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 #ifdef HAVE_GETADDRINFO_A
  98     struct in_addr ipv4_addr;
  99 #ifdef HAVE_INET_PTON
 100     if (inet_pton(AF_INET, pszName, &ipv4_addr) > 0) {
 101         vIP.push_back(CNetAddr(ipv4_addr));
 102         return true;
 103     }
 104
 105     struct in6_addr ipv6_addr;
 106     if (inet_pton(AF_INET6, pszName, &ipv6_addr) > 0) {
 107         vIP.push_back(CNetAddr(ipv6_addr));
 108         return true;
 109     }
 110 #else
 111     ipv4_addr.s_addr = inet_addr(pszName);
 112     if (ipv4_addr.s_addr != INADDR_NONE) {
 113         vIP.push_back(CNetAddr(ipv4_addr));
 114         return true;
 115     }
 116 #endif
 117 #endif
 118
 119     struct addrinfo aiHint;
 120     memset(&aiHint, 0, sizeof(struct addrinfo));
 121     aiHint.ai_socktype = SOCK_STREAM;
 122     aiHint.ai_protocol = IPPROTO_TCP;
 123     aiHint.ai_family = AF_UNSPEC;
 124 #ifdef WIN32
 125     aiHint.ai_flags = fAllowLookup ? 0 : AI_NUMERICHOST;
 126 #else
 127     aiHint.ai_flags = fAllowLookup ? AI_ADDRCONFIG : AI_NUMERICHOST;
 128 #endif
 129
 130     struct addrinfo *aiRes = NULL;
 131 #ifdef HAVE_GETADDRINFO_A
 132     struct gaicb gcb, *query = &gcb;
 133     memset(query, 0, sizeof(struct gaicb));
 134     gcb.ar_name = pszName;
 135     gcb.ar_request = &aiHint;
 136     int nErr = getaddrinfo_a(GAI_NOWAIT, &query, 1, NULL);
 137     if (nErr)
 138         return false;
 139
 140     do {
 141         // Should set the timeout limit to a reasonable value to avoid
 142         // generating unnecessary checking call during the polling loop,
 143         // while it can still response to stop request quick enough.
 144         // 2 seconds looks fine in our situation.
 145         struct timespec ts = { 2, 0 };
 146         gai_suspend(&query, 1, &ts);
 147         boost::this_thread::interruption_point();
 148
 149         nErr = gai_error(query);
 150         if (0 == nErr)
 151             aiRes = query->ar_result;
 152     } while (nErr == EAI_INPROGRESS);
 153 #else
 154     int nErr = getaddrinfo(pszName, NULL, &aiHint, &aiRes);
 155 #endif
 156     if (nErr)
 157         return false;
 158
 159     struct addrinfo *aiTrav = aiRes;
 160     while (aiTrav != NULL && (nMaxSolutions == 0 || vIP.size() < nMaxSolutions))
 161     {
 162         if (aiTrav->ai_family == AF_INET)
 163         {
 164             assert(aiTrav->ai_addrlen >= sizeof(sockaddr_in));
 165             vIP.push_back(CNetAddr(((struct sockaddr_in*)(aiTrav->ai_addr))->sin_addr));
 166         }
 167
 168         if (aiTrav->ai_family == AF_INET6)
 169         {
 170             assert(aiTrav->ai_addrlen >= sizeof(sockaddr_in6));
 171             struct sockaddr_in6* s6 = (struct sockaddr_in6*) aiTrav->ai_addr;
 172             vIP.push_back(CNetAddr(s6->sin6_addr, s6->sin6_scope_id));
 173         }
 174
 175         aiTrav = aiTrav->ai_next;
 176     }
 177
 178     freeaddrinfo(aiRes);
 179
 180     return (vIP.size() > 0);
 181 }
 182
 183 bool LookupHost(const char *pszName, std::vector<CNetAddr>& vIP, unsigned int nMaxSolutions, bool fAllowLookup)
