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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
25struct 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
44struct 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
55
56static unsigned int police_net_id;
57static struct tc_action_ops act_police_ops;
58
59static 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
69static 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
76static 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 int size;
89
90 if (nla == NULL)
91 return -EINVAL;
92
93 err = nla_parse_nested(tb, TCA_POLICE_MAX, nla, police_policy, NULL);
94 if (err < 0)
95 return err;
96
97 if (tb[TCA_POLICE_TBF] == NULL)
98 return -EINVAL;
99 size = nla_len(tb[TCA_POLICE_TBF]);
100 if (size != sizeof(*parm) && size != sizeof(struct tc_police_compat))
101 return -EINVAL;
102
103 parm = nla_data(tb[TCA_POLICE_TBF]);
104 err = tcf_idr_check_alloc(tn, &parm->index, a, bind);
105 if (err < 0)
106 return err;
107 exists = err;
108 if (exists && bind)
109 return 0;
110
111 if (!exists) {
112 ret = tcf_idr_create(tn, parm->index, NULL, a,
113 &act_police_ops, bind, false);
114 if (ret) {
115 tcf_idr_cleanup(tn, parm->index);
116 return ret;
117 }
118 ret = ACT_P_CREATED;
119 } else if (!ovr) {
120 tcf_idr_release(*a, bind);
121 return -EEXIST;
122 }
123
124 police = to_police(*a);
125 if (parm->rate.rate) {
126 err = -ENOMEM;
127 R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE], NULL);
128 if (R_tab == NULL)
129 goto failure;
130
131 if (parm->peakrate.rate) {
132 P_tab = qdisc_get_rtab(&parm->peakrate,
133 tb[TCA_POLICE_PEAKRATE], NULL);
134 if (P_tab == NULL)
135 goto failure;
136 }
137 }
138
139 if (est) {
140 err = gen_replace_estimator(&police->tcf_bstats, NULL,
141 &police->tcf_rate_est,
142 &police->tcf_lock,
143 NULL, est);
144 if (err)
145 goto failure;
146 } else if (tb[TCA_POLICE_AVRATE] &&
147 (ret == ACT_P_CREATED ||
148 !gen_estimator_active(&police->tcf_rate_est))) {
149 err = -EINVAL;
150 goto failure;
151 }
152
153 spin_lock_bh(&police->tcf_lock);
154
155 police->tcfp_mtu = parm->mtu;
156 if (police->tcfp_mtu == 0) {
157 police->tcfp_mtu = ~0;
158 if (R_tab)
159 police->tcfp_mtu = 255 << R_tab->rate.cell_log;
160 }
161 if (R_tab) {
162 police->rate_present = true;
163 psched_ratecfg_precompute(&police->rate, &R_tab->rate, 0);
164 qdisc_put_rtab(R_tab);
165 } else {
166 police->rate_present = false;
167 }
168 if (P_tab) {
169 police->peak_present = true;
170 psched_ratecfg_precompute(&police->peak, &P_tab->rate, 0);
171 qdisc_put_rtab(P_tab);
172 } else {
173 police->peak_present = false;
174 }
175
176 if (tb[TCA_POLICE_RESULT])
177 police->tcfp_result = nla_get_u32(tb[TCA_POLICE_RESULT]);
178 police->tcfp_burst = PSCHED_TICKS2NS(parm->burst);
179 police->tcfp_toks = police->tcfp_burst;
180 if (police->peak_present) {
181 police->tcfp_mtu_ptoks = (s64) psched_l2t_ns(&police->peak,
182 police->tcfp_mtu);
183 police->tcfp_ptoks = police->tcfp_mtu_ptoks;
184 }
185 police->tcf_action = parm->action;
186
187 if (tb[TCA_POLICE_AVRATE])
188 police->tcfp_ewma_rate = nla_get_u32(tb[TCA_POLICE_AVRATE]);
189
190 spin_unlock_bh(&police->tcf_lock);
191 if (ret != ACT_P_CREATED)
192 return ret;
193
194 police->tcfp_t_c = ktime_get_ns();
195 tcf_idr_insert(tn, *a);
196
197 return ret;
198
199failure:
200 qdisc_put_rtab(P_tab);
201 qdisc_put_rtab(R_tab);
202 tcf_idr_release(*a, bind);
203 return err;
204}
205
206static int tcf_police_act(struct sk_buff *skb, const struct tc_action *a,
207 struct tcf_result *res)
208{
209 struct tcf_police *police = to_police(a);
210 s64 now;
211 s64 toks;
212 s64 ptoks = 0;
213
214 spin_lock(&police->tcf_lock);
215
216 bstats_update(&police->tcf_bstats, skb);
217 tcf_lastuse_update(&police->tcf_tm);
218
219 if (police->tcfp_ewma_rate) {
220 struct gnet_stats_rate_est64 sample;
221
222 if (!gen_estimator_read(&police->tcf_rate_est, &sample) ||
223 sample.bps >= police->tcfp_ewma_rate) {
224 police->tcf_qstats.overlimits++;
225 if (police->tcf_action == TC_ACT_SHOT)
226 police->tcf_qstats.drops++;
227 spin_unlock(&police->tcf_lock);
228 return police->tcf_action;
229 }
230 }
231
232 if (qdisc_pkt_len(skb) <= police->tcfp_mtu) {
