// Copyright (c) 2009-2010 Satoshi Nakamoto // Copyright (c) 2009-2020 The Bitcoin Core developers // Distributed under the MIT software license, see the accompanying // file COPYING or http://www.opensource.org/licenses/mit-license.php. #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifndef WIN32 #include #else #include #endif #ifdef USE_POLL #include #endif // Settings static Mutex g_proxyinfo_mutex; static proxyType proxyInfo[NET_MAX] GUARDED_BY(g_proxyinfo_mutex); static proxyType nameProxy GUARDED_BY(g_proxyinfo_mutex); int nConnectTimeout = DEFAULT_CONNECT_TIMEOUT; bool fNameLookup = DEFAULT_NAME_LOOKUP; // Need ample time for negotiation for very slow proxies such as Tor (milliseconds) int g_socks5_recv_timeout = 20 * 1000; static std::atomic interruptSocks5Recv(false); std::vector WrappedGetAddrInfo(const std::string& name, bool allow_lookup) { addrinfo ai_hint{}; // We want a TCP port, which is a streaming socket type ai_hint.ai_socktype = SOCK_STREAM; ai_hint.ai_protocol = IPPROTO_TCP; // We don't care which address family (IPv4 or IPv6) is returned ai_hint.ai_family = AF_UNSPEC; // If we allow lookups of hostnames, use the AI_ADDRCONFIG flag to only // return addresses whose family we have an address configured for. // // If we don't allow lookups, then use the AI_NUMERICHOST flag for // getaddrinfo to only decode numerical network addresses and suppress // hostname lookups. ai_hint.ai_flags = allow_lookup ? AI_ADDRCONFIG : AI_NUMERICHOST; addrinfo* ai_res{nullptr}; const int n_err{getaddrinfo(name.c_str(), nullptr, &ai_hint, &ai_res)}; if (n_err != 0) { return {}; } // Traverse the linked list starting with ai_trav. addrinfo* ai_trav{ai_res}; std::vector resolved_addresses; while (ai_trav != nullptr) { if (ai_trav->ai_family == AF_INET) { assert(ai_trav->ai_addrlen >= sizeof(sockaddr_in)); resolved_addresses.emplace_back(reinterpret_cast(ai_trav->ai_addr)->sin_addr); } if (ai_trav->ai_family == AF_INET6) { assert(ai_trav->ai_addrlen >= sizeof(sockaddr_in6)); const sockaddr_in6* s6{reinterpret_cast(ai_trav->ai_addr)}; resolved_addresses.emplace_back(s6->sin6_addr, s6->sin6_scope_id); } ai_trav = ai_trav->ai_next; } freeaddrinfo(ai_res); return resolved_addresses; } DNSLookupFn g_dns_lookup{WrappedGetAddrInfo}; enum Network ParseNetwork(const std::string& net_in) { std::string net = ToLower(net_in); if (net == "ipv4") return NET_IPV4; if (net == "ipv6") return NET_IPV6; if (net == "onion") return NET_ONION; if (net == "tor") { LogPrintf("Warning: net name 'tor' is deprecated and will be removed in the future. You should use 'onion' instead.\n"); return NET_ONION; } if (net == "i2p") { return NET_I2P; } return NET_UNROUTABLE; } std::string GetNetworkName(enum Network net) { switch (net) { case NET_UNROUTABLE: return "not_publicly_routable"; case NET_IPV4: return "ipv4"; case NET_IPV6: return "ipv6"; case NET_ONION: return "onion"; case NET_I2P: return "i2p"; case NET_CJDNS: return "cjdns"; case NET_INTERNAL: return "internal"; case NET_MAX: assert(false); } // no default case, so the compiler can warn about missing cases assert(false); } std::vector GetNetworkNames(bool append_unroutable) { std::vector names; for (int n = 0; n < NET_MAX; ++n) { const enum Network network{static_cast(n)}; if (network == NET_UNROUTABLE || network == NET_CJDNS || network == NET_INTERNAL) continue; names.emplace_back(GetNetworkName(network)); } if (append_unroutable) { names.emplace_back(GetNetworkName(NET_UNROUTABLE)); } return