1// SPDX-License-Identifier: GPL-2.0-only
2/* net/core/xdp.c
3 *
4 * Copyright (c) 2017 Jesper Dangaard Brouer, Red Hat Inc.
5 */
6#include <linux/bpf.h>
7#include <linux/btf.h>
8#include <linux/btf_ids.h>
9#include <linux/filter.h>
10#include <linux/types.h>
11#include <linux/mm.h>
12#include <linux/netdevice.h>
13#include <linux/slab.h>
14#include <linux/idr.h>
15#include <linux/rhashtable.h>
16#include <linux/bug.h>
17#include <net/page_pool/helpers.h>
18
19#include <net/hotdata.h>
20#include <net/xdp.h>
21#include <net/xdp_priv.h> /* struct xdp_mem_allocator */
22#include <trace/events/xdp.h>
23#include <net/xdp_sock_drv.h>
24
25#define REG_STATE_NEW		0x0
26#define REG_STATE_REGISTERED	0x1
27#define REG_STATE_UNREGISTERED	0x2
28#define REG_STATE_UNUSED	0x3
29
30static DEFINE_IDA(mem_id_pool);
31static DEFINE_MUTEX(mem_id_lock);
32#define MEM_ID_MAX 0xFFFE
33#define MEM_ID_MIN 1
34static int mem_id_next = MEM_ID_MIN;
35
36static bool mem_id_init; /* false */
37static struct rhashtable *mem_id_ht;
38
39static u32 xdp_mem_id_hashfn(const void *data, u32 len, u32 seed)
40{
41	const u32 *k = data;
42	const u32 key = *k;
43
44	BUILD_BUG_ON(sizeof_field(struct xdp_mem_allocator, mem.id)
45		     != sizeof(u32));
46
47	/* Use cyclic increasing ID as direct hash key */
48	return key;
49}
50
51static int xdp_mem_id_cmp(struct rhashtable_compare_arg *arg,
52			  const void *ptr)
53{
54	const struct xdp_mem_allocator *xa = ptr;
55	u32 mem_id = *(u32 *)arg->key;
56
57	return xa->mem.id != mem_id;
58}
59
60static const struct rhashtable_params mem_id_rht_params = {
61	.nelem_hint = 64,
62	.head_offset = offsetof(struct xdp_mem_allocator, node),
63	.key_offset  = offsetof(struct xdp_mem_allocator, mem.id),
64	.key_len = sizeof_field(struct xdp_mem_allocator, mem.id),
65	.max_size = MEM_ID_MAX,
66	.min_size = 8,
67	.automatic_shrinking = true,
68	.hashfn    = xdp_mem_id_hashfn,
69	.obj_cmpfn = xdp_mem_id_cmp,
70};
71
72static void __xdp_mem_allocator_rcu_free(struct rcu_head *rcu)
73{
74	struct xdp_mem_allocator *xa;
75
76	xa = container_of(rcu, struct xdp_mem_allocator, rcu);
77
78	/* Allow this ID to be reused */
79	ida_free(&mem_id_pool, xa->mem.id);
80
81	kfree(xa);
82}
83
84static void mem_xa_remove(struct xdp_mem_allocator *xa)
85{
86	trace_mem_disconnect(xa);
87
88	if (!rhashtable_remove_fast(mem_id_ht, &xa->node, mem_id_rht_params))
89		call_rcu(&xa->rcu, __xdp_mem_allocator_rcu_free);
90}
91
92static void mem_allocator_disconnect(void *allocator)
93{
94	struct xdp_mem_allocator *xa;
95	struct rhashtable_iter iter;
96
97	mutex_lock(&mem_id_lock);
98
99	rhashtable_walk_enter(mem_id_ht, &iter);
100	do {
101		rhashtable_walk_start(&iter);
102
103		while ((xa = rhashtable_walk_next(&iter)) && !IS_ERR(xa)) {
104			if (xa->allocator == allocator)
105				mem_xa_remove(xa);
106		}
107
108		rhashtable_walk_stop(&iter);
109
110	} while (xa == ERR_PTR(-EAGAIN));
111	rhashtable_walk_exit(&iter);
112
113	mutex_unlock(&mem_id_lock);
114}
115
116void xdp_unreg_mem_model(struct xdp_mem_info *mem)
