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
19 struct nft_counter {
20 s64 bytes;
21 s64 packets;
22 };
23
24 struct nft_counter_percpu_priv {
25 struct nft_counter __percpu *counter;
26 };
27
28 static DEFINE_PER_CPU(seqcount_t, nft_counter_seq);
29
nft_counter_do_eval(struct nft_counter_percpu_priv * priv,struct nft_regs * regs,const struct nft_pktinfo * pkt)30 static 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
nft_counter_obj_eval(struct nft_object * obj,struct nft_regs * regs,const struct nft_pktinfo * pkt)50 static 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
nft_counter_do_init(const struct nlattr * const tb[],struct nft_counter_percpu_priv * priv)59 static 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
nft_counter_obj_init(const struct nft_ctx * ctx,const struct nlattr * const tb[],struct nft_object * obj)84 static 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
nft_counter_do_destroy(struct nft_counter_percpu_priv * priv)93 static void nft_counter_do_destroy(struct nft_counter_percpu_priv *priv)
94 {
95 free_percpu(priv->counter);
96 }
97
nft_counter_obj_destroy(const struct nft_ctx * ctx,struct nft_object * obj)98 static 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
nft_counter_reset(struct nft_counter_percpu_priv * priv,struct nft_counter * total)106 static void nft_counter_reset(struct nft_counter_percpu_priv *priv,
107 struct nft_counter *total)
108 {
109 struct nft_counter *this_cpu;
110 seqcount_t *myseq;
111
112 local_bh_disable();
113 this_cpu = this_cpu_ptr(priv->counter);
114 myseq = this_cpu_ptr(&nft_counter_seq);
115
116 write_seqcount_begin(myseq);
117 this_cpu->packets -= total->packets;
118 this_cpu->bytes -= total->bytes;
119 write_seqcount_end(myseq);
120 local_bh_enable();
121 }
122
nft_counter_fetch(struct nft_counter_percpu_priv * priv,struct nft_counter * total)123 static void nft_counter_fetch(struct nft_counter_percpu_priv *priv,
124 struct nft_counter *total)
125 {
126 struct nft_counter *this_cpu;
127 const seqcount_t *myseq;
128 u64 bytes, packets;
129 unsigned int seq;
130 int cpu;
131
132 memset(total, 0, sizeof(*total));
133 for_each_possible_cpu(cpu) {
134 myseq = per_cpu_ptr(&nft_counter_seq, cpu);
135 this_cpu = per_cpu_ptr(priv->counter, cpu);
136 do {
137 seq = read_seqcount_begin(myseq);
138 bytes = this_cpu->bytes;
139 packets = this_cpu->packets;
140 } while (read_seqcount_retry(myseq, seq));
141
142 total->bytes += bytes;
143 total->packets += packets;
144 }
145 }
146
nft_counter_do_dump(struct sk_buff * skb,struct nft_counter_percpu_priv * priv,bool reset)147 static int nft_counter_do_dump(struct sk_buff *skb,
148 struct nft_counter_percpu_priv *priv,
149 bool reset)
150 {
151 struct nft_counter total;
152
153 nft_counter_fetch(priv, &total);
154
155 if (nla_put_be64(skb, NFTA_COUNTER_BYTES, cpu_to_be64(total.bytes),
156 NFTA_COUNTER_PAD) ||
157 nla_put_be64(skb, NFTA_COUNTER_PACKETS, cpu_to_be64(total.packets),
158 NFTA_COUNTER_PAD))
159 goto nla_put_failure;
160
161 if (reset)
162 nft_counter_reset(priv, &total);
163
164 return 0;
165
166 nla_put_failure:
167 return -1;
168 }
169
nft_counter_obj_dump(struct sk_buff * skb,struct nft_object * obj,bool reset)170 static int nft_counter_obj_dump(struct sk_buff *skb,
171 struct nft_object *obj, bool reset)
172 {
173 struct nft_counter_percpu_priv *priv = nft_obj_data(obj);
174
175 return nft_counter_do_dump(skb, priv, reset);
176 }
177
178 static const struct nla_policy nft_counter_policy[NFTA_COUNTER_MAX + 1] = {
179 [NFTA_COUNTER_PACKETS] = { .type = NLA_U64 },
180 [NFTA_COUNTER_BYTES] = { .type = NLA_U64 },
181 };
182
183 struct nft_object_type nft_counter_obj_type;
184 static const struct nft_object_ops nft_counter_obj_ops = {
185 .type = &nft_counter_obj_type,
186 .size = sizeof(struct nft_counter_percpu_priv),
187 .eval = nft_counter_obj_eval,
188 .init = nft_counter_obj_init,
189 .destroy = nft_counter_obj_destroy,
190 .dump = nft_counter_obj_dump,
191 };
192
193 struct nft_object_type nft_counter_obj_type __read_mostly = {
194 .type = NFT_OBJECT_COUNTER,
