src/app/server/Dnssd.cpp - third_party/github/project-chip/connectedhomeip - Git at Google

 /*
  *
  *    Copyright (c) 2021 Project CHIP Authors
  *
  *    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.
  */

 #include <app/server/Dnssd.h>

 #include <app-common/zap-generated/cluster-enums.h>
 #include <inttypes.h>
 #include <lib/core/Optional.h>
 #include <lib/dnssd/Advertiser.h>
 #include <lib/dnssd/ServiceNaming.h>
 #include <lib/support/DefaultStorageKeyAllocator.h>
 #include <lib/support/Span.h>
 #include <lib/support/logging/CHIPLogging.h>
 #include <messaging/ReliableMessageProtocolConfig.h>
 #include <platform/CHIPDeviceLayer.h>
 #include <platform/CommissionableDataProvider.h>
 #include <platform/ConfigurationManager.h>
 #include <platform/DeviceInstanceInfoProvider.h>
 #include <protocols/secure_channel/PASESession.h>
 #if CHIP_ENABLE_ROTATING_DEVICE_ID && defined(CHIP_DEVICE_CONFIG_ROTATING_DEVICE_ID_UNIQUE_ID)
 #include <setup_payload/AdditionalDataPayloadGenerator.h>
 #endif
 #include <credentials/FabricTable.h>
 #include <setup_payload/SetupPayload.h>
 #include <system/TimeSource.h>

 #include <algorithm>

 using namespace chip;
 using namespace chip::DeviceLayer;

 namespace chip {
 namespace app {
 namespace {

 void OnPlatformEvent(const DeviceLayer::ChipDeviceEvent * event)
 {
     switch (event->Type)
     {
     case DeviceLayer::DeviceEventType::kDnssdInitialized:
     case DeviceLayer::DeviceEventType::kDnssdRestartNeeded:
         app::DnssdServer::Instance().StartServer();
         break;
     default:
         break;
     }
 }

 void OnPlatformEventWrapper(const DeviceLayer::ChipDeviceEvent * event, intptr_t arg)
 {
     (void) arg;
     OnPlatformEvent(event);
 }

 } // namespace

 constexpr System::Clock::Timestamp DnssdServer::kTimeoutCleared;

 bool DnssdServer::HaveOperationalCredentials()
 {
     VerifyOrDie(mFabricTable != nullptr);

     // Look for any fabric info that has a useful operational identity.
     return mFabricTable->FabricCount() != 0;
 }

 #if CHIP_DEVICE_CONFIG_ENABLE_EXTENDED_DISCOVERY

 void DnssdServer::SetExtendedDiscoveryTimeoutSecs(int32_t secs)
 {
     ChipLogDetail(Discovery, "Setting extended discovery timeout to %" PRId32 "s", secs);
     mExtendedDiscoveryTimeoutSecs = MakeOptional(secs);

     if (mExtendedDiscoveryExpiration != kTimeoutCleared &&
         mExtendedDiscoveryExpiration > mTimeSource.GetMonotonicTimestamp() + System::Clock::Seconds32(secs))
     {
         // Reset our timer to the new (shorter) timeout.
         ScheduleExtendedDiscoveryExpiration();
     }
 }

 int32_t DnssdServer::GetExtendedDiscoveryTimeoutSecs()
 {
     return mExtendedDiscoveryTimeoutSecs.ValueOr(CHIP_DEVICE_CONFIG_EXTENDED_DISCOVERY_TIMEOUT_SECS);
 }

 /// Callback from Extended Discovery Expiration timer
 void HandleExtendedDiscoveryExpiration(System::Layer * aSystemLayer, void * aAppState)
 {
     DnssdServer::Instance().OnExtendedDiscoveryExpiration(aSystemLayer, aAppState);
 }

 void DnssdServer::OnExtendedDiscoveryExpiration(System::Layer * aSystemLayer, void * aAppState)
 {
     ChipLogDetail(Discovery, "Extended discovery timed out");

     mExtendedDiscoveryExpiration = kTimeoutCleared;

     // Reset our advertising, now that we have flagged ourselves as possibly not
     // needing extended discovery anymore.
     StartServer();
 }

 CHIP_ERROR DnssdServer::ScheduleExtendedDiscoveryExpiration()
 {
     int32_t extendedDiscoveryTimeoutSecs = GetExtendedDiscoveryTimeoutSecs();
     if (extendedDiscoveryTimeoutSecs == CHIP_DEVICE_CONFIG_DISCOVERY_NO_TIMEOUT)
     {
         return CHIP_NO_ERROR;
     }
     ChipLogDetail(Discovery, "Scheduling extended discovery timeout in %" PRId32 "s", extendedDiscoveryTimeoutSecs);

     mExtendedDiscoveryExpiration = mTimeSource.GetMonotonicTimestamp() + System::Clock::Seconds32(extendedDiscoveryTimeoutSecs);

     return DeviceLayer::SystemLayer().StartTimer(System::Clock::Seconds32(extendedDiscoveryTimeoutSecs),
                                                  HandleExtendedDiscoveryExpiration, nullptr);
 }
 #endif // CHIP_DEVICE_CONFIG_ENABLE_EXTENDED_DISCOVERY

 CHIP_ERROR DnssdServer::GetCommissionableInstanceName(char * buffer, size_t bufferLen)
 {
     auto & mdnsAdvertiser = chip::Dnssd::ServiceAdvertiser::Instance();
     return mdnsAdvertiser.GetCommissionableInstanceName(buffer, bufferLen);
 }

 CHIP_ERROR DnssdServer::SetEphemeralDiscriminator(Optional<uint16_t> discriminator)
 {
     VerifyOrReturnError(discriminator.ValueOr(0) <= kMaxDiscriminatorValue, CHIP_ERROR_INVALID_ARGUMENT);
     mEphemeralDiscriminator = discriminator;

     return CHIP_NO_ERROR;
 }

 #if CHIP_CONFIG_ENABLE_ICD_SERVER
 template <class AdvertisingParams>
 void DnssdServer::AddICDKeyToAdvertisement(AdvertisingParams & advParams)
 {
     VerifyOrDieWithMsg(mICDManager != nullptr, Discovery,
                        "Invalid pointer to the ICDManager which is required for the LIT operating mode");

