Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
[pandora-kernel.git] / net / sched / act_api.c
1 /*
2  * net/sched/act_api.c  Packet action 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  * Author:      Jamal Hadi Salim
10  *
11  *
12  */
13
14 #include <linux/types.h>
15 #include <linux/kernel.h>
16 #include <linux/string.h>
17 #include <linux/errno.h>
18 #include <linux/slab.h>
19 #include <linux/skbuff.h>
20 #include <linux/init.h>
21 #include <linux/kmod.h>
22 #include <linux/err.h>
23 #include <linux/module.h>
24 #include <net/net_namespace.h>
25 #include <net/sock.h>
26 #include <net/sch_generic.h>
27 #include <net/act_api.h>
28 #include <net/netlink.h>
29
30 void tcf_hash_destroy(struct tcf_common *p, struct tcf_hashinfo *hinfo)
31 {
32         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
33         struct tcf_common **p1p;
34
35         for (p1p = &hinfo->htab[h]; *p1p; p1p = &(*p1p)->tcfc_next) {
36                 if (*p1p == p) {
37                         write_lock_bh(hinfo->lock);
38                         *p1p = p->tcfc_next;
39                         write_unlock_bh(hinfo->lock);
40                         gen_kill_estimator(&p->tcfc_bstats,
41                                            &p->tcfc_rate_est);
42                         /*
43                          * gen_estimator est_timer() might access p->tcfc_lock
44                          * or bstats, wait a RCU grace period before freeing p
45                          */
46                         kfree_rcu(p, tcfc_rcu);
47                         return;
48                 }
49         }
50         WARN_ON(1);
51 }
52 EXPORT_SYMBOL(tcf_hash_destroy);
53
54 int tcf_hash_release(struct tcf_common *p, int bind,
55                      struct tcf_hashinfo *hinfo)
56 {
57         int ret = 0;
58
59         if (p) {
60                 if (bind)
61                         p->tcfc_bindcnt--;
62
63                 p->tcfc_refcnt--;
64                 if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
65                         tcf_hash_destroy(p, hinfo);
66                         ret = 1;
67                 }
68         }
69         return ret;
70 }
71 EXPORT_SYMBOL(tcf_hash_release);
72
73 static int tcf_dump_walker(struct sk_buff *skb, struct netlink_callback *cb,
74                            struct tc_action *a, struct tcf_hashinfo *hinfo)
75 {
76         struct tcf_common *p;
77         int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
78         struct nlattr *nest;
79
80         read_lock_bh(hinfo->lock);
81
82         s_i = cb->args[0];
83
84         for (i = 0; i < (hinfo->hmask + 1); i++) {
85                 p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
86
87                 for (; p; p = p->tcfc_next) {
88                         index++;
89                         if (index < s_i)
90                                 continue;
91                         a->priv = p;
92                         a->order = n_i;
93
94                         nest = nla_nest_start(skb, a->order);
95                         if (nest == NULL)
96                                 goto nla_put_failure;
97                         err = tcf_action_dump_1(skb, a, 0, 0);
98                         if (err < 0) {
99                                 index--;
100                                 nlmsg_trim(skb, nest);
101                                 goto done;
102                         }
103                         nla_nest_end(skb, nest);
104                         n_i++;
105                         if (n_i >= TCA_ACT_MAX_PRIO)
106                                 goto done;
107                 }
108         }
109 done:
110         read_unlock_bh(hinfo->lock);
111         if (n_i)
112                 cb->args[0] += n_i;
113         return n_i;
114
115 nla_put_failure:
116         nla_nest_cancel(skb, nest);
117         goto done;
118 }
119
120 static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a,
121                           struct tcf_hashinfo *hinfo)
122 {
123         struct tcf_common *p, *s_p;
124         struct nlattr *nest;
125         int i = 0, n_i = 0;
126
127         nest = nla_nest_start(skb, a->order);
128         if (nest == NULL)
129                 goto nla_put_failure;
130         NLA_PUT_STRING(skb, TCA_KIND, a->ops->kind);
131         for (i = 0; i < (hinfo->hmask + 1); i++) {
132                 p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
133
134                 while (p != NULL) {
135                         s_p = p->tcfc_next;
136                         if (ACT_P_DELETED == tcf_hash_release(p, 0, hinfo))
137                                 module_put(a->ops->owner);
