[PATCH 13/13 RFC net-next] net: ipv4: make CONFIG_IPV4 boolean

[Fernando Fernandez Mancera]

Change CONFIG_IPV4 from hidden 'def_bool y' into an exposed boolean.
This allows users to explicitly disable IPv4 via Kconfig to build
IPv6-only or pure L2 kernel network stack. The default is kept at 'y' to
prevent breaking existing configurations.

Signed-off-by: Fernando Fernandez Mancera <fmancera@xxxxxxx>
---
 net/ipv4/Kconfig | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
index 51bf05d9770c..fa30cc407223 100644
--- a/net/ipv4/Kconfig
+++ b/net/ipv4/Kconfig
@@ -3,7 +3,15 @@
 # IP configuration
 #
 config IPV4
-	def_bool y
+	bool "The IPv4 protocol"
+	default y
+	help
+	  Support for IP version 4 (IPv4).
+
+	  Disabling this option compiles the kernel networking stack without
+	  IPv4 support, resulting in a IPv6-only or pure L2 system.
+
+	  If unsure, say Y.
 
 config IP_MULTICAST
 	bool "IP: multicasting"
-- 
2.54.0