     Dnssd::ICDModeAdvertise ICDModeToAdvertise = Dnssd::ICDModeAdvertise::kNone;
     // Only advertise the ICD key if the device can operate as a LIT
     if (mICDManager->SupportsFeature(Clusters::IcdManagement::Feature::kLongIdleTimeSupport))
     {
         if (mICDManager->GetICDMode() == ICDConfigurationData::ICDMode::LIT)
         {
             ICDModeToAdvertise = Dnssd::ICDModeAdvertise::kLIT;
         }
         else
         {
             ICDModeToAdvertise = Dnssd::ICDModeAdvertise::kSIT;
         }
     }

     advParams.SetICDModeToAdvertise(ICDModeToAdvertise);
 }
 #endif

 void DnssdServer::GetPrimaryOrFallbackMACAddress(chip::MutableByteSpan mac)
 {
     if (ConfigurationMgr().GetPrimaryMACAddress(mac) != CHIP_NO_ERROR)
     {
         // Only generate a fallback "MAC" once, so we don't keep constantly changing our host name.
         if (std::all_of(std::begin(mFallbackMAC), std::end(mFallbackMAC), [](uint8_t v) { return v == 0; }))
         {
             ChipLogError(Discovery, "Failed to get primary mac address of device. Generating a random one.");
             Crypto::DRBG_get_bytes(mFallbackMAC, sizeof(mFallbackMAC));
         }
         VerifyOrDie(mac.size() == sizeof(mFallbackMAC)); // kPrimaryMACAddressLength
         memcpy(mac.data(), mFallbackMAC, sizeof(mFallbackMAC));
     }
 }

 /// Set MDNS operational advertisement
 CHIP_ERROR DnssdServer::AdvertiseOperational()
 {
     VerifyOrReturnError(mFabricTable != nullptr, CHIP_ERROR_INCORRECT_STATE);

     for (const FabricInfo & fabricInfo : *mFabricTable)
     {
         if (!fabricInfo.ShouldAdvertiseIdentity())
         {
             continue;
         }

         uint8_t macBuffer[DeviceLayer::ConfigurationManager::kPrimaryMACAddressLength];
         MutableByteSpan mac(macBuffer);
         GetPrimaryOrFallbackMACAddress(mac);

         auto advertiseParameters = chip::Dnssd::OperationalAdvertisingParameters()
                                        .SetPeerId(fabricInfo.GetPeerId())
                                        .SetMac(mac)
                                        .SetPort(GetSecuredPort())
                                        .SetInterfaceId(GetInterfaceId())
                                        .SetLocalMRPConfig(GetLocalMRPConfig().std_optional())
                                        .EnableIpV4(true);

 #if CHIP_CONFIG_ENABLE_ICD_SERVER
         AddICDKeyToAdvertisement(advertiseParameters);
 #endif

 #if INET_CONFIG_ENABLE_TCP_ENDPOINT
         advertiseParameters.SetTCPSupportModes(chip::Dnssd::TCPModeAdvertise::kTCPClientServer);
 #endif
         auto & mdnsAdvertiser = chip::Dnssd::ServiceAdvertiser::Instance();

         ChipLogProgress(Discovery, "Advertise operational node " ChipLogFormatX64 "-" ChipLogFormatX64,
                         ChipLogValueX64(advertiseParameters.GetPeerId().GetCompressedFabricId()),
                         ChipLogValueX64(advertiseParameters.GetPeerId().GetNodeId()));
         // Should we keep trying to advertise the other operational
         // identities on failure?
         ReturnErrorOnFailure(mdnsAdvertiser.Advertise(advertiseParameters));
     }
     return CHIP_NO_ERROR;
 }

 CHIP_ERROR DnssdServer::Advertise(bool commissionableNode, chip::Dnssd::CommissioningMode mode)
 {
     auto advertiseParameters = chip::Dnssd::CommissionAdvertisingParameters()
                                    .SetPort(commissionableNode ? GetSecuredPort() : GetUnsecuredPort())
                                    .SetInterfaceId(GetInterfaceId())
                                    .EnableIpV4(true);
     advertiseParameters.SetCommissionAdvertiseMode(commissionableNode ? chip::Dnssd::CommssionAdvertiseMode::kCommissionableNode
                                                                       : chip::Dnssd::CommssionAdvertiseMode::kCommissioner);

     advertiseParameters.SetCommissioningMode(mode);

     char pairingInst[chip::Dnssd::kKeyPairingInstructionMaxLength + 1];

     uint8_t macBuffer[DeviceLayer::ConfigurationManager::kPrimaryMACAddressLength];
     MutableByteSpan mac(macBuffer);
     GetPrimaryOrFallbackMACAddress(mac);
     advertiseParameters.SetMac(mac);

     uint16_t value;
     uint32_t val32;
     if (DeviceLayer::GetDeviceInstanceInfoProvider()->GetVendorId(value) != CHIP_NO_ERROR)
     {
         ChipLogDetail(Discovery, "Vendor ID not known");
     }
     else
     {
         advertiseParameters.SetVendorId(std::make_optional<uint16_t>(value));
     }

     if (DeviceLayer::GetDeviceInstanceInfoProvider()->GetProductId(value) != CHIP_NO_ERROR)
     {
         ChipLogDetail(Discovery, "Product ID not known");
     }
     else
     {
         advertiseParameters.SetProductId(std::make_optional<uint16_t>(value));
     }

     if (DeviceLayer::ConfigurationMgr().IsCommissionableDeviceTypeEnabled() &&
         DeviceLayer::ConfigurationMgr().GetDeviceTypeId(val32) == CHIP_NO_ERROR)
     {
         advertiseParameters.SetDeviceType(std::make_optional<uint32_t>(val32));
     }

     char deviceName[chip::Dnssd::kKeyDeviceNameMaxLength + 1];
     if (DeviceLayer::ConfigurationMgr().IsCommissionableDeviceNameEnabled() &&
         DeviceLayer::ConfigurationMgr().GetCommissionableDeviceName(deviceName, sizeof(deviceName)) == CHIP_NO_ERROR)
     {
         advertiseParameters.SetDeviceName(std::make_optional<const char *>(deviceName));
     }

     advertiseParameters.SetLocalMRPConfig(GetLocalMRPConfig().std_optional());

