// Copyright (c) 2015-2022 The Bitcoin Core developers // Copyright (c) 2017 The Zcash 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /** Default control ip and port */ const std::string DEFAULT_TOR_CONTROL = "127.0.0.1:" + ToString(DEFAULT_TOR_CONTROL_PORT); /** Tor cookie size (from control-spec.txt) */ static const int TOR_COOKIE_SIZE = 32; /** Size of client/server nonce for SAFECOOKIE */ static const int TOR_NONCE_SIZE = 32; /** For computing serverHash in SAFECOOKIE */ static const std::string TOR_SAFE_SERVERKEY = "Tor safe cookie authentication server-to-controller hash"; /** For computing clientHash in SAFECOOKIE */ static const std::string TOR_SAFE_CLIENTKEY = "Tor safe cookie authentication controller-to-server hash"; /** Exponential backoff configuration - initial timeout in seconds */ static const float RECONNECT_TIMEOUT_START = 1.0; /** Exponential backoff configuration - growth factor */ static const float RECONNECT_TIMEOUT_EXP = 1.5; /** Maximum length for lines received on TorControlConnection. * tor-control-spec.txt mentions that there is explicitly no limit defined to line length, * this is belt-and-suspenders sanity limit to prevent memory exhaustion. */ static const int MAX_LINE_LENGTH = 100000; static const uint16_t DEFAULT_TOR_SOCKS_PORT = 9050; /****** Low-level TorControlConnection ********/ TorControlConnection::TorControlConnection(struct event_base* _base) : base(_base) { } TorControlConnection::~TorControlConnection() { if (b_conn) bufferevent_free(b_conn); } void TorControlConnection::readcb(struct bufferevent *bev, void *ctx) { TorControlConnection *self = static_cast(ctx); struct evbuffer *input = bufferevent_get_input(bev); size_t n_read_out = 0; char *line; assert(input); // If there is not a whole line to read, evbuffer_readln returns nullptr while((line = evbuffer_readln(input, &n_read_out, EVBUFFER_EOL_CRLF)) != nullptr) { std::string s(line, n_read_out); free(line); if (s.size() < 4) // Short line continue; // (-|+| ) self->message.code = ToIntegral(s.substr(0, 3)).value_or(0); self->message.lines.push_back(s.substr(4)); char ch = s[3]; // '-','+' or ' ' if (ch == ' ') { // Final line, dispatch reply and clean up if (self->message.code >= 600) { // (currently unused) // Dispatch async notifications to async handler // Synchronous and asynchronous messages are never interleaved } else { if (!self->reply_handlers.empty()) { // Invoke reply handler with message self->reply_handlers.front()(*self, self->message); self->reply_handlers.pop_front(); } else { LogPrint(BCLog::TOR, "Received unexpected sync reply %i\n", self->message.code); } } self->message.Clear(); } } // Check for size of buffer - protect against memory exhaustion with very long lines // Do this after evbuffer_readln to make sure all full lines have been // removed from the buffer. Everything left is an incomplete line. if (evbuffer_get_length(input) > MAX_LINE_LENGTH) { LogPrintf("tor: Disconnecting because MAX_LINE_LENGTH exceeded\n"); self->Disconnect(); } } void TorControlConnection::eventcb(struct bufferevent *bev, short what, void *ctx) { TorControlConnection *self = static_cast(ctx); if (what & BEV_EVENT_CONNECTED) { LogPrint(BCLog::TOR, "Successfully connected!\n"); self->connected(*self); } else if (what & (BEV_EVENT_EOF|BEV_EVENT_ERROR)) { if (what & BEV_EVENT_ERROR) { LogPrint(BCLog::TOR, "Error connecting to Tor control socket\n"); } else { LogPrint(BCLog::TOR, "End of stream\n"); } self->Disconnect(); self->disconnected(*self); } } bool TorControlConnection::Connect(const std::string& tor_control_center, const ConnectionCB& _connected, const ConnectionCB& _disconnected) { if (b_conn) { Disconnect(); } const std::optional control_service{Lookup(tor_control_center, DEFAULT_TOR_CONTROL_PORT, fNameLookup)}; if (!control_service.has_value()) { LogPrintf("tor: Failed to look up control center %s\n", tor_control_center); return false; } struct sockaddr_storage control_address; socklen_t control_address_len = sizeof(control_address); if (!control_service.value().GetSockAddr(reinterpret_cast(&control_address), &control_address_len)) { LogPrintf("tor: Error parsing socket address %s\n", tor_control_center); return false; } // Create a new socket, set up callbacks and enable notification bits b_conn = bufferevent_socket_new(base, -1, BEV_OPT_CLOSE_ON_FREE); if (!b_conn) { return false; } bufferevent_setcb(b_conn, TorControlConnection::readcb, nullptr, TorControlConnection::eventcb, this); bufferevent_enable(b_conn, EV_READ|EV_WRITE); this->connected = _connected; this->disconnected = _disconnected; // Finally, connect to tor_control_center if (bufferevent_socket_connect(b_conn, reinterpret_cast(&control_address), control_address_len) < 0) { LogPrintf("tor: Error connecting to address %s\n", tor_control_center); return false; } return true; } void TorControlConnection::Disconnect() { if (b_conn) bufferevent_free(b_conn); b_conn = nullptr; } bool TorControlConnection::Command(const std::string &cmd, const ReplyHandlerCB& reply_handler) { if (!b_conn) return false; struct evbuffer *buf = bufferevent_get_output(b_conn); if (!buf) return false; evbuffer_add(buf, cmd.data(), cmd.size()); evbuffer_add(buf, "\r\n", 2); reply_handlers.push_back(reply_handler); return true; } /****** General parsing utilities ********/ /* Split reply line in the form 'AUTH METHODS=...' into a type * 'AUTH' and arguments 'METHODS=...'. * Grammar is implicitly defined in https://spec.torproject.org/control-spec by * the server reply formats for PROTOCOLINFO (S3.21) and AUTHCHALLENGE (S3.24). */ std::pair SplitTorReplyLine(const std::string &s) { size_t ptr=0; std::string type; while (ptr < s.size() && s[ptr] != ' ') { type.push_back(s[ptr]); ++ptr; } if (ptr < s.size()) ++ptr; // skip ' ' return make_pair(type, s.substr(ptr)); } /** Parse reply arguments in the form 'METHODS=COOKIE,SAFECOOKIE COOKIEFILE=".../control_auth_cookie"'. * Returns a map of keys to values, or an empty map if there was an error. * Grammar is implicitly defined in https://spec.torproject.org/control-spec by * the server reply formats for PROTOCOLINFO (S3.21), AUTHCHALLENGE (S3.24), * and ADD_ONION (S3.27). See also sections 2.1 and 2.3. */ std::map ParseTorReplyMapping(const std::string &s) { std::map mapping; size_t ptr=0; while (ptr < s.size()) { std::string key, value; while (ptr < s.size() && s[ptr] != '=' && s[ptr] != ' ') { key.push_back(s[ptr]); ++ptr; } if (ptr == s.size()) // unexpected end of line return std::map(); if (s[ptr] == ' ') // The remaining string is an OptArguments break; ++ptr; // skip '=' if (ptr < s.size() && s[ptr] == '"') { // Quoted string ++ptr; // skip opening '"' bool escape_next = false; while (ptr < s.size() && (escape_next || s[ptr] != '"')) { // Repeated backslashes must be interpreted as pairs escape_next = (s[ptr] == '\\' && !escape_next); value.push_back(s[ptr]); ++ptr; } if (ptr == s.size()) // unexpected end of line return std::map(); ++ptr; // skip closing '"' /** * Unescape value. Per https://spec.torproject.org/control-spec section 2.1.1: * * For future-proofing, controller implementors MAY use the following * rules to be compatible with buggy Tor implementations and with * future ones that implement the spec as intended: * * Read \n \t \r and \0 ... \377 as C escapes. * Treat a backslash followed by any other character as that character. */ std::string escaped_value; for (size_t i = 0; i < value.size(); ++i) { if (value[i] == '\\') { // This will always be valid, because if the QuotedString // ended in an odd number of backslashes, then the parser // would already have returned above, due to a missing // terminating double-quote. ++i; if (value[i] == 'n') { escaped_value.push_back('\n'); } else if (value[i] == 