netfilter: nf_tables: add range expression

Inverse ranges != [a,b] are not currently possible because rules are
composites of && operations, and we need to express this:

	data < a || data > b

This patch adds a new range expression. Positive ranges can be already
through two cmp expressions:

	cmp(sreg, data, >=)
	cmp(sreg, data, <=)

This new range expression provides an alternative way to express this.

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

1 files changed, 29 insertions, 0 deletions

diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h
index 1cf41dd838b2..c6c4477c136b 100644
--- a/include/uapi/linux/netfilter/nf_tables.h
+++ b/include/uapi/linux/netfilter/nf_tables.h
@@ -546,6 +546,35 @@ enum nft_cmp_attributes {
 };
 #define NFTA_CMP_MAX		(__NFTA_CMP_MAX - 1)
 
+/**
+ * enum nft_range_ops - nf_tables range operator
+ *
+ * @NFT_RANGE_EQ: equal
+ * @NFT_RANGE_NEQ: not equal
+ */
+enum nft_range_ops {
+	NFT_RANGE_EQ,
+	NFT_RANGE_NEQ,
+};
+
+/**
+ * enum nft_range_attributes - nf_tables range expression netlink attributes
+ *
+ * @NFTA_RANGE_SREG: source register of data to compare (NLA_U32: nft_registers)
+ * @NFTA_RANGE_OP: cmp operation (NLA_U32: nft_cmp_ops)
+ * @NFTA_RANGE_FROM_DATA: data range from (NLA_NESTED: nft_data_attributes)
+ * @NFTA_RANGE_TO_DATA: data range to (NLA_NESTED: nft_data_attributes)
+ */
+enum nft_range_attributes {
+	NFTA_RANGE_UNSPEC,
+	NFTA_RANGE_SREG,
+	NFTA_RANGE_OP,
+	NFTA_RANGE_FROM_DATA,
+	NFTA_RANGE_TO_DATA,
+	__NFTA_RANGE_MAX
+};
+#define NFTA_RANGE_MAX		(__NFTA_RANGE_MAX - 1)
+
 enum nft_lookup_flags {
 	NFT_LOOKUP_F_INV = (1 << 0),
 };