[NET] NETNS: Omit sock->sk_net without CONFIG_NET_NS.
[linux-3.10.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 <net/net_namespace.h>
28 #include <net/sock.h>
29 #include <net/netlink.h>
30 #include <net/pkt_sched.h>
31 #include <net/pkt_cls.h>
32
33 /* The list of all installed classifier types */
34
35 static struct tcf_proto_ops *tcf_proto_base __read_mostly;
36
37 /* Protects list of registered TC modules. It is pure SMP lock. */
38 static DEFINE_RWLOCK(cls_mod_lock);
39
40 /* Find classifier type by string name */
41
42 static struct tcf_proto_ops *tcf_proto_lookup_ops(struct nlattr *kind)
43 {
44         struct tcf_proto_ops *t = NULL;
45
46         if (kind) {
47                 read_lock(&cls_mod_lock);
48                 for (t = tcf_proto_base; t; t = t->next) {
49                         if (nla_strcmp(kind, t->kind) == 0) {
50                                 if (!try_module_get(t->owner))
51                                         t = NULL;
52                                 break;
53                         }
54                 }
55                 read_unlock(&cls_mod_lock);
56         }
57         return t;
58 }
59
60 /* Register(unregister) new classifier type */
61
62 int register_tcf_proto_ops(struct tcf_proto_ops *ops)
63 {
64         struct tcf_proto_ops *t, **tp;
65         int rc = -EEXIST;
66
67         write_lock(&cls_mod_lock);
68         for (tp = &tcf_proto_base; (t = *tp) != NULL; tp = &t->next)
69                 if (!strcmp(ops->kind, t->kind))
70                         goto out;
71
72         ops->next = NULL;
73         *tp = ops;
74         rc = 0;
75 out:
76         write_unlock(&cls_mod_lock);
77         return rc;
78 }
79 EXPORT_SYMBOL(register_tcf_proto_ops);
80
81 int unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
82 {
83         struct tcf_proto_ops *t, **tp;
84         int rc = -ENOENT;
85
86         write_lock(&cls_mod_lock);
87         for (tp = &tcf_proto_base; (t=*tp) != NULL; tp = &t->next)
88                 if (t == ops)
89                         break;
90
91         if (!t)
92                 goto out;
93         *tp = t->next;
94         rc = 0;
95 out:
96         write_unlock(&cls_mod_lock);
97         return rc;
98 }
99 EXPORT_SYMBOL(unregister_tcf_proto_ops);
100
101 static int tfilter_notify(struct sk_buff *oskb, struct nlmsghdr *n,
102                           struct tcf_proto *tp, unsigned long fh, int event);
103
104
105 /* Select new prio value from the range, managed by kernel. */
106
107 static inline u32 tcf_auto_prio(struct tcf_proto *tp)
108 {
109         u32 first = TC_H_MAKE(0xC0000000U, 0U);
110
111         if (tp)
112                 first = tp->prio-1;
113
114         return first;
115 }
116
117 /* Add/change/delete/get a filter node */
118
119 static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
120 {
121         struct net *net = sock_net(skb->sk);
122         struct nlattr *tca[TCA_MAX + 1];
123         struct tcmsg *t;
124         u32 protocol;
125         u32 prio;
126         u32 nprio;
127         u32 parent;
128         struct net_device *dev;
129         struct Qdisc  *q;
130         struct tcf_proto **back, **chain;
131         struct tcf_proto *tp;
132         struct tcf_proto_ops *tp_ops;
133         const struct Qdisc_class_ops *cops;
134         unsigned long cl;
135         unsigned long fh;
136         int err;
137
138         if (net != &init_net)
139                 return -EINVAL;
140
141 replay:
142         t = NLMSG_DATA(n);
143         protocol = TC_H_MIN(t->tcm_info);
144         prio = TC_H_MAJ(t->tcm_info);
145         nprio = prio;
146         parent = t->tcm_parent;
147         cl = 0;
148
149         if (prio == 0) {
150                 /* If no priority is given, user wants we allocated it. */
151                 if (n->nlmsg_type != RTM_NEWTFILTER || !(n->nlmsg_flags&NLM_F_CREATE))
152                         return -ENOENT;
153                 prio = TC_H_MAKE(0x80000000U, 0U);
154         }
155
156         /* Find head of filter chain. */
157
158         /* Find link */
159         dev = __dev_get_by_index(&init_net, t->tcm_ifindex);
160         if (dev == NULL)
161                 return -ENODEV;
162
163         err = nlmsg_parse(n, sizeof(*t), tca, TCA_MAX, NULL);
164         if (err < 0)
165                 return err;
166
167         /* Find qdisc */
168         if (!parent) {
169                 q = dev->qdisc_sleeping;
170                 parent = q->handle;
171         } else {
172                 q = qdisc_lookup(dev, TC_H_MAJ(t->tcm_parent));
173                 if (q == NULL)
174                         return -EINVAL;
175         }
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] == 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;
220                 tp = kzalloc(sizeof(*tp), GFP_KERNEL);
221                 if (tp == NULL)
222                         goto errout;
223                 err = -EINVAL;
224                 tp_ops = tcf_proto_lookup_ops(tca[TCA_KIND]);
225                 if (tp_ops == NULL) {
226 #ifdef CONFIG_KMOD
227                         struct nlattr *kind = tca[TCA_KIND];
228                         char name[IFNAMSIZ];
229
230                         if (kind != NULL &&
231                             nla_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
232                                 rtnl_unlock();
233                                 request_module("cls_%s", name);
234                                 rtnl_lock();
235                                 tp_ops = tcf_proto_lookup_ops(kind);
236                                 /* We dropped the RTNL semaphore in order to
237                                  * perform the module load.  So, even if we
238                                  * succeeded in loading the module we have to
239                                  * replay the request.  We indicate this using
240                                  * -EAGAIN.
