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 #ifdef HAVE_CONFIG_H
  30 #include "config.h"
  31 #endif
  32
  33 #include <tcpdump-stdinc.h>
  34
  35 #include <stdio.h>
  36 #include <string.h>
  37
  38 #include "addrtoname.h"
  39 #include "interface.h"
  40 #include "extract.h"
  41
  42 static const char tstr[] = "[|babel]";
  43
  44 static void babel_print_v2(const u_char *cp, u_int length);
  45
  46 void
  47 babel_print(const u_char *cp, u_int length) {
  48     printf("babel");
  49
  50     TCHECK2(*cp, 4);
  51
  52     if(cp[0] != 42) {
  53         printf(" malformed header");
  54         return;
  55     } else {
  56         printf(" %d", cp[1]);
  57     }
  58
  59     switch(cp[1]) {
  60     case 2:
  61         babel_print_v2(cp,length);
  62         break;
  63     default:
  64         printf(" unknown version");
  65         break;
  66     }
  67
  68     return;
  69
  70  trunc:
  71     printf(" %s", tstr);
  72     return;
  73 }
  74
  75 /* TLVs */
  76 #define MESSAGE_PAD1 0
  77 #define MESSAGE_PADN 1
  78 #define MESSAGE_ACK_REQ 2
  79 #define MESSAGE_ACK 3
  80 #define MESSAGE_HELLO 4
  81 #define MESSAGE_IHU 5
  82 #define MESSAGE_ROUTER_ID 6
  83 #define MESSAGE_NH 7
  84 #define MESSAGE_UPDATE 8
  85 #define MESSAGE_REQUEST 9
  86 #define MESSAGE_MH_REQUEST 10
  87 #define MESSAGE_TSPC 11
  88 #define MESSAGE_HMAC 12
  89
  90 /* sub-TLVs */
  91 #define MESSAGE_SUB_PAD1 0
  92 #define MESSAGE_SUB_PADN 1
  93 #define MESSAGE_SUB_DIVERSITY 2
  94
  95 /* Diversity sub-TLV channel codes */
  96 static const struct tok diversity_str[] = {
  97     { 0,   "reserved" },
  98     { 255, "all"      },
  99     { 0, NULL }
 100 };
 101
 102 static const char *
 103 format_id(const u_char *id)
 104 {
 105     static char buf[25];
 106     snprintf(buf, 25, "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x",
 107              id[0], id[1], id[2], id[3], id[4], id[5], id[6], id[7]);
 108     buf[24] = '\0';
 109     return buf;
 110 }
 111
 112 static const unsigned char v4prefix[16] =
 113     {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF, 0, 0, 0, 0 };
 114
 115 static const char *
 116 format_prefix(const u_char *prefix, unsigned char plen)
 117 {
 118     static char buf[50];
 119     if(plen >= 96 && memcmp(prefix, v4prefix, 12) == 0)
 120         snprintf(buf, 50, "%s/%u", ipaddr_string(prefix + 12), plen - 96);
 121     else
 122 #ifdef INET6
 123         snprintf(buf, 50, "%s/%u", ip6addr_string(prefix), plen);
 124 #else
 125         snprintf(buf, 50, "IPv6 addresses not supported");
 126 #endif
 127     buf[49] = '\0';
 128     return buf;
 129 }
 130
 131 static const char *
 132 format_address(const u_char *prefix)
 133 {
 134     if(memcmp(prefix, v4prefix, 12) == 0)
 135         return ipaddr_string(prefix + 12);
 136     else
 137 #ifdef INET6
 138         return ip6addr_string(prefix);
 139 #else
 140         return "IPv6 addresses not supported";
 141 #endif
 142 }
 143
 144 static const char *
 145 format_interval(const u_int16_t i)
 146 {
 147     static char buf[sizeof("000.00s")];
 148
 149     if (i == 0)
 150         return "0.0s (bogus)";
 151     snprintf(buf, sizeof(buf), "%u.%02us", i / 100, i % 100);
 152     return buf;
 153 }
 154
 155 static const char *
 156 format_interval_update(const u_int16_t i)
 157 {
 158     return i == 0xFFFF ? "infinity" : format_interval(i);
 159 }
 160
 161 /* Return number of octets consumed from the input buffer (not the prefix length
 162  * in bytes), or -1 for encoding error. */
 163 static int
 164 network_prefix(int ae, int plen, unsigned int omitted,
 165                const unsigned char *p, const unsigned char *dp,
 166                unsigned int len, unsigned char *p_r)
 167 {
 168     unsigned pb;
 169     unsigned char prefix[16];
 170     int consumed = 0;
 171
 172     if(plen >= 0)
 173         pb = (plen + 7) / 8;
 174     else if(ae == 1)
 175         pb = 4;
 176     else
 177         pb = 16;
 178
 179     if(pb > 16)
 180         return -1;
 181
 182     memset(prefix, 0, 16);
 183
 184     switch(ae) {
 185     case 0: break;
 186     case 1:
 187         if(omitted > 4 || pb > 4 || (pb > omitted && len < pb - omitted))
 188             return -1;
 189         memcpy(prefix, v4prefix, 12);
 190         if(omitted) {
 191             if (dp == NULL) return -1;
 192             memcpy(prefix, dp, 12 + omitted);
 193         }
 194         if(pb > omitted) {
