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

   1 /*
   2  * Copyright (c) 2007-2011 Grégoire Henry, Juliusz Chroboczek
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  * 3. Neither the name of the project nor the names of its contributors
  13  *    may be used to endorse or promote products derived from this software
  14  *    without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 /* \summary: Babel Routing Protocol printer */
  30 /* Specifications:
  31  *
  32  * RFC 6126
  33  * RFC 7298
  34  * RFC 7557
  35  * draft-ietf-babel-rfc6126bis-17
  36  * draft-ietf-babel-hmac-10
  37  * draft-ietf-babel-source-specific-0
  38  */
  39
  40 #include <config.h>
  41
  42 #include "netdissect-stdinc.h"
  43
  44 #include <stdio.h>
  45 #include <string.h>
  46
  47 #include "netdissect.h"
  48 #include "addrtoname.h"
  49 #include "extract.h"
  50
  51 static void babel_print_v2(netdissect_options *, const u_char *cp, u_int length);
  52
  53 void
  54 babel_print(netdissect_options *ndo,
  55             const u_char *cp, u_int length)
  56 {
  57     ndo->ndo_protocol = "babel";
  58     nd_print_protocol(ndo);
  59
  60     ND_TCHECK_4(cp);
  61
  62     if(GET_U_1(cp) != 42) {
  63         ND_PRINT(" invalid header");
  64         return;
  65     } else {
  66         ND_PRINT(" %u", GET_U_1(cp + 1));
  67     }
  68
  69     switch(GET_U_1(cp + 1)) {
  70     case 2:
  71         babel_print_v2(ndo, cp, length);
  72         break;
  73     default:
  74         ND_PRINT(" unknown version");
  75         break;
  76     }
  77
  78     return;
  79
  80  trunc:
  81     nd_print_trunc(ndo);
  82 }
  83
  84 /* TLVs */
  85 #define MESSAGE_PAD1 0
  86 #define MESSAGE_PADN 1
  87 #define MESSAGE_ACK_REQ 2
  88 #define MESSAGE_ACK 3
  89 #define MESSAGE_HELLO 4
  90 #define MESSAGE_IHU 5
  91 #define MESSAGE_ROUTER_ID 6
  92 #define MESSAGE_NH 7
  93 #define MESSAGE_UPDATE 8
  94 #define MESSAGE_ROUTE_REQUEST 9
  95 #define MESSAGE_SEQNO_REQUEST 10
  96 #define MESSAGE_TSPC 11
  97 #define MESSAGE_HMAC 12
  98 #define MESSAGE_UPDATE_SRC_SPECIFIC 13 /* last appearance in draft-boutier-babel-source-specific-01 */
  99 #define MESSAGE_REQUEST_SRC_SPECIFIC 14 /* idem */
 100 #define MESSAGE_MH_REQUEST_SRC_SPECIFIC 15 /* idem */
 101 #define MESSAGE_MAC 16
 102 #define MESSAGE_PC 17
 103 #define MESSAGE_CHALLENGE_REQUEST 18
 104 #define MESSAGE_CHALLENGE_REPLY 19
 105
 106 /* sub-TLVs */
 107 #define MESSAGE_SUB_PAD1 0
 108 #define MESSAGE_SUB_PADN 1
 109 #define MESSAGE_SUB_DIVERSITY 2
 110 #define MESSAGE_SUB_TIMESTAMP 3
 111
 112 /* "Mandatory" bit in sub-TLV types */
 113 #define MANDATORY_MASK 0x80
 114
 115 /* Flags for the Hello TLV */
 116 #define UNICAST_MASK 0x8000
 117
 118 /* Diversity sub-TLV channel codes */
 119 static const struct tok diversity_str[] = {
 120     { 0,   "reserved" },
 121     { 255, "all"      },
 122     { 0, NULL }
 123 };
 124
 125 static const char *
 126 format_id(netdissect_options *ndo, const u_char *id)
 127 {
 128     static char buf[25];
 129     snprintf(buf, 25, "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x",
 130              GET_U_1(id), GET_U_1(id + 1), GET_U_1(id + 2),
 131              GET_U_1(id + 3), GET_U_1(id + 4), GET_U_1(id + 5),
 132              GET_U_1(id + 6), GET_U_1(id + 7));
 133     buf[24] = '\0';
 134     return buf;
 135 }
 136
 137 static const unsigned char v4prefix[16] =
 138     {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF, 0, 0, 0, 0 };
 139
 140 static const char *
 141 format_prefix(netdissect_options *ndo, const u_char *prefix, unsigned char plen)
 142 {
 143     static char buf[50];
 144
 145     /*
 146      * prefix points to a buffer on the stack into which the prefix has
 147      * been placed, so we can't use GET_IPADDR_STRING() or
 148      * GET_IP6ADDR_STRING() on it.