138                         n_i++;
139                         p = s_p;
140                 }
141         }
142         NLA_PUT_U32(skb, TCA_FCNT, n_i);
143         nla_nest_end(skb, nest);
144
145         return n_i;
146 nla_put_failure:
147         nla_nest_cancel(skb, nest);
148         return -EINVAL;
149 }
150
151 int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
152                        int type, struct tc_action *a)
153 {
154         struct tcf_hashinfo *hinfo = a->ops->hinfo;
155
156         if (type == RTM_DELACTION) {
157                 return tcf_del_walker(skb, a, hinfo);
158         } else if (type == RTM_GETACTION) {
159                 return tcf_dump_walker(skb, cb, a, hinfo);
160         } else {
161                 WARN(1, "tcf_generic_walker: unknown action %d\n", type);
162                 return -EINVAL;
163         }
164 }
165 EXPORT_SYMBOL(tcf_generic_walker);
166
167 struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
168 {
169         struct tcf_common *p;
170
171         read_lock_bh(hinfo->lock);
172         for (p = hinfo->htab[tcf_hash(index, hinfo->hmask)]; p;
173              p = p->tcfc_next) {
174                 if (p->tcfc_index == index)
175                         break;
176         }
177         read_unlock_bh(hinfo->lock);
178
179         return p;
180 }
181 EXPORT_SYMBOL(tcf_hash_lookup);
182
183 u32 tcf_hash_new_index(u32 *idx_gen, struct tcf_hashinfo *hinfo)
184 {
185         u32 val = *idx_gen;
186
187         do {
188                 if (++val == 0)
189                         val = 1;
190         } while (tcf_hash_lookup(val, hinfo));
191
192         return (*idx_gen = val);
193 }
194 EXPORT_SYMBOL(tcf_hash_new_index);
195
196 int tcf_hash_search(struct tc_action *a, u32 index)
197 {
198         struct tcf_hashinfo *hinfo = a->ops->hinfo;
199         struct tcf_common *p = tcf_hash_lookup(index, hinfo);
200
201         if (p) {
202                 a->priv = p;
203                 return 1;
204         }
205         return 0;
206 }
207 EXPORT_SYMBOL(tcf_hash_search);
208
209 struct tcf_common *tcf_hash_check(u32 index, struct tc_action *a, int bind,
210                                   struct tcf_hashinfo *hinfo)
211 {
212         struct tcf_common *p = NULL;
213         if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
214                 if (bind)
215                         p->tcfc_bindcnt++;
216                 p->tcfc_refcnt++;
217                 a->priv = p;
218         }
219         return p;
220 }
221 EXPORT_SYMBOL(tcf_hash_check);
222
223 struct tcf_common *tcf_hash_create(u32 index, struct nlattr *est,
224                                    struct tc_action *a, int size, int bind,
225                                    u32 *idx_gen, struct tcf_hashinfo *hinfo)
226 {
227         struct tcf_common *p = kzalloc(size, GFP_KERNEL);
228
229         if (unlikely(!p))
230                 return ERR_PTR(-ENOMEM);
231         p->tcfc_refcnt = 1;
232         if (bind)
233                 p->tcfc_bindcnt = 1;
234
235         spin_lock_init(&p->tcfc_lock);
236         p->tcfc_index = index ? index : tcf_hash_new_index(idx_gen, hinfo);
237         p->tcfc_tm.install = jiffies;
238         p->tcfc_tm.lastuse = jiffies;
239         if (est) {
240                 int err = gen_new_estimator(&p->tcfc_bstats, &p->tcfc_rate_est,
241                                             &p->tcfc_lock, est);
242                 if (err) {
243                         kfree(p);
244                         return ERR_PTR(err);
245                 }
246         }
247
248         a->priv = (void *) p;
249         return p;
250 }
251 EXPORT_SYMBOL(tcf_hash_create);
252
253 void tcf_hash_insert(struct tcf_common *p, struct tcf_hashinfo *hinfo)
254 {
255         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
256
257         write_lock_bh(hinfo->lock);
258         p->tcfc_next = hinfo->htab[h];
259         hinfo->htab[h] = p;
260         write_unlock_bh(hinfo->lock);
261 }
262 EXPORT_SYMBOL(tcf_hash_insert);
263
264 static struct tc_action_ops *act_base = NULL;
265 static DEFINE_RWLOCK(act_mod_lock);
266
267 int tcf_register_action(struct tc_action_ops *act)
268 {
269         struct tc_action_ops *a, **ap;
270
271         write_lock(&act_mod_lock);
272         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next) {
273                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
274                         write_unlock(&act_mod_lock);
275                         return -EEXIST;
276                 }
277         }
278         act->next = NULL;
279         *ap = act;
280         write_unlock(&act_mod_lock);
281         return 0;
282 }