117{
118	struct xdp_mem_allocator *xa;
119	int type = mem->type;
120	int id = mem->id;
121
122	/* Reset mem info to defaults */
123	mem->id = 0;
124	mem->type = 0;
125
126	if (id == 0)
127		return;
128
129	if (type == MEM_TYPE_PAGE_POOL) {
130		rcu_read_lock();
131		xa = rhashtable_lookup(mem_id_ht, &id, mem_id_rht_params);
132		page_pool_destroy(xa->page_pool);
133		rcu_read_unlock();
134	}
135}
136EXPORT_SYMBOL_GPL(xdp_unreg_mem_model);
137
138void xdp_rxq_info_unreg_mem_model(struct xdp_rxq_info *xdp_rxq)
139{
140	if (xdp_rxq->reg_state != REG_STATE_REGISTERED) {
141		WARN(1, "Missing register, driver bug");
142		return;
143	}
144
145	xdp_unreg_mem_model(&xdp_rxq->mem);
146}
147EXPORT_SYMBOL_GPL(xdp_rxq_info_unreg_mem_model);
148
149void xdp_rxq_info_unreg(struct xdp_rxq_info *xdp_rxq)
150{
151	/* Simplify driver cleanup code paths, allow unreg "unused" */
152	if (xdp_rxq->reg_state == REG_STATE_UNUSED)
153		return;
154
155	xdp_rxq_info_unreg_mem_model(xdp_rxq);
156
157	xdp_rxq->reg_state = REG_STATE_UNREGISTERED;
158	xdp_rxq->dev = NULL;
159}
160EXPORT_SYMBOL_GPL(xdp_rxq_info_unreg);
161
162static void xdp_rxq_info_init(struct xdp_rxq_info *xdp_rxq)
163{
164	memset(xdp_rxq, 0, sizeof(*xdp_rxq));
165}
166
167/* Returns 0 on success, negative on failure */
168int __xdp_rxq_info_reg(struct xdp_rxq_info *xdp_rxq,
169		       struct net_device *dev, u32 queue_index,
170		       unsigned int napi_id, u32 frag_size)
171{
172	if (!dev) {
173		WARN(1, "Missing net_device from driver");
174		return -ENODEV;
175	}
176
177	if (xdp_rxq->reg_state == REG_STATE_UNUSED) {
178		WARN(1, "Driver promised not to register this");
179		return -EINVAL;
180	}
181
182	if (xdp_rxq->reg_state == REG_STATE_REGISTERED) {
183		WARN(1, "Missing unregister, handled but fix driver");
184		xdp_rxq_info_unreg(xdp_rxq);
185	}
186
187	/* State either UNREGISTERED or NEW */
188	xdp_rxq_info_init(xdp_rxq);
189	xdp_rxq->dev = dev;
190	xdp_rxq->queue_index = queue_index;
191	xdp_rxq->napi_id = napi_id;
192	xdp_rxq->frag_size = frag_size;
193
194	xdp_rxq->reg_state = REG_STATE_REGISTERED;
195	return 0;
196}
197EXPORT_SYMBOL_GPL(__xdp_rxq_info_reg);
198
199void xdp_rxq_info_unused(struct xdp_rxq_info *xdp_rxq)
200{
201	xdp_rxq->reg_state = REG_STATE_UNUSED;
202}
203EXPORT_SYMBOL_GPL(xdp_rxq_info_unused);
204
205bool xdp_rxq_info_is_reg(struct xdp_rxq_info *xdp_rxq)
206{
207	return (xdp_rxq->reg_state == REG_STATE_REGISTERED);
208}
209EXPORT_SYMBOL_GPL(xdp_rxq_info_is_reg);
210
211static int __mem_id_init_hash_table(void)
212{
213	struct rhashtable *rht;
214	int ret;
215
216	if (unlikely(mem_id_init))
217		return 0;
218
219	rht = kzalloc(sizeof(*rht), GFP_KERNEL);
220	if (!rht)
221		return -ENOMEM;
222
223	ret = rhashtable_init(rht, &mem_id_rht_params);
224	if (ret < 0) {
225		kfree(rht);
226		return ret;
227	}
228	mem_id_ht = rht;
229	smp_mb(); /* mutex lock should provide enough pairing */
230	mem_id_init = true;
231
232	return 0;
233}
234
235/* Allocate a cyclic ID that maps to allocator pointer.
