zephyr/include/bluetooth/gatt.h

1564 lines
50 KiB
C

/** @file
* @brief Generic Attribute Profile handling.
*/
/*
* Copyright (c) 2015-2016 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
#ifndef ZEPHYR_INCLUDE_BLUETOOTH_GATT_H_
#define ZEPHYR_INCLUDE_BLUETOOTH_GATT_H_
/**
* @brief Generic Attribute Profile (GATT)
* @defgroup bt_gatt Generic Attribute Profile (GATT)
* @ingroup bluetooth
* @{
*/
#include <stddef.h>
#include <sys/types.h>
#include <sys/util.h>
#include <bluetooth/conn.h>
#include <bluetooth/uuid.h>
#include <bluetooth/att.h>
#ifdef __cplusplus
extern "C" {
#endif
/** GATT attribute permission bit field values */
enum {
/** No operations supported, e.g. for notify-only */
BT_GATT_PERM_NONE = 0,
/** Attribute read permission. */
BT_GATT_PERM_READ = BIT(0),
/** Attribute write permission. */
BT_GATT_PERM_WRITE = BIT(1),
/** @brief Attribute read permission with encryption.
*
* If set, requires encryption for read access.
*/
BT_GATT_PERM_READ_ENCRYPT = BIT(2),
/** @brief Attribute write permission with encryption.
*
* If set, requires encryption for write access.
*/
BT_GATT_PERM_WRITE_ENCRYPT = BIT(3),
/** @brief Attribute read permission with authentication.
*
* If set, requires encryption using authenticated link-key for read
* access.
*/
BT_GATT_PERM_READ_AUTHEN = BIT(4),
/** @brief Attribute write permission with authentication.
*
* If set, requires encryption using authenticated link-key for write
* access.
*/
BT_GATT_PERM_WRITE_AUTHEN = BIT(5),
/** @brief Attribute prepare write permission.
*
* If set, allows prepare writes with use of BT_GATT_WRITE_FLAG_PREPARE
* passed to write callback.
*/
BT_GATT_PERM_PREPARE_WRITE = BIT(6),
};
/** @def BT_GATT_ERR
* @brief Construct error return value for attribute read and write callbacks.
*
* @param _att_err ATT error code
*
* @return Appropriate error code for the attribute callbacks.
*/
#define BT_GATT_ERR(_att_err) (-(_att_err))
/** GATT attribute write flags */
enum {
/** @brief Attribute prepare write flag
*
* If set, write callback should only check if the device is
* authorized but no data shall be written.
*/
BT_GATT_WRITE_FLAG_PREPARE = BIT(0),
/** @brief Attribute write command flag
*
* If set, indicates that write operation is a command (Write without
* response) which doesn't generate any response.
*/
BT_GATT_WRITE_FLAG_CMD = BIT(1),
};
/** @brief GATT Attribute structure. */
struct bt_gatt_attr {
/** Attribute UUID */
const struct bt_uuid *uuid;
/** @brief Attribute read callback
*
* The callback can also be used locally to read the contents of the
* attribute in which case no connection will be set.
*
* @param conn The connection that is requesting to read
* @param attr The attribute that's being read
* @param buf Buffer to place the read result in
* @param len Length of data to read
* @param offset Offset to start reading from
*
* @return Number fo bytes read, or in case of an error
* BT_GATT_ERR() with a specific ATT error code.
*/
ssize_t (*read)(struct bt_conn *conn, const struct bt_gatt_attr *attr,
void *buf, uint16_t len, uint16_t offset);
/** @brief Attribute write callback
*
* @param conn The connection that is requesting to write
* @param attr The attribute that's being written
* @param buf Buffer with the data to write
* @param len Number of bytes in the buffer
* @param offset Offset to start writing from
* @param flags Flags (BT_GATT_WRITE_*)
*
* @return Number of bytes written, or in case of an error
* BT_GATT_ERR() with a specific ATT error code.
*/
ssize_t (*write)(struct bt_conn *conn, const struct bt_gatt_attr *attr,
const void *buf, uint16_t len, uint16_t offset,
uint8_t flags);
/** Attribute user data */
void *user_data;
/** Attribute handle */
uint16_t handle;
/** Attribute permissions */
uint8_t perm;
};
/** @brief GATT Service structure */
struct bt_gatt_service_static {
/** Service Attributes */
const struct bt_gatt_attr *attrs;
/** Service Attribute count */
size_t attr_count;
};
/** @brief GATT Service structure */
struct bt_gatt_service {
/** Service Attributes */
struct bt_gatt_attr *attrs;
/** Service Attribute count */
size_t attr_count;
sys_snode_t node;
};
/** @brief Service Attribute Value. */
struct bt_gatt_service_val {
/** Service UUID. */
const struct bt_uuid *uuid;
/** Service end handle. */
uint16_t end_handle;
};
/** @brief Include Attribute Value. */
struct bt_gatt_include {
/** Service UUID. */
const struct bt_uuid *uuid;
/** Service start handle. */
uint16_t start_handle;
/** Service end handle. */
uint16_t end_handle;
};
/** Characteristic Properties Bit field values */
/** @def BT_GATT_CHRC_BROADCAST
* @brief Characteristic broadcast property.
*
* If set, permits broadcasts of the Characteristic Value using Server
* Characteristic Configuration Descriptor.
*/
#define BT_GATT_CHRC_BROADCAST 0x01
/** @def BT_GATT_CHRC_READ
* @brief Characteristic read property.
*
* If set, permits reads of the Characteristic Value.
*/
#define BT_GATT_CHRC_READ 0x02
/** @def BT_GATT_CHRC_WRITE_WITHOUT_RESP
* @brief Characteristic write without response property.
*
* If set, permits write of the Characteristic Value without response.
*/
#define BT_GATT_CHRC_WRITE_WITHOUT_RESP 0x04
/** @def BT_GATT_CHRC_WRITE
* @brief Characteristic write with response property.
*
* If set, permits write of the Characteristic Value with response.
*/
#define BT_GATT_CHRC_WRITE 0x08
/** @def BT_GATT_CHRC_NOTIFY
* @brief Characteristic notify property.
*
* If set, permits notifications of a Characteristic Value without
* acknowledgment.
*/
#define BT_GATT_CHRC_NOTIFY 0x10
/** @def BT_GATT_CHRC_INDICATE
* @brief Characteristic indicate property.
