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net.cpp
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net.cpp
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// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2014 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#if defined(HAVE_CONFIG_H)
#include "config/bitcoin-config.h"
#endif
#include "net.h"
#include "addrman.h"
#include "chainparams.h"
#include "clientversion.h"
#include "primitives/transaction.h"
#include "scheduler.h"
#include "ui_interface.h"
#include "crypto/common.h"
#ifdef WIN32
#include <string.h>
#else
#include <fcntl.h>
#endif
#ifdef USE_UPNP
#include <miniupnpc/miniupnpc.h>
#include <miniupnpc/miniwget.h>
#include <miniupnpc/upnpcommands.h>
#include <miniupnpc/upnperrors.h>
#endif
#include <boost/filesystem.hpp>
#include <boost/thread.hpp>
// Dump addresses to peers.dat every 15 minutes (900s)
#define DUMP_ADDRESSES_INTERVAL 900
#if !defined(HAVE_MSG_NOSIGNAL) && !defined(MSG_NOSIGNAL)
#define MSG_NOSIGNAL 0
#endif
// Fix for ancient MinGW versions, that don't have defined these in ws2tcpip.h.
// Todo: Can be removed when our pull-tester is upgraded to a modern MinGW version.
#ifdef WIN32
#ifndef PROTECTION_LEVEL_UNRESTRICTED
#define PROTECTION_LEVEL_UNRESTRICTED 10
#endif
#ifndef IPV6_PROTECTION_LEVEL
#define IPV6_PROTECTION_LEVEL 23
#endif
#endif
using namespace std;
namespace {
const int MAX_OUTBOUND_CONNECTIONS = 8;
struct ListenSocket {
SOCKET socket;
bool whitelisted;
ListenSocket(SOCKET socket, bool whitelisted) : socket(socket), whitelisted(whitelisted) {}
};
}
//
// Global state variables
//
bool fDiscover = true;
bool fListen = true;
uint64_t nLocalServices = NODE_NETWORK;
CCriticalSection cs_mapLocalHost;
map<CNetAddr, LocalServiceInfo> mapLocalHost;
static bool vfReachable[NET_MAX] = {};
static bool vfLimited[NET_MAX] = {};
static CNode* pnodeLocalHost = NULL;
uint64_t nLocalHostNonce = 0;
static std::vector<ListenSocket> vhListenSocket;
CAddrMan addrman;
int nMaxConnections = 125;
bool fAddressesInitialized = false;
vector<CNode*> vNodes;
CCriticalSection cs_vNodes;
map<CInv, CDataStream> mapRelay;
deque<pair<int64_t, CInv> > vRelayExpiration;
CCriticalSection cs_mapRelay;
limitedmap<CInv, int64_t> mapAlreadyAskedFor(MAX_INV_SZ);
static deque<string> vOneShots;
CCriticalSection cs_vOneShots;
set<CNetAddr> setservAddNodeAddresses;
CCriticalSection cs_setservAddNodeAddresses;
vector<std::string> vAddedNodes;
CCriticalSection cs_vAddedNodes;
NodeId nLastNodeId = 0;
CCriticalSection cs_nLastNodeId;
static CSemaphore *semOutbound = NULL;
boost::condition_variable messageHandlerCondition;
// Signals for message handling
static CNodeSignals g_signals;
CNodeSignals& GetNodeSignals() { return g_signals; }
void AddOneShot(string strDest)
{
LOCK(cs_vOneShots);
vOneShots.push_back(strDest);
}
unsigned short GetListenPort()
{
return (unsigned short)(GetArg("-port", Params().GetDefaultPort()));
}
// find 'best' local address for a particular peer
bool GetLocal(CService& addr, const CNetAddr *paddrPeer)
{
if (!fListen)
return false;
int nBestScore = -1;
int nBestReachability = -1;
{
LOCK(cs_mapLocalHost);
for (map<CNetAddr, LocalServiceInfo>::iterator it = mapLocalHost.begin(); it != mapLocalHost.end(); it++)
{
int nScore = (*it).second.nScore;
int nReachability = (*it).first.GetReachabilityFrom(paddrPeer);
if (nReachability > nBestReachability || (nReachability == nBestReachability && nScore > nBestScore))
{
addr = CService((*it).first, (*it).second.nPort);
nBestReachability = nReachability;
nBestScore = nScore;
}
}
}
return nBestScore >= 0;
}
//! Convert the pnSeeds6 array into usable address objects.