 184 {
 185     std::string strHost(pszName);
 186     if (strHost.empty())
 187         return false;
 188     if (boost::algorithm::starts_with(strHost, "[") && boost::algorithm::ends_with(strHost, "]"))
 189     {
 190         strHost = strHost.substr(1, strHost.size() - 2);
 191     }
 192
 193     return LookupIntern(strHost.c_str(), vIP, nMaxSolutions, fAllowLookup);
 194 }
 195
 196 bool LookupHost(const char *pszName, CNetAddr& addr, bool fAllowLookup)
 197 {
 198     std::vector<CNetAddr> vIP;
 199     LookupHost(pszName, vIP, 1, fAllowLookup);
 200     if(vIP.empty())
 201         return false;
 202     addr = vIP.front();
 203     return true;
 204 }
 205
 206 bool Lookup(const char *pszName, std::vector<CService>& vAddr, int portDefault, bool fAllowLookup, unsigned int nMaxSolutions)
 207 {
 208     if (pszName[0] == 0)
 209         return false;
 210     int port = portDefault;
 211     std::string hostname = "";
 212     SplitHostPort(std::string(pszName), port, hostname);
 213
 214     std::vector<CNetAddr> vIP;
 215     bool fRet = LookupIntern(hostname.c_str(), vIP, nMaxSolutions, fAllowLookup);
 216     if (!fRet)
 217         return false;
 218     vAddr.resize(vIP.size());
 219     for (unsigned int i = 0; i < vIP.size(); i++)
 220         vAddr[i] = CService(vIP[i], port);
 221     return true;
 222 }
 223
 224 bool Lookup(const char *pszName, CService& addr, int portDefault, bool fAllowLookup)
 225 {
 226     std::vector<CService> vService;
 227     bool fRet = Lookup(pszName, vService, portDefault, fAllowLookup, 1);
 228     if (!fRet)
 229         return false;
 230     addr = vService[0];
 231     return true;
 232 }
 233
 234 CService LookupNumeric(const char *pszName, int portDefault)
 235 {
 236     CService addr;
 237     // "1.2:345" will fail to resolve the ip, but will still set the port.
 238     // If the ip fails to resolve, re-init the result.
 239     if(!Lookup(pszName, addr, portDefault, false))
 240         addr = CService();
 241     return addr;
 242 }
 243
 244 struct timeval MillisToTimeval(int64_t nTimeout)
 245 {
 246     struct timeval timeout;
 247     timeout.tv_sec  = nTimeout / 1000;
 248     timeout.tv_usec = (nTimeout % 1000) * 1000;
 249     return timeout;
 250 }
 251
 252 /**
 253  * Read bytes from socket. This will either read the full number of bytes requested
 254  * or return False on error or timeout.
 255  * This function can be interrupted by boost thread interrupt.
 256  *
 257  * @param data Buffer to receive into
 258  * @param len  Length of data to receive
 259  * @param timeout  Timeout in milliseconds for receive operation
 260  *
 261  * @note This function requires that hSocket is in non-blocking mode.
 262  */
 263 bool static InterruptibleRecv(char* data, size_t len, int timeout, SOCKET& hSocket)
 264 {
 265     int64_t curTime = GetTimeMillis();
 266     int64_t endTime = curTime + timeout;
 267     // Maximum time to wait in one select call. It will take up until this time (in millis)
 268     // to break off in case of an interruption.
