#include "config.h"
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <netinet/in.h>
#include <time.h>
#include <sys/time.h>
#include "option.h"
#include "address.h"
#include "prng.h"
#include "pdu.h"
#include "coap_time.h"

Data Structures
struct	coap_queue_t

struct	coap_mid_cache_t

struct	coap_context_t
	The CoAP stack's global state is stored in a coap_context_t object. More...

Macros
#define	COAP_MID_CACHE_SIZE 3

Typedefs
typedef struct coap_queue_t	coap_queue_t

typedef void(*	coap_response_handler_t )(struct coap_context_t , const coap_address_t remote, coap_pdu_t sent, coap_pdu_t received, const coap_tid_t id)
	Message handler that is used as call-back in coap_context_t. More...

typedef struct coap_context_t	coap_context_t
	The CoAP stack's global state is stored in a coap_context_t object. More...

Functions
int	coap_insert_node (coap_queue_t *queue, coap_queue_t node)
	Adds node to given queue, ordered by node->t. More...

int	coap_delete_node (coap_queue_t *node)
	Destroys specified node. More...

void	coap_delete_all (coap_queue_t *queue)
	Removes all items from given queue and frees the allocated storage. More...

coap_queue_t *	coap_new_node ()
	Creates a new node suitable for adding to the CoAP sendqueue. More...

static void	coap_register_response_handler (coap_context_t *context, coap_response_handler_t handler)
	Registers a new message handler that is called whenever a response was received that matches an ongoing transaction. More...

static void	coap_register_option (coap_context_t *ctx, unsigned char type)
	Registers the option type `type` with the given context object `ctx`. More...

unsigned int	coap_adjust_basetime (coap_context_t *ctx, coap_tick_t now)
	Set sendqueue_basetime in the given context object `ctx` to `now`. More...

coap_queue_t *	coap_peek_next (coap_context_t *context)
	Returns the next pdu to send without removing from sendqeue. More...

coap_queue_t *	coap_pop_next (coap_context_t *context)
	Returns the next pdu to send and removes it from the sendqeue. More...

coap_context_t *	coap_new_context (const coap_address_t *listen_addr)
	Creates a new coap_context_t object that will hold the CoAP stack status. More...

static unsigned short	coap_new_message_id (coap_context_t *context)
	Returns a new message id and updates `context->message_id` accordingly. More...

void	coap_free_context (coap_context_t *context)

coap_tid_t	coap_send_confirmed (coap_context_t context, const coap_address_t dst, coap_pdu_t *pdu)
	Sends a confirmed CoAP message to given destination. More...

coap_pdu_t *	coap_new_error_response (coap_pdu_t *request, unsigned char code, coap_opt_filter_t opts)
	Creates a new ACK PDU with specified error `code`. More...

coap_tid_t	coap_send (coap_context_t context, const coap_address_t dst, coap_pdu_t *pdu)
	Sends a non-confirmed CoAP message to given destination. More...

coap_tid_t	coap_send_error (coap_context_t context, coap_pdu_t request, const coap_address_t *dst, unsigned char code, coap_opt_filter_t opts)
	Sends an error response with code `code` for request `request` to `dst`. More...

coap_tid_t	coap_send_message_type (coap_context_t context, const coap_address_t dst, coap_pdu_t *request, unsigned char type)
	Helper funktion to create and send a message with `type` (usually ACK or RST). More...

coap_tid_t	coap_send_ack (coap_context_t context, const coap_address_t dst, coap_pdu_t *request)
	Sends an ACK message with code `0` for the specified `request` to `dst`. More...

static coap_tid_t	coap_send_rst (coap_context_t context, const coap_address_t dst, coap_pdu_t *request)
	Sends an RST message with code `0` for the specified `request` to `dst`. More...

coap_tid_t	coap_retransmit (coap_context_t context, coap_queue_t node)
	Handles retransmissions of confirmable messages. More...

int	coap_read (coap_context_t *context)
	Reads data from the network and tries to parse as CoAP PDU. More...

void	coap_transaction_id (const coap_address_t peer, const coap_pdu_t pdu, coap_tid_t *id)
	Calculates a unique transaction id from given arguments `peer` and `pdu`. More...

