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/xdp.h>
 20#include <net/xdp_priv.h> /* struct xdp_mem_allocator */
 21#include <trace/events/xdp.h>
 22#include <net/xdp_sock_drv.h>
 23
 24#define REG_STATE_NEW		0x0
 25#define REG_STATE_REGISTERED	0x1
 26#define REG_STATE_UNREGISTERED	0x2
 27#define REG_STATE_UNUSED	0x3
 28
 29static DEFINE_IDA(mem_id_pool);
 30static DEFINE_MUTEX(mem_id_lock);
 31#define MEM_ID_MAX 0xFFFE
 32#define MEM_ID_MIN 1
 33static int mem_id_next = MEM_ID_MIN;
 34
 35static bool mem_id_init; /* false */
 36static struct rhashtable *mem_id_ht;
 37
 38static u32 xdp_mem_id_hashfn(const void *data, u32 len, u32 seed)
 39{
 40	const u32 *k = data;
 41	const u32 key = *k;
 42
 43	BUILD_BUG_ON(sizeof_field(struct xdp_mem_allocator, mem.id)
 44		     != sizeof(u32));
 45
 46	/* Use cyclic increasing ID as direct hash key */
 47	return key;
 48}
 49
 50static int xdp_mem_id_cmp(struct rhashtable_compare_arg *arg,
 51			  const void *ptr)
 52{
 53	const struct xdp_mem_allocator *xa = ptr;
 54	u32 mem_id = *(u32 *)arg->key;
 55
 56	return xa->mem.id != mem_id;
 57}
 58
 59static const struct rhashtable_params mem_id_rht_params = {
 60	.nelem_hint = 64,
 61	.head_offset = offsetof(struct xdp_mem_allocator, node),
 62	.key_offset  = offsetof(struct xdp_mem_allocator, mem.id),
 63	.key_len = sizeof_field(struct xdp_mem_allocator, mem.id),
 64	.max_size = MEM_ID_MAX,
 65	.min_size = 8,
 66	.automatic_shrinking = true,
 67	.hashfn    = xdp_mem_id_hashfn,
 68	.obj_cmpfn = xdp_mem_id_cmp,
 69};
 70
 71static void __xdp_mem_allocator_rcu_free(struct rcu_head *rcu)
 72{
 73	struct xdp_mem_allocator *xa;
 74
 75	xa = container_of(rcu, struct xdp_mem_allocator, rcu);
 76
 77	/* Allow this ID to be reused */
 78	ida_simple_remove(&mem_id_pool, xa->mem.id);
 79
 80	kfree(xa);
 81}
 82
 83static void mem_xa_remove(struct xdp_mem_allocator *xa)
 84{
 85	trace_mem_disconnect(xa);
 86
 87	if (!rhashtable_remove_fast(mem_id_ht, &xa->node, mem_id_rht_params))
 88		call_rcu(&xa->rcu, __xdp_mem_allocator_rcu_free);
 89}
 90
 91static void mem_allocator_disconnect(void *allocator)
 92{
 93	struct xdp_mem_allocator *xa;
 94	struct rhashtable_iter iter;
 95
 96	mutex_lock(&mem_id_lock);
 97
 98	rhashtable_walk_enter(mem_id_ht, &iter);
 99	do {
100		rhashtable_walk_start(&iter);
101
102		while ((xa = rhashtable_walk_next(&iter)) && !IS_ERR(xa)) {
103			if (xa->allocator == allocator)
104				mem_xa_remove(xa);
105		}
106
107		rhashtable_walk_stop(&iter);
108
109	} while (xa == ERR_PTR(-EAGAIN));
110	rhashtable_walk_exit(&iter);
111
112	mutex_unlock(&mem_id_lock);
113}
114
115void xdp_unreg_mem_model(struct xdp_mem_info *mem)
116{
117	struct xdp_mem_allocator *xa;
118	int type = mem->type;
119	int id = mem->id;
120
121	/* Reset mem info to defaults */
122	mem->id = 0;
123	mem->type = 0;
 