 269     const int64_t maxWait = 1000;
 270     while (len > 0 && curTime < endTime) {
 271         ssize_t ret = recv(hSocket, data, len, 0); // Optimistically try the recv first
 272         if (ret > 0) {
 273             len -= ret;
 274             data += ret;
 275         } else if (ret == 0) { // Unexpected disconnection
 276             return false;
 277         } else { // Other error or blocking
 278             int nErr = WSAGetLastError();
 279             if (nErr == WSAEINPROGRESS || nErr == WSAEWOULDBLOCK || nErr == WSAEINVAL) {
 280                 if (!IsSelectableSocket(hSocket)) {
 281                     return false;
 282                 }
 283                 struct timeval tval = MillisToTimeval(std::min(endTime - curTime, maxWait));
 284                 fd_set fdset;
 285                 FD_ZERO(&fdset);
 286                 FD_SET(hSocket, &fdset);
 287                 int nRet = select(hSocket + 1, &fdset, NULL, NULL, &tval);
 288                 if (nRet == SOCKET_ERROR) {
 289                     return false;
 290                 }
 291             } else {
 292                 return false;
 293             }
 294         }
 295         boost::this_thread::interruption_point();
 296         curTime = GetTimeMillis();
 297     }
 298     return len == 0;
 299 }
 300
 301 struct ProxyCredentials
 302 {
 303     std::string username;
 304     std::string password;
 305 };
 306
 307 std::string Socks5ErrorString(int err)
 308 {
 309     switch(err) {
 310         case 0x01: return "general failure";
 311         case 0x02: return "connection not allowed";
 312         case 0x03: return "network unreachable";
 313         case 0x04: return "host unreachable";
 314         case 0x05: return "connection refused";
 315         case 0x06: return "TTL expired";
 316         case 0x07: return "protocol error";
 317         case 0x08: return "address type not supported";
 318         default:   return "unknown";
 319     }
 320 }
 321
 322 /** Connect using SOCKS5 (as described in RFC1928) */
 323 static bool Socks5(const std::string& strDest, int port, const ProxyCredentials *auth, SOCKET& hSocket)
 324 {
 325     LogPrint("net", "SOCKS5 connecting %s\n", strDest);
 326     if (strDest.size() > 255) {
 327         CloseSocket(hSocket);
 328         return error("Hostname too long");
 329     }
 330     // Accepted authentication methods
 331     std::vector<uint8_t> vSocks5Init;
 332     vSocks5Init.push_back(0x05);
 333     if (auth) {
 334         vSocks5Init.push_back(0x02); // # METHODS
 335         vSocks5Init.push_back(0x00); // X'00' NO AUTHENTICATION REQUIRED
 336         vSocks5Init.push_back(0x02); // X'02' USERNAME/PASSWORD (RFC1929)
 337     } else {
 338         vSocks5Init.push_back(0x01); // # METHODS
 339         vSocks5Init.push_back(0x00); // X'00' NO AUTHENTICATION REQUIRED
 340     }
 341     ssize_t ret = send(hSocket, (const char*)begin_ptr(vSocks5Init), vSocks5Init.size(), MSG_NOSIGNAL);
 342     if (ret != (ssize_t)vSocks5Init.size()) {
 343         CloseSocket(hSocket);
 344         return error("Error sending to proxy");
 345     }
 346     char pchRet1[2];
 347     if (!InterruptibleRecv(pchRet1, 2, SOCKS5_RECV_TIMEOUT, hSocket)) {
 348         CloseSocket(hSocket);
 349         LogPrintf("Socks5() connect to %s:%d failed: InterruptibleRecv() timeout or other failure\n", strDest, port);
 350         return false;
 351     }
 352     if (pchRet1[0] != 0x05) {
 353         CloseSocket(hSocket);
 354         return error("Proxy failed to initialize");
 355     }
 356     if (pchRet1[1] == 0x02 && auth) {
 357         // Perform username/password authentication (as described in RFC1929)
 358         std::vector<uint8_t> vAuth;
 359         vAuth.push_back(0x01);
 360         if (auth->username.size() > 255 || auth->password.size() > 255)
