[PATCH nf-next v6 6/8] netfilter: nft_tunnel: add NFTA_TUNNEL_KEY_RELEASE action

[wenxu@xxxxxxxxx]

From: wenxu <wenxu@xxxxxxxxx>

Add new NFTA_TUNNEL_KEY_RELEASE action for future offload
feature

Signed-off-by: wenxu <wenxu@xxxxxxxxx>
---
 include/uapi/linux/netfilter/nf_tables.h |  1 +
 net/netfilter/nft_tunnel.c               | 24 +++++++++++++++++++++---
 2 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h
index da9b1d1..0e24c27 100644
--- a/include/uapi/linux/netfilter/nf_tables.h
+++ b/include/uapi/linux/netfilter/nf_tables.h
@@ -1766,6 +1766,7 @@ enum nft_tunnel_key_attributes {
 	NFTA_TUNNEL_KEY_SPORT,
 	NFTA_TUNNEL_KEY_DPORT,
 	NFTA_TUNNEL_KEY_OPTS,
+	NFTA_TUNNEL_KEY_RELEASE,
 	__NFTA_TUNNEL_KEY_MAX
 };
 #define NFTA_TUNNEL_KEY_MAX	(__NFTA_TUNNEL_KEY_MAX - 1)
diff --git a/net/netfilter/nft_tunnel.c b/net/netfilter/nft_tunnel.c
index 68ca894..15d5dc9 100644
--- a/net/netfilter/nft_tunnel.c
+++ b/net/netfilter/nft_tunnel.c
@@ -262,6 +262,7 @@ struct nft_tunnel_opts {
 struct nft_tunnel_obj {
 	struct metadata_dst	*md;
 	struct nft_tunnel_opts	opts;
+	bool tunnel_key_release;
 };
 
 static const struct nla_policy nft_tunnel_ip_policy[NFTA_TUNNEL_KEY_IP_MAX + 1] = {
@@ -446,6 +447,7 @@ static int nft_tunnel_obj_opts_init(const struct nft_ctx *ctx,
 	[NFTA_TUNNEL_KEY_TOS]	= { .type = NLA_U8, },
 	[NFTA_TUNNEL_KEY_TTL]	= { .type = NLA_U8, },
 	[NFTA_TUNNEL_KEY_OPTS]	= { .type = NLA_NESTED, },
+	[NFTA_TUNNEL_KEY_RELEASE]	= { .type = NLA_U8, },
 };
 
 static int nft_tunnel_obj_init(const struct nft_ctx *ctx,
@@ -457,6 +459,12 @@ static int nft_tunnel_obj_init(const struct nft_ctx *ctx,
 	struct metadata_dst *md;
 	int err;
 
+	if (tb[NFTA_TUNNEL_KEY_RELEASE] &&
+	    nla_get_u8(tb[NFTA_TUNNEL_KEY_RELEASE])) {
+		priv->tunnel_key_release = true;
+		return 0;
+	}
+
 	if (!tb[NFTA_TUNNEL_KEY_ID])
 		return -EINVAL;
 
@@ -539,8 +547,11 @@ static inline void nft_tunnel_obj_eval(struct nft_object *obj,
 	struct sk_buff *skb = pkt->skb;
 
 	skb_dst_drop(skb);
-	dst_hold((struct dst_entry *) priv->md);
-	skb_dst_set(skb, (struct dst_entry *) priv->md);
+
+	if (!priv->tunnel_key_release) {
+		dst_hold((struct dst_entry *)priv->md);
+		skb_dst_set(skb, (struct dst_entry *)priv->md);
+	}
 }
 
 static int nft_tunnel_ip_dump(struct sk_buff *skb, struct ip_tunnel_info *info)
@@ -642,6 +653,12 @@ static int nft_tunnel_obj_dump(struct sk_buff *skb,
 	struct nft_tunnel_obj *priv = nft_obj_data(obj);
 	struct ip_tunnel_info *info = &priv->md->u.tun_info;
 
+	if (priv->tunnel_key_release) {
+		if (nla_put_u8(skb, NFTA_TUNNEL_KEY_RELEASE, 1))
+			goto nla_put_failure;
+		return 0;
+	}
+
 	if (nla_put_be32(skb, NFTA_TUNNEL_KEY_ID,
 			 tunnel_id_to_key32(info->key.tun_id)) ||
 	    nft_tunnel_ip_dump(skb, info) < 0 ||
@@ -663,7 +680,8 @@ static void nft_tunnel_obj_destroy(const struct nft_ctx *ctx,
 {
 	struct nft_tunnel_obj *priv = nft_obj_data(obj);
 
-	metadata_dst_free(priv->md);
+	if (!priv->tunnel_key_release)
+		metadata_dst_free(priv->md);
 }
 
 static struct nft_object_type nft_tunnel_obj_type;
-- 
1.8.3.1