VPNConnection using NWUDPSession disconnecting after sleep/wake

Question

Created Jun ’21

Replies 3

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Participants 2

Hi again all, We have a weird situation here on sleep/wake in our NEPacketTunnelProvider-based app. The sleep and wake callbacks are called properly and we have noticed that the NWUDPSession is disconnected just after the Mac has awakened... if the Mac is running on an Ethernet connection? The same sleep/wake behaves properly if the Mac is running on Wifi?!? Weird. Do we need to wait for some state after wake? It's hard to understand since it's only happening when running on the Ethernet-port. Confused here 🤪. Best regards / Jorgen / Clavister AB

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Answer 1

Systems Engineer OP

Apple

Jun ’21

Do we need to wait for some state after wake? It's hard to understand since it's only happening when running on the Ethernet-port.

It's hard to say. It may be just that your packet tunnel needs to reconnect itself with the VPN server and the NWUDPSession has gone into the .failed or .cancelled state. What is NWUDPSessionState reporting when this happens?

Matt Eaton
DTS Engineering, CoreOS
meaton3@apple.com

0

Answer 2

jogga OP

Jun ’21

Hi again Matt,

I can see this error when trying to writeDatagram just after wake from sleep...

Failed to write data to udpSession. Error: The operation couldn’t be completed. No buffer space available, (code=55)

Best regards / Jorgen

0

Answer 3

Systems Engineer OP

Apple

Jun ’21

It seems like if we keep trying the NWUDPSession eventually can start to write

Is it a situation where your packet tunnel just needs to re-establish the connection to the server in the wake method and until it does the NWUDPSession is not available? If this is true I am assuming that based on the successful call to setTunnelNetworkSettings you could go through and establish the session for NWUDPSession once again.

You may also want to check the NWUDPSessionState in this condition and if it reports .failed or .cancelled it would be worth testing out whether you can establish the NWUDPSession once again. If you cannot then I would suspect that your packet tunnel is not setup from coming alive on wake.

Matt Eaton
DTS Engineering, CoreOS
meaton3@apple.com

0