 195             memcpy(prefix + 12 + omitted, p, pb - omitted);
 196             consumed = pb - omitted;
 197         }
 198         break;
 199     case 2:
 200         if(omitted > 16 || (pb > omitted && len < pb - omitted))
 201             return -1;
 202         if(omitted) {
 203             if (dp == NULL) return -1;
 204             memcpy(prefix, dp, omitted);
 205         }
 206         if(pb > omitted) {
 207             memcpy(prefix + omitted, p, pb - omitted);
 208             consumed = pb - omitted;
 209         }
 210         break;
 211     case 3:
 212         if(pb > 8 && len < pb - 8) return -1;
 213         prefix[0] = 0xfe;
 214         prefix[1] = 0x80;
 215         if(pb > 8) {
 216             memcpy(prefix + 8, p, pb - 8);
 217             consumed = pb - 8;
 218         }
 219         break;
 220     default:
 221         return -1;
 222     }
 223
 224     memcpy(p_r, prefix, 16);
 225     return consumed;
 226 }
 227
 228 static int
 229 network_address(int ae, const unsigned char *a, unsigned int len,
 230                 unsigned char *a_r)
 231 {
 232     return network_prefix(ae, -1, 0, a, NULL, len, a_r);
 233 }
 234
 235 /*
 236  * Sub-TLVs consume the "extra data" of Babel TLVs (see Section 4.3 of RFC6126),
 237  * their encoding is similar to the encoding of TLVs, but the type namespace is
 238  * different:
 239  *
 240  * o Type 0 stands for Pad1 sub-TLV with the same encoding as the Pad1 TLV.
 241  * o Type 1 stands for PadN sub-TLV with the same encoding as the PadN TLV.
 242  * o Type 2 stands for Diversity sub-TLV, which propagates diversity routing
 243  *   data. Its body is a variable-length sequence of 8-bit unsigned integers,
 244  *   each representing per-hop number of interferring radio channel for the
 245  *   prefix. Channel 0 is invalid and must not be used in the sub-TLV, channel
 246  *   255 interferes with any other channel.
 247  *
 248  * Sub-TLV types 0 and 1 are valid for any TLV type, whether sub-TLV type 2 is
 249  * only valid for TLV type 8 (Update). Note that within an Update TLV a missing
 250  * Diversity sub-TLV is not the same as a Diversity sub-TLV with an empty body.
 251  * The former would mean a lack of any claims about the interference, and the
 252  * latter would state that interference is definitely absent. */
 253 static void
 254 subtlvs_print(const u_char *cp, const u_char *ep, const uint8_t tlv_type) {
 255     uint8_t subtype, sublen;
 256     const char *sep;
 257
 258     while (cp < ep) {
 259         subtype = *cp++;
 260         if(subtype == MESSAGE_SUB_PAD1) {
 261             printf(" sub-pad1");
 262             continue;
 263         }
 264         if(cp == ep)
 265             goto corrupt;
 266         sublen = *cp++;
 267         if(cp + sublen > ep)
 268             goto corrupt;
 269
 270         switch(subtype) {
 271         case MESSAGE_SUB_PADN:
 272             printf(" sub-padn");
 273             cp += sublen;
 274             break;
 275         case MESSAGE_SUB_DIVERSITY:
 276             printf(" sub-diversity");
 277             if (sublen == 0) {
 278                 printf(" empty");
 279                 break;
 280             }
 281             sep = " ";
 282             while(sublen--) {
 283                 printf("%s%s", sep, tok2str(diversity_str, "%u", *cp++));
 284                 sep = "-";
 285             }
 286             if(tlv_type != MESSAGE_UPDATE)
 287                 printf(" (bogus)");
 288             break;
 289         default:
 290             printf(" sub-unknown-0x%02x", subtype);
 291             cp += sublen;
 292         } /* switch */
 293     } /* while */
 294     return;
 295
 296  corrupt:
 297     printf(" (corrupt)");
 298 }
 299
 300 #define ICHECK(i, l) \
 301         if ((i) + (l) > bodylen || (i) + (l) > length) goto corrupt;
 302
 303 static void
 304 babel_print_v2(const u_char *cp, u_int length) {
 305     u_int i;
 306     u_short bodylen;
 307     u_char v4_prefix[16] =
 308         {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF, 0, 0, 0, 0 };
 309     u_char v6_prefix[16] = {0};
 310
 311     TCHECK2(*cp, 4);
 312     if (length < 4)
 313         goto corrupt;
 314     bodylen = EXTRACT_16BITS(cp + 2);
 315     printf(" (%u)", bodylen);
 316
 317     /* Process the TLVs in the body */
 318     i = 0;
 319     while(i < bodylen) {
 320         const u_char *message;
 321         u_int type, len;
 322
 323         message = cp + 4 + i;
