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  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
 36#define IFE_TAB_MASK 15
 37
 38static int ife_net_id;
 39static int max_metacnt = IFE_META_MAX + 1;
 40
 41static 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/* Caller takes care of presenting data in network order
 49*/
 50int ife_tlv_meta_encode(void *skbdata, u16 attrtype, u16 dlen, const void *dval)
 51{
 52	u32 *tlv = (u32 *)(skbdata);
 53	u16 totlen = nla_total_size(dlen);	/*alignment + hdr */
 54	char *dptr = (char *)tlv + NLA_HDRLEN;
 55	u32 htlv = attrtype << 16 | totlen;
 56
 57	*tlv = htonl(htlv);
 58	memset(dptr, 0, totlen - NLA_HDRLEN);
 59	memcpy(dptr, dval, dlen);
 60
 61	return totlen;
 62}
 63EXPORT_SYMBOL_GPL(ife_tlv_meta_encode);
 64
 65int 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}
 72EXPORT_SYMBOL_GPL(ife_get_meta_u32);
 73
 74int 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}
 81EXPORT_SYMBOL_GPL(ife_check_meta_u32);
 82
 83int ife_encode_meta_u32(u32 metaval, void *skbdata, struct tcf_meta_info *mi)
 84{
 85	u32 edata = metaval;
 86
 87	if (mi->metaval)
 88		edata = *(u32 *)mi->metaval;
 89	else if (metaval)
 90		edata = metaval;
 91
 92	if (!edata) /* will not encode */
 93		return 0;
 94
 95	edata = htonl(edata);
 96	return ife_tlv_meta_encode(skbdata, mi->metaid, 4, &edata);
 97}
 98EXPORT_SYMBOL_GPL(ife_encode_meta_u32);
 99
100int ife_get_meta_u16(struct sk_buff *skb, struct tcf_meta_info *mi)
101{
102	if (mi->metaval)
103		return nla_put_u16(skb, mi->metaid, *(u16 *)mi->metaval);
104	else
105		return nla_put(skb, mi->metaid, 0, NULL);
106}
107EXPORT_SYMBOL_GPL(ife_get_meta_u16);
108
109int ife_alloc_meta_u32(struct tcf_meta_info *mi, void *metaval)
110{
111	mi->metaval = kmemdup(metaval, sizeof(u32), GFP_KERNEL);
112	if (!mi->metaval)
113		return -ENOMEM;
114
115	return 0;
116}
117EXPORT_SYMBOL_GPL(ife_alloc_meta_u32);
118
119int ife_alloc_meta_u16(struct tcf_meta_info *mi, void *metaval)
120{
121	mi->metaval = kmemdup(metaval, sizeof(u16), GFP_KERNEL);
122	if (!mi->metaval)
123		return -ENOMEM;
124
125	return 0;
126}
127EXPORT_SYMBOL_GPL(ife_alloc_meta_u16);
128
129void ife_release_meta_gen(struct tcf_meta_info *mi)
130{
131	kfree(mi->metaval);
132}
133EXPORT_SYMBOL_GPL(ife_release_meta_gen);
134
135int ife_validate_meta_u32(void *val, int len)
136{
137	if (len == 4)
138		return 0;
139
140	return -EINVAL;
141}
142EXPORT_SYMBOL_GPL(ife_validate_meta_u32);
143
144int ife_validate_meta_u16(void *val, int len)
145{
146	/* length will include padding */
147	if (len == NLA_ALIGN(2))
148		return 0;
149
150	return -EINVAL;
151}
152EXPORT_SYMBOL_GPL(ife_validate_meta_u16);
153
154static LIST_HEAD(ifeoplist);
155static DEFINE_RWLOCK(ife_mod_lock);
156
157static struct tcf_meta_ops *find_ife_oplist(u16 metaid)
158{
159	struct tcf_meta_ops *o;
160
161	read_lock(&ife_mod_lock);
162	list_for_each_entry(o, &ifeoplist, list) {
163		if (o->metaid == metaid) {
164			if (!try_module_get(o->owner))
165				o = NULL;
166			read_unlock(&ife_mod_lock);
167			return o;
168		}
169	}
170	read_unlock(&ife_mod_lock);
171
172	return NULL;
173}
174
