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.
23 #warning "assertions are disabled"
30 #ifdef HAVE_NETINET_IN_H
31 #include <netinet/in.h>
36 #ifdef HAVE_SYS_TIME_H
41 #include <lwip/ip_addr.h>
48 #include "coap_time.h"
52 typedef struct coap_queue_t
54 struct coap_queue_t *next;
56 coap_tick_t t; /**< when to send PDU for the next time */
57 unsigned char retransmit_cnt; /**< retransmission counter, will be removed when zero */
58 unsigned int timeout; /**< the randomized timeout value */
60 coap_address_t local; /**< local address */
61 coap_address_t remote; /**< remote address */
62 coap_tid_t id; /**< unique transaction id */
64 coap_pdu_t *pdu; /**< the CoAP PDU to send */
67 /** Adds node to given queue, ordered by node->t. */
68 int coap_insert_node(coap_queue_t **queue, coap_queue_t *node);
70 /** Destroys specified node. */
71 int coap_delete_node(coap_queue_t *node);
73 /** Removes all items from given queue and frees the allocated storage. */
74 void coap_delete_all(coap_queue_t *queue);
76 /** Creates a new node suitable for adding to the CoAP sendqueue. */
77 coap_queue_t *coap_new_node();
79 struct coap_resource_t;
80 struct coap_context_t;
82 struct coap_async_state_t;
85 /** Message handler that is used as call-back in coap_context_t */
86 typedef void (*coap_response_handler_t)(struct coap_context_t *, const coap_address_t *remote,
87 coap_pdu_t *sent, coap_pdu_t *received, const coap_tid_t id);
89 #define COAP_MID_CACHE_SIZE 3
92 unsigned char flags[COAP_MID_CACHE_SIZE];
93 coap_key_t item[COAP_MID_CACHE_SIZE];
96 /** The CoAP stack's global state is stored in a coap_context_t object */
97 typedef struct coap_context_t
99 coap_opt_filter_t known_options;
101 struct coap_resource_t *resources; /**< hash table or list of known resources */
102 #endif /* WITH_CONTIKI */
103 #ifndef WITHOUT_ASYNC
104 /** list of asynchronous transactions */
105 struct coap_async_state_t *async_state;
106 #endif /* WITHOUT_ASYNC */
108 * The time stamp in the first element of the sendqeue is relative
109 * to sendqueue_basetime. */
110 coap_tick_t sendqueue_basetime;
111 coap_queue_t *sendqueue, *recvqueue;
113 int sockfd; /**< send/receive socket */
114 #endif /* WITH_POSIX */
116 struct uip_udp_conn *conn; /**< uIP connection object */
118 struct etimer retransmit_timer; /**< fires when the next packet must be sent */
119 struct etimer notify_timer; /**< used to check resources periodically */
120 #endif /* WITH_CONTIKI */
122 struct udp_pcb *pcb; /**< the underlying lwIP UDP PCB */
123 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. */
124 ip_addr_t pending_address; /**< the address associated with pending_package */
125 u16_t pending_port; /**< the port associated with pending_package */
127 uint8_t timer_configured; /**< Set to 1 when a retransmission is scheduled using lwIP timers for this context, otherwise 0. */
128 #endif /* WITH_LWIP */
131 * The last message id that was used is stored in this field. The
132 * initial value is set by coap_new_context() and is usually a
133 * random value. A new message id can be created with
134 * coap_new_message_id().
136 unsigned short message_id;
139 * The next value to be used for Observe. This field is global for
140 * all resources and will be updated when notifications are created.
142 unsigned int observe;
144 coap_response_handler_t response_handler;
148 * Registers a new message handler that is called whenever a response
149 * was received that matches an ongoing transaction.
151 * @param context The context to register the handler for.
152 * @param handler The response handler to register.
154 static inline void coap_register_response_handler(coap_context_t *context,
155 coap_response_handler_t handler)
157 context->response_handler = handler;
161 * Registers the option type @p type with the given context object @p
164 * @param ctx The context to use.
165 * @param type The option type to register.
167 inline static void coap_register_option(coap_context_t *ctx, unsigned char type)
169 coap_option_setb(ctx->known_options, type);
173 * Set sendqueue_basetime in the given context object @p ctx to @p
174 * now. This function returns the number of elements in the queue
175 * head that have timed out.
