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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_offload.h>
17
18struct nft_counter {
19 s64 bytes;
20 s64 packets;
21};
22
23struct nft_counter_percpu_priv {
24 struct nft_counter __percpu *counter;
25};
26
27static DEFINE_PER_CPU(seqcount_t, nft_counter_seq);
28
29static inline void nft_counter_do_eval(struct nft_counter_percpu_priv *priv,
30 struct nft_regs *regs,
31 const struct nft_pktinfo *pkt)
32{
33 struct nft_counter *this_cpu;
34 seqcount_t *myseq;
35
36 local_bh_disable();
37 this_cpu = this_cpu_ptr(priv->counter);
38 myseq = this_cpu_ptr(&nft_counter_seq);
39
40 write_seqcount_begin(myseq);
41
42 this_cpu->bytes += pkt->skb->len;
43 this_cpu->packets++;
44
45 write_seqcount_end(myseq);
46 local_bh_enable();
47}
48
49static inline void nft_counter_obj_eval(struct nft_object *obj,
50 struct nft_regs *regs,
51 const struct nft_pktinfo *pkt)
52{
53 struct nft_counter_percpu_priv *priv = nft_obj_data(obj);
54
55 nft_counter_do_eval(priv, regs, pkt);
56}
57
58static int nft_counter_do_init(const struct nlattr * const tb[],
59 struct nft_counter_percpu_priv *priv)
60{
61 struct nft_counter __percpu *cpu_stats;
62 struct nft_counter *this_cpu;
63
64 cpu_stats = alloc_percpu(struct nft_counter);
65 if (cpu_stats == NULL)
66 return -ENOMEM;
67
68 preempt_disable();
69 this_cpu = this_cpu_ptr(cpu_stats);
70 if (tb[NFTA_COUNTER_PACKETS]) {
71 this_cpu->packets =
72 be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_PACKETS]));
73 }
74 if (tb[NFTA_COUNTER_BYTES]) {
75 this_cpu->bytes =
76 be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_BYTES]));
77 }
78 preempt_enable();
79 priv->counter = cpu_stats;
80 return 0;
81}
82
83static int nft_counter_obj_init(const struct nft_ctx *ctx,
84 const struct nlattr * const tb[],
85 struct nft_object *obj)
86{
87 struct nft_counter_percpu_priv *priv = nft_obj_data(obj);
88
89 return nft_counter_do_init(tb, priv);
90}
91
92static void nft_counter_do_destroy(struct nft_counter_percpu_priv *priv)
93{
94 free_percpu(priv->counter);
95}
96
97static void nft_counter_obj_destroy(const struct nft_ctx *ctx,
98 struct nft_object *obj)
99{
100 struct nft_counter_percpu_priv *priv = nft_obj_data(obj);
101
102 nft_counter_do_destroy(priv);
103}
104
105static void nft_counter_reset(struct nft_counter_percpu_priv *priv,
106 struct nft_counter *total)
107{
108 struct nft_counter *this_cpu;
109
110 local_bh_disable();
111 this_cpu = this_cpu_ptr(priv->counter);
112 this_cpu->packets -= total->packets;
113 this_cpu->bytes -= total->bytes;
114 local_bh_enable();
115}
116
117static void nft_counter_fetch(struct nft_counter_percpu_priv *priv,
118 struct nft_counter *total)
119{
120 struct nft_counter *this_cpu;
121 const seqcount_t *myseq;
122 u64 bytes, packets;
123 unsigned int seq;
124 int cpu;
125
126 memset(total, 0, sizeof(*total));
127 for_each_possible_cpu(cpu) {
128 myseq = per_cpu_ptr(&nft_counter_seq, cpu);
129 this_cpu = per_cpu_ptr(priv->counter, cpu);
130 do {
131 seq = read_seqcount_begin(myseq);
132 bytes = this_cpu->bytes;
133 packets = this_cpu->packets;
134 } while (read_seqcount_retry(myseq, seq));
135
136 total->bytes += bytes;
137 total->packets += packets;
138 }
139}
140
141static int nft_counter_do_dump(struct sk_buff *skb,
142 struct nft_counter_percpu_priv *priv,
143 bool reset)
144{
145 struct nft_counter total;
146
147 nft_counter_fetch(priv, &total);
148
149 if (nla_put_be64(skb, NFTA_COUNTER_BYTES, cpu_to_be64(total.bytes),
150 NFTA_COUNTER_PAD) ||
151 nla_put_be64(skb, NFTA_COUNTER_PACKETS, cpu_to_be64(total.packets),
152 NFTA_COUNTER_PAD))
153 goto nla_put_failure;
154
155 if (reset)
156 nft_counter_reset(priv, &total);
157
158 return 0;
159
160nla_put_failure:
161 return -1;
162}
163
164static int nft_counter_obj_dump(struct sk_buff *skb,
165 struct nft_object *obj, bool reset)
166{
167 struct nft_counter_percpu_priv *priv = nft_obj_data(obj);
168
169 return nft_counter_do_dump(skb, priv, reset);
170}
171
172static const struct nla_policy nft_counter_policy[NFTA_COUNTER_MAX + 1] = {
173 [NFTA_COUNTER_PACKETS] = { .type = NLA_U64 },
174 [NFTA_COUNTER_BYTES] = { .type = NLA_U64 },
175};
176
177static struct nft_object_type nft_counter_obj_type;
178static const struct nft_object_ops nft_counter_obj_ops = {
