Merge pull request #6 from vale981/reverse-forwarding

Add forwarding for reverse tunnels.

README.md

@@ -54,6 +54,7 @@ The `connect` event will fire only once when the initial ssh connection is made.
 - `kill` - a method to kill autossh
 - `pid` - the autossh process id
 - `host`
+- `localHost` - The host, to which the tunnel applies.
 - `username`
 - `remotePort`
 - `localPort`
@@ -127,6 +128,27 @@ autossh({
 
 <br />
 
+#### Tunneling Ports from another Host
+
+It is also possible to use the tunnel as gateway to another host in the local network (for example a webcam).
+
+By default, the `localHost` property is set to `localhost`, but you can overwrite it.
+
+**Note that setting this property to a value different from `localhost` will make the tunnel reverse automaticly.**
+
+``` javascript
+autossh({
+  host: '111.22.333.444',
+  localhost: '192.168.1.25',
+  username: 'root',
+  localPort: '64444',
+  remotePort: 5432
+})
+.on('connect', connection => {
+  console.log('connected: ', connection);
+});
+```
+
 #### Killing the Autossh Process
 
 The autossh process will automatically die if the node process is closed, but you can manually kill the process using `kill`.

index.js

@@ -55,9 +55,10 @@ var AutoSSH = function (_EventEmitter) {
   _createClass(AutoSSH, [{
     key: 'configure',
     value: function configure(conf) {
-      this.reverse = conf.reverse === true || false;
-
       this.host = conf.host;
+      this.localHost = conf.localHost || 'localhost';
+      this.reverse = conf.reverse === true || this.localHost !== 'localhost';
+
       this.username = conf.username || 'root';
       this.remotePort = conf.remotePort;
 
@@ -84,7 +85,7 @@ var AutoSSH = function (_EventEmitter) {
       var _this2 = this;
 
       var port = this.localPort === 'auto' ? this.generateRandomPort() : this.localPort;
-      if (this.reverse) {
+      if (this.reverse || this.localHost !== 'localhost') {
         this.execTunnel(function () {
           _this2.pollConnection();
         });
@@ -117,6 +118,7 @@ var AutoSSH = function (_EventEmitter) {
         },
         pid: null,
         host: this.host || null,
+        localHost: this.localHost || null,
         username: this.username || null,
         remotePort: parseInt(this.remotePort),
         localPort: parseInt(this.localPort),
@@ -193,11 +195,18 @@ var AutoSSH = function (_EventEmitter) {
     value: function isConnectionEstablished(connEstablishedCb) {
       var _this6 = this;
 
+      if (this.localHost !== 'localhost' || this.reverse) {
+        connEstablishedCb(true);
+        return;
+      }
+
       _portfinder2.default.getPort({ port: this.localPort }, function (portfinderErr, freePort) {
         if (portfinderErr) return connEstablishedCb(false);
 
         if (_this6.localPort === freePort) return connEstablishedCb(false);else return connEstablishedCb(true);
       });
+
+      return;
     }
 
     /* parses the conf for errors
@@ -272,8 +281,9 @@ var AutoSSH = function (_EventEmitter) {
       var defaultOpts = this.generateDefaultOptions();
       var privateKey = this.privateKey ? '-i ' + this.privateKey : '';
       var sshPort = this.sshPort === 22 ? '' : '-p ' + this.sshPort;
+      var gatewayPorts = this.localHost === 'localhost' ? '' : '-o GatewayPorts=yes';
 
-      return defaultOpts + ' ' + serverAliveOpts + ' ' + privateKey + ' ' + sshPort;
+      return defaultOpts + ' ' + serverAliveOpts + ' ' + gatewayPorts + ' ' + privateKey + ' ' + sshPort;
     }
 
     /*
@@ -284,7 +294,7 @@ var AutoSSH = function (_EventEmitter) {
     value: function generateExecString() {
       var startPort = this.reverse ? this.remotePort : this.localPort;
       var endPort = this.reverse ? this.localPort : this.remotePort;
-      var bindAddress = startPort + ':localhost:' + endPort;
+      var bindAddress = startPort + ':' + this.localHost + ':' + endPort;
       var options = this.generateExecOptions();
       var userAtHost = this.username + '@' + this.host;
       var method = this.reverse ? 'R' : 'L';

src/index.js

@@ -27,9 +27,10 @@ class AutoSSH extends EventEmitter {
   }
 
   configure(conf) {
-    this.reverse = conf.reverse === true || false;
-
     this.host = conf.host;
+    this.localHost = conf.localHost || 'localhost';
+    this.reverse = conf.reverse === true || (this.localHost !== 'localhost');
+
     this.username = conf.username || 'root';
     this.remotePort = conf.remotePort;
 
@@ -56,7 +57,7 @@ class AutoSSH extends EventEmitter {
   */
   connect(conf) {
     const port = this.localPort === 'auto' ? this.generateRandomPort() : this.localPort;
-    if (this.reverse) {
+    if (this.reverse || this.localHost !== 'localhost') {
       this.execTunnel(() => {
         this.pollConnection();
       });
@@ -87,6 +88,7 @@ class AutoSSH extends EventEmitter {
       kill: () => this.kill,
       pid: null,
       host: this.host || null,
+      localHost: this.localHost || null,
       username: this.username || null,
       remotePort: parseInt(this.remotePort),
       localPort: parseInt(this.localPort),
@@ -150,6 +152,11 @@ class AutoSSH extends EventEmitter {
   /* checks if connection is established at port
   */
   isConnectionEstablished(connEstablishedCb) {
+    if (this.localHost !== 'localhost' || this.reverse) {
+      connEstablishedCb(true);
+      return;
+    }
+
     portfinder.getPort({ port: this.localPort }, (portfinderErr, freePort) => {
       if (portfinderErr)
         return connEstablishedCb(false);
@@ -159,6 +166,8 @@ class AutoSSH extends EventEmitter {
       else
         return connEstablishedCb(true);
     });
+
+    return;
   }
 
   /* parses the conf for errors
@@ -236,8 +245,9 @@ class AutoSSH extends EventEmitter {
     const defaultOpts = this.generateDefaultOptions();
     const privateKey = this.privateKey ? `-i ${this.privateKey}` : '';
     const sshPort = this.sshPort === 22 ? '' : `-p ${this.sshPort}`;
+    const gatewayPorts = this.localHost === 'localhost' ? '' : '-o GatewayPorts=yes';
 
-    return `${defaultOpts} ${serverAliveOpts} ${privateKey} ${sshPort}`;
+    return `${defaultOpts} ${serverAliveOpts} ${gatewayPorts} ${privateKey} ${sshPort}`;
   }
 
   /*
@@ -245,7 +255,7 @@ class AutoSSH extends EventEmitter {
   generateExecString() {
     const startPort = this.reverse ? this.remotePort : this.localPort;
     const endPort = this.reverse ? this.localPort : this.remotePort;
-    const bindAddress = `${startPort}:localhost:${endPort}`;
+    const bindAddress = `${startPort}:${this.localHost}:${endPort}`;
     const options = this.generateExecOptions();
     const userAtHost = `${this.username}@${this.host}`;
     const method = this.reverse ? 'R' : 'L';