bluetooth: hid: make Android code conditional
[linux-2.6.git] / net / sched / cls_api.c
1 /*
2  * net/sched/cls_api.c  Packet classifier API.
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  *
11  * Changes:
12  *
13  * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support
14  *
15  */
16
17 #include <linux/module.h>
18 #include <linux/types.h>
19 #include <linux/kernel.h>
20 #include <linux/string.h>
21 #include <linux/errno.h>
22 #include <linux/skbuff.h>
23 #include <linux/init.h>
24 #include <linux/kmod.h>
25 #include <linux/netlink.h>
26 #include <linux/err.h>
27 #include <linux/slab.h>
28 #include <net/net_namespace.h>
29 #include <net/sock.h>
30 #include <net/netlink.h>
31 #include <net/pkt_sched.h>
32 #include <net/pkt_cls.h>
33
34 /* The list of all installed classifier types */
35
36 static struct tcf_proto_ops *tcf_proto_base __read_mostly;
37
38 /* Protects list of registered TC modules. It is pure SMP lock. */
39 static DEFINE_RWLOCK(cls_mod_lock);
40
41 /* Find classifier type by string name */
42
43 static const struct tcf_proto_ops *tcf_proto_lookup_ops(struct nlattr *kind)
44 {
45         const struct tcf_proto_ops *t = NULL;
46
47         if (kind) {
48                 read_lock(&cls_mod_lock);
49                 for (t = tcf_proto_base; t; t = t->next) {
50                         if (nla_strcmp(kind, t->kind) == 0) {
51                                 if (!try_module_get(t->owner))
52                                         t = NULL;
53                                 break;
54                         }
55                 }
56                 read_unlock(&cls_mod_lock);
57         }
58         return t;
59 }
60
61 /* Register(unregister) new classifier type */
62
63 int register_tcf_proto_ops(struct tcf_proto_ops *ops)
64 {
65         struct tcf_proto_ops *t, **tp;
66         int rc = -EEXIST;
67
68         write_lock(&cls_mod_lock);
69         for (tp = &tcf_proto_base; (t = *tp) != NULL; tp = &t->next)
70                 if (!strcmp(ops->kind, t->kind))
71                         goto out;
72
73         ops->next = NULL;
74         *tp = ops;
75         rc = 0;
76 out:
77         write_unlock(&cls_mod_lock);
78         return rc;
79 }
80 EXPORT_SYMBOL(register_tcf_proto_ops);
81
82 int unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
83 {
84         struct tcf_proto_ops *t, **tp;
85         int rc = -ENOENT;
86
87         write_lock(&cls_mod_lock);
88         for (tp = &tcf_proto_base; (t = *tp) != NULL; tp = &t->next)
89                 if (t == ops)
90                         break;
91
92         if (!t)
93                 goto out;
94         *tp = t->next;
95         rc = 0;
96 out:
97         write_unlock(&cls_mod_lock);
98         return rc;
99 }
100 EXPORT_SYMBOL(unregister_tcf_proto_ops);
101
102 static int tfilter_notify(struct net *net, struct sk_buff *oskb,
103                           struct nlmsghdr *n, struct tcf_proto *tp,
104                           unsigned long fh, int event);
105
106
107 /* Select new prio value from the range, managed by kernel. */
108
109 static inline u32 tcf_auto_prio(struct tcf_proto *tp)
110 {
111         u32 first = TC_H_MAKE(0xC0000000U, 0U);
112
113         if (tp)
114                 first = tp->prio - 1;
115
116         return first;
117 }
118
119 /* Add/change/delete/get a filter node */
120
121 static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
122 {
123         struct net *net = sock_net(skb->sk);
124         struct nlattr *tca[TCA_MAX + 1];
125         spinlock_t *root_lock;
126         struct tcmsg *t;
127         u32 protocol;
128         u32 prio;
129         u32 nprio;
130         u32 parent;
131         struct net_device *dev;
132         struct Qdisc  *q;
133         struct tcf_proto **back, **chain;
134         struct tcf_proto *tp;
135         const struct tcf_proto_ops *tp_ops;
136         const struct Qdisc_class_ops *cops;
137         unsigned long cl;
138         unsigned long fh;
139         int err;
140         int tp_created = 0;
141
142 replay:
143         t = NLMSG_DATA(n);
144         protocol = TC_H_MIN(t->tcm_info);
