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[PKT_SCHED] cls: Use rtnl registration interface
[net-next-2.6.git] / net / sched / cls_api.c
CommitLineData
1da177e4
LT		 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 <asm/uaccess.h>
18#include <asm/system.h>
19#include <linux/bitops.h>
1da177e4
LT		 20#include <linux/module.h>
21#include <linux/types.h>
22#include <linux/kernel.h>
1da177e4
LT		 23#include <linux/string.h>
24#include <linux/mm.h>
25#include <linux/socket.h>
26#include <linux/sockios.h>
27#include <linux/in.h>
28#include <linux/errno.h>
29#include <linux/interrupt.h>
30#include <linux/netdevice.h>
31#include <linux/skbuff.h>
1da177e4
LT		 32#include <linux/init.h>
33#include <linux/kmod.h>
dc5fc579
ACM		 34#include <linux/netlink.h>
35#include <net/netlink.h>
1da177e4
LT		 36#include <net/sock.h>
37#include <net/pkt_sched.h>
38#include <net/pkt_cls.h>
39
40#if 0 /* control */
41#define DPRINTK(format,args...) printk(KERN_DEBUG format,##args)
42#else
43#define DPRINTK(format,args...)
44#endif
45
46/* The list of all installed classifier types */
47
48static struct tcf_proto_ops *tcf_proto_base;
49
50/* Protects list of registered TC modules. It is pure SMP lock. */
51static DEFINE_RWLOCK(cls_mod_lock);
52
53/* Find classifier type by string name */
54
55static struct tcf_proto_ops * tcf_proto_lookup_ops(struct rtattr *kind)
56{
57 struct tcf_proto_ops *t = NULL;
58
59 if (kind) {
60 read_lock(&cls_mod_lock);
61 for (t = tcf_proto_base; t; t = t->next) {
62 if (rtattr_strcmp(kind, t->kind) == 0) {
63 if (!try_module_get(t->owner))
64 t = NULL;
65 break;
66 }
67 }
68 read_unlock(&cls_mod_lock);
69 }
70 return t;
71}
72
73/* Register(unregister) new classifier type */
74
75int register_tcf_proto_ops(struct tcf_proto_ops *ops)
76{
77 struct tcf_proto_ops *t, **tp;
78 int rc = -EEXIST;
79
80 write_lock(&cls_mod_lock);
81 for (tp = &tcf_proto_base; (t = *tp) != NULL; tp = &t->next)
82 if (!strcmp(ops->kind, t->kind))
83 goto out;
84
85 ops->next = NULL;
86 *tp = ops;
87 rc = 0;
88out:
89 write_unlock(&cls_mod_lock);
90 return rc;
91}
92
93int unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
94{
95 struct tcf_proto_ops *t, **tp;
96 int rc = -ENOENT;
97
98 write_lock(&cls_mod_lock);
99 for (tp = &tcf_proto_base; (t=*tp) != NULL; tp = &t->next)
100 if (t == ops)
101 break;
102
103 if (!t)
104 goto out;
105 *tp = t->next;
106 rc = 0;
107out:
108 write_unlock(&cls_mod_lock);
109 return rc;
110}
111
112static int tfilter_notify(struct sk_buff *oskb, struct nlmsghdr *n,
113 struct tcf_proto *tp, unsigned long fh, int event);
114
115
116/* Select new prio value from the range, managed by kernel. */
117
118static __inline__ u32 tcf_auto_prio(struct tcf_proto *tp)
119{
120 u32 first = TC_H_MAKE(0xC0000000U,0U);
121
122 if (tp)
123 first = tp->prio-1;
124
125 return first;
126}
127
128/* Add/change/delete/get a filter node */
129
130static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
131{
132 struct rtattr **tca;
133 struct tcmsg *t;
134 u32 protocol;
135 u32 prio;
136 u32 nprio;
137 u32 parent;
138 struct net_device *dev;
139 struct Qdisc *q;
140 struct tcf_proto **back, **chain;
141 struct tcf_proto *tp;
142 struct tcf_proto_ops *tp_ops;
143 struct Qdisc_class_ops *cops;
144 unsigned long cl;
145 unsigned long fh;
146 int err;
