1 files changed, 308 insertions, 0 deletions

diff --git a/net/netfilter/nft_counter.c b/net/netfilter/nft_counter.c
new file mode 100644
index 000000000..f4d3573e8
--- /dev/null
+++ b/net/netfilter/nft_counter.c
@@ -0,0 +1,308 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
+ *
+ * Development of this code funded by Astaro AG (http://www.astaro.com/)
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/seqlock.h>
+#include <linux/netlink.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter/nf_tables.h>
+#include <net/netfilter/nf_tables.h>
+#include <net/netfilter/nf_tables_core.h>
+#include <net/netfilter/nf_tables_offload.h>
+
+struct nft_counter {
+	s64		bytes;
+	s64		packets;
+};
+
+struct nft_counter_percpu_priv {
+	struct nft_counter __percpu *counter;
+};
+
+static DEFINE_PER_CPU(seqcount_t, nft_counter_seq);
+
+static inline void nft_counter_do_eval(struct nft_counter_percpu_priv *priv,
+				       struct nft_regs *regs,
+				       const struct nft_pktinfo *pkt)
+{
+	struct nft_counter *this_cpu;
+	seqcount_t *myseq;
+
+	local_bh_disable();
+	this_cpu = this_cpu_ptr(priv->counter);
+	myseq = this_cpu_ptr(&nft_counter_seq);
+
+	write_seqcount_begin(myseq);
+
+	this_cpu->bytes += pkt->skb->len;
+	this_cpu->packets++;
+
+	write_seqcount_end(myseq);
+	local_bh_enable();
+}
+
+static inline void nft_counter_obj_eval(struct nft_object *obj,
+					struct nft_regs *regs,
+					const struct nft_pktinfo *pkt)
+{
+	struct nft_counter_percpu_priv *priv = nft_obj_data(obj);
+
+	nft_counter_do_eval(priv, regs, pkt);
+}
+
+static int nft_counter_do_init(const struct nlattr * const tb[],
+			       struct nft_counter_percpu_priv *priv)
+{
+	struct nft_counter __percpu *cpu_stats;
+	struct nft_counter *this_cpu;
+
+	cpu_stats = alloc_percpu_gfp(struct nft_counter, GFP_KERNEL_ACCOUNT);
+	if (cpu_stats == NULL)
+		return -ENOMEM;
+
+	preempt_disable();
+	this_cpu = this_cpu_ptr(cpu_stats);
+	if (tb[NFTA_COUNTER_PACKETS]) {
+	        this_cpu->packets =
+			be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_PACKETS]));
+	}
+	if (tb[NFTA_COUNTER_BYTES]) {
+		this_cpu->bytes =
+			be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_BYTES]));
+	}
+	preempt_enable();
+	priv->counter = cpu_stats;
+	return 0;
+}
+
+static int nft_counter_obj_init(const struct nft_ctx *ctx,
+				const struct nlattr * const tb[],
+				struct nft_object *obj)
+{
+	struct nft_counter_percpu_priv *priv = nft_obj_data(obj);
+
+	return nft_counter_do_init(tb, priv);
+}
+
+static void nft_counter_do_destroy(struct nft_counter_percpu_priv *priv)
+{
+	free_percpu(priv->counter);
+}
+
+static void nft_counter_obj_destroy(const struct nft_ctx *ctx,
+				    struct nft_object *obj)
+{
+	struct nft_counter_percpu_priv *priv = nft_obj_data(obj);
+
+	nft_counter_do_destroy(priv);
+}
+
+static void nft_counter_reset(struct nft_counter_percpu_priv *priv,
+			      struct nft_counter *total)
+{
+	struct nft_counter *this_cpu;
+
+	local_bh_disable();
+	this_cpu = this_cpu_ptr(priv->counter);
+	this_cpu->packets -= total->packets;
+	this_cpu->bytes -= total->bytes;
+	local_bh_enable();
+}
+
+static void nft_counter_fetch(struct nft_counter_percpu_priv *priv,
+			      struct nft_counter *total)
+{
+	struct nft_counter *this_cpu;
+	const seqcount_t *myseq;
+	u64 bytes, packets;
+	unsigned int seq;
+	int cpu;
+
+	memset(total, 0, sizeof(*total));
+	for_each_possible_cpu(cpu) {
+		myseq = per_cpu_ptr(&nft_counter_seq, cpu);
+		this_cpu = per_cpu_ptr(priv->counter, cpu);
+		do {
+			seq	= read_seqcount_begin(myseq);
+			bytes	= this_cpu->bytes;
+			packets	= this_cpu->packets;
+		} while (read_seqcount_retry(myseq, seq));
+
+		total->bytes	+= bytes;
+		total->packets	+= packets;
+	}
+}
+
+static int nft_counter_do_dump(struct sk_buff *skb,
+			       struct nft_counter_percpu_priv *priv,
+			       bool reset)
+{
+	struct nft_counter total;
+
+	nft_counter_fetch(priv, &total);
+
+	if (nla_put_be64(skb, NFTA_COUNTER_BYTES, cpu_to_be64(total.bytes),
+			 NFTA_COUNTER_PAD) ||
+	    nla_put_be64(skb, NFTA_COUNTER_PACKETS, cpu_to_be64(total.packets),
+			 NFTA_COUNTER_PAD))
+		goto nla_put_failure;
+
+	if (reset)
