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  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * net/sched/ife.c	Inter-FE action based on ForCES WG InterFE LFB
  4 *
  5 *		Refer to:
  6 *		draft-ietf-forces-interfelfb-03
  7 *		and
  8 *		netdev01 paper:
  9 *		"Distributing Linux Traffic Control Classifier-Action
 10 *		Subsystem"
 11 *		Authors: Jamal Hadi Salim and Damascene M. Joachimpillai
 12 *
 13 * copyright Jamal Hadi Salim (2015)
 14*/
 15
 16#include <linux/types.h>
 17#include <linux/kernel.h>
 18#include <linux/string.h>
 19#include <linux/errno.h>
 20#include <linux/skbuff.h>
 21#include <linux/rtnetlink.h>
 22#include <linux/module.h>
 23#include <linux/init.h>
 24#include <net/net_namespace.h>
 25#include <net/netlink.h>
 26#include <net/pkt_sched.h>
 27#include <net/pkt_cls.h>
 28#include <uapi/linux/tc_act/tc_ife.h>
 29#include <net/tc_act/tc_ife.h>
 30#include <linux/etherdevice.h>
 31#include <net/ife.h>
 32#include <net/tc_wrapper.h>
 33
 34static int max_metacnt = IFE_META_MAX + 1;
 35static struct tc_action_ops act_ife_ops;
 36
 37static const struct nla_policy ife_policy[TCA_IFE_MAX + 1] = {
 38	[TCA_IFE_PARMS] = { .len = sizeof(struct tc_ife)},
 39	[TCA_IFE_DMAC] = { .len = ETH_ALEN},
 40	[TCA_IFE_SMAC] = { .len = ETH_ALEN},
 41	[TCA_IFE_TYPE] = { .type = NLA_U16},
 42};
 43
 44int ife_encode_meta_u16(u16 metaval, void *skbdata, struct tcf_meta_info *mi)
 45{
 46	u16 edata = 0;
 47
 48	if (mi->metaval)
 49		edata = *(u16 *)mi->metaval;
 50	else if (metaval)
 51		edata = metaval;
 52
 53	if (!edata) /* will not encode */
 54		return 0;
 55
 56	edata = htons(edata);
 57	return ife_tlv_meta_encode(skbdata, mi->metaid, 2, &edata);
 58}
 59EXPORT_SYMBOL_GPL(ife_encode_meta_u16);
 60
 61int ife_get_meta_u32(struct sk_buff *skb, struct tcf_meta_info *mi)
 62{
 63	if (mi->metaval)
 64		return nla_put_u32(skb, mi->metaid, *(u32 *)mi->metaval);
 65	else
 66		return nla_put(skb, mi->metaid, 0, NULL);
 67}
 68EXPORT_SYMBOL_GPL(ife_get_meta_u32);
 69
 70int ife_check_meta_u32(u32 metaval, struct tcf_meta_info *mi)
 71{
 72	if (metaval || mi->metaval)
 73		return 8; /* T+L+V == 2+2+4 */
 74
 75	return 0;
 76}
 77EXPORT_SYMBOL_GPL(ife_check_meta_u32);
 78
 79int ife_check_meta_u16(u16 metaval, struct tcf_meta_info *mi)
 80{
 81	if (metaval || mi->metaval)
 82		return 8; /* T+L+(V) == 2+2+(2+2bytepad) */
 83
 84	return 0;
 85}
 86EXPORT_SYMBOL_GPL(ife_check_meta_u16);
 87
 88int ife_encode_meta_u32(u32 metaval, void *skbdata, struct tcf_meta_info *mi)
 89{
 90	u32 edata = metaval;
 91
 92	if (mi->metaval)
 93		edata = *(u32 *)mi->metaval;
 94	else if (metaval)
 95		edata = metaval;
 96
 97	if (!edata) /* will not encode */
 98		return 0;
 99
100	edata = htonl(edata);
101	return ife_tlv_meta_encode(skbdata, mi->metaid, 4, &edata);
102}
103EXPORT_SYMBOL_GPL(ife_encode_meta_u32);
104
105int ife_get_meta_u16(struct sk_buff *skb, struct tcf_meta_info *mi)
106{
107	if (mi->metaval)
108		return nla_put_u16(skb, mi->metaid, *(u16 *)mi->metaval);
109	else
110		return nla_put(skb, mi->metaid, 0, NULL);
