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13#include <linux/module.h>
14#include <linux/types.h>
15#include <linux/kernel.h>
16#include <linux/string.h>
17#include <linux/errno.h>
18#include <linux/skbuff.h>
19#include <linux/rtnetlink.h>
20#include <linux/init.h>
21#include <linux/slab.h>
22#include <net/act_api.h>
23#include <net/netlink.h>
24
25struct tcf_police {
26 struct tcf_common common;
27 int tcfp_result;
28 u32 tcfp_ewma_rate;
29 s64 tcfp_burst;
30 u32 tcfp_mtu;
31 s64 tcfp_toks;
32 s64 tcfp_ptoks;
33 s64 tcfp_mtu_ptoks;
34 s64 tcfp_t_c;
35 struct psched_ratecfg rate;
36 bool rate_present;
37 struct psched_ratecfg peak;
38 bool peak_present;
39};
40#define to_police(pc) \
41 container_of(pc, struct tcf_police, common)
42
43#define POL_TAB_MASK 15
44static struct tcf_common *tcf_police_ht[POL_TAB_MASK + 1];
45static u32 police_idx_gen;
46static DEFINE_RWLOCK(police_lock);
47
48static struct tcf_hashinfo police_hash_info = {
49 .htab = tcf_police_ht,
50 .hmask = POL_TAB_MASK,
51 .lock = &police_lock,
52};
53
54
55struct tc_police_compat {
56 u32 index;
57 int action;
58 u32 limit;
59 u32 burst;
60 u32 mtu;
61 struct tc_ratespec rate;
62 struct tc_ratespec peakrate;
63};
64
65
66
67static int tcf_act_police_walker(struct sk_buff *skb, struct netlink_callback *cb,
68 int type, struct tc_action *a)
69{
70 struct tcf_common *p;
71 int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
72 struct nlattr *nest;
73
74 read_lock_bh(&police_lock);
75
76 s_i = cb->args[0];
77
78 for (i = 0; i < (POL_TAB_MASK + 1); i++) {
79 p = tcf_police_ht[tcf_hash(i, POL_TAB_MASK)];
80
81 for (; p; p = p->tcfc_next) {
82 index++;
83 if (index < s_i)
84 continue;
85 a->priv = p;
86 a->order = index;
87 nest = nla_nest_start(skb, a->order);
88 if (nest == NULL)
89 goto nla_put_failure;
90 if (type == RTM_DELACTION)
91 err = tcf_action_dump_1(skb, a, 0, 1);
92 else
93 err = tcf_action_dump_1(skb, a, 0, 0);
94 if (err < 0) {
95 index--;
96 nla_nest_cancel(skb, nest);
97 goto done;
98 }
99 nla_nest_end(skb, nest);
100 n_i++;
101 }
102 }
103done:
104 read_unlock_bh(&police_lock);
105 if (n_i)
106 cb->args[0] += n_i;
107 return n_i;
108
109nla_put_failure:
110 nla_nest_cancel(skb, nest);
111 goto done;
112}
113
114static void tcf_police_destroy(struct tcf_police *p)
115{
116 unsigned int h = tcf_hash(p->tcf_index, POL_TAB_MASK);
117 struct tcf_common **p1p;
118
119 for (p1p = &tcf_police_ht[h]; *p1p; p1p = &(*p1p)->tcfc_next) {
120 if (*p1p == &p->common) {
121 write_lock_bh(&police_lock);
122 *p1p = p->tcf_next;
123 write_unlock_bh(&police_lock);
124 gen_kill_estimator(&p->tcf_bstats,
125 &p->tcf_rate_est);
126
127
128
129
130 kfree_rcu(p, tcf_rcu);
131 return;
132 }
133 }
134 WARN_ON(1);
135}
136
137static const struct nla_policy police_policy[TCA_POLICE_MAX + 1] = {
138 [TCA_POLICE_RATE] = { .len = TC_RTAB_SIZE },
139 [TCA_POLICE_PEAKRATE] = { .len = TC_RTAB_SIZE },
140 [TCA_POLICE_AVRATE] = { .type = NLA_U32 },
141 [TCA_POLICE_RESULT] = { .type = NLA_U32 },
142};
143
144static int tcf_act_police_locate(struct net *net, struct nlattr *nla,
145 struct nlattr *est, struct tc_action *a,
146 int ovr, int bind)
147{
148 unsigned int h;
149 int ret = 0, err;
150 struct nlattr *tb[TCA_POLICE_MAX + 1];
151 struct tc_police *parm;
152 struct tcf_police *police;
153 struct qdisc_rate_table *R_tab = NULL, *P_tab = NULL;
154 int size;
155
156 if (nla == NULL)
157 return -EINVAL;
158
159 err = nla_parse_nested(tb, TCA_POLICE_MAX, nla, police_policy);
160 if (err < 0)
161 return err;
162
