net/sched: act_police: add missing spinlock initialization
[sfrench/cifs-2.6.git] / net / sched / act_police.c
1 /*
2  * net/sched/act_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 struct tcf_police_params {
26         int                     tcfp_result;
27         u32                     tcfp_ewma_rate;
28         s64                     tcfp_burst;
29         u32                     tcfp_mtu;
30         s64                     tcfp_mtu_ptoks;
31         struct psched_ratecfg   rate;
32         bool                    rate_present;
33         struct psched_ratecfg   peak;
34         bool                    peak_present;
35         struct rcu_head rcu;
36 };
37
38 struct tcf_police {
39         struct tc_action        common;
40         struct tcf_police_params __rcu *params;
41
42         spinlock_t              tcfp_lock ____cacheline_aligned_in_smp;
43         s64                     tcfp_toks;
44         s64                     tcfp_ptoks;
45         s64                     tcfp_t_c;
46 };
47
48 #define to_police(pc) ((struct tcf_police *)pc)
49
50 /* old policer structure from before tc actions */
51 struct tc_police_compat {
52         u32                     index;
53         int                     action;
54         u32                     limit;
55         u32                     burst;
56         u32                     mtu;
57         struct tc_ratespec      rate;
58         struct tc_ratespec      peakrate;
59 };
60
61 /* Each policer is serialized by its individual spinlock */
62
63 static unsigned int police_net_id;
64 static struct tc_action_ops act_police_ops;
65
66 static int tcf_police_walker(struct net *net, struct sk_buff *skb,
67                                  struct netlink_callback *cb, int type,
68                                  const struct tc_action_ops *ops,
69                                  struct netlink_ext_ack *extack)
70 {
71         struct tc_action_net *tn = net_generic(net, police_net_id);
72
73         return tcf_generic_walker(tn, skb, cb, type, ops, extack);
74 }
75
76 static const struct nla_policy police_policy[TCA_POLICE_MAX + 1] = {
77         [TCA_POLICE_RATE]       = { .len = TC_RTAB_SIZE },
78         [TCA_POLICE_PEAKRATE]   = { .len = TC_RTAB_SIZE },
79         [TCA_POLICE_AVRATE]     = { .type = NLA_U32 },
80         [TCA_POLICE_RESULT]     = { .type = NLA_U32 },
81 };
82
83 static int tcf_police_init(struct net *net, struct nlattr *nla,
84                                struct nlattr *est, struct tc_action **a,
85                                int ovr, int bind, bool rtnl_held,
86                                struct netlink_ext_ack *extack)
87 {
88         int ret = 0, err;
89         struct nlattr *tb[TCA_POLICE_MAX + 1];
90         struct tc_police *parm;
91         struct tcf_police *police;
92         struct qdisc_rate_table *R_tab = NULL, *P_tab = NULL;
93         struct tc_action_net *tn = net_generic(net, police_net_id);
94         struct tcf_police_params *new;
95         bool exists = false;
96         int size;
97
98         if (nla == NULL)
99                 return -EINVAL;
100
101         err = nla_parse_nested(tb, TCA_POLICE_MAX, nla, police_policy, NULL);
102         if (err < 0)
103                 return err;
104
105         if (tb[TCA_POLICE_TBF] == NULL)
106                 return -EINVAL;
107         size = nla_len(tb[TCA_POLICE_TBF]);
108         if (size != sizeof(*parm) && size != sizeof(struct tc_police_compat))
109                 return -EINVAL;
110
111         parm = nla_data(tb[TCA_POLICE_TBF]);
112         err = tcf_idr_check_alloc(tn, &parm->index, a, bind);
113         if (err < 0)
114                 return err;
115         exists = err;
116         if (exists && bind)
117                 return 0;
118
119         if (!exists) {
120                 ret = tcf_idr_create(tn, parm->index, NULL, a,
121                                      &act_police_ops, bind, true);
122                 if (ret) {
123                         tcf_idr_cleanup(tn, parm->index);
124                         return ret;
125                 }
126                 ret = ACT_P_CREATED;
127                 spin_lock_init(&(to_police(*a)->tcfp_lock));
128         } else if (!ovr) {
129                 tcf_idr_release(*a, bind);
130                 return -EEXIST;
131         }
132
133         police = to_police(*a);
134         if (parm->rate.rate) {
135                 err = -ENOMEM;
136                 R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE], NULL);
137                 if (R_tab == NULL)
138                         goto failure;
139
140                 if (parm->peakrate.rate) {
141                         P_tab = qdisc_get_rtab(&parm->peakrate,
142                                                tb[TCA_POLICE_PEAKRATE], NULL);
143                         if (P_tab == NULL)
144                                 goto failure;
145                 }
146         }
147
148         if (est) {
149                 err = gen_replace_estimator(&police->tcf_bstats,
150                                             police->common.cpu_bstats,
