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11#include <linux/kernel.h>
12#include <linux/init.h>
13#include <linux/module.h>
14#include <linux/seqlock.h>
15#include <linux/netlink.h>
16#include <linux/netfilter.h>
17#include <linux/netfilter/nf_tables.h>
18#include <net/netfilter/nf_tables.h>
19
20struct nft_counter {
21 s64 bytes;
22 s64 packets;
23};
24
25struct nft_counter_percpu_priv {
26 struct nft_counter __percpu *counter;
27};
28
29static DEFINE_PER_CPU(seqcount_t, nft_counter_seq);
30
31static inline void nft_counter_do_eval(struct nft_counter_percpu_priv *priv,
32 struct nft_regs *regs,
33 const struct nft_pktinfo *pkt)
34{
35 struct nft_counter *this_cpu;
36 seqcount_t *myseq;
37
38 local_bh_disable();
39 this_cpu = this_cpu_ptr(priv->counter);
40 myseq = this_cpu_ptr(&nft_counter_seq);
41
42 write_seqcount_begin(myseq);
43
44 this_cpu->bytes += pkt->skb->len;
45 this_cpu->packets++;
46
47 write_seqcount_end(myseq);
48 local_bh_enable();
49}
50
51static inline void nft_counter_obj_eval(struct nft_object *obj,
52 struct nft_regs *regs,
53 const struct nft_pktinfo *pkt)
54{
55 struct nft_counter_percpu_priv *priv = nft_obj_data(obj);
56
57 nft_counter_do_eval(priv, regs, pkt);
58}
59
60static int nft_counter_do_init(const struct nlattr * const tb[],
61 struct nft_counter_percpu_priv *priv)
62{
63 struct nft_counter __percpu *cpu_stats;
64 struct nft_counter *this_cpu;
65
66 cpu_stats = alloc_percpu(struct nft_counter);
67 if (cpu_stats == NULL)
68 return -ENOMEM;
69
70 preempt_disable();
71 this_cpu = this_cpu_ptr(cpu_stats);
72 if (tb[NFTA_COUNTER_PACKETS]) {
73 this_cpu->packets =
74 be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_PACKETS]));
75 }
76 if (tb[NFTA_COUNTER_BYTES]) {
77 this_cpu->bytes =
78 be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_BYTES]));
79 }
80 preempt_enable();
81 priv->counter = cpu_stats;
82 return 0;
83}
84
85static int nft_counter_obj_init(const struct nft_ctx *ctx,
86 const struct nlattr * const tb[],
87 struct nft_object *obj)
88{
89 struct nft_counter_percpu_priv *priv = nft_obj_data(obj);
90
91 return nft_counter_do_init(tb, priv);
92}
93
94static void nft_counter_do_destroy(struct nft_counter_percpu_priv *priv)
95{
96 free_percpu(priv->counter);
97}
98
99static void nft_counter_obj_destroy(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 __percpu *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
178static struct 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
188static struct 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
196static void nft_counter_eval(const struct nft_expr *expr,
197 struct nft_regs *regs,
198 const struct nft_pktinfo *pkt)
199{
200 struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
201
202 nft_counter_do_eval(priv, regs, pkt);
203}
204
205static int nft_counter_dump(struct sk_buff *skb, const struct nft_expr *expr)
206{
207 struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
208
209 return nft_counter_do_dump(skb, priv, false);
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 struct nft_expr_type nft_counter_type;
254static const struct nft_expr_ops nft_counter_ops = {
255 .type = &nft_counter_type,
256 .size = NFT_EXPR_SIZE(sizeof(struct nft_counter_percpu_priv)),
257 .eval = nft_counter_eval,
258 .init = nft_counter_init,
259 .destroy = nft_counter_destroy,
260 .dump = nft_counter_dump,
261 .clone = nft_counter_clone,
262};
263
264static struct nft_expr_type nft_counter_type __read_mostly = {
265 .name = "counter",
266 .ops = &nft_counter_ops,
267 .policy = nft_counter_policy,
268 .maxattr = NFTA_COUNTER_MAX,
269 .flags = NFT_EXPR_STATEFUL,
270 .owner = THIS_MODULE,
271};
272
273static int __init nft_counter_module_init(void)
274{
275 int cpu, err;
276
277 for_each_possible_cpu(cpu)
278 seqcount_init(per_cpu_ptr(&nft_counter_seq, cpu));
279
280 err = nft_register_obj(&nft_counter_obj_type);
281 if (err < 0)
282 return err;
283
284 err = nft_register_expr(&nft_counter_type);
285 if (err < 0)
286 goto err1;
287
288 return 0;
289err1:
290 nft_unregister_obj(&nft_counter_obj_type);
291 return err;
292}
293
294static void __exit nft_counter_module_exit(void)
295{
296 nft_unregister_expr(&nft_counter_type);
297 nft_unregister_obj(&nft_counter_obj_type);
298}
299
300module_init(nft_counter_module_init);
301module_exit(nft_counter_module_exit);
302
303MODULE_LICENSE("GPL");
304MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
305MODULE_ALIAS_NFT_EXPR("counter");
306MODULE_ALIAS_NFT_OBJ(NFT_OBJECT_COUNTER);
307