145         prio = TC_H_MAJ(t->tcm_info);
146         nprio = prio;
147         parent = t->tcm_parent;
148         cl = 0;
149
150         if (prio == 0) {
151                 /* If no priority is given, user wants we allocated it. */
152                 if (n->nlmsg_type != RTM_NEWTFILTER ||
153                     !(n->nlmsg_flags & NLM_F_CREATE))
154                         return -ENOENT;
155                 prio = TC_H_MAKE(0x80000000U, 0U);
156         }
157
158         /* Find head of filter chain. */
159
160         /* Find link */
161         dev = __dev_get_by_index(net, t->tcm_ifindex);
162         if (dev == NULL)
163                 return -ENODEV;
164
165         err = nlmsg_parse(n, sizeof(*t), tca, TCA_MAX, NULL);
166         if (err < 0)
167                 return err;
168
169         /* Find qdisc */
170         if (!parent) {
171                 q = dev->qdisc;
172                 parent = q->handle;
173         } else {
174                 q = qdisc_lookup(dev, TC_H_MAJ(t->tcm_parent));
175                 if (q == NULL)
176                         return -EINVAL;
177         }
178
179         /* Is it classful? */
180         cops = q->ops->cl_ops;
181         if (!cops)
182                 return -EINVAL;
183
184         if (cops->tcf_chain == NULL)
185                 return -EOPNOTSUPP;
186
187         /* Do we search for filter, attached to class? */
188         if (TC_H_MIN(parent)) {
189                 cl = cops->get(q, parent);
190                 if (cl == 0)
191                         return -ENOENT;
192         }
193
194         /* And the last stroke */
195         chain = cops->tcf_chain(q, cl);
196         err = -EINVAL;
197         if (chain == NULL)
198                 goto errout;
199
200         /* Check the chain for existence of proto-tcf with this priority */
201         for (back = chain; (tp = *back) != NULL; back = &tp->next) {
202                 if (tp->prio >= prio) {
203                         if (tp->prio == prio) {
204                                 if (!nprio ||
205                                     (tp->protocol != protocol && protocol))
206                                         goto errout;
207                         } else
208                                 tp = NULL;
209                         break;
210                 }
211         }
212
213         root_lock = qdisc_root_sleeping_lock(q);
214
215         if (tp == NULL) {
216                 /* Proto-tcf does not exist, create new one */
217
218                 if (tca[TCA_KIND] == NULL || !protocol)
219                         goto errout;
220
221                 err = -ENOENT;
222                 if (n->nlmsg_type != RTM_NEWTFILTER ||
223                     !(n->nlmsg_flags & NLM_F_CREATE))
224                         goto errout;
225
226
227                 /* Create new proto tcf */
228
229                 err = -ENOBUFS;
230                 tp = kzalloc(sizeof(*tp), GFP_KERNEL);
231                 if (tp == NULL)
232                         goto errout;
233                 err = -ENOENT;
234                 tp_ops = tcf_proto_lookup_ops(tca[TCA_KIND]);
235                 if (tp_ops == NULL) {
236 #ifdef CONFIG_MODULES
237                         struct nlattr *kind = tca[TCA_KIND];
238                         char name[IFNAMSIZ];
239
240                         if (kind != NULL &&
241                             nla_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
242                                 rtnl_unlock();
243                                 request_module("cls_%s", name);
244                                 rtnl_lock();
245                                 tp_ops = tcf_proto_lookup_ops(kind);
246                                 /* We dropped the RTNL semaphore in order to
247                                  * perform the module load.  So, even if we
248                                  * succeeded in loading the module we have to
249                                  * replay the request.  We indicate this using
250                                  * -EAGAIN.