175int register_ife_op(struct tcf_meta_ops *mops)
176{
177	struct tcf_meta_ops *m;
178
179	if (!mops->metaid || !mops->metatype || !mops->name ||
180	    !mops->check_presence || !mops->encode || !mops->decode ||
181	    !mops->get || !mops->alloc)
182		return -EINVAL;
183
184	write_lock(&ife_mod_lock);
185
186	list_for_each_entry(m, &ifeoplist, list) {
187		if (m->metaid == mops->metaid ||
188		    (strcmp(mops->name, m->name) == 0)) {
189			write_unlock(&ife_mod_lock);
190			return -EEXIST;
191		}
192	}
193
194	if (!mops->release)
195		mops->release = ife_release_meta_gen;
196
197	list_add_tail(&mops->list, &ifeoplist);
198	write_unlock(&ife_mod_lock);
199	return 0;
200}
201EXPORT_SYMBOL_GPL(unregister_ife_op);
202
203int unregister_ife_op(struct tcf_meta_ops *mops)
204{
205	struct tcf_meta_ops *m;
206	int err = -ENOENT;
207
208	write_lock(&ife_mod_lock);
209	list_for_each_entry(m, &ifeoplist, list) {
210		if (m->metaid == mops->metaid) {
211			list_del(&mops->list);
212			err = 0;
213			break;
214		}
215	}
216	write_unlock(&ife_mod_lock);
217
218	return err;
219}
220EXPORT_SYMBOL_GPL(register_ife_op);
221
222static int ife_validate_metatype(struct tcf_meta_ops *ops, void *val, int len)
223{
224	int ret = 0;
225	/* XXX: unfortunately cant use nla_policy at this point
226	* because a length of 0 is valid in the case of
227	* "allow". "use" semantics do enforce for proper
228	* length and i couldve use nla_policy but it makes it hard
229	* to use it just for that..
230	*/
231	if (ops->validate)
232		return ops->validate(val, len);
233
234	if (ops->metatype == NLA_U32)
235		ret = ife_validate_meta_u32(val, len);
236	else if (ops->metatype == NLA_U16)
237		ret = ife_validate_meta_u16(val, len);
238
239	return ret;
240}
241
242/* called when adding new meta information
243 * under ife->tcf_lock
244*/
245static int load_metaops_and_vet(struct tcf_ife_info *ife, u32 metaid,
246				void *val, int len)
247{
248	struct tcf_meta_ops *ops = find_ife_oplist(metaid);
249	int ret = 0;
250
251	if (!ops) {
252		ret = -ENOENT;
253#ifdef CONFIG_MODULES
254		spin_unlock_bh(&ife->tcf_lock);
255		rtnl_unlock();
256		request_module("ifemeta%u", metaid);
257		rtnl_lock();
258		spin_lock_bh(&ife->tcf_lock);
259		ops = find_ife_oplist(metaid);
260#endif
261	}
262
263	if (ops) {
264		ret = 0;
265		if (len)
266			ret = ife_validate_metatype(ops, val, len);
267
268		module_put(ops->owner);
269	}
270
271	return ret;
272}
273
274/* called when adding new meta information
275 * under ife->tcf_lock
276*/
277static int add_metainfo(struct tcf_ife_info *ife, u32 metaid, void *metaval,
278			int len)
279{
280	struct tcf_meta_info *mi = NULL;
281	struct tcf_meta_ops *ops = find_ife_oplist(metaid);
282	int ret = 0;
283
284	if (!ops)
285		return -ENOENT;
286
287	mi = kzalloc(sizeof(*mi), GFP_KERNEL);
288	if (!mi) {
289		/*put back what find_ife_oplist took */
290		module_put(ops->owner);
291		return -ENOMEM;
292	}
293
294	mi->metaid = metaid;
295	mi->ops = ops;
296	if (len > 0) {
297		ret = ops->alloc(mi, metaval);
298		if (ret != 0) {
299			kfree(mi);
300			module_put(ops->owner);
301			return ret;
302		}
303	}
304