111}
112EXPORT_SYMBOL_GPL(ife_get_meta_u16);
113
114int ife_alloc_meta_u32(struct tcf_meta_info *mi, void *metaval, gfp_t gfp)
115{
116	mi->metaval = kmemdup(metaval, sizeof(u32), gfp);
117	if (!mi->metaval)
118		return -ENOMEM;
119
120	return 0;
121}
122EXPORT_SYMBOL_GPL(ife_alloc_meta_u32);
123
124int ife_alloc_meta_u16(struct tcf_meta_info *mi, void *metaval, gfp_t gfp)
125{
126	mi->metaval = kmemdup(metaval, sizeof(u16), gfp);
127	if (!mi->metaval)
128		return -ENOMEM;
129
130	return 0;
131}
132EXPORT_SYMBOL_GPL(ife_alloc_meta_u16);
133
134void ife_release_meta_gen(struct tcf_meta_info *mi)
135{
136	kfree(mi->metaval);
137}
138EXPORT_SYMBOL_GPL(ife_release_meta_gen);
139
140int ife_validate_meta_u32(void *val, int len)
141{
142	if (len == sizeof(u32))
143		return 0;
144
145	return -EINVAL;
146}
147EXPORT_SYMBOL_GPL(ife_validate_meta_u32);
148
149int ife_validate_meta_u16(void *val, int len)
150{
151	/* length will not include padding */
152	if (len == sizeof(u16))
153		return 0;
154
155	return -EINVAL;
156}
157EXPORT_SYMBOL_GPL(ife_validate_meta_u16);
158
159static LIST_HEAD(ifeoplist);
160static DEFINE_RWLOCK(ife_mod_lock);
161
162static struct tcf_meta_ops *find_ife_oplist(u16 metaid)
163{
164	struct tcf_meta_ops *o;
165
166	read_lock(&ife_mod_lock);
167	list_for_each_entry(o, &ifeoplist, list) {
168		if (o->metaid == metaid) {
169			if (!try_module_get(o->owner))
170				o = NULL;
171			read_unlock(&ife_mod_lock);
172			return o;
173		}
174	}
175	read_unlock(&ife_mod_lock);
176
177	return NULL;
178}
179
180int register_ife_op(struct tcf_meta_ops *mops)
181{
182	struct tcf_meta_ops *m;
183
184	if (!mops->metaid || !mops->metatype || !mops->name ||
185	    !mops->check_presence || !mops->encode || !mops->decode ||
186	    !mops->get || !mops->alloc)
187		return -EINVAL;
188
189	write_lock(&ife_mod_lock);
190
191	list_for_each_entry(m, &ifeoplist, list) {
192		if (m->metaid == mops->metaid ||
193		    (strcmp(mops->name, m->name) == 0)) {
194			write_unlock(&ife_mod_lock);
195			return -EEXIST;
196		}
197	}
198
199	if (!mops->release)
200		mops->release = ife_release_meta_gen;
201
202	list_add_tail(&mops->list, &ifeoplist);
203	write_unlock(&ife_mod_lock);
204	return 0;
205}
206EXPORT_SYMBOL_GPL(unregister_ife_op);
207
208int unregister_ife_op(struct tcf_meta_ops *mops)
209{
210	struct tcf_meta_ops *m;
211	int err = -ENOENT;
212
213	write_lock(&ife_mod_lock);
214	list_for_each_entry(m, &ifeoplist, list) {
215		if (m->metaid == mops->metaid) {
216			list_del(&mops->list);
217			err = 0;
218			break;
219		}
220	}
221	write_unlock(&ife_mod_lock);
222
223	return err;
224}
225EXPORT_SYMBOL_GPL(register_ife_op);
226
227static int ife_validate_metatype(struct tcf_meta_ops *ops, void *val, int len)
228{
229	int ret = 0;
230	/* XXX: unfortunately cant use nla_policy at this point
231	* because a length of 0 is valid in the case of
232	* "allow". "use" semantics do enforce for proper
233	* length and i couldve use nla_policy but it makes it hard
234	* to use it just for that..
