telebit-relay.js/lib/relay.js

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'use strict';
var url = require('url');
var PromiseA = require('bluebird');
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var sni = require('sni');
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var Packer = require('proxy-packer');
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var PortServers = {};
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function timeoutPromise(duration) {
return new PromiseA(function (resolve) {
setTimeout(resolve, duration);
});
}
var Devices = require('./device-tracker');
var pipeWs = require('./pipe-ws.js');
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var Server = {
_initCommandHandlers: function (state, srv) {
var commandHandlers = {
add_token: function addToken(newAuth) {
return Server.addToken(state, srv, newAuth);
}
, delete_token: function (token) {
return state.Promise.resolve(function () {
var err;
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if (token !== '*') {
err = Server.removeToken(state, srv, token);
if (err) { return state.Promise.reject(err); }
}
Object.keys(srv.grants).some(function (jwtoken) {
err = Server.removeToken(state, srv, jwtoken);
return err;
});
if (err) { return state.Promise.reject(err); }
return null;
});
}
};
commandHandlers.auth = commandHandlers.add_token;
commandHandlers.authn = commandHandlers.add_token;
commandHandlers.authz = commandHandlers.add_token;
srv._commandHandlers = commandHandlers;
}
, _initPackerHandlers: function (state, srv) {
var packerHandlers = {
oncontrol: function (tun) {
var cmd;
try {
cmd = JSON.parse(tun.data.toString());
} catch (e) {}
if (!Array.isArray(cmd) || typeof cmd[0] !== 'number') {
var msg = 'received bad command "' + tun.data.toString() + '"';
console.warn(msg, 'from websocket', srv.socketId);
Server.sendTunnelMsg(srv, null, [0, {message: msg, code: 'E_BAD_COMMAND'}], 'control');
return;
}
if (cmd[0] < 0) {
// We only ever send one command and we send it once, so we just hard coded the ID as 1.
if (cmd[0] === -1) {
if (cmd[1]) {
console.warn('received error response to hello from', srv.socketId, cmd[1]);
}
}
else {
console.warn('received response to unknown command', cmd, 'from', srv.socketId);
}
return;
}
if (cmd[0] === 0) {
console.warn('received dis-associated error from', srv.socketId, cmd[1]);
return;
}
function onSuccess() {
Server.sendTunnelMsg(srv, null, [-cmd[0], null], 'control');
}
function onError(err) {
Server.sendTunnelMsg(srv, null, [-cmd[0], err], 'control');
}
if (!srv._commandHandlers[cmd[1]]) {
onError({ message: 'unknown command "'+cmd[1]+'"', code: 'E_UNKNOWN_COMMAND' });
return;
}
console.log('command:', cmd[1], cmd.slice(2));
return srv._commandHandlers[cmd[1]].apply(null, cmd.slice(2)).then(onSuccess, onError);
}
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, onconnection: function (tun) {
// I don't think this event can happen since this relay
// is acting the part of the client, but just in case...
// (in fact it should probably be explicitly disallowed)
console.error("[SANITY FAIL] reverse connection start");
}
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, onmessage: function (tun) {
var cid = Packer.addrToId(tun);
if (state.debug) { console.log("remote '" + Server.logName(state, srv) + "' has data for '" + cid + "'", tun.data.byteLength); }
var browserConn = Server.getBrowserConn(state, srv, cid);
if (!browserConn) {
Server.sendTunnelMsg(srv, tun, {message: 'no matching connection', code: 'E_NO_CONN'}, 'error');
return;
}
browserConn.write(tun.data);
// tunnelRead is how many bytes we've read from the tunnel, and written to the browser.
browserConn.tunnelRead = (browserConn.tunnelRead || 0) + tun.data.byteLength;
// If we have more than 1MB buffered data we need to tell the other side to slow down.
// Once we've finished sending what we have we can tell the other side to keep going.
