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 void babel_print_v2(const u_char *cp, u_int length);
  43
  44 void
  45 babel_print(const u_char *cp, u_int length) {
  46     printf("babel");
  47
  48     TCHECK2(*cp, 4);
  49
  50     if(cp[0] != 42) {
  51         printf(" malformed header");
  52         return;
  53     } else {
  54         printf(" %d", cp[1]);
  55     }
  56
  57     switch(cp[1]) {
  58     case 2:
  59         babel_print_v2(cp,length);
  60         break;
  61     default:
  62         printf(" unknown version");
  63         break;
  64     }
  65
  66     return;
  67
  68  trunc:
  69     printf(" [|babel]");
  70     return;
  71 }
  72
  73 /* TLVs */
  74 #define MESSAGE_PAD1 0
  75 #define MESSAGE_PADN 1
  76 #define MESSAGE_ACK_REQ 2
  77 #define MESSAGE_ACK 3
  78 #define MESSAGE_HELLO 4
  79 #define MESSAGE_IHU 5
  80 #define MESSAGE_ROUTER_ID 6
  81 #define MESSAGE_NH 7
  82 #define MESSAGE_UPDATE 8
  83 #define MESSAGE_REQUEST 9
  84 #define MESSAGE_MH_REQUEST 10
  85 #define MESSAGE_TSPC 11
  86 #define MESSAGE_HMAC 12
  87
  88 /* sub-TLVs */
  89 #define MESSAGE_SUB_PAD1 0
  90 #define MESSAGE_SUB_PADN 1
  91 #define MESSAGE_SUB_DIVERSITY 2
  92
  93 /* Diversity sub-TLV channel codes */
  94 static const struct tok diversity_str[] = {
  95     { 0,   "reserved" },
  96     { 255, "all"      },
  97     { 0, NULL }
  98 };
  99
 100 static const char *
 101 format_id(const u_char *id)
 102 {
 103     static char buf[25];
 104     snprintf(buf, 25, "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x",
 105              id[0], id[1], id[2], id[3], id[4], id[5], id[6], id[7]);
 106     buf[24] = '\0';
 107     return buf;
 108 }
 109
 110 static const unsigned char v4prefix[16] =
 111     {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF, 0, 0, 0, 0 };
 112
 113 static const char *
 114 format_prefix(const u_char *prefix, unsigned char plen)
 115 {
 116     static char buf[50];
 117     if(plen >= 96 && memcmp(prefix, v4prefix, 12) == 0)
 118         snprintf(buf, 50, "%s/%u", ipaddr_string(prefix + 12), plen - 96);
 119     else
 120 #ifdef INET6
 121         snprintf(buf, 50, "%s/%u", ip6addr_string(prefix), plen);
 122 #else
 123         snprintf(buf, 50, "IPv6 addresses not supported");
 124 #endif
 125     buf[49] = '\0';
 126     return buf;
 127 }
 128
 129 static const char *
 130 format_address(const u_char *prefix)
 131 {
 132     if(memcmp(prefix, v4prefix, 12) == 0)
 133         return ipaddr_string(prefix + 12);
 134     else
 135 #ifdef INET6
 136         return ip6addr_string(prefix);
 137 #else
 138         return "IPv6 addresses not supported";
 139 #endif
 140 }
 141
 142 static const char *
 143 format_interval(const u_int16_t i)
 144 {
 145     static char buf[sizeof("0000.0s")];
 146
 147     if (i == 0)
 148         return "0.0s (bogus)";
 149     snprintf(buf, sizeof(buf), "%u.%us", i / 10, i % 10);
 150     return buf;
 151 }
 152
 153 static const char *
 154 format_interval_update(const u_int16_t i)
 155 {
 156     return i == 0xFFFF ? "infinity" : format_interval(i);
 157 }
 158
 159 /* Return number of octets consumed from the input buffer (not the prefix length
 160  * in bytes), or -1 for encoding error. */
 161 static int
 162 network_prefix(int ae, int plen, unsigned int omitted,
 163                const unsigned char *p, const unsigned char *dp,
 164                unsigned int len, unsigned char *p_r)
 165 {
 166     unsigned pb;
 167     unsigned char prefix[16];
 168     int consumed = 0;
 169
 170     if(plen >= 0)
 171         pb = (plen + 7) / 8;
 172     else if(ae == 1)
 173         pb = 4;
 174     else
 175         pb = 16;
 176
 177     if(pb > 16)
 178         return -1;
 179
 180     memset(prefix, 0, 16);
 181
 182     switch(ae) {
 183     case 0: break;
 184     case 1:
 185         if(omitted > 4 || pb > 4 || (pb > omitted && len < pb - omitted))
 186             return -1;
 187         memcpy(prefix, v4prefix, 12);
 188         if(omitted) {
 189             if (dp == NULL) return -1;
 190             memcpy(prefix, dp, 12 + omitted);
 191         }
 192         if(pb > omitted) {
 193             memcpy(prefix + 12 + omitted, p, pb - omitted);
 194             consumed = pb - omitted;
 195         }
 196         break;
 197     case 2:
 198         if(omitted > 16 || (pb > omitted && len < pb - omitted))
 199             return -1;
