// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2018 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 <netbase.h>
#include <sync.h>
#include <tinyformat.h>
#include <util/system.h>
#include <util/strencodings.h>
#include <atomic>
#ifndef WIN32
#include <fcntl.h>
#else
#include <codecvt>
#endif
#ifdef USE_POLL
#include <poll.h>
#endif
#if !defined(MSG_NOSIGNAL)
#define MSG_NOSIGNAL 0
#endif
// Settings
static CCriticalSection cs_proxyInfos;
static proxyType proxyInfo[NET_MAX] GUARDED_BY(cs_proxyInfos);
static proxyType nameProxy GUARDED_BY(cs_proxyInfos);
int nConnectTimeout = DEFAULT_CONNECT_TIMEOUT;
bool fNameLookup = DEFAULT_NAME_LOOKUP;
// Need ample time for negotiation for very slow proxies such as Tor (milliseconds)
static const int SOCKS5_RECV_TIMEOUT = 20 * 1000;
static std::atomic<bool> interruptSocks5Recv(false);
enum Network ParseNetwork(std::string net) {
Downcase(net);
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;
}
return NET_UNROUTABLE;
}
std::string GetNetworkName(enum Network net) {
switch(net)
{
case NET_IPV4: return "ipv4";
case NET_IPV6: return "ipv6";
case NET_ONION: return "onion";
default: return "";
}
}
bool static LookupIntern(const char *pszName, std::vector<CNetAddr>& vIP, unsigned int nMaxSolutions, bool fAllowLookup)
{
vIP.clear();
{
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(std::string(pszName))) {
vIP.push_back(addr);
return true;
}
}
struct addrinfo aiHint;
memset(&aiHint, 0, sizeof(struct addrinfo));
// We want a TCP port, which is a streaming socket type
aiHint.ai_socktype = SOCK_STREAM;
aiHint.ai_protocol = IPPROTO_TCP;
// We don't care which address family (IPv4 or IPv6) is returned
aiHint.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.
aiHint.ai_flags = fAllowLookup ? AI_ADDRCONFIG : AI_NUMERICHOST;
struct addrinfo *aiRes = nullptr;
int nErr = getaddrinfo(pszName, nullptr, &aiHint, &aiRes);
if (nErr)
return false;
// Traverse the linked list starting with aiTrav, add all non-internal
// IPv4,v6 addresses to vIP while respecting nMaxSolutions.
struct addrinfo *aiTrav = aiRes;
while (aiTrav != nullptr && (nMaxSolutions == 0 || vIP.size() < nMaxSolutions))
{
CNetAddr resolved;
if (aiTrav->ai_family == AF_INET)
{
assert(aiTrav->ai_addrlen >= sizeof(sockaddr_in));
resolved = CNetAddr(((struct sockaddr_in*)(aiTrav->ai_addr))->sin_addr);
}
if (aiTrav->ai_family == AF_INET6)
{
assert(aiTrav->ai_addrlen >= sizeof(sockaddr_in6));
struct sockaddr_in6* s6 = (struct sockaddr_in6*) aiTrav->ai_addr;
resolved = CNetAddr(s6->sin6_addr, s6->sin6_scope_id);
}
/* Never allow resolving to an internal address. Consider any such result invalid */
if (!resolved.IsInternal()) {
vIP.push_back(resolved);
}
aiTrav = aiTrav->ai_next;
}
freeaddrinfo(aiRes);
return (vIP.size() > 0);
}
/**
* Resolve a host string to its corresponding network addresses.
*
* @param pszName 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<CService>&, int, bool, unsigned int)
* for additional parameter descriptions.
*/
bool LookupHost(const char *pszName, std::vector<CNetAddr>& vIP, unsigned int nMaxSolutions, bool fAllowLookup)
{
std::string strHost(pszName);
if (strHost.empty())
return false;
if (strHost.front() == '[' && strHost.back() == ']') {
strHost = strHost.substr(1, strHost.size() - 2);
}
return LookupIntern(strHost.c_str(), vIP, nMaxSolutions, fAllowLookup);
}
/**
* Resolve a host string to its first corresponding network address.
*
* @see LookupHost(const char *, std::vector<CNetAddr>&, unsigned int, bool) for
* additional parameter descriptions.
*/
bool LookupHost(const char *pszName, CNetAddr& addr, bool fAllowLookup)
{
std::vector<CNetAddr> vIP;
LookupHost(pszName, vIP, 1, fAllowLookup);
if(vIP.empty())
return false;
addr = vIP.front();
return true;
}
/**
* Resolve a service string to its corresponding service.
