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/*
This file is part of cpp-ethereum.
cpp-ethereum is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
cpp-ethereum is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with cpp-ethereum. If not, see <http://www.gnu.org/licenses/>.
*/
/** @file PeerSession.cpp
* @author Gav Wood <i@gavwood.com>
* @date 2014
*/
#include "PeerSession.h"
#include <chrono>
#include <libethential/Common.h>
#include <libethcore/Exceptions.h>
#include "BlockChain.h"
#include "PeerServer.h"
using namespace std;
using namespace eth;
#define clogS(X) eth::LogOutputStream<X, true>(false) << "| " << std::setw(2) << m_socket.native_handle() << "] "
static const eth::uint c_maxHashes = 32; ///< Maximum number of hashes GetChain will ever send.
static const eth::uint c_maxBlocks = 64; ///< Maximum number of blocks Blocks will ever send. BUG: if this gets too big (e.g. 2048) stuff starts going wrong.
static const eth::uint c_maxBlocksAsk = 256; ///< Maximum number of blocks we ask to receive in Blocks (when using GetChain).
PeerSession::PeerSession(PeerServer* _s, bi::tcp::socket _socket, uint _rNId, bi::address _peerAddress, unsigned short _peerPort):
m_server(_s),
m_strand(_socket.get_io_service()),
m_socket(std::move(_socket)),
m_reqNetworkId(_rNId),
m_listenPort(_peerPort),
m_rating(0)
{
m_disconnect = std::chrono::steady_clock::time_point::max();
m_connect = std::chrono::steady_clock::now();
m_info = PeerInfo({"?", _peerAddress.to_string(), m_listenPort, std::chrono::steady_clock::duration(0)});
}
PeerSession::~PeerSession()
{
m_strand.post([=]()
{
if (!m_writeq.empty())
m_writeq.clear();
try {
if (m_socket.is_open())
m_socket.close();
}catch (...){}
});
}
bi::tcp::endpoint PeerSession::endpoint() const
{
if (m_socket.is_open())
try {
return bi::tcp::endpoint(m_socket.remote_endpoint().address(), m_listenPort);
} catch (...){}
return bi::tcp::endpoint();
}
bool PeerSession::interpret(RLP const& _r)
{
clogS(NetRight) << _r;
switch (_r[0].toInt<unsigned>())
{
case HelloPacket:
{
m_protocolVersion = _r[1].toInt<uint>();
m_networkId = _r[2].toInt<uint>();
auto clientVersion = _r[3].toString();
m_caps = _r[4].toInt<uint>();
m_listenPort = _r[5].toInt<unsigned short>();
m_id = _r[6].toHash<h512>();
clogS(NetMessageSummary) << "Hello: " << clientVersion << "V[" << m_protocolVersion << "/" << m_networkId << "]" << m_id.abridged() << showbase << hex << m_caps << dec << m_listenPort;
if (m_server->m_peers.count(m_id))
if (auto l = m_server->m_peers[m_id].lock())
if (l.get() != this && l->isOpen())
{
// Already connected.
cwarn << "Already have peer id" << m_id.abridged() << "at" << l->endpoint() << "rather than" << endpoint();
disconnect(DuplicatePeer);
return false;
}
if (m_protocolVersion != PeerServer::protocolVersion() || m_networkId != m_server->networkId() || !m_id)
{
disconnect(IncompatibleProtocol);
return false;
}
try
{ m_info = PeerInfo({clientVersion, m_socket.remote_endpoint().address().to_string(), m_listenPort, std::chrono::steady_clock::duration()}); }
catch (...)
{
disconnect(BadProtocol);
return false;
}
m_server->m_peers[m_id] = shared_from_this();
// Grab their block chain off them.
