Source/charon/message.c

   1 /**
   2  * @file message.c
   3  *
   4  * @brief Class message_t. Object of this type represents an IKEv2-Message.
   5  *
   6  */
   7
   8 /*
   9  * Copyright (C) 2005 Jan Hutter, Martin Willi
  10  * Hochschule fuer Technik Rapperswil
  11  *
  12  * This program is free software; you can redistribute it and/or modify it
  13  * under the terms of the GNU General Public License as published by the
  14  * Free Software Foundation; either version 2 of the License, or (at your
  15  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  16  *
  17  * This program is distributed in the hope that it will be useful, but
  18  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  19  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  20  * for more details.
  21  */
  22
  23 #include <stdlib.h>
  24
  25 #include "message.h"
  26
  27 #include "types.h"
  28 #include "globals.h"
  29 #include "ike_sa_id.h"
  30 #include "generator.h"
  31 #include "utils/linked_list.h"
  32 #include "utils/allocator.h"
  33 #include "utils/logger_manager.h"
  34 #include "payloads/encodings.h"
  35 #include "payloads/payload.h"
  36 #include "parser.h"
  37
  38
  39 /**
  40  * Supported payload entry used in message_rule_t
  41  *
  42  */
  43 typedef struct supported_payload_entry_s supported_payload_entry_t;
  44
  45 struct supported_payload_entry_s {
  46         /**
  47          * Payload type
  48          */
  49          payload_type_t payload_type;
  50
  51          /**
  52           * Minimal occurence of this payload
  53           */
  54          size_t min_occurence;
  55
  56          /**
  57           * Max occurence of this payload
  58           */
  59          size_t max_occurence;
  60 };
  61
  62 /**
  63  * Message Rule used to find out which payloads are supported by each message type
  64  *
  65  */
  66 typedef struct message_rule_s message_rule_t;
  67
  68 struct message_rule_s {
  69         /**
  70          * Type of message
  71          */
  72         exchange_type_t exchange_type;
  73
  74         /**
  75          * Is message a request or response
  76          */
  77         bool is_request;
  78          /**
  79           * Number of supported payloads
  80           */
  81          size_t supported_payloads_count;
  82         /**
  83          * Pointer to first supported payload entry
  84          */
  85          supported_payload_entry_t *supported_payloads;
  86 };
  87
  88
  89 static supported_payload_entry_t supported_ike_sa_init_i_payloads[] =
  90 {
  91         {SECURITY_ASSOCIATION,1,1},
  92         {KEY_EXCHANGE,1,1},
  93         {NONCE,1,1},
  94 };
  95
  96 static supported_payload_entry_t supported_ike_sa_init_r_payloads[] =
  97 {
  98         {SECURITY_ASSOCIATION,1,1},
  99         {KEY_EXCHANGE,1,1},
 100         {NONCE,1,1},
 101 };
 102
 103 static message_rule_t message_rules[] = {
 104         {IKE_SA_INIT,TRUE,(sizeof(supported_ike_sa_init_i_payloads)/sizeof(supported_payload_entry_t)),supported_ike_sa_init_i_payloads},
 105         {IKE_SA_INIT,FALSE,(sizeof(supported_ike_sa_init_r_payloads)/sizeof(supported_payload_entry_t)),supported_ike_sa_init_r_payloads}
 106 };
 107
 108 /**
 109  * Entry for a payload in the internal used linked list
 110  *
 111  */
 112 typedef struct payload_entry_s payload_entry_t;
 113
 114 struct payload_entry_s {
 115         /**
 116          * Type of payload
 117          */
 118         payload_type_t payload_type;
 119         /**
 120          * Data struct holding the data of given payload
 121          */
 122         void *data_struct;
 123 };
 124
 125
 126 /**
 127  * Private data of an message_t object
 128  */
 129 typedef struct private_message_s private_message_t;
 130
 131 struct private_message_s {
 132
 133         /**
 134          * Public part of a message_t object
 135          */
 136         message_t public;
 137
 138
 139         /**
 140          * Minor version of message
 141          */
 142         u_int8_t major_version;
 143
 144         /**
 145          * Major version of message
 146          */
 147         u_int8_t minor_version;
 148
 149         /**
 150          * First Payload in message
 151          */
 152         payload_type_t first_payload;
 153
 154         /**
 155          * Assigned exchange type
 156          */
 157         exchange_type_t exchange_type;
 158
 159
 160         /**
 161          * TRUE if message is request.
