Border Routing Manager

This module includes definitions related to Border Routing Manager.

Summary

All the functions in this module require OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE to be enabled.

Border Routing Manager handles bi-directional routing between Thread network and adjacent infrastructure link (AIL).

It emits ICMRv6 ND Router Advertisement (RA) messages on AIL to advertise on-link and route prefixes. It also processes received RA messages from infrastructure and mirrors the discovered prefixes on the Thread Network Data to ensure devices on Thread mesh can reach AIL through the Border Router.

Routing Manager manages the Off-Mesh Routable (OMR) prefix on the Thread Network data which configures Thread devices with a suitable Off-Mesh Routable IPv6 address. It announces the reachability of this prefix on AIL by including it in the emitted RA messages as an IPv6 Route Information Option (RIO).

Routing Manager also monitors and adds on-link prefix on the infrastructure network. If a router on AIL is already providing RA messages containing an IPv6 Prefix Information Option (PIO) that enables IPv6 devices on the link to self-configure their own routable unicast IPv6 address, this address can be used by Thread devices to reach AIL. If Border Router finds no such RA message on AIL, it generates a ULA on-link prefix which it then advertises on AIL in the emitted RA messages.

Enumerations
otBorderRoutingDhcp6PdState{   OT_BORDER_ROUTING_DHCP6_PD_STATE_DISABLED,   OT_BORDER_ROUTING_DHCP6_PD_STATE_STOPPED,   OT_BORDER_ROUTING_DHCP6_PD_STATE_RUNNING }	enum This enumeration represents the state of DHCPv6 Prefix Delegation State.
otBorderRoutingState{   OT_BORDER_ROUTING_STATE_UNINITIALIZED,   OT_BORDER_ROUTING_STATE_DISABLED,   OT_BORDER_ROUTING_STATE_STOPPED,   OT_BORDER_ROUTING_STATE_RUNNING }	enum Represents the state of Border Routing Manager.

Typedefs
otBorderRoutingPrefixTableEntry	typedef struct otBorderRoutingPrefixTableEntry Represents an entry from the discovered prefix table.
otBorderRoutingPrefixTableIterator	typedef struct otBorderRoutingPrefixTableIterator Represents an iterator to iterate through the Border Router's discovered prefix table.