 149      */
 150     if(plen >= 96 && memcmp(prefix, v4prefix, 12) == 0)
 151         snprintf(buf, 50, "%s/%u", ipaddr_string(ndo, prefix + 12), plen - 96);
 152     else
 153         snprintf(buf, 50, "%s/%u", ip6addr_string(ndo, prefix), plen);
 154     buf[49] = '\0';
 155     return buf;
 156 }
 157
 158 static const char *
 159 format_address(netdissect_options *ndo, const u_char *prefix)
 160 {
 161     /*
 162      * prefix points to a buffer on the stack into which the prefix has
 163      * been placed, so we can't use GET_IPADDR_STRING() or
 164      * GET_IP6ADDR_STRING() on it.
 165      */
 166     if(memcmp(prefix, v4prefix, 12) == 0)
 167         return ipaddr_string(ndo, prefix + 12);
 168     else
 169         return ip6addr_string(ndo, prefix);
 170 }
 171
 172 static const char *
 173 format_interval(const uint16_t i)
 174 {
 175     static char buf[sizeof("000.00s")];
 176
 177     if (i == 0)
 178         return "0.0s (bogus)";
 179     snprintf(buf, sizeof(buf), "%u.%02us", i / 100, i % 100);
 180     return buf;
 181 }
 182
 183 static const char *
 184 format_interval_update(const uint16_t i)
 185 {
 186     return i == 0xFFFF ? "infinity" : format_interval(i);
 187 }
 188
 189 static const char *
 190 format_timestamp(const uint32_t i)
 191 {
 192     static char buf[sizeof("0000.000000s")];
 193     snprintf(buf, sizeof(buf), "%u.%06us", i / 1000000, i % 1000000);
 194     return buf;
 195 }
 196
 197 /* Return number of octets consumed from the input buffer (not the prefix length
 198  * in bytes), or -1 for encoding error. */
 199 static int
 200 network_prefix(int ae, int plen, unsigned int omitted,
 201                const unsigned char *p, const unsigned char *dp,
 202                unsigned int len, unsigned char *p_r)
 203 {
 204     unsigned pb;
 205     unsigned char prefix[16];
 206     int consumed = 0;
 207
 208     if(plen >= 0)
 209         pb = (plen + 7) / 8;
 210     else if(ae == 1)
 211         pb = 4;
 212     else
 213         pb = 16;
 214
 215     if(pb > 16)
 216         return -1;
 217
 218     memset(prefix, 0, 16);
 219
 220     switch(ae) {
 221     case 0: break;
 222     case 1:
 223         if(omitted > 4 || pb > 4 || (pb > omitted && len < pb - omitted))
 224             return -1;
 225         memcpy(prefix, v4prefix, 12);
 226         if(omitted) {
 227             if (dp == NULL) return -1;
 228             memcpy(prefix, dp, 12 + omitted);
 229         }
 230         if(pb > omitted) {
 231             memcpy(prefix + 12 + omitted, p, pb - omitted);
 232             consumed = pb - omitted;
 233         }
 234         break;
 235     case 2:
 236         if(omitted > 16 || (pb > omitted && len < pb - omitted))
 237             return -1;
 238         if(omitted) {
 239             if (dp == NULL) return -1;
 240             memcpy(prefix, dp, omitted);
 241         }
 242         if(pb > omitted) {
 243             memcpy(prefix + omitted, p, pb - omitted);
 244             consumed = pb - omitted;
 245         }
 246         break;
 247     case 3:
 248         if(pb > 8 && len < pb - 8) return -1;
 249         prefix[0] = 0xfe;
 250         prefix[1] = 0x80;
 251         if(pb > 8) {
 252             memcpy(prefix + 8, p, pb - 8);
 253             consumed = pb - 8;
 254         }
 255         break;
 256     default:
 257         return -1;
 258     }
 259
 260     memcpy(p_r, prefix, 16);
 261     return consumed;
 262 }
 263
 264 static int
 265 network_address(int ae, const unsigned char *a, unsigned int len,
 266                 unsigned char *a_r)
 267 {
 268     return network_prefix(ae, -1, 0, a, NULL, len, a_r);
 269 }
 270
 271 /*
 272  * Sub-TLVs consume the "extra data" of Babel TLVs (see Section 4.3 of RFC6126),
 273  * their encoding is similar to the encoding of TLVs, but the type namespace is
 274  * different:
 275  *
 276  * o Type 0 stands for Pad1 sub-TLV with the same encoding as the Pad1 TLV.
