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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc
[cris-mirror.git] / net / sched / act_police.c
blob8a1630774fd6bdd6536f199b9665517e67312381
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_free_rcu(struct rcu_head *head)
100 {
101 kfree(container_of(head, struct tcf_police, tcf_rcu));
102 }
103
104 static void tcf_police_destroy(struct tcf_police *p)
105 {
106 unsigned int h = tcf_hash(p->tcf_index, POL_TAB_MASK);
107 struct tcf_common **p1p;
108
109 for (p1p = &tcf_police_ht[h]; *p1p; p1p = &(*p1p)->tcfc_next) {
110 if (*p1p == &p->common) {
111 write_lock_bh(&police_lock);
112 *p1p = p->tcf_next;
113 write_unlock_bh(&police_lock);
114 gen_kill_estimator(&p->tcf_bstats,
115 &p->tcf_rate_est);
116 if (p->tcfp_R_tab)
117 qdisc_put_rtab(p->tcfp_R_tab);
118 if (p->tcfp_P_tab)
119 qdisc_put_rtab(p->tcfp_P_tab);
120 /*
121 * gen_estimator est_timer() might access p->tcf_lock
122 * or bstats, wait a RCU grace period before freeing p
123 */
124 call_rcu(&p->tcf_rcu, tcf_police_free_rcu);
125 return;
126 }
127 }
128 WARN_ON(1);
129 }
130
131 static const struct nla_policy police_policy[TCA_POLICE_MAX + 1] = {
132 [TCA_POLICE_RATE] = { .len = TC_RTAB_SIZE },
133 [TCA_POLICE_PEAKRATE] = { .len = TC_RTAB_SIZE },
134 [TCA_POLICE_AVRATE] = { .type = NLA_U32 },
135 [TCA_POLICE_RESULT] = { .type = NLA_U32 },
136 };
137
138 static int tcf_act_police_locate(struct nlattr *nla, struct nlattr *est,
139 struct tc_action *a, int ovr, int bind)
140 {
141 unsigned int h;
142 int ret = 0, err;
143 struct nlattr *tb[TCA_POLICE_MAX + 1];
144 struct tc_police *parm;
145 struct tcf_police *police;
146 struct qdisc_rate_table *R_tab = NULL, *P_tab = NULL;
147 int size;
148
149 if (nla == NULL)
150 return -EINVAL;
151
152 err = nla_parse_nested(tb, TCA_POLICE_MAX, nla, police_policy);
153 if (err < 0)
154 return err;
155
156 if (tb[TCA_POLICE_TBF] == NULL)
157 return -EINVAL;
158 size = nla_len(tb[TCA_POLICE_TBF]);
159 if (size != sizeof(*parm) && size != sizeof(struct tc_police_compat))
160 return -EINVAL;
161 parm = nla_data(tb[TCA_POLICE_TBF]);
162
163 if (parm->index) {
164 struct tcf_common *pc;
165
166 pc = tcf_hash_lookup(parm->index, &police_hash_info);
167 if (pc != NULL) {
168 a->priv = pc;
169 police = to_police(pc);
170 if (bind) {
171 police->tcf_bindcnt += 1;
172 police->tcf_refcnt += 1;
173 }
174 if (ovr)
175 goto override;
176 return ret;
177 }
178 }
179
180 police = kzalloc(sizeof(*police), GFP_KERNEL);
181 if (police == NULL)
182 return -ENOMEM;
183 ret = ACT_P_CREATED;
184 police->tcf_refcnt = 1;
185 spin_lock_init(&police->tcf_lock);
186 if (bind)
187 police->tcf_bindcnt = 1;
188 override:
189 if (parm->rate.rate) {
190 err = -ENOMEM;
191 R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE]);
192 if (R_tab == NULL)
193 goto failure;
194
195 if (parm->peakrate.rate) {
196 P_tab = qdisc_get_rtab(&parm->peakrate,
