i2pd/core/AddressBook.cpp

#include <string.h>
#include <inttypes.h>
#include <string>
#include <map>
#include <fstream>
#include <chrono>
#include <condition_variable>
#include <boost/filesystem.hpp>
#include <boost/lexical_cast.hpp>
#include <cryptopp/osrng.h>
#include "util/base64.h"
#include "util/util.h"
#include "Identity.h"
#include "util/Log.h"
#include "NetworkDatabase.h"
#include "AddressBook.h"
#include "Destination.h"

namespace i2p
{
namespace client
{

    class AddressBookFilesystemStorage: public AddressBookStorage
    {
        public:

            AddressBookFilesystemStorage ();
            bool GetAddress (const i2p::data::IdentHash& ident, i2p::data::IdentityEx& address) const;
            void AddAddress (const i2p::data::IdentityEx& address);
            void RemoveAddress (const i2p::data::IdentHash& ident);

            int Load (std::map<std::string, i2p::data::IdentHash>& addresses);
            int Save (const std::map<std::string, i2p::data::IdentHash>& addresses);

        private:    
            
            boost::filesystem::path GetPath () const { return i2p::util::filesystem::GetDefaultDataDir() / "addressbook"; };

    };

    AddressBookFilesystemStorage::AddressBookFilesystemStorage ()
    {
        auto path = GetPath ();
        if (!boost::filesystem::exists (path))
        {
            // Create directory is necessary
            if (!boost::filesystem::create_directory (path))
                LogPrint (eLogError, "Failed to create addressbook directory");
        }
    }

    bool AddressBookFilesystemStorage::GetAddress (const i2p::data::IdentHash& ident, i2p::data::IdentityEx& address) const
    {
        auto filename = GetPath () / (ident.ToBase32() + ".b32");
        std::ifstream f(filename.c_str (), std::ifstream::binary);
        if (f.is_open ())   
        {
            f.seekg (0,std::ios::end);
            size_t len = f.tellg ();
            if (len < i2p::data::DEFAULT_IDENTITY_SIZE)
            {
                LogPrint (eLogError, "File ", filename, " is too short. ", len);
                return false;
            }
            f.seekg(0, std::ios::beg);
            uint8_t * buf = new uint8_t[len];
            f.read((char *)buf, len);
            address.FromBuffer (buf, len);
            delete[] buf;
            return true;
        }
        else
            return false;
    }

    void AddressBookFilesystemStorage::AddAddress (const i2p::data::IdentityEx& address)
    {
        auto filename = GetPath () / (address.GetIdentHash ().ToBase32() + ".b32");
        std::ofstream f (filename.c_str (), std::ofstream::binary | std::ofstream::out);
        if (f.is_open ())   
        {
            size_t len = address.GetFullLen ();
            uint8_t * buf = new uint8_t[len];
            address.ToBuffer (buf, len);
            f.write ((char *)buf, len);
            delete[] buf;
        }
        else
            LogPrint (eLogError, "Can't open file ", filename); 
    }   

    void AddressBookFilesystemStorage::RemoveAddress (const i2p::data::IdentHash& ident)
    {
        auto filename = GetPath () / (ident.ToBase32() + ".b32");
        if (boost::filesystem::exists (filename))  
            boost::filesystem::remove (filename);
    }

    int AddressBookFilesystemStorage::Load (std::map<std::string, i2p::data::IdentHash>& addresses)
    {
        int num = 0;    
        auto filename = GetPath () / "addresses.csv";
        std::ifstream f (filename.c_str (), std::ofstream::in); // in text mode
        if (f.is_open ())   
        {
            addresses.clear ();
            while (!f.eof ())
            {
                std::string s;
                getline(f, s);
                if (!s.length())
                    continue; // skip empty line

                size_t pos = s.find(',');
                if (pos != std::string::npos)
                {
                    std::string name = s.substr(0, pos++);
                    std::string addr = s.substr(pos);

