Show Bad Gateway rather than disconnect when south-end has gone missing.

bin/telebit-relay.js

@@ -47,7 +47,13 @@ function applyConfig(config) {
   } else {
     state.Promise = require('bluebird');
   }
-  state.tlsOptions = {}; // TODO just close the sockets that would use this early? or use the admin servername
+  state.tlsOptions = {
+    // Handles disconnected devices
+    // TODO allow user to opt-in to wildcard hosting for a better error page?
+    SNICallback: function (servername, cb) {
+      return state.greenlock.tlsOptions.SNICallback(state.config.webminDomain || state.servernames[0], cb);
+    }
+  }; // TODO just close the sockets that would use this early? or use the admin servername
   state.config = config;
   state.servernames = config.servernames || [];
   state.secret = state.config.secret;

lib/handlers.js

@@ -10,7 +10,7 @@ function noSniCallback(tag) {
     var err = new Error("[noSniCallback] no handler set for '" + tag + "':'" + servername + "'");
     console.error(err.message);
     cb(new Error(err));
-  }
+  };
 }
 
 module.exports.create = function (state) {
@@ -72,6 +72,28 @@ module.exports.create = function (state) {
   state.tlsInvalidSniServer.on('tlsClientError', function () {
     console.error('tlsClientError InvalidSniServer');
   });
+  state.createHttpInvalid = function (servername) {
+    return http.createServer(function (req, res) {
+      if (!servername) {
+        res.statusCode = 422;
+        res.end(
+          "3. An inexplicable temporal shift of the quantum realm... that makes me feel uncomfortable.\n\n"
+        + "[ERROR] No SNI header was sent. I can only think of two possible explanations for this:\n"
+        + "\t1. You really love Windows XP and you just won't let go of Internet Explorer 6\n"
+        + "\t2. You're writing a bot and you forgot to set the servername parameter\n"
+        );
+        return;
+      }
+
+      // TODO use req.headers.host instead of servername (since domain fronting is disabled anyway)
+      res.statusCode = 502;
+      res.end(
+        "<h1>Oops!</h1>"
+      + "<p>It looks like '" + encodeURIComponent(servername) + "' isn't connected right now.</p>"
+      + "<small>Error: 502 Bad Gateway</small>"
+      );
+    });
+  };
   state.httpsInvalid = function (servername, socket) {
     // none of these methods work:
     // httpsServer.emit('connection', socket);  // this didn't work
@@ -82,28 +104,9 @@ module.exports.create = function (state) {
     //state.tlsInvalidSniServer.emit('connection', wrapSocket(socket));
     var tlsInvalidSniServer = tls.createServer(state.tlsOptions, function (tlsSocket) {
       console.log('[tlsInvalid] tls connection');
-      // things get a little messed up here
-      var httpInvalidSniServer = http.createServer(function (req, res) {
-        if (!servername) {
-          res.statusCode = 422;
-          res.end(
-            "3. An inexplicable temporal shift of the quantum realm... that makes me feel uncomfortable.\n\n"
-          + "[ERROR] No SNI header was sent. I can only think of two possible explanations for this:\n"
-          + "\t1. You really love Windows XP and you just won't let go of Internet Explorer 6\n"
-          + "\t2. You're writing a bot and you forgot to set the servername parameter\n"
-          );
-          return;
-        }
-
-        res.end(
-          "You came in hot looking for '" + servername + "' and, granted, the IP address for that domain"
-        + " must be pointing here (or else how could you be here?), nevertheless either it's not registered"
-        + " in the internal system at all (which Seth says isn't even a thing) or there is no device"
-        + " connected on the south side of the network which has informed me that it's ready to have traffic"
-        + " for that domain forwarded to it (sorry I didn't check that deeply to determine which).\n\n"
-        + "Either way, you're doing strange things that make me feel uncomfortable... Please don't touch me there any more.");
-      });
-      httpInvalidSniServer.emit('connection', tlsSocket);
+      // We create an entire http server object because it's difficult to figure out
+      // how to access the original tlsSocket to get the servername
+      state.createHttpInvalid(servername).emit('connection', tlsSocket);
     });
     tlsInvalidSniServer.on('tlsClientError', function () {
       console.error('tlsClientError InvalidSniServer httpsInvalid');

lib/unwrap-tls.js

@@ -27,6 +27,16 @@ module.exports.createTcpConnectionHandler = function (state) {
       var str;
       var m;
 
