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Linux 3.8-rc7
[cris-mirror.git] / net / sched / act_police.c
bloba9de23297d47759f3fa50113b1bf190f51bf4063
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 u32 index;
42 int action;
43 u32 limit;
44 u32 burst;
45 u32 mtu;
46 struct tc_ratespec rate;
47 struct tc_ratespec peakrate;
48 };
49
50 /* Each policer is serialized by its individual spinlock */
51
52 static int tcf_act_police_walker(struct sk_buff *skb, struct netlink_callback *cb,
53 int type, struct tc_action *a)
54 {
55 struct tcf_common *p;
56 int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
57 struct nlattr *nest;
58
59 read_lock_bh(&police_lock);
60
61 s_i = cb->args[0];
62
63 for (i = 0; i < (POL_TAB_MASK + 1); i++) {
64 p = tcf_police_ht[tcf_hash(i, POL_TAB_MASK)];
65
66 for (; p; p = p->tcfc_next) {
67 index++;
68 if (index < s_i)
69 continue;
70 a->priv = p;
71 a->order = index;
72 nest = nla_nest_start(skb, a->order);
73 if (nest == NULL)
74 goto nla_put_failure;
75 if (type == RTM_DELACTION)
76 err = tcf_action_dump_1(skb, a, 0, 1);
77 else
78 err = tcf_action_dump_1(skb, a, 0, 0);
79 if (err < 0) {
80 index--;
81 nla_nest_cancel(skb, nest);
82 goto done;
83 }
84 nla_nest_end(skb, nest);
85 n_i++;
86 }
87 }
88 done:
89 read_unlock_bh(&police_lock);
90 if (n_i)
91 cb->args[0] += n_i;
92 return n_i;
93
94 nla_put_failure:
95 nla_nest_cancel(skb, nest);
96 goto done;
97 }
98
99 static void tcf_police_destroy(struct tcf_police *p)
100 {
101 unsigned int h = tcf_hash(p->tcf_index, POL_TAB_MASK);
102 struct tcf_common **p1p;
103
104 for (p1p = &tcf_police_ht[h]; *p1p; p1p = &(*p1p)->tcfc_next) {
105 if (*p1p == &p->common) {
106 write_lock_bh(&police_lock);
107 *p1p = p->tcf_next;
108 write_unlock_bh(&police_lock);
109 gen_kill_estimator(&p->tcf_bstats,
110 &p->tcf_rate_est);
111 if (p->tcfp_R_tab)
112 qdisc_put_rtab(p->tcfp_R_tab);
113 if (p->tcfp_P_tab)
114 qdisc_put_rtab(p->tcfp_P_tab);
115 /*
116 * gen_estimator est_timer() might access p->tcf_lock
117 * or bstats, wait a RCU grace period before freeing p
118 */
119 kfree_rcu(p, tcf_rcu);
120 return;
121 }
122 }
123 WARN_ON(1);
124 }
125
126 static const struct nla_policy police_policy[TCA_POLICE_MAX + 1] = {
127 [TCA_POLICE_RATE] = { .len = TC_RTAB_SIZE },
128 [TCA_POLICE_PEAKRATE] = { .len = TC_RTAB_SIZE },
129 [TCA_POLICE_AVRATE] = { .type = NLA_U32 },
130 [TCA_POLICE_RESULT] = { .type = NLA_U32 },
131 };
132
133 static int tcf_act_police_locate(struct nlattr *nla, struct nlattr *est,
134 struct tc_action *a, int ovr, int bind)
135 {
136 unsigned int h;
137 int ret = 0, err;
138 struct nlattr *tb[TCA_POLICE_MAX + 1];
139 struct tc_police *parm;
140 struct tcf_police *police;
141 struct qdisc_rate_table *R_tab = NULL, *P_tab = NULL;
142 int size;
143
144 if (nla == NULL)
145 return -EINVAL;
146
147 err = nla_parse_nested(tb, TCA_POLICE_MAX, nla, police_policy);
148 if (err < 0)
149 return err;
150
151 if (tb[TCA_POLICE_TBF] == NULL)
152 return -EINVAL;
153 size = nla_len(tb[TCA_POLICE_TBF]);
154 if (size != sizeof(*parm) && size != sizeof(struct tc_police_compat))
155 return -EINVAL;
156 parm = nla_data(tb[TCA_POLICE_TBF]);
157
158 if (parm->index) {
159 struct tcf_common *pc;
160
161 pc = tcf_hash_lookup(parm->index, &police_hash_info);
