src/netbase.cpp

   1 // Copyright (c) 2009-2010 Satoshi Nakamoto
   2 // Copyright (c) 2009-2016 The Bitcoin Core developers
   3 // Distributed under the MIT software license, see the accompanying
   4 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
   5
   6 #ifdef HAVE_CONFIG_H
   7 #include "config/bitcoin-config.h"
   8 #endif
   9
  10 #include "netbase.h"
  11
  12 #include "hash.h"
  13 #include "sync.h"
  14 #include "uint256.h"
  15 #include "random.h"
  16 #include "util.h"
  17 #include "utilstrencodings.h"
  18
  19 #include <atomic>
  20
  21 #ifndef WIN32
  22 #include <fcntl.h>
  23 #endif
  24
  25 #include <boost/algorithm/string/case_conv.hpp> // for to_lower()
  26 #include <boost/algorithm/string/predicate.hpp> // for startswith() and endswith()
  27
  28 #if !defined(HAVE_MSG_NOSIGNAL)
  29 #define MSG_NOSIGNAL 0
  30 #endif
  31
  32 // Settings
  33 static proxyType proxyInfo[NET_MAX];
  34 static proxyType nameProxy;
  35 static CCriticalSection cs_proxyInfos;
  36 int nConnectTimeout = DEFAULT_CONNECT_TIMEOUT;
  37 bool fNameLookup = DEFAULT_NAME_LOOKUP;
  38
  39 // Need ample time for negotiation for very slow proxies such as Tor (milliseconds)
  40 static const int SOCKS5_RECV_TIMEOUT = 20 * 1000;
  41 static std::atomic<bool> interruptSocks5Recv(false);
  42
  43 enum Network ParseNetwork(std::string net) {
  44     boost::to_lower(net);
  45     if (net == "ipv4") return NET_IPV4;
  46     if (net == "ipv6") return NET_IPV6;
  47     if (net == "tor" || net == "onion")  return NET_TOR;
  48     return NET_UNROUTABLE;
  49 }
  50
  51 std::string GetNetworkName(enum Network net) {
  52     switch(net)
  53     {
  54     case NET_IPV4: return "ipv4";
  55     case NET_IPV6: return "ipv6";
  56     case NET_TOR: return "onion";
  57     default: return "";
  58     }
  59 }
  60
  61 void SplitHostPort(std::string in, int &portOut, std::string &hostOut) {
  62     size_t colon = in.find_last_of(':');
  63     // if a : is found, and it either follows a [...], or no other : is in the string, treat it as port separator
  64     bool fHaveColon = colon != in.npos;
  65     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
  66     bool fMultiColon = fHaveColon && (in.find_last_of(':',colon-1) != in.npos);
  67     if (fHaveColon && (colon==0 || fBracketed || !fMultiColon)) {
  68         int32_t n;
  69         if (ParseInt32(in.substr(colon + 1), &n) && n > 0 && n < 0x10000) {
  70             in = in.substr(0, colon);
  71             portOut = n;
  72         }
  73     }
  74     if (in.size()>0 && in[0] == '[' && in[in.size()-1] == ']')
  75         hostOut = in.substr(1, in.size()-2);
  76     else
  77         hostOut = in;
  78 }
  79
  80 bool static LookupIntern(const char *pszName, std::vector<CNetAddr>& vIP, unsigned int nMaxSolutions, bool fAllowLookup)
  81 {
  82     vIP.clear();
  83
  84     {
  85         CNetAddr addr;
  86         if (addr.SetSpecial(std::string(pszName))) {
  87             vIP.push_back(addr);
  88             return true;
  89         }
  90     }
  91
  92     struct addrinfo aiHint;
  93     memset(&aiHint, 0, sizeof(struct addrinfo));
  94
  95     aiHint.ai_socktype = SOCK_STREAM;
  96     aiHint.ai_protocol = IPPROTO_TCP;
