1  /*
  2  * Copyright (c) 2013-2025, The PurpleI2P Project
  3  *
  4  * This file is part of Purple i2pd project and licensed under BSD3
  5  *
  6  * See full license text in LICENSE file at top of project tree
  7  */
  8  
  9  #ifndef ADDRESS_BOOK_H__
 10  #define ADDRESS_BOOK_H__
 11  
 12  #include <string.h>
 13  #include <string>
 14  #include <string_view>
 15  #include <map>
 16  #include <vector>
 17  #include <iostream>
 18  #include <mutex>
 19  #include <future>
 20  #include <memory>
 21  #include <boost/asio.hpp>
 22  #include "Base.h"
 23  #include "Identity.h"
 24  #include "Log.h"
 25  #include "Destination.h"
 26  #include "LeaseSet.h"
 27  
 28  namespace i2p
 29  {
 30  namespace client
 31  {
 32  	const int INITIAL_SUBSCRIPTION_UPDATE_TIMEOUT = 3; // in minutes
 33  	const int INITIAL_SUBSCRIPTION_RETRY_TIMEOUT = 1; // in minutes
 34  	const int CONTINIOUS_SUBSCRIPTION_UPDATE_TIMEOUT = 720; // in minutes (12 hours)
 35  	const int CONTINIOUS_SUBSCRIPTION_RETRY_TIMEOUT = 5; // in minutes
 36  	const int CONTINIOUS_SUBSCRIPTION_MAX_NUM_RETRIES = 10; // then update timeout
 37  	const int SUBSCRIPTION_REQUEST_TIMEOUT = 120; //in seconds
 38  	const int ADDRESS_CACHE_EXPIRATION_TIMEOUT = 710; // in seconds
 39  	const int ADDRESS_CACHE_UPDATE_INTERVAL = 76; // in seconds
 40  
 41  	const uint16_t ADDRESS_RESOLVER_DATAGRAM_PORT = 53;
 42  	const uint16_t ADDRESS_RESPONSE_DATAGRAM_PORT = 54;
 43  
 44  	const size_t B33_ADDRESS_THRESHOLD = 52; // characters
 45  
 46  	struct Address
 47  	{
 48  		enum { eAddressIndentHash, eAddressBlindedPublicKey, eAddressInvalid } addressType;
 49  		i2p::data::IdentHash identHash;
 50  		std::shared_ptr<i2p::data::BlindedPublicKey> blindedPublicKey;
 51  
 52  		Address (std::string_view b32);
 53  		Address (const i2p::data::IdentHash& hash);
 54  		bool IsIdentHash () const { return addressType == eAddressIndentHash; };
 55  		bool IsValid () const { return addressType != eAddressInvalid; };
 56  	};
 57  
 58  	inline std::string GetB32Address(const i2p::data::IdentHash& ident) { return ident.ToBase32().append(".b32.i2p"); }
 59  
 60  	class AddressBookStorage // interface for storage
 61  	{
 62  		public:
 63  
 64  			typedef std::map<std::string, std::shared_ptr<Address>, std::less<> > Addresses;
 65  			
 66  			virtual ~AddressBookStorage () {};
 67  			virtual std::shared_ptr<const i2p::data::IdentityEx> GetAddress (const i2p::data::IdentHash& ident) = 0;
 68  			virtual void AddAddress (std::shared_ptr<const i2p::data::IdentityEx> address) = 0;
 69  			virtual void RemoveAddress (const i2p::data::IdentHash& ident) = 0;
 70  			virtual void CleanUpCache () = 0;
 71  
 72  			virtual bool Init () = 0;
 73  			virtual int Load (Addresses& addresses) = 0;
 74  			virtual int LoadLocal (Addresses& addresses) = 0;
 75  			virtual int Save (const Addresses& addresses) = 0;
 76  
 77  			virtual void SaveEtag (const i2p::data::IdentHash& subscription, const std::string& etag, const std::string& lastModified) = 0;
 78  			virtual bool GetEtag (const i2p::data::IdentHash& subscription, std::string& etag, std::string& lastModified) = 0;
 79  			virtual void ResetEtags () = 0;
 80  	};
 81  
 82  	class AddressBookSubscription;
 83  	class AddressResolver;
 84  	class AddressBook
 85  	{
 86  		public:
 87  			
 88  			AddressBook ();
 89  			~AddressBook ();
 90  			void Start ();
 91  			void StartResolvers ();
 92  			void Stop ();
 93  			std::shared_ptr<const Address> GetAddress (std::string_view address);
