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kevacoin/src/netbase.cpp

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// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2015 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#ifdef HAVE_CONFIG_H
#include "config/bitcoin-config.h"
#endif
#include "netbase.h"
#include "hash.h"
#include "sync.h"
#include "uint256.h"
#include "random.h"
#include "util.h"
#include "utilstrencodings.h"
#ifdef HAVE_GETADDRINFO_A
#include <netdb.h>
#endif
#ifndef WIN32
#if HAVE_INET_PTON
#include <arpa/inet.h>
#endif
#include <fcntl.h>
#endif
#include <boost/algorithm/string/case_conv.hpp> // for to_lower()
#include <boost/algorithm/string/predicate.hpp> // for startswith() and endswith()
#include <boost/thread.hpp>
#if !defined(HAVE_MSG_NOSIGNAL) && !defined(MSG_NOSIGNAL)
#define MSG_NOSIGNAL 0
#endif
// Settings
static proxyType proxyInfo[NET_MAX];
static proxyType nameProxy;
static CCriticalSection cs_proxyInfos;
int nConnectTimeout = DEFAULT_CONNECT_TIMEOUT;
bool fNameLookup = DEFAULT_NAME_LOOKUP;
// Need ample time for negotiation for very slow proxies such as Tor (milliseconds)
static const int SOCKS5_RECV_TIMEOUT = 20 * 1000;
enum Network ParseNetwork(std::string net) {
boost::to_lower(net);
if (net == "ipv4") return NET_IPV4;
if (net == "ipv6") return NET_IPV6;
if (net == "tor" || net == "onion") return NET_TOR;
return NET_UNROUTABLE;
}
std::string GetNetworkName(enum Network net) {
switch(net)
{
case NET_IPV4: return "ipv4";
case NET_IPV6: return "ipv6";
case NET_TOR: return "onion";
default: return "";
}
}
void SplitHostPort(std::string in, int &portOut, std::string &hostOut) {
size_t colon = in.find_last_of(':');
// if a : is found, and it either follows a [...], or no other : is in the string, treat it as port separator
bool fHaveColon = colon != in.npos;
bool fBracketed = fHaveColon && (in[0]=='[' && in[colon-1]==']'); // if there is a colon, and in[0]=='[', colon is not 0, so in[colon-1] is safe
bool fMultiColon = fHaveColon && (in.find_last_of(':',colon-1) != in.npos);
if (fHaveColon && (colon==0 || fBracketed || !fMultiColon)) {
int32_t n;
if (ParseInt32(in.substr(colon + 1), &n) && n > 0 && n < 0x10000) {
in = in.substr(0, colon);
portOut = n;
}
}
if (in.size()>0 && in[0] == '[' && in[in.size()-1] == ']')
hostOut = in.substr(1, in.size()-2);
else
hostOut = in;
}
bool static LookupIntern(const char *pszName, std::vector<CNetAddr>& vIP, unsigned int nMaxSolutions, bool fAllowLookup)
{
vIP.clear();
{
CNetAddr addr;
if (addr.SetSpecial(std::string(pszName))) {
vIP.push_back(addr);
return true;
}
}
struct addrinfo aiHint;
memset(&aiHint, 0, sizeof(struct addrinfo));
aiHint.ai_socktype = SOCK_STREAM;
aiHint.ai_protocol = IPPROTO_TCP;
aiHint.ai_family = AF_UNSPEC;
#ifdef WIN32
aiHint.ai_flags = fAllowLookup ? 0 : AI_NUMERICHOST;
#else
aiHint.ai_flags = fAllowLookup ? AI_ADDRCONFIG : AI_NUMERICHOST;
#endif
struct addrinfo *aiRes = NULL;
int nErr = getaddrinfo(pszName, NULL, &aiHint, &aiRes);
if (nErr)
return false;
struct addrinfo *aiTrav = aiRes;