*
* If set, permits indications of a Characteristic Value with acknowledgment.
*/
#define BT_GATT_CHRC_INDICATE 0x20
/** @def BT_GATT_CHRC_AUTH
* @brief Characteristic Authenticated Signed Writes property.
*
* If set, permits signed writes to the Characteristic Value.
*/
#define BT_GATT_CHRC_AUTH 0x40
/** @def BT_GATT_CHRC_EXT_PROP
* @brief Characteristic Extended Properties property.
*
* If set, additional characteristic properties are defined in the
* Characteristic Extended Properties Descriptor.
*/
#define BT_GATT_CHRC_EXT_PROP 0x80
/** @brief Characteristic Attribute Value. */
struct bt_gatt_chrc {
/** Characteristic UUID. */
const struct bt_uuid *uuid;
/** Characteristic Value handle. */
uint16_t value_handle;
/** Characteristic properties. */
uint8_t properties;
};
/** Characteristic Extended Properties Bit field values */
#define BT_GATT_CEP_RELIABLE_WRITE 0x0001
#define BT_GATT_CEP_WRITABLE_AUX 0x0002
/** @brief Characteristic Extended Properties Attribute Value. */
struct bt_gatt_cep {
/** Characteristic Extended properties */
uint16_t properties;
};
/** Client Characteristic Configuration Values */
/** @def BT_GATT_CCC_NOTIFY
* @brief Client Characteristic Configuration Notification.
*
* If set, changes to Characteristic Value shall be notified.
*/
#define BT_GATT_CCC_NOTIFY 0x0001
/** @def BT_GATT_CCC_INDICATE
* @brief Client Characteristic Configuration Indication.
*
* If set, changes to Characteristic Value shall be indicated.
*/
#define BT_GATT_CCC_INDICATE 0x0002
/** Client Characteristic Configuration Attribute Value */
struct bt_gatt_ccc {
/** Client Characteristic Configuration flags */
uint16_t flags;
};
/** @brief GATT Characteristic Presentation Format Attribute Value. */
struct bt_gatt_cpf {
/** Format of the value of the characteristic */
uint8_t format;
/** Exponent field to determine how the value of this characteristic is
* further formatted
*/
int8_t exponent;
/** Unit of the characteristic */
uint16_t unit;
/** Name space of the description */
uint8_t name_space;
/** Description of the characteristic as defined in a higher layer profile */
uint16_t description;
} __packed;
/**
* @defgroup bt_gatt_server GATT Server APIs
* @ingroup bt_gatt
* @{
*/
/** @brief Register GATT service.
*
* Register GATT service. Applications can make use of
* macros such as BT_GATT_PRIMARY_SERVICE, BT_GATT_CHARACTERISTIC,
* BT_GATT_DESCRIPTOR, etc.
*
* When using @option{CONFIG_BT_SETTINGS} then all services that should have
* bond configuration loaded, i.e. CCC values, must be registered before
* calling @ref settings_load.
*
* When using @option{CONFIG_BT_GATT_CACHING} and @option{CONFIG_BT_SETTINGS}
* then all services that should be included in the GATT Database Hash
* calculation should be added before calling @ref settings_load.
* All services registered after settings_load will trigger a new database hash
* calculation and a new hash stored.
*
* @param svc Service containing the available attributes
*
* @return 0 in case of success or negative value in case of error.
*/
int bt_gatt_service_register(struct bt_gatt_service *svc);
/** @brief Unregister GATT service.
* *
* @param svc Service to be unregistered.
*
* @return 0 in case of success or negative value in case of error.
*/
int bt_gatt_service_unregister(struct bt_gatt_service *svc);
enum {
BT_GATT_ITER_STOP = 0,
BT_GATT_ITER_CONTINUE,
};
/** @typedef bt_gatt_attr_func_t
* @brief Attribute iterator callback.
*
* @param attr Attribute found.
* @param handle Attribute handle found.
* @param user_data Data given.
*
* @return BT_GATT_ITER_CONTINUE if should continue to the next attribute.
* @return BT_GATT_ITER_STOP to stop.
*/
typedef uint8_t (*bt_gatt_attr_func_t)(const struct bt_gatt_attr *attr,
uint16_t handle,
void *user_data);
/** @brief Attribute iterator by type.
*
* Iterate attributes in the given range matching given UUID and/or data.
*
* @param start_handle Start handle.
* @param end_handle End handle.
* @param uuid UUID to match, passing NULL skips UUID matching.
* @param attr_data Attribute data to match, passing NULL skips data matching.
* @param num_matches Number matches, passing 0 makes it unlimited.
* @param func Callback function.
* @param user_data Data to pass to the callback.
*/
void bt_gatt_foreach_attr_type(uint16_t start_handle, uint16_t end_handle,
const struct bt_uuid *uuid,
const void *attr_data, uint16_t num_matches,
bt_gatt_attr_func_t func,
void *user_data);
/** @brief Attribute iterator.
*
* Iterate attributes in the given range.
*
* @param start_handle Start handle.
* @param end_handle End handle.
* @param func Callback function.
* @param user_data Data to pass to the callback.
*/
static inline void bt_gatt_foreach_attr(uint16_t start_handle, uint16_t end_handle,
bt_gatt_attr_func_t func,
void *user_data)
{
bt_gatt_foreach_attr_type(start_handle, end_handle, NULL, NULL, 0, func,
user_data);
}
/** @brief Iterate to the next attribute
*
* Iterate to the next attribute following a given attribute.
*
* @param attr Current Attribute.
*
* @return The next attribute or NULL if it cannot be found.
*/
struct bt_gatt_attr *bt_gatt_attr_next(const struct bt_gatt_attr *attr);
/** @brief Get Attribute handle.
*
* @param attr Attribute object.
*
* @return Handle of the corresponding attribute or zero if the attribute
* could not be found.
*/
uint16_t bt_gatt_attr_get_handle(const struct bt_gatt_attr *attr);
/** @brief Get the handle of the characteristic value descriptor.
*
* @param attr A Characteristic Attribute.
*
* @note The user_data of the attribute must of type @ref bt_gatt_chrc.
*
* @return the handle of the corresponding Characteristic Value. The value will
* be zero (the invalid handle) if @p attr was not a characteristic
* attribute.
