src/netbase.cpp

   1 // Copyright (c) 2009-2010 Satoshi Nakamoto
   2 // Copyright (c) 2009-2015 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 #ifdef HAVE_GETADDRINFO_A
  20 #include <netdb.h>
  21 #endif
  22
  23 #ifndef WIN32
  24 #if HAVE_INET_PTON
  25 #include <arpa/inet.h>
  26 #endif
  27 #include <fcntl.h>
  28 #endif
  29
  30 #include <boost/algorithm/string/case_conv.hpp> // for to_lower()
  31 #include <boost/algorithm/string/predicate.hpp> // for startswith() and endswith()
  32 #include <boost/thread.hpp>
  33
  34 #if !defined(HAVE_MSG_NOSIGNAL) && !defined(MSG_NOSIGNAL)
  35 #define MSG_NOSIGNAL 0
  36 #endif
  37
  38 // Settings
  39 static proxyType proxyInfo[NET_MAX];
  40 static proxyType nameProxy;
  41 static CCriticalSection cs_proxyInfos;
  42 int nConnectTimeout = DEFAULT_CONNECT_TIMEOUT;
  43 bool fNameLookup = DEFAULT_NAME_LOOKUP;
  44
  45 // Need ample time for negotiation for very slow proxies such as Tor (milliseconds)
  46 static const int SOCKS5_RECV_TIMEOUT = 20 * 1000;
  47
  48 enum Network ParseNetwork(std::string net) {
  49     boost::to_lower(net);
  50     if (net == "ipv4") return NET_IPV4;
  51     if (net == "ipv6") return NET_IPV6;
  52     if (net == "tor" || net == "onion")  return NET_TOR;
  53     return NET_UNROUTABLE;
  54 }
  55
  56 std::string GetNetworkName(enum Network net) {
  57     switch(net)
  58     {
  59     case NET_IPV4: return "ipv4";
  60     case NET_IPV6: return "ipv6";
  61     case NET_TOR: return "onion";
  62     default: return "";
  63     }
  64 }
  65
  66 void SplitHostPort(std::string in, int &portOut, std::string &hostOut) {
  67     size_t colon = in.find_last_of(':');
  68     // if a : is found, and it either follows a [...], or no other : is in the string, treat it as port separator
  69     bool fHaveColon = colon != in.npos;
  70     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
  71     bool fMultiColon = fHaveColon && (in.find_last_of(':',colon-1) != in.npos);
  72     if (fHaveColon && (colon==0 || fBracketed || !fMultiColon)) {
  73         int32_t n;
  74         if (ParseInt32(in.substr(colon + 1), &n) && n > 0 && n < 0x10000) {
  75             in = in.substr(0, colon);
  76             portOut = n;
  77         }
  78     }
  79     if (in.size()>0 && in[0] == '[' && in[in.size()-1] == ']')
  80         hostOut = in.substr(1, in.size()-2);
  81     else
  82         hostOut = in;
  83 }
  84
  85 bool static LookupIntern(const char *pszName, std::vector<CNetAddr>& vIP, unsigned int nMaxSolutions, bool fAllowLookup)
  86 {
  87     vIP.clear();
  88
  89     {
  90         CNetAddr addr;
  91         if (addr.SetSpecial(std::string(pszName))) {
  92             vIP.push_back(addr);
  93             return true;
  94         }
  95     }
  96
  97     struct addrinfo aiHint;
  98     memset(&aiHint, 0, sizeof(struct addrinfo));
  99
 100     aiHint.ai_socktype = SOCK_STREAM;
 101     aiHint.ai_protocol = IPPROTO_TCP;
 102     aiHint.ai_family = AF_UNSPEC;
 103 #ifdef WIN32
 104     aiHint.ai_flags = fAllowLookup ? 0 : AI_NUMERICHOST;
 105 #else
 106     aiHint.ai_flags = fAllowLookup ? AI_ADDRCONFIG : AI_NUMERICHOST;
 107 #endif
 108     struct addrinfo *aiRes = NULL;
 109     int nErr = getaddrinfo(pszName, NULL, &aiHint, &aiRes);
 110     if (nErr)
 111         return false;
 112
 113     struct addrinfo *aiTrav = aiRes;
 114     while (aiTrav != NULL && (nMaxSolutions == 0 || vIP.size() < nMaxSolutions))