305	list_add_tail(&mi->metalist, &ife->metalist);
306
307	return ret;
308}
309
310static int use_all_metadata(struct tcf_ife_info *ife)
311{
312	struct tcf_meta_ops *o;
313	int rc = 0;
314	int installed = 0;
315
316	list_for_each_entry(o, &ifeoplist, list) {
317		rc = add_metainfo(ife, o->metaid, NULL, 0);
318		if (rc == 0)
319			installed += 1;
320	}
321
322	if (installed)
323		return 0;
324	else
325		return -EINVAL;
326}
327
328static int dump_metalist(struct sk_buff *skb, struct tcf_ife_info *ife)
329{
330	struct tcf_meta_info *e;
331	struct nlattr *nest;
332	unsigned char *b = skb_tail_pointer(skb);
333	int total_encoded = 0;
334
335	/*can only happen on decode */
336	if (list_empty(&ife->metalist))
337		return 0;
338
339	nest = nla_nest_start(skb, TCA_IFE_METALST);
340	if (!nest)
341		goto out_nlmsg_trim;
342
343	list_for_each_entry(e, &ife->metalist, metalist) {
344		if (!e->ops->get(skb, e))
345			total_encoded += 1;
346	}
347
348	if (!total_encoded)
349		goto out_nlmsg_trim;
350
351	nla_nest_end(skb, nest);
352
353	return 0;
354
355out_nlmsg_trim:
356	nlmsg_trim(skb, b);
357	return -1;
358}
359
360/* under ife->tcf_lock */
361static void _tcf_ife_cleanup(struct tc_action *a, int bind)
362{
363	struct tcf_ife_info *ife = a->priv;
364	struct tcf_meta_info *e, *n;
365
366	list_for_each_entry_safe(e, n, &ife->metalist, metalist) {
367		module_put(e->ops->owner);
368		list_del(&e->metalist);
369		if (e->metaval) {
370			if (e->ops->release)
371				e->ops->release(e);
372			else
373				kfree(e->metaval);
374		}
375		kfree(e);
376	}
377}
378
379static void tcf_ife_cleanup(struct tc_action *a, int bind)
380{
381	struct tcf_ife_info *ife = a->priv;
382
383	spin_lock_bh(&ife->tcf_lock);
384	_tcf_ife_cleanup(a, bind);
385	spin_unlock_bh(&ife->tcf_lock);
386}
387
388/* under ife->tcf_lock */
389static int populate_metalist(struct tcf_ife_info *ife, struct nlattr **tb)
390{
391	int len = 0;
392	int rc = 0;
393	int i = 0;
394	void *val;
395
396	for (i = 1; i < max_metacnt; i++) {
397		if (tb[i]) {
398			val = nla_data(tb[i]);
399			len = nla_len(tb[i]);
400
401			rc = load_metaops_and_vet(ife, i, val, len);
402			if (rc != 0)
403				return rc;
404
405			rc = add_metainfo(ife, i, val, len);
406			if (rc)
407				return rc;
408		}
409	}
410
411	return rc;
412}
413
414static int tcf_ife_init(struct net *net, struct nlattr *nla,
415			struct nlattr *est, struct tc_action *a,
416			int ovr, int bind)
417{
418	struct tc_action_net *tn = net_generic(net, ife_net_id);
419	struct nlattr *tb[TCA_IFE_MAX + 1];
420	struct nlattr *tb2[IFE_META_MAX + 1];
421	struct tcf_ife_info *ife;
422	struct tc_ife *parm;
423	u16 ife_type = 0;
424	u8 *daddr = NULL;
425	u8 *saddr = NULL;
426	int ret = 0, exists = 0;
427	int err;
428
429	err = nla_parse_nested(tb, TCA_IFE_MAX, nla, ife_policy);
430	if (err < 0)
431		return err;
432
433	if (!tb[TCA_IFE_PARMS])
434		return -EINVAL;
435
436	parm = nla_data(tb[TCA_IFE_PARMS]);
437
438	exists = tcf_hash_check(tn, parm->index, a, bind);
439	if (exists && bind)
440		return 0;
441
442	if (parm->flags & IFE_ENCODE) {
443		/* Until we get issued the ethertype, we cant have
444		 * a default..