162 if (pc != NULL) {
163 a->priv = pc;
164 police = to_police(pc);
165 if (bind) {
166 police->tcf_bindcnt += 1;
167 police->tcf_refcnt += 1;
168 }
169 if (ovr)
170 goto override;
171 return ret;
172 }
173 }
174
175 police = kzalloc(sizeof(*police), GFP_KERNEL);
176 if (police == NULL)
177 return -ENOMEM;
178 ret = ACT_P_CREATED;
179 police->tcf_refcnt = 1;
180 spin_lock_init(&police->tcf_lock);
181 if (bind)
182 police->tcf_bindcnt = 1;
183 override:
184 if (parm->rate.rate) {
185 err = -ENOMEM;
186 R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE]);
187 if (R_tab == NULL)
188 goto failure;
189
190 if (parm->peakrate.rate) {
191 P_tab = qdisc_get_rtab(&parm->peakrate,
192 tb[TCA_POLICE_PEAKRATE]);
193 if (P_tab == NULL)
194 goto failure;
195 }
196 }
197
198 spin_lock_bh(&police->tcf_lock);
199 if (est) {
200 err = gen_replace_estimator(&police->tcf_bstats,
201 &police->tcf_rate_est,
202 &police->tcf_lock, est);
203 if (err)
204 goto failure_unlock;
205 } else if (tb[TCA_POLICE_AVRATE] &&
206 (ret == ACT_P_CREATED ||
207 !gen_estimator_active(&police->tcf_bstats,
208 &police->tcf_rate_est))) {
209 err = -EINVAL;
210 goto failure_unlock;
211 }
212
213 /* No failure allowed after this point */
214 if (R_tab != NULL) {
215 qdisc_put_rtab(police->tcfp_R_tab);
216 police->tcfp_R_tab = R_tab;
217 }
218 if (P_tab != NULL) {
219 qdisc_put_rtab(police->tcfp_P_tab);
220 police->tcfp_P_tab = P_tab;
221 }
222
223 if (tb[TCA_POLICE_RESULT])
224 police->tcfp_result = nla_get_u32(tb[TCA_POLICE_RESULT]);
225 police->tcfp_toks = police->tcfp_burst = parm->burst;
226 police->tcfp_mtu = parm->mtu;
227 if (police->tcfp_mtu == 0) {
228 police->tcfp_mtu = ~0;
229 if (police->tcfp_R_tab)
230 police->tcfp_mtu = 255<<police->tcfp_R_tab->rate.cell_log;
231 }
232 if (police->tcfp_P_tab)
233 police->tcfp_ptoks = L2T_P(police, police->tcfp_mtu);
234 police->tcf_action = parm->action;
235
236 if (tb[TCA_POLICE_AVRATE])
237 police->tcfp_ewma_rate = nla_get_u32(tb[TCA_POLICE_AVRATE]);
238
239 spin_unlock_bh(&police->tcf_lock);
240 if (ret != ACT_P_CREATED)
241 return ret;
242
243 police->tcfp_t_c = psched_get_time();
244 police->tcf_index = parm->index ? parm->index :
245 tcf_hash_new_index(&police_idx_gen, &police_hash_info);
246 h = tcf_hash(police->tcf_index, POL_TAB_MASK);
247 write_lock_bh(&police_lock);
248 police->tcf_next = tcf_police_ht[h];
249 tcf_police_ht[h] = &police->common;
250 write_unlock_bh(&police_lock);
251
252 a->priv = police;
253 return ret;
254
255 failure_unlock:
256 spin_unlock_bh(&police->tcf_lock);
257 failure:
258 if (P_tab)
259 qdisc_put_rtab(P_tab);
260 if (R_tab)
261 qdisc_put_rtab(R_tab);
262 if (ret == ACT_P_CREATED)
263 kfree(police);
264 return err;
265 }
266
267 static int tcf_act_police_cleanup(struct tc_action *a, int bind)
268 {
269 struct tcf_police *p = a->priv;
270 int ret = 0;
271
272 if (p != NULL) {
273 if (bind)
274 p->tcf_bindcnt--;
275
276 p->tcf_refcnt--;
277 if (p->tcf_refcnt <= 0 && !p->tcf_bindcnt) {
278 tcf_police_destroy(p);
279 ret = 1;
280 }
281 }
282 return ret;
283 }
284
285 static int tcf_act_police(struct sk_buff *skb, const struct tc_action *a,
286 struct tcf_result *res)
287 {
288 struct tcf_police *police = a->priv;
289 psched_time_t now;
290 long toks;
291 long ptoks = 0;
292
