src/send_eth.c

   1 /*
   2  * Mausezahn - A fast versatile traffic generator
   3  * Copyright (C) 2008 Herbert Haas
   4  *
   5  * This program is free software; you can redistribute it and/or modify it under
   6  * the terms of the GNU General Public License version 2 as published by the
   7  * Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  11  * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
  12  * details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, see http://www.gnu.org/licenses/gpl-2.0.html
  16  *
  17 */
  18
  19
  20
  21
  22 // ***************************************************************************
  23 //    This sections contains (as alternative to 'send_frame' in send.c)
  24 //    a layer-2 based flexible sending function.
  25 //
  26 //    Layer-2 modifications such as 802.1Q and MPLS is considered here!
  27 //
  28 // ***************************************************************************
  29
  30
  31
  32 #include "mz.h"
  33
  34 libnet_ptag_t  create_eth_frame (libnet_t *l, libnet_ptag_t  t3, libnet_ptag_t  t4)
  35 {
  36    libnet_t *L=NULL;
  37    char errbuf[LIBNET_ERRBUF_SIZE];
  38    libnet_ptag_t  t=0, tmpls;
  39    char argval[128];
  40    u_int8_t et[2];
  41    int et_len;
  42
  43    int i=0, j, mlen, mkomma, len, count, offset=0, found_colon=0;
  44    char *left, *right;
  45    char *f, mtag[64];
  46    char verbose_mpls_string[128];
  47
  48    u_int8_t *packet;
  49    u_int32_t packet_s;
  50
  51    char *saveptr, *ptrsubstring, substring[16], tmp[4*MAX_8021Q_TAGS];
  52    u_int8_t  CoS;       // 0..7
  53    u_int16_t vlan;      // 12 bit value (0..4095)
  54    u_int8_t dot1Q[4*MAX_8021Q_TAGS], *ptr;
  55    u_int16_t dot1Q_eth_type=0x8100;
  56    int bytecnt=0;
  57
  58    int  isdot1Q, tcp_seq_delta, dp_isrange, sp_isrange, ip_dst_isrange, ip_src_isrange, eth_src_rand, rtp_mode=0;
  59    unsigned int delay;
  60
  61
  62
  63
  64
  65
  66    ////////////////////////////////////////////////////
  67    // Prepare MPLS header if required
  68    if (tx.mpls)
  69      {
  70         // first check how many labels have been specified:
  71         mlen = strlen (tx.mpls_txt);
  72         mkomma=0;
  73
  74         for (i=0; i<mlen; i++)
  75           {
  76              if (tx.mpls_txt[i]==',') mkomma++;
  77           }
  78
  79         f = strtok_r (tx.mpls_txt, ",", &saveptr);
  80
  81         tx.mpls_bos=1;
  82
  83         do
  84           {
  85              strncpy(mtag, f, 64);
  86              /*
  87              if (mkomma==0)
  88                {
  89                   tx.mpls_bos=0;
  90                }
  91              else
  92                {
  93                   printf("BOS=1\n");
  94                   tx.mpls_bos=1;
  95                }
  96              */
  97
  98
  99              if ( get_mpls_params(mtag) ) // error?
 100                {
 101                   fprintf(stderr," mz/get_mpls_params: MPLS Parameters problem.\n");
 102                   exit (0);
 103                }
 104
 105              tmpls = libnet_build_mpls(tx.mpls_label,
 106                                        tx.mpls_exp,
 107                                        tx.mpls_bos,
 108                                        tx.mpls_ttl,
 109                                        NULL,
 110                                        0,
 111                                        l,
 112                                        0);
 113
 114              if (tmpls == -1)
 115                {
 116                   fprintf(stderr, " mz/create_ip_packet: Can't build MPLS header: %s\n", libnet_geterror(l));
 117                   exit (0);
 118                }
 119
 120              if (verbose)
 121                {
 122                   sprintf(verbose_mpls_string,"[%u:%u:%u:%u]",
 123                           tx.mpls_label,
 124                           tx.mpls_exp,
 125                           tx.mpls_bos,
 126                           tx.mpls_ttl);
 127                   strcat(tx.mpls_verbose_string, verbose_mpls_string);
 128                   strcat(tx.mpls_verbose_string, " ");
 129                }
 130
 131              tx.mpls_bos=0;
 132              mkomma--;
 133           }
 134         while ( (f=strtok_r(NULL, ",", &saveptr)) != NULL);
 135
 136      }
 137
 138
 139
 140
 141
 142
 143
 144    ////////////////////////////////////////////////////////////////////////////////////////////
 145    // Evaluate Ethernet CLI options (-a and -b)
 146    if (check_eth_mac_txt(ETH_DST))  // if true then problem (invalid user input?)