static std::vector<CAddress> convertSeed6(const std::vector<SeedSpec6> &vSeedsIn)
{
// It'll only connect to one or two seed nodes because once it connects,
// it'll get a pile of addresses with newer timestamps.
// Seed nodes are given a random 'last seen time' of between one and two
// weeks ago.
const int64_t nOneWeek = 7*24*60*60;
std::vector<CAddress> vSeedsOut;
vSeedsOut.reserve(vSeedsIn.size());
for (std::vector<SeedSpec6>::const_iterator i(vSeedsIn.begin()); i != vSeedsIn.end(); ++i)
{
struct in6_addr ip;
memcpy(&ip, i->addr, sizeof(ip));
CAddress addr(CService(ip, i->port));
addr.nTime = GetTime() - GetRand(nOneWeek) - nOneWeek;
vSeedsOut.push_back(addr);
}
return vSeedsOut;
}
// get best local address for a particular peer as a CAddress
// Otherwise, return the unroutable 0.0.0.0 but filled in with
// the normal parameters, since the IP may be changed to a useful
// one by discovery.
CAddress GetLocalAddress(const CNetAddr *paddrPeer)
{
CAddress ret(CService("0.0.0.0",GetListenPort()),0);
CService addr;
if (GetLocal(addr, paddrPeer))
{
ret = CAddress(addr);
}
ret.nServices = nLocalServices;
ret.nTime = GetAdjustedTime();
return ret;
}
int GetnScore(const CService& addr)
{
LOCK(cs_mapLocalHost);
if (mapLocalHost.count(addr) == LOCAL_NONE)
return 0;
return mapLocalHost[addr].nScore;
}
// Is our peer's addrLocal potentially useful as an external IP source?
bool IsPeerAddrLocalGood(CNode *pnode)
{
return fDiscover && pnode->addr.IsRoutable() && pnode->addrLocal.IsRoutable() &&
!IsLimited(pnode->addrLocal.GetNetwork());
}
// pushes our own address to a peer
void AdvertizeLocal(CNode *pnode)
{
if (fListen && pnode->fSuccessfullyConnected)
{
CAddress addrLocal = GetLocalAddress(&pnode->addr);
// If discovery is enabled, sometimes give our peer the address it
// tells us that it sees us as in case it has a better idea of our
// address than we do.