283 EXPORT_SYMBOL(tcf_register_action);
284
285 int tcf_unregister_action(struct tc_action_ops *act)
286 {
287         struct tc_action_ops *a, **ap;
288         int err = -ENOENT;
289
290         write_lock(&act_mod_lock);
291         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next)
292                 if (a == act)
293                         break;
294         if (a) {
295                 *ap = a->next;
296                 a->next = NULL;
297                 err = 0;
298         }
299         write_unlock(&act_mod_lock);
300         return err;
301 }
302 EXPORT_SYMBOL(tcf_unregister_action);
303
304 /* lookup by name */
305 static struct tc_action_ops *tc_lookup_action_n(char *kind)
306 {
307         struct tc_action_ops *a = NULL;
308
309         if (kind) {
310                 read_lock(&act_mod_lock);
311                 for (a = act_base; a; a = a->next) {
312                         if (strcmp(kind, a->kind) == 0) {
313                                 if (!try_module_get(a->owner)) {
314                                         read_unlock(&act_mod_lock);
315                                         return NULL;
316                                 }
317                                 break;
318                         }
319                 }
320                 read_unlock(&act_mod_lock);
321         }
322         return a;
323 }
324
325 /* lookup by nlattr */
326 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
327 {
328         struct tc_action_ops *a = NULL;
329
330         if (kind) {
331                 read_lock(&act_mod_lock);
332                 for (a = act_base; a; a = a->next) {
333                         if (nla_strcmp(kind, a->kind) == 0) {
334                                 if (!try_module_get(a->owner)) {
335                                         read_unlock(&act_mod_lock);
336                                         return NULL;
337                                 }
338                                 break;
339                         }
340                 }
341                 read_unlock(&act_mod_lock);
342         }
343         return a;
344 }
345
346 #if 0
347 /* lookup by id */
348 static struct tc_action_ops *tc_lookup_action_id(u32 type)
349 {
350         struct tc_action_ops *a = NULL;
351
352         if (type) {
353                 read_lock(&act_mod_lock);
354                 for (a = act_base; a; a = a->next) {
355                         if (a->type == type) {
356                                 if (!try_module_get(a->owner)) {
357                                         read_unlock(&act_mod_lock);
358                                         return NULL;
359                                 }
360                                 break;
361                         }
362                 }
363                 read_unlock(&act_mod_lock);
364         }
365         return a;
366 }
367 #endif
368
369 int tcf_action_exec(struct sk_buff *skb, const struct tc_action *act,
370                     struct tcf_result *res)
371 {
372         const struct tc_action *a;
373         int ret = -1;
374
375         if (skb->tc_verd & TC_NCLS) {
376                 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
377                 ret = TC_ACT_OK;
378                 goto exec_done;
379         }
380         while ((a = act) != NULL) {
381 repeat:
382                 if (a->ops && a->ops->act) {
383                         ret = a->ops->act(skb, a, res);
384                         if (TC_MUNGED & skb->tc_verd) {
385                                 /* copied already, allow trampling */
386                                 skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
387                                 skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
388                         }
389                         if (ret == TC_ACT_REPEAT)
390                                 goto repeat;    /* we need a ttl - JHS */
391                         if (ret != TC_ACT_PIPE)
392                                 goto exec_done;
393                 }
394                 act = a->next;
395         }
396 exec_done:
397         return ret;
398 }
399 EXPORT_SYMBOL(tcf_action_exec);
400
401 void tcf_action_destroy(struct tc_action *act, int bind)
402 {
403         struct tc_action *a;
404
405         for (a = act; a; a = act) {
406                 if (a->ops && a->ops->cleanup) {
407                         if (a->ops->cleanup(a, bind) == ACT_P_DELETED)
408                                 module_put(a->ops->owner);
409                         act = act->next;
410                         kfree(a);
411                 } else {
412                         /*FIXME: Remove later - catch insertion bugs*/
