/* * Copyright (c) 2021, The OpenThread Authors. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the copyright holder nor the * names of its contributors may be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ /** * @file * @brief * This file includes the platform abstraction for Thread Radio Encapsulation Link (TREL) using DNS-SD and UDP/IPv6. */ #ifndef OPENTHREAD_PLATFORM_TREL_H_ #define OPENTHREAD_PLATFORM_TREL_H_ #include #include #include #include #ifdef __cplusplus extern "C" { #endif /** * @addtogroup plat-trel * * @brief * This module includes the platform abstraction for Thread Radio Encapsulation Link (TREL) using DNS-SD and * UDP/IPv6. * * @{ */ /** * Initializes and enables TREL platform layer. * * Upon this call, the platform layer MUST perform the following: * * 1) TREL platform layer MUST open a UDP socket to listen for and receive TREL messages from peers. The socket is * bound to an ephemeral port number chosen by the platform layer. The port number MUST be returned in @p aUdpPort. * The socket is also bound to network interface(s) on which TREL is to be supported. The socket and the chosen port * should stay valid while TREL is enabled. * * 2) Platform layer MUST initiate an ongoing DNS-SD browse on the service name "_trel._udp" within the local browsing * domain to discover other devices supporting TREL. The ongoing browse will produce two different types of events: * "add" events and "remove" events. When the browse is started, it should produce an "add" event for every TREL peer * currently present on the network. Whenever a TREL peer goes offline, a "remove" event should be produced. "remove" * events are not guaranteed, however. When a TREL service instance is discovered, a new ongoing DNS-SD query for an * AAAA record should be started on the hostname indicated in the SRV record of the discovered instance. If multiple * host IPv6 addressees are discovered for a peer, one with highest scope among all addresses MUST be reported (if * there are multiple address at same scope, one must be selected randomly). * * TREL platform MUST signal back the discovered peer info using `otPlatTrelHandleDiscoveredPeerInfo()` callback. This * callback MUST be invoked when a new peer is discovered, when there is a change in an existing entry (e.g., new * TXT record or new port number or new IPv6 address), or when the peer is removed. * * @param[in] aInstance The OpenThread instance. * @param[out] aUdpPort A pointer to return the selected port number by platform layer. */ void otPlatTrelEnable(otInstance *aInstance, uint16_t *aUdpPort); /** * Disables TREL platform layer. * * After this call, the platform layer MUST stop DNS-SD browse on the service name "_trel._udp", stop advertising the * TREL DNS-SD service (from `otPlatTrelRegisterService()`) and MUST close the UDP socket used to receive TREL messages. * * @pram[in] aInstance The OpenThread instance. */ void otPlatTrelDisable(otInstance *aInstance); /** * Represents a TREL peer info discovered using DNS-SD browse on the service name "_trel._udp". */ typedef struct otPlatTrelPeerInfo { /** * This boolean flag indicates whether the entry is being removed or added. * * - TRUE indicates that peer is removed. * - FALSE indicates that it is a new entry or an update to an existing entry. */ bool mRemoved; /** * The TXT record data (encoded as specified by DNS-SD) from the SRV record of the discovered TREL peer service * instance. */ const uint8_t *mTxtData; uint16_t mTxtLength; ///< Number of bytes in @p mTxtData buffer. /** * The TREL peer socket address (IPv6 address and port number). * * The port number is determined from the SRV record of the discovered TREL peer service instance. The IPv6 address * is determined from the DNS-SD query for AAAA records on the hostname indicated in the SRV record of the * discovered service instance. If multiple host IPv6 addressees are discovered, one with highest scope is used. */ otSockAddr mSockAddr; } otPlatTrelPeerInfo; /** * This is a callback function from platform layer to report a discovered TREL peer info. * * @note The @p aInfo structure and its content (e.g., the `mTxtData` buffer) does not need to persist after returning * from this call. OpenThread code will make a copy of all the info it needs. * * @param[in] aInstance The OpenThread instance. * @param[in] aInfo A pointer to the TREL peer info. */ extern void otPlatTrelHandleDiscoveredPeerInfo(otInstance *aInstance, const