xref: /openbmc/linux/net/sched/act_ife.c (revision adb57164)
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 
33 static unsigned int ife_net_id;
34 static int max_metacnt = IFE_META_MAX + 1;
35 static struct tc_action_ops act_ife_ops;
36 
37 static 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 
44 int 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 }
59 EXPORT_SYMBOL_GPL(ife_encode_meta_u16);
60 
61 int 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 }
68 EXPORT_SYMBOL_GPL(ife_get_meta_u32);
69 
70 int 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 }
77 EXPORT_SYMBOL_GPL(ife_check_meta_u32);
78 
79 int 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 }
86 EXPORT_SYMBOL_GPL(ife_check_meta_u16);
87 
88 int 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 }
103 EXPORT_SYMBOL_GPL(ife_encode_meta_u32);
104 
105 int 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 }
112 EXPORT_SYMBOL_GPL(ife_get_meta_u16);
113 
114 int 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 }
122 EXPORT_SYMBOL_GPL(ife_alloc_meta_u32);
123 
124 int 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 }
132 EXPORT_SYMBOL_GPL(ife_alloc_meta_u16);
133 
134 void ife_release_meta_gen(struct tcf_meta_info *mi)
135 {
136 	kfree(mi->metaval);
137 }
138 EXPORT_SYMBOL_GPL(ife_release_meta_gen);
139 
140 int ife_validate_meta_u32(void *val, int len)
141 {
142 	if (len == sizeof(u32))
143 		return 0;
144 
145 	return -EINVAL;
146 }
147 EXPORT_SYMBOL_GPL(ife_validate_meta_u32);
148 
149 int 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 }
157 EXPORT_SYMBOL_GPL(ife_validate_meta_u16);
158 
159 static LIST_HEAD(ifeoplist);
160 static DEFINE_RWLOCK(ife_mod_lock);
161 
162 static 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 
180 int 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 }
206 EXPORT_SYMBOL_GPL(unregister_ife_op);
207 
208 int 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 }
225 EXPORT_SYMBOL_GPL(register_ife_op);
226 
227 static 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
248 static 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 */
265 static 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 */
295 static 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 
325 static 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 
339 static 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 
354 static 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 
374 static 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 
401 out_nlmsg_trim:
402 	nlmsg_trim(skb, b);
403 	return -1;
404 }
405 
406 /* under ife->tcf_lock */
407 static 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 
425 static 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 
439 static int populate_metalist(struct tcf_ife_info *ife, struct nlattr **tb,
440 			     bool exists, bool rtnl_held)
441 {
442 	int len = 0;
443 	int rc = 0;
444 	int i = 0;
445 	void *val;
446 
447 	for (i = 1; i < max_metacnt; i++) {
448 		if (tb[i]) {
449 			val = nla_data(tb[i]);
450 			len = nla_len(tb[i]);
451 
452 			rc = load_metaops_and_vet(i, val, len, rtnl_held);
453 			if (rc != 0)
454 				return rc;
455 
456 			rc = add_metainfo(ife, i, val, len, exists);
457 			if (rc)
458 				return rc;
459 		}
460 	}
461 
462 	return rc;
463 }
464 
465 static int tcf_ife_init(struct net *net, struct nlattr *nla,
466 			struct nlattr *est, struct tc_action **a,
467 			int ovr, int bind, bool rtnl_held,
468 			struct tcf_proto *tp, u32 flags,
469 			struct netlink_ext_ack *extack)
470 {
471 	struct tc_action_net *tn = net_generic(net, ife_net_id);
472 	struct nlattr *tb[TCA_IFE_MAX + 1];
473 	struct nlattr *tb2[IFE_META_MAX + 1];
474 	struct tcf_chain *goto_ch = NULL;
475 	struct tcf_ife_params *p;
476 	struct tcf_ife_info *ife;
477 	u16 ife_type = ETH_P_IFE;
478 	struct tc_ife *parm;
479 	u8 *daddr = NULL;
480 	u8 *saddr = NULL;
481 	bool exists = false;
482 	int ret = 0;
483 	u32 index;
484 	int err;
485 
486 	if (!nla) {
487 		NL_SET_ERR_MSG_MOD(extack, "IFE requires attributes to be passed");
488 		return -EINVAL;
489 	}
490 
491 	err = nla_parse_nested_deprecated(tb, TCA_IFE_MAX, nla, ife_policy,
492 					  NULL);
493 	if (err < 0)
494 		return err;
495 
496 	if (!tb[TCA_IFE_PARMS])
497 		return -EINVAL;
498 
499 	parm = nla_data(tb[TCA_IFE_PARMS]);
500 
501 	/* IFE_DECODE is 0 and indicates the opposite of IFE_ENCODE because
502 	 * they cannot run as the same time. Check on all other values which
503 	 * are not supported right now.