413                         WARN(1, "tcf_action_destroy: BUG? destroying NULL ops\n");
414                         act = act->next;
415                         kfree(a);
416                 }
417         }
418 }
419
420 int
421 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
422 {
423         int err = -EINVAL;
424
425         if (a->ops == NULL || a->ops->dump == NULL)
426                 return err;
427         return a->ops->dump(skb, a, bind, ref);
428 }
429
430 int
431 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
432 {
433         int err = -EINVAL;
434         unsigned char *b = skb_tail_pointer(skb);
435         struct nlattr *nest;
436
437         if (a->ops == NULL || a->ops->dump == NULL)
438                 return err;
439
440         NLA_PUT_STRING(skb, TCA_KIND, a->ops->kind);
441         if (tcf_action_copy_stats(skb, a, 0))
442                 goto nla_put_failure;
443         nest = nla_nest_start(skb, TCA_OPTIONS);
444         if (nest == NULL)
445                 goto nla_put_failure;
446         err = tcf_action_dump_old(skb, a, bind, ref);
447         if (err > 0) {
448                 nla_nest_end(skb, nest);
449                 return err;
450         }
451
452 nla_put_failure:
453         nlmsg_trim(skb, b);
454         return -1;
455 }
456 EXPORT_SYMBOL(tcf_action_dump_1);
457
458 int
459 tcf_action_dump(struct sk_buff *skb, struct tc_action *act, int bind, int ref)
460 {
461         struct tc_action *a;
462         int err = -EINVAL;
463         struct nlattr *nest;
464
465         while ((a = act) != NULL) {
466                 act = a->next;
467                 nest = nla_nest_start(skb, a->order);
468                 if (nest == NULL)
469                         goto nla_put_failure;
470                 err = tcf_action_dump_1(skb, a, bind, ref);
471                 if (err < 0)
472                         goto errout;
473                 nla_nest_end(skb, nest);
474         }
475
476         return 0;
477
478 nla_put_failure:
479         err = -EINVAL;
480 errout:
481         nla_nest_cancel(skb, nest);
482         return err;
483 }
484
485 struct tc_action *tcf_action_init_1(struct nlattr *nla, struct nlattr *est,
486                                     char *name, int ovr, int bind)
487 {
488         struct tc_action *a;
489         struct tc_action_ops *a_o;
490         char act_name[IFNAMSIZ];
491         struct nlattr *tb[TCA_ACT_MAX + 1];
492         struct nlattr *kind;
493         int err;
494
495         if (name == NULL) {
496                 err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
497                 if (err < 0)
498                         goto err_out;
499                 err = -EINVAL;
500                 kind = tb[TCA_ACT_KIND];
501                 if (kind == NULL)
502                         goto err_out;
503                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
504                         goto err_out;
505         } else {
506                 err = -EINVAL;
507                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
508                         goto err_out;
509         }
510
511         a_o = tc_lookup_action_n(act_name);
512         if (a_o == NULL) {
513 #ifdef CONFIG_MODULES
514                 rtnl_unlock();
515                 request_module("act_%s", act_name);
516                 rtnl_lock();
517
518                 a_o = tc_lookup_action_n(act_name);
519
520                 /* We dropped the RTNL semaphore in order to
521                  * perform the module load.  So, even if we
522                  * succeeded in loading the module we have to
523                  * tell the caller to replay the request.  We
524                  * indicate this using -EAGAIN.
525                  */
526                 if (a_o != NULL) {
527                         err = -EAGAIN;
528                         goto err_mod;
529                 }
530 #endif
531                 err = -ENOENT;
532                 goto err_out;
533         }
534
535         err = -ENOMEM;
536         a = kzalloc(sizeof(*a), GFP_KERNEL);
537         if (a == NULL)
538                 goto err_mod;
539
540         /* backward compatibility for policer */
541         if (name == NULL)
542                 err = a_o->init(tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
543         else
544                 err = a_o->init(nla, est, a, ovr, bind);
545         if (err < 0)
546                 goto err_free;
547
548         /* module count goes up only when brand new policy is created
549          * if it exists and is only bound to in a_o->init() then
550          * ACT_P_CREATED is not returned (a zero is).
