generic resource handling More...

#include "config.h"
#include "t_list.h"
#include <assert.h>
#include "uthash.h"
#include "hashkey.h"
#include "async.h"
#include "str.h"
#include "pdu.h"
#include "net.h"
#include "subscribe.h"

Data Structures
struct	coap_attr_t

struct	coap_resource_t

Macros
#define	COAP_RESOURCE_CHECK_TIME 2
	The interval in seconds to check if resources have changed. More...

#define	COAP_ATTR_FLAGS_RELEASE_NAME 0x1

#define	COAP_ATTR_FLAGS_RELEASE_VALUE 0x2

#define	COAP_RESOURCE_FLAGS_RELEASE_URI 0x1

#define	COAP_PRINT_STATUS_MASK 0xF0000000u

#define	COAP_PRINT_OUTPUT_LENGTH(v) ((v) & ~COAP_PRINT_STATUS_MASK)

#define	COAP_PRINT_STATUS_ERROR 0x80000000u

#define	COAP_PRINT_STATUS_TRUNC 0x40000000u

Typedefs
typedef void(*	coap_method_handler_t )(coap_context_t , struct coap_resource_t , coap_address_t , coap_pdu_t , str , coap_pdu_t )
	Definition of message handler function (. More...

typedef struct coap_attr_t	coap_attr_t

typedef struct coap_resource_t	coap_resource_t

typedef unsigned int	coap_print_status_t
	Status word to encode the result of conditional print or copy operations such as coap_print_link(). More...

Functions
coap_resource_t *	coap_resource_init (const unsigned char *uri, size_t len, int flags)
	Creates a new resource object and initializes the link field to the string of length `len`. More...

void	coap_add_resource (coap_context_t context, coap_resource_t resource)
	Registers the given `resource` for `context`. More...

int	coap_delete_resource (coap_context_t *context, coap_key_t key)
	Deletes a resource identified by `key`. More...

coap_attr_t *	coap_add_attr (coap_resource_t resource, const unsigned char name, size_t nlen, const unsigned char *val, size_t vlen, int flags)
	Registers a new attribute with the given `resource`. More...

coap_attr_t *	coap_find_attr (coap_resource_t resource, const unsigned char name, size_t nlen)
	Returns `resource's` coap_attr_t object with given `name` if found, `NULL` otherwise. More...

void	coap_delete_attr (coap_attr_t *attr)
	Deletes an attribute. More...

coap_print_status_t	coap_print_link (const coap_resource_t resource, unsigned char buf, size_t len, size_t offset)
	Writes a description of this resource in link-format to given text buffer. More...

static void	coap_register_handler (coap_resource_t *resource, unsigned char method, coap_method_handler_t handler)
	Registers the specified `handler` as message handler for the request type `method`. More...

coap_resource_t *	coap_get_resource_from_key (coap_context_t *context, coap_key_t key)
	Returns the resource identified by the unique string `key`. More...

void	coap_hash_request_uri (const coap_pdu_t *request, coap_key_t key)
	Calculates the hash key for the resource requested by the Uri-Options of `request`. More...

coap_subscription_t *	coap_add_observer (coap_resource_t resource, const coap_address_t observer, const str *token)
	Adds the specified peer as observer for `resource`. More...

coap_subscription_t *	coap_find_observer (coap_resource_t resource, const coap_address_t peer, const str *token)
	Returns a subscription object for given `peer`. More...

void	coap_touch_observer (coap_context_t context, const coap_address_t observer, const str *token)
	Marks an observer as alive. More...

void	coap_delete_observer (coap_resource_t resource, const coap_address_t observer, const str *token)
	Removes any subscription for `observer` from `resource` and releases the allocated storage. More...

void	coap_check_notify (coap_context_t *context)
	Checks for all known resources, if they are dirty and notifies subscribed observers. More...

Detailed Description

generic resource handling

Definition in file resource.h.

Macro Definition Documentation

#define COAP_ATTR_FLAGS_RELEASE_NAME 0x1

Definition at line 49 of file resource.h.