 147      {
 148         str2hex("ff:ff:ff:ff:ff:ff",tx.eth_dst, 6); // the default
 149      }
 150
 151    // if not specified then own MAC will be used automatically
 152    (void) check_eth_mac_txt(ETH_SRC);
 153
 154
 155    // Get CLI arguments:
 156    // If NOT set, default: 0x800 or ETHERTYPE_MPLS if MPLS is used (see init.c)
 157    if (getarg(tx.arg_string,"ether_type", argval)==1)
 158      {
 159         et_len = str2hex (argval, et, 2);
 160
 161         if (et_len==1)
 162           tx.eth_type = et[0];
 163         else // 2 bytes specified
 164           tx.eth_type = 256 * et[0] + et[1];
 165
 166         //tx.eth_type = (u_int16_t) str2int(argval);
 167      }
 168
 169
 170
 171
 172
 173
 174
 175
 176    /////////////////////////////////////////////////////////////////////////////////
 177    // Ethernet with 802.1Q
 178    //
 179    // If multiple 802.1Q tags are specified then we need to build the whole
 180    // frame manually because libnet only supports adding a single VLAN header.
 181    // The easiest solution is to create the hex-string of the 802.1Q-chain as
 182    // u_int8_t QinQ[] then add the IP packet as payload...
 183    //
 184    if (tx.dot1Q) // actually contains the number of VLAN tags
 185      {
 186
 187         // we want our own context!
 188         L = libnet_init(LIBNET_LINK_ADV, tx.device, errbuf);
 189         if (L == NULL)
 190           {
 191              fprintf(stderr, "%s", errbuf);
 192              exit(EXIT_FAILURE);
 193           }
 194
 195         strncpy(tmp,tx.dot1Q_txt,(4*MAX_8021Q_TAGS));
 196         ptrsubstring = strtok_r(tmp, ",.", &saveptr);
 197         bytecnt=0;
 198         do
 199           {
 200              // make a local copy
 201              strncpy(substring, ptrsubstring, 16);
 202              CoS=0; vlan=0;
 203              // Get CoS and VLAN ID from partial string
 204              len = strlen(substring);
 205              found_colon=0;
 206              for (i=0; i<len; i++)
 207                {
 208                   if  (substring[i]==':')  found_colon=1;
 209                }
 210              if (found_colon) // Both CoS and VLAN specified
 211                {
 212                   left = strtok (substring, ":");
 213                   right = strtok (NULL, ":");
 214                   CoS = (u_int8_t) str2int (left);
 215                   vlan = (u_int16_t) str2int (right);
 216                }
 217              else  // Only VLAN specified
 218                {
 219                   vlan = (u_int16_t) str2int (substring);
 220                }
 221
 222              if (CoS > 7)
 223                {
 224                   fprintf(stderr, " mz/create_eth_frame: CoS too high, adjusted to 7\n");
 225                   CoS = 7;
 226                }
 227
 228              if (vlan > 4095)
 229                {
 230                   fprintf(stderr, " mz/create_eth_frame: VLAN number too high, adjusted to 4095\n");
 231                   vlan = 4095;
 232                }
 233
 234              // create 4 byte 802.1Q header:
 235
 236              dot1Q[bytecnt+0]=0x81;
 237              dot1Q[bytecnt+1]=0x00;
 238              ptr = (u_int8_t*) &vlan;
 239              dot1Q[bytecnt+3]=*ptr;
 240              ptr++;
 241              *ptr = *ptr ^ (CoS<<5);  // add CoS
 242              dot1Q[bytecnt+2]=*ptr;
 243              //check:
 244              //printf("%02x %02x %02x %02x\n",dot1Q[bytecnt+0],dot1Q[bytecnt+1],dot1Q[bytecnt+2],dot1Q[bytecnt+3]);
 245              bytecnt+=4; // next tag (note that bytecnt will finally hold the number of used bytes!)