551          */
552         if (err != ACT_P_CREATED)
553                 module_put(a_o->owner);
554         a->ops = a_o;
555
556         return a;
557
558 err_free:
559         kfree(a);
560 err_mod:
561         module_put(a_o->owner);
562 err_out:
563         return ERR_PTR(err);
564 }
565
566 struct tc_action *tcf_action_init(struct nlattr *nla, struct nlattr *est,
567                                   char *name, int ovr, int bind)
568 {
569         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
570         struct tc_action *head = NULL, *act, *act_prev = NULL;
571         int err;
572         int i;
573
574         err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
575         if (err < 0)
576                 return ERR_PTR(err);
577
578         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
579                 act = tcf_action_init_1(tb[i], est, name, ovr, bind);
580                 if (IS_ERR(act))
581                         goto err;
582                 act->order = i;
583
584                 if (head == NULL)
585                         head = act;
586                 else
587                         act_prev->next = act;
588                 act_prev = act;
589         }
590         return head;
591
592 err:
593         if (head != NULL)
594                 tcf_action_destroy(head, bind);
595         return act;
596 }
597
598 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
599                           int compat_mode)
600 {
601         int err = 0;
602         struct gnet_dump d;
603         struct tcf_act_hdr *h = a->priv;
604
605         if (h == NULL)
606                 goto errout;
607
608         /* compat_mode being true specifies a call that is supposed
609          * to add additional backward compatibility statistic TLVs.
610          */
611         if (compat_mode) {
612                 if (a->type == TCA_OLD_COMPAT)
613                         err = gnet_stats_start_copy_compat(skb, 0,
614                                 TCA_STATS, TCA_XSTATS, &h->tcf_lock, &d);
615                 else
616                         return 0;
617         } else
618                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
619                                             &h->tcf_lock, &d);
620
621         if (err < 0)
622                 goto errout;
623
624         if (a->ops != NULL && a->ops->get_stats != NULL)
625                 if (a->ops->get_stats(skb, a) < 0)
626                         goto errout;
627
628         if (gnet_stats_copy_basic(&d, &h->tcf_bstats) < 0 ||
629             gnet_stats_copy_rate_est(&d, &h->tcf_bstats,
630                                      &h->tcf_rate_est) < 0 ||
631             gnet_stats_copy_queue(&d, &h->tcf_qstats) < 0)
632                 goto errout;
633
634         if (gnet_stats_finish_copy(&d) < 0)
635                 goto errout;
636
637         return 0;
638
639 errout:
640         return -1;
641 }
642
643 static int
644 tca_get_fill(struct sk_buff *skb, struct tc_action *a, u32 pid, u32 seq,
645              u16 flags, int event, int bind, int ref)
646 {
647         struct tcamsg *t;
648         struct nlmsghdr *nlh;
649         unsigned char *b = skb_tail_pointer(skb);
650         struct nlattr *nest;
651
652         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
653
654         t = NLMSG_DATA(nlh);
655         t->tca_family = AF_UNSPEC;
656         t->tca__pad1 = 0;
657         t->tca__pad2 = 0;
658
659         nest = nla_nest_start(skb, TCA_ACT_TAB);
660         if (nest == NULL)
661                 goto nla_put_failure;
662
663         if (tcf_action_dump(skb, a, bind, ref) < 0)
664                 goto nla_put_failure;
665
666         nla_nest_end(skb, nest);
667
668         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
669         return skb->len;
670
671 nla_put_failure:
672 nlmsg_failure:
673         nlmsg_trim(skb, b);
674         return -1;
675 }
676
677 static int
678 act_get_notify(struct net *net, u32 pid, struct nlmsghdr *n,
679                struct tc_action *a, int event)
680 {
681         struct sk_buff *skb;
682
683         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
684         if (!skb)
685                 return -ENOBUFS;
686         if (tca_get_fill(skb, a, pid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
687                 kfree_skb(skb);
688                 return -EINVAL;
689         }
690
691         return rtnl_unicast(skb, net, pid);
692 }
693
694 static struct tc_action *
695 tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 pid)
696 {
697         struct nlattr *tb[TCA_ACT_MAX + 1];
698         struct tc_action *a;