233 if (!police->rate_present) {
234 spin_unlock(&police->tcf_lock);
235 return police->tcfp_result;
236 }
237
238 now = ktime_get_ns();
239 toks = min_t(s64, now - police->tcfp_t_c,
240 police->tcfp_burst);
241 if (police->peak_present) {
242 ptoks = toks + police->tcfp_ptoks;
243 if (ptoks > police->tcfp_mtu_ptoks)
244 ptoks = police->tcfp_mtu_ptoks;
245 ptoks -= (s64) psched_l2t_ns(&police->peak,
246 qdisc_pkt_len(skb));
247 }
248 toks += police->tcfp_toks;
249 if (toks > police->tcfp_burst)
250 toks = police->tcfp_burst;
251 toks -= (s64) psched_l2t_ns(&police->rate, qdisc_pkt_len(skb));
252 if ((toks|ptoks) >= 0) {
253 police->tcfp_t_c = now;
254 police->tcfp_toks = toks;
255 police->tcfp_ptoks = ptoks;
256 if (police->tcfp_result == TC_ACT_SHOT)
257 police->tcf_qstats.drops++;
258 spin_unlock(&police->tcf_lock);
259 return police->tcfp_result;
260 }
261 }
262
263 police->tcf_qstats.overlimits++;
264 if (police->tcf_action == TC_ACT_SHOT)
265 police->tcf_qstats.drops++;
266 spin_unlock(&police->tcf_lock);
267 return police->tcf_action;
268}
269
270static int tcf_police_dump(struct sk_buff *skb, struct tc_action *a,
271 int bind, int ref)
272{
273 unsigned char *b = skb_tail_pointer(skb);
274 struct tcf_police *police = to_police(a);
275 struct tc_police opt = {
276 .index = police->tcf_index,
277 .refcnt = refcount_read(&police->tcf_refcnt) - ref,
278 .bindcnt = atomic_read(&police->tcf_bindcnt) - bind,
279 };
280 struct tcf_t t;
281
282 spin_lock_bh(&police->tcf_lock);
283 opt.action = police->tcf_action;
284 opt.mtu = police->tcfp_mtu;
285 opt.burst = PSCHED_NS2TICKS(police->tcfp_burst);
286 if (police->rate_present)
287 psched_ratecfg_getrate(&opt.rate, &police->rate);
288 if (police->peak_present)
289 psched_ratecfg_getrate(&opt.peakrate, &police->peak);
290 if (nla_put(skb, TCA_POLICE_TBF, sizeof(opt), &opt))
291 goto nla_put_failure;
292 if (police->tcfp_result &&
293 nla_put_u32(skb, TCA_POLICE_RESULT, police->tcfp_result))
294 goto nla_put_failure;
295 if (police->tcfp_ewma_rate &&
296 nla_put_u32(skb, TCA_POLICE_AVRATE, police->tcfp_ewma_rate))
297 goto nla_put_failure;
298
299 t.install = jiffies_to_clock_t(jiffies - police->tcf_tm.install);
300 t.lastuse = jiffies_to_clock_t(jiffies - police->tcf_tm.lastuse);
301 t.firstuse = jiffies_to_clock_t(jiffies - police->tcf_tm.firstuse);
302 t.expires = jiffies_to_clock_t(police->tcf_tm.expires);
303 if (nla_put_64bit(skb, TCA_POLICE_TM, sizeof(t), &t, TCA_POLICE_PAD))
304 goto nla_put_failure;
305 spin_unlock_bh(&police->tcf_lock);
306
307 return skb->len;
308
309nla_put_failure:
310 spin_unlock_bh(&police->tcf_lock);
311 nlmsg_trim(skb, b);
312 return -1;
313}
314
315static int tcf_police_search(struct net *net, struct tc_action **a, u32 index,
316 struct netlink_ext_ack *extack)
317{
318 struct tc_action_net *tn = net_generic(net, police_net_id);
319
320 return tcf_idr_search(tn, a, index);
321}
322
323MODULE_AUTHOR("Alexey Kuznetsov");
324MODULE_DESCRIPTION("Policing actions");
325MODULE_LICENSE("GPL");
326
327static struct tc_action_ops act_police_ops = {
328 .kind = "police",
329 .type = TCA_ID_POLICE,
330 .owner = THIS_MODULE,
331 .act = tcf_police_act,
332 .dump = tcf_police_dump,
333 .init = tcf_police_init,
334 .walk = tcf_police_walker,
335 .lookup = tcf_police_search,
336 .size = sizeof(struct tcf_police),
337};
338
339static __net_init int police_init_net(struct net *net)
340{
341 struct tc_action_net *tn = net_generic(net, police_net_id);
342
343 return tc_action_net_init(tn, &act_police_ops);
344}
345
346static void __net_exit police_exit_net(struct list_head *net_list)
347{
348 tc_action_net_exit(net_list, police_net_id);
349}
350
351static struct pernet_operations police_net_ops = {
352 .init = police_init_net,
353 .exit_batch = police_exit_net,
354 .id = &police_net_id,
355 .size = sizeof(struct tc_action_net),
356};
357
358static int __init police_init_module(void)
359{
360 return tcf_register_action(&act_police_ops, &police_net_ops);
361}
362
363static void __exit police_cleanup_module(void)
364{
365 tcf_unregister_action(&act_police_ops, &police_net_ops);
366}
367
368module_init(police_init_module);
369module_exit(police_cleanup_module);
370