1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
4 *
5 * Development of this code funded by Astaro AG (http://www.astaro.com/)
6 */
7
8#include <linux/kernel.h>
9#include <linux/init.h>
10#include <linux/module.h>
11#include <linux/seqlock.h>
12#include <linux/netlink.h>
13#include <linux/netfilter.h>
14#include <linux/netfilter/nf_tables.h>
15#include <net/netfilter/nf_tables.h>
16#include <net/netfilter/nf_tables_core.h>
17#include <net/netfilter/nf_tables_offload.h>
18
19struct nft_counter {
20	s64		bytes;
21	s64		packets;
22};
23
24struct nft_counter_percpu_priv {
25	struct nft_counter __percpu *counter;
26};
27
28static DEFINE_PER_CPU(seqcount_t, nft_counter_seq);
29
30static inline void nft_counter_do_eval(struct nft_counter_percpu_priv *priv,
31				       struct nft_regs *regs,
32				       const struct nft_pktinfo *pkt)
33{
34	struct nft_counter *this_cpu;
35	seqcount_t *myseq;
36
37	local_bh_disable();
38	this_cpu = this_cpu_ptr(priv->counter);
39	myseq = this_cpu_ptr(&nft_counter_seq);
40
41	write_seqcount_begin(myseq);
42
43	this_cpu->bytes += pkt->skb->len;
44	this_cpu->packets++;
45
46	write_seqcount_end(myseq);
47	local_bh_enable();
48}
49
50static inline void nft_counter_obj_eval(struct nft_object *obj,
51					struct nft_regs *regs,
52					const struct nft_pktinfo *pkt)
53{
54	struct nft_counter_percpu_priv *priv = nft_obj_data(obj);
55
56	nft_counter_do_eval(priv, regs, pkt);
57}
58
59static int nft_counter_do_init(const struct nlattr * const tb[],
60			       struct nft_counter_percpu_priv *priv)
61{
62	struct nft_counter __percpu *cpu_stats;
63	struct nft_counter *this_cpu;
64
65	cpu_stats = alloc_percpu_gfp(struct nft_counter, GFP_KERNEL_ACCOUNT);
66	if (cpu_stats == NULL)
67		return -ENOMEM;
68
69	preempt_disable();
70	this_cpu = this_cpu_ptr(cpu_stats);
71	if (tb[NFTA_COUNTER_PACKETS]) {
72	        this_cpu->packets =
73			be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_PACKETS]));
74	}
75	if (tb[NFTA_COUNTER_BYTES]) {
76		this_cpu->bytes =
77			be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_BYTES]));
78	}
79	preempt_enable();
80	priv->counter = cpu_stats;
81	return 0;
82}
83
84static int nft_counter_obj_init(const struct nft_ctx *ctx,
85				const struct nlattr * const tb[],
86				struct nft_object *obj)
87{
88	struct nft_counter_percpu_priv *priv = nft_obj_data(obj);
89
90	return nft_counter_do_init(tb, priv);
91}
92
93static void nft_counter_do_destroy(struct nft_counter_percpu_priv *priv)
94{
95	free_percpu(priv->counter);
96}
97
98static void nft_counter_obj_destroy(const struct nft_ctx *ctx,
99				    struct nft_object *obj)
100{
101	struct nft_counter_percpu_priv *priv = nft_obj_data(obj);
102
103	nft_counter_do_destroy(priv);
104}
105
106static void nft_counter_reset(struct nft_counter_percpu_priv *priv,
107			      struct nft_counter *total)
108{
109	struct nft_counter *this_cpu;
110
111	local_bh_disable();
112	this_cpu = this_cpu_ptr(priv->counter);
113	this_cpu->packets -= total->packets;
114	this_cpu->bytes -= total->bytes;
115	local_bh_enable();
116}
117
118static void nft_counter_fetch(struct nft_counter_percpu_priv *priv,
119			      struct nft_counter *total)
120{
121	struct nft_counter *this_cpu;
122	const seqcount_t *myseq;
123	u64 bytes, packets;
124	unsigned int seq;
125	int cpu;
126
127	memset(total, 0, sizeof(*total));
128	for_each_possible_cpu(cpu) {
129		myseq = per_cpu_ptr(&nft_counter_seq, cpu);
130		this_cpu = per_cpu_ptr(priv->counter, cpu);
131		do {
132			seq	= read_seqcount_begin(myseq);
133			bytes	= this_cpu->bytes;
134			packets	= this_cpu->packets;
135		} while (read_seqcount_retry(myseq, seq));
136
137		total->bytes	+= bytes;
138		total->packets	+= packets;
139	}
140}
141
142static int nft_counter_do_dump(struct sk_buff *skb,
143			       struct nft_counter_percpu_priv *priv,
144			       bool reset)
145{
146	struct nft_counter total;
147
148	nft_counter_fetch(priv, &total);
149
150	if (nla_put_be64(skb, NFTA_COUNTER_BYTES, cpu_to_be64(total.bytes),
151			 NFTA_COUNTER_PAD) ||
152	    nla_put_be64(skb, NFTA_COUNTER_PACKETS, cpu_to_be64(total.packets),
153			 NFTA_COUNTER_PAD))
154		goto nla_put_failure;
155
156	if (reset)
157		nft_counter_reset(priv, &total);
158
159	return 0;
160
161nla_put_failure:
162	return -1;
163}
164
165static int nft_counter_obj_dump(struct sk_buff *skb,
