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writeback: split writeback_inodes_wb
[linux-2.6/next.git] / net / sched / act_police.c
blob654f73dff7c1c8d7f9d5fb6541174299c4b32f05
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_destroy(struct tcf_police *p)
101 {
102 unsigned int h = tcf_hash(p->tcf_index, POL_TAB_MASK);
103 struct tcf_common **p1p;
104
105 for (p1p = &tcf_police_ht[h]; *p1p; p1p = &(*p1p)->tcfc_next) {
106 if (*p1p == &p->common) {
107 write_lock_bh(&police_lock);
108 *p1p = p->tcf_next;
109 write_unlock_bh(&police_lock);
110 gen_kill_estimator(&p->tcf_bstats,
111 &p->tcf_rate_est);
112 if (p->tcfp_R_tab)
113 qdisc_put_rtab(p->tcfp_R_tab);
114 if (p->tcfp_P_tab)
115 qdisc_put_rtab(p->tcfp_P_tab);
116 kfree(p);
117 return;
118 }
119 }
120 WARN_ON(1);
121 }
122
123 static const struct nla_policy police_policy[TCA_POLICE_MAX + 1] = {
124 [TCA_POLICE_RATE] = { .len = TC_RTAB_SIZE },
125 [TCA_POLICE_PEAKRATE] = { .len = TC_RTAB_SIZE },
126 [TCA_POLICE_AVRATE] = { .type = NLA_U32 },
127 [TCA_POLICE_RESULT] = { .type = NLA_U32 },
128 };
129
130 static int tcf_act_police_locate(struct nlattr *nla, struct nlattr *est,
131 struct tc_action *a, int ovr, int bind)
132 {
133 unsigned h;
134 int ret = 0, err;
135 struct nlattr *tb[TCA_POLICE_MAX + 1];
136 struct tc_police *parm;
137 struct tcf_police *police;
138 struct qdisc_rate_table *R_tab = NULL, *P_tab = NULL;
139 int size;
140
141 if (nla == NULL)
142 return -EINVAL;
143
144 err = nla_parse_nested(tb, TCA_POLICE_MAX, nla, police_policy);
145 if (err < 0)
146 return err;
147
148 if (tb[TCA_POLICE_TBF] == NULL)
149 return -EINVAL;
150 size = nla_len(tb[TCA_POLICE_TBF]);
151 if (size != sizeof(*parm) && size != sizeof(struct tc_police_compat))
152 return -EINVAL;
153 parm = nla_data(tb[TCA_POLICE_TBF]);
154
155 if (parm->index) {
156 struct tcf_common *pc;
157
158 pc = tcf_hash_lookup(parm->index, &police_hash_info);
159 if (pc != NULL) {
160 a->priv = pc;
161 police = to_police(pc);
162 if (bind) {
163 police->tcf_bindcnt += 1;
164 police->tcf_refcnt += 1;
165 }
166 if (ovr)
167 goto override;
168 return ret;
169 }
170 }
171
172 police = kzalloc(sizeof(*police), GFP_KERNEL);
173 if (police == NULL)
174 return -ENOMEM;
175 ret = ACT_P_CREATED;
176 police->tcf_refcnt = 1;
177 spin_lock_init(&police->tcf_lock);
178 if (bind)
179 police->tcf_bindcnt = 1;
180 override:
181 if (parm->rate.rate) {
182 err = -ENOMEM;
183 R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE]);
184 if (R_tab == NULL)
185 goto failure;
186
187 if (parm->peakrate.rate) {
188 P_tab = qdisc_get_rtab(&parm->peakrate,
189 tb[TCA_POLICE_PEAKRATE]);
190 if (P_tab == NULL)
191 goto failure;
192 }
193 }
194
195 spin_lock_bh(&police->tcf_lock);
196 if (est) {
197 err = gen_replace_estimator(&police->tcf_bstats,
198 &police->tcf_rate_est,