*
* @param pszName 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 char *pszName, std::vector<CService>& vAddr, int portDefault, bool fAllowLookup, unsigned int nMaxSolutions)
{
if (pszName[0] == 0)
return false;
int port = portDefault;
std::string hostname;
SplitHostPort(std::string(pszName), port, hostname);
std::vector<CNetAddr> vIP;
bool fRet = LookupIntern(hostname.c_str(), vIP, nMaxSolutions, fAllowLookup);
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<CService>&, int, bool, unsigned int)
* for additional parameter descriptions.
*/
bool Lookup(const char *pszName, CService& addr, int portDefault, bool fAllowLookup)
{
std::vector<CService> vService;
bool fRet = Lookup(pszName, vService, portDefault, fAllowLookup, 1);
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 char *pszName, int portDefault)
{
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(pszName, addr, portDefault, false))
addr = CService();
return addr;
}
struct timeval MillisToTimeval(int64_t nTimeout)
{
struct timeval timeout;
timeout.tv_sec = nTimeout / 1000;
timeout.tv_usec = (nTimeout % 1000) * 1000;
return timeout;
}
/** 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 hSocket 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 SOCKET& hSocket)
{
int64_t curTime = GetTimeMillis();
int64_t endTime = curTime + timeout;
// Maximum time to wait for I/O readiness. It will take up until this time
// (in millis) to break off in case of an interruption.
const int64_t maxWait = 1000;
while (len > 0 && curTime < endTime) {
ssize_t ret = recv(hSocket, (char*)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) {
if (!IsSelectableSocket(hSocket)) {
return IntrRecvError::NetworkError;
}
// Only wait at most maxWait milliseconds at a time, unless
// we're approaching the end of the specified total timeout
int timeout_ms = std::min(endTime - curTime, maxWait);
#ifdef USE_POLL
struct pollfd pollfd = {};
pollfd.fd = hSocket;
pollfd.events = POLLIN;
int nRet = poll(&pollfd, 1, timeout_ms);
#else
struct timeval tval = MillisToTimeval(timeout_ms);
fd_set fdset;
FD_ZERO(&fdset);
FD_SET(hSocket, &fdset);
int nRet = select(hSocket + 1, &fdset, nullptr, nullptr, &tval);
#endif
if (nRet == SOCKET_ERROR) {
return IntrRecvError::NetworkError;
}
} else {
return IntrRecvError::NetworkError;
}
}
if (interruptSocks5Recv)
return IntrRecvError::Interrupted;
curTime = GetTimeMillis();
}
return len == 0 ? IntrRecvError::OK : IntrRecvError::Timeout;
}
/** Credentials for proxy authentication */
struct ProxyCredentials
{
std::string username;
std::string password;
};
/** 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 hSocket 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 <a href="https://www.ietf.org/rfc/rfc1928.txt">RFC1928: SOCKS Protocol
* Version 5</a>
*/
static bool Socks5(const std::string& strDest, int port, const ProxyCredentials *auth, const SOCKET& hSocket)
{
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<uint8_t> 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 = send(hSocket, (const char*)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, SOCKS5_RECV_TIMEOUT, hSocket)) != 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<uint8_t> 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 = send(hSocket, (const char*)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, SOCKS5_RECV_TIMEOUT, hSocket)) != 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<uint8_t> 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 = send(hSocket, (const char*)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, SOCKS5_RECV_TIMEOUT, hSocket)) != 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, SOCKS5_RECV_TIMEOUT, hSocket); break;
case SOCKS5Atyp::IPV6: recvr = InterruptibleRecv(pchRet3, 16, SOCKS5_RECV_TIMEOUT, hSocket); break;
case SOCKS5Atyp::DOMAINNAME:
{
recvr = InterruptibleRecv(pchRet3, 1, SOCKS5_RECV_TIMEOUT, hSocket);
if (recvr != IntrRecvError::OK) {
return error("Error reading from proxy");
}
int nRecv = pchRet3[0];
recvr = InterruptibleRecv(pchRet3, nRecv, SOCKS5_RECV_TIMEOUT, hSocket);
break;
}
default: return error("Error: malformed proxy response");
}
if (recvr != IntrRecvError::OK) {
return error("Error reading from proxy");
}
if ((recvr = InterruptibleRecv(pchRet3, 2, SOCKS5_RECV_TIMEOUT, hSocket)) != IntrRecvError::OK) {
return error("Error reading from proxy");
}
LogPrint(BCLog::NET, "SOCKS5 connected %s\n", strDest);
return true;
}
/**
* Try to create a socket file descriptor with specific properties in the
* communications domain (address family) of the specified service.
