/* * coap_session_internal.h -- Structures, Enums & Functions that are not * exposed to application programming * * Copyright (C) 2010-2019 Olaf Bergmann * * SPDX-License-Identifier: BSD-2-Clause * * This file is part of the CoAP library libcoap. Please see README for terms * of use. */ /** * @file coap_session_internal.h * @brief COAP session internal information */ #ifndef COAP_SESSION_INTERNAL_H_ #define COAP_SESSION_INTERNAL_H_ #include "coap_io_internal.h" #define COAP_DEFAULT_SESSION_TIMEOUT 300 #define COAP_PARTIAL_SESSION_TIMEOUT_TICKS (30 * COAP_TICKS_PER_SECOND) #define COAP_DEFAULT_MAX_HANDSHAKE_SESSIONS 100 /** * @defgroup session_internal Sessions (Internal) * CoAP Session Structures, Enums and Functions that are not exposed to * applications * @{ */ /** * Only used for servers for hashing incoming packets. Cannot have local IP * address as this may be an initial multicast and subsequent unicast address */ struct coap_addr_hash_t { coap_address_t remote; /**< remote address and port */ uint16_t lport; /**< local port */ coap_proto_t proto; /**< CoAP protocol */ }; /** * Abstraction of virtual session that can be attached to coap_context_t * (client) or coap_endpoint_t (server). */ struct coap_session_t { coap_proto_t proto; /**< protocol used */ coap_session_type_t type; /**< client or server side socket */ coap_session_state_t state; /**< current state of relationaship with peer */ unsigned ref; /**< reference count from queues */ size_t tls_overhead; /**< overhead of TLS layer */ size_t mtu; /**< path or CSM mtu */ coap_addr_hash_t addr_hash; /**< Address hash for server incoming packets */ UT_hash_handle hh; coap_addr_tuple_t addr_info; /**< key: remote/local address info */ int ifindex; /**< interface index */ coap_socket_t sock; /**< socket object for the session, if any */ coap_endpoint_t *endpoint; /**< session's endpoint */ coap_context_t *context; /**< session's context */ void *tls; /**< security parameters */ uint16_t tx_mid; /**< the last message id that was used in this session */ uint8_t con_active; /**< Active CON request sent */ uint8_t csm_block_supported; /**< CSM TCP blocks supported */ coap_mid_t last_ping_mid; /**< the last keepalive message id that was used in this session */ coap_queue_t *delayqueue; /**< list of delayed messages waiting to be sent */ coap_lg_xmit_t *lg_xmit; /**< list of large transmissions */ coap_lg_crcv_t *lg_crcv; /**< Client list of expected large receives */ coap_lg_srcv_t *lg_srcv; /**< Server list of expected large receives */ size_t partial_write; /**< if > 0 indicates number of bytes already written from the pdu at the head of sendqueue */ uint8_t read_header[8]; /**< storage space for header of incoming message header */ size_t partial_read; /**< if > 0 indicates number of bytes already read for an incoming message */ coap_pdu_t *partial_pdu; /**< incomplete incoming pdu */ coap_tick_t last_rx_tx; coap_tick_t last_tx_rst; coap_tick_t last_ping; coap_tick_t last_pong; coap_tick_t csm_tx; coap_dtls_cpsk_t cpsk_setup_data; /**< client provided PSK initial setup data */ coap_bin_const_t *psk_identity; /**< If client, this field contains the current identity for server; When this field is NULL, the current identity is contained in cpsk_setup_data If server, this field contains the client provided identity. Value maintained internally */ coap_bin_const_t *psk_key; /**< If client, this field contains the current pre-shared key for server; When this field is NULL, the current key is contained in cpsk_setup_data If server, this field contains the client's current key. Value maintained internally */ coap_bin_const_t *psk_hint; /**< If client, this field contains the server provided identity hint. If server, this field contains the current hint for the client; When this field is NULL, the current hint is contained in context->spsk_setup_data Value maintained internally */ void *app; /**< application-specific data */ unsigned int max_retransmit; /**< maximum re-transmit count (default 4) */ coap_fixed_point_t ack_timeout; /**< timeout waiting for ack (default 2 secs) */ coap_fixed_point_t ack_random_factor; /**< ack random factor backoff (default 1.5) */ unsigned int dtls_timeout_count; /**< dtls setup retry counter */ int dtls_event; /**< Tracking any (D)TLS events on this sesison */ uint8_t block_mode; /**< Zero or more COAP_BLOCK_ or'd options */ uint64_t tx_token; /**< Next token number to use */ }; /** * Abstraction of virtual endpoint that can be attached to coap_context_t. The * keys (port, bind_addr) must uniquely identify this endpoint. */ struct coap_endpoint_t { struct coap_endpoint_t *next; coap_context_t *context; /**< endpoint's context */ coap_proto_t proto; /**< protocol