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Linux/net/sched/act_api.c

Version: ~ [ linux-5.15-rc1 ] ~ [ linux-5.14.5 ] ~ [ linux-5.13.18 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.66 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.147 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.206 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.246 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.282 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.283 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
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  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 static void free_tcf(struct rcu_head *head)
 31 {
 32         struct tcf_common *p = container_of(head, struct tcf_common, tcfc_rcu);
 33 
 34         free_percpu(p->cpu_bstats);
 35         free_percpu(p->cpu_qstats);
 36         kfree(p);
 37 }
 38 
 39 static void tcf_hash_destroy(struct tc_action *a)
 40 {
 41         struct tcf_common *p = a->priv;
 42         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 43 
 44         spin_lock_bh(&hinfo->lock);
 45         hlist_del(&p->tcfc_head);
 46         spin_unlock_bh(&hinfo->lock);
 47         gen_kill_estimator(&p->tcfc_bstats,
 48                            &p->tcfc_rate_est);
 49         /*
 50          * gen_estimator est_timer() might access p->tcfc_lock
 51          * or bstats, wait a RCU grace period before freeing p
 52          */
 53         call_rcu(&p->tcfc_rcu, free_tcf);
 54 }
 55 
 56 int __tcf_hash_release(struct tc_action *a, bool bind, bool strict)
 57 {
 58         struct tcf_common *p = a->priv;
 59         int ret = 0;
 60 
 61         if (p) {
 62                 if (bind)
 63                         p->tcfc_bindcnt--;
 64                 else if (strict && p->tcfc_bindcnt > 0)
 65                         return -EPERM;
 66 
 67                 p->tcfc_refcnt--;
 68                 if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
 69                         if (a->ops->cleanup)
 70                                 a->ops->cleanup(a, bind);
 71                         tcf_hash_destroy(a);
 72                         ret = 1;
 73                 }
 74         }
 75 
 76         return ret;
 77 }
 78 EXPORT_SYMBOL(__tcf_hash_release);
 79 
 80 static int tcf_dump_walker(struct sk_buff *skb, struct netlink_callback *cb,
 81                            struct tc_action *a)
 82 {
 83         struct tcf_hashinfo *hinfo = a->ops->hinfo;
 84         struct hlist_head *head;
 85         struct tcf_common *p;
 86         int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
 87         struct nlattr *nest;
 88 
 89         spin_lock_bh(&hinfo->lock);
 90 
 91         s_i = cb->args[0];
 92 
 93         for (i = 0; i < (hinfo->hmask + 1); i++) {
 94                 head = &hinfo->htab[tcf_hash(i, hinfo->hmask)];
 95 
 96                 hlist_for_each_entry_rcu(p, head, tcfc_head) {
 97                         index++;
 98                         if (index < s_i)
 99                                 continue;
100                         a->priv = p;
101                         a->order = n_i;
102 
103                         nest = nla_nest_start(skb, a->order);
104                         if (nest == NULL)
105                                 goto nla_put_failure;
106                         err = tcf_action_dump_1(skb, a, 0, 0);
107                         if (err < 0) {
108                                 index--;
109                                 nlmsg_trim(skb, nest);
110                                 goto done;
111                         }
112                         nla_nest_end(skb, nest);
113                         n_i++;
114                         if (n_i >= TCA_ACT_MAX_PRIO)
115                                 goto done;
116                 }
117         }
118 done:
119         spin_unlock_bh(&hinfo->lock);
120         if (n_i)
121                 cb->args[0] += n_i;
122         return n_i;
123 
124 nla_put_failure:
125         nla_nest_cancel(skb, nest);
126         goto done;
127 }
128 
129 static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a)
130 {
131         struct tcf_hashinfo *hinfo = a->ops->hinfo;
132         struct hlist_head *head;
133         struct hlist_node *n;
134         struct tcf_common *p;
135         struct nlattr *nest;
136         int i = 0, n_i = 0;
137         int ret = -EINVAL;
138 
139         nest = nla_nest_start(skb, a->order);
140         if (nest == NULL)
141                 goto nla_put_failure;
142         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