{
uint n = m_server->m_chain->number(m_server->m_latestBlockSent);
clogS(NetAllDetail) << "Want chain. Latest:" << m_server->m_latestBlockSent << ", number:" << n;
uint count = std::min(c_maxHashes, n + 1);
RLPStream s;
prep(s).appendList(2 + count);
s << GetChainPacket;
auto h = m_server->m_latestBlockSent;
for (uint i = 0; i < count; ++i, h = m_server->m_chain->details(h).parent)
{
clogS(NetAllDetail) << " " << i << ":" << h;
s << h;
}
s << c_maxBlocksAsk;
sealAndSend(s);
s.clear();
prep(s).appendList(1);
s << GetTransactionsPacket;
sealAndSend(s);
}
break;
}
case DisconnectPacket:
{
string reason = "Unspecified";
if (_r[1].isInt())
reason = reasonOf((DisconnectReason)_r[1].toInt<int>());
clogS(NetMessageSummary) << "Disconnect (reason: " << reason << ")";
if (m_socket.is_open())
clogS(NetNote) << "Closing " << m_socket.remote_endpoint();
else
clogS(NetNote) << "Remote closed.";
m_socket.close();
return false;
}
case PingPacket:
{
clogS(NetTriviaSummary) << "Ping";
RLPStream s;
sealAndSend(prep(s).appendList(1) << PongPacket);
break;
}
case PongPacket:
m_info.lastPing = std::chrono::steady_clock::now() - m_ping;
clogS(NetTriviaSummary) << "Latency: " << chrono::duration_cast<chrono::milliseconds>(m_info.lastPing).count() << " ms";
break;
case GetPeersPacket:
{
clogS(NetTriviaSummary) << "GetPeers";
auto peers = m_server->potentialPeers();
RLPStream s;
prep(s).appendList(peers.size() + 1);
s << PeersPacket;
for (auto i: peers)
{
clogS(NetTriviaDetail) << "Sending peer " << toHex(i.first.ref().cropped(0, 4)) << i.second;
s.appendList(3) << bytesConstRef(i.second.address().to_v4().to_bytes().data(), 4) << i.second.port() << i.first;
}
sealAndSend(s);
break;
}
case PeersPacket:
clogS(NetTriviaSummary) << "Peers (" << dec << (_r.itemCount() - 1) << " entries)";
for (unsigned i = 1; i < _r.itemCount(); ++i)
{
bi::address_v4 peerAddress(_r[i][0].toHash<FixedHash<4>>().asArray());
auto ep = bi::tcp::endpoint(peerAddress, _r[i][1].toInt<short>());
Public id = _r[i][2].toHash<Public>();
if (isPrivateAddress(peerAddress))
goto CONTINUE;
clogS(NetAllDetail) << "Checking: " << ep << "(" << toHex(id.ref().cropped(0, 4)) << ")";
// check that it's not us or one we already know:
if (id && (m_server->m_key.pub() == id || m_server->m_peers.count(id) || m_server->m_incomingPeers.count(id)))
goto CONTINUE;
// check that we're not already connected to addr:
if (!ep.port())
goto CONTINUE;
for (auto i: m_server->m_addresses)
if (ep.address() == i && ep.port() == m_server->listenPort())
goto CONTINUE;
for (auto i: m_server->m_peers)
if (shared_ptr<PeerSession> p = i.second.lock())
{
clogS(NetAllDetail) << " ...against " << p->endpoint();
if (p->m_socket.is_open() && p->endpoint() == ep)
goto CONTINUE;
}
for (auto i: m_server->m_incomingPeers)
if (i.second.first == ep)
goto CONTINUE;
m_server->m_incomingPeers[id] = make_pair(ep, 0);
m_server->m_freePeers.push_back(id);
clogS(NetTriviaDetail) << "New peer: " << ep << "(" << id << ")";
CONTINUE:;
}
break;
case TransactionsPacket:
if (m_server->m_mode == NodeMode::PeerServer)
break;
clogS(NetMessageSummary) << "Transactions (" << dec << (_r.itemCount() - 1) << " entries)";
m_rating += _r.itemCount() - 1;
for (unsigned i = 1; i < _r.itemCount(); ++i)
{
m_server->m_incomingTransactions.push_back(_r[i].data().toBytes());
