Support

Internal API for handling CoAP proxies. More...

Collaboration diagram for Support:

Data Structures
struct	coap_proxy_req_t
struct	coap_proxy_list_t

Typedefs
typedef struct coap_proxy_req_t	coap_proxy_req_t

Functions
void	coap_proxy_cleanup (coap_context_t *context)
	Close down proxy tracking, releasing any memory used.
int	coap_proxy_check_timeouts (coap_context_t *context, coap_tick_t now, coap_tick_t *tim_rem)
	Idle timeout inactive proxy sessions as well as return in tim_rem the time to remaining to timeout the inactive proxy.
int	coap_proxy_remove_association (coap_session_t *session, int send_failure)
	Remove the upstream proxy connection from list for session.
int	coap_proxy_forward_request_lkd (coap_session_t *session, const coap_pdu_t *request, coap_pdu_t *response, coap_resource_t *resource, coap_cache_key_t *cache_key, coap_proxy_server_list_t *server_list)
	Forward incoming request upstream to the next proxy/server.
coap_response_t	coap_proxy_forward_response_lkd (coap_session_t *session, const coap_pdu_t *received, coap_cache_key_t **cache_key)
	Forward the returning response back to the appropriate client.
coap_session_t *	coap_new_client_session_proxy_lkd (coap_context_t *context, coap_proxy_server_list_t *server_list)
	Creates a new client session to use the proxy logic going to the defined upstream server.
coap_mid_t	coap_proxy_local_write (coap_session_t *session, coap_pdu_t *pdu)
struct coap_proxy_req_t *	coap_proxy_map_outgoing_request (coap_session_t *ongoing, const coap_pdu_t *received, coap_proxy_list_t **proxy_entry)

Detailed Description

Internal API for handling CoAP proxies.

Typedef Documentation

coap_proxy_req_t

typedef struct coap_proxy_req_t coap_proxy_req_t

Function Documentation

coap_new_client_session_proxy_lkd()

coap_session_t * coap_new_client_session_proxy_lkd	(	coap_context_t *	context,
		coap_proxy_server_list_t *	server_list
	)

Creates a new client session to use the proxy logic going to the defined upstream server.

Note: This function must be called in the locked state,

Note: If server_list contains more than one server, the first server is not always chosen.

Note: server_list must exist for the duration of the returned session as it is used for every coap_send() or coap_send_recv().

Note: Unless coap_send_recv() is used, the response is sent to the handler defined by coap_register_response_handler(), not to the handler defined by coap_register_proxy_response_handler().

Parameters

context	The CoAP context.
server_list	The upstream server list to connect to.

Returns

A new CoAP session or NULL if failed. Call coap_session_release() to free.

coap_proxy_check_timeouts()

int coap_proxy_check_timeouts	(	coap_context_t *	context,
		coap_tick_t	now,
		coap_tick_t *	tim_rem
	)

Idle timeout inactive proxy sessions as well as return in tim_rem the time to remaining to timeout the inactive proxy.

Parameters

context	Context to check against.
now	Current time in ticks.
tim_rem	Where to update timeout time to the next expiry.

Returns

Return 1 if there is a future expire time, else 0.

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coap_proxy_cleanup()

void coap_proxy_cleanup

(

coap_context_t *

context

)

Close down proxy tracking, releasing any memory used.

Parameters

context

The current CoAP context.

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coap_proxy_forward_request_lkd()

int coap_proxy_forward_request_lkd	(	coap_session_t *	session,
		const coap_pdu_t *	request,
		coap_pdu_t *	response,
		coap_resource_t *	resource,
		coap_cache_key_t *	cache_key,
		coap_proxy_server_list_t *	server_list
	)

Forward incoming request upstream to the next proxy/server.

Possible scenarios: Acting as a reverse proxy - connect to defined internal server (possibly round robin load balancing over multiple servers). Acting as a forward proxy - connect to host defined in Proxy-Uri or Proxy-Scheme with Uri-Host (and maybe Uri-Port). Acting as a relay proxy - connect to defined upstream server (possibly round robin load balancing over multiple servers).

A request that should go direct to this server is not supported here.

Note: This function must be called in the locked state,

Parameters

session	The client session.
request	The client's request PDU.
response	The response PDU that will get sent back to the client.
resource	The resource associated with this request.
cache_key	A cache key generated from the request PDU or NULL.
server_list	The upstream server list to connect to.

Returns

1 if success, or 0 if failure (response code set to appropriate value).

coap_proxy_forward_response_lkd()

coap_response_t coap_proxy_forward_response_lkd	(	coap_session_t *	session,
		const coap_pdu_t *	received,
		coap_cache_key_t **	cache_key
	)

Forward the returning response back to the appropriate client.

Note: This function must be called in the locked state,

Parameters

session	The session handling the response.
received	The received PDU.
cache_key	Updated with the cache key pointer provided to coap_proxy_forward_request_lkd(). The caller should delete this cach key (unless the client request set up an Observe and there will be unsolicited responses).

Returns

One of COAP_RESPONSE_FAIL or COAP_RESPONSE_OK.

coap_proxy_local_write()

coap_mid_t coap_proxy_local_write	(	coap_session_t *	session,
		coap_pdu_t *	pdu
	)

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coap_proxy_map_outgoing_request()

struct coap_proxy_req_t * coap_proxy_map_outgoing_request	(	coap_session_t *	ongoing,
		const coap_pdu_t *	received,
		coap_proxy_list_t **	proxy_entry
	)

coap_proxy_remove_association()

int coap_proxy_remove_association	(	coap_session_t *	session,
		int	send_failure
	)

Remove the upstream proxy connection from list for session.

Parameters

session	Either incoming or ongoiing session.
send_failure	Indicate to incoming session proxy issues.

Returns

Return 1 if proxy_entry deleted.

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