  97     aiHint.ai_family = AF_UNSPEC;
  98 #ifdef WIN32
  99     aiHint.ai_flags = fAllowLookup ? 0 : AI_NUMERICHOST;
 100 #else
 101     aiHint.ai_flags = fAllowLookup ? AI_ADDRCONFIG : AI_NUMERICHOST;
 102 #endif
 103     struct addrinfo *aiRes = NULL;
 104     int nErr = getaddrinfo(pszName, NULL, &aiHint, &aiRes);
 105     if (nErr)
 106         return false;
 107
 108     struct addrinfo *aiTrav = aiRes;
 109     while (aiTrav != NULL && (nMaxSolutions == 0 || vIP.size() < nMaxSolutions))
 110     {
 111         if (aiTrav->ai_family == AF_INET)
 112         {
 113             assert(aiTrav->ai_addrlen >= sizeof(sockaddr_in));
 114             vIP.push_back(CNetAddr(((struct sockaddr_in*)(aiTrav->ai_addr))->sin_addr));
 115         }
 116
 117         if (aiTrav->ai_family == AF_INET6)
 118         {
 119             assert(aiTrav->ai_addrlen >= sizeof(sockaddr_in6));
 120             struct sockaddr_in6* s6 = (struct sockaddr_in6*) aiTrav->ai_addr;
 121             vIP.push_back(CNetAddr(s6->sin6_addr, s6->sin6_scope_id));
 122         }
 123
 124         aiTrav = aiTrav->ai_next;
 125     }
 126
 127     freeaddrinfo(aiRes);
 128
 129     return (vIP.size() > 0);
 130 }
 131
 132 bool LookupHost(const char *pszName, std::vector<CNetAddr>& vIP, unsigned int nMaxSolutions, bool fAllowLookup)
 133 {
 134     std::string strHost(pszName);
 135     if (strHost.empty())
 136         return false;
 137     if (boost::algorithm::starts_with(strHost, "[") && boost::algorithm::ends_with(strHost, "]"))
 138     {
 139         strHost = strHost.substr(1, strHost.size() - 2);
 140     }
 141
 142     return LookupIntern(strHost.c_str(), vIP, nMaxSolutions, fAllowLookup);
 143 }
 144
 145 bool LookupHost(const char *pszName, CNetAddr& addr, bool fAllowLookup)
 146 {
 147     std::vector<CNetAddr> vIP;
 148     LookupHost(pszName, vIP, 1, fAllowLookup);
 149     if(vIP.empty())
 150         return false;
 151     addr = vIP.front();
 152     return true;
 153 }
 154
 155 bool Lookup(const char *pszName, std::vector<CService>& vAddr, int portDefault, bool fAllowLookup, unsigned int nMaxSolutions)
 156 {
 157     if (pszName[0] == 0)
 158         return false;
 159     int port = portDefault;
 160     std::string hostname = "";
 161     SplitHostPort(std::string(pszName), port, hostname);
 162
 163     std::vector<CNetAddr> vIP;
 164     bool fRet = LookupIntern(hostname.c_str(), vIP, nMaxSolutions, fAllowLookup);
 165     if (!fRet)
 166         return false;
 167     vAddr.resize(vIP.size());
 168     for (unsigned int i = 0; i < vIP.size(); i++)
 169         vAddr[i] = CService(vIP[i], port);
 170     return true;
 171 }
 172
 173 bool Lookup(const char *pszName, CService& addr, int portDefault, bool fAllowLookup)
 174 {
 175     std::vector<CService> vService;
 176     bool fRet = Lookup(pszName, vService, portDefault, fAllowLookup, 1);
 177     if (!fRet)
 178         return false;
 179     addr = vService[0];
 180     return true;
 181 }
 182
 183 CService LookupNumeric(const char *pszName, int portDefault)
 184 {
 185     CService addr;
 186     // "1.2:345" will fail to resolve the ip, but will still set the port.
 187     // If the ip fails to resolve, re-init the result.
