GNU Linux-libre 6.8.9-gnu
[releases.git] / net / sched / act_mirred.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * net/sched/act_mirred.c       packet mirroring and redirect actions
4  *
5  * Authors:     Jamal Hadi Salim (2002-4)
6  *
7  * TODO: Add ingress support (and socket redirect support)
8  */
9
10 #include <linux/types.h>
11 #include <linux/kernel.h>
12 #include <linux/string.h>
13 #include <linux/errno.h>
14 #include <linux/skbuff.h>
15 #include <linux/rtnetlink.h>
16 #include <linux/module.h>
17 #include <linux/init.h>
18 #include <linux/gfp.h>
19 #include <linux/if_arp.h>
20 #include <net/net_namespace.h>
21 #include <net/netlink.h>
22 #include <net/dst.h>
23 #include <net/pkt_sched.h>
24 #include <net/pkt_cls.h>
25 #include <linux/tc_act/tc_mirred.h>
26 #include <net/tc_act/tc_mirred.h>
27 #include <net/tc_wrapper.h>
28
29 static LIST_HEAD(mirred_list);
30 static DEFINE_SPINLOCK(mirred_list_lock);
31
32 #define MIRRED_NEST_LIMIT    4
33 static DEFINE_PER_CPU(unsigned int, mirred_nest_level);
34
35 static bool tcf_mirred_is_act_redirect(int action)
36 {
37         return action == TCA_EGRESS_REDIR || action == TCA_INGRESS_REDIR;
38 }
39
40 static bool tcf_mirred_act_wants_ingress(int action)
41 {
42         switch (action) {
43         case TCA_EGRESS_REDIR:
44         case TCA_EGRESS_MIRROR:
45                 return false;
46         case TCA_INGRESS_REDIR:
47         case TCA_INGRESS_MIRROR:
48                 return true;
49         default:
50                 BUG();
51         }
52 }
53
54 static bool tcf_mirred_can_reinsert(int action)
55 {
56         switch (action) {
57         case TC_ACT_SHOT:
58         case TC_ACT_STOLEN:
59         case TC_ACT_QUEUED:
60         case TC_ACT_TRAP:
61                 return true;
62         }
63         return false;
64 }
65
66 static struct net_device *tcf_mirred_dev_dereference(struct tcf_mirred *m)
67 {
68         return rcu_dereference_protected(m->tcfm_dev,
69                                          lockdep_is_held(&m->tcf_lock));
70 }
71
72 static void tcf_mirred_release(struct tc_action *a)
73 {
74         struct tcf_mirred *m = to_mirred(a);
75         struct net_device *dev;
76
77         spin_lock(&mirred_list_lock);
78         list_del(&m->tcfm_list);
79         spin_unlock(&mirred_list_lock);
80
81         /* last reference to action, no need to lock */
82         dev = rcu_dereference_protected(m->tcfm_dev, 1);
83         netdev_put(dev, &m->tcfm_dev_tracker);
84 }
85
86 static const struct nla_policy mirred_policy[TCA_MIRRED_MAX + 1] = {
87         [TCA_MIRRED_PARMS]      = { .len = sizeof(struct tc_mirred) },
88         [TCA_MIRRED_BLOCKID]    = NLA_POLICY_MIN(NLA_U32, 1),
89 };
90
91 static struct tc_action_ops act_mirred_ops;
92
93 static void tcf_mirred_replace_dev(struct tcf_mirred *m,
94                                    struct net_device *ndev)
95 {
96         struct net_device *odev;
97
98         odev = rcu_replace_pointer(m->tcfm_dev, ndev,
99                                    lockdep_is_held(&m->tcf_lock));
100         netdev_put(odev, &m->tcfm_dev_tracker);
101 }
102
103 static int tcf_mirred_init(struct net *net, struct nlattr *nla,
104                            struct nlattr *est, struct tc_action **a,
105                            struct tcf_proto *tp,
106                            u32 flags, struct netlink_ext_ack *extack)
107 {
108         struct tc_action_net *tn = net_generic(net, act_mirred_ops.net_id);
109         bool bind = flags & TCA_ACT_FLAGS_BIND;
110         struct nlattr *tb[TCA_MIRRED_MAX + 1];
111         struct tcf_chain *goto_ch = NULL;
112         bool mac_header_xmit = false;
113         struct tc_mirred *parm;
114         struct tcf_mirred *m;
115         bool exists = false;
116         int ret, err;
117         u32 index;
118
119         if (!nla) {
120                 NL_SET_ERR_MSG_MOD(extack, "Mirred requires attributes to be passed");
121                 return -EINVAL;
122         }
123         ret = nla_parse_nested_deprecated(tb, TCA_MIRRED_MAX, nla,
124                                           mirred_policy, extack);
125         if (ret < 0)
