Proxy

API for Proxies. More...

Collaboration diagram for Proxy:

Data Structures
struct	coap_proxy_server_t
struct	coap_proxy_server_list_t

Typedefs
typedef struct coap_proxy_server_t	coap_proxy_server_t
typedef struct coap_proxy_server_list_t	coap_proxy_server_list_t
typedef coap_pdu_t *(*	coap_proxy_response_handler_t) (coap_session_t *session, const coap_pdu_t *sent, coap_pdu_t *received, coap_cache_key_t *cache_key)
	Proxy response handler that is used as callback held in coap_context_t.

Enumerations
enum	coap_proxy_t {   COAP_PROXY_REVERSE , COAP_PROXY_REVERSE_STRIP , COAP_PROXY_FORWARD_STATIC , COAP_PROXY_FORWARD_STATIC_STRIP ,   COAP_PROXY_FORWARD_DYNAMIC , COAP_PROXY_FORWARD_DYNAMIC_STRIP , COAP_PROXY_FORWARD = COAP_PROXY_FORWARD_STATIC , COAP_PROXY_FORWARD_STRIP = COAP_PROXY_FORWARD_STATIC_STRIP ,   COAP_PROXY_DIRECT = COAP_PROXY_FORWARD_DYNAMIC , COAP_PROXY_DIRECT_STRIP = COAP_PROXY_FORWARD_DYNAMIC_STRIP }

Functions
void	coap_register_proxy_response_handler (coap_context_t *context, coap_proxy_response_handler_t handler)
	Registers a new message handler that is called whenever a response is received by the proxy logic.
int	coap_verify_proxy_scheme_supported (coap_uri_scheme_t scheme)
	Verify that the CoAP Scheme is supported for an ongoing proxy connection.
COAP_API int	coap_proxy_forward_request (coap_session_t *req_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_API	coap_proxy_forward_response (coap_session_t *rsp_session, const coap_pdu_t *received, coap_cache_key_t **cache_key)
	Forward the returning response back to the appropriate client.
COAP_API coap_session_t *	coap_new_client_session_proxy (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.

Detailed Description

API for Proxies.

Typedef Documentation

coap_proxy_response_handler_t

typedef coap_pdu_t *(* coap_proxy_response_handler_t) (coap_session_t *session, const coap_pdu_t *sent, coap_pdu_t *received, coap_cache_key_t *cache_key)

Proxy response handler that is used as callback held in coap_context_t.

Parameters

session	CoAP session.
sent	The PDU that was transmitted.
received	The respose PDU that was received, or returned from cache.
cache_key	Updated with the cache key pointer provided to coap_proxy_forward_request(). The caller should delete this cache key (unless the client request set up an Observe and there will be unsolicited responses).

Returns

The PDU to be sent back to the client (usually received) or NULL if error. If NULL, this will cause sending a RST packet to the upstream server if the received PDU is a CON or NON. If the returned PDU is not received or NULL, then received must be freed off in the handler.

Definition at line 85 of file coap_proxy.h.

coap_proxy_server_list_t

typedef struct coap_proxy_server_list_t coap_proxy_server_list_t

coap_proxy_server_t

typedef struct coap_proxy_server_t coap_proxy_server_t

Enumeration Type Documentation

coap_proxy_t

enum coap_proxy_t

Enumerator
COAP_PROXY_REVERSE	Act as a reverse proxy.
COAP_PROXY_REVERSE_STRIP	Act as a reverse proxy, strip out proxy options.
COAP_PROXY_FORWARD_STATIC	Act as a forward-static proxy.
COAP_PROXY_FORWARD_STATIC_STRIP	Act as a forward-static proxy, strip out proxy options.
COAP_PROXY_FORWARD_DYNAMIC	Act as a forward-dynamic proxy using the request's Proxy-Uri or Proxy-Scheme options to determine server.
COAP_PROXY_FORWARD_DYNAMIC_STRIP	Act as a forward-dynamic proxy, strip out proxy options.
COAP_PROXY_FORWARD
COAP_PROXY_FORWARD_STRIP
COAP_PROXY_DIRECT
COAP_PROXY_DIRECT_STRIP

Definition at line 27 of file coap_proxy.h.

Function Documentation

coap_new_client_session_proxy()

COAP_API coap_session_t * coap_new_client_session_proxy	(	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: 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_forward_request()

COAP_API int coap_proxy_forward_request	(	coap_session_t *	req_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-dynamic proxy - connect to host defined in Proxy-Uri or Proxy-Scheme with Uri-Host (and maybe Uri-Port). Acting as a forward-static 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.

Parameters

req_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).

Definition at line 1411 of file coap_proxy.c.

coap_proxy_forward_response()

coap_response_t COAP_API coap_proxy_forward_response	(	coap_session_t *	rsp_session,
		const coap_pdu_t *	received,
		coap_cache_key_t **	cache_key
	)

Forward the returning response back to the appropriate client.

Parameters

rsp_session	The upstream session receiving the response.
received	The received PDU.
cache_key	Updated with the cache key pointer provided to coap_proxy_forward_request(). The caller should delete this cache 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.

Definition at line 1427 of file coap_proxy.c.

coap_register_proxy_response_handler()

void coap_register_proxy_response_handler	(	coap_context_t *	context,
		coap_proxy_response_handler_t	handler
	)

Registers a new message handler that is called whenever a response is received by the proxy logic.

Note: If this is not defined, then the handler registered by coap_register_response_handler() will be used.

Parameters

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

Definition at line 5009 of file coap_net.c.

coap_verify_proxy_scheme_supported()

int coap_verify_proxy_scheme_supported

(

coap_uri_scheme_t

scheme

)

Verify that the CoAP Scheme is supported for an ongoing proxy connection.

Parameters

scheme

The CoAP scheme to check.

Returns

1 if supported, or 0 if not supported.

Definition at line 1437 of file coap_proxy.c.