143                 goto nla_put_failure;
144         for (i = 0; i < (hinfo->hmask + 1); i++) {
145                 head = &hinfo->htab[tcf_hash(i, hinfo->hmask)];
146                 hlist_for_each_entry_safe(p, n, head, tcfc_head) {
147                         a->priv = p;
148                         ret = __tcf_hash_release(a, false, true);
149                         if (ret == ACT_P_DELETED) {
150                                 module_put(a->ops->owner);
151                                 n_i++;
152                         } else if (ret < 0)
153                                 goto nla_put_failure;
154                 }
155         }
156         if (nla_put_u32(skb, TCA_FCNT, n_i))
157                 goto nla_put_failure;
158         nla_nest_end(skb, nest);
159 
160         return n_i;
161 nla_put_failure:
162         nla_nest_cancel(skb, nest);
163         return ret;
164 }
165 
166 static int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
167                               int type, struct tc_action *a)
168 {
169         if (type == RTM_DELACTION) {
170                 return tcf_del_walker(skb, a);
171         } else if (type == RTM_GETACTION) {
172                 return tcf_dump_walker(skb, cb, a);
173         } else {
174                 WARN(1, "tcf_generic_walker: unknown action %d\n", type);
175                 return -EINVAL;
176         }
177 }
178 
179 static struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
180 {
181         struct tcf_common *p = NULL;
182         struct hlist_head *head;
183 
184         spin_lock_bh(&hinfo->lock);
185         head = &hinfo->htab[tcf_hash(index, hinfo->hmask)];
186         hlist_for_each_entry_rcu(p, head, tcfc_head)
187                 if (p->tcfc_index == index)
188                         break;
189         spin_unlock_bh(&hinfo->lock);
190 
191         return p;
192 }
193 
194 u32 tcf_hash_new_index(struct tcf_hashinfo *hinfo)
195 {
196         u32 val = hinfo->index;
197 
198         do {
199                 if (++val == 0)
200                         val = 1;
201         } while (tcf_hash_lookup(val, hinfo));
202 
203         hinfo->index = val;
204         return val;
205 }
206 EXPORT_SYMBOL(tcf_hash_new_index);
207 
208 int tcf_hash_search(struct tc_action *a, u32 index)
209 {
210         struct tcf_hashinfo *hinfo = a->ops->hinfo;
211         struct tcf_common *p = tcf_hash_lookup(index, hinfo);
212 
213         if (p) {
214                 a->priv = p;
215                 return 1;
216         }
217         return 0;
218 }
219 EXPORT_SYMBOL(tcf_hash_search);
220 
221 int tcf_hash_check(u32 index, struct tc_action *a, int bind)
222 {
223         struct tcf_hashinfo *hinfo = a->ops->hinfo;
224         struct tcf_common *p = NULL;
225         if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
226                 if (bind)
227                         p->tcfc_bindcnt++;
228                 p->tcfc_refcnt++;
229                 a->priv = p;
230                 return 1;
231         }
232         return 0;
233 }
234 EXPORT_SYMBOL(tcf_hash_check);
235 
236 void tcf_hash_cleanup(struct tc_action *a, struct nlattr *est)
237 {
238         struct tcf_common *pc = a->priv;
239         if (est)
240                 gen_kill_estimator(&pc->tcfc_bstats,
241                                    &pc->tcfc_rate_est);
242         call_rcu(&pc->tcfc_rcu, free_tcf);
243 }
244 EXPORT_SYMBOL(tcf_hash_cleanup);
245 
246 int tcf_hash_create(u32 index, struct nlattr *est, struct tc_action *a,
247                     int size, int bind, bool cpustats)
248 {
249         struct tcf_hashinfo *hinfo = a->ops->hinfo;
250         struct tcf_common *p = kzalloc(size, GFP_KERNEL);
251         int err = -ENOMEM;
252 
253         if (unlikely(!p))
254                 return -ENOMEM;
255         p->tcfc_refcnt = 1;
256         if (bind)
257                 p->tcfc_bindcnt = 1;
258 
259         if (cpustats) {
260                 p->cpu_bstats = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
261                 if (!p->cpu_bstats) {
262 err1:
263                         kfree(p);
264                         return err;
265                 }
266                 p->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
267                 if (!p->cpu_qstats) {
268 err2:
269                         free_percpu(p->cpu_bstats);
270                         goto err1;
271                 }
272         }
273         spin_lock_init(&p->tcfc_lock);
274         INIT_HLIST_NODE(&p->tcfc_head);
275         p->tcfc_index = index ? index : tcf_hash_new_index(hinfo);