 162          * FALSE if message is reply.
 163          */
 164         bool is_request;
 165
 166         /**
 167          * Message ID of this message
 168          */
 169         u_int32_t message_id;
 170
 171         /**
 172          * ID of assigned IKE_SA
 173          */
 174         ike_sa_id_t *ike_sa_id;
 175
 176         /**
 177          * Assigned UDP packet.
 178          *
 179          * Stores incoming packet or last generated one.
 180          */
 181         packet_t *packet;
 182
 183         /**
 184          * Linked List where payload data are stored in
 185          */
 186         linked_list_t *payloads;
 187
 188          /**
 189           * Assigned parser to parse Header and Body of this message
 190           */
 191         parser_t *parser;
 192
 193         /**
 194          * logger for this message
 195          */
 196         logger_t *logger;
 197
 198         /**
 199          * Gets a list of supported payloads of this message type
 200          *
 201          * @param this                                                  calling object
 202          * @param[out] supported_payloads               first entry of supported payloads
 203          * @param[out] supported_payloads_count number of supported payload entries
 204          *
 205          * @return                                                              SUCCESS
 206          *                                                                              NOT_FOUND if no supported payload definition could be found
 207          */
 208         status_t (*get_supported_payloads) (private_message_t *this, supported_payload_entry_t **supported_payloads,size_t *supported_payloads_count);
 209
 210 };
 211
 212 /**
 213  * Implements private_message_t's get_supported_payloads function.
 214  * See #private_message_t.get_supported_payloads.
 215  */
 216 status_t get_supported_payloads (private_message_t *this, supported_payload_entry_t **supported_payloads,size_t *supported_payloads_count)
 217 {
 218         int i;
 219         exchange_type_t exchange_type = this->public.get_exchange_type(&(this->public));
 220         bool is_request = this->public.get_request(&(this->public));
 221
 222
 223         for (i = 0; i < (sizeof(message_rules) / sizeof(message_rule_t)); i++)
 224         {
 225                 if ((exchange_type == message_rules[i].exchange_type) &&
 226                         (is_request == message_rules[i].is_request))
 227                 {
 228                         /* found rule for given exchange_type*/
 229                         *supported_payloads = message_rules[i].supported_payloads;
 230                         *supported_payloads_count = message_rules[i].supported_payloads_count;
 231
 232                         return SUCCESS;
 233                 }
 234
 235
 236         }
 237         *supported_payloads = NULL;
 238         *supported_payloads_count = 0;
 239         return NOT_FOUND;
 240 }
 241
 242 /**
 243  * Implements message_t's set_ike_sa_id function.
 244  * See #message_s.set_ike_sa_id.
 245  */
 246 static status_t set_ike_sa_id (private_message_t *this,ike_sa_id_t *ike_sa_id)
 247 {
 248         status_t status;
 249         status = ike_sa_id->clone(ike_sa_id,&(this->ike_sa_id));
 250         return status;
 251 }
 252
 253 /**
 254  * Implements message_t's get_ike_sa_id function.
 255  * See #message_s.get_ike_sa_id.
 256  */
 257 static status_t get_ike_sa_id (private_message_t *this,ike_sa_id_t **ike_sa_id)
 258 {
 259         status_t status;
 260         if (this->ike_sa_id == NULL)
 261         {
 262                 return FAILED;
 263         }
 264         status = this->ike_sa_id->clone(this->ike_sa_id,ike_sa_id);
 265         return status;
 266 }
 267
 268
 269 /**
 270  * Implements message_t's set_message_id function.
 271  * See #message_s.set_message_id.
