i2pd/client/SAM.h

#ifndef SAM_H__
#define SAM_H__

#include <inttypes.h>
#include <string>
#include <map>
#include <list>
#include <thread>
#include <mutex>
#include <memory>
#include <boost/asio.hpp>
#include "Identity.h"
#include "LeaseSet.h"
#include "Streaming.h"
#include "Destination.h"

namespace i2p
{
namespace client
{
    const size_t SAM_SOCKET_BUFFER_SIZE = 8192;
    const int SAM_SOCKET_CONNECTION_MAX_IDLE = 3600; // in seconds
    const int SAM_SESSION_READINESS_CHECK_INTERVAL = 20; // in seconds  
    const char SAM_HANDSHAKE[] = "HELLO VERSION";
    const char SAM_HANDSHAKE_REPLY[] = "HELLO REPLY RESULT=OK VERSION=%s\n";
    const char SAM_HANDSHAKE_I2P_ERROR[] = "HELLO REPLY RESULT=I2P_ERROR\n";    
    const char SAM_SESSION_CREATE[] = "SESSION CREATE";
    const char SAM_SESSION_CREATE_REPLY_OK[] = "SESSION STATUS RESULT=OK DESTINATION=%s\n";
    const char SAM_SESSION_CREATE_DUPLICATED_ID[] = "SESSION STATUS RESULT=DUPLICATED_ID\n";
    const char SAM_SESSION_CREATE_DUPLICATED_DEST[] = "SESSION STATUS RESULT=DUPLICATED_DEST\n";    
    const char SAM_SESSION_STATUS_INVALID_KEY[] = "SESSION STATUS RESULT=INVALID_KEY\n";
    const char SAM_STREAM_CONNECT[] = "STREAM CONNECT";
    const char SAM_STREAM_STATUS_OK[] = "STREAM STATUS RESULT=OK\n";
    const char SAM_STREAM_STATUS_INVALID_ID[] = "STREAM STATUS RESULT=INVALID_ID\n";
    const char SAM_STREAM_STATUS_CANT_REACH_PEER[] = "STREAM STATUS RESULT=CANT_REACH_PEER\n";
    const char SAM_STREAM_STATUS_I2P_ERROR[] = "STREAM STATUS RESULT=I2P_ERROR\n";
    const char SAM_STREAM_ACCEPT[] = "STREAM ACCEPT";   
    const char SAM_DATAGRAM_SEND[] = "DATAGRAM SEND";
    const char SAM_DEST_GENERATE[] = "DEST GENERATE";
    const char SAM_DEST_REPLY[] = "DEST REPLY PUB=%s PRIV=%s\n";    
    const char SAM_DEST_REPLY_I2P_ERROR[] = "DEST REPLY RESULT=I2P_ERROR\n";
    const char SAM_NAMING_LOOKUP[] = "NAMING LOOKUP";
    const char SAM_NAMING_REPLY[] = "NAMING REPLY RESULT=OK NAME=ME VALUE=%s\n";
    const char SAM_DATAGRAM_RECEIVED[] = "DATAGRAM RECEIVED DESTINATION=%s SIZE=%lu\n"; 
    const char SAM_NAMING_REPLY_INVALID_KEY[] = "NAMING REPLY RESULT=INVALID_KEY NAME=%s\n";
    const char SAM_NAMING_REPLY_KEY_NOT_FOUND[] = "NAMING REPLY RESULT=INVALID_KEY_NOT_FOUND NAME=%s\n";
    const char SAM_PARAM_MIN[] = "MIN"; 
    const char SAM_PARAM_MAX[] = "MAX";             
    const char SAM_PARAM_STYLE[] = "STYLE";     
    const char SAM_PARAM_ID[] = "ID";   
    const char SAM_PARAM_SILENT[] = "SILENT";
    const char SAM_PARAM_DESTINATION[] = "DESTINATION"; 
    const char SAM_PARAM_NAME[] = "NAME";
    const char SAM_PARAM_SIGNATURE_TYPE[] = "SIGNATURE_TYPE";   
    const char SAM_PARAM_SIZE[] = "SIZE";
    const char SAM_PARAM_FORWARD[] = "FORWARD";
    const char SAM_PARAM_HOST[] = "HOST";
    const char SAM_PARAM_PORT[] = "PORT";
    const char SAM_VALUE_TRANSIENT[] = "TRANSIENT"; 
    const char SAM_VALUE_STREAM[] = "STREAM";
    const char SAM_VALUE_DATAGRAM[] = "DATAGRAM";
    const char SAM_VALUE_RAW[] = "RAW";
    const char SAM_VALUE_TRUE[] = "true";   
    const char SAM_VALUE_FALSE[] = "false"; 

    enum SAMSocketType
    {
        eSAMSocketTypeUnknown,
        eSAMSocketTypeSession,
        eSAMSocketTypeStream,
        eSAMSocketTypeAcceptor,
        eSAMSocketTypeUDPForward,
        eSAMSocketTypeTerminated,
    };

    class SAMBridge;
    struct SAMSession;
    class SAMSocket: public std::enable_shared_from_this<SAMSocket>
    {
        public:

            SAMSocket (SAMBridge& owner);
            ~SAMSocket ();          
            void CloseStream (); // TODO: implement it better   

            boost::asio::ip::tcp::socket& GetSocket () { return m_Socket; };
            void ReceiveHandshake ();
            void SetSocketType (SAMSocketType socketType) { m_SocketType = socketType; };
            SAMSocketType GetSocketType () const { return m_SocketType; };

        private:

            void Terminate ();  
            void HandleHandshakeReceived (const boost::system::error_code& ecode, std::size_t bytes_transferred);
            void HandleHandshakeReplySent (const boost::system::error_code& ecode, std::size_t bytes_transferred);
            void HandleMessage (const boost::system::error_code& ecode, std::size_t bytes_transferred);
            void SendMessageReply (const char * msg, size_t len, bool close);           
            void HandleMessageReplySent (const boost::system::error_code& ecode, std::size_t bytes_transferred, bool close);
            void Receive ();
            void HandleReceived (const boost::system::error_code& ecode, std::size_t bytes_transferred);

            void I2PReceive (); 
            void HandleI2PReceive (const boost::system::error_code& ecode, std::size_t bytes_transferred);
            void HandleI2PAccept (std::shared_ptr<i2p::stream::Stream> stream);
            void HandleWriteI2PData (const boost::system::error_code& ecode);
            void HandleI2PDatagramReceive (const i2p::data::IdentityEx& from, uint16_t fromPort, uint16_t toPort, const uint8_t * buf, size_t len);

            void ProcessSessionCreate (char * buf, size_t len);
            void ProcessStreamConnect (char * buf, size_t len);
            void ProcessStreamAccept (char * buf, size_t len);
            void ProcessDestGenerate ();
            void ProcessNamingLookup (char * buf, size_t len);
            size_t ProcessDatagramSend (char * buf, size_t len, const char * data); // from SAM 1.0 
            void ExtractParams (char * buf, std::map<std::string, std::string>& params);

            void Connect (std::shared_ptr<const i2p::data::LeaseSet> remote);
            void HandleConnectLeaseSetRequestComplete (std::shared_ptr<i2p::data::LeaseSet> leaseSet);
            void SendNamingLookupReply (const i2p::data::IdentityEx& identity);
            void HandleNamingLookupLeaseSetRequestComplete (std::shared_ptr<i2p::data::LeaseSet> leaseSet, i2p::data::IdentHash ident);
            void HandleSessionReadinessCheckTimer (const boost::system::error_code& ecode);
            void SendSessionCreateReplyOk ();

        private:

            SAMBridge& m_Owner;
            boost::asio::ip::udp::endpoint m_udpForward;
            boost::asio::ip::tcp::socket m_Socket;
            boost::asio::deadline_timer m_Timer;
            char m_Buffer[SAM_SOCKET_BUFFER_SIZE + 1];
            size_t m_BufferOffset;
            uint8_t m_StreamBuffer[SAM_SOCKET_BUFFER_SIZE];
            SAMSocketType m_SocketType;
            std::string m_ID; // nickname
            bool m_IsSilent;
            std::shared_ptr<i2p::stream::Stream> m_Stream;
            SAMSession * m_Session;
    };  

    struct SAMSession
    {
        std::shared_ptr<ClientDestination> localDestination;
        std::list<std::shared_ptr<SAMSocket> > sockets;
        
        SAMSession (std::shared_ptr<ClientDestination> dest);       
        ~SAMSession ();

        void CloseStreams ();
    };

    class SAMBridge
    {
        public:

            SAMBridge(const std::string& address, int port);
            ~SAMBridge ();

            void Start ();
            void Stop ();
            
            boost::asio::io_service& GetService () { return m_Service; };
            SAMSession * CreateSession (const std::string& id, const std::string& destination, // empty string  means transient
                const std::map<std::string, std::string> * params);
            void CloseSession (const std::string& id);
            SAMSession * FindSession (const std::string& id) const;

            // forward a datagram to a udp endpoint
            void ForwardUDP(const boost::asio::ip::udp::endpoint & to_ep, const i2p::data::IdentityEx& from, const uint8_t * buff, size_t bufflen);
      
        private:

            void Run ();

            void Accept ();
            void HandleAccept(const boost::system::error_code& ecode, std::shared_ptr<SAMSocket> socket);

            void ReceiveDatagram ();
            void HandleReceivedDatagram (const boost::system::error_code& ecode, std::size_t bytes_transferred);
            void HandleForwardedUDP(const boost::system::error_code& ecode, std::size_t bytes_transferrted);
      
        private:

            bool m_IsRunning;
            std::thread * m_Thread; 
            boost::asio::io_service m_Service;
            boost::asio::ip::tcp::acceptor m_Acceptor;
            boost::asio::ip::udp::endpoint m_DatagramEndpoint, m_SenderEndpoint;
            boost::asio::ip::udp::socket m_DatagramSocket;
            mutable std::mutex m_SessionsMutex;
            std::map<std::string, SAMSession *> m_Sessions;
            uint8_t m_DatagramReceiveBuffer[i2p::datagram::MAX_DATAGRAM_SIZE+1];
            uint8_t * m_Forward; // current buffer to forward or nullptr if there is none to forward now
        public:

            // for HTTP
            const decltype(m_Sessions)& GetSessions () const { return m_Sessions; };
    };      
}
}

#endif