Functions
otBorderRoutingClearRouteInfoOptionPreference(otInstance *aInstance)	void Clears a previously set preference value for advertised Route Info Options.
otBorderRoutingClearRoutePreference(otInstance *aInstance)	void Clears a previously set preference value for published routes in Network Data.
otBorderRoutingDhcp6PdSetEnabled(otInstance *aInstance, bool aEnabled)	void Enables / Disables DHCPv6 Prefix Delegation.
otBorderRoutingGetFavoredNat64Prefix(otInstance *aInstance, otIp6Prefix *aPrefix, otRoutePreference *aPreference)	otError Gets the currently favored NAT64 prefix.
otBorderRoutingGetFavoredOmrPrefix(otInstance *aInstance, otIp6Prefix *aPrefix, otRoutePreference *aPreference)	otError Gets the currently favored Off-Mesh-Routable (OMR) Prefix.
otBorderRoutingGetFavoredOnLinkPrefix(otInstance *aInstance, otIp6Prefix *aPrefix)	otError Gets the currently favored On-Link Prefix.
otBorderRoutingGetNat64Prefix(otInstance *aInstance, otIp6Prefix *aPrefix)	otError Gets the local NAT64 Prefix of the Border Router.
otBorderRoutingGetNextPrefixTableEntry(otInstance *aInstance, otBorderRoutingPrefixTableIterator *aIterator, otBorderRoutingPrefixTableEntry *aEntry)	otError Iterates over the entries in the Border Router's discovered prefix table.
otBorderRoutingGetOmrPrefix(otInstance *aInstance, otIp6Prefix *aPrefix)	otError Gets the local Off-Mesh-Routable (OMR) Prefix, for example fdfc:1ff5:1512:5622::/64.
otBorderRoutingGetOnLinkPrefix(otInstance *aInstance, otIp6Prefix *aPrefix)	otError Gets the local On-Link Prefix for the adjacent infrastructure link.
otBorderRoutingGetPdOmrPrefix(otInstance *aInstance, otBorderRoutingPrefixTableEntry *aPrefixInfo)	otError Gets the DHCPv6 Prefix Delegation (PD) provided off-mesh-routable (OMR) prefix.
otBorderRoutingGetRouteInfoOptionPreference(otInstance *aInstance)	otRoutePreference Gets the current preference used when advertising Route Info Options (RIO) in Router Advertisement messages sent over the infrastructure link.
otBorderRoutingGetRoutePreference(otInstance *aInstance)	otRoutePreference Gets the current preference used for published routes in Network Data.
otBorderRoutingGetState(otInstance *aInstance)	otBorderRoutingState Gets the current state of Border Routing Manager.
otBorderRoutingInit(otInstance *aInstance, uint32_t aInfraIfIndex, bool aInfraIfIsRunning)	otError Initializes the Border Routing Manager on given infrastructure interface.
otBorderRoutingPrefixTableInitIterator(otInstance *aInstance, otBorderRoutingPrefixTableIterator *aIterator)	void Initializes an otBorderRoutingPrefixTableIterator.
otBorderRoutingSetEnabled(otInstance *aInstance, bool aEnabled)	otError Enables or disables the Border Routing Manager.
otBorderRoutingSetRouteInfoOptionPreference(otInstance *aInstance, otRoutePreference aPreference)	void Explicitly sets the preference to use when advertising Route Info Options (RIO) in Router Advertisement messages sent over the infrastructure link.
otBorderRoutingSetRoutePreference(otInstance *aInstance, otRoutePreference aPreference)	void Explicitly sets the preference of published routes in Network Data.

Structs
otBorderRoutingPrefixTableEntry	Represents an entry from the discovered prefix table.
otBorderRoutingPrefixTableIterator	Represents an iterator to iterate through the Border Router's discovered prefix table.

Enumerations

otBorderRoutingDhcp6PdState

 otBorderRoutingDhcp6PdState

This enumeration represents the state of DHCPv6 Prefix Delegation State.

Properties
OT_BORDER_ROUTING_DHCP6_PD_STATE_DISABLED	DHCPv6 PD is disabled on the border router.
OT_BORDER_ROUTING_DHCP6_PD_STATE_RUNNING	DHCPv6 PD is enabled and will try to request and publish a prefix.
OT_BORDER_ROUTING_DHCP6_PD_STATE_STOPPED	DHCPv6 PD in enabled but won't try to request and publish a prefix.

otBorderRoutingState

 otBorderRoutingState

Represents the state of Border Routing Manager.

Properties
OT_BORDER_ROUTING_STATE_DISABLED	Routing Manager is initialized but disabled.
OT_BORDER_ROUTING_STATE_RUNNING	Routing Manager is initialized, enabled, and running.
OT_BORDER_ROUTING_STATE_STOPPED	Routing Manager in initialized and enabled but currently stopped.
OT_BORDER_ROUTING_STATE_UNINITIALIZED	Routing Manager is uninitialized.

Typedefs

otBorderRoutingPrefixTableEntry

struct otBorderRoutingPrefixTableEntry otBorderRoutingPrefixTableEntry

Represents an entry from the discovered prefix table.

The entries in the discovered table track the Prefix/Route Info Options in the received Router Advertisement messages from other routers on infrastructure link.

otBorderRoutingPrefixTableIterator

struct otBorderRoutingPrefixTableIterator otBorderRoutingPrefixTableIterator

Represents an iterator to iterate through the Border Router's discovered prefix table.

The fields in this type are opaque (intended for use by OpenThread core only) and therefore should not be accessed or used by caller.

Before using an iterator, it MUST be initialized using otBorderRoutingPrefixTableInitIterator().

