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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 Host.cpp
* @authors:
* Gav Wood <i@gavwood.com>
* Eric Lombrozo <elombrozo@gmail.com> (Windows version of populateAddresses())
* @date 2014
*/
#include "Host.h"
#include <sys/types.h>
#ifdef _WIN32
// winsock is already included
// #include <winsock.h>
#else
#include <ifaddrs.h>
#endif
#include <set>
#include <chrono>
#include <thread>
#include <libdevcore/Common.h>
#include <libethcore/Exceptions.h>
#include "Session.h"
#include "Capability.h"
#include "UPnP.h"
using namespace std;
using namespace dev;
using namespace dev::p2p;
// Addresses we will skip during network interface discovery
// Use a vector as the list is small
// Why this and not names?
// Under MacOSX loopback (127.0.0.1) can be named lo0 and br0 are bridges (0.0.0.0)
static const set<bi::address> c_rejectAddresses = {
{bi::address_v4::from_string("127.0.0.1")},
{bi::address_v6::from_string("::1")},
{bi::address_v4::from_string("0.0.0.0")},
{bi::address_v6::from_string("::")}
};
Host::Host(std::string const& _clientVersion, NetworkPreferences const& _n, bool _start):
Worker("p2p"),
m_clientVersion(_clientVersion),
m_netPrefs(_n),
m_acceptor(m_ioService),
m_socket(m_ioService),
m_id(h512::random())
{
populateAddresses();
m_lastPeersRequest = chrono::steady_clock::time_point::min();
clog(NetNote) << "Id:" << m_id.abridged();
if (_start)
start();
}
Host::~Host()
{
stop();
}
void Host::start()
{
stop();
for (unsigned i = 0; i < 2; ++i)
{
bi::tcp::endpoint endpoint(bi::tcp::v4(), i ? 0 : m_netPrefs.listenPort);
try
{
m_acceptor.open(endpoint.protocol());
m_acceptor.set_option(ba::socket_base::reuse_address(true));
m_acceptor.bind(endpoint);
m_acceptor.listen();
m_listenPort = i ? m_acceptor.local_endpoint().port() : m_netPrefs.listenPort;
break;
}
catch (...)
{
if (i)
{
cwarn << "Couldn't start accepting connections on host. Something very wrong with network?";
return;
}
m_acceptor.close();
continue;
}
}
determinePublic(m_netPrefs.publicIP, m_netPrefs.upnp);
ensureAccepting();
m_lastPeersRequest = chrono::steady_clock::time_point::min();
clog(NetNote) << "Id:" << m_id.abridged();
for (auto const& h: m_capabilities)
h.second->onStarting();
startWorking();
}
void Host::stop()
{
for (auto const& h: m_capabilities)
h.second->onStopping();
stopWorking();
if (m_acceptor.is_open())
{
if (m_accepting)
m_acceptor.cancel();
m_acceptor.close();
m_accepting = false;
}
if (m_socket.is_open())
m_socket.close();
disconnectPeers();
m_ioService.reset();
}
unsigned Host::protocolVersion() const
{
return 0;
}
void Host::registerPeer(std::shared_ptr<Session> _s, vector<string> const& _caps)
{
{
Guard l(x_peers);
m_peers[_s->m_id] = _s;
}
for (auto const& i: _caps)
if (haveCapability(i))
_s->m_capabilities[i] = shared_ptr<Capability>(m_capabilities[i]->newPeerCapability(_s.get()));
}
void Host::disconnectPeers()
{
for (unsigned n = 0;; n = 0)
{
{
Guard l(x_peers);
for (auto i: m_peers)
if (auto p = i.second.lock())
{
p->disconnect(ClientQuit);
n++;
}
}
if (!n)
break;
m_ioService.poll();
this_thread::sleep_for(chrono::milliseconds(100));
}
delete m_upnp;
}
void Host::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 Host::determinePublic(string const& _publicAddress, bool _upnp)
{
if (_upnp)
try
{
m_upnp = new UPnP;
}
catch (NoUPnPDevice) {} // let m_upnp continue as null - we handle it properly.
bi::tcp::resolver r(m_ioService);
if (m_upnp && m_upnp->isValid() && m_peerAddresses.size())
{
clog(NetNote) << "External addr:" << m_upnp->externalIP();
int p = m_upnp->addRedirect(m_peerAddresses[0].to_string().c_str(), m_listenPort);
if (p)
clog(NetNote) << "Punched through NAT and mapped local port" << m_listenPort << "onto external port" << p << ".";
else
{
// couldn't map
clog(NetWarn) << "Couldn't punch through NAT (or no NAT in place). Assuming" << m_listenPort << "is local & external port.";
p = m_listenPort;
}
auto eip = m_upnp->externalIP();
if (eip == string("0.0.0.0") && _publicAddress.empty())
m_public = bi::tcp::endpoint(bi::address(), (unsigned short)p);
else
{
m_public = bi::tcp::endpoint(bi::address::from_string(_publicAddress.empty() ? eip : _publicAddress), (unsigned short)p);
m_addresses.push_back(m_public.address().to_v4());
}
}
else
{
// No UPnP - fallback on given public address or, if empty, the assumed peer address.