                    i2p::data::IdentHash ident;
                    ident.FromBase32 (addr);
                    addresses[name] = ident;
                    num++;
                }       
            }
            LogPrint (eLogInfo, num, " addresses loaded");
        }
        else
            LogPrint (eLogWarning, filename, " not found");
        return num;
    }

    int AddressBookFilesystemStorage::Save (const std::map<std::string, i2p::data::IdentHash>& addresses)
    {
        int num = 0;
        auto filename = GetPath () / "addresses.csv";
        std::ofstream f (filename.c_str (), std::ofstream::out); // in text mode
        if (f.is_open ())   
        {
            for (auto it: addresses)
            {
                f << it.first << "," << it.second.ToBase32 () << std::endl;
                num++;
            }
            LogPrint (eLogInfo, num, " addresses saved");
        }
        else    
            LogPrint (eLogError, "Can't open file ", filename); 
        return num; 
    }   

//---------------------------------------------------------------------
    AddressBook::AddressBook ()
        : m_Storage (nullptr), m_IsLoaded (false), m_IsDownloading (false), 
        m_DefaultSubscription (nullptr), m_SubscriptionsUpdateTimer (nullptr),
        m_SharedLocalDestination(nullptr)
    {
    }

    AddressBook::~AddressBook ()
    {   
        Stop ();
    }

    void AddressBook::Start (ClientDestination* local_destination)
    {
        m_SharedLocalDestination = local_destination;
        StartSubscriptions ();
    }
    
    void AddressBook::Stop ()
    {
        StopSubscriptions ();
        if (m_SubscriptionsUpdateTimer)
        {   
            delete m_SubscriptionsUpdateTimer;  
            m_SubscriptionsUpdateTimer = nullptr;
        }   
        if (m_IsDownloading)
        {
            LogPrint (eLogInfo, "Subscription is downloading. Waiting for temination...");
            for (int i = 0; i < 30; i++)
            {
                if (!m_IsDownloading)
                {
                    LogPrint (eLogInfo, "Subscription download complete");
                    break;
                }   
                std::this_thread::sleep_for (std::chrono::seconds (1)); // wait for 1 seconds
            }   
            LogPrint (eLogError, "Subscription download hangs");
            m_IsDownloading = false;
        }   
        if (m_Storage)
        {
            m_Storage->Save (m_Addresses);
            delete m_Storage;
            m_Storage = nullptr;
        }
        if (m_DefaultSubscription)
        {   
            delete m_DefaultSubscription;
            m_DefaultSubscription = nullptr;
        }   
        for (auto it: m_Subscriptions)
            delete it;
        m_Subscriptions.clear ();   
    }   
    
    AddressBookStorage * AddressBook::CreateStorage ()
    {
        return new AddressBookFilesystemStorage ();
    }   

    bool AddressBook::GetIdentHash (const std::string& address, i2p::data::IdentHash& ident)
    {
        auto pos = address.find(".b32.i2p");
        if (pos != std::string::npos)
        {
            i2p::util::Base32ToByteStream (address.c_str(), pos, ident, 32);
            return true;
        }
        else
        {   
            pos = address.find (".i2p");
            if (pos != std::string::npos)
            {
                auto identHash = FindAddress (address); 
                if (identHash)
                {
                    ident = *identHash;
                    return true;
                }
                else
                    return false;
            }
        }   
        // if not .b32 we assume full base64 address
        i2p::data::IdentityEx dest;
        if (!dest.FromBase64 (address))
            return false;
        ident = dest.GetIdentHash ();
        return true;
    }
    
    const i2p::data::IdentHash * AddressBook::FindAddress (const std::string& address)
    {
        if (!m_IsLoaded)
            LoadHosts ();
        if (m_IsLoaded)
        {
            auto it = m_Addresses.find (address);
            if (it != m_Addresses.end ())
                return &it->second;
        }
        return nullptr; 
    }