 277  * o Type 1 stands for PadN sub-TLV with the same encoding as the PadN TLV.
 278  * o Type 2 stands for Diversity sub-TLV, which propagates diversity routing
 279  *   data. Its body is a variable-length sequence of 8-bit unsigned integers,
 280  *   each representing per-hop number of interfering radio channel for the
 281  *   prefix. Channel 0 is invalid and must not be used in the sub-TLV, channel
 282  *   255 interferes with any other channel.
 283  * o Type 3 stands for Timestamp sub-TLV, used to compute RTT between
 284  *   neighbours. In the case of a Hello TLV, the body stores a 32-bits
 285  *   timestamp, while in the case of a IHU TLV, two 32-bits timestamps are
 286  *   stored.
 287  *
 288  * Sub-TLV types 0 and 1 are valid for any TLV type, whether sub-TLV type 2 is
 289  * only valid for TLV type 8 (Update). Note that within an Update TLV a missing
 290  * Diversity sub-TLV is not the same as a Diversity sub-TLV with an empty body.
 291  * The former would mean a lack of any claims about the interference, and the
 292  * latter would state that interference is definitely absent.
 293  * A type 3 sub-TLV is valid both for Hello and IHU TLVs, though the exact
 294  * semantic of the sub-TLV is different in each case.
 295  */
 296 static void
 297 subtlvs_print(netdissect_options *ndo,
 298               const u_char *cp, const u_char *ep, const uint8_t tlv_type)
 299 {
 300     uint8_t subtype, sublen;
 301     const char *sep;
 302     uint32_t t1, t2;
 303
 304     while (cp < ep) {
 305         subtype = GET_U_1(cp);
 306         cp++;
 307         if(subtype == MESSAGE_SUB_PAD1) {
 308             ND_PRINT(" sub-pad1");
 309             continue;
 310         }
 311         if ((MANDATORY_MASK & subtype) != 0)
 312             ND_PRINT(" (M)");
 313         if(cp == ep)
 314             goto invalid;
 315         sublen = GET_U_1(cp);
 316         cp++;
 317         if(cp + sublen > ep)
 318             goto invalid;
 319
 320         switch(subtype) {
 321         case MESSAGE_SUB_PADN:
 322             ND_PRINT(" sub-padn");
 323             cp += sublen;
 324             break;
 325         case MESSAGE_SUB_DIVERSITY:
 326             ND_PRINT(" sub-diversity");
 327             if (sublen == 0) {
 328                 ND_PRINT(" empty");
 329                 break;
 330             }
 331             sep = " ";
 332             while (sublen) {
 333                 ND_PRINT("%s%s", sep,
 334                          tok2str(diversity_str, "%u", GET_U_1(cp)));
 335                 cp++;
 336                 sep = "-";
 337                 sublen--;
 338             }
 339             if(tlv_type != MESSAGE_UPDATE &&
 340                tlv_type != MESSAGE_UPDATE_SRC_SPECIFIC)
 341                 ND_PRINT(" (bogus)");
 342             break;
 343         case MESSAGE_SUB_TIMESTAMP:
 344             ND_PRINT(" sub-timestamp");
 345             if(tlv_type == MESSAGE_HELLO) {
 346                 if(sublen < 4)
 347                     goto invalid;
 348                 t1 = GET_BE_U_4(cp);
 349                 ND_PRINT(" %s", format_timestamp(t1));
 350             } else if(tlv_type == MESSAGE_IHU) {
 351                 if(sublen < 8)
 352                     goto invalid;
 353                 t1 = GET_BE_U_4(cp);
 354                 ND_PRINT(" %s", format_timestamp(t1));
 355                 t2 = GET_BE_U_4(cp + 4);
 356                 ND_PRINT("|%s", format_timestamp(t2));
 357             } else
 358                 ND_PRINT(" (bogus)");
 359             cp += sublen;
 360             break;
 361         default:
 362             ND_PRINT(" sub-unknown-0x%02x", subtype);
 363             cp += sublen;
 364         } /* switch */
 365     } /* while */
 366     return;
 367
 368  invalid:
 369     nd_print_invalid(ndo);
 370 }
 371
 372 #define ICHECK(i, l) \
 373         if ((i) + (l) > tlvs_length || (i) + (l) > packet_length_remaining) \
