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
  41 static void babel_print_v2(const u_char *cp, u_int length);
  42
  43 void
  44 babel_print(const u_char *cp, u_int length) {
  45     printf("babel");
  46
  47     TCHECK2(*cp, 4);
  48
  49     if(cp[0] != 42) {
  50         printf(" malformed header");
  51         return;
  52     } else {
  53         printf(" %d", cp[1]);
  54     }
  55
  56     switch(cp[1]) {
  57     case 2:
  58         babel_print_v2(cp,length);
  59         break;
  60     default:
  61         printf(" unknown version");
  62         break;
  63     }
  64
  65     return;
  66
  67  trunc:
  68     printf(" [|babel]");
  69     return;
  70 }
  71
  72 #if defined __GNUC__
  73 struct __us { unsigned short x __attribute__((packed)); };
  74 #define DO_NTOHS(_d, _s) \
  75     do { _d = ntohs(((const struct __us*)(_s))->x); } while(0)
  76 #define DO_HTONS(_d, _s) \
  77     do { ((struct __us*)(_d))->x = htons(_s); } while(0)
  78 #else
  79 #define DO_NTOHS(_d, _s) \
  80     do { short _dd; \
  81          memcpy(&(_dd), (_s), 2); \
  82          _d = ntohs(_dd); } while(0)
  83 #define DO_HTONS(_d, _s) \
  84     do { unsigned short _dd; \
  85          _dd = htons(_s); \
  86          memcpy((_d), &(_dd), 2); } while(0)
  87 #endif
  88
  89 #define MESSAGE_PAD1 0
  90 #define MESSAGE_PADN 1
  91 #define MESSAGE_ACK_REQ 2
  92 #define MESSAGE_ACK 3
  93 #define MESSAGE_HELLO 4
  94 #define MESSAGE_IHU 5
  95 #define MESSAGE_ROUTER_ID 6
  96 #define MESSAGE_NH 7
  97 #define MESSAGE_UPDATE 8
  98 #define MESSAGE_REQUEST 9
  99 #define MESSAGE_MH_REQUEST 10
 100
 101 static const char *
 102 format_id(const u_char *id)
 103 {
 104     static char buf[25];
 105     snprintf(buf, 25, "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x",
 106              id[0], id[1], id[2], id[3], id[4], id[5], id[6], id[7]);
 107     buf[24] = '\0';
 108     return buf;
 109 }
 110
 111 static const unsigned char v4prefix[16] =
 112     {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF, 0, 0, 0, 0 };
 113
 114 static const char *
 115 format_prefix(const u_char *prefix, unsigned char plen)
 116 {
 117     static char buf[50];
 118     if(plen >= 96 && memcmp(prefix, v4prefix, 12) == 0)
 119         snprintf(buf, 50, "%s/%u", ipaddr_string(prefix + 12), plen - 96);
 120     else
 121         snprintf(buf, 50, "%s/%u", ip6addr_string(prefix), plen);
 122     buf[49] = '\0';
 123     return buf;
 124 }
 125
 126 static const char *
 127 format_address(const u_char *prefix)
 128 {
 129     if(memcmp(prefix, v4prefix, 12) == 0)
 130         return ipaddr_string(prefix + 12);
 131     else
 132         return ip6addr_string(prefix);
 133 }
 134
 135 static int
 136 network_prefix(int ae, int plen, unsigned int omitted,
 137                const unsigned char *p, const unsigned char *dp,
 138                unsigned int len, unsigned char *p_r)
 139 {
 140     unsigned pb;
 141     unsigned char prefix[16];
 142
 143     if(plen >= 0)
 144         pb = (plen + 7) / 8;
 145     else if(ae == 1)
 146         pb = 4;
 147     else
 148         pb = 16;
 149
 150     if(pb > 16)
 151         return -1;
 152
 153     memset(prefix, 0, 16);
 154
 155     switch(ae) {
 156     case 0: break;
 157     case 1:
 158         if(omitted > 4 || pb > 4 || (pb > omitted && len < pb - omitted))
 159             return -1;
 160         memcpy(prefix, v4prefix, 12);
 161         if(omitted) {
 162             if (dp == NULL) return -1;
 163             memcpy(prefix, dp, 12 + omitted);
 164         }
 165         if(pb > omitted) memcpy(prefix + 12 + omitted, p, pb - omitted);
 166         break;
 167     case 2:
 168         if(omitted > 16 || (pb > omitted && len < pb - omitted))
 169             return -1;
 170         if(omitted) {
 171             if (dp == NULL) return -1;
 172             memcpy(prefix, dp, omitted);
 173         }
 174         if(pb > omitted) memcpy(prefix + omitted, p, pb - omitted);
 175         break;
 176     case 3:
 177         if(pb > 8 && len < pb - 8) return -1;
 178         prefix[0] = 0xfe;
 179         prefix[1] = 0x80;
 180         if(pb > 8) memcpy(prefix + 8, p, pb - 8);
 181         break;
 182     default:
 183         return -1;
 184     }