197 tb[TCA_POLICE_PEAKRATE]);
198 if (P_tab == NULL)
199 goto failure;
200 }
201 }
202
203 spin_lock_bh(&police->tcf_lock);
204 if (est) {
205 err = gen_replace_estimator(&police->tcf_bstats,
206 &police->tcf_rate_est,
207 &police->tcf_lock, est);
208 if (err)
209 goto failure_unlock;
210 } else if (tb[TCA_POLICE_AVRATE] &&
211 (ret == ACT_P_CREATED ||
212 !gen_estimator_active(&police->tcf_bstats,
213 &police->tcf_rate_est))) {
214 err = -EINVAL;
215 goto failure_unlock;
216 }
217
218 /* No failure allowed after this point */
219 if (R_tab != NULL) {
220 qdisc_put_rtab(police->tcfp_R_tab);
221 police->tcfp_R_tab = R_tab;
222 }
223 if (P_tab != NULL) {
224 qdisc_put_rtab(police->tcfp_P_tab);
225 police->tcfp_P_tab = P_tab;
226 }
227
228 if (tb[TCA_POLICE_RESULT])
229 police->tcfp_result = nla_get_u32(tb[TCA_POLICE_RESULT]);
230 police->tcfp_toks = police->tcfp_burst = parm->burst;
231 police->tcfp_mtu = parm->mtu;
232 if (police->tcfp_mtu == 0) {
233 police->tcfp_mtu = ~0;
234 if (police->tcfp_R_tab)
235 police->tcfp_mtu = 255<<police->tcfp_R_tab->rate.cell_log;
236 }
237 if (police->tcfp_P_tab)
238 police->tcfp_ptoks = L2T_P(police, police->tcfp_mtu);
239 police->tcf_action = parm->action;
240
241 if (tb[TCA_POLICE_AVRATE])
242 police->tcfp_ewma_rate = nla_get_u32(tb[TCA_POLICE_AVRATE]);
243
244 spin_unlock_bh(&police->tcf_lock);
245 if (ret != ACT_P_CREATED)
246 return ret;
247
248 police->tcfp_t_c = psched_get_time();
249 police->tcf_index = parm->index ? parm->index :
250 tcf_hash_new_index(&police_idx_gen, &police_hash_info);
251 h = tcf_hash(police->tcf_index, POL_TAB_MASK);
252 write_lock_bh(&police_lock);
253 police->tcf_next = tcf_police_ht[h];
254 tcf_police_ht[h] = &police->common;
255 write_unlock_bh(&police_lock);
256
257 a->priv = police;
258 return ret;
259
260 failure_unlock:
261 spin_unlock_bh(&police->tcf_lock);
262 failure:
263 if (P_tab)
264 qdisc_put_rtab(P_tab);
265 if (R_tab)
266 qdisc_put_rtab(R_tab);
267 if (ret == ACT_P_CREATED)
268 kfree(police);
269 return err;
270 }
271
272 static int tcf_act_police_cleanup(struct tc_action *a, int bind)
273 {
274 struct tcf_police *p = a->priv;
275 int ret = 0;
276
277 if (p != NULL) {
278 if (bind)
279 p->tcf_bindcnt--;
280
281 p->tcf_refcnt--;
282 if (p->tcf_refcnt <= 0 && !p->tcf_bindcnt) {
283 tcf_police_destroy(p);
284 ret = 1;
285 }
286 }
287 return ret;
288 }
289
290 static int tcf_act_police(struct sk_buff *skb, struct tc_action *a,
291 struct tcf_result *res)
292 {
293 struct tcf_police *police = a->priv;
294 psched_time_t now;
295 long toks;
296 long ptoks = 0;
297
298 spin_lock(&police->tcf_lock);
299
300 bstats_update(&police->tcf_bstats, skb);
301
302 if (police->tcfp_ewma_rate &&
303 police->tcf_rate_est.bps >= police->tcfp_ewma_rate) {
304 police->tcf_qstats.overlimits++;
305 if (police->tcf_action == TC_ACT_SHOT)
306 police->tcf_qstats.drops++;
307 spin_unlock(&police->tcf_lock);
308 return police->tcf_action;
