/*

 * Copyright (C) 2005-2010 Martin Willi

 * Copyright (C) 2005 Jan Hutter

 *

 * Copyright (C) secunet Security Networks AG

 *

 * This program is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License as published by the

 * Free Software Foundation; either version 2 of the License, or (at your

 * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.

 *

 * This program is distributed in the hope that it will be useful, but

 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY

 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * for more details.

 */

#include <stddef.h>

#include "ts_payload.h"

#include <encoding/payloads/encodings.h>

#include <collections/linked_list.h>

typedef struct private_ts_payload_t private_ts_payload_t;

/**

 * Private data of an ts_payload_t object.

 */

struct private_ts_payload_t {

  /**

   * Public ts_payload_t interface.

   */

  ts_payload_t public;

  /**

   * TRUE if this TS payload is of type TSi, FALSE for TSr.

   */

  bool is_initiator;

  /**

   * Next payload type.

   */

  uint8_t  next_payload;

  /**

   * Critical flag.

   */

  bool critical;

  /**

   * reserved bits

   */

  bool reserved_bit[7];

  /**

   * reserved bytes

   */

  bool reserved_byte[3];

  /**

   * Length of this payload.

   */

  uint16_t payload_length;

  /**

   * Number of traffic selectors

   */

  uint8_t ts_num;

  /**

   * Contains the traffic selectors of type traffic_selector_substructure_t.

   */

  linked_list_t *substrs;

};

/**

 * Encoding rules to parse or generate a TS payload

 *

 * The defined offsets are the positions in a object of type

 * private_ts_payload_t.

 */

static encoding_rule_t encodings[] = {

  /* 1 Byte next payload type, stored in the field next_payload */

  { U_INT_8,      offsetof(private_ts_payload_t, next_payload)  },

  /* the critical bit */

  { FLAG,       offsetof(private_ts_payload_t, critical)    },

  /* 7 Bit reserved bits */

  { RESERVED_BIT,   offsetof(private_ts_payload_t, reserved_bit[0]) },

  { RESERVED_BIT,   offsetof(private_ts_payload_t, reserved_bit[1]) },

  { RESERVED_BIT,   offsetof(private_ts_payload_t, reserved_bit[2]) },

  { RESERVED_BIT,   offsetof(private_ts_payload_t, reserved_bit[3]) },

  { RESERVED_BIT,   offsetof(private_ts_payload_t, reserved_bit[4]) },

  { RESERVED_BIT,   offsetof(private_ts_payload_t, reserved_bit[5]) },

  { RESERVED_BIT,   offsetof(private_ts_payload_t, reserved_bit[6]) },

  /* Length of the whole payload*/

  { PAYLOAD_LENGTH, offsetof(private_ts_payload_t, payload_length)  },

  /* 1 Byte TS type*/

  { U_INT_8,      offsetof(private_ts_payload_t, ts_num)      },

  /* 3 reserved bytes */

  { RESERVED_BYTE,  offsetof(private_ts_payload_t, reserved_byte[0])},

  { RESERVED_BYTE,  offsetof(private_ts_payload_t, reserved_byte[1])},

  { RESERVED_BYTE,  offsetof(private_ts_payload_t, reserved_byte[2])},

  /* wrapped list of traffic selectors substructures */

  { PAYLOAD_LIST + PLV2_TRAFFIC_SELECTOR_SUBSTRUCTURE,

            offsetof(private_ts_payload_t, substrs)     },

};

/*

                           1                   2                   3

       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1

      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      ! Next Payload  !C!  RESERVED   !         Payload Length        !

      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      ! Number of TSs !                 RESERVED                      !

      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      !                                                               !

      ~                       <Traffic Selectors>                     ~

      !                                                               !

      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

*/

METHOD(payload_t, verify, status_t,

  private_ts_payload_t *this)

{

  enumerator_t *enumerator;

  payload_t *substr;

  status_t status = SUCCESS;

  if (this->ts_num != this->substrs->get_count(this->substrs))

  {

    return FAILED;

  }

  enumerator = this->substrs->create_enumerator(this->substrs);

  while (enumerator->enumerate(enumerator, &substr))

  {

    status = substr->verify(substr);

    if (status != SUCCESS)

    {

      break;

    }

  }

  enumerator->destroy(enumerator);

  return status;

}

METHOD(payload_t, get_encoding_rules, int,

  private_ts_payload_t *this, encoding_rule_t **rules)

{

  *rules = encodings;

  return countof(encodings);

}

METHOD(payload_t, get_header_length, int,

  private_ts_payload_t *this)

{

  return 8;

}

METHOD(payload_t, get_type, payload_type_t,

  private_ts_payload_t *this)

{

  if (this->is_initiator)

  {

    return PLV2_TS_INITIATOR;

  }

  return PLV2_TS_RESPONDER;

}

METHOD(payload_t, get_next_type, payload_type_t,

  private_ts_payload_t *this)

{

  return this->next_payload;

}

METHOD(payload_t, set_next_type, void,

  private_ts_payload_t *this,payload_type_t type)

{

  this->next_payload = type;

}

/**

 * recompute the length of the payload.