 185
 186     memcpy(p_r, prefix, 16);
 187     return 1;
 188 }
 189
 190 static int
 191 network_address(int ae, const unsigned char *a, unsigned int len,
 192                 unsigned char *a_r)
 193 {
 194     return network_prefix(ae, -1, 0, a, NULL, len, a_r);
 195 }
 196
 197 static void
 198 babel_print_v2(const u_char *cp, u_int length) {
 199     int i;
 200     u_short bodylen;
 201     u_char v4_prefix[16] =
 202         {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF, 0, 0, 0, 0 };
 203     u_char v6_prefix[16] = {0};
 204
 205     DO_NTOHS(bodylen, cp + 2);
 206     printf(" (%d)", bodylen);
 207
 208     i = 0;
 209     while(i < bodylen) {
 210         const u_char *message;
 211         u_char type, len;
 212
 213         TCHECK2(*cp, 4 + i);
 214
 215         message = cp + 4 + i;
 216         type = message[0];
 217         len = message[1];
 218
 219         TCHECK2(*cp, 4 + i + 2 + len);
 220
 221         switch(type) {
 222         case MESSAGE_PAD1: {
 223             if(!vflag)
 224                 printf(" pad1");
 225             else
 226                 printf("\n\tPad 1");
 227         }
 228             break;
 229
 230         case MESSAGE_PADN: {
 231             if(!vflag)
 232                 printf(" padN");
 233             else
 234                 printf("\n\tPad %d", len + 2);
 235         }
 236             break;
 237
 238         case MESSAGE_ACK_REQ: {
 239             u_short nonce, interval;
 240             if(!vflag)
 241                 printf(" ack-req");
 242             else {
 243                 printf("\n\tAcknowledgment Request ");
 244                 if(len < 6) goto corrupt;
 245                 DO_NTOHS(nonce, message + 4);
 246                 DO_NTOHS(interval, message + 6);
 247                 printf("%04x %d", nonce, interval);
 248             }
 249         }
 250             break;
 251
 252         case MESSAGE_ACK: {
 253             u_short nonce;
 254             if(!vflag)
 255                 printf(" ack");
 256             else {
 257                 printf("\n\tAcknowledgment ");
 258                 if(len < 2) goto corrupt;
 259                 DO_NTOHS(nonce, message + 2);
 260                 printf("%04x", nonce);
 261             }
 262         }
 263             break;
 264
 265         case MESSAGE_HELLO:  {
 266             u_short seqno, interval;
 267             if(!vflag)
 268                 printf(" hello");
 269             else {
 270                 printf("\n\tHello ");
 271                 if(len < 6) goto corrupt;
 272                 DO_NTOHS(seqno, message + 4);
 273                 DO_NTOHS(interval, message + 6);
 274                 printf("seqno %u interval %u", seqno, interval);
 275             }
 276         }
 277             break;
 278
 279         case MESSAGE_IHU: {
 280             unsigned short txcost, interval;
 281             if(!vflag)
 282                 printf(" ihu");
 283             else {
 284                 u_char address[16];
 285                 int rc;
 286                 printf("\n\tIHU ");
 287                 if(len < 6) goto corrupt;
 288                 DO_NTOHS(txcost, message + 4);
 289                 DO_NTOHS(interval, message + 6);
 290                 rc = network_address(message[2], message + 8, len - 6, address);
 291                 if(rc < 0) { printf("[|babel]"); break; }
 292                 printf("%s txcost %u interval %d",
 293                        format_address(address), txcost, interval);
 294             }
 295         }
 296             break;
 297
 298         case MESSAGE_ROUTER_ID: {
 299             if(!vflag)
 300                 printf(" router-id");
 301             else {
 302                 printf("\n\tRouter Id");
 303                 if(len < 10) goto corrupt;
 304                 printf(" %s", format_id(message + 4));
 305             }
 306         }
 307             break;
 308
 309         case MESSAGE_NH: {
 310             if(!vflag)
 311                 printf(" nh");
 312             else {
 313                 int rc;
 314                 u_char nh[16];
 315                 printf("\n\tNext Hop");
 316                 if(len < 2) goto corrupt;
 317                 rc = network_address(message[2], message + 4, len - 2, nh);
