xref: /openbmc/linux/net/sched/act_ife.c (revision b2313077)
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 
38 static int ife_net_id;
39 static int max_metacnt = IFE_META_MAX + 1;
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 /* Caller takes care of presenting data in network order
49 */
50 int 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 }
63 EXPORT_SYMBOL_GPL(ife_tlv_meta_encode);
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_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 }
98 EXPORT_SYMBOL_GPL(ife_encode_meta_u32);
99 
100 int 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 }
107 EXPORT_SYMBOL_GPL(ife_get_meta_u16);
108 
109 int 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 }
117 EXPORT_SYMBOL_GPL(ife_alloc_meta_u32);
118 
119 int 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 }
127 EXPORT_SYMBOL_GPL(ife_alloc_meta_u16);
128 
129 void ife_release_meta_gen(struct tcf_meta_info *mi)
130 {
131 	kfree(mi->metaval);
132 }
133 EXPORT_SYMBOL_GPL(ife_release_meta_gen);
134 
135 int ife_validate_meta_u32(void *val, int len)
136 {
137 	if (len == 4)
138 		return 0;
139 
140 	return -EINVAL;
141 }
142 EXPORT_SYMBOL_GPL(ife_validate_meta_u32);
143 
144 int 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 }
152 EXPORT_SYMBOL_GPL(ife_validate_meta_u16);
153 
154 static LIST_HEAD(ifeoplist);
155 static DEFINE_RWLOCK(ife_mod_lock);
156 
157 static 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 
175 int 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 }
201 EXPORT_SYMBOL_GPL(unregister_ife_op);
202 
203 int 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 }
220 EXPORT_SYMBOL_GPL(register_ife_op);
221 
222 static 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 */
245 static 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 */
277 static 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 
310 static 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 
328 static 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 
355 out_nlmsg_trim:
356 	nlmsg_trim(skb, b);
357 	return -1;
358 }
359 
360 /* under ife->tcf_lock */
361 static 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 
379 static 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 */
389 static 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 
414 static 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 	bool exists = false;
427 	int ret = 0;
428 	int err;
429 
430 	err = nla_parse_nested(tb, TCA_IFE_MAX, nla, ife_policy);
431 	if (err < 0)
432 		return err;
433 
434 	if (!tb[TCA_IFE_PARMS])
435 		return -EINVAL;
436 
437 	parm = nla_data(tb[TCA_IFE_PARMS]);
438 
439 	exists = tcf_hash_check(tn, parm->index, a, bind);
440 	if (exists && bind)
441 		return 0;
442 
443 	if (parm->flags & IFE_ENCODE) {
444 		/* Until we get issued the ethertype, we cant have
445 		 * a default..
446 		**/
447 		if (!tb[TCA_IFE_TYPE]) {
448 			if (exists)
449 				tcf_hash_release(a, bind);
450 			pr_info("You MUST pass etherype for encoding\n");
451 			return -EINVAL;
452 		}
453 	}
454 
455 	if (!exists) {
456 		ret = tcf_hash_create(tn, parm->index, est, a, sizeof(*ife),
457 				      bind, false);
458 		if (ret)
459 			return ret;
460 		ret = ACT_P_CREATED;
461 	} else {
462 		tcf_hash_release(a, bind);
463 		if (!ovr)
464 			return -EEXIST;
465 	}
466 
467 	ife = to_ife(a);
468 	ife->flags = parm->flags;
469 
470 	if (parm->flags & IFE_ENCODE) {
471 		ife_type = nla_get_u16(tb[TCA_IFE_TYPE]);
472 		if (tb[TCA_IFE_DMAC])
473 			daddr = nla_data(tb[TCA_IFE_DMAC]);
474 		if (tb[TCA_IFE_SMAC])
475 			saddr = nla_data(tb[TCA_IFE_SMAC]);
476 	}
477 
478 	spin_lock_bh(&ife->tcf_lock);
479 	ife->tcf_action = parm->action;
480 
481 	if (parm->flags & IFE_ENCODE) {
482 		if (daddr)
