Bypassing Middleboxes Blocking MPTCP with eBPF
2025-07-18
The MPTCP protocol can be blocked by middleboxes (like NATs, firewalls) in certain network environments. This article introduces an eBPF-based TCP-in-UDP solution that cleverly bypasses these limitations by encapsulating TCP packets within UDP packets. This solution requires no extra data layers or VPNs, simply reordering the TCP header and using eBPF to efficiently handle checksums, ultimately solving challenges posed by network stack optimizations and hardware offloading. While some minor issues remain, such as the loss of the URG flag and MTU/MSS adjustments, this approach offers an effective way to improve MPTCP performance in complex network environments.
Development
Network Optimization