236 * See: https://www.kernel.org/doc/html/latest/core-api/idr.html
237 *
238 * Caller must lock mem_id_lock.
239 */
240static int __mem_id_cyclic_get(gfp_t gfp)
241{
242	int retries = 1;
243	int id;
244
245again:
246	id = ida_alloc_range(&mem_id_pool, mem_id_next, MEM_ID_MAX - 1, gfp);
247	if (id < 0) {
248		if (id == -ENOSPC) {
249			/* Cyclic allocator, reset next id */
250			if (retries--) {
251				mem_id_next = MEM_ID_MIN;
252				goto again;
253			}
254		}
255		return id; /* errno */
256	}
257	mem_id_next = id + 1;
258
259	return id;
260}
261
262static bool __is_supported_mem_type(enum xdp_mem_type type)
263{
264	if (type == MEM_TYPE_PAGE_POOL)
265		return is_page_pool_compiled_in();
266
267	if (type >= MEM_TYPE_MAX)
268		return false;
269
270	return true;
271}
272
273static struct xdp_mem_allocator *__xdp_reg_mem_model(struct xdp_mem_info *mem,
274						     enum xdp_mem_type type,
275						     void *allocator)
276{
277	struct xdp_mem_allocator *xdp_alloc;
278	gfp_t gfp = GFP_KERNEL;
279	int id, errno, ret;
280	void *ptr;
281
282	if (!__is_supported_mem_type(type))
283		return ERR_PTR(-EOPNOTSUPP);
284
285	mem->type = type;
286
287	if (!allocator) {
288		if (type == MEM_TYPE_PAGE_POOL)
289			return ERR_PTR(-EINVAL); /* Setup time check page_pool req */
290		return NULL;
291	}
292
293	/* Delay init of rhashtable to save memory if feature isn't used */
294	if (!mem_id_init) {
295		mutex_lock(&mem_id_lock);
296		ret = __mem_id_init_hash_table();
297		mutex_unlock(&mem_id_lock);
298		if (ret < 0) {
299			WARN_ON(1);
300			return ERR_PTR(ret);
301		}
302	}
303
304	xdp_alloc = kzalloc(sizeof(*xdp_alloc), gfp);
305	if (!xdp_alloc)
306		return ERR_PTR(-ENOMEM);
307
308	mutex_lock(&mem_id_lock);
309	id = __mem_id_cyclic_get(gfp);
310	if (id < 0) {
311		errno = id;
312		goto err;
313	}
314	mem->id = id;
315	xdp_alloc->mem = *mem;
316	xdp_alloc->allocator = allocator;
317
318	/* Insert allocator into ID lookup table */
319	ptr = rhashtable_insert_slow(mem_id_ht, &id, &xdp_alloc->node);
320	if (IS_ERR(ptr)) {
321		ida_free(&mem_id_pool, mem->id);
322		mem->id = 0;
323		errno = PTR_ERR(ptr);
324		goto err;
325	}
326
327	if (type == MEM_TYPE_PAGE_POOL)
328		page_pool_use_xdp_mem(allocator, mem_allocator_disconnect, mem);
329
330	mutex_unlock(&mem_id_lock);
331
332	return xdp_alloc;
333err:
334	mutex_unlock(&mem_id_lock);
335	kfree(xdp_alloc);
336	return ERR_PTR(errno);
337}
338
339int xdp_reg_mem_model(struct xdp_mem_info *mem,
340		      enum xdp_mem_type type, void *allocator)
341{
342	struct xdp_mem_allocator *xdp_alloc;
343
344	xdp_alloc = __xdp_reg_mem_model(mem, type, allocator);
345	if (IS_ERR(xdp_alloc))
346		return PTR_ERR(xdp_alloc);
347	return 0;
348}
349EXPORT_SYMBOL_GPL(xdp_reg_mem_model);
350
351int xdp_rxq_info_reg_mem_model(struct xdp_rxq_info *xdp_rxq,
352			       enum xdp_mem_type type, void *allocator)
353{
354	struct xdp_mem_allocator *xdp_alloc;
355
356	if (xdp_rxq->reg_state != REG_STATE_REGISTERED) {