 188     if(!Lookup(pszName, addr, portDefault, false))
 189         addr = CService();
 190     return addr;
 191 }
 192
 193 struct timeval MillisToTimeval(int64_t nTimeout)
 194 {
 195     struct timeval timeout;
 196     timeout.tv_sec  = nTimeout / 1000;
 197     timeout.tv_usec = (nTimeout % 1000) * 1000;
 198     return timeout;
 199 }
 200
 201 enum class IntrRecvError {
 202     OK,
 203     Timeout,
 204     Disconnected,
 205     NetworkError,
 206     Interrupted
 207 };
 208
 209 /**
 210  * Read bytes from socket. This will either read the full number of bytes requested
 211  * or return False on error or timeout.
 212  * This function can be interrupted by calling InterruptSocks5()
 213  *
 214  * @param data Buffer to receive into
 215  * @param len  Length of data to receive
 216  * @param timeout  Timeout in milliseconds for receive operation
 217  *
 218  * @note This function requires that hSocket is in non-blocking mode.
 219  */
 220 static IntrRecvError InterruptibleRecv(char* data, size_t len, int timeout, SOCKET& hSocket)
 221 {
 222     int64_t curTime = GetTimeMillis();
 223     int64_t endTime = curTime + timeout;
 224     // Maximum time to wait in one select call. It will take up until this time (in millis)
 225     // to break off in case of an interruption.
 226     const int64_t maxWait = 1000;
 227     while (len > 0 && curTime < endTime) {
 228         ssize_t ret = recv(hSocket, data, len, 0); // Optimistically try the recv first
 229         if (ret > 0) {
 230             len -= ret;
 231             data += ret;
 232         } else if (ret == 0) { // Unexpected disconnection
 233             return IntrRecvError::Disconnected;
 234         } else { // Other error or blocking
 235             int nErr = WSAGetLastError();
 236             if (nErr == WSAEINPROGRESS || nErr == WSAEWOULDBLOCK || nErr == WSAEINVAL) {
 237                 if (!IsSelectableSocket(hSocket)) {
 238                     return IntrRecvError::NetworkError;
 239                 }
 240                 struct timeval tval = MillisToTimeval(std::min(endTime - curTime, maxWait));
 241                 fd_set fdset;
 242                 FD_ZERO(&fdset);
 243                 FD_SET(hSocket, &fdset);
 244                 int nRet = select(hSocket + 1, &fdset, NULL, NULL, &tval);
 245                 if (nRet == SOCKET_ERROR) {
 246                     return IntrRecvError::NetworkError;
 247                 }
 248             } else {
 249                 return IntrRecvError::NetworkError;
 250             }
 251         }
 252         if (interruptSocks5Recv)
 253             return IntrRecvError::Interrupted;
 254         curTime = GetTimeMillis();
 255     }
 256     return len == 0 ? IntrRecvError::OK : IntrRecvError::Timeout;
 257 }
 258
 259 struct ProxyCredentials
 260 {
 261     std::string username;
 262     std::string password;
 263 };
 264
 265 std::string Socks5ErrorString(int err)
 266 {
 267     switch(err) {
 268         case 0x01: return "general failure";
 269         case 0x02: return "connection not allowed";
 270         case 0x03: return "network unreachable";
 271         case 0x04: return "host unreachable";
 272         case 0x05: return "connection refused";
 273         case 0x06: return "TTL expired";
 274         case 0x07: return "protocol error";
 275         case 0x08: return "address type not supported";
 276         default:   return "unknown";
 277     }
 278 }
 279
 280 /** Connect using SOCKS5 (as described in RFC1928) */
