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  * tcpdump filter 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
  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 #define IPv4_AFI                        1
 113 #define IPv6_AFI                        2
 114 #define TYPE_INDEX                      4
 115 #define LISP_MAP_NOTIFY_IBIT_MASK       8
 116 #define LISP_MAP_REGISTER_IBIT_MASK     2
 117
 118 enum {
 119         LISP_MAP_REQUEST = 1,
 120         LISP_MAP_REPLY,
 121         LISP_MAP_REGISTER,
 122         LISP_MAP_NOTIFY,
 123         LISP_ENCAPSULATED_CONTROL_MESSAGE = 8
 124 };
 125
 126 enum {
 127         LISP_AUTH_NONE,
 128         LISP_AUTH_SHA1,
 129         LISP_AUTH_SHA256
 130 };
 131
 132 static const struct tok lisp_type [] = {
 133         { 0, "LISP-Reserved"                    },
 134         { 1, "LISP-Map-Request"                 },
 135         { 2, "LISP-Map-Reply"                   },
 136         { 3, "LISP-Map-Register"                },
 137         { 4, "LISP-Map-Notify"                  },
 138         { 8, "LISP-Encapsulated-Contol-Message" },
 139         { 0, NULL }
 140 };
 141
 142 /*
 143  * P-Bit : Request for Proxy Map-Reply from the MS/MR
 144  * S-Bit : Security Enhancement. ETR is LISP-SEC enabled. draft-ietf-lisp-sec
 145  * I-Bit : 128 bit xTR-ID and 64 bit Site-ID present.
 146  *         xTR-ID and Site-ID help in differentiation of xTRs in multi xTR
 147  *         and multi Site deployment scenarios.
 148  * R-Bit : Built for a Reencapsulating-Tunnel-Router. Used in Traffic
 149  *         Engineering and Service Chaining
 150  */
 151 static const struct tok map_register_hdr_flag[] = {
 152         { 0x08000000, "P-Proxy-Map-Reply"  },
 153         { 0x04000000, "S-LISP-SEC-Capable" },
 154         { 0x02000000, "I-xTR-ID-Present"   },
 155         { 0x01000000, "R-Build-For-RTR"    },
 156         { 0x00000100, "M-Want-Map-Notify"  },
 157         { 0, NULL }
 158 };
 159
 160 static const struct tok map_notify_hdr_flag[] = {
 161         { 0x08000000, "I-xTR-ID-Present"   },
 162         { 0x04000000, "R-Build-For-RTR"    },
 163         { 0, NULL }
 164 };
 165
 166 static const struct tok auth_type[] = {
 167         { LISP_AUTH_NONE,   "None"   },
 168         { LISP_AUTH_SHA1,   "SHA1"   },
 169         { LISP_AUTH_SHA256, "SHA256" },
 170         { 0, NULL}
 171 };
 172
 173 static const struct tok lisp_eid_action[] = {
 174         { 0, "No-Action"        },
 175         { 1, "Natively-Forward" },
 176         { 2, "Send-Map-Request" },
 177         { 3, "Drop"             },
 178         { 0, NULL}
 179 };
 180
 181 static const struct tok lisp_loc_flag[] = {
 182         { 0x0004, "Local-Locator" },
 183         { 0x0002, "RLoc-Probed"   },
 184         { 0x0001, "Reachable"     },
 185         { 0, NULL }
 186 };
 187
 188 typedef struct map_register_hdr {
 189         uint8_t type_and_flag;
 190         uint8_t reserved;
 191         uint8_t reserved_and_flag2;
 192         uint8_t record_count;
 193         uint64_t nonce;
 194         uint16_t key_id;
 195         uint16_t auth_data_len;
 196 } UNALIGNED lisp_map_register_hdr;
 197
 198 #define MAP_REGISTER_HDR_LEN sizeof(lisp_map_register_hdr)
 199
 200 typedef struct map_register_eid {
 201         uint32_t ttl;
 202         uint8_t locator_count;
 203         uint8_t eid_prefix_mask_length;
 204         uint8_t act_auth_inc_res;
 205         uint8_t reserved;
 206         uint8_t reserved_version_hi;
 207         uint8_t version_low;
 208         uint16_t eid_prefix_afi;
 209 } UNALIGNED lisp_map_register_eid;
 210
 211 #define MAP_REGISTER_EID_LEN sizeof(lisp_map_register_eid)
 212
 213 typedef struct map_register_loc {
 214         uint8_t priority;
 215         uint8_t weight;
 216         uint8_t m_priority;
