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         CNetAddr resolved;
 112         if (aiTrav->ai_family == AF_INET)
 113         {
 114             assert(aiTrav->ai_addrlen >= sizeof(sockaddr_in));
 115             resolved = CNetAddr(((struct sockaddr_in*)(aiTrav->ai_addr))->sin_addr);
 116         }
 117
 118         if (aiTrav->ai_family == AF_INET6)
 119         {
 120             assert(aiTrav->ai_addrlen >= sizeof(sockaddr_in6));
 121             struct sockaddr_in6* s6 = (struct sockaddr_in6*) aiTrav->ai_addr;
 122             resolved = CNetAddr(s6->sin6_addr, s6->sin6_scope_id);
 123         }
 124         /* Never allow resolving to an internal address. Consider any such result invalid */
 125         if (!resolved.IsInternal()) {
 126             vIP.push_back(resolved);
 127         }
 128
 129         aiTrav = aiTrav->ai_next;
 130     }
 131
 132     freeaddrinfo(aiRes);
 133
 134     return (vIP.size() > 0);
 135 }
 136
 137 bool LookupHost(const char *pszName, std::vector<CNetAddr>& vIP, unsigned int nMaxSolutions, bool fAllowLookup)
 138 {
 139     std::string strHost(pszName);
 140     if (strHost.empty())
 141         return false;
 142     if (boost::algorithm::starts_with(strHost, "[") && boost::algorithm::ends_with(strHost, "]"))
 143     {
 144         strHost = strHost.substr(1, strHost.size() - 2);
 145     }
 146
 147     return LookupIntern(strHost.c_str(), vIP, nMaxSolutions, fAllowLookup);
 148 }
 149
 150 bool LookupHost(const char *pszName, CNetAddr& addr, bool fAllowLookup)
 151 {
 152     std::vector<CNetAddr> vIP;
 153     LookupHost(pszName, vIP, 1, fAllowLookup);
 154     if(vIP.empty())
 155         return false;
 156     addr = vIP.front();
 157     return true;
 158 }
 159
 160 bool Lookup(const char *pszName, std::vector<CService>& vAddr, int portDefault, bool fAllowLookup, unsigned int nMaxSolutions)
 161 {
 162     if (pszName[0] == 0)
 163         return false;
 164     int port = portDefault;
 165     std::string hostname = "";
 166     SplitHostPort(std::string(pszName), port, hostname);
 167
 168     std::vector<CNetAddr> vIP;
 169     bool fRet = LookupIntern(hostname.c_str(), vIP, nMaxSolutions, fAllowLookup);
 170     if (!fRet)
 171         return false;
 172     vAddr.resize(vIP.size());
 173     for (unsigned int i = 0; i < vIP.size(); i++)
 174         vAddr[i] = CService(vIP[i], port);
 175     return true;
 176 }
 177
 178 bool Lookup(const char *pszName, CService& addr, int portDefault, bool fAllowLookup)
 179 {
 180     std::vector<CService> vService;
 181     bool fRet = Lookup(pszName, vService, portDefault, fAllowLookup, 1);
 182     if (!fRet)
 183         return false;
 184     addr = vService[0];
 185     return true;
 186 }
 187
 188 CService LookupNumeric(const char *pszName, int portDefault)
 189 {
 190     CService addr;
 191     // "1.2:345" will fail to resolve the ip, but will still set the port.
 192     // If the ip fails to resolve, re-init the result.
 193     if(!Lookup(pszName, addr, portDefault, false))
 194         addr = CService();
 195     return addr;
 196 }
 197
 198 struct timeval MillisToTimeval(int64_t nTimeout)
 199 {
 200     struct timeval timeout;
 201     timeout.tv_sec  = nTimeout / 1000;
 202     timeout.tv_usec = (nTimeout % 1000) * 1000;
 203     return timeout;
 204 }
 205
 206 enum class IntrRecvError {
 207     OK,
 208     Timeout,
 209     Disconnected,
 210     NetworkError,
 211     Interrupted
 212 };
 213
 214 /**
 215  * Read bytes from socket. This will either read the full number of bytes requested
 216  * or return False on error or timeout.