504 	 */
505 	if (parm->flags & ~IFE_ENCODE)
506 		return -EINVAL;
507 
508 	p = kzalloc(sizeof(*p), GFP_KERNEL);
509 	if (!p)
510 		return -ENOMEM;
511 
512 	index = parm->index;
513 	err = tcf_idr_check_alloc(tn, &index, a, bind);
514 	if (err < 0) {
515 		kfree(p);
516 		return err;
517 	}
518 	exists = err;
519 	if (exists && bind) {
520 		kfree(p);
521 		return 0;
522 	}
523 
524 	if (!exists) {
525 		ret = tcf_idr_create(tn, index, est, a, &act_ife_ops,
526 				     bind, true, 0);
527 		if (ret) {
528 			tcf_idr_cleanup(tn, index);
529 			kfree(p);
530 			return ret;
531 		}
532 		ret = ACT_P_CREATED;
533 	} else if (!ovr) {
534 		tcf_idr_release(*a, bind);
535 		kfree(p);
536 		return -EEXIST;
537 	}
538 
539 	ife = to_ife(*a);
540 	if (ret == ACT_P_CREATED)
541 		INIT_LIST_HEAD(&ife->metalist);
542 
543 	err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
544 	if (err < 0)
545 		goto release_idr;
546 
547 	p->flags = parm->flags;
548 
549 	if (parm->flags & IFE_ENCODE) {
550 		if (tb[TCA_IFE_TYPE])
551 			ife_type = nla_get_u16(tb[TCA_IFE_TYPE]);
552 		if (tb[TCA_IFE_DMAC])
553 			daddr = nla_data(tb[TCA_IFE_DMAC]);
554 		if (tb[TCA_IFE_SMAC])
555 			saddr = nla_data(tb[TCA_IFE_SMAC]);
556 	}
557 
558 	if (parm->flags & IFE_ENCODE) {
559 		if (daddr)
560 			ether_addr_copy(p->eth_dst, daddr);
561 		else
562 			eth_zero_addr(p->eth_dst);
563 
564 		if (saddr)
565 			ether_addr_copy(p->eth_src, saddr);
566 		else
567 			eth_zero_addr(p->eth_src);
568 
569 		p->eth_type = ife_type;
570 	}
571 
572 	if (tb[TCA_IFE_METALST]) {
573 		err = nla_parse_nested_deprecated(tb2, IFE_META_MAX,
574 						  tb[TCA_IFE_METALST], NULL,
575 						  NULL);
576 		if (err)
577 			goto metadata_parse_err;
578 		err = populate_metalist(ife, tb2, exists, rtnl_held);
579 		if (err)
580 			goto metadata_parse_err;
581 
582 	} else {
583 		/* if no passed metadata allow list or passed allow-all
584 		 * then here we process by adding as many supported metadatum
585 		 * as we can. You better have at least one else we are
586 		 * going to bail out
587 		 */
588 		err = use_all_metadata(ife, exists);
589 		if (err)
590 			goto metadata_parse_err;
591 	}
592 
593 	if (exists)
594 		spin_lock_bh(&ife->tcf_lock);
595 	/* protected by tcf_lock when modifying existing action */
596 	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
597 	p = rcu_replace_pointer(ife->params, p, 1);
598 
599 	if (exists)
600 		spin_unlock_bh(&ife->tcf_lock);
601 	if (goto_ch)
602 		tcf_chain_put_by_act(goto_ch);
603 	if (p)
604 		kfree_rcu(p, rcu);
605 
606 	if (ret == ACT_P_CREATED)
607 		tcf_idr_insert(tn, *a);
608 
609 	return ret;
610 metadata_parse_err:
611 	if (goto_ch)
612 		tcf_chain_put_by_act(goto_ch);
613 release_idr:
614 	kfree(p);
615 	tcf_idr_release(*a, bind);
616 	return err;
617 }
618 
619 static int tcf_ife_dump(struct sk_buff *skb, struct tc_action *a, int bind,