177 unsigned int coap_adjust_basetime(coap_context_t *ctx, coap_tick_t now);
179 /** Returns the next pdu to send without removing from sendqeue. */
180 coap_queue_t *coap_peek_next(coap_context_t *context);
182 /** Returns the next pdu to send and removes it from the sendqeue. */
183 coap_queue_t *coap_pop_next(coap_context_t *context);
185 /** Creates a new coap_context_t object that will hold the CoAP stack status. */
186 coap_context_t *coap_new_context(const coap_address_t *listen_addr);
189 * Returns a new message id and updates @p context->message_id
190 * accordingly. The message id is returned in network byte order
191 * to make it easier to read in tracing tools.
193 * @param context the current coap_context_t object
194 * @return incremented message id in network byte order
196 static inline unsigned short coap_new_message_id(coap_context_t *context)
199 return htons(++(context->message_id));
200 #else /* WITH_CONTIKI */
201 return uip_htons(++context->message_id);
205 /* CoAP stack context must be released with coap_free_context() */
206 void coap_free_context(coap_context_t *context);
209 * Sends a confirmed CoAP message to given destination. The memory
210 * that is allocated by pdu will not be released by
211 * coap_send_confirmed(). The caller must release the memory.
213 * @param context The CoAP context to use.
214 * @param dst The address to send to.
215 * @param pdu The CoAP PDU to send.
216 * @return The message id of the sent message or @c COAP_INVALID_TID on error.
218 coap_tid_t coap_send_confirmed(coap_context_t *context, const coap_address_t *dst,
222 * Creates a new ACK PDU with specified error @p code. The options
223 * specified by the filter expression @p opts will be copied from the
224 * original request contained in @p request. Unless @c
225 * SHORT_ERROR_RESPONSE was defined at build time, the textual reason
226 * phrase for @p code will be added as payload, with Content-Type @c
227 * 0. This function returns a pointer to the new response message, or
228 * @c NULL on error. The storage allocated for the new message must be
229 * relased with coap_free().
231 * @param request Specification of the received (confirmable) request.
232 * @param code The error code to set.
233 * @param opts An option filter that specifies which options to copy
234 * from the original request in @p node.
236 * @return A pointer to the new message or @c NULL on error.
238 coap_pdu_t *coap_new_error_response(coap_pdu_t *request, unsigned char code,
239 coap_opt_filter_t opts);
241 * Sends a non-confirmed CoAP message to given destination. The memory
242 * that is allocated by pdu will not be released by coap_send().
243 * The caller must release the memory.
245 * @param context The CoAP context to use.
246 * @param dst The address to send to.
247 * @param pdu The CoAP PDU to send.
248 * @return The message id of the sent message or @c COAP_INVALID_TID on error.
250 coap_tid_t coap_send(coap_context_t *context, const coap_address_t *dst, coap_pdu_t *pdu);
253 * Sends an error response with code @p code for request @p request to
254 * @p dst. @p opts will be passed to coap_new_error_response() to
255 * copy marked options from the request. This function returns the
256 * transaction id if the message was sent, or @c COAP_INVALID_TID
259 * @param context The context to use.
260 * @param request The original request to respond to.
261 * @param dst The remote peer that sent the request.
262 * @param code The reponse code.
263 * @param opts A filter that specifies the options to copy from the
266 * @return The transaction id if the message was sent, or @c
267 * COAP_INVALID_TID otherwise.
269 coap_tid_t coap_send_error(coap_context_t *context, coap_pdu_t *request,
270 const coap_address_t *dst, unsigned char code, coap_opt_filter_t opts);
273 * Helper funktion to create and send a message with @p type (usually
274 * ACK or RST). This function returns @c COAP_INVALID_TID when the
275 * message was not sent, a valid transaction id otherwise.
277 * @param context The CoAP context.
278 * @param dst Where to send the context.
279 * @param request The request that should be responded to.
280 * @param type Which type to set
281 * @return transaction id on success or @c COAP_INVALID_TID otherwise.
284 coap_send_message_type(coap_context_t *context, const coap_address_t *dst, coap_pdu_t *request,
287 * Sends an ACK message with code @c 0 for the specified @p request to
288 * @p dst. This function returns the corresponding transaction id if
289 * the message was sent or @c COAP_INVALID_TID on error.
291 * @param context The context to use.
292 * @param dst The destination address.
293 * @param request The request to be acknowledged.
295 * @return The transaction id if ACK was sent or @c COAP_INVALID_TID
298 coap_tid_t coap_send_ack(coap_context_t *context, const coap_address_t *dst,
299 coap_pdu_t *request);
302 * Sends an RST message with code @c 0 for the specified @p request to
303 * @p dst. This function returns the corresponding transaction id if
304 * the message was sent or @c COAP_INVALID_TID on error.
306 * @param context The context to use.
307 * @param dst The destination address.
308 * @param request The request to be reset.