 361             return error("Proxy username or password too long");
 362         vAuth.push_back(auth->username.size());
 363         vAuth.insert(vAuth.end(), auth->username.begin(), auth->username.end());
 364         vAuth.push_back(auth->password.size());
 365         vAuth.insert(vAuth.end(), auth->password.begin(), auth->password.end());
 366         ret = send(hSocket, (const char*)begin_ptr(vAuth), vAuth.size(), MSG_NOSIGNAL);
 367         if (ret != (ssize_t)vAuth.size()) {
 368             CloseSocket(hSocket);
 369             return error("Error sending authentication to proxy");
 370         }
 371         LogPrint("proxy", "SOCKS5 sending proxy authentication %s:%s\n", auth->username, auth->password);
 372         char pchRetA[2];
 373         if (!InterruptibleRecv(pchRetA, 2, SOCKS5_RECV_TIMEOUT, hSocket)) {
 374             CloseSocket(hSocket);
 375             return error("Error reading proxy authentication response");
 376         }
 377         if (pchRetA[0] != 0x01 || pchRetA[1] != 0x00) {
 378             CloseSocket(hSocket);
 379             return error("Proxy authentication unsuccessful");
 380         }
 381     } else if (pchRet1[1] == 0x00) {
 382         // Perform no authentication
 383     } else {
 384         CloseSocket(hSocket);
 385         return error("Proxy requested wrong authentication method %02x", pchRet1[1]);
 386     }
 387     std::vector<uint8_t> vSocks5;
 388     vSocks5.push_back(0x05); // VER protocol version
 389     vSocks5.push_back(0x01); // CMD CONNECT
 390     vSocks5.push_back(0x00); // RSV Reserved
 391     vSocks5.push_back(0x03); // ATYP DOMAINNAME
 392     vSocks5.push_back(strDest.size()); // Length<=255 is checked at beginning of function
 393     vSocks5.insert(vSocks5.end(), strDest.begin(), strDest.end());
 394     vSocks5.push_back((port >> 8) & 0xFF);
 395     vSocks5.push_back((port >> 0) & 0xFF);
 396     ret = send(hSocket, (const char*)begin_ptr(vSocks5), vSocks5.size(), MSG_NOSIGNAL);
 397     if (ret != (ssize_t)vSocks5.size()) {
 398         CloseSocket(hSocket);
 399         return error("Error sending to proxy");
 400     }
 401     char pchRet2[4];
 402     if (!InterruptibleRecv(pchRet2, 4, SOCKS5_RECV_TIMEOUT, hSocket)) {
 403         CloseSocket(hSocket);
 404         return error("Error reading proxy response");
 405     }
 406     if (pchRet2[0] != 0x05) {
 407         CloseSocket(hSocket);
 408         return error("Proxy failed to accept request");
 409     }
 410     if (pchRet2[1] != 0x00) {
 411         // Failures to connect to a peer that are not proxy errors
 412         CloseSocket(hSocket);
 413         LogPrintf("Socks5() connect to %s:%d failed: %s\n", strDest, port, Socks5ErrorString(pchRet2[1]));
 414         return false;
 415     }
 416     if (pchRet2[2] != 0x00) {
 417         CloseSocket(hSocket);
 418         return error("Error: malformed proxy response");
 419     }
 420     char pchRet3[256];
 421     switch (pchRet2[3])
 422     {
 423         case 0x01: ret = InterruptibleRecv(pchRet3, 4, SOCKS5_RECV_TIMEOUT, hSocket); break;
 424         case 0x04: ret = InterruptibleRecv(pchRet3, 16, SOCKS5_RECV_TIMEOUT, hSocket); break;
 425         case 0x03:
 426         {
 427             ret = InterruptibleRecv(pchRet3, 1, SOCKS5_RECV_TIMEOUT, hSocket);
 428             if (!ret) {
 429                 CloseSocket(hSocket);
 430                 return error("Error reading from proxy");
 431             }
 432             int nRecv = pchRet3[0];
 433             ret = InterruptibleRecv(pchRet3, nRecv, SOCKS5_RECV_TIMEOUT, hSocket);
 434             break;
 435         }
 436         default: CloseSocket(hSocket); return error("Error: malformed proxy response");
 437     }
 438     if (!ret) {
 439         CloseSocket(hSocket);
 440         return error("Error reading from proxy");
 441     }