 94  			std::shared_ptr<const i2p::data::IdentityEx> GetFullAddress (const std::string& address);
 95  			std::shared_ptr<const Address> FindAddress (std::string_view address);
 96  			void LookupAddress (std::string_view address);
 97  			void InsertAddress (const std::string& address, const std::string& jump); // for jump links
 98  			void InsertFullAddress (std::shared_ptr<const i2p::data::IdentityEx> address);
 99  
100  			bool RecordExists (const std::string& address, const std::string& jump);
101  
102  			bool LoadHostsFromStream (std::istream& f, bool is_update);
103  			void DownloadComplete (bool success, const i2p::data::IdentHash& subscription, const std::string& etag, const std::string& lastModified);
104  			//This method returns the ".b32.i2p" address
105  			std::string ToAddress(const i2p::data::IdentHash& ident) { return GetB32Address(ident); }
106  			std::string ToAddress(std::shared_ptr<const i2p::data::IdentityEx> ident) { return ToAddress(ident->GetIdentHash ()); }
107  
108  			bool GetEtag (const i2p::data::IdentHash& subscription, std::string& etag, std::string& lastModified);
109  			bool IsEnabled () const { return m_IsEnabled; }
110  			
111  		private:
112  
113  			void StartSubscriptions ();
114  			void StopSubscriptions ();
115  
116  			void LoadHosts ();
117  			void LoadSubscriptions ();
118  			void LoadLocal ();
119  
120  			void HandleSubscriptionsUpdateTimer (const boost::system::error_code& ecode);
121  
122  			void StartLookups ();
123  			void StopLookups ();
124  			void HandleLookupResponse (const i2p::data::IdentityEx& from, uint16_t fromPort, uint16_t toPort, const uint8_t * buf, size_t len);
125  
126  			void ScheduleCacheUpdate ();
127  			
128  		private:
129  
130  			std::mutex m_AddressBookMutex;
131  			AddressBookStorage::Addresses m_Addresses;
132  			std::map<i2p::data::IdentHash, std::shared_ptr<AddressResolver> > m_Resolvers; // local destination->resolver
133  			std::mutex m_LookupsMutex;
134  			std::map<uint32_t, std::string> m_Lookups; // nonce -> address
135  			AddressBookStorage * m_Storage;
136  			volatile bool m_IsLoaded;
137  			std::future<void> m_Downloading;
138  			int m_NumRetries;
139  			std::vector<std::shared_ptr<AddressBookSubscription> > m_Subscriptions;
140  			std::shared_ptr<AddressBookSubscription> m_DefaultSubscription; // in case if we don't know any addresses yet
141  			std::unique_ptr<boost::asio::deadline_timer> m_SubscriptionsUpdateTimer, m_AddressCacheUpdateTimer;
142  			bool m_IsEnabled;
143  	};
144  
145  	class AddressBookSubscription
146  	{
147  		public:
148  
149  			AddressBookSubscription (AddressBook& book, std::string_view link);
150  			void CheckUpdates ();
151  
152  		private:
153  
154  			bool MakeRequest ();
155  
156  		private:
157  
158  			AddressBook& m_Book;
159  			std::string m_Link, m_Etag, m_LastModified;
160  			i2p::data::IdentHash m_Ident;
161  			// m_Etag must be surrounded by ""
162  	};
163  
164  	class AddressResolver
165  	{
166  		public:
167  
168  			AddressResolver (std::shared_ptr<ClientDestination> destination);
169  			~AddressResolver ();
170  			void AddAddress (const std::string& name, const i2p::data::IdentHash& ident);
171  
172  		private:
173  
174  			void HandleRequest (const i2p::data::IdentityEx& from, uint16_t fromPort, uint16_t toPort, const uint8_t * buf, size_t len);
175  
176  		private:
177  
178  			std::shared_ptr<ClientDestination> m_LocalDestination;
179  			std::map<std::string, i2p::data::IdentHash> m_LocalAddresses;
180  	};
181  }
182  }
183  
184  #endif