndo, " EID %s/%u,", ip6addr_string(ndo,
 315                                 packet_iterator + packet_offset), mask_len));
 316                         packet_offset += 16;
 317                         break;
 318                 default:
 319                         /*
 320                          * No support for LCAF right now.
 321                          */
 322                         return;
 323                         break;
 324                 }
 325
 326                 ND_PRINT((ndo, " %u locator(s)", loc_count));
 327
 328                 while (loc_count--) {
 329                         ND_TCHECK2(*(packet_iterator + packet_offset), MAP_REGISTER_LOC_LEN);
 330                         lisp_loc = (const lisp_map_register_loc *) (packet_iterator + packet_offset);
 331                         loc_ip_pointer = (const u_char *) (lisp_loc + 1);
 332                         packet_offset += MAP_REGISTER_LOC_LEN;
 333                         loc_afi = EXTRACT_16BITS(&lisp_loc->locator_afi);
 334
 335                         if (ndo->ndo_vflag)
 336                                 ND_PRINT((ndo, "\n       "));
 337
 338                         switch (loc_afi) {
 339                         case IPv4_AFI:
 340                                 ND_TCHECK2(*(packet_iterator + packet_offset), 4);
 341                                 ND_PRINT((ndo, " LOC %s", ipaddr_string(ndo, loc_ip_pointer)));
 342                                 packet_offset += 4;
 343                                 break;
 344                         case IPv6_AFI:
 345                                 ND_TCHECK2(*(packet_iterator + packet_offset), 16);
 346                                 ND_PRINT((ndo, " LOC %s", ip6addr_string(ndo, loc_ip_pointer)));
 347                                 packet_offset += 16;
 348                                 break;
 349                         default:
 350                                 break;
 351                         }
 352                         if (ndo->ndo_vflag) {
 353                                 ND_PRINT((ndo, "\n          Priority/Weight %u/%u,"
 354                                                 " Multicast Priority/Weight %u/%u,",
 355                                                 lisp_loc->priority, lisp_loc->weight,
 356                                                 lisp_loc->m_priority, lisp_loc->m_weight));
 357                                 loc_hdr_flag(ndo, EXTRACT_16BITS(&lisp_loc->unused_and_flag));
 358                         }
 359                 }
 360         }
 361
 362         /*
 363          * Print xTR and Site ID. Handle the fact that the packet could be invalid.
 364          * If the xTR_ID_Present bit is not set, and we still have data to display,
 365          * show it as hex data.
 366          */
 367         if (xtr_present) {
 368                 if (!ND_TTEST2(*(packet_iterator + packet_offset), 24))
 369                         goto invalid;
 370                 hex_print_with_offset(ndo, "\n    xTR-ID: ", packet_iterator + packet_offset, 16, 0);
 371                 ND_PRINT((ndo, "\n    SITE-ID: %" PRIu64,
 372                         EXTRACT_64BITS(packet_iterator + packet_offset + 16)));
 373         } else {
 374                 /* Check if packet isn't over yet */
 375                 if (packet_iterator + packet_offset < ndo->ndo_snapend) {
 376                         hex_print_with_offset(ndo, "\n    Data: ", packet_iterator + packet_offset,
 377                                 (ndo->ndo_snapend - (packet_iterator + packet_offset)), 0);
 378                 }
 379         }
 380         return;
 381 trunc:
 382         ND_PRINT((ndo, "\n   %s", tstr));
 383         return;
 384 invalid:
 385         ND_PRINT((ndo, "\n   %s", istr));
 386         return;
 387 }
 388
 389 static inline uint8_t extract_lisp_type(uint8_t lisp_hdr_flags)
 390 {
 391         return (lisp_hdr_flags) >> TYPE_INDEX;
 392 }
 393
 394 static inline uint8_t is_xtr_data_present(uint8_t type, uint8_t lisp_hdr_flags)
 395 {
 396         uint8_t xtr_present = 0;
 397
 398         if (type == LISP_MAP_REGISTER)
 399                 xtr_present = (lisp_hdr_flags) & LISP_MAP_REGISTER_IBIT_MASK;
 400         else if (type == LISP_MAP_NOTIFY)
 401                 xtr_present = (lisp_hdr_flags) & LISP_MAP_NOTIFY_IBIT_MASK;
 402
 403         return xtr_present;
 404 }
 405
 406 static void lisp_hdr_flag(netdissect_options *ndo, const lisp_map_register_hdr *lisp_hdr)
 407 {
 408         uint8_t type = extract_lisp_type(lisp_hdr->type_and_flag);
 409
 410         if (!ndo->ndo_vflag) {
 411                 ND_PRINT((ndo, "%s,", tok2str(lisp_type, "unknown-type-%u", type)));
 412                 return;
 413         } else {
 414                 ND_PRINT((ndo, "%s,", tok2str(lisp_type, "unknown-type-%u", type)));
 415         }
 416
 417         if (type == LISP_MAP_REGISTER) {
 418                 ND_PRINT((ndo, " flags [%s],", bittok2str(map_register_hdr_flag,
 419                          "none", EXTRACT_32BITS(lisp_hdr))));
 420         } else if (type == LISP_MAP_NOTIFY) {
 421                 ND_PRINT((ndo, " flags [%s],", bittok2str(map_notify_hdr_flag,
 422                          "none", EXTRACT_32BITS(lisp_hdr))));
 423         }
 424
 425         return;
 426 }
 427
 428 static void action_flag(netdissect_options *ndo, uint8_t act_auth_inc_res)
 429 {
 430         uint8_t action;
 431         uint8_t authoritative;
 432
 433         authoritative  = ((act_auth_inc_res >> 4) & 1);
 434
 435         if (authoritative)
 436                 ND_PRINT((ndo, " Authoritative,"));
 437         else
 438                 ND_PRINT((ndo, " Non-Authoritative,"));
 439
 440         action = act_auth_inc_res >> 5;
 441         ND_PRINT((ndo, " %s,", tok2str(lisp_eid_action, "unknown", action)));
 442 }
 443
 444 static void loc_hdr_flag(netdissect_options *ndo, uint16_t flag)
 445 {
 446         ND_PRINT((ndo, " flags [%s],", bittok2str(lisp_loc_flag, "none", flag)));
 447 }
 448