 374             goto invalid;
 375
 376 static int
 377 babel_print_v2_tlvs(netdissect_options *ndo,
 378                     const u_char *cp, u_int tlvs_length,
 379                     u_int packet_length_remaining)
 380 {
 381     u_int i;
 382     u_char v4_prefix[16] =
 383         {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF, 0, 0, 0, 0 };
 384     u_char v6_prefix[16] = {0};
 385
 386     i = 0;
 387     while(i < tlvs_length) {
 388         const u_char *message;
 389         uint8_t type;
 390         u_int len;
 391
 392         message = cp + i;
 393
 394         ICHECK(i, 1);
 395         if((type = GET_U_1(message)) == MESSAGE_PAD1) {
 396             ND_PRINT(ndo->ndo_vflag ? "\n\tPad 1" : " pad1");
 397             i += 1;
 398             continue;
 399         }
 400
 401         ICHECK(i, 2);
 402         ND_TCHECK_2(message);
 403         len = GET_U_1(message + 1);
 404
 405         ICHECK(i, 2 + len);
 406         ND_TCHECK_LEN(message, 2 + len);
 407
 408         switch(type) {
 409         case MESSAGE_PADN: {
 410             if (!ndo->ndo_vflag)
 411                 ND_PRINT(" padN");
 412             else
 413                 ND_PRINT("\n\tPad %u", len + 2);
 414         }
 415             break;
 416
 417         case MESSAGE_ACK_REQ: {
 418             u_short nonce, interval;
 419             if (!ndo->ndo_vflag)
 420                 ND_PRINT(" ack-req");
 421             else {
 422                 ND_PRINT("\n\tAcknowledgment Request ");
 423                 if(len < 6) goto invalid;
 424                 nonce = GET_BE_U_2(message + 4);
 425                 interval = GET_BE_U_2(message + 6);
 426                 ND_PRINT("%04x %s", nonce, format_interval(interval));
 427             }
 428         }
 429             break;
 430
 431         case MESSAGE_ACK: {
 432             u_short nonce;
 433             if (!ndo->ndo_vflag)
 434                 ND_PRINT(" ack");
 435             else {
 436                 ND_PRINT("\n\tAcknowledgment ");
 437                 if(len < 2) goto invalid;
 438                 nonce = GET_BE_U_2(message + 2);
 439                 ND_PRINT("%04x", nonce);
 440             }
 441         }
 442             break;
 443
 444         case MESSAGE_HELLO:  {
 445             u_short seqno, interval, unicast;
 446             if (!ndo->ndo_vflag)
 447                 ND_PRINT(" hello");
 448             else {
 449                 ND_PRINT("\n\tHello ");
 450                 if(len < 6) goto invalid;
 451                 unicast = (GET_BE_U_2(message + 2) & UNICAST_MASK);
 452                 seqno = GET_BE_U_2(message + 4);
 453                 interval = GET_BE_U_2(message + 6);
 454                 if(unicast)
 455                      ND_PRINT("(Unicast) ");
 456                 ND_PRINT("seqno %u ", seqno);
 457                 if(interval!=0)
 458                     ND_PRINT("interval %s", format_interval(interval));
 459                 else
 460                     ND_PRINT("unscheduled");
 461                 /* Extra data. */
 462                 if(len > 6)
 463                     subtlvs_print(ndo, message + 8, message + 2 + len, type);
 464             }
 465         }
 466             break;
 467
 468         case MESSAGE_IHU: {
 469             unsigned short rxcost, interval;
 470             if (!ndo->ndo_vflag)
 471                 ND_PRINT(" ihu");
 472             else {
 473                 u_char address[16];
 474                 u_char ae;
 475                 int rc;
 476                 ND_PRINT("\n\tIHU ");
 477                 if(len < 6) goto invalid;
 478                 rxcost = GET_BE_U_2(message + 4);
 479                 interval = GET_BE_U_2(message + 6);
 480                 ae = GET_U_1(message + 2);
 481                 rc = network_address(ae, message + 8,
 482                                      len - 6, address);