126                 return ret;
127         if (!tb[TCA_MIRRED_PARMS]) {
128                 NL_SET_ERR_MSG_MOD(extack, "Missing required mirred parameters");
129                 return -EINVAL;
130         }
131         parm = nla_data(tb[TCA_MIRRED_PARMS]);
132         index = parm->index;
133         err = tcf_idr_check_alloc(tn, &index, a, bind);
134         if (err < 0)
135                 return err;
136         exists = err;
137         if (exists && bind)
138                 return ACT_P_BOUND;
139
140         if (tb[TCA_MIRRED_BLOCKID] && parm->ifindex) {
141                 NL_SET_ERR_MSG_MOD(extack,
142                                    "Cannot specify Block ID and dev simultaneously");
143                 if (exists)
144                         tcf_idr_release(*a, bind);
145                 else
146                         tcf_idr_cleanup(tn, index);
147
148                 return -EINVAL;
149         }
150
151         switch (parm->eaction) {
152         case TCA_EGRESS_MIRROR:
153         case TCA_EGRESS_REDIR:
154         case TCA_INGRESS_REDIR:
155         case TCA_INGRESS_MIRROR:
156                 break;
157         default:
158                 if (exists)
159                         tcf_idr_release(*a, bind);
160                 else
161                         tcf_idr_cleanup(tn, index);
162                 NL_SET_ERR_MSG_MOD(extack, "Unknown mirred option");
163                 return -EINVAL;
164         }
165
166         if (!exists) {
167                 if (!parm->ifindex && !tb[TCA_MIRRED_BLOCKID]) {
168                         tcf_idr_cleanup(tn, index);
169                         NL_SET_ERR_MSG_MOD(extack,
170                                            "Must specify device or block");
171                         return -EINVAL;
172                 }
173                 ret = tcf_idr_create_from_flags(tn, index, est, a,
174                                                 &act_mirred_ops, bind, flags);
175                 if (ret) {
176                         tcf_idr_cleanup(tn, index);
177                         return ret;
178                 }
179                 ret = ACT_P_CREATED;
180         } else if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
181                 tcf_idr_release(*a, bind);
182                 return -EEXIST;
183         }
184
185         m = to_mirred(*a);
186         if (ret == ACT_P_CREATED)
187                 INIT_LIST_HEAD(&m->tcfm_list);
188
189         err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
190         if (err < 0)
191                 goto release_idr;
192
193         spin_lock_bh(&m->tcf_lock);
194
195         if (parm->ifindex) {
196                 struct net_device *ndev;
197
198                 ndev = dev_get_by_index(net, parm->ifindex);
199                 if (!ndev) {
200                         spin_unlock_bh(&m->tcf_lock);
201                         err = -ENODEV;
202                         goto put_chain;
203                 }
204                 mac_header_xmit = dev_is_mac_header_xmit(ndev);
205                 tcf_mirred_replace_dev(m, ndev);
206                 netdev_tracker_alloc(ndev, &m->tcfm_dev_tracker, GFP_ATOMIC);
207                 m->tcfm_mac_header_xmit = mac_header_xmit;
208                 m->tcfm_blockid = 0;
209         } else if (tb[TCA_MIRRED_BLOCKID]) {
210                 tcf_mirred_replace_dev(m, NULL);
211                 m->tcfm_mac_header_xmit = false;
212                 m->tcfm_blockid = nla_get_u32(tb[TCA_MIRRED_BLOCKID]);
213         }
214         goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
215         m->tcfm_eaction = parm->eaction;
216         spin_unlock_bh(&m->tcf_lock);
217         if (goto_ch)
218                 tcf_chain_put_by_act(goto_ch);
219
220         if (ret == ACT_P_CREATED) {
221                 spin_lock(&mirred_list_lock);
222                 list_add(&m->tcfm_list, &mirred_list);
223                 spin_unlock(&mirred_list_lock);
224         }
225
226         return ret;
227 put_chain:
228         if (goto_ch)
229                 tcf_chain_put_by_act(goto_ch);
230 release_idr:
231         tcf_idr_release(*a, bind);
232         return err;
