An implementation of CoAP

This is an implementation of the Constrained Application Protocol. More...

Modules
	CoAP keystore API
	The CoAP keystore API defines a common interface for retrieving authorization information for CoAP/DTLS.
	CoAP timer API
	The CoAP timer API defines a common interface for CoAP timer and time functionality.
	CoAP transport API
	The CoAP transport API defines a common interface for sending/receiving CoAP messages.

Files
file	coap-request-state.h
	Common request state for all the APIs

Macros
#define	COAP_MAX_PACKET_SIZE   (COAP_MAX_HEADER_SIZE + COAP_MAX_CHUNK_SIZE)
	The max size of the CoAP messages.

Enumerations
enum	coap_resource_flags_t
	Resource flags for allowed methods and special functionalities.

Functions
int	coap_block1_handler (coap_message_t *request, coap_message_t *response, uint8_t *target, size_t *len, size_t max_len)
	Block 1 support within a coap-ressource. More...
int	coap_send_request (coap_callback_request_state_t *callback_state, coap_endpoint_t *endpoint, coap_message_t *request, void(*callback)(coap_callback_request_state_t *callback_state))
	Send a CoAP request to a remote endpoint. More...
void	coap_activate_resource (coap_resource_t *resource, const char *path)
	Makes a resource available under the given URI path. More...
coap_resource_t *	coap_get_first_resource (void)
	Returns the first of registered CoAP resources. More...
coap_resource_t *	coap_get_next_resource (coap_resource_t *resource)
	Returns the next registered CoAP resource. More...
void	coap_log_string (const char *text, size_t len)
	Logs a CoAP string that has a length but might not be 0-terminated. More...
void	coap_separate_reject ()
	Reject a request that would require a separate response with an error message. More...
void	coap_separate_accept (coap_message_t *coap_req, coap_separate_t *separate_store)
	Initiate a separate response with an empty ACK. More...

Detailed Description

This is an implementation of the Constrained Application Protocol.

Function Documentation

coap_activate_resource()

void coap_activate_resource	(	coap_resource_t *	resource,
		const char *	path
	)

Makes a resource available under the given URI path.

Resources wanted to be accessible should be activated with the following code.

Parameters

resource	A pointer to a resource implementation
path	The URI path string for this resource

The resource implementation must be imported first using the extern keyword. The build system takes care of compiling every *.c file in the ./resources/ sub-directory (see example Makefile).

Parameters

resource	A CoAP resource defined through the RESOURCE macros.
path	The local URI path where to provide the resource.

Definition at line 399 of file coap-engine.c.

coap_block1_handler()

int coap_block1_handler	(	coap_message_t *	request,
		coap_message_t *	response,
		uint8_t *	target,
		size_t *	len,
		size_t	max_len
	)

Block 1 support within a coap-ressource.

This function will help you to use block 1. If target is null error handling and response configuration is active. On return value 0, the last block was recived, while on return value 1 more blocks will follow. With target, len and maxlen this function will assemble the blocks.

You can find an example in: examples/er-rest-example/resources/res-b1-sep-b2.c

Parameters

request	Request pointer from the handler
response	Response pointer from the handler
target	Pointer to the buffer where the request payload can be assembled
len	Pointer to the variable, where the function stores the actual length
max_len	Length of the "target"-Buffer

Returns

0 if initialisation was successful -1 if initialisation failed

Definition at line 79 of file coap-block1.c.

coap_get_first_resource()

coap_resource_t * coap_get_first_resource

(

void

)

Returns the first of registered CoAP resources.

Returns

The first registered CoAP resource or NULL if none exists.

Definition at line 424 of file coap-engine.c.

References list_head().

coap_get_next_resource()

coap_resource_t * coap_get_next_resource

(

coap_resource_t *

resource

)

Returns the next registered CoAP resource.

Returns

The next resource or NULL if no more exists.

Definition at line 430 of file coap-engine.c.

References list_item_next().

coap_log_string()

void coap_log_string	(	const char *	text,
		size_t	len
	)

Logs a CoAP string that has a length but might not be 0-terminated.

Parameters

text	The CoAP string
len	The number of characters in the CoAP string

Definition at line 47 of file coap-log.c.

coap_send_request()

int coap_send_request	(	coap_callback_request_state_t *	callback_state,
		coap_endpoint_t *	endpoint,
		coap_message_t *	request,
		void(*)(coap_callback_request_state_t *callback_state)	callback
	)

Send a CoAP request to a remote endpoint.

Parameters

callback_state	The callback state to handle the CoAP request
endpoint	The destination endpoint
request	The request to be sent
callback	callback to execute when the response arrives or the timeout expires

Returns

1 if there is a transaction available to send, 0 otherwise

Definition at line 150 of file coap-callback-api.c.

coap_separate_accept()

void coap_separate_accept	(	coap_message_t *	coap_req,
		coap_separate_t *	separate_store
	)

Initiate a separate response with an empty ACK.

Parameters

coap_req	The request to accept
separate_store	A pointer to the data structure that will store the relevant information for the response

When the server does not have enough resources left to store the information for a separate response or otherwise cannot execute the resource handler, this function will respond with 5.03 Service Unavailable. The client can then retry later.

Definition at line 86 of file coap-separate.c.

coap_separate_reject()

void coap_separate_reject

(

)

Reject a request that would require a separate response with an error message.

When the server does not have enough resources left to store the information for a separate response or otherwise cannot execute the resource handler, this function will respond with 5.03 Service Unavailable. The client can then retry later.

Definition at line 67 of file coap-separate.c.