if (IsPeerAddrLocalGood(pnode) && (!addrLocal.IsRoutable() ||
GetRand((GetnScore(addrLocal) > LOCAL_MANUAL) ? 8:2) == 0))
{
addrLocal.SetIP(pnode->addrLocal);
}
if (addrLocal.IsRoutable())
{
pnode->PushAddress(addrLocal);
}
}
}
void SetReachable(enum Network net, bool fFlag)
{
LOCK(cs_mapLocalHost);
vfReachable[net] = fFlag;
if (net == NET_IPV6 && fFlag)
vfReachable[NET_IPV4] = true;
}
// learn a new local address
bool AddLocal(const CService& addr, int nScore)
{
if (!addr.IsRoutable())
return false;
if (!fDiscover && nScore < LOCAL_MANUAL)
return false;
if (IsLimited(addr))
return false;
LogPrintf("AddLocal(%s,%i)\n", addr.ToString(), nScore);
{
LOCK(cs_mapLocalHost);
bool fAlready = mapLocalHost.count(addr) > 0;
LocalServiceInfo &info = mapLocalHost[addr];
if (!fAlready || nScore >= info.nScore) {
info.nScore = nScore + (fAlready ? 1 : 0);
info.nPort = addr.GetPort();
}
SetReachable(addr.GetNetwork());
}
return true;
}
bool AddLocal(const CNetAddr &addr, int nScore)
{
return AddLocal(CService(addr, GetListenPort()), nScore);
}
/** Make a particular network entirely off-limits (no automatic connects to it) */
void SetLimited(enum Network net, bool fLimited)
{
if (net == NET_UNROUTABLE)
return;
LOCK(cs_mapLocalHost);
vfLimited[net] = fLimited;
}
bool IsLimited(enum Network net)
{
LOCK(cs_mapLocalHost);
return vfLimited[net];
}
bool IsLimited(const CNetAddr &addr)
{
return IsLimited(addr.GetNetwork());
}
/** vote for a local address */
bool SeenLocal(const CService& addr)
{
{
LOCK(cs_mapLocalHost);
if (mapLocalHost.count(addr) == 0)
return false;
mapLocalHost[addr].nScore++;
}
return true;
}
/** check whether a given address is potentially local */
bool IsLocal(const CService& addr)
{
LOCK(cs_mapLocalHost);
return mapLocalHost.count(addr) > 0;
}
/** check whether a given network is one we can probably connect to */
bool IsReachable(enum Network net)
{
LOCK(cs_mapLocalHost);
return vfReachable[net] && !vfLimited[net];
}
/** check whether a given address is in a network we can probably connect to */
bool IsReachable(const CNetAddr& addr)
{
enum Network net = addr.GetNetwork();
return IsReachable(net);
}
void AddressCurrentlyConnected(const CService& addr)
{
addrman.Connected(addr);
}
uint64_t CNode::nTotalBytesRecv = 0;
uint64_t CNode::nTotalBytesSent = 0;
CCriticalSection CNode::cs_totalBytesRecv;
CCriticalSection CNode::cs_totalBytesSent;
CNode* FindNode(const CNetAddr& ip)
{
LOCK(cs_vNodes);
BOOST_FOREACH(CNode* pnode, vNodes)
if ((CNetAddr)pnode->addr == ip)
return (pnode);
return NULL;
}
CNode* FindNode(const std::string& addrName)
{
LOCK(cs_vNodes);
BOOST_FOREACH(CNode* pnode, vNodes)
if (pnode->addrName == addrName)
return (pnode);
return NULL;
}
CNode* FindNode(const CService& addr)
{
LOCK(cs_vNodes);
BOOST_FOREACH(CNode* pnode, vNodes)
if ((CService)pnode->addr == addr)
return (pnode);
return NULL;
}
CNode* ConnectNode(CAddress addrConnect, const char *pszDest)
{
if (pszDest == NULL) {
if (IsLocal(addrConnect))
return NULL;
// Look for an existing connection
CNode* pnode = FindNode((CService)addrConnect);
if (pnode)
{
pnode->AddRef();
return pnode;
}
}
/// debug print
LogPrint("net", "trying connection %s lastseen=%.1fhrs\n",
pszDest ? pszDest : addrConnect.ToString(),
pszDest ? 0.0 : (double)(GetAdjustedTime() - addrConnect.nTime)/3600.0);
// Connect
SOCKET hSocket;
bool proxyConnectionFailed = false;
if (pszDest ? ConnectSocketByName(addrConnect, hSocket, pszDest, Params().GetDefaultPort(), nConnectTimeout, &proxyConnectionFailed) :
ConnectSocket(addrConnect, hSocket, nConnectTimeout, &proxyConnectionFailed))
{
if (!IsSelectableSocket(hSocket)) {
LogPrintf("Cannot create connection: non-selectable socket created (fd >= FD_SETSIZE ?)\n");
CloseSocket(hSocket);
return NULL;
}
addrman.Attempt(addrConnect);
// Add node
CNode* pnode = new CNode(hSocket, addrConnect, pszDest ? pszDest : "", false);
pnode->AddRef();
{
LOCK(cs_vNodes);
vNodes.push_back(pnode);
}
pnode->nTimeConnected = GetTime();
return pnode;
} else if (!proxyConnectionFailed) {
// If connecting to the node failed, and failure is not caused by a problem connecting to
// the proxy, mark this as an attempt.