166				struct nft_object *obj, bool reset)
167{
168	struct nft_counter_percpu_priv *priv = nft_obj_data(obj);
169
170	return nft_counter_do_dump(skb, priv, reset);
171}
172
173static const struct nla_policy nft_counter_policy[NFTA_COUNTER_MAX + 1] = {
174	[NFTA_COUNTER_PACKETS]	= { .type = NLA_U64 },
175	[NFTA_COUNTER_BYTES]	= { .type = NLA_U64 },
176};
177
178struct nft_object_type nft_counter_obj_type;
179static const struct nft_object_ops nft_counter_obj_ops = {
180	.type		= &nft_counter_obj_type,
181	.size		= sizeof(struct nft_counter_percpu_priv),
182	.eval		= nft_counter_obj_eval,
183	.init		= nft_counter_obj_init,
184	.destroy	= nft_counter_obj_destroy,
185	.dump		= nft_counter_obj_dump,
186};
187
188struct nft_object_type nft_counter_obj_type __read_mostly = {
189	.type		= NFT_OBJECT_COUNTER,
190	.ops		= &nft_counter_obj_ops,
191	.maxattr	= NFTA_COUNTER_MAX,
192	.policy		= nft_counter_policy,
193	.owner		= THIS_MODULE,
194};
195
196void nft_counter_eval(const struct nft_expr *expr, struct nft_regs *regs,
197		      const struct nft_pktinfo *pkt)
198{
199	struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
200
201	nft_counter_do_eval(priv, regs, pkt);
202}
203
204static int nft_counter_dump(struct sk_buff *skb,
205			    const struct nft_expr *expr, bool reset)
206{
207	struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
208
209	return nft_counter_do_dump(skb, priv, reset);
210}
211
212static int nft_counter_init(const struct nft_ctx *ctx,
213			    const struct nft_expr *expr,
214			    const struct nlattr * const tb[])
215{
216	struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
217
218	return nft_counter_do_init(tb, priv);
219}
220
221static void nft_counter_destroy(const struct nft_ctx *ctx,
222				const struct nft_expr *expr)
223{
224	struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
225
226	nft_counter_do_destroy(priv);
227}
228
229static int nft_counter_clone(struct nft_expr *dst, const struct nft_expr *src)
230{
231	struct nft_counter_percpu_priv *priv = nft_expr_priv(src);
232	struct nft_counter_percpu_priv *priv_clone = nft_expr_priv(dst);
233	struct nft_counter __percpu *cpu_stats;
234	struct nft_counter *this_cpu;
235	struct nft_counter total;
236
237	nft_counter_fetch(priv, &total);
238
239	cpu_stats = alloc_percpu_gfp(struct nft_counter, GFP_ATOMIC);
240	if (cpu_stats == NULL)
241		return -ENOMEM;
242
243	preempt_disable();
244	this_cpu = this_cpu_ptr(cpu_stats);
245	this_cpu->packets = total.packets;
246	this_cpu->bytes = total.bytes;
247	preempt_enable();
248
249	priv_clone->counter = cpu_stats;
250	return 0;
251}
252
253static int nft_counter_offload(struct nft_offload_ctx *ctx,
254			       struct nft_flow_rule *flow,
255			       const struct nft_expr *expr)
256{
257	/* No specific offload action is needed, but report success. */
258	return 0;
259}
260
261static void nft_counter_offload_stats(struct nft_expr *expr,
262				      const struct flow_stats *stats)
263{
264	struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
265	struct nft_counter *this_cpu;
266	seqcount_t *myseq;
267
268	preempt_disable();
269	this_cpu = this_cpu_ptr(priv->counter);
270	myseq = this_cpu_ptr(&nft_counter_seq);
271
272	write_seqcount_begin(myseq);
273	this_cpu->packets += stats->pkts;
274	this_cpu->bytes += stats->bytes;
275	write_seqcount_end(myseq);
276	preempt_enable();
277}
278
279void nft_counter_init_seqcount(void)
280{
281	int cpu;
282
283	for_each_possible_cpu(cpu)
284		seqcount_init(per_cpu_ptr(&nft_counter_seq, cpu));
285}
286
287struct nft_expr_type nft_counter_type;
288static const struct nft_expr_ops nft_counter_ops = {
289	.type		= &nft_counter_type,
290	.size		= NFT_EXPR_SIZE(sizeof(struct nft_counter_percpu_priv)),
291	.eval		= nft_counter_eval,
292	.init		= nft_counter_init,
293	.destroy	= nft_counter_destroy,
294	.destroy_clone	= nft_counter_destroy,
295	.dump		= nft_counter_dump,
296	.clone		= nft_counter_clone,
297	.reduce		= NFT_REDUCE_READONLY,
298	.offload	= nft_counter_offload,
299	.offload_stats	= nft_counter_offload_stats,
300};
301
302struct nft_expr_type nft_counter_type __read_mostly = {
303	.name		= "counter",
304	.ops		= &nft_counter_ops,
305	.policy		= nft_counter_policy,
306	.maxattr	= NFTA_COUNTER_MAX,
307	.flags		= NFT_EXPR_STATEFUL,
308	.owner		= THIS_MODULE,
309};
310