276         p->tcfc_tm.install = jiffies;
277         p->tcfc_tm.lastuse = jiffies;
278         if (est) {
279                 err = gen_new_estimator(&p->tcfc_bstats, p->cpu_bstats,
280                                         &p->tcfc_rate_est,
281                                         &p->tcfc_lock, est);
282                 if (err) {
283                         free_percpu(p->cpu_qstats);
284                         goto err2;
285                 }
286         }
287 
288         a->priv = (void *) p;
289         return 0;
290 }
291 EXPORT_SYMBOL(tcf_hash_create);
292 
293 void tcf_hash_insert(struct tc_action *a)
294 {
295         struct tcf_common *p = a->priv;
296         struct tcf_hashinfo *hinfo = a->ops->hinfo;
297         unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
298 
299         spin_lock_bh(&hinfo->lock);
300         hlist_add_head(&p->tcfc_head, &hinfo->htab[h]);
301         spin_unlock_bh(&hinfo->lock);
302 }
303 EXPORT_SYMBOL(tcf_hash_insert);
304 
305 static LIST_HEAD(act_base);
306 static DEFINE_RWLOCK(act_mod_lock);
307 
308 int tcf_register_action(struct tc_action_ops *act, unsigned int mask)
309 {
310         struct tc_action_ops *a;
311         int err;
312 
313         /* Must supply act, dump and init */
314         if (!act->act || !act->dump || !act->init)
315                 return -EINVAL;
316 
317         /* Supply defaults */
318         if (!act->lookup)
319                 act->lookup = tcf_hash_search;
320         if (!act->walk)
321                 act->walk = tcf_generic_walker;
322 
323         act->hinfo = kmalloc(sizeof(struct tcf_hashinfo), GFP_KERNEL);
324         if (!act->hinfo)
325                 return -ENOMEM;
326         err = tcf_hashinfo_init(act->hinfo, mask);
327         if (err) {
328                 kfree(act->hinfo);
329                 return err;
330         }
331 
332         write_lock(&act_mod_lock);
333         list_for_each_entry(a, &act_base, head) {
334                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
335                         write_unlock(&act_mod_lock);
336                         tcf_hashinfo_destroy(act->hinfo);
337                         kfree(act->hinfo);
338                         return -EEXIST;
339                 }
340         }
341         list_add_tail(&act->head, &act_base);
342         write_unlock(&act_mod_lock);
343         return 0;
344 }
345 EXPORT_SYMBOL(tcf_register_action);
346 
347 int tcf_unregister_action(struct tc_action_ops *act)
348 {
349         struct tc_action_ops *a;
350         int err = -ENOENT;
351 
352         write_lock(&act_mod_lock);
353         list_for_each_entry(a, &act_base, head) {
354                 if (a == act) {
355                         list_del(&act->head);
356                         tcf_hashinfo_destroy(act->hinfo);
357                         kfree(act->hinfo);
358                         err = 0;
359                         break;
360                 }
361         }
362         write_unlock(&act_mod_lock);
363         return err;
364 }
365 EXPORT_SYMBOL(tcf_unregister_action);
366 
367 /* lookup by name */
368 static struct tc_action_ops *tc_lookup_action_n(char *kind)
369 {
370         struct tc_action_ops *a, *res = NULL;
371 
372         if (kind) {
373                 read_lock(&act_mod_lock);
374                 list_for_each_entry(a, &act_base, head) {
375                         if (strcmp(kind, a->kind) == 0) {
376                                 if (try_module_get(a->owner))
377                                         res = a;
378                                 break;
379                         }
380                 }
381                 read_unlock(&act_mod_lock);
382         }
383         return res;
384 }
385 
386 /* lookup by nlattr */
387 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
388 {
389         struct tc_action_ops *a, *res = NULL;
390 
391         if (kind) {
392                 read_lock(&act_mod_lock);
393                 list_for_each_entry(a, &act_base, head) {
394                         if (nla_strcmp(kind, a->kind) == 0) {
395                                 if (try_module_get(a->owner))
396                                         res = a;
397                                 break;
398                         }
399                 }
400                 read_unlock(&act_mod_lock);
401         }
402         return res;
403 }
404 
405 int tcf_action_exec(struct sk_buff *skb, const struct list_head *actions,
406                     struct tcf_result *res)
407 {
408         const struct tc_action *a;
409         int ret = -1;
