1 files changed, 262 insertions, 0 deletions
diff --git a/net/netfilter/nft_objref.c b/net/netfilter/nft_objref.c
new file mode 100644
index 000000000..0017bd341
--- /dev/null
+++ b/net/netfilter/nft_objref.c
@@ -0,0 +1,262 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2012-2016 Pablo Neira Ayuso <pablo@netfilter.org>
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/netlink.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter/nf_tables.h>
+#include <net/netfilter/nf_tables_core.h>
+
+#define nft_objref_priv(expr)	*((struct nft_object **)nft_expr_priv(expr))
+
+static void nft_objref_eval(const struct nft_expr *expr,
+			    struct nft_regs *regs,
+			    const struct nft_pktinfo *pkt)
+{
+	struct nft_object *obj = nft_objref_priv(expr);
+
+	obj->ops->eval(obj, regs, pkt);
+}
+
+static int nft_objref_init(const struct nft_ctx *ctx,
+			   const struct nft_expr *expr,
+			   const struct nlattr * const tb[])
+{
+	struct nft_object *obj = nft_objref_priv(expr);
+	u8 genmask = nft_genmask_next(ctx->net);
+	u32 objtype;
+
+	if (!tb[NFTA_OBJREF_IMM_NAME] ||
+	    !tb[NFTA_OBJREF_IMM_TYPE])
+		return -EINVAL;
+
+	objtype = ntohl(nla_get_be32(tb[NFTA_OBJREF_IMM_TYPE]));
+	obj = nft_obj_lookup(ctx->net, ctx->table,
+			     tb[NFTA_OBJREF_IMM_NAME], objtype,
+			     genmask);
+	if (IS_ERR(obj))
+		return -ENOENT;
+
+	if (!nft_use_inc(&obj->use))
+		return -EMFILE;
+
+	nft_objref_priv(expr) = obj;
+
+	return 0;
+}
+
+static int nft_objref_dump(struct sk_buff *skb, const struct nft_expr *expr)
+{
+	const struct nft_object *obj = nft_objref_priv(expr);
+
+	if (nla_put_string(skb, NFTA_OBJREF_IMM_NAME, obj->key.name) ||
+	    nla_put_be32(skb, NFTA_OBJREF_IMM_TYPE,
+			 htonl(obj->ops->type->type)))
+		goto nla_put_failure;
+
+	return 0;
+
+nla_put_failure:
+	return -1;
+}
+
+static void nft_objref_deactivate(const struct nft_ctx *ctx,
+				  const struct nft_expr *expr,
+				  enum nft_trans_phase phase)
+{
+	struct nft_object *obj = nft_objref_priv(expr);
+
+	if (phase == NFT_TRANS_COMMIT)
+		return;
+
+	nft_use_dec(&obj->use);
+}
+
+static void nft_objref_activate(const struct nft_ctx *ctx,
+				const struct nft_expr *expr)
+{
+	struct nft_object *obj = nft_objref_priv(expr);
+
+	nft_use_inc_restore(&obj->use);
+}
+
+static struct nft_expr_type nft_objref_type;
+static const struct nft_expr_ops nft_objref_ops = {
+	.type		= &nft_objref_type,
+	.size		= NFT_EXPR_SIZE(sizeof(struct nft_object *)),
+	.eval		= nft_objref_eval,
+	.init		= nft_objref_init,
+	.activate	= nft_objref_activate,
+	.deactivate	= nft_objref_deactivate,
+	.dump		= nft_objref_dump,
+	.reduce		= NFT_REDUCE_READONLY,
+};
+
+struct nft_objref_map {
+	struct nft_set		*set;
+	u8			sreg;
+	struct nft_set_binding	binding;
+};
+
+static void nft_objref_map_eval(const struct nft_expr *expr,
+				struct nft_regs *regs,
+				const struct nft_pktinfo *pkt)
+{
+	struct nft_objref_map *priv = nft_expr_priv(expr);
+	const struct nft_set *set = priv->set;
+	struct net *net = nft_net(pkt);
+	const struct nft_set_ext *ext;
+	struct nft_object *obj;
+	bool found;
+
+	found = nft_set_do_lookup(net, set, &regs->data[priv->sreg], &ext);
+	if (!found) {
+		ext = nft_set_catchall_lookup(net, set);
+		if (!ext) {
+			regs->verdict.code = NFT_BREAK;
+			return;
+		}
+	}
+	obj = *nft_set_ext_obj(ext);
+	obj->ops->eval(obj, regs, pkt);
+}
+
+static int nft_objref_map_init(const struct nft_ctx *ctx,
+			       const struct nft_expr *expr,
+			       const struct nlattr * const tb[])
+{
+	struct nft_objref_map *priv = nft_expr_priv(expr);
