[PATCH nf-next 0/3] support for stateful expressions in set definition

[PATCH nf-next 0/3] support for stateful expressions in set definition

[Pablo Neira Ayuso]

Hi,

This patchset allows user to specify a stateful expression in the set
definition, eg.

 table ip x {
        set y {
                typeof ip saddr
                counter
                elements = { 192.168.10.35, 192.168.10.101, 192.168.10.135 }
        }

        chain z {
                type filter hook output priority filter; policy accept;
                ip daddr @y
        }
 }

The example above turns on counters for each element in the set 'y'.

Pablo Neira Ayuso (3):
  netfilter: nf_tables: move nft_expr_clone() to nf_tables_api.c
  netfilter: nf_tables: pass context to nft_set_destroy()
  netfilter: nf_tables: allow to specify stateful expression in set definition

 include/net/netfilter/nf_tables.h        |  3 ++
 include/uapi/linux/netfilter/nf_tables.h |  2 +
 net/netfilter/nf_tables_api.c            | 88 ++++++++++++++++++++++++++------
 net/netfilter/nft_dynset.c               | 17 ------
 4 files changed, 76 insertions(+), 34 deletions(-)

--
2.11.0

[PATCH nf-next 1/3] netfilter: nf_tables: move nft_expr_clone() to nf_tables_api.c

[Pablo Neira Ayuso]

Move the nft_expr_clone() helper function to the core.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 include/net/netfilter/nf_tables.h |  1 +
 net/netfilter/nf_tables_api.c     | 18 ++++++++++++++++++
 net/netfilter/nft_dynset.c        | 17 -----------------
 3 files changed, 19 insertions(+), 17 deletions(-)

diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index 5d80e09f8148..af2ed70d7eed 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -846,6 +846,7 @@ static inline void *nft_expr_priv(const struct nft_expr *expr)
 	return (void *)expr->data;
 }
 
+int nft_expr_clone(struct nft_expr *dst, struct nft_expr *src);
 void nft_expr_destroy(const struct nft_ctx *ctx, struct nft_expr *expr);
 int nft_expr_dump(struct sk_buff *skb, unsigned int attr,
 		  const struct nft_expr *expr);
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index f92fb6003745..4f6245e7988e 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -2557,6 +2557,24 @@ static struct nft_expr *nft_expr_init(const struct nft_ctx *ctx,
 	return ERR_PTR(err);
 }
 
+int nft_expr_clone(struct nft_expr *dst, struct nft_expr *src)
+{
+	int err;
+
+	if (src->ops->clone) {
+		dst->ops = src->ops;
+		err = src->ops->clone(dst, src);
+		if (err < 0)
+			return err;
+	} else {
+		memcpy(dst, src, src->ops->size);
+	}
+
+	__module_get(src->ops->type->owner);
+
+	return 0;
+}
+
 void nft_expr_destroy(const struct nft_ctx *ctx, struct nft_expr *expr)
 {
 	nf_tables_expr_destroy(ctx, expr);
diff --git a/net/netfilter/nft_dynset.c b/net/netfilter/nft_dynset.c
index 46ab28ec4b53..d1b64c8de585 100644
--- a/net/netfilter/nft_dynset.c
+++ b/net/netfilter/nft_dynset.c
@@ -24,23 +24,6 @@ struct nft_dynset {
 	struct nft_set_binding		binding;
 };
 
-static int nft_expr_clone(struct nft_expr *dst, struct nft_expr *src)
-{
-	int err;
-
-	if (src->ops->clone) {
-		dst->ops = src->ops;
-		err = src->ops->clone(dst, src);
-		if (err < 0)
-			return err;
-	} else {
-		memcpy(dst, src, src->ops->size);
-	}
-
-	__module_get(src->ops->type->owner);
-	return 0;
-}
-
 static void *nft_dynset_new(struct nft_set *set, const struct nft_expr *expr,
 			    struct nft_regs *regs)
 {
-- 
2.11.0

[PATCH nf-next 2/3] netfilter: nf_tables: pass context to nft_set_destroy()

[Pablo Neira Ayuso]

The patch that adds support for stateful expressions in set definitions
require this.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_tables_api.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 4f6245e7988e..df046cd97fa7 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -4126,7 +4126,7 @@ static int nf_tables_newset(struct net *net, struct sock *nlsk,
 	return err;
 }
 
-static void nft_set_destroy(struct nft_set *set)
+static void nft_set_destroy(const struct nft_ctx *ctx, struct nft_set *set)
 {
 	if (WARN_ON(set->use > 0))
 		return;
@@ -4271,7 +4271,7 @@ EXPORT_SYMBOL_GPL(nf_tables_deactivate_set);
 void nf_tables_destroy_set(const struct nft_ctx *ctx, struct nft_set *set)
 {
 	if (list_empty(&set->bindings) && nft_set_is_anonymous(set))
-		nft_set_destroy(set);
+		nft_set_destroy(ctx, set);
 }
 EXPORT_SYMBOL_GPL(nf_tables_destroy_set);
 