 #if CHIP_CONFIG_ENABLE_ICD_SERVER
     AddICDKeyToAdvertisement(advertiseParameters);
 #endif

     if (commissionableNode)
     {
         uint16_t discriminator = 0;
         CHIP_ERROR error       = DeviceLayer::GetCommissionableDataProvider()->GetSetupDiscriminator(discriminator);
         if (error != CHIP_NO_ERROR)
         {
             ChipLogError(Discovery,
                          "Setup discriminator read error (%" CHIP_ERROR_FORMAT ")! Critical error, will not be commissionable.",
                          error.Format());
             return error;
         }

         // Override discriminator with temporary one if one is set
         discriminator = mEphemeralDiscriminator.ValueOr(discriminator);

         advertiseParameters.SetShortDiscriminator(static_cast<uint8_t>((discriminator >> 8) & 0x0F))
             .SetLongDiscriminator(discriminator);

 #if CHIP_ENABLE_ROTATING_DEVICE_ID && defined(CHIP_DEVICE_CONFIG_ROTATING_DEVICE_ID_UNIQUE_ID)
         char rotatingDeviceIdHexBuffer[RotatingDeviceId::kHexMaxLength];
         ReturnErrorOnFailure(GenerateRotatingDeviceId(rotatingDeviceIdHexBuffer, ArraySize(rotatingDeviceIdHexBuffer)));
         advertiseParameters.SetRotatingDeviceId(std::make_optional<const char *>(rotatingDeviceIdHexBuffer));
 #endif

         if (!HaveOperationalCredentials())
         {
             if (DeviceLayer::ConfigurationMgr().GetInitialPairingHint(value) != CHIP_NO_ERROR)
             {
                 ChipLogDetail(Discovery, "DNS-SD Pairing Hint not set");
             }
             else
             {
                 advertiseParameters.SetPairingHint(std::make_optional<uint16_t>(value));
             }

             if (DeviceLayer::ConfigurationMgr().GetInitialPairingInstruction(pairingInst, sizeof(pairingInst)) != CHIP_NO_ERROR)
             {
                 ChipLogDetail(Discovery, "DNS-SD Pairing Instruction not set");
             }
             else
             {
                 advertiseParameters.SetPairingInstruction(std::make_optional<const char *>(pairingInst));
             }
         }
         else
         {
             if (DeviceLayer::ConfigurationMgr().GetSecondaryPairingHint(value) != CHIP_NO_ERROR)
             {
                 ChipLogDetail(Discovery, "DNS-SD Pairing Hint not set");
             }
             else
             {
                 advertiseParameters.SetPairingHint(std::make_optional<uint16_t>(value));
             }

             if (DeviceLayer::ConfigurationMgr().GetSecondaryPairingInstruction(pairingInst, sizeof(pairingInst)) != CHIP_NO_ERROR)
             {
                 ChipLogDetail(Discovery, "DNS-SD Pairing Instruction not set");
             }
             else
             {
                 advertiseParameters.SetPairingInstruction(std::make_optional<const char *>(pairingInst));
             }
         }
     }
 #if CHIP_DEVICE_CONFIG_ENABLE_COMMISSIONER_PASSCODE
     else
     {
         advertiseParameters.SetCommissionerPasscodeSupported(std::make_optional<bool>(true));
     }
 #endif

     auto & mdnsAdvertiser = chip::Dnssd::ServiceAdvertiser::Instance();

     ChipLogProgress(Discovery, "Advertise commission parameter vendorID=%u productID=%u discriminator=%04u/%02u cm=%u cp=%u",
                     advertiseParameters.GetVendorId().value_or(0), advertiseParameters.GetProductId().value_or(0),
                     advertiseParameters.GetLongDiscriminator(), advertiseParameters.GetShortDiscriminator(),
                     to_underlying(advertiseParameters.GetCommissioningMode()),
                     advertiseParameters.GetCommissionerPasscodeSupported().value_or(false) ? 1 : 0);
     return mdnsAdvertiser.Advertise(advertiseParameters);
 }

 CHIP_ERROR DnssdServer::AdvertiseCommissioner()
 {
     return Advertise(false /* commissionableNode */, chip::Dnssd::CommissioningMode::kDisabled);
 }

 CHIP_ERROR DnssdServer::AdvertiseCommissionableNode(chip::Dnssd::CommissioningMode mode)
 {
 #if CHIP_DEVICE_CONFIG_ENABLE_EXTENDED_DISCOVERY
     mCurrentCommissioningMode = mode;
     if (mode != Dnssd::CommissioningMode::kDisabled)
     {
         // We're not doing extended discovery right now.
         DeviceLayer::SystemLayer().CancelTimer(HandleExtendedDiscoveryExpiration, nullptr);
         mExtendedDiscoveryExpiration = kTimeoutCleared;
     }
 #endif // CHIP_DEVICE_CONFIG_ENABLE_EXTENDED_DISCOVERY

     return Advertise(true /* commissionableNode */, mode);
 }

 void DnssdServer::StartServer()
 {
     Dnssd::CommissioningMode mode = Dnssd::CommissioningMode::kDisabled;
     if (mCommissioningModeProvider)
     {
         mode = mCommissioningModeProvider->GetCommissioningMode();
     }
     return StartServer(mode);
 }

 void DnssdServer::StopServer()
 {
     // Make sure we don't hold on to a dangling fabric table pointer.
     mFabricTable = nullptr;

     DeviceLayer::PlatformMgr().RemoveEventHandler(OnPlatformEventWrapper, 0);