+      if (!firstChunk) {
+        try {
+          conn.end();
+        } catch(e) {
+          console.error("[lib/unwrap-tls.js] Error:", e);
+          conn.destroy();
+        }
+        return;
+      }
+
       //conn.pause();
       conn.unshift(firstChunk);
 
@@ -40,6 +50,8 @@ module.exports.createTcpConnectionHandler = function (state) {
       function deferData(fn) {
         if (fn) {
           state[fn](servername, conn);
+        } else {
+          console.error("[SANITY ERROR] '" + fn + "' doesn't have a state handler");
         }
         /*
         process.nextTick(function () {
@@ -48,33 +60,78 @@ module.exports.createTcpConnectionHandler = function (state) {
         */
       }
 
-      function tryTls() {
-        var vhost;
+      var httpOutcomes = {
+        missingServername: function () {
+          console.log("[debug] [http] missing servername");
+          // TODO use a more specific error page
+          deferData('handleInsecureHttp');
+        }
+      , requiresSetup: function () {
+          console.log("[debug] [http] requires setup");
+          // TODO Insecure connections for setup will not work on secure domains (i.e. .app)
+          state.httpSetupServer.emit('connection', conn);
+        }
+      , isInternal: function () {
+          console.log("[debug] [http] is known internally (admin)");
+          if (/well-known/.test(str)) {
+            deferData('handleHttp');
+          } else {
+            deferData('handleInsecureHttp');
+          }
+        }
+      , isVhost: function () {
+          console.log("[debug] [http] is vhost (normal server)");
+          if (/well-known/.test(str)) {
+            deferData('handleHttp');
+          } else {
+            deferData('handleInsecureHttp');
+          }
+        }
+      , assumeExternal: function () {
+          console.log("[debug] [http] assume external");
+          var service = 'http';
+
+          if (!Devices.exist(state.deviceLists, servername)) {
+            // It would be better to just re-read the host header rather
+            // than creating a whole server object, but this is a "rare"
+            // case and I'm feeling lazy right now.
+            console.log("[debug] [http] no device connected");
+            state.createHttpInvalid(servername).emit('connection', conn);
+            return;
+          }
 
-        if (!state.servernames.length) {
+          // TODO make https redirect configurable on a per-domain basis
+          // /^\/\.well-known\/acme-challenge\//.test(str)
+          if (/well-known/.test(str)) {
+            // HTTP
+            console.log("[debug] [http] passthru");
+            pipeWs(servername, service, Devices.next(state.deviceLists, servername), conn, serviceport);
+            return;
+          } else {
+            console.log("[debug] [http] redirect to https");
+            deferData('handleInsecureHttp');
+          }
+        }
+      };
+      var tlsOutcomes = {
+        missingServername: function () {
+          if (state.debug) { console.log("No SNI was given, so there's nothing we can do here"); }
+          deferData('httpsInvalid');
+        }
+      , requiresSetup: function () {
           console.info("[Setup] https => admin => setup => (needs bogus tls certs to start?)");
           deferData('httpsSetupServer');
-          return;
         }
-
-        if (-1 !== state.servernames.indexOf(servername)) {
+      , isInternal: function () {
           if (state.debug) { console.log("[Admin]", servername); }
           deferData('httpsTunnel');
-          return;
         }
-
-        if (state.config.nowww && /^www\./i.test(servername)) {
-          console.log("TODO: use www bare redirect");
-        }
-
-        if (!servername) {
-          if (state.debug) { console.log("No SNI was given, so there's nothing we can do here"); }
-          deferData('httpsInvalid');
-          return;
+      , isVhost: function (vhost) {
+          if (state.debug) { console.log("[tcp] [vhost]", state.config.vhost, "=>", vhost); }
+          deferData('httpsVhost');
         }
-
-        function run() {
-          var nextDevice = Devices.next(state.deviceLists, servername);
+      , assumeExternal: function () {
+         var nextDevice = Devices.next(state.deviceLists, servername);
           if (!nextDevice) {
             if (state.debug) { console.log("No devices match the given servername"); }
             deferData('httpsInvalid');
@@ -82,27 +139,33 @@ module.exports.createTcpConnectionHandler = function (state) {
           }
 