 281 static bool Socks5(const std::string& strDest, int port, const ProxyCredentials *auth, SOCKET& hSocket)
 282 {
 283     IntrRecvError recvr;
 284     LogPrint(BCLog::NET, "SOCKS5 connecting %s\n", strDest);
 285     if (strDest.size() > 255) {
 286         CloseSocket(hSocket);
 287         return error("Hostname too long");
 288     }
 289     // Accepted authentication methods
 290     std::vector<uint8_t> vSocks5Init;
 291     vSocks5Init.push_back(0x05);
 292     if (auth) {
 293         vSocks5Init.push_back(0x02); // # METHODS
 294         vSocks5Init.push_back(0x00); // X'00' NO AUTHENTICATION REQUIRED
 295         vSocks5Init.push_back(0x02); // X'02' USERNAME/PASSWORD (RFC1929)
 296     } else {
 297         vSocks5Init.push_back(0x01); // # METHODS
 298         vSocks5Init.push_back(0x00); // X'00' NO AUTHENTICATION REQUIRED
 299     }
 300     ssize_t ret = send(hSocket, (const char*)vSocks5Init.data(), vSocks5Init.size(), MSG_NOSIGNAL);
 301     if (ret != (ssize_t)vSocks5Init.size()) {
 302         CloseSocket(hSocket);
 303         return error("Error sending to proxy");
 304     }
 305     char pchRet1[2];
 306     if ((recvr = InterruptibleRecv(pchRet1, 2, SOCKS5_RECV_TIMEOUT, hSocket)) != IntrRecvError::OK) {
 307         CloseSocket(hSocket);
 308         LogPrintf("Socks5() connect to %s:%d failed: InterruptibleRecv() timeout or other failure\n", strDest, port);
 309         return false;
 310     }
 311     if (pchRet1[0] != 0x05) {
 312         CloseSocket(hSocket);
 313         return error("Proxy failed to initialize");
 314     }
 315     if (pchRet1[1] == 0x02 && auth) {
 316         // Perform username/password authentication (as described in RFC1929)
 317         std::vector<uint8_t> vAuth;
 318         vAuth.push_back(0x01);
 319         if (auth->username.size() > 255 || auth->password.size() > 255)
 320             return error("Proxy username or password too long");
 321         vAuth.push_back(auth->username.size());
 322         vAuth.insert(vAuth.end(), auth->username.begin(), auth->username.end());
 323         vAuth.push_back(auth->password.size());
 324         vAuth.insert(vAuth.end(), auth->password.begin(), auth->password.end());
 325         ret = send(hSocket, (const char*)vAuth.data(), vAuth.size(), MSG_NOSIGNAL);
 326         if (ret != (ssize_t)vAuth.size()) {
 327             CloseSocket(hSocket);
 328             return error("Error sending authentication to proxy");
 329         }
 330         LogPrint(BCLog::PROXY, "SOCKS5 sending proxy authentication %s:%s\n", auth->username, auth->password);
 331         char pchRetA[2];
 332         if ((recvr = InterruptibleRecv(pchRetA, 2, SOCKS5_RECV_TIMEOUT, hSocket)) != IntrRecvError::OK) {
 333             CloseSocket(hSocket);
 334             return error("Error reading proxy authentication response");
 335         }
 336         if (pchRetA[0] != 0x01 || pchRetA[1] != 0x00) {
 337             CloseSocket(hSocket);
 338             return error("Proxy authentication unsuccessful");
 339         }
 340     } else if (pchRet1[1] == 0x00) {
 341         // Perform no authentication
 342     } else {
 343         CloseSocket(hSocket);
 344         return error("Proxy requested wrong authentication method %02x", pchRet1[1]);
 345     }
 346     std::vector<uint8_t> vSocks5;
 347     vSocks5.push_back(0x05); // VER protocol version
 348     vSocks5.push_back(0x01); // CMD CONNECT
 349     vSocks5.push_back(0x00); // RSV Reserved
 350     vSocks5.push_back(0x03); // ATYP DOMAINNAME
 351     vSocks5.push_back(strDest.size()); // Length<=255 is checked at beginning of function