 442     if (!InterruptibleRecv(pchRet3, 2, SOCKS5_RECV_TIMEOUT, hSocket)) {
 443         CloseSocket(hSocket);
 444         return error("Error reading from proxy");
 445     }
 446     LogPrint("net", "SOCKS5 connected %s\n", strDest);
 447     return true;
 448 }
 449
 450 bool static ConnectSocketDirectly(const CService &addrConnect, SOCKET& hSocketRet, int nTimeout)
 451 {
 452     hSocketRet = INVALID_SOCKET;
 453
 454     struct sockaddr_storage sockaddr;
 455     socklen_t len = sizeof(sockaddr);
 456     if (!addrConnect.GetSockAddr((struct sockaddr*)&sockaddr, &len)) {
 457         LogPrintf("Cannot connect to %s: unsupported network\n", addrConnect.ToString());
 458         return false;
 459     }
 460
 461     SOCKET hSocket = socket(((struct sockaddr*)&sockaddr)->sa_family, SOCK_STREAM, IPPROTO_TCP);
 462     if (hSocket == INVALID_SOCKET)
 463         return false;
 464
 465     int set = 1;
 466 #ifdef SO_NOSIGPIPE
 467     // Different way of disabling SIGPIPE on BSD
 468     setsockopt(hSocket, SOL_SOCKET, SO_NOSIGPIPE, (void*)&set, sizeof(int));
 469 #endif
 470
 471     //Disable Nagle's algorithm
 472 #ifdef WIN32
 473     setsockopt(hSocket, IPPROTO_TCP, TCP_NODELAY, (const char*)&set, sizeof(int));
 474 #else
 475     setsockopt(hSocket, IPPROTO_TCP, TCP_NODELAY, (void*)&set, sizeof(int));
 476 #endif
 477
 478     // Set to non-blocking
 479     if (!SetSocketNonBlocking(hSocket, true))
 480         return error("ConnectSocketDirectly: Setting socket to non-blocking failed, error %s\n", NetworkErrorString(WSAGetLastError()));
 481
 482     if (connect(hSocket, (struct sockaddr*)&sockaddr, len) == SOCKET_ERROR)
 483     {
 484         int nErr = WSAGetLastError();
 485         // WSAEINVAL is here because some legacy version of winsock uses it
 486         if (nErr == WSAEINPROGRESS || nErr == WSAEWOULDBLOCK || nErr == WSAEINVAL)
 487         {
 488             struct timeval timeout = MillisToTimeval(nTimeout);
 489             fd_set fdset;
 490             FD_ZERO(&fdset);
 491             FD_SET(hSocket, &fdset);
 492             int nRet = select(hSocket + 1, NULL, &fdset, NULL, &timeout);
 493             if (nRet == 0)
 494             {
 495                 LogPrint("net", "connection to %s timeout\n", addrConnect.ToString());
 496                 CloseSocket(hSocket);
 497                 return false;
 498             }
 499             if (nRet == SOCKET_ERROR)
 500             {
 501                 LogPrintf("select() for %s failed: %s\n", addrConnect.ToString(), NetworkErrorString(WSAGetLastError()));
 502                 CloseSocket(hSocket);
 503                 return false;
 504             }
 505             socklen_t nRetSize = sizeof(nRet);
 506 #ifdef WIN32
 507             if (getsockopt(hSocket, SOL_SOCKET, SO_ERROR, (char*)(&nRet), &nRetSize) == SOCKET_ERROR)
 508 #else
 509             if (getsockopt(hSocket, SOL_SOCKET, SO_ERROR, &nRet, &nRetSize) == SOCKET_ERROR)
 510 #endif
 511             {
 512                 LogPrintf("getsockopt() for %s failed: %s\n", addrConnect.ToString(), NetworkErrorString(WSAGetLastError()));
 513                 CloseSocket(hSocket);
 514                 return false;
 515             }
 516             if (nRet != 0)
 517             {
 518                 LogPrintf("connect() to %s failed after select(): %s\n", addrConnect.ToString(), NetworkErrorString(nRet));
 519                 CloseSocket(hSocket);
 520                 return false;
 521             }
 522         }
 523 #ifdef WIN32
 524         else if (WSAGetLastError() != WSAEISCONN)
 525 #else
 526         else
 527 #endif
 528         {
 529             LogPrintf("connect() to %s failed: %s\n", addrConnect.ToString(), NetworkErrorString(WSAGetLastError()));
 530             CloseSocket(hSocket);
 531             return false;
 532         }