otPlatTrelPeerInfo *aInfo); /** * Notifies platform that a TREL packet is received from a peer using a different socket address than the one reported * earlier from `otPlatTrelHandleDiscoveredPeerInfo()`. * * Ideally the platform underlying DNS-SD should detect changes to advertised port and addresses by peers, however, * there are situations where this is not detected reliably. This function signals to the platform layer than we * received a packet from a peer with it using a different port or address. This can be used by the playroom layer to * restart/confirm the DNS-SD service/address resolution for the peer service and/or take any other relevant actions. * * @param[in] aInstance The OpenThread instance. * @param[in] aPeerSockAddr The address of the peer, reported from `otPlatTrelHandleDiscoveredPeerInfo()` call. * @param[in] aRxSockAddr The address of received packet from the same peer (differs from @p aPeerSockAddr). */ void otPlatTrelNotifyPeerSocketAddressDifference(otInstance *aInstance, const otSockAddr *aPeerSockAddr, const otSockAddr *aRxSockAddr); /** * Registers a new service to be advertised using DNS-SD [RFC6763]. * * The service name is "_trel._udp". The platform should use its own hostname, which when combined with the service * name and the local DNS-SD domain name will produce the full service instance name, for example * "example-host._trel._udp.local.". * * The domain under which the service instance name appears will be 'local' for mDNS, and will be whatever domain is * used for service registration in the case of a non-mDNS local DNS-SD service. * * A subsequent call to this function updates the previous service. It is used to update the TXT record data and/or the * port number. * * The @p aTxtData buffer is not persisted after the return from this function. The platform layer MUST NOT keep the * pointer and instead copy the content if needed. * * @param[in] aInstance The OpenThread instance. * @param[in] aPort The port number to include in the SRV record of the advertised service. * @param[in] aTxtData A pointer to the TXT record data (encoded) to be include in the advertised service. * @param[in] aTxtLength The length of @p aTxtData (number of bytes). */ void otPlatTrelRegisterService(otInstance *aInstance, uint16_t aPort, const uint8_t *aTxtData, uint8_t aTxtLength); /** * Requests a TREL UDP packet to be sent to a given destination. * * @param[in] aInstance The OpenThread instance structure. * @param[in] aUdpPayload A pointer to UDP payload. * @param[in] aUdpPayloadLen The payload length (number of bytes). * @param[in] aDestSockAddr The destination socket address. */ void otPlatTrelSend(otInstance *aInstance, const uint8_t *aUdpPayload, uint16_t aUdpPayloadLen, const otSockAddr *aDestSockAddr); /** * Is a callback from platform to notify of a received TREL UDP packet. * * @note The buffer content (up to its specified length) may get changed during processing by OpenThread core (e.g., * decrypted in place), so the platform implementation should expect that after returning from this function the * @p aBuffer content may have been altered. * * @param[in] aInstance The OpenThread instance structure. * @param[in] aBuffer A buffer containing the received UDP payload. * @param[in] aLength UDP payload length (number of bytes). * @param[in] aSockAddr The sender address. */ extern void otPlatTrelHandleReceived(otInstance *aInstance, uint8_t *aBuffer, uint16_t aLength, const otSockAddr *aSenderAddr); /** * Represents a group of TREL related counters in the platform layer. */ typedef struct otPlatTrelCounters { uint64_t mTxPackets; ///< Number of packets successfully transmitted through TREL. uint64_t mTxBytes; ///< Sum of size of packets successfully transmitted through TREL. uint64_t mTxFailure; ///< Number of packet transmission failures through TREL. uint64_t mRxPackets; ///< Number of packets received through TREL. uint64_t mRxBytes; ///< Sum of size of packets received through TREL. } otPlatTrelCounters; /** * Gets the pointer to the TREL counters in the platform layer. * * @param[in] aInstance The OpenThread instance structure. */ const otPlatTrelCounters *otPlatTrelGetCounters(otInstance *aInstance); /** * Resets the TREL counters in the platform layer. * * @param[in] aInstance The OpenThread instance structure. */ void otPlatTrelResetCounters(otInstance *aInstance); /** * @} */ #ifdef __cplusplus } // end of extern "C" #endif #endif // OPENTHREAD_PLATFORM_TREL_H_