xref: /linux/net/sched/act_police.c (revision aec499c75cf8e0b599be4d559e6922b613085f8f)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * net/sched/act_police.c	Input police filter
4  *
5  * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
6  * 		J Hadi Salim (action changes)
7  */
8 
9 #include <linux/module.h>
10 #include <linux/types.h>
11 #include <linux/kernel.h>
12 #include <linux/string.h>
13 #include <linux/errno.h>
14 #include <linux/skbuff.h>
15 #include <linux/rtnetlink.h>
16 #include <linux/init.h>
17 #include <linux/slab.h>
18 #include <net/act_api.h>
19 #include <net/netlink.h>
20 #include <net/pkt_cls.h>
21 #include <net/tc_act/tc_police.h>
22 
23 /* Each policer is serialized by its individual spinlock */
24 
25 static unsigned int police_net_id;
26 static struct tc_action_ops act_police_ops;
27 
28 static int tcf_police_walker(struct net *net, struct sk_buff *skb,
29 				 struct netlink_callback *cb, int type,
30 				 const struct tc_action_ops *ops,
31 				 struct netlink_ext_ack *extack)
32 {
33 	struct tc_action_net *tn = net_generic(net, police_net_id);
34 
35 	return tcf_generic_walker(tn, skb, cb, type, ops, extack);
36 }
37 
38 static const struct nla_policy police_policy[TCA_POLICE_MAX + 1] = {
39 	[TCA_POLICE_RATE]	= { .len = TC_RTAB_SIZE },
40 	[TCA_POLICE_PEAKRATE]	= { .len = TC_RTAB_SIZE },
41 	[TCA_POLICE_AVRATE]	= { .type = NLA_U32 },
42 	[TCA_POLICE_RESULT]	= { .type = NLA_U32 },
43 	[TCA_POLICE_RATE64]     = { .type = NLA_U64 },
44 	[TCA_POLICE_PEAKRATE64] = { .type = NLA_U64 },
45 	[TCA_POLICE_PKTRATE64]  = { .type = NLA_U64, .min = 1 },
46 	[TCA_POLICE_PKTBURST64] = { .type = NLA_U64, .min = 1 },
47 };
48 
49 static int tcf_police_init(struct net *net, struct nlattr *nla,
50 			       struct nlattr *est, struct tc_action **a,
51 			       struct tcf_proto *tp, u32 flags,
52 			       struct netlink_ext_ack *extack)
53 {
54 	int ret = 0, tcfp_result = TC_ACT_OK, err, size;
55 	bool bind = flags & TCA_ACT_FLAGS_BIND;
56 	struct nlattr *tb[TCA_POLICE_MAX + 1];
57 	struct tcf_chain *goto_ch = NULL;
58 	struct tc_police *parm;
59 	struct tcf_police *police;
60 	struct qdisc_rate_table *R_tab = NULL, *P_tab = NULL;
61 	struct tc_action_net *tn = net_generic(net, police_net_id);
62 	struct tcf_police_params *new;
63 	bool exists = false;
64 	u32 index;
65 	u64 rate64, prate64;
66 	u64 pps, ppsburst;
67 
68 	if (nla == NULL)
69 		return -EINVAL;
70 
71 	err = nla_parse_nested_deprecated(tb, TCA_POLICE_MAX, nla,
72 					  police_policy, NULL);
73 	if (err < 0)
74 		return err;
75 
76 	if (tb[TCA_POLICE_TBF] == NULL)
77 		return -EINVAL;
78 	size = nla_len(tb[TCA_POLICE_TBF]);
79 	if (size != sizeof(*parm) && size != sizeof(struct tc_police_compat))
80 		return -EINVAL;
81 
82 	parm = nla_data(tb[TCA_POLICE_TBF]);
83 	index = parm->index;
84 	err = tcf_idr_check_alloc(tn, &index, a, bind);
85 	if (err < 0)
86 		return err;
87 	exists = err;