483 			ether_addr_copy(ife->eth_dst, daddr);
484 		else
485 			eth_zero_addr(ife->eth_dst);
486 
487 		if (saddr)
488 			ether_addr_copy(ife->eth_src, saddr);
489 		else
490 			eth_zero_addr(ife->eth_src);
491 
492 		ife->eth_type = ife_type;
493 	}
494 
495 	if (ret == ACT_P_CREATED)
496 		INIT_LIST_HEAD(&ife->metalist);
497 
498 	if (tb[TCA_IFE_METALST]) {
499 		err = nla_parse_nested(tb2, IFE_META_MAX, tb[TCA_IFE_METALST],
500 				       NULL);
501 		if (err) {
502 metadata_parse_err:
503 			if (exists)
504 				tcf_hash_release(a, bind);
505 			if (ret == ACT_P_CREATED)
506 				_tcf_ife_cleanup(a, bind);
507 
508 			spin_unlock_bh(&ife->tcf_lock);
509 			return err;
510 		}
511 
512 		err = populate_metalist(ife, tb2);
513 		if (err)
514 			goto metadata_parse_err;
515 
516 	} else {
517 		/* if no passed metadata allow list or passed allow-all
518 		 * then here we process by adding as many supported metadatum
519 		 * as we can. You better have at least one else we are
520 		 * going to bail out
521 		 */
522 		err = use_all_metadata(ife);
523 		if (err) {
524 			if (ret == ACT_P_CREATED)
525 				_tcf_ife_cleanup(a, bind);
526 
527 			spin_unlock_bh(&ife->tcf_lock);
528 			return err;
529 		}
530 	}
531 
532 	spin_unlock_bh(&ife->tcf_lock);
533 
534 	if (ret == ACT_P_CREATED)
535 		tcf_hash_insert(tn, a);
536 
537 	return ret;
538 }
539 
540 static int tcf_ife_dump(struct sk_buff *skb, struct tc_action *a, int bind,
541 			int ref)
542 {
543 	unsigned char *b = skb_tail_pointer(skb);
544 	struct tcf_ife_info *ife = a->priv;
545 	struct tc_ife opt = {
546 		.index = ife->tcf_index,
547 		.refcnt = ife->tcf_refcnt - ref,
548 		.bindcnt = ife->tcf_bindcnt - bind,
549 		.action = ife->tcf_action,
550 		.flags = ife->flags,
551 	};
552 	struct tcf_t t;
553 
554 	if (nla_put(skb, TCA_IFE_PARMS, sizeof(opt), &opt))
555 		goto nla_put_failure;
556 
557 	tcf_tm_dump(&t, &ife->tcf_tm);
558 	if (nla_put_64bit(skb, TCA_IFE_TM, sizeof(t), &t, TCA_IFE_PAD))
559 		goto nla_put_failure;
560 
561 	if (!is_zero_ether_addr(ife->eth_dst)) {
562 		if (nla_put(skb, TCA_IFE_DMAC, ETH_ALEN, ife->eth_dst))
563 			goto nla_put_failure;
564 	}
565 
566 	if (!is_zero_ether_addr(ife->eth_src)) {
567 		if (nla_put(skb, TCA_IFE_SMAC, ETH_ALEN, ife->eth_src))
568 			goto nla_put_failure;
569 	}
570 
571 	if (nla_put(skb, TCA_IFE_TYPE, 2, &ife->eth_type))
572 		goto nla_put_failure;
573 
574 	if (dump_metalist(skb, ife)) {
575 		/*ignore failure to dump metalist */
576 		pr_info("Failed to dump metalist\n");
577 	}
578 
579 	return skb->len;
580 
581 nla_put_failure:
582 	nlmsg_trim(skb, b);
583 	return -1;
584 }
585 
586 int find_decode_metaid(struct sk_buff *skb, struct tcf_ife_info *ife,
587 		       u16 metaid, u16 mlen, void *mdata)
588 {
589 	struct tcf_meta_info *e;
590 
591 	/* XXX: use hash to speed up */
592 	list_for_each_entry(e, &ife->metalist, metalist) {
593 		if (metaid == e->metaid) {
594 			if (e->ops) {
595 				/* We check for decode presence already */
596 				return e->ops->decode(skb, mdata, mlen);
597 			}
598 		}
599 	}
600 
601 	return 0;
602 }
603 
604 struct ifeheadr {
605 	__be16 metalen;
606 	u8 tlv_data[];
607 };
608 
609 struct meta_tlvhdr {
610 	__be16 type;
611 	__be16 len;
612 };
613 
614 static int tcf_ife_decode(struct sk_buff *skb, const struct tc_action *a,
615 			  struct tcf_result *res)
616 {
617 	struct tcf_ife_info *ife = a->priv;
618 	int action = ife->tcf_action;
619 	struct ifeheadr *ifehdr = (struct ifeheadr *)skb->data;
620 	u16 ifehdrln = ifehdr->metalen;
621 	struct meta_tlvhdr *tlv = (struct meta_tlvhdr *)(ifehdr->tlv_data);
622 
623 	spin_lock(&ife->tcf_lock);
624 	bstats_update(&ife->tcf_bstats, skb);
625 	tcf_lastuse_update(&ife->tcf_tm);
626 	spin_unlock(&ife->tcf_lock);
627 