163 if (tb[TCA_POLICE_TBF] == NULL)
164 return -EINVAL;
165 size = nla_len(tb[TCA_POLICE_TBF]);
166 if (size != sizeof(*parm) && size != sizeof(struct tc_police_compat))
167 return -EINVAL;
168 parm = nla_data(tb[TCA_POLICE_TBF]);
169
170 if (parm->index) {
171 struct tcf_common *pc;
172
173 pc = tcf_hash_lookup(parm->index, &police_hash_info);
174 if (pc != NULL) {
175 a->priv = pc;
176 police = to_police(pc);
177 if (bind) {
178 police->tcf_bindcnt += 1;
179 police->tcf_refcnt += 1;
180 }
181 if (ovr)
182 goto override;
183 return ret;
184 }
185 }
186
187 police = kzalloc(sizeof(*police), GFP_KERNEL);
188 if (police == NULL)
189 return -ENOMEM;
190 ret = ACT_P_CREATED;
191 police->tcf_refcnt = 1;
192 spin_lock_init(&police->tcf_lock);
193 if (bind)
194 police->tcf_bindcnt = 1;
195override:
196 if (parm->rate.rate) {
197 err = -ENOMEM;
198 R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE]);
199 if (R_tab == NULL)
200 goto failure;
201
202 if (parm->peakrate.rate) {
203 P_tab = qdisc_get_rtab(&parm->peakrate,
204 tb[TCA_POLICE_PEAKRATE]);
205 if (P_tab == NULL)
206 goto failure;
207 }
208 }
209
210 spin_lock_bh(&police->tcf_lock);
211 if (est) {
212 err = gen_replace_estimator(&police->tcf_bstats,
213 &police->tcf_rate_est,
214 &police->tcf_lock, est);
215 if (err)
216 goto failure_unlock;
217 } else if (tb[TCA_POLICE_AVRATE] &&
218 (ret == ACT_P_CREATED ||
219 !gen_estimator_active(&police->tcf_bstats,
220 &police->tcf_rate_est))) {
221 err = -EINVAL;
222 goto failure_unlock;
223 }
224
225
226 police->tcfp_mtu = parm->mtu;
227 if (police->tcfp_mtu == 0) {
228 police->tcfp_mtu = ~0;
229 if (R_tab)
230 police->tcfp_mtu = 255 << R_tab->rate.cell_log;
231 }
232 if (R_tab) {
233 police->rate_present = true;
234 psched_ratecfg_precompute(&police->rate, &R_tab->rate);
235 qdisc_put_rtab(R_tab);
236 } else {
237 police->rate_present = false;
238 }
239 if (P_tab) {
240 police->peak_present = true;
241 psched_ratecfg_precompute(&police->peak, &P_tab->rate);
242 qdisc_put_rtab(P_tab);
243 } else {
244 police->peak_present = false;
245 }
246
247 if (tb[TCA_POLICE_RESULT])
248 police->tcfp_result = nla_get_u32(tb[TCA_POLICE_RESULT]);
249 police->tcfp_burst = PSCHED_TICKS2NS(parm->burst);
250 police->tcfp_toks = police->tcfp_burst;
251 if (police->peak_present) {
252 police->tcfp_mtu_ptoks = (s64) psched_l2t_ns(&police->peak,
253 police->tcfp_mtu);
254 police->tcfp_ptoks = police->tcfp_mtu_ptoks;
255 }
256 police->tcf_action = parm->action;
257
258 if (tb[TCA_POLICE_AVRATE])
259 police->tcfp_ewma_rate = nla_get_u32(tb[TCA_POLICE_AVRATE]);
260
261 spin_unlock_bh(&police->tcf_lock);
262 if (ret != ACT_P_CREATED)
263 return ret;
264
265 police->tcfp_t_c = ktime_to_ns(ktime_get());
266 police->tcf_index = parm->index ? parm->index :
267 tcf_hash_new_index(&police_idx_gen, &police_hash_info);
268 h = tcf_hash(police->tcf_index, POL_TAB_MASK);
269 write_lock_bh(&police_lock);
270 police->tcf_next = tcf_police_ht[h];
271 tcf_police_ht[h] = &police->common;
272 write_unlock_bh(&police_lock);
273
274 a->priv = police;
275 return ret;
276
277failure_unlock:
278 spin_unlock_bh(&police->tcf_lock);
279failure:
280 if (P_tab)
281 qdisc_put_rtab(P_tab);
282 if (R_tab)
283 qdisc_put_rtab(R_tab);
284 if (ret == ACT_P_CREATED)
285 kfree(police);
286 return err;
287}
288
289static int tcf_act_police_cleanup(struct tc_action *a, int bind)
290{
291 struct tcf_police *p = a->priv;
292 int ret = 0;
293
294 if (p != NULL) {
295 if (bind)
296 p->tcf_bindcnt--;
297
298 p->tcf_refcnt--;
299 if (p->tcf_refcnt <= 0 && !p->tcf_bindcnt) {