addrman.Attempt(addrConnect);
}
return NULL;
}
void CNode::CloseSocketDisconnect()
{
fDisconnect = true;
if (hSocket != INVALID_SOCKET)
{
LogPrint("net", "disconnecting peer=%d\n", id);
CloseSocket(hSocket);
}
// in case this fails, we'll empty the recv buffer when the CNode is deleted
TRY_LOCK(cs_vRecvMsg, lockRecv);
if (lockRecv)
vRecvMsg.clear();
}
void CNode::PushVersion()
{
int nBestHeight = g_signals.GetHeight().get_value_or(0);
int64_t nTime = (fInbound ? GetAdjustedTime() : GetTime());
CAddress addrYou = (addr.IsRoutable() && !IsProxy(addr) ? addr : CAddress(CService("0.0.0.0",0)));
CAddress addrMe = GetLocalAddress(&addr);
GetRandBytes((unsigned char*)&nLocalHostNonce, sizeof(nLocalHostNonce));
if (fLogIPs)
LogPrint("net", "send version message: version %d, blocks=%d, us=%s, them=%s, peer=%d\n", PROTOCOL_VERSION, nBestHeight, addrMe.ToString(), addrYou.ToString(), id);
else
LogPrint("net", "send version message: version %d, blocks=%d, us=%s, peer=%d\n", PROTOCOL_VERSION, nBestHeight, addrMe.ToString(), id);
PushMessage("version", PROTOCOL_VERSION, nLocalServices, nTime, addrYou, addrMe,
nLocalHostNonce, FormatSubVersion(CLIENT_NAME, CLIENT_VERSION, std::vector<string>()), nBestHeight, true);
}
std::map<CNetAddr, int64_t> CNode::setBanned;
CCriticalSection CNode::cs_setBanned;
void CNode::ClearBanned()
{
setBanned.clear();
}
bool CNode::IsBanned(CNetAddr ip)
{
bool fResult = false;
{
LOCK(cs_setBanned);
std::map<CNetAddr, int64_t>::iterator i = setBanned.find(ip);
if (i != setBanned.end())
{
int64_t t = (*i).second;
if (GetTime() < t)
fResult = true;
}
}
return fResult;
}
bool CNode::Ban(const CNetAddr &addr) {
int64_t banTime = GetTime()+GetArg("-bantime", 60*60*24); // Default 24-hour ban
{
LOCK(cs_setBanned);
if (setBanned[addr] < banTime)
setBanned[addr] = banTime;
}
return true;
}
std::vector<CSubNet> CNode::vWhitelistedRange;
CCriticalSection CNode::cs_vWhitelistedRange;
bool CNode::IsWhitelistedRange(const CNetAddr &addr) {
LOCK(cs_vWhitelistedRange);
BOOST_FOREACH(const CSubNet& subnet, vWhitelistedRange) {
if (subnet.Match(addr))
return true;
}
return false;
}
void CNode::AddWhitelistedRange(const CSubNet &subnet) {
LOCK(cs_vWhitelistedRange);
vWhitelistedRange.push_back(subnet);
}
#undef X
#define X(name) stats.name = name
void CNode::copyStats(CNodeStats &stats)
{
stats.nodeid = this->GetId();
X(nServices);
X(nLastSend);
X(nLastRecv);
X(nTimeConnected);
X(nTimeOffset);
X(addrName);
X(nVersion);
X(cleanSubVer);
X(fInbound);
X(nStartingHeight);
X(nSendBytes);
X(nRecvBytes);
X(fWhitelisted);
// It is common for nodes with good ping times to suddenly become lagged,
// due to a new block arriving or other large transfer.
