1 /* net.h -- CoAP network interface
3 * Copyright (C) 2010--2013 Olaf Bergmann <bergmann@tzi.org>
5 * This file is part of the CoAP library libcoap. Please see
6 * README for terms of use.
14 #endif /* WITH_ARDUINO */
27 #warning "assertions are disabled"
34 #ifdef HAVE_NETINET_IN_H
35 #include <netinet/in.h>
40 #ifdef HAVE_SYS_TIME_H
45 #include <lwip/ip_addr.h>
52 #include "coap_time.h"
56 typedef struct coap_queue_t
58 struct coap_queue_t *next;
60 coap_tick_t t; /**< when to send PDU for the next time */
61 unsigned char retransmit_cnt; /**< retransmission counter, will be removed when zero */
62 unsigned int timeout; /**< the randomized timeout value */
64 coap_address_t local; /**< local address */
65 coap_address_t remote; /**< remote address */
66 coap_tid_t id; /**< unique transaction id */
68 coap_pdu_t *pdu; /**< the CoAP PDU to send */
71 /** Adds node to given queue, ordered by node->t. */
72 int coap_insert_node(coap_queue_t **queue, coap_queue_t *node);
74 /** Destroys specified node. */
75 int coap_delete_node(coap_queue_t *node);
77 /** Removes all items from given queue and frees the allocated storage. */
78 void coap_delete_all(coap_queue_t *queue);
80 /** Creates a new node suitable for adding to the CoAP sendqueue. */
81 coap_queue_t *coap_new_node();
83 struct coap_resource_t;
84 struct coap_context_t;
86 struct coap_async_state_t;
89 /** Message handler that is used as call-back in coap_context_t */
90 typedef void (*coap_response_handler_t)(struct coap_context_t *, const coap_address_t *remote,
91 coap_pdu_t *sent, coap_pdu_t *received, const coap_tid_t id);
93 #define COAP_MID_CACHE_SIZE 3
96 unsigned char flags[COAP_MID_CACHE_SIZE];
97 coap_key_t item[COAP_MID_CACHE_SIZE];
100 /** The CoAP stack's global state is stored in a coap_context_t object */
101 typedef struct coap_context_t
103 coap_opt_filter_t known_options;
105 struct coap_resource_t *resources; /**< hash table or list of known resources */
106 #endif /* WITH_CONTIKI */
107 #ifndef WITHOUT_ASYNC
108 /** list of asynchronous transactions */
109 struct coap_async_state_t *async_state;
110 #endif /* WITHOUT_ASYNC */
112 * The time stamp in the first element of the sendqeue is relative
113 * to sendqueue_basetime. */
114 coap_tick_t sendqueue_basetime;
115 coap_queue_t *sendqueue, *recvqueue;
116 #if defined(WITH_POSIX) || defined(WITH_ARDUINO)
117 int sockfd; /**< send/receive socket */
118 #endif /* WITH_POSIX || WITH_ARDUINO */
120 struct uip_udp_conn *conn; /**< uIP connection object */
122 struct etimer retransmit_timer; /**< fires when the next packet must be sent */
123 struct etimer notify_timer; /**< used to check resources periodically */
124 #endif /* WITH_CONTIKI */
126 struct udp_pcb *pcb; /**< the underlying lwIP UDP PCB */
127 struct pbuf *pending_package; /**< pbuf containing the last received package if not handled yet. This is only used to pass the package from the udp_recv callback into the coap_read function, which frees the pbuf and clears this field. */
128 ip_addr_t pending_address; /**< the address associated with pending_package */
129 u16_t pending_port; /**< the port associated with pending_package */
131 uint8_t timer_configured; /**< Set to 1 when a retransmission is scheduled using lwIP timers for this context, otherwise 0. */
132 #endif /* WITH_LWIP */
135 * The last message id that was used is stored in this field. The
136 * initial value is set by coap_new_context() and is usually a
137 * random value. A new message id can be created with
138 * coap_new_message_id().
140 unsigned short message_id;
143 * The next value to be used for Observe. This field is global for
144 * all resources and will be updated when notifications are created.
146 unsigned int observe;
148 coap_response_handler_t response_handler;
152 * Registers a new message handler that is called whenever a response
153 * was received that matches an ongoing transaction.
155 * @param context The context to register the handler for.
156 * @param handler The response handler to register.
158 static inline void coap_register_response_handler(coap_context_t *context,
159 coap_response_handler_t handler)
161 context->response_handler = handler;
165 * Registers the option type @p type with the given context object @p
168 * @param ctx The context to use.
169 * @param type The option type to register.
171 inline static void coap_register_option(coap_context_t *ctx, unsigned char type)
173 coap_option_setb(ctx->known_options, type);
177 * Set sendqueue_basetime in the given context object @p ctx to @p
178 * now. This function returns the number of elements in the queue
179 * head that have timed out.