620 			int ref)
621 {
622 	unsigned char *b = skb_tail_pointer(skb);
623 	struct tcf_ife_info *ife = to_ife(a);
624 	struct tcf_ife_params *p;
625 	struct tc_ife opt = {
626 		.index = ife->tcf_index,
627 		.refcnt = refcount_read(&ife->tcf_refcnt) - ref,
628 		.bindcnt = atomic_read(&ife->tcf_bindcnt) - bind,
629 	};
630 	struct tcf_t t;
631 
632 	spin_lock_bh(&ife->tcf_lock);
633 	opt.action = ife->tcf_action;
634 	p = rcu_dereference_protected(ife->params,
635 				      lockdep_is_held(&ife->tcf_lock));
636 	opt.flags = p->flags;
637 
638 	if (nla_put(skb, TCA_IFE_PARMS, sizeof(opt), &opt))
639 		goto nla_put_failure;
640 
641 	tcf_tm_dump(&t, &ife->tcf_tm);
642 	if (nla_put_64bit(skb, TCA_IFE_TM, sizeof(t), &t, TCA_IFE_PAD))
643 		goto nla_put_failure;
644 
645 	if (!is_zero_ether_addr(p->eth_dst)) {
646 		if (nla_put(skb, TCA_IFE_DMAC, ETH_ALEN, p->eth_dst))
647 			goto nla_put_failure;
648 	}
649 
650 	if (!is_zero_ether_addr(p->eth_src)) {
651 		if (nla_put(skb, TCA_IFE_SMAC, ETH_ALEN, p->eth_src))
652 			goto nla_put_failure;
653 	}
654 
655 	if (nla_put(skb, TCA_IFE_TYPE, 2, &p->eth_type))
656 		goto nla_put_failure;
657 
658 	if (dump_metalist(skb, ife)) {
659 		/*ignore failure to dump metalist */
660 		pr_info("Failed to dump metalist\n");
661 	}
662 
663 	spin_unlock_bh(&ife->tcf_lock);
664 	return skb->len;
665 
666 nla_put_failure:
667 	spin_unlock_bh(&ife->tcf_lock);
668 	nlmsg_trim(skb, b);
669 	return -1;
670 }
671 
672 static int find_decode_metaid(struct sk_buff *skb, struct tcf_ife_info *ife,
673 			      u16 metaid, u16 mlen, void *mdata)
674 {
675 	struct tcf_meta_info *e;
676 
677 	/* XXX: use hash to speed up */
678 	list_for_each_entry(e, &ife->metalist, metalist) {
679 		if (metaid == e->metaid) {
680 			if (e->ops) {
681 				/* We check for decode presence already */
682 				return e->ops->decode(skb, mdata, mlen);
683 			}
684 		}
685 	}
686 
687 	return -ENOENT;
688 }
689 
690 static int tcf_ife_decode(struct sk_buff *skb, const struct tc_action *a,
691 			  struct tcf_result *res)
692 {
693 	struct tcf_ife_info *ife = to_ife(a);
694 	int action = ife->tcf_action;
695 	u8 *ifehdr_end;
696 	u8 *tlv_data;
697 	u16 metalen;
698 
699 	bstats_cpu_update(this_cpu_ptr(ife->common.cpu_bstats), skb);
700 	tcf_lastuse_update(&ife->tcf_tm);
701 
702 	if (skb_at_tc_ingress(skb))
703 		skb_push(skb, skb->dev->hard_header_len);
704 
705 	tlv_data = ife_decode(skb, &metalen);
706 	if (unlikely(!tlv_data)) {
707 		qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
708 		return TC_ACT_SHOT;
709 	}
710 
711 	ifehdr_end = tlv_data + metalen;
712 	for (; tlv_data < ifehdr_end; tlv_data = ife_tlv_meta_next(tlv_data)) {
713 		u8 *curr_data;
714 		u16 mtype;
715 		u16 dlen;
716 
717 		curr_data = ife_tlv_meta_decode(tlv_data, ifehdr_end, &mtype,
718 						&dlen, NULL);
719 		if (!curr_data) {