 352     vSocks5.insert(vSocks5.end(), strDest.begin(), strDest.end());
 353     vSocks5.push_back((port >> 8) & 0xFF);
 354     vSocks5.push_back((port >> 0) & 0xFF);
 355     ret = send(hSocket, (const char*)vSocks5.data(), vSocks5.size(), MSG_NOSIGNAL);
 356     if (ret != (ssize_t)vSocks5.size()) {
 357         CloseSocket(hSocket);
 358         return error("Error sending to proxy");
 359     }
 360     char pchRet2[4];
 361     if ((recvr = InterruptibleRecv(pchRet2, 4, SOCKS5_RECV_TIMEOUT, hSocket)) != IntrRecvError::OK) {
 362         CloseSocket(hSocket);
 363         if (recvr == IntrRecvError::Timeout) {
 364             /* If a timeout happens here, this effectively means we timed out while connecting
 365              * to the remote node. This is very common for Tor, so do not print an
 366              * error message. */
 367             return false;
 368         } else {
 369             return error("Error while reading proxy response");
 370         }
 371     }
 372     if (pchRet2[0] != 0x05) {
 373         CloseSocket(hSocket);
 374         return error("Proxy failed to accept request");
 375     }
 376     if (pchRet2[1] != 0x00) {
 377         // Failures to connect to a peer that are not proxy errors
 378         CloseSocket(hSocket);
 379         LogPrintf("Socks5() connect to %s:%d failed: %s\n", strDest, port, Socks5ErrorString(pchRet2[1]));
 380         return false;
 381     }
 382     if (pchRet2[2] != 0x00) {
 383         CloseSocket(hSocket);
 384         return error("Error: malformed proxy response");
 385     }
 386     char pchRet3[256];
 387     switch (pchRet2[3])
 388     {
 389         case 0x01: recvr = InterruptibleRecv(pchRet3, 4, SOCKS5_RECV_TIMEOUT, hSocket); break;
 390         case 0x04: recvr = InterruptibleRecv(pchRet3, 16, SOCKS5_RECV_TIMEOUT, hSocket); break;
 391         case 0x03:
 392         {
 393             recvr = InterruptibleRecv(pchRet3, 1, SOCKS5_RECV_TIMEOUT, hSocket);
 394             if (recvr != IntrRecvError::OK) {
 395                 CloseSocket(hSocket);
 396                 return error("Error reading from proxy");
 397             }
 398             int nRecv = pchRet3[0];
 399             recvr = InterruptibleRecv(pchRet3, nRecv, SOCKS5_RECV_TIMEOUT, hSocket);
 400             break;
 401         }
 402         default: CloseSocket(hSocket); return error("Error: malformed proxy response");
 403     }
 404     if (recvr != IntrRecvError::OK) {
 405         CloseSocket(hSocket);
 406         return error("Error reading from proxy");
 407     }
 408     if ((recvr = InterruptibleRecv(pchRet3, 2, SOCKS5_RECV_TIMEOUT, hSocket)) != IntrRecvError::OK) {
 409         CloseSocket(hSocket);
 410         return error("Error reading from proxy");
 411     }
 412     LogPrint(BCLog::NET, "SOCKS5 connected %s\n", strDest);
 413     return true;
 414 }
 415
 416 bool static ConnectSocketDirectly(const CService &addrConnect, SOCKET& hSocketRet, int nTimeout)
 417 {
 418     hSocketRet = INVALID_SOCKET;
 419
 420     struct sockaddr_storage sockaddr;
 421     socklen_t len = sizeof(sockaddr);
 422     if (!addrConnect.GetSockAddr((struct sockaddr*)&sockaddr, &len)) {
 423         LogPrintf("Cannot connect to %s: unsupported network\n", addrConnect.ToString());
 424         return false;
 425     }
 426
 427     SOCKET hSocket = socket(((struct sockaddr*)&sockaddr)->sa_family, SOCK_STREAM, IPPROTO_TCP);
 428     if (hSocket == INVALID_SOCKET)
 429         return false;
 430
 431     int set = 1;
 432 #ifdef SO_NOSIGPIPE