233 }
234
235 static int
236 tcf_mirred_forward(bool at_ingress, bool want_ingress, struct sk_buff *skb)
237 {
238         int err;
239
240         if (!want_ingress)
241                 err = tcf_dev_queue_xmit(skb, dev_queue_xmit);
242         else if (!at_ingress)
243                 err = netif_rx(skb);
244         else
245                 err = netif_receive_skb(skb);
246
247         return err;
248 }
249
250 static int tcf_mirred_to_dev(struct sk_buff *skb, struct tcf_mirred *m,
251                              struct net_device *dev,
252                              const bool m_mac_header_xmit, int m_eaction,
253                              int retval)
254 {
255         struct sk_buff *skb_to_send = skb;
256         bool want_ingress;
257         bool is_redirect;
258         bool expects_nh;
259         bool at_ingress;
260         bool dont_clone;
261         int mac_len;
262         bool at_nh;
263         int err;
264
265         is_redirect = tcf_mirred_is_act_redirect(m_eaction);
266         if (unlikely(!(dev->flags & IFF_UP)) || !netif_carrier_ok(dev)) {
267                 net_notice_ratelimited("tc mirred to Houston: device %s is down\n",
268                                        dev->name);
269                 goto err_cant_do;
270         }
271
272         /* we could easily avoid the clone only if called by ingress and clsact;
273          * since we can't easily detect the clsact caller, skip clone only for
274          * ingress - that covers the TC S/W datapath.
275          */
276         at_ingress = skb_at_tc_ingress(skb);
277         dont_clone = skb_at_tc_ingress(skb) && is_redirect &&
278                 tcf_mirred_can_reinsert(retval);
279         if (!dont_clone) {
280                 skb_to_send = skb_clone(skb, GFP_ATOMIC);
281                 if (!skb_to_send)
282                         goto err_cant_do;
283         }
284
285         want_ingress = tcf_mirred_act_wants_ingress(m_eaction);
286
287         /* All mirred/redirected skbs should clear previous ct info */
288         nf_reset_ct(skb_to_send);
289         if (want_ingress && !at_ingress) /* drop dst for egress -> ingress */
290                 skb_dst_drop(skb_to_send);
291
292         expects_nh = want_ingress || !m_mac_header_xmit;
293         at_nh = skb->data == skb_network_header(skb);
294         if (at_nh != expects_nh) {
295                 mac_len = at_ingress ? skb->mac_len :
296                           skb_network_offset(skb);
297                 if (expects_nh) {
298                         /* target device/action expect data at nh */
299                         skb_pull_rcsum(skb_to_send, mac_len);
300                 } else {
301                         /* target device/action expect data at mac */
302                         skb_push_rcsum(skb_to_send, mac_len);
303                 }
304         }
305
306         skb_to_send->skb_iif = skb->dev->ifindex;
307         skb_to_send->dev = dev;
308
309         if (is_redirect) {
310                 if (skb == skb_to_send)
311                         retval = TC_ACT_CONSUMED;
312
313                 skb_set_redirected(skb_to_send, skb_to_send->tc_at_ingress);
314
315                 err = tcf_mirred_forward(at_ingress, want_ingress, skb_to_send);
316         } else {
317                 err = tcf_mirred_forward(at_ingress, want_ingress, skb_to_send);
318         }
319         if (err)
320                 tcf_action_inc_overlimit_qstats(&m->common);
321
322         return retval;
323
324 err_cant_do:
325         if (is_redirect)
326                 retval = TC_ACT_SHOT;
327         tcf_action_inc_overlimit_qstats(&m->common);
328         return retval;
329 }
330
331 static int tcf_blockcast_redir(struct sk_buff *skb, struct tcf_mirred *m,
332                                struct tcf_block *block, int m_eaction,
333                                const u32 exception_ifindex, int retval)
334 {
335         struct net_device *dev_prev = NULL;
336         struct net_device *dev = NULL;
337         unsigned long index;
338         int mirred_eaction;
339
340         mirred_eaction = tcf_mirred_act_wants_ingress(m_eaction) ?