151                                             &police->tcf_rate_est,
152                                             &police->tcf_lock,
153                                             NULL, est);
154                 if (err)
155                         goto failure;
156         } else if (tb[TCA_POLICE_AVRATE] &&
157                    (ret == ACT_P_CREATED ||
158                     !gen_estimator_active(&police->tcf_rate_est))) {
159                 err = -EINVAL;
160                 goto failure;
161         }
162
163         new = kzalloc(sizeof(*new), GFP_KERNEL);
164         if (unlikely(!new)) {
165                 err = -ENOMEM;
166                 goto failure;
167         }
168
169         /* No failure allowed after this point */
170         new->tcfp_mtu = parm->mtu;
171         if (!new->tcfp_mtu) {
172                 new->tcfp_mtu = ~0;
173                 if (R_tab)
174                         new->tcfp_mtu = 255 << R_tab->rate.cell_log;
175         }
176         if (R_tab) {
177                 new->rate_present = true;
178                 psched_ratecfg_precompute(&new->rate, &R_tab->rate, 0);
179                 qdisc_put_rtab(R_tab);
180         } else {
181                 new->rate_present = false;
182         }
183         if (P_tab) {
184                 new->peak_present = true;
185                 psched_ratecfg_precompute(&new->peak, &P_tab->rate, 0);
186                 qdisc_put_rtab(P_tab);
187         } else {
188                 new->peak_present = false;
189         }
190
191         new->tcfp_burst = PSCHED_TICKS2NS(parm->burst);
192         if (new->peak_present)
193                 new->tcfp_mtu_ptoks = (s64)psched_l2t_ns(&new->peak,
194                                                          new->tcfp_mtu);
195
196         if (tb[TCA_POLICE_AVRATE])
197                 new->tcfp_ewma_rate = nla_get_u32(tb[TCA_POLICE_AVRATE]);
198
199         if (tb[TCA_POLICE_RESULT]) {
200                 new->tcfp_result = nla_get_u32(tb[TCA_POLICE_RESULT]);
201                 if (TC_ACT_EXT_CMP(new->tcfp_result, TC_ACT_GOTO_CHAIN)) {
202                         NL_SET_ERR_MSG(extack,
203                                        "goto chain not allowed on fallback");
204                         err = -EINVAL;
205                         goto failure;
206                 }
207         }
208
209         spin_lock_bh(&police->tcf_lock);
210         spin_lock_bh(&police->tcfp_lock);
211         police->tcfp_t_c = ktime_get_ns();
212         police->tcfp_toks = new->tcfp_burst;
213         if (new->peak_present)
214                 police->tcfp_ptoks = new->tcfp_mtu_ptoks;
215         spin_unlock_bh(&police->tcfp_lock);
216         police->tcf_action = parm->action;
217         rcu_swap_protected(police->params,
218                            new,
219                            lockdep_is_held(&police->tcf_lock));
220         spin_unlock_bh(&police->tcf_lock);
221
222         if (new)
223                 kfree_rcu(new, rcu);
224
225         if (ret == ACT_P_CREATED)
226                 tcf_idr_insert(tn, *a);
227         return ret;
228
229 failure:
230         qdisc_put_rtab(P_tab);
231         qdisc_put_rtab(R_tab);
232         tcf_idr_release(*a, bind);
233         return err;
234 }
235
236 static int tcf_police_act(struct sk_buff *skb, const struct tc_action *a,
237                           struct tcf_result *res)
238 {
239         struct tcf_police *police = to_police(a);
240         struct tcf_police_params *p;
241         s64 now, toks, ptoks = 0;
242         int ret;
243
244         tcf_lastuse_update(&police->tcf_tm);
245         bstats_cpu_update(this_cpu_ptr(police->common.cpu_bstats), skb);
246
247         ret = READ_ONCE(police->tcf_action);
248         p = rcu_dereference_bh(police->params);
249
250         if (p->tcfp_ewma_rate) {
251                 struct gnet_stats_rate_est64 sample;
252
253                 if (!gen_estimator_read(&police->tcf_rate_est, &sample) ||
254                     sample.bps >= p->tcfp_ewma_rate)
255                         goto inc_overlimits;
256         }
257
258         if (qdisc_pkt_len(skb) <= p->tcfp_mtu) {
259                 if (!p->rate_present) {
260                         ret = p->tcfp_result;
261                         goto end;
262                 }
263
264                 now = ktime_get_ns();
265                 spin_lock_bh(&police->tcfp_lock);
266                 toks = min_t(s64, now - police->tcfp_t_c, p->tcfp_burst);
267                 if (p->peak_present) {
268                         ptoks = toks + police->tcfp_ptoks;
269                         if (ptoks > p->tcfp_mtu_ptoks)
270                                 ptoks = p->tcfp_mtu_ptoks;
271                         ptoks -= (s64)psched_l2t_ns(&p->peak,
272                                                     qdisc_pkt_len(skb));
273                 }
274                 toks += police->tcfp_toks;
275                 if (toks > p->tcfp_burst)
276                         toks = p->tcfp_burst;