357		WARN(1, "Missing register, driver bug");
358		return -EFAULT;
359	}
360
361	xdp_alloc = __xdp_reg_mem_model(&xdp_rxq->mem, type, allocator);
362	if (IS_ERR(xdp_alloc))
363		return PTR_ERR(xdp_alloc);
364
365	if (trace_mem_connect_enabled() && xdp_alloc)
366		trace_mem_connect(xdp_alloc, xdp_rxq);
367	return 0;
368}
369
370EXPORT_SYMBOL_GPL(xdp_rxq_info_reg_mem_model);
371
372/* XDP RX runs under NAPI protection, and in different delivery error
373 * scenarios (e.g. queue full), it is possible to return the xdp_frame
374 * while still leveraging this protection.  The @napi_direct boolean
375 * is used for those calls sites.  Thus, allowing for faster recycling
376 * of xdp_frames/pages in those cases.
377 */
378void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct,
379		  struct xdp_buff *xdp)
380{
381	struct page *page;
382
383	switch (mem->type) {
384	case MEM_TYPE_PAGE_POOL:
385		page = virt_to_head_page(data);
386		if (napi_direct && xdp_return_frame_no_direct())
387			napi_direct = false;
388		/* No need to check ((page->pp_magic & ~0x3UL) == PP_SIGNATURE)
389		 * as mem->type knows this a page_pool page
390		 */
391		page_pool_put_full_page(page->pp, page, napi_direct);
392		break;
393	case MEM_TYPE_PAGE_SHARED:
394		page_frag_free(data);
395		break;
396	case MEM_TYPE_PAGE_ORDER0:
397		page = virt_to_page(data); /* Assumes order0 page*/
398		put_page(page);
399		break;
400	case MEM_TYPE_XSK_BUFF_POOL:
401		/* NB! Only valid from an xdp_buff! */
402		xsk_buff_free(xdp);
403		break;
404	default:
405		/* Not possible, checked in xdp_rxq_info_reg_mem_model() */
406		WARN(1, "Incorrect XDP memory type (%d) usage", mem->type);
407		break;
408	}
409}
410
411void xdp_return_frame(struct xdp_frame *xdpf)
412{
413	struct skb_shared_info *sinfo;
414	int i;
415
416	if (likely(!xdp_frame_has_frags(xdpf)))
417		goto out;
418
419	sinfo = xdp_get_shared_info_from_frame(xdpf);
420	for (i = 0; i < sinfo->nr_frags; i++) {
421		struct page *page = skb_frag_page(&sinfo->frags[i]);
422
423		__xdp_return(page_address(page), &xdpf->mem, false, NULL);
424	}
425out:
426	__xdp_return(xdpf->data, &xdpf->mem, false, NULL);
427}
428EXPORT_SYMBOL_GPL(xdp_return_frame);
429
430void xdp_return_frame_rx_napi(struct xdp_frame *xdpf)
431{
432	struct skb_shared_info *sinfo;
433	int i;
434
435	if (likely(!xdp_frame_has_frags(xdpf)))
436		goto out;
437
438	sinfo = xdp_get_shared_info_from_frame(xdpf);
439	for (i = 0; i < sinfo->nr_frags; i++) {
440		struct page *page = skb_frag_page(&sinfo->frags[i]);
441
442		__xdp_return(page_address(page), &xdpf->mem, true, NULL);
443	}
444out:
445	__xdp_return(xdpf->data, &xdpf->mem, true, NULL);
446}
447EXPORT_SYMBOL_GPL(xdp_return_frame_rx_napi);
448
449/* XDP bulk APIs introduce a defer/flush mechanism to return
450 * pages belonging to the same xdp_mem_allocator object
451 * (identified via the mem.id field) in bulk to optimize
452 * I-cache and D-cache.
