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Stop writing to global opt.brokerURL variable.

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This variable was being written to by multiple goroutines, overwriting
the Path to either "/proxy" or "/answer" as necessary, which was racy.
This commit is contained in:
David Fifield 2017-08-01 15:51:34 -07:00
parent 461dbeba80
commit 1eb5c66428
1 changed files with 16 additions and 6 deletions
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22
proxy-go/snowflake.go
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@ -28,7 +28,6 @@ const defaultSTUNURL = "stun:stun.l.google.com:19302"
type snowflakeOptions struct {
capacity uint
broker string
brokerURL *url.URL
stun string
relay string
}
@ -102,7 +101,17 @@ func genSessionID() string {
return strings.TrimRight(base64.StdEncoding.EncodeToString(buf), "=")
}
func pollOffer(sid string, broker *url.URL) *webrtc.SessionDescription {
// Parses a URL with url.Parse and panics on any error.
func mustParseURL(rawurl string) *url.URL {
u, err := url.Parse(rawurl)
if err != nil {
panic(err)
}
return u
}
func pollOffer(sid string) *webrtc.SessionDescription {
broker := mustParseURL(opt.broker)
broker.Path = "/proxy"
for {
req, _ := http.NewRequest("POST", broker.String(), bytes.NewBuffer([]byte(sid)))
@ -126,7 +135,8 @@ func pollOffer(sid string, broker *url.URL) *webrtc.SessionDescription {
}
}
func sendAnswer(sid string, broker *url.URL, pc *webrtc.PeerConnection) error {
func sendAnswer(sid string, pc *webrtc.PeerConnection) error {
broker := mustParseURL(opt.broker)
broker.Path = "/answer"
body := bytes.NewBuffer([]byte(pc.LocalDescription().Serialize()))
req, _ := http.NewRequest("POST", broker.String(), body)
@ -272,7 +282,7 @@ func makePeerConnectionFromOffer(sdp *webrtc.SessionDescription, config *webrtc.
}
func runSession(sid string) {
offer := pollOffer(sid, opt.brokerURL)
offer := pollOffer(sid)
if offer == nil {
log.Printf("bad offer from broker")
retToken()
@ -284,7 +294,7 @@ func runSession(sid string) {
retToken()
return
}
err = sendAnswer(sid, opt.brokerURL, pc)
err = sendAnswer(sid, pc)
if err != nil {
log.Printf("error sending answer to client through broker: %s", err)
pc.Close()
@ -314,7 +324,7 @@ func main() {
}
var err error
opt.brokerURL, err = url.Parse(opt.broker)
_, err = url.Parse(opt.broker)
if err != nil {
log.Fatalf("invalid broker url: %s", err)
}