410 
411         if (skb->tc_verd & TC_NCLS) {
412                 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
413                 ret = TC_ACT_OK;
414                 goto exec_done;
415         }
416         list_for_each_entry(a, actions, list) {
417 repeat:
418                 ret = a->ops->act(skb, a, res);
419                 if (ret == TC_ACT_REPEAT)
420                         goto repeat;    /* we need a ttl - JHS */
421                 if (ret != TC_ACT_PIPE)
422                         goto exec_done;
423         }
424 exec_done:
425         return ret;
426 }
427 EXPORT_SYMBOL(tcf_action_exec);
428 
429 int tcf_action_destroy(struct list_head *actions, int bind)
430 {
431         struct tc_action *a, *tmp;
432         int ret = 0;
433 
434         list_for_each_entry_safe(a, tmp, actions, list) {
435                 ret = __tcf_hash_release(a, bind, true);
436                 if (ret == ACT_P_DELETED)
437                         module_put(a->ops->owner);
438                 else if (ret < 0)
439                         return ret;
440                 list_del(&a->list);
441                 kfree(a);
442         }
443         return ret;
444 }
445 
446 int
447 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
448 {
449         return a->ops->dump(skb, a, bind, ref);
450 }
451 
452 int
453 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
454 {
455         int err = -EINVAL;
456         unsigned char *b = skb_tail_pointer(skb);
457         struct nlattr *nest;
458 
459         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
460                 goto nla_put_failure;
461         if (tcf_action_copy_stats(skb, a, 0))
462                 goto nla_put_failure;
463         nest = nla_nest_start(skb, TCA_OPTIONS);
464         if (nest == NULL)
465                 goto nla_put_failure;
466         err = tcf_action_dump_old(skb, a, bind, ref);
467         if (err > 0) {
468                 nla_nest_end(skb, nest);
469                 return err;
470         }
471 
472 nla_put_failure:
473         nlmsg_trim(skb, b);
474         return -1;
475 }
476 EXPORT_SYMBOL(tcf_action_dump_1);
477 
478 int
479 tcf_action_dump(struct sk_buff *skb, struct list_head *actions, int bind, int ref)
480 {
481         struct tc_action *a;
482         int err = -EINVAL;
483         struct nlattr *nest;
484 
485         list_for_each_entry(a, actions, list) {
486                 nest = nla_nest_start(skb, a->order);
487                 if (nest == NULL)
488                         goto nla_put_failure;
489                 err = tcf_action_dump_1(skb, a, bind, ref);
490                 if (err < 0)
491                         goto errout;
492                 nla_nest_end(skb, nest);
493         }
494 
495         return 0;
496 
497 nla_put_failure:
498         err = -EINVAL;
499 errout:
500         nla_nest_cancel(skb, nest);
501         return err;
502 }
503 
504 struct tc_action *tcf_action_init_1(struct net *net, struct nlattr *nla,
505                                     struct nlattr *est, char *name, int ovr,
506                                     int bind)
507 {
508         struct tc_action *a;
509         struct tc_action_ops *a_o;
510         char act_name[IFNAMSIZ];
511         struct nlattr *tb[TCA_ACT_MAX + 1];
512         struct nlattr *kind;
513         int err;
514 
515         if (name == NULL) {
516                 err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
517                 if (err < 0)
518                         goto err_out;
519                 err = -EINVAL;
520                 kind = tb[TCA_ACT_KIND];
521                 if (kind == NULL)
522                         goto err_out;
523                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
524                         goto err_out;
525         } else {
526                 err = -EINVAL;
527                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
528                         goto err_out;
529         }
530 
531         a_o = tc_lookup_action_n(act_name);
532         if (a_o == NULL) {
533 #ifdef CONFIG_MODULES
534                 rtnl_unlock();
535                 request_module("act_%s", act_name);
536                 rtnl_lock();
537 
538                 a_o = tc_lookup_action_n(act_name);
539 
540                 /* We dropped the RTNL semaphore in order to
541                  * perform the module load.  So, even if we
542                  * succeeded in loading the module we have to
543                  * tell the caller to replay the request.  We
544                  * indicate this using -EAGAIN.