// Merely reporting pingtime might fool the caller into thinking the node was still responsive,
// since pingtime does not update until the ping is complete, which might take a while.
// So, if a ping is taking an unusually long time in flight,
// the caller can immediately detect that this is happening.
int64_t nPingUsecWait = 0;
if ((0 != nPingNonceSent) && (0 != nPingUsecStart)) {
nPingUsecWait = GetTimeMicros() - nPingUsecStart;
}
// Raw ping time is in microseconds, but show it to user as whole seconds (Bitcoin users should be well used to small numbers with many decimal places by now :)
stats.dPingTime = (((double)nPingUsecTime) / 1e6);
stats.dPingWait = (((double)nPingUsecWait) / 1e6);
// Leave string empty if addrLocal invalid (not filled in yet)
stats.addrLocal = addrLocal.IsValid() ? addrLocal.ToString() : "";
}
#undef X
// requires LOCK(cs_vRecvMsg)
bool CNode::ReceiveMsgBytes(const char *pch, unsigned int nBytes)
{
while (nBytes > 0) {
// get current incomplete message, or create a new one
if (vRecvMsg.empty() ||
vRecvMsg.back().complete())
vRecvMsg.push_back(CNetMessage(Params().MessageStart(), SER_NETWORK, nRecvVersion));
CNetMessage& msg = vRecvMsg.back();
// absorb network data
int handled;
if (!msg.in_data)
handled = msg.readHeader(pch, nBytes);
else
handled = msg.readData(pch, nBytes);
if (handled < 0)
return false;
if (msg.in_data && msg.hdr.nMessageSize > MAX_PROTOCOL_MESSAGE_LENGTH) {
LogPrint("net", "Oversized message from peer=%i, disconnecting\n", GetId());
return false;
}
pch += handled;
nBytes -= handled;
if (msg.complete()) {
msg.nTime = GetTimeMicros();
messageHandlerCondition.notify_one();
}
}
return true;
}
int CNetMessage::readHeader(const char *pch, unsigned int nBytes)
{
// copy data to temporary parsing buffer
unsigned int nRemaining = 24 - nHdrPos;
unsigned int nCopy = std::min(nRemaining, nBytes);
memcpy(&hdrbuf[nHdrPos], pch, nCopy);
nHdrPos += nCopy;
// if header incomplete, exit
if (nHdrPos < 24)
return nCopy;
// deserialize to CMessageHeader
try {
hdrbuf >> hdr;
}
catch (const std::exception&) {
return -1;
}
// reject messages larger than MAX_SIZE
if (hdr.nMessageSize > MAX_SIZE)
return -1;
// switch state to reading message data
in_data = true;
return nCopy;
}
int CNetMessage::readData(const char *pch, unsigned int nBytes)
{
unsigned int nRemaining = hdr.nMessageSize - nDataPos;
unsigned int nCopy = std::min(nRemaining, nBytes);
if (vRecv.size() < nDataPos + nCopy) {
// Allocate up to 256 KiB ahead, but never more than the total message size.