 217  * This function can be interrupted by calling InterruptSocks5()
 218  *
 219  * @param data Buffer to receive into
 220  * @param len  Length of data to receive
 221  * @param timeout  Timeout in milliseconds for receive operation
 222  *
 223  * @note This function requires that hSocket is in non-blocking mode.
 224  */
 225 static IntrRecvError InterruptibleRecv(char* data, size_t len, int timeout, SOCKET& hSocket)
 226 {
 227     int64_t curTime = GetTimeMillis();
 228     int64_t endTime = curTime + timeout;
 229     // Maximum time to wait in one select call. It will take up until this time (in millis)
 230     // to break off in case of an interruption.
 231     const int64_t maxWait = 1000;
 232     while (len > 0 && curTime < endTime) {
 233         ssize_t ret = recv(hSocket, data, len, 0); // Optimistically try the recv first
 234         if (ret > 0) {
 235             len -= ret;
 236             data += ret;
 237         } else if (ret == 0) { // Unexpected disconnection
 238             return IntrRecvError::Disconnected;
 239         } else { // Other error or blocking
 240             int nErr = WSAGetLastError();
 241             if (nErr == WSAEINPROGRESS || nErr == WSAEWOULDBLOCK || nErr == WSAEINVAL) {
 242                 if (!IsSelectableSocket(hSocket)) {
 243                     return IntrRecvError::NetworkError;
 244                 }
 245                 struct timeval tval = MillisToTimeval(std::min(endTime - curTime, maxWait));
 246                 fd_set fdset;
 247                 FD_ZERO(&fdset);
 248                 FD_SET(hSocket, &fdset);
 249                 int nRet = select(hSocket + 1, &fdset, NULL, NULL, &tval);
 250                 if (nRet == SOCKET_ERROR) {
 251                     return IntrRecvError::NetworkError;
 252                 }
 253             } else {
 254                 return IntrRecvError::NetworkError;
 255             }
 256         }
 257         if (interruptSocks5Recv)
 258             return IntrRecvError::Interrupted;
 259         curTime = GetTimeMillis();
 260     }
 261     return len == 0 ? IntrRecvError::OK : IntrRecvError::Timeout;
 262 }
 263
 264 struct ProxyCredentials
 265 {
 266     std::string username;
 267     std::string password;
 268 };
 269
 270 std::string Socks5ErrorString(int err)
 271 {
 272     switch(err) {
 273         case 0x01: return "general failure";
 274         case 0x02: return "connection not allowed";
 275         case 0x03: return "network unreachable";
 276         case 0x04: return "host unreachable";
 277         case 0x05: return "connection refused";
 278         case 0x06: return "TTL expired";
 279         case 0x07: return "protocol error";
 280         case 0x08: return "address type not supported";
 281         default:   return "unknown";
 282     }
 283 }
 284
 285 /** Connect using SOCKS5 (as described in RFC1928) */
 286 static bool Socks5(const std::string& strDest, int port, const ProxyCredentials *auth, SOCKET& hSocket)
 287 {
 288     IntrRecvError recvr;
 289     LogPrint(BCLog::NET, "SOCKS5 connecting %s\n", strDest);
 290     if (strDest.size() > 255) {
 291         CloseSocket(hSocket);
 292         return error("Hostname too long");
 293     }
 294     // Accepted authentication methods
 295     std::vector<uint8_t> vSocks5Init;
 296     vSocks5Init.push_back(0x05);
 297     if (auth) {
 298         vSocks5Init.push_back(0x02); // # METHODS
 299         vSocks5Init.push_back(0x00); // X'00' NO AUTHENTICATION REQUIRED
