netfilter: nf_tables: add NFTA_SET_ELEM_KEY_END attribute

Add NFTA_SET_ELEM_KEY_END attribute to convey the closing element of the
interval between kernel and userspace.

This patch also adds the NFT_SET_EXT_KEY_END extension to store the
closing element value in this interval.

v4: No changes
v3: New patch

[sbrivio: refactor error paths and labels; add corresponding
  nft_set_ext_type for new key; rebase]
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

2 files changed, 64 insertions, 23 deletions

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 58e3b285a3d1..5f645a85538a 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -4215,6 +4215,9 @@ const struct nft_set_ext_type nft_set_ext_types[] = {
 		.len	= sizeof(struct nft_userdata),
 		.align	= __alignof__(struct nft_userdata),
 	},
+	[NFT_SET_EXT_KEY_END]		= {
+		.align	= __alignof__(u32),
+	},
 };
 EXPORT_SYMBOL_GPL(nft_set_ext_types);
 
@@ -4233,6 +4236,7 @@ static const struct nla_policy nft_set_elem_policy[NFTA_SET_ELEM_MAX + 1] = {
 	[NFTA_SET_ELEM_EXPR]		= { .type = NLA_NESTED },
 	[NFTA_SET_ELEM_OBJREF]		= { .type = NLA_STRING,
 					    .len = NFT_OBJ_MAXNAMELEN - 1 },
+	[NFTA_SET_ELEM_KEY_END]		= { .type = NLA_NESTED },
 };
 
 static const struct nla_policy nft_set_elem_list_policy[NFTA_SET_ELEM_LIST_MAX + 1] = {
@@ -4282,6 +4286,11 @@ static int nf_tables_fill_setelem(struct sk_buff *skb,
 			  NFT_DATA_VALUE, set->klen) < 0)
 		goto nla_put_failure;
 
+	if (nft_set_ext_exists(ext, NFT_SET_EXT_KEY_END) &&
+	    nft_data_dump(skb, NFTA_SET_ELEM_KEY_END, nft_set_ext_key_end(ext),
+			  NFT_DATA_VALUE, set->klen) < 0)
+		goto nla_put_failure;
+
 	if (nft_set_ext_exists(ext, NFT_SET_EXT_DATA) &&
 	    nft_data_dump(skb, NFTA_SET_ELEM_DATA, nft_set_ext_data(ext),
 			  set->dtype == NFT_DATA_VERDICT ? NFT_DATA_VERDICT : NFT_DATA_VALUE,
@@ -4569,6 +4578,13 @@ static int nft_get_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 	if (err < 0)
 		return err;
 
+	if (nla[NFTA_SET_ELEM_KEY_END]) {
+		err = nft_setelem_parse_key(ctx, set, &elem.key_end.val,
+					    nla[NFTA_SET_ELEM_KEY_END]);
+		if (err < 0)
+			return err;
+	}
+
 	priv = set->ops->get(ctx->net, set, &elem, flags);
 	if (IS_ERR(priv))
 		return PTR_ERR(priv);
@@ -4694,8 +4710,8 @@ static struct nft_trans *nft_trans_elem_alloc(struct nft_ctx *ctx,
 
 void *nft_set_elem_init(const struct nft_set *set,
 			const struct nft_set_ext_tmpl *tmpl,
-			const u32 *key, const u32 *data,
-			u64 timeout, u64 expiration, gfp_t gfp)
+			const u32 *key, const u32 *key_end,
+			const u32 *data, u64 timeout, u64 expiration, gfp_t gfp)
 {
 	struct nft_set_ext *ext;
 	void *elem;
@@ -4708,6 +4724,8 @@ void *nft_set_elem_init(const struct nft_set *set,
 	nft_set_ext_init(ext, tmpl);
 
 	memcpy(nft_set_ext_key(ext), key, set->klen);
+	if (nft_set_ext_exists(ext, NFT_SET_EXT_KEY_END))
+		memcpy(nft_set_ext_key_end(ext), key_end, set->klen);
 	if (nft_set_ext_exists(ext, NFT_SET_EXT_DATA))
 		memcpy(nft_set_ext_data(ext), data, set->dlen);
 	if (nft_set_ext_exists(ext, NFT_SET_EXT_EXPIRATION)) {
@@ -4842,9 +4860,19 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 	err = nft_setelem_parse_key(ctx, set, &elem.key.val,
 				    nla[NFTA_SET_ELEM_KEY]);
 	if (err < 0)
-		goto err1;
+		return err;
 
 	nft_set_ext_add_length(&tmpl, NFT_SET_EXT_KEY, set->klen);
+
+	if (nla[NFTA_SET_ELEM_KEY_END]) {
+		err = nft_setelem_parse_key(ctx, set, &elem.key_end.val,
+					    nla[NFTA_SET_ELEM_KEY_END]);
+		if (err < 0)
+			goto err_parse_key;
+
+		nft_set_ext_add_length(&tmpl, NFT_SET_EXT_KEY_END, set->klen);
+	}
+
 	if (timeout > 0) {
 		nft_set_ext_add(&tmpl, NFT_SET_EXT_EXPIRATION);
 		if (timeout != set->timeout)
@@ -4854,14 +4882,14 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 	if (nla[NFTA_SET_ELEM_OBJREF] != NULL) {
 		if (!(set->flags & NFT_SET_OBJECT)) {
 			err = -EINVAL;
-			goto err2;
+			goto err_parse_key_end;
 		}
 		obj = nft_obj_lookup(ctx->net, ctx->table,
 				     nla[NFTA_SET_ELEM_OBJREF],
 				     set->objtype, genmask);
 		if (IS_ERR(obj)) {
 			err = PTR_ERR(obj);
-			goto err2;
+			goto err_parse_key_end;
 		}
 		nft_set_ext_add(&tmpl, NFT_SET_EXT_OBJREF);
 	}
@@ -4870,11 +4898,11 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 		err = nft_data_init(ctx, &data, sizeof(data), &desc,
 				    nla[NFTA_SET_ELEM_DATA]);
 		if (err < 0)
-			goto err2;
+			goto err_parse_key_end;
 