// If we've already sent the 'pause' message though don't send it again, because we're
// probably just dealing with data queued before our message got to them.
if (!browserConn.remotePaused && browserConn.bufferSize > 1024*1024) {
Server.sendTunnelMsg(srv, tun, browserConn.tunnelRead, 'pause');
browserConn.remotePaused = true;
browserConn.once('drain', function () {
Server.sendTunnelMsg(srv, tun, browserConn.tunnelRead, 'resume');
browserConn.remotePaused = false;
});
}
}
, onpause: function (tun) {
var cid = Packer.addrToId(tun);
console.log('[TunnelPause]', cid);
var browserConn = Server.getBrowserConn(state, srv, cid);
if (browserConn) {
browserConn.manualPause = true;
browserConn.pause();
} else {
Server.sendTunnelMsg(srv, tun, {message: 'no matching connection', code: 'E_NO_CONN'}, 'error');
}
}
, onresume: function (tun) {
var cid = Packer.addrToId(tun);
console.log('[TunnelResume]', cid);
var browserConn = Server.getBrowserConn(state, srv, cid);
if (browserConn) {
browserConn.manualPause = false;
browserConn.resume();
} else {
Server.sendTunnelMsg(srv, tun, {message: 'no matching connection', code: 'E_NO_CONN'}, 'error');
}
}
, onend: function (tun) {
var cid = Packer.addrToId(tun);
console.log('[TunnelEnd]', cid);
Server.closeBrowserConn(state, srv, cid);
}
, onerror: function (tun) {
var cid = Packer.addrToId(tun);
console.warn('[TunnelError]', cid, tun.message);
Server.closeBrowserConn(state, srv, cid);
}
};
srv._packerHandlers = packerHandlers;
srv.unpacker = Packer.create(srv._packerHandlers);
}
, _initSocketHandlers: function (state, srv) {
function refreshTimeout() {
srv.lastActivity = Date.now();
}
function checkTimeout() {
// Determine how long the connection has been "silent", ie no activity.
var silent = Date.now() - srv.lastActivity;
// If we have had activity within the last activityTimeout then all we need to do is
// call this function again at the soonest time when the connection could be timed out.
if (silent < state.activityTimeout) {
srv.timeoutId = setTimeout(checkTimeout, state.activityTimeout - silent);
}
// Otherwise we check to see if the pong has also timed out, and if not we send a ping
// and call this function again when the pong will have timed out.
else if (silent < state.activityTimeout + state.pongTimeout) {
if (state.debug) { console.log('pinging', Server.logName(state, srv)); }
try {
srv.ws.ping();
} catch (err) {
console.warn('failed to ping home cloud', Server.logName(state, srv));
}
srv.timeoutId = setTimeout(checkTimeout, state.pongTimeout);
}
// Last case means the ping we sent before didn't get a response soon enough, so we
// need to close the websocket connection.
else {
console.warn('home cloud', Server.logName(state, srv), 'connection timed out');
srv.ws.close(1013, 'connection timeout');
}
}
function forwardMessage(chunk) {
refreshTimeout();
if (state.debug) { console.log('[ws] device => client : demultiplexing message ', chunk.byteLength, 'bytes'); }
//console.log(chunk.toString());
srv.unpacker.fns.addChunk(chunk);
}
function hangup() {
clearTimeout(srv.timeoutId);
console.log('[ws] device hangup', Server.logName(state, srv), 'connection closing');
// remove the allowed domains from the list (but leave the socket)
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Object.keys(srv.grants).forEach(function (jwtoken) {
Server.removeToken(state, srv, jwtoken);
});
srv.ws.terminate();
// remove the socket from the list, period
Devices.close(state.deviceLists, srv);
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}
srv.lastActivity = Date.now();
srv.timeoutId = null;
srv.timeoutId = setTimeout(checkTimeout, state.activityTimeout);
// Note that our websocket library automatically handles pong responses on ping requests
// before it even emits the event.