 272  */
 273 static status_t set_message_id (private_message_t *this,u_int32_t message_id)
 274 {
 275         this->message_id = message_id;
 276         return SUCCESS;
 277 }
 278
 279
 280 /**
 281  * Implements message_t's set_message_id function.
 282  * See #message_s.set_message_id.
 283  */
 284 static u_int32_t get_message_id (private_message_t *this)
 285 {
 286         return this->message_id;
 287 }
 288
 289 /**
 290  * Implements message_t's set_major_version function.
 291  * See #message_s.set_major_version.
 292  */
 293 static status_t set_major_version (private_message_t *this,u_int8_t major_version)
 294 {
 295         this->major_version = major_version;
 296         return SUCCESS;
 297 }
 298
 299
 300 /**
 301  * Implements message_t's get_major_version function.
 302  * See #message_s.get_major_version.
 303  */
 304 static u_int8_t get_major_version (private_message_t *this)
 305 {
 306         return this->major_version;
 307 }
 308
 309 /**
 310  * Implements message_t's set_minor_version function.
 311  * See #message_s.set_minor_version.
 312  */
 313 static status_t set_minor_version (private_message_t *this,u_int8_t minor_version)
 314 {
 315         this->minor_version = minor_version;
 316         return SUCCESS;
 317 }
 318
 319
 320 /**
 321  * Implements message_t's get_minor_version function.
 322  * See #message_s.get_minor_version.
 323  */
 324 static u_int8_t get_minor_version (private_message_t *this)
 325 {
 326         return this->minor_version;
 327 }
 328
 329 /**
 330  * Implements message_t's set_exchange_type function.
 331  * See #message_s.set_exchange_type.
 332  */
 333 static status_t set_exchange_type (private_message_t *this,exchange_type_t exchange_type)
 334 {
 335         this->exchange_type = exchange_type;
 336         return SUCCESS;
 337 }
 338
 339
 340 /**
 341  * Implements message_t's get_exchange_type function.
 342  * See #message_s.get_exchange_type.
 343  */
 344 static exchange_type_t get_exchange_type (private_message_t *this)
 345 {
 346         return this->exchange_type;
 347 }
 348
 349
 350 /**
 351  * Implements message_t's set_request function.
 352  * See #message_s.set_request.
 353  */
 354 static status_t set_request (private_message_t *this,bool request)
 355 {
 356         this->is_request = request;
 357         return SUCCESS;
 358 }
 359
 360 /**
 361  * Implements message_t's get_request function.
 362  * See #message_s.get_request.
 363  */
 364 static exchange_type_t get_request (private_message_t *this)
 365 {
 366         return this->is_request;
 367 }
 368
 369 static status_t add_payload(private_message_t *this, payload_t *payload)
 370 {
 371         payload_t *last_payload;
 372         if ((this->payloads->get_count(this->payloads) > 0) &&
 373             (this->payloads->get_last(this->payloads,(void **) &last_payload) != SUCCESS))
 374         {
 375                 return OUT_OF_RES;
 376         }
 377
 378         if (this->payloads->insert_last(this->payloads, payload) != SUCCESS)
 379         {
 380                 return OUT_OF_RES;
 381         }
 382         if (this->payloads->get_count(this->payloads) == 1)
 383         {
 384                 this->first_payload = payload->get_type(payload);
 385         }
 386         else
 387         {
 388                 last_payload->set_next_type(last_payload,payload->get_type(payload));
 389         }
 390
 391         return SUCCESS;
 392 }
 393
 394 static status_t set_source(private_message_t *this, host_t *host)
 395 {
 396         if (this->packet->source != NULL)
 397         {
 398                 this->packet->source->destroy(this->packet->source);
 399         }
 400         this->packet->source = host;
 401         return SUCCESS;
 402 }
 403
 404 static status_t set_destination(private_message_t *this, host_t *host)
 405 {
 406         if (this->packet->destination != NULL)
 407         {
 408                 this->packet->destination->destroy(this->packet->destination);
 409         }
 410         this->packet->destination = host;
 411         return SUCCESS;
 412 }
 413
 414 static status_t get_source(private_message_t *this, host_t **host)
 415 {
 416         *host = this->packet->source;
 417         return SUCCESS;
 418 }
 419
 420 static status_t get_destination(private_message_t *this, host_t **host)
 421 {
 422         *host = this->packet->destination;
 423         return SUCCESS;
 424 }
 425
 426
 427 static status_t get_payload_iterator(private_message_t *this, linked_list_iterator_t **iterator)
 428 {
 429         return this->payloads->create_iterator(this->payloads, iterator, TRUE);
 430 }
 431
 432
 433 /**
 434  * Implements message_t's generate function.