453 * The bulk queue size is set to 16 to be aligned to how
454 * XDP_REDIRECT bulking works. The bulk is flushed when
455 * it is full or when mem.id changes.
456 * xdp_frame_bulk is usually stored/allocated on the function
457 * call-stack to avoid locking penalties.
458 */
459void xdp_flush_frame_bulk(struct xdp_frame_bulk *bq)
460{
461	struct xdp_mem_allocator *xa = bq->xa;
462
463	if (unlikely(!xa || !bq->count))
464		return;
465
466	page_pool_put_page_bulk(xa->page_pool, bq->q, bq->count);
467	/* bq->xa is not cleared to save lookup, if mem.id same in next bulk */
468	bq->count = 0;
469}
470EXPORT_SYMBOL_GPL(xdp_flush_frame_bulk);
471
472/* Must be called with rcu_read_lock held */
473void xdp_return_frame_bulk(struct xdp_frame *xdpf,
474			   struct xdp_frame_bulk *bq)
475{
476	struct xdp_mem_info *mem = &xdpf->mem;
477	struct xdp_mem_allocator *xa;
478
479	if (mem->type != MEM_TYPE_PAGE_POOL) {
480		xdp_return_frame(xdpf);
481		return;
482	}
483
484	xa = bq->xa;
485	if (unlikely(!xa)) {
486		xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params);
487		bq->count = 0;
488		bq->xa = xa;
489	}
490
491	if (bq->count == XDP_BULK_QUEUE_SIZE)
492		xdp_flush_frame_bulk(bq);
493
494	if (unlikely(mem->id != xa->mem.id)) {
495		xdp_flush_frame_bulk(bq);
496		bq->xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params);
497	}
498
499	if (unlikely(xdp_frame_has_frags(xdpf))) {
500		struct skb_shared_info *sinfo;
501		int i;
502
503		sinfo = xdp_get_shared_info_from_frame(xdpf);
504		for (i = 0; i < sinfo->nr_frags; i++) {
505			skb_frag_t *frag = &sinfo->frags[i];
506
507			bq->q[bq->count++] = skb_frag_address(frag);
508			if (bq->count == XDP_BULK_QUEUE_SIZE)
509				xdp_flush_frame_bulk(bq);
510		}
511	}
512	bq->q[bq->count++] = xdpf->data;
513}
514EXPORT_SYMBOL_GPL(xdp_return_frame_bulk);
515
516void xdp_return_buff(struct xdp_buff *xdp)
517{
518	struct skb_shared_info *sinfo;
519	int i;
520
521	if (likely(!xdp_buff_has_frags(xdp)))
522		goto out;
523
524	sinfo = xdp_get_shared_info_from_buff(xdp);
525	for (i = 0; i < sinfo->nr_frags; i++) {
526		struct page *page = skb_frag_page(&sinfo->frags[i]);
527
528		__xdp_return(page_address(page), &xdp->rxq->mem, true, xdp);
529	}
530out:
531	__xdp_return(xdp->data, &xdp->rxq->mem, true, xdp);
532}
533EXPORT_SYMBOL_GPL(xdp_return_buff);
534
535void xdp_attachment_setup(struct xdp_attachment_info *info,
536			  struct netdev_bpf *bpf)
537{
538	if (info->prog)
539		bpf_prog_put(info->prog);
540	info->prog = bpf->prog;
541	info->flags = bpf->flags;
542}
543EXPORT_SYMBOL_GPL(xdp_attachment_setup);
544
545struct xdp_frame *xdp_convert_zc_to_xdp_frame(struct xdp_buff *xdp)
546{
547	unsigned int metasize, totsize;
548	void *addr, *data_to_copy;
549	struct xdp_frame *xdpf;
550	struct page *page;
551
552	/* Clone into a MEM_TYPE_PAGE_ORDER0 xdp_frame. */
553	metasize = xdp_data_meta_unsupported(xdp) ? 0 :
554		   xdp->data - xdp->data_meta;
555	totsize = xdp->data_end - xdp->data + metasize;
556