235	*/
236	if (ops->validate)
237		return ops->validate(val, len);
238
239	if (ops->metatype == NLA_U32)
240		ret = ife_validate_meta_u32(val, len);
241	else if (ops->metatype == NLA_U16)
242		ret = ife_validate_meta_u16(val, len);
243
244	return ret;
245}
246
247#ifdef CONFIG_MODULES
248static const char *ife_meta_id2name(u32 metaid)
249{
250	switch (metaid) {
251	case IFE_META_SKBMARK:
252		return "skbmark";
253	case IFE_META_PRIO:
254		return "skbprio";
255	case IFE_META_TCINDEX:
256		return "tcindex";
257	default:
258		return "unknown";
259	}
260}
261#endif
262
263/* called when adding new meta information
264*/
265static int load_metaops_and_vet(u32 metaid, void *val, int len, bool rtnl_held)
266{
267	struct tcf_meta_ops *ops = find_ife_oplist(metaid);
268	int ret = 0;
269
270	if (!ops) {
271		ret = -ENOENT;
272#ifdef CONFIG_MODULES
273		if (rtnl_held)
274			rtnl_unlock();
275		request_module("ife-meta-%s", ife_meta_id2name(metaid));
276		if (rtnl_held)
277			rtnl_lock();
278		ops = find_ife_oplist(metaid);
279#endif
280	}
281
282	if (ops) {
283		ret = 0;
284		if (len)
285			ret = ife_validate_metatype(ops, val, len);
286
287		module_put(ops->owner);
288	}
289
290	return ret;
291}
292
293/* called when adding new meta information
294*/
295static int __add_metainfo(const struct tcf_meta_ops *ops,
296			  struct tcf_ife_info *ife, u32 metaid, void *metaval,
297			  int len, bool atomic, bool exists)
298{
299	struct tcf_meta_info *mi = NULL;
300	int ret = 0;
301
302	mi = kzalloc(sizeof(*mi), atomic ? GFP_ATOMIC : GFP_KERNEL);
303	if (!mi)
304		return -ENOMEM;
305
306	mi->metaid = metaid;
307	mi->ops = ops;
308	if (len > 0) {
309		ret = ops->alloc(mi, metaval, atomic ? GFP_ATOMIC : GFP_KERNEL);
310		if (ret != 0) {
311			kfree(mi);
312			return ret;
313		}
314	}
315
316	if (exists)
317		spin_lock_bh(&ife->tcf_lock);
318	list_add_tail(&mi->metalist, &ife->metalist);
319	if (exists)
320		spin_unlock_bh(&ife->tcf_lock);
321
322	return ret;
323}
324
325static int add_metainfo_and_get_ops(const struct tcf_meta_ops *ops,
326				    struct tcf_ife_info *ife, u32 metaid,
327				    bool exists)
328{
329	int ret;
330
331	if (!try_module_get(ops->owner))
332		return -ENOENT;
333	ret = __add_metainfo(ops, ife, metaid, NULL, 0, true, exists);
334	if (ret)
335		module_put(ops->owner);
336	return ret;
337}
338
339static int add_metainfo(struct tcf_ife_info *ife, u32 metaid, void *metaval,
340			int len, bool exists)
341{
342	const struct tcf_meta_ops *ops = find_ife_oplist(metaid);
343	int ret;
344
345	if (!ops)
346		return -ENOENT;
347	ret = __add_metainfo(ops, ife, metaid, metaval, len, false, exists);
348	if (ret)
349		/*put back what find_ife_oplist took */
350		module_put(ops->owner);
351	return ret;
352}
353
354static int use_all_metadata(struct tcf_ife_info *ife, bool exists)
355{
356	struct tcf_meta_ops *o;
357	int rc = 0;
358	int installed = 0;
359
360	read_lock(&ife_mod_lock);
361	list_for_each_entry(o, &ifeoplist, list) {
362		rc = add_metainfo_and_get_ops(o, ife, o->metaid, exists);
