NAT64

This module includes functions and structs for the NAT64 function on the border router. These functions are only available when OPENTHREAD_CONFIG_BORDER_ROUTING_NAT64_ENABLE is enabled. More...

Collaboration diagram for NAT64:

Data Structures
struct	otIp4Address
struct	otIp4Cidr

Macros
#define	OT_IP4_ADDRESS_SIZE   4
	Size of an IPv4 address (bytes) More...

Typedefs
typedef struct otIp4Address	otIp4Address
typedef struct otIp4Cidr	otIp4Cidr
typedef void(*	otNat64ReceiveIp4Callback) (otMessage *aMessage, void *aContext)

Functions
void	otIp4ExtractFromIp6Address (uint8_t aPrefixLength, const otIp6Address *aIp6Address, otIp4Address *aIp4Address)
bool	otIp4IsAddressEqual (const otIp4Address *aFirst, const otIp4Address *aSecond)
otMessage *	otIp4NewMessage (otInstance *aInstance, const otMessageSettings *aSettings)
otError	otNat64Send (otInstance *aInstance, otMessage *aMessage)
otError	otNat64SetIp4Cidr (otInstance *aInstance, const otIp4Cidr *aCidr)
void	otNat64SetReceiveIp4Callback (otInstance *aInstance, otNat64ReceiveIp4Callback aCallback, void *aContext)

Variables
OT_TOOL_PACKED_BEGIN struct otIp4Address	OT_TOOL_PACKED_END

Detailed Description

This module includes functions and structs for the NAT64 function on the border router. These functions are only available when OPENTHREAD_CONFIG_BORDER_ROUTING_NAT64_ENABLE is enabled.

Macro Definition Documentation

OT_IP4_ADDRESS_SIZE

#define OT_IP4_ADDRESS_SIZE   4

Size of an IPv4 address (bytes)

Typedef Documentation

otIp4Address

typedef struct otIp4Address otIp4Address

This structure represents an IPv4 address.

otIp4Cidr

typedef struct otIp4Cidr otIp4Cidr

otNat64ReceiveIp4Callback

typedef void(* otNat64ReceiveIp4Callback) (otMessage *aMessage, void *aContext)

This function pointer is called when an IPv4 datagram (translated by NAT64 translator) is received.

Parameters

[in]	aMessage	A pointer to the message buffer containing the received IPv6 datagram. This function transfers the ownership of the aMessage to the receiver of the callback. The message should be freed by the receiver of the callback after it is processed.
[in]	aContext	A pointer to application-specific context.

Function Documentation

otIp4NewMessage()

otMessage* otIp4NewMessage	(	otInstance *	aInstance,
		const otMessageSettings *	aSettings
	)

Allocate a new message buffer for sending an IPv4 message to the NAT64 translator.

Message buffers allocated by this function will have 20 bytes (difference between the size of IPv6 headers and IPv4 header sizes) reserved.

This function is available only when OPENTHREAD_CONFIG_NAT64_TRANSLATOR_ENABLE is enabled.

Note

If aSettings is NULL, the link layer security is enabled and the message priority is set to OT_MESSAGE_PRIORITY_NORMAL by default.

Parameters

[in]	aInstance	A pointer to an OpenThread instance.
[in]	aSettings	A pointer to the message settings or NULL to set default settings.

Returns

A pointer to the message buffer or NULL if no message buffers are available or parameters are invalid.

See also

otNat64Send

Referenced by otSysGetThreadNetifIndex().

otNat64SetIp4Cidr()

otError otNat64SetIp4Cidr	(	otInstance *	aInstance,
		const otIp4Cidr *	aCidr
	)

Sets the CIDR used when setting the source address of the outgoing translated IPv4 packets.

This function is available only when OPENTHREAD_CONFIG_NAT64_TRANSLATOR_ENABLE is enabled.

Note

A valid CIDR must have a non-zero prefix length. The actual addresses pool is limited by the size of the mapping pool and the number of addresses available in the CIDR block.

This function can be called at any time, but the NAT64 translator will be reset and all existing sessions will be expired when updating the configured CIDR.

Parameters

[in]	aInstance	A pointer to an OpenThread instance.
[in]	aCidr	A pointer to an otIp4Cidr for the IPv4 CIDR block for NAT64.

Return values

OT_ERROR_INVALID_ARGS	The given CIDR is not a valid IPv4 CIDR for NAT64.
OT_ERROR_NONE	Successfully set the CIDR for NAT64.

See also

otBorderRouterSend

otBorderRouterSetReceiveCallback

Referenced by otSysGetThreadNetifIndex().

otNat64Send()

otError otNat64Send	(	otInstance *	aInstance,
		otMessage *	aMessage
	)

Translates an IPv4 datagram to an IPv6 datagram and sends via the Thread interface.

The caller transfers ownership of aMessage when making this call. OpenThread will free aMessage when processing is complete, including when a value other than OT_ERROR_NONE is returned.

Parameters

[in]	aInstance	A pointer to an OpenThread instance.
[in]	aMessage	A pointer to the message buffer containing the IPv4 datagram.

Return values

OT_ERROR_NONE	Successfully processed the message.
OT_ERROR_DROP	Message was well-formed but not fully processed due to packet processing rules.
OT_ERROR_NO_BUFS	Could not allocate necessary message buffers when processing the datagram.
OT_ERROR_NO_ROUTE	No route to host.
OT_ERROR_INVALID_SOURCE_ADDRESS	Source address is invalid, e.g. an anycast address or a multicast address.
OT_ERROR_PARSE	Encountered a malformed header when processing the message.

Referenced by otSysGetThreadNetifIndex().

otNat64SetReceiveIp4Callback()

void otNat64SetReceiveIp4Callback	(	otInstance *	aInstance,
		otNat64ReceiveIp4Callback	aCallback,
		void *	aContext
	)

Registers a callback to provide received IPv4 datagrams.

Parameters

[in]	aInstance	A pointer to an OpenThread instance.
[in]	aCallback	A pointer to a function that is called when an IPv4 datagram is received or NULL to disable the callback.
[in]	aCallbackContext	A pointer to application-specific context.

Referenced by otSysGetThreadNetifIndex().

otIp4IsAddressEqual()

bool otIp4IsAddressEqual	(	const otIp4Address *	aFirst,
		const otIp4Address *	aSecond
	)

Test if two IPv4 addresses are the same.

Parameters

[in]	aFirst	A pointer to the first IPv4 address to compare.
[in]	aSecond	A pointer to the second IPv4 address to compare.

Return values

TRUE	The two IPv4 addresses are the same.
FALSE	The two IPv4 addresses are not the same.

References ot::AsCoreType().

otIp4ExtractFromIp6Address()

void otIp4ExtractFromIp6Address	(	uint8_t	aPrefixLength,
		const otIp6Address *	aIp6Address,
		otIp4Address *	aIp4Address
	)

Set aIp4Address by performing NAT64 address translation from aIp6Address as specified in RFC 6052.

The NAT64 aPrefixLength MUST be one of the following values: 32, 40, 48, 56, 64, or 96, otherwise the behavior of this method is undefined.

Parameters

[in]	aPrefixLength	The prefix length to use for IPv4/IPv6 translation.
[in]	aIp6Address	A pointer to an IPv6 address.
[out]	aIp4Address	A pointer to output the IPv4 address.

References ot::AsCoreType().

Variable Documentation

OT_TOOL_PACKED_END

OT_TOOL_PACKED_BEGIN struct otIp4Address OT_TOOL_PACKED_END