124
125	if (id == 0)
126		return;
127
128	if (type == MEM_TYPE_PAGE_POOL) {
129		rcu_read_lock();
130		xa = rhashtable_lookup(mem_id_ht, &id, mem_id_rht_params);
131		page_pool_destroy(xa->page_pool);
132		rcu_read_unlock();
133	}
134}
135EXPORT_SYMBOL_GPL(xdp_unreg_mem_model);
136
137void xdp_rxq_info_unreg_mem_model(struct xdp_rxq_info *xdp_rxq)
138{
139	if (xdp_rxq->reg_state != REG_STATE_REGISTERED) {
140		WARN(1, "Missing register, driver bug");
141		return;
142	}
143
144	xdp_unreg_mem_model(&xdp_rxq->mem);
145}
146EXPORT_SYMBOL_GPL(xdp_rxq_info_unreg_mem_model);
147
148void xdp_rxq_info_unreg(struct xdp_rxq_info *xdp_rxq)
149{
150	/* Simplify driver cleanup code paths, allow unreg "unused" */
151	if (xdp_rxq->reg_state == REG_STATE_UNUSED)
152		return;
153
 
 
154	xdp_rxq_info_unreg_mem_model(xdp_rxq);
155
156	xdp_rxq->reg_state = REG_STATE_UNREGISTERED;
157	xdp_rxq->dev = NULL;
 
 
 
 
158}
159EXPORT_SYMBOL_GPL(xdp_rxq_info_unreg);
160
161static void xdp_rxq_info_init(struct xdp_rxq_info *xdp_rxq)
162{
163	memset(xdp_rxq, 0, sizeof(*xdp_rxq));
164}
165
166/* Returns 0 on success, negative on failure */
167int __xdp_rxq_info_reg(struct xdp_rxq_info *xdp_rxq,
168		       struct net_device *dev, u32 queue_index,
169		       unsigned int napi_id, u32 frag_size)
170{
171	if (!dev) {
172		WARN(1, "Missing net_device from driver");
173		return -ENODEV;
174	}
175
176	if (xdp_rxq->reg_state == REG_STATE_UNUSED) {
177		WARN(1, "Driver promised not to register this");
178		return -EINVAL;
179	}
180
181	if (xdp_rxq->reg_state == REG_STATE_REGISTERED) {
182		WARN(1, "Missing unregister, handled but fix driver");
183		xdp_rxq_info_unreg(xdp_rxq);
184	}
185
 
 
 
 
 
186	/* State either UNREGISTERED or NEW */
187	xdp_rxq_info_init(xdp_rxq);
188	xdp_rxq->dev = dev;
189	xdp_rxq->queue_index = queue_index;
190	xdp_rxq->napi_id = napi_id;
191	xdp_rxq->frag_size = frag_size;
192
193	xdp_rxq->reg_state = REG_STATE_REGISTERED;
194	return 0;
195}
196EXPORT_SYMBOL_GPL(__xdp_rxq_info_reg);
197
198void xdp_rxq_info_unused(struct xdp_rxq_info *xdp_rxq)
199{
200	xdp_rxq->reg_state = REG_STATE_UNUSED;
201}
202EXPORT_SYMBOL_GPL(xdp_rxq_info_unused);
203
204bool xdp_rxq_info_is_reg(struct xdp_rxq_info *xdp_rxq)
205{
206	return (xdp_rxq->reg_state == REG_STATE_REGISTERED);
207}
208EXPORT_SYMBOL_GPL(xdp_rxq_info_is_reg);
209
210static int __mem_id_init_hash_table(void)
211{
212	struct rhashtable *rht;
213	int ret;
214
215	if (unlikely(mem_id_init))
216		return 0;
217
218	rht = kzalloc(sizeof(*rht), GFP_KERNEL);
219	if (!rht)
220		return -ENOMEM;
221
222	ret = rhashtable_init(rht, &mem_id_rht_params);
223	if (ret < 0) {
224		kfree(rht);
225		return ret;
226	}
227	mem_id_ht = rht;
228	smp_mb(); /* mutex lock should provide enough pairing */
229	mem_id_init = true;
230
231	return 0;
232}
233
234/* Allocate a cyclic ID that maps to allocator pointer.
235 * See: https://www.kernel.org/doc/html/latest/core-api/idr.html
236 *
237 * Caller must lock mem_id_lock.
238 */
239static int __mem_id_cyclic_get(gfp_t gfp)
240{
241	int retries = 1;
242	int id;
243
244again:
245	id = ida_simple_get(&mem_id_pool, mem_id_next, MEM_ID_MAX, gfp);
246	if (id < 0) {
247		if (id == -ENOSPC) {
248			/* Cyclic allocator, reset next id */
249			if (retries--) {
250				mem_id_next = MEM_ID_MIN;
251				goto again;
252			}
253		}
254		return id; /* errno */
255	}
256	mem_id_next = id + 1;
257
258	return id;
259}
260
261static bool __is_supported_mem_type(enum xdp_mem_type type)
262{
263	if (type == MEM_TYPE_PAGE_POOL)
264		return is_page_pool_compiled_in();
265
266	if (type >= MEM_TYPE_MAX)
267		return false;
268
269	return true;
270}
271
272static struct xdp_mem_allocator *__xdp_reg_mem_model(struct xdp_mem_info *mem,
273						     enum xdp_mem_type type,
274						     void *allocator)
275{
276	struct xdp_mem_allocator *xdp_alloc;
277	gfp_t gfp = GFP_KERNEL;
278	int id, errno, ret;
279	void *ptr;
280
 