 483                 if(rc < 0) { nd_print_trunc(ndo); break; }
 484                 ND_PRINT("%s rxcost %u interval %s",
 485                        ae == 0 ? "any" : format_address(ndo, address),
 486                        rxcost, format_interval(interval));
 487                 /* Extra data. */
 488                 if((u_int)rc < len - 6)
 489                     subtlvs_print(ndo, message + 8 + rc, message + 2 + len,
 490                                   type);
 491             }
 492         }
 493             break;
 494
 495         case MESSAGE_ROUTER_ID: {
 496             if (!ndo->ndo_vflag)
 497                 ND_PRINT(" router-id");
 498             else {
 499                 ND_PRINT("\n\tRouter Id");
 500                 if(len < 10) goto invalid;
 501                 ND_PRINT(" %s", format_id(ndo, message + 4));
 502             }
 503         }
 504             break;
 505
 506         case MESSAGE_NH: {
 507             if (!ndo->ndo_vflag)
 508                 ND_PRINT(" nh");
 509             else {
 510                 int rc;
 511                 u_char ae;
 512                 u_char nh[16];
 513                 ND_PRINT("\n\tNext Hop");
 514                 if(len < 2) goto invalid;
 515                 ae = GET_U_1(message + 2);
 516                 rc = network_address(ae, message + 4,
 517                                      len - 2, nh);
 518                 if(rc < 0) goto invalid;
 519                 ND_PRINT(" %s", ae == 0 ? "invalid AE 0" : format_address(ndo, nh));
 520             }
 521         }
 522             break;
 523
 524         case MESSAGE_UPDATE: {
 525             if (!ndo->ndo_vflag) {
 526                 ND_PRINT(" update");
 527                 if(len < 10)
 528                     goto invalid;
 529                 else
 530                     ND_PRINT("%s%s%s",
 531                            (GET_U_1(message + 3) & 0x80) ? "/prefix": "",
 532                            (GET_U_1(message + 3) & 0x40) ? "/id" : "",
 533                            (GET_U_1(message + 3) & 0x3f) ? "/unknown" : "");
 534             } else {
 535                 u_short interval, seqno, metric;
 536                 u_char ae, plen;
 537                 int rc;
 538                 u_char prefix[16];
 539                 ND_PRINT("\n\tUpdate");
 540                 if(len < 10) goto invalid;
 541                 ae = GET_U_1(message + 2);
 542                 plen = GET_U_1(message + 4) + (GET_U_1(message + 2) == 1 ? 96 : 0);
 543                 rc = network_prefix(ae,
 544                                     GET_U_1(message + 4),
 545                                     GET_U_1(message + 5),
 546                                     message + 12,
 547                                     GET_U_1(message + 2) == 1 ? v4_prefix : v6_prefix,
 548                                     len - 10, prefix);
 549                 if(rc < 0) goto invalid;
 550                 interval = GET_BE_U_2(message + 6);
 551                 seqno = GET_BE_U_2(message + 8);
 552                 metric = GET_BE_U_2(message + 10);
 553                 ND_PRINT("%s%s%s %s metric %u seqno %u interval %s",
 554                        (GET_U_1(message + 3) & 0x80) ? "/prefix": "",
 555                        (GET_U_1(message + 3) & 0x40) ? "/id" : "",
 556                        (GET_U_1(message + 3) & 0x3f) ? "/unknown" : "",
 557                        ae == 0 ? "any" : format_prefix(ndo, prefix, plen),
 558                        metric, seqno, format_interval_update(interval));
 559                 if(GET_U_1(message + 3) & 0x80) {
 560                     if(GET_U_1(message + 2) == 1)
 561                         memcpy(v4_prefix, prefix, 16);
 562                     else
 563                         memcpy(v6_prefix, prefix, 16);
 564                 }
 565                 /* extra data? */
