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Commit 43da04a5 authored by Pablo Neira Ayuso's avatar Pablo Neira Ayuso
Browse files

netfilter: nf_tables: atomic dump and reset for stateful objects 



This patch adds a new NFT_MSG_GETOBJ_RESET command perform an atomic
dump-and-reset of the stateful object. This also comes with add support
for atomic dump and reset for counter and quota objects.

Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 795595f6

include/net/netfilter/nf_tables.h

+2 −1
Original line number Diff line number Diff line
@@ -997,7 +997,8 @@ struct nft_object_type { 
						struct nft_object *obj);

	void				(*destroy)(struct nft_object *obj);

	int				(*dump)(struct sk_buff *skb,

						const struct nft_object *obj);

						struct nft_object *obj,

						bool reset);

};



int nft_register_obj(struct nft_object_type *obj_type);

include/uapi/linux/netfilter/nf_tables.h

+2 −0
Original line number Diff line number Diff line
@@ -89,6 +89,7 @@ enum nft_verdicts { 
 * @NFT_MSG_NEWOBJ: create a stateful object (enum nft_obj_attributes)

 * @NFT_MSG_GETOBJ: get a stateful object (enum nft_obj_attributes)

 * @NFT_MSG_DELOBJ: delete a stateful object (enum nft_obj_attributes)

 * @NFT_MSG_GETOBJ_RESET: get and reset a stateful object (enum nft_obj_attributes)

 */

enum nf_tables_msg_types {

	NFT_MSG_NEWTABLE,
@@ -112,6 +113,7 @@ enum nf_tables_msg_types { 
	NFT_MSG_NEWOBJ,

	NFT_MSG_GETOBJ,

	NFT_MSG_DELOBJ,

	NFT_MSG_GETOBJ_RESET,

	NFT_MSG_MAX,

};

net/netfilter/nf_tables_api.c

+21 −8
Original line number Diff line number Diff line
@@ -3972,14 +3972,14 @@ static struct nft_object *nft_obj_init(const struct nft_object_type *type, 
}



static int nft_object_dump(struct sk_buff *skb, unsigned int attr,

			   const struct nft_object *obj)

			   struct nft_object *obj, bool reset)

{

	struct nlattr *nest;



	nest = nla_nest_start(skb, attr);

	if (!nest)

		goto nla_put_failure;

	if (obj->type->dump(skb, obj) < 0)

	if (obj->type->dump(skb, obj, reset) < 0)

		goto nla_put_failure;

	nla_nest_end(skb, nest);

	return 0;
@@ -4096,7 +4096,7 @@ static int nf_tables_newobj(struct net *net, struct sock *nlsk, 
static int nf_tables_fill_obj_info(struct sk_buff *skb, struct net *net,

				   u32 portid, u32 seq, int event, u32 flags,

				   int family, const struct nft_table *table,

				   const struct nft_object *obj)

				   struct nft_object *obj, bool reset)

{

	struct nfgenmsg *nfmsg;

	struct nlmsghdr *nlh;
@@ -4115,7 +4115,7 @@ static int nf_tables_fill_obj_info(struct sk_buff *skb, struct net *net, 
	    nla_put_string(skb, NFTA_OBJ_NAME, obj->name) ||

	    nla_put_be32(skb, NFTA_OBJ_TYPE, htonl(obj->type->type)) ||

	    nla_put_be32(skb, NFTA_OBJ_USE, htonl(obj->use)) ||

	    nft_object_dump(skb, NFTA_OBJ_DATA, obj))

	    nft_object_dump(skb, NFTA_OBJ_DATA, obj, reset))

		goto nla_put_failure;



	nlmsg_end(skb, nlh);
@@ -4131,10 +4131,14 @@ static int nf_tables_dump_obj(struct sk_buff *skb, struct netlink_callback *cb) 
	const struct nfgenmsg *nfmsg = nlmsg_data(cb->nlh);

	const struct nft_af_info *afi;

	const struct nft_table *table;

