commit 07291a0136b8a01bd8761a14a51876f08ca0d578 Author: David Fifield david@bamsoftware.com Date: Wed Mar 21 22:52:30 2018 -0700

Add a 5s delay between polls in proxy-go.

https://bugs.torproject.org/25344

5s matches DEFAULT_BROKER_POLL_INTERVAL in the JavaScript proxy.

This is set up so as long as the actual HTTPS requests take less time than pollInterval, there will a steady one poll per pollInterval. If the HTTPS requests take longer than that, there will be no delay between polls. --- proxy-go/snowflake.go | 13 +++++++++++++ 1 file changed, 13 insertions(+)

diff --git a/proxy-go/snowflake.go b/proxy-go/snowflake.go index 5a5925e..7bb435c 100644 --- a/proxy-go/snowflake.go +++ b/proxy-go/snowflake.go @@ -25,6 +25,7 @@ import ( const defaultBrokerURL = "https://snowflake-reg.appspot.com/" const defaultRelayURL = "wss://snowflake.bamsoftware.com/" const defaultSTUNURL = "stun:stun.l.google.com:19302" +const pollInterval = 5 * time.Second

var brokerURL *url.URL var relayURL string @@ -133,7 +134,19 @@ func genSessionID() string {

func pollOffer(sid string) *webrtc.SessionDescription { broker := brokerURL.ResolveReference(&url.URL{Path: "proxy"}) + timeOfNextPoll := time.Now() for { + // Sleep until we're scheduled to poll again. + now := time.Now() + time.Sleep(timeOfNextPoll.Sub(now)) + // Compute the next time to poll -- if it's in the past, that + // means that the POST took longer than pollInterval, so we're + // allowed to do another one immediately. + timeOfNextPoll = timeOfNextPoll.Add(pollInterval) + if timeOfNextPoll.Before(now) { + timeOfNextPoll = now + } + req, _ := http.NewRequest("POST", broker.String(), bytes.NewBuffer([]byte(sid))) req.Header.Set("X-Session-ID", sid) resp, err := client.Do(req)