src/platform/android/DnssdImpl.cpp - third_party/github/project-chip/connectedhomeip - Git at Google

 /*
  *
  *    Copyright (c) 2020-2021 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 "DnssdImpl.h"

 #include <lib/dnssd/platform/Dnssd.h>
 #include <lib/support/CHIPJNIError.h>
 #include <lib/support/CHIPMemString.h>
 #include <lib/support/CodeUtils.h>
 #include <lib/support/JniReferences.h>
 #include <lib/support/JniTypeWrappers.h>
 #include <lib/support/SafeInt.h>
 #include <lib/support/logging/CHIPLogging.h>
 #include <platform/internal/CHIPDeviceLayerInternal.h>

 #include <cstddef>
 #include <jni.h>
 #include <memory>
 #include <sstream>
 #include <string>

 namespace chip {
 namespace Dnssd {

 using namespace chip::Platform;

 namespace {
 jobject sResolverObject           = nullptr;
 jobject sBrowserObject            = nullptr;
 jobject sMdnsCallbackObject       = nullptr;
 jmethodID sResolveMethod          = nullptr;
 jmethodID sBrowseMethod           = nullptr;
 jmethodID sGetTextEntryKeysMethod = nullptr;
 jmethodID sGetTextEntryDataMethod = nullptr;
 jclass sMdnsCallbackClass         = nullptr;
 jmethodID sPublishMethod          = nullptr;
 jmethodID sRemoveServicesMethod   = nullptr;
 } // namespace

 // Implementation of functions declared in lib/dnssd/platform/Dnssd.h

 constexpr const char * kProtocolTcp = "._tcp";
 constexpr const char * kProtocolUdp = "._udp";

 CHIP_ERROR ChipDnssdInit(DnssdAsyncReturnCallback initCallback, DnssdAsyncReturnCallback errorCallback, void * context)
 {
     VerifyOrReturnError(initCallback != nullptr, CHIP_ERROR_INVALID_ARGUMENT);
     VerifyOrReturnError(errorCallback != nullptr, CHIP_ERROR_INVALID_ARGUMENT);

     initCallback(context, CHIP_NO_ERROR);
     return CHIP_NO_ERROR;
 }

 void ChipDnssdShutdown() {}

 CHIP_ERROR ChipDnssdRemoveServices()
 {

     VerifyOrReturnError(sResolverObject != nullptr && sRemoveServicesMethod != nullptr, CHIP_ERROR_INCORRECT_STATE);
     JNIEnv * env = JniReferences::GetInstance().GetEnvForCurrentThread();

     {
         DeviceLayer::StackUnlock unlock;
         env->CallVoidMethod(sResolverObject, sRemoveServicesMethod);
     }

     if (env->ExceptionCheck())
     {
         ChipLogError(Discovery, "Java exception in ChipDnssdRemoveServices");
         env->ExceptionDescribe();
         env->ExceptionClear();
         return CHIP_JNI_ERROR_EXCEPTION_THROWN;
     }

     return CHIP_NO_ERROR;
 }

 CHIP_ERROR ChipDnssdPublishService(const DnssdService * service, DnssdPublishCallback callback, void * context)
 {
     VerifyOrReturnError(service != nullptr, CHIP_ERROR_INVALID_ARGUMENT);
     VerifyOrReturnError(sResolverObject != nullptr && sPublishMethod != nullptr, CHIP_ERROR_INCORRECT_STATE);
     VerifyOrReturnError(CanCastTo<uint32_t>(service->mTextEntrySize), CHIP_ERROR_INVALID_ARGUMENT);
     VerifyOrReturnError(CanCastTo<uint32_t>(service->mSubTypeSize), CHIP_ERROR_INVALID_ARGUMENT);

     JNIEnv * env = JniReferences::GetInstance().GetEnvForCurrentThread();
     UtfString jniName(env, service->mName);
     UtfString jniHostName(env, service->mHostName);

     std::string serviceType = service->mType;
     serviceType += '.';
     serviceType += (service->mProtocol == DnssdServiceProtocol::kDnssdProtocolUdp ? "_udp" : "_tcp");
     UtfString jniServiceType(env, serviceType.c_str());

     auto textEntrySize = static_cast<uint32_t>(service->mTextEntrySize);

     jclass stringClass = env->FindClass("java/lang/String");
     jobjectArray keys  = env->NewObjectArray(textEntrySize, stringClass, nullptr);

     jclass arrayElemType = env->FindClass("[B");
     jobjectArray datas   = env->NewObjectArray(textEntrySize, arrayElemType, nullptr);

     for (uint32_t i = 0; i < textEntrySize; i++)
     {
         UtfString jniKey(env, service->mTextEntries[i].mKey);
         env->SetObjectArrayElement(keys, i, jniKey.jniValue());

         VerifyOrReturnError(CanCastTo<uint32_t>(service->mTextEntries[i].mDataSize), CHIP_ERROR_INVALID_ARGUMENT);
         auto dataSize = static_cast<uint32_t>(service->mTextEntries[i].mDataSize);
         ByteArray jniData(env, (const jbyte *) service->mTextEntries[i].mData, dataSize);
         env->SetObjectArrayElement(datas, i, jniData.jniValue());
     }

     auto subTypeSize      = static_cast<uint32_t>(service->mSubTypeSize);
     jobjectArray subTypes = env->NewObjectArray(subTypeSize, stringClass, nullptr);
     for (uint32_t i = 0; i < subTypeSize; i++)
     {
         UtfString jniSubType(env, service->mSubTypes[i]);
         env->SetObjectArrayElement(subTypes, i, jniSubType.jniValue());
     }

