Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6-microblaze.git] / net / sched / act_ife.c
1 /*
2  * net/sched/ife.c      Inter-FE action based on ForCES WG InterFE LFB
3  *
4  *              Refer to:
5  *              draft-ietf-forces-interfelfb-03
6  *              and
7  *              netdev01 paper:
8  *              "Distributing Linux Traffic Control Classifier-Action
9  *              Subsystem"
10  *              Authors: Jamal Hadi Salim and Damascene M. Joachimpillai
11  *
12  *              This program is free software; you can redistribute it and/or
13  *              modify it under the terms of the GNU General Public License
14  *              as published by the Free Software Foundation; either version
15  *              2 of the License, or (at your option) any later version.
16  *
17  * copyright Jamal Hadi Salim (2015)
18  *
19 */
20
21 #include <linux/types.h>
22 #include <linux/kernel.h>
23 #include <linux/string.h>
24 #include <linux/errno.h>
25 #include <linux/skbuff.h>
26 #include <linux/rtnetlink.h>
27 #include <linux/module.h>
28 #include <linux/init.h>
29 #include <net/net_namespace.h>
30 #include <net/netlink.h>
31 #include <net/pkt_sched.h>
32 #include <uapi/linux/tc_act/tc_ife.h>
33 #include <net/tc_act/tc_ife.h>
34 #include <linux/etherdevice.h>
35 #include <net/ife.h>
36
37 static unsigned int ife_net_id;
38 static int max_metacnt = IFE_META_MAX + 1;
39 static struct tc_action_ops act_ife_ops;
40
41 static const struct nla_policy ife_policy[TCA_IFE_MAX + 1] = {
42         [TCA_IFE_PARMS] = { .len = sizeof(struct tc_ife)},
43         [TCA_IFE_DMAC] = { .len = ETH_ALEN},
44         [TCA_IFE_SMAC] = { .len = ETH_ALEN},
45         [TCA_IFE_TYPE] = { .type = NLA_U16},
46 };
47
48 int ife_encode_meta_u16(u16 metaval, void *skbdata, struct tcf_meta_info *mi)
49 {
50         u16 edata = 0;
51
52         if (mi->metaval)
53                 edata = *(u16 *)mi->metaval;
54         else if (metaval)
55                 edata = metaval;
56
57         if (!edata) /* will not encode */
58                 return 0;
59
60         edata = htons(edata);
61         return ife_tlv_meta_encode(skbdata, mi->metaid, 2, &edata);
62 }
63 EXPORT_SYMBOL_GPL(ife_encode_meta_u16);
64
65 int ife_get_meta_u32(struct sk_buff *skb, struct tcf_meta_info *mi)
66 {
67         if (mi->metaval)
68                 return nla_put_u32(skb, mi->metaid, *(u32 *)mi->metaval);
69         else
70                 return nla_put(skb, mi->metaid, 0, NULL);
71 }
72 EXPORT_SYMBOL_GPL(ife_get_meta_u32);
73
74 int ife_check_meta_u32(u32 metaval, struct tcf_meta_info *mi)
75 {
76         if (metaval || mi->metaval)
77                 return 8; /* T+L+V == 2+2+4 */
78
79         return 0;
80 }
81 EXPORT_SYMBOL_GPL(ife_check_meta_u32);
82
83 int ife_check_meta_u16(u16 metaval, struct tcf_meta_info *mi)
84 {
85         if (metaval || mi->metaval)
86                 return 8; /* T+L+(V) == 2+2+(2+2bytepad) */
87
88         return 0;
89 }
90 EXPORT_SYMBOL_GPL(ife_check_meta_u16);
91
92 int ife_encode_meta_u32(u32 metaval, void *skbdata, struct tcf_meta_info *mi)
93 {
94         u32 edata = metaval;
95
96         if (mi->metaval)
97                 edata = *(u32 *)mi->metaval;
98         else if (metaval)
99                 edata = metaval;
100
101         if (!edata) /* will not encode */
102                 return 0;
103
104         edata = htonl(edata);
105         return ife_tlv_meta_encode(skbdata, mi->metaid, 4, &edata);
106 }
107 EXPORT_SYMBOL_GPL(ife_encode_meta_u32);
108
109 int ife_get_meta_u16(struct sk_buff *skb, struct tcf_meta_info *mi)
110 {
111         if (mi->metaval)
112                 return nla_put_u16(skb, mi->metaid, *(u16 *)mi->metaval);
113         else
114                 return nla_put(skb, mi->metaid, 0, NULL);
115 }
