>From 00fc5af96f90846f1e1882b141699fb62a9f0a73 Mon Sep 17 00:00:00 2001
From: Antony Antony <antony.antony@secunet.com>
Date: Mon, 13 Nov 2023 14:20:45 +0100
Subject: [PATCH] xfrm iptfs migrate poc

proof of concept for IP-TFS migrate support
---
 include/net/xfrm.h    |  1 +
 net/xfrm/xfrm_iptfs.c | 20 ++++++++++++++++++++
 net/xfrm/xfrm_state.c |  6 ++++++
 3 files changed, 27 insertions(+)

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index a6e0e848918d..176ab5ac436e 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -456,6 +456,7 @@ struct xfrm_mode_cbs {
 	int	(*user_init)(struct net *net, struct xfrm_state *x,
 			     struct nlattr **attrs);
 	int	(*copy_to_user)(struct xfrm_state *x, struct sk_buff *skb);
+	int     (*clone)(struct xfrm_state *orig, struct xfrm_state *x);
 
 	u32	(*get_inner_mtu)(struct xfrm_state *x, int outer_mtu);
 
diff --git a/net/xfrm/xfrm_iptfs.c b/net/xfrm/xfrm_iptfs.c
index 65f7acdbe6a8..cef269a02b11 100644
--- a/net/xfrm/xfrm_iptfs.c
+++ b/net/xfrm/xfrm_iptfs.c
@@ -2613,6 +2613,25 @@ static int iptfs_copy_to_user(struct xfrm_state *x, struct sk_buff *skb)
 	return ret;
 }
 
+static int iptfs_clone(struct xfrm_state *orig,  struct xfrm_state *x)
+{
+
+	x->mode_data = kmemdup(orig->mode_data, sizeof(*x->mode_data),
+			       GFP_KERNEL);
+	/**  may be some values, such as the following, should not be copied ??
+	 * and need different handling ?
+	 * xtfs->iptfs_timer;
+	 * xtfs->drop_timer
+         * xtfs->drop_lock
+         * xtfs->w_saved
+         * xtfs;
+	 */
+
+	if (!x->mode_data)
+		return -ENOMEM;
+
+	return 0;
+}
 static int iptfs_create_state(struct xfrm_state *x)
 {
 	struct xfrm_iptfs_data *xtfs;
@@ -2667,6 +2686,7 @@ static const struct xfrm_mode_cbs iptfs_mode_cbs = {
 	.delete_state = iptfs_delete_state,
 	.user_init = iptfs_user_init,
 	.copy_to_user = iptfs_copy_to_user,
+	.clone = iptfs_clone,
 	.get_inner_mtu = iptfs_get_inner_mtu,
 	.input = iptfs_input,
 	.output = iptfs_output_collect,
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 786f3fc0d428..c56d3be56229 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -720,6 +720,7 @@ struct xfrm_state *xfrm_state_alloc(struct net *net)
 		x->replay_maxage = 0;
 		x->replay_maxdiff = 0;
 		spin_lock_init(&x->lock);
+		x->mode_data = NULL;
 	}
 	return x;
 }
@@ -1787,6 +1788,11 @@ static struct xfrm_state *xfrm_state_clone(struct xfrm_state *orig,
 	x->new_mapping = 0;
 	x->new_mapping_sport = 0;
 
+	if (x->mode_cbs && x->mode_cbs->clone && orig->mode_data) {
+		if (!x->mode_cbs->clone(x,orig))
+			goto error;
+	}
+
 	return x;
 
  error:
-- 
2.42.0