 533     }
 534
 535     hSocketRet = hSocket;
 536     return true;
 537 }
 538
 539 bool SetProxy(enum Network net, const proxyType &addrProxy) {
 540     assert(net >= 0 && net < NET_MAX);
 541     if (!addrProxy.IsValid())
 542         return false;
 543     LOCK(cs_proxyInfos);
 544     proxyInfo[net] = addrProxy;
 545     return true;
 546 }
 547
 548 bool GetProxy(enum Network net, proxyType &proxyInfoOut) {
 549     assert(net >= 0 && net < NET_MAX);
 550     LOCK(cs_proxyInfos);
 551     if (!proxyInfo[net].IsValid())
 552         return false;
 553     proxyInfoOut = proxyInfo[net];
 554     return true;
 555 }
 556
 557 bool SetNameProxy(const proxyType &addrProxy) {
 558     if (!addrProxy.IsValid())
 559         return false;
 560     LOCK(cs_proxyInfos);
 561     nameProxy = addrProxy;
 562     return true;
 563 }
 564
 565 bool GetNameProxy(proxyType &nameProxyOut) {
 566     LOCK(cs_proxyInfos);
 567     if(!nameProxy.IsValid())
 568         return false;
 569     nameProxyOut = nameProxy;
 570     return true;
 571 }
 572
 573 bool HaveNameProxy() {
 574     LOCK(cs_proxyInfos);
 575     return nameProxy.IsValid();
 576 }
 577
 578 bool IsProxy(const CNetAddr &addr) {
 579     LOCK(cs_proxyInfos);
 580     for (int i = 0; i < NET_MAX; i++) {
 581         if (addr == (CNetAddr)proxyInfo[i].proxy)
 582             return true;
 583     }
 584     return false;
 585 }
 586
 587 static bool ConnectThroughProxy(const proxyType &proxy, const std::string& strDest, int port, SOCKET& hSocketRet, int nTimeout, bool *outProxyConnectionFailed)
 588 {
 589     SOCKET hSocket = INVALID_SOCKET;
 590     // first connect to proxy server
 591     if (!ConnectSocketDirectly(proxy.proxy, hSocket, nTimeout)) {
 592         if (outProxyConnectionFailed)
 593             *outProxyConnectionFailed = true;
 594         return false;
 595     }
 596     // do socks negotiation
 597     if (proxy.randomize_credentials) {
 598         ProxyCredentials random_auth;
 599         static std::atomic_int counter;
 600         random_auth.username = random_auth.password = strprintf("%i", counter++);
 601         if (!Socks5(strDest, (unsigned short)port, &random_auth, hSocket))
 602             return false;
 603     } else {
 604         if (!Socks5(strDest, (unsigned short)port, 0, hSocket))
 605             return false;
 606     }
 607
 608     hSocketRet = hSocket;
 609     return true;
 610 }
 611
 612 bool ConnectSocket(const CService &addrDest, SOCKET& hSocketRet, int nTimeout, bool *outProxyConnectionFailed)
 613 {
 614     proxyType proxy;
 615     if (outProxyConnectionFailed)
 616         *outProxyConnectionFailed = false;
 617
 618     if (GetProxy(addrDest.GetNetwork(), proxy))
 619         return ConnectThroughProxy(proxy, addrDest.ToStringIP(), addrDest.GetPort(), hSocketRet, nTimeout, outProxyConnectionFailed);
 620     else // no proxy needed (none set for target network)
 621         return ConnectSocketDirectly(addrDest, hSocketRet, nTimeout);
 622 }
 623
 624 bool ConnectSocketByName(CService &addr, SOCKET& hSocketRet, const char *pszDest, int portDefault, int nTimeout, bool *outProxyConnectionFailed)
 625 {
 626     std::string strDest;
 627     int port = portDefault;
 628
 629     if (outProxyConnectionFailed)
 630         *outProxyConnectionFailed = false;
 631
 632     SplitHostPort(std::string(pszDest), port, strDest);
 633
 634     proxyType proxy;
 635     GetNameProxy(proxy);
 636
 637     std::vector<CService> addrResolved;
 638     if (Lookup(strDest.c_str(), addrResolved, port, fNameLookup && !HaveNameProxy(), 256)) {
 639         if (addrResolved.size() > 0) {
 640             addr = addrResolved[GetRand(addrResolved.size())];
 641             return ConnectSocket(addr, hSocketRet, nTimeout);
 642         }
 643     }
 644
 645     addr = CService();
 646
 647     if (!HaveNameProxy())