88 	if (exists && bind)
89 		return 0;
90 
91 	if (!exists) {
92 		ret = tcf_idr_create(tn, index, NULL, a,
93 				     &act_police_ops, bind, true, flags);
94 		if (ret) {
95 			tcf_idr_cleanup(tn, index);
96 			return ret;
97 		}
98 		ret = ACT_P_CREATED;
99 		spin_lock_init(&(to_police(*a)->tcfp_lock));
100 	} else if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
101 		tcf_idr_release(*a, bind);
102 		return -EEXIST;
103 	}
104 	err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
105 	if (err < 0)
106 		goto release_idr;
107 
108 	police = to_police(*a);
109 	if (parm->rate.rate) {
110 		err = -ENOMEM;
111 		R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE], NULL);
112 		if (R_tab == NULL)
113 			goto failure;
114 
115 		if (parm->peakrate.rate) {
116 			P_tab = qdisc_get_rtab(&parm->peakrate,
117 					       tb[TCA_POLICE_PEAKRATE], NULL);
118 			if (P_tab == NULL)
119 				goto failure;
120 		}
121 	}
122 
123 	if (est) {
124 		err = gen_replace_estimator(&police->tcf_bstats,
125 					    police->common.cpu_bstats,
126 					    &police->tcf_rate_est,
127 					    &police->tcf_lock,
128 					    false, est);
129 		if (err)
130 			goto failure;
131 	} else if (tb[TCA_POLICE_AVRATE] &&
132 		   (ret == ACT_P_CREATED ||
133 		    !gen_estimator_active(&police->tcf_rate_est))) {
134 		err = -EINVAL;
135 		goto failure;
136 	}
137 
138 	if (tb[TCA_POLICE_RESULT]) {
139 		tcfp_result = nla_get_u32(tb[TCA_POLICE_RESULT]);
140 		if (TC_ACT_EXT_CMP(tcfp_result, TC_ACT_GOTO_CHAIN)) {
141 			NL_SET_ERR_MSG(extack,
142 				       "goto chain not allowed on fallback");
143 			err = -EINVAL;
144 			goto failure;
145 		}
146 	}
147 
148 	if ((tb[TCA_POLICE_PKTRATE64] && !tb[TCA_POLICE_PKTBURST64]) ||
149 	    (!tb[TCA_POLICE_PKTRATE64] && tb[TCA_POLICE_PKTBURST64])) {
150 		NL_SET_ERR_MSG(extack,
151 			       "Both or neither packet-per-second burst and rate must be provided");
152 		err = -EINVAL;
153 		goto failure;
154 	}
155 
156 	if (tb[TCA_POLICE_PKTRATE64] && R_tab) {
157 		NL_SET_ERR_MSG(extack,
158 			       "packet-per-second and byte-per-second rate limits not allowed in same action");
159 		err = -EINVAL;
160 		goto failure;
161 	}
162 
163 	new = kzalloc(sizeof(*new), GFP_KERNEL);
164 	if (unlikely(!new)) {
165 		err = -ENOMEM;
166 		goto failure;
167 	}
168 
169 	/* No failure allowed after this point */
170 	new->tcfp_result = tcfp_result;
171 	new->tcfp_mtu = parm->mtu;
172 	if (!new->tcfp_mtu) {
173 		new->tcfp_mtu = ~0;
174 		if (R_tab)
175 			new->tcfp_mtu = 255 << R_tab->rate.cell_log;
176 	}
177 	if (R_tab) {
178 		new->rate_present = true;
179 		rate64 = tb[TCA_POLICE_RATE64] ?
180 			 nla_get_u64(tb[TCA_POLICE_RATE64]) : 0;
181 		psched_ratecfg_precompute(&new->rate, &R_tab->rate, rate64);
182 		qdisc_put_rtab(R_tab);
183 	} else {
184 		new->rate_present = false;
185 	}
186 	if (P_tab) {
187 		new->peak_present = true;
188 		prate64 = tb[TCA_POLICE_PEAKRATE64] ?
