netfilter: nf_tables: allow to specify stateful expression in set definition

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>

diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index af2ed70..642bc3e 100644 (file)
--- 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 9c3d2d0..4e3a597 100644 (file)
--- 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 df046cd..f1910cd 100644 (file)
--- 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,