 #if CHIP_DEVICE_CONFIG_ENABLE_EXTENDED_DISCOVERY
     if (mExtendedDiscoveryExpiration != kTimeoutCleared)
     {
         DeviceLayer::SystemLayer().CancelTimer(HandleExtendedDiscoveryExpiration, nullptr);
         mExtendedDiscoveryExpiration = kTimeoutCleared;
     }
 #endif // CHIP_DEVICE_CONFIG_ENABLE_EXTENDED_DISCOVERY

     if (Dnssd::ServiceAdvertiser::Instance().IsInitialized())
     {
         auto err = Dnssd::ServiceAdvertiser::Instance().RemoveServices();
         if (err != CHIP_NO_ERROR)
         {
             ChipLogError(Discovery, "Failed to remove advertised services: %" CHIP_ERROR_FORMAT, err.Format());
         }

         Dnssd::ServiceAdvertiser::Instance().Shutdown();
     }
 }

 void DnssdServer::StartServer(Dnssd::CommissioningMode mode)
 {
     ChipLogProgress(Discovery, "Updating services using commissioning mode %d", static_cast<int>(mode));

     DeviceLayer::PlatformMgr().AddEventHandler(OnPlatformEventWrapper, 0);

     CHIP_ERROR err = Dnssd::ServiceAdvertiser::Instance().Init(chip::DeviceLayer::UDPEndPointManager());
     if (err != CHIP_NO_ERROR)
     {
         ChipLogError(Discovery, "Failed to initialize advertiser: %" CHIP_ERROR_FORMAT, err.Format());
     }

     err = Dnssd::ServiceAdvertiser::Instance().RemoveServices();
     if (err != CHIP_NO_ERROR)
     {
         ChipLogError(Discovery, "Failed to remove advertised services: %" CHIP_ERROR_FORMAT, err.Format());
     }

     err = AdvertiseOperational();
     if (err != CHIP_NO_ERROR)
     {
         ChipLogError(Discovery, "Failed to advertise operational node: %" CHIP_ERROR_FORMAT, err.Format());
     }

     if (mode != Dnssd::CommissioningMode::kDisabled)
     {
         err = AdvertiseCommissionableNode(mode);
         if (err != CHIP_NO_ERROR)
         {
             ChipLogError(Discovery, "Failed to advertise commissionable node: %" CHIP_ERROR_FORMAT, err.Format());
         }
     }
 #if CHIP_DEVICE_CONFIG_ENABLE_EXTENDED_DISCOVERY
     else if (GetExtendedDiscoveryTimeoutSecs() != CHIP_DEVICE_CONFIG_DISCOVERY_DISABLED)
     {
         bool alwaysAdvertiseExtended = (GetExtendedDiscoveryTimeoutSecs() == CHIP_DEVICE_CONFIG_DISCOVERY_NO_TIMEOUT);
         // We do extended discovery advertising in three cases:
         // 1) We don't have a timeout for extended discovery.
         // 2) We are transitioning out of commissioning mode (basic or enhanced)
         //    and should therefore start extended discovery.
         // 3) We are resetting advertising while we are in the middle of an
         //    existing extended discovery advertising period.
         if (alwaysAdvertiseExtended || mCurrentCommissioningMode != Dnssd::CommissioningMode::kDisabled ||
             mExtendedDiscoveryExpiration != kTimeoutCleared)
         {
             err = AdvertiseCommissionableNode(mode);
             if (err != CHIP_NO_ERROR)
             {
                 ChipLogError(Discovery, "Failed to advertise extended commissionable node: %" CHIP_ERROR_FORMAT, err.Format());
             }
             if (mExtendedDiscoveryExpiration == kTimeoutCleared)
             {
                 // set timeout
                 ScheduleExtendedDiscoveryExpiration();
             }
         }
     }
 #endif // CHIP_DEVICE_CONFIG_ENABLE_EXTENDED_DISCOVERY

 #if CHIP_DEVICE_CONFIG_ENABLE_COMMISSIONER_DISCOVERY
     err = AdvertiseCommissioner();
     if (err != CHIP_NO_ERROR)
     {
         ChipLogError(Discovery, "Failed to advertise commissioner: %" CHIP_ERROR_FORMAT, err.Format());
     }
 #endif // CHIP_DEVICE_CONFIG_ENABLE_COMMISSIONER_DISCOVERY

     err = Dnssd::ServiceAdvertiser::Instance().FinalizeServiceUpdate();
     if (err != CHIP_NO_ERROR)
     {
         ChipLogError(Discovery, "Failed to finalize service update: %" CHIP_ERROR_FORMAT, err.Format());
     }
 }

 #if CHIP_ENABLE_ROTATING_DEVICE_ID && defined(CHIP_DEVICE_CONFIG_ROTATING_DEVICE_ID_UNIQUE_ID)
 CHIP_ERROR DnssdServer::GenerateRotatingDeviceId(char rotatingDeviceIdHexBuffer[], size_t rotatingDeviceIdHexBufferSize)
 {
     AdditionalDataPayloadGeneratorParams additionalDataPayloadParams;
     uint8_t rotatingDeviceIdUniqueId[chip::DeviceLayer::ConfigurationManager::kRotatingDeviceIDUniqueIDLength];
     MutableByteSpan rotatingDeviceIdUniqueIdSpan(rotatingDeviceIdUniqueId);
     size_t rotatingDeviceIdValueOutputSize = 0;

     ReturnErrorOnFailure(
         chip::DeviceLayer::GetDeviceInstanceInfoProvider()->GetRotatingDeviceIdUniqueId(rotatingDeviceIdUniqueIdSpan));
     ReturnErrorOnFailure(
         chip::DeviceLayer::ConfigurationMgr().GetLifetimeCounter(additionalDataPayloadParams.rotatingDeviceIdLifetimeCounter));
     additionalDataPayloadParams.rotatingDeviceIdUniqueId = rotatingDeviceIdUniqueIdSpan;

     return AdditionalDataPayloadGenerator().generateRotatingDeviceIdAsHexString(
         additionalDataPayloadParams, rotatingDeviceIdHexBuffer, rotatingDeviceIdHexBufferSize, rotatingDeviceIdValueOutputSize);
 }
 #endif

 void DnssdServer::OnICDModeChange()
 {
     // ICDMode changed, restart DNS-SD advertising, because SII and ICD key are affected by this change.
     // StartServer will take care of setting the operational and commissionable advertisements
     StartServer();
 }

