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staging: iio: adis16400 add _index attribute registration
[zen-stable.git] / net / sched / act_police.c
blob537a48732e9e0b8513dd324801c342ec00cd3820
1 /*
2 * net/sched/police.c Input police filter.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
8 *
9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10 * J Hadi Salim (action changes)
11 */
12
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
25 #define L2T(p,L) qdisc_l2t((p)->tcfp_R_tab, L)
26 #define L2T_P(p,L) qdisc_l2t((p)->tcfp_P_tab, L)
27
28 #define POL_TAB_MASK 15
29 static struct tcf_common *tcf_police_ht[POL_TAB_MASK + 1];
30 static u32 police_idx_gen;
31 static DEFINE_RWLOCK(police_lock);
32
33 static struct tcf_hashinfo police_hash_info = {
34 .htab = tcf_police_ht,
35 .hmask = POL_TAB_MASK,
36 .lock = &police_lock,
37 };
38
39 /* old policer structure from before tc actions */
40 struct tc_police_compat
41 {
42 u32 index;
43 int action;
44 u32 limit;
45 u32 burst;
46 u32 mtu;
47 struct tc_ratespec rate;
48 struct tc_ratespec peakrate;
49 };
50
51 /* Each policer is serialized by its individual spinlock */
52
53 static int tcf_act_police_walker(struct sk_buff *skb, struct netlink_callback *cb,
54 int type, struct tc_action *a)
55 {
56 struct tcf_common *p;
57 int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
58 struct nlattr *nest;
59
60 read_lock_bh(&police_lock);
61
62 s_i = cb->args[0];
63
64 for (i = 0; i < (POL_TAB_MASK + 1); i++) {
65 p = tcf_police_ht[tcf_hash(i, POL_TAB_MASK)];
66
67 for (; p; p = p->tcfc_next) {
68 index++;
69 if (index < s_i)
70 continue;
71 a->priv = p;
72 a->order = index;
73 nest = nla_nest_start(skb, a->order);
74 if (nest == NULL)
75 goto nla_put_failure;
76 if (type == RTM_DELACTION)
77 err = tcf_action_dump_1(skb, a, 0, 1);
78 else
79 err = tcf_action_dump_1(skb, a, 0, 0);
80 if (err < 0) {
81 index--;
82 nla_nest_cancel(skb, nest);
83 goto done;
84 }
85 nla_nest_end(skb, nest);
86 n_i++;
87 }
88 }
89 done:
90 read_unlock_bh(&police_lock);
91 if (n_i)
92 cb->args[0] += n_i;
93 return n_i;
94
95 nla_put_failure:
96 nla_nest_cancel(skb, nest);
97 goto done;
98 }
99
100 static void tcf_police_free_rcu(struct rcu_head *head)
101 {
102 kfree(container_of(head, struct tcf_police, tcf_rcu));
103 }
104
105 static void tcf_police_destroy(struct tcf_police *p)
106 {
107 unsigned int h = tcf_hash(p->tcf_index, POL_TAB_MASK);
108 struct tcf_common **p1p;
109
110 for (p1p = &tcf_police_ht[h]; *p1p; p1p = &(*p1p)->tcfc_next) {
111 if (*p1p == &p->common) {
112 write_lock_bh(&police_lock);
113 *p1p = p->tcf_next;
114 write_unlock_bh(&police_lock);
115 gen_kill_estimator(&p->tcf_bstats,
116 &p->tcf_rate_est);
117 if (p->tcfp_R_tab)
118 qdisc_put_rtab(p->tcfp_R_tab);
119 if (p->tcfp_P_tab)
120 qdisc_put_rtab(p->tcfp_P_tab);
121 /*
122 * gen_estimator est_timer() might access p->tcf_lock
123 * or bstats, wait a RCU grace period before freeing p
124 */
125 call_rcu(&p->tcf_rcu, tcf_police_free_rcu);
126 return;
127 }
128 }
129 WARN_ON(1);
130 }
131
132 static const struct nla_policy police_policy[TCA_POLICE_MAX + 1] = {
133 [TCA_POLICE_RATE] = { .len = TC_RTAB_SIZE },
134 [TCA_POLICE_PEAKRATE] = { .len = TC_RTAB_SIZE },
135 [TCA_POLICE_AVRATE] = { .type = NLA_U32 },
136 [TCA_POLICE_RESULT] = { .type = NLA_U32 },
137 };
138
139 static int tcf_act_police_locate(struct nlattr *nla, struct nlattr *est,
140 struct tc_action *a, int ovr, int bind)
141 {
142 unsigned h;
143 int ret = 0, err;
144 struct nlattr *tb[TCA_POLICE_MAX + 1];
145 struct tc_police *parm;
146 struct tcf_police *police;