     {
         DeviceLayer::StackUnlock unlock;
         env->CallVoidMethod(sResolverObject, sPublishMethod, jniName.jniValue(), jniHostName.jniValue(), jniServiceType.jniValue(),
                             service->mPort, keys, datas, subTypes);
     }

     if (env->ExceptionCheck())
     {
         ChipLogError(Discovery, "Java exception in ChipDnssdPublishService");
         env->ExceptionDescribe();
         env->ExceptionClear();
         return CHIP_JNI_ERROR_EXCEPTION_THROWN;
     }

     return CHIP_NO_ERROR;
 }

 CHIP_ERROR ChipDnssdFinalizeServiceUpdate()
 {
     return CHIP_NO_ERROR;
 }

 std::string GetFullType(const char * type, DnssdServiceProtocol protocol)
 {
     std::ostringstream typeBuilder;
     typeBuilder << type;
     typeBuilder << (protocol == DnssdServiceProtocol::kDnssdProtocolUdp ? kProtocolUdp : kProtocolTcp);
     return typeBuilder.str();
 }

 std::string GetFullTypeWithSubTypes(const char * type, DnssdServiceProtocol protocol)
 {
     auto fullType = GetFullType(type, protocol);

     std::string subtypeDelimiter = "._sub.";
     size_t position              = fullType.find(subtypeDelimiter);
     if (position != std::string::npos)
     {
         fullType = fullType.substr(position + subtypeDelimiter.size()) + "," + fullType.substr(0, position);
     }

     return fullType;
 }

 std::string GetFullType(const DnssdService * service)
 {
     return GetFullType(service->mType, service->mProtocol);
 }

 CHIP_ERROR ChipDnssdBrowse(const char * type, DnssdServiceProtocol protocol, Inet::IPAddressType addressType,
                            Inet::InterfaceId interface, DnssdBrowseCallback callback, void * context, intptr_t * browseIdentifier)
 {
     VerifyOrReturnError(type != nullptr && callback != nullptr, CHIP_ERROR_INVALID_ARGUMENT);
     VerifyOrReturnError(sBrowserObject != nullptr && sBrowseMethod != nullptr, CHIP_ERROR_INVALID_ARGUMENT);
     VerifyOrReturnError(sMdnsCallbackObject != nullptr, CHIP_ERROR_INCORRECT_STATE);

     std::string serviceType = GetFullTypeWithSubTypes(type, protocol);
     JNIEnv * env            = JniReferences::GetInstance().GetEnvForCurrentThread();
     UtfString jniServiceType(env, serviceType.c_str());

     env->CallVoidMethod(sBrowserObject, sBrowseMethod, jniServiceType.jniValue(), reinterpret_cast<jlong>(callback),
                         reinterpret_cast<jlong>(context), sMdnsCallbackObject);

     if (env->ExceptionCheck())
     {
         ChipLogError(Discovery, "Java exception in ChipDnssdBrowse");
         env->ExceptionDescribe();
         env->ExceptionClear();
         return CHIP_JNI_ERROR_EXCEPTION_THROWN;
     }

     *browseIdentifier = reinterpret_cast<intptr_t>(nullptr);
     return CHIP_NO_ERROR;
 }

 CHIP_ERROR ChipDnssdStopBrowse(intptr_t browseIdentifier)
 {
     return CHIP_ERROR_NOT_IMPLEMENTED;
 }

 template <size_t N>
 CHIP_ERROR extractProtocol(const char * serviceType, char (&outServiceName)[N], DnssdServiceProtocol & outProtocol)
 {
     const char * dotPos = strrchr(serviceType, '.');
     ReturnErrorCodeIf(dotPos == nullptr, CHIP_ERROR_INVALID_ARGUMENT);

     size_t lengthWithoutProtocol = static_cast<size_t>(dotPos - serviceType);
     ReturnErrorCodeIf(lengthWithoutProtocol + 1 > N, CHIP_ERROR_INVALID_ARGUMENT);

     memcpy(outServiceName, serviceType, lengthWithoutProtocol);
     outServiceName[lengthWithoutProtocol] = '\0'; // Set a null terminator

     outProtocol = DnssdServiceProtocol::kDnssdProtocolUnknown;
     if (strstr(dotPos, "._tcp") != 0)
     {
         outProtocol = DnssdServiceProtocol::kDnssdProtocolTcp;
     }
     else if (strstr(dotPos, "._udp") != 0)
     {
         outProtocol = DnssdServiceProtocol::kDnssdProtocolUdp;
     }
     else
     {
         ChipLogError(Discovery, "protocol type don't include neithor TCP nor UDP!");
         return CHIP_ERROR_INVALID_ARGUMENT;
     }

     ReturnErrorCodeIf(outProtocol == DnssdServiceProtocol::kDnssdProtocolUnknown, CHIP_ERROR_INVALID_ARGUMENT);

     return CHIP_NO_ERROR;
 }

 CHIP_ERROR ChipDnssdResolve(DnssdService * service, Inet::InterfaceId interface, DnssdResolveCallback callback, void * context)
 {
     VerifyOrReturnError(service != nullptr && callback != nullptr, CHIP_ERROR_INVALID_ARGUMENT);
     VerifyOrReturnError(sResolverObject != nullptr && sResolveMethod != nullptr, CHIP_ERROR_INCORRECT_STATE);
     VerifyOrReturnError(sMdnsCallbackObject != nullptr, CHIP_ERROR_INCORRECT_STATE);

     std::string serviceType = GetFullType(service);
     JNIEnv * env            = JniReferences::GetInstance().GetEnvForCurrentThread();
     UtfString jniInstanceName(env, service->mName);
     UtfString jniServiceType(env, serviceType.c_str());