 
 
 
 
281	if (!__is_supported_mem_type(type))
282		return ERR_PTR(-EOPNOTSUPP);
283
284	mem->type = type;
285
286	if (!allocator) {
287		if (type == MEM_TYPE_PAGE_POOL)
288			return ERR_PTR(-EINVAL); /* Setup time check page_pool req */
289		return NULL;
290	}
291
292	/* Delay init of rhashtable to save memory if feature isn't used */
293	if (!mem_id_init) {
294		mutex_lock(&mem_id_lock);
295		ret = __mem_id_init_hash_table();
296		mutex_unlock(&mem_id_lock);
297		if (ret < 0) {
298			WARN_ON(1);
299			return ERR_PTR(ret);
300		}
301	}
302
303	xdp_alloc = kzalloc(sizeof(*xdp_alloc), gfp);
304	if (!xdp_alloc)
305		return ERR_PTR(-ENOMEM);
306
307	mutex_lock(&mem_id_lock);
308	id = __mem_id_cyclic_get(gfp);
309	if (id < 0) {
310		errno = id;
311		goto err;
312	}
313	mem->id = id;
314	xdp_alloc->mem = *mem;
315	xdp_alloc->allocator = allocator;
316
317	/* Insert allocator into ID lookup table */
318	ptr = rhashtable_insert_slow(mem_id_ht, &id, &xdp_alloc->node);
319	if (IS_ERR(ptr)) {
320		ida_simple_remove(&mem_id_pool, mem->id);
321		mem->id = 0;
322		errno = PTR_ERR(ptr);
323		goto err;
324	}
325
326	if (type == MEM_TYPE_PAGE_POOL)
327		page_pool_use_xdp_mem(allocator, mem_allocator_disconnect, mem);
328
329	mutex_unlock(&mem_id_lock);
330
331	return xdp_alloc;
 
332err:
333	mutex_unlock(&mem_id_lock);
334	kfree(xdp_alloc);
335	return ERR_PTR(errno);
336}
337
338int xdp_reg_mem_model(struct xdp_mem_info *mem,
339		      enum xdp_mem_type type, void *allocator)
340{
341	struct xdp_mem_allocator *xdp_alloc;
342
343	xdp_alloc = __xdp_reg_mem_model(mem, type, allocator);
344	if (IS_ERR(xdp_alloc))
345		return PTR_ERR(xdp_alloc);
346	return 0;
347}
348EXPORT_SYMBOL_GPL(xdp_reg_mem_model);
349
350int xdp_rxq_info_reg_mem_model(struct xdp_rxq_info *xdp_rxq,
351			       enum xdp_mem_type type, void *allocator)
352{
353	struct xdp_mem_allocator *xdp_alloc;
354
355	if (xdp_rxq->reg_state != REG_STATE_REGISTERED) {
356		WARN(1, "Missing register, driver bug");
357		return -EFAULT;
358	}
359
360	xdp_alloc = __xdp_reg_mem_model(&xdp_rxq->mem, type, allocator);
361	if (IS_ERR(xdp_alloc))
362		return PTR_ERR(xdp_alloc);
363
364	if (trace_mem_connect_enabled() && xdp_alloc)
365		trace_mem_connect(xdp_alloc, xdp_rxq);
366	return 0;
367}
368
369EXPORT_SYMBOL_GPL(xdp_rxq_info_reg_mem_model);
370
371/* XDP RX runs under NAPI protection, and in different delivery error
372 * scenarios (e.g. queue full), it is possible to return the xdp_frame
373 * while still leveraging this protection.  The @napi_direct boolean
374 * is used for those calls sites.  Thus, allowing for faster recycling
375 * of xdp_frames/pages in those cases.
 
