Packets sent through an OpenVPN TAP tunnel are missing the Ethernet header

[glovaschi]

Summary

Packets sent by the Passepartout app for iOS through an OpenVPN TAP tunnel are missing the Ethernet header. A tcpdump on the server reveals that the Ethernet frame that comes from the Passsepartout client is actually an IP packet (the Ethernet payload) and the Ethernet header is missing.

Steps to reproduce

Set up an OpenVPN TAP tunnel and observe the frames received by the server from the client.

What is the current bug behavior?

Ethernet frames are missing the header.

What is the expected correct behavior?

Ethernet frames should be sent with a header.

Relevant logs and/or screenshots

I attached a sample client config (tap-client.ovpn) and an Ethernet capture from the TAP interface on the OpenVPN server (tap.pcap) in the archive tap.zip.

Possible fixes suggested remediation