vRecv.resize(std::min(hdr.nMessageSize, nDataPos + nCopy + 256 * 1024));
}
memcpy(&vRecv[nDataPos], pch, nCopy);
nDataPos += nCopy;
return nCopy;
}
// requires LOCK(cs_vSend)
void SocketSendData(CNode *pnode)
{
std::deque<CSerializeData>::iterator it = pnode->vSendMsg.begin();
while (it != pnode->vSendMsg.end()) {
const CSerializeData &data = *it;
assert(data.size() > pnode->nSendOffset);
int nBytes = send(pnode->hSocket, &data[pnode->nSendOffset], data.size() - pnode->nSendOffset, MSG_NOSIGNAL | MSG_DONTWAIT);
if (nBytes > 0) {
pnode->nLastSend = GetTime();
pnode->nSendBytes += nBytes;
pnode->nSendOffset += nBytes;
pnode->RecordBytesSent(nBytes);
if (pnode->nSendOffset == data.size()) {
pnode->nSendOffset = 0;
pnode->nSendSize -= data.size();
it++;
} else {
// could not send full message; stop sending more
break;
}
} else {
if (nBytes < 0) {
// error
int nErr = WSAGetLastError();
if (nErr != WSAEWOULDBLOCK && nErr != WSAEMSGSIZE && nErr != WSAEINTR && nErr != WSAEINPROGRESS)
{
LogPrintf("socket send error %s\n", NetworkErrorString(nErr));
pnode->CloseSocketDisconnect();
}
}
// couldn't send anything at all
break;
}
}
if (it == pnode->vSendMsg.end()) {
assert(pnode->nSendOffset == 0);
assert(pnode->nSendSize == 0);
}
pnode->vSendMsg.erase(pnode->vSendMsg.begin(), it);
}
static list<CNode*> vNodesDisconnected;
class CNodeRef {
public:
CNodeRef(CNode *pnode) : _pnode(pnode) {
LOCK(cs_vNodes);
_pnode->AddRef();
}
~CNodeRef() {
LOCK(cs_vNodes);
_pnode->Release();
}
CNode& operator *() const {return *_pnode;};
CNode* operator ->() const {return _pnode;};
CNodeRef& operator =(const CNodeRef& other)
{
if (this != &other) {
LOCK(cs_vNodes);
_pnode->Release();
_pnode = other._pnode;
_pnode->AddRef();
}
return *this;
}
CNodeRef(const CNodeRef& other):
_pnode(other._pnode)
{
LOCK(cs_vNodes);
_pnode->AddRef();
}
private:
CNode *_pnode;
};
static bool ReverseCompareNodeMinPingTime(const CNodeRef &a, const CNodeRef &b)
{
return a->nMinPingUsecTime > b->nMinPingUsecTime;
}
static bool ReverseCompareNodeTimeConnected(const CNodeRef &a, const CNodeRef &b)
{
return a->nTimeConnected > b->nTimeConnected;
}
class CompareNetGroupKeyed
{
std::vector<unsigned char> vchSecretKey;
public:
CompareNetGroupKeyed()
{
vchSecretKey.resize(32, 0);
GetRandBytes(vchSecretKey.data(), vchSecretKey.size());
}
bool operator()(const CNodeRef &a, const CNodeRef &b)
{
std::vector<unsigned char> vchGroupA, vchGroupB;
CSHA256 hashA, hashB;
std::vector<unsigned char> vchA(32), vchB(32);
vchGroupA = a->addr.GetGroup();
vchGroupB = b->addr.GetGroup();
hashA.Write(begin_ptr(vchGroupA), vchGroupA.size());
hashB.Write(begin_ptr(vchGroupB), vchGroupB.size());
hashA.Write(begin_ptr(vchSecretKey), vchSecretKey.size());
hashB.Write(begin_ptr(vchSecretKey), vchSecretKey.size());
hashA.Finalize(begin_ptr(vchA));
hashB.Finalize(begin_ptr(vchB));
return vchA < vchB;
}
};
static bool AttemptToEvictConnection(bool fPreferNewConnection) {
std::vector<CNodeRef> vEvictionCandidates;
{
LOCK(cs_vNodes);
BOOST_FOREACH(CNode *node, vNodes) {
if (node->fWhitelisted)
continue;
if (!node->fInbound)
continue;
if (node->fDisconnect)
continue;
if (node->addr.IsLocal())
continue;
vEvictionCandidates.push_back(CNodeRef(node));
}
}
if (vEvictionCandidates.empty()) return false;
// Protect connections with certain characteristics
// Deterministically select 4 peers to protect by netgroup.