545                  */
546                 if (a_o != NULL) {
547                         err = -EAGAIN;
548                         goto err_mod;
549                 }
550 #endif
551                 err = -ENOENT;
552                 goto err_out;
553         }
554 
555         err = -ENOMEM;
556         a = kzalloc(sizeof(*a), GFP_KERNEL);
557         if (a == NULL)
558                 goto err_mod;
559 
560         a->ops = a_o;
561         INIT_LIST_HEAD(&a->list);
562         /* backward compatibility for policer */
563         if (name == NULL)
564                 err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
565         else
566                 err = a_o->init(net, nla, est, a, ovr, bind);
567         if (err < 0)
568                 goto err_free;
569 
570         /* module count goes up only when brand new policy is created
571          * if it exists and is only bound to in a_o->init() then
572          * ACT_P_CREATED is not returned (a zero is).
573          */
574         if (err != ACT_P_CREATED)
575                 module_put(a_o->owner);
576 
577         return a;
578 
579 err_free:
580         kfree(a);
581 err_mod:
582         module_put(a_o->owner);
583 err_out:
584         return ERR_PTR(err);
585 }
586 
587 int tcf_action_init(struct net *net, struct nlattr *nla,
588                                   struct nlattr *est, char *name, int ovr,
589                                   int bind, struct list_head *actions)
590 {
591         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
592         struct tc_action *act;
593         int err;
594         int i;
595 
596         err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
597         if (err < 0)
598                 return err;
599 
600         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
601                 act = tcf_action_init_1(net, tb[i], est, name, ovr, bind);
602                 if (IS_ERR(act)) {
603                         err = PTR_ERR(act);
604                         goto err;
605                 }
606                 act->order = i;
607                 list_add_tail(&act->list, actions);
608         }
609         return 0;
610 
611 err:
612         tcf_action_destroy(actions, bind);
613         return err;
614 }
615 
616 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
617                           int compat_mode)
618 {
619         int err = 0;
620         struct gnet_dump d;
621         struct tcf_common *p = a->priv;
622 
623         if (p == NULL)
624                 goto errout;
625 
626         /* compat_mode being true specifies a call that is supposed
627          * to add additional backward compatibility statistic TLVs.
628          */
629         if (compat_mode) {
630                 if (a->type == TCA_OLD_COMPAT)
631                         err = gnet_stats_start_copy_compat(skb, 0,
632                                 TCA_STATS, TCA_XSTATS, &p->tcfc_lock, &d);
633                 else
634                         return 0;
635         } else
636                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
637                                             &p->tcfc_lock, &d);
638 
639         if (err < 0)
640                 goto errout;
641 
642         if (gnet_stats_copy_basic(&d, p->cpu_bstats, &p->tcfc_bstats) < 0 ||
643             gnet_stats_copy_rate_est(&d, &p->tcfc_bstats,
644                                      &p->tcfc_rate_est) < 0 ||
645             gnet_stats_copy_queue(&d, p->cpu_qstats,
646                                   &p->tcfc_qstats,
647                                   p->tcfc_qstats.qlen) < 0)
648                 goto errout;
649 
650         if (gnet_stats_finish_copy(&d) < 0)
651                 goto errout;
652 
653         return 0;
654 
655 errout:
656         return -1;
657 }
658 
659 static int
660 tca_get_fill(struct sk_buff *skb, struct list_head *actions, u32 portid, u32 seq,
661              u16 flags, int event, int bind, int ref)
662 {
663         struct tcamsg *t;
664         struct nlmsghdr *nlh;
665         unsigned char *b = skb_tail_pointer(skb);
666         struct nlattr *nest;
667 
668         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
669         if (!nlh)
670                 goto out_nlmsg_trim;
671         t = nlmsg_data(nlh);
672         t->tca_family = AF_UNSPEC;
673         t->tca__pad1 = 0;
674         t->tca__pad2 = 0;
675 
676         nest = nla_nest_start(skb, TCA_ACT_TAB);
677         if (nest == NULL)
678                 goto out_nlmsg_trim;
679 
680         if (tcf_action_dump(skb, actions, bind, ref) < 0)
681                 goto out_nlmsg_trim;
682 
683         nla_nest_end(skb, nest);
684 
