I2NPMessage * CreateDatabaseStoreMsg (const i2p::data::LeaseSet * leaseSet, uint32_t replyToken)
{
if (!leaseSet) return nullptr;
I2NPMessage * m = NewI2NPShortMessage ();
uint8_t * payload = m->GetPayload ();
I2NPDatabaseStoreMsg * msg = (I2NPDatabaseStoreMsg *)payload;
memcpy (msg->key, leaseSet->GetIdentHash (), 32);
msg->type = 1; // LeaseSet
msg->replyToken = htobe32 (replyToken);
size_t size = sizeof (I2NPDatabaseStoreMsg);
if (replyToken)
{
auto leases = leaseSet->GetNonExpiredLeases ();
if (leases.size () > 0)
{
*(uint32_t *)(payload + size) = htobe32 (leases[0].tunnelID);
size += 4; // reply tunnelID
memcpy (payload + size, leases[0].tunnelGateway, 32);
size += 32; // reply tunnel gateway
}
else
msg->replyToken = 0;
}
memcpy (payload + size, leaseSet->GetBuffer (), leaseSet->GetBufferLen ());
size += leaseSet->GetBufferLen ();
m->len += size;
FillI2NPMessageHeader (m, eI2NPDatabaseStore);
return m;
}
I2NPMessage * CreateDatabaseStoreMsg (const i2p::data::RouterInfo * router)
{
if (!router) // we send own RouterInfo
router = &context.GetRouterInfo ();
I2NPMessage * m = NewI2NPShortMessage ();
I2NPDatabaseStoreMsg * msg = (I2NPDatabaseStoreMsg *)m->GetPayload ();
memcpy (msg->key, router->GetIdentHash (), 32);
msg->type = 0;
msg->replyToken = 0;
CryptoPP::Gzip compressor;
compressor.Put (router->GetBuffer (), router->GetBufferLen ());
compressor.MessageEnd();
auto size = compressor.MaxRetrievable ();
uint8_t * buf = m->GetPayload () + sizeof (I2NPDatabaseStoreMsg);
*(uint16_t *)buf = htobe16 (size); // size
buf += 2;
// TODO: check if size doesn't exceed buffer
compressor.Get (buf, size);
m->len += sizeof (I2NPDatabaseStoreMsg) + 2 + size; // payload size
FillI2NPMessageHeader (m, eI2NPDatabaseStore);
return m;
}
I2NPMessage * CreateI2NPMessage (const uint8_t * buf, int len, i2p::tunnel::InboundTunnel * from)
{
I2NPMessage * msg = NewI2NPMessage ();
memcpy (msg->GetBuffer (), buf, len);
msg->len = msg->offset + len;
msg->from = from;
return msg;
}
I2NPMessage * CreateI2NPMessage (I2NPMessageType msgType, const uint8_t * buf, int len, uint32_t replyMsgID)
{
I2NPMessage * msg = NewI2NPMessage (len);
memcpy (msg->GetPayload (), buf, len);
msg->len += len;
FillI2NPMessageHeader (msg, msgType, replyMsgID);
return msg;
}
I2NPMessage * CreateTunnelDataMsg (const uint8_t * buf)
{
I2NPMessage * msg = NewI2NPMessage ();
memcpy (msg->GetPayload (), buf, i2p::tunnel::TUNNEL_DATA_MSG_SIZE);
msg->len += i2p::tunnel::TUNNEL_DATA_MSG_SIZE;
FillI2NPMessageHeader (msg, eI2NPTunnelData);
return msg;
}
I2NPMessage * CreateTunnelDataMsg (uint32_t tunnelID, const uint8_t * payload)
{
I2NPMessage * msg = NewI2NPMessage ();
memcpy (msg->GetPayload () + 4, payload, i2p::tunnel::TUNNEL_DATA_MSG_SIZE - 4);
*(uint32_t *)(msg->GetPayload ()) = htobe32 (tunnelID);
msg->len += i2p::tunnel::TUNNEL_DATA_MSG_SIZE;
FillI2NPMessageHeader (msg, eI2NPTunnelData);
return msg;
}
I2NPMessage * CreateTunnelGatewayMsg (uint32_t tunnelID, const uint8_t * buf, size_t len)
{
I2NPMessage * msg = NewI2NPMessage (len);
TunnelGatewayHeader * header = (TunnelGatewayHeader *)msg->GetPayload ();
header->tunnelID = htobe32 (tunnelID);
header->length = htobe16 (len);