 115     {
 116         if (aiTrav->ai_family == AF_INET)
 117         {
 118             assert(aiTrav->ai_addrlen >= sizeof(sockaddr_in));
 119             vIP.push_back(CNetAddr(((struct sockaddr_in*)(aiTrav->ai_addr))->sin_addr));
 120         }
 121
 122         if (aiTrav->ai_family == AF_INET6)
 123         {
 124             assert(aiTrav->ai_addrlen >= sizeof(sockaddr_in6));
 125             struct sockaddr_in6* s6 = (struct sockaddr_in6*) aiTrav->ai_addr;
 126             vIP.push_back(CNetAddr(s6->sin6_addr, s6->sin6_scope_id));
 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 /**
 207  * Read bytes from socket. This will either read the full number of bytes requested
 208  * or return False on error or timeout.
 209  * This function can be interrupted by boost thread interrupt.
 210  *
 211  * @param data Buffer to receive into
 212  * @param len  Length of data to receive
 213  * @param timeout  Timeout in milliseconds for receive operation
 214  *
 215  * @note This function requires that hSocket is in non-blocking mode.
 216  */
 217 bool static InterruptibleRecv(char* data, size_t len, int timeout, SOCKET& hSocket)
 218 {
 219     int64_t curTime = GetTimeMillis();
 220     int64_t endTime = curTime + timeout;
 221     // Maximum time to wait in one select call. It will take up until this time (in millis)
 222     // to break off in case of an interruption.
 223     const int64_t maxWait = 1000;
 224     while (len > 0 && curTime < endTime) {
 225         ssize_t ret = recv(hSocket, data, len, 0); // Optimistically try the recv first
 226         if (ret > 0) {
 227             len -= ret;
 228             data += ret;
 229         } else if (ret == 0) { // Unexpected disconnection
 230             return false;
 231         } else { // Other error or blocking
 232             int nErr = WSAGetLastError();
 233             if (nErr == WSAEINPROGRESS || nErr == WSAEWOULDBLOCK || nErr == WSAEINVAL) {
 234                 if (!IsSelectableSocket(hSocket)) {
 235                     return false;
 236                 }
 237                 struct timeval tval = MillisToTimeval(std::min(endTime - curTime, maxWait));
 238                 fd_set fdset;
 239                 FD_ZERO(&fdset);
 240                 FD_SET(hSocket, &fdset);
 241                 int nRet = select(hSocket + 1, &fdset, NULL, NULL, &tval);
 242                 if (nRet == SOCKET_ERROR) {
 243                     return false;
 244                 }
 245             } else {
 246                 return false;
 247             }
 248         }
 249         boost::this_thread::interruption_point();
 250         curTime = GetTimeMillis();
 251     }
 252     return len == 0;
 253 }
 254
 255 struct ProxyCredentials
 256 {
 257     std::string username;
 258     std::string password;
 259 };
 260
 261 std::string Socks5ErrorString(int err)
 262 {
 263     switch(err) {
 264         case 0x01: return "general failure";
 265         case 0x02: return "connection not allowed";
 266         case 0x03: return "network unreachable";
 267         case 0x04: return "host unreachable";
 268         case 0x05: return "connection refused";
 269         case 0x06: return "TTL expired";
 270         case 0x07: return "protocol error";
 271         case 0x08: return "address type not supported";
 272         default:   return "unknown";
 273     }
 274 }
 275
 276 /** Connect using SOCKS5 (as described in RFC1928) */