685         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
686         return skb->len;
687 
688 out_nlmsg_trim:
689         nlmsg_trim(skb, b);
690         return -1;
691 }
692 
693 static int
694 act_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
695                struct list_head *actions, int event)
696 {
697         struct sk_buff *skb;
698 
699         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
700         if (!skb)
701                 return -ENOBUFS;
702         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
703                 kfree_skb(skb);
704                 return -EINVAL;
705         }
706 
707         return rtnl_unicast(skb, net, portid);
708 }
709 
710 static struct tc_action *create_a(int i)
711 {
712         struct tc_action *act;
713 
714         act = kzalloc(sizeof(*act), GFP_KERNEL);
715         if (act == NULL) {
716                 pr_debug("create_a: failed to alloc!\n");
717                 return NULL;
718         }
719         act->order = i;
720         INIT_LIST_HEAD(&act->list);
721         return act;
722 }
723 
724 static struct tc_action *
725 tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 portid)
726 {
727         struct nlattr *tb[TCA_ACT_MAX + 1];
728         struct tc_action *a;
729         int index;
730         int err;
731 
732         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
733         if (err < 0)
734                 goto err_out;
735 
736         err = -EINVAL;
737         if (tb[TCA_ACT_INDEX] == NULL ||
738             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
739                 goto err_out;
740         index = nla_get_u32(tb[TCA_ACT_INDEX]);
741 
742         err = -ENOMEM;
743         a = create_a(0);
744         if (a == NULL)
745                 goto err_out;
746 
747         err = -EINVAL;
748         a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
749         if (a->ops == NULL) /* could happen in batch of actions */
750                 goto err_free;
751         err = -ENOENT;
752         if (a->ops->lookup(a, index) == 0)
753                 goto err_mod;
754 
755         module_put(a->ops->owner);
756         return a;
757 
758 err_mod:
759         module_put(a->ops->owner);
760 err_free:
761         kfree(a);
762 err_out:
763         return ERR_PTR(err);
764 }
765 
766 static void cleanup_a(struct list_head *actions)
767 {
768         struct tc_action *a, *tmp;
769 
770         list_for_each_entry_safe(a, tmp, actions, list) {
771                 list_del(&a->list);
772                 kfree(a);
773         }
774 }
775 
776 static int tca_action_flush(struct net *net, struct nlattr *nla,
777                             struct nlmsghdr *n, u32 portid)
778 {
779         struct sk_buff *skb;
780         unsigned char *b;
781         struct nlmsghdr *nlh;
782         struct tcamsg *t;
783         struct netlink_callback dcb;
784         struct nlattr *nest;
785         struct nlattr *tb[TCA_ACT_MAX + 1];
786         struct nlattr *kind;
787         struct tc_action a;
788         int err = -ENOMEM;
789 
790         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
791         if (!skb) {
792                 pr_debug("tca_action_flush: failed skb alloc\n");
793                 return err;
794         }
795 
796         b = skb_tail_pointer(skb);
797 
798         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
799         if (err < 0)
800                 goto err_out;
801 
802         err = -EINVAL;
803         kind = tb[TCA_ACT_KIND];
804         memset(&a, 0, sizeof(struct tc_action));
805         INIT_LIST_HEAD(&a.list);
806         a.ops = tc_lookup_action(kind);
807         if (a.ops == NULL) /*some idjot trying to flush unknown action */
808                 goto err_out;
809 
810         nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t), 0);
811         if (!nlh)
812                 goto out_module_put;
813         t = nlmsg_data(nlh);
814         t->tca_family = AF_UNSPEC;
815         t->tca__pad1 = 0;
816         t->tca__pad2 = 0;
817 
818         nest = nla_nest_start(skb, TCA_ACT_TAB);
819         if (nest == NULL)
820                 goto out_module_put;
821 
822         err = a.ops->walk(skb, &dcb, RTM_DELACTION, &a);
823         if (err < 0)
824                 goto out_module_put;
825         if (err == 0)
826                 goto noflush_out;
827 
828         nla_nest_end(skb, nest);
829 
830         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
831         nlh->nlmsg_flags |= NLM_F_ROOT;
832         module_put(a.ops->owner);
833         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
834                              n->nlmsg_flags & NLM_F_ECHO);
