PrivateDnsConfiguration.h - platform/packages/modules/DnsResolver - Gitiles

 /*
  * Copyright (C) 2018 The Android Open Source Project
  *
  * 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.
  */

 #pragma once

 #include <array>
 #include <list>
 #include <map>
 #include <mutex>
 #include <vector>

 #include <android-base/format.h>
 #include <android-base/logging.h>
 #include <android-base/result.h>
 #include <android-base/thread_annotations.h>
 #include <netdutils/BackoffSequence.h>
 #include <netdutils/DumpWriter.h>
 #include <netdutils/InternetAddresses.h>
 #include <netdutils/Slice.h>

 #include "DnsTlsServer.h"
 #include "LockedQueue.h"
 #include "PrivateDnsValidationObserver.h"
 #include "doh.h"

 namespace android {
 namespace net {

 // TODO: decouple the dependency of DnsTlsServer.
 struct PrivateDnsStatus {
     PrivateDnsMode mode;

     // TODO: change the type to std::vector<DnsTlsServer>.
     std::map<DnsTlsServer, Validation, AddressComparator> dotServersMap;

     std::map<netdutils::IPSockAddr, Validation> dohServersMap;

     std::list<DnsTlsServer> validatedServers() const {
         std::list<DnsTlsServer> servers;

         for (const auto& pair : dotServersMap) {
             if (pair.second == Validation::success) {
                 servers.push_back(pair.first);
             }
         }
         return servers;
     }

     bool hasValidatedDohServers() const {
         for (const auto& [_, status] : dohServersMap) {
             if (status == Validation::success) {
                 return true;
             }
         }
         return false;
     }
 };

 class PrivateDnsConfiguration {
   public:
     static constexpr int kDohQueryDefaultTimeoutMs = 30000;
     static constexpr int kDohProbeDefaultTimeoutMs = 60000;

     // The default value for QUIC max_idle_timeout.
     static constexpr int kDohIdleDefaultTimeoutMs = 55000;

     struct ServerIdentity {
         const netdutils::IPSockAddr sockaddr;
         const std::string provider;

         explicit ServerIdentity(const IPrivateDnsServer& server)
             : sockaddr(server.addr()), provider(server.provider()) {}
         ServerIdentity(const netdutils::IPSockAddr& addr, const std::string& host)
             : sockaddr(addr), provider(host) {}

         bool operator<(const ServerIdentity& other) const {
             return std::tie(sockaddr, provider) < std::tie(other.sockaddr, other.provider);
         }
         bool operator==(const ServerIdentity& other) const {
             return std::tie(sockaddr, provider) == std::tie(other.sockaddr, other.provider);
         }
     };

     // The only instance of PrivateDnsConfiguration.
     static PrivateDnsConfiguration& getInstance() {
         static PrivateDnsConfiguration instance;
         return instance;
     }

     int set(int32_t netId, uint32_t mark, const std::vector<std::string>& servers,
             const std::string& name, const std::string& caCert) EXCLUDES(mPrivateDnsLock);

     void initDoh() EXCLUDES(mPrivateDnsLock);

     int setDoh(int32_t netId, uint32_t mark, const std::vector<std::string>& servers,
                const std::string& name, const std::string& caCert) EXCLUDES(mPrivateDnsLock);

     PrivateDnsStatus getStatus(unsigned netId) const EXCLUDES(mPrivateDnsLock);

     void clear(unsigned netId) EXCLUDES(mPrivateDnsLock);

     void clearDoh(unsigned netId) EXCLUDES(mPrivateDnsLock);

     ssize_t dohQuery(unsigned netId, const netdutils::Slice query, const netdutils::Slice answer,
                      uint64_t timeoutMs) EXCLUDES(mPrivateDnsLock);

     // Request the server to be revalidated on a connection tagged with |mark|.
     // Returns a Result to indicate if the request is accepted.
     base::Result<void> requestValidation(unsigned netId, const ServerIdentity& identity,
                                          uint32_t mark) EXCLUDES(mPrivateDnsLock);

     void setObserver(PrivateDnsValidationObserver* observer);

     void dump(netdutils::DumpWriter& dw) const;

     void onDohStatusUpdate(uint32_t netId, bool success, const char* ipAddr, const char* host)
             EXCLUDES(mPrivateDnsLock);

     base::Result<netdutils::IPSockAddr> getDohServer(unsigned netId) const
             EXCLUDES(mPrivateDnsLock);

   private:
     typedef std::map<ServerIdentity, std::unique_ptr<IPrivateDnsServer>> PrivateDnsTracker;

