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Memoryless nodes: Generic management of nodemasks for various purposes
[linux-2.6/mini2440.git] / net / sched / act_police.c
bloba73e3e6d87ea378f3f72b36b69d3ca3266061949
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 <net/act_api.h>
22 #include <net/netlink.h>
23
24 #define L2T(p,L) qdisc_l2t((p)->tcfp_R_tab, L)
25 #define L2T_P(p,L) qdisc_l2t((p)->tcfp_P_tab, L)
26
27 #define POL_TAB_MASK 15
28 static struct tcf_common *tcf_police_ht[POL_TAB_MASK + 1];
29 static u32 police_idx_gen;
30 static DEFINE_RWLOCK(police_lock);
31
32 static struct tcf_hashinfo police_hash_info = {
33 .htab = tcf_police_ht,
34 .hmask = POL_TAB_MASK,
35 .lock = &police_lock,
36 };
37
38 /* old policer structure from before tc actions */
39 struct tc_police_compat
40 {
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 rtattr *r;
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 r = (struct rtattr *)skb_tail_pointer(skb);
73 RTA_PUT(skb, a->order, 0, NULL);
74 if (type == RTM_DELACTION)
75 err = tcf_action_dump_1(skb, a, 0, 1);
76 else
77 err = tcf_action_dump_1(skb, a, 0, 0);
78 if (err < 0) {
79 index--;
80 nlmsg_trim(skb, r);
81 goto done;
82 }
83 r->rta_len = skb_tail_pointer(skb) - (u8 *)r;
84 n_i++;
85 }
86 }
87 done:
88 read_unlock_bh(&police_lock);
89 if (n_i)
90 cb->args[0] += n_i;
91 return n_i;
92
93 rtattr_failure:
94 nlmsg_trim(skb, r);
95 goto done;
96 }
97
98 static void tcf_police_destroy(struct tcf_police *p)
99 {
100 unsigned int h = tcf_hash(p->tcf_index, POL_TAB_MASK);
101 struct tcf_common **p1p;
102
103 for (p1p = &tcf_police_ht[h]; *p1p; p1p = &(*p1p)->tcfc_next) {
104 if (*p1p == &p->common) {
105 write_lock_bh(&police_lock);
106 *p1p = p->tcf_next;
107 write_unlock_bh(&police_lock);
108 gen_kill_estimator(&p->tcf_bstats,
109 &p->tcf_rate_est);
110 if (p->tcfp_R_tab)
111 qdisc_put_rtab(p->tcfp_R_tab);
112 if (p->tcfp_P_tab)
113 qdisc_put_rtab(p->tcfp_P_tab);
114 kfree(p);
115 return;
116 }
117 }
118 BUG_TRAP(0);
119 }
120
121 static int tcf_act_police_locate(struct rtattr *rta, struct rtattr *est,
122 struct tc_action *a, int ovr, int bind)
123 {
124 unsigned h;
125 int ret = 0, err;
126 struct rtattr *tb[TCA_POLICE_MAX];
127 struct tc_police *parm;
128 struct tcf_police *police;
129 struct qdisc_rate_table *R_tab = NULL, *P_tab = NULL;
130 int size;
131
132 if (rta == NULL || rtattr_parse_nested(tb, TCA_POLICE_MAX, rta) < 0)
133 return -EINVAL;
134
135 if (tb[TCA_POLICE_TBF-1] == NULL)
136 return -EINVAL;
137 size = RTA_PAYLOAD(tb[TCA_POLICE_TBF-1]);
138 if (size != sizeof(*parm) && size != sizeof(struct tc_police_compat))
139 return -EINVAL;
140 parm = RTA_DATA(tb[TCA_POLICE_TBF-1]);
141
142 if (tb[TCA_POLICE_RESULT-1] != NULL &&
143 RTA_PAYLOAD(tb[TCA_POLICE_RESULT-1]) != sizeof(u32))
144 return -EINVAL;
145 if (tb[TCA_POLICE_RESULT-1] != NULL &&
146 RTA_PAYLOAD(tb[TCA_POLICE_RESULT-1]) != sizeof(u32))
147 return -EINVAL;
148
149 if (parm->index) {
150 struct tcf_common *pc;
151
152 pc = tcf_hash_lookup(parm->index, &police_hash_info);