*/
uint16_t bt_gatt_attr_value_handle(const struct bt_gatt_attr *attr);
/** @brief Generic Read Attribute value helper.
*
* Read attribute value from local database storing the result into buffer.
*
* @param conn Connection object.
* @param attr Attribute to read.
* @param buf Buffer to store the value.
* @param buf_len Buffer length.
* @param offset Start offset.
* @param value Attribute value.
* @param value_len Length of the attribute value.
*
* @return number of bytes read in case of success or negative values in
* case of error.
*/
ssize_t bt_gatt_attr_read(struct bt_conn *conn, const struct bt_gatt_attr *attr,
void *buf, uint16_t buf_len, uint16_t offset,
const void *value, uint16_t value_len);
/** @brief Read Service Attribute helper.
*
* Read service attribute value from local database storing the result into
* buffer after encoding it.
* @note Only use this with attributes which user_data is a bt_uuid.
*
* @param conn Connection object.
* @param attr Attribute to read.
* @param buf Buffer to store the value read.
* @param len Buffer length.
* @param offset Start offset.
*
* @return number of bytes read in case of success or negative values in
* case of error.
*/
ssize_t bt_gatt_attr_read_service(struct bt_conn *conn,
const struct bt_gatt_attr *attr,
void *buf, uint16_t len, uint16_t offset);
/** @def BT_GATT_SERVICE_DEFINE
* @brief Statically define and register a service.
*
* Helper macro to statically define and register a service.
*
* @param _name Service name.
*/
#define BT_GATT_SERVICE_DEFINE(_name, ...) \
const struct bt_gatt_attr attr_##_name[] = { __VA_ARGS__ }; \
const Z_STRUCT_SECTION_ITERABLE(bt_gatt_service_static, _name) =\
BT_GATT_SERVICE(attr_##_name)
#define _BT_GATT_ATTRS_ARRAY_DEFINE(n, _instances, _attrs_def) \
static struct bt_gatt_attr attrs_##n[] = _attrs_def(_instances[n]);
#define _BT_GATT_SERVICE_ARRAY_ITEM(_n, _) BT_GATT_SERVICE(attrs_##_n),
/** @def BT_GATT_SERVICE_INSTANCE_DEFINE
* @brief Statically define service structure array.
*
* Helper macro to statically define service structure array. Each element
* of the array is linked to the service attribute array which is also
* defined in this scope using _attrs_def macro.
*
* @param _name Name of service structure array.
* @param _instances Array of instances to pass as user context to the
* attribute callbacks.
* @param _instance_num Number of elements in instance array.
* @param _attrs_def Macro provided by the user that defines attribute
* array for the serivce. This macro should accept single
* parameter which is the instance context.
*/
#define BT_GATT_SERVICE_INSTANCE_DEFINE( \
_name, _instances, _instance_num, _attrs_def) \
BUILD_ASSERT(ARRAY_SIZE(_instances) == _instance_num, \
"The number of array elements does not match its size"); \
UTIL_EVAL(UTIL_REPEAT( \
_instance_num, _BT_GATT_ATTRS_ARRAY_DEFINE, _instances, \
_attrs_def)) \
static struct bt_gatt_service _name[] = { \
UTIL_LISTIFY(_instance_num, _BT_GATT_SERVICE_ARRAY_ITEM) \
}
/** @def BT_GATT_SERVICE
* @brief Service Structure Declaration Macro.
*
* Helper macro to declare a service structure.
*
* @param _attrs Service attributes.
*/
#define BT_GATT_SERVICE(_attrs) \
{ \
.attrs = _attrs, \
.attr_count = ARRAY_SIZE(_attrs), \
}
/** @def BT_GATT_PRIMARY_SERVICE
* @brief Primary Service Declaration Macro.
*
* Helper macro to declare a primary service attribute.
*
* @param _service Service attribute value.
*/
#define BT_GATT_PRIMARY_SERVICE(_service) \
BT_GATT_ATTRIBUTE(BT_UUID_GATT_PRIMARY, BT_GATT_PERM_READ, \
bt_gatt_attr_read_service, NULL, _service)
/** @def BT_GATT_SECONDARY_SERVICE
* @brief Secondary Service Declaration Macro.
*
* Helper macro to declare a secondary service attribute.
*
* @param _service Service attribute value.
*/
#define BT_GATT_SECONDARY_SERVICE(_service) \
BT_GATT_ATTRIBUTE(BT_UUID_GATT_SECONDARY, BT_GATT_PERM_READ, \
bt_gatt_attr_read_service, NULL, _service)
/** @brief Read Include Attribute helper.
*
* Read include service attribute value from local database storing the result
* into buffer after encoding it.
* @note Only use this with attributes which user_data is a bt_gatt_include.
*
* @param conn Connection object.
* @param attr Attribute to read.
* @param buf Buffer to store the value read.
* @param len Buffer length.
* @param offset Start offset.
*
* @return number of bytes read in case of success or negative values in
* case of error.
*/
ssize_t bt_gatt_attr_read_included(struct bt_conn *conn,
const struct bt_gatt_attr *attr,
void *buf, uint16_t len, uint16_t offset);
/** @def BT_GATT_INCLUDE_SERVICE
* @brief Include Service Declaration Macro.
*
* Helper macro to declare database internal include service attribute.
*
* @param _service_incl the first service attribute of service to include
*/
#define BT_GATT_INCLUDE_SERVICE(_service_incl) \
BT_GATT_ATTRIBUTE(BT_UUID_GATT_INCLUDE, BT_GATT_PERM_READ, \
bt_gatt_attr_read_included, NULL, _service_incl)
/** @brief Read Characteristic Attribute helper.
*
* Read characteristic attribute value from local database storing the result
* into buffer after encoding it.
* @note Only use this with attributes which user_data is a bt_gatt_chrc.
*
* @param conn Connection object.
* @param attr Attribute to read.
* @param buf Buffer to store the value read.
* @param len Buffer length.
* @param offset Start offset.
*
* @return number of bytes read in case of success or negative values in
* case of error.
*/
ssize_t bt_gatt_attr_read_chrc(struct bt_conn *conn,
const struct bt_gatt_attr *attr, void *buf,
uint16_t len, uint16_t offset);
#define BT_GATT_CHRC_INIT(_uuid, _handle, _props) \
{ \
.uuid = _uuid, \
.value_handle = _handle, \
.properties = _props, \
}
/** @def BT_GATT_CHARACTERISTIC
* @brief Characteristic and Value Declaration Macro.