116 EXPORT_SYMBOL_GPL(ife_get_meta_u16);
117
118 int ife_alloc_meta_u32(struct tcf_meta_info *mi, void *metaval, gfp_t gfp)
119 {
120         mi->metaval = kmemdup(metaval, sizeof(u32), gfp);
121         if (!mi->metaval)
122                 return -ENOMEM;
123
124         return 0;
125 }
126 EXPORT_SYMBOL_GPL(ife_alloc_meta_u32);
127
128 int ife_alloc_meta_u16(struct tcf_meta_info *mi, void *metaval, gfp_t gfp)
129 {
130         mi->metaval = kmemdup(metaval, sizeof(u16), gfp);
131         if (!mi->metaval)
132                 return -ENOMEM;
133
134         return 0;
135 }
136 EXPORT_SYMBOL_GPL(ife_alloc_meta_u16);
137
138 void ife_release_meta_gen(struct tcf_meta_info *mi)
139 {
140         kfree(mi->metaval);
141 }
142 EXPORT_SYMBOL_GPL(ife_release_meta_gen);
143
144 int ife_validate_meta_u32(void *val, int len)
145 {
146         if (len == sizeof(u32))
147                 return 0;
148
149         return -EINVAL;
150 }
151 EXPORT_SYMBOL_GPL(ife_validate_meta_u32);
152
153 int ife_validate_meta_u16(void *val, int len)
154 {
155         /* length will not include padding */
156         if (len == sizeof(u16))
157                 return 0;
158
159         return -EINVAL;
160 }
161 EXPORT_SYMBOL_GPL(ife_validate_meta_u16);
162
163 static LIST_HEAD(ifeoplist);
164 static DEFINE_RWLOCK(ife_mod_lock);
165
166 static struct tcf_meta_ops *find_ife_oplist(u16 metaid)
167 {
168         struct tcf_meta_ops *o;
169
170         read_lock(&ife_mod_lock);
171         list_for_each_entry(o, &ifeoplist, list) {
172                 if (o->metaid == metaid) {
173                         if (!try_module_get(o->owner))
174                                 o = NULL;
175                         read_unlock(&ife_mod_lock);
176                         return o;
177                 }
178         }
179         read_unlock(&ife_mod_lock);
180
181         return NULL;
182 }
183
184 int register_ife_op(struct tcf_meta_ops *mops)
185 {
186         struct tcf_meta_ops *m;
187
188         if (!mops->metaid || !mops->metatype || !mops->name ||
189             !mops->check_presence || !mops->encode || !mops->decode ||
190             !mops->get || !mops->alloc)
191                 return -EINVAL;
192
193         write_lock(&ife_mod_lock);
194
195         list_for_each_entry(m, &ifeoplist, list) {
196                 if (m->metaid == mops->metaid ||
197                     (strcmp(mops->name, m->name) == 0)) {
198                         write_unlock(&ife_mod_lock);
199                         return -EEXIST;
200                 }
201         }
202
203         if (!mops->release)
204                 mops->release = ife_release_meta_gen;
205
206         list_add_tail(&mops->list, &ifeoplist);
207         write_unlock(&ife_mod_lock);
208         return 0;
209 }
210 EXPORT_SYMBOL_GPL(unregister_ife_op);
211
212 int unregister_ife_op(struct tcf_meta_ops *mops)
213 {
214         struct tcf_meta_ops *m;
215         int err = -ENOENT;
216
217         write_lock(&ife_mod_lock);
218         list_for_each_entry(m, &ifeoplist, list) {
219                 if (m->metaid == mops->metaid) {
220                         list_del(&mops->list);
221                         err = 0;
222                         break;
223                 }
224         }
225         write_unlock(&ife_mod_lock);
226
227         return err;
228 }
229 EXPORT_SYMBOL_GPL(register_ife_op);
230
231 static int ife_validate_metatype(struct tcf_meta_ops *ops, void *val, int len)
232 {
233         int ret = 0;
234         /* XXX: unfortunately cant use nla_policy at this point
235         * because a length of 0 is valid in the case of
236         * "allow". "use" semantics do enforce for proper
237         * length and i couldve use nla_policy but it makes it hard
238         * to use it just for that..