	const struct nft_object *obj;

	unsigned int idx = 0, s_idx = cb->args[0];

	struct net *net = sock_net(skb->sk);

	int family = nfmsg->nfgen_family;

	struct nft_object *obj;

	bool reset = false;



	if (NFNL_MSG_TYPE(cb->nlh->nlmsg_type) == NFT_MSG_GETOBJ_RESET)

		reset = true;



	rcu_read_lock();

	cb->seq = net->nft.base_seq;
@@ -4156,7 +4160,7 @@ static int nf_tables_dump_obj(struct sk_buff *skb, struct netlink_callback *cb) 
							    cb->nlh->nlmsg_seq,

							    NFT_MSG_NEWOBJ,

							    NLM_F_MULTI | NLM_F_APPEND,

							    afi->family, table, obj) < 0)

							    afi->family, table, obj, reset) < 0)

					goto done;



				nl_dump_check_consistent(cb, nlmsg_hdr(skb));
@@ -4183,6 +4187,7 @@ static int nf_tables_getobj(struct net *net, struct sock *nlsk, 
	const struct nft_table *table;

	struct nft_object *obj;

	struct sk_buff *skb2;

	bool reset = false;

	u32 objtype;

	int err;
@@ -4214,9 +4219,12 @@ static int nf_tables_getobj(struct net *net, struct sock *nlsk, 
	if (!skb2)

		return -ENOMEM;



	if (NFNL_MSG_TYPE(nlh->nlmsg_type) == NFT_MSG_GETOBJ_RESET)

		reset = true;



	err = nf_tables_fill_obj_info(skb2, net, NETLINK_CB(skb).portid,

				      nlh->nlmsg_seq, NFT_MSG_NEWOBJ, 0,

				      family, table, obj);

				      family, table, obj, reset);

	if (err < 0)

		goto err;
@@ -4291,7 +4299,7 @@ static int nf_tables_obj_notify(const struct nft_ctx *ctx, 


	err = nf_tables_fill_obj_info(skb, ctx->net, ctx->portid, ctx->seq,

				      event, 0, ctx->afi->family, ctx->table,

				      obj);

				      obj, false);

	if (err < 0) {

		kfree_skb(skb);

		goto err;
@@ -4482,6 +4490,11 @@ static const struct nfnl_callback nf_tables_cb[NFT_MSG_MAX] = { 
		.attr_count	= NFTA_OBJ_MAX,

		.policy		= nft_obj_policy,

	},

	[NFT_MSG_GETOBJ_RESET] = {

		.call		= nf_tables_getobj,

		.attr_count	= NFTA_OBJ_MAX,

		.policy		= nft_obj_policy,

	},

};



static void nft_chain_commit_update(struct nft_trans *trans)

net/netfilter/nft_counter.c

+48 −8
Original line number Diff line number Diff line
@@ -100,10 +100,10 @@ static void nft_counter_obj_destroy(struct nft_object *obj) 
	nft_counter_do_destroy(priv);

}



static void nft_counter_fetch(const struct nft_counter_percpu __percpu *counter,

static void nft_counter_fetch(struct nft_counter_percpu __percpu *counter,

			      struct nft_counter *total)

{

	const struct nft_counter_percpu *cpu_stats;

	struct nft_counter_percpu *cpu_stats;

	u64 bytes, packets;

	unsigned int seq;

	int cpu;
@@ -122,11 +122,51 @@ static void nft_counter_fetch(const struct nft_counter_percpu __percpu *counter, 
	}

}



static u64 __nft_counter_reset(u64 *counter)

{

	u64 ret, old;



	do {

		old = *counter;

		ret = cmpxchg64(counter, old, 0);

	} while (ret != old);



	return ret;

}



static void nft_counter_reset(struct nft_counter_percpu __percpu *counter,

			      struct nft_counter *total)