 		err = -EINVAL;
 		if (set->dtype != NFT_DATA_VERDICT && desc.len != set->dlen)
-			goto err3;
+			goto err_parse_data;
 
 		dreg = nft_type_to_reg(set->dtype);
 		list_for_each_entry(binding, &set->bindings, list) {
@@ -4892,7 +4920,7 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 							  &data,
 							  desc.type, desc.len);
 			if (err < 0)
-				goto err3;
+				goto err_parse_data;
 
 			if (desc.type == NFT_DATA_VERDICT &&
 			    (data.verdict.code == NFT_GOTO ||
@@ -4917,10 +4945,11 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 	}
 
 	err = -ENOMEM;
-	elem.priv = nft_set_elem_init(set, &tmpl, elem.key.val.data, data.data,
+	elem.priv = nft_set_elem_init(set, &tmpl, elem.key.val.data,
+				      elem.key_end.val.data, data.data,
 				      timeout, expiration, GFP_KERNEL);
 	if (elem.priv == NULL)
-		goto err3;
+		goto err_parse_data;
 
 	ext = nft_set_elem_ext(set, elem.priv);
 	if (flags)
@@ -4937,7 +4966,7 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 
 	trans = nft_trans_elem_alloc(ctx, NFT_MSG_NEWSETELEM, set);
 	if (trans == NULL)
-		goto err4;
+		goto err_trans;
 
 	ext->genmask = nft_genmask_cur(ctx->net) | NFT_SET_ELEM_BUSY_MASK;
 	err = set->ops->insert(ctx->net, set, &elem, &ext2);
@@ -4948,7 +4977,7 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 			    nft_set_ext_exists(ext, NFT_SET_EXT_OBJREF) ^
 			    nft_set_ext_exists(ext2, NFT_SET_EXT_OBJREF)) {
 				err = -EBUSY;
-				goto err5;
+				goto err_element_clash;
 			}
 			if ((nft_set_ext_exists(ext, NFT_SET_EXT_DATA) &&
 			     nft_set_ext_exists(ext2, NFT_SET_EXT_DATA) &&
@@ -4961,33 +4990,35 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 			else if (!(nlmsg_flags & NLM_F_EXCL))
 				err = 0;
 		}
-		goto err5;
+		goto err_element_clash;
 	}
 
 	if (set->size &&
 	    !atomic_add_unless(&set->nelems, 1, set->size + set->ndeact)) {
 		err = -ENFILE;
-		goto err6;
+		goto err_set_full;
 	}
 
 	nft_trans_elem(trans) = elem;
 	list_add_tail(&trans->list, &ctx->net->nft.commit_list);
 	return 0;
 
-err6:
+err_set_full:
 	set->ops->remove(ctx->net, set, &elem);
-err5:
+err_element_clash:
 	kfree(trans);
-err4:
+err_trans:
 	if (obj)
 		obj->use--;
 	kfree(elem.priv);
-err3:
+err_parse_data:
 	if (nla[NFTA_SET_ELEM_DATA] != NULL)
 		nft_data_release(&data, desc.type);
-err2:
+err_parse_key_end:
+	nft_data_release(&elem.key_end.val, NFT_DATA_VALUE);
+err_parse_key:
 	nft_data_release(&elem.key.val, NFT_DATA_VALUE);
-err1:
+
 	return err;
 }
 
@@ -5112,9 +5143,19 @@ static int nft_del_setelem(struct nft_ctx *ctx, struct nft_set *set,
 
 	nft_set_ext_add_length(&tmpl, NFT_SET_EXT_KEY, set->klen);
 
+	if (nla[NFTA_SET_ELEM_KEY_END]) {
+		err = nft_setelem_parse_key(ctx, set, &elem.key_end.val,
+					    nla[NFTA_SET_ELEM_KEY_END]);
+		if (err < 0)
+			return err;
+
+		nft_set_ext_add_length(&tmpl, NFT_SET_EXT_KEY_END, set->klen);
+	}
+
 	err = -ENOMEM;
-	elem.priv = nft_set_elem_init(set, &tmpl, elem.key.val.data, NULL, 0,
-				      0, GFP_KERNEL);
+	elem.priv = nft_set_elem_init(set, &tmpl, elem.key.val.data,
+				      elem.key_end.val.data, NULL, 0, 0,
+				      GFP_KERNEL);
 	if (elem.priv == NULL)
 		goto fail_elem;
 
diff --git a/net/netfilter/nft_dynset.c b/net/netfilter/nft_dynset.c
index 8887295414dc..683785225a3e 100644
--- a/net/netfilter/nft_dynset.c
+++ b/net/netfilter/nft_dynset.c
@@ -54,7 +54,7 @@ static void *nft_dynset_new(struct nft_set *set, const struct nft_expr *expr,
 
 	timeout = priv->timeout ? : set->timeout;
 	elem = nft_set_elem_init(set, &priv->tmpl,
-				 &regs->data[priv->sreg_key],
+				 &regs->data[priv->sreg_key], NULL,
 				 &regs->data[priv->sreg_data],
 				 timeout, 0, GFP_ATOMIC);
 	if (elem == NULL)