GNU Linux-libre 4.19.211-gnu1
[releases.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 {
26         struct tc_action        common;
27         int                     tcfp_result;
28         u32                     tcfp_ewma_rate;
29         s64                     tcfp_burst;
30         u32                     tcfp_mtu;
31         s64                     tcfp_toks;
32         s64                     tcfp_ptoks;
33         s64                     tcfp_mtu_ptoks;
34         s64                     tcfp_t_c;
35         struct psched_ratecfg   rate;
36         bool                    rate_present;
37         struct psched_ratecfg   peak;
38         bool                    peak_present;
39 };
40
41 #define to_police(pc) ((struct tcf_police *)pc)
42
43 /* old policer structure from before tc actions */
44 struct tc_police_compat {
45         u32                     index;
46         int                     action;
47         u32                     limit;
48         u32                     burst;
49         u32                     mtu;
50         struct tc_ratespec      rate;
51         struct tc_ratespec      peakrate;
52 };
53
54 /* Each policer is serialized by its individual spinlock */
55
56 static unsigned int police_net_id;
57 static struct tc_action_ops act_police_ops;
58
59 static int tcf_police_walker(struct net *net, struct sk_buff *skb,
60                                  struct netlink_callback *cb, int type,
61                                  const struct tc_action_ops *ops,
62                                  struct netlink_ext_ack *extack)
63 {
64         struct tc_action_net *tn = net_generic(net, police_net_id);
65
66         return tcf_generic_walker(tn, skb, cb, type, ops, extack);
67 }
68
69 static const struct nla_policy police_policy[TCA_POLICE_MAX + 1] = {
70         [TCA_POLICE_RATE]       = { .len = TC_RTAB_SIZE },
71         [TCA_POLICE_PEAKRATE]   = { .len = TC_RTAB_SIZE },
72         [TCA_POLICE_AVRATE]     = { .type = NLA_U32 },
73         [TCA_POLICE_RESULT]     = { .type = NLA_U32 },
74 };
75
76 static int tcf_police_init(struct net *net, struct nlattr *nla,
77                                struct nlattr *est, struct tc_action **a,
78                                int ovr, int bind, bool rtnl_held,
79                                struct netlink_ext_ack *extack)
80 {
81         int ret = 0, err;
82         struct nlattr *tb[TCA_POLICE_MAX + 1];
83         struct tc_police *parm;
84         struct tcf_police *police;
85         struct qdisc_rate_table *R_tab = NULL, *P_tab = NULL;
86         struct tc_action_net *tn = net_generic(net, police_net_id);
87         bool exists = false;
88         u32 index;
89         int size;
90
91         if (nla == NULL)
92                 return -EINVAL;
93
94         err = nla_parse_nested(tb, TCA_POLICE_MAX, nla, police_policy, NULL);
95         if (err < 0)
96                 return err;
97
98         if (tb[TCA_POLICE_TBF] == NULL)
99                 return -EINVAL;
100         size = nla_len(tb[TCA_POLICE_TBF]);
101         if (size != sizeof(*parm) && size != sizeof(struct tc_police_compat))
102                 return -EINVAL;
103
104         parm = nla_data(tb[TCA_POLICE_TBF]);
105         index = parm->index;
106         err = tcf_idr_check_alloc(tn, &index, a, bind);
107         if (err < 0)
108                 return err;
109         exists = err;
110         if (exists && bind)
111                 return 0;
112
113         if (!exists) {
114                 ret = tcf_idr_create(tn, index, NULL, a,
115                                      &act_police_ops, bind, false);
116                 if (ret) {
117                         tcf_idr_cleanup(tn, index);
118                         return ret;
119                 }
120                 ret = ACT_P_CREATED;
121         } else if (!ovr) {
122                 tcf_idr_release(*a, bind);
123                 return -EEXIST;
124         }
125
126         police = to_police(*a);
127         if (parm->rate.rate) {
128                 err = -ENOMEM;
129                 R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE], NULL);
130                 if (R_tab == NULL)
131                         goto failure;
132
133                 if (parm->peakrate.rate) {
134                         P_tab = qdisc_get_rtab(&parm->peakrate,
135                                                tb[TCA_POLICE_PEAKRATE], NULL);
136                         if (P_tab == NULL)
137                                 goto failure;
138                 }
139         }
140
141         if (est) {
142                 err = gen_replace_estimator(&police->tcf_bstats, NULL,
