[NET_SCHED]: Convert packet schedulers from rtnetlink to new netlink API
[linux-3.10.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 <net/act_api.h>
22 #include <net/netlink.h>
23
24 #define L2T(p,L)   qdisc_l2t((p)->tcfp_R_tab, L)
25 #define L2T_P(p,L) qdisc_l2t((p)->tcfp_P_tab, L)
26
27 #define POL_TAB_MASK     15
28 static struct tcf_common *tcf_police_ht[POL_TAB_MASK + 1];
29 static u32 police_idx_gen;
30 static DEFINE_RWLOCK(police_lock);
31
32 static struct tcf_hashinfo police_hash_info = {
33         .htab   =       tcf_police_ht,
34         .hmask  =       POL_TAB_MASK,
35         .lock   =       &police_lock,
36 };
37
38 /* old policer structure from before tc actions */
39 struct tc_police_compat
40 {
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 rtattr *r;
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                         r = (struct rtattr *)skb_tail_pointer(skb);
73                         RTA_PUT(skb, a->order, 0, NULL);
74                         if (type == RTM_DELACTION)
75                                 err = tcf_action_dump_1(skb, a, 0, 1);
76                         else
77                                 err = tcf_action_dump_1(skb, a, 0, 0);
78                         if (err < 0) {
79                                 index--;
80                                 nlmsg_trim(skb, r);
81                                 goto done;
82                         }
83                         r->rta_len = skb_tail_pointer(skb) - (u8 *)r;
84                         n_i++;
85                 }
86         }
87 done:
88         read_unlock_bh(&police_lock);
89         if (n_i)
90                 cb->args[0] += n_i;
91         return n_i;
92
93 rtattr_failure:
94         nlmsg_trim(skb, r);
95         goto done;
96 }
97
98 static void tcf_police_destroy(struct tcf_police *p)
99 {
100         unsigned int h = tcf_hash(p->tcf_index, POL_TAB_MASK);
101         struct tcf_common **p1p;
102
103         for (p1p = &tcf_police_ht[h]; *p1p; p1p = &(*p1p)->tcfc_next) {
104                 if (*p1p == &p->common) {
105                         write_lock_bh(&police_lock);
106                         *p1p = p->tcf_next;
107                         write_unlock_bh(&police_lock);
108                         gen_kill_estimator(&p->tcf_bstats,
109                                            &p->tcf_rate_est);
110                         if (p->tcfp_R_tab)
111                                 qdisc_put_rtab(p->tcfp_R_tab);
112                         if (p->tcfp_P_tab)
113                                 qdisc_put_rtab(p->tcfp_P_tab);
114                         kfree(p);
115                         return;
116                 }
117         }
118         BUG_TRAP(0);
119 }
120
121 static int tcf_act_police_locate(struct rtattr *rta, struct rtattr *est,
122                                  struct tc_action *a, int ovr, int bind)
123 {
124         unsigned h;
125         int ret = 0, err;
126         struct rtattr *tb[TCA_POLICE_MAX];
127         struct tc_police *parm;
128         struct tcf_police *police;
129         struct qdisc_rate_table *R_tab = NULL, *P_tab = NULL;
130         int size;
131
132         if (rta == NULL || rtattr_parse_nested(tb, TCA_POLICE_MAX, rta) < 0)
133                 return -EINVAL;
134
135         if (tb[TCA_POLICE_TBF-1] == NULL)
136                 return -EINVAL;
137         size = RTA_PAYLOAD(tb[TCA_POLICE_TBF-1]);
138         if (size != sizeof(*parm) && size != sizeof(struct tc_police_compat))
139                 return -EINVAL;
140         parm = RTA_DATA(tb[TCA_POLICE_TBF-1]);
141
142         if (tb[TCA_POLICE_RESULT-1] != NULL &&
143             RTA_PAYLOAD(tb[TCA_POLICE_RESULT-1]) != sizeof(u32))
144                 return -EINVAL;
145         if (tb[TCA_POLICE_RESULT-1] != NULL &&
146             RTA_PAYLOAD(tb[TCA_POLICE_RESULT-1]) != sizeof(u32))
147                 return -EINVAL;
148
149         if (parm->index) {
150                 struct tcf_common *pc;
151
152                 pc = tcf_hash_lookup(parm->index, &police_hash_info);
153                 if (pc != NULL) {
154                         a->priv = pc;
155                         police = to_police(pc);
156                         if (bind) {
157                                 police->tcf_bindcnt += 1;