445		**/
446		if (!tb[TCA_IFE_TYPE]) {
447			if (exists)
448				tcf_hash_release(a, bind);
449			pr_info("You MUST pass etherype for encoding\n");
450			return -EINVAL;
451		}
452	}
453
454	if (!exists) {
455		ret = tcf_hash_create(tn, parm->index, est, a, sizeof(*ife),
456				      bind, false);
457		if (ret)
458			return ret;
459		ret = ACT_P_CREATED;
460	} else {
461		tcf_hash_release(a, bind);
462		if (!ovr)
463			return -EEXIST;
464	}
465
466	ife = to_ife(a);
467	ife->flags = parm->flags;
468
469	if (parm->flags & IFE_ENCODE) {
470		ife_type = nla_get_u16(tb[TCA_IFE_TYPE]);
471		if (tb[TCA_IFE_DMAC])
472			daddr = nla_data(tb[TCA_IFE_DMAC]);
473		if (tb[TCA_IFE_SMAC])
474			saddr = nla_data(tb[TCA_IFE_SMAC]);
475	}
476
477	spin_lock_bh(&ife->tcf_lock);
478	ife->tcf_action = parm->action;
479
480	if (parm->flags & IFE_ENCODE) {
481		if (daddr)
482			ether_addr_copy(ife->eth_dst, daddr);
483		else
484			eth_zero_addr(ife->eth_dst);
485
486		if (saddr)
487			ether_addr_copy(ife->eth_src, saddr);
488		else
489			eth_zero_addr(ife->eth_src);
490
491		ife->eth_type = ife_type;
492	}
493
494	if (ret == ACT_P_CREATED)
495		INIT_LIST_HEAD(&ife->metalist);
496
497	if (tb[TCA_IFE_METALST]) {
498		err = nla_parse_nested(tb2, IFE_META_MAX, tb[TCA_IFE_METALST],
499				       NULL);
500		if (err) {
501metadata_parse_err:
502			if (exists)
503				tcf_hash_release(a, bind);
504			if (ret == ACT_P_CREATED)
505				_tcf_ife_cleanup(a, bind);
506
507			spin_unlock_bh(&ife->tcf_lock);
508			return err;
509		}
510
511		err = populate_metalist(ife, tb2);
512		if (err)
513			goto metadata_parse_err;
514
515	} else {
516		/* if no passed metadata allow list or passed allow-all
517		 * then here we process by adding as many supported metadatum
518		 * as we can. You better have at least one else we are
519		 * going to bail out
520		 */
521		err = use_all_metadata(ife);
522		if (err) {
523			if (ret == ACT_P_CREATED)
524				_tcf_ife_cleanup(a, bind);
525
526			spin_unlock_bh(&ife->tcf_lock);
527			return err;
528		}
529	}
530
531	spin_unlock_bh(&ife->tcf_lock);
532
533	if (ret == ACT_P_CREATED)
534		tcf_hash_insert(tn, a);
535
536	return ret;
537}
538
539static int tcf_ife_dump(struct sk_buff *skb, struct tc_action *a, int bind,
540			int ref)
541{
542	unsigned char *b = skb_tail_pointer(skb);
543	struct tcf_ife_info *ife = a->priv;
544	struct tc_ife opt = {
545		.index = ife->tcf_index,
546		.refcnt = ife->tcf_refcnt - ref,
547		.bindcnt = ife->tcf_bindcnt - bind,
548		.action = ife->tcf_action,
549		.flags = ife->flags,
550	};
551	struct tcf_t t;
552
553	if (nla_put(skb, TCA_IFE_PARMS, sizeof(opt), &opt))
554		goto nla_put_failure;
555
556	t.install = jiffies_to_clock_t(jiffies - ife->tcf_tm.install);