 433     // Different way of disabling SIGPIPE on BSD
 434     setsockopt(hSocket, SOL_SOCKET, SO_NOSIGPIPE, (void*)&set, sizeof(int));
 435 #endif
 436
 437     //Disable Nagle's algorithm
 438 #ifdef WIN32
 439     setsockopt(hSocket, IPPROTO_TCP, TCP_NODELAY, (const char*)&set, sizeof(int));
 440 #else
 441     setsockopt(hSocket, IPPROTO_TCP, TCP_NODELAY, (void*)&set, sizeof(int));
 442 #endif
 443
 444     // Set to non-blocking
 445     if (!SetSocketNonBlocking(hSocket, true))
 446         return error("ConnectSocketDirectly: Setting socket to non-blocking failed, error %s\n", NetworkErrorString(WSAGetLastError()));
 447
 448     if (connect(hSocket, (struct sockaddr*)&sockaddr, len) == SOCKET_ERROR)
 449     {
 450         int nErr = WSAGetLastError();
 451         // WSAEINVAL is here because some legacy version of winsock uses it
 452         if (nErr == WSAEINPROGRESS || nErr == WSAEWOULDBLOCK || nErr == WSAEINVAL)
 453         {
 454             struct timeval timeout = MillisToTimeval(nTimeout);
 455             fd_set fdset;
 456             FD_ZERO(&fdset);
 457             FD_SET(hSocket, &fdset);
 458             int nRet = select(hSocket + 1, NULL, &fdset, NULL, &timeout);
 459             if (nRet == 0)
 460             {
 461                 LogPrint(BCLog::NET, "connection to %s timeout\n", addrConnect.ToString());
 462                 CloseSocket(hSocket);
 463                 return false;
 464             }
 465             if (nRet == SOCKET_ERROR)
 466             {
 467                 LogPrintf("select() for %s failed: %s\n", addrConnect.ToString(), NetworkErrorString(WSAGetLastError()));
 468                 CloseSocket(hSocket);
 469                 return false;
 470             }
 471             socklen_t nRetSize = sizeof(nRet);
 472 #ifdef WIN32
 473             if (getsockopt(hSocket, SOL_SOCKET, SO_ERROR, (char*)(&nRet), &nRetSize) == SOCKET_ERROR)
 474 #else
 475             if (getsockopt(hSocket, SOL_SOCKET, SO_ERROR, &nRet, &nRetSize) == SOCKET_ERROR)
 476 #endif
 477             {
 478                 LogPrintf("getsockopt() for %s failed: %s\n", addrConnect.ToString(), NetworkErrorString(WSAGetLastError()));
 479                 CloseSocket(hSocket);
 480                 return false;
 481             }
 482             if (nRet != 0)
 483             {
 484                 LogPrintf("connect() to %s failed after select(): %s\n", addrConnect.ToString(), NetworkErrorString(nRet));
 485                 CloseSocket(hSocket);
 486                 return false;
 487             }
 488         }
 489 #ifdef WIN32
 490         else if (WSAGetLastError() != WSAEISCONN)
 491 #else
 492         else
 493 #endif
 494         {
 495             LogPrintf("connect() to %s failed: %s\n", addrConnect.ToString(), NetworkErrorString(WSAGetLastError()));
 496             CloseSocket(hSocket);
 497             return false;
 498         }
 499     }
 500
 501     hSocketRet = hSocket;
 502     return true;
 503 }
 504
 505 bool SetProxy(enum Network net, const proxyType &addrProxy) {
 506     assert(net >= 0 && net < NET_MAX);
 507     if (!addrProxy.IsValid())
 508         return false;
 509     LOCK(cs_proxyInfos);
 510     proxyInfo[net] = addrProxy;
 511     return true;
 512 }
 513
 514 bool GetProxy(enum Network net, proxyType &proxyInfoOut) {
 515     assert(net >= 0 && net < NET_MAX);
 516     LOCK(cs_proxyInfos);
 517     if (!proxyInfo[net].IsValid())
 518         return false;
 519     proxyInfoOut = proxyInfo[net];
 520     return true;
 521 }
 522
 523 bool SetNameProxy(const proxyType &addrProxy) {
