Context Handling

Internal API for Context Handling. More...

Collaboration diagram for Context Handling:

Data Structures
struct	coap_queue_t
	Queue entry. More...
struct	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 variable t in node. 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 (void)
	Creates a new node suitable for adding to the CoAP sendqueue. 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_mid_t	coap_retransmit (coap_context_t *context, coap_queue_t *node)
	Handles retransmissions of confirmable messages. More...
int	coap_handle_dgram (coap_context_t *ctx, coap_session_t *session, uint8_t *data, size_t data_len)
	Parses and interprets a CoAP datagram with context ctx. More...
int	coap_remove_from_queue (coap_queue_t **queue, coap_session_t *session, coap_mid_t id, coap_queue_t **node)
	This function removes the element with given id from the list given list. More...
coap_mid_t	coap_wait_ack (coap_context_t *context, coap_session_t *session, coap_queue_t *node)
void	coap_cancel_all_messages (coap_context_t *context, coap_session_t *session, const uint8_t *token, size_t token_length)
	Cancels all outstanding messages for session session that have the specified token. More...
void	coap_cancel_session_messages (coap_context_t *context, coap_session_t *session, coap_nack_reason_t reason)
	Cancels all outstanding messages for session session. More...
void	coap_dispatch (coap_context_t *context, coap_session_t *session, coap_pdu_t *pdu)
	Dispatches the PDUs from the receive queue in given context. More...
int	coap_option_check_critical (coap_session_t *session, coap_pdu_t *pdu, coap_opt_filter_t *unknown)
	Verifies that pdu contains no unknown critical options. More...
coap_pdu_t *	coap_wellknown_response (coap_context_t *context, coap_session_t *session, coap_pdu_t *request)
	Creates a new response for given request with the contents of .well-known/core. More...
unsigned int	coap_calc_timeout (coap_session_t *session, unsigned char r)
	Calculates the initial timeout based on the session CoAP transmission parameters 'ack_timeout', 'ack_random_factor', and COAP_TICKS_PER_SECOND. More...
coap_mid_t	coap_send_internal (coap_session_t *session, coap_pdu_t *pdu)
	Sends a CoAP message to given peer. More...
int	coap_client_delay_first (coap_session_t *session)
	Delay the sending of the first client request until some other negotiation has completed. More...

Detailed Description

Internal API for Context Handling.

Function Documentation

coap_adjust_basetime()

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 162 of file net.c.

coap_calc_timeout()

unsigned int coap_calc_timeout	(	coap_session_t *	session,
		unsigned char	r
	)

Calculates the initial timeout based on the session CoAP transmission parameters 'ack_timeout', 'ack_random_factor', and COAP_TICKS_PER_SECOND.

The calculation requires 'ack_timeout' and 'ack_random_factor' to be in Qx.FRAC_BITS fixed point notation, whereas the passed parameter r is interpreted as the fractional part of a Q0.MAX_BITS random value.

Parameters

session	session timeout is associated with
r	random value as fractional part of a Q0.MAX_BITS fixed point value

Returns

COAP_TICKS_PER_SECOND * 'ack_timeout' * (1 + ('ack_random_factor' - 1) * r)

Definition at line 956 of file net.c.

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coap_cancel_all_messages()

void coap_cancel_all_messages	(	coap_context_t *	context,
		coap_session_t *	session,
		const uint8_t *	token,
		size_t	token_length
	)

Cancels all outstanding messages for session session that have the specified token.

Parameters

context	The context in use.
session	Session of the messages to remove.
token	Message token.
token_length	Actual length of token.

Definition at line 2158 of file net.c.

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coap_cancel_session_messages()

void coap_cancel_session_messages	(	coap_context_t *	context,
		coap_session_t *	session,
		coap_nack_reason_t	reason
	)

Cancels all outstanding messages for session session.

Parameters

context	The context in use.
session	Session of the messages to remove.
reason	The reasion for the session cancellation

Definition at line 2121 of file net.c.

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coap_client_delay_first()

int coap_client_delay_first

(

coap_session_t *

session

)

Delay the sending of the first client request until some other negotiation has completed.