557	t.lastuse = jiffies_to_clock_t(jiffies - ife->tcf_tm.lastuse);
558	t.expires = jiffies_to_clock_t(ife->tcf_tm.expires);
559	if (nla_put(skb, TCA_IFE_TM, sizeof(t), &t))
560		goto nla_put_failure;
561
562	if (!is_zero_ether_addr(ife->eth_dst)) {
563		if (nla_put(skb, TCA_IFE_DMAC, ETH_ALEN, ife->eth_dst))
564			goto nla_put_failure;
565	}
566
567	if (!is_zero_ether_addr(ife->eth_src)) {
568		if (nla_put(skb, TCA_IFE_SMAC, ETH_ALEN, ife->eth_src))
569			goto nla_put_failure;
570	}
571
572	if (nla_put(skb, TCA_IFE_TYPE, 2, &ife->eth_type))
573		goto nla_put_failure;
574
575	if (dump_metalist(skb, ife)) {
576		/*ignore failure to dump metalist */
577		pr_info("Failed to dump metalist\n");
578	}
579
580	return skb->len;
581
582nla_put_failure:
583	nlmsg_trim(skb, b);
584	return -1;
585}
586
587int find_decode_metaid(struct sk_buff *skb, struct tcf_ife_info *ife,
588		       u16 metaid, u16 mlen, void *mdata)
589{
590	struct tcf_meta_info *e;
591
592	/* XXX: use hash to speed up */
593	list_for_each_entry(e, &ife->metalist, metalist) {
594		if (metaid == e->metaid) {
595			if (e->ops) {
596				/* We check for decode presence already */
597				return e->ops->decode(skb, mdata, mlen);
598			}
599		}
600	}
601
602	return 0;
603}
604
605struct ifeheadr {
606	__be16 metalen;
607	u8 tlv_data[];
608};
609
610struct meta_tlvhdr {
611	__be16 type;
612	__be16 len;
613};
614
615static int tcf_ife_decode(struct sk_buff *skb, const struct tc_action *a,
616			  struct tcf_result *res)
617{
618	struct tcf_ife_info *ife = a->priv;
619	int action = ife->tcf_action;
620	struct ifeheadr *ifehdr = (struct ifeheadr *)skb->data;
621	u16 ifehdrln = ifehdr->metalen;
622	struct meta_tlvhdr *tlv = (struct meta_tlvhdr *)(ifehdr->tlv_data);
623
624	spin_lock(&ife->tcf_lock);
625	bstats_update(&ife->tcf_bstats, skb);
626	ife->tcf_tm.lastuse = jiffies;
627	spin_unlock(&ife->tcf_lock);
628
629	ifehdrln = ntohs(ifehdrln);
630	if (unlikely(!pskb_may_pull(skb, ifehdrln))) {
631		spin_lock(&ife->tcf_lock);
632		ife->tcf_qstats.drops++;
633		spin_unlock(&ife->tcf_lock);
634		return TC_ACT_SHOT;
635	}
636
637	skb_set_mac_header(skb, ifehdrln);
638	__skb_pull(skb, ifehdrln);
639	skb->protocol = eth_type_trans(skb, skb->dev);
640	ifehdrln -= IFE_METAHDRLEN;
641
642	while (ifehdrln > 0) {
643		u8 *tlvdata = (u8 *)tlv;
644		u16 mtype = tlv->type;
645		u16 mlen = tlv->len;
646
647		mtype = ntohs(mtype);
648		mlen = ntohs(mlen);
649
650		if (find_decode_metaid(skb, ife, mtype, (mlen - 4),
651				       (void *)(tlvdata + 4))) {
652			/* abuse overlimits to count when we receive metadata
653			 * but dont have an ops for it
654			 */
655			pr_info_ratelimited("Unknown metaid %d alnlen %d\n",
656					    mtype, mlen);
657			ife->tcf_qstats.overlimits++;
658		}
659