 } // namespace app
 } // namespace chip
	/*
	*
	* Copyright (c) 2021 Project CHIP Authors
	*
	* 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.
	*/

	#include <app/server/Dnssd.h>

	#include <app-common/zap-generated/cluster-enums.h>
	#include <inttypes.h>
	#include <lib/core/Optional.h>
	#include <lib/dnssd/Advertiser.h>
	#include <lib/dnssd/ServiceNaming.h>
	#include <lib/support/DefaultStorageKeyAllocator.h>
	#include <lib/support/Span.h>
	#include <lib/support/logging/CHIPLogging.h>
	#include <messaging/ReliableMessageProtocolConfig.h>
	#include <platform/CHIPDeviceLayer.h>
	#include <platform/CommissionableDataProvider.h>
	#include <platform/ConfigurationManager.h>
	#include <platform/DeviceInstanceInfoProvider.h>
	#include <protocols/secure_channel/PASESession.h>
	#if CHIP_ENABLE_ROTATING_DEVICE_ID && defined(CHIP_DEVICE_CONFIG_ROTATING_DEVICE_ID_UNIQUE_ID)
	#include <setup_payload/AdditionalDataPayloadGenerator.h>
	#endif
	#include <credentials/FabricTable.h>
	#include <setup_payload/SetupPayload.h>
	#include <system/TimeSource.h>

	#include <algorithm>

	using namespace chip;
	using namespace chip::DeviceLayer;

	namespace chip {
	namespace app {
	namespace {

	void OnPlatformEvent(const DeviceLayer::ChipDeviceEvent * event)
	{
	switch (event->Type)
	{
	case DeviceLayer::DeviceEventType::kDnssdInitialized:
	case DeviceLayer::DeviceEventType::kDnssdRestartNeeded:
	app::DnssdServer::Instance().StartServer();
	break;
	default:
	break;
	}
	}

	void OnPlatformEventWrapper(const DeviceLayer::ChipDeviceEvent * event, intptr_t arg)
	{
	(void) arg;
	OnPlatformEvent(event);
	}

	} // namespace

	constexpr System::Clock::Timestamp DnssdServer::kTimeoutCleared;

	bool DnssdServer::HaveOperationalCredentials()
	{
	VerifyOrDie(mFabricTable != nullptr);

	// Look for any fabric info that has a useful operational identity.
	return mFabricTable->FabricCount() != 0;
	}

	#if CHIP_DEVICE_CONFIG_ENABLE_EXTENDED_DISCOVERY

	void DnssdServer::SetExtendedDiscoveryTimeoutSecs(int32_t secs)
	{
	ChipLogDetail(Discovery, "Setting extended discovery timeout to %" PRId32 "s", secs);
	mExtendedDiscoveryTimeoutSecs = MakeOptional(secs);

	if (mExtendedDiscoveryExpiration != kTimeoutCleared &&
	mExtendedDiscoveryExpiration > mTimeSource.GetMonotonicTimestamp() + System::Clock::Seconds32(secs))
	{
	// Reset our timer to the new (shorter) timeout.
	ScheduleExtendedDiscoveryExpiration();
	}
	}

	int32_t DnssdServer::GetExtendedDiscoveryTimeoutSecs()
	{
	return mExtendedDiscoveryTimeoutSecs.ValueOr(CHIP_DEVICE_CONFIG_EXTENDED_DISCOVERY_TIMEOUT_SECS);
	}

	/// Callback from Extended Discovery Expiration timer
	void HandleExtendedDiscoveryExpiration(System::Layer * aSystemLayer, void * aAppState)
	{
	DnssdServer::Instance().OnExtendedDiscoveryExpiration(aSystemLayer, aAppState);
	}

	void DnssdServer::OnExtendedDiscoveryExpiration(System::Layer * aSystemLayer, void * aAppState)
	{
	ChipLogDetail(Discovery, "Extended discovery timed out");

	mExtendedDiscoveryExpiration = kTimeoutCleared;

	// Reset our advertising, now that we have flagged ourselves as possibly not
	// needing extended discovery anymore.
	StartServer();
	}

	CHIP_ERROR DnssdServer::ScheduleExtendedDiscoveryExpiration()
	{
	int32_t extendedDiscoveryTimeoutSecs = GetExtendedDiscoveryTimeoutSecs();
	if (extendedDiscoveryTimeoutSecs == CHIP_DEVICE_CONFIG_DISCOVERY_NO_TIMEOUT)
	{
	return CHIP_NO_ERROR;
	}
	ChipLogDetail(Discovery, "Scheduling extended discovery timeout in %" PRId32 "s", extendedDiscoveryTimeoutSecs);

	mExtendedDiscoveryExpiration = mTimeSource.GetMonotonicTimestamp() + System::Clock::Seconds32(extendedDiscoveryTimeoutSecs);

	return DeviceLayer::SystemLayer().StartTimer(System::Clock::Seconds32(extendedDiscoveryTimeoutSecs),
	HandleExtendedDiscoveryExpiration, nullptr);
	}
	#endif // CHIP_DEVICE_CONFIG_ENABLE_EXTENDED_DISCOVERY

	CHIP_ERROR DnssdServer::GetCommissionableInstanceName(char * buffer, size_t bufferLen)
	{
	auto & mdnsAdvertiser = chip::Dnssd::ServiceAdvertiser::Instance();
	return mdnsAdvertiser.GetCommissionableInstanceName(buffer, bufferLen);
	}

	CHIP_ERROR DnssdServer::SetEphemeralDiscriminator(Optional<uint16_t> discriminator)
	{
	VerifyOrReturnError(discriminator.ValueOr(0) <= kMaxDiscriminatorValue, CHIP_ERROR_INVALID_ARGUMENT);
	mEphemeralDiscriminator = discriminator;

	return CHIP_NO_ERROR;
	}

	#if CHIP_CONFIG_ENABLE_ICD_SERVER
	template <class AdvertisingParams>
	void DnssdServer::AddICDKeyToAdvertisement(AdvertisingParams & advParams)
	{
	VerifyOrDieWithMsg(mICDManager != nullptr, Discovery,
	"Invalid pointer to the ICDManager which is required for the LIT operating mode");