// An attacker cannot predict which netgroups will be protected.
static CompareNetGroupKeyed comparerNetGroupKeyed;
std::sort(vEvictionCandidates.begin(), vEvictionCandidates.end(), comparerNetGroupKeyed);
vEvictionCandidates.erase(vEvictionCandidates.end() - std::min(4, static_cast<int>(vEvictionCandidates.size())), vEvictionCandidates.end());
if (vEvictionCandidates.empty()) return false;
// Protect the 8 nodes with the best ping times.
// An attacker cannot manipulate this metric without physically moving nodes closer to the target.
std::sort(vEvictionCandidates.begin(), vEvictionCandidates.end(), ReverseCompareNodeMinPingTime);
vEvictionCandidates.erase(vEvictionCandidates.end() - std::min(8, static_cast<int>(vEvictionCandidates.size())), vEvictionCandidates.end());
if (vEvictionCandidates.empty()) return false;
// Protect the half of the remaining nodes which have been connected the longest.
// This replicates the existing implicit behavior.
std::sort(vEvictionCandidates.begin(), vEvictionCandidates.end(), ReverseCompareNodeTimeConnected);
vEvictionCandidates.erase(vEvictionCandidates.end() - static_cast<int>(vEvictionCandidates.size() / 2), vEvictionCandidates.end());
if (vEvictionCandidates.empty()) return false;
// Identify the network group with the most connections
std::vector<unsigned char> naMostConnections;
unsigned int nMostConnections = 0;
std::map<std::vector<unsigned char>, std::vector<CNodeRef> > mapAddrCounts;
BOOST_FOREACH(const CNodeRef &node, vEvictionCandidates) {
mapAddrCounts[node->addr.GetGroup()].push_back(node);
if (mapAddrCounts[node->addr.GetGroup()].size() > nMostConnections) {
nMostConnections = mapAddrCounts[node->addr.GetGroup()].size();
naMostConnections = node->addr.GetGroup();
}
}
// Reduce to the network group with the most connections
vEvictionCandidates = mapAddrCounts[naMostConnections];
// Do not disconnect peers if there is only 1 connection from their network group
if (vEvictionCandidates.size() <= 1)
// unless we prefer the new connection (for whitelisted peers)
if (!fPreferNewConnection)
return false;
// Disconnect the most recent connection from the network group with the most connections
std::sort(vEvictionCandidates.begin(), vEvictionCandidates.end(), ReverseCompareNodeTimeConnected);
vEvictionCandidates[0]->fDisconnect = true;
return true;
}
static void AcceptConnection(const ListenSocket& hListenSocket) {
struct sockaddr_storage sockaddr;
socklen_t len = sizeof(sockaddr);
SOCKET hSocket = accept(hListenSocket.socket, (struct sockaddr*)&sockaddr, &len);
CAddress addr;
int nInbound = 0;
int nMaxInbound = nMaxConnections - MAX_OUTBOUND_CONNECTIONS;
if (hSocket != INVALID_SOCKET)
if (!addr.SetSockAddr((const struct sockaddr*)&sockaddr))
LogPrintf("Warning: Unknown socket family\n");
bool whitelisted = hListenSocket.whitelisted || CNode::IsWhitelistedRange(addr);
{
LOCK(cs_vNodes);
BOOST_FOREACH(CNode* pnode, vNodes)
if (pnode->fInbound)
nInbound++;
}
if (hSocket == INVALID_SOCKET)
{
int nErr = WSAGetLastError();
if (nErr != WSAEWOULDBLOCK)
LogPrintf("socket error accept failed: %s\n", NetworkErrorString(nErr));
return;
}
if (!IsSelectableSocket(hSocket))
{
LogPrintf("connection from %s dropped: non-selectable socket\n", addr.ToString());
CloseSocket(hSocket);
return;
}
if (CNode::IsBanned(addr) && !whitelisted)
{
LogPrintf("connection from %s dropped (banned)\n", addr.ToString());
CloseSocket(hSocket);
return;
}
if (nInbound >= nMaxInbound)
{
if (!AttemptToEvictConnection(whitelisted)) {
// No connection to evict, disconnect the new connection
LogPrint("net", "failed to find an eviction candidate - connection dropped (full)\n");
CloseSocket(hSocket);
return;
}
}
// According to the internet TCP_NODELAY is not carried into accepted sockets
// on all platforms. Set it again here just to be sure.