363		if (rc == 0)
364			installed += 1;
365	}
366	read_unlock(&ife_mod_lock);
367
368	if (installed)
369		return 0;
370	else
371		return -EINVAL;
372}
373
374static int dump_metalist(struct sk_buff *skb, struct tcf_ife_info *ife)
375{
376	struct tcf_meta_info *e;
377	struct nlattr *nest;
378	unsigned char *b = skb_tail_pointer(skb);
379	int total_encoded = 0;
380
381	/*can only happen on decode */
382	if (list_empty(&ife->metalist))
383		return 0;
384
385	nest = nla_nest_start_noflag(skb, TCA_IFE_METALST);
386	if (!nest)
387		goto out_nlmsg_trim;
388
389	list_for_each_entry(e, &ife->metalist, metalist) {
390		if (!e->ops->get(skb, e))
391			total_encoded += 1;
392	}
393
394	if (!total_encoded)
395		goto out_nlmsg_trim;
396
397	nla_nest_end(skb, nest);
398
399	return 0;
400
401out_nlmsg_trim:
402	nlmsg_trim(skb, b);
403	return -1;
404}
405
406/* under ife->tcf_lock */
407static void _tcf_ife_cleanup(struct tc_action *a)
408{
409	struct tcf_ife_info *ife = to_ife(a);
410	struct tcf_meta_info *e, *n;
411
412	list_for_each_entry_safe(e, n, &ife->metalist, metalist) {
413		list_del(&e->metalist);
414		if (e->metaval) {
415			if (e->ops->release)
416				e->ops->release(e);
417			else
418				kfree(e->metaval);
419		}
420		module_put(e->ops->owner);
421		kfree(e);
422	}
423}
424
425static void tcf_ife_cleanup(struct tc_action *a)
426{
427	struct tcf_ife_info *ife = to_ife(a);
428	struct tcf_ife_params *p;
429
430	spin_lock_bh(&ife->tcf_lock);
431	_tcf_ife_cleanup(a);
432	spin_unlock_bh(&ife->tcf_lock);
433
434	p = rcu_dereference_protected(ife->params, 1);
435	if (p)
436		kfree_rcu(p, rcu);
437}
438
439static int load_metalist(struct nlattr **tb, bool rtnl_held)
440{
441	int i;
442
443	for (i = 1; i < max_metacnt; i++) {
444		if (tb[i]) {
445			void *val = nla_data(tb[i]);
446			int len = nla_len(tb[i]);
447			int rc;
448
449			rc = load_metaops_and_vet(i, val, len, rtnl_held);
450			if (rc != 0)
451				return rc;
452		}
453	}
454
455	return 0;
456}
457
458static int populate_metalist(struct tcf_ife_info *ife, struct nlattr **tb,
459			     bool exists, bool rtnl_held)
460{
461	int len = 0;
462	int rc = 0;
463	int i = 0;
464	void *val;
465
466	for (i = 1; i < max_metacnt; i++) {
467		if (tb[i]) {
468			val = nla_data(tb[i]);
469			len = nla_len(tb[i]);
470
471			rc = add_metainfo(ife, i, val, len, exists);
472			if (rc)
473				return rc;
474		}
475	}
476
477	return rc;
478}
479
480static int tcf_ife_init(struct net *net, struct nlattr *nla,
481			struct nlattr *est, struct tc_action **a,
482			struct tcf_proto *tp, u32 flags,
483			struct netlink_ext_ack *extack)
484{
485	struct tc_action_net *tn = net_generic(net, act_ife_ops.net_id);
486	bool bind = flags & TCA_ACT_FLAGS_BIND;
487	struct nlattr *tb[TCA_IFE_MAX + 1];
488	struct nlattr *tb2[IFE_META_MAX + 1];
489	struct tcf_chain *goto_ch = NULL;
490	struct tcf_ife_params *p;
491	struct tcf_ife_info *ife;
492	u16 ife_type = ETH_P_IFE;
493	struct tc_ife *parm;
494	u8 *daddr = NULL;
495	u8 *saddr = NULL;
496	bool exists = false;
497	int ret = 0;