+		nft_counter_reset(priv, &total);
+
+	return 0;
+
+nla_put_failure:
+	return -1;
+}
+
+static int nft_counter_obj_dump(struct sk_buff *skb,
+				struct nft_object *obj, bool reset)
+{
+	struct nft_counter_percpu_priv *priv = nft_obj_data(obj);
+
+	return nft_counter_do_dump(skb, priv, reset);
+}
+
+static const struct nla_policy nft_counter_policy[NFTA_COUNTER_MAX + 1] = {
+	[NFTA_COUNTER_PACKETS]	= { .type = NLA_U64 },
+	[NFTA_COUNTER_BYTES]	= { .type = NLA_U64 },
+};
+
+struct nft_object_type nft_counter_obj_type;
+static const struct nft_object_ops nft_counter_obj_ops = {
+	.type		= &nft_counter_obj_type,
+	.size		= sizeof(struct nft_counter_percpu_priv),
+	.eval		= nft_counter_obj_eval,
+	.init		= nft_counter_obj_init,
+	.destroy	= nft_counter_obj_destroy,
+	.dump		= nft_counter_obj_dump,
+};
+
+struct nft_object_type nft_counter_obj_type __read_mostly = {
+	.type		= NFT_OBJECT_COUNTER,
+	.ops		= &nft_counter_obj_ops,
+	.maxattr	= NFTA_COUNTER_MAX,
+	.policy		= nft_counter_policy,
+	.owner		= THIS_MODULE,
+};
+
+void nft_counter_eval(const struct nft_expr *expr, struct nft_regs *regs,
+		      const struct nft_pktinfo *pkt)
+{
+	struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
+
+	nft_counter_do_eval(priv, regs, pkt);
+}
+
+static int nft_counter_dump(struct sk_buff *skb, const struct nft_expr *expr)
+{
+	struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
+
+	return nft_counter_do_dump(skb, priv, false);
+}
+
+static int nft_counter_init(const struct nft_ctx *ctx,
+			    const struct nft_expr *expr,
+			    const struct nlattr * const tb[])
+{
+	struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
+
+	return nft_counter_do_init(tb, priv);
+}
+
+static void nft_counter_destroy(const struct nft_ctx *ctx,
+				const struct nft_expr *expr)
+{
+	struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
+
+	nft_counter_do_destroy(priv);
+}
+
+static int nft_counter_clone(struct nft_expr *dst, const struct nft_expr *src)
+{
+	struct nft_counter_percpu_priv *priv = nft_expr_priv(src);
+	struct nft_counter_percpu_priv *priv_clone = nft_expr_priv(dst);
+	struct nft_counter __percpu *cpu_stats;
+	struct nft_counter *this_cpu;
+	struct nft_counter total;
+
+	nft_counter_fetch(priv, &total);
+
+	cpu_stats = alloc_percpu_gfp(struct nft_counter, GFP_ATOMIC);
+	if (cpu_stats == NULL)
+		return -ENOMEM;
+
+	preempt_disable();
+	this_cpu = this_cpu_ptr(cpu_stats);
+	this_cpu->packets = total.packets;
+	this_cpu->bytes = total.bytes;
+	preempt_enable();
+
+	priv_clone->counter = cpu_stats;
+	return 0;
+}
+
+static int nft_counter_offload(struct nft_offload_ctx *ctx,
+			       struct nft_flow_rule *flow,
+			       const struct nft_expr *expr)
+{
+	/* No specific offload action is needed, but report success. */
+	return 0;
+}
+
+static void nft_counter_offload_stats(struct nft_expr *expr,
+				      const struct flow_stats *stats)
+{
+	struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
+	struct nft_counter *this_cpu;
+	seqcount_t *myseq;
+
+	preempt_disable();
+	this_cpu = this_cpu_ptr(priv->counter);
+	myseq = this_cpu_ptr(&nft_counter_seq);
+
+	write_seqcount_begin(myseq);
+	this_cpu->packets += stats->pkts;
+	this_cpu->bytes += stats->bytes;
+	write_seqcount_end(myseq);
+	preempt_enable();
+}
+
+void nft_counter_init_seqcount(void)
+{
+	int cpu;
+
+	for_each_possible_cpu(cpu)
+		seqcount_init(per_cpu_ptr(&nft_counter_seq, cpu));
+}
+
+struct nft_expr_type nft_counter_type;
+static const struct nft_expr_ops nft_counter_ops = {
+	.type		= &nft_counter_type,
+	.size		= NFT_EXPR_SIZE(sizeof(struct nft_counter_percpu_priv)),
+	.eval		= nft_counter_eval,
+	.init		= nft_counter_init,
+	.destroy	= nft_counter_destroy,
+	.destroy_clone	= nft_counter_destroy,
+	.dump		= nft_counter_dump,
+	.clone		= nft_counter_clone,
+	.reduce		= NFT_REDUCE_READONLY,
+	.offload	= nft_counter_offload,
+	.offload_stats	= nft_counter_offload_stats,
+};
+
+struct nft_expr_type nft_counter_type __read_mostly = {
+	.name		= "counter",
+	.ops		= &nft_counter_ops,
+	.policy		= nft_counter_policy,
+	.maxattr	= NFTA_COUNTER_MAX,
+	.flags		= NFT_EXPR_STATEFUL,
+	.owner		= THIS_MODULE,
+};