*
* For details on the desired properties, see the inline comments in the source
* code.
*/
SOCKET CreateSocket(const CService &addrConnect)
{
// Create a sockaddr from the specified service.
struct sockaddr_storage sockaddr;
socklen_t len = sizeof(sockaddr);
if (!addrConnect.GetSockAddr((struct sockaddr*)&sockaddr, &len)) {
LogPrintf("Cannot create socket for %s: unsupported network\n", addrConnect.ToString());
return INVALID_SOCKET;
}
// 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 INVALID_SOCKET;
// 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 INVALID_SOCKET;
}
#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("CreateSocket: Setting socket to non-blocking failed, error %s\n", NetworkErrorString(WSAGetLastError()));
}
return hSocket;
}
template<typename... Args>
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. thru 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(cs_proxyInfos);
proxyInfo[net] = addrProxy;
return true;
}
bool GetProxy(enum Network net, proxyType &proxyInfoOut) {
assert(net >= 0 && net < NET_MAX);
LOCK(cs_proxyInfos);
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 sepcified 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(cs_proxyInfos);
nameProxy = addrProxy;
return true;
}
bool GetNameProxy(proxyType &nameProxyOut) {
LOCK(cs_proxyInfos);
if(!nameProxy.IsValid())
return false;
nameProxyOut = nameProxy;
return true;
}
bool HaveNameProxy() {
LOCK(cs_proxyInfos);
return nameProxy.IsValid();
}
bool IsProxy(const CNetAddr &addr) {
LOCK(cs_proxyInfos);
for (int i = 0; i < NET_MAX; i++) {
if (addr == static_cast<CNetAddr>(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 hSocket 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 outProxyConnectionFailed[out] 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 SOCKET& hSocket, int nTimeout, bool *outProxyConnectionFailed)
{
// first connect to proxy server
if (!ConnectSocketDirectly(proxy.proxy, hSocket, nTimeout, true)) {
if (outProxyConnectionFailed)
*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, (unsigned short)port, &random_auth, hSocket)) {
return false;
}
} else {
if (!Socks5(strDest, (unsigned short)port, 0, hSocket)) {
return false;
}
}
return true;
}
/**
* Parse and resolve a specified subnet string into the appropriate internal
* representation.
*
* @param pszName 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 char* pszName, CSubNet& ret)
{
std::string strSubnet(pszName);
size_t slash = strSubnet.find_last_of('/');
std::vector<CNetAddr> vIP;
std::string strAddress = strSubnet.substr(0, slash);
// TODO: Use LookupHost(const char *, CNetAddr&, bool) instead to just get
// one CNetAddr.
if (LookupHost(strAddress.c_str(), vIP, 1, false))
{
CNetAddr network = vIP[0];
if (slash != strSubnet.npos)
{
std::string strNetmask = strSubnet.substr(slash + 1);
int32_t n;
if (ParseInt32(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.c_str(), vIP, 1, false)) {
ret = CSubNet(network, vIP[0]);
return ret.IsValid();
}
}
}
else
{
ret = CSubNet(network);
return ret.IsValid();
}
}
return false;
}
#ifdef WIN32
std::string NetworkErrorString(int err)
{
wchar_t buf[256];
buf[0] = 0;
if(FormatMessageW(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_MAX_WIDTH_MASK,
nullptr, err, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
buf, ARRAYSIZE(buf), nullptr))
{
return strprintf("%s (%d)", std::wstring_convert<std::codecvt_utf8_utf16<wchar_t>,wchar_t>().to_bytes(buf), err);
}
else
{
return strprintf("Unknown error (%d)", err);
}
}
#else
std::string NetworkErrorString(int err)
{
char buf[256];
buf[0] = 0;
/* Too bad there are two incompatible implementations of the
* thread-safe strerror. */
const char *s;
#ifdef STRERROR_R_CHAR_P /* GNU variant can return a pointer outside the passed buffer */
s = strerror_r(err, buf, sizeof(buf));
#else /* POSIX variant always returns message in buffer */
s = buf;
if (strerror_r(err, buf, sizeof(buf)))
buf[0] = 0;
#endif
return strprintf("%s (%d)", s, err);
}
#endif
bool CloseSocket(SOCKET& hSocket)
{
if (hSocket == INVALID_SOCKET)
return false;
#ifdef WIN32
int ret = closesocket(hSocket);
#else
int ret = close(hSocket);
#endif
if (ret) {
LogPrintf("Socket close failed: %d. Error: %s\n", hSocket, NetworkErrorString(WSAGetLastError()));
}
hSocket = INVALID_SOCKET;
return ret != SOCKET_ERROR;
}
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;
}