memcpy (msg->GetPayload () + sizeof (TunnelGatewayHeader), buf, len);
msg->len += sizeof (TunnelGatewayHeader) + len;
FillI2NPMessageHeader (msg, eI2NPTunnelGateway);
return msg;
}
I2NPMessage * DatagramDestination::CreateDataMessage (const uint8_t * payload, size_t len)
{
I2NPMessage * msg = NewI2NPMessage ();
CryptoPP::Gzip compressor; // default level
compressor.Put (payload, len);
compressor.MessageEnd();
int size = compressor.MaxRetrievable ();
uint8_t * buf = msg->GetPayload ();
*(uint32_t *)buf = htobe32 (size); // length
buf += 4;
compressor.Get (buf, size);
memset (buf + 4, 0, 4); // source and destination are zeroes
buf[9] = i2p::client::PROTOCOL_TYPE_DATAGRAM; // datagram protocol
msg->len += size + 4;
FillI2NPMessageHeader (msg, eI2NPData);
return msg;
}
I2NPMessage * CreateTunnelGatewayMsg (uint32_t tunnelID, I2NPMessageType msgType,
const uint8_t * buf, size_t len, uint32_t replyMsgID)
{
I2NPMessage * msg = NewI2NPMessage (len);
size_t gatewayMsgOffset = sizeof (I2NPHeader) + sizeof (TunnelGatewayHeader);
msg->offset += gatewayMsgOffset;
msg->len += gatewayMsgOffset;
memcpy (msg->GetPayload (), buf, len);
msg->len += len;
FillI2NPMessageHeader (msg, msgType, replyMsgID); // create content message
len = msg->GetLength ();
msg->offset -= gatewayMsgOffset;
TunnelGatewayHeader * header = (TunnelGatewayHeader *)msg->GetPayload ();
header->tunnelID = htobe32 (tunnelID);
header->length = htobe16 (len);
FillI2NPMessageHeader (msg, eI2NPTunnelGateway); // gateway message
return msg;
}
I2NPMessage * DatagramDestination::CreateDataMessage (const uint8_t * payload, size_t len, uint16_t fromPort, uint16_t toPort)
{
I2NPMessage * msg = NewI2NPMessage ();
CryptoPP::Gzip compressor; // default level
compressor.Put (payload, len);
compressor.MessageEnd();
int size = compressor.MaxRetrievable ();
uint8_t * buf = msg->GetPayload ();
htobe32buf (buf, size); // length
buf += 4;
compressor.Get (buf, size);
htobe16buf (buf + 4, fromPort); // source port
htobe16buf (buf + 6, toPort); // destination port
buf[9] = i2p::client::PROTOCOL_TYPE_DATAGRAM; // datagram protocol
msg->len += size + 4;
FillI2NPMessageHeader (msg, eI2NPData);
return msg;
}
I2NPMessage * CreateDatabaseSearchReply (const i2p::data::IdentHash& ident,
const i2p::data::RouterInfo * floodfill)
{
I2NPMessage * m = NewI2NPShortMessage ();
uint8_t * buf = m->GetPayload ();
size_t len = 0;
memcpy (buf, ident, 32);
len += 32;
buf[len] = floodfill ? 1 : 0; // 1 router for now
len++;
if (floodfill)
{
memcpy (buf + len, floodfill->GetIdentHash (), 32);
len += 32;
}
memcpy (buf + len, i2p::context.GetRouterInfo ().GetIdentHash (), 32);
len += 32;
m->len += len;
FillI2NPMessageHeader (m, eI2NPDatabaseSearchReply);
return m;
}
void NetDb::Run ()
{
uint32_t lastTs = 0;
m_IsRunning = true;
while (m_IsRunning)
{
try
{
I2NPMessage * msg = m_Queue.GetNextWithTimeout (10000); // 10 sec
if (msg)
{
while (msg)
{
if (msg->GetHeader ()->typeID == eI2NPDatabaseStore)
{
HandleDatabaseStoreMsg (msg->GetPayload (), msg->GetLength ()); // TODO
i2p::DeleteI2NPMessage (msg);
}
else if (msg->GetHeader ()->typeID == eI2NPDatabaseSearchReply)
HandleDatabaseSearchReplyMsg (msg);
else // WTF?