 277 static bool Socks5(const std::string& strDest, int port, const ProxyCredentials *auth, SOCKET& hSocket)
 278 {
 279     LogPrint("net", "SOCKS5 connecting %s\n", strDest);
 280     if (strDest.size() > 255) {
 281         CloseSocket(hSocket);
 282         return error("Hostname too long");
 283     }
 284     // Accepted authentication methods
 285     std::vector<uint8_t> vSocks5Init;
 286     vSocks5Init.push_back(0x05);
 287     if (auth) {
 288         vSocks5Init.push_back(0x02); // # METHODS
 289         vSocks5Init.push_back(0x00); // X'00' NO AUTHENTICATION REQUIRED
 290         vSocks5Init.push_back(0x02); // X'02' USERNAME/PASSWORD (RFC1929)
 291     } else {
 292         vSocks5Init.push_back(0x01); // # METHODS
 293         vSocks5Init.push_back(0x00); // X'00' NO AUTHENTICATION REQUIRED
 294     }
 295     ssize_t ret = send(hSocket, (const char*)begin_ptr(vSocks5Init), vSocks5Init.size(), MSG_NOSIGNAL);
 296     if (ret != (ssize_t)vSocks5Init.size()) {
 297         CloseSocket(hSocket);
 298         return error("Error sending to proxy");
 299     }
 300     char pchRet1[2];
 301     if (!InterruptibleRecv(pchRet1, 2, SOCKS5_RECV_TIMEOUT, hSocket)) {
 302         CloseSocket(hSocket);
 303         LogPrintf("Socks5() connect to %s:%d failed: InterruptibleRecv() timeout or other failure\n", strDest, port);
 304         return false;
 305     }
 306     if (pchRet1[0] != 0x05) {
 307         CloseSocket(hSocket);
 308         return error("Proxy failed to initialize");
 309     }
 310     if (pchRet1[1] == 0x02 && auth) {
 311         // Perform username/password authentication (as described in RFC1929)
 312         std::vector<uint8_t> vAuth;
 313         vAuth.push_back(0x01);
 314         if (auth->username.size() > 255 || auth->password.size() > 255)
 315             return error("Proxy username or password too long");
 316         vAuth.push_back(auth->username.size());
 317         vAuth.insert(vAuth.end(), auth->username.begin(), auth->username.end());
 318         vAuth.push_back(auth->password.size());
 319         vAuth.insert(vAuth.end(), auth->password.begin(), auth->password.end());
 320         ret = send(hSocket, (const char*)begin_ptr(vAuth), vAuth.size(), MSG_NOSIGNAL);
 321         if (ret != (ssize_t)vAuth.size()) {
 322             CloseSocket(hSocket);
 323             return error("Error sending authentication to proxy");
 324         }
 325         LogPrint("proxy", "SOCKS5 sending proxy authentication %s:%s\n", auth->username, auth->password);
 326         char pchRetA[2];
 327         if (!InterruptibleRecv(pchRetA, 2, SOCKS5_RECV_TIMEOUT, hSocket)) {
 328             CloseSocket(hSocket);
 329             return error("Error reading proxy authentication response");
 330         }
 331         if (pchRetA[0] != 0x01 || pchRetA[1] != 0x00) {
 332             CloseSocket(hSocket);
 333             return error("Proxy authentication unsuccessful");
 334         }
 335     } else if (pchRet1[1] == 0x00) {
 336         // Perform no authentication
 337     } else {
 338         CloseSocket(hSocket);
 339         return error("Proxy requested wrong authentication method %02x", pchRet1[1]);
 340     }
 341     std::vector<uint8_t> vSocks5;
 342     vSocks5.push_back(0x05); // VER protocol version
 343     vSocks5.push_back(0x01); // CMD CONNECT
 344     vSocks5.push_back(0x00); // RSV Reserved
 345     vSocks5.push_back(0x03); // ATYP DOMAINNAME