int	coap_remove_from_queue (coap_queue_t queue, coap_tid_t id, coap_queue_t node)
	This function removes the element with given `id` from the list given list. More...

static int	coap_remove_transaction (coap_queue_t **queue, coap_tid_t id)
	Removes the transaction identified by `id` from given `queue`. More...

coap_queue_t *	coap_find_transaction (coap_queue_t *queue, coap_tid_t id)
	Retrieves transaction from queue. More...

void	coap_cancel_all_messages (coap_context_t context, const coap_address_t dst, const unsigned char *token, size_t token_length)
	Cancels all outstanding messages for peer `dst` that have the specified token. More...

void	coap_dispatch (coap_context_t *context)
	Dispatches the PDUs from the receive queue in given context. More...

int	coap_can_exit (coap_context_t *context)
	Returns 1 if there are no messages to send or to dispatch in the context's queues. More...

void	coap_ticks (coap_tick_t *)
	Returns the current value of an internal tick counter. More...

int	coap_option_check_critical (coap_context_t ctx, coap_pdu_t pdu, coap_opt_filter_t unknown)
	Verifies that `pdu` contains no unknown critical options. More...

Macro Definition Documentation

#define COAP_MID_CACHE_SIZE 3

Definition at line 90 of file net.h.

Typedef Documentation

typedef struct coap_context_t coap_context_t

The CoAP stack's global state is stored in a coap_context_t object.

typedef struct coap_queue_t coap_queue_t

typedef void(* coap_response_handler_t)(struct coap_context_t *, const coap_address_t *remote, coap_pdu_t *sent, coap_pdu_t *received, const coap_tid_t id)

Message handler that is used as call-back in coap_context_t.

Definition at line 84 of file net.h.

Function Documentation

unsigned int coap_adjust_basetime	(	coap_context_t *	ctx,
		coap_tick_t	now
	)

Set sendqueue_basetime in the given context object ctx to now.

This function returns the number of elements in the queue head that have timed out.

Definition at line 143 of file net.c.

int coap_can_exit ( coap_context_t * context )

Returns 1 if there are no messages to send or to dispatch in the context's queues.

Definition at line 1555 of file net.c.

void coap_cancel_all_messages	(	coap_context_t *	context,
		const coap_address_t *	dst,
		const unsigned char *	token,
		size_t	token_length
	)

Cancels all outstanding messages for peer dst that have the specified token.

Parameters

context	The context in use
dst	Destination address of the messages to remove.
token	Message token
token_length	Actual length of `token`

Definition at line 1002 of file net.c.

void coap_delete_all ( coap_queue_t * queue )

Removes all items from given queue and frees the allocated storage.

Definition at line 228 of file net.c.

int coap_delete_node ( coap_queue_t * node )

Destroys specified node.

Definition at line 217 of file net.c.

void coap_dispatch ( coap_context_t * context )

Dispatches the PDUs from the receive queue in given context.

Definition at line 1452 of file net.c.

coap_queue_t* coap_find_transaction	(	coap_queue_t *	queue,
		coap_tid_t	id
	)

Retrieves transaction from queue.

The transaction queue to be searched Unique key of the transaction to find.

Returns: A pointer to the transaction object or NULL if not found

Definition at line 1043 of file net.c.

void coap_free_context ( coap_context_t * context )

Definition at line 419 of file net.c.

int coap_insert_node	(	coap_queue_t **	queue,
		coap_queue_t *	node
	)

Adds node to given queue, ordered by node->t.

Definition at line 180 of file net.c.

coap_context_t* coap_new_context ( const coap_address_t * listen_addr )

Creates a new coap_context_t object that will hold the CoAP stack status.

Definition at line 296 of file net.c.

coap_pdu_t* coap_new_error_response	(	coap_pdu_t *	request,
		unsigned char	code,
		coap_opt_filter_t	opts
	)

Creates a new ACK PDU with specified error code.

The options specified by the filter expression opts will be copied from the original request contained in request. Unless SHORT_ERROR_RESPONSE was defined at build time, the textual reason phrase for code will be added as payload, with Content-Type 0. This function returns a pointer to the new response message, or NULL on error. The storage allocated for the new message must be relased with coap_free().