835         if (err > 0)
836                 return 0;
837 
838         return err;
839 
840 out_module_put:
841         module_put(a.ops->owner);
842 err_out:
843 noflush_out:
844         kfree_skb(skb);
845         return err;
846 }
847 
848 static int
849 tcf_del_notify(struct net *net, struct nlmsghdr *n, struct list_head *actions,
850                u32 portid)
851 {
852         int ret;
853         struct sk_buff *skb;
854 
855         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
856         if (!skb)
857                 return -ENOBUFS;
858 
859         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, RTM_DELACTION,
860                          0, 1) <= 0) {
861                 kfree_skb(skb);
862                 return -EINVAL;
863         }
864 
865         /* now do the delete */
866         ret = tcf_action_destroy(actions, 0);
867         if (ret < 0) {
868                 kfree_skb(skb);
869                 return ret;
870         }
871 
872         ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
873                              n->nlmsg_flags & NLM_F_ECHO);
874         if (ret > 0)
875                 return 0;
876         return ret;
877 }
878 
879 static int
880 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
881               u32 portid, int event)
882 {
883         int i, ret;
884         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
885         struct tc_action *act;
886         LIST_HEAD(actions);
887 
888         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
889         if (ret < 0)
890                 return ret;
891 
892         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
893                 if (tb[1] != NULL)
894                         return tca_action_flush(net, tb[1], n, portid);
895                 else
896                         return -EINVAL;
897         }
898 
899         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
900                 act = tcf_action_get_1(tb[i], n, portid);
901                 if (IS_ERR(act)) {
902                         ret = PTR_ERR(act);
903                         goto err;
904                 }
905                 act->order = i;
906                 list_add_tail(&act->list, &actions);
907         }
908 
909         if (event == RTM_GETACTION)
910                 ret = act_get_notify(net, portid, n, &actions, event);
911         else { /* delete */
912                 ret = tcf_del_notify(net, n, &actions, portid);
913                 if (ret)
914                         goto err;
915                 return ret;
916         }
917 err:
918         cleanup_a(&actions);
919         return ret;
920 }
921 
922 static int
923 tcf_add_notify(struct net *net, struct nlmsghdr *n, struct list_head *actions,
924                u32 portid)
925 {
926         struct sk_buff *skb;
927         int err = 0;
928 
929         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
930         if (!skb)
931                 return -ENOBUFS;
932 
933         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, n->nlmsg_flags,
934                          RTM_NEWACTION, 0, 0) <= 0) {
935                 kfree_skb(skb);
936                 return -EINVAL;
937         }
938 
939         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
940                              n->nlmsg_flags & NLM_F_ECHO);
941         if (err > 0)
942                 err = 0;
943         return err;
944 }
945 
946 static int
947 tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
948                u32 portid, int ovr)
949 {
950         int ret = 0;
951         LIST_HEAD(actions);
952 
953         ret = tcf_action_init(net, nla, NULL, NULL, ovr, 0, &actions);
954         if (ret)
955                 goto done;
956 
957         /* dump then free all the actions after update; inserted policy
958          * stays intact
959          */
960         ret = tcf_add_notify(net, n, &actions, portid);
961         cleanup_a(&actions);
962 done:
963         return ret;
964 }
965 
966 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n)
967 {
968         struct net *net = sock_net(skb->sk);
969         struct nlattr *tca[TCA_ACT_MAX + 1];
970         u32 portid = skb ? NETLINK_CB(skb).portid : 0;
971         int ret = 0, ovr = 0;
972 
973         if ((n->nlmsg_type != RTM_GETACTION) && !netlink_capable(skb, CAP_NET_ADMIN))
974                 return -EPERM;
975 
976         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
977         if (ret < 0)
978                 return ret;
979 
980         if (tca[TCA_ACT_TAB] == NULL) {
981                 pr_notice("tc_ctl_action: received NO action attribs\n");
982                 return -EINVAL;