699         int index;
700         int err;
701
702         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
703         if (err < 0)
704                 goto err_out;
705
706         err = -EINVAL;
707         if (tb[TCA_ACT_INDEX] == NULL ||
708             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
709                 goto err_out;
710         index = nla_get_u32(tb[TCA_ACT_INDEX]);
711
712         err = -ENOMEM;
713         a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
714         if (a == NULL)
715                 goto err_out;
716
717         err = -EINVAL;
718         a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
719         if (a->ops == NULL)
720                 goto err_free;
721         if (a->ops->lookup == NULL)
722                 goto err_mod;
723         err = -ENOENT;
724         if (a->ops->lookup(a, index) == 0)
725                 goto err_mod;
726
727         module_put(a->ops->owner);
728         return a;
729
730 err_mod:
731         module_put(a->ops->owner);
732 err_free:
733         kfree(a);
734 err_out:
735         return ERR_PTR(err);
736 }
737
738 static void cleanup_a(struct tc_action *act)
739 {
740         struct tc_action *a;
741
742         for (a = act; a; a = act) {
743                 act = a->next;
744                 kfree(a);
745         }
746 }
747
748 static struct tc_action *create_a(int i)
749 {
750         struct tc_action *act;
751
752         act = kzalloc(sizeof(*act), GFP_KERNEL);
753         if (act == NULL) {
754                 pr_debug("create_a: failed to alloc!\n");
755                 return NULL;
756         }
757         act->order = i;
758         return act;
759 }
760
761 static int tca_action_flush(struct net *net, struct nlattr *nla,
762                             struct nlmsghdr *n, u32 pid)
763 {
764         struct sk_buff *skb;
765         unsigned char *b;
766         struct nlmsghdr *nlh;
767         struct tcamsg *t;
768         struct netlink_callback dcb;
769         struct nlattr *nest;
770         struct nlattr *tb[TCA_ACT_MAX + 1];
771         struct nlattr *kind;
772         struct tc_action *a = create_a(0);
773         int err = -ENOMEM;
774
775         if (a == NULL) {
776                 pr_debug("tca_action_flush: couldnt create tc_action\n");
777                 return err;
778         }
779
780         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
781         if (!skb) {
782                 pr_debug("tca_action_flush: failed skb alloc\n");
783                 kfree(a);
784                 return err;
785         }
786
787         b = skb_tail_pointer(skb);
788
789         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
790         if (err < 0)
791                 goto err_out;
792
793         err = -EINVAL;
794         kind = tb[TCA_ACT_KIND];
795         a->ops = tc_lookup_action(kind);
796         if (a->ops == NULL)
797                 goto err_out;
798
799         nlh = NLMSG_PUT(skb, pid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t));
800         t = NLMSG_DATA(nlh);
801         t->tca_family = AF_UNSPEC;
802         t->tca__pad1 = 0;
803         t->tca__pad2 = 0;
804
805         nest = nla_nest_start(skb, TCA_ACT_TAB);
806         if (nest == NULL)
807                 goto nla_put_failure;
808
809         err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
810         if (err < 0)
811                 goto nla_put_failure;
812         if (err == 0)
813                 goto noflush_out;
814
815         nla_nest_end(skb, nest);
816
817         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
818         nlh->nlmsg_flags |= NLM_F_ROOT;
819         module_put(a->ops->owner);
820         kfree(a);
821         err = rtnetlink_send(skb, net, pid, RTNLGRP_TC,
822                              n->nlmsg_flags & NLM_F_ECHO);
823         if (err > 0)
824                 return 0;
825
826         return err;
827
828 nla_put_failure:
829 nlmsg_failure:
830         module_put(a->ops->owner);
831 err_out:
832 noflush_out:
833         kfree_skb(skb);
834         kfree(a);
835         return err;
836 }
837
838 static int
839 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
840               u32 pid, int event)
841 {
842         int i, ret;
843         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
844         struct tc_action *head = NULL, *act, *act_prev = NULL;
845
846         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
847         if (ret < 0)
848                 return ret;
849
850         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
851                 if (tb[1] != NULL)