 566                 if((u_int)rc < len - 10)
 567                     subtlvs_print(ndo, message + 12 + rc, message + 2 + len, type);
 568             }
 569         }
 570             break;
 571
 572         case MESSAGE_ROUTE_REQUEST: {
 573             if (!ndo->ndo_vflag)
 574                 ND_PRINT(" route-request");
 575             else {
 576                 int rc;
 577                 u_char prefix[16], ae, plen;
 578                 ND_PRINT("\n\tRoute Request ");
 579                 if(len < 2) goto invalid;
 580                 ae = GET_U_1(message + 2);
 581                 plen = GET_U_1(message + 3) + (GET_U_1(message + 2) == 1 ? 96 : 0);
 582                 rc = network_prefix(ae,
 583                                     GET_U_1(message + 3), 0,
 584                                     message + 4, NULL, len - 2, prefix);
 585                 if(rc < 0) goto invalid;
 586                 ND_PRINT("for %s",
 587                        ae == 0 ? "any" : format_prefix(ndo, prefix, plen));
 588             }
 589         }
 590             break;
 591
 592         case MESSAGE_SEQNO_REQUEST : {
 593             if (!ndo->ndo_vflag)
 594                 ND_PRINT(" seqno-request");
 595             else {
 596                 int rc;
 597                 u_short seqno;
 598                 u_char prefix[16], ae, plen;
 599                 ND_PRINT("\n\tSeqno Request ");
 600                 if(len < 14) goto invalid;
 601                 ae = GET_U_1(message + 2);
 602                 seqno = GET_BE_U_2(message + 4);
 603                 rc = network_prefix(ae,
 604                                     GET_U_1(message + 3), 0,
 605                                     message + 16, NULL, len - 14, prefix);
 606                 if(rc < 0) goto invalid;
 607                 plen = GET_U_1(message + 3) + (GET_U_1(message + 2) == 1 ? 96 : 0);
 608                 ND_PRINT("(%u hops) for %s seqno %u id %s",
 609                        GET_U_1(message + 6),
 610                        ae == 0 ? "invalid AE 0" : format_prefix(ndo, prefix, plen),
 611                        seqno, format_id(ndo, message + 8));
 612             }
 613         }
 614             break;
 615         case MESSAGE_TSPC :
 616             if (!ndo->ndo_vflag)
 617                 ND_PRINT(" tspc");
 618             else {
 619                 ND_PRINT("\n\tTS/PC ");
 620                 if(len < 6) goto invalid;
 621                 ND_PRINT("timestamp %u packetcounter %u",
 622                           GET_BE_U_4(message + 4),
 623                           GET_BE_U_2(message + 2));
 624             }
 625             break;
 626         case MESSAGE_HMAC : {
 627             if (!ndo->ndo_vflag)
 628                 ND_PRINT(" hmac");
 629             else {
 630                 unsigned j;
 631                 ND_PRINT("\n\tHMAC ");
 632                 if(len < 18) goto invalid;
 633                 ND_PRINT("key-id %u digest-%u ", GET_BE_U_2(message + 2),
 634                          len - 2);
 635                 for (j = 0; j < len - 2; j++)
 636                     ND_PRINT("%02X", GET_U_1(message + j + 4));
 637             }
 638         }
 639             break;
 640
 641         case MESSAGE_UPDATE_SRC_SPECIFIC : {
 642             if(!ndo->ndo_vflag) {
 643                 ND_PRINT(" ss-update");
 644             } else {
 645                 u_char prefix[16], src_prefix[16];
 646                 u_short interval, seqno, metric;
 647                 u_char ae, plen, src_plen, omitted;
 648                 int rc;
 649                 int parsed_len = 10;
 650                 ND_PRINT("\n\tSS-Update");
 651                 if(len < 10) goto invalid;
 652                 ae = GET_U_1(message + 2);
 653                 src_plen = GET_U_1(message + 3);
 654                 plen = GET_U_1(message + 4);
 655                 omitted = GET_U_1(message + 5);