     {
         DeviceLayer::StackUnlock unlock;
         env->CallVoidMethod(sResolverObject, sResolveMethod, jniInstanceName.jniValue(), jniServiceType.jniValue(),
                             reinterpret_cast<jlong>(callback), reinterpret_cast<jlong>(context), sMdnsCallbackObject);
     }

     if (env->ExceptionCheck())
     {
         ChipLogError(Discovery, "Java exception in ChipDnssdResolve");
         env->ExceptionDescribe();
         env->ExceptionClear();
         return CHIP_JNI_ERROR_EXCEPTION_THROWN;
     }

     return CHIP_NO_ERROR;
 }

 void ChipDnssdResolveNoLongerNeeded(const char * instanceName) {}

 CHIP_ERROR ChipDnssdReconfirmRecord(const char * hostname, chip::Inet::IPAddress address, chip::Inet::InterfaceId interface)
 {
     return CHIP_ERROR_NOT_IMPLEMENTED;
 }

 // Implemention of Java-specific functions

 void InitializeWithObjects(jobject resolverObject, jobject browserObject, jobject mdnsCallbackObject)
 {
     JNIEnv * env         = JniReferences::GetInstance().GetEnvForCurrentThread();
     sResolverObject      = env->NewGlobalRef(resolverObject);
     sBrowserObject       = env->NewGlobalRef(browserObject);
     sMdnsCallbackObject  = env->NewGlobalRef(mdnsCallbackObject);
     jclass resolverClass = env->GetObjectClass(sResolverObject);
     jclass browserClass  = env->GetObjectClass(browserObject);
     sMdnsCallbackClass   = env->GetObjectClass(sMdnsCallbackObject);

     VerifyOrReturn(browserClass != nullptr, ChipLogError(Discovery, "Failed to get Browse Java class"));
     VerifyOrReturn(resolverClass != nullptr, ChipLogError(Discovery, "Failed to get Resolver Java class"));

     sGetTextEntryKeysMethod = env->GetMethodID(sMdnsCallbackClass, "getTextEntryKeys", "(Ljava/util/Map;)[Ljava/lang/String;");

     sGetTextEntryDataMethod = env->GetMethodID(sMdnsCallbackClass, "getTextEntryData", "(Ljava/util/Map;Ljava/lang/String;)[B");

     sResolveMethod =
         env->GetMethodID(resolverClass, "resolve", "(Ljava/lang/String;Ljava/lang/String;JJLchip/platform/ChipMdnsCallback;)V");

     sBrowseMethod = env->GetMethodID(browserClass, "browse", "(Ljava/lang/String;JJLchip/platform/ChipMdnsCallback;)V");

     if (sResolveMethod == nullptr)
     {
         ChipLogError(Discovery, "Failed to access Resolver 'resolve' method");
         env->ExceptionClear();
     }

     if (sBrowseMethod == nullptr)
     {
         ChipLogError(Discovery, "Failed to access Discover 'browse' method");
         env->ExceptionClear();
     }

     if (sGetTextEntryKeysMethod == nullptr)
     {
         ChipLogError(Discovery, "Failed to access MdnsCallback 'getTextEntryKeys' method");
         env->ExceptionClear();
     }

     if (sGetTextEntryDataMethod == nullptr)
     {
         ChipLogError(Discovery, "Failed to access MdnsCallback 'getTextEntryData' method");
         env->ExceptionClear();
     }

     sPublishMethod =
         env->GetMethodID(resolverClass, "publish",
                          "(Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;I[Ljava/lang/String;[[B[Ljava/lang/String;)V");
     if (sPublishMethod == nullptr)
     {
         ChipLogError(Discovery, "Failed to access Resolver 'publish' method");
         env->ExceptionClear();
     }

     sRemoveServicesMethod = env->GetMethodID(resolverClass, "removeServices", "()V");
     if (sRemoveServicesMethod == nullptr)
     {
         ChipLogError(Discovery, "Failed to access Resolver 'removeServices' method");
         env->ExceptionClear();
     }
 }

 void HandleResolve(jstring instanceName, jstring serviceType, jstring hostName, jstring address, jint port, jobject textEntries,
                    jlong callbackHandle, jlong contextHandle)
 {
     VerifyOrReturn(callbackHandle != 0, ChipLogError(Discovery, "HandleResolve called with callback equal to nullptr"));

     const auto dispatch = [callbackHandle, contextHandle](CHIP_ERROR error, DnssdService * service = nullptr,
                                                           Inet::IPAddress * address = nullptr) {
         DeviceLayer::StackLock lock;
         DnssdResolveCallback callback = reinterpret_cast<DnssdResolveCallback>(callbackHandle);
         size_t addr_count             = (address == nullptr) ? 0 : 1;
         callback(reinterpret_cast<void *>(contextHandle), service, Span<Inet::IPAddress>(address, addr_count), error);
     };

     VerifyOrReturn(address != nullptr && port != 0, dispatch(CHIP_ERROR_UNKNOWN_RESOURCE_ID));

     JNIEnv * env = JniReferences::GetInstance().GetEnvForCurrentThread();
     JniUtfString jniInstanceName(env, instanceName);
     JniUtfString jniServiceType(env, serviceType);
     JniUtfString jnihostName(env, hostName);
     JniUtfString jniAddress(env, address);
     Inet::IPAddress ipAddress;
     Inet::InterfaceId iface;

