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mbed-os/features/FEATURE_BLE/ble/UUID.h

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/* mbed Microcontroller Library
* Copyright (c) 2006-2013 ARM Limited
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef MBED_UUID_H__
#define MBED_UUID_H__
#include <stddef.h>
#include <stdint.h>
#include <string.h>
#include <algorithm>
#include "blecommon.h"
/**
* @file
* @addtogroup ble
* @{
* @addtogroup common
* @{
*/
/**
* Convert a character containing an hexadecimal digit into an unsigned integer.
*
* @param[in] c Hexadecimal digit in a character representation.
*
* @return The corresponding value as unsigned integer.
*/
static uint8_t char2int(char c)
{
if ((c >= '0') && (c <= '9')) {
return c - '0';
} else if ((c >= 'a') && (c <= 'f')) {
return c - 'a' + 10;
} else if ((c >= 'A') && (c <= 'F')) {
return c - 'A' + 10;
} else {
return 0;
}
}
/**
* Representation of a Universally Unique Identifier (UUID).
*
* UUIDs are 128-bit wide numbers used to identify data type and elements in
* many layers of the Bluetooth specification.
*
* Two representations of UUIDS exist:
* - 16-bit UUIDs: Shortened representation of the 128 bit UUID
* 0000xxxx-0000-1000-8000-00805F9B34FB where xxxx is the 16 bit UUID.
* Values of those UUIDs are defined by the Bluetooth body. The short
* representation saves bandwidth during protocol transactions.
* - 128-bit UUIDs: Complete representation of a UUID. They are commonly
* used for user defined UUID.
*
* This class acts as an adapter over these two kinds of UUIDs to allow
* indiscriminate use of both forms in Mbed BLE APIs.
*
* @note 32-bit UUID representation is not supported currently.
*/
class UUID {
public:
/**
* Enumeration of the types of UUIDs.
*/
enum UUID_Type_t {
/**
* 16-bit wide UUID representation.
*/
UUID_TYPE_SHORT = 0,
/**
* 128-bit wide UUID representation.
*/
UUID_TYPE_LONG = 1
};
/**
* Enumeration of byte ordering.
*
* It is used to construct 128-byte UUIDs.
*/
typedef enum {
/**
* Most significant byte first (at the smallest address).
*/
MSB,
/**
* Least significant byte first (at the smallest address).
*/
LSB
} ByteOrder_t;
/**
* Type for a 16-bit UUID.
*/
typedef uint16_t ShortUUIDBytes_t;
/**
* Length in bytes of a long UUID.
*/
static const unsigned LENGTH_OF_LONG_UUID = 16;
/**
* Type for a 128-bit UUID.
*/
typedef uint8_t LongUUIDBytes_t[LENGTH_OF_LONG_UUID];
/**
* Maximum length for the string representation of a UUID excluding the null
* terminator.
*
* The string is composed of two characters per byte plus four '-'
* characters.
*/
static const unsigned MAX_UUID_STRING_LENGTH = LENGTH_OF_LONG_UUID * 2 + 4;
public:
/**
* Construct a 128-bit UUID from a string.
*
* @param[in] stringUUID Human readable representation of the UUID following
* the format XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX.
*
* @note Upper and lower case are supported.
* @note Hyphens are optional. The string must include at most four hyphens.
*
* @note Internally, the UUID is stored in the little endian order as a
* 16-byte array.
*/
UUID(const char* stringUUID) :
type(UUID_TYPE_LONG),
baseUUID(),
shortUUID(0)
{
bool nibble = false;
uint8_t byte = 0;
size_t baseIndex = 0;
uint8_t tempUUID[LENGTH_OF_LONG_UUID];
/*
* Iterate through string; abort if NULL is encountered prematurely.
* Ignore up to four hyphens.
*/
for (size_t index = 0; (index < MAX_UUID_STRING_LENGTH) && (baseIndex < LENGTH_OF_LONG_UUID); index++) {
if (stringUUID[index] == '\0') {
/* Error abort */
break;
} else if (stringUUID[index] == '-') {
/* Ignore hyphen */
continue;
} else if (nibble) {
/* Got second nibble */
byte |= char2int(stringUUID[index]);
nibble = false;
/* Store copy */
tempUUID[baseIndex++] = byte;
} else {
/* Got first nibble */
byte = char2int(stringUUID[index]) << 4;
nibble = true;
}
}
/* Populate internal variables if string was successfully parsed */
if (baseIndex == LENGTH_OF_LONG_UUID) {
setupLong(tempUUID, UUID::MSB);
} else {
const uint8_t sig[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00,
0x80, 0x00, 0x00, 0x80, 0x5F, 0x9B, 0x34, 0xFB };
setupLong(sig, UUID::MSB);
}
}
/**
* Construct a new UUID from a 128-bit representation.
*
* @param[in] longUUID The 128-bit (16-byte) of the UUID value.
* @param[in] order Bytes order of @p longUUID.