     PrivateDnsConfiguration() = default;

     // Launchs a thread to run the validation for |server| on the network |netId|.
     // |isRevalidation| is true if this call is due to a revalidation request.
     void startValidation(const ServerIdentity& identity, unsigned netId, bool isRevalidation)
             REQUIRES(mPrivateDnsLock);

     bool recordPrivateDnsValidation(const ServerIdentity& identity, unsigned netId, bool success,
                                     bool isRevalidation) EXCLUDES(mPrivateDnsLock);

     void sendPrivateDnsValidationEvent(const ServerIdentity& identity, unsigned netId,
                                        bool success) const REQUIRES(mPrivateDnsLock);

     // Decide if a validation for |server| is needed. Note that servers that have failed
     // multiple validation attempts but for which there is still a validating
     // thread running are marked as being Validation::in_process.
     bool needsValidation(const IPrivateDnsServer& server) const REQUIRES(mPrivateDnsLock);

     void updateServerState(const ServerIdentity& identity, Validation state, uint32_t netId)
             REQUIRES(mPrivateDnsLock);

     // For testing.
     base::Result<IPrivateDnsServer*> getPrivateDns(const ServerIdentity& identity, unsigned netId)
             EXCLUDES(mPrivateDnsLock);

     base::Result<IPrivateDnsServer*> getPrivateDnsLocked(const ServerIdentity& identity,
                                                          unsigned netId) REQUIRES(mPrivateDnsLock);

     void initDohLocked() REQUIRES(mPrivateDnsLock);
     void clearDohLocked(unsigned netId) REQUIRES(mPrivateDnsLock);

     mutable std::mutex mPrivateDnsLock;
     std::map<unsigned, PrivateDnsMode> mPrivateDnsModes GUARDED_BY(mPrivateDnsLock);

     // Contains all servers for a network, along with their current validation status.
     // In case a server is removed due to a configuration change, it remains in this map,
     // but is marked inactive.
     // Any pending validation threads will continue running because we have no way to cancel them.
     std::map<unsigned, PrivateDnsTracker> mPrivateDnsTransports GUARDED_BY(mPrivateDnsLock);

     void notifyValidationStateUpdate(const netdutils::IPSockAddr& sockaddr, Validation validation,
                                      uint32_t netId) const REQUIRES(mPrivateDnsLock);

     bool needReportEvent(uint32_t netId, ServerIdentity identity, bool success) const
             REQUIRES(mPrivateDnsLock);

     // TODO: fix the reentrancy problem.
     PrivateDnsValidationObserver* mObserver GUARDED_BY(mPrivateDnsLock);

     DohDispatcher* mDohDispatcher;

     friend class PrivateDnsConfigurationTest;

     // It's not const because PrivateDnsConfigurationTest needs to override it.
     // TODO: make it const by dependency injection.
     netdutils::BackoffSequence<>::Builder mBackoffBuilder =
             netdutils::BackoffSequence<>::Builder()
                     .withInitialRetransmissionTime(std::chrono::seconds(60))
                     .withMaximumRetransmissionTime(std::chrono::seconds(3600));

     struct DohIdentity {
         std::string httpsTemplate;
         std::string ipAddr;
         std::string host;
         Validation status;
         bool operator<(const DohIdentity& other) const {
             return std::tie(ipAddr, host) < std::tie(other.ipAddr, other.host);
         }
         bool operator==(const DohIdentity& other) const {
             return std::tie(ipAddr, host) == std::tie(other.ipAddr, other.host);
         }
         bool operator<(const ServerIdentity& other) const {
             std::string otherIp = other.sockaddr.ip().toString();
             return std::tie(ipAddr, host) < std::tie(otherIp, other.provider);
         }
         bool operator==(const ServerIdentity& other) const {
             std::string otherIp = other.sockaddr.ip().toString();
             return std::tie(ipAddr, host) == std::tie(otherIp, other.provider);
         }
     };

     struct DohProviderEntry {
         std::string provider;
         std::set<std::string> ips;
         std::string host;
         std::string httpsTemplate;
         bool requireRootPermission;
         base::Result<DohIdentity> getDohIdentity(const std::vector<std::string>& ips,
                                                  const std::string& host) const {
             if (!host.empty() && this->host != host) return Errorf("host {} not matched", host);
             for (const auto& ip : ips) {
                 if (this->ips.find(ip) == this->ips.end()) continue;
                 LOG(INFO) << fmt::format("getDohIdentity: {} {}", ip, host);
                 // Only pick the first one for now.
                 return DohIdentity{httpsTemplate, ip, host, Validation::in_process};
             }
             return Errorf("server not matched");
         };
     };