Functions

otBorderRoutingClearRouteInfoOptionPreference

void otBorderRoutingClearRouteInfoOptionPreference(
  otInstance *aInstance
)

Clears a previously set preference value for advertised Route Info Options.

After a call to this function, BR will use device's role to determine the RIO preference: Medium preference when in router/leader role and low preference when in child role.

Details
Parameters	[in] aInstance A pointer to an OpenThread instance.

otBorderRoutingClearRoutePreference

void otBorderRoutingClearRoutePreference(
  otInstance *aInstance
)

Clears a previously set preference value for published routes in Network Data.

After a call to this function, BR will determine the preference automatically based on the device's role and link quality (to the parent when acting as end-device).

Details
Parameters	[in] aInstance A pointer to an OpenThread instance.

otBorderRoutingDhcp6PdSetEnabled

void otBorderRoutingDhcp6PdSetEnabled(
  otInstance *aInstance,
  bool aEnabled
)

Enables / Disables DHCPv6 Prefix Delegation.

OPENTHREAD_CONFIG_BORDER_ROUTING_DHCP6_PD_ENABLE must be enabled.

Details
Parameters	[in] aInstance A pointer to an OpenThread instance. [in] aEnabled Whether to accept platform generated RA messages.

otBorderRoutingGetFavoredNat64Prefix

otError otBorderRoutingGetFavoredNat64Prefix(
  otInstance *aInstance,
  otIp6Prefix *aPrefix,
  otRoutePreference *aPreference
)

Gets the currently favored NAT64 prefix.

The favored NAT64 prefix can be discovered from infrastructure link or can be this device's local NAT64 prefix.

Details
Parameters	[in] aInstance A pointer to an OpenThread instance. [out] aPrefix A pointer to output the favored NAT64 prefix. [out] aPreference A pointer to output the preference associated the favored prefix.
Return Values	OT_ERROR_INVALID_STATE The Border Routing Manager is not initialized yet. OT_ERROR_NONE Successfully retrieved the favored NAT64 prefix.

otBorderRoutingGetFavoredOmrPrefix

otError otBorderRoutingGetFavoredOmrPrefix(
  otInstance *aInstance,
  otIp6Prefix *aPrefix,
  otRoutePreference *aPreference
)

Gets the currently favored Off-Mesh-Routable (OMR) Prefix.

The favored OMR prefix can be discovered from Network Data or can be this device's local OMR prefix.

Details
Parameters	[in] aInstance A pointer to an OpenThread instance. [out] aPrefix A pointer to output the favored OMR prefix. [out] aPreference A pointer to output the preference associated the favored prefix.
Return Values	OT_ERROR_INVALID_STATE The Border Routing Manager is not running yet. OT_ERROR_NONE Successfully retrieved the favored OMR prefix.

otBorderRoutingGetFavoredOnLinkPrefix

otError otBorderRoutingGetFavoredOnLinkPrefix(
  otInstance *aInstance,
  otIp6Prefix *aPrefix
)

Gets the currently favored On-Link Prefix.

The favored prefix is either a discovered on-link prefix on the infrastructure link or the local on-link prefix.

Details
Parameters	[in] aInstance A pointer to an OpenThread instance. [out] aPrefix A pointer to where the prefix will be output to.
Return Values	OT_ERROR_INVALID_STATE The Border Routing Manager is not initialized yet. OT_ERROR_NONE Successfully retrieved the favored on-link prefix.

otBorderRoutingGetNat64Prefix

otError otBorderRoutingGetNat64Prefix(
  otInstance *aInstance,
  otIp6Prefix *aPrefix
)

Gets the local NAT64 Prefix of the Border Router.

NAT64 Prefix might not be advertised in the Thread network.

OPENTHREAD_CONFIG_NAT64_BORDER_ROUTING_ENABLE must be enabled.