*
* Helper macro to declare a characteristic attribute along with its
* attribute value.
*
* @param _uuid Characteristic attribute uuid.
* @param _props Characteristic attribute properties.
* @param _perm Characteristic Attribute access permissions.
* @param _read Characteristic Attribute read callback.
* @param _write Characteristic Attribute write callback.
* @param _value Characteristic Attribute value.
*/
#define BT_GATT_CHARACTERISTIC(_uuid, _props, _perm, _read, _write, _value) \
BT_GATT_ATTRIBUTE(BT_UUID_GATT_CHRC, BT_GATT_PERM_READ, \
bt_gatt_attr_read_chrc, NULL, \
((struct bt_gatt_chrc[]) { \
BT_GATT_CHRC_INIT(_uuid, 0U, _props), \
})), \
BT_GATT_ATTRIBUTE(_uuid, _perm, _read, _write, _value)
#if IS_ENABLED(CONFIG_BT_SETTINGS_CCC_LAZY_LOADING)
#define BT_GATT_CCC_MAX (CONFIG_BT_MAX_CONN)
#else
#define BT_GATT_CCC_MAX (CONFIG_BT_MAX_PAIRED + CONFIG_BT_MAX_CONN)
#endif
/** @brief GATT CCC configuration entry. */
struct bt_gatt_ccc_cfg {
/** Local identity, BT_ID_DEFAULT in most cases. */
uint8_t id;
/** Remote peer address. */
bt_addr_le_t peer;
/** Configuration value. */
uint16_t value;
};
/** Internal representation of CCC value */
struct _bt_gatt_ccc {
/** Configuration for each connection */
struct bt_gatt_ccc_cfg cfg[BT_GATT_CCC_MAX];
/** Highest value of all connected peer's subscriptions */
uint16_t value;
/** @brief CCC attribute changed callback
*
* @param attr The attribute that's changed value
* @param value New value
*/
void (*cfg_changed)(const struct bt_gatt_attr *attr, uint16_t value);
/** @brief CCC attribute write validation callback
*
* @param conn The connection that is requesting to write
* @param attr The attribute that's being written
* @param value CCC value to write
*
* @return Number of bytes to write, or in case of an error
* BT_GATT_ERR() with a specific error code.
*/
ssize_t (*cfg_write)(struct bt_conn *conn,
const struct bt_gatt_attr *attr, uint16_t value);
/** @brief CCC attribute match handler
*
* Indicate if it is OK to send a notification or indication
* to the subscriber.
*
* @param conn The connection that is being checked
* @param attr The attribute that's being checked
*
* @return true if application has approved notification/indication,
* false if application does not approve.
*/
bool (*cfg_match)(struct bt_conn *conn,
const struct bt_gatt_attr *attr);
};
/** @brief Read Client Characteristic Configuration Attribute helper.
*
* Read CCC attribute value from local database storing the result into buffer
* after encoding it.
*
* @note Only use this with attributes which user_data is a _bt_gatt_ccc.
*
* @param conn Connection object.
* @param attr Attribute to read.
* @param buf Buffer to store the value read.
* @param len Buffer length.
* @param offset Start offset.
*
* @return number of bytes read in case of success or negative values in
* case of error.
*/
ssize_t bt_gatt_attr_read_ccc(struct bt_conn *conn,
const struct bt_gatt_attr *attr, void *buf,
uint16_t len, uint16_t offset);
/** @brief Write Client Characteristic Configuration Attribute helper.
*
* Write value in the buffer into CCC attribute.
*
* @note Only use this with attributes which user_data is a _bt_gatt_ccc.
*
* @param conn Connection object.
* @param attr Attribute to read.
* @param buf Buffer to store the value read.
* @param len Buffer length.
* @param offset Start offset.
* @param flags Write flags.
*
* @return number of bytes written in case of success or negative values in
* case of error.
*/
ssize_t bt_gatt_attr_write_ccc(struct bt_conn *conn,
const struct bt_gatt_attr *attr, const void *buf,
uint16_t len, uint16_t offset, uint8_t flags);
/** @def BT_GATT_CCC_INITIALIZER
* @brief Initialize Client Characteristic Configuration Declaration Macro.
*
* Helper macro to initialize a Managed CCC attribute value.
*
* @param _changed Configuration changed callback.
* @param _write Configuration write callback.
* @param _match Configuration match callback.
*/
#define BT_GATT_CCC_INITIALIZER(_changed, _write, _match) \
{ \
.cfg = {}, \
.cfg_changed = _changed, \
.cfg_write = _write, \
.cfg_match = _match, \
}
/** @def BT_GATT_CCC_MANAGED
* @brief Managed Client Characteristic Configuration Declaration Macro.
*
* Helper macro to declare a Managed CCC attribute.
*
* @param _ccc CCC attribute user data, shall point to a _bt_gatt_ccc.
* @param _perm CCC access permissions.
*/
#define BT_GATT_CCC_MANAGED(_ccc, _perm) \
BT_GATT_ATTRIBUTE(BT_UUID_GATT_CCC, _perm, \
bt_gatt_attr_read_ccc, bt_gatt_attr_write_ccc, \
_ccc)
/** @def BT_GATT_CCC
* @brief Client Characteristic Configuration Declaration Macro.
*
* Helper macro to declare a CCC attribute.
*
* @param _changed Configuration changed callback.
* @param _perm CCC access permissions.
*/
#define BT_GATT_CCC(_changed, _perm) \
BT_GATT_CCC_MANAGED(((struct _bt_gatt_ccc[]) \
{BT_GATT_CCC_INITIALIZER(_changed, NULL, NULL)}), _perm)
/** @brief Read Characteristic Extended Properties Attribute helper
*
* Read CEP attribute value from local database storing the result into buffer
* after encoding it.
*
* @note Only use this with attributes which user_data is a bt_gatt_cep.
*
* @param conn Connection object
* @param attr Attribute to read
* @param buf Buffer to store the value read
* @param len Buffer length
* @param offset Start offset
*
* @return number of bytes read in case of success or negative values in
* case of error.
*/
ssize_t bt_gatt_attr_read_cep(struct bt_conn *conn,
const struct bt_gatt_attr *attr, void *buf,
uint16_t len, uint16_t offset);
/** @def BT_GATT_CEP
* @brief Characteristic Extended Properties Declaration Macro.