names; } static bool LookupIntern(const std::string& name, std::vector& vIP, unsigned int nMaxSolutions, bool fAllowLookup, DNSLookupFn dns_lookup_function) { vIP.clear(); if (!ValidAsCString(name)) { return false; } { CNetAddr addr; // From our perspective, onion addresses are not hostnames but rather // direct encodings of CNetAddr much like IPv4 dotted-decimal notation // or IPv6 colon-separated hextet notation. Since we can't use // getaddrinfo to decode them and it wouldn't make sense to resolve // them, we return a network address representing it instead. See // CNetAddr::SetSpecial(const std::string&) for more details. if (addr.SetSpecial(name)) { vIP.push_back(addr); return true; } } for (const CNetAddr& resolved : dns_lookup_function(name, fAllowLookup)) { if (nMaxSolutions > 0 && vIP.size() >= nMaxSolutions) { break; } /* Never allow resolving to an internal address. Consider any such result invalid */ if (!resolved.IsInternal()) { vIP.push_back(resolved); } } return (vIP.size() > 0); } /** * Resolve a host string to its corresponding network addresses. * * @param name The string representing a host. Could be a name or a numerical * IP address (IPv6 addresses in their bracketed form are * allowed). * @param[out] vIP The resulting network addresses to which the specified host * string resolved. * * @returns Whether or not the specified host string successfully resolved to * any resulting network addresses. * * @see Lookup(const char *, std::vector&, int, bool, unsigned int) * for additional parameter descriptions. */ bool LookupHost(const std::string& name, std::vector& vIP, unsigned int nMaxSolutions, bool fAllowLookup, DNSLookupFn dns_lookup_function) { if (!ValidAsCString(name)) { return false; } std::string strHost = name; if (strHost.empty()) return false; if (strHost.front() == '[' && strHost.back() == ']') { strHost = strHost.substr(1, strHost.size() - 2); } return LookupIntern(strHost, vIP, nMaxSolutions, fAllowLookup, dns_lookup_function); } /** * Resolve a host string to its first corresponding network address. * * @see LookupHost(const std::string&, std::vector&, unsigned int, bool) for * additional parameter descriptions. */ bool LookupHost(const std::string& name, CNetAddr& addr, bool fAllowLookup, DNSLookupFn dns_lookup_function) { if (!ValidAsCString(name)) { return false; } std::vector vIP; LookupHost(name, vIP, 1, fAllowLookup, dns_lookup_function); if(vIP.empty()) return false; addr = vIP.front(); return true; } /** * Resolve a service string to its corresponding service. * * @param name The string representing a service. Could be a name or a * numerical IP address (IPv6 addresses should be in their * disambiguated bracketed form), optionally followed by a port * number. (e.g. example.com:8333 or * [2001:db8:85a3:8d3:1319:8a2e:370:7348]:420) * @param[out] vAddr The resulting services to which the specified service string * resolved. * @param portDefault The default port for resulting services if not specified * by the service string. * @param fAllowLookup Whether or not hostname lookups are permitted. If yes, * external queries may be performed. * @param nMaxSolutions The maximum number of results we want, specifying 0 * means "as many solutions as we get." * * @returns Whether or not the service string successfully resolved to any * resulting services. */ bool Lookup(const std::string& name, std::vector& vAddr, int portDefault, bool