CoAP client API

CoAP client API . More...

Data Structures
struct	coap_client_request
	Representation of a CoAP client request. More...
struct	coap_client_option
	Representation of extra options for the CoAP client request. More...

Macros
#define	MAX_COAP_MSG_LEN
	Maximum size of a CoAP message.

Typedefs
typedef void(*	coap_client_response_cb_t) (int16_t result_code, size_t offset, const uint8_t *payload, size_t len, bool last_block, void *user_data)
	Callback for CoAP request.

Functions
int	coap_client_init (struct coap_client *client, const char *info)
	Initialize the CoAP client.
int	coap_client_req (struct coap_client *client, int sock, const struct sockaddr *addr, struct coap_client_request *req, struct coap_transmission_parameters *params)
	Send CoAP request.
void	coap_client_cancel_requests (struct coap_client *client)
	Cancel all current requests.
static struct coap_client_option	coap_client_option_initial_block2 (void)
	Initialise a Block2 option to be added to a request.

Detailed Description

CoAP client API .

Since

3.4

Version

0.1.0

Macro Definition Documentation

MAX_COAP_MSG_LEN

#define MAX_COAP_MSG_LEN

#include <zephyr/net/coap_client.h>

Value:

                          (CONFIG_COAP_CLIENT_MESSAGE_HEADER_SIZE + \
                          CONFIG_COAP_CLIENT_MESSAGE_SIZE)

Maximum size of a CoAP message.

Typedef Documentation

coap_client_response_cb_t

typedef void(* coap_client_response_cb_t) (int16_t result_code, size_t offset, const uint8_t *payload, size_t len, bool last_block, void *user_data)

#include <zephyr/net/coap_client.h>

Callback for CoAP request.

This callback is called for responses to CoAP client requests. It is used to indicate errors, response codes from server or to deliver payload. Blockwise transfers cause this callback to be called sequentially with increasing payload offset and only partial content in buffer pointed by payload parameter.

Parameters

result_code	Result code of the response. Negative if there was a failure in send. coap_response_code for positive.
offset	Payload offset from the beginning of a blockwise transfer.
payload	Buffer containing the payload from the response. NULL for empty payload.
len	Size of the payload.
last_block	Indicates the last block of the response.
user_data	User provided context.

Function Documentation

coap_client_cancel_requests()

void coap_client_cancel_requests

(

struct coap_client *

client

)

#include <zephyr/net/coap_client.h>

Cancel all current requests.

This is intended for canceling long-running requests (e.g. GETs with the OBSERVE option set) which has gone stale for some reason.

Parameters

client

Client instance.

coap_client_init()

int coap_client_init	(	struct coap_client *	client,
		const char *	info )

#include <zephyr/net/coap_client.h>

Initialize the CoAP client.

Parameters

[in]	client	Client instance.
[in]	info	Name for the receiving thread of the client. Setting this NULL will result as default name of "coap_client".

Returns

int Zero on success, otherwise a negative error code.

coap_client_option_initial_block2()

static struct coap_client_option coap_client_option_initial_block2 ( void )

inlinestatic

#include <zephyr/net/coap_client.h>

Initialise a Block2 option to be added to a request.

If the application expects a request to require a blockwise transfer, it may pre-emptively suggest a maximum block size to the server - see RFC7959 Figure 3: Block-Wise GET with Early Negotiation.

This helper function returns a Block2 option to send with the initial request.

Returns

CoAP client initial Block2 option structure

coap_client_req()

int coap_client_req	(	struct coap_client *	client,
		int	sock,
		const struct sockaddr *	addr,
		struct coap_client_request *	req,
		struct coap_transmission_parameters *	params )

#include <zephyr/net/coap_client.h>

Send CoAP request.

Operation is handled asynchronously using a background thread. If the socket isn't connected to a destination address, user must provide a destination address, otherwise the address should be set as NULL. Once the callback is called with last block set as true, socket can be closed or used for another query.

Parameters

client	Client instance.
sock	Open socket file descriptor.
addr	the destination address of the request, NULL if socket is already connected.
req	CoAP request structure
params	Pointer to transmission parameters structure or NULL to use default values.

Returns

zero when operation started successfully or negative error code otherwise.