    ClientDestination* AddressBook::getSharedLocalDestination() const
    {
        return m_SharedLocalDestination;
    }

    void AddressBook::InsertAddress (const std::string& address, const std::string& base64)
    {
        i2p::data::IdentityEx ident;
        ident.FromBase64 (base64);
        if (!m_Storage)
             m_Storage = CreateStorage ();
        m_Storage->AddAddress (ident);
        m_Addresses[address] = ident.GetIdentHash ();
        LogPrint (address,"->", ToAddress(ident.GetIdentHash ()), " added");
    }

    void AddressBook::InsertAddress (const i2p::data::IdentityEx& address)
    {
        if (!m_Storage) 
            m_Storage = CreateStorage ();
        m_Storage->AddAddress (address);
    }

    bool AddressBook::GetAddress (const std::string& address, i2p::data::IdentityEx& identity)
    {
        if (!m_Storage) 
            m_Storage = CreateStorage ();
        i2p::data::IdentHash ident;
        if (!GetIdentHash (address, ident)) return false;
        return m_Storage->GetAddress (ident, identity);
    }   

    void AddressBook::LoadHosts ()
    {
        if (!m_Storage)
             m_Storage = CreateStorage ();
        if (m_Storage->Load (m_Addresses) > 0)
        {
            m_IsLoaded = true;
            return;
        }
    
        // try hosts.txt first
        std::ifstream f (i2p::util::filesystem::GetFullPath ("hosts.txt").c_str (), std::ofstream::in); // in text mode
        if (f.is_open ())   
        {
            LoadHostsFromStream (f);
            m_IsLoaded = true;
        }
        else
        {
            // if not found download it from http://i2p-projekt.i2p/hosts.txt 
            LogPrint (eLogInfo, "hosts.txt not found. Try to download it from default subscription...");
            if (!m_IsDownloading)
            {
                m_IsDownloading = true;
                if (!m_DefaultSubscription)
                    m_DefaultSubscription = new AddressBookSubscription (*this, DEFAULT_SUBSCRIPTION_ADDRESS);
                m_DefaultSubscription->CheckSubscription ();
            }
        }   
        
    }

    void AddressBook::LoadHostsFromStream (std::istream& f)
    {
        std::unique_lock<std::mutex> l(m_AddressBookMutex);
        int numAddresses = 0;
        std::string s;
        while (!f.eof ())
        {
            getline(f, s);

            if (!s.length())
                continue; // skip empty line

            size_t pos = s.find('=');

            if (pos != std::string::npos)
            {
                std::string name = s.substr(0, pos++);
                std::string addr = s.substr(pos);

                i2p::data::IdentityEx ident;
                if (ident.FromBase64(addr))
                {   
                    m_Addresses[name] = ident.GetIdentHash ();
                    m_Storage->AddAddress (ident);
                    numAddresses++;
                }   
                else
                    LogPrint (eLogError, "Malformed address ", addr, " for ", name);
            }       
        }
        LogPrint (eLogInfo, numAddresses, " addresses processed");
        if (numAddresses > 0)
        {   
            m_IsLoaded = true;
            m_Storage->Save (m_Addresses);
        }   
    }   
    
    void AddressBook::LoadSubscriptions ()
    {
        if (!m_Subscriptions.size ())
        {
            std::ifstream f (i2p::util::filesystem::GetFullPath ("subscriptions.txt").c_str (), std::ofstream::in); // in text mode
            if (f.is_open ())
            {
                std::string s;
                while (!f.eof ())
                {
                    getline(f, s);
                    if (!s.length()) continue; // skip empty line
                    m_Subscriptions.push_back (new AddressBookSubscription (*this, s));
                }
                LogPrint (eLogInfo, m_Subscriptions.size (), " subscriptions loaded");
            }
            else
                LogPrint (eLogWarning, "subscriptions.txt not found");
        }
        else
            LogPrint (eLogError, "Subscriptions already loaded");
    }