 346     vSocks5.push_back(strDest.size()); // Length<=255 is checked at beginning of function
 347     vSocks5.insert(vSocks5.end(), strDest.begin(), strDest.end());
 348     vSocks5.push_back((port >> 8) & 0xFF);
 349     vSocks5.push_back((port >> 0) & 0xFF);
 350     ret = send(hSocket, (const char*)begin_ptr(vSocks5), vSocks5.size(), MSG_NOSIGNAL);
 351     if (ret != (ssize_t)vSocks5.size()) {
 352         CloseSocket(hSocket);
 353         return error("Error sending to proxy");
 354     }
 355     char pchRet2[4];
 356     if (!InterruptibleRecv(pchRet2, 4, SOCKS5_RECV_TIMEOUT, hSocket)) {
 357         CloseSocket(hSocket);
 358         return error("Error reading proxy response");
 359     }
 360     if (pchRet2[0] != 0x05) {
 361         CloseSocket(hSocket);
 362         return error("Proxy failed to accept request");
 363     }
 364     if (pchRet2[1] != 0x00) {
 365         // Failures to connect to a peer that are not proxy errors
 366         CloseSocket(hSocket);
 367         LogPrintf("Socks5() connect to %s:%d failed: %s\n", strDest, port, Socks5ErrorString(pchRet2[1]));
 368         return false;
 369     }
 370     if (pchRet2[2] != 0x00) {
 371         CloseSocket(hSocket);
 372         return error("Error: malformed proxy response");
 373     }
 374     char pchRet3[256];
 375     switch (pchRet2[3])
 376     {
 377         case 0x01: ret = InterruptibleRecv(pchRet3, 4, SOCKS5_RECV_TIMEOUT, hSocket); break;
 378         case 0x04: ret = InterruptibleRecv(pchRet3, 16, SOCKS5_RECV_TIMEOUT, hSocket); break;
 379         case 0x03:
 380         {
 381             ret = InterruptibleRecv(pchRet3, 1, SOCKS5_RECV_TIMEOUT, hSocket);
 382             if (!ret) {
 383                 CloseSocket(hSocket);
 384                 return error("Error reading from proxy");
 385             }
 386             int nRecv = pchRet3[0];
 387             ret = InterruptibleRecv(pchRet3, nRecv, SOCKS5_RECV_TIMEOUT, hSocket);
 388             break;
 389         }
 390         default: CloseSocket(hSocket); return error("Error: malformed proxy response");
 391     }
 392     if (!ret) {
 393         CloseSocket(hSocket);
 394         return error("Error reading from proxy");
 395     }
 396     if (!InterruptibleRecv(pchRet3, 2, SOCKS5_RECV_TIMEOUT, hSocket)) {
 397         CloseSocket(hSocket);
 398         return error("Error reading from proxy");
 399     }
 400     LogPrint("net", "SOCKS5 connected %s\n", strDest);
 401     return true;
 402 }
 403
 404 bool static ConnectSocketDirectly(const CService &addrConnect, SOCKET& hSocketRet, int nTimeout)
 405 {
 406     hSocketRet = INVALID_SOCKET;
 407
 408     struct sockaddr_storage sockaddr;
 409     socklen_t len = sizeof(sockaddr);
 410     if (!addrConnect.GetSockAddr((struct sockaddr*)&sockaddr, &len)) {
 411         LogPrintf("Cannot connect to %s: unsupported network\n", addrConnect.ToString());
 412         return false;
 413     }
 414
 415     SOCKET hSocket = socket(((struct sockaddr*)&sockaddr)->sa_family, SOCK_STREAM, IPPROTO_TCP);
 416     if (hSocket == INVALID_SOCKET)
 417         return false;
 418
 419     int set = 1;
 420 #ifdef SO_NOSIGPIPE
 421     // Different way of disabling SIGPIPE on BSD
 422     setsockopt(hSocket, SOL_SOCKET, SO_NOSIGPIPE, (void*)&set, sizeof(int));
 423 #endif
 424
 425     //Disable Nagle's algorithm
 426 #ifdef WIN32
 427     setsockopt(hSocket, IPPROTO_TCP, TCP_NODELAY, (const char*)&set, sizeof(int));