{
LogPrint ("NetDb: unexpected message type ", msg->GetHeader ()->typeID);
i2p::HandleI2NPMessage (msg);
}
msg = m_Queue.Get ();
}
}
else // if no new DatabaseStore coming, explore it
Explore ();
uint32_t ts = i2p::util::GetSecondsSinceEpoch ();
if (ts - lastTs >= 60) // save routers every minute
{
if (lastTs)
SaveUpdated ("netDb");
lastTs = ts;
}
}
catch (std::exception& ex)
{
LogPrint ("NetDb: ", ex.what ());
}
}
}
I2NPMessage * TunnelGatewayBuffer::CreateNextTunnelMessage (int& ind)
{
int cnt = m_I2NPMsgs.size ();
if (ind > cnt - 1) return nullptr; // no more messages
// calculate payload size
size_t size = 0;
int i = ind;
if (m_NextOffset)
{
size = m_I2NPMsgs[i]->data->GetLength () - m_NextOffset + 7; // including follow-on header
i++;
}
while (i < cnt)
{
auto msg = m_I2NPMsgs[i];
size += msg->totalLen;
if (size >= TUNNEL_DATA_MAX_PAYLOAD_SIZE)
{
size = TUNNEL_DATA_MAX_PAYLOAD_SIZE;
break;
}
if (msg->isFragmented) break;
i++;
}
I2NPMessage * tunnelMsg = NewI2NPMessage ();
uint8_t * buf = tunnelMsg->GetPayload ();
*(uint32_t *)(buf) = htobe32 (m_TunnelID);
CryptoPP::RandomNumberGenerator& rnd = i2p::context.GetRandomNumberGenerator ();
rnd.GenerateBlock (buf + 4, 16); // original IV
memcpy (buf + TUNNEL_DATA_MSG_SIZE, buf + 4, 16); // copy IV for checksum
size_t zero = TUNNEL_DATA_MSG_SIZE - size -1;
buf[zero] = 0; // zero
size_t s = 0;
while (ind < cnt)
{
auto msg = m_I2NPMsgs[ind];
if (m_NextOffset)
{
s += CreateFollowOnFragment (msg, buf + zero + 1 + s, size - s);
m_NextOffset = 0; // TODO:
}
else
{
s += CreateFirstFragment (msg, buf + zero + 1 + s, size - s);
if (msg->isFragmented) break; // payload is full, but we stay at the same message
}
ind++;
if (s >= size) break; // payload is full but we moved to next message
}
if (s != size)
{
LogPrint ("TunnelData payload size mismatch ", s, "!=", size);
return nullptr;
}
uint8_t hash[32];
CryptoPP::SHA256().CalculateDigest(hash, buf+zero+1, size+16);
memcpy (buf+20, hash, 4); // checksum
if (zero > 24)
memset (buf+24, 1, zero-24); // padding TODO: fill with random data
tunnelMsg->len += TUNNEL_DATA_MSG_SIZE;
// we can't fill message header yet because encryption is required
return tunnelMsg;
}
I2NPMessage * CreateDatabaseLookupMsg (const uint8_t * key, const uint8_t * from,
uint32_t replyTunnelID, bool exploratory, std::set<i2p::data::IdentHash> * excludedPeers,
bool encryption, i2p::tunnel::TunnelPool * pool)
{
I2NPMessage * m = NewI2NPMessage ();
uint8_t * buf = m->GetPayload ();
memcpy (buf, key, 32); // key
buf += 32;
memcpy (buf, from, 32); // from
buf += 32;
if (replyTunnelID)
{
*buf = encryption ? 0x03: 0x01; // set delivery flag
*(uint32_t *)(buf+1) = htobe32 (replyTunnelID);
buf += 5;
}
else
{
encryption = false; // encryption can we set for tunnels only
*buf = 0; // flag
buf++;
}
if (exploratory)
{
*(uint16_t *)buf = htobe16 (1); // one exlude record
buf += 2;
// reply with non-floodfill routers only
memset (buf, 0, 32);
buf += 32;
}
else
{
if (excludedPeers)
{
int cnt = excludedPeers->size ();
*(uint16_t *)buf = htobe16 (cnt);
buf += 2;
for (auto& it: *excludedPeers)
{
memcpy (buf, it, 32);
buf += 32;
}
}
else
{
// nothing to exclude
*(uint16_t *)buf = htobe16 (0);
buf += 2;
}
}
if (encryption)
{
// session key and tag for reply