+	u8 genmask = nft_genmask_next(ctx->net);
+	struct nft_set *set;
+	int err;
+
+	set = nft_set_lookup_global(ctx->net, ctx->table,
+				    tb[NFTA_OBJREF_SET_NAME],
+				    tb[NFTA_OBJREF_SET_ID], genmask);
+	if (IS_ERR(set))
+		return PTR_ERR(set);
+
+	if (!(set->flags & NFT_SET_OBJECT))
+		return -EINVAL;
+
+	err = nft_parse_register_load(tb[NFTA_OBJREF_SET_SREG], &priv->sreg,
+				      set->klen);
+	if (err < 0)
+		return err;
+
+	priv->binding.flags = set->flags & NFT_SET_OBJECT;
+
+	err = nf_tables_bind_set(ctx, set, &priv->binding);
+	if (err < 0)
+		return err;
+
+	priv->set = set;
+	return 0;
+}
+
+static int nft_objref_map_dump(struct sk_buff *skb, const struct nft_expr *expr)
+{
+	const struct nft_objref_map *priv = nft_expr_priv(expr);
+
+	if (nft_dump_register(skb, NFTA_OBJREF_SET_SREG, priv->sreg) ||
+	    nla_put_string(skb, NFTA_OBJREF_SET_NAME, priv->set->name))
+		goto nla_put_failure;
+
+	return 0;
+
+nla_put_failure:
+	return -1;
+}
+
+static void nft_objref_map_deactivate(const struct nft_ctx *ctx,
+				      const struct nft_expr *expr,
+				      enum nft_trans_phase phase)
+{
+	struct nft_objref_map *priv = nft_expr_priv(expr);
+
+	nf_tables_deactivate_set(ctx, priv->set, &priv->binding, phase);
+}
+
+static void nft_objref_map_activate(const struct nft_ctx *ctx,
+				    const struct nft_expr *expr)
+{
+	struct nft_objref_map *priv = nft_expr_priv(expr);
+
+	nf_tables_activate_set(ctx, priv->set);
+}
+
+static void nft_objref_map_destroy(const struct nft_ctx *ctx,
+				   const struct nft_expr *expr)
+{
+	struct nft_objref_map *priv = nft_expr_priv(expr);
+
+	nf_tables_destroy_set(ctx, priv->set);
+}
+
+static struct nft_expr_type nft_objref_type;
+static const struct nft_expr_ops nft_objref_map_ops = {
+	.type		= &nft_objref_type,
+	.size		= NFT_EXPR_SIZE(sizeof(struct nft_objref_map)),
+	.eval		= nft_objref_map_eval,
+	.init		= nft_objref_map_init,
+	.activate	= nft_objref_map_activate,
+	.deactivate	= nft_objref_map_deactivate,
+	.destroy	= nft_objref_map_destroy,
+	.dump		= nft_objref_map_dump,
+	.reduce		= NFT_REDUCE_READONLY,
+};
+
+static const struct nft_expr_ops *
+nft_objref_select_ops(const struct nft_ctx *ctx,
+                      const struct nlattr * const tb[])
+{
+	if (tb[NFTA_OBJREF_SET_SREG] &&
+	    (tb[NFTA_OBJREF_SET_NAME] ||
+	     tb[NFTA_OBJREF_SET_ID]))
+		return &nft_objref_map_ops;
+	else if (tb[NFTA_OBJREF_IMM_NAME] &&
+		 tb[NFTA_OBJREF_IMM_TYPE])
+		return &nft_objref_ops;
+
+	return ERR_PTR(-EOPNOTSUPP);
+}
+
+static const struct nla_policy nft_objref_policy[NFTA_OBJREF_MAX + 1] = {
+	[NFTA_OBJREF_IMM_NAME]	= { .type = NLA_STRING,
+				    .len = NFT_OBJ_MAXNAMELEN - 1 },
+	[NFTA_OBJREF_IMM_TYPE]	= { .type = NLA_U32 },
+	[NFTA_OBJREF_SET_SREG]	= { .type = NLA_U32 },
+	[NFTA_OBJREF_SET_NAME]	= { .type = NLA_STRING,
+				    .len = NFT_SET_MAXNAMELEN - 1 },
+	[NFTA_OBJREF_SET_ID]	= { .type = NLA_U32 },
+};
+
+static struct nft_expr_type nft_objref_type __read_mostly = {
+	.name		= "objref",
+	.select_ops	= nft_objref_select_ops,
+	.policy		= nft_objref_policy,
+	.maxattr	= NFTA_OBJREF_MAX,
+	.owner		= THIS_MODULE,
+};
+
+static int __init nft_objref_module_init(void)
+{
+	return nft_register_expr(&nft_objref_type);
+}
+
+static void __exit nft_objref_module_exit(void)
+{
+	nft_unregister_expr(&nft_objref_type);
+}
+
+module_init(nft_objref_module_init);
+module_exit(nft_objref_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
+MODULE_ALIAS_NFT_EXPR("objref");
+MODULE_DESCRIPTION("nftables stateful object reference module");