           if (state.debug) { console.log("pipeWs(servername, service, deviceLists['" + servername + "'], socket)"); }
-          deferData();
           pipeWs(servername, service, nextDevice, conn, serviceport);
         }
+      };
+
+      function handleConnection(outcomes) {
+        var vhost;
+
+        // No routing information available
+        if (!servername) { outcomes.missingServername(); return; }
+        // Server needs to be set up
+        if (!state.servernames.length) { outcomes.requiresSetup(); return; }
+        // This is one of the admin domains
+        if (-1 !== state.servernames.indexOf(servername)) { outcomes.isInternal(); return; }
 
         // TODO don't run an fs check if we already know this is working elsewhere
         //if (!state.validHosts) { state.validHosts = {}; }
         if (state.config.vhost) {
-          vhost = state.config.vhost.replace(/:hostname/, (servername||'reallydoesntexist'));
-          if (state.debug) { console.log("[tcp] [vhost]", state.config.vhost, "=>", vhost); }
-          //state.httpsVhost(servername, conn);
-          //return;
+          vhost = state.config.vhost.replace(/:hostname/, servername);
           require('fs').readdir(vhost, function (err, nodes) {
             if (state.debug && err) { console.log("VHOST error", err); }
-            if (err || !nodes) { run(); return; }
-            //if (nodes) { deferData('httpsVhost'); return; }
-            deferData('httpsVhost');
+            if (err || !nodes) { outcomes.assumeExternal(); return; }
+            outcomes.isVhost(vhost);
           });
           return;
         }
 
-        run();
+        outcomes.assumeExternal();
       }
 
       // https://github.com/mscdex/httpolyglot/issues/3#issuecomment-173680155
@@ -111,40 +174,19 @@ module.exports.createTcpConnectionHandler = function (state) {
         service = 'https';
         servername = (sni(firstChunk)||'').toLowerCase().trim();
         if (state.debug) { console.log("[tcp] tls hello from '" + servername + "'"); }
-        tryTls();
+        handleConnection(tlsOutcomes);
         return;
       }
 
       if (firstChunk[0] > 32 && firstChunk[0] < 127) {
+        // (probably) HTTP
         str = firstChunk.toString();
         m = str.match(/(?:^|[\r\n])Host: ([^\r\n]+)[\r\n]*/im);
         servername = (m && m[1].toLowerCase() || '').split(':')[0];
         if (state.debug) { console.log("[tcp] http hostname '" + servername + "'"); }
 
         if (/HTTP\//i.test(str)) {
-          if (!state.servernames.length) {
-            console.info("[tcp] No admin servername. Entering setup mode.");
-            deferData();
-            state.httpSetupServer.emit('connection', conn);
-            return;
-          }
-
-          service = 'http';
-          // TODO make https redirect configurable
-          // /^\/\.well-known\/acme-challenge\//.test(str)
-          if (/well-known/.test(str)) {
-            // HTTP
-            if (Devices.exist(state.deviceLists, servername)) {
-              deferData();
-              pipeWs(servername, service, Devices.next(state.deviceLists, servername), conn, serviceport);
-              return;
-            }
-            deferData('handleHttp');
-            return;
-          }
-
-          // redirect to https
-          deferData('handleInsecureHttp');
+          handleConnection(httpOutcomes);
           return;
         }
       }