m_knownTransactions.insert(sha3(_r[i].data()));
}
break;
case BlocksPacket:
{
if (m_server->m_mode == NodeMode::PeerServer)
break;
clogS(NetMessageSummary) << "Blocks (" << dec << (_r.itemCount() - 1) << " entries)";
unsigned used = 0;
for (unsigned i = 1; i < _r.itemCount(); ++i)
{
auto h = sha3(_r[i].data());
if (m_server->noteBlock(h, _r[i].data()))
{
m_knownBlocks.insert(h);
used++;
}
}
m_rating += used;
if (g_logVerbosity >= 3)
for (unsigned i = 1; i < _r.itemCount(); ++i)
{
auto h = sha3(_r[i].data());
BlockInfo bi(_r[i].data());
if (!m_server->m_chain->details(bi.parentHash) && !m_knownBlocks.count(bi.parentHash))
clogS(NetMessageDetail) << "Unknown parent " << bi.parentHash << " of block " << h;
else
clogS(NetMessageDetail) << "Known parent " << bi.parentHash << " of block " << h;
}
if (used) // we received some - check if there's any more
{
RLPStream s;
prep(s).appendList(3);
s << GetChainPacket;
s << sha3(_r[1].data());
s << c_maxBlocksAsk;
sealAndSend(s);
}
break;
}
case GetChainPacket:
{
if (m_server->m_mode == NodeMode::PeerServer)
break;
clogS(NetMessageSummary) << "GetChain (" << (_r.itemCount() - 2) << " hashes, " << (_r[_r.itemCount() - 1].toInt<bigint>()) << ")";
// ********************************************************************
// NEEDS FULL REWRITE!
h256s parents;
parents.reserve(_r.itemCount() - 2);
for (unsigned i = 1; i < _r.itemCount() - 1; ++i)
parents.push_back(_r[i].toHash<h256>());
if (_r.itemCount() == 2)
break;
// return 2048 block max.
uint baseCount = (uint)min<bigint>(_r[_r.itemCount() - 1].toInt<bigint>(), c_maxBlocks);
clogS(NetMessageSummary) << "GetChain (" << baseCount << " max, from " << parents.front() << " to " << parents.back() << ")";
for (auto parent: parents)
{
auto h = m_server->m_chain->currentHash();
h256 latest = m_server->m_chain->currentHash();
uint latestNumber = 0;
uint parentNumber = 0;
RLPStream s;
// try to find parent in our blockchain
// todo: add some delta() fn to blockchain
BlockDetails fParent = m_server->m_chain->details(parent);
if (fParent)
{
latestNumber = m_server->m_chain->number(latest);
parentNumber = fParent.number;
uint count = min<uint>(latestNumber - parentNumber, baseCount);
clogS(NetAllDetail) << "Requires " << dec << (latestNumber - parentNumber) << " blocks from " << latestNumber << " to " << parentNumber;
clogS(NetAllDetail) << latest << " - " << parent;
prep(s);
s.appendList(1 + count) << BlocksPacket;
uint endNumber = parentNumber;
uint startNumber = endNumber + count;
clogS(NetAllDetail) << "Sending " << dec << count << " blocks from " << startNumber << " to " << endNumber;
// append blocks
uint n = latestNumber;
// seek back (occurs when count is limited by baseCount)
for (; n > startNumber; n--, h = m_server->m_chain->details(h).parent) {}
for (uint i = 0; i < count; ++i, --n, h = m_server->m_chain->details(h).parent)
{
if (h == parent || n == endNumber)
{
cwarn << "BUG! Couldn't create the reply for GetChain!";
return true;
}
clogS(NetAllDetail) << " " << dec << i << " " << h;
s.appendRaw(m_server->m_chain->block(h));
}
clogS(NetAllDetail) << "Parent: " << h;
}
else if (parent != parents.back())
continue;
if (h != parent)
{
// not in the blockchain;
if (parent == parents.back())
{
// out of parents...