277                 toks -= (s64)psched_l2t_ns(&p->rate, qdisc_pkt_len(skb));
278                 if ((toks|ptoks) >= 0) {
279                         police->tcfp_t_c = now;
280                         police->tcfp_toks = toks;
281                         police->tcfp_ptoks = ptoks;
282                         spin_unlock_bh(&police->tcfp_lock);
283                         ret = p->tcfp_result;
284                         goto inc_drops;
285                 }
286                 spin_unlock_bh(&police->tcfp_lock);
287         }
288
289 inc_overlimits:
290         qstats_overlimit_inc(this_cpu_ptr(police->common.cpu_qstats));
291 inc_drops:
292         if (ret == TC_ACT_SHOT)
293                 qstats_drop_inc(this_cpu_ptr(police->common.cpu_qstats));
294 end:
295         return ret;
296 }
297
298 static void tcf_police_cleanup(struct tc_action *a)
299 {
300         struct tcf_police *police = to_police(a);
301         struct tcf_police_params *p;
302
303         p = rcu_dereference_protected(police->params, 1);
304         if (p)
305                 kfree_rcu(p, rcu);
306 }
307
308 static int tcf_police_dump(struct sk_buff *skb, struct tc_action *a,
309                                int bind, int ref)
310 {
311         unsigned char *b = skb_tail_pointer(skb);
312         struct tcf_police *police = to_police(a);
313         struct tcf_police_params *p;
314         struct tc_police opt = {
315                 .index = police->tcf_index,
316                 .refcnt = refcount_read(&police->tcf_refcnt) - ref,
317                 .bindcnt = atomic_read(&police->tcf_bindcnt) - bind,
318         };
319         struct tcf_t t;
320
321         spin_lock_bh(&police->tcf_lock);
322         opt.action = police->tcf_action;
323         p = rcu_dereference_protected(police->params,
324                                       lockdep_is_held(&police->tcf_lock));
325         opt.mtu = p->tcfp_mtu;
326         opt.burst = PSCHED_NS2TICKS(p->tcfp_burst);
327         if (p->rate_present)
328                 psched_ratecfg_getrate(&opt.rate, &p->rate);
329         if (p->peak_present)
330                 psched_ratecfg_getrate(&opt.peakrate, &p->peak);
331         if (nla_put(skb, TCA_POLICE_TBF, sizeof(opt), &opt))
332                 goto nla_put_failure;
333         if (p->tcfp_result &&
334             nla_put_u32(skb, TCA_POLICE_RESULT, p->tcfp_result))
335                 goto nla_put_failure;
336         if (p->tcfp_ewma_rate &&
337             nla_put_u32(skb, TCA_POLICE_AVRATE, p->tcfp_ewma_rate))
338                 goto nla_put_failure;
339
340         t.install = jiffies_to_clock_t(jiffies - police->tcf_tm.install);
341         t.lastuse = jiffies_to_clock_t(jiffies - police->tcf_tm.lastuse);
342         t.firstuse = jiffies_to_clock_t(jiffies - police->tcf_tm.firstuse);
343         t.expires = jiffies_to_clock_t(police->tcf_tm.expires);
344         if (nla_put_64bit(skb, TCA_POLICE_TM, sizeof(t), &t, TCA_POLICE_PAD))
345                 goto nla_put_failure;
346         spin_unlock_bh(&police->tcf_lock);
347
348         return skb->len;
349
350 nla_put_failure:
351         spin_unlock_bh(&police->tcf_lock);
352         nlmsg_trim(skb, b);
353         return -1;
354 }
355
356 static int tcf_police_search(struct net *net, struct tc_action **a, u32 index)
357 {
358         struct tc_action_net *tn = net_generic(net, police_net_id);
359
360         return tcf_idr_search(tn, a, index);
361 }
362
363 MODULE_AUTHOR("Alexey Kuznetsov");
364 MODULE_DESCRIPTION("Policing actions");
365 MODULE_LICENSE("GPL");
366
367 static struct tc_action_ops act_police_ops = {
368         .kind           =       "police",
369         .type           =       TCA_ID_POLICE,
370         .owner          =       THIS_MODULE,
371         .act            =       tcf_police_act,
372         .dump           =       tcf_police_dump,
373         .init           =       tcf_police_init,
374         .walk           =       tcf_police_walker,
375         .lookup         =       tcf_police_search,
376         .cleanup        =       tcf_police_cleanup,
377         .size           =       sizeof(struct tcf_police),
378 };
379
380 static __net_init int police_init_net(struct net *net)
381 {
382         struct tc_action_net *tn = net_generic(net, police_net_id);
383
384         return tc_action_net_init(tn, &act_police_ops);
385 }
386
387 static void __net_exit police_exit_net(struct list_head *net_list)
388 {
389         tc_action_net_exit(net_list, police_net_id);
390 }
391
392 static struct pernet_operations police_net_ops = {
393         .init = police_init_net,
394         .exit_batch = police_exit_net,
395         .id   = &police_net_id,
396         .size = sizeof(struct tc_action_net),
397 };
398
399 static int __init police_init_module(void)
400 {
401         return tcf_register_action(&act_police_ops, &police_net_ops);
402 }
403
404 static void __exit police_cleanup_module(void)
405 {
406         tcf_unregister_action(&act_police_ops, &police_net_ops);
407 }
408
409 module_init(police_init_module);
410 module_exit(police_cleanup_module);