983         }
984 
985         /* n->nlmsg_flags & NLM_F_CREATE */
986         switch (n->nlmsg_type) {
987         case RTM_NEWACTION:
988                 /* we are going to assume all other flags
989                  * imply create only if it doesn't exist
990                  * Note that CREATE | EXCL implies that
991                  * but since we want avoid ambiguity (eg when flags
992                  * is zero) then just set this
993                  */
994                 if (n->nlmsg_flags & NLM_F_REPLACE)
995                         ovr = 1;
996 replay:
997                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr);
998                 if (ret == -EAGAIN)
999                         goto replay;
1000                 break;
1001         case RTM_DELACTION:
1002                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1003                                     portid, RTM_DELACTION);
1004                 break;
1005         case RTM_GETACTION:
1006                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1007                                     portid, RTM_GETACTION);
1008                 break;
1009         default:
1010                 BUG();
1011         }
1012 
1013         return ret;
1014 }
1015 
1016 static struct nlattr *
1017 find_dump_kind(const struct nlmsghdr *n)
1018 {
1019         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1020         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1021         struct nlattr *nla[TCAA_MAX + 1];
1022         struct nlattr *kind;
1023 
1024         if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
1025                 return NULL;
1026         tb1 = nla[TCA_ACT_TAB];
1027         if (tb1 == NULL)
1028                 return NULL;
1029 
1030         if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1031                       NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1032                 return NULL;
1033 
1034         if (tb[1] == NULL)
1035                 return NULL;
1036         if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1037                       nla_len(tb[1]), NULL) < 0)
1038                 return NULL;
1039         kind = tb2[TCA_ACT_KIND];
1040 
1041         return kind;
1042 }
1043 
1044 static int
1045 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1046 {
1047         struct nlmsghdr *nlh;
1048         unsigned char *b = skb_tail_pointer(skb);
1049         struct nlattr *nest;
1050         struct tc_action_ops *a_o;
1051         struct tc_action a;
1052         int ret = 0;
1053         struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1054         struct nlattr *kind = find_dump_kind(cb->nlh);
1055 
1056         if (kind == NULL) {
1057                 pr_info("tc_dump_action: action bad kind\n");
1058                 return 0;
1059         }
1060 
1061         a_o = tc_lookup_action(kind);
1062         if (a_o == NULL)
1063                 return 0;
1064 
1065         memset(&a, 0, sizeof(struct tc_action));
1066         a.ops = a_o;
1067 
1068         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1069                         cb->nlh->nlmsg_type, sizeof(*t), 0);
1070         if (!nlh)
1071                 goto out_module_put;
1072         t = nlmsg_data(nlh);
1073         t->tca_family = AF_UNSPEC;
1074         t->tca__pad1 = 0;
1075         t->tca__pad2 = 0;
1076 
1077         nest = nla_nest_start(skb, TCA_ACT_TAB);
1078         if (nest == NULL)
1079                 goto out_module_put;
1080 
1081         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1082         if (ret < 0)
1083                 goto out_module_put;
1084 
1085         if (ret > 0) {
1086                 nla_nest_end(skb, nest);
1087                 ret = skb->len;
1088         } else
1089                 nla_nest_cancel(skb, nest);
1090 
1091         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1092         if (NETLINK_CB(cb->skb).portid && ret)
1093                 nlh->nlmsg_flags |= NLM_F_MULTI;
1094         module_put(a_o->owner);
1095         return skb->len;
1096 
1097 out_module_put:
1098         module_put(a_o->owner);
1099         nlmsg_trim(skb, b);
1100         return skb->len;
1101 }
1102 
1103 static int __init tc_action_init(void)
1104 {
1105         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, NULL);
1106         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, NULL);
1107         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1108                       NULL);
1109 
1110         return 0;
1111 }
1112 
1113 subsys_initcall(tc_action_init);
1114 

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