auto& rnd = i2p::context.GetRandomNumberGenerator ();
rnd.GenerateBlock (buf, 32); // key
buf[32] = 1; // 1 tag
rnd.GenerateBlock (buf + 33, 32); // tag
if (pool)
pool->GetLocalDestination ().SubmitSessionKey (buf, buf + 33); // introduce new key-tag to garlic engine
else
LogPrint ("Destination for encrypteed reply not specified");
buf += 65;
}
m->len += (buf - m->GetPayload ());
FillI2NPMessageHeader (m, eI2NPDatabaseLookup);
return m;
}
void TunnelGatewayBuffer::PutI2NPMsg (const TunnelMessageBlock& block)
{
if (!m_CurrentTunnelDataMsg)
CreateCurrentTunnelDataMessage ();
// create delivery instructions
uint8_t di[43]; // max delivery instruction length is 43 for tunnel
size_t diLen = 1;// flag
if (block.deliveryType != eDeliveryTypeLocal) // tunnel or router
{
if (block.deliveryType == eDeliveryTypeTunnel)
{
*(uint32_t *)(di + diLen) = htobe32 (block.tunnelID);
diLen += 4; // tunnelID
}
memcpy (di + diLen, block.hash, 32);
diLen += 32; //len
}
di[0] = block.deliveryType << 5; // set delivery type
// create fragments
I2NPMessage * msg = block.data;
if (diLen + msg->GetLength () + 2<= m_RemainingSize)
{
// message fits. First and last fragment
*(uint16_t *)(di + diLen) = htobe16 (msg->GetLength ());
diLen += 2; // size
memcpy (m_CurrentTunnelDataMsg->buf + m_CurrentTunnelDataMsg->len, di, diLen);
memcpy (m_CurrentTunnelDataMsg->buf + m_CurrentTunnelDataMsg->len + diLen, msg->GetBuffer (), msg->GetLength ());
m_CurrentTunnelDataMsg->len += diLen + msg->GetLength ();
m_RemainingSize -= diLen + msg->GetLength ();
if (!m_RemainingSize)
CompleteCurrentTunnelDataMessage ();
DeleteI2NPMessage (msg);
}
else
{
if (diLen + 6 <= m_RemainingSize)
{
// delivery instructions fit
uint32_t msgID = msg->GetHeader ()->msgID;
size_t size = m_RemainingSize - diLen - 6; // 6 = 4 (msgID) + 2 (size)
// first fragment
di[0] |= 0x08; // fragmented
*(uint32_t *)(di + diLen) = htobe32 (msgID);
diLen += 4; // Message ID
*(uint16_t *)(di + diLen) = htobe16 (size);
diLen += 2; // size
memcpy (m_CurrentTunnelDataMsg->buf + m_CurrentTunnelDataMsg->len, di, diLen);
memcpy (m_CurrentTunnelDataMsg->buf + m_CurrentTunnelDataMsg->len + diLen, msg->GetBuffer (), size);
m_CurrentTunnelDataMsg->len += diLen + size;
CompleteCurrentTunnelDataMessage ();
// follow on fragments
int fragmentNumber = 1;
while (size < msg->GetLength ())
{
CreateCurrentTunnelDataMessage ();
uint8_t * buf = m_CurrentTunnelDataMsg->GetBuffer ();
buf[0] = 0x80 | (fragmentNumber << 1); // frag
bool isLastFragment = false;
size_t s = msg->GetLength () - size;
if (s > TUNNEL_DATA_MAX_PAYLOAD_SIZE - 7) // 7 follow on instructions
s = TUNNEL_DATA_MAX_PAYLOAD_SIZE - 7;
else // last fragment
{
buf[0] |= 0x01;
isLastFragment = true;
}
*(uint32_t *)(buf + 1) = htobe32 (msgID); //Message ID
*(uint16_t *)(buf + 5) = htobe16 (s); // size
memcpy (buf + 7, msg->GetBuffer () + size, s);
m_CurrentTunnelDataMsg->len += s+7;
if (isLastFragment)
{
m_RemainingSize -= s+7;
if (!m_RemainingSize)
CompleteCurrentTunnelDataMessage ();
}
else
CompleteCurrentTunnelDataMessage ();
size += s;
fragmentNumber++;
}
DeleteI2NPMessage (msg);
}
else
{
// delivery instructions don't fit. Create new message
CompleteCurrentTunnelDataMessage ();
PutI2NPMsg (block);
// don't delete msg because it's taken care inside
}
}
}