 435  * See #message_s.generate.
 436  */
 437 static status_t generate(private_message_t *this, packet_t **packet)
 438 {
 439         generator_t *generator;
 440         ike_header_t *ike_header;
 441         payload_t *payload, *next_payload;
 442         linked_list_iterator_t *iterator;
 443         status_t status;
 444
 445         if (this->exchange_type == EXCHANGE_TYPE_UNDEFINED)
 446         {
 447                 return INVALID_STATE;
 448         }
 449
 450         if (this->packet->source == NULL ||
 451                 this->packet->destination == NULL)
 452         {
 453                 return INVALID_STATE;
 454         }
 455
 456         ike_header = ike_header_create();
 457         if (ike_header == NULL)
 458         {
 459                 return OUT_OF_RES;
 460         }
 461
 462
 463         ike_header->set_exchange_type(ike_header, this->exchange_type);
 464         ike_header->set_message_id(ike_header, this->message_id);
 465         ike_header->set_response_flag(ike_header, !this->is_request);
 466         ike_header->set_initiator_flag(ike_header, this->ike_sa_id->is_initiator(this->ike_sa_id));
 467         ike_header->set_initiator_spi(ike_header, this->ike_sa_id->get_initiator_spi(this->ike_sa_id));
 468         ike_header->set_responder_spi(ike_header, this->ike_sa_id->get_responder_spi(this->ike_sa_id));
 469
 470         generator = generator_create();
 471         if (generator == NULL)
 472         {
 473                 return OUT_OF_RES;
 474         }
 475
 476         payload = (payload_t*)ike_header;
 477
 478         if (this->payloads->create_iterator(this->payloads, &iterator, TRUE) != SUCCESS)
 479         {
 480                 generator->destroy(generator);
 481                 ike_header->destroy(ike_header);
 482                 return OUT_OF_RES;
 483         }
 484         while(iterator->has_next(iterator))
 485         {
 486                 iterator->current(iterator, (void**)&next_payload);
 487                 payload->set_next_type(payload, next_payload->get_type(next_payload));
 488                 status = generator->generate_payload(generator, payload);
 489                 if (status != SUCCESS)
 490                 {
 491                         generator->destroy(generator);
 492                         ike_header->destroy(ike_header);
 493                         return status;
 494                 }
 495                 payload = next_payload;
 496         }
 497         iterator->destroy(iterator);
 498
 499         payload->set_next_type(payload, NO_PAYLOAD);
 500         status = generator->generate_payload(generator, payload);
 501         if (status != SUCCESS)
 502         {
 503                 generator->destroy(generator);
 504                 ike_header->destroy(ike_header);
 505                 return status;
 506         }
 507
 508         ike_header->destroy(ike_header);
 509
 510
 511
 512         if (this->packet->data.ptr != NULL)
 513         {
 514                 allocator_free(this->packet->data.ptr);
 515         }
 516
 517         status = generator->write_to_chunk(generator, &(this->packet->data));
 518         if (status != SUCCESS)
 519         {
 520                 generator->destroy(generator);
 521                 return status;
 522         }
 523
 524         this->packet->clone(this->packet, packet);
 525
 526         generator->destroy(generator);
 527         return SUCCESS;
 528 }
 529
 530 /**
 531  * Implements message_t's parse_header function.
 532  * See #message_s.parse_header.
