peer.h

00001 /* dtls -- a very basic DTLS implementation
00002  *
00003  * Copyright (C) 2011--2013 Olaf Bergmann <bergmann@tzi.org>
00004  *
00005  * Permission is hereby granted, free of charge, to any person
00006  * obtaining a copy of this software and associated documentation
00007  * files (the "Software"), to deal in the Software without
00008  * restriction, including without limitation the rights to use, copy,
00009  * modify, merge, publish, distribute, sublicense, and/or sell copies
00010  * of the Software, and to permit persons to whom the Software is
00011  * furnished to do so, subject to the following conditions:
00012  *
00013  * The above copyright notice and this permission notice shall be
00014  * included in all copies or substantial portions of the Software.
00015  *
00016  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
00017  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
00018  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
00019  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
00020  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
00021  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
00022  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
00023  * SOFTWARE.
00024  */
00025 
00026 /**
00027  * @file peer.h
00028  * @brief information about peers in a DTLS session
00029  */
00030 
00031 #ifndef _PEER_H_
00032 #define _PEER_H_
00033 
00034 #include "config.h"
00035 #include "global.h"
00036 
00037 #include "state.h"
00038 #include "crypto.h"
00039 
00040 #ifndef WITH_CONTIKI
00041 #include "uthash.h"
00042 #endif /* WITH_CONTIKI */
00043 
00044 typedef enum { DTLS_CLIENT=0, DTLS_SERVER } dtls_peer_type;
00045 
00046 /** 
00047  * Holds security parameters, local state and the transport address
00048  * for each peer. */
00049 typedef struct dtls_peer_t {
00050 #ifndef WITH_CONTIKI
00051   UT_hash_handle hh;
00052 #else /* WITH_CONTIKI */
00053   struct dtls_peer_t *next;
00054 #endif /* WITH_CONTIKI */
00055 
00056   session_t session;         /**< peer address and local interface */
00057 
00058   dtls_peer_type role;       /**< denotes if this host is DTLS_CLIENT or DTLS_SERVER */
00059   dtls_state_t state;        /**< DTLS engine state */
00060   uint16 epoch;          /**< counter for cipher state changes*/
00061   uint48 rseq;           /**< sequence number of last record sent */
00062 
00063   dtls_hs_state_t hs_state;  /**< handshake protocol status */
00064 
00065   dtls_security_parameters_t security_params;
00066   dtls_handshake_parameters_t handshake_params;
00067 } dtls_peer_t;
00068 
00069 void peer_init();
00070 
00071 /**
00072  * Creates a new peer for given @p session. The current configuration
00073  * is initialized with the cipher suite TLS_NULL_WITH_NULL_NULL (i.e.
00074  * no security at all). This function returns a pointer to the new
00075  * peer or NULL on error. The caller is responsible for releasing the
00076  * storage allocated for this peer using dtls_free_peer().
00077  *
00078  * @param session  The remote peer's address and local interface index.
00079  * @return A pointer to a newly created and initialized peer object
00080  * or NULL on error.
00081  */
00082 dtls_peer_t *dtls_new_peer(const session_t *session);
00083 
00084 /** Releases the storage allocated to @p peer. */
00085 void dtls_free_peer(dtls_peer_t *peer);
00086 
00087 /** Returns the current state of @p peer. */
00088 static inline dtls_state_t dtls_peer_state(const dtls_peer_t *peer) {
00089   return peer->state;
00090 }
00091 
00092 /**
00093  * Checks if given @p peer is connected. This function returns
00094  * @c 1 if connected, or @c 0 otherwise.
00095  */
00096 static inline int dtls_peer_is_connected(const dtls_peer_t *peer) {
00097   return peer->state == DTLS_STATE_CONNECTED;
00098 }
00099 
00100 #endif /* _PEER_H_ */