251                                  */
252                                 if (tp_ops != NULL) {
253                                         module_put(tp_ops->owner);
254                                         err = -EAGAIN;
255                                 }
256                         }
257 #endif
258                         kfree(tp);
259                         goto errout;
260                 }
261                 tp->ops = tp_ops;
262                 tp->protocol = protocol;
263                 tp->prio = nprio ? : TC_H_MAJ(tcf_auto_prio(*back));
264                 tp->q = q;
265                 tp->classify = tp_ops->classify;
266                 tp->classid = parent;
267
268                 err = tp_ops->init(tp);
269                 if (err != 0) {
270                         module_put(tp_ops->owner);
271                         kfree(tp);
272                         goto errout;
273                 }
274
275                 tp_created = 1;
276
277         } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind))
278                 goto errout;
279
280         fh = tp->ops->get(tp, t->tcm_handle);
281
282         if (fh == 0) {
283                 if (n->nlmsg_type == RTM_DELTFILTER && t->tcm_handle == 0) {
284                         spin_lock_bh(root_lock);
285                         *back = tp->next;
286                         spin_unlock_bh(root_lock);
287
288                         tfilter_notify(net, skb, n, tp, fh, RTM_DELTFILTER);
289                         tcf_destroy(tp);
290                         err = 0;
291                         goto errout;
292                 }
293
294                 err = -ENOENT;
295                 if (n->nlmsg_type != RTM_NEWTFILTER ||
296                     !(n->nlmsg_flags & NLM_F_CREATE))
297                         goto errout;
298         } else {
299                 switch (n->nlmsg_type) {
300                 case RTM_NEWTFILTER:
301                         err = -EEXIST;
302                         if (n->nlmsg_flags & NLM_F_EXCL) {
303                                 if (tp_created)
304                                         tcf_destroy(tp);
305                                 goto errout;
306                         }
307                         break;
308                 case RTM_DELTFILTER:
309                         err = tp->ops->delete(tp, fh);
310                         if (err == 0)
311                                 tfilter_notify(net, skb, n, tp, fh, RTM_DELTFILTER);
312                         goto errout;
313                 case RTM_GETTFILTER:
314                         err = tfilter_notify(net, skb, n, tp, fh, RTM_NEWTFILTER);
315                         goto errout;
316                 default:
317                         err = -EINVAL;
318                         goto errout;
319                 }
320         }
321
322         err = tp->ops->change(tp, cl, t->tcm_handle, tca, &fh);
323         if (err == 0) {
324                 if (tp_created) {
325                         spin_lock_bh(root_lock);
326                         tp->next = *back;
327                         *back = tp;
328                         spin_unlock_bh(root_lock);
329                 }
330                 tfilter_notify(net, skb, n, tp, fh, RTM_NEWTFILTER);
331         } else {
332                 if (tp_created)
333                         tcf_destroy(tp);
334         }
335
336 errout:
337         if (cl)
338                 cops->put(q, cl);
339         if (err == -EAGAIN)
340                 /* Replay the request. */
341                 goto replay;
342         return err;
343 }
344
345 static int tcf_fill_node(struct sk_buff *skb, struct tcf_proto *tp,
346                          unsigned long fh, u32 pid, u32 seq, u16 flags, int event)
347 {
348         struct tcmsg *tcm;
349         struct nlmsghdr  *nlh;
350         unsigned char *b = skb_tail_pointer(skb);
351
352         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags);
353         tcm = NLMSG_DATA(nlh);
354         tcm->tcm_family = AF_UNSPEC;
355         tcm->tcm__pad1 = 0;
356         tcm->tcm__pad2 = 0;
357         tcm->tcm_ifindex = qdisc_dev(tp->q)->ifindex;
358         tcm->tcm_parent = tp->classid;
359         tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
360         NLA_PUT_STRING(skb, TCA_KIND, tp->ops->kind);
361         tcm->tcm_handle = fh;
362         if (RTM_DELTFILTER != event) {
363                 tcm->tcm_handle = 0;
364                 if (tp->ops->dump && tp->ops->dump(tp, fh, skb, tcm) < 0)
365                         goto nla_put_failure;
366         }