int set = 1;
#ifdef WIN32
setsockopt(hSocket, IPPROTO_TCP, TCP_NODELAY, (const char*)&set, sizeof(int));
#else
setsockopt(hSocket, IPPROTO_TCP, TCP_NODELAY, (void*)&set, sizeof(int));
#endif
CNode* pnode = new CNode(hSocket, addr, "", true);
pnode->AddRef();
pnode->fWhitelisted = whitelisted;
LogPrint("net", "connection from %s accepted\n", addr.ToString());
{
LOCK(cs_vNodes);
vNodes.push_back(pnode);
}
}
void ThreadSocketHandler()
{
unsigned int nPrevNodeCount = 0;
while (true)
{
//
// Disconnect nodes
//
{
LOCK(cs_vNodes);
// Disconnect unused nodes
vector<CNode*> vNodesCopy = vNodes;
BOOST_FOREACH(CNode* pnode, vNodesCopy)
{
if (pnode->fDisconnect ||
(pnode->GetRefCount() <= 0 && pnode->vRecvMsg.empty() && pnode->nSendSize == 0 && pnode->ssSend.empty()))
{
// remove from vNodes
vNodes.erase(remove(vNodes.begin(), vNodes.end(), pnode), vNodes.end());
// release outbound grant (if any)
pnode->grantOutbound.Release();
// close socket and cleanup
pnode->CloseSocketDisconnect();
// hold in disconnected pool until all refs are released
if (pnode->fNetworkNode || pnode->fInbound)
pnode->Release();
vNodesDisconnected.push_back(pnode);
}
}
}
{
// Delete disconnected nodes
list<CNode*> vNodesDisconnectedCopy = vNodesDisconnected;
BOOST_FOREACH(CNode* pnode, vNodesDisconnectedCopy)
{
// wait until threads are done using it
if (pnode->GetRefCount() <= 0)
{
bool fDelete = false;
{
TRY_LOCK(pnode->cs_vSend, lockSend);
if (lockSend)
{
TRY_LOCK(pnode->cs_vRecvMsg, lockRecv);
if (lockRecv)
{
TRY_LOCK(pnode->cs_inventory, lockInv);
if (lockInv)
fDelete = true;
}
}
}
if (fDelete)
{
vNodesDisconnected.remove(pnode);
delete pnode;
}
}
}
}
if(vNodes.size() != nPrevNodeCount) {
nPrevNodeCount = vNodes.size();
uiInterface.NotifyNumConnectionsChanged(nPrevNodeCount);
}
//
// Find which sockets have data to receive
//
struct timeval timeout;
timeout.tv_sec = 0;
timeout.tv_usec = 50000; // frequency to poll pnode->vSend
fd_set fdsetRecv;
fd_set fdsetSend;
fd_set fdsetError;
FD_ZERO(&fdsetRecv);
FD_ZERO(&fdsetSend);
FD_ZERO(&fdsetError);
SOCKET hSocketMax = 0;
bool have_fds = false;
BOOST_FOREACH(const ListenSocket& hListenSocket, vhListenSocket) {
FD_SET(hListenSocket.socket, &fdsetRecv);
hSocketMax = max(hSocketMax, hListenSocket.socket);
have_fds = true;
}
{
LOCK(cs_vNodes);
BOOST_FOREACH(CNode* pnode, vNodes)
{
if (pnode->hSocket == INVALID_SOCKET)
continue;
FD_SET(pnode->hSocket, &fdsetError);
hSocketMax = max(hSocketMax, pnode->hSocket);
have_fds = true;
// Implement the following logic:
// * If there is data to send, select() for sending data. As this only