while (aiTrav != NULL && (nMaxSolutions == 0 || vIP.size() < nMaxSolutions))
{
if (aiTrav->ai_family == AF_INET)
{
assert(aiTrav->ai_addrlen >= sizeof(sockaddr_in));
vIP.push_back(CNetAddr(((struct sockaddr_in*)(aiTrav->ai_addr))->sin_addr));
}
if (aiTrav->ai_family == AF_INET6)
{
assert(aiTrav->ai_addrlen >= sizeof(sockaddr_in6));
struct sockaddr_in6* s6 = (struct sockaddr_in6*) aiTrav->ai_addr;
vIP.push_back(CNetAddr(s6->sin6_addr, s6->sin6_scope_id));
}
aiTrav = aiTrav->ai_next;
}
freeaddrinfo(aiRes);
return (vIP.size() > 0);
}
bool LookupHost(const char *pszName, std::vector<CNetAddr>& vIP, unsigned int nMaxSolutions, bool fAllowLookup)
{
std::string strHost(pszName);
if (strHost.empty())
return false;
if (boost::algorithm::starts_with(strHost, "[") && boost::algorithm::ends_with(strHost, "]"))
{
strHost = strHost.substr(1, strHost.size() - 2);
}
return LookupIntern(strHost.c_str(), vIP, nMaxSolutions, fAllowLookup);
}
bool LookupHost(const char *pszName, CNetAddr& addr, bool fAllowLookup)
{
std::vector<CNetAddr> vIP;
LookupHost(pszName, vIP, 1, fAllowLookup);
if(vIP.empty())
return false;
addr = vIP.front();
return true;
}
bool Lookup(const char *pszName, std::vector<CService>& vAddr, int portDefault, bool fAllowLookup, unsigned int nMaxSolutions)
{
if (pszName[0] == 0)
return false;
int port = portDefault;
std::string hostname = "";
SplitHostPort(std::string(pszName), port, hostname);
std::vector<CNetAddr> vIP;
bool fRet = LookupIntern(hostname.c_str(), vIP, nMaxSolutions, fAllowLookup);
if (!fRet)
return false;
vAddr.resize(vIP.size());
for (unsigned int i = 0; i < vIP.size(); i++)
vAddr[i] = CService(vIP[i], port);
return true;
}
bool Lookup(const char *pszName, CService& addr, int portDefault, bool fAllowLookup)
{
std::vector<CService> vService;
bool fRet = Lookup(pszName, vService, portDefault, fAllowLookup, 1);
if (!fRet)
return false;
addr = vService[0];
return true;
}
CService LookupNumeric(const char *pszName, int portDefault)
{
CService addr;
// "1.2:345" will fail to resolve the ip, but will still set the port.
// If the ip fails to resolve, re-init the result.
if(!Lookup(pszName, addr, portDefault, false))
addr = CService();
return addr;
}
struct timeval MillisToTimeval(int64_t nTimeout)
{
struct timeval timeout;
timeout.tv_sec = nTimeout / 1000;
timeout.tv_usec = (nTimeout % 1000) * 1000;
return timeout;
}
/**
* Read bytes from socket. This will either read the full number of bytes requested
* or return False on error or timeout.
* This function can be interrupted by boost thread interrupt.
*
* @param data Buffer to receive into
* @param len Length of data to receive
* @param timeout Timeout in milliseconds for receive operation
*
* @note This function requires that hSocket is in non-blocking mode.
*/
bool static InterruptibleRecv(char* data, size_t len, int timeout, SOCKET& hSocket)
{
int64_t curTime = GetTimeMillis();
int64_t endTime = curTime + timeout;
// Maximum time to wait in one select call. It will take up until this time (in millis)
// to break off in case of an interruption.