181 unsigned int coap_adjust_basetime(coap_context_t *ctx, coap_tick_t now);
183 /** Returns the next pdu to send without removing from sendqeue. */
184 coap_queue_t *coap_peek_next(coap_context_t *context);
186 /** Returns the next pdu to send and removes it from the sendqeue. */
187 coap_queue_t *coap_pop_next(coap_context_t *context);
189 /** Creates a new coap_context_t object that will hold the CoAP stack status. */
190 coap_context_t *coap_new_context(const coap_address_t *listen_addr);
193 * Returns a new message id and updates @p context->message_id
194 * accordingly. The message id is returned in network byte order
195 * to make it easier to read in tracing tools.
197 * @param context the current coap_context_t object
198 * @return incremented message id in network byte order
200 static inline unsigned short coap_new_message_id(coap_context_t *context)
202 ++(context->message_id);
203 #if defined(WITH_ARDUINO)
204 return ((context->message_id << 8) | ((context->message_id >> 8) & (0xFF)));
205 #elif defined(WITH_CONTIKI)
206 return uip_htons(context->message_id);
207 #else /* WITH_CONTIKI */
208 return htons(context->message_id);
212 /* CoAP stack context must be released with coap_free_context() */
213 void coap_free_context(coap_context_t *context);
216 * Sends a confirmed CoAP message to given destination. The memory
217 * that is allocated by pdu will not be released by
218 * coap_send_confirmed(). The caller must release the memory.
220 * @param context The CoAP context to use.
221 * @param dst The address to send to.
222 * @param pdu The CoAP PDU to send.
223 * @return The message id of the sent message or @c COAP_INVALID_TID on error.
225 coap_tid_t coap_send_confirmed(coap_context_t *context, const coap_address_t *dst,
229 * Creates a new ACK PDU with specified error @p code. The options
230 * specified by the filter expression @p opts will be copied from the
231 * original request contained in @p request. Unless @c
232 * SHORT_ERROR_RESPONSE was defined at build time, the textual reason
233 * phrase for @p code will be added as payload, with Content-Type @c
234 * 0. This function returns a pointer to the new response message, or
235 * @c NULL on error. The storage allocated for the new message must be
236 * relased with coap_free().
238 * @param request Specification of the received (confirmable) request.
239 * @param code The error code to set.
240 * @param opts An option filter that specifies which options to copy
241 * from the original request in @p node.
243 * @return A pointer to the new message or @c NULL on error.
245 coap_pdu_t *coap_new_error_response(coap_pdu_t *request, unsigned char code,
246 coap_opt_filter_t opts);
248 * Sends a non-confirmed CoAP message to given destination. The memory
249 * that is allocated by pdu will not be released by coap_send().
250 * The caller must release the memory.
252 * @param context The CoAP context to use.
253 * @param dst The address to send to.
254 * @param pdu The CoAP PDU to send.
255 * @return The message id of the sent message or @c COAP_INVALID_TID on error.
257 coap_tid_t coap_send(coap_context_t *context, const coap_address_t *dst, coap_pdu_t *pdu);
260 * Sends an error response with code @p code for request @p request to
261 * @p dst. @p opts will be passed to coap_new_error_response() to
262 * copy marked options from the request. This function returns the
263 * transaction id if the message was sent, or @c COAP_INVALID_TID
266 * @param context The context to use.
267 * @param request The original request to respond to.
268 * @param dst The remote peer that sent the request.
269 * @param code The reponse code.
270 * @param opts A filter that specifies the options to copy from the
273 * @return The transaction id if the message was sent, or @c
274 * COAP_INVALID_TID otherwise.
276 coap_tid_t coap_send_error(coap_context_t *context, coap_pdu_t *request,
277 const coap_address_t *dst, unsigned char code, coap_opt_filter_t opts);
280 * Helper funktion to create and send a message with @p type (usually
281 * ACK or RST). This function returns @c COAP_INVALID_TID when the
282 * message was not sent, a valid transaction id otherwise.
284 * @param context The CoAP context.
285 * @param dst Where to send the context.
286 * @param request The request that should be responded to.
287 * @param type Which type to set
288 * @return transaction id on success or @c COAP_INVALID_TID otherwise.
291 coap_send_message_type(coap_context_t *context, const coap_address_t *dst, coap_pdu_t *request,
294 * Sends an ACK message with code @c 0 for the specified @p request to
295 * @p dst. This function returns the corresponding transaction id if
296 * the message was sent or @c COAP_INVALID_TID on error.
298 * @param context The context to use.
299 * @param dst The destination address.
300 * @param request The request to be acknowledged.
302 * @return The transaction id if ACK was sent or @c COAP_INVALID_TID
305 coap_tid_t coap_send_ack(coap_context_t *context, const coap_address_t *dst,
306 coap_pdu_t *request);
309 * Sends an RST message with code @c 0 for the specified @p request to
310 * @p dst. This function returns the corresponding transaction id if
311 * the message was sent or @c COAP_INVALID_TID on error.