628 	ifehdrln = ntohs(ifehdrln);
629 	if (unlikely(!pskb_may_pull(skb, ifehdrln))) {
630 		spin_lock(&ife->tcf_lock);
631 		ife->tcf_qstats.drops++;
632 		spin_unlock(&ife->tcf_lock);
633 		return TC_ACT_SHOT;
634 	}
635 
636 	skb_set_mac_header(skb, ifehdrln);
637 	__skb_pull(skb, ifehdrln);
638 	skb->protocol = eth_type_trans(skb, skb->dev);
639 	ifehdrln -= IFE_METAHDRLEN;
640 
641 	while (ifehdrln > 0) {
642 		u8 *tlvdata = (u8 *)tlv;
643 		u16 mtype = tlv->type;
644 		u16 mlen = tlv->len;
645 
646 		mtype = ntohs(mtype);
647 		mlen = ntohs(mlen);
648 
649 		if (find_decode_metaid(skb, ife, mtype, (mlen - 4),
650 				       (void *)(tlvdata + 4))) {
651 			/* abuse overlimits to count when we receive metadata
652 			 * but dont have an ops for it
653 			 */
654 			pr_info_ratelimited("Unknown metaid %d alnlen %d\n",
655 					    mtype, mlen);
656 			ife->tcf_qstats.overlimits++;
657 		}
658 
659 		tlvdata += mlen;
660 		ifehdrln -= mlen;
661 		tlv = (struct meta_tlvhdr *)tlvdata;
662 	}
663 
664 	skb_reset_network_header(skb);
665 	return action;
666 }
667 
668 /*XXX: check if we can do this at install time instead of current
669  * send data path
670 **/
671 static int ife_get_sz(struct sk_buff *skb, struct tcf_ife_info *ife)
672 {
673 	struct tcf_meta_info *e, *n;
674 	int tot_run_sz = 0, run_sz = 0;
675 
676 	list_for_each_entry_safe(e, n, &ife->metalist, metalist) {
677 		if (e->ops->check_presence) {
678 			run_sz = e->ops->check_presence(skb, e);
679 			tot_run_sz += run_sz;
680 		}
681 	}
682 
683 	return tot_run_sz;
684 }
685 
686 static int tcf_ife_encode(struct sk_buff *skb, const struct tc_action *a,
687 			  struct tcf_result *res)
688 {
689 	struct tcf_ife_info *ife = a->priv;
690 	int action = ife->tcf_action;
691 	struct ethhdr *oethh;	/* outer ether header */
692 	struct ethhdr *iethh;	/* inner eth header */
693 	struct tcf_meta_info *e;
694 	/*
695 	   OUTERHDR:TOTMETALEN:{TLVHDR:Metadatum:TLVHDR..}:ORIGDATA
696 	   where ORIGDATA = original ethernet header ...
697 	 */
698 	u16 metalen = ife_get_sz(skb, ife);
699 	int hdrm = metalen + skb->dev->hard_header_len + IFE_METAHDRLEN;
700 	unsigned int skboff = skb->dev->hard_header_len;
701 	u32 at = G_TC_AT(skb->tc_verd);
702 	int new_len = skb->len + hdrm;
703 	bool exceed_mtu = false;
704 	int err;
705 
706 	if (at & AT_EGRESS) {
707 		if (new_len > skb->dev->mtu)
708 			exceed_mtu = true;
709 	}
710 
711 	spin_lock(&ife->tcf_lock);
712 	bstats_update(&ife->tcf_bstats, skb);
713 	tcf_lastuse_update(&ife->tcf_tm);
714 
715 	if (!metalen) {		/* no metadata to send */
716 		/* abuse overlimits to count when we allow packet
717 		 * with no metadata
718 		 */
719 		ife->tcf_qstats.overlimits++;
720 		spin_unlock(&ife->tcf_lock);
721 		return action;
722 	}
723 	/* could be stupid policy setup or mtu config
724 	 * so lets be conservative.. */
725 	if ((action == TC_ACT_SHOT) || exceed_mtu) {
726 		ife->tcf_qstats.drops++;
727 		spin_unlock(&ife->tcf_lock);
728 		return TC_ACT_SHOT;
729 	}
730 
731 	iethh = eth_hdr(skb);
732 
733 	err = skb_cow_head(skb, hdrm);
734 	if (unlikely(err)) {
735 		ife->tcf_qstats.drops++;
736 		spin_unlock(&ife->tcf_lock);
737 		return TC_ACT_SHOT;
738 	}
739 
740 	if (!(at & AT_EGRESS))
741 		skb_push(skb, skb->dev->hard_header_len);
742 
743 	__skb_push(skb, hdrm);
744 	memcpy(skb->data, iethh, skb->mac_len);
745 	skb_reset_mac_header(skb);
746 	oethh = eth_hdr(skb);
747 
748 	/*total metadata length */
749 	metalen += IFE_METAHDRLEN;
750 	metalen = htons(metalen);
751 	memcpy((skb->data + skboff), &metalen, IFE_METAHDRLEN);
752 	skboff += IFE_METAHDRLEN;
753 
754 	/* XXX: we dont have a clever way of telling encode to
755 	 * not repeat some of the computations that are done by
756 	 * ops->presence_check...
