Merge branches 'upstream-fixes', 'bkl-removal', 'debugfs-fixes' and 'hid-suspend...
[pandora-kernel.git] / net / sched / act_police.c
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);