 524     if (!addrProxy.IsValid())
 525         return false;
 526     LOCK(cs_proxyInfos);
 527     nameProxy = addrProxy;
 528     return true;
 529 }
 530
 531 bool GetNameProxy(proxyType &nameProxyOut) {
 532     LOCK(cs_proxyInfos);
 533     if(!nameProxy.IsValid())
 534         return false;
 535     nameProxyOut = nameProxy;
 536     return true;
 537 }
 538
 539 bool HaveNameProxy() {
 540     LOCK(cs_proxyInfos);
 541     return nameProxy.IsValid();
 542 }
 543
 544 bool IsProxy(const CNetAddr &addr) {
 545     LOCK(cs_proxyInfos);
 546     for (int i = 0; i < NET_MAX; i++) {
 547         if (addr == (CNetAddr)proxyInfo[i].proxy)
 548             return true;
 549     }
 550     return false;
 551 }
 552
 553 static bool ConnectThroughProxy(const proxyType &proxy, const std::string& strDest, int port, SOCKET& hSocketRet, int nTimeout, bool *outProxyConnectionFailed)
 554 {
 555     SOCKET hSocket = INVALID_SOCKET;
 556     // first connect to proxy server
 557     if (!ConnectSocketDirectly(proxy.proxy, hSocket, nTimeout)) {
 558         if (outProxyConnectionFailed)
 559             *outProxyConnectionFailed = true;
 560         return false;
 561     }
 562     // do socks negotiation
 563     if (proxy.randomize_credentials) {
 564         ProxyCredentials random_auth;
 565         static std::atomic_int counter;
 566         random_auth.username = random_auth.password = strprintf("%i", counter++);
 567         if (!Socks5(strDest, (unsigned short)port, &random_auth, hSocket))
 568             return false;
 569     } else {
 570         if (!Socks5(strDest, (unsigned short)port, 0, hSocket))
 571             return false;
 572     }
 573
 574     hSocketRet = hSocket;
 575     return true;
 576 }
 577
 578 bool ConnectSocket(const CService &addrDest, SOCKET& hSocketRet, int nTimeout, bool *outProxyConnectionFailed)
 579 {
 580     proxyType proxy;
 581     if (outProxyConnectionFailed)
 582         *outProxyConnectionFailed = false;
 583
 584     if (GetProxy(addrDest.GetNetwork(), proxy))
 585         return ConnectThroughProxy(proxy, addrDest.ToStringIP(), addrDest.GetPort(), hSocketRet, nTimeout, outProxyConnectionFailed);
 586     else // no proxy needed (none set for target network)
 587         return ConnectSocketDirectly(addrDest, hSocketRet, nTimeout);
 588 }
 589
 590 bool ConnectSocketByName(CService &addr, SOCKET& hSocketRet, const char *pszDest, int portDefault, int nTimeout, bool *outProxyConnectionFailed)
 591 {
 592     std::string strDest;
 593     int port = portDefault;
 594
 595     if (outProxyConnectionFailed)
 596         *outProxyConnectionFailed = false;
 597
 598     SplitHostPort(std::string(pszDest), port, strDest);
 599
 600     proxyType proxy;
 601     GetNameProxy(proxy);
 602
 603     std::vector<CService> addrResolved;
 604     if (Lookup(strDest.c_str(), addrResolved, port, fNameLookup && !HaveNameProxy(), 256)) {
 605         if (addrResolved.size() > 0) {
 606             addr = addrResolved[GetRand(addrResolved.size())];
 607             return ConnectSocket(addr, hSocketRet, nTimeout);
 608         }
 609     }
 610
 611     addr = CService();
 612
 613     if (!HaveNameProxy())
 614         return false;
 615     return ConnectThroughProxy(proxy, strDest, port, hSocketRet, nTimeout, outProxyConnectionFailed);
 616 }
 617
 618 bool LookupSubNet(const char* pszName, CSubNet& ret)
 619 {
 620     std::string strSubnet(pszName);
 621     size_t slash = strSubnet.find_last_of('/');
 622     std::vector<CNetAddr> vIP;
 623