 300         vSocks5Init.push_back(0x02); // X'02' USERNAME/PASSWORD (RFC1929)
 301     } else {
 302         vSocks5Init.push_back(0x01); // # METHODS
 303         vSocks5Init.push_back(0x00); // X'00' NO AUTHENTICATION REQUIRED
 304     }
 305     ssize_t ret = send(hSocket, (const char*)vSocks5Init.data(), vSocks5Init.size(), MSG_NOSIGNAL);
 306     if (ret != (ssize_t)vSocks5Init.size()) {
 307         CloseSocket(hSocket);
 308         return error("Error sending to proxy");
 309     }
 310     char pchRet1[2];
 311     if ((recvr = InterruptibleRecv(pchRet1, 2, SOCKS5_RECV_TIMEOUT, hSocket)) != IntrRecvError::OK) {
 312         CloseSocket(hSocket);
 313         LogPrintf("Socks5() connect to %s:%d failed: InterruptibleRecv() timeout or other failure\n", strDest, port);
 314         return false;
 315     }
 316     if (pchRet1[0] != 0x05) {
 317         CloseSocket(hSocket);
 318         return error("Proxy failed to initialize");
 319     }
 320     if (pchRet1[1] == 0x02 && auth) {
 321         // Perform username/password authentication (as described in RFC1929)
 322         std::vector<uint8_t> vAuth;
 323         vAuth.push_back(0x01);
 324         if (auth->username.size() > 255 || auth->password.size() > 255)
 325             return error("Proxy username or password too long");
 326         vAuth.push_back(auth->username.size());
 327         vAuth.insert(vAuth.end(), auth->username.begin(), auth->username.end());
 328         vAuth.push_back(auth->password.size());
 329         vAuth.insert(vAuth.end(), auth->password.begin(), auth->password.end());
 330         ret = send(hSocket, (const char*)vAuth.data(), vAuth.size(), MSG_NOSIGNAL);
 331         if (ret != (ssize_t)vAuth.size()) {
 332             CloseSocket(hSocket);
 333             return error("Error sending authentication to proxy");
 334         }
 335         LogPrint(BCLog::PROXY, "SOCKS5 sending proxy authentication %s:%s\n", auth->username, auth->password);
 336         char pchRetA[2];
 337         if ((recvr = InterruptibleRecv(pchRetA, 2, SOCKS5_RECV_TIMEOUT, hSocket)) != IntrRecvError::OK) {
 338             CloseSocket(hSocket);
 339             return error("Error reading proxy authentication response");
 340         }
 341         if (pchRetA[0] != 0x01 || pchRetA[1] != 0x00) {
 342             CloseSocket(hSocket);
 343             return error("Proxy authentication unsuccessful");
 344         }
 345     } else if (pchRet1[1] == 0x00) {
 346         // Perform no authentication
 347     } else {
 348         CloseSocket(hSocket);
 349         return error("Proxy requested wrong authentication method %02x", pchRet1[1]);
 350     }
 351     std::vector<uint8_t> vSocks5;
 352     vSocks5.push_back(0x05); // VER protocol version
 353     vSocks5.push_back(0x01); // CMD CONNECT
 354     vSocks5.push_back(0x00); // RSV Reserved
 355     vSocks5.push_back(0x03); // ATYP DOMAINNAME
 356     vSocks5.push_back(strDest.size()); // Length<=255 is checked at beginning of function
 357     vSocks5.insert(vSocks5.end(), strDest.begin(), strDest.end());
 358     vSocks5.push_back((port >> 8) & 0xFF);
 359     vSocks5.push_back((port >> 0) & 0xFF);
 360     ret = send(hSocket, (const char*)vSocks5.data(), vSocks5.size(), MSG_NOSIGNAL);
 361     if (ret != (ssize_t)vSocks5.size()) {
 362         CloseSocket(hSocket);
 363         return error("Error sending to proxy");
 364     }
 365     char pchRet2[4];