179 .type = &nft_counter_obj_type,
180 .size = sizeof(struct nft_counter_percpu_priv),
181 .eval = nft_counter_obj_eval,
182 .init = nft_counter_obj_init,
183 .destroy = nft_counter_obj_destroy,
184 .dump = nft_counter_obj_dump,
185};
186
187static struct nft_object_type nft_counter_obj_type __read_mostly = {
188 .type = NFT_OBJECT_COUNTER,
189 .ops = &nft_counter_obj_ops,
190 .maxattr = NFTA_COUNTER_MAX,
191 .policy = nft_counter_policy,
192 .owner = THIS_MODULE,
193};
194
195static void nft_counter_eval(const struct nft_expr *expr,
196 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, const struct nft_expr *expr)
205{
206 struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
207
208 return nft_counter_do_dump(skb, priv, false);
209}
210
211static int nft_counter_init(const struct nft_ctx *ctx,
212 const struct nft_expr *expr,
213 const struct nlattr * const tb[])
214{
215 struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
216
217 return nft_counter_do_init(tb, priv);
218}
219
220static void nft_counter_destroy(const struct nft_ctx *ctx,
221 const struct nft_expr *expr)
222{
223 struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
224
225 nft_counter_do_destroy(priv);
226}
227
228static int nft_counter_clone(struct nft_expr *dst, const struct nft_expr *src)
229{
230 struct nft_counter_percpu_priv *priv = nft_expr_priv(src);
231 struct nft_counter_percpu_priv *priv_clone = nft_expr_priv(dst);
232 struct nft_counter __percpu *cpu_stats;
233 struct nft_counter *this_cpu;
234 struct nft_counter total;
235
236 nft_counter_fetch(priv, &total);
237
238 cpu_stats = alloc_percpu_gfp(struct nft_counter, GFP_ATOMIC);
239 if (cpu_stats == NULL)
240 return -ENOMEM;
241
242 preempt_disable();
243 this_cpu = this_cpu_ptr(cpu_stats);
244 this_cpu->packets = total.packets;
245 this_cpu->bytes = total.bytes;
246 preempt_enable();
247
248 priv_clone->counter = cpu_stats;
249 return 0;
250}
251
252static int nft_counter_offload(struct nft_offload_ctx *ctx,
253 struct nft_flow_rule *flow,
254 const struct nft_expr *expr)
255{
256
257 return 0;
258}
259
260static void nft_counter_offload_stats(struct nft_expr *expr,
261 const struct flow_stats *stats)
262{
263 struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
264 struct nft_counter *this_cpu;
265 seqcount_t *myseq;
266
267 preempt_disable();
268 this_cpu = this_cpu_ptr(priv->counter);
269 myseq = this_cpu_ptr(&nft_counter_seq);
270
271 write_seqcount_begin(myseq);
272 this_cpu->packets += stats->pkts;
273 this_cpu->bytes += stats->bytes;
274 write_seqcount_end(myseq);
275 preempt_enable();
276}
277
278static struct nft_expr_type nft_counter_type;
279static const struct nft_expr_ops nft_counter_ops = {
280 .type = &nft_counter_type,
281 .size = NFT_EXPR_SIZE(sizeof(struct nft_counter_percpu_priv)),
282 .eval = nft_counter_eval,
283 .init = nft_counter_init,
284 .destroy = nft_counter_destroy,
285 .destroy_clone = nft_counter_destroy,
286 .dump = nft_counter_dump,
287 .clone = nft_counter_clone,
288 .offload = nft_counter_offload,
289 .offload_stats = nft_counter_offload_stats,
290};
291
292static struct nft_expr_type nft_counter_type __read_mostly = {
293 .name = "counter",
294 .ops = &nft_counter_ops,
295 .policy = nft_counter_policy,
296 .maxattr = NFTA_COUNTER_MAX,
297 .flags = NFT_EXPR_STATEFUL,
298 .owner = THIS_MODULE,
299};
300
301static int __init nft_counter_module_init(void)
302{
303 int cpu, err;
304
305 for_each_possible_cpu(cpu)
306 seqcount_init(per_cpu_ptr(&nft_counter_seq, cpu));
307
308 err = nft_register_obj(&nft_counter_obj_type);
309 if (err < 0)
310 return err;
311
312 err = nft_register_expr(&nft_counter_type);
313 if (err < 0)
314 goto err1;
315
316 return 0;
317err1:
318 nft_unregister_obj(&nft_counter_obj_type);
319 return err;
320}
321
322static void __exit nft_counter_module_exit(void)
323{
324 nft_unregister_expr(&nft_counter_type);
325 nft_unregister_obj(&nft_counter_obj_type);
326}
327
328module_init(nft_counter_module_init);
329module_exit(nft_counter_module_exit);
330
331MODULE_LICENSE("GPL");
332MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
333MODULE_ALIAS_NFT_EXPR("counter");
334MODULE_ALIAS_NFT_OBJ(NFT_OBJECT_COUNTER);
335MODULE_DESCRIPTION("nftables counter rule support");
336