    void AddressBook::DownloadComplete (bool success)
    {
        m_IsDownloading = false;
        if (m_SubscriptionsUpdateTimer)
        {
            m_SubscriptionsUpdateTimer->expires_from_now (boost::posix_time::minutes(
                success ? CONTINIOUS_SUBSCRIPTION_UPDATE_TIMEOUT : CONTINIOUS_SUBSCRIPTION_RETRY_TIMEOUT));
            m_SubscriptionsUpdateTimer->async_wait (std::bind (&AddressBook::HandleSubscriptionsUpdateTimer,
                this, std::placeholders::_1));
        }
    }

    void AddressBook::StartSubscriptions ()
    {
        LoadSubscriptions ();
        if (!m_Subscriptions.size ()) return;   

        if (m_SharedLocalDestination)
        {
            m_SubscriptionsUpdateTimer = new boost::asio::deadline_timer(
                m_SharedLocalDestination->GetService()
            );
            m_SubscriptionsUpdateTimer->expires_from_now(
                boost::posix_time::minutes(INITIAL_SUBSCRIPTION_UPDATE_TIMEOUT)
            );
            m_SubscriptionsUpdateTimer->async_wait(std::bind(
                &AddressBook::HandleSubscriptionsUpdateTimer,
                this, std::placeholders::_1
            ));
        }
        else
            LogPrint (eLogError, "Can't start subscriptions: missing shared local destination");
    }

    void AddressBook::StopSubscriptions ()
    {
        if (m_SubscriptionsUpdateTimer)
            m_SubscriptionsUpdateTimer->cancel ();
    }

    void AddressBook::HandleSubscriptionsUpdateTimer (const boost::system::error_code& ecode)
    {
        if (ecode != boost::asio::error::operation_aborted)
        {
            if (!m_SharedLocalDestination)
                return; // TODO: error handling
            if (m_IsLoaded && !m_IsDownloading && m_SharedLocalDestination->IsReady ())
            {
                // pick random subscription
                CryptoPP::AutoSeededRandomPool rnd;
                auto ind = rnd.GenerateWord32 (0, m_Subscriptions.size() - 1);  
                m_IsDownloading = true; 
                m_Subscriptions[ind]->CheckSubscription ();     
            }
            else
            {
                if (!m_IsLoaded)
                    LoadHosts ();
                // try it again later
                m_SubscriptionsUpdateTimer->expires_from_now (boost::posix_time::minutes(INITIAL_SUBSCRIPTION_RETRY_TIMEOUT));
                m_SubscriptionsUpdateTimer->async_wait (std::bind (&AddressBook::HandleSubscriptionsUpdateTimer,
                    this, std::placeholders::_1));
            }
        }
    }

    AddressBookSubscription::AddressBookSubscription (AddressBook& book, const std::string& link):
        m_Book (book), m_Link (link)
    {
    }

    void AddressBookSubscription::CheckSubscription ()
    {
        std::thread load_hosts(&AddressBookSubscription::Request, this);
        load_hosts.detach(); // TODO: use join
    }

    void AddressBookSubscription::Request ()
    {
        // must be run in separate thread   
        LogPrint (eLogInfo, "Downloading hosts from ", m_Link, " ETag: ", m_Etag, " Last-Modified: ", m_LastModified);
        bool success = false;   
        i2p::util::http::url u (m_Link);
        i2p::data::IdentHash ident;
        if (m_Book.GetIdentHash (u.host_, ident) && m_Book.getSharedLocalDestination())
        {
            std::condition_variable newDataReceived;
            std::mutex newDataReceivedMutex;
            auto leaseSet = m_Book.getSharedLocalDestination()->FindLeaseSet (ident);
            if (!leaseSet)
            {
                std::unique_lock<std::mutex> l(newDataReceivedMutex);
                m_Book.getSharedLocalDestination()->RequestDestination (ident,
                    [&newDataReceived, &leaseSet](std::shared_ptr<i2p::data::LeaseSet> ls)
                    {
                        leaseSet = ls;
                        newDataReceived.notify_all ();
                    });
                if (newDataReceived.wait_for (l, std::chrono::seconds (SUBSCRIPTION_REQUEST_TIMEOUT)) == std::cv_status::timeout)
                    LogPrint (eLogError, "Subscription LeseseSet request timeout expired");
            }
            if (leaseSet)
            {
                std::stringstream request, response;
                // standard header
                request << "GET " << u.path_ << " HTTP/1.1\r\nHost: " << u.host_
                << "\r\nAccept: */*\r\n" << "User-Agent: Wget/1.11.4\r\n" << "Connection: close\r\n";
                if (m_Etag.length () > 0) // etag
                    request << i2p::util::http::IF_NONE_MATCH << ": \"" << m_Etag << "\"\r\n";
                if (m_LastModified.length () > 0) // if-modfief-since
                    request << i2p::util::http::IF_MODIFIED_SINCE << ": " << m_LastModified << "\r\n";
                request << "\r\n"; // end of header
                auto stream = m_Book.getSharedLocalDestination()->CreateStream (leaseSet, u.port_);
                stream->Send ((uint8_t *)request.str ().c_str (), request.str ().length ());
                