m_public = bi::tcp::endpoint(_publicAddress.size() ? bi::address::from_string(_publicAddress)
: m_peerAddresses.size() ? m_peerAddresses[0]
: bi::address(), m_listenPort);
m_addresses.push_back(m_public.address().to_v4());
}
}
void Host::populateAddresses()
{
#ifdef _WIN32
WSAData wsaData;
if (WSAStartup(MAKEWORD(1, 1), &wsaData) != 0)
throw NoNetworking();
char ac[80];
if (gethostname(ac, sizeof(ac)) == SOCKET_ERROR)
{
clog(NetWarn) << "Error " << WSAGetLastError() << " when getting local host name.";
WSACleanup();
throw NoNetworking();
}
struct hostent* phe = gethostbyname(ac);
if (phe == 0)
{
clog(NetWarn) << "Bad host lookup.";
WSACleanup();
throw NoNetworking();
}
for (int i = 0; phe->h_addr_list[i] != 0; ++i)
{
struct in_addr addr;
memcpy(&addr, phe->h_addr_list[i], sizeof(struct in_addr));
char *addrStr = inet_ntoa(addr);
bi::address ad(bi::address::from_string(addrStr));
m_addresses.push_back(ad.to_v4());
bool isLocal = std::find(c_rejectAddresses.begin(), c_rejectAddresses.end(), ad) != c_rejectAddresses.end();
if (!isLocal)
m_peerAddresses.push_back(ad.to_v4());
clog(NetNote) << "Address: " << ac << " = " << m_addresses.back() << (isLocal ? " [LOCAL]" : " [PEER]");
}
WSACleanup();
#else
ifaddrs* ifaddr;
if (getifaddrs(&ifaddr) == -1)
throw NoNetworking();
bi::tcp::resolver r(m_ioService);
for (ifaddrs* ifa = ifaddr; ifa; ifa = ifa->ifa_next)
{
if (!ifa->ifa_addr)
continue;
if (ifa->ifa_addr->sa_family == AF_INET)
{
char host[NI_MAXHOST];
if (getnameinfo(ifa->ifa_addr, sizeof(struct sockaddr_in), host, NI_MAXHOST, NULL, 0, NI_NUMERICHOST))
continue;
try
{
auto it = r.resolve({host, "30303"});
bi::tcp::endpoint ep = it->endpoint();
bi::address ad = ep.address();
m_addresses.push_back(ad.to_v4());
bool isLocal = std::find(c_rejectAddresses.begin(), c_rejectAddresses.end(), ad) != c_rejectAddresses.end();
if (!isLocal)
m_peerAddresses.push_back(ad.to_v4());
clog(NetNote) << "Address: " << host << " = " << m_addresses.back() << (isLocal ? " [LOCAL]" : " [PEER]");
}
catch (...)
{
clog(NetNote) << "Couldn't resolve: " << host;
}
}
}
freeifaddrs(ifaddr);
#endif
}
std::map<h512, bi::tcp::endpoint> Host::potentialPeers()
{
std::map<h512, bi::tcp::endpoint> ret;
if (!m_public.address().is_unspecified())
ret.insert(make_pair(m_id, m_public));
Guard l(x_peers);
for (auto i: m_peers)
if (auto j = i.second.lock())
{
auto ep = j->endpoint();
// Skip peers with a listen port of zero or are on a private network
bool peerOnNet = (j->m_listenPort != 0 && (!isPrivateAddress(ep.address()) || m_netPrefs.localNetworking));
if (peerOnNet && ep.port() && j->m_id)
ret.insert(make_pair(i.first, ep));
}
return ret;
}
void Host::ensureAccepting()
{
if (!m_accepting)
{
clog(NetConnect) << "Listening on local port " << m_listenPort << " (public: " << m_public << ")";
m_accepting = true;
m_acceptor.async_accept(m_socket, [=](boost::system::error_code ec)
{
if (!ec)
try
{
try {
clog(NetConnect) << "Accepted connection from " << m_socket.remote_endpoint();
} catch (...){}
bi::address remoteAddress = m_socket.remote_endpoint().address();
// Port defaults to 0 - we let the hello tell us which port the peer listens to
auto p = std::make_shared<Session>(this, std::move(m_socket), remoteAddress);
p->start();
}
catch (std::exception const& _e)
{
clog(NetWarn) << "ERROR: " << _e.what();
}
m_accepting = false;
if (ec.value() < 1)
ensureAccepting();
});
}
}
void Host::connect(std::string const& _addr, unsigned short _port) noexcept
{
try
{
// TODO: actual DNS lookup.