 533  */
 534 static status_t parse_header (private_message_t *this)
 535 {
 536         ike_header_t *ike_header;
 537         status_t status;
 538
 539         this->parser->reset_context(this->parser);
 540         status = this->parser->parse_payload(this->parser,HEADER,(payload_t **) &ike_header);
 541         if (status != SUCCESS)
 542         {
 543                 this->logger->log(this->logger, ERROR, "Header could not be parsed");
 544                 return status;
 545
 546         }
 547
 548         /* verify payload */
 549         status = ike_header->payload_interface.verify(&(ike_header->payload_interface));
 550         if (status != SUCCESS)
 551         {
 552                 this->logger->log(this->logger, ERROR, "Header could not be verified");
 553                 return status;
 554         }
 555
 556         if (this->ike_sa_id != NULL)
 557         {
 558                 this->ike_sa_id->destroy(this->ike_sa_id);
 559         }
 560
 561         this->ike_sa_id = ike_sa_id_create(ike_header->get_initiator_spi(ike_header),
 562                                                                            ike_header->get_responder_spi(ike_header),
 563                                                                            !ike_header->get_initiator_flag(ike_header));
 564         if (this->ike_sa_id == NULL)
 565         {
 566                 this->logger->log(this->logger, ERROR, "Could not creaee ike_sa_id object");
 567                 ike_header->destroy(ike_header);
 568                 return OUT_OF_RES;
 569         }
 570         this->exchange_type = ike_header->get_exchange_type(ike_header);
 571         this->message_id = ike_header->get_message_id(ike_header);
 572         this->is_request = (!(ike_header->get_response_flag(ike_header)));
 573         this->major_version = ike_header->get_maj_version(ike_header);
 574         this->minor_version = ike_header->get_min_version(ike_header);
 575         this->first_payload = ike_header->payload_interface.get_next_type(&(ike_header->payload_interface));
 576
 577         ike_header->destroy(ike_header);
 578         return SUCCESS;
 579 }
 580
 581 /**
 582  * Implements message_t's parse_body function.
 583  * See #message_s.parse_body.
 584  */
 585 static status_t parse_body (private_message_t *this)
 586 {
 587         status_t status = SUCCESS;
 588         int i;
 589         payload_type_t current_payload_type = this->first_payload;
 590         supported_payload_entry_t *supported_payloads;
 591         size_t supported_payloads_count;
 592
 593
 594         if (this->get_supported_payloads (this,&supported_payloads,&supported_payloads_count) != SUCCESS)
 595         {
 596                 this->logger->log(this->logger, ERROR, "could not get supported payloads");
 597                 /* message type is not supported */
 598                 return FAILED;
 599         }
 600
 601
 602         this->logger->log(this->logger, ERROR, "first payload %s", mapping_find(payload_type_m, current_payload_type));
 603
 604         while (current_payload_type != NO_PAYLOAD)
 605         {
 606                 payload_t *current_payload;
 607
 608                 bool supported = FALSE;
 609                 for (i = 0; i < supported_payloads_count;i++)
 610                 {
 611                         if (supported_payloads[i].payload_type == current_payload_type)
 612                         {
 613                                 supported = TRUE;
 614                                 break;
 615                         }
 616                 }
 617                 if (!supported && (current_payload_type != NO_PAYLOAD))
 618                 {
 619                         /* type not supported */
 620                         status = NOT_SUPPORTED;
 621                         this->logger->log(this->logger, ERROR, "Payload type %s not supported",mapping_find(payload_type_m,current_payload_type));
 622                         break;
 623                 }
 624
 625                 status = this->parser->parse_payload(this->parser,current_payload_type,(payload_t **) &current_payload);
 626                 if (status != SUCCESS)
 627                 {
 628                         this->logger->log(this->logger, ERROR, "Payload type %s could not be parsed",mapping_find(payload_type_m,current_payload_type));
 629                         break;
 630                 }
 631