     // TODO: Move below DoH relevant stuff into Rust implementation.
     std::map<unsigned, DohIdentity> mDohTracker GUARDED_BY(mPrivateDnsLock);
     std::array<DohProviderEntry, 4> mAvailableDoHProviders = {{
             {"Google",
              {"2001:4860:4860::8888", "2001:4860:4860::8844", "8.8.8.8", "8.8.4.4"},
              "dns.google",
              "https://dns.google/dns-query",
              false},
             {"Cloudflare",
              {"2606:4700::6810:f8f9", "2606:4700::6810:f9f9", "104.16.248.249", "104.16.249.249"},
              "cloudflare-dns.com",
              "https://cloudflare-dns.com/dns-query",
              false},

             // The DoH providers for testing only.
             // Using ResolverTestProvider requires that the DnsResolver is configured by someone
             // who has root permission, which should be run by tests only.
             {"ResolverTestProvider",
              {"127.0.0.3", "::1"},
              "example.com",
              "https://example.com/dns-query",
              true},
             {"AndroidTesting",
              {"192.0.2.100"},
              "dns.androidtesting.org",
              "https://dns.androidtesting.org/dns-query",
              false},
     }};

     struct RecordEntry {
         RecordEntry(uint32_t netId, const ServerIdentity& identity, Validation state)
             : netId(netId), serverIdentity(identity), state(state) {}

         const uint32_t netId;
         const ServerIdentity serverIdentity;
         const Validation state;
         const std::chrono::system_clock::time_point timestamp = std::chrono::system_clock::now();
     };

     LockedRingBuffer<RecordEntry> mPrivateDnsLog{100};
 };

 }  // namespace net
 }  // namespace android
	/*
	* Copyright (C) 2018 The Android Open Source Project
	*
	* 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.
	*/

	#pragma once

	#include <array>
	#include <list>
	#include <map>
	#include <mutex>
	#include <vector>

	#include <android-base/format.h>
	#include <android-base/logging.h>
	#include <android-base/result.h>
	#include <android-base/thread_annotations.h>
	#include <netdutils/BackoffSequence.h>
	#include <netdutils/DumpWriter.h>
	#include <netdutils/InternetAddresses.h>
	#include <netdutils/Slice.h>

	#include "DnsTlsServer.h"
	#include "LockedQueue.h"
	#include "PrivateDnsValidationObserver.h"
	#include "doh.h"

	namespace android {
	namespace net {

	// TODO: decouple the dependency of DnsTlsServer.
	struct PrivateDnsStatus {
	PrivateDnsMode mode;

	// TODO: change the type to std::vector<DnsTlsServer>.
	std::map<DnsTlsServer, Validation, AddressComparator> dotServersMap;

	std::map<netdutils::IPSockAddr, Validation> dohServersMap;

	std::list<DnsTlsServer> validatedServers() const {
	std::list<DnsTlsServer> servers;

	for (const auto& pair : dotServersMap) {
	if (pair.second == Validation::success) {
	servers.push_back(pair.first);
	}
	}
	return servers;
	}

	bool hasValidatedDohServers() const {
	for (const auto& [_, status] : dohServersMap) {
	if (status == Validation::success) {
	return true;
	}
	}
	return false;
	}
	};

	class PrivateDnsConfiguration {
	public:
	static constexpr int kDohQueryDefaultTimeoutMs = 30000;
	static constexpr int kDohProbeDefaultTimeoutMs = 60000;