341                 TCA_INGRESS_MIRROR : TCA_EGRESS_MIRROR;
342
343         xa_for_each(&block->ports, index, dev) {
344                 if (index == exception_ifindex)
345                         continue;
346
347                 if (!dev_prev)
348                         goto assign_prev;
349
350                 tcf_mirred_to_dev(skb, m, dev_prev,
351                                   dev_is_mac_header_xmit(dev),
352                                   mirred_eaction, retval);
353 assign_prev:
354                 dev_prev = dev;
355         }
356
357         if (dev_prev)
358                 return tcf_mirred_to_dev(skb, m, dev_prev,
359                                          dev_is_mac_header_xmit(dev_prev),
360                                          m_eaction, retval);
361
362         return retval;
363 }
364
365 static int tcf_blockcast_mirror(struct sk_buff *skb, struct tcf_mirred *m,
366                                 struct tcf_block *block, int m_eaction,
367                                 const u32 exception_ifindex, int retval)
368 {
369         struct net_device *dev = NULL;
370         unsigned long index;
371
372         xa_for_each(&block->ports, index, dev) {
373                 if (index == exception_ifindex)
374                         continue;
375
376                 tcf_mirred_to_dev(skb, m, dev,
377                                   dev_is_mac_header_xmit(dev),
378                                   m_eaction, retval);
379         }
380
381         return retval;
382 }
383
384 static int tcf_blockcast(struct sk_buff *skb, struct tcf_mirred *m,
385                          const u32 blockid, struct tcf_result *res,
386                          int retval)
387 {
388         const u32 exception_ifindex = skb->dev->ifindex;
389         struct tcf_block *block;
390         bool is_redirect;
391         int m_eaction;
392
393         m_eaction = READ_ONCE(m->tcfm_eaction);
394         is_redirect = tcf_mirred_is_act_redirect(m_eaction);
395
396         /* we are already under rcu protection, so can call block lookup
397          * directly.
398          */
399         block = tcf_block_lookup(dev_net(skb->dev), blockid);
400         if (!block || xa_empty(&block->ports)) {
401                 tcf_action_inc_overlimit_qstats(&m->common);
402                 return retval;
403         }
404
405         if (is_redirect)
406                 return tcf_blockcast_redir(skb, m, block, m_eaction,
407                                            exception_ifindex, retval);
408
409         /* If it's not redirect, it is mirror */
410         return tcf_blockcast_mirror(skb, m, block, m_eaction, exception_ifindex,
411                                     retval);
412 }
413
414 TC_INDIRECT_SCOPE int tcf_mirred_act(struct sk_buff *skb,
415                                      const struct tc_action *a,
416                                      struct tcf_result *res)
417 {
418         struct tcf_mirred *m = to_mirred(a);
419         int retval = READ_ONCE(m->tcf_action);
420         unsigned int nest_level;
421         bool m_mac_header_xmit;
422         struct net_device *dev;
423         int m_eaction;
424         u32 blockid;
425
426         nest_level = __this_cpu_inc_return(mirred_nest_level);
427         if (unlikely(nest_level > MIRRED_NEST_LIMIT)) {
428                 net_warn_ratelimited("Packet exceeded mirred recursion limit on dev %s\n",
429                                      netdev_name(skb->dev));
430                 retval = TC_ACT_SHOT;
431                 goto dec_nest_level;
432         }
433
434         tcf_lastuse_update(&m->tcf_tm);
435         tcf_action_update_bstats(&m->common, skb);
436
437         blockid = READ_ONCE(m->tcfm_blockid);
438         if (blockid) {
439                 retval = tcf_blockcast(skb, m, blockid, res, retval);
440                 goto dec_nest_level;
441         }
442
443         dev = rcu_dereference_bh(m->tcfm_dev);
444         if (unlikely(!dev)) {
445                 pr_notice_once("tc mirred: target device is gone\n");
446                 tcf_action_inc_overlimit_qstats(&m->common);
447                 goto dec_nest_level;
448         }
449
450         m_mac_header_xmit = READ_ONCE(m->tcfm_mac_header_xmit);
451         m_eaction = READ_ONCE(m->tcfm_eaction);
452
453         retval = tcf_mirred_to_dev(skb, m, dev, m_mac_header_xmit, m_eaction,
