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1/*
2 * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * Development of this code funded by Astaro AG (http://www.astaro.com/)
9 */
10
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 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(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 __percpu *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 __read_mostly = {
178 .type = NFT_OBJECT_COUNTER,
179 .size = sizeof(struct nft_counter_percpu_priv),
180 .maxattr = NFTA_COUNTER_MAX,
181 .policy = nft_counter_policy,
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 .owner = THIS_MODULE,
187};
188
189static void nft_counter_eval(const struct nft_expr *expr,
190 struct nft_regs *regs,
191 const struct nft_pktinfo *pkt)
192{
193 struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
194
195 nft_counter_do_eval(priv, regs, pkt);
196}
197
198static int nft_counter_dump(struct sk_buff *skb, const struct nft_expr *expr)
199{
200 struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
201
202 return nft_counter_do_dump(skb, priv, false);
203}
204
205static int nft_counter_init(const struct nft_ctx *ctx,
206 const struct nft_expr *expr,
207 const struct nlattr * const tb[])
208{
209 struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
210
211 return nft_counter_do_init(tb, priv);
212}
213
214static void nft_counter_destroy(const struct nft_ctx *ctx,
215 const struct nft_expr *expr)
216{
217 struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
218
219 nft_counter_do_destroy(priv);
220}
221
222static int nft_counter_clone(struct nft_expr *dst, const struct nft_expr *src)
223{
224 struct nft_counter_percpu_priv *priv = nft_expr_priv(src);
225 struct nft_counter_percpu_priv *priv_clone = nft_expr_priv(dst);
226 struct nft_counter __percpu *cpu_stats;
227 struct nft_counter *this_cpu;
228 struct nft_counter total;
229
230 nft_counter_fetch(priv, &total);
231
232 cpu_stats = alloc_percpu_gfp(struct nft_counter, GFP_ATOMIC);
233 if (cpu_stats == NULL)
234 return -ENOMEM;
235
236 preempt_disable();
237 this_cpu = this_cpu_ptr(cpu_stats);
238 this_cpu->packets = total.packets;
239 this_cpu->bytes = total.bytes;
240 preempt_enable();
241
242 priv_clone->counter = cpu_stats;
243 return 0;
244}
245
246static struct nft_expr_type nft_counter_type;
247static const struct nft_expr_ops nft_counter_ops = {
248 .type = &nft_counter_type,
249 .size = NFT_EXPR_SIZE(sizeof(struct nft_counter_percpu_priv)),
250 .eval = nft_counter_eval,
251 .init = nft_counter_init,
252 .destroy = nft_counter_destroy,
253 .dump = nft_counter_dump,
254 .clone = nft_counter_clone,
255};
256
257static struct nft_expr_type nft_counter_type __read_mostly = {
258 .name = "counter",
259 .ops = &nft_counter_ops,
260 .policy = nft_counter_policy,
261 .maxattr = NFTA_COUNTER_MAX,
262 .flags = NFT_EXPR_STATEFUL,
263 .owner = THIS_MODULE,
264};
265
266static int __init nft_counter_module_init(void)
267{
268 int cpu, err;
269
270 for_each_possible_cpu(cpu)
271 seqcount_init(per_cpu_ptr(&nft_counter_seq, cpu));
272
273 err = nft_register_obj(&nft_counter_obj);
274 if (err < 0)
275 return err;
276
277 err = nft_register_expr(&nft_counter_type);
278 if (err < 0)
279 goto err1;
280
281 return 0;
282err1:
283 nft_unregister_obj(&nft_counter_obj);
284 return err;
285}
286
287static void __exit nft_counter_module_exit(void)
288{
289 nft_unregister_expr(&nft_counter_type);
290 nft_unregister_obj(&nft_counter_obj);
291}
292
293module_init(nft_counter_module_init);
294module_exit(nft_counter_module_exit);
295
296MODULE_LICENSE("GPL");
297MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
298MODULE_ALIAS_NFT_EXPR("counter");
299MODULE_ALIAS_NFT_OBJ(NFT_OBJECT_COUNTER);