[PATCH ipsec-next] pfkey: Deprecate pfkey

[Steffen Klassert <steffen.klassert@secunet.com>]

The pfkey user configuration interface was replaced by the netlink
user configuration interface more than a decade ago. In between
all maintained IKE implementations moved to the netlink interface.
So let config NET_KEY default to no in Kconfig. The pfkey code
will be remoced in a secomd step.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Antony Antony <antony.antony@secunet.com>
Acked-by: Tobias Brunner <tobias@strongswan.org>
---

Antony, Tobias, I kept the Acked-by tags from the RFC version.
Let me know if that's ok.

 net/key/af_key.c |  2 ++
 net/xfrm/Kconfig | 11 +++++++----
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/net/key/af_key.c b/net/key/af_key.c
index 2ebde0352245..571200433aa9 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -3903,6 +3903,8 @@ static int __init ipsec_pfkey_init(void)
 {
 	int err = proto_register(&key_proto, 0);
 
+	pr_warn_once("PFKEY is deprecated and scheduled to be removed in 2027, "
+	             "please contact the netdev mailing list\n");
 	if (err != 0)
 		goto out;
 
diff --git a/net/xfrm/Kconfig b/net/xfrm/Kconfig
index f0157702718f..4a62817a88f8 100644
--- a/net/xfrm/Kconfig
+++ b/net/xfrm/Kconfig
@@ -110,14 +110,17 @@ config XFRM_IPCOMP
 	select CRYPTO_DEFLATE
 
 config NET_KEY
-	tristate "PF_KEY sockets"
+	tristate "PF_KEY sockets (deprecated)"
 	select XFRM_ALGO
 	help
 	  PF_KEYv2 socket family, compatible to KAME ones.
-	  They are required if you are going to use IPsec tools ported
-	  from KAME.
 
-	  Say Y unless you know what you are doing.
+	  The PF_KEYv2 socket interface is deprecated and
+	  scheduled for removal. All maintained IKE daemons
+	  no longer need PF_KEY sockets. Please use the netlink
+	  interface (XFRM_USER) to configure IPsec.
+
+	  If unsure, say N.
 
 config NET_KEY_MIGRATE
 	bool "PF_KEY MIGRATE"
-- 
2.43.0