arduino-esp32/tools/sdk/include/coap/coap/subscribe.h
2017-01-16 16:03:13 +02:00

73 lines
2.2 KiB
C

/*
* subscribe.h -- subscription handling for CoAP
* see draft-ietf-core-observe-16
*
* Copyright (C) 2010-2012,2014-2015 Olaf Bergmann <bergmann@tzi.org>
*
* This file is part of the CoAP library libcoap. Please see README for terms
* of use.
*/
#ifndef _COAP_SUBSCRIBE_H_
#define _COAP_SUBSCRIBE_H_
#include "address.h"
#include "coap_io.h"
/**
* @defgroup observe Resource observation
* @{
*/
/**
* The value COAP_OBSERVE_ESTABLISH in a GET request indicates a new observe
* relationship for (sender address, token) is requested.
*/
#define COAP_OBSERVE_ESTABLISH 0
/**
* The value COAP_OBSERVE_CANCEL in a GET request indicates that the observe
* relationship for (sender address, token) must be cancelled.
*/
#define COAP_OBSERVE_CANCEL 1
#ifndef COAP_OBS_MAX_NON
/**
* Number of notifications that may be sent non-confirmable before a confirmable
* message is sent to detect if observers are alive. The maximum allowed value
* here is @c 15.
*/
#define COAP_OBS_MAX_NON 5
#endif /* COAP_OBS_MAX_NON */
#ifndef COAP_OBS_MAX_FAIL
/**
* Number of confirmable notifications that may fail (i.e. time out without
* being ACKed) before an observer is removed. The maximum value for
* COAP_OBS_MAX_FAIL is @c 3.
*/
#define COAP_OBS_MAX_FAIL 3
#endif /* COAP_OBS_MAX_FAIL */
/** Subscriber information */
typedef struct coap_subscription_t {
struct coap_subscription_t *next; /**< next element in linked list */
coap_endpoint_t local_if; /**< local communication interface */
coap_address_t subscriber; /**< address and port of subscriber */
unsigned int non_cnt:4; /**< up to 15 non-confirmable notifies allowed */
unsigned int fail_cnt:2; /**< up to 3 confirmable notifies can fail */
unsigned int dirty:1; /**< set if the notification temporarily could not be
* sent (in that case, the resource's partially
* dirty flag is set too) */
size_t token_length; /**< actual length of token */
unsigned char token[8]; /**< token used for subscription */
} coap_subscription_t;
void coap_subscription_init(coap_subscription_t *);
/** @} */
#endif /* _COAP_SUBSCRIBE_H_ */