300 tcf_police_destroy(p);
301 ret = 1;
302 }
303 }
304 return ret;
305}
306
307static int tcf_act_police(struct sk_buff *skb, const struct tc_action *a,
308 struct tcf_result *res)
309{
310 struct tcf_police *police = a->priv;
311 s64 now;
312 s64 toks;
313 s64 ptoks = 0;
314
315 spin_lock(&police->tcf_lock);
316
317 bstats_update(&police->tcf_bstats, skb);
318
319 if (police->tcfp_ewma_rate &&
320 police->tcf_rate_est.bps >= police->tcfp_ewma_rate) {
321 police->tcf_qstats.overlimits++;
322 if (police->tcf_action == TC_ACT_SHOT)
323 police->tcf_qstats.drops++;
324 spin_unlock(&police->tcf_lock);
325 return police->tcf_action;
326 }
327
328 if (qdisc_pkt_len(skb) <= police->tcfp_mtu) {
329 if (!police->rate_present) {
330 spin_unlock(&police->tcf_lock);
331 return police->tcfp_result;
332 }
333
334 now = ktime_to_ns(ktime_get());
335 toks = min_t(s64, now - police->tcfp_t_c,
336 police->tcfp_burst);
337 if (police->peak_present) {
338 ptoks = toks + police->tcfp_ptoks;
339 if (ptoks > police->tcfp_mtu_ptoks)
340 ptoks = police->tcfp_mtu_ptoks;
341 ptoks -= (s64) psched_l2t_ns(&police->peak,
342 qdisc_pkt_len(skb));
343 }
344 toks += police->tcfp_toks;
345 if (toks > police->tcfp_burst)
346 toks = police->tcfp_burst;
347 toks -= (s64) psched_l2t_ns(&police->rate, qdisc_pkt_len(skb));
348 if ((toks|ptoks) >= 0) {
349 police->tcfp_t_c = now;
350 police->tcfp_toks = toks;
351 police->tcfp_ptoks = ptoks;
352 spin_unlock(&police->tcf_lock);
353 return police->tcfp_result;
354 }
355 }
356
357 police->tcf_qstats.overlimits++;
358 if (police->tcf_action == TC_ACT_SHOT)
359 police->tcf_qstats.drops++;
360 spin_unlock(&police->tcf_lock);
361 return police->tcf_action;
362}
363
364static int
365tcf_act_police_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
366{
367 unsigned char *b = skb_tail_pointer(skb);
368 struct tcf_police *police = a->priv;
369 struct tc_police opt = {
370 .index = police->tcf_index,
371 .action = police->tcf_action,
372 .mtu = police->tcfp_mtu,
373 .burst = PSCHED_NS2TICKS(police->tcfp_burst),
374 .refcnt = police->tcf_refcnt - ref,
375 .bindcnt = police->tcf_bindcnt - bind,
376 };
377
378 if (police->rate_present)
379 psched_ratecfg_getrate(&opt.rate, &police->rate);
380 if (police->peak_present)
381 psched_ratecfg_getrate(&opt.peakrate, &police->peak);
382 if (nla_put(skb, TCA_POLICE_TBF, sizeof(opt), &opt))
383 goto nla_put_failure;
384 if (police->tcfp_result &&
385 nla_put_u32(skb, TCA_POLICE_RESULT, police->tcfp_result))
386 goto nla_put_failure;
387 if (police->tcfp_ewma_rate &&
388 nla_put_u32(skb, TCA_POLICE_AVRATE, police->tcfp_ewma_rate))
389 goto nla_put_failure;
390 return skb->len;
391
392nla_put_failure:
393 nlmsg_trim(skb, b);
394 return -1;
395}
396
397MODULE_AUTHOR("Alexey Kuznetsov");
398MODULE_DESCRIPTION("Policing actions");
399MODULE_LICENSE("GPL");
400
401static struct tc_action_ops act_police_ops = {
402 .kind = "police",
403 .hinfo = &police_hash_info,
404 .type = TCA_ID_POLICE,
405 .capab = TCA_CAP_NONE,
406 .owner = THIS_MODULE,
407 .act = tcf_act_police,
408 .dump = tcf_act_police_dump,
409 .cleanup = tcf_act_police_cleanup,
410 .lookup = tcf_hash_search,
411 .init = tcf_act_police_locate,
412 .walk = tcf_act_police_walker
413};
414
415static int __init
416police_init_module(void)
417{
418 return tcf_register_action(&act_police_ops);
419}
420
421static void __exit
422police_cleanup_module(void)
423{
424 tcf_unregister_action(&act_police_ops);
425}
426
427module_init(police_init_module);
428module_exit(police_cleanup_module);
429