241                                  */
242                                 if (tp_ops != NULL) {
243                                         module_put(tp_ops->owner);
244                                         err = -EAGAIN;
245                                 }
246                         }
247 #endif
248                         kfree(tp);
249                         goto errout;
250                 }
251                 tp->ops = tp_ops;
252                 tp->protocol = protocol;
253                 tp->prio = nprio ? : tcf_auto_prio(*back);
254                 tp->q = q;
255                 tp->classify = tp_ops->classify;
256                 tp->classid = parent;
257
258                 err = tp_ops->init(tp);
259                 if (err != 0) {
260                         module_put(tp_ops->owner);
261                         kfree(tp);
262                         goto errout;
263                 }
264
265                 qdisc_lock_tree(dev);
266                 tp->next = *back;
267                 *back = tp;
268                 qdisc_unlock_tree(dev);
269
270         } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind))
271                 goto errout;
272
273         fh = tp->ops->get(tp, t->tcm_handle);
274
275         if (fh == 0) {
276                 if (n->nlmsg_type == RTM_DELTFILTER && t->tcm_handle == 0) {
277                         qdisc_lock_tree(dev);
278                         *back = tp->next;
279                         qdisc_unlock_tree(dev);
280
281                         tfilter_notify(skb, n, tp, fh, RTM_DELTFILTER);
282                         tcf_destroy(tp);
283                         err = 0;
284                         goto errout;
285                 }
286
287                 err = -ENOENT;
288                 if (n->nlmsg_type != RTM_NEWTFILTER ||
289                     !(n->nlmsg_flags & NLM_F_CREATE))
290                         goto errout;
291         } else {
292                 switch (n->nlmsg_type) {
293                 case RTM_NEWTFILTER:
294                         err = -EEXIST;
295                         if (n->nlmsg_flags & NLM_F_EXCL)
296                                 goto errout;
297                         break;
298                 case RTM_DELTFILTER:
299                         err = tp->ops->delete(tp, fh);
300                         if (err == 0)
301                                 tfilter_notify(skb, n, tp, fh, RTM_DELTFILTER);
302                         goto errout;
303                 case RTM_GETTFILTER:
304                         err = tfilter_notify(skb, n, tp, fh, RTM_NEWTFILTER);
305                         goto errout;
306                 default:
307                         err = -EINVAL;
308                         goto errout;
309                 }
310         }
311
312         err = tp->ops->change(tp, cl, t->tcm_handle, tca, &fh);
313         if (err == 0)
314                 tfilter_notify(skb, n, tp, fh, RTM_NEWTFILTER);
315
316 errout:
317         if (cl)
318                 cops->put(q, cl);
319         if (err == -EAGAIN)
320                 /* Replay the request. */
321                 goto replay;
322         return err;
323 }
324
325 static int tcf_fill_node(struct sk_buff *skb, struct tcf_proto *tp,
326                          unsigned long fh, u32 pid, u32 seq, u16 flags, int event)
327 {
328         struct tcmsg *tcm;
329         struct nlmsghdr  *nlh;
330         unsigned char *b = skb_tail_pointer(skb);
331
332         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags);
333         tcm = NLMSG_DATA(nlh);
334         tcm->tcm_family = AF_UNSPEC;
335         tcm->tcm__pad1 = 0;
336         tcm->tcm__pad1 = 0;
337         tcm->tcm_ifindex = tp->q->dev->ifindex;
338         tcm->tcm_parent = tp->classid;
339         tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
340         NLA_PUT_STRING(skb, TCA_KIND, tp->ops->kind);
341         tcm->tcm_handle = fh;
342         if (RTM_DELTFILTER != event) {
343                 tcm->tcm_handle = 0;
344                 if (tp->ops->dump && tp->ops->dump(tp, fh, skb, tcm) < 0)
345                         goto nla_put_failure;
346         }
347         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
348         return skb->len;
349
350 nlmsg_failure:
351 nla_put_failure:
352         nlmsg_trim(skb, b);
353         return -1;
354 }
355
356 static int tfilter_notify(struct sk_buff *oskb, struct nlmsghdr *n,