@@ -7020,7 +7020,7 @@ static void nft_commit_release(struct nft_trans *trans)
 		nf_tables_rule_destroy(&trans->ctx, nft_trans_rule(trans));
 		break;
 	case NFT_MSG_DELSET:
-		nft_set_destroy(nft_trans_set(trans));
+		nft_set_destroy(&trans->ctx, nft_trans_set(trans));
 		break;
 	case NFT_MSG_DELSETELEM:
 		nf_tables_set_elem_destroy(&trans->ctx,
@@ -7451,7 +7451,7 @@ static void nf_tables_abort_release(struct nft_trans *trans)
 		nf_tables_rule_destroy(&trans->ctx, nft_trans_rule(trans));
 		break;
 	case NFT_MSG_NEWSET:
-		nft_set_destroy(nft_trans_set(trans));
+		nft_set_destroy(&trans->ctx, nft_trans_set(trans));
 		break;
 	case NFT_MSG_NEWSETELEM:
 		nft_set_elem_destroy(nft_trans_elem_set(trans),
@@ -8177,7 +8177,7 @@ static void __nft_release_tables(struct net *net)
 		list_for_each_entry_safe(set, ns, &table->sets, list) {
 			list_del(&set->list);
 			table->use--;
-			nft_set_destroy(set);
+			nft_set_destroy(&ctx, set);
 		}
 		list_for_each_entry_safe(obj, ne, &table->objects, list) {
 			nft_obj_del(obj);
-- 
2.11.0

[PATCH nf-next 3/3] netfilter: nf_tables: allow to specify stateful expression in set definition

[Pablo Neira Ayuso]

This patch allows users to specify the stateful expression for the
elements in this set via NFTA_SET_EXPR. This new feature allows you to
turn on counters for all of the elements in this set.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 include/net/netfilter/nf_tables.h        |  2 ++
 include/uapi/linux/netfilter/nf_tables.h |  2 ++
 net/netfilter/nf_tables_api.c            | 60 +++++++++++++++++++++++++-------
 3 files changed, 52 insertions(+), 12 deletions(-)

diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index af2ed70d7eed..642bc3ef81aa 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -416,6 +416,7 @@ struct nft_set_type {
  *	@policy: set parameterization (see enum nft_set_policies)
  *	@udlen: user data length
  *	@udata: user data
+ *	@expr: stateful expression
  * 	@ops: set ops
  * 	@flags: set flags
  *	@genmask: generation mask
@@ -444,6 +445,7 @@ struct nft_set {
 	u16				policy;
 	u16				udlen;
 	unsigned char			*udata;
+	struct nft_expr			*expr;
 	/* runtime data below here */
 	const struct nft_set_ops	*ops ____cacheline_aligned;
 	u16				flags:14,
diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h
index 9c3d2d04d6a1..4e3a5971d4ee 100644
--- a/include/uapi/linux/netfilter/nf_tables.h
+++ b/include/uapi/linux/netfilter/nf_tables.h
@@ -342,6 +342,7 @@ enum nft_set_field_attributes {
  * @NFTA_SET_USERDATA: user data (NLA_BINARY)
  * @NFTA_SET_OBJ_TYPE: stateful object type (NLA_U32: NFT_OBJECT_*)
  * @NFTA_SET_HANDLE: set handle (NLA_U64)
+ * @NFTA_SET_EXPR: set expression (NLA_NESTED: nft_expr_attributes)
  */
 enum nft_set_attributes {
 	NFTA_SET_UNSPEC,
@@ -361,6 +362,7 @@ enum nft_set_attributes {
 	NFTA_SET_PAD,
 	NFTA_SET_OBJ_TYPE,
 	NFTA_SET_HANDLE,
+	NFTA_SET_EXPR,
 	__NFTA_SET_MAX
 };
 #define NFTA_SET_MAX		(__NFTA_SET_MAX - 1)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index df046cd97fa7..f1910cd795fd 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -3394,6 +3394,7 @@ static const struct nla_policy nft_set_policy[NFTA_SET_MAX + 1] = {
 					    .len  = NFT_USERDATA_MAXLEN },
 	[NFTA_SET_OBJ_TYPE]		= { .type = NLA_U32 },
 	[NFTA_SET_HANDLE]		= { .type = NLA_U64 },
+	[NFTA_SET_EXPR]			= { .type = NLA_NESTED },
 };
 
 static const struct nla_policy nft_set_desc_policy[NFTA_SET_DESC_MAX + 1] = {
@@ -3597,8 +3598,8 @@ static int nf_tables_fill_set(struct sk_buff *skb, const struct nft_ctx *ctx,
 {
 	struct nfgenmsg *nfmsg;
 	struct nlmsghdr *nlh;
-	struct nlattr *desc;
 	u32 portid = ctx->portid;
+	struct nlattr *nest;
 	u32 seq = ctx->seq;
 
 	event = nfnl_msg_type(NFNL_SUBSYS_NFTABLES, event);
@@ -3654,9 +3655,8 @@ static int nf_tables_fill_set(struct sk_buff *skb, const struct nft_ctx *ctx,
 	if (nla_put(skb, NFTA_SET_USERDATA, set->udlen, set->udata))
 		goto nla_put_failure;
 