195 .ops = &nft_counter_obj_ops,
196 .maxattr = NFTA_COUNTER_MAX,
197 .policy = nft_counter_policy,
198 .owner = THIS_MODULE,
199 };
200
nft_counter_eval(const struct nft_expr * expr,struct nft_regs * regs,const struct nft_pktinfo * pkt)201 void nft_counter_eval(const struct nft_expr *expr, struct nft_regs *regs,
202 const struct nft_pktinfo *pkt)
203 {
204 struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
205
206 nft_counter_do_eval(priv, regs, pkt);
207 }
208
nft_counter_dump(struct sk_buff * skb,const struct nft_expr * expr,bool reset)209 static int nft_counter_dump(struct sk_buff *skb,
210 const struct nft_expr *expr, bool reset)
211 {
212 struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
213
214 return nft_counter_do_dump(skb, priv, reset);
215 }
216
nft_counter_init(const struct nft_ctx * ctx,const struct nft_expr * expr,const struct nlattr * const tb[])217 static int nft_counter_init(const struct nft_ctx *ctx,
218 const struct nft_expr *expr,
219 const struct nlattr * const tb[])
220 {
221 struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
222
223 return nft_counter_do_init(tb, priv);
224 }
225
nft_counter_destroy(const struct nft_ctx * ctx,const struct nft_expr * expr)226 static void nft_counter_destroy(const struct nft_ctx *ctx,
227 const struct nft_expr *expr)
228 {
229 struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
230
231 nft_counter_do_destroy(priv);
232 }
233
nft_counter_clone(struct nft_expr * dst,const struct nft_expr * src)234 static int nft_counter_clone(struct nft_expr *dst, const struct nft_expr *src)
235 {
236 struct nft_counter_percpu_priv *priv = nft_expr_priv(src);
237 struct nft_counter_percpu_priv *priv_clone = nft_expr_priv(dst);
238 struct nft_counter __percpu *cpu_stats;
239 struct nft_counter *this_cpu;
240 struct nft_counter total;
241
242 nft_counter_fetch(priv, &total);
243
244 cpu_stats = alloc_percpu_gfp(struct nft_counter, GFP_ATOMIC);
245 if (cpu_stats == NULL)
246 return -ENOMEM;
247
248 preempt_disable();
249 this_cpu = this_cpu_ptr(cpu_stats);
250 this_cpu->packets = total.packets;
251 this_cpu->bytes = total.bytes;
252 preempt_enable();
253
254 priv_clone->counter = cpu_stats;
255 return 0;
256 }
257
nft_counter_offload(struct nft_offload_ctx * ctx,struct nft_flow_rule * flow,const struct nft_expr * expr)258 static int nft_counter_offload(struct nft_offload_ctx *ctx,
259 struct nft_flow_rule *flow,
260 const struct nft_expr *expr)
261 {
262 /* No specific offload action is needed, but report success. */
263 return 0;
264 }
265
nft_counter_offload_stats(struct nft_expr * expr,const struct flow_stats * stats)266 static void nft_counter_offload_stats(struct nft_expr *expr,
267 const struct flow_stats *stats)
268 {
269 struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
270 struct nft_counter *this_cpu;
271 seqcount_t *myseq;
272
273 local_bh_disable();
274 this_cpu = this_cpu_ptr(priv->counter);
275 myseq = this_cpu_ptr(&nft_counter_seq);
276
277 write_seqcount_begin(myseq);
278 this_cpu->packets += stats->pkts;
279 this_cpu->bytes += stats->bytes;
280 write_seqcount_end(myseq);
281 local_bh_enable();
282 }
283
nft_counter_init_seqcount(void)284 void nft_counter_init_seqcount(void)
285 {
286 int cpu;
287
288 for_each_possible_cpu(cpu)
289 seqcount_init(per_cpu_ptr(&nft_counter_seq, cpu));
290 }
291
292 struct nft_expr_type nft_counter_type;
293 static const struct nft_expr_ops nft_counter_ops = {
294 .type = &nft_counter_type,
295 .size = NFT_EXPR_SIZE(sizeof(struct nft_counter_percpu_priv)),
296 .eval = nft_counter_eval,
297 .init = nft_counter_init,
298 .destroy = nft_counter_destroy,
299 .destroy_clone = nft_counter_destroy,
300 .dump = nft_counter_dump,
301 .clone = nft_counter_clone,
302 .reduce = NFT_REDUCE_READONLY,
303 .offload = nft_counter_offload,
304 .offload_stats = nft_counter_offload_stats,
305 };
306
307 struct nft_expr_type nft_counter_type __read_mostly = {
308 .name = "counter",
309 .ops = &nft_counter_ops,
310 .policy = nft_counter_policy,
311 .maxattr = NFTA_COUNTER_MAX,
312 .flags = NFT_EXPR_STATEFUL,
313 .owner = THIS_MODULE,
314 };
315