 324
 325         TCHECK2(*message, 1);
 326         if((type = message[0]) == MESSAGE_PAD1) {
 327             printf(vflag ? "\n\tPad 1" : " pad1");
 328             i += 1;
 329             continue;
 330         }
 331
 332         TCHECK2(*message, 2);
 333         ICHECK(i, 2);
 334         len = message[1];
 335
 336         TCHECK2(*message, 2 + len);
 337         ICHECK(i, 2 + len);
 338
 339         switch(type) {
 340         case MESSAGE_PADN: {
 341             if(!vflag)
 342                 printf(" padN");
 343             else
 344                 printf("\n\tPad %d", len + 2);
 345         }
 346             break;
 347
 348         case MESSAGE_ACK_REQ: {
 349             u_short nonce, interval;
 350             if(!vflag)
 351                 printf(" ack-req");
 352             else {
 353                 printf("\n\tAcknowledgment Request ");
 354                 if(len < 6) goto corrupt;
 355                 nonce = EXTRACT_16BITS(message + 4);
 356                 interval = EXTRACT_16BITS(message + 6);
 357                 printf("%04x %s", nonce, format_interval(interval));
 358             }
 359         }
 360             break;
 361
 362         case MESSAGE_ACK: {
 363             u_short nonce;
 364             if(!vflag)
 365                 printf(" ack");
 366             else {
 367                 printf("\n\tAcknowledgment ");
 368                 if(len < 2) goto corrupt;
 369                 nonce = EXTRACT_16BITS(message + 2);
 370                 printf("%04x", nonce);
 371             }
 372         }
 373             break;
 374
 375         case MESSAGE_HELLO:  {
 376             u_short seqno, interval;
 377             if(!vflag)
 378                 printf(" hello");
 379             else {
 380                 printf("\n\tHello ");
 381                 if(len < 6) goto corrupt;
 382                 seqno = EXTRACT_16BITS(message + 4);
 383                 interval = EXTRACT_16BITS(message + 6);
 384                 printf("seqno %u interval %s", seqno, format_interval(interval));
 385             }
 386         }
 387             break;
 388
 389         case MESSAGE_IHU: {
 390             unsigned short txcost, interval;
 391             if(!vflag)
 392                 printf(" ihu");
 393             else {
 394                 u_char address[16];
 395                 int rc;
 396                 printf("\n\tIHU ");
 397                 if(len < 6) goto corrupt;
 398                 txcost = EXTRACT_16BITS(message + 4);
 399                 interval = EXTRACT_16BITS(message + 6);
 400                 rc = network_address(message[2], message + 8, len - 6, address);
 401                 if(rc < 0) { printf("%s", tstr); break; }
 402                 printf("%s txcost %u interval %s",
 403                        format_address(address), txcost, format_interval(interval));
 404             }
 405         }
 406             break;
 407
 408         case MESSAGE_ROUTER_ID: {
 409             if(!vflag)
 410                 printf(" router-id");
 411             else {
 412                 printf("\n\tRouter Id");
 413                 if(len < 10) goto corrupt;
 414                 printf(" %s", format_id(message + 4));
 415             }
 416         }
 417             break;
 418
 419         case MESSAGE_NH: {
 420             if(!vflag)
 421                 printf(" nh");
 422             else {
 423                 int rc;
 424                 u_char nh[16];
 425                 printf("\n\tNext Hop");
 426                 if(len < 2) goto corrupt;
 427                 rc = network_address(message[2], message + 4, len - 2, nh);
 428                 if(rc < 0) goto corrupt;
 429                 printf(" %s", format_address(nh));
 430             }
 431         }
 432             break;
 433
 434         case MESSAGE_UPDATE: {
 435             if(!vflag) {
 436                 printf(" update");
 437                 if(len < 1)
 438                     printf("/truncated");
 439                 else
 440                     printf("%s%s%s",
 441                            (message[3] & 0x80) ? "/prefix": "",
 442                            (message[3] & 0x40) ? "/id" : "",
 443                            (message[3] & 0x3f) ? "/unknown" : "");
 444             } else {
 445                 u_short interval, seqno, metric;
 446                 u_char plen;
 447                 int rc;
 448                 u_char prefix[16];
 449                 printf("\n\tUpdate");