498	u32 index;
499	int err;
500
501	if (!nla) {
502		NL_SET_ERR_MSG_MOD(extack, "IFE requires attributes to be passed");
503		return -EINVAL;
504	}
505
506	err = nla_parse_nested_deprecated(tb, TCA_IFE_MAX, nla, ife_policy,
507					  NULL);
508	if (err < 0)
509		return err;
510
511	if (!tb[TCA_IFE_PARMS])
512		return -EINVAL;
513
514	parm = nla_data(tb[TCA_IFE_PARMS]);
515
516	/* IFE_DECODE is 0 and indicates the opposite of IFE_ENCODE because
517	 * they cannot run as the same time. Check on all other values which
518	 * are not supported right now.
519	 */
520	if (parm->flags & ~IFE_ENCODE)
521		return -EINVAL;
522
523	p = kzalloc(sizeof(*p), GFP_KERNEL);
524	if (!p)
525		return -ENOMEM;
526
527	if (tb[TCA_IFE_METALST]) {
528		err = nla_parse_nested_deprecated(tb2, IFE_META_MAX,
529						  tb[TCA_IFE_METALST], NULL,
530						  NULL);
531		if (err) {
532			kfree(p);
533			return err;
534		}
535		err = load_metalist(tb2, !(flags & TCA_ACT_FLAGS_NO_RTNL));
536		if (err) {
537			kfree(p);
538			return err;
539		}
540	}
541
542	index = parm->index;
543	err = tcf_idr_check_alloc(tn, &index, a, bind);
544	if (err < 0) {
545		kfree(p);
546		return err;
547	}
548	exists = err;
549	if (exists && bind) {
550		kfree(p);
551		return ACT_P_BOUND;
552	}
553
554	if (!exists) {
555		ret = tcf_idr_create(tn, index, est, a, &act_ife_ops,
556				     bind, true, flags);
557		if (ret) {
558			tcf_idr_cleanup(tn, index);
559			kfree(p);
560			return ret;
561		}
562		ret = ACT_P_CREATED;
563	} else if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
564		tcf_idr_release(*a, bind);
565		kfree(p);
566		return -EEXIST;
567	}
568
569	ife = to_ife(*a);
570	if (ret == ACT_P_CREATED)
571		INIT_LIST_HEAD(&ife->metalist);
572
573	err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
574	if (err < 0)
575		goto release_idr;
576
577	p->flags = parm->flags;
578
579	if (parm->flags & IFE_ENCODE) {
580		if (tb[TCA_IFE_TYPE])
581			ife_type = nla_get_u16(tb[TCA_IFE_TYPE]);
582		if (tb[TCA_IFE_DMAC])
583			daddr = nla_data(tb[TCA_IFE_DMAC]);
584		if (tb[TCA_IFE_SMAC])
585			saddr = nla_data(tb[TCA_IFE_SMAC]);
586	}
587
588	if (parm->flags & IFE_ENCODE) {
589		if (daddr)
590			ether_addr_copy(p->eth_dst, daddr);
591		else
592			eth_zero_addr(p->eth_dst);
593
594		if (saddr)
595			ether_addr_copy(p->eth_src, saddr);
596		else
597			eth_zero_addr(p->eth_src);
598
599		p->eth_type = ife_type;
600	}
601
602	if (tb[TCA_IFE_METALST]) {
603		err = populate_metalist(ife, tb2, exists,
604					!(flags & TCA_ACT_FLAGS_NO_RTNL));
605		if (err)
606			goto metadata_parse_err;
607	} else {
608		/* if no passed metadata allow list or passed allow-all
609		 * then here we process by adding as many supported metadatum
610		 * as we can. You better have at least one else we are
611		 * going to bail out
612		 */
613		err = use_all_metadata(ife, exists);
614		if (err)
615			goto metadata_parse_err;
616	}
617
618	if (exists)
619		spin_lock_bh(&ife->tcf_lock);
620	/* protected by tcf_lock when modifying existing action */