 246
 247           } while ( (ptrsubstring = strtok_r(NULL, ",.", &saveptr)) !=NULL); //get all VLAN tags
 248
 249         // now create the whole packet:
 250
 251         dot1Q_eth_type = 0x8100; //these are also the first two bytes of dot1Q[]
 252         bytecnt = bytecnt-2;
 253
 254         for (i=0;i<bytecnt;i++)
 255           {
 256              tx.eth_payload[i]=dot1Q[i+2];
 257           }
 258
 259         // now add official EtherType for the payload (this has been determined some lines above)
 260         ptr = (u_int8_t*) & tx.eth_type;
 261         tx.eth_payload[i+1]= *ptr;
 262         ptr++;
 263         tx.eth_payload[i]= *ptr;
 264         offset = i+2;
 265
 266         // -
 267         // --
 268         // ---
 269         // ---- now all 802.1Q headers are genereated    ----
 270         // ---- and are placed already in tx.eth_payload ----
 271         // ---- (and 'i' points to the next free byte)   ----
 272         // ---
 273         // --
 274         // -
 275
 276         // Finally get all bytes of upper layers (IP packet and payload)
 277         if (libnet_adv_cull_packet(l, &packet, &packet_s) == -1)
 278           {
 279              fprintf(stderr, "%s", libnet_geterror(l));
 280           }
 281
 282         // Copy the upper layer data to the eth_payload
 283         for (j=0; j<packet_s; j++)
 284           {
 285              tx.eth_payload[j+offset]=packet[j];
 286           }
 287
 288         // 'libnet_adv_cull_packet' performs an implicit malloc() and a corresponding call
 289         // to libnet_adv_free_packet() should be made to free the memory packet occupies:
 290         libnet_adv_free_packet(l, packet);
 291
 292         tx.eth_payload_s = j+offset;
 293         tx.eth_type = dot1Q_eth_type;
 294
 295         t = libnet_build_ethernet (tx.eth_dst,
 296                                    tx.eth_src,
 297                                    tx.eth_type,
 298                                    tx.eth_payload,
 299                                    tx.eth_payload_s,
 300                                    L,
 301                                    0);
 302
 303         if (t == -1)
 304           {
 305              fprintf(stderr, " mz/create_eth_frame: Can't build Ethernet header: %s\n",
 306                      libnet_geterror(l));
 307              exit(EXIT_FAILURE);
 308           }
 309
 310         // NOW the whole frame is ready to send!
 311
 312      }
 313
 314    else // normal Ethernet header without any 802.1Q-tag or MPLS-label
 315
 316      {
 317
 318         t = libnet_build_ethernet (tx.eth_dst,
 319                                    tx.eth_src,
 320                                    tx.eth_type,
 321                                    NULL,              // the payload
 322                                    0,
 323                                    l,
 324                                    0);
 325
 326         if (t == -1)
 327           {
 328              fprintf(stderr, " mz/create_eth_frame: Can't build Ethernet header: %s\n",
 329                      libnet_geterror(l));
 330              exit(EXIT_FAILURE);
 331           }
 332      }
 333
 334    /////////////////////////////////////////////////////////////////////////////
 335    //
 336    // Now send everything - maybe lots of times with modifications.