367         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
368         return skb->len;
369
370 nlmsg_failure:
371 nla_put_failure:
372         nlmsg_trim(skb, b);
373         return -1;
374 }
375
376 static int tfilter_notify(struct net *net, struct sk_buff *oskb,
377                           struct nlmsghdr *n, struct tcf_proto *tp,
378                           unsigned long fh, int event)
379 {
380         struct sk_buff *skb;
381         u32 pid = oskb ? NETLINK_CB(oskb).pid : 0;
382
383         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
384         if (!skb)
385                 return -ENOBUFS;
386
387         if (tcf_fill_node(skb, tp, fh, pid, n->nlmsg_seq, 0, event) <= 0) {
388                 kfree_skb(skb);
389                 return -EINVAL;
390         }
391
392         return rtnetlink_send(skb, net, pid, RTNLGRP_TC,
393                               n->nlmsg_flags & NLM_F_ECHO);
394 }
395
396 struct tcf_dump_args {
397         struct tcf_walker w;
398         struct sk_buff *skb;
399         struct netlink_callback *cb;
400 };
401
402 static int tcf_node_dump(struct tcf_proto *tp, unsigned long n,
403                          struct tcf_walker *arg)
404 {
405         struct tcf_dump_args *a = (void *)arg;
406
407         return tcf_fill_node(a->skb, tp, n, NETLINK_CB(a->cb->skb).pid,
408                              a->cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTFILTER);
409 }
410
411 /* called with RTNL */
412 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
413 {
414         struct net *net = sock_net(skb->sk);
415         int t;
416         int s_t;
417         struct net_device *dev;
418         struct Qdisc *q;
419         struct tcf_proto *tp, **chain;
420         struct tcmsg *tcm = (struct tcmsg *)NLMSG_DATA(cb->nlh);
421         unsigned long cl = 0;
422         const struct Qdisc_class_ops *cops;
423         struct tcf_dump_args arg;
424
425         if (cb->nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*tcm)))
426                 return skb->len;
427         dev = __dev_get_by_index(net, tcm->tcm_ifindex);
428         if (!dev)
429                 return skb->len;
430
431         if (!tcm->tcm_parent)
432                 q = dev->qdisc;
433         else
434                 q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
435         if (!q)
436                 goto out;
437         cops = q->ops->cl_ops;
438         if (!cops)
439                 goto errout;
440         if (cops->tcf_chain == NULL)
441                 goto errout;
442         if (TC_H_MIN(tcm->tcm_parent)) {
443                 cl = cops->get(q, tcm->tcm_parent);
444                 if (cl == 0)
445                         goto errout;
446         }
447         chain = cops->tcf_chain(q, cl);
448         if (chain == NULL)
449                 goto errout;
450
451         s_t = cb->args[0];
452
453         for (tp = *chain, t = 0; tp; tp = tp->next, t++) {
454                 if (t < s_t)
455                         continue;
456                 if (TC_H_MAJ(tcm->tcm_info) &&
457                     TC_H_MAJ(tcm->tcm_info) != tp->prio)
458                         continue;
459                 if (TC_H_MIN(tcm->tcm_info) &&
460                     TC_H_MIN(tcm->tcm_info) != tp->protocol)
461                         continue;
462                 if (t > s_t)
463                         memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
464                 if (cb->args[1] == 0) {
465                         if (tcf_fill_node(skb, tp, 0, NETLINK_CB(cb->skb).pid,
466                                           cb->nlh->nlmsg_seq, NLM_F_MULTI,
467                                           RTM_NEWTFILTER) <= 0)
468                                 break;
469
470                         cb->args[1] = 1;
471                 }
472                 if (tp->ops->walk == NULL)
473                         continue;
474                 arg.w.fn = tcf_node_dump;
475                 arg.skb = skb;
476                 arg.cb = cb;
477                 arg.w.stop = 0;
478                 arg.w.skip = cb->args[1] - 1;
479                 arg.w.count = 0;
480                 tp->ops->walk(tp, &arg.w);
481                 cb->args[1] = arg.w.count + 1;
482                 if (arg.w.stop)
483                         break;
484         }
485
486         cb->args[0] = t;
487
488 errout:
489         if (cl)
490                 cops->put(q, cl);
491 out:
492         return skb->len;
493 }
494
495 void tcf_exts_destroy(struct tcf_proto *tp, struct tcf_exts *exts)
496 {
497 #ifdef CONFIG_NET_CLS_ACT
498         if (exts->action) {