 */

static void compute_length(private_ts_payload_t *this)

{

  enumerator_t *enumerator;

  payload_t *subst;

  this->payload_length = get_header_length(this);

  this->ts_num = 0;

  enumerator = this->substrs->create_enumerator(this->substrs);

  while (enumerator->enumerate(enumerator, &subst))

  {

    this->payload_length += subst->get_length(subst);

    this->ts_num++;

  }

  enumerator->destroy(enumerator);

}

METHOD(payload_t, get_length, size_t,

  private_ts_payload_t *this)

{

  return this->payload_length;

}

METHOD(ts_payload_t, get_initiator, bool,

  private_ts_payload_t *this)

{

  return this->is_initiator;

}

METHOD(ts_payload_t, set_initiator, void,

  private_ts_payload_t *this,bool is_initiator)

{

  this->is_initiator = is_initiator;

}

/**

 * Get a list of either traffic selectors or labels

 */

static linked_list_t *get_list(private_ts_payload_t *this, bool labels)

{

  enumerator_t *enumerator;

  traffic_selector_substructure_t *subst;

  linked_list_t *list;

  list = linked_list_create();

  enumerator = this->substrs->create_enumerator(this->substrs);

  while (enumerator->enumerate(enumerator, &subst))

  {

    if (labels)

    {

      sec_label_t *label = subst->get_sec_label(subst);

      if (label)

      {

        list->insert_last(list, label);

      }

    }

    else

    {

      traffic_selector_t *ts = subst->get_traffic_selector(subst);

      if (ts)

      {

        list->insert_last(list, ts);

      }

    }

  }

  enumerator->destroy(enumerator);

  return list;

}

METHOD(ts_payload_t, get_traffic_selectors, linked_list_t*,

  private_ts_payload_t *this)

{

  return get_list(this, FALSE);

}

METHOD(ts_payload_t, get_sec_labels, linked_list_t*,

  private_ts_payload_t *this)

{

  return get_list(this, TRUE);

}

METHOD2(payload_t, ts_payload_t, destroy, void,

  private_ts_payload_t *this)

{

  this->substrs->destroy_offset(this->substrs, offsetof(payload_t, destroy));

  free(this);

}

/*

 * Described in header

 */

ts_payload_t *ts_payload_create(bool is_initiator)

{

  private_ts_payload_t *this;

  INIT(this,

    .public = {

      .payload_interface = {

        .verify = _verify,

        .get_encoding_rules = _get_encoding_rules,

        .get_header_length = _get_header_length,

        .get_length = _get_length,

        .get_next_type = _get_next_type,

        .set_next_type = _set_next_type,

        .get_type = _get_type,

        .destroy = _destroy,

      },

      .get_initiator = _get_initiator,

      .set_initiator = _set_initiator,

      .get_traffic_selectors = _get_traffic_selectors,

      .get_sec_labels = _get_sec_labels,

      .destroy = _destroy,

    },

    .next_payload = PL_NONE,

    .payload_length = get_header_length(this),

    .is_initiator = is_initiator,

    .substrs = linked_list_create(),

  );

  return &this->public;

}

/*

 * Described in header

 */

ts_payload_t *ts_payload_create_from_traffic_selectors(bool is_initiator,

                      linked_list_t *traffic_selectors,

                      sec_label_t *label)

{

  enumerator_t *enumerator;

  traffic_selector_t *ts;

  traffic_selector_substructure_t *subst;

  private_ts_payload_t *this;

  this = (private_ts_payload_t*)ts_payload_create(is_initiator);

  enumerator = traffic_selectors->create_enumerator(traffic_selectors);

  while (enumerator->enumerate(enumerator, &ts))

  {

    subst = traffic_selector_substructure_create_from_traffic_selector(ts);

    this->substrs->insert_last(this->substrs, subst);

  }

  enumerator->destroy(enumerator);

  if (label)

  {

    subst = traffic_selector_substructure_create_from_sec_label(label);

    this->substrs->insert_last(this->substrs, subst);

  }

  compute_length(this);

  return &this->public;

}