147 struct qdisc_rate_table *R_tab = NULL, *P_tab = NULL;
148 int size;
149
150 if (nla == NULL)
151 return -EINVAL;
152
153 err = nla_parse_nested(tb, TCA_POLICE_MAX, nla, police_policy);
154 if (err < 0)
155 return err;
156
157 if (tb[TCA_POLICE_TBF] == NULL)
158 return -EINVAL;
159 size = nla_len(tb[TCA_POLICE_TBF]);
160 if (size != sizeof(*parm) && size != sizeof(struct tc_police_compat))
161 return -EINVAL;
162 parm = nla_data(tb[TCA_POLICE_TBF]);
163
164 if (parm->index) {
165 struct tcf_common *pc;
166
167 pc = tcf_hash_lookup(parm->index, &police_hash_info);
168 if (pc != NULL) {
169 a->priv = pc;
170 police = to_police(pc);
171 if (bind) {
172 police->tcf_bindcnt += 1;
173 police->tcf_refcnt += 1;
174 }
175 if (ovr)
176 goto override;
177 return ret;
178 }
179 }
180
181 police = kzalloc(sizeof(*police), GFP_KERNEL);
182 if (police == NULL)
183 return -ENOMEM;
184 ret = ACT_P_CREATED;
185 police->tcf_refcnt = 1;
186 spin_lock_init(&police->tcf_lock);
187 if (bind)
188 police->tcf_bindcnt = 1;
189 override:
190 if (parm->rate.rate) {
191 err = -ENOMEM;
192 R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE]);
193 if (R_tab == NULL)
194 goto failure;
195
196 if (parm->peakrate.rate) {
197 P_tab = qdisc_get_rtab(&parm->peakrate,
198 tb[TCA_POLICE_PEAKRATE]);
199 if (P_tab == NULL)
200 goto failure;
201 }
202 }
203
204 spin_lock_bh(&police->tcf_lock);
205 if (est) {
206 err = gen_replace_estimator(&police->tcf_bstats,
207 &police->tcf_rate_est,
208 &police->tcf_lock, est);
209 if (err)
210 goto failure_unlock;
211 } else if (tb[TCA_POLICE_AVRATE] &&
212 (ret == ACT_P_CREATED ||
213 !gen_estimator_active(&police->tcf_bstats,
214 &police->tcf_rate_est))) {
215 err = -EINVAL;
216 goto failure_unlock;
217 }
218
219 /* No failure allowed after this point */
220 if (R_tab != NULL) {
221 qdisc_put_rtab(police->tcfp_R_tab);
222 police->tcfp_R_tab = R_tab;
223 }
224 if (P_tab != NULL) {
225 qdisc_put_rtab(police->tcfp_P_tab);
226 police->tcfp_P_tab = P_tab;
227 }
228
229 if (tb[TCA_POLICE_RESULT])
230 police->tcfp_result = nla_get_u32(tb[TCA_POLICE_RESULT]);
231 police->tcfp_toks = police->tcfp_burst = parm->burst;
232 police->tcfp_mtu = parm->mtu;
233 if (police->tcfp_mtu == 0) {
234 police->tcfp_mtu = ~0;
235 if (police->tcfp_R_tab)
236 police->tcfp_mtu = 255<<police->tcfp_R_tab->rate.cell_log;
237 }
238 if (police->tcfp_P_tab)
239 police->tcfp_ptoks = L2T_P(police, police->tcfp_mtu);
240 police->tcf_action = parm->action;
241
242 if (tb[TCA_POLICE_AVRATE])
243 police->tcfp_ewma_rate = nla_get_u32(tb[TCA_POLICE_AVRATE]);
244
245 spin_unlock_bh(&police->tcf_lock);
246 if (ret != ACT_P_CREATED)
247 return ret;
248
249 police->tcfp_t_c = psched_get_time();
250 police->tcf_index = parm->index ? parm->index :
251 tcf_hash_new_index(&police_idx_gen, &police_hash_info);
252 h = tcf_hash(police->tcf_index, POL_TAB_MASK);
253 write_lock_bh(&police_lock);
254 police->tcf_next = tcf_police_ht[h];
255 tcf_police_ht[h] = &police->common;
256 write_unlock_bh(&police_lock);
257
258 a->priv = police;
259 return ret;
260
261 failure_unlock:
262 spin_unlock_bh(&police->tcf_lock);
263 failure:
264 if (P_tab)
265 qdisc_put_rtab(P_tab);
266 if (R_tab)
267 qdisc_put_rtab(R_tab);
268 if (ret == ACT_P_CREATED)
269 kfree(police);
270 return err;
271 }
272
273 static int tcf_act_police_cleanup(struct tc_action *a, int bind)
274 {
275 struct tcf_police *p = a->priv;
276 int ret = 0;
277
278 if (p != NULL) {
279 if (bind)
280 p->tcf_bindcnt--;
281
282 p->tcf_refcnt--;
283 if (p->tcf_refcnt <= 0 && !p->tcf_bindcnt) {
284 tcf_police_destroy(p);
285 ret = 1;
286 }
287 }
288 return ret;