 428 #else
 429     setsockopt(hSocket, IPPROTO_TCP, TCP_NODELAY, (void*)&set, sizeof(int));
 430 #endif
 431
 432     // Set to non-blocking
 433     if (!SetSocketNonBlocking(hSocket, true))
 434         return error("ConnectSocketDirectly: Setting socket to non-blocking failed, error %s\n", NetworkErrorString(WSAGetLastError()));
 435
 436     if (connect(hSocket, (struct sockaddr*)&sockaddr, len) == SOCKET_ERROR)
 437     {
 438         int nErr = WSAGetLastError();
 439         // WSAEINVAL is here because some legacy version of winsock uses it
 440         if (nErr == WSAEINPROGRESS || nErr == WSAEWOULDBLOCK || nErr == WSAEINVAL)
 441         {
 442             struct timeval timeout = MillisToTimeval(nTimeout);
 443             fd_set fdset;
 444             FD_ZERO(&fdset);
 445             FD_SET(hSocket, &fdset);
 446             int nRet = select(hSocket + 1, NULL, &fdset, NULL, &timeout);
 447             if (nRet == 0)
 448             {
 449                 LogPrint("net", "connection to %s timeout\n", addrConnect.ToString());
 450                 CloseSocket(hSocket);
 451                 return false;
 452             }
 453             if (nRet == SOCKET_ERROR)
 454             {
 455                 LogPrintf("select() for %s failed: %s\n", addrConnect.ToString(), NetworkErrorString(WSAGetLastError()));
 456                 CloseSocket(hSocket);
 457                 return false;
 458             }
 459             socklen_t nRetSize = sizeof(nRet);
 460 #ifdef WIN32
 461             if (getsockopt(hSocket, SOL_SOCKET, SO_ERROR, (char*)(&nRet), &nRetSize) == SOCKET_ERROR)
 462 #else
 463             if (getsockopt(hSocket, SOL_SOCKET, SO_ERROR, &nRet, &nRetSize) == SOCKET_ERROR)
 464 #endif
 465             {
 466                 LogPrintf("getsockopt() for %s failed: %s\n", addrConnect.ToString(), NetworkErrorString(WSAGetLastError()));
 467                 CloseSocket(hSocket);
 468                 return false;
 469             }
 470             if (nRet != 0)
 471             {
 472                 LogPrintf("connect() to %s failed after select(): %s\n", addrConnect.ToString(), NetworkErrorString(nRet));
 473                 CloseSocket(hSocket);
 474                 return false;
 475             }
 476         }
 477 #ifdef WIN32
 478         else if (WSAGetLastError() != WSAEISCONN)
 479 #else
 480         else
 481 #endif
 482         {
 483             LogPrintf("connect() to %s failed: %s\n", addrConnect.ToString(), NetworkErrorString(WSAGetLastError()));
 484             CloseSocket(hSocket);
 485             return false;
 486         }
 487     }
 488
 489     hSocketRet = hSocket;
 490     return true;
 491 }
 492
 493 bool SetProxy(enum Network net, const proxyType &addrProxy) {
 494     assert(net >= 0 && net < NET_MAX);
 495     if (!addrProxy.IsValid())
 496         return false;
 497     LOCK(cs_proxyInfos);
 498     proxyInfo[net] = addrProxy;
 499     return true;
 500 }
 501
 502 bool GetProxy(enum Network net, proxyType &proxyInfoOut) {
 503     assert(net >= 0 && net < NET_MAX);
 504     LOCK(cs_proxyInfos);
 505     if (!proxyInfo[net].IsValid())
 506         return false;
 507     proxyInfoOut = proxyInfo[net];
 508     return true;
 509 }
 510
 511 bool SetNameProxy(const proxyType &addrProxy) {
 512     if (!addrProxy.IsValid())
 513         return false;
 514     LOCK(cs_proxyInfos);
 515     nameProxy = addrProxy;