199 &police->tcf_lock, est);
200 if (err)
201 goto failure_unlock;
202 } else if (tb[TCA_POLICE_AVRATE] &&
203 (ret == ACT_P_CREATED ||
204 !gen_estimator_active(&police->tcf_bstats,
205 &police->tcf_rate_est))) {
206 err = -EINVAL;
207 goto failure_unlock;
208 }
209
210 /* No failure allowed after this point */
211 if (R_tab != NULL) {
212 qdisc_put_rtab(police->tcfp_R_tab);
213 police->tcfp_R_tab = R_tab;
214 }
215 if (P_tab != NULL) {
216 qdisc_put_rtab(police->tcfp_P_tab);
217 police->tcfp_P_tab = P_tab;
218 }
219
220 if (tb[TCA_POLICE_RESULT])
221 police->tcfp_result = nla_get_u32(tb[TCA_POLICE_RESULT]);
222 police->tcfp_toks = police->tcfp_burst = parm->burst;
223 police->tcfp_mtu = parm->mtu;
224 if (police->tcfp_mtu == 0) {
225 police->tcfp_mtu = ~0;
226 if (police->tcfp_R_tab)
227 police->tcfp_mtu = 255<<police->tcfp_R_tab->rate.cell_log;
228 }
229 if (police->tcfp_P_tab)
230 police->tcfp_ptoks = L2T_P(police, police->tcfp_mtu);
231 police->tcf_action = parm->action;
232
233 if (tb[TCA_POLICE_AVRATE])
234 police->tcfp_ewma_rate = nla_get_u32(tb[TCA_POLICE_AVRATE]);
235
236 spin_unlock_bh(&police->tcf_lock);
237 if (ret != ACT_P_CREATED)
238 return ret;
239
240 police->tcfp_t_c = psched_get_time();
241 police->tcf_index = parm->index ? parm->index :
242 tcf_hash_new_index(&police_idx_gen, &police_hash_info);
243 h = tcf_hash(police->tcf_index, POL_TAB_MASK);
244 write_lock_bh(&police_lock);
245 police->tcf_next = tcf_police_ht[h];
246 tcf_police_ht[h] = &police->common;
247 write_unlock_bh(&police_lock);
248
249 a->priv = police;
250 return ret;
251
252 failure_unlock:
253 spin_unlock_bh(&police->tcf_lock);
254 failure:
255 if (P_tab)
256 qdisc_put_rtab(P_tab);
257 if (R_tab)
258 qdisc_put_rtab(R_tab);
259 if (ret == ACT_P_CREATED)
260 kfree(police);
261 return err;
262 }
263
264 static int tcf_act_police_cleanup(struct tc_action *a, int bind)
265 {
266 struct tcf_police *p = a->priv;
267 int ret = 0;
268
269 if (p != NULL) {
270 if (bind)
271 p->tcf_bindcnt--;
272
273 p->tcf_refcnt--;
274 if (p->tcf_refcnt <= 0 && !p->tcf_bindcnt) {
275 tcf_police_destroy(p);
276 ret = 1;
277 }
278 }
279 return ret;
280 }
281
282 static int tcf_act_police(struct sk_buff *skb, struct tc_action *a,
283 struct tcf_result *res)
284 {
285 struct tcf_police *police = a->priv;
286 psched_time_t now;
287 long toks;
288 long ptoks = 0;
289
290 spin_lock(&police->tcf_lock);
291
292 police->tcf_bstats.bytes += qdisc_pkt_len(skb);
293 police->tcf_bstats.packets++;
294
295 if (police->tcfp_ewma_rate &&
296 police->tcf_rate_est.bps >= police->tcfp_ewma_rate) {
297 police->tcf_qstats.overlimits++;
298 if (police->tcf_action == TC_ACT_SHOT)
299 police->tcf_qstats.drops++;
300 spin_unlock(&police->tcf_lock);
301 return police->tcf_action;
302 }
303
304 if (qdisc_pkt_len(skb) <= police->tcfp_mtu) {
305 if (police->tcfp_R_tab == NULL) {
