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Commit 43da04a5 authored by Pablo Neira Ayuso's avatar Pablo Neira Ayuso
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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
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+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);
+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,
};

+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)
+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,
+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;