143                                             &police->tcf_rate_est,
144                                             &police->tcf_lock,
145                                             NULL, est);
146                 if (err)
147                         goto failure;
148         } else if (tb[TCA_POLICE_AVRATE] &&
149                    (ret == ACT_P_CREATED ||
150                     !gen_estimator_active(&police->tcf_rate_est))) {
151                 err = -EINVAL;
152                 goto failure;
153         }
154
155         spin_lock_bh(&police->tcf_lock);
156         /* No failure allowed after this point */
157         police->tcfp_mtu = parm->mtu;
158         if (police->tcfp_mtu == 0) {
159                 police->tcfp_mtu = ~0;
160                 if (R_tab)
161                         police->tcfp_mtu = 255 << R_tab->rate.cell_log;
162         }
163         if (R_tab) {
164                 police->rate_present = true;
165                 psched_ratecfg_precompute(&police->rate, &R_tab->rate, 0);
166                 qdisc_put_rtab(R_tab);
167         } else {
168                 police->rate_present = false;
169         }
170         if (P_tab) {
171                 police->peak_present = true;
172                 psched_ratecfg_precompute(&police->peak, &P_tab->rate, 0);
173                 qdisc_put_rtab(P_tab);
174         } else {
175                 police->peak_present = false;
176         }
177
178         if (tb[TCA_POLICE_RESULT])
179                 police->tcfp_result = nla_get_u32(tb[TCA_POLICE_RESULT]);
180         police->tcfp_burst = PSCHED_TICKS2NS(parm->burst);
181         police->tcfp_toks = police->tcfp_burst;
182         if (police->peak_present) {
183                 police->tcfp_mtu_ptoks = (s64) psched_l2t_ns(&police->peak,
184                                                              police->tcfp_mtu);
185                 police->tcfp_ptoks = police->tcfp_mtu_ptoks;
186         }
187         police->tcf_action = parm->action;
188
189         if (tb[TCA_POLICE_AVRATE])
190                 police->tcfp_ewma_rate = nla_get_u32(tb[TCA_POLICE_AVRATE]);
191
192         spin_unlock_bh(&police->tcf_lock);
193         if (ret != ACT_P_CREATED)
194                 return ret;
195
196         police->tcfp_t_c = ktime_get_ns();
197         tcf_idr_insert(tn, *a);
198
199         return ret;
200
201 failure:
202         qdisc_put_rtab(P_tab);
203         qdisc_put_rtab(R_tab);
204         tcf_idr_release(*a, bind);
205         return err;
206 }
207
208 static int tcf_police_act(struct sk_buff *skb, const struct tc_action *a,
209                           struct tcf_result *res)
210 {
211         struct tcf_police *police = to_police(a);
212         s64 now;
213         s64 toks;
214         s64 ptoks = 0;
215
216         spin_lock(&police->tcf_lock);
217
218         bstats_update(&police->tcf_bstats, skb);
219         tcf_lastuse_update(&police->tcf_tm);
220
221         if (police->tcfp_ewma_rate) {
222                 struct gnet_stats_rate_est64 sample;
223
224                 if (!gen_estimator_read(&police->tcf_rate_est, &sample) ||
225                     sample.bps >= police->tcfp_ewma_rate) {
226                         police->tcf_qstats.overlimits++;
227                         if (police->tcf_action == TC_ACT_SHOT)
228                                 police->tcf_qstats.drops++;
229                         spin_unlock(&police->tcf_lock);
230                         return police->tcf_action;
231                 }
232         }
233
234         if (qdisc_pkt_len(skb) <= police->tcfp_mtu) {
235                 if (!police->rate_present) {
236                         spin_unlock(&police->tcf_lock);
237                         return police->tcfp_result;
238                 }
239
240                 now = ktime_get_ns();
241                 toks = min_t(s64, now - police->tcfp_t_c,
242                              police->tcfp_burst);
243                 if (police->peak_present) {
244                         ptoks = toks + police->tcfp_ptoks;
245                         if (ptoks > police->tcfp_mtu_ptoks)
246                                 ptoks = police->tcfp_mtu_ptoks;
247                         ptoks -= (s64) psched_l2t_ns(&police->peak,
248                                                      qdisc_pkt_len(skb));
249                 }
250                 toks += police->tcfp_toks;
251                 if (toks > police->tcfp_burst)
252                         toks = police->tcfp_burst;
253                 toks -= (s64) psched_l2t_ns(&police->rate, qdisc_pkt_len(skb));