757 	 */
758 	list_for_each_entry(e, &ife->metalist, metalist) {
759 		if (e->ops->encode) {
760 			err = e->ops->encode(skb, (void *)(skb->data + skboff),
761 					     e);
762 		}
763 		if (err < 0) {
764 			/* too corrupt to keep around if overwritten */
765 			ife->tcf_qstats.drops++;
766 			spin_unlock(&ife->tcf_lock);
767 			return TC_ACT_SHOT;
768 		}
769 		skboff += err;
770 	}
771 
772 	if (!is_zero_ether_addr(ife->eth_src))
773 		ether_addr_copy(oethh->h_source, ife->eth_src);
774 	else
775 		ether_addr_copy(oethh->h_source, iethh->h_source);
776 	if (!is_zero_ether_addr(ife->eth_dst))
777 		ether_addr_copy(oethh->h_dest, ife->eth_dst);
778 	else
779 		ether_addr_copy(oethh->h_dest, iethh->h_dest);
780 	oethh->h_proto = htons(ife->eth_type);
781 
782 	if (!(at & AT_EGRESS))
783 		skb_pull(skb, skb->dev->hard_header_len);
784 
785 	spin_unlock(&ife->tcf_lock);
786 
787 	return action;
788 }
789 
790 static int tcf_ife_act(struct sk_buff *skb, const struct tc_action *a,
791 		       struct tcf_result *res)
792 {
793 	struct tcf_ife_info *ife = a->priv;
794 
795 	if (ife->flags & IFE_ENCODE)
796 		return tcf_ife_encode(skb, a, res);
797 
798 	if (!(ife->flags & IFE_ENCODE))
799 		return tcf_ife_decode(skb, a, res);
800 
801 	pr_info_ratelimited("unknown failure(policy neither de/encode\n");
802 	spin_lock(&ife->tcf_lock);
803 	bstats_update(&ife->tcf_bstats, skb);
804 	tcf_lastuse_update(&ife->tcf_tm);
805 	ife->tcf_qstats.drops++;
806 	spin_unlock(&ife->tcf_lock);
807 
808 	return TC_ACT_SHOT;
809 }
810 
811 static int tcf_ife_walker(struct net *net, struct sk_buff *skb,
812 			  struct netlink_callback *cb, int type,
813 			  struct tc_action *a)
814 {
815 	struct tc_action_net *tn = net_generic(net, ife_net_id);
816 
817 	return tcf_generic_walker(tn, skb, cb, type, a);
818 }
819 
820 static int tcf_ife_search(struct net *net, struct tc_action *a, u32 index)
821 {
822 	struct tc_action_net *tn = net_generic(net, ife_net_id);
823 
824 	return tcf_hash_search(tn, a, index);
825 }
826 
827 static struct tc_action_ops act_ife_ops = {
828 	.kind = "ife",
829 	.type = TCA_ACT_IFE,
830 	.owner = THIS_MODULE,
831 	.act = tcf_ife_act,
832 	.dump = tcf_ife_dump,
833 	.cleanup = tcf_ife_cleanup,
834 	.init = tcf_ife_init,
835 	.walk = tcf_ife_walker,
836 	.lookup = tcf_ife_search,
837 };
838 
839 static __net_init int ife_init_net(struct net *net)
840 {
841 	struct tc_action_net *tn = net_generic(net, ife_net_id);
842 
843 	return tc_action_net_init(tn, &act_ife_ops, IFE_TAB_MASK);
844 }
845 
846 static void __net_exit ife_exit_net(struct net *net)
847 {
848 	struct tc_action_net *tn = net_generic(net, ife_net_id);
849 
850 	tc_action_net_exit(tn);
851 }
852 
853 static struct pernet_operations ife_net_ops = {
854 	.init = ife_init_net,
855 	.exit = ife_exit_net,
856 	.id   = &ife_net_id,
857 	.size = sizeof(struct tc_action_net),
858 };
859 
860 static int __init ife_init_module(void)
861 {
862 	return tcf_register_action(&act_ife_ops, &ife_net_ops);
863 }
864 
865 static void __exit ife_cleanup_module(void)
866 {
867 	tcf_unregister_action(&act_ife_ops, &ife_net_ops);
868 }
869 
870 module_init(ife_init_module);
871 module_exit(ife_cleanup_module);
872 
873 MODULE_AUTHOR("Jamal Hadi Salim(2015)");
874 MODULE_DESCRIPTION("Inter-FE LFB action");
875 MODULE_LICENSE("GPL");
876