ipv6: fix bad free of addrconf_init_net
[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         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         NLA_PUT(skb, TCA_POLICE_TBF, sizeof(opt), &opt);
360         if (police->tcfp_result)
361                 NLA_PUT_U32(skb, TCA_POLICE_RESULT, police->tcfp_result);
362         if (police->tcfp_ewma_rate)
363                 NLA_PUT_U32(skb, TCA_POLICE_AVRATE, police->tcfp_ewma_rate);
364         return skb->len;
365
366 nla_put_failure:
367         nlmsg_trim(skb, b);
368         return -1;
369 }
370
371 MODULE_AUTHOR("Alexey Kuznetsov");
372 MODULE_DESCRIPTION("Policing actions");
373 MODULE_LICENSE("GPL");
374
375 static struct tc_action_ops act_police_ops = {
376         .kind           =       "police",
377         .hinfo          =       &police_hash_info,
378         .type           =       TCA_ID_POLICE,
379         .capab          =       TCA_CAP_NONE,
380         .owner          =       THIS_MODULE,
381         .act            =       tcf_act_police,
382         .dump           =       tcf_act_police_dump,
383         .cleanup        =       tcf_act_police_cleanup,
384         .lookup         =       tcf_hash_search,
385         .init           =       tcf_act_police_locate,
386         .walk           =       tcf_act_police_walker
387 };
388
389 static int __init
390 police_init_module(void)
391 {
392         return tcf_register_action(&act_police_ops);
393 }
394
395 static void __exit
396 police_cleanup_module(void)
397 {
398         tcf_unregister_action(&act_police_ops);
399 }
400
401 module_init(police_init_module);
402 module_exit(police_cleanup_module);