#define COAP_ATTR_FLAGS_RELEASE_VALUE 0x2

Definition at line 50 of file resource.h.

#define COAP_PRINT_OUTPUT_LENGTH ( v ) ((v) & ~COAP_PRINT_STATUS_MASK)

Definition at line 189 of file resource.h.

#define COAP_PRINT_STATUS_ERROR 0x80000000u

Definition at line 190 of file resource.h.

#define COAP_PRINT_STATUS_MASK 0xF0000000u

Definition at line 188 of file resource.h.

#define COAP_PRINT_STATUS_TRUNC 0x40000000u

Definition at line 191 of file resource.h.

#define COAP_RESOURCE_CHECK_TIME 2

The interval in seconds to check if resources have changed.

Definition at line 26 of file resource.h.

#define COAP_RESOURCE_FLAGS_RELEASE_URI 0x1

Definition at line 59 of file resource.h.

Typedef Documentation

typedef struct coap_attr_t coap_attr_t

typedef void(* coap_method_handler_t)(coap_context_t *, struct coap_resource_t *, coap_address_t *, coap_pdu_t *, str *, coap_pdu_t *)

Definition of message handler function (.

See Also: coap_resource_t).

Definition at line 46 of file resource.h.

typedef unsigned int coap_print_status_t

Status word to encode the result of conditional print or copy operations such as coap_print_link().

The lower 28 bits of coap_print_status_t are used to encode the number of characters that has actually been printed, bits 28 to 31 encode the status. When COAP_PRINT_STATUS_ERROR is set, an error occurred during output. In this case, the other bits are undefined. COAP_PRINT_STATUS_TRUNC indicates that the output is truncated, i.e. the printing would have exceeded the current buffer.

Definition at line 186 of file resource.h.

typedef struct coap_resource_t coap_resource_t

Function Documentation

coap_attr_t* coap_add_attr	(	coap_resource_t *	resource,
		const unsigned char *	name,
		size_t	nlen,
		const unsigned char *	val,
		size_t	vlen,
		int	flags
	)

Registers a new attribute with the given resource.

As the attributes str fields will point to name and val the caller must ensure that these pointers are valid during the attribute's lifetime.

Parameters

resource	The resource to register the attribute with.
name	The attribute's name.
nlen	Length of `name`.
val	The attribute's value or `NULL` if none.
vlen	Length of `val` if specified.
flags	Flags for memory management (in particular release of memory)

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

Definition at line 341 of file resource.c.

coap_subscription_t* coap_add_observer	(	coap_resource_t *	resource,
		const coap_address_t *	observer,
		const str *	token
	)

Adds the specified peer as observer for resource.

The subscription is identified by the given token. This function returns the registered subscription information if the observer has been added, or NULL on error.

Parameters

resource	The observed resource.
observer	The remote peer that wants to received status updates.
token	The token that identifies this subscription.
token_length	The actual length of `token`. Must be `0` when `token` is `NULL`.

Returns: A pointer to the added/updated subscription information or NULL on error.

Definition at line 607 of file resource.c.

void coap_add_resource	(	coap_context_t *	context,
		coap_resource_t *	resource
	)

Registers the given resource for context.

The resource must have been created by coap_resource_init(), the storage allocated for the resource will be released by coap_delete_resource().

Parameters

context	The context to use.
resource	The resource to store.

Definition at line 440 of file resource.c.

void coap_check_notify ( coap_context_t * context )

Checks for all known resources, if they are dirty and notifies subscribed observers.

Definition at line 764 of file resource.c.

void coap_delete_attr ( coap_attr_t * attr )

Deletes an attribute.

Parameters

attr	Pointer to a previously created attribute

Definition at line 405 of file resource.c.

void coap_delete_observer	(	coap_resource_t *	resource,
		const coap_address_t *	observer,
		const str *	token
	)

Removes any subscription for observer from resource and releases the allocated storage.

Parameters

resource	The observed resource.
observer	The observer's address.
token	The token that identifies this subscription or `NULL` for any token.

