/*

 * Copyright (C) 2009-2012 Free Software Foundation, Inc.

 *

 * Author: Jonathan Bastien-Filiatrault

 *

 * This file is part of GNUTLS.

 *

 * The GNUTLS library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public License

 * as published by the Free Software Foundation; either version 2.1 of

 * the License, or (at your option) any later version.

 *

 * This library 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

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public License

 * along with this program.  If not, see <https://www.gnu.org/licenses/>

 *

 */

#ifndef GNUTLS_LIB_DTLS_H

#define GNUTLS_LIB_DTLS_H

#include <config.h>

#include "gnutls_int.h"

#include <buffers.h>

#include <mbuffers.h>

#include <constate.h>

int _dtls_transmit(gnutls_session_t session);

int _dtls_record_check(struct record_parameters_st *rp, uint64_t seq_num);

void _dtls_reset_hsk_state(gnutls_session_t session);

void _dtls_reset_window(struct record_parameters_st *rp);

#define MAX_DTLS_TIMEOUT 60000

#define RETURN_DTLS_EAGAIN_OR_TIMEOUT(session, r) { \

  struct timespec _now; \

  unsigned int _diff; \

  gnutls_gettime(&_now); \

   \

  _diff = timespec_sub_ms(&_now, &session->internals.handshake_start_time); \

  if (_diff > session->internals.handshake_timeout_ms) \

    { \

      _gnutls_dtls_log("Session timeout: %u ms\n", _diff); \

      return gnutls_assert_val(GNUTLS_E_TIMEDOUT); \

    } \

  else \

    { \

      int _rr; \

      if (r != GNUTLS_E_INTERRUPTED) _rr = GNUTLS_E_AGAIN; \

      else _rr = r; \

      if (!(session->internals.flags & GNUTLS_NONBLOCK)) \

	millisleep(50); \

      return gnutls_assert_val(_rr); \

    } \

  }

int _dtls_wait_and_retransmit(gnutls_session_t session);

/* returns true or false depending on whether we need to

 * handle asynchronously handshake data.

 */

inline static int _dtls_is_async(gnutls_session_t session)

{

	if ((session->security_parameters.entity == GNUTLS_SERVER

	     && session->internals.resumed == RESUME_FALSE)

	    || (session->security_parameters.entity == GNUTLS_CLIENT

		&& session->internals.resumed == RESUME_TRUE))

		return 1;

	else

		return 0;

}

inline static void _dtls_async_timer_init(gnutls_session_t session)

{

	if (_dtls_is_async(session)) {

		_gnutls_dtls_log

		    ("DTLS[%p]: Initializing timer for handshake state.\n",

		     session);

		session->internals.dtls.async_term =

		    gnutls_time(0) + MAX_DTLS_TIMEOUT / 1000;

	} else {

		_dtls_reset_hsk_state(session);

		_gnutls_handshake_io_buffer_clear(session);

		_gnutls_epoch_gc(session);

		session->internals.dtls.async_term = 0;

	}

}

void _dtls_async_timer_delete(gnutls_session_t session);

/* Checks whether it is time to terminate the timer

 */

inline static void _dtls_async_timer_check(gnutls_session_t session)

{

	if (!IS_DTLS(session))

		return;

	if (session->internals.dtls.async_term != 0) {

		time_t _now = time(0);

		/* check if we need to expire the queued handshake data */

		if (_now > session->internals.dtls.async_term) {

			_dtls_async_timer_delete(session);

		}

	}

}

unsigned _gnutls_record_overhead(const version_entry_st *ver,

				 const cipher_entry_st *cipher,

				 const mac_entry_st *mac,

				 unsigned max);

/* Returns non-zero if the async timer is active */

inline static int _dtls_async_timer_active(gnutls_session_t session)

{

	if (!IS_DTLS(session))

		return 0;

	return session->internals.dtls.async_term;

}

/* This function is to be called from record layer once

 * a handshake replay is detected. It will make sure

 * it transmits only once per few seconds. Otherwise

 * it is the same as _dtls_transmit().

 */

inline static int _dtls_retransmit(gnutls_session_t session)

{

	return _dtls_transmit(session);

}

#endif /* GNUTLS_LIB_DTLS_H */