153 if (pc != NULL) {
154 a->priv = pc;
155 police = to_police(pc);
156 if (bind) {
157 police->tcf_bindcnt += 1;
158 police->tcf_refcnt += 1;
159 }
160 if (ovr)
161 goto override;
162 return ret;
163 }
164 }
165
166 police = kzalloc(sizeof(*police), GFP_KERNEL);
167 if (police == NULL)
168 return -ENOMEM;
169 ret = ACT_P_CREATED;
170 police->tcf_refcnt = 1;
171 spin_lock_init(&police->tcf_lock);
172 if (bind)
173 police->tcf_bindcnt = 1;
174 override:
175 if (parm->rate.rate) {
176 err = -ENOMEM;
177 R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE-1]);
178 if (R_tab == NULL)
179 goto failure;
180 if (parm->peakrate.rate) {
181 P_tab = qdisc_get_rtab(&parm->peakrate,
182 tb[TCA_POLICE_PEAKRATE-1]);
183 if (P_tab == NULL) {
184 qdisc_put_rtab(R_tab);
185 goto failure;
186 }
187 }
188 }
189 /* No failure allowed after this point */
190 spin_lock_bh(&police->tcf_lock);
191 if (R_tab != NULL) {
192 qdisc_put_rtab(police->tcfp_R_tab);
193 police->tcfp_R_tab = R_tab;
194 }
195 if (P_tab != NULL) {
196 qdisc_put_rtab(police->tcfp_P_tab);
197 police->tcfp_P_tab = P_tab;
198 }
199
200 if (tb[TCA_POLICE_RESULT-1])
201 police->tcfp_result = *(u32*)RTA_DATA(tb[TCA_POLICE_RESULT-1]);
202 police->tcfp_toks = police->tcfp_burst = parm->burst;
203 police->tcfp_mtu = parm->mtu;
204 if (police->tcfp_mtu == 0) {
205 police->tcfp_mtu = ~0;
206 if (police->tcfp_R_tab)
207 police->tcfp_mtu = 255<<police->tcfp_R_tab->rate.cell_log;
208 }
209 if (police->tcfp_P_tab)
210 police->tcfp_ptoks = L2T_P(police, police->tcfp_mtu);
211 police->tcf_action = parm->action;
212
213 if (tb[TCA_POLICE_AVRATE-1])
214 police->tcfp_ewma_rate =
215 *(u32*)RTA_DATA(tb[TCA_POLICE_AVRATE-1]);
216 if (est)
217 gen_replace_estimator(&police->tcf_bstats,
218 &police->tcf_rate_est,
219 &police->tcf_lock, est);
220
221 spin_unlock_bh(&police->tcf_lock);
222 if (ret != ACT_P_CREATED)
223 return ret;
224
225 police->tcfp_t_c = psched_get_time();
226 police->tcf_index = parm->index ? parm->index :
227 tcf_hash_new_index(&police_idx_gen, &police_hash_info);
228 h = tcf_hash(police->tcf_index, POL_TAB_MASK);
229 write_lock_bh(&police_lock);
230 police->tcf_next = tcf_police_ht[h];
231 tcf_police_ht[h] = &police->common;
232 write_unlock_bh(&police_lock);
233
234 a->priv = police;
235 return ret;
236
237 failure:
238 if (ret == ACT_P_CREATED)
239 kfree(police);
240 return err;
241 }
242
243 static int tcf_act_police_cleanup(struct tc_action *a, int bind)
244 {
245 struct tcf_police *p = a->priv;
246 int ret = 0;
247
248 if (p != NULL) {
249 if (bind)
250 p->tcf_bindcnt--;
251
252 p->tcf_refcnt--;
253 if (p->tcf_refcnt <= 0 && !p->tcf_bindcnt) {
254 tcf_police_destroy(p);
255 ret = 1;
256 }
257 }
258 return ret;
259 }
260
261 static int tcf_act_police(struct sk_buff *skb, struct tc_action *a,
262 struct tcf_result *res)
263 {
264 struct tcf_police *police = a->priv;
265 psched_time_t now;
266 long toks;
267 long ptoks = 0;
268
269 spin_lock(&police->tcf_lock);
270
271 police->tcf_bstats.bytes += skb->len;
272 police->tcf_bstats.packets++;
273