306 spin_unlock(&police->tcf_lock);
307 return police->tcfp_result;
308 }
309
310 now = psched_get_time();
311 toks = psched_tdiff_bounded(now, police->tcfp_t_c,
312 police->tcfp_burst);
313 if (police->tcfp_P_tab) {
314 ptoks = toks + police->tcfp_ptoks;
315 if (ptoks > (long)L2T_P(police, police->tcfp_mtu))
316 ptoks = (long)L2T_P(police, police->tcfp_mtu);
317 ptoks -= L2T_P(police, qdisc_pkt_len(skb));
318 }
319 toks += police->tcfp_toks;
320 if (toks > (long)police->tcfp_burst)
321 toks = police->tcfp_burst;
322 toks -= L2T(police, qdisc_pkt_len(skb));
323 if ((toks|ptoks) >= 0) {
324 police->tcfp_t_c = now;
325 police->tcfp_toks = toks;
326 police->tcfp_ptoks = ptoks;
327 spin_unlock(&police->tcf_lock);
328 return police->tcfp_result;
329 }
330 }
331
332 police->tcf_qstats.overlimits++;
333 if (police->tcf_action == TC_ACT_SHOT)
334 police->tcf_qstats.drops++;
335 spin_unlock(&police->tcf_lock);
336 return police->tcf_action;
337 }
338
339 static int
340 tcf_act_police_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
341 {
342 unsigned char *b = skb_tail_pointer(skb);
343 struct tcf_police *police = a->priv;
344 struct tc_police opt;
345
346 opt.index = police->tcf_index;
347 opt.action = police->tcf_action;
348 opt.mtu = police->tcfp_mtu;
349 opt.burst = police->tcfp_burst;
350 opt.refcnt = police->tcf_refcnt - ref;
351 opt.bindcnt = police->tcf_bindcnt - bind;
352 if (police->tcfp_R_tab)
353 opt.rate = police->tcfp_R_tab->rate;
354 else
355 memset(&opt.rate, 0, sizeof(opt.rate));
356 if (police->tcfp_P_tab)
357 opt.peakrate = police->tcfp_P_tab->rate;
358 else
359 memset(&opt.peakrate, 0, sizeof(opt.peakrate));
360 NLA_PUT(skb, TCA_POLICE_TBF, sizeof(opt), &opt);
361 if (police->tcfp_result)
362 NLA_PUT_U32(skb, TCA_POLICE_RESULT, police->tcfp_result);
363 if (police->tcfp_ewma_rate)
364 NLA_PUT_U32(skb, TCA_POLICE_AVRATE, police->tcfp_ewma_rate);
365 return skb->len;
366
367 nla_put_failure:
368 nlmsg_trim(skb, b);
369 return -1;
370 }
371
372 MODULE_AUTHOR("Alexey Kuznetsov");
373 MODULE_DESCRIPTION("Policing actions");
374 MODULE_LICENSE("GPL");
375
376 static struct tc_action_ops act_police_ops = {
377 .kind = "police",
378 .hinfo = &police_hash_info,
379 .type = TCA_ID_POLICE,
380 .capab = TCA_CAP_NONE,
381 .owner = THIS_MODULE,
382 .act = tcf_act_police,
383 .dump = tcf_act_police_dump,
384 .cleanup = tcf_act_police_cleanup,
385 .lookup = tcf_hash_search,
386 .init = tcf_act_police_locate,
387 .walk = tcf_act_police_walker
388 };
389
390 static int __init
391 police_init_module(void)
392 {
393 return tcf_register_action(&act_police_ops);
394 }
395
396 static void __exit
397 police_cleanup_module(void)
398 {
399 tcf_unregister_action(&act_police_ops);
400 }
401
402 module_init(police_init_module);
403 module_exit(police_cleanup_module);
linux-next