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Make the proxy to report the number of clients to the broker

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So the assignment of proxies is based on the load. The number of clients
is ronded down to 8. Existing proxies that doesn't report the number
of clients will be distributed equaly to new proxies until they get 8
clients, that is okish as the existing proxies do have a maximum
capacity of 10.

Fixes #40048
This commit is contained in:
meskio 2021-06-25 13:47:47 +02:00
parent 74bdb85b30
commit 7a1857c42f
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GPG key ID: 52B8F5AC97A2DA86
9 changed files with 165 additions and 77 deletions
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63
proxy/snowflake.go
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@ -55,7 +55,7 @@ const (
)
var (
tokens chan bool
tokens *tokens_t
config webrtc.Configuration
client http.Client
)
@ -171,14 +171,6 @@ func (c *webRTCConn) SetWriteDeadline(t time.Time) error {
return fmt.Errorf("SetWriteDeadline not implemented")
}
func getToken() {
<-tokens
}
func retToken() {
tokens <- true
}
func genSessionID() string {
buf := make([]byte, sessionIDLength)
_, err := rand.Read(buf)
@ -204,6 +196,21 @@ type SignalingServer struct {
keepLocalAddresses bool
}
func newSignalingServer(rawURL string, keepLocalAddresses bool) (*SignalingServer, error) {
var err error
s := new(SignalingServer)
s.keepLocalAddresses = keepLocalAddresses
s.url, err = url.Parse(rawURL)
if err != nil {
return nil, fmt.Errorf("invalid broker url: %s", err)
}
s.transport = http.DefaultTransport.(*http.Transport)
s.transport.(*http.Transport).ResponseHeaderTimeout = 30 * time.Second
return s, nil
}
func (s *SignalingServer) Post(path string, payload io.Reader) ([]byte, error) {
req, err := http.NewRequest("POST", path, payload)
@ -238,7 +245,8 @@ func (s *SignalingServer) pollOffer(sid string) *webrtc.SessionDescription {
timeOfNextPoll = now
}
body, err := messages.EncodePollRequest(sid, "standalone", currentNATType)
numClients := int((tokens.count() / 8) * 8) // Round down to 8
body, err := messages.EncodePollRequest(sid, "standalone", currentNATType, numClients)
if err != nil {
log.Printf("Error encoding poll message: %s", err.Error())
return nil
@ -323,7 +331,7 @@ func CopyLoop(c1 io.ReadWriteCloser, c2 io.ReadWriteCloser) {
// RemoteAddr). https://bugs.torproject.org/18628#comment:8
func datachannelHandler(conn *webRTCConn, remoteAddr net.Addr) {
defer conn.Close()
defer retToken()
defer tokens.ret()
u, err := url.Parse(relayURL)
if err != nil {
@ -494,14 +502,14 @@ func runSession(sid string) {
offer := broker.pollOffer(sid)
if offer == nil {
log.Printf("bad offer from broker")
retToken()
tokens.ret()
return
}
dataChan := make(chan struct{})
pc, err := makePeerConnectionFromOffer(offer, config, dataChan, datachannelHandler)
if err != nil {
log.Printf("error making WebRTC connection: %s", err)
retToken()
tokens.ret()
return
}
err = broker.sendAnswer(sid, pc)
@ -510,7 +518,7 @@ func runSession(sid string) {
if inerr := pc.Close(); inerr != nil {
log.Printf("error calling pc.Close: %v", inerr)
}
retToken()
tokens.ret()
return
}
// Set a timeout on peerconnection. If the connection state has not
@ -524,7 +532,7 @@ func runSession(sid string) {
if err := pc.Close(); err != nil {
log.Printf("error calling pc.Close: %v", err)
}
retToken()
tokens.ret()
}
}
@ -536,7 +544,7 @@ func main() {
var unsafeLogging bool
var keepLocalAddresses bool
flag.UintVar(&capacity, "capacity", 10, "maximum concurrent clients")
flag.UintVar(&capacity, "capacity", 0, "maximum concurrent clients")
flag.StringVar(&rawBrokerURL, "broker", defaultBrokerURL, "broker URL")
flag.StringVar(&relayURL, "relay", defaultRelayURL, "websocket relay URL")
flag.StringVar(&stunURL, "stun", defaultSTUNURL, "stun URL")
@ -565,12 +573,11 @@ func main() {
log.Println("starting")
var err error
broker = new(SignalingServer)
broker.keepLocalAddresses = keepLocalAddresses
broker.url, err = url.Parse(rawBrokerURL)
broker, err = newSignalingServer(rawBrokerURL, keepLocalAddresses)
if err != nil {
log.Fatalf("invalid broker url: %s", err)
log.Fatal(err)
}
_, err = url.Parse(stunURL)
if err != nil {
log.Fatalf("invalid stun url: %s", err)
@ -580,8 +587,6 @@ func main() {
log.Fatalf("invalid relay url: %s", err)
}
broker.transport = http.DefaultTransport.(*http.Transport)
broker.transport.(*http.Transport).ResponseHeaderTimeout = 15 * time.Second
config = webrtc.Configuration{
ICEServers: []webrtc.ICEServer{
{
@ -589,17 +594,14 @@ func main() {
},
},
}
tokens = make(chan bool, capacity)
for i := uint(0); i < capacity; i++ {
tokens <- true
}
tokens = newTokens(capacity)
// use probetest to determine NAT compatability
checkNATType(config, defaultProbeURL)
log.Printf("NAT type: %s", currentNATType)
for {
getToken()
tokens.get()
sessionID := genSessionID()
runSession(sessionID)
}
@ -607,12 +609,7 @@ func main() {
func checkNATType(config webrtc.Configuration, probeURL string) {
var err error
probe := new(SignalingServer)
probe.transport = http.DefaultTransport.(*http.Transport)
probe.transport.(*http.Transport).ResponseHeaderTimeout = 30 * time.Second
probe.url, err = url.Parse(probeURL)
probe, err := newSignalingServer(probeURL, false)
if err != nil {
log.Printf("Error parsing url: %s", err.Error())
}