310 * @return The transaction id if RST was sent or @c COAP_INVALID_TID
313 static inline coap_tid_t coap_send_rst(coap_context_t *context, const coap_address_t *dst,
316 return coap_send_message_type(context, dst, request, COAP_MESSAGE_RST);
319 /** Handles retransmissions of confirmable messages */
320 coap_tid_t coap_retransmit(coap_context_t *context, coap_queue_t *node);
323 * Reads data from the network and tries to parse as CoAP PDU. On success, 0 is returned
324 * and a new node with the parsed PDU is added to the receive queue in the specified context
327 int coap_read(coap_context_t *context, char* data);
330 * Calculates a unique transaction id from given arguments @p peer and
331 * @p pdu. The id is returned in @p id.
333 * @param peer The remote party who sent @p pdu.
334 * @param pdu The message that initiated the transaction.
335 * @param id Set to the new id.
337 void coap_transaction_id(const coap_address_t *peer, const coap_pdu_t *pdu, coap_tid_t *id);
340 * This function removes the element with given @p id from the list
341 * given list. If @p id was found, @p node is updated to point to the
342 * removed element. Note that the storage allocated by @p node is
343 * @b not released. The caller must do this manually using
344 * coap_delete_node(). This function returns @c 1 if the element with
345 * id @p id was found, @c 0 otherwise. For a return value of @c 0,
346 * the contents of @p node is undefined.
348 * @param queue The queue to search for @p id.
349 * @param id The node id to look for.
350 * @param node If found, @p node is updated to point to the
351 * removed node. You must release the storage pointed to by
354 * @return @c 1 if @p id was found, @c 0 otherwise.
356 int coap_remove_from_queue(coap_queue_t **queue, coap_tid_t id, coap_queue_t **node);
359 * Removes the transaction identified by @p id from given @p queue.
360 * This is a convenience function for coap_remove_from_queue() with
361 * automatic deletion of the removed node.
363 * @param queue The queue to search for @p id.
364 * @param id The transaction id.
366 * @return @c 1 if node was found, removed and destroyed, @c 0 otherwise.
368 inline static int coap_remove_transaction(coap_queue_t **queue, coap_tid_t id)
371 if (!coap_remove_from_queue(queue, id, &node))
374 coap_delete_node(node);
379 * Retrieves transaction from queue.
380 * @queue The transaction queue to be searched
381 * @id Unique key of the transaction to find.
382 * @return A pointer to the transaction object or NULL if not found
384 coap_queue_t *coap_find_transaction(coap_queue_t *queue, coap_tid_t id);
387 * Cancels all outstanding messages for peer @p dst that have the
390 * @param context The context in use
391 * @param dst Destination address of the messages to remove.
392 * @param token Message token
393 * @param token_length Actual length of @p token
395 void coap_cancel_all_messages(coap_context_t *context, const coap_address_t *dst,
396 const unsigned char *token, size_t token_length);
398 /** Dispatches the PDUs from the receive queue in given context. */
399 void coap_dispatch(coap_context_t *context, const char* responseData);
401 /** Returns 1 if there are no messages to send or to dispatch in the context's queues. */
402 int coap_can_exit(coap_context_t *context);
405 * Returns the current value of an internal tick counter. The counter
406 * counts \c COAP_TICKS_PER_SECOND ticks every second.
408 void coap_ticks(coap_tick_t *);
411 * Verifies that @p pdu contains no unknown critical options. Options
412 * must be registered at @p ctx, using the function
413 * coap_register_option(). A basic set of options is registered
414 * automatically by coap_new_context(). This function returns @c 1 if
415 * @p pdu is ok, @c 0 otherwise. The given filter object @p unknown
416 * will be updated with the unknown options. As only @c COAP_MAX_OPT
417 * options can be signalled this way, remaining options must be
421 coap_opt_filter_t f = COAP_OPT_NONE;
422 coap_opt_iterator_t opt_iter;
424 if (coap_option_check_critical(ctx, pdu, f) == 0) {
425 coap_option_iterator_init(pdu, &opt_iter, f);
427 while (coap_option_next(&opt_iter)) {
428 if (opt_iter.type & 0x01) {
429 ... handle unknown critical option in opt_iter ...
435 * @param ctx The context where all known options are registered.
436 * @param pdu The PDU to check.
437 * @param unknown The output filter that will be updated to indicate the
438 * unknown critical options found in @p pdu.
440 * @return @c 1 if everything was ok, @c 0 otherwise.
442 int coap_option_check_critical(coap_context_t *ctx, coap_pdu_t *pdu, coap_opt_filter_t unknown);
448 #endif /* _COAP_NET_H_ */