 318                 if(rc < 0) goto corrupt;
 319                 printf(" %s", format_address(nh));
 320             }
 321         }
 322             break;
 323
 324         case MESSAGE_UPDATE: {
 325             if(!vflag) {
 326                 printf(" update");
 327                 if(len < 1)
 328                     printf("/truncated");
 329                 else
 330                     printf("%s%s%s",
 331                            (message[3] & 0x80) ? "/prefix": "",
 332                            (message[3] & 0x40) ? "/id" : "",
 333                            (message[3] & 0x3f) ? "/unknown" : "");
 334             } else {
 335                 u_short interval, seqno, metric;
 336                 u_char plen;
 337                 int rc;
 338                 u_char prefix[16];
 339                 printf("\n\tUpdate");
 340                 if(len < 10) goto corrupt;
 341                 plen = message[4] + (message[2] == 1 ? 96 : 0);
 342                 rc = network_prefix(message[2], message[4], message[5],
 343                                     message + 12,
 344                                     message[2] == 1 ? v4_prefix : v6_prefix,
 345                                     len - 10, prefix);
 346                 if(rc < 0) goto corrupt;
 347                 DO_NTOHS(interval, message + 6);
 348                 DO_NTOHS(seqno, message + 8);
 349                 DO_NTOHS(metric, message + 10);
 350                 printf("%s%s%s %s metric %u seqno %u interval %u",
 351                        (message[3] & 0x80) ? "/prefix": "",
 352                        (message[3] & 0x40) ? "/id" : "",
 353                        (message[3] & 0x3f) ? "/unknown" : "",
 354                        format_prefix(prefix, plen),
 355                        metric, seqno, interval);
 356                 if(message[3] & 0x80) {
 357                     if(message[2] == 1)
 358                         memcpy(v4_prefix, prefix, 16);
 359                     else
 360                         memcpy(v6_prefix, prefix, 16);
 361                 }
 362             }
 363         }
 364             break;
 365
 366         case MESSAGE_REQUEST: {
 367             if(!vflag)
 368                 printf(" request");
 369             else {
 370                 int rc;
 371                 u_char prefix[16], plen;
 372                 printf("\n\tRequest ");
 373                 if(len < 2) goto corrupt;
 374                 plen = message[3] + (message[2] == 1 ? 96 : 0);
 375                 rc = network_prefix(message[2], message[3], 0,
 376                                     message + 4, NULL, len - 2, prefix);
 377                 if(rc < 0) goto corrupt;
 378                 plen = message[3] + (message[2] == 1 ? 96 : 0);
 379                 printf("for %s",
 380                        message[2] == 0 ? "any" : format_prefix(prefix, plen));
 381             }
 382         }
 383             break;
 384
 385         case MESSAGE_MH_REQUEST : {
 386             if(!vflag)
 387                 printf(" mh-request");
 388             else {
 389                 int rc;
 390                 u_short seqno;
 391                 u_char prefix[16], plen;
 392                 printf("\n\tMH-Request ");
 393                 if(len < 14) goto corrupt;
 394                 DO_NTOHS(seqno, message + 4);
 395                 rc = network_prefix(message[2], message[3], 0,
 396                                     message + 16, NULL, len - 14, prefix);
 397                 if(rc < 0) goto corrupt;
 398                 plen = message[3] + (message[2] == 1 ? 96 : 0);
 399                 printf("(%u hops) for %s seqno %u id %s",
 400                        message[6], format_prefix(prefix, plen),
 401                        seqno, format_id(message + 8));
 402             }
 403         }
 404             break;
 405         default:
 406             if(!vflag)
 407                 printf(" unknown");
 408             else
 409                 printf("\n\tUnknown message type %d", type);
 410         }
 411         i += len + 2;
 412     }
 413     return;
 414
 415  trunc:
 416     printf(" [|babel]");
 417     return;
 418
 419  corrupt:
 420     printf(" (corrupt)");
 421     return;
 422 }