*
* Helper macro to declare a CEP attribute.
*
* @param _value Descriptor attribute value.
*/
#define BT_GATT_CEP(_value) \
BT_GATT_DESCRIPTOR(BT_UUID_GATT_CEP, BT_GATT_PERM_READ, \
bt_gatt_attr_read_cep, NULL, (void *)_value)
/** @brief Read Characteristic User Description Descriptor Attribute helper
*
* Read CUD attribute value from local database storing the result into buffer
* after encoding it.
*
* @note Only use this with attributes which user_data is a NULL-terminated C
* string.
*
* @param conn Connection object
* @param attr Attribute to read
* @param buf Buffer to store the value read
* @param len Buffer length
* @param offset Start offset
*
* @return number of bytes read in case of success or negative values in
* case of error.
*/
ssize_t bt_gatt_attr_read_cud(struct bt_conn *conn,
const struct bt_gatt_attr *attr, void *buf,
uint16_t len, uint16_t offset);
/** @def BT_GATT_CUD
* @brief Characteristic User Format Descriptor Declaration Macro.
*
* Helper macro to declare a CUD attribute.
*
* @param _value User description NULL-terminated C string.
* @param _perm Descriptor attribute access permissions.
*/
#define BT_GATT_CUD(_value, _perm) \
BT_GATT_DESCRIPTOR(BT_UUID_GATT_CUD, _perm, bt_gatt_attr_read_cud, \
NULL, (void *)_value)
/** @brief Read Characteristic Presentation format Descriptor Attribute helper
*
* Read CPF attribute value from local database storing the result into buffer
* after encoding it.
*
* @note Only use this with attributes which user_data is a bt_gatt_pf.
*
* @param conn Connection object
* @param attr Attribute to read
* @param buf Buffer to store the value read
* @param len Buffer length
* @param offset Start offset
*
* @return number of bytes read in case of success or negative values in
* case of error.
*/
ssize_t bt_gatt_attr_read_cpf(struct bt_conn *conn,
const struct bt_gatt_attr *attr, void *buf,
uint16_t len, uint16_t offset);
/** @def BT_GATT_CPF
* @brief Characteristic Presentation Format Descriptor Declaration Macro.
*
* Helper macro to declare a CPF attribute.
*
* @param _value Descriptor attribute value.
*/
#define BT_GATT_CPF(_value) \
BT_GATT_DESCRIPTOR(BT_UUID_GATT_CPF, BT_GATT_PERM_READ, \
bt_gatt_attr_read_cpf, NULL, (void *)_value)
/** @def BT_GATT_DESCRIPTOR
* @brief Descriptor Declaration Macro.
*
* Helper macro to declare a descriptor attribute.
*
* @param _uuid Descriptor attribute uuid.
* @param _perm Descriptor attribute access permissions.
* @param _read Descriptor attribute read callback.
* @param _write Descriptor attribute write callback.
* @param _value Descriptor attribute value.
*/
#define BT_GATT_DESCRIPTOR(_uuid, _perm, _read, _write, _value) \
BT_GATT_ATTRIBUTE(_uuid, _perm, _read, _write, _value)
/** @def BT_GATT_ATTRIBUTE
* @brief Attribute Declaration Macro.
*
* Helper macro to declare an attribute.
*
* @param _uuid Attribute uuid.
* @param _perm Attribute access permissions.
* @param _read Attribute read callback.
* @param _write Attribute write callback.
* @param _value Attribute value.
*/
#define BT_GATT_ATTRIBUTE(_uuid, _perm, _read, _write, _value) \
{ \
.uuid = _uuid, \
.read = _read, \
.write = _write, \
.user_data = _value, \
.handle = 0, \
.perm = _perm, \
}
/** @brief Notification complete result callback.
*
* @param conn Connection object.
*/
typedef void (*bt_gatt_complete_func_t) (struct bt_conn *conn, void *user_data);
struct bt_gatt_notify_params {
/** Notification Attribute UUID type */
const struct bt_uuid *uuid;
/** Notification Attribute object*/
const struct bt_gatt_attr *attr;
/** Notification Value data */
const void *data;
/** Notification Value length */
uint16_t len;
/** Notification Value callback */
bt_gatt_complete_func_t func;
/** Notification Value callback user data */
void *user_data;
};
/** @brief Notify attribute value change.
*
* This function works in the same way as @ref bt_gatt_notify.
* With the addition that after sending the notification the
* callback function will be called.
*
* The callback is run from System Workqueue context.
*
* Alternatively it is possible to notify by UUID by setting it on the
* parameters, when using this method the attribute given is used as the
* start range when looking up for possible matches.
*
* @param conn Connection object.
* @param params Notification parameters.
*
* @return 0 in case of success or negative value in case of error.
*/
int bt_gatt_notify_cb(struct bt_conn *conn,
struct bt_gatt_notify_params *params);
/** @brief Notify multiple attribute value change.
*
* @param conn Connection object.
* @param num_params Number of notification parameters.
* @param params Array of notification parameters.
*
* @return 0 in case of success or negative value in case of error.
*/
int bt_gatt_notify_multiple(struct bt_conn *conn, uint16_t num_params,
struct bt_gatt_notify_params *params);
/** @brief Notify attribute value change.
*
* Send notification of attribute value change, if connection is NULL notify
* all peer that have notification enabled via CCC otherwise do a direct
* notification only the given connection.
*
* The attribute object on the parameters can be the so called Characteristic
* Declaration, which is usually declared with BT_GATT_CHARACTERISTIC followed
* by BT_GATT_CCC, or the Characteristic Value Declaration which is
* automatically created after the Characteristic Declaration when using
* BT_GATT_CHARACTERISTIC.
*
* @param conn Connection object.
* @param attr Characteristic or Characteristic Value attribute.
* @param data Pointer to Attribute data.
* @param len Attribute value length.
*
* @return 0 in case of success or negative value in case of error.
*/
static inline int bt_gatt_notify(struct bt_conn *conn,
const struct bt_gatt_attr *attr,
const void *data, uint16_t len)
{
struct bt_gatt_notify_params params;
memset(&params, 0, sizeof(params));
params.attr = attr;
params.data = data;
params.len = len;
return bt_gatt_notify_cb(conn, &params);
}
/** @brief Notify attribute value change by UUID.