Parameters

request	Specification of the received (confirmable) request.
code	The error code to set.
opts	An option filter that specifies which options to copy from the original request in `node`.

Returns: A pointer to the new message or NULL on error.

Definition at line 1051 of file net.c.

static unsigned short coap_new_message_id ( coap_context_t * context )

inlinestatic

Returns a new message id and updates context->message_id accordingly.

The message id is returned in network byte order to make it easier to read in tracing tools.

Parameters

context the current coap_context_t object

Returns: incremented message id in network byte order

Definition at line 197 of file net.h.

coap_queue_t* coap_new_node ( )

Creates a new node suitable for adding to the CoAP sendqueue.

Definition at line 237 of file net.c.

int coap_option_check_critical	(	coap_context_t *	ctx,
		coap_pdu_t *	pdu,
		coap_opt_filter_t	unknown
	)

Verifies that pdu contains no unknown critical options.

Options must be registered at ctx, using the function coap_register_option(). A basic set of options is registered automatically by coap_new_context(). This function returns 1 if pdu is ok, 0 otherwise. The given filter object unknown will be updated with the unknown options. As only COAP_MAX_OPT options can be signalled this way, remaining options must be examined manually.

coap_opt_filter_t f = COAP_OPT_NONE;
coap_opt_iterator_t opt_iter;
if (coap_option_check_critical(ctx, pdu, f) == 0) {
  coap_option_iterator_init(pdu, &opt_iter, f);
  while (coap_option_next(&opt_iter)) {
    if (opt_iter.type & 0x01) {
  ... handle unknown critical option in opt_iter ...
    }
  }
}

Parameters

ctx	The context where all known options are registered.
pdu	The PDU to check.
unknown	The output filter that will be updated to indicate the unknown critical options found in `pdu`.

Returns: 1 if everything was ok, 0 otherwise.

Definition at line 463 of file net.c.

coap_queue_t* coap_peek_next ( coap_context_t * context )

Returns the next pdu to send without removing from sendqeue.

Definition at line 253 of file net.c.

coap_queue_t* coap_pop_next ( coap_context_t * context )

Returns the next pdu to send and removes it from the sendqeue.

Definition at line 261 of file net.c.

int coap_read ( coap_context_t * context )

Reads data from the network and tries to parse as CoAP PDU.

On success, 0 is returned and a new node with the parsed PDU is added to the receive queue in the specified context object.

Definition at line 831 of file net.c.

static void coap_register_option	(	coap_context_t *	ctx,
		unsigned char	type
	)

inlinestatic

Registers the option type type with the given context object ctx.

Parameters

ctx	The context to use.
type	The option type to register.

Definition at line 167 of file net.h.

static void coap_register_response_handler	(	coap_context_t *	context,
		coap_response_handler_t	handler
	)

inlinestatic

Registers a new message handler that is called whenever a response was received that matches an ongoing transaction.

Parameters

context	The context to register the handler for.
handler	The response handler to register.

Definition at line 154 of file net.h.

int coap_remove_from_queue	(	coap_queue_t **	queue,
		coap_tid_t	id,
		coap_queue_t **	node
	)

This function removes the element with given id from the list given list.

If id was found, node is updated to point to the removed element. Note that the storage allocated by node is not released. The caller must do this manually using coap_delete_node(). This function returns 1 if the element with id id was found, 0 otherwise. For a return value of 0, the contents of node is undefined.

Parameters

queue	The queue to search for `id`.
id	The node id to look for.
node	If found, `node` is updated to point to the removed node. You must release the storage pointed to by `node` manually.

Returns: 1 if id was found, 0 otherwise.

Definition at line 952 of file net.c.

static int coap_remove_transaction	(	coap_queue_t **	queue,
		coap_tid_t	id
	)

inlinestatic

Removes the transaction identified by id from given queue.

This is a convenience function for coap_remove_from_queue() with automatic deletion of the removed node.

Parameters

queue	The queue to search for `id`.
id	The transaction id.

Returns: 1 if node was found, removed and destroyed, 0 otherwise.