     VerifyOrReturn(strlen(jniInstanceName.c_str()) <= Operational::kInstanceNameMaxLength, dispatch(CHIP_ERROR_INVALID_ARGUMENT));
     VerifyOrReturn(strlen(jniServiceType.c_str()) <= kDnssdTypeAndProtocolMaxSize, dispatch(CHIP_ERROR_INVALID_ARGUMENT));
     VerifyOrReturn(CanCastTo<uint16_t>(port), dispatch(CHIP_ERROR_INVALID_ARGUMENT));
     VerifyOrReturn(Inet::IPAddress::FromString(const_cast<char *>(jniAddress.c_str()), ipAddress, iface),
                    dispatch(CHIP_ERROR_INVALID_ARGUMENT));

     DnssdService service = {};
     CopyString(service.mName, jniInstanceName.c_str());
     CopyString(service.mHostName, jnihostName.c_str());

     VerifyOrReturn(extractProtocol(jniServiceType.c_str(), service.mType, service.mProtocol) == CHIP_NO_ERROR,
                    dispatch(CHIP_ERROR_INVALID_ARGUMENT));

     service.mPort          = static_cast<uint16_t>(port);
     service.mInterface     = iface;
     service.mTextEntrySize = 0;
     service.mTextEntries   = nullptr;

     // Note on alloc/free memory use
     // We are only allocating the entries list and the data field of each entry
     // so we free these in the exit section
     if (textEntries != nullptr)
     {
         jobjectArray keys   = (jobjectArray) env->CallObjectMethod(sMdnsCallbackObject, sGetTextEntryKeysMethod, textEntries);
         auto size           = env->GetArrayLength(keys);
         TextEntry * entries = new (std::nothrow) TextEntry[size];
         VerifyOrExit(entries != nullptr, ChipLogError(Discovery, "entries alloc failure"));
         memset(entries, 0, sizeof(entries[0]) * size);

         service.mTextEntries = entries;
         for (decltype(size) i = 0; i < size; i++)
         {
             jstring jniKeyObject = (jstring) env->GetObjectArrayElement(keys, i);
             JniUtfString key(env, jniKeyObject);
             entries[i].mKey = strdup(key.c_str());

             jbyteArray datas =
                 (jbyteArray) env->CallObjectMethod(sMdnsCallbackObject, sGetTextEntryDataMethod, textEntries, jniKeyObject);
             if (datas != nullptr)
             {
                 size_t dataSize = env->GetArrayLength(datas);
                 uint8_t * data  = new (std::nothrow) uint8_t[dataSize];
                 VerifyOrExit(data != nullptr, ChipLogError(Discovery, "data alloc failure"));

                 jbyte * jnidata = env->GetByteArrayElements(datas, nullptr);
                 for (size_t j = 0; j < dataSize; j++)
                 {
                     data[j] = static_cast<uint8_t>(jnidata[j]);
                 }
                 entries[i].mDataSize = dataSize;
                 entries[i].mData     = data;

                 ChipLogProgress(Discovery, " ----- entry [%u] : %s %s\n", static_cast<unsigned int>(i), entries[i].mKey,
                                 std::string(reinterpret_cast<char *>(data), dataSize).c_str());
             }
             else
             {
                 ChipLogProgress(Discovery, " ----- entry [%u] : %s NULL\n", static_cast<unsigned int>(i), entries[i].mKey);

                 entries[i].mDataSize = 0;
                 entries[i].mData     = nullptr;
             }
             service.mTextEntrySize = size;
         }
     }

 exit:
     dispatch(CHIP_NO_ERROR, &service, &ipAddress);

     if (service.mTextEntries != nullptr)
     {
         size_t size = service.mTextEntrySize;
         for (size_t i = 0; i < size; i++)
         {
             delete[] service.mTextEntries[i].mKey;
             if (service.mTextEntries[i].mData != nullptr)
             {
                 delete[] service.mTextEntries[i].mData;
             }
         }
         delete[] service.mTextEntries;
     }
 }

 void HandleBrowse(jobjectArray instanceName, jstring serviceType, jlong callbackHandle, jlong contextHandle)
 {
     VerifyOrReturn(callbackHandle != 0, ChipLogError(Discovery, "HandleDiscover called with callback equal to nullptr"));

     const auto dispatch = [callbackHandle, contextHandle](CHIP_ERROR error, DnssdService * service = nullptr, size_t size = 0) {
         DeviceLayer::StackLock lock;
         DnssdBrowseCallback callback = reinterpret_cast<DnssdBrowseCallback>(callbackHandle);
         callback(reinterpret_cast<void *>(contextHandle), service, size, true, error);
     };

     JNIEnv * env = JniReferences::GetInstance().GetEnvForCurrentThread();
     JniUtfString jniServiceType(env, serviceType);

     auto size              = env->GetArrayLength(instanceName);
     DnssdService * service = new DnssdService[size];
     for (decltype(size) i = 0; i < size; i++)
     {
         JniUtfString jniInstanceName(env, (jstring) env->GetObjectArrayElement(instanceName, i));
         VerifyOrReturn(strlen(jniInstanceName.c_str()) <= Operational::kInstanceNameMaxLength,
                        dispatch(CHIP_ERROR_INVALID_ARGUMENT));

         CopyString(service[i].mName, jniInstanceName.c_str());
         VerifyOrReturn(extractProtocol(jniServiceType.c_str(), service[i].mType, service[i].mProtocol) == CHIP_NO_ERROR,
                        dispatch(CHIP_ERROR_INVALID_ARGUMENT));
     }

     dispatch(CHIP_NO_ERROR, service, size);
     delete[] service;
 }

 } // namespace Dnssd
 } // namespace chip
	/*
	*
	* Copyright (c) 2020-2021 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 "DnssdImpl.h"