357                           struct tcf_proto *tp, unsigned long fh, int event)
358 {
359         struct sk_buff *skb;
360         u32 pid = oskb ? NETLINK_CB(oskb).pid : 0;
361
362         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
363         if (!skb)
364                 return -ENOBUFS;
365
366         if (tcf_fill_node(skb, tp, fh, pid, n->nlmsg_seq, 0, event) <= 0) {
367                 kfree_skb(skb);
368                 return -EINVAL;
369         }
370
371         return rtnetlink_send(skb, &init_net, pid, RTNLGRP_TC,
372                               n->nlmsg_flags & NLM_F_ECHO);
373 }
374
375 struct tcf_dump_args {
376         struct tcf_walker w;
377         struct sk_buff *skb;
378         struct netlink_callback *cb;
379 };
380
381 static int tcf_node_dump(struct tcf_proto *tp, unsigned long n,
382                          struct tcf_walker *arg)
383 {
384         struct tcf_dump_args *a = (void *)arg;
385
386         return tcf_fill_node(a->skb, tp, n, NETLINK_CB(a->cb->skb).pid,
387                              a->cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTFILTER);
388 }
389
390 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
391 {
392         struct net *net = sock_net(skb->sk);
393         int t;
394         int s_t;
395         struct net_device *dev;
396         struct Qdisc *q;
397         struct tcf_proto *tp, **chain;
398         struct tcmsg *tcm = (struct tcmsg *)NLMSG_DATA(cb->nlh);
399         unsigned long cl = 0;
400         const struct Qdisc_class_ops *cops;
401         struct tcf_dump_args arg;
402
403         if (net != &init_net)
404                 return 0;
405
406         if (cb->nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*tcm)))
407                 return skb->len;
408         if ((dev = dev_get_by_index(&init_net, tcm->tcm_ifindex)) == NULL)
409                 return skb->len;
410
411         if (!tcm->tcm_parent)
412                 q = dev->qdisc_sleeping;
413         else
414                 q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
415         if (!q)
416                 goto out;
417         if ((cops = q->ops->cl_ops) == NULL)
418                 goto errout;
419         if (TC_H_MIN(tcm->tcm_parent)) {
420                 cl = cops->get(q, tcm->tcm_parent);
421                 if (cl == 0)
422                         goto errout;
423         }
424         chain = cops->tcf_chain(q, cl);
425         if (chain == NULL)
426                 goto errout;
427
428         s_t = cb->args[0];
429
430         for (tp=*chain, t=0; tp; tp = tp->next, t++) {
431                 if (t < s_t) continue;
432                 if (TC_H_MAJ(tcm->tcm_info) &&
433                     TC_H_MAJ(tcm->tcm_info) != tp->prio)
434                         continue;
435                 if (TC_H_MIN(tcm->tcm_info) &&
436                     TC_H_MIN(tcm->tcm_info) != tp->protocol)
437                         continue;
438                 if (t > s_t)
439                         memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
440                 if (cb->args[1] == 0) {
441                         if (tcf_fill_node(skb, tp, 0, NETLINK_CB(cb->skb).pid,
442                                           cb->nlh->nlmsg_seq, NLM_F_MULTI,
443                                           RTM_NEWTFILTER) <= 0)
444                                 break;
445
446                         cb->args[1] = 1;
447                 }
448                 if (tp->ops->walk == NULL)
449                         continue;
450                 arg.w.fn = tcf_node_dump;
451                 arg.skb = skb;
452                 arg.cb = cb;
453                 arg.w.stop = 0;
454                 arg.w.skip = cb->args[1]-1;
455                 arg.w.count = 0;
456                 tp->ops->walk(tp, &arg.w);
457                 cb->args[1] = arg.w.count+1;
458                 if (arg.w.stop)
459                         break;
460         }
461
462         cb->args[0] = t;
463
464 errout:
465         if (cl)
466                 cops->put(q, cl);
467 out:
468         dev_put(dev);
469         return skb->len;
470 }
471
472 void tcf_exts_destroy(struct tcf_proto *tp, struct tcf_exts *exts)
473 {
474 #ifdef CONFIG_NET_CLS_ACT
475         if (exts->action) {
476                 tcf_action_destroy(exts->action, TCA_ACT_UNBIND);
477                 exts->action = NULL;
478         }
479 #endif
480 }
481 EXPORT_SYMBOL(tcf_exts_destroy);
482