454                                    retval);
455
456 dec_nest_level:
457         __this_cpu_dec(mirred_nest_level);
458
459         return retval;
460 }
461
462 static void tcf_stats_update(struct tc_action *a, u64 bytes, u64 packets,
463                              u64 drops, u64 lastuse, bool hw)
464 {
465         struct tcf_mirred *m = to_mirred(a);
466         struct tcf_t *tm = &m->tcf_tm;
467
468         tcf_action_update_stats(a, bytes, packets, drops, hw);
469         tm->lastuse = max_t(u64, tm->lastuse, lastuse);
470 }
471
472 static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind,
473                            int ref)
474 {
475         unsigned char *b = skb_tail_pointer(skb);
476         struct tcf_mirred *m = to_mirred(a);
477         struct tc_mirred opt = {
478                 .index   = m->tcf_index,
479                 .refcnt  = refcount_read(&m->tcf_refcnt) - ref,
480                 .bindcnt = atomic_read(&m->tcf_bindcnt) - bind,
481         };
482         struct net_device *dev;
483         struct tcf_t t;
484         u32 blockid;
485
486         spin_lock_bh(&m->tcf_lock);
487         opt.action = m->tcf_action;
488         opt.eaction = m->tcfm_eaction;
489         dev = tcf_mirred_dev_dereference(m);
490         if (dev)
491                 opt.ifindex = dev->ifindex;
492
493         if (nla_put(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt))
494                 goto nla_put_failure;
495
496         blockid = m->tcfm_blockid;
497         if (blockid && nla_put_u32(skb, TCA_MIRRED_BLOCKID, blockid))
498                 goto nla_put_failure;
499
500         tcf_tm_dump(&t, &m->tcf_tm);
501         if (nla_put_64bit(skb, TCA_MIRRED_TM, sizeof(t), &t, TCA_MIRRED_PAD))
502                 goto nla_put_failure;
503         spin_unlock_bh(&m->tcf_lock);
504
505         return skb->len;
506
507 nla_put_failure:
508         spin_unlock_bh(&m->tcf_lock);
509         nlmsg_trim(skb, b);
510         return -1;
511 }
512
513 static int mirred_device_event(struct notifier_block *unused,
514                                unsigned long event, void *ptr)
515 {
516         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
517         struct tcf_mirred *m;
518
519         ASSERT_RTNL();
520         if (event == NETDEV_UNREGISTER) {
521                 spin_lock(&mirred_list_lock);
522                 list_for_each_entry(m, &mirred_list, tcfm_list) {
523                         spin_lock_bh(&m->tcf_lock);
524                         if (tcf_mirred_dev_dereference(m) == dev) {
525                                 netdev_put(dev, &m->tcfm_dev_tracker);
526                                 /* Note : no rcu grace period necessary, as
527                                  * net_device are already rcu protected.
528                                  */
529                                 RCU_INIT_POINTER(m->tcfm_dev, NULL);
530                         }
531                         spin_unlock_bh(&m->tcf_lock);
532                 }
533                 spin_unlock(&mirred_list_lock);
534         }
535
536         return NOTIFY_DONE;
537 }
538
539 static struct notifier_block mirred_device_notifier = {
540         .notifier_call = mirred_device_event,
541 };
542
543 static void tcf_mirred_dev_put(void *priv)
544 {
545         struct net_device *dev = priv;
546
547         dev_put(dev);
548 }
549
550 static struct net_device *
551 tcf_mirred_get_dev(const struct tc_action *a,
552                    tc_action_priv_destructor *destructor)
553 {
554         struct tcf_mirred *m = to_mirred(a);
555         struct net_device *dev;
556
557         rcu_read_lock();
558         dev = rcu_dereference(m->tcfm_dev);
559         if (dev) {
560                 dev_hold(dev);
561                 *destructor = tcf_mirred_dev_put;
562         }
563         rcu_read_unlock();
564
565         return dev;
566 }
567
568 static size_t tcf_mirred_get_fill_size(const struct tc_action *act)
569 {
570         return nla_total_size(sizeof(struct tc_mirred));
571 }
572
573 static void tcf_offload_mirred_get_dev(struct flow_action_entry *entry,
574                                        const struct tc_action *act)
575 {
576         entry->dev = act->ops->get_dev(act, &entry->destructor);
577         if (!entry->dev)
578                 return;