fAllowLookup, unsigned int nMaxSolutions, DNSLookupFn dns_lookup_function) { if (name.empty() || !ValidAsCString(name)) { return false; } int port = portDefault; std::string hostname; SplitHostPort(name, port, hostname); std::vector vIP; bool fRet = LookupIntern(hostname, vIP, nMaxSolutions, fAllowLookup, dns_lookup_function); if (!fRet) return false; vAddr.resize(vIP.size()); for (unsigned int i = 0; i < vIP.size(); i++) vAddr[i] = CService(vIP[i], port); return true; } /** * Resolve a service string to its first corresponding service. * * @see Lookup(const char *, std::vector&, int, bool, unsigned int) * for additional parameter descriptions. */ bool Lookup(const std::string& name, CService& addr, int portDefault, bool fAllowLookup, DNSLookupFn dns_lookup_function) { if (!ValidAsCString(name)) { return false; } std::vector vService; bool fRet = Lookup(name, vService, portDefault, fAllowLookup, 1, dns_lookup_function); if (!fRet) return false; addr = vService[0]; return true; } /** * Resolve a service string with a numeric IP to its first corresponding * service. * * @returns The resulting CService if the resolution was successful, [::]:0 * otherwise. * * @see Lookup(const char *, CService&, int, bool) for additional parameter * descriptions. */ CService LookupNumeric(const std::string& name, int portDefault, DNSLookupFn dns_lookup_function) { if (!ValidAsCString(name)) { return {}; } CService addr; // "1.2:345" will fail to resolve the ip, but will still set the port. // If the ip fails to resolve, re-init the result. if(!Lookup(name, addr, portDefault, false, dns_lookup_function)) addr = CService(); return addr; } /** SOCKS version */ enum SOCKSVersion: uint8_t { SOCKS4 = 0x04, SOCKS5 = 0x05 }; /** Values defined for METHOD in RFC1928 */ enum SOCKS5Method: uint8_t { NOAUTH = 0x00, //!< No authentication required GSSAPI = 0x01, //!< GSSAPI USER_PASS = 0x02, //!< Username/password NO_ACCEPTABLE = 0xff, //!< No acceptable methods }; /** Values defined for CMD in RFC1928 */ enum SOCKS5Command: uint8_t { CONNECT = 0x01, BIND = 0x02, UDP_ASSOCIATE = 0x03 }; /** Values defined for REP in RFC1928 */ enum SOCKS5Reply: uint8_t { SUCCEEDED = 0x00, //!< Succeeded GENFAILURE = 0x01, //!< General failure NOTALLOWED = 0x02, //!< Connection not allowed by ruleset NETUNREACHABLE = 0x03, //!< Network unreachable HOSTUNREACHABLE = 0x04, //!< Network unreachable CONNREFUSED = 0x05, //!< Connection refused TTLEXPIRED = 0x06, //!< TTL expired CMDUNSUPPORTED = 0x07, //!< Command not supported ATYPEUNSUPPORTED = 0x08, //!< Address type not supported }; /** Values defined for ATYPE in RFC1928 */ enum SOCKS5Atyp: uint8_t { IPV4 = 0x01, DOMAINNAME = 0x03, IPV6 = 0x04, }; /** Status codes that can be returned by InterruptibleRecv */ enum class IntrRecvError { OK, Timeout, Disconnected, NetworkError, Interrupted }; /** * Try to read a specified number of bytes from a socket. Please read the "see * also" section for more detail. * * @param data The buffer where the read bytes should be stored. * @param len The number of bytes to read into the specified buffer. * @param timeout The total timeout in milliseconds for this read. * @param sock The socket (has to be in non-blocking mode) from which to read bytes. * * @returns An IntrRecvError indicating the resulting status of this read. * IntrRecvError::OK only if all of the specified number of bytes were * read. * * @see This function can be interrupted by calling