*/
UUID(const LongUUIDBytes_t longUUID, ByteOrder_t order = UUID::MSB) : type(UUID_TYPE_LONG), baseUUID(), shortUUID(0) {
setupLong(longUUID, order);
}
/**
* Creates a new 16-bit UUID.
*
* The Bluetooth standard body defines 16-bit wide UUIDs. They are the
* shortened version of the UUID 0000xxxx-0000-1000-8000-00805F9B34FB, where
* xxxx is the value of the 16-bit UUID.
*
* @attention 16-bit UUIDs are not used in user defined data type or
* user defined element ID.
*
* @param[in] _shortUUID 16-bit part of the standard UUID.
* The short UUID value.
*
* @note User defined UUIDs are commonly named vendor-specific UUIDs across
* the Bluetooth literature.
*/
UUID(ShortUUIDBytes_t _shortUUID) :
type(UUID_TYPE_SHORT),
baseUUID(),
shortUUID(_shortUUID) {
}
/**
* UUID copy constructor.
*
* @param[in] source The UUID to copy.
*/
UUID(const UUID &source)
{
type = source.type;
shortUUID = source.shortUUID;
memcpy(baseUUID, source.baseUUID, LENGTH_OF_LONG_UUID);
}
/**
* Default constructor.
*
* Construct an invalid UUID.
*
* @post shortOrLong() returns the value UUID_TYPE_SHORT.
* @post getShortUUID() returns the value BLE_UUID_UNKNOWN.
*/
UUID(void) :
type(UUID_TYPE_SHORT),
shortUUID(BLE_UUID_UNKNOWN) {
}
/**
* Replace existing value with a 128-bit UUID.
*
* @param[in] longUUID New 16-byte wide UUID value.
* @param[in] order Byte ordering of @p longUUID.
*/
void setupLong(const LongUUIDBytes_t longUUID, ByteOrder_t order = UUID::MSB)
{
type = UUID_TYPE_LONG;
if (order == UUID::MSB) {
/*
* Switch endian. Input is big-endian, internal representation
* is little endian.
*/
std::reverse_copy(longUUID, longUUID + LENGTH_OF_LONG_UUID, baseUUID);
} else {
std::copy(longUUID, longUUID + LENGTH_OF_LONG_UUID, baseUUID);
}
shortUUID = (uint16_t)((baseUUID[13] << 8) | (baseUUID[12]));
}
public:
/**
* Return the internal type of the UUID.
*
* @return UUID_TYPE_SHORT if the UUID is 16-bit wide.
* @return UUID_TYPE_LONG if the UUID is 128-bit wide.
*/
UUID_Type_t shortOrLong(void) const
{
return type;
}
/**
* Get a pointer to the UUID value based on the current UUID type.
*
* @return A pointer to an uint16_t object if the UUID is 16 bits long.
* @return A pointer to an array of 16 bytes if the UUID is 128 bits long.
*/
const uint8_t *getBaseUUID(void) const
{
if (type == UUID_TYPE_SHORT) {
return (const uint8_t*)&shortUUID;
} else {
return baseUUID;
}
}
/**
* Get the uint16_t value of the UUID.
*
* @attention This function is not used on long UUIDs.
*
* @return The value of the shortened UUID.
*/
ShortUUIDBytes_t getShortUUID(void) const
{
return shortUUID;
}
/**
* Get the length (in bytes) of the internal UUID representation.
*
* @return sizeof(ShortUUIDBytes_t) if the UUID type is UUID_TYPE_SHORT.
* @return LENGTH_OF_LONG_UUID if the UUID type is UUID_TYPE_LONG.
*/
uint8_t getLen(void) const
{
return ((type == UUID_TYPE_SHORT) ?
sizeof(ShortUUIDBytes_t) :
LENGTH_OF_LONG_UUID);
}
/**
* Equal to operator between UUIDs.
*
* @param[in] other The UUID to compare to this.
*
* @return true if both UUIDs are equal and false otherwise.
*/
bool operator== (const UUID &other) const
{
if ((this->type == UUID_TYPE_SHORT) && (other.type == UUID_TYPE_SHORT) &&
(this->shortUUID == other.shortUUID)) {
return true;
}
if ((this->type == UUID_TYPE_LONG) && (other.type == UUID_TYPE_LONG) &&
(memcmp(this->baseUUID, other.baseUUID, LENGTH_OF_LONG_UUID) == 0)) {
return true;
}
return false;
}
/**
* Not equal to operator.
*
* @param[in] other The UUID compared to this.
*
* @return true if both UUIDs are not equal and false otherwise.
*/
bool operator!= (const UUID &other) const
{
return !(*this == other);
}
private:
/**
* Representation type of the UUID.
*/
UUID_Type_t type;
/**
* Container of UUID value if the UUID type is equal to UUID_TYPE_LONG.
*/
LongUUIDBytes_t baseUUID;
/**
* Container of UUID value if the UUID type is equal to UUID_TYPE_SHORT.
*/
ShortUUIDBytes_t shortUUID;
};
/**
* @}
* @}
*/
#endif // ifndef MBED_UUID_H__
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