srv.ws.on('ping', refreshTimeout);
srv.ws.on('pong', refreshTimeout);
srv.ws.on('message', forwardMessage);
srv.ws.on('close', hangup);
srv.ws.on('error', hangup);
}
, init: function init(state, srv) {
Server._initCommandHandlers(state, srv);
Server._initPackerHandlers(state, srv);
Server._initSocketHandlers(state, srv);
// Status Code '1' for Status 'hello'
Server.sendTunnelMsg(srv, null, [1, 'hello', [srv.unpacker._version], Object.keys(srv._commandHandlers)], 'control');
}
, sendTunnelMsg: function sendTunnelMsg(srv, addr, data, service) {
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if (data && !Buffer.isBuffer()) {
data = Buffer.from(JSON.stringify(data));
}
srv.ws.send(Packer.packHeader(addr, data, service), {binary: true});
srv.ws.send(data, {binary: true});
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}
, logName: function logName(state, srv) {
var result = Object.keys(srv.grants).map(function (jwtoken) {
return srv.grants[jwtoken].currentDesc;
}).join(';');
return result || srv.socketId;
}
, onAuth: function onAuth(state, srv, newAuth, grant) {
console.log('\n[relay.js] onAuth');
console.log(newAuth);
console.log(grant);
//var stringauth;
var err;
if (!grant || 'object' !== typeof grant) {
console.log('[relay.js] invalid token', grant);
err = new Error("invalid access token");
err.code = "E_INVALID_TOKEN";
return state.Promise.reject(err);
}
if ('string' !== typeof newAuth) {
newAuth = JSON.stringify(newAuth);
}
console.log('check for upgrade token');
if (grant.jwt && newAuth !== grant.jwt) {
console.log('new token to send back');
// Access Token
Server.sendTunnelMsg(
srv
, null
, [ 3
, 'access_token'
, { jwt: grant.jwt }
]
, 'control'
);
// these aren't needed internally once they're sent
grant.jwt = null;
}
/*
if (!Array.isArray(grant.domains) || !grant.domains.length) {
err = new Error("invalid domains array");
err.code = "E_INVALID_NAME";
return state.Promise.reject(err);
}
*/
if (grant.domains.some(function (name) { return typeof name !== 'string'; })) {
console.log('bad domain names');
err = new Error("invalid domain name(s)");
err.code = "E_INVALID_NAME";
return state.Promise.reject(err);
}
console.log('strolling through pleasantries');
// Add the custom properties we need to manage this remote, then add it to all the relevant
// domains and the list of all this websocket's grants.
grant.domains.forEach(function (domainname) {
console.log('add', domainname, 'to device lists');
srv.domainsMap[domainname] = true;
Devices.add(state.deviceLists, domainname, srv);
});
srv.domains = Object.keys(srv.domainsMap);
srv.currentDesc = (grant.device && (grant.device.id || grant.device.hostname)) || srv.domains.join(',');
grant.currentDesc = (grant.device && (grant.device.id || grant.device.hostname)) || grant.domains.join(',');
grant.srv = srv;
//grant.ws = srv.ws;
//grant.upgradeReq = srv.upgradeReq;
grant.clients = {};
if (!grant.ports) { grant.ports = []; }
function openPort(serviceport) {
function tcpListener(conn) {
Server.onDynTcpConn(state, srv, srv.portsMap[serviceport], conn);
}
serviceport = parseInt(serviceport, 10) || 0;
if (!serviceport) {
// TODO error message about bad port
return;
}
if (PortServers[serviceport]) {
console.log('reuse', serviceport, 'for this connection');
//grant.ports = [];
srv.portsMap[serviceport] = PortServers[serviceport];
srv.portsMap[serviceport].on('connection', tcpListener);
srv.portsMap[serviceport].tcpListener = tcpListener;
Devices.add(state.deviceLists, serviceport, srv);
} else {
try {
console.log('use new', serviceport, 'for this connection');
srv.portsMap[serviceport] = PortServers[serviceport] = require('net').createServer(tcpListener);
srv.portsMap[serviceport].tcpListener = tcpListener;
srv.portsMap[serviceport].listen(serviceport, function () {
console.info('[DynTcpConn] Port', serviceport, 'now open for', grant.currentDesc);
Devices.add(state.deviceLists, serviceport, srv);
});
srv.portsMap[serviceport].on('error', function (e) {
// TODO try again with random port
console.error("Server Error assigning a dynamic port to a new connection:", e);
});
} catch(e) {
// what a wonderful problem it will be the day that this bug needs to be fixed
// (i.e. there are enough users to run out of ports)
console.error("Error assigning a dynamic port to a new connection:", e);
}
}
}
grant.ports.forEach(openPort);
srv.grants[newAuth] = grant;
console.info("[ws] authorized", srv.socketId, "for", grant.currentDesc);
console.log('notify of grants', grant.domains, grant.ports);
Server.sendTunnelMsg(
srv
, null
, [ 2
, 'grant'
, [ ['ssh+https', grant.domains[0], 443 ]
, ['ssh', 'ssh.' + state.config.sharedDomain, grant.ports ]
, ['tcp', 'tcp.' + state.config.sharedDomain, grant.ports ]
, ['https', grant.domains[0] ]
]
]
, 'control'
);
return null;
}
, onDynTcpConn: function onDynTcpConn(state, srv, server, conn) {
var serviceport = server.address().port;
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console.log('[DynTcpConn] new connection on', serviceport);