InterruptSocks5(bool). * Sockets can be made non-blocking with SetSocketNonBlocking(const * SOCKET&, bool). */ static IntrRecvError InterruptibleRecv(uint8_t* data, size_t len, int timeout, const Sock& sock) { int64_t curTime = GetTimeMillis(); int64_t endTime = curTime + timeout; while (len > 0 && curTime < endTime) { ssize_t ret = sock.Recv(data, len, 0); // Optimistically try the recv first if (ret > 0) { len -= ret; data += ret; } else if (ret == 0) { // Unexpected disconnection return IntrRecvError::Disconnected; } else { // Other error or blocking int nErr = WSAGetLastError(); if (nErr == WSAEINPROGRESS || nErr == WSAEWOULDBLOCK || nErr == WSAEINVAL) { // Only wait at most MAX_WAIT_FOR_IO at a time, unless // we're approaching the end of the specified total timeout const auto remaining = std::chrono::milliseconds{endTime - curTime}; const auto timeout = std::min(remaining, std::chrono::milliseconds{MAX_WAIT_FOR_IO}); if (!sock.Wait(timeout, Sock::RECV)) { return IntrRecvError::NetworkError; } } else { return IntrRecvError::NetworkError; } } if (interruptSocks5Recv) return IntrRecvError::Interrupted; curTime = GetTimeMillis(); } return len == 0 ? IntrRecvError::OK : IntrRecvError::Timeout; } /** Convert SOCKS5 reply to an error message */ static std::string Socks5ErrorString(uint8_t err) { switch(err) { case SOCKS5Reply::GENFAILURE: return "general failure"; case SOCKS5Reply::NOTALLOWED: return "connection not allowed"; case SOCKS5Reply::NETUNREACHABLE: return "network unreachable"; case SOCKS5Reply::HOSTUNREACHABLE: return "host unreachable"; case SOCKS5Reply::CONNREFUSED: return "connection refused"; case SOCKS5Reply::TTLEXPIRED: return "TTL expired"; case SOCKS5Reply::CMDUNSUPPORTED: return "protocol error"; case SOCKS5Reply::ATYPEUNSUPPORTED: return "address type not supported"; default: return "unknown"; } } /** * Connect to a specified destination service through an already connected * SOCKS5 proxy. * * @param strDest The destination fully-qualified domain name. * @param port The destination port. * @param auth The credentials with which to authenticate with the specified * SOCKS5 proxy. * @param sock The SOCKS5 proxy socket. * * @returns Whether or not the operation succeeded. * * @note The specified SOCKS5 proxy socket must already be connected to the * SOCKS5 proxy. * * @see RFC1928: SOCKS Protocol * Version 5 */ bool Socks5(const std::string& strDest, int port, const ProxyCredentials* auth, const Sock& sock) { IntrRecvError recvr; LogPrint(BCLog::NET, "SOCKS5 connecting %s\n", strDest); if (strDest.size() > 255) { return error("Hostname too long"); } // Construct the version identifier/method selection message std::vector vSocks5Init; vSocks5Init.push_back(SOCKSVersion::SOCKS5); // We want the SOCK5 protocol if (auth) { vSocks5Init.push_back(0x02); // 2 method identifiers follow... vSocks5Init.push_back(SOCKS5Method::NOAUTH); vSocks5Init.push_back(SOCKS5Method::USER_PASS); } else { vSocks5Init.push_back(0x01); // 1 method identifier follows... vSocks5Init.push_back(SOCKS5Method::NOAUTH); } ssize_t ret = sock.Send(vSocks5Init.data(), vSocks5Init.size(), MSG_NOSIGNAL); if (ret != (ssize_t)vSocks5Init.size()) { return error("Error sending to proxy"); } uint8_t pchRet1[2]; if ((recvr = InterruptibleRecv(pchRet1, 2, g_socks5_recv_timeout, sock)) != IntrRecvError::OK) { LogPrintf("Socks5() connect to %s:%d failed: InterruptibleRecv() timeout or other failure\n", strDest, port); return false; } if (pchRet1[0] != SOCKSVersion::SOCKS5) { return error("Proxy failed to initialize"); } if (pchRet1[1] == SOCKS5Method::USER_PASS && auth) { // Perform username/password authentication (as described in RFC1929) std::vector vAuth; vAuth.push_back(0x01); // Current (and only) version of user/pass subnegotiation if (auth->username.size() > 255 || auth->password.size() > 255) return error("Proxy username or password too long"); vAuth.push_back(auth->username.size()); vAuth.insert(vAuth.end(), auth->username.begin(), auth->username.end()); vAuth.push_back(auth->password.size()); vAuth.insert(vAuth.end(), auth->password.begin(), auth->password.end()); ret = sock.Send(vAuth.data(), vAuth.size(), MSG_NOSIGNAL); if (ret != (ssize_t)vAuth.size()) { return error("Error sending authentication to proxy"); } LogPrint(BCLog::PROXY, "SOCKS5 sending proxy authentication %s:%s\n", auth->username, auth->password); uint8_t pchRetA[2]; if ((recvr = InterruptibleRecv(pchRetA, 2, g_socks5_recv_timeout, sock)) != IntrRecvError::OK) { return error("Error reading proxy authentication response"); } if (pchRetA[0] != 0x01 || pchRetA[1] != 0x00) { return error("Proxy authentication unsuccessful"); } } else if (pchRet1[1] == SOCKS5Method::NOAUTH) { // Perform no authentication } else { return error("Proxy requested wrong authentication method %02x", pchRet1[1]); } std::vector vSocks5; vSocks5.push_back(SOCKSVersion::SOCKS5); // VER protocol version vSocks5.push_back(SOCKS5Command::CONNECT); // CMD CONNECT vSocks5.push_back(0x00); // RSV Reserved must be 0 vSocks5.push_back(SOCKS5Atyp::DOMAINNAME); // ATYP DOMAINNAME vSocks5.push_back(strDest.size()); // Length<=255 is checked at beginning of function vSocks5.insert(vSocks5.end(), strDest.begin(), strDest.end()); vSocks5.push_back((port >> 8) & 0xFF); vSocks5.push_back((port >> 0) & 0xFF); ret = sock.Send(vSocks5.data(), vSocks5.size(), MSG_NOSIGNAL); if (ret != (ssize_t)vSocks5.size()) { return error("Error sending to proxy"); } uint8_t pchRet2[4]; if ((recvr = InterruptibleRecv(pchRet2, 4, g_socks5_recv_timeout, sock)) != IntrRecvError::OK) { if (recvr == IntrRecvError::Timeout) { /* If a timeout happens here, this effectively means we timed out while connecting * to the remote node. This is very common for Tor, so do not print an * error message. */ return false; } else { return error("Error while reading proxy response"); } } if (pchRet2[0] != SOCKSVersion::SOCKS5) { return error("Proxy failed to accept request"); } if (pchRet2[1] != SOCKS5Reply::SUCCEEDED) { // Failures to connect to a peer that are not proxy errors LogPrintf("Socks5() connect to %s:%d failed: %s\n", strDest, port, Socks5ErrorString(pchRet2[1])); return false; } if (pchRet2[2] != 0x00) { // Reserved field must be 0 return error("Error: malformed proxy response"); } uint8_t pchRet3[256]; switch (pchRet2[3]) { case SOCKS5Atyp::IPV4: recvr = InterruptibleRecv(pchRet3, 4, g_socks5_recv_timeout, sock); break; case SOCKS5Atyp::IPV6: recvr = InterruptibleRecv(pchRet3, 16, g_socks5_recv_timeout, sock); break; case SOCKS5Atyp::DOMAINNAME: { recvr = InterruptibleRecv(pchRet3, 1, g_socks5_recv_timeout, sock); if (recvr != IntrRecvError::OK) { return error("Error reading from proxy"); } int nRecv = pchRet3[0]; recvr = InterruptibleRecv(pchRet3, nRecv, g_socks5_recv_timeout, sock); break; } default: return error("Error: malformed proxy response"); } if (recvr != IntrRecvError::OK) { return error("Error reading from