309 }
310
311 if (qdisc_pkt_len(skb) <= police->tcfp_mtu) {
312 if (police->tcfp_R_tab == NULL) {
313 spin_unlock(&police->tcf_lock);
314 return police->tcfp_result;
315 }
316
317 now = psched_get_time();
318 toks = psched_tdiff_bounded(now, police->tcfp_t_c,
319 police->tcfp_burst);
320 if (police->tcfp_P_tab) {
321 ptoks = toks + police->tcfp_ptoks;
322 if (ptoks > (long)L2T_P(police, police->tcfp_mtu))
323 ptoks = (long)L2T_P(police, police->tcfp_mtu);
324 ptoks -= L2T_P(police, qdisc_pkt_len(skb));
325 }
326 toks += police->tcfp_toks;
327 if (toks > (long)police->tcfp_burst)
328 toks = police->tcfp_burst;
329 toks -= L2T(police, qdisc_pkt_len(skb));
330 if ((toks|ptoks) >= 0) {
331 police->tcfp_t_c = now;
332 police->tcfp_toks = toks;
333 police->tcfp_ptoks = ptoks;
334 spin_unlock(&police->tcf_lock);
335 return police->tcfp_result;
336 }
337 }
338
339 police->tcf_qstats.overlimits++;
340 if (police->tcf_action == TC_ACT_SHOT)
341 police->tcf_qstats.drops++;
342 spin_unlock(&police->tcf_lock);
343 return police->tcf_action;
344 }
345
346 static int
347 tcf_act_police_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
348 {
349 unsigned char *b = skb_tail_pointer(skb);
350 struct tcf_police *police = a->priv;
351 struct tc_police opt = {
352 .index = police->tcf_index,
353 .action = police->tcf_action,
354 .mtu = police->tcfp_mtu,
355 .burst = police->tcfp_burst,
356 .refcnt = police->tcf_refcnt - ref,
357 .bindcnt = police->tcf_bindcnt - bind,
358 };
359
360 if (police->tcfp_R_tab)
361 opt.rate = police->tcfp_R_tab->rate;
362 if (police->tcfp_P_tab)
363 opt.peakrate = police->tcfp_P_tab->rate;
364 NLA_PUT(skb, TCA_POLICE_TBF, sizeof(opt), &opt);
365 if (police->tcfp_result)
366 NLA_PUT_U32(skb, TCA_POLICE_RESULT, police->tcfp_result);
367 if (police->tcfp_ewma_rate)
368 NLA_PUT_U32(skb, TCA_POLICE_AVRATE, police->tcfp_ewma_rate);
369 return skb->len;
370
371 nla_put_failure:
372 nlmsg_trim(skb, b);
373 return -1;
374 }
375
376 MODULE_AUTHOR("Alexey Kuznetsov");
377 MODULE_DESCRIPTION("Policing actions");
378 MODULE_LICENSE("GPL");
379
380 static struct tc_action_ops act_police_ops = {
381 .kind = "police",
382 .hinfo = &police_hash_info,
383 .type = TCA_ID_POLICE,
384 .capab = TCA_CAP_NONE,
385 .owner = THIS_MODULE,
386 .act = tcf_act_police,
387 .dump = tcf_act_police_dump,
388 .cleanup = tcf_act_police_cleanup,
389 .lookup = tcf_hash_search,
390 .init = tcf_act_police_locate,
391 .walk = tcf_act_police_walker
392 };
393
394 static int __init
395 police_init_module(void)
396 {
397 return tcf_register_action(&act_police_ops);
398 }
399
400 static void __exit
401 police_cleanup_module(void)
402 {
403 tcf_unregister_action(&act_police_ops);
404 rcu_barrier(); /* Wait for completion of call_rcu()'s (tcf_police_free_rcu) */
405 }
406
407 module_init(police_init_module);
408 module_exit(police_cleanup_module);
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