313 * @param context The context to use.
314 * @param dst The destination address.
315 * @param request The request to be reset.
317 * @return The transaction id if RST was sent or @c COAP_INVALID_TID
320 static inline coap_tid_t coap_send_rst(coap_context_t *context, const coap_address_t *dst,
323 return coap_send_message_type(context, dst, request, COAP_MESSAGE_RST);
326 /** Handles retransmissions of confirmable messages */
327 coap_tid_t coap_retransmit(coap_context_t *context, coap_queue_t *node);
330 * Reads data from the network and tries to parse as CoAP PDU. On success, 0 is returned
331 * and a new node with the parsed PDU is added to the receive queue in the specified context
334 int coap_read(coap_context_t *context);
337 * Calculates a unique transaction id from given arguments @p peer and
338 * @p pdu. The id is returned in @p id.
340 * @param peer The remote party who sent @p pdu.
341 * @param pdu The message that initiated the transaction.
342 * @param id Set to the new id.
344 void coap_transaction_id(const coap_address_t *peer, const coap_pdu_t *pdu, coap_tid_t *id);
347 * This function removes the element with given @p id from the list
348 * given list. If @p id was found, @p node is updated to point to the
349 * removed element. Note that the storage allocated by @p node is
350 * @b not released. The caller must do this manually using
351 * coap_delete_node(). This function returns @c 1 if the element with
352 * id @p id was found, @c 0 otherwise. For a return value of @c 0,
353 * the contents of @p node is undefined.
355 * @param queue The queue to search for @p id.
356 * @param id The node id to look for.
357 * @param node If found, @p node is updated to point to the
358 * removed node. You must release the storage pointed to by
361 * @return @c 1 if @p id was found, @c 0 otherwise.
363 int coap_remove_from_queue(coap_queue_t **queue, coap_tid_t id, coap_queue_t **node);
366 * Removes the transaction identified by @p id from given @p queue.
367 * This is a convenience function for coap_remove_from_queue() with
368 * automatic deletion of the removed node.
370 * @param queue The queue to search for @p id.
371 * @param id The transaction id.
373 * @return @c 1 if node was found, removed and destroyed, @c 0 otherwise.
375 inline static int coap_remove_transaction(coap_queue_t **queue, coap_tid_t id)
378 if (!coap_remove_from_queue(queue, id, &node))
381 coap_delete_node(node);
386 * Retrieves transaction from queue.
387 * @queue The transaction queue to be searched
388 * @id Unique key of the transaction to find.
389 * @return A pointer to the transaction object or NULL if not found
391 coap_queue_t *coap_find_transaction(coap_queue_t *queue, coap_tid_t id);
394 * Cancels all outstanding messages for peer @p dst that have the
397 * @param context The context in use
398 * @param dst Destination address of the messages to remove.
399 * @param token Message token
400 * @param token_length Actual length of @p token
402 void coap_cancel_all_messages(coap_context_t *context, const coap_address_t *dst,
403 const unsigned char *token, size_t token_length);
405 /** Dispatches the PDUs from the receive queue in given context. */
406 void coap_dispatch(coap_context_t *context, const char* responseData);
408 /** Returns 1 if there are no messages to send or to dispatch in the context's queues. */
409 int coap_can_exit(coap_context_t *context);
412 * Returns the current value of an internal tick counter. The counter
413 * counts \c COAP_TICKS_PER_SECOND ticks every second.
415 void coap_ticks(coap_tick_t *);
418 * Verifies that @p pdu contains no unknown critical options. Options
419 * must be registered at @p ctx, using the function
420 * coap_register_option(). A basic set of options is registered
421 * automatically by coap_new_context(). This function returns @c 1 if
422 * @p pdu is ok, @c 0 otherwise. The given filter object @p unknown
423 * will be updated with the unknown options. As only @c COAP_MAX_OPT
424 * options can be signalled this way, remaining options must be
428 coap_opt_filter_t f = COAP_OPT_NONE;
429 coap_opt_iterator_t opt_iter;
431 if (coap_option_check_critical(ctx, pdu, f) == 0) {
432 coap_option_iterator_init(pdu, &opt_iter, f);
434 while (coap_option_next(&opt_iter)) {
435 if (opt_iter.type & 0x01) {
436 ... handle unknown critical option in opt_iter ...
442 * @param ctx The context where all known options are registered.
443 * @param pdu The PDU to check.
444 * @param unknown The output filter that will be updated to indicate the
445 * unknown critical options found in @p pdu.
447 * @return @c 1 if everything was ok, @c 0 otherwise.
449 int coap_option_check_critical(coap_context_t *ctx, coap_pdu_t *pdu, coap_opt_filter_t unknown);
455 #endif /* _COAP_NET_H_ */