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Support recurring NAT Type measurement

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currentNATType will from now on be guarded by currentNATTypeAccess for any access.

NAT Type update rule is flattened into state transfer lookup table to assist reading.
This commit is contained in:
Shelikhoo 2021-11-04 19:55:48 +00:00
parent ead5a960d7
commit 04bc471a63
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GPG key ID: C4D5E79D22B25316
1 changed files with 58 additions and 4 deletions
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62
proxy/lib/snowflake.go
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@ -73,6 +73,10 @@ const readLimit = 100000 //Maximum number of bytes to be read from an HTTP reque
var broker *SignalingServer
var currentNATTypeAccess = &sync.RWMutex{}
// currentNATType describes local network environment.
// Obtain currentNATTypeAccess before access.
var currentNATType = NATUnknown
const (
@ -183,7 +187,10 @@ func (s *SignalingServer) pollOffer(sid string, shutdown chan struct{}) *webrtc.
return nil
default:
numClients := int((tokens.count() / 8) * 8) // Round down to 8
body, err := messages.EncodePollRequest(sid, "standalone", currentNATType, numClients)
currentNATTypeAccess.RLock()
currentNATTypeLoaded := currentNATType
currentNATTypeAccess.RUnlock()
body, err := messages.EncodePollRequest(sid, "standalone", currentNATTypeLoaded, numClients)
if err != nil {
log.Printf("Error encoding poll message: %s", err.Error())
return nil
@ -530,7 +537,12 @@ func (sf *SnowflakeProxy) Start() error {
// use probetest to determine NAT compatability
sf.checkNATType(config, sf.NATProbeURL)
log.Printf("NAT type: %s", currentNATType)
currentNATTypeAccess.RLock()
currentNATTypeLoaded := currentNATType
currentNATTypeAccess.RUnlock()
log.Printf("NAT type: %s", currentNATTypeLoaded)
ticker := time.NewTicker(pollInterval)
defer ticker.Stop()
@ -604,12 +616,54 @@ func (sf *SnowflakeProxy) checkNATType(config webrtc.Configuration, probeURL str
return
}
currentNATTypeAccess.RLock()
currentNATTypeLoaded := currentNATType
currentNATTypeAccess.RUnlock()
currentNATTypeTestResult := NATUnknown
select {
case <-dataChan:
currentNATType = NATUnrestricted
currentNATTypeTestResult = NATUnrestricted
case <-time.After(dataChannelTimeout):
currentNATType = NATRestricted
currentNATTypeTestResult = NATRestricted
}
currentNATTypeToStore := NATUnknown
switch currentNATTypeLoaded + "->" + currentNATTypeTestResult {
case NATUnknown + "->" + NATUnknown:
currentNATTypeToStore = NATUnknown
case NATUnknown + "->" + NATUnrestricted:
currentNATTypeToStore = NATUnrestricted
case NATUnknown + "->" + NATRestricted:
currentNATTypeToStore = NATRestricted
case NATUnrestricted + "->" + NATUnknown:
currentNATTypeToStore = NATUnrestricted
case NATUnrestricted + "->" + NATUnrestricted:
currentNATTypeToStore = NATUnrestricted
case NATUnrestricted + "->" + NATRestricted:
currentNATTypeToStore = NATRestricted
case NATRestricted + "->" + NATUnknown:
currentNATTypeToStore = NATRestricted
case NATRestricted + "->" + NATUnrestricted:
currentNATTypeToStore = NATUnrestricted
case NATRestricted + "->" + NATRestricted:
currentNATTypeToStore = NATRestricted
}
log.Printf("NAT Type measurement: %v -> %v = %v\n", currentNATTypeLoaded, currentNATTypeTestResult, currentNATTypeToStore)
currentNATTypeAccess.Lock()
currentNATType = currentNATTypeToStore
currentNATTypeAccess.Unlock()
if err := pc.Close(); err != nil {
log.Printf("error calling pc.Close: %v", err)
}