mmproxy - Creative Linux routing to preserve client IP addresses in L7 proxies

This post introduces mmproxy, a new tool that enables the preservation of client IP addresses for applications that do not natively support protocols like PROXY protocol. It details how mmproxy, in conjunction with Cloudflare Spectrum and Linux routing tricks (IP_TRANSPARENT, CONNMARK, and custom routing tables), allows for spoofing client IPs to target applications, effectively extending the reach of edge computing capabilities to legacy or non-standard applications.