147
148replay:
149 tca = arg;
150 t = NLMSG_DATA(n);
151 protocol = TC_H_MIN(t->tcm_info);
152 prio = TC_H_MAJ(t->tcm_info);
153 nprio = prio;
154 parent = t->tcm_parent;
155 cl = 0;
156
157 if (prio == 0) {
158 /* If no priority is given, user wants we allocated it. */
159 if (n->nlmsg_type != RTM_NEWTFILTER || !(n->nlmsg_flags&NLM_F_CREATE))
160 return -ENOENT;
161 prio = TC_H_MAKE(0x80000000U,0U);
162 }
163
164 /* Find head of filter chain. */
165
166 /* Find link */
167 if ((dev = __dev_get_by_index(t->tcm_ifindex)) == NULL)
168 return -ENODEV;
169
170 /* Find qdisc */
171 if (!parent) {
172 q = dev->qdisc_sleeping;
173 parent = q->handle;
174 } else if ((q = qdisc_lookup(dev, TC_H_MAJ(t->tcm_parent))) == NULL)
175 return -EINVAL;
176
177 /* Is it classful? */
178 if ((cops = q->ops->cl_ops) == NULL)
179 return -EINVAL;
180
181 /* Do we search for filter, attached to class? */
182 if (TC_H_MIN(parent)) {
183 cl = cops->get(q, parent);
184 if (cl == 0)
185 return -ENOENT;
186 }
187
188 /* And the last stroke */
189 chain = cops->tcf_chain(q, cl);
190 err = -EINVAL;
191 if (chain == NULL)
192 goto errout;
193
194 /* Check the chain for existence of proto-tcf with this priority */
195 for (back = chain; (tp=*back) != NULL; back = &tp->next) {
196 if (tp->prio >= prio) {
197 if (tp->prio == prio) {
198 if (!nprio || (tp->protocol != protocol && protocol))
199 goto errout;
200 } else
201 tp = NULL;
202 break;
203 }
204 }
205
206 if (tp == NULL) {
207 /* Proto-tcf does not exist, create new one */
208
209 if (tca[TCA_KIND-1] == NULL || !protocol)
210 goto errout;
211
212 err = -ENOENT;
213 if (n->nlmsg_type != RTM_NEWTFILTER || !(n->nlmsg_flags&NLM_F_CREATE))
214 goto errout;
215
216
217 /* Create new proto tcf */
218
219 err = -ENOBUFS;
c7b1b249 220 if ((tp = kzalloc(sizeof(*tp), GFP_KERNEL)) == NULL)
1da177e4
LT		 221 goto errout;
222 err = -EINVAL;
223 tp_ops = tcf_proto_lookup_ops(tca[TCA_KIND-1]);
224 if (tp_ops == NULL) {
225#ifdef CONFIG_KMOD
226 struct rtattr *kind = tca[TCA_KIND-1];
227 char name[IFNAMSIZ];
228
229 if (kind != NULL &&
230 rtattr_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
231 rtnl_unlock();
232 request_module("cls_%s", name);
233 rtnl_lock();
234 tp_ops = tcf_proto_lookup_ops(kind);
235 /* We dropped the RTNL semaphore in order to
236 * perform the module load. So, even if we
237 * succeeded in loading the module we have to
238 * replay the request. We indicate this using
239 * -EAGAIN.
240 */
241 if (tp_ops != NULL) {
242 module_put(tp_ops->owner);
243 err = -EAGAIN;
244 }
245 }
246#endif
247 kfree(tp);
248 goto errout;
249 }
1da177e4
LT		 250 tp->ops = tp_ops;
251 tp->protocol = protocol;
252 tp->prio = nprio ? : tcf_auto_prio(*back);
253 tp->q = q;
254 tp->classify = tp_ops->classify;
255 tp->classid = parent;
256 if ((err = tp_ops->init(tp)) != 0) {
257 module_put(tp_ops->owner);
258 kfree(tp);
259 goto errout;
260 }
261
262 qdisc_lock_tree(dev);
263 tp->next = *back;
264 *back = tp;
265 qdisc_unlock_tree(dev);
266
267 } else if (tca[TCA_KIND-1] && rtattr_strcmp(tca[TCA_KIND-1], tp->ops->kind))
268 goto errout;
269
270 fh = tp->ops->get(tp, t->tcm_handle);
271
272 if (fh == 0) {
273 if (n->nlmsg_type == RTM_DELTFILTER && t->tcm_handle == 0) {
274 qdisc_lock_tree(dev);
275 *back = tp->next;
276 qdisc_unlock_tree(dev);