239         */
240         if (ops->validate)
241                 return ops->validate(val, len);
242
243         if (ops->metatype == NLA_U32)
244                 ret = ife_validate_meta_u32(val, len);
245         else if (ops->metatype == NLA_U16)
246                 ret = ife_validate_meta_u16(val, len);
247
248         return ret;
249 }
250
251 #ifdef CONFIG_MODULES
252 static const char *ife_meta_id2name(u32 metaid)
253 {
254         switch (metaid) {
255         case IFE_META_SKBMARK:
256                 return "skbmark";
257         case IFE_META_PRIO:
258                 return "skbprio";
259         case IFE_META_TCINDEX:
260                 return "tcindex";
261         default:
262                 return "unknown";
263         }
264 }
265 #endif
266
267 /* called when adding new meta information
268  * under ife->tcf_lock for existing action
269 */
270 static int load_metaops_and_vet(struct tcf_ife_info *ife, u32 metaid,
271                                 void *val, int len, bool exists)
272 {
273         struct tcf_meta_ops *ops = find_ife_oplist(metaid);
274         int ret = 0;
275
276         if (!ops) {
277                 ret = -ENOENT;
278 #ifdef CONFIG_MODULES
279                 if (exists)
280                         spin_unlock_bh(&ife->tcf_lock);
281                 rtnl_unlock();
282                 request_module("ife-meta-%s", ife_meta_id2name(metaid));
283                 rtnl_lock();
284                 if (exists)
285                         spin_lock_bh(&ife->tcf_lock);
286                 ops = find_ife_oplist(metaid);
287 #endif
288         }
289
290         if (ops) {
291                 ret = 0;
292                 if (len)
293                         ret = ife_validate_metatype(ops, val, len);
294
295                 module_put(ops->owner);
296         }
297
298         return ret;
299 }
300
301 /* called when adding new meta information
302  * under ife->tcf_lock for existing action
303 */
304 static int add_metainfo(struct tcf_ife_info *ife, u32 metaid, void *metaval,
305                         int len, bool atomic)
306 {
307         struct tcf_meta_info *mi = NULL;
308         struct tcf_meta_ops *ops = find_ife_oplist(metaid);
309         int ret = 0;
310
311         if (!ops)
312                 return -ENOENT;
313
314         mi = kzalloc(sizeof(*mi), atomic ? GFP_ATOMIC : GFP_KERNEL);
315         if (!mi) {
316                 /*put back what find_ife_oplist took */
317                 module_put(ops->owner);
318                 return -ENOMEM;
319         }
320
321         mi->metaid = metaid;
322         mi->ops = ops;
323         if (len > 0) {
324                 ret = ops->alloc(mi, metaval, atomic ? GFP_ATOMIC : GFP_KERNEL);
325                 if (ret != 0) {
326                         kfree(mi);
327                         module_put(ops->owner);
328                         return ret;
329                 }
330         }
331
332         list_add_tail(&mi->metalist, &ife->metalist);
333
334         return ret;
335 }
336
337 static int use_all_metadata(struct tcf_ife_info *ife)
338 {
339         struct tcf_meta_ops *o;
340         int rc = 0;
341         int installed = 0;
342
343         read_lock(&ife_mod_lock);
344         list_for_each_entry(o, &ifeoplist, list) {
345                 rc = add_metainfo(ife, o->metaid, NULL, 0, true);
346                 if (rc == 0)
347                         installed += 1;
348         }
349         read_unlock(&ife_mod_lock);
350
351         if (installed)
352                 return 0;
353         else
354                 return -EINVAL;
355 }
356
357 static int dump_metalist(struct sk_buff *skb, struct tcf_ife_info *ife)
358 {
359         struct tcf_meta_info *e;
360         struct nlattr *nest;
361         unsigned char *b = skb_tail_pointer(skb);
