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