't') { escaped_value.push_back('\t'); } else if (value[i] == 'r') { escaped_value.push_back('\r'); } else if ('0' <= value[i] && value[i] <= '7') { size_t j; // Octal escape sequences have a limit of three octal digits, // but terminate at the first character that is not a valid // octal digit if encountered sooner. for (j = 1; j < 3 && (i+j) < value.size() && '0' <= value[i+j] && value[i+j] <= '7'; ++j) {} // Tor restricts first digit to 0-3 for three-digit octals. // A leading digit of 4-7 would therefore be interpreted as // a two-digit octal. if (j == 3 && value[i] > '3') { j--; } const auto end{i + j}; uint8_t val{0}; while (i < end) { val *= 8; val += value[i++] - '0'; } escaped_value.push_back(char(val)); // Account for automatic incrementing at loop end --i; } else { escaped_value.push_back(value[i]); } } else { escaped_value.push_back(value[i]); } } value = escaped_value; } else { // Unquoted value. Note that values can contain '=' at will, just no spaces while (ptr < s.size() && s[ptr] != ' ') { value.push_back(s[ptr]); ++ptr; } } if (ptr < s.size() && s[ptr] == ' ') ++ptr; // skip ' ' after key=value mapping[key] = value; } return mapping; } TorController::TorController(struct event_base* _base, const std::string& tor_control_center, const CService& target): base(_base), m_tor_control_center(tor_control_center), conn(base), reconnect(true), reconnect_timeout(RECONNECT_TIMEOUT_START), m_target(target) { reconnect_ev = event_new(base, -1, 0, reconnect_cb, this); if (!reconnect_ev) LogPrintf("tor: Failed to create event for reconnection: out of memory?\n"); // Start connection attempts immediately if (!conn.Connect(m_tor_control_center, std::bind(&TorController::connected_cb, this, std::placeholders::_1), std::bind(&TorController::disconnected_cb, this, std::placeholders::_1) )) { LogPrintf("tor: Initiating connection to Tor control port %s failed\n", m_tor_control_center); } // Read service private key if cached std::pair pkf = ReadBinaryFile(GetPrivateKeyFile()); if (pkf.first) { LogPrint(BCLog::TOR, "Reading cached private key from %s\n", fs::PathToString(GetPrivateKeyFile())); private_key = pkf.second; } } TorController::~TorController() { if (reconnect_ev) { event_free(reconnect_ev); reconnect_ev = nullptr; } if (service.IsValid()) { RemoveLocal(service); } } void TorController::get_socks_cb(TorControlConnection& _conn, const TorControlReply& reply) { // NOTE: We can only get here if -onion is unset std::string socks_location; if (reply.code == 250) { for (const auto& line : reply.lines) { if (0 == line.compare(0, 20, "net/listeners/socks=")) { const std::string port_list_str = line.substr(20); std::vector port_list = SplitString(port_list_str, ' '); for (auto& portstr : port_list) { if (portstr.empty()) continue; if ((portstr[0] == '"' || portstr[0] == '\'') && portstr.size() >= 2 && (*portstr.rbegin() == portstr[0])) { portstr = portstr.substr(1, portstr.size() - 2); if (portstr.empty()) continue; } socks_location = portstr; if (0 == portstr.compare(0, 10, "127.0.0.1:")) { // Prefer localhost - ignore other ports break; } } } } if (!socks_location.empty()) { LogPrint(BCLog::TOR, "Get SOCKS port command yielded %s\n", socks_location); } else { LogPrintf("tor: Get SOCKS port command returned nothing\n"); } } else if (reply.code == 510) { // 510 Unrecognized command LogPrintf("tor: Get SOCKS port command failed with unrecognized command (You probably should upgrade Tor)\n"); } else { LogPrintf("tor: Get SOCKS port command failed; error code %d\n", reply.code); } CService resolved; Assume(!resolved.IsValid()); if (!socks_location.empty()) { resolved = LookupNumeric(socks_location, DEFAULT_TOR_SOCKS_PORT); } if (!resolved.IsValid()) { // Fallback to old behaviour resolved = LookupNumeric("127.0.0.1", DEFAULT_TOR_SOCKS_PORT); } Assume(resolved.IsValid()); LogPrint(BCLog::TOR, "Configuring onion proxy for %s\n", resolved.ToStringAddrPort()); Proxy addrOnion = Proxy(resolved, true); SetProxy(NET_ONION, addrOnion); const auto onlynets = gArgs.GetArgs("-onlynet"); const bool onion_allowed_by_onlynet{ !gArgs.IsArgSet("-onlynet") || std::any_of(onlynets.begin(), onlynets.end(), [](const auto& n) { return ParseNetwork(n) == NET_ONION; })}; if (onion_allowed_by_onlynet) { // If NET_ONION is reachable, then the below is a noop. // // If NET_ONION is not reachable, then none of -proxy or -onion was given. // Since we are here, then -torcontrol and -torpassword were given. g_reachable_nets.Add(NET_ONION); } } void TorController::add_onion_cb(TorControlConnection& _conn, const TorControlReply& reply) { if (reply.code == 250) { LogPrint(BCLog::TOR, "ADD_ONION successful\n"); for (const std::string &s : reply.lines) { std::map m = ParseTorReplyMapping(s); std::map::iterator i; if ((i = m.find("ServiceID")) != m.end()) service_id = i->second; if ((i = m.find("PrivateKey")) != m.end()) private_key = i->second; } if (service_id.empty()) { LogPrintf("tor: Error parsing ADD_ONION parameters:\n"); for (const std::string &s : reply.lines) { LogPrintf(" %s\n", SanitizeString(s)); } return; } service = LookupNumeric(std::string(service_id+".onion"), Params().GetDefaultPort()); LogPrintfCategory(BCLog::TOR, "Got service ID %s, advertising service %s\n", service_id, service.ToStringAddrPort()); if (WriteBinaryFile(GetPrivateKeyFile(), private_key)) { LogPrint(BCLog::TOR, "Cached service private key to %s\n", fs::PathToString(GetPrivateKeyFile())); } else { LogPrintf("tor: Error writing service private key to %s\n", fs::PathToString(GetPrivateKeyFile())); } AddLocal(service, LOCAL_MANUAL); // ... onion requested - keep connection open } else if (reply.code == 510) { // 510 Unrecognized command LogPrintf("tor: Add onion failed with unrecognized command (You probably need to upgrade Tor)\n"); } else { LogPrintf("tor: Add onion failed; error code %d\n", reply.code); } } void TorController::auth_cb(TorControlConnection& _conn, const TorControlReply& reply) { if (reply.code == 250) { LogPrint(BCLog::TOR, "Authentication successful\n"); // Now that we know Tor is running setup the proxy for onion addresses // if -onion isn't set to something else. if (gArgs.GetArg("-onion", "") == "") { _conn.Command("GETINFO net/listeners/socks", std::bind(&TorController::get_socks_cb, this, std::placeholders::_1, std::placeholders::_2)); } // Finally - now create the service if (private_key.empty()) { // No private key, generate one private_key = "NEW:ED25519-V3"; // Explicitly request key type - see issue #9214 } // Request onion service, redirect port. // Note that the 'virtual' port is always the default port to avoid decloaking nodes using other ports. _conn.Command(strprintf("ADD_ONION %s Port=%i,%s", private_key, Params().GetDefaultPort(), m_target.ToStringAddrPort()), std::bind(&TorController::add_onion_cb, this, std::placeholders::_1, std::placeholders::_2)); } else { LogPrintf("tor: Authentication failed\n"); } } /** Compute Tor SAFECOOKIE response. * * ServerHash is computed as: * HMAC-SHA256("Tor safe cookie authentication server-to-controller hash", * CookieString | ClientNonce | ServerNonce) * (with the HMAC key as its first argument) * * After a controller sends a successful AUTHCHALLENGE command, the * next command sent on the connection must be an AUTHENTICATE command, * and the only authentication string which that AUTHENTICATE command * will accept is: * * HMAC-SHA256("Tor safe cookie authentication controller-to-server hash", * CookieString | ClientNonce | ServerNonce) * */ static std::vector ComputeResponse(const std::string &key, const std::vector &cookie, const std::vector &clientNonce, const std::vector &serverNonce) { CHMAC_SHA256 computeHash((const uint8_t*)key.data(), key.size()); std::vector computedHash(CHMAC_SHA256::OUTPUT_SIZE, 