peer.h

/* dtls -- a very basic DTLS implementation
 *
 * Copyright (C) 2011--2013 Olaf Bergmann <bergmann@tzi.org>
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use, copy,
 * modify, merge, publish, distribute, sublicense, and/or sell copies
 * of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

/**
 * @file peer.h
 * @brief information about peers in a DTLS session
 */

#ifndef _PEER_H_
#define _PEER_H_

#include "config.h"
#include "global.h"

#include "state.h"
#include "crypto.h"

#ifndef WITH_CONTIKI
#include "uthash.h"
#else
#include "ctimer.h"
#endif /* WITH_CONTIKI */

typedef enum { DTLS_CLIENT=0, DTLS_SERVER } dtls_peer_type;

/** 
 * Holds security parameters, local state and the transport address
 * for each peer. */
typedef struct dtls_peer_t {
#ifndef WITH_CONTIKI
  UT_hash_handle hh;
#else /* WITH_CONTIKI */
  struct dtls_peer_t *next;
  struct ctimer timeout;
#if DTLS_CONN_TIMEOUT
  struct dtls_context_t *ctx;
#endif
#endif /* WITH_CONTIKI */

  session_t session;	     /**< peer address and local interface */

  dtls_peer_type role;       /**< denotes if this host is DTLS_CLIENT or DTLS_SERVER */
  dtls_state_t state;        /**< DTLS engine state */
  uint16 epoch;		     /**< counter for cipher state changes*/
  uint48 rseq;		     /**< sequence number of last record sent */

  dtls_hs_state_t hs_state;  /**< handshake protocol status */

  dtls_security_parameters_t security_params;
  dtls_handshake_parameters_t handshake_params;
} dtls_peer_t;

void peer_init();

/**
 * Creates a new peer for given @p session. The current configuration
 * is initialized with the cipher suite TLS_NULL_WITH_NULL_NULL (i.e.
 * no security at all). This function returns a pointer to the new
 * peer or NULL on error. The caller is responsible for releasing the
 * storage allocated for this peer using dtls_free_peer().
 *
 * @param session  The remote peer's address and local interface index.
 * @return A pointer to a newly created and initialized peer object
 * or NULL on error.
 */
dtls_peer_t *dtls_new_peer(struct dtls_context_t *ctx, const session_t *session);

/** Releases the storage allocated to @p peer. */
void dtls_free_peer(dtls_peer_t *peer);

/** Returns the current state of @p peer. */
static inline dtls_state_t dtls_peer_state(const dtls_peer_t *peer) {
  return peer->state;
}

/**
 * Checks if given @p peer is connected. This function returns
 * @c 1 if connected, or @c 0 otherwise.
 */
static inline int dtls_peer_is_connected(const dtls_peer_t *peer) {
  return peer->state == DTLS_STATE_CONNECTED;
}

/**
 * Reset the connection timeout of @p peer
 */
void dtls_peer_refresh_timeout(dtls_peer_t *peer);

#endif /* _PEER_H_ */