[PATCH,nf-next RFC 1/2] netfilter: nf_tables: add nft_setelem_parse_key()

[Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>]

Add helper function to parse the set element key netlink attribute.

Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
 net/netfilter/nf_tables_api.c | 56 ++++++++++++++++++++++++-------------------
 1 file changed, 32 insertions(+), 24 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 0db2784fee9a..13e291fac26f 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -4490,11 +4490,31 @@ static int nft_setelem_parse_flags(const struct nft_set *set,
 	return 0;
 }
 
+static int nft_setelem_parse_key(struct nft_ctx *ctx, struct nft_set *set,
+				 struct nft_data *key, struct nlattr *attr)
+{
+	struct nft_data_desc desc;
+	int err;
+
+	err = nft_data_init(ctx, key, sizeof(*key), &desc, attr);
+	if (err < 0)
+		goto err1;
+
+	err = -EINVAL;
+	if (desc.type != NFT_DATA_VALUE || desc.len != set->klen)
+		goto err2;
+
+	return 0;
+err2:
+	nft_data_release(key, desc.type);
+err1:
+	return err;
+}
+
 static int nft_get_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 			    const struct nlattr *attr)
 {
 	struct nlattr *nla[NFTA_SET_ELEM_MAX + 1];
-	struct nft_data_desc desc;
 	struct nft_set_elem elem;
 	struct sk_buff *skb;
 	uint32_t flags = 0;
@@ -4513,15 +4533,11 @@ static int nft_get_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 	if (err < 0)
 		return err;
 
-	err = nft_data_init(ctx, &elem.key.val, sizeof(elem.key), &desc,
-			    nla[NFTA_SET_ELEM_KEY]);
+	err = nft_setelem_parse_key(ctx, set, &elem.key.val,
+				    nla[NFTA_SET_ELEM_KEY]);
 	if (err < 0)
 		return err;
 
-	err = -EINVAL;
-	if (desc.type != NFT_DATA_VALUE || desc.len != set->klen)
-		return err;
-
 	priv = set->ops->get(ctx->net, set, &elem, flags);
 	if (IS_ERR(priv))
 		return PTR_ERR(priv);
@@ -4720,13 +4736,13 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 {
 	struct nlattr *nla[NFTA_SET_ELEM_MAX + 1];
 	u8 genmask = nft_genmask_next(ctx->net);
-	struct nft_data_desc d1, d2;
 	struct nft_set_ext_tmpl tmpl;
 	struct nft_set_ext *ext, *ext2;
 	struct nft_set_elem elem;
 	struct nft_set_binding *binding;
 	struct nft_object *obj = NULL;
 	struct nft_userdata *udata;
+	struct nft_data_desc d2;
 	struct nft_data data;
 	enum nft_registers dreg;
 	struct nft_trans *trans;
@@ -4792,15 +4808,12 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 			return err;
 	}
 
-	err = nft_data_init(ctx, &elem.key.val, sizeof(elem.key), &d1,
-			    nla[NFTA_SET_ELEM_KEY]);
+	err = nft_setelem_parse_key(ctx, set, &elem.key.val,
+				    nla[NFTA_SET_ELEM_KEY]);
 	if (err < 0)
 		goto err1;
-	err = -EINVAL;
-	if (d1.type != NFT_DATA_VALUE || d1.len != set->klen)
-		goto err2;
 
-	nft_set_ext_add_length(&tmpl, NFT_SET_EXT_KEY, d1.len);
+	nft_set_ext_add_length(&tmpl, NFT_SET_EXT_KEY, set->klen);
 	if (timeout > 0) {
 		nft_set_ext_add(&tmpl, NFT_SET_EXT_EXPIRATION);
 		if (timeout != set->timeout)
@@ -4942,7 +4955,7 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 	if (nla[NFTA_SET_ELEM_DATA] != NULL)
 		nft_data_release(&data, d2.type);
 err2:
-	nft_data_release(&elem.key.val, d1.type);
+	nft_data_release(&elem.key.val, NFT_DATA_VALUE);
 err1:
 	return err;
 }
@@ -5038,7 +5051,6 @@ static int nft_del_setelem(struct nft_ctx *ctx, struct nft_set *set,
 {
 	struct nlattr *nla[NFTA_SET_ELEM_MAX + 1];
 	struct nft_set_ext_tmpl tmpl;
-	struct nft_data_desc desc;
 	struct nft_set_elem elem;
 	struct nft_set_ext *ext;
 	struct nft_trans *trans;
@@ -5063,16 +5075,12 @@ static int nft_del_setelem(struct nft_ctx *ctx, struct nft_set *set,
 	if (flags != 0)
 		nft_set_ext_add(&tmpl, NFT_SET_EXT_FLAGS);
 
-	err = nft_data_init(ctx, &elem.key.val, sizeof(elem.key), &desc,
-			    nla[NFTA_SET_ELEM_KEY]);
+	err = nft_setelem_parse_key(ctx, set, &elem.key.val,
+				    nla[NFTA_SET_ELEM_KEY]);
 	if (err < 0)
 		goto err1;
 
-	err = -EINVAL;
-	if (desc.type != NFT_DATA_VALUE || desc.len != set->klen)
-		goto err2;
-
-	nft_set_ext_add_length(&tmpl, NFT_SET_EXT_KEY, desc.len);
+	nft_set_ext_add_length(&tmpl, NFT_SET_EXT_KEY, set->klen);
 
 	err = -ENOMEM;
 	elem.priv = nft_set_elem_init(set, &tmpl, elem.key.val.data, NULL, 0,
@@ -5109,7 +5117,7 @@ static int nft_del_setelem(struct nft_ctx *ctx, struct nft_set *set,
 err3:
 	kfree(elem.priv);
 err2:
-	nft_data_release(&elem.key.val, desc.type);
+	nft_data_release(&elem.key.val, NFT_DATA_VALUE);
 err1:
 	return err;
 }
-- 
2.11.0