{

	struct nft_counter_percpu *cpu_stats;

	u64 bytes, packets;

	unsigned int seq;

	int cpu;



	memset(total, 0, sizeof(*total));

	for_each_possible_cpu(cpu) {

		bytes = packets = 0;



		cpu_stats = per_cpu_ptr(counter, cpu);

		do {

			seq	= u64_stats_fetch_begin_irq(&cpu_stats->syncp);

			packets	+= __nft_counter_reset(&cpu_stats->counter.packets);

			bytes	+= __nft_counter_reset(&cpu_stats->counter.bytes);

		} while (u64_stats_fetch_retry_irq(&cpu_stats->syncp, seq));



		total->packets += packets;

		total->bytes += bytes;

	}

}



static int nft_counter_do_dump(struct sk_buff *skb,

			       const struct nft_counter_percpu_priv *priv)

			       const struct nft_counter_percpu_priv *priv,

			       bool reset)

{

	struct nft_counter total;



	if (reset)

		nft_counter_reset(priv->counter, &total);

	else

		nft_counter_fetch(priv->counter, &total);



	if (nla_put_be64(skb, NFTA_COUNTER_BYTES, cpu_to_be64(total.bytes),
@@ -141,11 +181,11 @@ static int nft_counter_do_dump(struct sk_buff *skb, 
}



static int nft_counter_obj_dump(struct sk_buff *skb,

				const struct nft_object *obj)

				struct nft_object *obj, bool reset)

{

	const struct nft_counter_percpu_priv *priv = nft_obj_data(obj);

	struct nft_counter_percpu_priv *priv = nft_obj_data(obj);



	return nft_counter_do_dump(skb, priv);

	return nft_counter_do_dump(skb, priv, reset);

}



static const struct nla_policy nft_counter_policy[NFTA_COUNTER_MAX + 1] = {
@@ -178,7 +218,7 @@ static int nft_counter_dump(struct sk_buff *skb, const struct nft_expr *expr) 
{

	const struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);



	return nft_counter_do_dump(skb, priv);

	return nft_counter_do_dump(skb, priv, false);

}



static int nft_counter_init(const struct nft_ctx *ctx,

net/netfilter/nft_quota.c

+12 −6
Original line number Diff line number Diff line
@@ -83,12 +83,17 @@ static int nft_quota_obj_init(const struct nlattr * const tb[], 
	return nft_quota_do_init(tb, priv);

}



static int nft_quota_do_dump(struct sk_buff *skb, const struct nft_quota *priv)

static int nft_quota_do_dump(struct sk_buff *skb, struct nft_quota *priv,

			     bool reset)

{

	u32 flags = priv->invert ? NFT_QUOTA_F_INV : 0;

	u64 consumed;



	if (reset)

		consumed = atomic64_xchg(&priv->consumed, 0);

	else

		consumed = atomic64_read(&priv->consumed);



	/* Since we inconditionally increment consumed quota for each packet

	 * that we see, don't go over the quota boundary in what we send to

	 * userspace.
@@ -108,11 +113,12 @@ static int nft_quota_do_dump(struct sk_buff *skb, const struct nft_quota *priv) 
	return -1;

}



static int nft_quota_obj_dump(struct sk_buff *skb, const struct nft_object *obj)

static int nft_quota_obj_dump(struct sk_buff *skb, struct nft_object *obj,

			      bool reset)

{

	struct nft_quota *priv = nft_obj_data(obj);



	return nft_quota_do_dump(skb, priv);

	return nft_quota_do_dump(skb, priv, reset);

}



static struct nft_object_type nft_quota_obj __read_mostly = {
@@ -146,9 +152,9 @@ static int nft_quota_init(const struct nft_ctx *ctx, 


static int nft_quota_dump(struct sk_buff *skb, const struct nft_expr *expr)

{

	const struct nft_quota *priv = nft_expr_priv(expr);

	struct nft_quota *priv = nft_expr_priv(expr);



	return nft_quota_do_dump(skb, priv);

	return nft_quota_do_dump(skb, priv, false);

}



static struct nft_expr_type nft_quota_type;