 624     std::string strAddress = strSubnet.substr(0, slash);
 625     if (LookupHost(strAddress.c_str(), vIP, 1, false))
 626     {
 627         CNetAddr network = vIP[0];
 628         if (slash != strSubnet.npos)
 629         {
 630             std::string strNetmask = strSubnet.substr(slash + 1);
 631             int32_t n;
 632             // IPv4 addresses start at offset 12, and first 12 bytes must match, so just offset n
 633             if (ParseInt32(strNetmask, &n)) { // If valid number, assume /24 syntax
 634                 ret = CSubNet(network, n);
 635                 return ret.IsValid();
 636             }
 637             else // If not a valid number, try full netmask syntax
 638             {
 639                 // Never allow lookup for netmask
 640                 if (LookupHost(strNetmask.c_str(), vIP, 1, false)) {
 641                     ret = CSubNet(network, vIP[0]);
 642                     return ret.IsValid();
 643                 }
 644             }
 645         }
 646         else
 647         {
 648             ret = CSubNet(network);
 649             return ret.IsValid();
 650         }
 651     }
 652     return false;
 653 }
 654
 655 #ifdef WIN32
 656 std::string NetworkErrorString(int err)
 657 {
 658     char buf[256];
 659     buf[0] = 0;
 660     if(FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_MAX_WIDTH_MASK,
 661             NULL, err, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
 662             buf, sizeof(buf), NULL))
 663     {
 664         return strprintf("%s (%d)", buf, err);
 665     }
 666     else
 667     {
 668         return strprintf("Unknown error (%d)", err);
 669     }
 670 }
 671 #else
 672 std::string NetworkErrorString(int err)
 673 {
 674     char buf[256];
 675     const char *s = buf;
 676     buf[0] = 0;
 677     /* Too bad there are two incompatible implementations of the
 678      * thread-safe strerror. */
 679 #ifdef STRERROR_R_CHAR_P /* GNU variant can return a pointer outside the passed buffer */
 680     s = strerror_r(err, buf, sizeof(buf));
 681 #else /* POSIX variant always returns message in buffer */
 682     if (strerror_r(err, buf, sizeof(buf)))
 683         buf[0] = 0;
 684 #endif
 685     return strprintf("%s (%d)", s, err);
 686 }
 687 #endif
 688
 689 bool CloseSocket(SOCKET& hSocket)
 690 {
 691     if (hSocket == INVALID_SOCKET)
 692         return false;
 693 #ifdef WIN32
 694     int ret = closesocket(hSocket);
 695 #else
 696     int ret = close(hSocket);
 697 #endif
 698     hSocket = INVALID_SOCKET;
 699     return ret != SOCKET_ERROR;
 700 }
 701
 702 bool SetSocketNonBlocking(SOCKET& hSocket, bool fNonBlocking)
 703 {
 704     if (fNonBlocking) {
 705 #ifdef WIN32
 706         u_long nOne = 1;
 707         if (ioctlsocket(hSocket, FIONBIO, &nOne) == SOCKET_ERROR) {
 708 #else
 709         int fFlags = fcntl(hSocket, F_GETFL, 0);
 710         if (fcntl(hSocket, F_SETFL, fFlags | O_NONBLOCK) == SOCKET_ERROR) {
 711 #endif
 712             CloseSocket(hSocket);
 713             return false;
 714         }
 715     } else {
 716 #ifdef WIN32
 717         u_long nZero = 0;
 718         if (ioctlsocket(hSocket, FIONBIO, &nZero) == SOCKET_ERROR) {
 719 #else
 720         int fFlags = fcntl(hSocket, F_GETFL, 0);
 721         if (fcntl(hSocket, F_SETFL, fFlags & ~O_NONBLOCK) == SOCKET_ERROR) {
 722 #endif
 723             CloseSocket(hSocket);
 724             return false;
 725         }
 726     }
 727
 728     return true;
 729 }
 730
 731 void InterruptSocks5(bool interrupt)
 732 {
 733     interruptSocks5Recv = interrupt;
 734 }