362         int total_encoded = 0;
363
364         /*can only happen on decode */
365         if (list_empty(&ife->metalist))
366                 return 0;
367
368         nest = nla_nest_start(skb, TCA_IFE_METALST);
369         if (!nest)
370                 goto out_nlmsg_trim;
371
372         list_for_each_entry(e, &ife->metalist, metalist) {
373                 if (!e->ops->get(skb, e))
374                         total_encoded += 1;
375         }
376
377         if (!total_encoded)
378                 goto out_nlmsg_trim;
379
380         nla_nest_end(skb, nest);
381
382         return 0;
383
384 out_nlmsg_trim:
385         nlmsg_trim(skb, b);
386         return -1;
387 }
388
389 /* under ife->tcf_lock */
390 static void _tcf_ife_cleanup(struct tc_action *a)
391 {
392         struct tcf_ife_info *ife = to_ife(a);
393         struct tcf_meta_info *e, *n;
394
395         list_for_each_entry_safe(e, n, &ife->metalist, metalist) {
396                 module_put(e->ops->owner);
397                 list_del(&e->metalist);
398                 if (e->metaval) {
399                         if (e->ops->release)
400                                 e->ops->release(e);
401                         else
402                                 kfree(e->metaval);
403                 }
404                 kfree(e);
405         }
406 }
407
408 static void tcf_ife_cleanup(struct tc_action *a)
409 {
410         struct tcf_ife_info *ife = to_ife(a);
411         struct tcf_ife_params *p;
412
413         spin_lock_bh(&ife->tcf_lock);
414         _tcf_ife_cleanup(a);
415         spin_unlock_bh(&ife->tcf_lock);
416
417         p = rcu_dereference_protected(ife->params, 1);
418         if (p)
419                 kfree_rcu(p, rcu);
420 }
421
422 /* under ife->tcf_lock for existing action */
423 static int populate_metalist(struct tcf_ife_info *ife, struct nlattr **tb,
424                              bool exists)
425 {
426         int len = 0;
427         int rc = 0;
428         int i = 0;
429         void *val;
430
431         for (i = 1; i < max_metacnt; i++) {
432                 if (tb[i]) {
433                         val = nla_data(tb[i]);
434                         len = nla_len(tb[i]);
435
436                         rc = load_metaops_and_vet(ife, i, val, len, exists);
437                         if (rc != 0)
438                                 return rc;
439
440                         rc = add_metainfo(ife, i, val, len, exists);
441                         if (rc)
442                                 return rc;
443                 }
444         }
445
446         return rc;
447 }
448
449 static int tcf_ife_init(struct net *net, struct nlattr *nla,
450                         struct nlattr *est, struct tc_action **a,
451                         int ovr, int bind, struct netlink_ext_ack *extack)
452 {
453         struct tc_action_net *tn = net_generic(net, ife_net_id);
454         struct nlattr *tb[TCA_IFE_MAX + 1];
455         struct nlattr *tb2[IFE_META_MAX + 1];
456         struct tcf_ife_params *p, *p_old;
457         struct tcf_ife_info *ife;
458         u16 ife_type = ETH_P_IFE;
459         struct tc_ife *parm;
460         u8 *daddr = NULL;
461         u8 *saddr = NULL;
462         bool exists = false;
463         int ret = 0;
464         int err;
465
466         err = nla_parse_nested(tb, TCA_IFE_MAX, nla, ife_policy, NULL);
467         if (err < 0)
468                 return err;
469
470         if (!tb[TCA_IFE_PARMS])
471                 return -EINVAL;
472
473         parm = nla_data(tb[TCA_IFE_PARMS]);
474
475         /* IFE_DECODE is 0 and indicates the opposite of IFE_ENCODE because
476          * they cannot run as the same time. Check on all other values which
477          * are not supported right now.