483 int tcf_exts_validate(struct tcf_proto *tp, struct nlattr **tb,
484                   struct nlattr *rate_tlv, struct tcf_exts *exts,
485                   const struct tcf_ext_map *map)
486 {
487         memset(exts, 0, sizeof(*exts));
488
489 #ifdef CONFIG_NET_CLS_ACT
490         {
491                 struct tc_action *act;
492
493                 if (map->police && tb[map->police]) {
494                         act = tcf_action_init_1(tb[map->police], rate_tlv,
495                                                 "police", TCA_ACT_NOREPLACE,
496                                                 TCA_ACT_BIND);
497                         if (IS_ERR(act))
498                                 return PTR_ERR(act);
499
500                         act->type = TCA_OLD_COMPAT;
501                         exts->action = act;
502                 } else if (map->action && tb[map->action]) {
503                         act = tcf_action_init(tb[map->action], rate_tlv, NULL,
504                                               TCA_ACT_NOREPLACE, TCA_ACT_BIND);
505                         if (IS_ERR(act))
506                                 return PTR_ERR(act);
507
508                         exts->action = act;
509                 }
510         }
511 #else
512         if ((map->action && tb[map->action]) ||
513             (map->police && tb[map->police]))
514                 return -EOPNOTSUPP;
515 #endif
516
517         return 0;
518 }
519 EXPORT_SYMBOL(tcf_exts_validate);
520
521 void tcf_exts_change(struct tcf_proto *tp, struct tcf_exts *dst,
522                      struct tcf_exts *src)
523 {
524 #ifdef CONFIG_NET_CLS_ACT
525         if (src->action) {
526                 struct tc_action *act;
527                 tcf_tree_lock(tp);
528                 act = xchg(&dst->action, src->action);
529                 tcf_tree_unlock(tp);
530                 if (act)
531                         tcf_action_destroy(act, TCA_ACT_UNBIND);
532         }
533 #endif
534 }
535 EXPORT_SYMBOL(tcf_exts_change);
536
537 int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts,
538                   const struct tcf_ext_map *map)
539 {
540 #ifdef CONFIG_NET_CLS_ACT
541         if (map->action && exts->action) {
542                 /*
543                  * again for backward compatible mode - we want
544                  * to work with both old and new modes of entering
545                  * tc data even if iproute2  was newer - jhs
546                  */
547                 struct nlattr *nest;
548
549                 if (exts->action->type != TCA_OLD_COMPAT) {
550                         nest = nla_nest_start(skb, map->action);
551                         if (nest == NULL)
552                                 goto nla_put_failure;
553                         if (tcf_action_dump(skb, exts->action, 0, 0) < 0)
554                                 goto nla_put_failure;
555                         nla_nest_end(skb, nest);
556                 } else if (map->police) {
557                         nest = nla_nest_start(skb, map->police);
558                         if (nest == NULL)
559                                 goto nla_put_failure;
560                         if (tcf_action_dump_old(skb, exts->action, 0, 0) < 0)
561                                 goto nla_put_failure;
562                         nla_nest_end(skb, nest);
563                 }
564         }
565 #endif
566         return 0;
567 nla_put_failure: __attribute__ ((unused))
568         return -1;
569 }
570 EXPORT_SYMBOL(tcf_exts_dump);
571
572
573 int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts,
574                         const struct tcf_ext_map *map)
575 {
576 #ifdef CONFIG_NET_CLS_ACT
577         if (exts->action)
578                 if (tcf_action_copy_stats(skb, exts->action, 1) < 0)
579                         goto nla_put_failure;
580 #endif
581         return 0;
582 nla_put_failure: __attribute__ ((unused))
583         return -1;
584 }
585 EXPORT_SYMBOL(tcf_exts_dump_stats);
586
587 static int __init tc_filter_init(void)
588 {
589         rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_ctl_tfilter, NULL);
590         rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_ctl_tfilter, NULL);
591         rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_ctl_tfilter,
592                                                  tc_dump_tfilter);
593
594         return 0;
595 }
596
597 subsys_initcall(tc_filter_init);