I2P: End-to-End encrypted and anonymous Internet https://i2pd.website/
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#ifndef STREAMING_H__
#define STREAMING_H__
#include <inttypes.h>
#include <map>
#include <set>
#include <cryptopp/dsa.h>
#include "I2PEndian.h"
#include "Queue.h"
#include "Identity.h"
#include "LeaseSet.h"
#include "I2NPProtocol.h"
#include "Tunnel.h"
namespace i2p
{
namespace stream
{
const uint16_t PACKET_FLAG_SYNCHRONIZE = 0x0001;
const uint16_t PACKET_FLAG_CLOSE = 0x0002;
const uint16_t PACKET_FLAG_RESET = 0x0004;
const uint16_t PACKET_FLAG_SIGNATURE_INCLUDED = 0x0008;
const uint16_t PACKET_FLAG_SIGNATURE_REQUESTED = 0x0010;
const uint16_t PACKET_FLAG_FROM_INCLUDED = 0x0020;
const uint16_t PACKET_FLAG_DELAY_REQUESTED = 0x0040;
const uint16_t PACKET_FLAG_MAX_PACKET_SIZE_INCLUDED = 0x0080;
const uint16_t PACKET_FLAG_PROFILE_INTERACTIVE = 0x0100;
const uint16_t PACKET_FLAG_ECHO = 0x0200;
const uint16_t PACKET_FLAG_NO_ACK = 0x0400;
const size_t STREAMING_MTU = 1730;
const size_t MAX_PACKET_SIZE = 1754;
struct Packet
{
uint8_t buf[1754];
size_t len, offset;
Packet (): len (0), offset (0) {};
uint8_t * GetBuffer () { return buf + offset; };
size_t GetLength () const { return len - offset; };
uint32_t GetSendStreamID () const { return be32toh (*(uint32_t *)buf); };
uint32_t GetReceiveStreamID () const { return be32toh (*(uint32_t *)(buf + 4)); };
uint32_t GetSeqn () const { return be32toh (*(uint32_t *)(buf + 8)); };
uint32_t GetAckThrough () const { return be32toh (*(uint32_t *)(buf + 12)); };
uint8_t GetNACKCount () const { return buf[16]; };
const uint8_t * GetOption () const { return buf + 17 + GetNACKCount ()*4 + 3; }; // 3 = resendDelay + flags
uint16_t GetFlags () const { return be16toh (*(uint16_t *)(GetOption () - 2)); };
uint16_t GetOptionSize () const { return be16toh (*(uint16_t *)GetOption ()); };
const uint8_t * GetOptionData () const { return GetOption () + 2; };
const uint8_t * GetPayload () const { return GetOptionData () + GetOptionSize (); };
};
struct PacketCmp
{
bool operator() (const Packet * p1, const Packet * p2) const
{
return p1->GetSeqn () < p2->GetSeqn ();
};
};
class StreamingDestination;
class Stream
{
public:
Stream (StreamingDestination * local, const i2p::data::LeaseSet * remote);
~Stream ();
uint32_t GetSendStreamID () const { return m_SendStreamID; };
uint32_t GetRecvStreamID () const { return m_RecvStreamID; };
const i2p::data::LeaseSet * GetRemoteLeaseSet () const { return m_RemoteLeaseSet; };
bool IsOpen () const { return m_IsOpen; };
bool IsEstablished () const { return m_SendStreamID; };
void HandleNextPacket (Packet * packet);
size_t Send (uint8_t * buf, size_t len, int timeout); // timeout in seconds
size_t Receive (uint8_t * buf, size_t len, int timeout = 0); // returns 0 if timeout expired
void Close ();
private:
void ConnectAndSend (uint8_t * buf, size_t len);
void SendQuickAck ();
void SavePacket (Packet * packet);
void ProcessPacket (Packet * packet);
private:
uint32_t m_SendStreamID, m_RecvStreamID, m_SequenceNumber, m_LastReceivedSequenceNumber;
bool m_IsOpen;
StreamingDestination * m_LocalDestination;
const i2p::data::LeaseSet * m_RemoteLeaseSet;
i2p::util::Queue<Packet> m_ReceiveQueue;
std::set<Packet *, PacketCmp> m_SavedPackets;
i2p::tunnel::OutboundTunnel * m_OutboundTunnel;
};
class StreamingDestination
{
public:
StreamingDestination ();
~StreamingDestination ();
const i2p::data::Keys& GetKeys () const { return m_Keys; };
const i2p::data::Identity& GetIdentity () const { return m_Identity; };
I2NPMessage * GetLeaseSet ();
void Sign (uint8_t * buf, int len, uint8_t * signature) const;
Stream * CreateNewStream (const i2p::data::LeaseSet * remote);
void DeleteStream (Stream * stream);
void HandleNextPacket (Packet * packet);
private:
I2NPMessage * CreateLeaseSet () const;
private:
std::map<uint32_t, Stream *> m_Streams;
i2p::data::Keys m_Keys;
i2p::data::Identity m_Identity;
i2p::data::IdentHash m_IdentHash;
I2NPMessage * m_LeaseSet;
CryptoPP::DSA::PrivateKey m_SigningPrivateKey;
};
Stream * CreateStream (const i2p::data::LeaseSet * remote);
void DeleteStream (Stream * stream);
// assuming data is I2CP message
void HandleDataMessage (i2p::data::IdentHash * destination, const uint8_t * buf, size_t len);
I2NPMessage * CreateDataMessage (Stream * s, uint8_t * payload, size_t len);
}
}
#endif