[nf-next PATCH v3 3/4] netfilter: nf_tables: Introduce expression flags

[Phil Sutter <phil@nwl.cc>]

Allow dumping some info bits about expressions to user space.

Signed-off-by: Phil Sutter <phil@nwl.cc>
---
 include/net/netfilter/nf_tables.h        | 1 +
 include/uapi/linux/netfilter/nf_tables.h | 1 +
 net/netfilter/nf_tables_api.c            | 4 ++++
 3 files changed, 6 insertions(+)

diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index 708593dd4142e..16f6f36073522 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -349,6 +349,7 @@ struct nft_set_estimate {
  */
 struct nft_expr {
 	const struct nft_expr_ops	*ops;
+	u32				flags;
 	unsigned char			data[]
 		__attribute__((aligned(__alignof__(u64))));
 };
diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h
index 466fd3f4447c2..36bf019322a44 100644
--- a/include/uapi/linux/netfilter/nf_tables.h
+++ b/include/uapi/linux/netfilter/nf_tables.h
@@ -518,6 +518,7 @@ enum nft_expr_attributes {
 	NFTA_EXPR_UNSPEC,
 	NFTA_EXPR_NAME,
 	NFTA_EXPR_DATA,
+	NFTA_EXPR_FLAGS,
 	__NFTA_EXPR_MAX
 };
 #define NFTA_EXPR_MAX		(__NFTA_EXPR_MAX - 1)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index ba2f712823776..608c5e684dff7 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -2731,6 +2731,7 @@ static const struct nft_expr_type *nft_expr_type_get(struct net *net,
 static const struct nla_policy nft_expr_policy[NFTA_EXPR_MAX + 1] = {
 	[NFTA_EXPR_NAME]	= { .type = NLA_STRING,
 				    .len = NFT_MODULE_AUTOLOAD_LIMIT },
+	[NFTA_EXPR_FLAGS]	= { .type = NLA_U32 },
 	[NFTA_EXPR_DATA]	= { .type = NLA_NESTED },
 };
 
@@ -2740,6 +2741,9 @@ static int nf_tables_fill_expr_info(struct sk_buff *skb,
 	if (nla_put_string(skb, NFTA_EXPR_NAME, expr->ops->type->name))
 		goto nla_put_failure;
 
+	if (nla_put_u32(skb, NFTA_EXPR_FLAGS, expr->flags))
+		goto nla_put_failure;
+
 	if (expr->ops->dump) {
 		struct nlattr *data = nla_nest_start_noflag(skb,
 							    NFTA_EXPR_DATA);
-- 
2.34.1