*
* Send notification of attribute value change, if connection is NULL notify
* all peer that have notification enabled via CCC otherwise do a direct
* notification only on the given connection.
*
* The attribute object is the starting point for the search of the UUID.
*
* @param conn Connection object.
* @param uuid The UUID. If the server contains multiple services with the same
* UUID, then the first occurrence, starting from the attr given,
* is used.
* @param attr Pointer to an attribute that serves as the starting point for
* the search of a match for the UUID.
* @param data Pointer to Attribute data.
* @param len Attribute value length.
*
* @return 0 in case of success or negative value in case of error.
*/
static inline int bt_gatt_notify_uuid(struct bt_conn *conn,
const struct bt_uuid *uuid,
const struct bt_gatt_attr *attr,
const void *data, uint16_t len)
{
struct bt_gatt_notify_params params;
memset(&params, 0, sizeof(params));
params.uuid = uuid;
params.attr = attr;
params.data = data;
params.len = len;
return bt_gatt_notify_cb(conn, &params);
}
/* Forward declaration of the bt_gatt_indicate_params structure */
struct bt_gatt_indicate_params;
/** @typedef bt_gatt_indicate_func_t
* @brief Indication complete result callback.
*
* @param conn Connection object.
* @param params Indication params object.
* @param err ATT error code
*/
typedef void (*bt_gatt_indicate_func_t)(struct bt_conn *conn,
struct bt_gatt_indicate_params *params,
uint8_t err);
typedef void (*bt_gatt_indicate_params_destroy_t)(
struct bt_gatt_indicate_params *params);
/** @brief GATT Indicate Value parameters */
struct bt_gatt_indicate_params {
/** Notification Attribute UUID type */
const struct bt_uuid *uuid;
/** Indicate Attribute object*/
const struct bt_gatt_attr *attr;
/** Indicate Value callback */
bt_gatt_indicate_func_t func;
/** Indicate operation complete callback */
bt_gatt_indicate_params_destroy_t destroy;
/** Indicate Value data*/
const void *data;
/** Indicate Value length*/
uint16_t len;
/** Private reference counter */
uint8_t _ref;
};
/** @brief Indicate attribute value change.
*
* Send an indication of attribute value change. if connection is NULL
* indicate all peer that have notification enabled via CCC otherwise do a
* direct indication only the given connection.
*
* The attribute object on the parameters can be the so called Characteristic
* Declaration, which is usually declared with BT_GATT_CHARACTERISTIC followed
* by BT_GATT_CCC, or the Characteristic Value Declaration which is
* automatically created after the Characteristic Declaration when using
* BT_GATT_CHARACTERISTIC.
*
* The callback is run from System Workqueue context.
*
* Alternatively it is possible to indicate by UUID by setting it on the
* parameters, when using this method the attribute given is used as the
* start range when looking up for possible matches.
*
* @note This procedure is asynchronous therefore the parameters need to
* remains valid while it is active. The procedure is active until
* the destroy callback is run.
*
* @param conn Connection object.
* @param params Indicate parameters.
*
* @return 0 in case of success or negative value in case of error.
*/
int bt_gatt_indicate(struct bt_conn *conn,
struct bt_gatt_indicate_params *params);
/** @brief Check if connection have subscribed to attribute
*
* Check if connection has subscribed to attribute value change.
*
* The attribute object can be the so called Characteristic Declaration,
* which is usually declared with BT_GATT_CHARACTERISTIC followed
* by BT_GATT_CCC, or the Characteristic Value Declaration which is
* automatically created after the Characteristic Declaration when using
* BT_GATT_CHARACTERISTIC, or the Client Characteristic Configuration
* Descriptor (CCCD) which is created by BT_GATT_CCC.
*
* @param conn Connection object.
* @param attr Attribute object.
* @param ccc_value The subscription type, either notifications or indications.
*
* @return true if the attribute object has been subscribed.
*/
bool bt_gatt_is_subscribed(struct bt_conn *conn,
const struct bt_gatt_attr *attr, uint16_t ccc_value);
/** @brief Get ATT MTU for a connection
*
* Get negotiated ATT connection MTU, note that this does not equal the largest
* amount of attribute data that can be transferred within a single packet.
*
* @param conn Connection object.
*
* @return MTU in bytes
*/
uint16_t bt_gatt_get_mtu(struct bt_conn *conn);
/** @} */
/**
* @defgroup bt_gatt_client GATT Client APIs
* @ingroup bt_gatt
* @{
*/
/** @brief GATT Exchange MTU parameters */
struct bt_gatt_exchange_params {
/** Response callback */
void (*func)(struct bt_conn *conn, uint8_t err,
struct bt_gatt_exchange_params *params);
};
/** @brief Exchange MTU
*
* This client procedure can be used to set the MTU to the maximum possible
* size the buffers can hold.
*
* @note Shall only be used once per connection.
*
* @param conn Connection object.
* @param params Exchange MTU parameters.
*
* @return 0 in case of success or negative value in case of error.
*/
int bt_gatt_exchange_mtu(struct bt_conn *conn,
struct bt_gatt_exchange_params *params);
struct bt_gatt_discover_params;
/** @typedef bt_gatt_discover_func_t
* @brief Discover attribute callback function.
*
* @param conn Connection object.
* @param attr Attribute found, or NULL if not found.
* @param params Discovery parameters given.
*
* If discovery procedure has completed this callback will be called with
* attr set to NULL. This will not happen if procedure was stopped by returning
* BT_GATT_ITER_STOP.
*
* The attribute object as well as its UUID and value objects are temporary and
* must be copied to in order to cache its information.
* Only the following fields of the attribute contains valid information:
* - uuid UUID representing the type of attribute.
* - handle Handle in the remote database.
* - user_data The value of the attribute.
* Will be NULL when discovering descriptors
*
* To be able to read the value of the discovered attribute the user_data
* must be cast to an appropriate type.
* - @ref bt_gatt_service_val when UUID is @ref BT_UUID_GATT_PRIMARY or
* @ref BT_UUID_GATT_SECONDARY.
* - @ref bt_gatt_include when UUID is @ref BT_UUID_GATT_INCLUDE.
* - @ref bt_gatt_chrc when UUID is @ref BT_UUID_GATT_CHRC.
*
* @return BT_GATT_ITER_CONTINUE to continue discovery procedure.