proxy"); } if ((recvr = InterruptibleRecv(pchRet3, 2, g_socks5_recv_timeout, sock)) != IntrRecvError::OK) { return error("Error reading from proxy"); } LogPrint(BCLog::NET, "SOCKS5 connected %s\n", strDest); return true; } std::unique_ptr CreateSockTCP(const CService& address_family) { // Create a sockaddr from the specified service. struct sockaddr_storage sockaddr; socklen_t len = sizeof(sockaddr); if (!address_family.GetSockAddr((struct sockaddr*)&sockaddr, &len)) { LogPrintf("Cannot create socket for %s: unsupported network\n", address_family.ToString()); return nullptr; } // Create a TCP socket in the address family of the specified service. SOCKET hSocket = socket(((struct sockaddr*)&sockaddr)->sa_family, SOCK_STREAM, IPPROTO_TCP); if (hSocket == INVALID_SOCKET) { return nullptr; } // Ensure that waiting for I/O on this socket won't result in undefined // behavior. if (!IsSelectableSocket(hSocket)) { CloseSocket(hSocket); LogPrintf("Cannot create connection: non-selectable socket created (fd >= FD_SETSIZE ?)\n"); return nullptr; } #ifdef SO_NOSIGPIPE int set = 1; // Set the no-sigpipe option on the socket for BSD systems, other UNIXes // should use the MSG_NOSIGNAL flag for every send. setsockopt(hSocket, SOL_SOCKET, SO_NOSIGPIPE, (void*)&set, sizeof(int)); #endif // Set the no-delay option (disable Nagle's algorithm) on the TCP socket. SetSocketNoDelay(hSocket); // Set the non-blocking option on the socket. if (!SetSocketNonBlocking(hSocket, true)) { CloseSocket(hSocket); LogPrintf("Error setting socket to non-blocking: %s\n", NetworkErrorString(WSAGetLastError())); return nullptr; } return std::make_unique(hSocket); } std::function(const CService&)> CreateSock = CreateSockTCP; template static void LogConnectFailure(bool manual_connection, const char* fmt, const Args&... args) { std::string error_message = tfm::format(fmt, args...); if (manual_connection) { LogPrintf("%s\n", error_message); } else { LogPrint(BCLog::NET, "%s\n", error_message); } } /** * Try to connect to the specified service on the specified socket. * * @param addrConnect The service to which to connect. * @param hSocket The socket on which to connect. * @param nTimeout Wait this many milliseconds for the connection to be * established. * @param manual_connection Whether or not the connection was manually requested * (e.g. through the addnode RPC) * * @returns Whether or not a connection was successfully made. */ bool ConnectSocketDirectly(const CService &addrConnect, const SOCKET& hSocket, int nTimeout, bool manual_connection) { // Create a sockaddr from the specified service. struct sockaddr_storage sockaddr; socklen_t len = sizeof(sockaddr); if (hSocket == INVALID_SOCKET) { LogPrintf("Cannot connect to %s: invalid socket\n", addrConnect.ToString()); return false; } if (!addrConnect.GetSockAddr((struct sockaddr*)&sockaddr, &len)) { LogPrintf("Cannot connect to %s: unsupported network\n", addrConnect.ToString()); return false; } // Connect to the addrConnect service on the hSocket socket. if (connect(hSocket, (struct sockaddr*)&sockaddr, len) == SOCKET_ERROR) { int nErr = WSAGetLastError(); // WSAEINVAL is here because some legacy version of winsock uses it if (nErr == WSAEINPROGRESS || nErr == WSAEWOULDBLOCK || nErr == WSAEINVAL) { // Connection didn't actually fail, but is being established // asynchronously. Thus, use async I/O api (select/poll) // synchronously to check for successful connection with a timeout. #ifdef