660		tlvdata += mlen;
661		ifehdrln -= mlen;
662		tlv = (struct meta_tlvhdr *)tlvdata;
663	}
664
665	skb_reset_network_header(skb);
666	return action;
667}
668
669/*XXX: check if we can do this at install time instead of current
670 * send data path
671**/
672static int ife_get_sz(struct sk_buff *skb, struct tcf_ife_info *ife)
673{
674	struct tcf_meta_info *e, *n;
675	int tot_run_sz = 0, run_sz = 0;
676
677	list_for_each_entry_safe(e, n, &ife->metalist, metalist) {
678		if (e->ops->check_presence) {
679			run_sz = e->ops->check_presence(skb, e);
680			tot_run_sz += run_sz;
681		}
682	}
683
684	return tot_run_sz;
685}
686
687static int tcf_ife_encode(struct sk_buff *skb, const struct tc_action *a,
688			  struct tcf_result *res)
689{
690	struct tcf_ife_info *ife = a->priv;
691	int action = ife->tcf_action;
692	struct ethhdr *oethh;	/* outer ether header */
693	struct ethhdr *iethh;	/* inner eth header */
694	struct tcf_meta_info *e;
695	/*
696	   OUTERHDR:TOTMETALEN:{TLVHDR:Metadatum:TLVHDR..}:ORIGDATA
697	   where ORIGDATA = original ethernet header ...
698	 */
699	u16 metalen = ife_get_sz(skb, ife);
700	int hdrm = metalen + skb->dev->hard_header_len + IFE_METAHDRLEN;
701	unsigned int skboff = skb->dev->hard_header_len;
702	u32 at = G_TC_AT(skb->tc_verd);
703	int new_len = skb->len + hdrm;
704	bool exceed_mtu = false;
705	int err;
706
707	if (at & AT_EGRESS) {
708		if (new_len > skb->dev->mtu)
709			exceed_mtu = true;
710	}
711
712	spin_lock(&ife->tcf_lock);
713	bstats_update(&ife->tcf_bstats, skb);
714	ife->tcf_tm.lastuse = jiffies;
715
716	if (!metalen) {		/* no metadata to send */
717		/* abuse overlimits to count when we allow packet
718		 * with no metadata
719		 */
720		ife->tcf_qstats.overlimits++;
721		spin_unlock(&ife->tcf_lock);
722		return action;
723	}
724	/* could be stupid policy setup or mtu config
725	 * so lets be conservative.. */
726	if ((action == TC_ACT_SHOT) || exceed_mtu) {
727		ife->tcf_qstats.drops++;
728		spin_unlock(&ife->tcf_lock);
729		return TC_ACT_SHOT;
730	}
731
732	iethh = eth_hdr(skb);
733
734	err = skb_cow_head(skb, hdrm);
735	if (unlikely(err)) {
736		ife->tcf_qstats.drops++;
737		spin_unlock(&ife->tcf_lock);
738		return TC_ACT_SHOT;
739	}
740
741	if (!(at & AT_EGRESS))
742		skb_push(skb, skb->dev->hard_header_len);
743
744	__skb_push(skb, hdrm);
745	memcpy(skb->data, iethh, skb->mac_len);
746	skb_reset_mac_header(skb);
747	oethh = eth_hdr(skb);
748
749	/*total metadata length */
750	metalen += IFE_METAHDRLEN;
751	metalen = htons(metalen);
752	memcpy((skb->data + skboff), &metalen, IFE_METAHDRLEN);
753	skboff += IFE_METAHDRLEN;
754
755	/* XXX: we dont have a clever way of telling encode to
756	 * not repeat some of the computations that are done by
757	 * ops->presence_check...