557	if (sizeof(*xdpf) + totsize > PAGE_SIZE)
558		return NULL;
559
560	page = dev_alloc_page();
561	if (!page)
562		return NULL;
563
564	addr = page_to_virt(page);
565	xdpf = addr;
566	memset(xdpf, 0, sizeof(*xdpf));
567
568	addr += sizeof(*xdpf);
569	data_to_copy = metasize ? xdp->data_meta : xdp->data;
570	memcpy(addr, data_to_copy, totsize);
571
572	xdpf->data = addr + metasize;
573	xdpf->len = totsize - metasize;
574	xdpf->headroom = 0;
575	xdpf->metasize = metasize;
576	xdpf->frame_sz = PAGE_SIZE;
577	xdpf->mem.type = MEM_TYPE_PAGE_ORDER0;
578
579	xsk_buff_free(xdp);
580	return xdpf;
581}
582EXPORT_SYMBOL_GPL(xdp_convert_zc_to_xdp_frame);
583
584/* Used by XDP_WARN macro, to avoid inlining WARN() in fast-path */
585void xdp_warn(const char *msg, const char *func, const int line)
586{
587	WARN(1, "XDP_WARN: %s(line:%d): %s\n", func, line, msg);
588};
589EXPORT_SYMBOL_GPL(xdp_warn);
590
591int xdp_alloc_skb_bulk(void **skbs, int n_skb, gfp_t gfp)
592{
593	n_skb = kmem_cache_alloc_bulk(net_hotdata.skbuff_cache, gfp, n_skb, skbs);
594	if (unlikely(!n_skb))
595		return -ENOMEM;
596
597	return 0;
598}
599EXPORT_SYMBOL_GPL(xdp_alloc_skb_bulk);
600
601struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf,
602					   struct sk_buff *skb,
603					   struct net_device *dev)
604{
605	struct skb_shared_info *sinfo = xdp_get_shared_info_from_frame(xdpf);
606	unsigned int headroom, frame_size;
607	void *hard_start;
608	u8 nr_frags;
609
610	/* xdp frags frame */
611	if (unlikely(xdp_frame_has_frags(xdpf)))
612		nr_frags = sinfo->nr_frags;
613
614	/* Part of headroom was reserved to xdpf */
615	headroom = sizeof(*xdpf) + xdpf->headroom;
616
617	/* Memory size backing xdp_frame data already have reserved
618	 * room for build_skb to place skb_shared_info in tailroom.
619	 */
620	frame_size = xdpf->frame_sz;
621
622	hard_start = xdpf->data - headroom;
623	skb = build_skb_around(skb, hard_start, frame_size);
624	if (unlikely(!skb))
625		return NULL;
626
627	skb_reserve(skb, headroom);
628	__skb_put(skb, xdpf->len);
629	if (xdpf->metasize)
630		skb_metadata_set(skb, xdpf->metasize);
631
632	if (unlikely(xdp_frame_has_frags(xdpf)))
633		xdp_update_skb_shared_info(skb, nr_frags,
634					   sinfo->xdp_frags_size,
635					   nr_frags * xdpf->frame_sz,
636					   xdp_frame_is_frag_pfmemalloc(xdpf));
637
638	/* Essential SKB info: protocol and skb->dev */
639	skb->protocol = eth_type_trans(skb, dev);
640
641	/* Optional SKB info, currently missing:
642	 * - HW checksum info		(skb->ip_summed)
643	 * - HW RX hash			(skb_set_hash)
644	 * - RX ring dev queue index	(skb_record_rx_queue)
645	 */
646
647	if (xdpf->mem.type == MEM_TYPE_PAGE_POOL)
648		skb_mark_for_recycle(skb);
649
650	/* Allow SKB to reuse area used by xdp_frame */
651	xdp_scrub_frame(xdpf);
652
653	return skb;
654}
655EXPORT_SYMBOL_GPL(__xdp_build_skb_from_frame);
656
657struct sk_buff *xdp_build_skb_from_frame(struct xdp_frame *xdpf,
658					 struct net_device *dev)
659{
660	struct sk_buff *skb;
661