const int64_t maxWait = 1000;
while (len > 0 && curTime < endTime) {
ssize_t ret = recv(hSocket, data, len, 0); // Optimistically try the recv first
if (ret > 0) {
len -= ret;
data += ret;
} else if (ret == 0) { // Unexpected disconnection
return false;
} else { // Other error or blocking
int nErr = WSAGetLastError();
if (nErr == WSAEINPROGRESS || nErr == WSAEWOULDBLOCK || nErr == WSAEINVAL) {
if (!IsSelectableSocket(hSocket)) {
return false;
}
struct timeval tval = MillisToTimeval(std::min(endTime - curTime, maxWait));
fd_set fdset;
FD_ZERO(&fdset);
FD_SET(hSocket, &fdset);
int nRet = select(hSocket + 1, &fdset, NULL, NULL, &tval);
if (nRet == SOCKET_ERROR) {
return false;
}
} else {
return false;
}
}
boost::this_thread::interruption_point();
curTime = GetTimeMillis();
}
return len == 0;
}
struct ProxyCredentials
{
std::string username;
std::string password;
};
std::string Socks5ErrorString(int err)
{
switch(err) {
case 0x01: return "general failure";
case 0x02: return "connection not allowed";
case 0x03: return "network unreachable";
case 0x04: return "host unreachable";
case 0x05: return "connection refused";
case 0x06: return "TTL expired";
case 0x07: return "protocol error";
case 0x08: return "address type not supported";
default: return "unknown";
}
}
/** Connect using SOCKS5 (as described in RFC1928) */
static bool Socks5(const std::string& strDest, int port, const ProxyCredentials *auth, SOCKET& hSocket)
{
LogPrint("net", "SOCKS5 connecting %s\n", strDest);
if (strDest.size() > 255) {
CloseSocket(hSocket);
return error("Hostname too long");
}
// Accepted authentication methods
std::vector<uint8_t> vSocks5Init;
vSocks5Init.push_back(0x05);
if (auth) {
vSocks5Init.push_back(0x02); // # METHODS
vSocks5Init.push_back(0x00); // X'00' NO AUTHENTICATION REQUIRED
vSocks5Init.push_back(0x02); // X'02' USERNAME/PASSWORD (RFC1929)
} else {
vSocks5Init.push_back(0x01); // # METHODS
vSocks5Init.push_back(0x00); // X'00' NO AUTHENTICATION REQUIRED
}
ssize_t ret = send(hSocket, (const char*)vSocks5Init.data(), vSocks5Init.size(), MSG_NOSIGNAL);
if (ret != (ssize_t)vSocks5Init.size()) {
CloseSocket(hSocket);
return error("Error sending to proxy");
}
char pchRet1[2];
if (!InterruptibleRecv(pchRet1, 2, SOCKS5_RECV_TIMEOUT, hSocket)) {
CloseSocket(hSocket);
LogPrintf("Socks5() connect to %s:%d failed: InterruptibleRecv() timeout or other failure\n", strDest, port);
return false;
}
if (pchRet1[0] != 0x05) {
CloseSocket(hSocket);
return error("Proxy failed to initialize");
}
if (pchRet1[1] == 0x02 && auth) {
// Perform username/password authentication (as described in RFC1929)
std::vector<uint8_t> vAuth;
vAuth.push_back(0x01);
if (auth->username.size() > 255 || auth->password.size() > 255)
return error("Proxy username or password too long");
vAuth.push_back(auth->username.size());
vAuth.insert(vAuth.end(), auth->username.begin(), auth->username.end());
vAuth.push_back(auth->password.size());
vAuth.insert(vAuth.end(), auth->password.begin(), auth->password.end());
ret = send(hSocket, (const char*)vAuth.data(), vAuth.size(), MSG_NOSIGNAL);
if (ret != (ssize_t)vAuth.size()) {
CloseSocket(hSocket);
return error("Error sending authentication to proxy");
}
LogPrint("proxy", "SOCKS5 sending proxy authentication %s:%s\n", auth->username, auth->password);
char pchRetA[2];
if (!InterruptibleRecv(pchRetA, 2, SOCKS5_RECV_TIMEOUT, hSocket)) {
CloseSocket(hSocket);