 366     if ((recvr = InterruptibleRecv(pchRet2, 4, SOCKS5_RECV_TIMEOUT, hSocket)) != IntrRecvError::OK) {
 367         CloseSocket(hSocket);
 368         if (recvr == IntrRecvError::Timeout) {
 369             /* If a timeout happens here, this effectively means we timed out while connecting
 370              * to the remote node. This is very common for Tor, so do not print an
 371              * error message. */
 372             return false;
 373         } else {
 374             return error("Error while reading proxy response");
 375         }
 376     }
 377     if (pchRet2[0] != 0x05) {
 378         CloseSocket(hSocket);
 379         return error("Proxy failed to accept request");
 380     }
 381     if (pchRet2[1] != 0x00) {
 382         // Failures to connect to a peer that are not proxy errors
 383         CloseSocket(hSocket);
 384         LogPrintf("Socks5() connect to %s:%d failed: %s\n", strDest, port, Socks5ErrorString(pchRet2[1]));
 385         return false;
 386     }
 387     if (pchRet2[2] != 0x00) {
 388         CloseSocket(hSocket);
 389         return error("Error: malformed proxy response");
 390     }
 391     char pchRet3[256];
 392     switch (pchRet2[3])
 393     {
 394         case 0x01: recvr = InterruptibleRecv(pchRet3, 4, SOCKS5_RECV_TIMEOUT, hSocket); break;
 395         case 0x04: recvr = InterruptibleRecv(pchRet3, 16, SOCKS5_RECV_TIMEOUT, hSocket); break;
 396         case 0x03:
 397         {
 398             recvr = InterruptibleRecv(pchRet3, 1, SOCKS5_RECV_TIMEOUT, hSocket);
 399             if (recvr != IntrRecvError::OK) {
 400                 CloseSocket(hSocket);
 401                 return error("Error reading from proxy");
 402             }
 403             int nRecv = pchRet3[0];
 404             recvr = InterruptibleRecv(pchRet3, nRecv, SOCKS5_RECV_TIMEOUT, hSocket);
 405             break;
 406         }
 407         default: CloseSocket(hSocket); return error("Error: malformed proxy response");
 408     }
 409     if (recvr != IntrRecvError::OK) {
 410         CloseSocket(hSocket);
 411         return error("Error reading from proxy");
 412     }
 413     if ((recvr = InterruptibleRecv(pchRet3, 2, SOCKS5_RECV_TIMEOUT, hSocket)) != IntrRecvError::OK) {
 414         CloseSocket(hSocket);
 415         return error("Error reading from proxy");
 416     }
 417     LogPrint(BCLog::NET, "SOCKS5 connected %s\n", strDest);
 418     return true;
 419 }
 420
 421 bool static ConnectSocketDirectly(const CService &addrConnect, SOCKET& hSocketRet, int nTimeout)
 422 {
 423     hSocketRet = INVALID_SOCKET;
 424
 425     struct sockaddr_storage sockaddr;
 426     socklen_t len = sizeof(sockaddr);
 427     if (!addrConnect.GetSockAddr((struct sockaddr*)&sockaddr, &len)) {
 428         LogPrintf("Cannot connect to %s: unsupported network\n", addrConnect.ToString());
 429         return false;
 430     }
 431
 432     SOCKET hSocket = socket(((struct sockaddr*)&sockaddr)->sa_family, SOCK_STREAM, IPPROTO_TCP);
 433     if (hSocket == INVALID_SOCKET)
 434         return false;
 435
 436 #ifdef SO_NOSIGPIPE
 437     int set = 1;
 438     // Different way of disabling SIGPIPE on BSD
 439     setsockopt(hSocket, SOL_SOCKET, SO_NOSIGPIPE, (void*)&set, sizeof(int));
 440 #endif
 441
 442     //Disable Nagle's algorithm
 443     SetSocketNoDelay(hSocket);
 444
 445     // Set to non-blocking
 446     if (!SetSocketNonBlocking(hSocket, true))