478          */
479         if (parm->flags & ~IFE_ENCODE)
480                 return -EINVAL;
481
482         p = kzalloc(sizeof(*p), GFP_KERNEL);
483         if (!p)
484                 return -ENOMEM;
485
486         exists = tcf_idr_check(tn, parm->index, a, bind);
487         if (exists && bind) {
488                 kfree(p);
489                 return 0;
490         }
491
492         if (!exists) {
493                 ret = tcf_idr_create(tn, parm->index, est, a, &act_ife_ops,
494                                      bind, true);
495                 if (ret) {
496                         kfree(p);
497                         return ret;
498                 }
499                 ret = ACT_P_CREATED;
500         } else {
501                 tcf_idr_release(*a, bind);
502                 if (!ovr) {
503                         kfree(p);
504                         return -EEXIST;
505                 }
506         }
507
508         ife = to_ife(*a);
509         p->flags = parm->flags;
510
511         if (parm->flags & IFE_ENCODE) {
512                 if (tb[TCA_IFE_TYPE])
513                         ife_type = nla_get_u16(tb[TCA_IFE_TYPE]);
514                 if (tb[TCA_IFE_DMAC])
515                         daddr = nla_data(tb[TCA_IFE_DMAC]);
516                 if (tb[TCA_IFE_SMAC])
517                         saddr = nla_data(tb[TCA_IFE_SMAC]);
518         }
519
520         if (parm->flags & IFE_ENCODE) {
521                 if (daddr)
522                         ether_addr_copy(p->eth_dst, daddr);
523                 else
524                         eth_zero_addr(p->eth_dst);
525
526                 if (saddr)
527                         ether_addr_copy(p->eth_src, saddr);
528                 else
529                         eth_zero_addr(p->eth_src);
530
531                 p->eth_type = ife_type;
532         }
533
534         if (exists)
535                 spin_lock_bh(&ife->tcf_lock);
536
537         if (ret == ACT_P_CREATED)
538                 INIT_LIST_HEAD(&ife->metalist);
539
540         if (tb[TCA_IFE_METALST]) {
541                 err = nla_parse_nested(tb2, IFE_META_MAX, tb[TCA_IFE_METALST],
542                                        NULL, NULL);
543                 if (err) {
544 metadata_parse_err:
545                         if (ret == ACT_P_CREATED)
546                                 tcf_idr_release(*a, bind);
547
548                         if (exists)
549                                 spin_unlock_bh(&ife->tcf_lock);
550                         kfree(p);
551                         return err;
552                 }
553
554                 err = populate_metalist(ife, tb2, exists);
555                 if (err)
556                         goto metadata_parse_err;
557
558         } else {
559                 /* if no passed metadata allow list or passed allow-all
560                  * then here we process by adding as many supported metadatum
561                  * as we can. You better have at least one else we are
562                  * going to bail out
563                  */
564                 err = use_all_metadata(ife);
565                 if (err) {
566                         if (ret == ACT_P_CREATED)
567                                 tcf_idr_release(*a, bind);
568
569                         if (exists)
570                                 spin_unlock_bh(&ife->tcf_lock);
571                         kfree(p);
572                         return err;
573                 }
574         }
575
576         ife->tcf_action = parm->action;
577         if (exists)
578                 spin_unlock_bh(&ife->tcf_lock);
579
580         p_old = rtnl_dereference(ife->params);
581         rcu_assign_pointer(ife->params, p);