293 spin_lock(&police->tcf_lock);
294
295 bstats_update(&police->tcf_bstats, skb);
296
297 if (police->tcfp_ewma_rate &&
298 police->tcf_rate_est.bps >= police->tcfp_ewma_rate) {
299 police->tcf_qstats.overlimits++;
300 if (police->tcf_action == TC_ACT_SHOT)
301 police->tcf_qstats.drops++;
302 spin_unlock(&police->tcf_lock);
303 return police->tcf_action;
304 }
305
306 if (qdisc_pkt_len(skb) <= police->tcfp_mtu) {
307 if (police->tcfp_R_tab == NULL) {
308 spin_unlock(&police->tcf_lock);
309 return police->tcfp_result;
310 }
311
312 now = psched_get_time();
313 toks = psched_tdiff_bounded(now, police->tcfp_t_c,
314 police->tcfp_burst);
315 if (police->tcfp_P_tab) {
316 ptoks = toks + police->tcfp_ptoks;
317 if (ptoks > (long)L2T_P(police, police->tcfp_mtu))
318 ptoks = (long)L2T_P(police, police->tcfp_mtu);
319 ptoks -= L2T_P(police, qdisc_pkt_len(skb));
320 }
321 toks += police->tcfp_toks;
322 if (toks > (long)police->tcfp_burst)
323 toks = police->tcfp_burst;
324 toks -= L2T(police, qdisc_pkt_len(skb));
325 if ((toks|ptoks) >= 0) {
326 police->tcfp_t_c = now;
327 police->tcfp_toks = toks;
328 police->tcfp_ptoks = ptoks;
329 spin_unlock(&police->tcf_lock);
330 return police->tcfp_result;
331 }
332 }
333
334 police->tcf_qstats.overlimits++;
335 if (police->tcf_action == TC_ACT_SHOT)
336 police->tcf_qstats.drops++;
337 spin_unlock(&police->tcf_lock);
338 return police->tcf_action;
339 }
340
341 static int
342 tcf_act_police_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
343 {
344 unsigned char *b = skb_tail_pointer(skb);
345 struct tcf_police *police = a->priv;
346 struct tc_police opt = {
347 .index = police->tcf_index,
348 .action = police->tcf_action,
349 .mtu = police->tcfp_mtu,
350 .burst = police->tcfp_burst,
351 .refcnt = police->tcf_refcnt - ref,
352 .bindcnt = police->tcf_bindcnt - bind,
353 };
354
355 if (police->tcfp_R_tab)
356 opt.rate = police->tcfp_R_tab->rate;
357 if (police->tcfp_P_tab)
358 opt.peakrate = police->tcfp_P_tab->rate;
359 if (nla_put(skb, TCA_POLICE_TBF, sizeof(opt), &opt))
360 goto nla_put_failure;
361 if (police->tcfp_result &&
362 nla_put_u32(skb, TCA_POLICE_RESULT, police->tcfp_result))
363 goto nla_put_failure;
364 if (police->tcfp_ewma_rate &&
365 nla_put_u32(skb, TCA_POLICE_AVRATE, police->tcfp_ewma_rate))
366 goto nla_put_failure;
367 return skb->len;
368
369 nla_put_failure:
370 nlmsg_trim(skb, b);
371 return -1;
372 }
373
374 MODULE_AUTHOR("Alexey Kuznetsov");
375 MODULE_DESCRIPTION("Policing actions");
376 MODULE_LICENSE("GPL");
377
378 static struct tc_action_ops act_police_ops = {
379 .kind = "police",
380 .hinfo = &police_hash_info,
381 .type = TCA_ID_POLICE,
382 .capab = TCA_CAP_NONE,
383 .owner = THIS_MODULE,
384 .act = tcf_act_police,
385 .dump = tcf_act_police_dump,
386 .cleanup = tcf_act_police_cleanup,
387 .lookup = tcf_hash_search,
388 .init = tcf_act_police_locate,
389 .walk = tcf_act_police_walker
390 };
391
392 static int __init
393 police_init_module(void)
394 {
395 return tcf_register_action(&act_police_ops);
396 }
397
398 static void __exit
399 police_cleanup_module(void)
400 {
401 tcf_unregister_action(&act_police_ops);
402 }
403
404 module_init(police_init_module);
405 module_exit(police_cleanup_module);
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