From: David Woodhouse Add a new CONFIG_LEGACY_IP boolean option under CONFIG_INET that will gate Legacy IP functionality. When disabled, the kernel will not register the AF_INET socket family, IPv4 packet handler, ARP, or IPv4 routing, while the shared TCP/UDP/INET socket infrastructure remains available for IPv6. This is the first step toward making Legacy IP optional. The option defaults to y and currently has no effect — subsequent patches will use it to guard IPv4 entry points. Signed-off-by: David Woodhouse --- net/ipv4/Kconfig | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig index df922f9f5289..aef2c5349e62 100644 --- a/net/ipv4/Kconfig +++ b/net/ipv4/Kconfig @@ -2,6 +2,17 @@ # # IP configuration # +config LEGACY_IP + bool "The IPv4 protocol (Legacy IP)" + help + Support for IP version 4 (IPv4). + + Legacy IP is the protocol used by the early ARPANET, before IPv6 + was standardised in the final decade of the 1900s. It should only + be necessary these days to interoperate with legacy networks. + + If unsure, say N. + config IP_MULTICAST bool "IP: multicasting" help -- 2.51.0