579         entry->destructor_priv = entry->dev;
580 }
581
582 static int tcf_mirred_offload_act_setup(struct tc_action *act, void *entry_data,
583                                         u32 *index_inc, bool bind,
584                                         struct netlink_ext_ack *extack)
585 {
586         if (bind) {
587                 struct flow_action_entry *entry = entry_data;
588
589                 if (is_tcf_mirred_egress_redirect(act)) {
590                         entry->id = FLOW_ACTION_REDIRECT;
591                         tcf_offload_mirred_get_dev(entry, act);
592                 } else if (is_tcf_mirred_egress_mirror(act)) {
593                         entry->id = FLOW_ACTION_MIRRED;
594                         tcf_offload_mirred_get_dev(entry, act);
595                 } else if (is_tcf_mirred_ingress_redirect(act)) {
596                         entry->id = FLOW_ACTION_REDIRECT_INGRESS;
597                         tcf_offload_mirred_get_dev(entry, act);
598                 } else if (is_tcf_mirred_ingress_mirror(act)) {
599                         entry->id = FLOW_ACTION_MIRRED_INGRESS;
600                         tcf_offload_mirred_get_dev(entry, act);
601                 } else {
602                         NL_SET_ERR_MSG_MOD(extack, "Unsupported mirred offload");
603                         return -EOPNOTSUPP;
604                 }
605                 *index_inc = 1;
606         } else {
607                 struct flow_offload_action *fl_action = entry_data;
608
609                 if (is_tcf_mirred_egress_redirect(act))
610                         fl_action->id = FLOW_ACTION_REDIRECT;
611                 else if (is_tcf_mirred_egress_mirror(act))
612                         fl_action->id = FLOW_ACTION_MIRRED;
613                 else if (is_tcf_mirred_ingress_redirect(act))
614                         fl_action->id = FLOW_ACTION_REDIRECT_INGRESS;
615                 else if (is_tcf_mirred_ingress_mirror(act))
616                         fl_action->id = FLOW_ACTION_MIRRED_INGRESS;
617                 else
618                         return -EOPNOTSUPP;
619         }
620
621         return 0;
622 }
623
624 static struct tc_action_ops act_mirred_ops = {
625         .kind           =       "mirred",
626         .id             =       TCA_ID_MIRRED,
627         .owner          =       THIS_MODULE,
628         .act            =       tcf_mirred_act,
629         .stats_update   =       tcf_stats_update,
630         .dump           =       tcf_mirred_dump,
631         .cleanup        =       tcf_mirred_release,
632         .init           =       tcf_mirred_init,
633         .get_fill_size  =       tcf_mirred_get_fill_size,
634         .offload_act_setup =    tcf_mirred_offload_act_setup,
635         .size           =       sizeof(struct tcf_mirred),
636         .get_dev        =       tcf_mirred_get_dev,
637 };
638
639 static __net_init int mirred_init_net(struct net *net)
640 {
641         struct tc_action_net *tn = net_generic(net, act_mirred_ops.net_id);
642
643         return tc_action_net_init(net, tn, &act_mirred_ops);
644 }
645
646 static void __net_exit mirred_exit_net(struct list_head *net_list)
647 {
648         tc_action_net_exit(net_list, act_mirred_ops.net_id);
649 }
650
651 static struct pernet_operations mirred_net_ops = {
652         .init = mirred_init_net,
653         .exit_batch = mirred_exit_net,
654         .id   = &act_mirred_ops.net_id,
655         .size = sizeof(struct tc_action_net),
656 };
657
658 MODULE_AUTHOR("Jamal Hadi Salim(2002)");
659 MODULE_DESCRIPTION("Device Mirror/redirect actions");
660 MODULE_LICENSE("GPL");
661
662 static int __init mirred_init_module(void)
663 {
664         int err = register_netdevice_notifier(&mirred_device_notifier);
665         if (err)
666                 return err;
667
668         pr_info("Mirror/redirect action on\n");
669         err = tcf_register_action(&act_mirred_ops, &mirred_net_ops);
670         if (err)
671                 unregister_netdevice_notifier(&mirred_device_notifier);
672
673         return err;
674 }
675
676 static void __exit mirred_cleanup_module(void)
677 {
678         tcf_unregister_action(&act_mirred_ops, &mirred_net_ops);
679         unregister_netdevice_notifier(&mirred_device_notifier);
680 }
681
682 module_init(mirred_init_module);
683 module_exit(mirred_cleanup_module);