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var nextDevice = Devices.next(state.deviceLists, serviceport);
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if (!nextDevice) {
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conn.write("[Sanity Error] I've got a blank space baby, but nowhere to write your name.");
conn.end();
try {
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server.close();
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} catch(e) {
console.error("[DynTcpConn] failed to close server:", e);
}
return;
}
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// When using raw TCP we're already paired to the client by port
// and we can begin connecting right away, but we'll wait just a sec
// to reject known bad connections
var sendConnection = setTimeout(function () {
conn.removeListener('data', peekFirstPacket)
console.log("[debug tcp conn] Connecting possible telnet client to device...");
pipeWs(null, 'tcp', nextDevice, conn, serviceport);
}, 350);
function peekFirstPacket(firstChunk) {
clearTimeout(sendConnection);
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if (state.debug) { console.log("[DynTcp]", serviceport, "examining firstChunk from", Packer.socketToId(conn)); }
conn.pause();
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//conn.unshift(firstChunk);
conn._handle.onread(firstChunk.length, firstChunk);
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var servername;
var hostname;
var str;
var m;
if (22 === firstChunk[0]) {
servername = (sni(firstChunk)||'').toLowerCase();
} else if (firstChunk[0] > 32 && firstChunk[0] < 127) {
str = firstChunk.toString();
m = str.match(/(?:^|[\r\n])Host: ([^\r\n]+)[\r\n]*/im);
hostname = (m && m[1].toLowerCase() || '').split(':')[0];
}
if (servername || hostname) {
if (servername) {
conn.write("TLS with sni is allowed only on standard ports. If you've registered '" + servername + "' use port 443.");
} else {
conn.write("HTTP with Host headers is not allowed on dynamic ports. If you've registered '" + hostname + "' use port 80.");
}
conn.end();
return;
}
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// pipeWs(servername, servicename, srv, client, serviceport)
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// remote.clients is managed as part of the piping process
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if (state.debug) { console.log("[DynTcp]", serviceport, "piping to srv (via loadbal)"); }
pipeWs(null, 'tcp', nextDevice, conn, serviceport);
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process.nextTick(function () { conn.resume(); });
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}
conn.once('data', peekFirstPacket);
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}
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, addToken: function addToken(state, srv, newAuth) {
console.log("addToken", newAuth);
if (srv.grants[newAuth]) {
console.log("addToken - duplicate");
// return { message: "token sent multiple times", code: "E_TOKEN_REPEAT" };
return state.Promise.resolve(null);
}
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return state.authenticate({ auth: newAuth }).then(function (authnToken) {
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console.log('\n[relay.js] newAuth');
console.log(newAuth);
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console.log('\n[relay.js] authnToken');
console.log(authnToken);
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if (authnToken.id) {
state.srvs[authnToken.id] = state.srvs[authnToken.id] || {};
state.srvs[authnToken.id].updateAuth = function (validToken) {
return Server.onAuth(state, srv, newAuth, validToken);
};
}
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// will return rejection if necessary
return state.srvs[authnToken.id].updateAuth(authnToken);
});
}
, removeToken: function removeToken(state, srv, jwtoken) {
var grant = srv.grants[jwtoken];
if (!grant) {
return { message: 'specified token not present', code: 'E_INVALID_TOKEN'};
}
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// Prevent any more browser connections for this grant being sent to this srv,
// and any existing connections from trying to send more data across the connection.
grant.domains.forEach(function (domainname) {
Devices.remove(state.deviceLists, domainname, srv);
});
grant.ports.forEach(function (portnumber) {
Devices.remove(state.deviceLists, portnumber, srv);
if (!srv.portsMap[portnumber]) { return; }
try {
srv.portsMap[portnumber].close(function () {
console.log("[DynTcpConn] closing server for ", portnumber);
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delete srv.portsMap[portnumber];
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delete PortServers[portnumber];
});
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} catch(e) { /*ignore*/ }
});
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// Close all of the existing browser connections associated with this websocket connection.