720 			qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
721 			return TC_ACT_SHOT;
722 		}
723 
724 		if (find_decode_metaid(skb, ife, mtype, dlen, curr_data)) {
725 			/* abuse overlimits to count when we receive metadata
726 			 * but dont have an ops for it
727 			 */
728 			pr_info_ratelimited("Unknown metaid %d dlen %d\n",
729 					    mtype, dlen);
730 			qstats_overlimit_inc(this_cpu_ptr(ife->common.cpu_qstats));
731 		}
732 	}
733 
734 	if (WARN_ON(tlv_data != ifehdr_end)) {
735 		qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
736 		return TC_ACT_SHOT;
737 	}
738 
739 	skb->protocol = eth_type_trans(skb, skb->dev);
740 	skb_reset_network_header(skb);
741 
742 	return action;
743 }
744 
745 /*XXX: check if we can do this at install time instead of current
746  * send data path
747 **/
748 static int ife_get_sz(struct sk_buff *skb, struct tcf_ife_info *ife)
749 {
750 	struct tcf_meta_info *e, *n;
751 	int tot_run_sz = 0, run_sz = 0;
752 
753 	list_for_each_entry_safe(e, n, &ife->metalist, metalist) {
754 		if (e->ops->check_presence) {
755 			run_sz = e->ops->check_presence(skb, e);
756 			tot_run_sz += run_sz;
757 		}
758 	}
759 
760 	return tot_run_sz;
761 }
762 
763 static int tcf_ife_encode(struct sk_buff *skb, const struct tc_action *a,
764 			  struct tcf_result *res, struct tcf_ife_params *p)
765 {
766 	struct tcf_ife_info *ife = to_ife(a);
767 	int action = ife->tcf_action;
768 	struct ethhdr *oethh;	/* outer ether header */
769 	struct tcf_meta_info *e;
770 	/*
771 	   OUTERHDR:TOTMETALEN:{TLVHDR:Metadatum:TLVHDR..}:ORIGDATA
772 	   where ORIGDATA = original ethernet header ...
773 	 */
774 	u16 metalen = ife_get_sz(skb, ife);
775 	int hdrm = metalen + skb->dev->hard_header_len + IFE_METAHDRLEN;
776 	unsigned int skboff = 0;
777 	int new_len = skb->len + hdrm;
778 	bool exceed_mtu = false;
779 	void *ife_meta;
780 	int err = 0;
781 
782 	if (!skb_at_tc_ingress(skb)) {
783 		if (new_len > skb->dev->mtu)
784 			exceed_mtu = true;
785 	}
786 
787 	bstats_cpu_update(this_cpu_ptr(ife->common.cpu_bstats), skb);
788 	tcf_lastuse_update(&ife->tcf_tm);
789 
790 	if (!metalen) {		/* no metadata to send */
791 		/* abuse overlimits to count when we allow packet
792 		 * with no metadata
793 		 */
794 		qstats_overlimit_inc(this_cpu_ptr(ife->common.cpu_qstats));
795 		return action;
796 	}
797 	/* could be stupid policy setup or mtu config
798 	 * so lets be conservative.. */
799 	if ((action == TC_ACT_SHOT) || exceed_mtu) {
800 		qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
801 		return TC_ACT_SHOT;
802 	}
803 
804 	if (skb_at_tc_ingress(skb))
805 		skb_push(skb, skb->dev->hard_header_len);
806 
807 	ife_meta = ife_encode(skb, metalen);
808 
809 	spin_lock(&ife->tcf_lock);
810 
811 	/* XXX: we dont have a clever way of telling encode to
812 	 * not repeat some of the computations that are done by
813 	 * ops->presence_check...