	Dnssd::ICDModeAdvertise ICDModeToAdvertise = Dnssd::ICDModeAdvertise::kNone;
	// Only advertise the ICD key if the device can operate as a LIT
	if (mICDManager->SupportsFeature(Clusters::IcdManagement::Feature::kLongIdleTimeSupport))
	{
	if (mICDManager->GetICDMode() == ICDConfigurationData::ICDMode::LIT)
	{
	ICDModeToAdvertise = Dnssd::ICDModeAdvertise::kLIT;
	}
	else
	{
	ICDModeToAdvertise = Dnssd::ICDModeAdvertise::kSIT;
	}
	}

	advParams.SetICDModeToAdvertise(ICDModeToAdvertise);
	}
	#endif

	void DnssdServer::GetPrimaryOrFallbackMACAddress(chip::MutableByteSpan mac)
	{
	if (ConfigurationMgr().GetPrimaryMACAddress(mac) != CHIP_NO_ERROR)
	{
	// Only generate a fallback "MAC" once, so we don't keep constantly changing our host name.
	if (std::all_of(std::begin(mFallbackMAC), std::end(mFallbackMAC), [](uint8_t v) { return v == 0; }))
	{
	ChipLogError(Discovery, "Failed to get primary mac address of device. Generating a random one.");
	Crypto::DRBG_get_bytes(mFallbackMAC, sizeof(mFallbackMAC));
	}
	VerifyOrDie(mac.size() == sizeof(mFallbackMAC)); // kPrimaryMACAddressLength
	memcpy(mac.data(), mFallbackMAC, sizeof(mFallbackMAC));
	}
	}

	/// Set MDNS operational advertisement
	CHIP_ERROR DnssdServer::AdvertiseOperational()
	{
	VerifyOrReturnError(mFabricTable != nullptr, CHIP_ERROR_INCORRECT_STATE);

	for (const FabricInfo & fabricInfo : *mFabricTable)
	{
	if (!fabricInfo.ShouldAdvertiseIdentity())
	{
	continue;
	}

	uint8_t macBuffer[DeviceLayer::ConfigurationManager::kPrimaryMACAddressLength];
	MutableByteSpan mac(macBuffer);
	GetPrimaryOrFallbackMACAddress(mac);

	auto advertiseParameters = chip::Dnssd::OperationalAdvertisingParameters()
	.SetPeerId(fabricInfo.GetPeerId())
	.SetMac(mac)
	.SetPort(GetSecuredPort())
	.SetInterfaceId(GetInterfaceId())
	.SetLocalMRPConfig(GetLocalMRPConfig().std_optional())
	.EnableIpV4(true);

	#if CHIP_CONFIG_ENABLE_ICD_SERVER
	AddICDKeyToAdvertisement(advertiseParameters);
	#endif

	#if INET_CONFIG_ENABLE_TCP_ENDPOINT
	advertiseParameters.SetTCPSupportModes(chip::Dnssd::TCPModeAdvertise::kTCPClientServer);
	#endif
	auto & mdnsAdvertiser = chip::Dnssd::ServiceAdvertiser::Instance();

	ChipLogProgress(Discovery, "Advertise operational node " ChipLogFormatX64 "-" ChipLogFormatX64,
	ChipLogValueX64(advertiseParameters.GetPeerId().GetCompressedFabricId()),
	ChipLogValueX64(advertiseParameters.GetPeerId().GetNodeId()));
	// Should we keep trying to advertise the other operational
	// identities on failure?
	ReturnErrorOnFailure(mdnsAdvertiser.Advertise(advertiseParameters));
	}
	return CHIP_NO_ERROR;
	}

	CHIP_ERROR DnssdServer::Advertise(bool commissionableNode, chip::Dnssd::CommissioningMode mode)
	{
	auto advertiseParameters = chip::Dnssd::CommissionAdvertisingParameters()
	.SetPort(commissionableNode ? GetSecuredPort() : GetUnsecuredPort())
	.SetInterfaceId(GetInterfaceId())
	.EnableIpV4(true);
	advertiseParameters.SetCommissionAdvertiseMode(commissionableNode ? chip::Dnssd::CommssionAdvertiseMode::kCommissionableNode
	: chip::Dnssd::CommssionAdvertiseMode::kCommissioner);

	advertiseParameters.SetCommissioningMode(mode);

	char pairingInst[chip::Dnssd::kKeyPairingInstructionMaxLength + 1];

	uint8_t macBuffer[DeviceLayer::ConfigurationManager::kPrimaryMACAddressLength];
	MutableByteSpan mac(macBuffer);
	GetPrimaryOrFallbackMACAddress(mac);
	advertiseParameters.SetMac(mac);

	uint16_t value;
	uint32_t val32;
	if (DeviceLayer::GetDeviceInstanceInfoProvider()->GetVendorId(value) != CHIP_NO_ERROR)
	{
	ChipLogDetail(Discovery, "Vendor ID not known");
	}
	else
	{
	advertiseParameters.SetVendorId(std::make_optional<uint16_t>(value));
	}

	if (DeviceLayer::GetDeviceInstanceInfoProvider()->GetProductId(value) != CHIP_NO_ERROR)
	{
	ChipLogDetail(Discovery, "Product ID not known");
	}
	else
	{
	advertiseParameters.SetProductId(std::make_optional<uint16_t>(value));
	}

	if (DeviceLayer::ConfigurationMgr().IsCommissionableDeviceTypeEnabled() &&
	DeviceLayer::ConfigurationMgr().GetDeviceTypeId(val32) == CHIP_NO_ERROR)
	{
	advertiseParameters.SetDeviceType(std::make_optional<uint32_t>(val32));
	}

	char deviceName[chip::Dnssd::kKeyDeviceNameMaxLength + 1];
	if (DeviceLayer::ConfigurationMgr().IsCommissionableDeviceNameEnabled() &&
	DeviceLayer::ConfigurationMgr().GetCommissionableDeviceName(deviceName, sizeof(deviceName)) == CHIP_NO_ERROR)
	{
	advertiseParameters.SetDeviceName(std::make_optional<const char *>(deviceName));
	}

	advertiseParameters.SetLocalMRPConfig(GetLocalMRPConfig().std_optional());