662	skb = kmem_cache_alloc(net_hotdata.skbuff_cache, GFP_ATOMIC);
663	if (unlikely(!skb))
664		return NULL;
665
666	memset(skb, 0, offsetof(struct sk_buff, tail));
667
668	return __xdp_build_skb_from_frame(xdpf, skb, dev);
669}
670EXPORT_SYMBOL_GPL(xdp_build_skb_from_frame);
671
672struct xdp_frame *xdpf_clone(struct xdp_frame *xdpf)
673{
674	unsigned int headroom, totalsize;
675	struct xdp_frame *nxdpf;
676	struct page *page;
677	void *addr;
678
679	headroom = xdpf->headroom + sizeof(*xdpf);
680	totalsize = headroom + xdpf->len;
681
682	if (unlikely(totalsize > PAGE_SIZE))
683		return NULL;
684	page = dev_alloc_page();
685	if (!page)
686		return NULL;
687	addr = page_to_virt(page);
688
689	memcpy(addr, xdpf, totalsize);
690
691	nxdpf = addr;
692	nxdpf->data = addr + headroom;
693	nxdpf->frame_sz = PAGE_SIZE;
694	nxdpf->mem.type = MEM_TYPE_PAGE_ORDER0;
695	nxdpf->mem.id = 0;
696
697	return nxdpf;
698}
699
700__bpf_kfunc_start_defs();
701
702/**
703 * bpf_xdp_metadata_rx_timestamp - Read XDP frame RX timestamp.
704 * @ctx: XDP context pointer.
705 * @timestamp: Return value pointer.
706 *
707 * Return:
708 * * Returns 0 on success or ``-errno`` on error.
709 * * ``-EOPNOTSUPP`` : means device driver does not implement kfunc
710 * * ``-ENODATA``    : means no RX-timestamp available for this frame
711 */
712__bpf_kfunc int bpf_xdp_metadata_rx_timestamp(const struct xdp_md *ctx, u64 *timestamp)
713{
714	return -EOPNOTSUPP;
715}
716
717/**
718 * bpf_xdp_metadata_rx_hash - Read XDP frame RX hash.
719 * @ctx: XDP context pointer.
720 * @hash: Return value pointer.
721 * @rss_type: Return value pointer for RSS type.
722 *
723 * The RSS hash type (@rss_type) specifies what portion of packet headers NIC
724 * hardware used when calculating RSS hash value.  The RSS type can be decoded
725 * via &enum xdp_rss_hash_type either matching on individual L3/L4 bits
726 * ``XDP_RSS_L*`` or by combined traditional *RSS Hashing Types*
727 * ``XDP_RSS_TYPE_L*``.
728 *
729 * Return:
730 * * Returns 0 on success or ``-errno`` on error.
731 * * ``-EOPNOTSUPP`` : means device driver doesn't implement kfunc
732 * * ``-ENODATA``    : means no RX-hash available for this frame
733 */
734__bpf_kfunc int bpf_xdp_metadata_rx_hash(const struct xdp_md *ctx, u32 *hash,
735					 enum xdp_rss_hash_type *rss_type)
736{
737	return -EOPNOTSUPP;
738}
739
740/**
741 * bpf_xdp_metadata_rx_vlan_tag - Get XDP packet outermost VLAN tag
742 * @ctx: XDP context pointer.
743 * @vlan_proto: Destination pointer for VLAN Tag protocol identifier (TPID).
744 * @vlan_tci: Destination pointer for VLAN TCI (VID + DEI + PCP)
745 *
746 * In case of success, ``vlan_proto`` contains *Tag protocol identifier (TPID)*,
747 * usually ``ETH_P_8021Q`` or ``ETH_P_8021AD``, but some networks can use
748 * custom TPIDs. ``vlan_proto`` is stored in **network byte order (BE)**
749 * and should be used as follows:
750 * ``if (vlan_proto == bpf_htons(ETH_P_8021Q)) do_something();``
751 *
752 * ``vlan_tci`` contains the remaining 16 bits of a VLAN tag.