758	 */
759	list_for_each_entry(e, &ife->metalist, metalist) {
760		if (e->ops->encode) {
761			err = e->ops->encode(skb, (void *)(skb->data + skboff),
762					     e);
763		}
764		if (err < 0) {
765			/* too corrupt to keep around if overwritten */
766			ife->tcf_qstats.drops++;
767			spin_unlock(&ife->tcf_lock);
768			return TC_ACT_SHOT;
769		}
770		skboff += err;
771	}
772
773	if (!is_zero_ether_addr(ife->eth_src))
774		ether_addr_copy(oethh->h_source, ife->eth_src);
775	else
776		ether_addr_copy(oethh->h_source, iethh->h_source);
777	if (!is_zero_ether_addr(ife->eth_dst))
778		ether_addr_copy(oethh->h_dest, ife->eth_dst);
779	else
780		ether_addr_copy(oethh->h_dest, iethh->h_dest);
781	oethh->h_proto = htons(ife->eth_type);
782
783	if (!(at & AT_EGRESS))
784		skb_pull(skb, skb->dev->hard_header_len);
785
786	spin_unlock(&ife->tcf_lock);
787
788	return action;
789}
790
791static int tcf_ife_act(struct sk_buff *skb, const struct tc_action *a,
792		       struct tcf_result *res)
793{
794	struct tcf_ife_info *ife = a->priv;
795
796	if (ife->flags & IFE_ENCODE)
797		return tcf_ife_encode(skb, a, res);
798
799	if (!(ife->flags & IFE_ENCODE))
800		return tcf_ife_decode(skb, a, res);
801
802	pr_info_ratelimited("unknown failure(policy neither de/encode\n");
803	spin_lock(&ife->tcf_lock);
804	bstats_update(&ife->tcf_bstats, skb);
805	ife->tcf_tm.lastuse = jiffies;
806	ife->tcf_qstats.drops++;
807	spin_unlock(&ife->tcf_lock);
808
809	return TC_ACT_SHOT;
810}
811
812static int tcf_ife_walker(struct net *net, struct sk_buff *skb,
813			  struct netlink_callback *cb, int type,
814			  struct tc_action *a)
815{
816	struct tc_action_net *tn = net_generic(net, ife_net_id);
817
818	return tcf_generic_walker(tn, skb, cb, type, a);
819}
820
821static int tcf_ife_search(struct net *net, struct tc_action *a, u32 index)
822{
823	struct tc_action_net *tn = net_generic(net, ife_net_id);
824
825	return tcf_hash_search(tn, a, index);
826}
827
828static struct tc_action_ops act_ife_ops = {
829	.kind = "ife",
830	.type = TCA_ACT_IFE,
831	.owner = THIS_MODULE,
832	.act = tcf_ife_act,
833	.dump = tcf_ife_dump,
834	.cleanup = tcf_ife_cleanup,
835	.init = tcf_ife_init,
836	.walk = tcf_ife_walker,
837	.lookup = tcf_ife_search,
838};
839
840static __net_init int ife_init_net(struct net *net)
841{
842	struct tc_action_net *tn = net_generic(net, ife_net_id);
843
844	return tc_action_net_init(tn, &act_ife_ops, IFE_TAB_MASK);
845}
846
847static void __net_exit ife_exit_net(struct net *net)
848{
849	struct tc_action_net *tn = net_generic(net, ife_net_id);
850
851	tc_action_net_exit(tn);
852}
853
854static struct pernet_operations ife_net_ops = {
855	.init = ife_init_net,
856	.exit = ife_exit_net,
857	.id   = &ife_net_id,
858	.size = sizeof(struct tc_action_net),
859};
860
861static int __init ife_init_module(void)
862{
863	return tcf_register_action(&act_ife_ops, &ife_net_ops);
864}
865
866static void __exit ife_cleanup_module(void)
867{
868	tcf_unregister_action(&act_ife_ops, &ife_net_ops);
869}
870
871module_init(ife_init_module);
872module_exit(ife_cleanup_module);
873
874MODULE_AUTHOR("Jamal Hadi Salim(2015)");
875MODULE_DESCRIPTION("Inter-FE LFB action");
876MODULE_LICENSE("GPL");