Matthias Radestock
27c9e70ea9
Currently we cannot distinguish bi-directional and uni-directional connectivity between peers. This is what currently happens for a connection from A to B... A: remoteUDPAddr=X B: remoteUDPAddr=nil A: send fast heartbeats over UDP B: receive heartbeat; remoteUDPAddr is nil remoteUDPAddr=Y send 'established' over TCP established=true send slow heartbeats over UDP A: receive 'established' over TCP established=true send slow heartbeats over UDP If udp packets make it through from A to B but not B to A then both ends mark the connection as 'established'. Conversely, if udp packets make it through from B to A but not A to B then the connection is not marked as 'established' at either end. In the new scheme, this is what happens... A: receivedHeartbeat=false, remoteUDPAddr=X B: receivedHeartbeat=false, remoteUDPAddr=nil A: send fast heartbeats over UDP B: receive heartbeat; receivedHeartbeat is false remoteUDPAddr=Y receivedHeartbeat=true send 'established' over TCP send fast heartbeats over UDP A: receive 'established' over TCP (*) established=true send slow heartbeats over UDP A: receive heartbeat; receivedHeartbeat is false (*) receivedHeartbeat=true send 'established' over TCP B: receive 'established' over TCP established=true send slow heartbeats over UDP (*) either of these may occur first Now, if udp packets make it through from A to B not not B to A then A marks the connection as 'established' but B doesn't. Conversely, if udp packets make it through from B to A but not A to B then B marks the connection as 'established' but A doesn't.
52 lines
1.5 KiB
Go
52 lines
1.5 KiB
Go
package router
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import (
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"math"
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"time"
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)
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const (
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Protocol = "weave"
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ProtocolVersion = 9
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EthernetOverhead = 14
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UDPOverhead = 28 // 20 bytes for IPv4, 8 bytes for UDP
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Port = 6783
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HttpPort = Port + 1
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DefaultPMTU = 65535
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MaxUDPPacketSize = 65536
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ChannelSize = 16
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UDPNonceSendAt = 8192
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FragTestSize = 60001
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PMTUDiscoverySize = 60000
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FastHeartbeat = 500 * time.Millisecond
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SlowHeartbeat = 10 * time.Second
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FetchAllInterval = 30 * time.Second
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FragTestInterval = 5 * time.Minute
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ReadTimeout = 2 * FetchAllInterval
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PMTUVerifyAttempts = 8
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PMTUVerifyTimeout = 10 * time.Millisecond // gets doubled with every attempt
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MaxDuration = time.Duration(math.MaxInt64)
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)
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const (
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ProtocolConnectionEstablished = iota
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ProtocolFragmentationReceived
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ProtocolStartFragmentationTest
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ProtocolNonce
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ProtocolFetchAll
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ProtocolUpdate
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ProtocolPMTUVerified
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)
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var (
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FragTest = make([]byte, FragTestSize)
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PMTUDiscovery = make([]byte, PMTUDiscoverySize)
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ProtocolConnectionEstablishedByte = []byte{ProtocolConnectionEstablished}
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ProtocolFragmentationReceivedByte = []byte{ProtocolFragmentationReceived}
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ProtocolStartFragmentationTestByte = []byte{ProtocolStartFragmentationTest}
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ProtocolNonceByte = []byte{ProtocolNonce}
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ProtocolFetchAllByte = []byte{ProtocolFetchAll}
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ProtocolUpdateByte = []byte{ProtocolUpdate}
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ProtocolPMTUVerifiedByte = []byte{ProtocolPMTUVerified}
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)
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