582         if (p_old)
583                 kfree_rcu(p_old, rcu);
584
585         if (ret == ACT_P_CREATED)
586                 tcf_idr_insert(tn, *a);
587
588         return ret;
589 }
590
591 static int tcf_ife_dump(struct sk_buff *skb, struct tc_action *a, int bind,
592                         int ref)
593 {
594         unsigned char *b = skb_tail_pointer(skb);
595         struct tcf_ife_info *ife = to_ife(a);
596         struct tcf_ife_params *p = rtnl_dereference(ife->params);
597         struct tc_ife opt = {
598                 .index = ife->tcf_index,
599                 .refcnt = ife->tcf_refcnt - ref,
600                 .bindcnt = ife->tcf_bindcnt - bind,
601                 .action = ife->tcf_action,
602                 .flags = p->flags,
603         };
604         struct tcf_t t;
605
606         if (nla_put(skb, TCA_IFE_PARMS, sizeof(opt), &opt))
607                 goto nla_put_failure;
608
609         tcf_tm_dump(&t, &ife->tcf_tm);
610         if (nla_put_64bit(skb, TCA_IFE_TM, sizeof(t), &t, TCA_IFE_PAD))
611                 goto nla_put_failure;
612
613         if (!is_zero_ether_addr(p->eth_dst)) {
614                 if (nla_put(skb, TCA_IFE_DMAC, ETH_ALEN, p->eth_dst))
615                         goto nla_put_failure;
616         }
617
618         if (!is_zero_ether_addr(p->eth_src)) {
619                 if (nla_put(skb, TCA_IFE_SMAC, ETH_ALEN, p->eth_src))
620                         goto nla_put_failure;
621         }
622
623         if (nla_put(skb, TCA_IFE_TYPE, 2, &p->eth_type))
624                 goto nla_put_failure;
625
626         if (dump_metalist(skb, ife)) {
627                 /*ignore failure to dump metalist */
628                 pr_info("Failed to dump metalist\n");
629         }
630
631         return skb->len;
632
633 nla_put_failure:
634         nlmsg_trim(skb, b);
635         return -1;
636 }
637
638 static int find_decode_metaid(struct sk_buff *skb, struct tcf_ife_info *ife,
639                               u16 metaid, u16 mlen, void *mdata)
640 {
641         struct tcf_meta_info *e;
642
643         /* XXX: use hash to speed up */
644         list_for_each_entry(e, &ife->metalist, metalist) {
645                 if (metaid == e->metaid) {
646                         if (e->ops) {
647                                 /* We check for decode presence already */
648                                 return e->ops->decode(skb, mdata, mlen);
649                         }
650                 }
651         }
652
653         return -ENOENT;
654 }
655
656 static int tcf_ife_decode(struct sk_buff *skb, const struct tc_action *a,
657                           struct tcf_result *res)
658 {
659         struct tcf_ife_info *ife = to_ife(a);
660         int action = ife->tcf_action;
661         u8 *ifehdr_end;
662         u8 *tlv_data;
663         u16 metalen;
664
665         bstats_cpu_update(this_cpu_ptr(ife->common.cpu_bstats), skb);
666         tcf_lastuse_update(&ife->tcf_tm);
667
668         if (skb_at_tc_ingress(skb))
669                 skb_push(skb, skb->dev->hard_header_len);
670
671         tlv_data = ife_decode(skb, &metalen);
672         if (unlikely(!tlv_data)) {
673                 qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
674                 return TC_ACT_SHOT;
675         }
676
677         ifehdr_end = tlv_data + metalen;
678         for (; tlv_data < ifehdr_end; tlv_data = ife_tlv_meta_next(tlv_data)) {
679                 u8 *curr_data;
680                 u16 mtype;
681                 u16 dlen;
682
683                 curr_data = ife_tlv_meta_decode(tlv_data, ifehdr_end, &mtype,
684                                                 &dlen, NULL);
685                 if (!curr_data) {