Definition at line 384 of file net.h.

coap_tid_t coap_retransmit	(	coap_context_t *	context,
		coap_queue_t *	node
	)

Handles retransmissions of confirmable messages.

Definition at line 771 of file net.c.

coap_tid_t coap_send	(	coap_context_t *	context,
		const coap_address_t *	dst,
		coap_pdu_t *	pdu
	)

Sends a non-confirmed CoAP message to given destination.

The memory that is allocated by pdu will not be released by coap_send(). The caller must release the memory.

Parameters

context	The CoAP context to use.
dst	The address to send to.
pdu	The CoAP PDU to send.

Returns: The message id of the sent message or COAP_INVALID_TID on error.

Definition at line 653 of file net.c.

coap_tid_t coap_send_ack	(	coap_context_t *	context,
		const coap_address_t *	dst,
		coap_pdu_t *	request
	)

Sends an ACK message with code 0 for the specified request to dst.

This function returns the corresponding transaction id if the message was sent or COAP_INVALID_TID on error.

Parameters

context	The context to use.
dst	The destination address.
request	The request to be acknowledged.

Returns: The transaction id if ACK was sent or COAP_INVALID_TID on error.

Definition at line 534 of file net.c.

coap_tid_t coap_send_confirmed	(	coap_context_t *	context,
		const coap_address_t *	dst,
		coap_pdu_t *	pdu
	)

Sends a confirmed CoAP message to given destination.

The memory that is allocated by pdu will not be released by coap_send_confirmed(). The caller must release the memory.

Parameters

context	The CoAP context to use.
dst	The address to send to.
pdu	The CoAP PDU to send.

Returns: The message id of the sent message or COAP_INVALID_TID on error.

Definition at line 699 of file net.c.

coap_tid_t coap_send_error	(	coap_context_t *	context,
		coap_pdu_t *	request,
		const coap_address_t *	dst,
		unsigned char	code,
		coap_opt_filter_t	opts
	)

Sends an error response with code code for request request to dst.

opts will be passed to coap_new_error_response() to copy marked options from the request. This function returns the transaction id if the message was sent, or COAP_INVALID_TID otherwise.

Parameters

context	The context to use.
request	The original request to respond to.
dst	The remote peer that sent the request.
code	The reponse code.
opts	A filter that specifies the options to copy from the `request`.

Returns: The transaction id if the message was sent, or COAP_INVALID_TID otherwise.

Definition at line 660 of file net.c.

coap_tid_t coap_send_message_type	(	coap_context_t *	context,
		const coap_address_t *	dst,
		coap_pdu_t *	request,
		unsigned char	type
	)

Helper funktion to create and send a message with type (usually ACK or RST).

This function returns COAP_INVALID_TID when the message was not sent, a valid transaction id otherwise.

Parameters

context	The CoAP context.
dst	Where to send the context.
request	The request that should be responded to.
type	Which type to set

Returns: transaction id on success or COAP_INVALID_TID otherwise.

Definition at line 681 of file net.c.

static coap_tid_t coap_send_rst	(	coap_context_t *	context,
		const coap_address_t *	dst,
		coap_pdu_t *	request
	)

inlinestatic

Sends an RST message with code 0 for the specified request to dst.

This function returns the corresponding transaction id if the message was sent or COAP_INVALID_TID on error.

Parameters

context	The context to use.
dst	The destination address.
request	The request to be reset.

Returns: The transaction id if RST was sent or COAP_INVALID_TID on error.

Definition at line 325 of file net.h.

void coap_ticks ( coap_tick_t * )

Returns the current value of an internal tick counter.

The counter counts COAP_TICKS_PER_SECOND ticks every second.

void coap_transaction_id	(	const coap_address_t *	peer,
		const coap_pdu_t *	pdu,
		coap_tid_t *	id
	)

Calculates a unique transaction id from given arguments peer and pdu.

The id is returned in id.

Parameters

peer	The remote party who sent `pdu`.
pdu	The message that initiated the transaction.
id	Set to the new id.

Definition at line 498 of file net.c.

Data Structures

Macros

Typedefs

Functions

Macro Definition Documentation

Typedef Documentation

Function Documentation