 656                 interval = GET_BE_U_2(message + 6);
 657                 seqno = GET_BE_U_2(message + 8);
 658                 metric = GET_BE_U_2(message + 10);
 659                 rc = network_prefix(ae, plen, omitted, message + 2 + parsed_len,
 660                                     ae == 1 ? v4_prefix : v6_prefix,
 661                                     len - parsed_len, prefix);
 662                 if(rc < 0) goto invalid;
 663                 if(ae == 1)
 664                     plen += 96;
 665                 parsed_len += rc;
 666                 rc = network_prefix(ae, src_plen, 0, message + 2 + parsed_len,
 667                                     NULL, len - parsed_len, src_prefix);
 668                 if(rc < 0) goto invalid;
 669                 if(ae == 1)
 670                     src_plen += 96;
 671                 parsed_len += rc;
 672
 673                 ND_PRINT(" %s from", format_prefix(ndo, prefix, plen));
 674                 ND_PRINT(" %s metric %u seqno %u interval %s",
 675                           format_prefix(ndo, src_prefix, src_plen),
 676                           metric, seqno, format_interval_update(interval));
 677                 /* extra data? */
 678                 if((u_int)parsed_len < len)
 679                     subtlvs_print(ndo, message + 2 + parsed_len,
 680                                   message + 2 + len, type);
 681             }
 682         }
 683             break;
 684
 685         case MESSAGE_REQUEST_SRC_SPECIFIC : {
 686             if(!ndo->ndo_vflag)
 687                 ND_PRINT(" ss-request");
 688             else {
 689                 int rc, parsed_len = 3;
 690                 u_char ae, plen, src_plen, prefix[16], src_prefix[16];
 691                 ND_PRINT("\n\tSS-Request ");
 692                 if(len < 3) goto invalid;
 693                 ae = GET_U_1(message + 2);
 694                 plen = GET_U_1(message + 3);
 695                 src_plen = GET_U_1(message + 4);
 696                 rc = network_prefix(ae, plen, 0, message + 2 + parsed_len,
 697                                     NULL, len - parsed_len, prefix);
 698                 if(rc < 0) goto invalid;
 699                 if(ae == 1)
 700                     plen += 96;
 701                 parsed_len += rc;
 702                 rc = network_prefix(ae, src_plen, 0, message + 2 + parsed_len,
 703                                     NULL, len - parsed_len, src_prefix);
 704                 if(rc < 0) goto invalid;
 705                 if(ae == 1)
 706                     src_plen += 96;
 707                 parsed_len += rc;
 708                 if(ae == 0) {
 709                     ND_PRINT("for any");
 710                 } else {
 711                     ND_PRINT("for (%s, ", format_prefix(ndo, prefix, plen));
 712                     ND_PRINT("%s)", format_prefix(ndo, src_prefix, src_plen));
 713                 }
 714             }
 715         }
 716             break;
 717
 718         case MESSAGE_MH_REQUEST_SRC_SPECIFIC : {
 719             if(!ndo->ndo_vflag)
 720                 ND_PRINT(" ss-mh-request");
 721             else {
 722                 int rc, parsed_len = 14;
 723                 u_short seqno;
 724                 u_char ae, plen, src_plen, prefix[16], src_prefix[16], hopc;
 725                 const u_char *router_id = NULL;
 726                 ND_PRINT("\n\tSS-MH-Request ");
 727                 if(len < 14) goto invalid;
 728                 ae = GET_U_1(message + 2);
 729                 plen = GET_U_1(message + 3);
 730                 seqno = GET_BE_U_2(message + 4);
 731                 hopc = GET_U_1(message + 6);
 732                 src_plen = GET_U_1(message + 7);
 733                 router_id = message + 8;
 734                 rc = network_prefix(ae, plen, 0, message + 2 + parsed_len,
 735                                     NULL, len - parsed_len, prefix);