686                         qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
687                         return TC_ACT_SHOT;
688                 }
689
690                 if (find_decode_metaid(skb, ife, mtype, dlen, curr_data)) {
691                         /* abuse overlimits to count when we receive metadata
692                          * but dont have an ops for it
693                          */
694                         pr_info_ratelimited("Unknown metaid %d dlen %d\n",
695                                             mtype, dlen);
696                         qstats_overlimit_inc(this_cpu_ptr(ife->common.cpu_qstats));
697                 }
698         }
699
700         if (WARN_ON(tlv_data != ifehdr_end)) {
701                 qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
702                 return TC_ACT_SHOT;
703         }
704
705         skb->protocol = eth_type_trans(skb, skb->dev);
706         skb_reset_network_header(skb);
707
708         return action;
709 }
710
711 /*XXX: check if we can do this at install time instead of current
712  * send data path
713 **/
714 static int ife_get_sz(struct sk_buff *skb, struct tcf_ife_info *ife)
715 {
716         struct tcf_meta_info *e, *n;
717         int tot_run_sz = 0, run_sz = 0;
718
719         list_for_each_entry_safe(e, n, &ife->metalist, metalist) {
720                 if (e->ops->check_presence) {
721                         run_sz = e->ops->check_presence(skb, e);
722                         tot_run_sz += run_sz;
723                 }
724         }
725
726         return tot_run_sz;
727 }
728
729 static int tcf_ife_encode(struct sk_buff *skb, const struct tc_action *a,
730                           struct tcf_result *res, struct tcf_ife_params *p)
731 {
732         struct tcf_ife_info *ife = to_ife(a);
733         int action = ife->tcf_action;
734         struct ethhdr *oethh;   /* outer ether header */
735         struct tcf_meta_info *e;
736         /*
737            OUTERHDR:TOTMETALEN:{TLVHDR:Metadatum:TLVHDR..}:ORIGDATA
738            where ORIGDATA = original ethernet header ...
739          */
740         u16 metalen = ife_get_sz(skb, ife);
741         int hdrm = metalen + skb->dev->hard_header_len + IFE_METAHDRLEN;
742         unsigned int skboff = 0;
743         int new_len = skb->len + hdrm;
744         bool exceed_mtu = false;
745         void *ife_meta;
746         int err = 0;
747
748         if (!skb_at_tc_ingress(skb)) {
749                 if (new_len > skb->dev->mtu)
750                         exceed_mtu = true;
751         }
752
753         bstats_cpu_update(this_cpu_ptr(ife->common.cpu_bstats), skb);
754         tcf_lastuse_update(&ife->tcf_tm);
755
756         if (!metalen) {         /* no metadata to send */
757                 /* abuse overlimits to count when we allow packet
758                  * with no metadata
759                  */
760                 qstats_overlimit_inc(this_cpu_ptr(ife->common.cpu_qstats));
761                 return action;
762         }
763         /* could be stupid policy setup or mtu config
764          * so lets be conservative.. */
765         if ((action == TC_ACT_SHOT) || exceed_mtu) {
766                 qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
767                 return TC_ACT_SHOT;
768         }
769
770         if (skb_at_tc_ingress(skb))
771                 skb_push(skb, skb->dev->hard_header_len);
772
773         ife_meta = ife_encode(skb, metalen);
774
775         spin_lock(&ife->tcf_lock);
776
777         /* XXX: we dont have a clever way of telling encode to
778          * not repeat some of the computations that are done by
779          * ops->presence_check...