189 			  nla_get_u64(tb[TCA_POLICE_PEAKRATE64]) : 0;
190 		psched_ratecfg_precompute(&new->peak, &P_tab->rate, prate64);
191 		qdisc_put_rtab(P_tab);
192 	} else {
193 		new->peak_present = false;
194 	}
195 
196 	new->tcfp_burst = PSCHED_TICKS2NS(parm->burst);
197 	if (new->peak_present)
198 		new->tcfp_mtu_ptoks = (s64)psched_l2t_ns(&new->peak,
199 							 new->tcfp_mtu);
200 
201 	if (tb[TCA_POLICE_AVRATE])
202 		new->tcfp_ewma_rate = nla_get_u32(tb[TCA_POLICE_AVRATE]);
203 
204 	if (tb[TCA_POLICE_PKTRATE64]) {
205 		pps = nla_get_u64(tb[TCA_POLICE_PKTRATE64]);
206 		ppsburst = nla_get_u64(tb[TCA_POLICE_PKTBURST64]);
207 		new->pps_present = true;
208 		new->tcfp_pkt_burst = PSCHED_TICKS2NS(ppsburst);
209 		psched_ppscfg_precompute(&new->ppsrate, pps);
210 	}
211 
212 	spin_lock_bh(&police->tcf_lock);
213 	spin_lock_bh(&police->tcfp_lock);
214 	police->tcfp_t_c = ktime_get_ns();
215 	police->tcfp_toks = new->tcfp_burst;
216 	if (new->peak_present)
217 		police->tcfp_ptoks = new->tcfp_mtu_ptoks;
218 	spin_unlock_bh(&police->tcfp_lock);
219 	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
220 	new = rcu_replace_pointer(police->params,
221 				  new,
222 				  lockdep_is_held(&police->tcf_lock));
223 	spin_unlock_bh(&police->tcf_lock);
224 
225 	if (goto_ch)
226 		tcf_chain_put_by_act(goto_ch);
227 	if (new)
228 		kfree_rcu(new, rcu);
229 
230 	return ret;
231 
232 failure:
233 	qdisc_put_rtab(P_tab);
234 	qdisc_put_rtab(R_tab);
235 	if (goto_ch)
236 		tcf_chain_put_by_act(goto_ch);
237 release_idr:
238 	tcf_idr_release(*a, bind);
239 	return err;
240 }
241 
242 static int tcf_police_act(struct sk_buff *skb, const struct tc_action *a,
243 			  struct tcf_result *res)
244 {
245 	struct tcf_police *police = to_police(a);
246 	s64 now, toks, ppstoks = 0, ptoks = 0;
247 	struct tcf_police_params *p;
248 	int ret;
249 
250 	tcf_lastuse_update(&police->tcf_tm);
251 	bstats_update(this_cpu_ptr(police->common.cpu_bstats), skb);
252 
253 	ret = READ_ONCE(police->tcf_action);
254 	p = rcu_dereference_bh(police->params);
255 
256 	if (p->tcfp_ewma_rate) {
257 		struct gnet_stats_rate_est64 sample;
258 
259 		if (!gen_estimator_read(&police->tcf_rate_est, &sample) ||
260 		    sample.bps >= p->tcfp_ewma_rate)
261 			goto inc_overlimits;
262 	}
263 
264 	if (qdisc_pkt_len(skb) <= p->tcfp_mtu) {
265 		if (!p->rate_present && !p->pps_present) {
266 			ret = p->tcfp_result;
267 			goto end;
268 		}
269 
270 		now = ktime_get_ns();
271 		spin_lock_bh(&police->tcfp_lock);
272 		toks = min_t(s64, now - police->tcfp_t_c, p->tcfp_burst);
273 		if (p->peak_present) {
274 			ptoks = toks + police->tcfp_ptoks;
275 			if (ptoks > p->tcfp_mtu_ptoks)
276 				ptoks = p->tcfp_mtu_ptoks;
277 			ptoks -= (s64)psched_l2t_ns(&p->peak,
278 						    qdisc_pkt_len(skb));
279 		}
280 		if (p->rate_present) {
281 			toks += police->tcfp_toks;
282 			if (toks > p->tcfp_burst)
283 				toks = p->tcfp_burst;
284 			toks -= (s64)psched_l2t_ns(&p->rate, qdisc_pkt_len(skb));
285 		} else if (p->pps_present) {
286 			ppstoks = min_t(s64, now - police->tcfp_t_c, p->tcfp_pkt_burst);