clogS(NetAllDetail) << "GetChain failed; not in chain";
// No good - must have been on a different branch.
s.clear();
prep(s).appendList(2) << NotInChainPacket << parents.back();
}
else
// still some parents left - try them.
continue;
}
// send the packet (either Blocks or NotInChain) & exit.
sealAndSend(s);
break;
// ********************************************************************
}
break;
}
case NotInChainPacket:
{
if (m_server->m_mode == NodeMode::PeerServer)
break;
h256 noGood = _r[1].toHash<h256>();
clogS(NetMessageSummary) << "NotInChain (" << noGood << ")";
if (noGood == m_server->m_chain->genesisHash())
{
clogS(NetWarn) << "Discordance over genesis block! Disconnect.";
disconnect(WrongGenesis);
}
else
{
uint count = std::min(c_maxHashes, m_server->m_chain->number(noGood));
RLPStream s;
prep(s).appendList(2 + count);
s << GetChainPacket;
auto h = m_server->m_chain->details(noGood).parent;
for (uint i = 0; i < count; ++i, h = m_server->m_chain->details(h).parent)
s << h;
s << c_maxBlocksAsk;
sealAndSend(s);
}
break;
}
case GetTransactionsPacket:
{
if (m_server->m_mode == NodeMode::PeerServer)
break;
m_requireTransactions = true;
break;
}
default:
break;
}
return true;
}
void PeerSession::ping()
{
RLPStream s;
sealAndSend(prep(s).appendList(1) << PingPacket);
m_ping = std::chrono::steady_clock::now();
}
RLPStream& PeerSession::prep(RLPStream& _s)
{
return _s.appendRaw(bytes(8, 0));
}
void PeerServer::seal(bytes& _b)
{
_b[0] = 0x22;
_b[1] = 0x40;
_b[2] = 0x08;
_b[3] = 0x91;
uint32_t len = (uint32_t)_b.size() - 8;
_b[4] = (len >> 24) & 0xff;
_b[5] = (len >> 16) & 0xff;
_b[6] = (len >> 8) & 0xff;
_b[7] = len & 0xff;
}
void PeerSession::sealAndSend(RLPStream& _s)
{
bytes b;
_s.swapOut(b);
m_server->seal(b);
sendDestroy(b);
}
bool PeerSession::checkPacket(bytesConstRef _msg)
{
if (_msg.size() < 8)
return false;
if (!(_msg[0] == 0x22 && _msg[1] == 0x40 && _msg[2] == 0x08 && _msg[3] == 0x91))
return false;
uint32_t len = ((_msg[4] * 256 + _msg[5]) * 256 + _msg[6]) * 256 + _msg[7];
if (_msg.size() != len + 8)
return false;
RLP r(_msg.cropped(8));
if (r.actualSize() != len)
return false;
return true;
}
void PeerSession::sendDestroy(bytes& _msg)
{
clogS(NetLeft) << RLP(bytesConstRef(&_msg).cropped(8));
if (!checkPacket(bytesConstRef(&_msg)))
{
cwarn << "INVALID PACKET CONSTRUCTED!";
}
bytes buffer = bytes(std::move(_msg));
m_strand.post(boost::bind(&PeerSession::writeImpl, this, buffer));
}
void PeerSession::send(bytesConstRef _msg)
{
clogS(NetLeft) << RLP(_msg.cropped(8));
if (!checkPacket(_msg))
{
cwarn << "INVALID PACKET CONSTRUCTED!";
}
bytes buffer = bytes(_msg.toBytes());
m_strand.post(boost::bind(&PeerSession::writeImpl, this, buffer));
}
void PeerSession::writeImpl(bytes& _buffer)
{
m_writeq.push_back(_buffer);
if (m_writeq.size() > 1)
return;
this->write();
}
void PeerSession::write()
{
if (m_writeq.empty())
return;
const bytes& bytes = m_writeq[0];
if (m_socket.is_open())
ba::async_write(m_socket, ba::buffer(bytes), m_strand.wrap([this](boost::system::error_code ec, std::size_t /*length*/)
{