connect(bi::tcp::endpoint(bi::address::from_string(_addr), _port));
}
catch (exception const& e)
{
// Couldn't connect
clog(NetConnect) << "Bad host " << _addr << " (" << e.what() << ")";
}
}
void Host::connect(bi::tcp::endpoint const& _ep)
{
clog(NetConnect) << "Attempting connection to " << _ep;
bi::tcp::socket* s = new bi::tcp::socket(m_ioService);
s->async_connect(_ep, [=](boost::system::error_code const& ec)
{
if (ec)
{
clog(NetConnect) << "Connection refused to " << _ep << " (" << ec.message() << ")";
for (auto i = m_incomingPeers.begin(); i != m_incomingPeers.end(); ++i)
if (i->second.first == _ep && i->second.second < 3)
{
m_freePeers.push_back(i->first);
goto OK;
}
// for-else
clog(NetConnect) << "Giving up.";
OK:;
}
else
{
auto p = make_shared<Session>(this, std::move(*s), _ep.address(), _ep.port());
clog(NetConnect) << "Connected to " << _ep;
p->start();
}
delete s;
});
}
bool Host::havePeer(h512 _id) const
{
Guard l(x_peers);
// Remove dead peers from list.
for (auto i = m_peers.begin(); i != m_peers.end();)
if (i->second.lock().get())
++i;
else
i = m_peers.erase(i);
return !!m_peers.count(_id);
}
void Host::growPeers()
{
Guard l(x_peers);
while (m_peers.size() < m_idealPeerCount)
{
if (m_freePeers.empty())
{
if (chrono::steady_clock::now() > m_lastPeersRequest + chrono::seconds(10))
{
RLPStream s;
bytes b;
(Session::prep(s).appendList(1) << GetPeersPacket).swapOut(b);
seal(b);
for (auto const& i: m_peers)
if (auto p = i.second.lock())
if (p->isOpen())
p->send(&b);
m_lastPeersRequest = chrono::steady_clock::now();
}
if (!m_accepting)
ensureAccepting();
break;
}
auto x = time(0) % m_freePeers.size();
m_incomingPeers[m_freePeers[x]].second++;
connect(m_incomingPeers[m_freePeers[x]].first);
m_freePeers.erase(m_freePeers.begin() + x);
}
}
void Host::prunePeers()
{
Guard l(x_peers);
// We'll keep at most twice as many as is ideal, halfing what counts as "too young to kill" until we get there.
for (unsigned old = 15000; m_peers.size() > m_idealPeerCount * 2 && old > 100; old /= 2)
while (m_peers.size() > m_idealPeerCount)
{
// look for worst peer to kick off
// first work out how many are old enough to kick off.
shared_ptr<Session> worst;
unsigned agedPeers = 0;
for (auto i: m_peers)
if (auto p = i.second.lock())
if (/*(m_mode != NodeMode::Host || p->m_caps != 0x01) &&*/ chrono::steady_clock::now() > p->m_connect + chrono::milliseconds(old)) // don't throw off new peers; peer-servers should never kick off other peer-servers.
{
++agedPeers;
if ((!worst || p->m_rating < worst->m_rating || (p->m_rating == worst->m_rating && p->m_connect > worst->m_connect))) // kill older ones
worst = p;
}
if (!worst || agedPeers <= m_idealPeerCount)
break;
worst->disconnect(TooManyPeers);
}
// Remove dead peers from list.
for (auto i = m_peers.begin(); i != m_peers.end();)
if (i->second.lock().get())
++i;
else
i = m_peers.erase(i);
}
std::vector<PeerInfo> Host::peers(bool _updatePing) const
{
Guard l(x_peers);
if (_updatePing)
const_cast<Host*>(this)->pingAll();
this_thread::sleep_for(chrono::milliseconds(200));
std::vector<PeerInfo> ret;
for (auto& i: m_peers)
if (auto j = i.second.lock())
if (j->m_socket.is_open())
ret.push_back(j->m_info);
return ret;
}
void Host::doWork()
{
growPeers();
prunePeers();
m_ioService.poll();
}
void Host::pingAll()
{
Guard l(x_peers);
for (auto& i: m_peers)
if (auto j = i.second.lock())
j->ping();
}
bytes Host::savePeers() const
{
Guard l(x_peers);
RLPStream ret;
int n = 0;
for (auto& i: m_peers)
if (auto p = i.second.lock())
if (p->m_socket.is_open() && p->endpoint().port())
{
ret.appendList(3) << p->endpoint().address().to_v4().to_bytes() << p->endpoint().port() << p->m_id;
n++;
}
return RLPStream(n).appendRaw(ret.out(), n).out();
}
void Host::restorePeers(bytesConstRef _b)
{
for (auto i: RLP(_b))
{
auto k = (h512)i[2];
if (!m_incomingPeers.count(k))
{
m_incomingPeers.insert(make_pair(k, make_pair(bi::tcp::endpoint(bi::address_v4(i[0].toArray<byte, 4>()), i[1].toInt<short>()), 0)));
m_freePeers.push_back(k);
}
}
}