753 * Driver is expected to provide those in **host byte order (usually LE)**,
754 * so the bpf program should not perform byte conversion.
755 * According to 802.1Q standard, *VLAN TCI (Tag control information)*
756 * is a bit field that contains:
757 * *VLAN identifier (VID)* that can be read with ``vlan_tci & 0xfff``,
758 * *Drop eligible indicator (DEI)* - 1 bit,
759 * *Priority code point (PCP)* - 3 bits.
760 * For detailed meaning of DEI and PCP, please refer to other sources.
761 *
762 * Return:
763 * * Returns 0 on success or ``-errno`` on error.
764 * * ``-EOPNOTSUPP`` : device driver doesn't implement kfunc
765 * * ``-ENODATA``    : VLAN tag was not stripped or is not available
766 */
767__bpf_kfunc int bpf_xdp_metadata_rx_vlan_tag(const struct xdp_md *ctx,
768					     __be16 *vlan_proto, u16 *vlan_tci)
769{
770	return -EOPNOTSUPP;
771}
772
773__bpf_kfunc_end_defs();
774
775BTF_KFUNCS_START(xdp_metadata_kfunc_ids)
776#define XDP_METADATA_KFUNC(_, __, name, ___) BTF_ID_FLAGS(func, name, KF_TRUSTED_ARGS)
777XDP_METADATA_KFUNC_xxx
778#undef XDP_METADATA_KFUNC
779BTF_KFUNCS_END(xdp_metadata_kfunc_ids)
780
781static const struct btf_kfunc_id_set xdp_metadata_kfunc_set = {
782	.owner = THIS_MODULE,
783	.set   = &xdp_metadata_kfunc_ids,
784};
785
786BTF_ID_LIST(xdp_metadata_kfunc_ids_unsorted)
787#define XDP_METADATA_KFUNC(name, _, str, __) BTF_ID(func, str)
788XDP_METADATA_KFUNC_xxx
789#undef XDP_METADATA_KFUNC
790
791u32 bpf_xdp_metadata_kfunc_id(int id)
792{
793	/* xdp_metadata_kfunc_ids is sorted and can't be used */
794	return xdp_metadata_kfunc_ids_unsorted[id];
795}
796
797bool bpf_dev_bound_kfunc_id(u32 btf_id)
798{
799	return btf_id_set8_contains(&xdp_metadata_kfunc_ids, btf_id);
800}
801
802static int __init xdp_metadata_init(void)
803{
804	return register_btf_kfunc_id_set(BPF_PROG_TYPE_XDP, &xdp_metadata_kfunc_set);
805}
806late_initcall(xdp_metadata_init);
807
808void xdp_set_features_flag(struct net_device *dev, xdp_features_t val)
809{
810	val &= NETDEV_XDP_ACT_MASK;
811	if (dev->xdp_features == val)
812		return;
813
814	dev->xdp_features = val;
815
816	if (dev->reg_state == NETREG_REGISTERED)
817		call_netdevice_notifiers(NETDEV_XDP_FEAT_CHANGE, dev);
818}
819EXPORT_SYMBOL_GPL(xdp_set_features_flag);
820
821void xdp_features_set_redirect_target(struct net_device *dev, bool support_sg)
822{
823	xdp_features_t val = (dev->xdp_features | NETDEV_XDP_ACT_NDO_XMIT);
824
825	if (support_sg)
826		val |= NETDEV_XDP_ACT_NDO_XMIT_SG;
827	xdp_set_features_flag(dev, val);
828}
829EXPORT_SYMBOL_GPL(xdp_features_set_redirect_target);
830
831void xdp_features_clear_redirect_target(struct net_device *dev)
832{
833	xdp_features_t val = dev->xdp_features;
834
835	val &= ~(NETDEV_XDP_ACT_NDO_XMIT | NETDEV_XDP_ACT_NDO_XMIT_SG);
836	xdp_set_features_flag(dev, val);
837}
838EXPORT_SYMBOL_GPL(xdp_features_clear_redirect_target);
839