* @return BT_GATT_ITER_STOP to stop discovery procedure.
*/
typedef uint8_t (*bt_gatt_discover_func_t)(struct bt_conn *conn,
const struct bt_gatt_attr *attr,
struct bt_gatt_discover_params *params);
/** GATT Discover types */
enum {
/** Discover Primary Services. */
BT_GATT_DISCOVER_PRIMARY,
/** Discover Secondary Services. */
BT_GATT_DISCOVER_SECONDARY,
/** Discover Included Services. */
BT_GATT_DISCOVER_INCLUDE,
/** @brief Discover Characteristic Values.
*
* Discover Characteristic Value and its properties.
*/
BT_GATT_DISCOVER_CHARACTERISTIC,
/** @brief Discover Descriptors.
*
* Discover Attributes which are not services or characteristics.
*
* @note The use of this type of discover is not recommended for
* discovering in ranges across multiple services/characteristics
* as it may incur in extra round trips.
*/
BT_GATT_DISCOVER_DESCRIPTOR,
/** @brief Discover Attributes.
*
* Discover Attributes of any type.
*
* @note The use of this type of discover is not recommended for
* discovering in ranges across multiple services/characteristics
* as it may incur in more round trips.
*/
BT_GATT_DISCOVER_ATTRIBUTE,
};
/** @brief GATT Discover Attributes parameters */
struct bt_gatt_discover_params {
/** Discover UUID type */
const struct bt_uuid *uuid;
/** Discover attribute callback */
bt_gatt_discover_func_t func;
union {
struct {
/** Include service attribute declaration handle */
uint16_t attr_handle;
/** Included service start handle */
uint16_t start_handle;
/** Included service end handle */
uint16_t end_handle;
} _included;
/** Discover start handle */
uint16_t start_handle;
};
/** Discover end handle */
uint16_t end_handle;
/** Discover type */
uint8_t type;
#if defined(CONFIG_BT_GATT_AUTO_DISCOVER_CCC)
/** Only for stack-internal use, used for automatic discovery. */
struct bt_gatt_subscribe_params *sub_params;
#endif /* defined(CONFIG_BT_GATT_AUTO_DISCOVER_CCC) */
};
/** @brief GATT Discover function
*
* This procedure is used by a client to discover attributes on a server.
*
* Primary Service Discovery: Procedure allows to discover specific Primary
* Service based on UUID.
* Include Service Discovery: Procedure allows to discover all Include Services
* within specified range.
* Characteristic Discovery: Procedure allows to discover all characteristics
* within specified handle range as well as
* discover characteristics with specified UUID.
* Descriptors Discovery: Procedure allows to discover all characteristic
* descriptors within specified range.
*
* For each attribute found the callback is called which can then decide
* whether to continue discovering or stop.
*
* @note This procedure is asynchronous therefore the parameters need to
* remains valid while it is active.
*
* @param conn Connection object.
* @param params Discover parameters.
*
* @return 0 in case of success or negative value in case of error.
*/
int bt_gatt_discover(struct bt_conn *conn,
struct bt_gatt_discover_params *params);
struct bt_gatt_read_params;
/** @typedef bt_gatt_read_func_t
* @brief Read callback function
*
* @param conn Connection object.
* @param err ATT error code.
* @param params Read parameters used.
* @param data Attribute value data. NULL means read has completed.
* @param length Attribute value length.
*
* @return BT_GATT_ITER_CONTINUE if should continue to the next attribute.
* @return BT_GATT_ITER_STOP to stop.
*/
typedef uint8_t (*bt_gatt_read_func_t)(struct bt_conn *conn, uint8_t err,
struct bt_gatt_read_params *params,
const void *data, uint16_t length);
/** @brief GATT Read parameters */
struct bt_gatt_read_params {
/** Read attribute callback. */
bt_gatt_read_func_t func;
/** If equals to 1 single.handle and single.offset are used.
* If >1 Read Multiple Characteristic Values is performed and handles
* are used.
* If equals to 0 by_uuid is used for Read Using Characteristic UUID.
*/
size_t handle_count;
union {
struct {
/** Attribute handle. */
uint16_t handle;
/** Attribute data offset. */
uint16_t offset;
} single;
/** Handles to read in Read Multiple Characteristic Values. */
uint16_t *handles;
struct {
/** First requested handle number. */
uint16_t start_handle;
/** Last requested handle number. */
uint16_t end_handle;
/** 2 or 16 octet UUID. */
const struct bt_uuid *uuid;
} by_uuid;
};
};
/** @brief Read Attribute Value by handle
*
* This procedure read the attribute value and return it to the callback.
*
* When reading attributes by UUID the callback can be called multiple times
* depending on how many instances of given the UUID exists with the
* start_handle being updated for each instance.
*
* If an instance does contain a long value which cannot be read entirely the
* caller will need to read the remaining data separately using the handle and
* offset.
*
* @note This procedure is asynchronous therefore the parameters need to
* remains valid while it is active.
*
* @param conn Connection object.
* @param params Read parameters.
*
* @return 0 in case of success or negative value in case of error.
*/
int bt_gatt_read(struct bt_conn *conn, struct bt_gatt_read_params *params);
struct bt_gatt_write_params;
/** @typedef bt_gatt_write_func_t
* @brief Write callback function
*
* @param conn Connection object.
* @param err ATT error code.
* @param params Write parameters used.
*/
typedef void (*bt_gatt_write_func_t)(struct bt_conn *conn, uint8_t err,
struct bt_gatt_write_params *params);
/** @brief GATT Write parameters */
struct bt_gatt_write_params {
/** Response callback */
bt_gatt_write_func_t func;
/** Attribute handle */
uint16_t handle;
/** Attribute data offset */
uint16_t offset;
/** Data to be written */
const void *data;
/** Length of the data */
uint16_t length;
};
/** @brief Write Attribute Value by handle
*
* This procedure write the attribute value and return the result in the
* callback.
*
* @note This procedure is asynchronous therefore the parameters need to
* remains valid while it is active.
*
* @param conn Connection object.
* @param params Write parameters.
*
* @return 0 in case of success or negative value in case of error.
*/
int bt_gatt_write(struct bt_conn *conn, struct bt_gatt_write_params *params);
/** @brief Write Attribute Value by handle without response with callback.
*
* This function works in the same way as @ref bt_gatt_write_without_response.