287 			ppstoks += police->tcfp_pkttoks;
288 			if (ppstoks > p->tcfp_pkt_burst)
289 				ppstoks = p->tcfp_pkt_burst;
290 			ppstoks -= (s64)psched_pkt2t_ns(&p->ppsrate, 1);
291 		}
292 		if ((toks | ptoks | ppstoks) >= 0) {
293 			police->tcfp_t_c = now;
294 			police->tcfp_toks = toks;
295 			police->tcfp_ptoks = ptoks;
296 			police->tcfp_pkttoks = ppstoks;
297 			spin_unlock_bh(&police->tcfp_lock);
298 			ret = p->tcfp_result;
299 			goto inc_drops;
300 		}
301 		spin_unlock_bh(&police->tcfp_lock);
302 	}
303 
304 inc_overlimits:
305 	qstats_overlimit_inc(this_cpu_ptr(police->common.cpu_qstats));
306 inc_drops:
307 	if (ret == TC_ACT_SHOT)
308 		qstats_drop_inc(this_cpu_ptr(police->common.cpu_qstats));
309 end:
310 	return ret;
311 }
312 
313 static void tcf_police_cleanup(struct tc_action *a)
314 {
315 	struct tcf_police *police = to_police(a);
316 	struct tcf_police_params *p;
317 
318 	p = rcu_dereference_protected(police->params, 1);
319 	if (p)
320 		kfree_rcu(p, rcu);
321 }
322 
323 static void tcf_police_stats_update(struct tc_action *a,
324 				    u64 bytes, u64 packets, u64 drops,
325 				    u64 lastuse, bool hw)
326 {
327 	struct tcf_police *police = to_police(a);
328 	struct tcf_t *tm = &police->tcf_tm;
329 
330 	tcf_action_update_stats(a, bytes, packets, drops, hw);
331 	tm->lastuse = max_t(u64, tm->lastuse, lastuse);
332 }
333 
334 static int tcf_police_dump(struct sk_buff *skb, struct tc_action *a,
335 			       int bind, int ref)
336 {
337 	unsigned char *b = skb_tail_pointer(skb);
338 	struct tcf_police *police = to_police(a);
339 	struct tcf_police_params *p;
340 	struct tc_police opt = {
341 		.index = police->tcf_index,
342 		.refcnt = refcount_read(&police->tcf_refcnt) - ref,
343 		.bindcnt = atomic_read(&police->tcf_bindcnt) - bind,
344 	};
345 	struct tcf_t t;
346 
347 	spin_lock_bh(&police->tcf_lock);
348 	opt.action = police->tcf_action;
349 	p = rcu_dereference_protected(police->params,
350 				      lockdep_is_held(&police->tcf_lock));
351 	opt.mtu = p->tcfp_mtu;
352 	opt.burst = PSCHED_NS2TICKS(p->tcfp_burst);
353 	if (p->rate_present) {
354 		psched_ratecfg_getrate(&opt.rate, &p->rate);
355 		if ((police->params->rate.rate_bytes_ps >= (1ULL << 32)) &&
356 		    nla_put_u64_64bit(skb, TCA_POLICE_RATE64,
357 				      police->params->rate.rate_bytes_ps,
358 				      TCA_POLICE_PAD))
359 			goto nla_put_failure;
360 	}
361 	if (p->peak_present) {
362 		psched_ratecfg_getrate(&opt.peakrate, &p->peak);
363 		if ((police->params->peak.rate_bytes_ps >= (1ULL << 32)) &&
364 		    nla_put_u64_64bit(skb, TCA_POLICE_PEAKRATE64,
365 				      police->params->peak.rate_bytes_ps,
366 				      TCA_POLICE_PAD))
367 			goto nla_put_failure;
368 	}
369 	if (p->pps_present) {
370 		if (nla_put_u64_64bit(skb, TCA_POLICE_PKTRATE64,
371 				      police->params->ppsrate.rate_pkts_ps,
372 				      TCA_POLICE_PAD))
373 			goto nla_put_failure;
374 		if (nla_put_u64_64bit(skb, TCA_POLICE_PKTBURST64,
375 				      PSCHED_NS2TICKS(p->tcfp_pkt_burst),
376 				      TCA_POLICE_PAD))
377 			goto nla_put_failure;
