[tor-commits] [flashproxy/master] Connect to the client before trying to connect to the relay.

[dcf at torproject.org]

commit c1768feacccd71bbba821299b95c809c82c2dee1
Author: David Fifield <david at bamsoftware.com>
Date:   Fri May 31 10:06:45 2013 -0700

    Connect to the client before trying to connect to the relay.
    
    Many people are registering as flash proxy clients without actually
    being able to receive flash proxy connections, just because they are
    useing the pluggable transports bundles. Connecting to both client and
    relay simultaneously caused many momentary connection on the websocket
    relay, as the client side would fail. Check that we can connect to the
    client before bugging the relay.
---
 proxy/flashproxy.js |   73 +++++++++++++++++++++++++++------------------------
 1 file changed, 39 insertions(+), 34 deletions(-)

diff --git a/proxy/flashproxy.js b/proxy/flashproxy.js
index 07a94ea..48e2625 100644
--- a/proxy/flashproxy.js
+++ b/proxy/flashproxy.js
@@ -686,18 +686,34 @@ function ProxyPair(client_addr, relay_addr, rate_limit) {
     this.complete_callback = function() {
     };
 
-    /* Return a function that shows an error message and closes the other
-       half of a communication pair. */
-    this.make_onerror_callback = function(partner) {
-        return function(event) {
-            var ws = event.target;
-
-            log(ws.label + ": error.");
-            partner.close();
-        }.bind(this);
+    this.connect = function() {
+        log("Client: connecting.");
+        this.client_s = make_websocket(this.client_addr);
+
+        /* Try to connect to the client first (since that is more likely to
+           fail) and only after that try to connect to the relay. */
+        this.client_s.label = "Client";
+        this.client_s.onopen = this.client_onopen_callback;
+        this.client_s.onclose = this.onclose_callback;
+        this.client_s.onerror = this.onerror_callback;
+        this.client_s.onmessage = this.onmessage_client_to_relay;
     };
 
-    this.onopen_callback = function(event) {
+    this.client_onopen_callback = function(event) {
+        var ws = event.target;
+
+        log(ws.label + ": connected.");
+        log("Relay: connecting.");
+        this.relay_s = make_websocket(this.relay_addr);
+
+        this.relay_s.label = "Relay";
+        this.relay_s.onopen = this.relay_onopen_callback;
+        this.relay_s.onclose = this.onclose_callback;
+        this.relay_s.onerror = this.onerror_callback;
+        this.relay_s.onmessage = this.onmessage_relay_to_client;
+    }.bind(this);
+
+    this.relay_onopen_callback = function(event) {
         var ws = event.target;
 
         log(ws.label + ": connected.");
@@ -715,6 +731,13 @@ function ProxyPair(client_addr, relay_addr, rate_limit) {
         }
     }.bind(this);
 
+    this.onerror_callback = function(event) {
+        var ws = event.target;
+
+        log(ws.label + ": error.");
+        this.close();
+    }.bind(this);
+
     this.onmessage_client_to_relay = function(event) {
         this.c2r_schedule.push(event.data);
         this.flush();
@@ -725,37 +748,19 @@ function ProxyPair(client_addr, relay_addr, rate_limit) {
         this.flush();
     }.bind(this);
 
-    this.connect = function() {
-        log("Client: connecting.");
-        this.client_s = make_websocket(this.client_addr);
-
-        log("Relay: connecting.");
-        this.relay_s = make_websocket(this.relay_addr);
-
-        this.client_s.label = "Client";
-        this.client_s.onopen = this.onopen_callback;
-        this.client_s.onclose = this.onclose_callback;
-        this.client_s.onerror = this.make_onerror_callback(this.relay_s);
-        this.client_s.onmessage = this.onmessage_client_to_relay;
-
-        this.relay_s.label = "Relay";
-        this.relay_s.onopen = this.onopen_callback;
-        this.relay_s.onclose = this.onclose_callback;
-        this.relay_s.onerror = this.make_onerror_callback(this.client_s);
-        this.relay_s.onmessage = this.onmessage_relay_to_client;
-    };
-
     function is_open(ws) {
-        return ws.readyState === ws.OPEN;
+        return ws !== undefined && ws.readyState === ws.OPEN;
     }
 
     function is_closed(ws) {
-        return ws.readyState === ws.CLOSED;
+        return ws === undefined || ws.readyState === ws.CLOSED;
     }
 
     this.close = function() {
-        this.client_s.close();
-        this.relay_s.close();
+        if (!is_closed(this.client_s))
+            this.client_s.close();
+        if (!is_closed(this.relay_s))
+            this.relay_s.close();
     };
 
     /* Send as much data as the rate limit currently allows. */