netfilter: nftables: generalize set extension to support for several expressions

This patch replaces NFT_SET_EXPR by NFT_SET_EXT_EXPRESSIONS. This new
extension allows to attach several expressions to one set element (not
only one single expression as NFT_SET_EXPR provides). This patch
prepares for support for several expressions per set element in the
netlink userspace API.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 28 insertions, 8 deletions

diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index 0f4ae16a0c42..bba56f2ce60c 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -421,6 +421,20 @@ struct nft_set_type {
 };
 #define to_set_type(o) container_of(o, struct nft_set_type, ops)
 
+struct nft_set_elem_expr {
+	u8				size;
+	unsigned char			data[]
+		__attribute__((aligned(__alignof__(struct nft_expr))));
+};
+
+#define nft_setelem_expr_at(__elem_expr, __offset)			\
+	((struct nft_expr *)&__elem_expr->data[__offset])
+
+#define nft_setelem_expr_foreach(__expr, __elem_expr, __size)		\
+	for (__expr = nft_setelem_expr_at(__elem_expr, 0), __size = 0;	\
+	     __size < (__elem_expr)->size;				\
+	     __size += (__expr)->ops->size, __expr = ((void *)(__expr)) + (__expr)->ops->size)
+
 #define NFT_SET_EXPR_MAX	2
 
 /**
@@ -547,7 +561,7 @@ void nf_tables_destroy_set(const struct nft_ctx *ctx, struct nft_set *set);
  *	@NFT_SET_EXT_TIMEOUT: element timeout
  *	@NFT_SET_EXT_EXPIRATION: element expiration time
  *	@NFT_SET_EXT_USERDATA: user data associated with the element
- *	@NFT_SET_EXT_EXPR: expression assiociated with the element
+ *	@NFT_SET_EXT_EXPRESSIONS: expressions assiciated with the element
  *	@NFT_SET_EXT_OBJREF: stateful object reference associated with element
  *	@NFT_SET_EXT_NUM: number of extension types
  */
@@ -559,7 +573,7 @@ enum nft_set_extensions {
 	NFT_SET_EXT_TIMEOUT,
 	NFT_SET_EXT_EXPIRATION,
 	NFT_SET_EXT_USERDATA,
-	NFT_SET_EXT_EXPR,
+	NFT_SET_EXT_EXPRESSIONS,
 	NFT_SET_EXT_OBJREF,
 	NFT_SET_EXT_NUM
 };
@@ -677,9 +691,9 @@ static inline struct nft_userdata *nft_set_ext_userdata(const struct nft_set_ext
 	return nft_set_ext(ext, NFT_SET_EXT_USERDATA);
 }
 
-static inline struct nft_expr *nft_set_ext_expr(const struct nft_set_ext *ext)
+static inline struct nft_set_elem_expr *nft_set_ext_expr(const struct nft_set_ext *ext)
 {
-	return nft_set_ext(ext, NFT_SET_EXT_EXPR);
+	return nft_set_ext(ext, NFT_SET_EXT_EXPRESSIONS);
 }
 
 static inline bool nft_set_elem_expired(const struct nft_set_ext *ext)
@@ -909,11 +923,17 @@ static inline void nft_set_elem_update_expr(const struct nft_set_ext *ext,
 					    struct nft_regs *regs,
 					    const struct nft_pktinfo *pkt)
 {
+	struct nft_set_elem_expr *elem_expr;
 	struct nft_expr *expr;
-
-	if (__nft_set_ext_exists(ext, NFT_SET_EXT_EXPR)) {
-		expr = nft_set_ext_expr(ext);
-		expr->ops->eval(expr, regs, pkt);
+	u32 size;
+
+	if (__nft_set_ext_exists(ext, NFT_SET_EXT_EXPRESSIONS)) {
+		elem_expr = nft_set_ext_expr(ext);
+		nft_setelem_expr_foreach(expr, elem_expr, size) {
+			expr->ops->eval(expr, regs, pkt);
+			if (regs->verdict.code == NFT_BREAK)
+				return;
+		}
 	}
 }