378 	}
379 	if (nla_put(skb, TCA_POLICE_TBF, sizeof(opt), &opt))
380 		goto nla_put_failure;
381 	if (p->tcfp_result &&
382 	    nla_put_u32(skb, TCA_POLICE_RESULT, p->tcfp_result))
383 		goto nla_put_failure;
384 	if (p->tcfp_ewma_rate &&
385 	    nla_put_u32(skb, TCA_POLICE_AVRATE, p->tcfp_ewma_rate))
386 		goto nla_put_failure;
387 
388 	tcf_tm_dump(&t, &police->tcf_tm);
389 	if (nla_put_64bit(skb, TCA_POLICE_TM, sizeof(t), &t, TCA_POLICE_PAD))
390 		goto nla_put_failure;
391 	spin_unlock_bh(&police->tcf_lock);
392 
393 	return skb->len;
394 
395 nla_put_failure:
396 	spin_unlock_bh(&police->tcf_lock);
397 	nlmsg_trim(skb, b);
398 	return -1;
399 }
400 
401 static int tcf_police_search(struct net *net, struct tc_action **a, u32 index)
402 {
403 	struct tc_action_net *tn = net_generic(net, police_net_id);
404 
405 	return tcf_idr_search(tn, a, index);
406 }
407 
408 static int tcf_police_offload_act_setup(struct tc_action *act, void *entry_data,
409 					u32 *index_inc, bool bind)
410 {
411 	if (bind) {
412 		struct flow_action_entry *entry = entry_data;
413 
414 		entry->id = FLOW_ACTION_POLICE;
415 		entry->police.burst = tcf_police_burst(act);
416 		entry->police.rate_bytes_ps =
417 			tcf_police_rate_bytes_ps(act);
418 		entry->police.burst_pkt = tcf_police_burst_pkt(act);
419 		entry->police.rate_pkt_ps =
420 			tcf_police_rate_pkt_ps(act);
421 		entry->police.mtu = tcf_police_tcfp_mtu(act);
422 		*index_inc = 1;
423 	} else {
424 		struct flow_offload_action *fl_action = entry_data;
425 
426 		fl_action->id = FLOW_ACTION_POLICE;
427 	}
428 
429 	return 0;
430 }
431 
432 MODULE_AUTHOR("Alexey Kuznetsov");
433 MODULE_DESCRIPTION("Policing actions");
434 MODULE_LICENSE("GPL");
435 
436 static struct tc_action_ops act_police_ops = {
437 	.kind		=	"police",
438 	.id		=	TCA_ID_POLICE,
439 	.owner		=	THIS_MODULE,
440 	.stats_update	=	tcf_police_stats_update,
441 	.act		=	tcf_police_act,
442 	.dump		=	tcf_police_dump,
443 	.init		=	tcf_police_init,
444 	.walk		=	tcf_police_walker,
445 	.lookup		=	tcf_police_search,
446 	.cleanup	=	tcf_police_cleanup,
447 	.offload_act_setup =	tcf_police_offload_act_setup,
448 	.size		=	sizeof(struct tcf_police),
449 };
450 
451 static __net_init int police_init_net(struct net *net)
452 {
453 	struct tc_action_net *tn = net_generic(net, police_net_id);
454 
455 	return tc_action_net_init(net, tn, &act_police_ops);
456 }
457 
458 static void __net_exit police_exit_net(struct list_head *net_list)
459 {
460 	tc_action_net_exit(net_list, police_net_id);
461 }
462 
463 static struct pernet_operations police_net_ops = {
464 	.init = police_init_net,
465 	.exit_batch = police_exit_net,
466 	.id   = &police_net_id,
467 	.size = sizeof(struct tc_action_net),
468 };
469 
470 static int __init police_init_module(void)
471 {
472 	return tcf_register_action(&act_police_ops, &police_net_ops);
473 }
474 
475 static void __exit police_cleanup_module(void)
476 {
477 	tcf_unregister_action(&act_police_ops, &police_net_ops);
478 }
479 
480 module_init(police_init_module);
481 module_exit(police_cleanup_module);
482