                uint8_t buf[4096];
                bool end = false;
                while (!end)
                {
                    stream->AsyncReceive (boost::asio::buffer (buf, 4096), 
                        [&](const boost::system::error_code& ecode, std::size_t bytes_transferred)
                        {
                            if (bytes_transferred)
                                response.write ((char *)buf, bytes_transferred);
                            if (ecode == boost::asio::error::timed_out || !stream->IsOpen ())
                                end = true; 
                            newDataReceived.notify_all ();
                        },
                        30); // wait for 30 seconds
                    std::unique_lock<std::mutex> l(newDataReceivedMutex);
                    if (newDataReceived.wait_for (l, std::chrono::seconds (SUBSCRIPTION_REQUEST_TIMEOUT)) == std::cv_status::timeout)
                        LogPrint (eLogError, "Subscription timeout expired");
                }
                // process remaining buffer
                while (size_t len = stream->ReadSome (buf, 4096))
                    response.write ((char *)buf, len);
                
                // parse response
                std::string version;
                response >> version; // HTTP version
                int status = 0;
                response >> status; // status
                if (status == 200) // OK
                {
                    bool isChunked = false;
                    std::string header, statusMessage;
                    std::getline (response, statusMessage);
                    // read until new line meaning end of header
                    while (!response.eof () && header != "\r")
                    {
                        std::getline (response, header);
                        auto colon = header.find (':');
                        if (colon != std::string::npos)
                        {
                            std::string field = header.substr (0, colon);
                            header.resize (header.length () - 1); // delete \r  
                            if (field == i2p::util::http::ETAG)
                                m_Etag = header.substr (colon + 1);
                            else if (field == i2p::util::http::LAST_MODIFIED)
                                m_LastModified = header.substr (colon + 1);
                            else if (field == i2p::util::http::TRANSFER_ENCODING)
                                isChunked = !header.compare (colon + 1, std::string::npos, "chunked");
                        }   
                    }
                    LogPrint (eLogInfo, m_Link, " ETag: ", m_Etag, " Last-Modified: ", m_LastModified);
                    if (!response.eof ())   
                    {
                        success = true;
                        if (!isChunked)
                            m_Book.LoadHostsFromStream (response);
                        else
                        {
                            // merge chunks
                            std::stringstream merged;
                            i2p::util::http::MergeChunkedResponse (response, merged);
                            m_Book.LoadHostsFromStream (merged);
                        }   
                    }   
                }
                else if (status == 304)
                {   
                    success = true;
                    LogPrint (eLogInfo, "No updates from ", m_Link);
                }   
                else
                    LogPrint (eLogWarning, "Adressbook HTTP response ", status);
            }
            else
                LogPrint (eLogError, "Address ", u.host_, " not found");
        }
        else
            LogPrint (eLogError, "Can't resolve ", u.host_);
        LogPrint (eLogInfo, "Download complete ", success ? "Success" : "Failed");
        m_Book.DownloadComplete (success);
    }
}
}