 217         uint8_t m_weight;
 218         uint16_t unused_and_flag;
 219         uint16_t locator_afi;
 220 } UNALIGNED lisp_map_register_loc;
 221
 222 #define MAP_REGISTER_LOC_LEN sizeof(lisp_map_register_loc)
 223
 224 static inline uint8_t extract_lisp_type(uint8_t);
 225 static inline 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 lisp_print(netdissect_options *ndo, const u_char *bp, u_int length)
 231 {
 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         /* Check if enough bytes for header are available */
 251         ND_TCHECK2(*bp, MAP_REGISTER_HDR_LEN);
 252         lisp_hdr = (const lisp_map_register_hdr *) bp;
 253         lisp_hdr_flag(ndo, lisp_hdr);
 254         /* Supporting only MAP NOTIFY and MAP REGISTER LISP packets */
 255         type = extract_lisp_type(lisp_hdr->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, lisp_hdr->type_and_flag);
 261
 262         /* Extract the number of EID records present */
 263         auth_data_len = EXTRACT_16BITS(&lisp_hdr->auth_data_len);
 264         packet_iterator = (const u_char *)(lisp_hdr);
 265         packet_offset = MAP_REGISTER_HDR_LEN;
 266         record_count = lisp_hdr->record_count;
 267
 268         if (ndo->ndo_vflag) {
 269                 key_id = EXTRACT_16BITS(&lisp_hdr->key_id);
 270                 ND_PRINT((ndo, "\n    %u record(s), ", record_count));
 271                 ND_PRINT((ndo, "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((ndo, " %u record(s),", record_count));
 277         }
 278         packet_offset += auth_data_len;
 279
 280         if (record_count == 0)
 281                 goto malformed;
 282
 283         /* Print all the EID records */
 284         while ((length > packet_offset) && (record_count--)) {
 285
 286                 ND_TCHECK2(*(packet_iterator + packet_offset), MAP_REGISTER_EID_LEN);
 287                 ND_PRINT((ndo, "\n"));
 288                 lisp_eid = (const lisp_map_register_eid *)
 289                                 ((const u_char *)lisp_hdr + packet_offset);
 290                 packet_offset += MAP_REGISTER_EID_LEN;
 291                 mask_len = lisp_eid->eid_prefix_mask_length;
 292                 eid_afi = EXTRACT_16BITS(&lisp_eid->eid_prefix_afi);
 293                 loc_count = lisp_eid->locator_count;
 294
 295                 if (ndo->ndo_vflag) {
 296                         ttl = EXTRACT_32BITS(&lisp_eid->ttl);
 297                         ND_PRINT((ndo, "      Record TTL %u,", ttl));
 298                         action_flag(ndo, lisp_eid->act_auth_inc_res);
 299                         map_version = (((lisp_eid->reserved_version_hi) & 15 ) * 255) +
 300                                         lisp_eid->version_low;
 301                         ND_PRINT((ndo, " Map Version: %u,", map_version));
 302                 }
 303
 304                 switch (eid_afi) {
 305                 case IPv4_AFI:
 306                         ND_TCHECK2(*(packet_iterator + packet_offset), 4);
 307                         ND_PRINT((ndo, " EID %s/%u,", getname(ndo,
 308                                 packet_iterator + packet_offset), mask_len));
 309                         packet_offset += 4;
 310                         break;
 311                 case IPv6_AFI:
 312                         ND_TCHECK2(*(packet_iterator + packet_offset), 16);
 313                         ND_PRINT((ndo, " EID %s/%u,", getname6(ndo,
 314                                 packet_iterator + packet_offset), 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((ndo, " %u locator(s)", loc_count));
 326
 327                 while (loc_count--) {
 328                         ND_TCHECK2(*(packet_iterator + packet_offset), MAP_REGISTER_LOC_LEN);
 329                         lisp_loc = (const lisp_map_register_loc *) (packet_iterator + packet_offset);