852                         return tca_action_flush(net, tb[1], n, pid);
853                 else
854                         return -EINVAL;
855         }
856
857         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
858                 act = tcf_action_get_1(tb[i], n, pid);
859                 if (IS_ERR(act)) {
860                         ret = PTR_ERR(act);
861                         goto err;
862                 }
863                 act->order = i;
864
865                 if (head == NULL)
866                         head = act;
867                 else
868                         act_prev->next = act;
869                 act_prev = act;
870         }
871
872         if (event == RTM_GETACTION)
873                 ret = act_get_notify(net, pid, n, head, event);
874         else { /* delete */
875                 struct sk_buff *skb;
876
877                 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
878                 if (!skb) {
879                         ret = -ENOBUFS;
880                         goto err;
881                 }
882
883                 if (tca_get_fill(skb, head, pid, n->nlmsg_seq, 0, event,
884                                  0, 1) <= 0) {
885                         kfree_skb(skb);
886                         ret = -EINVAL;
887                         goto err;
888                 }
889
890                 /* now do the delete */
891                 tcf_action_destroy(head, 0);
892                 ret = rtnetlink_send(skb, net, pid, RTNLGRP_TC,
893                                      n->nlmsg_flags & NLM_F_ECHO);
894                 if (ret > 0)
895                         return 0;
896                 return ret;
897         }
898 err:
899         cleanup_a(head);
900         return ret;
901 }
902
903 static int tcf_add_notify(struct net *net, struct tc_action *a,
904                           u32 pid, u32 seq, int event, u16 flags)
905 {
906         struct tcamsg *t;
907         struct nlmsghdr *nlh;
908         struct sk_buff *skb;
909         struct nlattr *nest;
910         unsigned char *b;
911         int err = 0;
912
913         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
914         if (!skb)
915                 return -ENOBUFS;
916
917         b = skb_tail_pointer(skb);
918
919         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
920         t = NLMSG_DATA(nlh);
921         t->tca_family = AF_UNSPEC;
922         t->tca__pad1 = 0;
923         t->tca__pad2 = 0;
924
925         nest = nla_nest_start(skb, TCA_ACT_TAB);
926         if (nest == NULL)
927                 goto nla_put_failure;
928
929         if (tcf_action_dump(skb, a, 0, 0) < 0)
930                 goto nla_put_failure;
931
932         nla_nest_end(skb, nest);
933
934         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
935         NETLINK_CB(skb).dst_group = RTNLGRP_TC;
936
937         err = rtnetlink_send(skb, net, pid, RTNLGRP_TC, flags & NLM_F_ECHO);
938         if (err > 0)
939                 err = 0;
940         return err;
941
942 nla_put_failure:
943 nlmsg_failure:
944         kfree_skb(skb);
945         return -1;
946 }
947
948
949 static int
950 tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
951                u32 pid, int ovr)
952 {
953         int ret = 0;
954         struct tc_action *act;
955         struct tc_action *a;
956         u32 seq = n->nlmsg_seq;
957
958         act = tcf_action_init(nla, NULL, NULL, ovr, 0);
959         if (act == NULL)
960                 goto done;
961         if (IS_ERR(act)) {
962                 ret = PTR_ERR(act);
963                 goto done;
964         }
965
966         /* dump then free all the actions after update; inserted policy
967          * stays intact
968          */
969         ret = tcf_add_notify(net, act, pid, seq, RTM_NEWACTION, n->nlmsg_flags);
970         for (a = act; a; a = act) {
971                 act = a->next;
972                 kfree(a);
973         }
974 done:
975         return ret;
976 }
977
978 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
979 {
980         struct net *net = sock_net(skb->sk);
981         struct nlattr *tca[TCA_ACT_MAX + 1];
982         u32 pid = skb ? NETLINK_CB(skb).pid : 0;
983         int ret = 0, ovr = 0;
984
985         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
986         if (ret < 0)
987                 return ret;
988
989         if (tca[TCA_ACT_TAB] == NULL) {
990                 pr_notice("tc_ctl_action: received NO action attribs\n");
991                 return -EINVAL;
992         }
993
994         /* n->nlmsg_flags & NLM_F_CREATE */
995         switch (n->nlmsg_type) {
996         case RTM_NEWACTION:
997                 /* we are going to assume all other flags
998                  * imply create only if it doesn't exist
999                  * Note that CREATE | EXCL implies that
1000                  * but since we want avoid ambiguity (eg when flags
1001                  * is zero) then just set this
1002                  */
1003                 if (n->nlmsg_flags & NLM_F_REPLACE)
1004                         ovr = 1;
1005 replay:
1006                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, pid, ovr);
1007                 if (ret == -EAGAIN)
1008                         goto replay;
1009                 break;
1010         case RTM_DELACTION:
1011                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1012                                     pid, RTM_DELACTION);
1013                 break;
1014         case RTM_GETACTION:
1015                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1016                                     pid, RTM_GETACTION);
1017                 break;
1018         default:
1019                 BUG();
1020         }
1021
1022         return ret;
1023 }
1024
1025 static struct nlattr *
1026 find_dump_kind(const struct nlmsghdr *n)
1027 {
1028         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1029         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1030         struct nlattr *nla[TCAA_MAX + 1];
1031         struct nlattr *kind;
1032
1033         if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
1034                 return NULL;
1035         tb1 = nla[TCA_ACT_TAB];
1036         if (tb1 == NULL)
1037                 return NULL;
1038
1039         if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1040                       NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1041                 return NULL;
1042
1043         if (tb[1] == NULL)
1044                 return NULL;
1045         if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1046                       nla_len(tb[1]), NULL) < 0)
1047                 return NULL;
1048         kind = tb2[TCA_ACT_KIND];
1049
1050         return kind;
1051 }
1052
1053 static int
1054 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1055 {
1056         struct nlmsghdr *nlh;
1057         unsigned char *b = skb_tail_pointer(skb);
1058         struct nlattr *nest;
1059         struct tc_action_ops *a_o;
1060         struct tc_action a;
1061         int ret = 0;
1062         struct tcamsg *t = (struct tcamsg *) NLMSG_DATA(cb->nlh);
1063         struct nlattr *kind = find_dump_kind(cb->nlh);
1064
1065         if (kind == NULL) {
1066                 pr_info("tc_dump_action: action bad kind\n");
1067                 return 0;
1068         }
1069
1070         a_o = tc_lookup_action(kind);
1071         if (a_o == NULL)
1072                 return 0;
1073
1074         memset(&a, 0, sizeof(struct tc_action));
1075         a.ops = a_o;
1076
1077         if (a_o->walk == NULL) {
1078                 WARN(1, "tc_dump_action: %s !capable of dumping table\n",
1079                      a_o->kind);
1080                 goto nla_put_failure;
1081         }
1082
1083         nlh = NLMSG_PUT(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
1084                         cb->nlh->nlmsg_type, sizeof(*t));
1085         t = NLMSG_DATA(nlh);
1086         t->tca_family = AF_UNSPEC;
1087         t->tca__pad1 = 0;
1088         t->tca__pad2 = 0;
1089
1090         nest = nla_nest_start(skb, TCA_ACT_TAB);
1091         if (nest == NULL)
1092                 goto nla_put_failure;
1093
1094         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1095         if (ret < 0)
1096                 goto nla_put_failure;
1097
1098         if (ret > 0) {
1099                 nla_nest_end(skb, nest);
1100                 ret = skb->len;
1101         } else
1102                 nla_nest_cancel(skb, nest);
1103
1104         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1105         if (NETLINK_CB(cb->skb).pid && ret)
1106                 nlh->nlmsg_flags |= NLM_F_MULTI;
1107         module_put(a_o->owner);
1108         return skb->len;
1109
1110 nla_put_failure:
1111 nlmsg_failure:
1112         module_put(a_o->owner);
1113         nlmsg_trim(skb, b);
1114         return skb->len;
1115 }
1116
1117 static int __init tc_action_init(void)
1118 {
1119         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, NULL);
1120         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, NULL);
1121         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1122                       NULL);
1123
1124         return 0;
1125 }
1126
1127 subsys_initcall(tc_action_init);