277
278 tfilter_notify(skb, n, tp, fh, RTM_DELTFILTER);
279 tcf_destroy(tp);
280 err = 0;
281 goto errout;
282 }
283
284 err = -ENOENT;
285 if (n->nlmsg_type != RTM_NEWTFILTER || !(n->nlmsg_flags&NLM_F_CREATE))
286 goto errout;
287 } else {
288 switch (n->nlmsg_type) {
10297b99 289 case RTM_NEWTFILTER:
1da177e4
LT		 290 err = -EEXIST;
291 if (n->nlmsg_flags&NLM_F_EXCL)
292 goto errout;
293 break;
294 case RTM_DELTFILTER:
295 err = tp->ops->delete(tp, fh);
296 if (err == 0)
297 tfilter_notify(skb, n, tp, fh, RTM_DELTFILTER);
298 goto errout;
299 case RTM_GETTFILTER:
300 err = tfilter_notify(skb, n, tp, fh, RTM_NEWTFILTER);
301 goto errout;
302 default:
303 err = -EINVAL;
304 goto errout;
305 }
306 }
307
308 err = tp->ops->change(tp, cl, t->tcm_handle, tca, &fh);
309 if (err == 0)
310 tfilter_notify(skb, n, tp, fh, RTM_NEWTFILTER);
311
312errout:
313 if (cl)
314 cops->put(q, cl);
315 if (err == -EAGAIN)
316 /* Replay the request. */
317 goto replay;
318 return err;
319}
320
321static int
322tcf_fill_node(struct sk_buff *skb, struct tcf_proto *tp, unsigned long fh,
e431b8c0 323 u32 pid, u32 seq, u16 flags, int event)
1da177e4
LT		 324{
325 struct tcmsg *tcm;
326 struct nlmsghdr *nlh;
27a884dc 327 unsigned char *b = skb_tail_pointer(skb);
1da177e4 328
e431b8c0 329 nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags);
1da177e4
LT		 330 tcm = NLMSG_DATA(nlh);
331 tcm->tcm_family = AF_UNSPEC;
9ef1d4c7
PM		 332 tcm->tcm__pad1 = 0;
333 tcm->tcm__pad1 = 0;
1da177e4
LT		 334 tcm->tcm_ifindex = tp->q->dev->ifindex;
335 tcm->tcm_parent = tp->classid;
336 tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
337 RTA_PUT(skb, TCA_KIND, IFNAMSIZ, tp->ops->kind);
338 tcm->tcm_handle = fh;
339 if (RTM_DELTFILTER != event) {
340 tcm->tcm_handle = 0;
341 if (tp->ops->dump && tp->ops->dump(tp, fh, skb, tcm) < 0)
342 goto rtattr_failure;
343 }
27a884dc 344 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1da177e4
LT		 345 return skb->len;
346
347nlmsg_failure:
348rtattr_failure:
dc5fc579 349 nlmsg_trim(skb, b);
1da177e4
LT		 350 return -1;
351}
352
353static int tfilter_notify(struct sk_buff *oskb, struct nlmsghdr *n,
354 struct tcf_proto *tp, unsigned long fh, int event)
355{
356 struct sk_buff *skb;
357 u32 pid = oskb ? NETLINK_CB(oskb).pid : 0;
358
359 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
360 if (!skb)
361 return -ENOBUFS;
362
363 if (tcf_fill_node(skb, tp, fh, pid, n->nlmsg_seq, 0, event) <= 0) {
364 kfree_skb(skb);
365 return -EINVAL;
366 }
367
ac6d439d 368 return rtnetlink_send(skb, pid, RTNLGRP_TC, n->nlmsg_flags&NLM_F_ECHO);
1da177e4
LT		 369}
370
371struct tcf_dump_args
372{
373 struct tcf_walker w;
374 struct sk_buff *skb;
375 struct netlink_callback *cb;
376};
377
378static int tcf_node_dump(struct tcf_proto *tp, unsigned long n, struct tcf_walker *arg)
379{
380 struct tcf_dump_args *a = (void*)arg;
381
382 return tcf_fill_node(a->skb, tp, n, NETLINK_CB(a->cb->skb).pid,
383 a->cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTFILTER);
384}
385
386static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
387{
388 int t;
389 int s_t;
390 struct net_device *dev;
391 struct Qdisc *q;
392 struct tcf_proto *tp, **chain;
393 struct tcmsg *tcm = (struct tcmsg*)NLMSG_DATA(cb->nlh);
394 unsigned long cl = 0;
395 struct Qdisc_class_ops *cops;