	// The default value for QUIC max_idle_timeout.
	static constexpr int kDohIdleDefaultTimeoutMs = 55000;

	struct ServerIdentity {
	const netdutils::IPSockAddr sockaddr;
	const std::string provider;

	explicit ServerIdentity(const IPrivateDnsServer& server)
	: sockaddr(server.addr()), provider(server.provider()) {}
	ServerIdentity(const netdutils::IPSockAddr& addr, const std::string& host)
	: sockaddr(addr), provider(host) {}

	bool operator<(const ServerIdentity& other) const {
	return std::tie(sockaddr, provider) < std::tie(other.sockaddr, other.provider);
	}
	bool operator==(const ServerIdentity& other) const {
	return std::tie(sockaddr, provider) == std::tie(other.sockaddr, other.provider);
	}
	};

	// The only instance of PrivateDnsConfiguration.
	static PrivateDnsConfiguration& getInstance() {
	static PrivateDnsConfiguration instance;
	return instance;
	}

	int set(int32_t netId, uint32_t mark, const std::vector<std::string>& servers,
	const std::string& name, const std::string& caCert) EXCLUDES(mPrivateDnsLock);

	void initDoh() EXCLUDES(mPrivateDnsLock);

	int setDoh(int32_t netId, uint32_t mark, const std::vector<std::string>& servers,
	const std::string& name, const std::string& caCert) EXCLUDES(mPrivateDnsLock);

	PrivateDnsStatus getStatus(unsigned netId) const EXCLUDES(mPrivateDnsLock);

	void clear(unsigned netId) EXCLUDES(mPrivateDnsLock);

	void clearDoh(unsigned netId) EXCLUDES(mPrivateDnsLock);

	ssize_t dohQuery(unsigned netId, const netdutils::Slice query, const netdutils::Slice answer,
	uint64_t timeoutMs) EXCLUDES(mPrivateDnsLock);

	// Request the server to be revalidated on a connection tagged with \|mark\|.
	// Returns a Result to indicate if the request is accepted.
	base::Result<void> requestValidation(unsigned netId, const ServerIdentity& identity,
	uint32_t mark) EXCLUDES(mPrivateDnsLock);

	void setObserver(PrivateDnsValidationObserver* observer);

	void dump(netdutils::DumpWriter& dw) const;

	void onDohStatusUpdate(uint32_t netId, bool success, const char* ipAddr, const char* host)
	EXCLUDES(mPrivateDnsLock);

	base::Result<netdutils::IPSockAddr> getDohServer(unsigned netId) const
	EXCLUDES(mPrivateDnsLock);

	private:
	typedef std::map<ServerIdentity, std::unique_ptr<IPrivateDnsServer>> PrivateDnsTracker;

	PrivateDnsConfiguration() = default;

	// Launchs a thread to run the validation for \|server\| on the network \|netId\|.
	// \|isRevalidation\| is true if this call is due to a revalidation request.
	void startValidation(const ServerIdentity& identity, unsigned netId, bool isRevalidation)
	REQUIRES(mPrivateDnsLock);

	bool recordPrivateDnsValidation(const ServerIdentity& identity, unsigned netId, bool success,
	bool isRevalidation) EXCLUDES(mPrivateDnsLock);

	void sendPrivateDnsValidationEvent(const ServerIdentity& identity, unsigned netId,
	bool success) const REQUIRES(mPrivateDnsLock);

	// Decide if a validation for \|server\| is needed. Note that servers that have failed
	// multiple validation attempts but for which there is still a validating
	// thread running are marked as being Validation::in_process.
	bool needsValidation(const IPrivateDnsServer& server) const REQUIRES(mPrivateDnsLock);

	void updateServerState(const ServerIdentity& identity, Validation state, uint32_t netId)
	REQUIRES(mPrivateDnsLock);

	// For testing.
	base::Result<IPrivateDnsServer*> getPrivateDns(const ServerIdentity& identity, unsigned netId)
	EXCLUDES(mPrivateDnsLock);

	base::Result<IPrivateDnsServer*> getPrivateDnsLocked(const ServerIdentity& identity,
	unsigned netId) REQUIRES(mPrivateDnsLock);

	void initDohLocked() REQUIRES(mPrivateDnsLock);
	void clearDohLocked(unsigned netId) REQUIRES(mPrivateDnsLock);

	mutable std::mutex mPrivateDnsLock;
	std::map<unsigned, PrivateDnsMode> mPrivateDnsModes GUARDED_BY(mPrivateDnsLock);