 
376 */
377void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct,
378		  struct xdp_buff *xdp)
379{
 
380	struct page *page;
381
382	switch (mem->type) {
383	case MEM_TYPE_PAGE_POOL:
 
 
 
384		page = virt_to_head_page(data);
385		if (napi_direct && xdp_return_frame_no_direct())
386			napi_direct = false;
387		/* No need to check ((page->pp_magic & ~0x3UL) == PP_SIGNATURE)
388		 * as mem->type knows this a page_pool page
389		 */
390		page_pool_put_full_page(page->pp, page, napi_direct);
391		break;
392	case MEM_TYPE_PAGE_SHARED:
393		page_frag_free(data);
394		break;
395	case MEM_TYPE_PAGE_ORDER0:
396		page = virt_to_page(data); /* Assumes order0 page*/
397		put_page(page);
398		break;
399	case MEM_TYPE_XSK_BUFF_POOL:
400		/* NB! Only valid from an xdp_buff! */
401		xsk_buff_free(xdp);
402		break;
403	default:
404		/* Not possible, checked in xdp_rxq_info_reg_mem_model() */
405		WARN(1, "Incorrect XDP memory type (%d) usage", mem->type);
406		break;
407	}
408}
409
410void xdp_return_frame(struct xdp_frame *xdpf)
411{
412	struct skb_shared_info *sinfo;
413	int i;
414
415	if (likely(!xdp_frame_has_frags(xdpf)))
416		goto out;
417
418	sinfo = xdp_get_shared_info_from_frame(xdpf);
419	for (i = 0; i < sinfo->nr_frags; i++) {
420		struct page *page = skb_frag_page(&sinfo->frags[i]);
421
422		__xdp_return(page_address(page), &xdpf->mem, false, NULL);
423	}
424out:
425	__xdp_return(xdpf->data, &xdpf->mem, false, NULL);
426}
427EXPORT_SYMBOL_GPL(xdp_return_frame);
428
429void xdp_return_frame_rx_napi(struct xdp_frame *xdpf)
430{
431	struct skb_shared_info *sinfo;
432	int i;
433
434	if (likely(!xdp_frame_has_frags(xdpf)))
435		goto out;
436
437	sinfo = xdp_get_shared_info_from_frame(xdpf);
438	for (i = 0; i < sinfo->nr_frags; i++) {
439		struct page *page = skb_frag_page(&sinfo->frags[i]);
440
441		__xdp_return(page_address(page), &xdpf->mem, true, NULL);
442	}
443out:
444	__xdp_return(xdpf->data, &xdpf->mem, true, NULL);
445}
446EXPORT_SYMBOL_GPL(xdp_return_frame_rx_napi);
447
448/* XDP bulk APIs introduce a defer/flush mechanism to return
449 * pages belonging to the same xdp_mem_allocator object
450 * (identified via the mem.id field) in bulk to optimize
451 * I-cache and D-cache.
452 * The bulk queue size is set to 16 to be aligned to how
453 * XDP_REDIRECT bulking works. The bulk is flushed when
454 * it is full or when mem.id changes.
455 * xdp_frame_bulk is usually stored/allocated on the function
456 * call-stack to avoid locking penalties.
457 */
458void xdp_flush_frame_bulk(struct xdp_frame_bulk *bq)
459{
460	struct xdp_mem_allocator *xa = bq->xa;
461
462	if (unlikely(!xa || !bq->count))
463		return;
464
465	page_pool_put_page_bulk(xa->page_pool, bq->q, bq->count);
466	/* bq->xa is not cleared to save lookup, if mem.id same in next bulk */
467	bq->count = 0;
468}
469EXPORT_SYMBOL_GPL(xdp_flush_frame_bulk);
470
471/* Must be called with rcu_read_lock held */
472void xdp_return_frame_bulk(struct xdp_frame *xdpf,
473			   struct xdp_frame_bulk *bq)
474{
475	struct xdp_mem_info *mem = &xdpf->mem;
476	struct xdp_mem_allocator *xa;
 
