I2P: End-to-End encrypted and anonymous Internet https://i2pd.website/
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#include <endian.h>
#include <string>
#include <cryptopp/gzip.h>
#include "Log.h"
#include "RouterInfo.h"
#include "RouterContext.h"
#include "Streaming.h"
namespace i2p
{
namespace stream
{
Stream::Stream (const i2p::data::IdentHash& destination):
m_SendStreamID (0)
{
m_RecvStreamID = i2p::context.GetRandomNumberGenerator ().GenerateWord32 ();
}
void Stream::HandleNextPacket (const uint8_t * buf, size_t len)
{
const uint8_t * end = buf + len;
buf += 4; // sendStreamID
buf += 4; // receiveStreamID
buf += 4; // sequenceNum
buf += 4; // ackThrough
int nackCount = buf[0];
buf++; // NACK count
buf += 4*nackCount; // NACKs
buf++; // resendDelay
uint16_t flags = be16toh (*(uint16_t *)buf);
buf += 2; // flags
uint16_t optionalSize = be16toh (*(uint16_t *)buf);
buf += 2; // optional size
const uint8_t * optionalData = buf;
buf += optionalSize;
// process flags
if (flags & PACKET_FLAG_SYNCHRONIZE)
{
LogPrint ("Synchronize");
}
if (flags & PACKET_FLAG_SIGNATURE_INCLUDED)
{
LogPrint ("Signature");
optionalData += 40;
}
if (flags & PACKET_FLAG_FROM_INCLUDED)
{
LogPrint ("From identity");
optionalData += sizeof (i2p::data::Identity);
}
// we have reached payload section
std::string str((const char *)buf, end-buf);
LogPrint ("Payload: ", str);
}
StreamingDestination m_SharedLocalDestination;
void StreamingDestination::HandleNextPacket (const uint8_t * buf, size_t len)
{
uint32_t sendStreamID = *(uint32_t *)(buf);
auto it = m_Streams.find (sendStreamID);
if (it != m_Streams.end ())
it->second->HandleNextPacket (buf, len);
else
LogPrint ("Unknown stream ", sendStreamID);
}
Stream * StreamingDestination::CreateNewStream (const i2p::data::IdentHash& destination)
{
/*i2p::data::LeaseSet * leaseSet = i2p::data::netdb.FindLeaseSet (destination);
if (!leaseSet)
{
i2p::data::netdb.RequestDestination (destination);
sleep (5); // wait for 5 seconds
leaseSet = i2p::data::netdb.FindLeaseSet (destination);
if (!leaseSet)
{
LogPrint ("Couldn't find LeaseSet");
return nullptr;
}
} */
Stream * s = new Stream (destination);
m_Streams[s->GetRecvStreamID ()] = s;
return s;
}
void HandleDataMessage (i2p::data::IdentHash * destination, const uint8_t * buf, size_t len)
{
uint32_t length = be32toh (*(uint32_t *)buf);
buf += 4;
// we assume I2CP payload
if (buf[9] == 6) // streaming protocol
{
// unzip it
CryptoPP::Gunzip decompressor;
decompressor.Put (buf, length);
decompressor.MessageEnd();
uint8_t uncompressed[2048];
int uncompressedSize = decompressor.MaxRetrievable ();
decompressor.Get (uncompressed, uncompressedSize);
// then forward to streaming engine
// TODO: we have onle one destination, might be more
m_SharedLocalDestination.HandleNextPacket (uncompressed, uncompressedSize);
}
else
LogPrint ("Data: protocol ", buf[9], " is not supported");
}
I2NPMessage * CreateDataMessage (Stream * s, uint8_t * payload, size_t len)
{
I2NPMessage * msg = NewI2NPMessage ();
CryptoPP::Gzip compressor;
compressor.Put (payload, len);
compressor.MessageEnd();
int size = compressor.MaxRetrievable ();
uint8_t * buf = msg->GetPayload ();
*(uint16_t *)buf = htobe32 (size); // length
buf += 4;
compressor.Get (buf, size);
buf[9] = 6; // streaming protocol
msg->len += size + 4;
FillI2NPMessageHeader (msg, eI2NPData);
return msg;
}
}
}