	#include <lib/dnssd/platform/Dnssd.h>
	#include <lib/support/CHIPJNIError.h>
	#include <lib/support/CHIPMemString.h>
	#include <lib/support/CodeUtils.h>
	#include <lib/support/JniReferences.h>
	#include <lib/support/JniTypeWrappers.h>
	#include <lib/support/SafeInt.h>
	#include <lib/support/logging/CHIPLogging.h>
	#include <platform/internal/CHIPDeviceLayerInternal.h>

	#include <cstddef>
	#include <jni.h>
	#include <memory>
	#include <sstream>
	#include <string>

	namespace chip {
	namespace Dnssd {

	using namespace chip::Platform;

	namespace {
	jobject sResolverObject = nullptr;
	jobject sBrowserObject = nullptr;
	jobject sMdnsCallbackObject = nullptr;
	jmethodID sResolveMethod = nullptr;
	jmethodID sBrowseMethod = nullptr;
	jmethodID sGetTextEntryKeysMethod = nullptr;
	jmethodID sGetTextEntryDataMethod = nullptr;
	jclass sMdnsCallbackClass = nullptr;
	jmethodID sPublishMethod = nullptr;
	jmethodID sRemoveServicesMethod = nullptr;
	} // namespace

	// Implementation of functions declared in lib/dnssd/platform/Dnssd.h

	constexpr const char * kProtocolTcp = "._tcp";
	constexpr const char * kProtocolUdp = "._udp";

	CHIP_ERROR ChipDnssdInit(DnssdAsyncReturnCallback initCallback, DnssdAsyncReturnCallback errorCallback, void * context)
	{
	VerifyOrReturnError(initCallback != nullptr, CHIP_ERROR_INVALID_ARGUMENT);
	VerifyOrReturnError(errorCallback != nullptr, CHIP_ERROR_INVALID_ARGUMENT);

	initCallback(context, CHIP_NO_ERROR);
	return CHIP_NO_ERROR;
	}

	void ChipDnssdShutdown() {}

	CHIP_ERROR ChipDnssdRemoveServices()
	{

	VerifyOrReturnError(sResolverObject != nullptr && sRemoveServicesMethod != nullptr, CHIP_ERROR_INCORRECT_STATE);
	JNIEnv * env = JniReferences::GetInstance().GetEnvForCurrentThread();

	{
	DeviceLayer::StackUnlock unlock;
	env->CallVoidMethod(sResolverObject, sRemoveServicesMethod);
	}

	if (env->ExceptionCheck())
	{
	ChipLogError(Discovery, "Java exception in ChipDnssdRemoveServices");
	env->ExceptionDescribe();
	env->ExceptionClear();
	return CHIP_JNI_ERROR_EXCEPTION_THROWN;
	}

	return CHIP_NO_ERROR;
	}

	CHIP_ERROR ChipDnssdPublishService(const DnssdService * service, DnssdPublishCallback callback, void * context)
	{
	VerifyOrReturnError(service != nullptr, CHIP_ERROR_INVALID_ARGUMENT);
	VerifyOrReturnError(sResolverObject != nullptr && sPublishMethod != nullptr, CHIP_ERROR_INCORRECT_STATE);
	VerifyOrReturnError(CanCastTo<uint32_t>(service->mTextEntrySize), CHIP_ERROR_INVALID_ARGUMENT);
	VerifyOrReturnError(CanCastTo<uint32_t>(service->mSubTypeSize), CHIP_ERROR_INVALID_ARGUMENT);

	JNIEnv * env = JniReferences::GetInstance().GetEnvForCurrentThread();
	UtfString jniName(env, service->mName);
	UtfString jniHostName(env, service->mHostName);

	std::string serviceType = service->mType;
	serviceType += '.';
	serviceType += (service->mProtocol == DnssdServiceProtocol::kDnssdProtocolUdp ? "_udp" : "_tcp");
	UtfString jniServiceType(env, serviceType.c_str());

	auto textEntrySize = static_cast<uint32_t>(service->mTextEntrySize);

	jclass stringClass = env->FindClass("java/lang/String");
	jobjectArray keys = env->NewObjectArray(textEntrySize, stringClass, nullptr);

	jclass arrayElemType = env->FindClass("[B");
	jobjectArray datas = env->NewObjectArray(textEntrySize, arrayElemType, nullptr);

	for (uint32_t i = 0; i < textEntrySize; i++)
	{
	UtfString jniKey(env, service->mTextEntries[i].mKey);
	env->SetObjectArrayElement(keys, i, jniKey.jniValue());

	VerifyOrReturnError(CanCastTo<uint32_t>(service->mTextEntries[i].mDataSize), CHIP_ERROR_INVALID_ARGUMENT);
	auto dataSize = static_cast<uint32_t>(service->mTextEntries[i].mDataSize);
	ByteArray jniData(env, (const jbyte *) service->mTextEntries[i].mData, dataSize);
	env->SetObjectArrayElement(datas, i, jniData.jniValue());
	}

	auto subTypeSize = static_cast<uint32_t>(service->mSubTypeSize);
	jobjectArray subTypes = env->NewObjectArray(subTypeSize, stringClass, nullptr);
	for (uint32_t i = 0; i < subTypeSize; i++)
	{
	UtfString jniSubType(env, service->mSubTypes[i]);
	env->SetObjectArrayElement(subTypes, i, jniSubType.jniValue());
	}