477
478	if (mem->type != MEM_TYPE_PAGE_POOL) {
479		xdp_return_frame(xdpf);
480		return;
481	}
482
483	xa = bq->xa;
484	if (unlikely(!xa)) {
485		xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params);
486		bq->count = 0;
487		bq->xa = xa;
488	}
489
490	if (bq->count == XDP_BULK_QUEUE_SIZE)
491		xdp_flush_frame_bulk(bq);
492
493	if (unlikely(mem->id != xa->mem.id)) {
494		xdp_flush_frame_bulk(bq);
495		bq->xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params);
496	}
497
498	if (unlikely(xdp_frame_has_frags(xdpf))) {
499		struct skb_shared_info *sinfo;
500		int i;
501
502		sinfo = xdp_get_shared_info_from_frame(xdpf);
503		for (i = 0; i < sinfo->nr_frags; i++) {
504			skb_frag_t *frag = &sinfo->frags[i];
505
506			bq->q[bq->count++] = skb_frag_address(frag);
507			if (bq->count == XDP_BULK_QUEUE_SIZE)
508				xdp_flush_frame_bulk(bq);
509		}
510	}
511	bq->q[bq->count++] = xdpf->data;
512}
513EXPORT_SYMBOL_GPL(xdp_return_frame_bulk);
514
515void xdp_return_buff(struct xdp_buff *xdp)
516{
517	struct skb_shared_info *sinfo;
518	int i;
519
520	if (likely(!xdp_buff_has_frags(xdp)))
521		goto out;
522
523	sinfo = xdp_get_shared_info_from_buff(xdp);
524	for (i = 0; i < sinfo->nr_frags; i++) {
525		struct page *page = skb_frag_page(&sinfo->frags[i]);
526
527		__xdp_return(page_address(page), &xdp->rxq->mem, true, xdp);
528	}
529out:
530	__xdp_return(xdp->data, &xdp->rxq->mem, true, xdp);
531}
532EXPORT_SYMBOL_GPL(xdp_return_buff);
533
534void xdp_attachment_setup(struct xdp_attachment_info *info,
535			  struct netdev_bpf *bpf)
536{
537	if (info->prog)
538		bpf_prog_put(info->prog);
539	info->prog = bpf->prog;
540	info->flags = bpf->flags;
541}
542EXPORT_SYMBOL_GPL(xdp_attachment_setup);
543
544struct xdp_frame *xdp_convert_zc_to_xdp_frame(struct xdp_buff *xdp)
545{
546	unsigned int metasize, totsize;
547	void *addr, *data_to_copy;
548	struct xdp_frame *xdpf;
549	struct page *page;
550
551	/* Clone into a MEM_TYPE_PAGE_ORDER0 xdp_frame. */
552	metasize = xdp_data_meta_unsupported(xdp) ? 0 :
553		   xdp->data - xdp->data_meta;
554	totsize = xdp->data_end - xdp->data + metasize;
555
556	if (sizeof(*xdpf) + totsize > PAGE_SIZE)
557		return NULL;
558
559	page = dev_alloc_page();
560	if (!page)
561		return NULL;
562
563	addr = page_to_virt(page);
564	xdpf = addr;
565	memset(xdpf, 0, sizeof(*xdpf));
566
567	addr += sizeof(*xdpf);
568	data_to_copy = metasize ? xdp->data_meta : xdp->data;
569	memcpy(addr, data_to_copy, totsize);
570
571	xdpf->data = addr + metasize;
572	xdpf->len = totsize - metasize;
573	xdpf->headroom = 0;
574	xdpf->metasize = metasize;
575	xdpf->frame_sz = PAGE_SIZE;
576	xdpf->mem.type = MEM_TYPE_PAGE_ORDER0;
577
578	xsk_buff_free(xdp);
579	return xdpf;
580}
581EXPORT_SYMBOL_GPL(xdp_convert_zc_to_xdp_frame);
582
583/* Used by XDP_WARN macro, to avoid inlining WARN() in fast-path */
584void xdp_warn(const char *msg, const char *func, const int line)
585{
586	WARN(1, "XDP_WARN: %s(line:%d): %s\n", func, line, msg);
587};
588EXPORT_SYMBOL_GPL(xdp_warn);
589
590int xdp_alloc_skb_bulk(void **skbs, int n_skb, gfp_t gfp)
591{
592	n_skb = kmem_cache_alloc_bulk(skbuff_cache, gfp, n_skb, skbs);
593	if (unlikely(!n_skb))
594		return -ENOMEM;
595
596	return 0;
597}
598EXPORT_SYMBOL_GPL(xdp_alloc_skb_bulk);
599
600struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf,
601					   struct sk_buff *skb,
602					   struct net_device *dev)
603{
604	struct skb_shared_info *sinfo = xdp_get_shared_info_from_frame(xdpf);
605	unsigned int headroom, frame_size;
606	void *hard_start;
607	u8 nr_frags;