396 struct tcf_dump_args arg;
397
398 if (cb->nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*tcm)))
399 return skb->len;
400 if ((dev = dev_get_by_index(tcm->tcm_ifindex)) == NULL)
401 return skb->len;
402
85670cc1 403 read_lock(&qdisc_tree_lock);
1da177e4
LT		 404 if (!tcm->tcm_parent)
405 q = dev->qdisc_sleeping;
406 else
407 q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
408 if (!q)
409 goto out;
410 if ((cops = q->ops->cl_ops) == NULL)
411 goto errout;
412 if (TC_H_MIN(tcm->tcm_parent)) {
413 cl = cops->get(q, tcm->tcm_parent);
414 if (cl == 0)
415 goto errout;
416 }
417 chain = cops->tcf_chain(q, cl);
418 if (chain == NULL)
419 goto errout;
420
421 s_t = cb->args[0];
422
423 for (tp=*chain, t=0; tp; tp = tp->next, t++) {
424 if (t < s_t) continue;
425 if (TC_H_MAJ(tcm->tcm_info) &&
426 TC_H_MAJ(tcm->tcm_info) != tp->prio)
427 continue;
428 if (TC_H_MIN(tcm->tcm_info) &&
429 TC_H_MIN(tcm->tcm_info) != tp->protocol)
430 continue;
431 if (t > s_t)
432 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
433 if (cb->args[1] == 0) {
434 if (tcf_fill_node(skb, tp, 0, NETLINK_CB(cb->skb).pid,
435 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTFILTER) <= 0) {
436 break;
437 }
438 cb->args[1] = 1;
439 }
440 if (tp->ops->walk == NULL)
441 continue;
442 arg.w.fn = tcf_node_dump;
443 arg.skb = skb;
444 arg.cb = cb;
445 arg.w.stop = 0;
446 arg.w.skip = cb->args[1]-1;
447 arg.w.count = 0;
448 tp->ops->walk(tp, &arg.w);
449 cb->args[1] = arg.w.count+1;
450 if (arg.w.stop)
451 break;
452 }
453
454 cb->args[0] = t;
455
456errout:
457 if (cl)
458 cops->put(q, cl);
459out:
85670cc1 460 read_unlock(&qdisc_tree_lock);
1da177e4
LT		 461 dev_put(dev);
462 return skb->len;
463}
464
465void
466tcf_exts_destroy(struct tcf_proto *tp, struct tcf_exts *exts)
467{
468#ifdef CONFIG_NET_CLS_ACT
469 if (exts->action) {
470 tcf_action_destroy(exts->action, TCA_ACT_UNBIND);
471 exts->action = NULL;
472 }
473#elif defined CONFIG_NET_CLS_POLICE
474 if (exts->police) {
475 tcf_police_release(exts->police, TCA_ACT_UNBIND);
476 exts->police = NULL;
477 }
478#endif
479}
480
481
482int
483tcf_exts_validate(struct tcf_proto *tp, struct rtattr **tb,
10297b99
YH		 484 struct rtattr *rate_tlv, struct tcf_exts *exts,
485 struct tcf_ext_map *map)
1da177e4
LT		 486{
487 memset(exts, 0, sizeof(*exts));
10297b99 488
1da177e4
LT		 489#ifdef CONFIG_NET_CLS_ACT
490 {
491 int err;
492 struct tc_action *act;
493
494 if (map->police && tb[map->police-1]) {
495 act = tcf_action_init_1(tb[map->police-1], rate_tlv, "police",
496 TCA_ACT_NOREPLACE, TCA_ACT_BIND, &err);
497 if (act == NULL)
498 return err;
499
500 act->type = TCA_OLD_COMPAT;
501 exts->action = act;
502 } else if (map->action && tb[map->action-1]) {
503 act = tcf_action_init(tb[map->action-1], rate_tlv, NULL,
504 TCA_ACT_NOREPLACE, TCA_ACT_BIND, &err);
505 if (act == NULL)
506 return err;
507
508 exts->action = act;
509 }
510 }
511#elif defined CONFIG_NET_CLS_POLICE
512 if (map->police && tb[map->police-1]) {
513 struct tcf_police *p;
10297b99 514
1da177e4
LT		 515 p = tcf_police_locate(tb[map->police-1], rate_tlv);
516 if (p == NULL)
517 return -EINVAL;
518
519 exts->police = p;
520 } else if (map->action && tb[map->action-1])
521 return -EOPNOTSUPP;
522#else
523 if ((map->action && tb[map->action-1]) ||