 648         return false;
 649     return ConnectThroughProxy(proxy, strDest, port, hSocketRet, nTimeout, outProxyConnectionFailed);
 650 }
 651
 652 bool LookupSubNet(const char* pszName, CSubNet& ret)
 653 {
 654     std::string strSubnet(pszName);
 655     size_t slash = strSubnet.find_last_of('/');
 656     std::vector<CNetAddr> vIP;
 657
 658     std::string strAddress = strSubnet.substr(0, slash);
 659     if (LookupHost(strAddress.c_str(), vIP, 1, false))
 660     {
 661         CNetAddr network = vIP[0];
 662         if (slash != strSubnet.npos)
 663         {
 664             std::string strNetmask = strSubnet.substr(slash + 1);
 665             int32_t n;
 666             // IPv4 addresses start at offset 12, and first 12 bytes must match, so just offset n
 667             if (ParseInt32(strNetmask, &n)) { // If valid number, assume /24 syntax
 668                 ret = CSubNet(network, n);
 669                 return ret.IsValid();
 670             }
 671             else // If not a valid number, try full netmask syntax
 672             {
 673                 // Never allow lookup for netmask
 674                 if (LookupHost(strNetmask.c_str(), vIP, 1, false)) {
 675                     ret = CSubNet(network, vIP[0]);
 676                     return ret.IsValid();
 677                 }
 678             }
 679         }
 680         else
 681         {
 682             ret = CSubNet(network);
 683             return ret.IsValid();
 684         }
 685     }
 686     return false;
 687 }
 688
 689 #ifdef WIN32
 690 std::string NetworkErrorString(int err)
 691 {
 692     char buf[256];
 693     buf[0] = 0;
 694     if(FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_MAX_WIDTH_MASK,
 695             NULL, err, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
 696             buf, sizeof(buf), NULL))
 697     {
 698         return strprintf("%s (%d)", buf, err);
 699     }
 700     else
 701     {
 702         return strprintf("Unknown error (%d)", err);
 703     }
 704 }
 705 #else
 706 std::string NetworkErrorString(int err)
 707 {
 708     char buf[256];
 709     const char *s = buf;
 710     buf[0] = 0;
 711     /* Too bad there are two incompatible implementations of the
 712      * thread-safe strerror. */
 713 #ifdef STRERROR_R_CHAR_P /* GNU variant can return a pointer outside the passed buffer */
 714     s = strerror_r(err, buf, sizeof(buf));
 715 #else /* POSIX variant always returns message in buffer */
 716     if (strerror_r(err, buf, sizeof(buf)))
 717         buf[0] = 0;
 718 #endif
 719     return strprintf("%s (%d)", s, err);
 720 }
 721 #endif
 722
 723 bool CloseSocket(SOCKET& hSocket)
 724 {
 725     if (hSocket == INVALID_SOCKET)
 726         return false;
 727 #ifdef WIN32
 728     int ret = closesocket(hSocket);
 729 #else
 730     int ret = close(hSocket);
 731 #endif
 732     hSocket = INVALID_SOCKET;
 733     return ret != SOCKET_ERROR;
 734 }
 735
 736 bool SetSocketNonBlocking(SOCKET& hSocket, bool fNonBlocking)
 737 {
 738     if (fNonBlocking) {
 739 #ifdef WIN32
 740         u_long nOne = 1;
 741         if (ioctlsocket(hSocket, FIONBIO, &nOne) == SOCKET_ERROR) {
 742 #else
 743         int fFlags = fcntl(hSocket, F_GETFL, 0);
 744         if (fcntl(hSocket, F_SETFL, fFlags | O_NONBLOCK) == SOCKET_ERROR) {
 745 #endif
 746             CloseSocket(hSocket);
 747             return false;
 748         }
 749     } else {
 750 #ifdef WIN32
 751         u_long nZero = 0;
 752         if (ioctlsocket(hSocket, FIONBIO, &nZero) == SOCKET_ERROR) {
 753 #else
 754         int fFlags = fcntl(hSocket, F_GETFL, 0);
 755         if (fcntl(hSocket, F_SETFL, fFlags & ~O_NONBLOCK) == SOCKET_ERROR) {
 756 #endif
 757             CloseSocket(hSocket);
 758             return false;
 759         }
 760     }
 761
 762     return true;
 763 }