	#if CHIP_CONFIG_ENABLE_ICD_SERVER
	AddICDKeyToAdvertisement(advertiseParameters);
	#endif

	if (commissionableNode)
	{
	uint16_t discriminator = 0;
	CHIP_ERROR error = DeviceLayer::GetCommissionableDataProvider()->GetSetupDiscriminator(discriminator);
	if (error != CHIP_NO_ERROR)
	{
	ChipLogError(Discovery,
	"Setup discriminator read error (%" CHIP_ERROR_FORMAT ")! Critical error, will not be commissionable.",
	error.Format());
	return error;
	}

	// Override discriminator with temporary one if one is set
	discriminator = mEphemeralDiscriminator.ValueOr(discriminator);

	advertiseParameters.SetShortDiscriminator(static_cast<uint8_t>((discriminator >> 8) & 0x0F))
	.SetLongDiscriminator(discriminator);

	#if CHIP_ENABLE_ROTATING_DEVICE_ID && defined(CHIP_DEVICE_CONFIG_ROTATING_DEVICE_ID_UNIQUE_ID)
	char rotatingDeviceIdHexBuffer[RotatingDeviceId::kHexMaxLength];
	ReturnErrorOnFailure(GenerateRotatingDeviceId(rotatingDeviceIdHexBuffer, ArraySize(rotatingDeviceIdHexBuffer)));
	advertiseParameters.SetRotatingDeviceId(std::make_optional<const char *>(rotatingDeviceIdHexBuffer));
	#endif

	if (!HaveOperationalCredentials())
	{
	if (DeviceLayer::ConfigurationMgr().GetInitialPairingHint(value) != CHIP_NO_ERROR)
	{
	ChipLogDetail(Discovery, "DNS-SD Pairing Hint not set");
	}
	else
	{
	advertiseParameters.SetPairingHint(std::make_optional<uint16_t>(value));
	}

	if (DeviceLayer::ConfigurationMgr().GetInitialPairingInstruction(pairingInst, sizeof(pairingInst)) != CHIP_NO_ERROR)
	{
	ChipLogDetail(Discovery, "DNS-SD Pairing Instruction not set");
	}
	else
	{
	advertiseParameters.SetPairingInstruction(std::make_optional<const char *>(pairingInst));
	}
	}
	else
	{
	if (DeviceLayer::ConfigurationMgr().GetSecondaryPairingHint(value) != CHIP_NO_ERROR)
	{
	ChipLogDetail(Discovery, "DNS-SD Pairing Hint not set");
	}
	else
	{
	advertiseParameters.SetPairingHint(std::make_optional<uint16_t>(value));
	}

	if (DeviceLayer::ConfigurationMgr().GetSecondaryPairingInstruction(pairingInst, sizeof(pairingInst)) != CHIP_NO_ERROR)
	{
	ChipLogDetail(Discovery, "DNS-SD Pairing Instruction not set");
	}
	else
	{
	advertiseParameters.SetPairingInstruction(std::make_optional<const char *>(pairingInst));
	}
	}
	}
	#if CHIP_DEVICE_CONFIG_ENABLE_COMMISSIONER_PASSCODE
	else
	{
	advertiseParameters.SetCommissionerPasscodeSupported(std::make_optional<bool>(true));
	}
	#endif

	auto & mdnsAdvertiser = chip::Dnssd::ServiceAdvertiser::Instance();

	ChipLogProgress(Discovery, "Advertise commission parameter vendorID=%u productID=%u discriminator=%04u/%02u cm=%u cp=%u",
	advertiseParameters.GetVendorId().value_or(0), advertiseParameters.GetProductId().value_or(0),
	advertiseParameters.GetLongDiscriminator(), advertiseParameters.GetShortDiscriminator(),
	to_underlying(advertiseParameters.GetCommissioningMode()),
	advertiseParameters.GetCommissionerPasscodeSupported().value_or(false) ? 1 : 0);
	return mdnsAdvertiser.Advertise(advertiseParameters);
	}

	CHIP_ERROR DnssdServer::AdvertiseCommissioner()
	{
	return Advertise(false /* commissionableNode */, chip::Dnssd::CommissioningMode::kDisabled);
	}

	CHIP_ERROR DnssdServer::AdvertiseCommissionableNode(chip::Dnssd::CommissioningMode mode)
	{
	#if CHIP_DEVICE_CONFIG_ENABLE_EXTENDED_DISCOVERY
	mCurrentCommissioningMode = mode;
	if (mode != Dnssd::CommissioningMode::kDisabled)
	{
	// We're not doing extended discovery right now.
	DeviceLayer::SystemLayer().CancelTimer(HandleExtendedDiscoveryExpiration, nullptr);
	mExtendedDiscoveryExpiration = kTimeoutCleared;
	}
	#endif // CHIP_DEVICE_CONFIG_ENABLE_EXTENDED_DISCOVERY

	return Advertise(true /* commissionableNode */, mode);
	}

	void DnssdServer::StartServer()
	{
	Dnssd::CommissioningMode mode = Dnssd::CommissioningMode::kDisabled;
	if (mCommissioningModeProvider)
	{
	mode = mCommissioningModeProvider->GetCommissioningMode();
	}
	return StartServer(mode);
	}

	void DnssdServer::StopServer()
	{
	// Make sure we don't hold on to a dangling fabric table pointer.
	mFabricTable = nullptr;

	DeviceLayer::PlatformMgr().RemoveEventHandler(OnPlatformEventWrapper, 0);