used on this interface */ uint16_t default_mtu; /**< default mtu for this interface */ coap_socket_t sock; /**< socket object for the interface, if any */ coap_address_t bind_addr; /**< local interface address */ coap_session_t *sessions; /**< hash table or list of active sessions */ }; /** * Notify session transport has just connected and CSM exchange can now start. * * @param session The CoAP session. */ void coap_session_send_csm(coap_session_t *session); /** * Notify session that it has just connected or reconnected. * * @param session The CoAP session. */ void coap_session_connected(coap_session_t *session); /** * Refresh the session's current Identity Hint (PSK). * Note: A copy of @p psk_hint is maintained in the session by libcoap. * * @param session The current coap_session_t object. * @param psk_hint If NULL, the Identity Hint will revert to the * initial Identity Hint used at session setup. * * @return @c 1 if successful, else @c 0. */ int coap_session_refresh_psk_hint(coap_session_t *session, const coap_bin_const_t *psk_hint); /** * Refresh the session's current pre-shared key (PSK). * Note: A copy of @p psk_key is maintained in the session by libcoap. * * @param session The current coap_session_t object. * @param psk_key If NULL, the pre-shared key will revert to the * initial pre-shared key used as session setup. * * @return @c 1 if successful, else @c 0. */ int coap_session_refresh_psk_key(coap_session_t *session, const coap_bin_const_t *psk_key); /** * Creates a new server session for the specified endpoint. * @param ctx The CoAP context. * @param ep An endpoint where an incoming connection request is pending. * * @return A new CoAP session or NULL if failed. Call coap_session_release to * add to unused queue. */ coap_session_t *coap_new_server_session( coap_context_t *ctx, coap_endpoint_t *ep ); /** * Function interface for datagram data transmission. This function returns * the number of bytes that have been transmitted, or a value less than zero * on error. * * @param session Session to send data on. * @param data The data to send. * @param datalen The actual length of @p data. * * @return The number of bytes written on success, or a value * less than zero on error. */ ssize_t coap_session_send(coap_session_t *session, const uint8_t *data, size_t datalen); /** * Function interface for stream data transmission. This function returns * the number of bytes that have been transmitted, or a value less than zero * on error. The number of bytes written may be less than datalen because of * congestion control. * * @param session Session to send data on. * @param data The data to send. * @param datalen The actual length of @p data. * * @return The number of bytes written on success, or a value * less than zero on error. */ ssize_t coap_session_write(coap_session_t *session, const uint8_t *data, size_t datalen); /** * Send a pdu according to the session's protocol. This function returns * the number of bytes that have been transmitted, or a value less than zero * on error. * * @param session Session to send pdu on. * @param pdu The pdu to send. * * @return The number of bytes written on success, or a value * less than zero on error. */ ssize_t coap_session_send_pdu(coap_session_t *session, coap_pdu_t *pdu); ssize_t coap_session_delay_pdu(coap_session_t *session, coap_pdu_t *pdu, coap_queue_t *node); /** * Lookup the server session for the packet received on an endpoint, or create * a new one. * * @param endpoint Active endpoint the packet was received on. * @param packet Received packet. * @param now The current time in ticks. * @return The CoAP session or @c NULL if error. */ coap_session_t *coap_endpoint_get_session(coap_endpoint_t *endpoint, const coap_packet_t *packet, coap_tick_t now); /** * Create a new DTLS session for the @p session. * Note: the @p session is released if no DTLS server session can be created. * * @ingroup dtls_internal * * @param session Session to add DTLS session to * @param now The current time in ticks. * * @return CoAP session or @c NULL if error. */ coap_session_t *coap_session_new_dtls_session(coap_session_t *session, coap_tick_t now); void coap_session_free(coap_session_t *session); void coap_session_mfree(coap_session_t *session); /** @} */ #define SESSIONS_ADD(e, obj) \ HASH_ADD(hh, (e), addr_hash, sizeof((obj)->addr_hash), (obj)) #define SESSIONS_DELETE(e, obj) \ HASH_DELETE(hh, (e), (obj)) #define SESSIONS_ITER(e, el, rtmp) \ HASH_ITER(hh, (e), el, rtmp) #define SESSIONS_ITER_SAFE(e, el, rtmp) \ for ((el) = (e); (el) && ((rtmp) = (el)->hh.next, 1); (el) = (rtmp)) #define SESSIONS_FIND(e, k, res) { \ HASH_FIND(hh, (e), &(k), sizeof(k), (res)); \ } #endif /* COAP_SESSION_INTERNAL_H_ */