GoKawiilLongtime Linux developer David Woodhouse sent out a patch series today to "deprecate legacy IP" support within the Linux kernel. While some of his commentary his April 1st-esque, he does acknowledge much of this work has merit. Ultimately it can allow for building a Linux kernel with IPv6-only support and working on allowing "legacy" IPv4 support to be disabled as part of the kernel build.The set of six patches add a CONFIG_LEGACY_IP option to allow toggling IPv4 support for the kernel build. At the moment with the patches, there will just be a warning if a process listens on a legacy IP socket. It also "marks Legacy IP for deprecation" though in reality this part of the patch series is more akin for April Fools' Day.
"Yeah. The date notwithstanding, I do actually think we should do most of this for real.
Maybe we don't get away with the actual deprecation and the warnings on use *just* yet, and *maybe* we won't even get away with calling the config option CONFIG_LEGACY_IP, although I would genuinely like to see us moving consistently towards saying "Legacy IP" instead of "IPv4" everywhere.
But we *should* clean up the separation of CONFIG_INET and CONFIG_IPV[64] and make it possible to build with either protocol alone."