-	desc = nla_nest_start_noflag(skb, NFTA_SET_DESC);
-
-	if (desc == NULL)
+	nest = nla_nest_start_noflag(skb, NFTA_SET_DESC);
+	if (!nest)
 		goto nla_put_failure;
 	if (set->size &&
 	    nla_put_be32(skb, NFTA_SET_DESC_SIZE, htonl(set->size)))
@@ -3666,7 +3666,15 @@ static int nf_tables_fill_set(struct sk_buff *skb, const struct nft_ctx *ctx,
 	    nf_tables_fill_set_concat(skb, set))
 		goto nla_put_failure;
 
-	nla_nest_end(skb, desc);
+	nla_nest_end(skb, nest);
+
+	if (set->expr) {
+		nest = nla_nest_start_noflag(skb, NFTA_SET_EXPR);
+		if (nf_tables_fill_expr_info(skb, set->expr) < 0)
+			goto nla_put_failure;
+
+		nla_nest_end(skb, nest);
+	}
 
 	nlmsg_end(skb, nlh);
 	return 0;
@@ -3913,6 +3921,7 @@ static int nf_tables_newset(struct net *net, struct sock *nlsk,
 	u8 genmask = nft_genmask_next(net);
 	int family = nfmsg->nfgen_family;
 	const struct nft_set_ops *ops;
+	struct nft_expr *expr = NULL;
 	struct nft_table *table;
 	struct nft_set *set;
 	struct nft_ctx ctx;
@@ -4069,13 +4078,21 @@ static int nf_tables_newset(struct net *net, struct sock *nlsk,
 	name = nla_strdup(nla[NFTA_SET_NAME], GFP_KERNEL);
 	if (!name) {
 		err = -ENOMEM;
-		goto err2;
+		goto err_set_name;
 	}
 
 	err = nf_tables_set_alloc_name(&ctx, set, name);
 	kfree(name);
 	if (err < 0)
-		goto err2;
+		goto err_set_alloc_name;
+
+	if (nla[NFTA_SET_EXPR]) {
+		expr = nft_set_elem_expr_alloc(&ctx, set, nla[NFTA_SET_EXPR]);
+		if (IS_ERR(expr)) {
+			err = PTR_ERR(expr);
+			goto err_set_alloc_name;
+		}
+	}
 
 	udata = NULL;
 	if (udlen) {
@@ -4092,6 +4109,7 @@ static int nf_tables_newset(struct net *net, struct sock *nlsk,
 	set->dtype = dtype;
 	set->objtype = objtype;
 	set->dlen  = desc.dlen;
+	set->expr = expr;
 	set->flags = flags;
 	set->size  = desc.size;
 	set->policy = policy;
@@ -4107,21 +4125,24 @@ static int nf_tables_newset(struct net *net, struct sock *nlsk,
 
 	err = ops->init(set, &desc, nla);
 	if (err < 0)
-		goto err3;
+		goto err_set_init;
 
 	err = nft_trans_set_add(&ctx, NFT_MSG_NEWSET, set);
 	if (err < 0)
-		goto err4;
+		goto err_set_trans;
 
 	list_add_tail_rcu(&set->list, &table->sets);
 	table->use++;
 	return 0;
 
-err4:
+err_set_trans:
 	ops->destroy(set);
-err3:
+err_set_init:
+	if (expr)
+		nft_expr_destroy(&ctx, expr);
+err_set_alloc_name:
 	kfree(set->name);
-err2:
+err_set_name:
 	kvfree(set);
 	return err;
 }
@@ -4131,6 +4152,9 @@ static void nft_set_destroy(const struct nft_ctx *ctx, struct nft_set *set)
 	if (WARN_ON(set->use > 0))
 		return;
 
+	if (set->expr)
+		nft_expr_destroy(ctx, set->expr);
+
 	set->ops->destroy(set);
 	kfree(set->name);
 	kvfree(set);
@@ -4982,6 +5006,18 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 					       nla[NFTA_SET_ELEM_EXPR]);
 		if (IS_ERR(expr))
 			return PTR_ERR(expr);
+
+		err = -EOPNOTSUPP;
+		if (set->expr && set->expr->ops != expr->ops)
+			goto err_set_elem_expr;
+	} else if (set->expr) {
+		expr = kzalloc(set->expr->ops->size, GFP_KERNEL);
+		if (!expr)
+			return -ENOMEM;
+
+		err = nft_expr_clone(expr, set->expr);
+		if (err < 0)
+			goto err_set_elem_expr;
 	}
 
 	err = nft_setelem_parse_key(ctx, set, &elem.key.val,
-- 
2.11.0