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Pull request overview
This PR modifies the XDP Minecraft TCP filter to drop the final ACK of the TCP 3-way handshake so the backend only observes the first ACK-bearing packets when they also carry Minecraft handshake data.
Changes:
- Adjusts endianness handling for EtherType, TCP ports, and TCP sequence number parsing.
- Moves TCP payload boundary calculation earlier and enforces a payload bounds check against
data_end. - Changes the
AWAIT_ACKstate to transition toAWAIT_MC_HANDSHAKEand then drop the packet (intended to drop the handshake ACK).
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Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
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We can drop the ack of the 3 way handshake, and by doing so we ensure the tcp stack of linux will see the minecraft packet data tcp packets as first packets with the ack flag set, the backend tcp stack will now only accept connections that have send at least an minecraft handshake packet