Add simple set extension infrastructure for maintaining variable sized
and optional per element data.
Signed-off-by: Patrick McHardy <kaber@xxxxxxxxx>
---
include/net/netfilter/nf_tables.h | 105 ++++++++++++++++++++++++++++++++++++++
net/netfilter/nf_tables_api.c | 16 ++++++
2 files changed, 121 insertions(+)
diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index ace67a5..038f8a6 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -311,6 +311,111 @@ int nf_tables_bind_set(const struct nft_ctx *ctx, struct nft_set *set,
void nf_tables_unbind_set(const struct nft_ctx *ctx, struct nft_set *set,
struct nft_set_binding *binding);
+/**
+ * enum nft_set_extensions - set extension type IDs
+ *
+ * @NFT_SET_EXT_KEY: element key
+ * @NFT_SET_EXT_DATA: mapping data
+ * @NFT_SET_EXT_FLAGS: element flags
+ * @NFT_SET_EXT_NUM: number of extension types
+ */
+enum nft_set_extensions {
+ NFT_SET_EXT_KEY,
+ NFT_SET_EXT_DATA,
+ NFT_SET_EXT_FLAGS,
+ NFT_SET_EXT_NUM
+};
+
+/**
+ * struct nft_set_ext_type - set extension type
+ *
+ * @len: fixed part length of the extension
+ * @align: alignment requirements of the extension
+ */
+struct nft_set_ext_type {
+ u8 len;
+ u8 align;
+};
+
+extern const struct nft_set_ext_type nft_set_ext_types[];
+
+/**
+ * struct nft_set_ext_tmpl - set extension template
+ *
+ * @len: length of extension area
+ * @offset: offsets of individual extension types
+ */
+struct nft_set_ext_tmpl {
+ u16 len;
+ u8 offset[NFT_SET_EXT_NUM];
+};
+
+/**
+ * struct nft_set_ext - set extensions
+ *
+ * @offset: offsets of individual extension types
+ * @data: beginning of extension data
+ */
+struct nft_set_ext {
+ u8 offset[NFT_SET_EXT_NUM];
+ char data[0];
+};
+
+static inline void nft_set_ext_prepare(struct nft_set_ext_tmpl *tmpl)
+{
+ memset(tmpl, 0, sizeof(*tmpl));
+ tmpl->len = sizeof(struct nft_set_ext);
+}
+
+static inline void nft_set_ext_add_length(struct nft_set_ext_tmpl *tmpl, u8 id,
+ unsigned int len)
+{
+ tmpl->len = ALIGN(tmpl->len, nft_set_ext_types[id].align);
+ BUG_ON(tmpl->len > U8_MAX);
+ tmpl->offset[id] = tmpl->len;
+ tmpl->len += nft_set_ext_types[id].len + len;
+}
+
+static inline void nft_set_ext_add(struct nft_set_ext_tmpl *tmpl, u8 id)
+{
+ nft_set_ext_add_length(tmpl, id, 0);
+}
+
+static inline void nft_set_ext_init(struct nft_set_ext *ext,
+ const struct nft_set_ext_tmpl *tmpl)
+{
+ memcpy(ext->offset, tmpl->offset, sizeof(ext->offset));
+}
+
+static inline bool __nft_set_ext_exists(const struct nft_set_ext *ext, u8 id)
+{
+ return !!ext->offset[id];
+}
+
+static inline bool nft_set_ext_exists(const struct nft_set_ext *ext, u8 id)
+{
+ return ext && __nft_set_ext_exists(ext, id);
+}
+
+static inline void *nft_set_ext(const struct nft_set_ext *ext, u8 id)
+{
+ return (void *)ext + ext->offset[id];
+}
+
+static inline struct nft_data *nft_set_ext_key(const struct nft_set_ext *ext)
+{
+ return nft_set_ext(ext, NFT_SET_EXT_KEY);
+}
+
+static inline struct nft_data *nft_set_ext_data(const struct nft_set_ext *ext)
+{
+ return nft_set_ext(ext, NFT_SET_EXT_DATA);
+}
+
+static inline u8 *nft_set_ext_flags(const struct nft_set_ext *ext)
+{
+ return nft_set_ext(ext, NFT_SET_EXT_FLAGS);
+}
/**
* struct nft_expr_type - nf_tables expression type
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 0b969b6..972c47f 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -2827,6 +2827,22 @@ void nf_tables_unbind_set(const struct nft_ctx *ctx, struct nft_set *set,
nf_tables_set_destroy(ctx, set);
}
+const struct nft_set_ext_type nft_set_ext_types[] = {
+ [NFT_SET_EXT_KEY] = {
+ .len = sizeof(struct nft_data),
+ .align = __alignof__(struct nft_data),
+ },
+ [NFT_SET_EXT_DATA] = {
+ .len = sizeof(struct nft_data),
+ .align = __alignof__(struct nft_data),
+ },
+ [NFT_SET_EXT_FLAGS] = {
+ .len = sizeof(u8),
+ .align = __alignof__(u8),
+ },
+};
+EXPORT_SYMBOL_GPL(nft_set_ext_types);
+
/*
* Set elements
*/
--
2.1.0
--
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