Definition at line 674 of file resource.c.

int coap_delete_resource	(	coap_context_t *	context,
		coap_key_t	key
	)

Deletes a resource identified by key.

The storage allocated for that resource is freed.

Parameters

context	The context where the resources are stored.
key	The unique key for the resource to delete.

Returns: 1 if the resource was found (and destroyed), 0 otherwise.

Definition at line 451 of file resource.c.

coap_attr_t* coap_find_attr	(	coap_resource_t *	resource,
		const unsigned char *	name,
		size_t	nlen
	)

Returns resource's coap_attr_t object with given name if found, NULL otherwise.

Parameters

resource	The resource to search for attribute `name`.
name	Name of the requested attribute.
nlen	Actual length of `name`.

Returns: The first attribute with specified name or NULL if none was found.

Definition at line 383 of file resource.c.

coap_subscription_t* coap_find_observer	(	coap_resource_t *	resource,
		const coap_address_t *	peer,
		const str *	token
	)

Returns a subscription object for given peer.

Parameters

resource	The observed resource.
peer	The address to search for.
token	The token that identifies this subscription or `NULL` for any token.

Returns: A valid subscription if exists or NULL otherwise.

Definition at line 589 of file resource.c.

coap_resource_t* coap_get_resource_from_key	(	coap_context_t *	context,
		coap_key_t	key
	)

Returns the resource identified by the unique string key.

If no resource was found, this function returns NULL.

Parameters

context	The context to look for this resource.
key	The unique key of the resource.

Returns: A pointer to the resource or NULL if not found.

Definition at line 503 of file resource.c.

void coap_hash_request_uri	(	const coap_pdu_t *	request,
		coap_key_t	key
	)

Calculates the hash key for the resource requested by the Uri-Options of request.

This function calls coap_hash() for every path segment.

Parameters

request	The requesting pdu.
key	The resulting hash is stored in `key`

Definition at line 424 of file resource.c.

coap_print_status_t coap_print_link	(	const coap_resource_t *	resource,
		unsigned char *	buf,
		size_t *	len,
		size_t *	offset
	)

Writes a description of this resource in link-format to given text buffer.

len must be initialized to the maximum length of buf and will be set to the number of characters actually written if successful. This function returns 1 on success or 0 on error.

Parameters

resource	The resource to describe.
buf	The output buffer to write the description to.
len	Must be initialized to the length of `buf` and will be set to the length of the printed link description.
offset	The offset within the resource description where to start writing into `buf`. This is useful for dealing with the Block2 option. `offset` is updated during output as it is consumed.

Returns: If COAP_PRINT_STATUS_ERROR is set, an error occured. Otherwise, the lower 28 bits will indicate the number of characters that have actually been output into buffer. The flag COAP_PRINT_STATUS_TRUNC indicates that the output has been truncated.

Definition at line 538 of file resource.c.

static void coap_register_handler	(	coap_resource_t *	resource,
		unsigned char	method,
		coap_method_handler_t	handler
	)

inlinestatic

Registers the specified handler as message handler for the request type method.

Parameters

resource	The resource for which the handler shall be registered.
method	The CoAP request method to handle.
handler	The handler to register with `resource`.

Definition at line 227 of file resource.h.

coap_resource_t* coap_resource_init	(	const unsigned char *	uri,
		size_t	len,
		int	flags
	)

Creates a new resource object and initializes the link field to the string of length len.

This function returns the new coap_resource_t object.

Parameters

uri	The URI path of the new resource.
len	The length of `uri`.
flags	Flags for memory management (in particular release of memory)

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

Definition at line 307 of file resource.c.

void coap_touch_observer	(	coap_context_t *	context,
		const coap_address_t *	observer,
		const str *	token
	)

Marks an observer as alive.

Parameters

context	The CoAP context to use
observer	The transport address of the observer
token	The corresponding token that has been used for the subscription

Definition at line 643 of file resource.c.

Data Structures

Macros

Typedefs

Functions

Detailed Description

Macro Definition Documentation

Typedef Documentation

Function Documentation