[NET_SCHED]: Propagate nla_parse return value
[linux-2.6.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 nlattr *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 nlattr *)skb_tail_pointer(skb);
73                         NLA_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->nla_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 nla_put_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 nlattr *nla, struct nlattr *est,
122                                  struct tc_action *a, int ovr, int bind)
123 {
124         unsigned h;
125         int ret = 0, err;
126         struct nlattr *tb[TCA_POLICE_MAX + 1];
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 (nla == NULL)
133                 return -EINVAL;
134
135         err = nla_parse_nested(tb, TCA_POLICE_MAX, nla, NULL);
136         if (err < 0)
137                 return err;
138
139         if (tb[TCA_POLICE_TBF] == NULL)
140                 return -EINVAL;
141         size = nla_len(tb[TCA_POLICE_TBF]);
142         if (size != sizeof(*parm) && size != sizeof(struct tc_police_compat))
143                 return -EINVAL;
144         parm = nla_data(tb[TCA_POLICE_TBF]);
145
146         if (tb[TCA_POLICE_RESULT] != NULL &&
147             nla_len(tb[TCA_POLICE_RESULT]) != sizeof(u32))
148                 return -EINVAL;
149         if (tb[TCA_POLICE_RESULT] != NULL &&
150             nla_len(tb[TCA_POLICE_RESULT]) != sizeof(u32))
151                 return -EINVAL;
152
153         if (parm->index) {
154                 struct tcf_common *pc;
155
156                 pc = tcf_hash_lookup(parm->index, &police_hash_info);
157                 if (pc != NULL) {
158                         a->priv = pc;
159                         police = to_police(pc);
160                         if (bind) {
161                                 police->tcf_bindcnt += 1;
162                                 police->tcf_refcnt += 1;
163                         }
164                         if (ovr)
165                                 goto override;
166                         return ret;
167                 }
168         }
169
170         police = kzalloc(sizeof(*police), GFP_KERNEL);
171         if (police == NULL)
172                 return -ENOMEM;
173         ret = ACT_P_CREATED;
174         police->tcf_refcnt = 1;
175         spin_lock_init(&police->tcf_lock);
176         if (bind)
177                 police->tcf_bindcnt = 1;
178 override:
179         if (parm->rate.rate) {
180                 err = -ENOMEM;
181                 R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE]);
182                 if (R_tab == NULL)
183                         goto failure;
184                 if (parm->peakrate.rate) {
185                         P_tab = qdisc_get_rtab(&parm->peakrate,
186                                                tb[TCA_POLICE_PEAKRATE]);
187                         if (P_tab == NULL) {
188                                 qdisc_put_rtab(R_tab);
189                                 goto failure;
190                         }
191                 }
192         }
193         /* No failure allowed after this point */
194         spin_lock_bh(&police->tcf_lock);
195         if (R_tab != NULL) {
196                 qdisc_put_rtab(police->tcfp_R_tab);
197                 police->tcfp_R_tab = R_tab;
198         }
199         if (P_tab != NULL) {
200                 qdisc_put_rtab(police->tcfp_P_tab);
201                 police->tcfp_P_tab = P_tab;
202         }
203
204         if (tb[TCA_POLICE_RESULT])
205                 police->tcfp_result = *(u32*)nla_data(tb[TCA_POLICE_RESULT]);
206         police->tcfp_toks = police->tcfp_burst = parm->burst;
207         police->tcfp_mtu = parm->mtu;
208         if (police->tcfp_mtu == 0) {
209                 police->tcfp_mtu = ~0;
210                 if (police->tcfp_R_tab)
211                         police->tcfp_mtu = 255<<police->tcfp_R_tab->rate.cell_log;
212         }
213         if (police->tcfp_P_tab)
214                 police->tcfp_ptoks = L2T_P(police, police->tcfp_mtu);
215         police->tcf_action = parm->action;
216
217         if (tb[TCA_POLICE_AVRATE])
218                 police->tcfp_ewma_rate =
219                         *(u32*)nla_data(tb[TCA_POLICE_AVRATE]);
220         if (est)
221                 gen_replace_estimator(&police->tcf_bstats,
222                                       &police->tcf_rate_est,
223                                       &police->tcf_lock, est);
224
225         spin_unlock_bh(&police->tcf_lock);
226         if (ret != ACT_P_CREATED)
227                 return ret;
228
229         police->tcfp_t_c = psched_get_time();
230         police->tcf_index = parm->index ? parm->index :
231                 tcf_hash_new_index(&police_idx_gen, &police_hash_info);
232         h = tcf_hash(police->tcf_index, POL_TAB_MASK);
233         write_lock_bh(&police_lock);
234         police->tcf_next = tcf_police_ht[h];
235         tcf_police_ht[h] = &police->common;
236         write_unlock_bh(&police_lock);
237
238         a->priv = police;
239         return ret;
240
241 failure:
242         if (ret == ACT_P_CREATED)
243                 kfree(police);