	// Contains all servers for a network, along with their current validation status.
	// In case a server is removed due to a configuration change, it remains in this map,
	// but is marked inactive.
	// Any pending validation threads will continue running because we have no way to cancel them.
	std::map<unsigned, PrivateDnsTracker> mPrivateDnsTransports GUARDED_BY(mPrivateDnsLock);

	void notifyValidationStateUpdate(const netdutils::IPSockAddr& sockaddr, Validation validation,
	uint32_t netId) const REQUIRES(mPrivateDnsLock);

	bool needReportEvent(uint32_t netId, ServerIdentity identity, bool success) const
	REQUIRES(mPrivateDnsLock);

	// TODO: fix the reentrancy problem.
	PrivateDnsValidationObserver* mObserver GUARDED_BY(mPrivateDnsLock);

	DohDispatcher* mDohDispatcher;

	friend class PrivateDnsConfigurationTest;

	// It's not const because PrivateDnsConfigurationTest needs to override it.
	// TODO: make it const by dependency injection.
	netdutils::BackoffSequence<>::Builder mBackoffBuilder =
	netdutils::BackoffSequence<>::Builder()
	.withInitialRetransmissionTime(std::chrono::seconds(60))
	.withMaximumRetransmissionTime(std::chrono::seconds(3600));

	struct DohIdentity {
	std::string httpsTemplate;
	std::string ipAddr;
	std::string host;
	Validation status;
	bool operator<(const DohIdentity& other) const {
	return std::tie(ipAddr, host) < std::tie(other.ipAddr, other.host);
	}
	bool operator==(const DohIdentity& other) const {
	return std::tie(ipAddr, host) == std::tie(other.ipAddr, other.host);
	}
	bool operator<(const ServerIdentity& other) const {
	std::string otherIp = other.sockaddr.ip().toString();
	return std::tie(ipAddr, host) < std::tie(otherIp, other.provider);
	}
	bool operator==(const ServerIdentity& other) const {
	std::string otherIp = other.sockaddr.ip().toString();
	return std::tie(ipAddr, host) == std::tie(otherIp, other.provider);
	}
	};

	struct DohProviderEntry {
	std::string provider;
	std::set<std::string> ips;
	std::string host;
	std::string httpsTemplate;
	bool requireRootPermission;
	base::Result<DohIdentity> getDohIdentity(const std::vector<std::string>& ips,
	const std::string& host) const {
	if (!host.empty() && this->host != host) return Errorf("host {} not matched", host);
	for (const auto& ip : ips) {
	if (this->ips.find(ip) == this->ips.end()) continue;
	LOG(INFO) << fmt::format("getDohIdentity: {} {}", ip, host);
	// Only pick the first one for now.
	return DohIdentity{httpsTemplate, ip, host, Validation::in_process};
	}
	return Errorf("server not matched");
	};
	};

	// TODO: Move below DoH relevant stuff into Rust implementation.
	std::map<unsigned, DohIdentity> mDohTracker GUARDED_BY(mPrivateDnsLock);
	std::array<DohProviderEntry, 4> mAvailableDoHProviders = {{
	{"Google",
	{"2001:4860:4860::8888", "2001:4860:4860::8844", "8.8.8.8", "8.8.4.4"},
	"dns.google",
	"https://dns.google/dns-query",
	false},
	{"Cloudflare",
	{"2606:4700::6810:f8f9", "2606:4700::6810:f9f9", "104.16.248.249", "104.16.249.249"},
	"cloudflare-dns.com",
	"https://cloudflare-dns.com/dns-query",
	false},

	// The DoH providers for testing only.
	// Using ResolverTestProvider requires that the DnsResolver is configured by someone
	// who has root permission, which should be run by tests only.
	{"ResolverTestProvider",
	{"127.0.0.3", "::1"},
	"example.com",
	"https://example.com/dns-query",
	true},
	{"AndroidTesting",
	{"192.0.2.100"},
	"dns.androidtesting.org",
	"https://dns.androidtesting.org/dns-query",
	false},
	}};

	struct RecordEntry {
	RecordEntry(uint32_t netId, const ServerIdentity& identity, Validation state)
	: netId(netId), serverIdentity(identity), state(state) {}

	const uint32_t netId;
	const ServerIdentity serverIdentity;
	const Validation state;
	const std::chrono::system_clock::time_point timestamp = std::chrono::system_clock::now();
	};

	LockedRingBuffer<RecordEntry> mPrivateDnsLog{100};
	};

	} // namespace net
	} // namespace android