 632                 current_payload_type = current_payload->get_next_type(current_payload);
 633
 634                 status = current_payload->verify(current_payload);
 635                 if (status != SUCCESS)
 636                 {
 637                         this->logger->log(this->logger, ERROR, "Payload type %s could not be verified",mapping_find(payload_type_m,current_payload_type));
 638                         status = VERIFY_ERROR;
 639                         break;
 640                 }
 641
 642                 status = this->payloads->insert_last(this->payloads,current_payload);
 643                 if (status != SUCCESS)
 644                 {
 645                         this->logger->log(this->logger, ERROR, "Could not insert current payload to internal list cause of ressource exhausting");
 646                         break;
 647                 }
 648
 649         }
 650         if (status != SUCCESS)
 651         {
 652                 /* already parsed payload is destroyed later in destroy call from outside this object */
 653         }
 654         else
 655         {
 656                 linked_list_iterator_t *iterator;
 657
 658                 status = this->payloads->create_iterator(this->payloads,&iterator,TRUE);
 659                 if (status != SUCCESS)
 660                 {
 661                         this->logger->log(this->logger, ERROR, "Could not create iterator to check supported payloads");
 662                         return status;
 663                 }
 664
 665
 666                 /* check for payloads with wrong count*/
 667                 for (i = 0; i < supported_payloads_count;i++)
 668                 {
 669                         size_t min_occurence = supported_payloads[i].min_occurence;
 670                         size_t max_occurence = supported_payloads[i].max_occurence;
 671                         payload_type_t payload_type = supported_payloads[i].payload_type;
 672                         size_t found_payloads = 0;
 673
 674                         iterator->reset(iterator);
 675
 676                         while(iterator->has_next(iterator))
 677                         {
 678                                 payload_t *current_payload;
 679                                 status = iterator->current(iterator,(void **)&current_payload);
 680                                 if (status != SUCCESS)
 681                                 {
 682                                         this->logger->log(this->logger, CONTROL|MORE, "Could not get payload from internal list");
 683                                         iterator->destroy(iterator);
 684                                         return status;
 685                                 }
 686                                 if (current_payload->get_type(current_payload) == payload_type)
 687                                 {
 688                                         found_payloads++;
 689                                         if (found_payloads > max_occurence)
 690                                         {
 691                                                 this->logger->log(this->logger, CONTROL|MORE, "Payload of type %s more than %d times (%d) occured in current message",
 692                                                                                   mapping_find(payload_type_m,current_payload->get_type(current_payload)),max_occurence,found_payloads);
 693                                                 iterator->destroy(iterator);
 694                                                 return NOT_SUPPORTED;
 695                                         }
 696                                 }
 697
 698                         }
 699                         if (found_payloads < min_occurence)
 700                         {
 701                                         this->logger->log(this->logger, CONTROL|MORE, "Payload of type %s not occured %d times",
 702                                                                           mapping_find(payload_type_m,payload_type),min_occurence);
 703                                         iterator->destroy(iterator);
 704                                         return NOT_SUPPORTED;
 705                         }
 706
 707                 }
 708                 iterator->destroy(iterator);
 709         }
 710         return status;
 711 }
 712
 713
 714
 715 /**
 716  * Implements message_t's destroy function.
 717  * See #message_s.destroy.