Object.keys(grant.clients).forEach(function (cid) {
Server.closeBrowserConn(state, srv, cid);
});
delete srv.grants[jwtoken];
console.log("[ws] removed token '" + grant.currentDesc + "' from", srv.socketId);
return null;
}
, getBrowserConn: function getBrowserConn(state, srv, cid) {
return srv.clients[cid];
}
, closeBrowserConn: function closeBrowserConn(state, srv, cid) {
if (!srv.clients[cid]) {
return;
}
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PromiseA.resolve().then(function () {
var conn = srv.clients[cid];
conn.tunnelClosing = true;
conn.end();
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// If no data is buffered for writing then we don't need to wait for it to drain.
if (!conn.bufferSize) {
return timeoutPromise(500);
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}
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// Otherwise we want the connection to be able to finish, but we also want to impose
// a time limit for it to drain, since it shouldn't have more than 1MB buffered.
return new PromiseA(function (resolve) {
var timeoutId = setTimeout(resolve, 60*1000);
conn.once('drain', function () {
clearTimeout(timeoutId);
setTimeout(resolve, 500);
});
});
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}).then(function () {
if (srv.clients[cid]) {
console.warn(cid, 'browser connection still present after calling `end`');
srv.clients[cid].destroy();
return timeoutPromise(500);
}
}).then(function () {
if (srv.clients[cid]) {
console.error(cid, 'browser connection still present after calling `destroy`');
delete srv.clients[cid];
}
}).catch(function (err) {
console.warn('failed to close browser connection', cid, err);
});
}
, parseAuth: function parseAuth(state, srv) {
var authn = (srv.upgradeReq.headers.authorization||'').split(/\s+/);
if (authn[0] && 'basic' === authn[0].toLowerCase()) {
try {
authn = new Buffer(authn[1], 'base64').toString('ascii').split(':');
return authn[1];
} catch (err) { }
}
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return url.parse(srv.upgradeReq.url, true).query.access_token;
}
};
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module.exports.store = { Devices: Devices };
module.exports.create = function (state) {
state.deviceLists = { _domains: {}, _devices: {} };
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state.deviceCallbacks = {};
state.srvs = {};
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if (!parseInt(state.activityTimeout, 10)) {
state.activityTimeout = 2 * 60 * 1000;
}
if (!parseInt(state.pongTimeout, 10)) {
state.pongTimeout = 10 * 1000;
}
state.Devices = Devices;
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// TODO Use a Single TCP Handler
// Issues:
// * dynamic ports are dedicated to a device or cluster
// * servernames could come in on ports that belong to a different device
// * servernames could come in that belong to no device
// * this could lead to an attack / security vulnerability with ACME certificates
// Solutions
// * Restrict dynamic ports to a particular device
// * Restrict the use of servernames
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function onWsConnection(_ws, _upgradeReq) {
var srv = {};
var initToken;
srv.ws = _ws;
srv.upgradeReq = _upgradeReq;
// TODO use device's ECDSA thumbprint as device id
srv.id = null;
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srv.socketId = Packer.socketToId(srv.upgradeReq.socket);
srv.grants = {};
srv.clients = {};
srv.domainsMap = {};
srv.portsMap = {};
srv.pausedConns = [];
if (state.debug) { console.log('[ws] connection', srv.socketId); }
initToken = Server.parseAuth(state, srv);
srv.ws._socket.on('drain', function () {
// the websocket library has it's own buffer apart from node's socket buffer, but that one
// is much more difficult to watch, so we watch for the lower level buffer to drain and
// then check to see if the upper level buffer is still too full to write to. Note that
// the websocket library buffer has something to do with compression, so I'm not requiring
// that to be 0 before we start up again.
if (srv.ws.bufferedAmount > 128*1024) {
return;
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}
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srv.pausedConns.forEach(function (conn) {
if (!conn.manualPause) {
// console.log('resuming', conn.tunnelCid, 'now that the web socket has caught up');
conn.resume();
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}
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});
srv.pausedConns.length = 0;
});
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if (initToken) {
return Server.addToken(state, srv, initToken).then(function () {
Server.init(state, srv);
}).catch(function (err) {
Server.sendTunnelMsg(srv, null, [0, err], 'control');
srv.ws.close();
});
} else {
return Server.init(state, srv);
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}
}
return {
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tcp: require('./unwrap-tls').createTcpConnectionHandler(state)
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, ws: onWsConnection
, isClientDomain: Devices.exist.bind(null, state.deviceLists)
};
};