USE_POLL struct pollfd pollfd = {}; pollfd.fd = hSocket; pollfd.events = POLLIN | POLLOUT; int nRet = poll(&pollfd, 1, nTimeout); #else struct timeval timeout = MillisToTimeval(nTimeout); fd_set fdset; FD_ZERO(&fdset); FD_SET(hSocket, &fdset); int nRet = select(hSocket + 1, nullptr, &fdset, nullptr, &timeout); #endif // Upon successful completion, both select and poll return the total // number of file descriptors that have been selected. A value of 0 // indicates that the call timed out and no file descriptors have // been selected. if (nRet == 0) { LogPrint(BCLog::NET, "connection to %s timeout\n", addrConnect.ToString()); return false; } if (nRet == SOCKET_ERROR) { LogPrintf("select() for %s failed: %s\n", addrConnect.ToString(), NetworkErrorString(WSAGetLastError())); return false; } // Even if the select/poll was successful, the connect might not // have been successful. The reason for this failure is hidden away // in the SO_ERROR for the socket in modern systems. We read it into // nRet here. socklen_t nRetSize = sizeof(nRet); if (getsockopt(hSocket, SOL_SOCKET, SO_ERROR, (sockopt_arg_type)&nRet, &nRetSize) == SOCKET_ERROR) { LogPrintf("getsockopt() for %s failed: %s\n", addrConnect.ToString(), NetworkErrorString(WSAGetLastError())); return false; } if (nRet != 0) { LogConnectFailure(manual_connection, "connect() to %s failed after select(): %s", addrConnect.ToString(), NetworkErrorString(nRet)); return false; } } #ifdef WIN32 else if (WSAGetLastError() != WSAEISCONN) #else else #endif { LogConnectFailure(manual_connection, "connect() to %s failed: %s", addrConnect.ToString(), NetworkErrorString(WSAGetLastError())); return false; } } return true; } bool SetProxy(enum Network net, const proxyType &addrProxy) { assert(net >= 0 && net < NET_MAX); if (!addrProxy.IsValid()) return false; LOCK(g_proxyinfo_mutex); proxyInfo[net] = addrProxy; return true; } bool GetProxy(enum Network net, proxyType &proxyInfoOut) { assert(net >= 0 && net < NET_MAX); LOCK(g_proxyinfo_mutex); if (!proxyInfo[net].IsValid()) return false; proxyInfoOut = proxyInfo[net]; return true; } /** * Set the name proxy to use for all connections to nodes specified by a * hostname. After setting this proxy, connecting to a node specified by a * hostname won't result in a local lookup of said hostname, rather, connect to * the node by asking the name proxy for a proxy connection to the hostname, * effectively delegating the hostname lookup to the specified proxy. * * This delegation increases privacy for those who set the name proxy as they no * longer leak their external hostname queries to their DNS servers. * * @returns Whether or not the operation succeeded. * * @note SOCKS5's support for UDP-over-SOCKS5 has been considered, but no SOCK5 * server in common use (most notably Tor) actually implements UDP * support, and a DNS resolver is beyond the scope of this project. */ bool SetNameProxy(const proxyType &addrProxy) { if (!addrProxy.IsValid()) return false; LOCK(g_proxyinfo_mutex); nameProxy = addrProxy; return true; } bool GetNameProxy(proxyType &nameProxyOut) { LOCK(g_proxyinfo_mutex); if(!nameProxy.IsValid()) return false; nameProxyOut = nameProxy; return true; } bool HaveNameProxy() { LOCK(g_proxyinfo_mutex); return nameProxy.IsValid(); } bool IsProxy(const CNetAddr &addr) { LOCK(g_proxyinfo_mutex); for (int i = 0; i < NET_MAX; i++) { if (addr == static_cast(proxyInfo[i].proxy)) return true; } return false; } /** * Connect