621	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
622	p = rcu_replace_pointer(ife->params, p, 1);
623
624	if (exists)
625		spin_unlock_bh(&ife->tcf_lock);
626	if (goto_ch)
627		tcf_chain_put_by_act(goto_ch);
628	if (p)
629		kfree_rcu(p, rcu);
630
631	return ret;
632metadata_parse_err:
633	if (goto_ch)
634		tcf_chain_put_by_act(goto_ch);
635release_idr:
636	kfree(p);
637	tcf_idr_release(*a, bind);
638	return err;
639}
640
641static int tcf_ife_dump(struct sk_buff *skb, struct tc_action *a, int bind,
642			int ref)
643{
644	unsigned char *b = skb_tail_pointer(skb);
645	struct tcf_ife_info *ife = to_ife(a);
646	struct tcf_ife_params *p;
647	struct tc_ife opt = {
648		.index = ife->tcf_index,
649		.refcnt = refcount_read(&ife->tcf_refcnt) - ref,
650		.bindcnt = atomic_read(&ife->tcf_bindcnt) - bind,
651	};
652	struct tcf_t t;
653
654	spin_lock_bh(&ife->tcf_lock);
655	opt.action = ife->tcf_action;
656	p = rcu_dereference_protected(ife->params,
657				      lockdep_is_held(&ife->tcf_lock));
658	opt.flags = p->flags;
659
660	if (nla_put(skb, TCA_IFE_PARMS, sizeof(opt), &opt))
661		goto nla_put_failure;
662
663	tcf_tm_dump(&t, &ife->tcf_tm);
664	if (nla_put_64bit(skb, TCA_IFE_TM, sizeof(t), &t, TCA_IFE_PAD))
665		goto nla_put_failure;
666
667	if (!is_zero_ether_addr(p->eth_dst)) {
668		if (nla_put(skb, TCA_IFE_DMAC, ETH_ALEN, p->eth_dst))
669			goto nla_put_failure;
670	}
671
672	if (!is_zero_ether_addr(p->eth_src)) {
673		if (nla_put(skb, TCA_IFE_SMAC, ETH_ALEN, p->eth_src))
674			goto nla_put_failure;
675	}
676
677	if (nla_put(skb, TCA_IFE_TYPE, 2, &p->eth_type))
678		goto nla_put_failure;
679
680	if (dump_metalist(skb, ife)) {
681		/*ignore failure to dump metalist */
682		pr_info("Failed to dump metalist\n");
683	}
684
685	spin_unlock_bh(&ife->tcf_lock);
686	return skb->len;
687
688nla_put_failure:
689	spin_unlock_bh(&ife->tcf_lock);
690	nlmsg_trim(skb, b);
691	return -1;
692}
693
694static int find_decode_metaid(struct sk_buff *skb, struct tcf_ife_info *ife,
695			      u16 metaid, u16 mlen, void *mdata)
696{
697	struct tcf_meta_info *e;
698
699	/* XXX: use hash to speed up */
700	list_for_each_entry(e, &ife->metalist, metalist) {
701		if (metaid == e->metaid) {
702			if (e->ops) {
703				/* We check for decode presence already */
704				return e->ops->decode(skb, mdata, mlen);
705			}
706		}
707	}
708
709	return -ENOENT;
710}
711
712static int tcf_ife_decode(struct sk_buff *skb, const struct tc_action *a,
713			  struct tcf_result *res)
714{
715	struct tcf_ife_info *ife = to_ife(a);
716	int action = ife->tcf_action;
717	u8 *ifehdr_end;
718	u8 *tlv_data;
719	u16 metalen;
720
721	bstats_update(this_cpu_ptr(ife->common.cpu_bstats), skb);
722	tcf_lastuse_update(&ife->tcf_tm);
723
724	if (skb_at_tc_ingress(skb))
725		skb_push(skb, skb->dev->hard_header_len);
726
727	tlv_data = ife_decode(skb, &metalen);
728	if (unlikely(!tlv_data)) {
729		qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
730		return TC_ACT_SHOT;
731	}
732
733	ifehdr_end = tlv_data + metalen;