Details
Parameters	[in] aInstance A pointer to an OpenThread instance. [out] aPrefix A pointer to where the prefix will be output to.
Return Values	OT_ERROR_INVALID_STATE The Border Routing Manager is not initialized yet. OT_ERROR_NONE Successfully retrieved the NAT64 prefix.

otBorderRoutingGetNextPrefixTableEntry

otError otBorderRoutingGetNextPrefixTableEntry(
  otInstance *aInstance,
  otBorderRoutingPrefixTableIterator *aIterator,
  otBorderRoutingPrefixTableEntry *aEntry
)

Iterates over the entries in the Border Router's discovered prefix table.

Details
Parameters	[in] aInstance The OpenThread instance. [in,out] aIterator A pointer to the iterator. [out] aEntry A pointer to the entry to populate.
Return Values	OT_ERROR_NONE Iterated to the next entry, aEntry and aIterator are updated. OT_ERROR_NOT_FOUND No more entries in the table.

otBorderRoutingGetOmrPrefix

otError otBorderRoutingGetOmrPrefix(
  otInstance *aInstance,
  otIp6Prefix *aPrefix
)

Gets the local Off-Mesh-Routable (OMR) Prefix, for example fdfc:1ff5:1512:5622::/64.

An OMR Prefix is a randomly generated 64-bit prefix that's published in the Thread network if there isn't already an OMR prefix. This prefix can be reached from the local Wi-Fi or Ethernet network.

Note: When DHCPv6 PD is enabled, the border router may publish the prefix from DHCPv6 PD.

Details
Parameters	[in] aInstance A pointer to an OpenThread instance. [out] aPrefix A pointer to where the prefix will be output to.
Return Values	OT_ERROR_INVALID_STATE The Border Routing Manager is not initialized yet. OT_ERROR_NONE Successfully retrieved the OMR prefix.

See also:
otBorderRoutingGetPdOmrPrefix

otBorderRoutingGetOnLinkPrefix

otError otBorderRoutingGetOnLinkPrefix(
  otInstance *aInstance,
  otIp6Prefix *aPrefix
)

Gets the local On-Link Prefix for the adjacent infrastructure link.

The local On-Link Prefix is a 64-bit prefix that's advertised on the infrastructure link if there isn't already a usable on-link prefix being advertised on the link.

Details
Parameters	[in] aInstance A pointer to an OpenThread instance. [out] aPrefix A pointer to where the prefix will be output to.
Return Values	OT_ERROR_INVALID_STATE The Border Routing Manager is not initialized yet. OT_ERROR_NONE Successfully retrieved the local on-link prefix.

otBorderRoutingGetPdOmrPrefix

otError otBorderRoutingGetPdOmrPrefix(
  otInstance *aInstance,
  otBorderRoutingPrefixTableEntry *aPrefixInfo
)

Gets the DHCPv6 Prefix Delegation (PD) provided off-mesh-routable (OMR) prefix.

Only mPrefix, mValidLifetime and mPreferredLifetime fields are used in the returned prefix info.

OPENTHREAD_CONFIG_BORDER_ROUTING_DHCP6_PD_ENABLE must be enabled.

Details
Parameters	[in] aInstance A pointer to an OpenThread instance. [out] aPrefixInfo A pointer to where the prefix info will be output to.
Return Values	OT_ERROR_NONE Successfully retrieved the OMR prefix. OT_ERROR_INVALID_STATE The Border Routing Manager is not initialized yet. OT_ERROR_NOT_FOUND There are no valid PD prefix on this BR.

See also:
otBorderRoutingGetOmrPrefix
otPlatBorderRoutingProcessIcmp6Ra

otBorderRoutingGetRouteInfoOptionPreference

otRoutePreference otBorderRoutingGetRouteInfoOptionPreference(
  otInstance *aInstance
)

Gets the current preference used when advertising Route Info Options (RIO) in Router Advertisement messages sent over the infrastructure link.

The RIO preference is determined as follows:

• If explicitly set by user by calling otBorderRoutingSetRouteInfoOptionPreference(), the given preference is used.
• Otherwise, it is determined based on device's current role: Medium preference when in router/leader role and low preference when in child role.