0); computeHash.Write(cookie.data(), cookie.size()); computeHash.Write(clientNonce.data(), clientNonce.size()); computeHash.Write(serverNonce.data(), serverNonce.size()); computeHash.Finalize(computedHash.data()); return computedHash; } void TorController::authchallenge_cb(TorControlConnection& _conn, const TorControlReply& reply) { if (reply.code == 250) { LogPrint(BCLog::TOR, "SAFECOOKIE authentication challenge successful\n"); std::pair l = SplitTorReplyLine(reply.lines[0]); if (l.first == "AUTHCHALLENGE") { std::map m = ParseTorReplyMapping(l.second); if (m.empty()) { LogPrintf("tor: Error parsing AUTHCHALLENGE parameters: %s\n", SanitizeString(l.second)); return; } std::vector serverHash = ParseHex(m["SERVERHASH"]); std::vector serverNonce = ParseHex(m["SERVERNONCE"]); LogPrint(BCLog::TOR, "AUTHCHALLENGE ServerHash %s ServerNonce %s\n", HexStr(serverHash), HexStr(serverNonce)); if (serverNonce.size() != 32) { LogPrintf("tor: ServerNonce is not 32 bytes, as required by spec\n"); return; } std::vector computedServerHash = ComputeResponse(TOR_SAFE_SERVERKEY, cookie, clientNonce, serverNonce); if (computedServerHash != serverHash) { LogPrintf("tor: ServerHash %s does not match expected ServerHash %s\n", HexStr(serverHash), HexStr(computedServerHash)); return; } std::vector computedClientHash = ComputeResponse(TOR_SAFE_CLIENTKEY, cookie, clientNonce, serverNonce); _conn.Command("AUTHENTICATE " + HexStr(computedClientHash), std::bind(&TorController::auth_cb, this, std::placeholders::_1, std::placeholders::_2)); } else { LogPrintf("tor: Invalid reply to AUTHCHALLENGE\n"); } } else { LogPrintf("tor: SAFECOOKIE authentication challenge failed\n"); } } void TorController::protocolinfo_cb(TorControlConnection& _conn, const TorControlReply& reply) { if (reply.code == 250) { std::set methods; std::string cookiefile; /* * 250-AUTH METHODS=COOKIE,SAFECOOKIE COOKIEFILE="/home/x/.tor/control_auth_cookie" * 250-AUTH METHODS=NULL * 250-AUTH METHODS=HASHEDPASSWORD */ for (const std::string &s : reply.lines) { std::pair l = SplitTorReplyLine(s); if (l.first == "AUTH") { std::map m = ParseTorReplyMapping(l.second); std::map::iterator i; if ((i = m.find("METHODS")) != m.end()) { std::vector m_vec = SplitString(i->second, ','); methods = std::set(m_vec.begin(), m_vec.end()); } if ((i = m.find("COOKIEFILE")) != m.end()) cookiefile = i->second; } else if (l.first == "VERSION") { std::map m = ParseTorReplyMapping(l.second); std::map::iterator i; if ((i = m.find("Tor")) != m.end()) { LogPrint(BCLog::TOR, "Connected to Tor version %s\n", i->second); } } } for (const std::string &s : methods) { LogPrint(BCLog::TOR, "Supported authentication method: %s\n", s); } // Prefer NULL, otherwise SAFECOOKIE. If a password is provided, use HASHEDPASSWORD /* Authentication: * cookie: hex-encoded ~/.tor/control_auth_cookie * password: "password" */ std::string torpassword = gArgs.GetArg("-torpassword", ""); if (!torpassword.empty()) { if (methods.count("HASHEDPASSWORD")) { LogPrint(BCLog::TOR, "Using HASHEDPASSWORD authentication\n"); ReplaceAll(torpassword, "\"", "\\\""); _conn.Command("AUTHENTICATE \"" + torpassword + "\"", std::bind(&TorController::auth_cb, this, std::placeholders::_1, std::placeholders::_2)); } else { LogPrintf("tor: Password provided with -torpassword, but HASHEDPASSWORD authentication is not available\n"); } } else if (methods.count("NULL")) { LogPrint(BCLog::TOR, "Using NULL authentication\n"); _conn.Command("AUTHENTICATE", std::bind(&TorController::auth_cb, this, std::placeholders::_1, std::placeholders::_2)); } else if (methods.count("SAFECOOKIE")) { // Cookie: hexdump -e '32/1 "%02x""\n"' ~/.tor/control_auth_cookie LogPrint(BCLog::TOR, "Using SAFECOOKIE authentication, reading cookie authentication from %s\n", cookiefile); std::pair status_cookie = ReadBinaryFile(fs::PathFromString(cookiefile), TOR_COOKIE_SIZE); if (status_cookie.first && status_cookie.second.size() == TOR_COOKIE_SIZE) { // _conn.Command("AUTHENTICATE " + HexStr(status_cookie.second), std::bind(&TorController::auth_cb, this, std::placeholders::_1, std::placeholders::_2)); cookie = std::vector(status_cookie.second.begin(), status_cookie.second.end()); clientNonce = std::vector(TOR_NONCE_SIZE, 0); GetRandBytes(clientNonce); _conn.Command("AUTHCHALLENGE SAFECOOKIE " + HexStr(clientNonce), std::bind(&TorController::authchallenge_cb, this, std::placeholders::_1, std::placeholders::_2)); } else { if (status_cookie.first) { LogPrintf("tor: Authentication cookie %s is not exactly %i bytes, as is required by the spec\n", cookiefile, TOR_COOKIE_SIZE); } else { LogPrintf("tor: Authentication cookie %s could not be opened (check permissions)\n", cookiefile); } } } else if (methods.count("HASHEDPASSWORD")) { LogPrintf("tor: The only supported authentication mechanism left is password, but no password provided with -torpassword\n"); } else { LogPrintf("tor: No supported authentication method\n"); } } else { LogPrintf("tor: Requesting protocol info failed\n"); } } void TorController::connected_cb(TorControlConnection& _conn) { reconnect_timeout = RECONNECT_TIMEOUT_START; // First send a PROTOCOLINFO command to figure out what authentication is expected if (!_conn.Command("PROTOCOLINFO 1", std::bind(&TorController::protocolinfo_cb, this, std::placeholders::_1, std::placeholders::_2))) LogPrintf("tor: Error sending initial protocolinfo command\n"); } void TorController::disconnected_cb(TorControlConnection& _conn) { // Stop advertising service when disconnected if (service.IsValid()) RemoveLocal(service); service = CService(); if (!reconnect) return; LogPrint(BCLog::TOR, "Not connected to Tor control port %s, trying to reconnect\n", m_tor_control_center); // Single-shot timer for reconnect. Use exponential backoff. struct timeval time = MillisToTimeval(int64_t(reconnect_timeout * 1000.0)); if (reconnect_ev) event_add(reconnect_ev, &time); reconnect_timeout *= RECONNECT_TIMEOUT_EXP; } void TorController::Reconnect() { /* Try to reconnect and reestablish if we get booted - for example, Tor * may be restarting. */ if (!conn.Connect(m_tor_control_center, std::bind(&TorController::connected_cb, this, std::placeholders::_1), std::bind(&TorController::disconnected_cb, this, std::placeholders::_1) )) { LogPrintf("tor: Re-initiating connection to Tor control port %s failed\n", m_tor_control_center); } } fs::path TorController::GetPrivateKeyFile() { return gArgs.GetDataDirNet() / "onion_v3_private_key"; } void TorController::reconnect_cb(evutil_socket_t fd, short what, void *arg) { TorController *self = static_cast(arg); self->Reconnect(); } /****** Thread ********/ static struct event_base *gBase; static std::thread torControlThread; static void TorControlThread(CService onion_service_target) { TorController ctrl(gBase, gArgs.GetArg("-torcontrol", DEFAULT_TOR_CONTROL), onion_service_target); event_base_dispatch(gBase); } void StartTorControl(CService onion_service_target) { assert(!gBase); #ifdef WIN32 evthread_use_windows_threads(); #else evthread_use_pthreads(); #endif gBase = event_base_new(); if (!gBase) { LogPrintf("tor: Unable to create event_base\n"); return; } torControlThread = std::thread(&util::TraceThread, "torcontrol", [onion_service_target] { TorControlThread(onion_service_target); }); } void InterruptTorControl() { if (gBase) { LogPrintf("tor: Thread interrupt\n"); event_base_once(gBase, -1, EV_TIMEOUT, [](evutil_socket_t, short, void*) { event_base_loopbreak(gBase); }, nullptr, nullptr); } } void StopTorControl() { if (gBase) { torControlThread.join(); event_base_free(gBase); gBase = nullptr; } } CService DefaultOnionServiceTarget() { struct in_addr onion_service_target; onion_service_target.s_addr = htonl(INADDR_LOOPBACK); return {onion_service_target, BaseParams().OnionServiceTargetPort()}; }