289 }
290
291 static int tcf_act_police(struct sk_buff *skb, struct tc_action *a,
292 struct tcf_result *res)
293 {
294 struct tcf_police *police = a->priv;
295 psched_time_t now;
296 long toks;
297 long ptoks = 0;
298
299 spin_lock(&police->tcf_lock);
300
301 police->tcf_bstats.bytes += qdisc_pkt_len(skb);
302 police->tcf_bstats.packets++;
303
304 if (police->tcfp_ewma_rate &&
305 police->tcf_rate_est.bps >= police->tcfp_ewma_rate) {
306 police->tcf_qstats.overlimits++;
307 if (police->tcf_action == TC_ACT_SHOT)
308 police->tcf_qstats.drops++;
309 spin_unlock(&police->tcf_lock);
310 return police->tcf_action;
311 }
312
313 if (qdisc_pkt_len(skb) <= police->tcfp_mtu) {
314 if (police->tcfp_R_tab == NULL) {
315 spin_unlock(&police->tcf_lock);
316 return police->tcfp_result;
317 }
318
319 now = psched_get_time();
320 toks = psched_tdiff_bounded(now, police->tcfp_t_c,
321 police->tcfp_burst);
322 if (police->tcfp_P_tab) {
323 ptoks = toks + police->tcfp_ptoks;
324 if (ptoks > (long)L2T_P(police, police->tcfp_mtu))
325 ptoks = (long)L2T_P(police, police->tcfp_mtu);
326 ptoks -= L2T_P(police, qdisc_pkt_len(skb));
327 }
328 toks += police->tcfp_toks;
329 if (toks > (long)police->tcfp_burst)
330 toks = police->tcfp_burst;
331 toks -= L2T(police, qdisc_pkt_len(skb));
332 if ((toks|ptoks) >= 0) {
333 police->tcfp_t_c = now;
334 police->tcfp_toks = toks;
335 police->tcfp_ptoks = ptoks;
336 spin_unlock(&police->tcf_lock);
337 return police->tcfp_result;
338 }
339 }
340
341 police->tcf_qstats.overlimits++;
342 if (police->tcf_action == TC_ACT_SHOT)
343 police->tcf_qstats.drops++;
344 spin_unlock(&police->tcf_lock);
345 return police->tcf_action;
346 }
347
348 static int
349 tcf_act_police_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
350 {
351 unsigned char *b = skb_tail_pointer(skb);
352 struct tcf_police *police = a->priv;
353 struct tc_police opt;
354
355 opt.index = police->tcf_index;
356 opt.action = police->tcf_action;
357 opt.mtu = police->tcfp_mtu;
358 opt.burst = police->tcfp_burst;
359 opt.refcnt = police->tcf_refcnt - ref;
360 opt.bindcnt = police->tcf_bindcnt - bind;
361 if (police->tcfp_R_tab)
362 opt.rate = police->tcfp_R_tab->rate;
363 else
364 memset(&opt.rate, 0, sizeof(opt.rate));
365 if (police->tcfp_P_tab)
366 opt.peakrate = police->tcfp_P_tab->rate;
367 else
368 memset(&opt.peakrate, 0, sizeof(opt.peakrate));
369 NLA_PUT(skb, TCA_POLICE_TBF, sizeof(opt), &opt);
370 if (police->tcfp_result)
371 NLA_PUT_U32(skb, TCA_POLICE_RESULT, police->tcfp_result);
372 if (police->tcfp_ewma_rate)
373 NLA_PUT_U32(skb, TCA_POLICE_AVRATE, police->tcfp_ewma_rate);
374 return skb->len;
375
376 nla_put_failure:
377 nlmsg_trim(skb, b);
378 return -1;
379 }
380
381 MODULE_AUTHOR("Alexey Kuznetsov");
382 MODULE_DESCRIPTION("Policing actions");
383 MODULE_LICENSE("GPL");
384
385 static struct tc_action_ops act_police_ops = {
386 .kind = "police",
387 .hinfo = &police_hash_info,
388 .type = TCA_ID_POLICE,
389 .capab = TCA_CAP_NONE,
390 .owner = THIS_MODULE,
391 .act = tcf_act_police,
392 .dump = tcf_act_police_dump,
393 .cleanup = tcf_act_police_cleanup,
394 .lookup = tcf_hash_search,
395 .init = tcf_act_police_locate,
396 .walk = tcf_act_police_walker
397 };
398
399 static int __init
400 police_init_module(void)
401 {
402 return tcf_register_action(&act_police_ops);
403 }
404
405 static void __exit
406 police_cleanup_module(void)
407 {
408 tcf_unregister_action(&act_police_ops);
409 rcu_barrier(); /* Wait for completion of call_rcu()'s (tcf_police_free_rcu) */
410 }
411
412 module_init(police_init_module);
413 module_exit(police_cleanup_module);