// must check que, as write callback can occur following dropped()
if (!m_writeq.empty())
this->m_writeq.pop_front();
if (ec)
{
cwarn << "Error sending: " << ec.message();
this->dropped();
} else
m_strand.post(boost::bind(&PeerSession::write, this));
}));
}
void PeerSession::dropped()
{
if (m_socket.is_open())
try {
clogS(NetNote) << "Closing " << m_socket.remote_endpoint();
m_socket.close();
}catch (...){}
// block future writes by running in strand and clearing queue
m_strand.post([=]()
{
m_writeq.clear();
for (auto i = m_server->m_peers.begin(); i != m_server->m_peers.end(); ++i)
if (i->second.lock().get() == this)
{
m_server->m_peers.erase(i);
break;
}
});
}
void PeerSession::disconnect(int _reason)
{
clogS(NetNote) << "Disconnecting (reason:" << reasonOf((DisconnectReason)_reason) << ")";
if (m_socket.is_open())
{
if (m_disconnect == chrono::steady_clock::time_point::max())
{
RLPStream s;
prep(s);
s.appendList(2) << DisconnectPacket << _reason;
sealAndSend(s);
m_disconnect = chrono::steady_clock::now();
}
else
dropped();
}
}
void PeerSession::start()
{
RLPStream s;
prep(s);
s.appendList(7) << HelloPacket << (uint)PeerServer::protocolVersion() << m_server->networkId() << m_server->m_clientVersion << (m_server->m_mode == NodeMode::Full ? 0x07 : m_server->m_mode == NodeMode::PeerServer ? 0x01 : 0) << m_server->m_public.port() << m_server->m_key.pub();
sealAndSend(s);
ping();
doRead();
}
void PeerSession::doRead()
{
// ignore packets received while waiting to disconnect
if (chrono::steady_clock::now() - m_disconnect > chrono::seconds(0))
return;
auto self(shared_from_this());
m_socket.async_read_some(boost::asio::buffer(m_data), [this,self](boost::system::error_code ec, std::size_t length)
{
// If error is end of file, ignore
if (ec && ec.category() != boost::asio::error::get_misc_category() && ec.value() != boost::asio::error::eof)
{
// got here with length of 1241...
cwarn << "Error reading: " << ec.message();
dropped();
}
else if(ec && length == 0)
{
return;
}
else
{
try
{
m_incoming.resize(m_incoming.size() + length);
memcpy(m_incoming.data() + m_incoming.size() - length, m_data.data(), length);
while (m_incoming.size() > 8)
{
if (m_incoming[0] != 0x22 || m_incoming[1] != 0x40 || m_incoming[2] != 0x08 || m_incoming[3] != 0x91)
{
doRead();
}
else
{
uint32_t len = fromBigEndian<uint32_t>(bytesConstRef(m_incoming.data() + 4, 4));
uint32_t tlen = len + 8;
if (m_incoming.size() < tlen)
break;
// enough has come in.
auto data = bytesConstRef(m_incoming.data(), tlen);
if (!checkPacket(data))
{
cerr << "Received " << len << ": " << toHex(bytesConstRef(m_incoming.data() + 8, len)) << endl;
cwarn << "INVALID MESSAGE RECEIVED";
disconnect(BadProtocol);
return;
}
else
{
RLP r(data.cropped(8));
if (!interpret(r))
{
// error
dropped();
return;
}
}
memmove(m_incoming.data(), m_incoming.data() + tlen, m_incoming.size() - tlen);
m_incoming.resize(m_incoming.size() - tlen);
}
}
doRead();
}
catch (Exception const& _e)
{
clogS(NetWarn) << "ERROR: " << _e.description();
dropped();
}
catch (std::exception const& _e)
{
clogS(NetWarn) << "ERROR: " << _e.what();
dropped();
}
}
});
}