	{
	DeviceLayer::StackUnlock unlock;
	env->CallVoidMethod(sResolverObject, sPublishMethod, jniName.jniValue(), jniHostName.jniValue(), jniServiceType.jniValue(),
	service->mPort, keys, datas, subTypes);
	}

	if (env->ExceptionCheck())
	{
	ChipLogError(Discovery, "Java exception in ChipDnssdPublishService");
	env->ExceptionDescribe();
	env->ExceptionClear();
	return CHIP_JNI_ERROR_EXCEPTION_THROWN;
	}

	return CHIP_NO_ERROR;
	}

	CHIP_ERROR ChipDnssdFinalizeServiceUpdate()
	{
	return CHIP_NO_ERROR;
	}

	std::string GetFullType(const char * type, DnssdServiceProtocol protocol)
	{
	std::ostringstream typeBuilder;
	typeBuilder << type;
	typeBuilder << (protocol == DnssdServiceProtocol::kDnssdProtocolUdp ? kProtocolUdp : kProtocolTcp);
	return typeBuilder.str();
	}

	std::string GetFullTypeWithSubTypes(const char * type, DnssdServiceProtocol protocol)
	{
	auto fullType = GetFullType(type, protocol);

	std::string subtypeDelimiter = "._sub.";
	size_t position = fullType.find(subtypeDelimiter);
	if (position != std::string::npos)
	{
	fullType = fullType.substr(position + subtypeDelimiter.size()) + "," + fullType.substr(0, position);
	}

	return fullType;
	}

	std::string GetFullType(const DnssdService * service)
	{
	return GetFullType(service->mType, service->mProtocol);
	}

	CHIP_ERROR ChipDnssdBrowse(const char * type, DnssdServiceProtocol protocol, Inet::IPAddressType addressType,
	Inet::InterfaceId interface, DnssdBrowseCallback callback, void * context, intptr_t * browseIdentifier)
	{
	VerifyOrReturnError(type != nullptr && callback != nullptr, CHIP_ERROR_INVALID_ARGUMENT);
	VerifyOrReturnError(sBrowserObject != nullptr && sBrowseMethod != nullptr, CHIP_ERROR_INVALID_ARGUMENT);
	VerifyOrReturnError(sMdnsCallbackObject != nullptr, CHIP_ERROR_INCORRECT_STATE);

	std::string serviceType = GetFullTypeWithSubTypes(type, protocol);
	JNIEnv * env = JniReferences::GetInstance().GetEnvForCurrentThread();
	UtfString jniServiceType(env, serviceType.c_str());

	env->CallVoidMethod(sBrowserObject, sBrowseMethod, jniServiceType.jniValue(), reinterpret_cast<jlong>(callback),
	reinterpret_cast<jlong>(context), sMdnsCallbackObject);

	if (env->ExceptionCheck())
	{
	ChipLogError(Discovery, "Java exception in ChipDnssdBrowse");
	env->ExceptionDescribe();
	env->ExceptionClear();
	return CHIP_JNI_ERROR_EXCEPTION_THROWN;
	}

	*browseIdentifier = reinterpret_cast<intptr_t>(nullptr);
	return CHIP_NO_ERROR;
	}

	CHIP_ERROR ChipDnssdStopBrowse(intptr_t browseIdentifier)
	{
	return CHIP_ERROR_NOT_IMPLEMENTED;
	}

	template <size_t N>
	CHIP_ERROR extractProtocol(const char * serviceType, char (&outServiceName)[N], DnssdServiceProtocol & outProtocol)
	{
	const char * dotPos = strrchr(serviceType, '.');
	ReturnErrorCodeIf(dotPos == nullptr, CHIP_ERROR_INVALID_ARGUMENT);

	size_t lengthWithoutProtocol = static_cast<size_t>(dotPos - serviceType);
	ReturnErrorCodeIf(lengthWithoutProtocol + 1 > N, CHIP_ERROR_INVALID_ARGUMENT);

	memcpy(outServiceName, serviceType, lengthWithoutProtocol);
	outServiceName[lengthWithoutProtocol] = '\0'; // Set a null terminator

	outProtocol = DnssdServiceProtocol::kDnssdProtocolUnknown;
	if (strstr(dotPos, "._tcp") != 0)
	{
	outProtocol = DnssdServiceProtocol::kDnssdProtocolTcp;
	}
	else if (strstr(dotPos, "._udp") != 0)
	{
	outProtocol = DnssdServiceProtocol::kDnssdProtocolUdp;
	}
	else
	{
	ChipLogError(Discovery, "protocol type don't include neithor TCP nor UDP!");
	return CHIP_ERROR_INVALID_ARGUMENT;
	}

	ReturnErrorCodeIf(outProtocol == DnssdServiceProtocol::kDnssdProtocolUnknown, CHIP_ERROR_INVALID_ARGUMENT);

	return CHIP_NO_ERROR;
	}

	CHIP_ERROR ChipDnssdResolve(DnssdService * service, Inet::InterfaceId interface, DnssdResolveCallback callback, void * context)
	{
	VerifyOrReturnError(service != nullptr && callback != nullptr, CHIP_ERROR_INVALID_ARGUMENT);
	VerifyOrReturnError(sResolverObject != nullptr && sResolveMethod != nullptr, CHIP_ERROR_INCORRECT_STATE);
	VerifyOrReturnError(sMdnsCallbackObject != nullptr, CHIP_ERROR_INCORRECT_STATE);

	std::string serviceType = GetFullType(service);
	JNIEnv * env = JniReferences::GetInstance().GetEnvForCurrentThread();
	UtfString jniInstanceName(env, service->mName);
	UtfString jniServiceType(env, serviceType.c_str());