814 	 */
815 	list_for_each_entry(e, &ife->metalist, metalist) {
816 		if (e->ops->encode) {
817 			err = e->ops->encode(skb, (void *)(ife_meta + skboff),
818 					     e);
819 		}
820 		if (err < 0) {
821 			/* too corrupt to keep around if overwritten */
822 			spin_unlock(&ife->tcf_lock);
823 			qstats_drop_inc(this_cpu_ptr(ife->common.cpu_qstats));
824 			return TC_ACT_SHOT;
825 		}
826 		skboff += err;
827 	}
828 	spin_unlock(&ife->tcf_lock);
829 	oethh = (struct ethhdr *)skb->data;
830 
831 	if (!is_zero_ether_addr(p->eth_src))
832 		ether_addr_copy(oethh->h_source, p->eth_src);
833 	if (!is_zero_ether_addr(p->eth_dst))
834 		ether_addr_copy(oethh->h_dest, p->eth_dst);
835 	oethh->h_proto = htons(p->eth_type);
836 
837 	if (skb_at_tc_ingress(skb))
838 		skb_pull(skb, skb->dev->hard_header_len);
839 
840 	return action;
841 }
842 
843 static int tcf_ife_act(struct sk_buff *skb, const struct tc_action *a,
844 		       struct tcf_result *res)
845 {
846 	struct tcf_ife_info *ife = to_ife(a);
847 	struct tcf_ife_params *p;
848 	int ret;
849 
850 	p = rcu_dereference_bh(ife->params);
851 	if (p->flags & IFE_ENCODE) {
852 		ret = tcf_ife_encode(skb, a, res, p);
853 		return ret;
854 	}
855 
856 	return tcf_ife_decode(skb, a, res);
857 }
858 
859 static int tcf_ife_walker(struct net *net, struct sk_buff *skb,
860 			  struct netlink_callback *cb, int type,
861 			  const struct tc_action_ops *ops,
862 			  struct netlink_ext_ack *extack)
863 {
864 	struct tc_action_net *tn = net_generic(net, ife_net_id);
865 
866 	return tcf_generic_walker(tn, skb, cb, type, ops, extack);
867 }
868 
869 static int tcf_ife_search(struct net *net, struct tc_action **a, u32 index)
870 {
871 	struct tc_action_net *tn = net_generic(net, ife_net_id);
872 
873 	return tcf_idr_search(tn, a, index);
874 }
875 
876 static struct tc_action_ops act_ife_ops = {
877 	.kind = "ife",
878 	.id = TCA_ID_IFE,
879 	.owner = THIS_MODULE,
880 	.act = tcf_ife_act,
881 	.dump = tcf_ife_dump,
882 	.cleanup = tcf_ife_cleanup,
883 	.init = tcf_ife_init,
884 	.walk = tcf_ife_walker,
885 	.lookup = tcf_ife_search,
886 	.size =	sizeof(struct tcf_ife_info),
887 };
888 
889 static __net_init int ife_init_net(struct net *net)
890 {
891 	struct tc_action_net *tn = net_generic(net, ife_net_id);
892 
893 	return tc_action_net_init(net, tn, &act_ife_ops);
894 }
895 
896 static void __net_exit ife_exit_net(struct list_head *net_list)
897 {
898 	tc_action_net_exit(net_list, ife_net_id);
899 }
900 
901 static struct pernet_operations ife_net_ops = {
902 	.init = ife_init_net,
903 	.exit_batch = ife_exit_net,
904 	.id   = &ife_net_id,
905 	.size = sizeof(struct tc_action_net),
906 };
907 
908 static int __init ife_init_module(void)
909 {
910 	return tcf_register_action(&act_ife_ops, &ife_net_ops);
911 }
912 
913 static void __exit ife_cleanup_module(void)
914 {
915 	tcf_unregister_action(&act_ife_ops, &ife_net_ops);
916 }
917 
918 module_init(ife_init_module);
919 module_exit(ife_cleanup_module);
920 
921 MODULE_AUTHOR("Jamal Hadi Salim(2015)");
922 MODULE_DESCRIPTION("Inter-FE LFB action");
923 MODULE_LICENSE("GPL");
924