 337    //
 338    //
 339
 340    // local vars are faster :-)
 341    count = tx.count;
 342    delay = tx.delay;
 343    eth_src_rand = tx.eth_src_rand;
 344    tcp_seq_delta = tx.tcp_seq_delta;
 345    dp_isrange = tx.dp_isrange;
 346    sp_isrange = tx.sp_isrange;
 347    ip_dst_isrange = tx.ip_dst_isrange;
 348    ip_src_isrange = tx.ip_src_isrange | tx.ip_src_rand; // either case should call update_SA()
 349    isdot1Q = tx.dot1Q;
 350    if (mode == RTP) rtp_mode = 1;
 351
 352    if (count==0) goto AGAIN;
 353
 354    for (i=0; i<count; i++)
 355      {
 356
 357         AGAIN:
 358
 359         if (isdot1Q)
 360           {
 361              // Get all bytes of upper layers (IP packet and payload)
 362              if (libnet_adv_cull_packet(l, &packet, &packet_s) == -1)
 363                {
 364                   fprintf(stderr, "%s", libnet_geterror(l));
 365                }
 366
 367              // Copy the upper layer data to the eth_payload
 368              for (j=0; j<packet_s; j++)
 369                {
 370                   tx.eth_payload[j+offset]=packet[j];
 371                }
 372
 373              // 'libnet_adv_cull_packet' performs an implicit malloc() and a corresponding call
 374              // to libnet_adv_free_packet() should be made to free the memory packet occupies:
 375              libnet_adv_free_packet(l, packet);
 376
 377              if (eth_src_rand) update_Eth_SA(L, t);
 378
 379              t = libnet_build_ethernet (tx.eth_dst,
 380                                         tx.eth_src,
 381                                         tx.eth_type,
 382                                         tx.eth_payload,
 383                                         tx.eth_payload_s,
 384                                         L,
 385                                         t);
 386              if (t == -1)
 387                {
 388                   fprintf(stderr, " mz/create_eth_frame: Can't build Ethernet header: %s\n",
 389                           libnet_geterror(l));
 390                   exit(EXIT_FAILURE);
 391                }
 392              if (verbose) (void) print_frame_details();
 393              libnet_write(L);
 394           }
 395         else // No QinQ and/or MPLS modifications => use normal 'l' context:
 396           {
 397              if (eth_src_rand) update_Eth_SA(l, t);
 398              if (verbose) (void) print_frame_details();
 399              libnet_write(l);
 400           }
 401
 402
 403 //      if (verbose) (void) print_frame_details();
 404         if (delay) SLEEP (delay);
 405
 406
 407         if (tcp_seq_delta)
 408           {
 409              if (update_TCP_SQNR(l, t4)==0) // end of range not yet reached
 410                {
 411                   goto AGAIN;
 412                }
 413           }
 414
 415         if (dp_isrange)
 416           {
 417              if (update_DPORT(l, t4)==0) // end of range not yet reached
 418                {
 419                   goto AGAIN;
 420                }
 421           }
 422
 423         if (sp_isrange)
 424           {
 425              if (update_SPORT(l, t4)==0) // end of range not yet reached
 426                {
 427                   goto AGAIN;
 428                }
 429           }
 430
 431         if (ip_dst_isrange)
 432           {
 433              if (update_IP_DA(l, t3)==0) // end of range not yet reached
 434                {
 435                   goto AGAIN;
 436                }
 437           }
 438
 439         if (ip_src_isrange)
 440           {
 441              if (update_IP_SA(l, t3)==0) // end of range not yet reached
 442                {
 443                   goto AGAIN;
 444                }
 445           }
 446
 447
 448         if (rtp_mode) // update SQNR and Timestamps in RTP header and payload
 449           {
 450              update_RTP(l, t4);
 451           }
 452
 453
 454         if (!count) goto AGAIN;
 455      }
 456
 457
 458    libnet_destroy(l);
 459    if (isdot1Q)
 460    libnet_destroy(L);
 461
 462
 463    return t;
 464 }
 465
 466
 467
 468 void print_dot1Q_help(void)
 469 {
 470
 471              fprintf(stderr,"\n"
 472                      MAUSEZAHN_VERSION
 473                      "\n"
 474                      "| 802.1Q header Syntax: -Q tag[,tag[,tag[,...]]]\n"
 475                      "| where each tag may consist of a CoS value using the syntax:\n"
 476                      "|\n"
 477                      "|  <CoS>:<tag value>\n"
 478                      "|\n"
 479                      "| Examples:\n"
 480                      "|\n"
 481                      "|  # mz -Q 100\n"
 482                      "|  # mz -Q 5:100\n"
 483                      "|  # mz -Q 5:100,200\n"
 484                      "|  # mz -Q 5:100,7:200\n"
 485                      "|  # mz -Q 100,200,300,5:400\n"
 486                      "\n\n");
 487
 488              exit(0);
 489 }
 490
 491