return error("Error reading proxy authentication response");
}
if (pchRetA[0] != 0x01 || pchRetA[1] != 0x00) {
CloseSocket(hSocket);
return error("Proxy authentication unsuccessful");
}
} else if (pchRet1[1] == 0x00) {
// Perform no authentication
} else {
CloseSocket(hSocket);
return error("Proxy requested wrong authentication method %02x", pchRet1[1]);
}
std::vector<uint8_t> vSocks5;
vSocks5.push_back(0x05); // VER protocol version
vSocks5.push_back(0x01); // CMD CONNECT
vSocks5.push_back(0x00); // RSV Reserved
vSocks5.push_back(0x03); // ATYP DOMAINNAME
vSocks5.push_back(strDest.size()); // Length<=255 is checked at beginning of function
vSocks5.insert(vSocks5.end(), strDest.begin(), strDest.end());
vSocks5.push_back((port >> 8) & 0xFF);
vSocks5.push_back((port >> 0) & 0xFF);
ret = send(hSocket, (const char*)vSocks5.data(), vSocks5.size(), MSG_NOSIGNAL);
if (ret != (ssize_t)vSocks5.size()) {
CloseSocket(hSocket);
return error("Error sending to proxy");
}
char pchRet2[4];
if (!InterruptibleRecv(pchRet2, 4, SOCKS5_RECV_TIMEOUT, hSocket)) {
CloseSocket(hSocket);
return error("Error reading proxy response");
}
if (pchRet2[0] != 0x05) {
CloseSocket(hSocket);
return error("Proxy failed to accept request");
}
if (pchRet2[1] != 0x00) {
// Failures to connect to a peer that are not proxy errors
CloseSocket(hSocket);
LogPrintf("Socks5() connect to %s:%d failed: %s\n", strDest, port, Socks5ErrorString(pchRet2[1]));
return false;
}
if (pchRet2[2] != 0x00) {
CloseSocket(hSocket);
return error("Error: malformed proxy response");
}
char pchRet3[256];
switch (pchRet2[3])
{
case 0x01: ret = InterruptibleRecv(pchRet3, 4, SOCKS5_RECV_TIMEOUT, hSocket); break;
case 0x04: ret = InterruptibleRecv(pchRet3, 16, SOCKS5_RECV_TIMEOUT, hSocket); break;
case 0x03:
{
ret = InterruptibleRecv(pchRet3, 1, SOCKS5_RECV_TIMEOUT, hSocket);
if (!ret) {
CloseSocket(hSocket);
return error("Error reading from proxy");
}
int nRecv = pchRet3[0];
ret = InterruptibleRecv(pchRet3, nRecv, SOCKS5_RECV_TIMEOUT, hSocket);
break;
}
default: CloseSocket(hSocket); return error("Error: malformed proxy response");
}
if (!ret) {
CloseSocket(hSocket);
return error("Error reading from proxy");
}
if (!InterruptibleRecv(pchRet3, 2, SOCKS5_RECV_TIMEOUT, hSocket)) {
CloseSocket(hSocket);
return error("Error reading from proxy");
}
LogPrint("net", "SOCKS5 connected %s\n", strDest);
return true;
}
bool static ConnectSocketDirectly(const CService &addrConnect, SOCKET& hSocketRet, int nTimeout)
{
hSocketRet = INVALID_SOCKET;
struct sockaddr_storage sockaddr;
socklen_t len = sizeof(sockaddr);
if (!addrConnect.GetSockAddr((struct sockaddr*)&sockaddr, &len)) {
LogPrintf("Cannot connect to %s: unsupported network\n", addrConnect.ToString());
return false;
}
SOCKET hSocket = socket(((struct sockaddr*)&sockaddr)->sa_family, SOCK_STREAM, IPPROTO_TCP);
if (hSocket == INVALID_SOCKET)
return false;
int set = 1;
#ifdef SO_NOSIGPIPE
// Different way of disabling SIGPIPE on BSD
setsockopt(hSocket, SOL_SOCKET, SO_NOSIGPIPE, (void*)&set, sizeof(int));
#endif
//Disable Nagle's algorithm
#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
// Set to non-blocking
if (!SetSocketNonBlocking(hSocket, true))
return error("ConnectSocketDirectly: Setting socket to non-blocking failed, error %s\n", NetworkErrorString(WSAGetLastError()));
if (connect(hSocket, (struct sockaddr*)&sockaddr, len) == SOCKET_ERROR)
{
int nErr = WSAGetLastError();
// WSAEINVAL is here because some legacy version of winsock uses it