158                                 police->tcf_refcnt += 1;
159                         }
160                         if (ovr)
161                                 goto override;
162                         return ret;
163                 }
164         }
165
166         police = kzalloc(sizeof(*police), GFP_KERNEL);
167         if (police == NULL)
168                 return -ENOMEM;
169         ret = ACT_P_CREATED;
170         police->tcf_refcnt = 1;
171         spin_lock_init(&police->tcf_lock);
172         if (bind)
173                 police->tcf_bindcnt = 1;
174 override:
175         if (parm->rate.rate) {
176                 err = -ENOMEM;
177                 R_tab = qdisc_get_rtab(&parm->rate, (struct nlattr *)tb[TCA_POLICE_RATE-1]);
178                 if (R_tab == NULL)
179                         goto failure;
180                 if (parm->peakrate.rate) {
181                         P_tab = qdisc_get_rtab(&parm->peakrate,
182                                                (struct nlattr *)tb[TCA_POLICE_PEAKRATE-1]);
183                         if (P_tab == NULL) {
184                                 qdisc_put_rtab(R_tab);
185                                 goto failure;
186                         }
187                 }
188         }
189         /* No failure allowed after this point */
190         spin_lock_bh(&police->tcf_lock);
191         if (R_tab != NULL) {
192                 qdisc_put_rtab(police->tcfp_R_tab);
193                 police->tcfp_R_tab = R_tab;
194         }
195         if (P_tab != NULL) {
196                 qdisc_put_rtab(police->tcfp_P_tab);
197                 police->tcfp_P_tab = P_tab;
198         }
199
200         if (tb[TCA_POLICE_RESULT-1])
201                 police->tcfp_result = *(u32*)RTA_DATA(tb[TCA_POLICE_RESULT-1]);
202         police->tcfp_toks = police->tcfp_burst = parm->burst;
203         police->tcfp_mtu = parm->mtu;
204         if (police->tcfp_mtu == 0) {
205                 police->tcfp_mtu = ~0;
206                 if (police->tcfp_R_tab)
207                         police->tcfp_mtu = 255<<police->tcfp_R_tab->rate.cell_log;
208         }
209         if (police->tcfp_P_tab)
210                 police->tcfp_ptoks = L2T_P(police, police->tcfp_mtu);
211         police->tcf_action = parm->action;
212
213         if (tb[TCA_POLICE_AVRATE-1])
214                 police->tcfp_ewma_rate =
215                         *(u32*)RTA_DATA(tb[TCA_POLICE_AVRATE-1]);
216         if (est)
217                 gen_replace_estimator(&police->tcf_bstats,
218                                       &police->tcf_rate_est,
219                                       &police->tcf_lock, (struct nlattr *)est);
220
221         spin_unlock_bh(&police->tcf_lock);
222         if (ret != ACT_P_CREATED)
223                 return ret;
224
225         police->tcfp_t_c = psched_get_time();
226         police->tcf_index = parm->index ? parm->index :
227                 tcf_hash_new_index(&police_idx_gen, &police_hash_info);
228         h = tcf_hash(police->tcf_index, POL_TAB_MASK);
229         write_lock_bh(&police_lock);
230         police->tcf_next = tcf_police_ht[h];
231         tcf_police_ht[h] = &police->common;
232         write_unlock_bh(&police_lock);
233
234         a->priv = police;
235         return ret;
236
237 failure:
238         if (ret == ACT_P_CREATED)
239                 kfree(police);
240         return err;
241 }
242
243 static int tcf_act_police_cleanup(struct tc_action *a, int bind)
244 {
245         struct tcf_police *p = a->priv;
246         int ret = 0;
247
248         if (p != NULL) {
249                 if (bind)
250                         p->tcf_bindcnt--;
251
252                 p->tcf_refcnt--;
253                 if (p->tcf_refcnt <= 0 && !p->tcf_bindcnt) {
254                         tcf_police_destroy(p);
255                         ret = 1;
256                 }
257         }
258         return ret;
259 }
260
261 static int tcf_act_police(struct sk_buff *skb, struct tc_action *a,
262                           struct tcf_result *res)
263 {
264         struct tcf_police *police = a->priv;
265         psched_time_t now;
266         long toks;
267         long ptoks = 0;
268
269         spin_lock(&police->tcf_lock);
270