	{
	DeviceLayer::StackUnlock unlock;
	env->CallVoidMethod(sResolverObject, sResolveMethod, jniInstanceName.jniValue(), jniServiceType.jniValue(),
	reinterpret_cast<jlong>(callback), reinterpret_cast<jlong>(context), sMdnsCallbackObject);
	}

	if (env->ExceptionCheck())
	{
	ChipLogError(Discovery, "Java exception in ChipDnssdResolve");
	env->ExceptionDescribe();
	env->ExceptionClear();
	return CHIP_JNI_ERROR_EXCEPTION_THROWN;
	}

	return CHIP_NO_ERROR;
	}

	void ChipDnssdResolveNoLongerNeeded(const char * instanceName) {}

	CHIP_ERROR ChipDnssdReconfirmRecord(const char * hostname, chip::Inet::IPAddress address, chip::Inet::InterfaceId interface)
	{
	return CHIP_ERROR_NOT_IMPLEMENTED;
	}

	// Implemention of Java-specific functions

	void InitializeWithObjects(jobject resolverObject, jobject browserObject, jobject mdnsCallbackObject)
	{
	JNIEnv * env = JniReferences::GetInstance().GetEnvForCurrentThread();
	sResolverObject = env->NewGlobalRef(resolverObject);
	sBrowserObject = env->NewGlobalRef(browserObject);
	sMdnsCallbackObject = env->NewGlobalRef(mdnsCallbackObject);
	jclass resolverClass = env->GetObjectClass(sResolverObject);
	jclass browserClass = env->GetObjectClass(browserObject);
	sMdnsCallbackClass = env->GetObjectClass(sMdnsCallbackObject);

	VerifyOrReturn(browserClass != nullptr, ChipLogError(Discovery, "Failed to get Browse Java class"));
	VerifyOrReturn(resolverClass != nullptr, ChipLogError(Discovery, "Failed to get Resolver Java class"));

	sGetTextEntryKeysMethod = env->GetMethodID(sMdnsCallbackClass, "getTextEntryKeys", "(Ljava/util/Map;)[Ljava/lang/String;");

	sGetTextEntryDataMethod = env->GetMethodID(sMdnsCallbackClass, "getTextEntryData", "(Ljava/util/Map;Ljava/lang/String;)[B");

	sResolveMethod =
	env->GetMethodID(resolverClass, "resolve", "(Ljava/lang/String;Ljava/lang/String;JJLchip/platform/ChipMdnsCallback;)V");

	sBrowseMethod = env->GetMethodID(browserClass, "browse", "(Ljava/lang/String;JJLchip/platform/ChipMdnsCallback;)V");

	if (sResolveMethod == nullptr)
	{
	ChipLogError(Discovery, "Failed to access Resolver 'resolve' method");
	env->ExceptionClear();
	}

	if (sBrowseMethod == nullptr)
	{
	ChipLogError(Discovery, "Failed to access Discover 'browse' method");
	env->ExceptionClear();
	}

	if (sGetTextEntryKeysMethod == nullptr)
	{
	ChipLogError(Discovery, "Failed to access MdnsCallback 'getTextEntryKeys' method");
	env->ExceptionClear();
	}

	if (sGetTextEntryDataMethod == nullptr)
	{
	ChipLogError(Discovery, "Failed to access MdnsCallback 'getTextEntryData' method");
	env->ExceptionClear();
	}

	sPublishMethod =
	env->GetMethodID(resolverClass, "publish",
	"(Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;I[Ljava/lang/String;[[B[Ljava/lang/String;)V");
	if (sPublishMethod == nullptr)
	{
	ChipLogError(Discovery, "Failed to access Resolver 'publish' method");
	env->ExceptionClear();
	}

	sRemoveServicesMethod = env->GetMethodID(resolverClass, "removeServices", "()V");
	if (sRemoveServicesMethod == nullptr)
	{
	ChipLogError(Discovery, "Failed to access Resolver 'removeServices' method");
	env->ExceptionClear();
	}
	}

	void HandleResolve(jstring instanceName, jstring serviceType, jstring hostName, jstring address, jint port, jobject textEntries,
	jlong callbackHandle, jlong contextHandle)
	{
	VerifyOrReturn(callbackHandle != 0, ChipLogError(Discovery, "HandleResolve called with callback equal to nullptr"));

	const auto dispatch = [callbackHandle, contextHandle](CHIP_ERROR error, DnssdService * service = nullptr,
	Inet::IPAddress * address = nullptr) {
	DeviceLayer::StackLock lock;
	DnssdResolveCallback callback = reinterpret_cast<DnssdResolveCallback>(callbackHandle);
	size_t addr_count = (address == nullptr) ? 0 : 1;
	callback(reinterpret_cast<void *>(contextHandle), service, Span<Inet::IPAddress>(address, addr_count), error);
	};

	VerifyOrReturn(address != nullptr && port != 0, dispatch(CHIP_ERROR_UNKNOWN_RESOURCE_ID));

	JNIEnv * env = JniReferences::GetInstance().GetEnvForCurrentThread();
	JniUtfString jniInstanceName(env, instanceName);
	JniUtfString jniServiceType(env, serviceType);
	JniUtfString jnihostName(env, hostName);
	JniUtfString jniAddress(env, address);
	Inet::IPAddress ipAddress;
	Inet::InterfaceId iface;