 200         if(omitted) {
 201             if (dp == NULL) return -1;
 202             memcpy(prefix, dp, omitted);
 203         }
 204         if(pb > omitted) {
 205             memcpy(prefix + omitted, p, pb - omitted);
 206             consumed = pb - omitted;
 207         }
 208         break;
 209     case 3:
 210         if(pb > 8 && len < pb - 8) return -1;
 211         prefix[0] = 0xfe;
 212         prefix[1] = 0x80;
 213         if(pb > 8) {
 214             memcpy(prefix + 8, p, pb - 8);
 215             consumed = pb - 8;
 216         }
 217         break;
 218     default:
 219         return -1;
 220     }
 221
 222     memcpy(p_r, prefix, 16);
 223     return consumed;
 224 }
 225
 226 static int
 227 network_address(int ae, const unsigned char *a, unsigned int len,
 228                 unsigned char *a_r)
 229 {
 230     return network_prefix(ae, -1, 0, a, NULL, len, a_r);
 231 }
 232
 233 /*
 234  * Sub-TLVs consume the "extra data" of Babel TLVs (see Section 4.3 of RFC6126),
 235  * their encoding is similar to the encoding of TLVs, but the type namespace is
 236  * different:
 237  *
 238  * o Type 0 stands for Pad1 sub-TLV with the same encoding as the Pad1 TLV.
 239  * o Type 1 stands for PadN sub-TLV with the same encoding as the PadN TLV.
 240  * o Type 2 stands for Diversity sub-TLV, which propagates diversity routing
 241  *   data. Its body is a variable-length sequence of 8-bit unsigned integers,
 242  *   each representing per-hop number of interferring radio channel for the
 243  *   prefix. Channel 0 is invalid and must not be used in the sub-TLV, channel
 244  *   255 interferes with any other channel.
 245  *
 246  * Sub-TLV types 0 and 1 are valid for any TLV type, whether sub-TLV type 2 is
 247  * only valid for TLV type 8 (Update). Note that within an Update TLV a missing
 248  * Diversity sub-TLV is not the same as a Diversity sub-TLV with an empty body.
 249  * The former would mean a lack of any claims about the interference, and the
 250  * latter would state that interference is definitely absent. */
 251 static void
 252 subtlvs_print(const u_char *cp, const u_char *ep, const uint8_t tlv_type) {
 253     uint8_t subtype, sublen;
 254     const char *sep;
 255
 256     while (cp < ep) {
 257         subtype = *cp++;
 258         if(subtype == MESSAGE_SUB_PAD1) {
 259             printf(" sub-pad1");
 260             continue;
 261         }
 262         if(cp == ep)
 263             goto corrupt;
 264         sublen = *cp++;
 265         if(cp + sublen > ep)
 266             goto corrupt;
 267
 268         switch(subtype) {
 269         case MESSAGE_SUB_PADN:
 270             printf(" sub-padn");
 271             cp += sublen;
 272             break;
 273         case MESSAGE_SUB_DIVERSITY:
 274             printf(" sub-diversity");
 275             if (sublen == 0) {
 276                 printf(" empty");
 277                 break;
 278             }
 279             sep = " ";
 280             while(sublen--) {
 281                 printf("%s%s", sep, tok2str(diversity_str, "%u", *cp++));
 282                 sep = "-";
 283             }
 284             if(tlv_type != MESSAGE_UPDATE)
 285                 printf(" (bogus)");
 286             break;
 287         default:
 288             printf(" sub-unknown-0x%02x", subtype);
 289             cp += sublen;
 290         } /* switch */
 291     } /* while */
 292     return;
 293
 294  corrupt:
 295     printf(" (corrupt)");
 296 }
 297
 298 #define ICHECK(i, l) \
 299         if ((i) + (l) > bodylen || (i) + (l) > length) goto corrupt;
 300
 301 static void
 302 babel_print_v2(const u_char *cp, u_int length) {
 303     u_int i;
 304     u_short bodylen;
 305     u_char v4_prefix[16] =
 306         {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF, 0, 0, 0, 0 };
 307     u_char v6_prefix[16] = {0};
 308
 309     TCHECK2(*cp, 4);
 310     if (length < 4)
 311         goto corrupt;
 312     bodylen = EXTRACT_16BITS(cp + 2);
 313     printf(" (%u)", bodylen);
 314
 315     /* Process the TLVs in the body */
 316     i = 0;
 317     while(i < bodylen) {
 318         const u_char *message;
 319         u_int type, len;
 320
 321         message = cp + 4 + i;
 322
 323         TCHECK2(*message, 1);
 324         if((type = message[0]) == MESSAGE_PAD1) {
 325             printf(vflag ? "\n\tPad 1" : " pad1");
 326             i += 1;
 327             continue;