 516     return true;
 517 }
 518
 519 bool GetNameProxy(proxyType &nameProxyOut) {
 520     LOCK(cs_proxyInfos);
 521     if(!nameProxy.IsValid())
 522         return false;
 523     nameProxyOut = nameProxy;
 524     return true;
 525 }
 526
 527 bool HaveNameProxy() {
 528     LOCK(cs_proxyInfos);
 529     return nameProxy.IsValid();
 530 }
 531
 532 bool IsProxy(const CNetAddr &addr) {
 533     LOCK(cs_proxyInfos);
 534     for (int i = 0; i < NET_MAX; i++) {
 535         if (addr == (CNetAddr)proxyInfo[i].proxy)
 536             return true;
 537     }
 538     return false;
 539 }
 540
 541 static bool ConnectThroughProxy(const proxyType &proxy, const std::string& strDest, int port, SOCKET& hSocketRet, int nTimeout, bool *outProxyConnectionFailed)
 542 {
 543     SOCKET hSocket = INVALID_SOCKET;
 544     // first connect to proxy server
 545     if (!ConnectSocketDirectly(proxy.proxy, hSocket, nTimeout)) {
 546         if (outProxyConnectionFailed)
 547             *outProxyConnectionFailed = true;
 548         return false;
 549     }
 550     // do socks negotiation
 551     if (proxy.randomize_credentials) {
 552         ProxyCredentials random_auth;
 553         static std::atomic_int counter;
 554         random_auth.username = random_auth.password = strprintf("%i", counter++);
 555         if (!Socks5(strDest, (unsigned short)port, &random_auth, hSocket))
 556             return false;
 557     } else {
 558         if (!Socks5(strDest, (unsigned short)port, 0, hSocket))
 559             return false;
 560     }
 561
 562     hSocketRet = hSocket;
 563     return true;
 564 }
 565
 566 bool ConnectSocket(const CService &addrDest, SOCKET& hSocketRet, int nTimeout, bool *outProxyConnectionFailed)
 567 {
 568     proxyType proxy;
 569     if (outProxyConnectionFailed)
 570         *outProxyConnectionFailed = false;
 571
 572     if (GetProxy(addrDest.GetNetwork(), proxy))
 573         return ConnectThroughProxy(proxy, addrDest.ToStringIP(), addrDest.GetPort(), hSocketRet, nTimeout, outProxyConnectionFailed);
 574     else // no proxy needed (none set for target network)
 575         return ConnectSocketDirectly(addrDest, hSocketRet, nTimeout);
 576 }
 577
 578 bool ConnectSocketByName(CService &addr, SOCKET& hSocketRet, const char *pszDest, int portDefault, int nTimeout, bool *outProxyConnectionFailed)
 579 {
 580     std::string strDest;
 581     int port = portDefault;
 582
 583     if (outProxyConnectionFailed)
 584         *outProxyConnectionFailed = false;
 585
 586     SplitHostPort(std::string(pszDest), port, strDest);
 587
 588     proxyType proxy;
 589     GetNameProxy(proxy);
 590
 591     std::vector<CService> addrResolved;
 592     if (Lookup(strDest.c_str(), addrResolved, port, fNameLookup && !HaveNameProxy(), 256)) {
 593         if (addrResolved.size() > 0) {
 594             addr = addrResolved[GetRand(addrResolved.size())];
 595             return ConnectSocket(addr, hSocketRet, nTimeout);
 596         }
 597     }
 598
 599     addr = CService();
 600
 601     if (!HaveNameProxy())
 602         return false;
 603     return ConnectThroughProxy(proxy, strDest, port, hSocketRet, nTimeout, outProxyConnectionFailed);
 604 }
 605
 606 bool LookupSubNet(const char* pszName, CSubNet& ret)
 607 {
 608     std::string strSubnet(pszName);
 609     size_t slash = strSubnet.find_last_of('/');
 610     std::vector<CNetAddr> vIP;
 611
 612     std::string strAddress = strSubnet.substr(0, slash);