	#if CHIP_DEVICE_CONFIG_ENABLE_EXTENDED_DISCOVERY
	if (mExtendedDiscoveryExpiration != kTimeoutCleared)
	{
	DeviceLayer::SystemLayer().CancelTimer(HandleExtendedDiscoveryExpiration, nullptr);
	mExtendedDiscoveryExpiration = kTimeoutCleared;
	}
	#endif // CHIP_DEVICE_CONFIG_ENABLE_EXTENDED_DISCOVERY

	if (Dnssd::ServiceAdvertiser::Instance().IsInitialized())
	{
	auto err = Dnssd::ServiceAdvertiser::Instance().RemoveServices();
	if (err != CHIP_NO_ERROR)
	{
	ChipLogError(Discovery, "Failed to remove advertised services: %" CHIP_ERROR_FORMAT, err.Format());
	}

	Dnssd::ServiceAdvertiser::Instance().Shutdown();
	}
	}

	void DnssdServer::StartServer(Dnssd::CommissioningMode mode)
	{
	ChipLogProgress(Discovery, "Updating services using commissioning mode %d", static_cast<int>(mode));

	DeviceLayer::PlatformMgr().AddEventHandler(OnPlatformEventWrapper, 0);

	CHIP_ERROR err = Dnssd::ServiceAdvertiser::Instance().Init(chip::DeviceLayer::UDPEndPointManager());
	if (err != CHIP_NO_ERROR)
	{
	ChipLogError(Discovery, "Failed to initialize advertiser: %" CHIP_ERROR_FORMAT, err.Format());
	}

	err = Dnssd::ServiceAdvertiser::Instance().RemoveServices();
	if (err != CHIP_NO_ERROR)
	{
	ChipLogError(Discovery, "Failed to remove advertised services: %" CHIP_ERROR_FORMAT, err.Format());
	}

	err = AdvertiseOperational();
	if (err != CHIP_NO_ERROR)
	{
	ChipLogError(Discovery, "Failed to advertise operational node: %" CHIP_ERROR_FORMAT, err.Format());
	}

	if (mode != Dnssd::CommissioningMode::kDisabled)
	{
	err = AdvertiseCommissionableNode(mode);
	if (err != CHIP_NO_ERROR)
	{
	ChipLogError(Discovery, "Failed to advertise commissionable node: %" CHIP_ERROR_FORMAT, err.Format());
	}
	}
	#if CHIP_DEVICE_CONFIG_ENABLE_EXTENDED_DISCOVERY
	else if (GetExtendedDiscoveryTimeoutSecs() != CHIP_DEVICE_CONFIG_DISCOVERY_DISABLED)
	{
	bool alwaysAdvertiseExtended = (GetExtendedDiscoveryTimeoutSecs() == CHIP_DEVICE_CONFIG_DISCOVERY_NO_TIMEOUT);
	// We do extended discovery advertising in three cases:
	// 1) We don't have a timeout for extended discovery.
	// 2) We are transitioning out of commissioning mode (basic or enhanced)
	// and should therefore start extended discovery.
	// 3) We are resetting advertising while we are in the middle of an
	// existing extended discovery advertising period.
	if (alwaysAdvertiseExtended \|\| mCurrentCommissioningMode != Dnssd::CommissioningMode::kDisabled \|\|
	mExtendedDiscoveryExpiration != kTimeoutCleared)
	{
	err = AdvertiseCommissionableNode(mode);
	if (err != CHIP_NO_ERROR)
	{
	ChipLogError(Discovery, "Failed to advertise extended commissionable node: %" CHIP_ERROR_FORMAT, err.Format());
	}
	if (mExtendedDiscoveryExpiration == kTimeoutCleared)
	{
	// set timeout
	ScheduleExtendedDiscoveryExpiration();
	}
	}
	}
	#endif // CHIP_DEVICE_CONFIG_ENABLE_EXTENDED_DISCOVERY

	#if CHIP_DEVICE_CONFIG_ENABLE_COMMISSIONER_DISCOVERY
	err = AdvertiseCommissioner();
	if (err != CHIP_NO_ERROR)
	{
	ChipLogError(Discovery, "Failed to advertise commissioner: %" CHIP_ERROR_FORMAT, err.Format());
	}
	#endif // CHIP_DEVICE_CONFIG_ENABLE_COMMISSIONER_DISCOVERY

	err = Dnssd::ServiceAdvertiser::Instance().FinalizeServiceUpdate();
	if (err != CHIP_NO_ERROR)
	{
	ChipLogError(Discovery, "Failed to finalize service update: %" CHIP_ERROR_FORMAT, err.Format());
	}
	}

	#if CHIP_ENABLE_ROTATING_DEVICE_ID && defined(CHIP_DEVICE_CONFIG_ROTATING_DEVICE_ID_UNIQUE_ID)
	CHIP_ERROR DnssdServer::GenerateRotatingDeviceId(char rotatingDeviceIdHexBuffer[], size_t rotatingDeviceIdHexBufferSize)
	{
	AdditionalDataPayloadGeneratorParams additionalDataPayloadParams;
	uint8_t rotatingDeviceIdUniqueId[chip::DeviceLayer::ConfigurationManager::kRotatingDeviceIDUniqueIDLength];
	MutableByteSpan rotatingDeviceIdUniqueIdSpan(rotatingDeviceIdUniqueId);
	size_t rotatingDeviceIdValueOutputSize = 0;

	ReturnErrorOnFailure(
	chip::DeviceLayer::GetDeviceInstanceInfoProvider()->GetRotatingDeviceIdUniqueId(rotatingDeviceIdUniqueIdSpan));
	ReturnErrorOnFailure(
	chip::DeviceLayer::ConfigurationMgr().GetLifetimeCounter(additionalDataPayloadParams.rotatingDeviceIdLifetimeCounter));
	additionalDataPayloadParams.rotatingDeviceIdUniqueId = rotatingDeviceIdUniqueIdSpan;

	return AdditionalDataPayloadGenerator().generateRotatingDeviceIdAsHexString(
	additionalDataPayloadParams, rotatingDeviceIdHexBuffer, rotatingDeviceIdHexBufferSize, rotatingDeviceIdValueOutputSize);
	}
	#endif

	void DnssdServer::OnICDModeChange()
	{
	// ICDMode changed, restart DNS-SD advertising, because SII and ICD key are affected by this change.
	// StartServer will take care of setting the operational and commissionable advertisements
	StartServer();
	}

	} // namespace app
	} // namespace chip