Details
Returns	The current Route Info Option preference.

otBorderRoutingGetRoutePreference

otRoutePreference otBorderRoutingGetRoutePreference(
  otInstance *aInstance
)

Gets the current preference used for published routes in Network Data.

The preference is determined as follows:

• If explicitly set by user by calling otBorderRoutingSetRoutePreference(), the given preference is used.
• Otherwise, it is determined automatically by RoutingManager based on the device's role and link quality.

Details
Parameters	[in] aInstance A pointer to an OpenThread instance.
Returns	The current published route preference.

otBorderRoutingGetState

otBorderRoutingState otBorderRoutingGetState(
  otInstance *aInstance
)

Gets the current state of Border Routing Manager.

Details
Parameters	[in] aInstance A pointer to an OpenThread instance.
Returns	The current state of Border Routing Manager.

otBorderRoutingInit

otError otBorderRoutingInit(
  otInstance *aInstance,
  uint32_t aInfraIfIndex,
  bool aInfraIfIsRunning
)

Initializes the Border Routing Manager on given infrastructure interface.

Note: This method MUST be called before any other otBorderRouting* APIs.

Details
Parameters	[in] aInstance A pointer to an OpenThread instance. [in] aInfraIfIndex The infrastructure interface index. [in] aInfraIfIsRunning A boolean that indicates whether the infrastructure interface is running.
Return Values	OT_ERROR_NONE Successfully started the Border Routing Manager on given infrastructure. OT_ERROR_INVALID_STATE The Border Routing Manager has already been initialized. OT_ERROR_INVALID_ARGS The index of the infrastructure interface is not valid. OT_ERROR_FAILED Internal failure. Usually due to failure in generating random prefixes.

See also:
otPlatInfraIfStateChanged.

otBorderRoutingPrefixTableInitIterator

void otBorderRoutingPrefixTableInitIterator(
  otInstance *aInstance,
  otBorderRoutingPrefixTableIterator *aIterator
)

Initializes an otBorderRoutingPrefixTableIterator.

An iterator MUST be initialized before it is used.

An iterator can be initialized again to restart from the beginning of the table.

When iterating over entries in the table, to ensure the update times mMsecSinceLastUpdate of entries are consistent, they are given relative to the time the iterator was initialized.

Details
Parameters	[in] aInstance The OpenThread instance. [out] aIterator A pointer to the iterator to initialize.

otBorderRoutingSetEnabled

otError otBorderRoutingSetEnabled(
  otInstance *aInstance,
  bool aEnabled
)

Enables or disables the Border Routing Manager.

Note: The Border Routing Manager is disabled by default.

Details
Parameters	[in] aInstance A pointer to an OpenThread instance. [in] aEnabled A boolean to enable/disable the routing manager.
Return Values	OT_ERROR_INVALID_STATE The Border Routing Manager is not initialized yet. OT_ERROR_NONE Successfully enabled/disabled the Border Routing Manager.

otBorderRoutingSetRouteInfoOptionPreference

void otBorderRoutingSetRouteInfoOptionPreference(
  otInstance *aInstance,
  otRoutePreference aPreference
)

Explicitly sets the preference to use when advertising Route Info Options (RIO) in Router Advertisement messages sent over the infrastructure link.

After a call to this function, BR will use the given preference for all its advertised RIOs. The preference can be cleared by calling otBorderRoutingClearRouteInfoOptionPreference().

Details
Parameters	[in] aInstance A pointer to an OpenThread instance. [in] aPreference The route preference to use.

otBorderRoutingSetRoutePreference

void otBorderRoutingSetRoutePreference(
  otInstance *aInstance,
  otRoutePreference aPreference
)

Explicitly sets the preference of published routes in Network Data.

After a call to this function, BR will use the given preference. The preference can be cleared by calling otBorderRoutingClearRoutePreference().

Details
Parameters	[in] aInstance A pointer to an OpenThread instance. [in] aPreference The route preference to use.

Resources

OpenThread API Reference topics originate from the source code, available on GitHub. For more information, or to contribute to our documentation, refer to Resources.