254                 if ((toks|ptoks) >= 0) {
255                         police->tcfp_t_c = now;
256                         police->tcfp_toks = toks;
257                         police->tcfp_ptoks = ptoks;
258                         if (police->tcfp_result == TC_ACT_SHOT)
259                                 police->tcf_qstats.drops++;
260                         spin_unlock(&police->tcf_lock);
261                         return police->tcfp_result;
262                 }
263         }
264
265         police->tcf_qstats.overlimits++;
266         if (police->tcf_action == TC_ACT_SHOT)
267                 police->tcf_qstats.drops++;
268         spin_unlock(&police->tcf_lock);
269         return police->tcf_action;
270 }
271
272 static int tcf_police_dump(struct sk_buff *skb, struct tc_action *a,
273                                int bind, int ref)
274 {
275         unsigned char *b = skb_tail_pointer(skb);
276         struct tcf_police *police = to_police(a);
277         struct tc_police opt = {
278                 .index = police->tcf_index,
279                 .refcnt = refcount_read(&police->tcf_refcnt) - ref,
280                 .bindcnt = atomic_read(&police->tcf_bindcnt) - bind,
281         };
282         struct tcf_t t;
283
284         spin_lock_bh(&police->tcf_lock);
285         opt.action = police->tcf_action;
286         opt.mtu = police->tcfp_mtu;
287         opt.burst = PSCHED_NS2TICKS(police->tcfp_burst);
288         if (police->rate_present)
289                 psched_ratecfg_getrate(&opt.rate, &police->rate);
290         if (police->peak_present)
291                 psched_ratecfg_getrate(&opt.peakrate, &police->peak);
292         if (nla_put(skb, TCA_POLICE_TBF, sizeof(opt), &opt))
293                 goto nla_put_failure;
294         if (police->tcfp_result &&
295             nla_put_u32(skb, TCA_POLICE_RESULT, police->tcfp_result))
296                 goto nla_put_failure;
297         if (police->tcfp_ewma_rate &&
298             nla_put_u32(skb, TCA_POLICE_AVRATE, police->tcfp_ewma_rate))
299                 goto nla_put_failure;
300
301         t.install = jiffies_to_clock_t(jiffies - police->tcf_tm.install);
302         t.lastuse = jiffies_to_clock_t(jiffies - police->tcf_tm.lastuse);
303         t.firstuse = jiffies_to_clock_t(jiffies - police->tcf_tm.firstuse);
304         t.expires = jiffies_to_clock_t(police->tcf_tm.expires);
305         if (nla_put_64bit(skb, TCA_POLICE_TM, sizeof(t), &t, TCA_POLICE_PAD))
306                 goto nla_put_failure;
307         spin_unlock_bh(&police->tcf_lock);
308
309         return skb->len;
310
311 nla_put_failure:
312         spin_unlock_bh(&police->tcf_lock);
313         nlmsg_trim(skb, b);
314         return -1;
315 }
316
317 static int tcf_police_search(struct net *net, struct tc_action **a, u32 index,
318                              struct netlink_ext_ack *extack)
319 {
320         struct tc_action_net *tn = net_generic(net, police_net_id);
321
322         return tcf_idr_search(tn, a, index);
323 }
324
325 MODULE_AUTHOR("Alexey Kuznetsov");
326 MODULE_DESCRIPTION("Policing actions");
327 MODULE_LICENSE("GPL");
328
329 static struct tc_action_ops act_police_ops = {
330         .kind           =       "police",
331         .type           =       TCA_ID_POLICE,
332         .owner          =       THIS_MODULE,
333         .act            =       tcf_police_act,
334         .dump           =       tcf_police_dump,
335         .init           =       tcf_police_init,
336         .walk           =       tcf_police_walker,
337         .lookup         =       tcf_police_search,
338         .size           =       sizeof(struct tcf_police),
339 };
340
341 static __net_init int police_init_net(struct net *net)
342 {
343         struct tc_action_net *tn = net_generic(net, police_net_id);
344
345         return tc_action_net_init(net, tn, &act_police_ops);
346 }
347
348 static void __net_exit police_exit_net(struct list_head *net_list)
349 {
350         tc_action_net_exit(net_list, police_net_id);
351 }
352
353 static struct pernet_operations police_net_ops = {
354         .init = police_init_net,
355         .exit_batch = police_exit_net,
356         .id   = &police_net_id,
357         .size = sizeof(struct tc_action_net),
358 };
359
360 static int __init police_init_module(void)
361 {
362         return tcf_register_action(&act_police_ops, &police_net_ops);
363 }
364
365 static void __exit police_cleanup_module(void)
366 {
367         tcf_unregister_action(&act_police_ops, &police_net_ops);
368 }
369
370 module_init(police_init_module);
371 module_exit(police_cleanup_module);