244         return err;
245 }
246
247 static int tcf_act_police_cleanup(struct tc_action *a, int bind)
248 {
249         struct tcf_police *p = a->priv;
250         int ret = 0;
251
252         if (p != NULL) {
253                 if (bind)
254                         p->tcf_bindcnt--;
255
256                 p->tcf_refcnt--;
257                 if (p->tcf_refcnt <= 0 && !p->tcf_bindcnt) {
258                         tcf_police_destroy(p);
259                         ret = 1;
260                 }
261         }
262         return ret;
263 }
264
265 static int tcf_act_police(struct sk_buff *skb, struct tc_action *a,
266                           struct tcf_result *res)
267 {
268         struct tcf_police *police = a->priv;
269         psched_time_t now;
270         long toks;
271         long ptoks = 0;
272
273         spin_lock(&police->tcf_lock);
274
275         police->tcf_bstats.bytes += skb->len;
276         police->tcf_bstats.packets++;
277
278         if (police->tcfp_ewma_rate &&
279             police->tcf_rate_est.bps >= police->tcfp_ewma_rate) {
280                 police->tcf_qstats.overlimits++;
281                 spin_unlock(&police->tcf_lock);
282                 return police->tcf_action;
283         }
284
285         if (skb->len <= police->tcfp_mtu) {
286                 if (police->tcfp_R_tab == NULL) {
287                         spin_unlock(&police->tcf_lock);
288                         return police->tcfp_result;
289                 }
290
291                 now = psched_get_time();
292                 toks = psched_tdiff_bounded(now, police->tcfp_t_c,
293                                             police->tcfp_burst);
294                 if (police->tcfp_P_tab) {
295                         ptoks = toks + police->tcfp_ptoks;
296                         if (ptoks > (long)L2T_P(police, police->tcfp_mtu))
297                                 ptoks = (long)L2T_P(police, police->tcfp_mtu);
298                         ptoks -= L2T_P(police, skb->len);
299                 }
300                 toks += police->tcfp_toks;
301                 if (toks > (long)police->tcfp_burst)
302                         toks = police->tcfp_burst;
303                 toks -= L2T(police, skb->len);
304                 if ((toks|ptoks) >= 0) {
305                         police->tcfp_t_c = now;
306                         police->tcfp_toks = toks;
307                         police->tcfp_ptoks = ptoks;
308                         spin_unlock(&police->tcf_lock);
309                         return police->tcfp_result;
310                 }
311         }
312
313         police->tcf_qstats.overlimits++;
314         spin_unlock(&police->tcf_lock);
315         return police->tcf_action;
316 }
317
318 static int
319 tcf_act_police_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
320 {
321         unsigned char *b = skb_tail_pointer(skb);
322         struct tcf_police *police = a->priv;
323         struct tc_police opt;
324
325         opt.index = police->tcf_index;
326         opt.action = police->tcf_action;
327         opt.mtu = police->tcfp_mtu;
328         opt.burst = police->tcfp_burst;
329         opt.refcnt = police->tcf_refcnt - ref;
330         opt.bindcnt = police->tcf_bindcnt - bind;
331         if (police->tcfp_R_tab)
332                 opt.rate = police->tcfp_R_tab->rate;
333         else
334                 memset(&opt.rate, 0, sizeof(opt.rate));
335         if (police->tcfp_P_tab)
336                 opt.peakrate = police->tcfp_P_tab->rate;
337         else
338                 memset(&opt.peakrate, 0, sizeof(opt.peakrate));
339         NLA_PUT(skb, TCA_POLICE_TBF, sizeof(opt), &opt);
340         if (police->tcfp_result)
341                 NLA_PUT(skb, TCA_POLICE_RESULT, sizeof(int),
342                         &police->tcfp_result);
343         if (police->tcfp_ewma_rate)
344                 NLA_PUT(skb, TCA_POLICE_AVRATE, 4, &police->tcfp_ewma_rate);
345         return skb->len;
346
347 nla_put_failure:
348         nlmsg_trim(skb, b);
349         return -1;
350 }
351
352 MODULE_AUTHOR("Alexey Kuznetsov");
353 MODULE_DESCRIPTION("Policing actions");
354 MODULE_LICENSE("GPL");
355
356 static struct tc_action_ops act_police_ops = {
357         .kind           =       "police",
358         .hinfo          =       &police_hash_info,
359         .type           =       TCA_ID_POLICE,
360         .capab          =       TCA_CAP_NONE,
361         .owner          =       THIS_MODULE,
362         .act            =       tcf_act_police,
363         .dump           =       tcf_act_police_dump,
364         .cleanup        =       tcf_act_police_cleanup,
365         .lookup         =       tcf_hash_search,
366         .init           =       tcf_act_police_locate,
367         .walk           =       tcf_act_police_walker
368 };
369
370 static int __init
371 police_init_module(void)
372 {
373         return tcf_register_action(&act_police_ops);
374 }
375
376 static void __exit
377 police_cleanup_module(void)
378 {
379         tcf_unregister_action(&act_police_ops);
380 }
381
382 module_init(police_init_module);
383 module_exit(police_cleanup_module);