 447         return error("ConnectSocketDirectly: Setting socket to non-blocking failed, error %s\n", NetworkErrorString(WSAGetLastError()));
 448
 449     if (connect(hSocket, (struct sockaddr*)&sockaddr, len) == SOCKET_ERROR)
 450     {
 451         int nErr = WSAGetLastError();
 452         // WSAEINVAL is here because some legacy version of winsock uses it
 453         if (nErr == WSAEINPROGRESS || nErr == WSAEWOULDBLOCK || nErr == WSAEINVAL)
 454         {
 455             struct timeval timeout = MillisToTimeval(nTimeout);
 456             fd_set fdset;
 457             FD_ZERO(&fdset);
 458             FD_SET(hSocket, &fdset);
 459             int nRet = select(hSocket + 1, NULL, &fdset, NULL, &timeout);
 460             if (nRet == 0)
 461             {
 462                 LogPrint(BCLog::NET, "connection to %s timeout\n", addrConnect.ToString());
 463                 CloseSocket(hSocket);
 464                 return false;
 465             }
 466             if (nRet == SOCKET_ERROR)
 467             {
 468                 LogPrintf("select() for %s failed: %s\n", addrConnect.ToString(), NetworkErrorString(WSAGetLastError()));
 469                 CloseSocket(hSocket);
 470                 return false;
 471             }
 472             socklen_t nRetSize = sizeof(nRet);
 473 #ifdef WIN32
 474             if (getsockopt(hSocket, SOL_SOCKET, SO_ERROR, (char*)(&nRet), &nRetSize) == SOCKET_ERROR)
 475 #else
 476             if (getsockopt(hSocket, SOL_SOCKET, SO_ERROR, &nRet, &nRetSize) == SOCKET_ERROR)
 477 #endif
 478             {
 479                 LogPrintf("getsockopt() for %s failed: %s\n", addrConnect.ToString(), NetworkErrorString(WSAGetLastError()));
 480                 CloseSocket(hSocket);
 481                 return false;
 482             }
 483             if (nRet != 0)
 484             {
 485                 LogPrintf("connect() to %s failed after select(): %s\n", addrConnect.ToString(), NetworkErrorString(nRet));
 486                 CloseSocket(hSocket);
 487                 return false;
 488             }
 489         }
 490 #ifdef WIN32
 491         else if (WSAGetLastError() != WSAEISCONN)
 492 #else
 493         else
 494 #endif
 495         {
 496             LogPrintf("connect() to %s failed: %s\n", addrConnect.ToString(), NetworkErrorString(WSAGetLastError()));
 497             CloseSocket(hSocket);
 498             return false;
 499         }
 500     }
 501
 502     hSocketRet = hSocket;
 503     return true;
 504 }
 505
 506 bool SetProxy(enum Network net, const proxyType &addrProxy) {
 507     assert(net >= 0 && net < NET_MAX);
 508     if (!addrProxy.IsValid())
 509         return false;
 510     LOCK(cs_proxyInfos);
 511     proxyInfo[net] = addrProxy;
 512     return true;
 513 }
 514
 515 bool GetProxy(enum Network net, proxyType &proxyInfoOut) {
 516     assert(net >= 0 && net < NET_MAX);
 517     LOCK(cs_proxyInfos);
 518     if (!proxyInfo[net].IsValid())
 519         return false;
 520     proxyInfoOut = proxyInfo[net];
 521     return true;
 522 }
 523
 524 bool SetNameProxy(const proxyType &addrProxy) {
 525     if (!addrProxy.IsValid())
 526         return false;
 527     LOCK(cs_proxyInfos);
 528     nameProxy = addrProxy;
 529     return true;
 530 }
 531
 532 bool GetNameProxy(proxyType &nameProxyOut) {
 533     LOCK(cs_proxyInfos);
 534     if(!nameProxy.IsValid())
 535         return false;
 536     nameProxyOut = nameProxy;
 537     return true;
 538 }
 539
 540 bool HaveNameProxy() {