271         police->tcf_bstats.bytes += skb->len;
272         police->tcf_bstats.packets++;
273
274         if (police->tcfp_ewma_rate &&
275             police->tcf_rate_est.bps >= police->tcfp_ewma_rate) {
276                 police->tcf_qstats.overlimits++;
277                 spin_unlock(&police->tcf_lock);
278                 return police->tcf_action;
279         }
280
281         if (skb->len <= police->tcfp_mtu) {
282                 if (police->tcfp_R_tab == NULL) {
283                         spin_unlock(&police->tcf_lock);
284                         return police->tcfp_result;
285                 }
286
287                 now = psched_get_time();
288                 toks = psched_tdiff_bounded(now, police->tcfp_t_c,
289                                             police->tcfp_burst);
290                 if (police->tcfp_P_tab) {
291                         ptoks = toks + police->tcfp_ptoks;
292                         if (ptoks > (long)L2T_P(police, police->tcfp_mtu))
293                                 ptoks = (long)L2T_P(police, police->tcfp_mtu);
294                         ptoks -= L2T_P(police, skb->len);
295                 }
296                 toks += police->tcfp_toks;
297                 if (toks > (long)police->tcfp_burst)
298                         toks = police->tcfp_burst;
299                 toks -= L2T(police, skb->len);
300                 if ((toks|ptoks) >= 0) {
301                         police->tcfp_t_c = now;
302                         police->tcfp_toks = toks;
303                         police->tcfp_ptoks = ptoks;
304                         spin_unlock(&police->tcf_lock);
305                         return police->tcfp_result;
306                 }
307         }
308
309         police->tcf_qstats.overlimits++;
310         spin_unlock(&police->tcf_lock);
311         return police->tcf_action;
312 }
313
314 static int
315 tcf_act_police_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
316 {
317         unsigned char *b = skb_tail_pointer(skb);
318         struct tcf_police *police = a->priv;
319         struct tc_police opt;
320
321         opt.index = police->tcf_index;
322         opt.action = police->tcf_action;
323         opt.mtu = police->tcfp_mtu;
324         opt.burst = police->tcfp_burst;
325         opt.refcnt = police->tcf_refcnt - ref;
326         opt.bindcnt = police->tcf_bindcnt - bind;
327         if (police->tcfp_R_tab)
328                 opt.rate = police->tcfp_R_tab->rate;
329         else
330                 memset(&opt.rate, 0, sizeof(opt.rate));
331         if (police->tcfp_P_tab)
332                 opt.peakrate = police->tcfp_P_tab->rate;
333         else
334                 memset(&opt.peakrate, 0, sizeof(opt.peakrate));
335         RTA_PUT(skb, TCA_POLICE_TBF, sizeof(opt), &opt);
336         if (police->tcfp_result)
337                 RTA_PUT(skb, TCA_POLICE_RESULT, sizeof(int),
338                         &police->tcfp_result);
339         if (police->tcfp_ewma_rate)
340                 RTA_PUT(skb, TCA_POLICE_AVRATE, 4, &police->tcfp_ewma_rate);
341         return skb->len;
342
343 rtattr_failure:
344         nlmsg_trim(skb, b);
345         return -1;
346 }
347
348 MODULE_AUTHOR("Alexey Kuznetsov");
349 MODULE_DESCRIPTION("Policing actions");
350 MODULE_LICENSE("GPL");
351
352 static struct tc_action_ops act_police_ops = {
353         .kind           =       "police",
354         .hinfo          =       &police_hash_info,
355         .type           =       TCA_ID_POLICE,
356         .capab          =       TCA_CAP_NONE,
357         .owner          =       THIS_MODULE,
358         .act            =       tcf_act_police,
359         .dump           =       tcf_act_police_dump,
360         .cleanup        =       tcf_act_police_cleanup,
361         .lookup         =       tcf_hash_search,
362         .init           =       tcf_act_police_locate,
363         .walk           =       tcf_act_police_walker
364 };
365
366 static int __init
367 police_init_module(void)
368 {
369         return tcf_register_action(&act_police_ops);
370 }
371
372 static void __exit
373 police_cleanup_module(void)
374 {
375         tcf_unregister_action(&act_police_ops);
376 }
377
378 module_init(police_init_module);
379 module_exit(police_cleanup_module);