 328         }
 329
 330         TCHECK2(*message, 2);
 331         ICHECK(i, 2);
 332         len = message[1];
 333
 334         TCHECK2(*message, 2 + len);
 335         ICHECK(i, 2 + len);
 336
 337         switch(type) {
 338         case MESSAGE_PADN: {
 339             if(!vflag)
 340                 printf(" padN");
 341             else
 342                 printf("\n\tPad %d", len + 2);
 343         }
 344             break;
 345
 346         case MESSAGE_ACK_REQ: {
 347             u_short nonce, interval;
 348             if(!vflag)
 349                 printf(" ack-req");
 350             else {
 351                 printf("\n\tAcknowledgment Request ");
 352                 if(len < 6) goto corrupt;
 353                 nonce = EXTRACT_16BITS(message + 4);
 354                 interval = EXTRACT_16BITS(message + 6);
 355                 printf("%04x %s", nonce, format_interval(interval));
 356             }
 357         }
 358             break;
 359
 360         case MESSAGE_ACK: {
 361             u_short nonce;
 362             if(!vflag)
 363                 printf(" ack");
 364             else {
 365                 printf("\n\tAcknowledgment ");
 366                 if(len < 2) goto corrupt;
 367                 nonce = EXTRACT_16BITS(message + 2);
 368                 printf("%04x", nonce);
 369             }
 370         }
 371             break;
 372
 373         case MESSAGE_HELLO:  {
 374             u_short seqno, interval;
 375             if(!vflag)
 376                 printf(" hello");
 377             else {
 378                 printf("\n\tHello ");
 379                 if(len < 6) goto corrupt;
 380                 seqno = EXTRACT_16BITS(message + 4);
 381                 interval = EXTRACT_16BITS(message + 6);
 382                 printf("seqno %u interval %s", seqno, format_interval(interval));
 383             }
 384         }
 385             break;
 386
 387         case MESSAGE_IHU: {
 388             unsigned short txcost, interval;
 389             if(!vflag)
 390                 printf(" ihu");
 391             else {
 392                 u_char address[16];
 393                 int rc;
 394                 printf("\n\tIHU ");
 395                 if(len < 6) goto corrupt;
 396                 txcost = EXTRACT_16BITS(message + 4);
 397                 interval = EXTRACT_16BITS(message + 6);
 398                 rc = network_address(message[2], message + 8, len - 6, address);
 399                 if(rc < 0) { printf("[|babel]"); break; }
 400                 printf("%s txcost %u interval %s",
 401                        format_address(address), txcost, format_interval(interval));
 402             }
 403         }
 404             break;
 405
 406         case MESSAGE_ROUTER_ID: {
 407             if(!vflag)
 408                 printf(" router-id");
 409             else {
 410                 printf("\n\tRouter Id");
 411                 if(len < 10) goto corrupt;
 412                 printf(" %s", format_id(message + 4));
 413             }
 414         }
 415             break;
 416
 417         case MESSAGE_NH: {
 418             if(!vflag)
 419                 printf(" nh");
 420             else {
 421                 int rc;
 422                 u_char nh[16];
 423                 printf("\n\tNext Hop");
 424                 if(len < 2) goto corrupt;
 425                 rc = network_address(message[2], message + 4, len - 2, nh);
 426                 if(rc < 0) goto corrupt;
 427                 printf(" %s", format_address(nh));
 428             }
 429         }
 430             break;
 431
 432         case MESSAGE_UPDATE: {
 433             if(!vflag) {
 434                 printf(" update");
 435                 if(len < 1)
 436                     printf("/truncated");
 437                 else
 438                     printf("%s%s%s",
 439                            (message[3] & 0x80) ? "/prefix": "",
 440                            (message[3] & 0x40) ? "/id" : "",
 441                            (message[3] & 0x3f) ? "/unknown" : "");
 442             } else {
 443                 u_short interval, seqno, metric;
 444                 u_char plen;
 445                 int rc;
 446                 u_char prefix[16];
 447                 printf("\n\tUpdate");
 448                 if(len < 10) goto corrupt;
 449                 plen = message[4] + (message[2] == 1 ? 96 : 0);