 541     LOCK(cs_proxyInfos);
 542     return nameProxy.IsValid();
 543 }
 544
 545 bool IsProxy(const CNetAddr &addr) {
 546     LOCK(cs_proxyInfos);
 547     for (int i = 0; i < NET_MAX; i++) {
 548         if (addr == (CNetAddr)proxyInfo[i].proxy)
 549             return true;
 550     }
 551     return false;
 552 }
 553
 554 static bool ConnectThroughProxy(const proxyType &proxy, const std::string& strDest, int port, SOCKET& hSocketRet, int nTimeout, bool *outProxyConnectionFailed)
 555 {
 556     SOCKET hSocket = INVALID_SOCKET;
 557     // first connect to proxy server
 558     if (!ConnectSocketDirectly(proxy.proxy, hSocket, nTimeout)) {
 559         if (outProxyConnectionFailed)
 560             *outProxyConnectionFailed = true;
 561         return false;
 562     }
 563     // do socks negotiation
 564     if (proxy.randomize_credentials) {
 565         ProxyCredentials random_auth;
 566         static std::atomic_int counter;
 567         random_auth.username = random_auth.password = strprintf("%i", counter++);
 568         if (!Socks5(strDest, (unsigned short)port, &random_auth, hSocket))
 569             return false;
 570     } else {
 571         if (!Socks5(strDest, (unsigned short)port, 0, hSocket))
 572             return false;
 573     }
 574
 575     hSocketRet = hSocket;
 576     return true;
 577 }
 578
 579 bool ConnectSocket(const CService &addrDest, SOCKET& hSocketRet, int nTimeout, bool *outProxyConnectionFailed)
 580 {
 581     proxyType proxy;
 582     if (outProxyConnectionFailed)
 583         *outProxyConnectionFailed = false;
 584
 585     if (GetProxy(addrDest.GetNetwork(), proxy))
 586         return ConnectThroughProxy(proxy, addrDest.ToStringIP(), addrDest.GetPort(), hSocketRet, nTimeout, outProxyConnectionFailed);
 587     else // no proxy needed (none set for target network)
 588         return ConnectSocketDirectly(addrDest, hSocketRet, nTimeout);
 589 }
 590
 591 bool ConnectSocketByName(CService &addr, SOCKET& hSocketRet, const char *pszDest, int portDefault, int nTimeout, bool *outProxyConnectionFailed)
 592 {
 593     std::string strDest;
 594     int port = portDefault;
 595
 596     if (outProxyConnectionFailed)
 597         *outProxyConnectionFailed = false;
 598
 599     SplitHostPort(std::string(pszDest), port, strDest);
 600
 601     proxyType proxy;
 602     GetNameProxy(proxy);
 603
 604     std::vector<CService> addrResolved;
 605     if (Lookup(strDest.c_str(), addrResolved, port, fNameLookup && !HaveNameProxy(), 256)) {
 606         if (addrResolved.size() > 0) {
 607             addr = addrResolved[GetRand(addrResolved.size())];
 608             return ConnectSocket(addr, hSocketRet, nTimeout);
 609         }
 610     }
 611
 612     addr = CService();
 613
 614     if (!HaveNameProxy())
 615         return false;
 616     return ConnectThroughProxy(proxy, strDest, port, hSocketRet, nTimeout, outProxyConnectionFailed);
 617 }
 618
 619 bool LookupSubNet(const char* pszName, CSubNet& ret)
 620 {
 621     std::string strSubnet(pszName);
 622     size_t slash = strSubnet.find_last_of('/');
 623     std::vector<CNetAddr> vIP;
 624
 625     std::string strAddress = strSubnet.substr(0, slash);
 626     if (LookupHost(strAddress.c_str(), vIP, 1, false))
 627     {
 628         CNetAddr network = vIP[0];
 629         if (slash != strSubnet.npos)
 630         {
 631             std::string strNetmask = strSubnet.substr(slash + 1);
 632             int32_t n;