 450                 if(len < 10) goto corrupt;
 451                 plen = message[4] + (message[2] == 1 ? 96 : 0);
 452                 rc = network_prefix(message[2], message[4], message[5],
 453                                     message + 12,
 454                                     message[2] == 1 ? v4_prefix : v6_prefix,
 455                                     len - 10, prefix);
 456                 if(rc < 0) goto corrupt;
 457                 interval = EXTRACT_16BITS(message + 6);
 458                 seqno = EXTRACT_16BITS(message + 8);
 459                 metric = EXTRACT_16BITS(message + 10);
 460                 printf("%s%s%s %s metric %u seqno %u interval %s",
 461                        (message[3] & 0x80) ? "/prefix": "",
 462                        (message[3] & 0x40) ? "/id" : "",
 463                        (message[3] & 0x3f) ? "/unknown" : "",
 464                        format_prefix(prefix, plen),
 465                        metric, seqno, format_interval_update(interval));
 466                 if(message[3] & 0x80) {
 467                     if(message[2] == 1)
 468                         memcpy(v4_prefix, prefix, 16);
 469                     else
 470                         memcpy(v6_prefix, prefix, 16);
 471                 }
 472                 /* extra data? */
 473                 if((u_int)rc < len - 10)
 474                     subtlvs_print(message + 12 + rc, message + 2 + len, type);
 475             }
 476         }
 477             break;
 478
 479         case MESSAGE_REQUEST: {
 480             if(!vflag)
 481                 printf(" request");
 482             else {
 483                 int rc;
 484                 u_char prefix[16], plen;
 485                 printf("\n\tRequest ");
 486                 if(len < 2) goto corrupt;
 487                 plen = message[3] + (message[2] == 1 ? 96 : 0);
 488                 rc = network_prefix(message[2], message[3], 0,
 489                                     message + 4, NULL, len - 2, prefix);
 490                 if(rc < 0) goto corrupt;
 491                 printf("for %s",
 492                        message[2] == 0 ? "any" : format_prefix(prefix, plen));
 493             }
 494         }
 495             break;
 496
 497         case MESSAGE_MH_REQUEST : {
 498             if(!vflag)
 499                 printf(" mh-request");
 500             else {
 501                 int rc;
 502                 u_short seqno;
 503                 u_char prefix[16], plen;
 504                 printf("\n\tMH-Request ");
 505                 if(len < 14) goto corrupt;
 506                 seqno = EXTRACT_16BITS(message + 4);
 507                 rc = network_prefix(message[2], message[3], 0,
 508                                     message + 16, NULL, len - 14, prefix);
 509                 if(rc < 0) goto corrupt;
 510                 plen = message[3] + (message[2] == 1 ? 96 : 0);
 511                 printf("(%u hops) for %s seqno %u id %s",
 512                        message[6], format_prefix(prefix, plen),
 513                        seqno, format_id(message + 8));
 514             }
 515         }
 516             break;
 517         case MESSAGE_TSPC :
 518             if(!vflag)
 519                 printf(" tspc");
 520             else {
 521                 printf("\n\tTS/PC ");
 522                 if(len < 6) goto corrupt;
 523                 printf("timestamp %u packetcounter %u", EXTRACT_32BITS (message + 4),
 524                        EXTRACT_16BITS(message + 2));
 525             }
 526             break;
 527         case MESSAGE_HMAC : {
 528             if(!vflag)
 529                 printf(" hmac");
 530             else {
 531                 unsigned j;
 532                 printf("\n\tHMAC ");
 533                 if(len < 18) goto corrupt;
 534                 printf("key-id %u digest-%u ", EXTRACT_16BITS(message + 2), len - 2);
 535                 for (j = 0; j < len - 2; j++)
 536                     printf ("%02X", message[4 + j]);
 537             }
 538         }
 539             break;
 540         default:
 541             if(!vflag)
 542                 printf(" unknown");
 543             else
 544                 printf("\n\tUnknown message type %d", type);
 545         }
 546         i += len + 2;
 547     }
 548     return;
 549
 550  trunc:
 551     printf(" %s", tstr);
 552     return;
 553
 554  corrupt:
 555     printf(" (corrupt)");
 556     return;
 557 }