274 if (police->tcfp_ewma_rate &&
275 police->tcf_rate_est.bps >= police->tcfp_ewma_rate) {
276 police->tcf_qstats.overlimits++;
277 spin_unlock(&police->tcf_lock);
278 return police->tcf_action;
279 }
280
281 if (skb->len <= police->tcfp_mtu) {
282 if (police->tcfp_R_tab == NULL) {
283 spin_unlock(&police->tcf_lock);
284 return police->tcfp_result;
285 }
286
287 now = psched_get_time();
288 toks = psched_tdiff_bounded(now, police->tcfp_t_c,
289 police->tcfp_burst);
290 if (police->tcfp_P_tab) {
291 ptoks = toks + police->tcfp_ptoks;
292 if (ptoks > (long)L2T_P(police, police->tcfp_mtu))
293 ptoks = (long)L2T_P(police, police->tcfp_mtu);
294 ptoks -= L2T_P(police, skb->len);
295 }
296 toks += police->tcfp_toks;
297 if (toks > (long)police->tcfp_burst)
298 toks = police->tcfp_burst;
299 toks -= L2T(police, skb->len);
300 if ((toks|ptoks) >= 0) {
301 police->tcfp_t_c = now;
302 police->tcfp_toks = toks;
303 police->tcfp_ptoks = ptoks;
304 spin_unlock(&police->tcf_lock);
305 return police->tcfp_result;
306 }
307 }
308
309 police->tcf_qstats.overlimits++;
310 spin_unlock(&police->tcf_lock);
311 return police->tcf_action;
312 }
313
314 static int
315 tcf_act_police_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
316 {
317 unsigned char *b = skb_tail_pointer(skb);
318 struct tcf_police *police = a->priv;
319 struct tc_police opt;
320
321 opt.index = police->tcf_index;
322 opt.action = police->tcf_action;
323 opt.mtu = police->tcfp_mtu;
324 opt.burst = police->tcfp_burst;
325 opt.refcnt = police->tcf_refcnt - ref;
326 opt.bindcnt = police->tcf_bindcnt - bind;
327 if (police->tcfp_R_tab)
328 opt.rate = police->tcfp_R_tab->rate;
329 else
330 memset(&opt.rate, 0, sizeof(opt.rate));
331 if (police->tcfp_P_tab)
332 opt.peakrate = police->tcfp_P_tab->rate;
333 else
334 memset(&opt.peakrate, 0, sizeof(opt.peakrate));
335 RTA_PUT(skb, TCA_POLICE_TBF, sizeof(opt), &opt);
336 if (police->tcfp_result)
337 RTA_PUT(skb, TCA_POLICE_RESULT, sizeof(int),
338 &police->tcfp_result);
339 if (police->tcfp_ewma_rate)
340 RTA_PUT(skb, TCA_POLICE_AVRATE, 4, &police->tcfp_ewma_rate);
341 return skb->len;
342
343 rtattr_failure:
344 nlmsg_trim(skb, b);
345 return -1;
346 }
347
348 MODULE_AUTHOR("Alexey Kuznetsov");
349 MODULE_DESCRIPTION("Policing actions");
350 MODULE_LICENSE("GPL");
351
352 static struct tc_action_ops act_police_ops = {
353 .kind = "police",
354 .hinfo = &police_hash_info,
355 .type = TCA_ID_POLICE,
356 .capab = TCA_CAP_NONE,
357 .owner = THIS_MODULE,
358 .act = tcf_act_police,
359 .dump = tcf_act_police_dump,
360 .cleanup = tcf_act_police_cleanup,
361 .lookup = tcf_hash_search,
362 .init = tcf_act_police_locate,
363 .walk = tcf_act_police_walker
364 };
365
366 static int __init
367 police_init_module(void)
368 {
369 return tcf_register_action(&act_police_ops);
370 }
371
372 static void __exit
373 police_cleanup_module(void)
374 {
375 tcf_unregister_action(&act_police_ops);
376 }
377
378 module_init(police_init_module);
379 module_exit(police_cleanup_module);
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