if (nErr == WSAEINPROGRESS || nErr == WSAEWOULDBLOCK || nErr == WSAEINVAL)
{
struct timeval timeout = MillisToTimeval(nTimeout);
fd_set fdset;
FD_ZERO(&fdset);
FD_SET(hSocket, &fdset);
int nRet = select(hSocket + 1, NULL, &fdset, NULL, &timeout);
if (nRet == 0)
{
LogPrint("net", "connection to %s timeout\n", addrConnect.ToString());
CloseSocket(hSocket);
return false;
}
if (nRet == SOCKET_ERROR)
{
LogPrintf("select() for %s failed: %s\n", addrConnect.ToString(), NetworkErrorString(WSAGetLastError()));
CloseSocket(hSocket);
return false;
}
socklen_t nRetSize = sizeof(nRet);
#ifdef WIN32
if (getsockopt(hSocket, SOL_SOCKET, SO_ERROR, (char*)(&nRet), &nRetSize) == SOCKET_ERROR)
#else
if (getsockopt(hSocket, SOL_SOCKET, SO_ERROR, &nRet, &nRetSize) == SOCKET_ERROR)
#endif
{
LogPrintf("getsockopt() for %s failed: %s\n", addrConnect.ToString(), NetworkErrorString(WSAGetLastError()));
CloseSocket(hSocket);
return false;
}
if (nRet != 0)
{
LogPrintf("connect() to %s failed after select(): %s\n", addrConnect.ToString(), NetworkErrorString(nRet));
CloseSocket(hSocket);
return false;
}
}
#ifdef WIN32
else if (WSAGetLastError() != WSAEISCONN)
#else
else
#endif
{
LogPrintf("connect() to %s failed: %s\n", addrConnect.ToString(), NetworkErrorString(WSAGetLastError()));
CloseSocket(hSocket);
return false;
}
}
hSocketRet = hSocket;
return true;
}
bool SetProxy(enum Network net, const proxyType &addrProxy) {
assert(net >= 0 && net < NET_MAX);
if (!addrProxy.IsValid())
return false;
LOCK(cs_proxyInfos);
proxyInfo[net] = addrProxy;
return true;
}
bool GetProxy(enum Network net, proxyType &proxyInfoOut) {
assert(net >= 0 && net < NET_MAX);
LOCK(cs_proxyInfos);
if (!proxyInfo[net].IsValid())
return false;
proxyInfoOut = proxyInfo[net];
return true;
}
bool SetNameProxy(const proxyType &addrProxy) {
if (!addrProxy.IsValid())
return false;
LOCK(cs_proxyInfos);
nameProxy = addrProxy;
return true;
}
bool GetNameProxy(proxyType &nameProxyOut) {
LOCK(cs_proxyInfos);
if(!nameProxy.IsValid())
return false;
nameProxyOut = nameProxy;
return true;
}
bool HaveNameProxy() {
LOCK(cs_proxyInfos);
return nameProxy.IsValid();
}
bool IsProxy(const CNetAddr &addr) {
LOCK(cs_proxyInfos);
for (int i = 0; i < NET_MAX; i++) {
if (addr == (CNetAddr)proxyInfo[i].proxy)
return true;
}
return false;
}
static bool ConnectThroughProxy(const proxyType &proxy, const std::string& strDest, int port, SOCKET& hSocketRet, int nTimeout, bool *outProxyConnectionFailed)
{
SOCKET hSocket = INVALID_SOCKET;
// first connect to proxy server
if (!ConnectSocketDirectly(proxy.proxy, hSocket, nTimeout)) {
if (outProxyConnectionFailed)
*outProxyConnectionFailed = true;
return false;
}
// do socks negotiation
if (proxy.randomize_credentials) {
ProxyCredentials random_auth;
static std::atomic_int counter;
random_auth.username = random_auth.password = strprintf("%i", counter++);
if (!Socks5(strDest, (unsigned short)port, &random_auth, hSocket))
return false;
} else {
if (!Socks5(strDest, (unsigned short)port, 0, hSocket))
return false;
}
hSocketRet = hSocket;
return true;
}
bool ConnectSocket(const CService &addrDest, SOCKET& hSocketRet, int nTimeout, bool *outProxyConnectionFailed)
{
proxyType proxy;
if (outProxyConnectionFailed)
*outProxyConnectionFailed = false;
if (GetProxy(addrDest.GetNetwork(), proxy))
return ConnectThroughProxy(proxy, addrDest.ToStringIP(), addrDest.GetPort(), hSocketRet, nTimeout, outProxyConnectionFailed);