 613     if (LookupHost(strAddress.c_str(), vIP, 1, false))
 614     {
 615         CNetAddr network = vIP[0];
 616         if (slash != strSubnet.npos)
 617         {
 618             std::string strNetmask = strSubnet.substr(slash + 1);
 619             int32_t n;
 620             // IPv4 addresses start at offset 12, and first 12 bytes must match, so just offset n
 621             if (ParseInt32(strNetmask, &n)) { // If valid number, assume /24 syntax
 622                 ret = CSubNet(network, n);
 623                 return ret.IsValid();
 624             }
 625             else // If not a valid number, try full netmask syntax
 626             {
 627                 // Never allow lookup for netmask
 628                 if (LookupHost(strNetmask.c_str(), vIP, 1, false)) {
 629                     ret = CSubNet(network, vIP[0]);
 630                     return ret.IsValid();
 631                 }
 632             }
 633         }
 634         else
 635         {
 636             ret = CSubNet(network);
 637             return ret.IsValid();
 638         }
 639     }
 640     return false;
 641 }
 642
 643 #ifdef WIN32
 644 std::string NetworkErrorString(int err)
 645 {
 646     char buf[256];
 647     buf[0] = 0;
 648     if(FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_MAX_WIDTH_MASK,
 649             NULL, err, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
 650             buf, sizeof(buf), NULL))
 651     {
 652         return strprintf("%s (%d)", buf, err);
 653     }
 654     else
 655     {
 656         return strprintf("Unknown error (%d)", err);
 657     }
 658 }
 659 #else
 660 std::string NetworkErrorString(int err)
 661 {
 662     char buf[256];
 663     const char *s = buf;
 664     buf[0] = 0;
 665     /* Too bad there are two incompatible implementations of the
 666      * thread-safe strerror. */
 667 #ifdef STRERROR_R_CHAR_P /* GNU variant can return a pointer outside the passed buffer */
 668     s = strerror_r(err, buf, sizeof(buf));
 669 #else /* POSIX variant always returns message in buffer */
 670     if (strerror_r(err, buf, sizeof(buf)))
 671         buf[0] = 0;
 672 #endif
 673     return strprintf("%s (%d)", s, err);
 674 }
 675 #endif
 676
 677 bool CloseSocket(SOCKET& hSocket)
 678 {
 679     if (hSocket == INVALID_SOCKET)
 680         return false;
 681 #ifdef WIN32
 682     int ret = closesocket(hSocket);
 683 #else
 684     int ret = close(hSocket);
 685 #endif
 686     hSocket = INVALID_SOCKET;
 687     return ret != SOCKET_ERROR;
 688 }
 689
 690 bool SetSocketNonBlocking(SOCKET& hSocket, bool fNonBlocking)
 691 {
 692     if (fNonBlocking) {
 693 #ifdef WIN32
 694         u_long nOne = 1;
 695         if (ioctlsocket(hSocket, FIONBIO, &nOne) == SOCKET_ERROR) {
 696 #else
 697         int fFlags = fcntl(hSocket, F_GETFL, 0);
 698         if (fcntl(hSocket, F_SETFL, fFlags | O_NONBLOCK) == SOCKET_ERROR) {
 699 #endif
 700             CloseSocket(hSocket);
 701             return false;
 702         }
 703     } else {
 704 #ifdef WIN32
 705         u_long nZero = 0;
 706         if (ioctlsocket(hSocket, FIONBIO, &nZero) == SOCKET_ERROR) {
 707 #else
 708         int fFlags = fcntl(hSocket, F_GETFL, 0);
 709         if (fcntl(hSocket, F_SETFL, fFlags & ~O_NONBLOCK) == SOCKET_ERROR) {
 710 #endif
 711             CloseSocket(hSocket);
 712             return false;
 713         }
 714     }
 715
 716     return true;
 717 }