734	for (; tlv_data < ifehdr_end; tlv_data = ife_tlv_meta_next(tlv_data)) {
735		u8 *curr_data;
736		u16 mtype;
737		u16 dlen;
738
739		curr_data = ife_tlv_meta_decode(tlv_data, ifehdr_end, &mtype,
740						&dlen, NULL);
741		if (!curr_data) {
742			qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
743			return TC_ACT_SHOT;
744		}
745
746		if (find_decode_metaid(skb, ife, mtype, dlen, curr_data)) {
747			/* abuse overlimits to count when we receive metadata
748			 * but dont have an ops for it
749			 */
750			pr_info_ratelimited("Unknown metaid %d dlen %d\n",
751					    mtype, dlen);
752			qstats_overlimit_inc(this_cpu_ptr(ife->common.cpu_qstats));
753		}
754	}
755
756	if (WARN_ON(tlv_data != ifehdr_end)) {
757		qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
758		return TC_ACT_SHOT;
759	}
760
761	skb->protocol = eth_type_trans(skb, skb->dev);
762	skb_reset_network_header(skb);
763
764	return action;
765}
766
767/*XXX: check if we can do this at install time instead of current
768 * send data path
769**/
770static int ife_get_sz(struct sk_buff *skb, struct tcf_ife_info *ife)
771{
772	struct tcf_meta_info *e, *n;
773	int tot_run_sz = 0, run_sz = 0;
774
775	list_for_each_entry_safe(e, n, &ife->metalist, metalist) {
776		if (e->ops->check_presence) {
777			run_sz = e->ops->check_presence(skb, e);
778			tot_run_sz += run_sz;
779		}
780	}
781
782	return tot_run_sz;
783}
784
785static int tcf_ife_encode(struct sk_buff *skb, const struct tc_action *a,
786			  struct tcf_result *res, struct tcf_ife_params *p)
787{
788	struct tcf_ife_info *ife = to_ife(a);
789	int action = ife->tcf_action;
790	struct ethhdr *oethh;	/* outer ether header */
791	struct tcf_meta_info *e;
792	/*
793	   OUTERHDR:TOTMETALEN:{TLVHDR:Metadatum:TLVHDR..}:ORIGDATA
794	   where ORIGDATA = original ethernet header ...
795	 */
796	u16 metalen = ife_get_sz(skb, ife);
797	int hdrm = metalen + skb->dev->hard_header_len + IFE_METAHDRLEN;
798	unsigned int skboff = 0;
799	int new_len = skb->len + hdrm;
800	bool exceed_mtu = false;
801	void *ife_meta;
802	int err = 0;
803
804	if (!skb_at_tc_ingress(skb)) {
805		if (new_len > skb->dev->mtu)
806			exceed_mtu = true;
807	}
808
809	bstats_update(this_cpu_ptr(ife->common.cpu_bstats), skb);
810	tcf_lastuse_update(&ife->tcf_tm);
811
812	if (!metalen) {		/* no metadata to send */
813		/* abuse overlimits to count when we allow packet
814		 * with no metadata
815		 */
816		qstats_overlimit_inc(this_cpu_ptr(ife->common.cpu_qstats));
817		return action;
818	}
819	/* could be stupid policy setup or mtu config
820	 * so lets be conservative.. */
821	if ((action == TC_ACT_SHOT) || exceed_mtu) {
822		qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
823		return TC_ACT_SHOT;
824	}
825
826	if (skb_at_tc_ingress(skb))
827		skb_push(skb, skb->dev->hard_header_len);
828
829	ife_meta = ife_encode(skb, metalen);
830
831	spin_lock(&ife->tcf_lock);
832
833	/* XXX: we dont have a clever way of telling encode to
834	 * not repeat some of the computations that are done by
835	 * ops->presence_check...