 736                 if(rc < 0) goto invalid;
 737                 if(ae == 1)
 738                     plen += 96;
 739                 parsed_len += rc;
 740                 rc = network_prefix(ae, src_plen, 0, message + 2 + parsed_len,
 741                                     NULL, len - parsed_len, src_prefix);
 742                 if(rc < 0) goto invalid;
 743                 if(ae == 1)
 744                     src_plen += 96;
 745                 ND_PRINT("(%u hops) for (%s, ",
 746                           hopc, format_prefix(ndo, prefix, plen));
 747                 ND_PRINT("%s) seqno %u id %s",
 748                           format_prefix(ndo, src_prefix, src_plen),
 749                           seqno, format_id(ndo, router_id));
 750             }
 751         }
 752             break;
 753
 754         case MESSAGE_MAC: {
 755             if (!ndo->ndo_vflag)
 756                 ND_PRINT(" mac");
 757             else {
 758                 ND_PRINT("\n\tMAC ");
 759                 ND_PRINT("len %u", len);
 760             }
 761         }
 762             break;
 763
 764         case MESSAGE_PC: {
 765             if (!ndo->ndo_vflag)
 766                 ND_PRINT(" pc");
 767             else {
 768                 ND_PRINT("\n\tPC");
 769                 if(len < 4) goto invalid;
 770                 ND_PRINT(" value %u",
 771                     GET_BE_U_4(message + 2));
 772                 ND_PRINT(" index len %u", len-4);
 773             }
 774         }
 775             break;
 776
 777         case MESSAGE_CHALLENGE_REQUEST: {
 778             if (!ndo->ndo_vflag)
 779                 ND_PRINT(" challenge_request");
 780             else {
 781                 ND_PRINT("\n\tChallenge Request");
 782                 if(len > 192) goto invalid;
 783                 ND_PRINT(" len %u", len);
 784             }
 785         }
 786             break;
 787
 788         case MESSAGE_CHALLENGE_REPLY: {
 789             if (!ndo->ndo_vflag)
 790                 ND_PRINT(" challenge_reply");
 791             else {
 792                 ND_PRINT("\n\tChallenge Reply");
 793                 if (len > 192) goto invalid;
 794                 ND_PRINT(" len %u", len);
 795             }
 796         }
 797             break;
 798
 799         default:
 800             if (!ndo->ndo_vflag)
 801                 ND_PRINT(" unknown");
 802             else
 803                 ND_PRINT("\n\tUnknown message type %u", type);
 804         }
 805         i += len + 2;
 806     }
 807
 808     return 0; /* OK */
 809
 810 trunc:
 811     return -1; /* packet truncated by capture process */
 812
 813 invalid:
 814     return -2; /* packet is invalid */
 815 }
 816
 817 static void
 818 babel_print_v2(netdissect_options *ndo,
 819                const u_char *cp, u_int length)
 820 {
 821     u_short bodylen;
 822     int ret;
 823
 824     ND_TCHECK_4(cp);
 825     if (length < 4)
 826         goto invalid;
 827     bodylen = GET_BE_U_2(cp + 2);
 828     ND_PRINT(" (%u)", bodylen);
 829     length -= 4;
 830     cp += 4;
 831
 832     /* Process the TLVs in the body */
 833     if (length < bodylen)
 834         goto invalid;
 835     ret = babel_print_v2_tlvs(ndo, cp, bodylen, length);
 836     if (ret == -1)
 837         goto trunc;
 838     if (ret == -2)
 839         goto invalid;
 840     length -= bodylen;
 841     cp += bodylen;
 842
 843     /* If there's a trailer, process the TLVs in the trailer */
 844     if (length != 0) {
 845         if(ndo->ndo_vflag) ND_PRINT("\n\t----");
 846         else ND_PRINT(" |");
 847         ret = babel_print_v2_tlvs(ndo, cp, length, length);
 848         if (ret == -1)
 849             goto trunc;
 850         if (ret == -2)
 851             goto invalid;
 852     }
 853     return;
 854
 855  trunc:
 856     nd_print_trunc(ndo);
 857     return;
 858
 859  invalid:
 860     nd_print_invalid(ndo);
 861 }