 633             // IPv4 addresses start at offset 12, and first 12 bytes must match, so just offset n
 634             if (ParseInt32(strNetmask, &n)) { // If valid number, assume /24 syntax
 635                 ret = CSubNet(network, n);
 636                 return ret.IsValid();
 637             }
 638             else // If not a valid number, try full netmask syntax
 639             {
 640                 // Never allow lookup for netmask
 641                 if (LookupHost(strNetmask.c_str(), vIP, 1, false)) {
 642                     ret = CSubNet(network, vIP[0]);
 643                     return ret.IsValid();
 644                 }
 645             }
 646         }
 647         else
 648         {
 649             ret = CSubNet(network);
 650             return ret.IsValid();
 651         }
 652     }
 653     return false;
 654 }
 655
 656 #ifdef WIN32
 657 std::string NetworkErrorString(int err)
 658 {
 659     char buf[256];
 660     buf[0] = 0;
 661     if(FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_MAX_WIDTH_MASK,
 662             NULL, err, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
 663             buf, sizeof(buf), NULL))
 664     {
 665         return strprintf("%s (%d)", buf, err);
 666     }
 667     else
 668     {
 669         return strprintf("Unknown error (%d)", err);
 670     }
 671 }
 672 #else
 673 std::string NetworkErrorString(int err)
 674 {
 675     char buf[256];
 676     buf[0] = 0;
 677     /* Too bad there are two incompatible implementations of the
 678      * thread-safe strerror. */
 679     const char *s;
 680 #ifdef STRERROR_R_CHAR_P /* GNU variant can return a pointer outside the passed buffer */
 681     s = strerror_r(err, buf, sizeof(buf));
 682 #else /* POSIX variant always returns message in buffer */
 683     s = buf;
 684     if (strerror_r(err, buf, sizeof(buf)))
 685         buf[0] = 0;
 686 #endif
 687     return strprintf("%s (%d)", s, err);
 688 }
 689 #endif
 690
 691 bool CloseSocket(SOCKET& hSocket)
 692 {
 693     if (hSocket == INVALID_SOCKET)
 694         return false;
 695 #ifdef WIN32
 696     int ret = closesocket(hSocket);
 697 #else
 698     int ret = close(hSocket);
 699 #endif
 700     hSocket = INVALID_SOCKET;
 701     return ret != SOCKET_ERROR;
 702 }
 703
 704 bool SetSocketNonBlocking(SOCKET& hSocket, bool fNonBlocking)
 705 {
 706     if (fNonBlocking) {
 707 #ifdef WIN32
 708         u_long nOne = 1;
 709         if (ioctlsocket(hSocket, FIONBIO, &nOne) == SOCKET_ERROR) {
 710 #else
 711         int fFlags = fcntl(hSocket, F_GETFL, 0);
 712         if (fcntl(hSocket, F_SETFL, fFlags | O_NONBLOCK) == SOCKET_ERROR) {
 713 #endif
 714             CloseSocket(hSocket);
 715             return false;
 716         }
 717     } else {
 718 #ifdef WIN32
 719         u_long nZero = 0;
 720         if (ioctlsocket(hSocket, FIONBIO, &nZero) == SOCKET_ERROR) {
 721 #else
 722         int fFlags = fcntl(hSocket, F_GETFL, 0);
 723         if (fcntl(hSocket, F_SETFL, fFlags & ~O_NONBLOCK) == SOCKET_ERROR) {
 724 #endif
 725             CloseSocket(hSocket);
 726             return false;
 727         }
 728     }
 729
 730     return true;
 731 }
 732
 733 bool SetSocketNoDelay(SOCKET& hSocket)
 734 {
 735     int set = 1;
 736     int rc = setsockopt(hSocket, IPPROTO_TCP, TCP_NODELAY, (const char*)&set, sizeof(int));
 737     return rc == 0;
 738 }
 739
 740 void InterruptSocks5(bool interrupt)
 741 {
 742     interruptSocks5Recv = interrupt;
 743 }