499                 tcf_action_destroy(exts->action, TCA_ACT_UNBIND);
500                 exts->action = NULL;
501         }
502 #endif
503 }
504 EXPORT_SYMBOL(tcf_exts_destroy);
505
506 int tcf_exts_validate(struct tcf_proto *tp, struct nlattr **tb,
507                   struct nlattr *rate_tlv, struct tcf_exts *exts,
508                   const struct tcf_ext_map *map)
509 {
510         memset(exts, 0, sizeof(*exts));
511
512 #ifdef CONFIG_NET_CLS_ACT
513         {
514                 struct tc_action *act;
515
516                 if (map->police && tb[map->police]) {
517                         act = tcf_action_init_1(tb[map->police], rate_tlv,
518                                                 "police", TCA_ACT_NOREPLACE,
519                                                 TCA_ACT_BIND);
520                         if (IS_ERR(act))
521                                 return PTR_ERR(act);
522
523                         act->type = TCA_OLD_COMPAT;
524                         exts->action = act;
525                 } else if (map->action && tb[map->action]) {
526                         act = tcf_action_init(tb[map->action], rate_tlv, NULL,
527                                               TCA_ACT_NOREPLACE, TCA_ACT_BIND);
528                         if (IS_ERR(act))
529                                 return PTR_ERR(act);
530
531                         exts->action = act;
532                 }
533         }
534 #else
535         if ((map->action && tb[map->action]) ||
536             (map->police && tb[map->police]))
537                 return -EOPNOTSUPP;
538 #endif
539
540         return 0;
541 }
542 EXPORT_SYMBOL(tcf_exts_validate);
543
544 void tcf_exts_change(struct tcf_proto *tp, struct tcf_exts *dst,
545                      struct tcf_exts *src)
546 {
547 #ifdef CONFIG_NET_CLS_ACT
548         if (src->action) {
549                 struct tc_action *act;
550                 tcf_tree_lock(tp);
551                 act = dst->action;
552                 dst->action = src->action;
553                 tcf_tree_unlock(tp);
554                 if (act)
555                         tcf_action_destroy(act, TCA_ACT_UNBIND);
556         }
557 #endif
558 }
559 EXPORT_SYMBOL(tcf_exts_change);
560
561 int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts,
562                   const struct tcf_ext_map *map)
563 {
564 #ifdef CONFIG_NET_CLS_ACT
565         if (map->action && exts->action) {
566                 /*
567                  * again for backward compatible mode - we want
568                  * to work with both old and new modes of entering
569                  * tc data even if iproute2  was newer - jhs
570                  */
571                 struct nlattr *nest;
572
573                 if (exts->action->type != TCA_OLD_COMPAT) {
574                         nest = nla_nest_start(skb, map->action);
575                         if (nest == NULL)
576                                 goto nla_put_failure;
577                         if (tcf_action_dump(skb, exts->action, 0, 0) < 0)
578                                 goto nla_put_failure;
579                         nla_nest_end(skb, nest);
580                 } else if (map->police) {
581                         nest = nla_nest_start(skb, map->police);
582                         if (nest == NULL)
583                                 goto nla_put_failure;
584                         if (tcf_action_dump_old(skb, exts->action, 0, 0) < 0)
585                                 goto nla_put_failure;
586                         nla_nest_end(skb, nest);
587                 }
588         }
589 #endif
590         return 0;
591 nla_put_failure: __attribute__ ((unused))
592         return -1;
593 }
594 EXPORT_SYMBOL(tcf_exts_dump);
595
596
597 int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts,
598                         const struct tcf_ext_map *map)
599 {
600 #ifdef CONFIG_NET_CLS_ACT
601         if (exts->action)
602                 if (tcf_action_copy_stats(skb, exts->action, 1) < 0)
603                         goto nla_put_failure;
604 #endif
605         return 0;
606 nla_put_failure: __attribute__ ((unused))
607         return -1;
608 }
609 EXPORT_SYMBOL(tcf_exts_dump_stats);
610
611 static int __init tc_filter_init(void)
612 {
613         rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_ctl_tfilter, NULL, NULL);
614         rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_ctl_tfilter, NULL, NULL);
615         rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_ctl_tfilter,
616                       tc_dump_tfilter, NULL);
617
618         return 0;
619 }
620
621 subsys_initcall(tc_filter_init);