to a specified destination service through a SOCKS5 proxy by first * connecting to the SOCKS5 proxy. * * @param proxy The SOCKS5 proxy. * @param strDest The destination service to which to connect. * @param port The destination port. * @param sock The socket on which to connect to the SOCKS5 proxy. * @param nTimeout Wait this many milliseconds for the connection to the SOCKS5 * proxy to be established. * @param[out] outProxyConnectionFailed Whether or not the connection to the * SOCKS5 proxy failed. * * @returns Whether or not the operation succeeded. */ bool ConnectThroughProxy(const proxyType& proxy, const std::string& strDest, int port, const Sock& sock, int nTimeout, bool& outProxyConnectionFailed) { // first connect to proxy server if (!ConnectSocketDirectly(proxy.proxy, sock.Get(), nTimeout, true)) { outProxyConnectionFailed = true; return false; } // do socks negotiation if (proxy.randomize_credentials) { ProxyCredentials random_auth; static std::atomic_int counter(0); random_auth.username = random_auth.password = strprintf("%i", counter++); if (!Socks5(strDest, (uint16_t)port, &random_auth, sock)) { return false; } } else { if (!Socks5(strDest, (uint16_t)port, 0, sock)) { return false; } } return true; } /** * Parse and resolve a specified subnet string into the appropriate internal * representation. * * @param strSubnet A string representation of a subnet of the form `network * address [ "/", ( CIDR-style suffix | netmask ) ]`(e.g. * `2001:db8::/32`, `192.0.2.0/255.255.255.0`, or `8.8.8.8`). * @param ret The resulting internal representation of a subnet. * * @returns Whether the operation succeeded or not. */ bool LookupSubNet(const std::string& strSubnet, CSubNet& ret, DNSLookupFn dns_lookup_function) { if (!ValidAsCString(strSubnet)) { return false; } size_t slash = strSubnet.find_last_of('/'); std::vector vIP; std::string strAddress = strSubnet.substr(0, slash); // TODO: Use LookupHost(const std::string&, CNetAddr&, bool) instead to just get // one CNetAddr. if (LookupHost(strAddress, vIP, 1, false, dns_lookup_function)) { CNetAddr network = vIP[0]; if (slash != strSubnet.npos) { std::string strNetmask = strSubnet.substr(slash + 1); uint8_t n; if (ParseUInt8(strNetmask, &n)) { // If valid number, assume CIDR variable-length subnet masking ret = CSubNet(network, n); return ret.IsValid(); } else // If not a valid number, try full netmask syntax { // Never allow lookup for netmask if (LookupHost(strNetmask, vIP, 1, false, dns_lookup_function)) { ret = CSubNet(network, vIP[0]); return ret.IsValid(); } } } else { ret = CSubNet(network); return ret.IsValid(); } } return false; } bool SetSocketNonBlocking(const SOCKET& hSocket, bool fNonBlocking) { if (fNonBlocking) { #ifdef WIN32 u_long nOne = 1; if (ioctlsocket(hSocket, FIONBIO, &nOne) == SOCKET_ERROR) { #else int fFlags = fcntl(hSocket, F_GETFL, 0); if (fcntl(hSocket, F_SETFL, fFlags | O_NONBLOCK) == SOCKET_ERROR) { #endif return false; } } else { #ifdef WIN32 u_long nZero = 0; if (ioctlsocket(hSocket, FIONBIO, &nZero) == SOCKET_ERROR) { #else int fFlags = fcntl(hSocket, F_GETFL, 0); if (fcntl(hSocket, F_SETFL, fFlags & ~O_NONBLOCK) == SOCKET_ERROR) { #endif return false; } } return true; } bool SetSocketNoDelay(const SOCKET& hSocket) { int set = 1; int rc = setsockopt(hSocket, IPPROTO_TCP, TCP_NODELAY, (const char*)&set, sizeof(int)); return rc == 0; } void InterruptSocks5(bool interrupt) { interruptSocks5Recv = interrupt; }