else // no proxy needed (none set for target network)
return ConnectSocketDirectly(addrDest, hSocketRet, nTimeout);
}
bool ConnectSocketByName(CService &addr, SOCKET& hSocketRet, const char *pszDest, int portDefault, int nTimeout, bool *outProxyConnectionFailed)
{
std::string strDest;
int port = portDefault;
if (outProxyConnectionFailed)
*outProxyConnectionFailed = false;
SplitHostPort(std::string(pszDest), port, strDest);
proxyType proxy;
GetNameProxy(proxy);
std::vector<CService> addrResolved;
if (Lookup(strDest.c_str(), addrResolved, port, fNameLookup && !HaveNameProxy(), 256)) {
if (addrResolved.size() > 0) {
addr = addrResolved[GetRand(addrResolved.size())];
return ConnectSocket(addr, hSocketRet, nTimeout);
}
}
addr = CService();
if (!HaveNameProxy())
return false;
return ConnectThroughProxy(proxy, strDest, port, hSocketRet, nTimeout, outProxyConnectionFailed);
}
bool LookupSubNet(const char* pszName, CSubNet& ret)
{
std::string strSubnet(pszName);
size_t slash = strSubnet.find_last_of('/');
std::vector<CNetAddr> vIP;
std::string strAddress = strSubnet.substr(0, slash);
if (LookupHost(strAddress.c_str(), vIP, 1, false))
{
CNetAddr network = vIP[0];
if (slash != strSubnet.npos)
{
std::string strNetmask = strSubnet.substr(slash + 1);
int32_t n;
// IPv4 addresses start at offset 12, and first 12 bytes must match, so just offset n
if (ParseInt32(strNetmask, &n)) { // If valid number, assume /24 syntax
ret = CSubNet(network, n);
return ret.IsValid();
}
else // If not a valid number, try full netmask syntax
{
// Never allow lookup for netmask
if (LookupHost(strNetmask.c_str(), vIP, 1, false)) {
ret = CSubNet(network, vIP[0]);
return ret.IsValid();
}
}
}
else
{
ret = CSubNet(network);
return ret.IsValid();
}
}
return false;
}
#ifdef WIN32
std::string NetworkErrorString(int err)
{
char buf[256];
buf[0] = 0;
if(FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_MAX_WIDTH_MASK,
NULL, err, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
buf, sizeof(buf), NULL))
{
return strprintf("%s (%d)", buf, err);
}
else
{
return strprintf("Unknown error (%d)", err);
}
}
#else
std::string NetworkErrorString(int err)
{
char buf[256];
const char *s = buf;
buf[0] = 0;
/* Too bad there are two incompatible implementations of the
* thread-safe strerror. */
#ifdef STRERROR_R_CHAR_P /* GNU variant can return a pointer outside the passed buffer */
s = strerror_r(err, buf, sizeof(buf));
#else /* POSIX variant always returns message in buffer */
if (strerror_r(err, buf, sizeof(buf)))
buf[0] = 0;
#endif
return strprintf("%s (%d)", s, err);
}
#endif
bool CloseSocket(SOCKET& hSocket)
{
if (hSocket == INVALID_SOCKET)
return false;
#ifdef WIN32
int ret = closesocket(hSocket);
#else
int ret = close(hSocket);
#endif
hSocket = INVALID_SOCKET;
return ret != SOCKET_ERROR;
}
bool SetSocketNonBlocking(SOCKET& hSocket, bool fNonBlocking)
{
if (fNonBlocking) {
#ifdef WIN32
u_long nOne = 1;
if (ioctlsocket(hSocket, FIONBIO, &nOne) == SOCKET_ERROR) {
#else
int fFlags = fcntl(hSocket, F_GETFL, 0);
if (fcntl(hSocket, F_SETFL, fFlags | O_NONBLOCK) == SOCKET_ERROR) {
#endif
CloseSocket(hSocket);
return false;
}
} else {
#ifdef WIN32
u_long nZero = 0;
if (ioctlsocket(hSocket, FIONBIO, &nZero) == SOCKET_ERROR) {
#else
int fFlags = fcntl(hSocket, F_GETFL, 0);
if (fcntl(hSocket, F_SETFL, fFlags & ~O_NONBLOCK) == SOCKET_ERROR) {
#endif
CloseSocket(hSocket);
return false;
}
}
return true;
}