780          */
781         list_for_each_entry(e, &ife->metalist, metalist) {
782                 if (e->ops->encode) {
783                         err = e->ops->encode(skb, (void *)(ife_meta + skboff),
784                                              e);
785                 }
786                 if (err < 0) {
787                         /* too corrupt to keep around if overwritten */
788                         spin_unlock(&ife->tcf_lock);
789                         qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
790                         return TC_ACT_SHOT;
791                 }
792                 skboff += err;
793         }
794         spin_unlock(&ife->tcf_lock);
795         oethh = (struct ethhdr *)skb->data;
796
797         if (!is_zero_ether_addr(p->eth_src))
798                 ether_addr_copy(oethh->h_source, p->eth_src);
799         if (!is_zero_ether_addr(p->eth_dst))
800                 ether_addr_copy(oethh->h_dest, p->eth_dst);
801         oethh->h_proto = htons(p->eth_type);
802
803         if (skb_at_tc_ingress(skb))
804                 skb_pull(skb, skb->dev->hard_header_len);
805
806         return action;
807 }
808
809 static int tcf_ife_act(struct sk_buff *skb, const struct tc_action *a,
810                        struct tcf_result *res)
811 {
812         struct tcf_ife_info *ife = to_ife(a);
813         struct tcf_ife_params *p;
814         int ret;
815
816         rcu_read_lock();
817         p = rcu_dereference(ife->params);
818         if (p->flags & IFE_ENCODE) {
819                 ret = tcf_ife_encode(skb, a, res, p);
820                 rcu_read_unlock();
821                 return ret;
822         }
823         rcu_read_unlock();
824
825         return tcf_ife_decode(skb, a, res);
826 }
827
828 static int tcf_ife_walker(struct net *net, struct sk_buff *skb,
829                           struct netlink_callback *cb, int type,
830                           const struct tc_action_ops *ops,
831                           struct netlink_ext_ack *extack)
832 {
833         struct tc_action_net *tn = net_generic(net, ife_net_id);
834
835         return tcf_generic_walker(tn, skb, cb, type, ops, extack);
836 }
837
838 static int tcf_ife_search(struct net *net, struct tc_action **a, u32 index,
839                           struct netlink_ext_ack *extack)
840 {
841         struct tc_action_net *tn = net_generic(net, ife_net_id);
842
843         return tcf_idr_search(tn, a, index);
844 }
845
846 static struct tc_action_ops act_ife_ops = {
847         .kind = "ife",
848         .type = TCA_ACT_IFE,
849         .owner = THIS_MODULE,
850         .act = tcf_ife_act,
851         .dump = tcf_ife_dump,
852         .cleanup = tcf_ife_cleanup,
853         .init = tcf_ife_init,
854         .walk = tcf_ife_walker,
855         .lookup = tcf_ife_search,
856         .size = sizeof(struct tcf_ife_info),
857 };
858
859 static __net_init int ife_init_net(struct net *net)
860 {
861         struct tc_action_net *tn = net_generic(net, ife_net_id);
862
863         return tc_action_net_init(tn, &act_ife_ops);
864 }
865
866 static void __net_exit ife_exit_net(struct list_head *net_list)
867 {
868         tc_action_net_exit(net_list, ife_net_id);
869 }
870
871 static struct pernet_operations ife_net_ops = {
872         .init = ife_init_net,
873         .exit_batch = ife_exit_net,
874         .id   = &ife_net_id,
875         .size = sizeof(struct tc_action_net),
876 };
877
878 static int __init ife_init_module(void)
879 {
880         return tcf_register_action(&act_ife_ops, &ife_net_ops);
881 }
882
883 static void __exit ife_cleanup_module(void)
884 {
885         tcf_unregister_action(&act_ife_ops, &ife_net_ops);
886 }
887
888 module_init(ife_init_module);
889 module_exit(ife_cleanup_module);
890
891 MODULE_AUTHOR("Jamal Hadi Salim(2015)");
892 MODULE_DESCRIPTION("Inter-FE LFB action");
893 MODULE_LICENSE("GPL");