Parameters

session

The CoAP session.

Returns

1 if everything was ok, 0 otherwise.

Definition at line 1045 of file net.c.

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coap_delete_all()

void coap_delete_all

(

coap_queue_t *

queue

)

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

Internal function.

Parameters

queue

The queue to delete.

Definition at line 256 of file net.c.

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coap_delete_node()

int coap_delete_node

(

coap_queue_t *

node

)

Destroys specified node.

Parameters

node	Node entry to remove.

Returns

1 node deleted from queue, 0 failure.

Definition at line 236 of file net.c.

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coap_dispatch()

void coap_dispatch	(	coap_context_t *	context,
		coap_session_t *	session,
		coap_pdu_t *	pdu
	)

Dispatches the PDUs from the receive queue in given context.

Definition at line 3160 of file net.c.

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coap_handle_dgram()

int coap_handle_dgram	(	coap_context_t *	ctx,
		coap_session_t *	session,
		uint8_t *	data,
		size_t	data_len
	)

Parses and interprets a CoAP datagram with context ctx.

This function returns 0 if the datagram was handled, or a value less than zero on error.

Parameters

ctx	The current CoAP context.
session	The current CoAP session.
data	The received packet'd data.
data_len	The received packet'd data length.

Returns

0 if message was handled successfully, or less than zero on error.

Definition at line 2040 of file net.c.

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coap_insert_node()

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

Adds node to given queue, ordered by variable t in node.

Parameters

queue	Queue to add to.
node	Node entry to add to Queue.

Returns

1 added to queue, 0 failure.

Definition at line 199 of file net.c.

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coap_new_node()

coap_queue_t * coap_new_node

(

void

)

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

Returns

New node entry, or NULL if failure.

Definition at line 265 of file net.c.

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coap_option_check_critical()

int coap_option_check_critical	(	coap_session_t *	session,
		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(session, 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

session	The current session.
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 688 of file net.c.

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coap_peek_next()

coap_queue_t * coap_peek_next

(

coap_context_t *

context

)

Returns the next pdu to send without removing from sendqeue.

Definition at line 279 of file net.c.

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coap_pop_next()

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 287 of file net.c.

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coap_remove_from_queue()

int coap_remove_from_queue	(	coap_queue_t **	queue,
		coap_session_t *	session,
		coap_mid_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.
session	The session to look for.
id	The message 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 2077 of file net.c.

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coap_retransmit()

coap_mid_t coap_retransmit	(	coap_context_t *	context,
		coap_queue_t *	node
	)

Handles retransmissions of confirmable messages.

Parameters

context	The CoAP context.
node	The node to retransmit.

Returns

The message id of the sent message or COAP_INVALID_MID on error.

Definition at line 1447 of file net.c.

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coap_send_internal()

coap_mid_t coap_send_internal	(	coap_session_t *	session,
		coap_pdu_t *	pdu
	)

Sends a CoAP message to given peer.

The memory that is allocated for the pdu will be released by coap_send_internal(). The caller must not use the pdu after calling coap_send_internal().

If the response body is split into multiple payloads using blocks, libcoap will handle asking for the subsequent blocks and any necessary recovery needed.

Parameters

session	The CoAP session.
pdu	The CoAP PDU to send.

Returns

The message id of the sent message or COAP_INVALID_MID on error.

Definition at line 1242 of file net.c.

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coap_wait_ack()

coap_mid_t coap_wait_ack	(	coap_context_t *	context,
		coap_session_t *	session,
		coap_queue_t *	node
	)

Definition at line 982 of file net.c.

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coap_wellknown_response()

coap_pdu_t * coap_wellknown_response	(	coap_context_t *	context,
		coap_session_t *	session,
		coap_pdu_t *	request
	)

Creates a new response for given request with the contents of .well-known/core.

The result is NULL on error or a newly allocated PDU that must be either sent with coap_sent() or released by coap_delete_pdu().

Parameters

context	The current coap context to use.
session	The CoAP session.
request	The request for .well-known/core .

Returns

A new 2.05 response for .well-known/core or NULL on error.