 718  */
 719 static status_t destroy (private_message_t *this)
 720 {
 721         linked_list_iterator_t *iterator;
 722
 723         if (this->packet != NULL)
 724         {
 725                 this->packet->destroy(this->packet);
 726         }
 727         if (this->ike_sa_id != NULL)
 728         {
 729                 this->ike_sa_id->destroy(this->ike_sa_id);
 730         }
 731
 732         this->payloads->create_iterator(this->payloads, &iterator, TRUE);
 733         while (iterator->has_next(iterator))
 734         {
 735                 payload_t *payload;
 736                 iterator->current(iterator, (void**)&payload);
 737                 this->logger->log(this->logger, CONTROL|MORE, "Destroying payload of type %s",
 738                         mapping_find(payload_type_m, payload->get_type(payload)));
 739                 payload->destroy(payload);
 740         }
 741         iterator->destroy(iterator);
 742         this->payloads->destroy(this->payloads);
 743         this->parser->destroy(this->parser);
 744
 745 allocator_free(this);
 746         return SUCCESS;
 747 }
 748
 749 /*
 750  * Described in Header-File
 751  */
 752 message_t *message_create_from_packet(packet_t *packet)
 753 {
 754         private_message_t *this = allocator_alloc_thing(private_message_t);
 755         if (this == NULL)
 756         {
 757                 return NULL;
 758         }
 759
 760         /* public functions */
 761         this->public.set_major_version = (status_t(*)(message_t*, u_int8_t))set_major_version;
 762         this->public.get_major_version = (u_int8_t(*)(message_t*))get_major_version;
 763         this->public.set_minor_version = (status_t(*)(message_t*, u_int8_t))set_minor_version;
 764         this->public.get_minor_version = (u_int8_t(*)(message_t*))get_minor_version;
 765         this->public.set_message_id = (status_t(*)(message_t*, u_int32_t))set_message_id;
 766         this->public.get_message_id = (u_int32_t(*)(message_t*))get_message_id;
 767         this->public.set_ike_sa_id = (status_t(*)(message_t*, ike_sa_id_t *))set_ike_sa_id;
 768         this->public.get_ike_sa_id = (status_t(*)(message_t*, ike_sa_id_t **))get_ike_sa_id;
 769         this->public.set_exchange_type = (status_t(*)(message_t*, exchange_type_t))set_exchange_type;
 770         this->public.get_exchange_type = (exchange_type_t(*)(message_t*))get_exchange_type;
 771         this->public.set_request = (status_t(*)(message_t*, bool))set_request;
 772         this->public.get_request = (bool(*)(message_t*))get_request;
 773         this->public.add_payload = (status_t(*)(message_t*,payload_t*))add_payload;
 774         this->public.generate = (status_t (*) (message_t *, packet_t**)) generate;
 775         this->public.set_source = (status_t (*) (message_t*,host_t*)) set_source;
 776         this->public.get_source = (status_t (*) (message_t*,host_t**)) get_source;
 777         this->public.set_destination = (status_t (*) (message_t*,host_t*)) set_destination;
 778         this->public.get_destination = (status_t (*) (message_t*,host_t**)) get_destination;
 779         this->public.get_payload_iterator = (status_t (*) (message_t *, linked_list_iterator_t **)) get_payload_iterator;
 780         this->public.parse_header =     (status_t (*) (message_t *)) parse_header;
 781         this->public.parse_body =       (status_t (*) (message_t *)) parse_body;
 782         this->public.destroy = (status_t(*)(message_t*))destroy;
 783
 784         /* public values */
 785         this->exchange_type = EXCHANGE_TYPE_UNDEFINED;
 786         this->is_request = TRUE;
 787         this->ike_sa_id = NULL;
 788         this->first_payload = NO_PAYLOAD;
 789         this->message_id = 0;
 790
 791         /* private functions */
 792         this->get_supported_payloads = get_supported_payloads;
 793
 794         /* private values */
 795         if (packet == NULL)
 796         {
 797                 packet = packet_create();
 798         }
 799         if (packet == NULL)
 800         {
 801                 allocator_free(this);
 802                 return NULL;
 803         }
 804         this->packet = packet;
 805         this->payloads = linked_list_create();
 806         if (this->payloads == NULL)
 807         {
 808                 allocator_free(this);
 809                 return NULL;
 810         }
 811
 812         /* parser is created from data of packet */
 813         this->parser = parser_create(this->packet->data);
 814         if (this->parser == NULL)
 815         {
 816                 this->payloads->destroy(this->payloads);
 817                 allocator_free(this);
 818                 return NULL;
 819         }
 820
 821         this->logger = global_logger_manager->create_logger(global_logger_manager, MESSAGE, NULL);
 822         if (this->logger == NULL)
 823         {
 824                 this->parser->destroy(this->parser);
 825                 this->payloads->destroy(this->payloads);
 826                 allocator_free(this);
 827                 return NULL;
 828         }
 829
 830         return (&this->public);
 831 }
 832
 833 /*
 834  * Described in Header-File
 835  */
 836 message_t *message_create()
 837 {
 838         return message_create_from_packet(NULL);
 839 }