 450                 rc = network_prefix(message[2], message[4], message[5],
 451                                     message + 12,
 452                                     message[2] == 1 ? v4_prefix : v6_prefix,
 453                                     len - 10, prefix);
 454                 if(rc < 0) goto corrupt;
 455                 interval = EXTRACT_16BITS(message + 6);
 456                 seqno = EXTRACT_16BITS(message + 8);
 457                 metric = EXTRACT_16BITS(message + 10);
 458                 printf("%s%s%s %s metric %u seqno %u interval %s",
 459                        (message[3] & 0x80) ? "/prefix": "",
 460                        (message[3] & 0x40) ? "/id" : "",
 461                        (message[3] & 0x3f) ? "/unknown" : "",
 462                        format_prefix(prefix, plen),
 463                        metric, seqno, format_interval_update(interval));
 464                 if(message[3] & 0x80) {
 465                     if(message[2] == 1)
 466                         memcpy(v4_prefix, prefix, 16);
 467                     else
 468                         memcpy(v6_prefix, prefix, 16);
 469                 }
 470                 /* extra data? */
 471                 if((u_int)rc < len - 10)
 472                     subtlvs_print(message + 12 + rc, message + 2 + len, type);
 473             }
 474         }
 475             break;
 476
 477         case MESSAGE_REQUEST: {
 478             if(!vflag)
 479                 printf(" request");
 480             else {
 481                 int rc;
 482                 u_char prefix[16], plen;
 483                 printf("\n\tRequest ");
 484                 if(len < 2) goto corrupt;
 485                 plen = message[3] + (message[2] == 1 ? 96 : 0);
 486                 rc = network_prefix(message[2], message[3], 0,
 487                                     message + 4, NULL, len - 2, prefix);
 488                 if(rc < 0) goto corrupt;
 489                 plen = message[3] + (message[2] == 1 ? 96 : 0);
 490                 printf("for %s",
 491                        message[2] == 0 ? "any" : format_prefix(prefix, plen));
 492             }
 493         }
 494             break;
 495
 496         case MESSAGE_MH_REQUEST : {
 497             if(!vflag)
 498                 printf(" mh-request");
 499             else {
 500                 int rc;
 501                 u_short seqno;
 502                 u_char prefix[16], plen;
 503                 printf("\n\tMH-Request ");
 504                 if(len < 14) goto corrupt;
 505                 seqno = EXTRACT_16BITS(message + 4);
 506                 rc = network_prefix(message[2], message[3], 0,
 507                                     message + 16, NULL, len - 14, prefix);
 508                 if(rc < 0) goto corrupt;
 509                 plen = message[3] + (message[2] == 1 ? 96 : 0);
 510                 printf("(%u hops) for %s seqno %u id %s",
 511                        message[6], format_prefix(prefix, plen),
 512                        seqno, format_id(message + 8));
 513             }
 514         }
 515             break;
 516         case MESSAGE_TSPC :
 517             if(!vflag)
 518                 printf(" tspc");
 519             else {
 520                 printf("\n\tTS/PC ");
 521                 if(len < 6) goto corrupt;
 522                 printf("timestamp %u packetcounter %u", EXTRACT_32BITS (message + 4),
 523                        EXTRACT_16BITS(message + 2));
 524             }
 525             break;
 526         case MESSAGE_HMAC : {
 527             if(!vflag)
 528                 printf(" hmac");
 529             else {
 530                 unsigned j;
 531                 printf("\n\tHMAC ");
 532                 if(len < 18) goto corrupt;
 533                 printf("key-id %u digest-%u ", EXTRACT_16BITS(message + 2), len - 2);
 534                 for (j = 0; j < len - 2; j++)
 535                     printf ("%02X", message[4 + j]);
 536             }
 537         }
 538             break;
 539         default:
 540             if(!vflag)
 541                 printf(" unknown");
 542             else
 543                 printf("\n\tUnknown message type %d", type);
 544         }
 545         i += len + 2;
 546     }
 547     return;
 548
 549  trunc:
 550     printf(" [|babel]");
 551     return;
 552
 553  corrupt:
 554     printf(" (corrupt)");
 555     return;
 556 }