524 (map->police && tb[map->police-1]))
525 return -EOPNOTSUPP;
526#endif
527
528 return 0;
529}
530
531void
532tcf_exts_change(struct tcf_proto *tp, struct tcf_exts *dst,
10297b99 533 struct tcf_exts *src)
1da177e4
LT		 534{
535#ifdef CONFIG_NET_CLS_ACT
536 if (src->action) {
537 struct tc_action *act;
538 tcf_tree_lock(tp);
539 act = xchg(&dst->action, src->action);
540 tcf_tree_unlock(tp);
541 if (act)
542 tcf_action_destroy(act, TCA_ACT_UNBIND);
543 }
544#elif defined CONFIG_NET_CLS_POLICE
545 if (src->police) {
546 struct tcf_police *p;
547 tcf_tree_lock(tp);
548 p = xchg(&dst->police, src->police);
549 tcf_tree_unlock(tp);
550 if (p)
551 tcf_police_release(p, TCA_ACT_UNBIND);
552 }
553#endif
554}
555
556int
557tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts,
558 struct tcf_ext_map *map)
559{
560#ifdef CONFIG_NET_CLS_ACT
561 if (map->action && exts->action) {
562 /*
563 * again for backward compatible mode - we want
564 * to work with both old and new modes of entering
565 * tc data even if iproute2 was newer - jhs
566 */
27a884dc 567 struct rtattr *p_rta = (struct rtattr *)skb_tail_pointer(skb);
1da177e4
LT		 568
569 if (exts->action->type != TCA_OLD_COMPAT) {
570 RTA_PUT(skb, map->action, 0, NULL);
571 if (tcf_action_dump(skb, exts->action, 0, 0) < 0)
572 goto rtattr_failure;
27a884dc 573 p_rta->rta_len = skb_tail_pointer(skb) - (u8 *)p_rta;
1da177e4
LT		 574 } else if (map->police) {
575 RTA_PUT(skb, map->police, 0, NULL);
576 if (tcf_action_dump_old(skb, exts->action, 0, 0) < 0)
577 goto rtattr_failure;
27a884dc 578 p_rta->rta_len = skb_tail_pointer(skb) - (u8 *)p_rta;
1da177e4
LT		 579 }
580 }
581#elif defined CONFIG_NET_CLS_POLICE
582 if (map->police && exts->police) {
27a884dc 583 struct rtattr *p_rta = (struct rtattr *)skb_tail_pointer(skb);
1da177e4
LT		 584
585 RTA_PUT(skb, map->police, 0, NULL);
586
587 if (tcf_police_dump(skb, exts->police) < 0)
588 goto rtattr_failure;
589
27a884dc 590 p_rta->rta_len = skb_tail_pointer(skb) - (u8 *)p_rta;
1da177e4
LT		 591 }
592#endif
593 return 0;
594rtattr_failure: __attribute__ ((unused))
595 return -1;
596}
597
598int
599tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts,
10297b99 600 struct tcf_ext_map *map)
1da177e4
LT		 601{
602#ifdef CONFIG_NET_CLS_ACT
603 if (exts->action)
604 if (tcf_action_copy_stats(skb, exts->action, 1) < 0)
605 goto rtattr_failure;
606#elif defined CONFIG_NET_CLS_POLICE
607 if (exts->police)
608 if (tcf_police_dump_stats(skb, exts->police) < 0)
609 goto rtattr_failure;
610#endif
611 return 0;
612rtattr_failure: __attribute__ ((unused))
613 return -1;
614}
615
616static int __init tc_filter_init(void)
617{
82623c0d
TG		 618 rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_ctl_tfilter, NULL);
619 rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_ctl_tfilter, NULL);
620 rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_ctl_tfilter,
621 tc_dump_tfilter);
1da177e4 622
1da177e4
LT		 623 return 0;
624}
625
626subsys_initcall(tc_filter_init);
627
628EXPORT_SYMBOL(register_tcf_proto_ops);
629EXPORT_SYMBOL(unregister_tcf_proto_ops);
630EXPORT_SYMBOL(tcf_exts_validate);
631EXPORT_SYMBOL(tcf_exts_destroy);
632EXPORT_SYMBOL(tcf_exts_change);
633EXPORT_SYMBOL(tcf_exts_dump);
634EXPORT_SYMBOL(tcf_exts_dump_stats);
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