	VerifyOrReturn(strlen(jniInstanceName.c_str()) <= Operational::kInstanceNameMaxLength, dispatch(CHIP_ERROR_INVALID_ARGUMENT));
	VerifyOrReturn(strlen(jniServiceType.c_str()) <= kDnssdTypeAndProtocolMaxSize, dispatch(CHIP_ERROR_INVALID_ARGUMENT));
	VerifyOrReturn(CanCastTo<uint16_t>(port), dispatch(CHIP_ERROR_INVALID_ARGUMENT));
	VerifyOrReturn(Inet::IPAddress::FromString(const_cast<char *>(jniAddress.c_str()), ipAddress, iface),
	dispatch(CHIP_ERROR_INVALID_ARGUMENT));

	DnssdService service = {};
	CopyString(service.mName, jniInstanceName.c_str());
	CopyString(service.mHostName, jnihostName.c_str());

	VerifyOrReturn(extractProtocol(jniServiceType.c_str(), service.mType, service.mProtocol) == CHIP_NO_ERROR,
	dispatch(CHIP_ERROR_INVALID_ARGUMENT));

	service.mPort = static_cast<uint16_t>(port);
	service.mInterface = iface;
	service.mTextEntrySize = 0;
	service.mTextEntries = nullptr;

	// Note on alloc/free memory use
	// We are only allocating the entries list and the data field of each entry
	// so we free these in the exit section
	if (textEntries != nullptr)
	{
	jobjectArray keys = (jobjectArray) env->CallObjectMethod(sMdnsCallbackObject, sGetTextEntryKeysMethod, textEntries);
	auto size = env->GetArrayLength(keys);
	TextEntry * entries = new (std::nothrow) TextEntry[size];
	VerifyOrExit(entries != nullptr, ChipLogError(Discovery, "entries alloc failure"));
	memset(entries, 0, sizeof(entries[0]) * size);

	service.mTextEntries = entries;
	for (decltype(size) i = 0; i < size; i++)
	{
	jstring jniKeyObject = (jstring) env->GetObjectArrayElement(keys, i);
	JniUtfString key(env, jniKeyObject);
	entries[i].mKey = strdup(key.c_str());

	jbyteArray datas =
	(jbyteArray) env->CallObjectMethod(sMdnsCallbackObject, sGetTextEntryDataMethod, textEntries, jniKeyObject);
	if (datas != nullptr)
	{
	size_t dataSize = env->GetArrayLength(datas);
	uint8_t * data = new (std::nothrow) uint8_t[dataSize];
	VerifyOrExit(data != nullptr, ChipLogError(Discovery, "data alloc failure"));

	jbyte * jnidata = env->GetByteArrayElements(datas, nullptr);
	for (size_t j = 0; j < dataSize; j++)
	{
	data[j] = static_cast<uint8_t>(jnidata[j]);
	}
	entries[i].mDataSize = dataSize;
	entries[i].mData = data;

	ChipLogProgress(Discovery, " ----- entry [%u] : %s %s\n", static_cast<unsigned int>(i), entries[i].mKey,
	std::string(reinterpret_cast<char *>(data), dataSize).c_str());
	}
	else
	{
	ChipLogProgress(Discovery, " ----- entry [%u] : %s NULL\n", static_cast<unsigned int>(i), entries[i].mKey);

	entries[i].mDataSize = 0;
	entries[i].mData = nullptr;
	}
	service.mTextEntrySize = size;
	}
	}

	exit:
	dispatch(CHIP_NO_ERROR, &service, &ipAddress);

	if (service.mTextEntries != nullptr)
	{
	size_t size = service.mTextEntrySize;
	for (size_t i = 0; i < size; i++)
	{
	delete[] service.mTextEntries[i].mKey;
	if (service.mTextEntries[i].mData != nullptr)
	{
	delete[] service.mTextEntries[i].mData;
	}
	}
	delete[] service.mTextEntries;
	}
	}

	void HandleBrowse(jobjectArray instanceName, jstring serviceType, jlong callbackHandle, jlong contextHandle)
	{
	VerifyOrReturn(callbackHandle != 0, ChipLogError(Discovery, "HandleDiscover called with callback equal to nullptr"));

	const auto dispatch = [callbackHandle, contextHandle](CHIP_ERROR error, DnssdService * service = nullptr, size_t size = 0) {
	DeviceLayer::StackLock lock;
	DnssdBrowseCallback callback = reinterpret_cast<DnssdBrowseCallback>(callbackHandle);
	callback(reinterpret_cast<void *>(contextHandle), service, size, true, error);
	};

	JNIEnv * env = JniReferences::GetInstance().GetEnvForCurrentThread();
	JniUtfString jniServiceType(env, serviceType);

	auto size = env->GetArrayLength(instanceName);
	DnssdService * service = new DnssdService[size];
	for (decltype(size) i = 0; i < size; i++)
	{
	JniUtfString jniInstanceName(env, (jstring) env->GetObjectArrayElement(instanceName, i));
	VerifyOrReturn(strlen(jniInstanceName.c_str()) <= Operational::kInstanceNameMaxLength,
	dispatch(CHIP_ERROR_INVALID_ARGUMENT));

	CopyString(service[i].mName, jniInstanceName.c_str());
	VerifyOrReturn(extractProtocol(jniServiceType.c_str(), service[i].mType, service[i].mProtocol) == CHIP_NO_ERROR,
	dispatch(CHIP_ERROR_INVALID_ARGUMENT));
	}

	dispatch(CHIP_NO_ERROR, service, size);
	delete[] service;
	}

	} // namespace Dnssd
	} // namespace chip