* With the addition that after sending the write the callback function will be
* called.
*
* The callback is run from System Workqueue context.
*
* @note By using a callback it also disable the internal flow control
* which would prevent sending multiple commands without waiting for
* their transmissions to complete, so if that is required the caller
* shall not submit more data until the callback is called.
*
* @param conn Connection object.
* @param handle Attribute handle.
* @param data Data to be written.
* @param length Data length.
* @param sign Whether to sign data
* @param func Transmission complete callback.
* @param user_data User data to be passed back to callback.
*
* @return 0 in case of success or negative value in case of error.
*/
int bt_gatt_write_without_response_cb(struct bt_conn *conn, uint16_t handle,
const void *data, uint16_t length,
bool sign, bt_gatt_complete_func_t func,
void *user_data);
/** @brief Write Attribute Value by handle without response
*
* This procedure write the attribute value without requiring an
* acknowledgment that the write was successfully performed
*
* @param conn Connection object.
* @param handle Attribute handle.
* @param data Data to be written.
* @param length Data length.
* @param sign Whether to sign data
*
* @return 0 in case of success or negative value in case of error.
*/
static inline int bt_gatt_write_without_response(struct bt_conn *conn,
uint16_t handle, const void *data,
uint16_t length, bool sign)
{
return bt_gatt_write_without_response_cb(conn, handle, data, length,
sign, NULL, NULL);
}
struct bt_gatt_subscribe_params;
/** @typedef bt_gatt_notify_func_t
* @brief Notification callback function
*
* @param conn Connection object. May be NULL, indicating that the peer is
* being unpaired
* @param params Subscription parameters.
* @param data Attribute value data. If NULL then subscription was removed.
* @param length Attribute value length.
*
* @return BT_GATT_ITER_CONTINUE to continue receiving value notifications.
* BT_GATT_ITER_STOP to unsubscribe from value notifications.
*/
typedef uint8_t (*bt_gatt_notify_func_t)(struct bt_conn *conn,
struct bt_gatt_subscribe_params *params,
const void *data, uint16_t length);
/** Subscription flags */
enum {
/** @brief Persistence flag
*
* If set, indicates that the subscription is not saved
* on the GATT server side. Therefore, upon disconnection,
* the subscription will be automatically removed
* from the client's subscriptions list and
* when the client reconnects, it will have to
* issue a new subscription.
*/
BT_GATT_SUBSCRIBE_FLAG_VOLATILE,
/** @brief No resubscribe flag
*
* By default when BT_GATT_SUBSCRIBE_FLAG_VOLATILE is unset, the
* subscription will be automatically renewed when the client
* reconnects, as a workaround for GATT servers that do not persist
* subscriptions.
*
* This flag will disable the automatic resubscription. It is useful
* if the application layer knows that the GATT server remembers
* subscriptions from previous connections and wants to avoid renewing
* the subscriptions.
*/
BT_GATT_SUBSCRIBE_FLAG_NO_RESUB,
/** @brief Write pending flag
*
* If set, indicates write operation is pending waiting remote end to
* respond.
*/
BT_GATT_SUBSCRIBE_FLAG_WRITE_PENDING,
BT_GATT_SUBSCRIBE_NUM_FLAGS
};
/** @brief GATT Subscribe parameters */
struct bt_gatt_subscribe_params {
/** Notification value callback */
bt_gatt_notify_func_t notify;
/** Subscribe CCC write request response callback */
bt_gatt_write_func_t write;
/** Subscribe value handle */
uint16_t value_handle;
/** Subscribe CCC handle */
uint16_t ccc_handle;
#if defined(CONFIG_BT_GATT_AUTO_DISCOVER_CCC)
/** Subscribe End handle (for automatic discovery) */
uint16_t end_handle;
/** Discover parameters used when ccc_handle = 0 */
struct bt_gatt_discover_params *disc_params;
#endif /* CONFIG_BT_GATT_AUTO_DISCOVER_CCC */
/** Subscribe value */
uint16_t value;
/** Subscription flags */
ATOMIC_DEFINE(flags, BT_GATT_SUBSCRIBE_NUM_FLAGS);
sys_snode_t node;
};
/** @brief Subscribe Attribute Value Notification
*
* This procedure subscribe to value notification using the Client
* Characteristic Configuration handle.
* If notification received subscribe value callback is called to return
* notified value. One may then decide whether to unsubscribe directly from
* this callback. Notification callback with NULL data will not be called if
* subscription was removed by this method.
*
* @note Notifications are asynchronous therefore the parameters need to
* remain valid while subscribed.
*
* @param conn Connection object.
* @param params Subscribe parameters.
*
* @return 0 in case of success or negative value in case of error.
*/
int bt_gatt_subscribe(struct bt_conn *conn,
struct bt_gatt_subscribe_params *params);
/** @brief Resubscribe Attribute Value Notification subscription
*
* Resubscribe to Attribute Value Notification when already subscribed from a
* previous connection. The GATT server will remember subscription from
* previous connections when bonded, so resubscribing can be done without
* performing a new subscribe procedure after a power cycle.
*
* @note Notifications are asynchronous therefore the parameters need to
* remain valid while subscribed.
*
* @param id Local identity (in most cases BT_ID_DEFAULT).
* @param peer Remote address.
* @param params Subscribe parameters.
*
* @return 0 in case of success or negative value in case of error.
*/
int bt_gatt_resubscribe(uint8_t id, const bt_addr_le_t *peer,
struct bt_gatt_subscribe_params *params);
/** @brief Unsubscribe Attribute Value Notification
*
* This procedure unsubscribe to value notification using the Client
* Characteristic Configuration handle. Notification callback with NULL data
* will be called if subscription was removed by this call, until then the
* parameters cannot be reused.
*
* @param conn Connection object.
* @param params Subscribe parameters.
*
* @return 0 in case of success or negative value in case of error.
*/
int bt_gatt_unsubscribe(struct bt_conn *conn,
struct bt_gatt_subscribe_params *params);
/** @brief Cancel GATT pending request
*
* @param conn Connection object.
* @param params Requested params address.
*/
void bt_gatt_cancel(struct bt_conn *conn, void *params);
/** @} */
#ifdef __cplusplus
}
#endif
/**
* @}
*/
#endif /* ZEPHYR_INCLUDE_BLUETOOTH_GATT_H_ */