836	 */
837	list_for_each_entry(e, &ife->metalist, metalist) {
838		if (e->ops->encode) {
839			err = e->ops->encode(skb, (void *)(ife_meta + skboff),
840					     e);
841		}
842		if (err < 0) {
843			/* too corrupt to keep around if overwritten */
844			spin_unlock(&ife->tcf_lock);
845			qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
846			return TC_ACT_SHOT;
847		}
848		skboff += err;
849	}
850	spin_unlock(&ife->tcf_lock);
851	oethh = (struct ethhdr *)skb->data;
852
853	if (!is_zero_ether_addr(p->eth_src))
854		ether_addr_copy(oethh->h_source, p->eth_src);
855	if (!is_zero_ether_addr(p->eth_dst))
856		ether_addr_copy(oethh->h_dest, p->eth_dst);
857	oethh->h_proto = htons(p->eth_type);
858
859	if (skb_at_tc_ingress(skb))
860		skb_pull(skb, skb->dev->hard_header_len);
861
862	return action;
863}
864
865TC_INDIRECT_SCOPE int tcf_ife_act(struct sk_buff *skb,
866				  const struct tc_action *a,
867				  struct tcf_result *res)
868{
869	struct tcf_ife_info *ife = to_ife(a);
870	struct tcf_ife_params *p;
871	int ret;
872
873	p = rcu_dereference_bh(ife->params);
874	if (p->flags & IFE_ENCODE) {
875		ret = tcf_ife_encode(skb, a, res, p);
876		return ret;
877	}
878
879	return tcf_ife_decode(skb, a, res);
880}
881
882static struct tc_action_ops act_ife_ops = {
883	.kind = "ife",
884	.id = TCA_ID_IFE,
885	.owner = THIS_MODULE,
886	.act = tcf_ife_act,
887	.dump = tcf_ife_dump,
888	.cleanup = tcf_ife_cleanup,
889	.init = tcf_ife_init,
890	.size =	sizeof(struct tcf_ife_info),
891};
892MODULE_ALIAS_NET_ACT("ife");
893
894static __net_init int ife_init_net(struct net *net)
895{
896	struct tc_action_net *tn = net_generic(net, act_ife_ops.net_id);
897
898	return tc_action_net_init(net, tn, &act_ife_ops);
899}
900
901static void __net_exit ife_exit_net(struct list_head *net_list)
902{
903	tc_action_net_exit(net_list, act_ife_ops.net_id);
904}
905
906static struct pernet_operations ife_net_ops = {
907	.init = ife_init_net,
908	.exit_batch = ife_exit_net,
909	.id   = &act_ife_ops.net_id,
910	.size = sizeof(struct tc_action_net),
911};
912
913static int __init ife_init_module(void)
914{
915	return tcf_register_action(&act_ife_ops, &ife_net_ops);
916}
917
918static void __exit ife_cleanup_module(void)
919{
920	tcf_unregister_action(&act_ife_ops, &ife_net_ops);
921}
922
923module_init(ife_init_module);
924module_exit(ife_cleanup_module);
925
926MODULE_AUTHOR("Jamal Hadi Salim(2015)");
927MODULE_DESCRIPTION("Inter-FE LFB action");
928MODULE_LICENSE("GPL");