 330                         loc_ip_pointer = (const u_char *) (lisp_loc + 1);
 331                         packet_offset += MAP_REGISTER_LOC_LEN;
 332                         loc_afi = EXTRACT_16BITS(&lisp_loc->locator_afi);
 333
 334                         if (ndo->ndo_vflag)
 335                                 ND_PRINT((ndo, "\n       "));
 336
 337                         switch (loc_afi) {
 338                         case IPv4_AFI:
 339                                 ND_TCHECK2(*(packet_iterator + packet_offset), 4);
 340                                 ND_PRINT((ndo, " LOC %s", getname(ndo, loc_ip_pointer)));
 341                                 packet_offset += 4;
 342                                 break;
 343                         case IPv6_AFI:
 344                                 ND_TCHECK2(*(packet_iterator + packet_offset), 16);
 345                                 ND_PRINT((ndo, " LOC %s", getname6(ndo, loc_ip_pointer)));
 346                                 packet_offset += 16;
 347                                 break;
 348                         default:
 349                                 break;
 350                         }
 351                         if (ndo->ndo_vflag) {
 352                                 ND_PRINT((ndo, "\n          Priority/Weight %u/%u,"
 353                                                 " Multicast Priority/Weight %u/%u,",
 354                                                 lisp_loc->priority, lisp_loc->weight,
 355                                                 lisp_loc->m_priority, lisp_loc->m_weight));
 356                                 loc_hdr_flag(ndo, EXTRACT_16BITS(&lisp_loc->unused_and_flag));
 357                         }
 358                 }
 359         }
 360
 361         /*
 362          * Print xTR and Site ID. Handle the fact that the packet could be malformed.
 363          * If the xTR_ID_Present bit is not set, and we still have data to display,
 364          * show it as hex data.
 365          */
 366         if (xtr_present) {
 367                 if (!ND_TTEST2(*(packet_iterator + packet_offset), 24))
 368                         goto malformed;
 369                 hex_print_with_offset(ndo, "\n    xTR-ID: ", packet_iterator + packet_offset, 16, 0);
 370                 ND_PRINT((ndo, "\n    SITE-ID: %" PRIu64,
 371                         EXTRACT_64BITS(packet_iterator + packet_offset + 16)));
 372         } else {
 373                 /* Check if packet isn't over yet */
 374                 if (packet_iterator + packet_offset < ndo->ndo_snapend) {
 375                         hex_print_with_offset(ndo, "\n    Data: ", packet_iterator + packet_offset,
 376                                 (ndo->ndo_snapend - (packet_iterator + packet_offset)), 0);
 377                 }
 378         }
 379         return;
 380 trunc:
 381         ND_PRINT((ndo, "\n    [|LISP]"));
 382         return;
 383 malformed:
 384         ND_PRINT((ndo, "\n    (malformed-packet)"));
 385         return;
 386 }
 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
 429 static void action_flag(netdissect_options *ndo, uint8_t act_auth_inc_res)
 430 {
 431         uint8_t action;
 432         uint8_t authoritative;
 433
 434         authoritative  = ((act_auth_inc_res >> 4) & 1);
 435
 436         if (authoritative)
 437                 ND_PRINT((ndo, " Authoritative,"));
 438         else
 439                 ND_PRINT((ndo, " Non-Authoritative,"));
 440
 441         action = act_auth_inc_res >> 5;
 442         ND_PRINT((ndo, " %s,", tok2str(lisp_eid_action, "unknown", action)));
 443 }
 444
 445
 446 static void loc_hdr_flag(netdissect_options *ndo, uint16_t flag)
 447 {
 448         ND_PRINT((ndo, " flags [%s],", bittok2str(lisp_loc_flag, "none", flag)));
 449 }
 450