608
609	/* xdp frags frame */
610	if (unlikely(xdp_frame_has_frags(xdpf)))
611		nr_frags = sinfo->nr_frags;
612
613	/* Part of headroom was reserved to xdpf */
614	headroom = sizeof(*xdpf) + xdpf->headroom;
615
616	/* Memory size backing xdp_frame data already have reserved
617	 * room for build_skb to place skb_shared_info in tailroom.
618	 */
619	frame_size = xdpf->frame_sz;
620
621	hard_start = xdpf->data - headroom;
622	skb = build_skb_around(skb, hard_start, frame_size);
623	if (unlikely(!skb))
624		return NULL;
625
626	skb_reserve(skb, headroom);
627	__skb_put(skb, xdpf->len);
628	if (xdpf->metasize)
629		skb_metadata_set(skb, xdpf->metasize);
630
631	if (unlikely(xdp_frame_has_frags(xdpf)))
632		xdp_update_skb_shared_info(skb, nr_frags,
633					   sinfo->xdp_frags_size,
634					   nr_frags * xdpf->frame_sz,
635					   xdp_frame_is_frag_pfmemalloc(xdpf));
636
637	/* Essential SKB info: protocol and skb->dev */
638	skb->protocol = eth_type_trans(skb, dev);
639
640	/* Optional SKB info, currently missing:
641	 * - HW checksum info		(skb->ip_summed)
642	 * - HW RX hash			(skb_set_hash)
643	 * - RX ring dev queue index	(skb_record_rx_queue)
644	 */
645
646	if (xdpf->mem.type == MEM_TYPE_PAGE_POOL)
647		skb_mark_for_recycle(skb);
648
649	/* Allow SKB to reuse area used by xdp_frame */
650	xdp_scrub_frame(xdpf);
651
652	return skb;
653}
654EXPORT_SYMBOL_GPL(__xdp_build_skb_from_frame);
655
656struct sk_buff *xdp_build_skb_from_frame(struct xdp_frame *xdpf,
657					 struct net_device *dev)
658{
659	struct sk_buff *skb;
660
661	skb = kmem_cache_alloc(skbuff_cache, GFP_ATOMIC);
662	if (unlikely(!skb))
663		return NULL;
664
665	memset(skb, 0, offsetof(struct sk_buff, tail));
666
667	return __xdp_build_skb_from_frame(xdpf, skb, dev);
668}
669EXPORT_SYMBOL_GPL(xdp_build_skb_from_frame);
670
671struct xdp_frame *xdpf_clone(struct xdp_frame *xdpf)
672{
673	unsigned int headroom, totalsize;
674	struct xdp_frame *nxdpf;
675	struct page *page;
676	void *addr;
677
678	headroom = xdpf->headroom + sizeof(*xdpf);
679	totalsize = headroom + xdpf->len;
680
681	if (unlikely(totalsize > PAGE_SIZE))
682		return NULL;
683	page = dev_alloc_page();
684	if (!page)
685		return NULL;
686	addr = page_to_virt(page);
687
688	memcpy(addr, xdpf, totalsize);
689
690	nxdpf = addr;
691	nxdpf->data = addr + headroom;
692	nxdpf->frame_sz = PAGE_SIZE;
693	nxdpf->mem.type = MEM_TYPE_PAGE_ORDER0;
694	nxdpf->mem.id = 0;
695
696	return nxdpf;
697}
698
699__bpf_kfunc_start_defs();
700
701/**
702 * bpf_xdp_metadata_rx_timestamp - Read XDP frame RX timestamp.
703 * @ctx: XDP context pointer.
704 * @timestamp: Return value pointer.
705 *
706 * Return:
707 * * Returns 0 on success or ``-errno`` on error.
708 * * ``-EOPNOTSUPP`` : means device driver does not implement kfunc
709 * * ``-ENODATA``    : means no RX-timestamp available for this frame
710 */
711__bpf_kfunc int bpf_xdp_metadata_rx_timestamp(const struct xdp_md *ctx, u64 *timestamp)
712{
713	return -EOPNOTSUPP;
714}
715
716/**
717 * bpf_xdp_metadata_rx_hash - Read XDP frame RX hash.
718 * @ctx: XDP context pointer.
719 * @hash: Return value pointer.
720 * @rss_type: Return value pointer for RSS type.
721 *
722 * The RSS hash type (@rss_type) specifies what portion of packet headers NIC
723 * hardware used when calculating RSS hash value.  The RSS type can be decoded
724 * via &enum xdp_rss_hash_type either matching on individual L3/L4 bits
725 * ``XDP_RSS_L*`` or by combined traditional *RSS Hashing Types*
726 * ``XDP_RSS_TYPE_L*``.
727 *
728 * Return:
729 * * Returns 0 on success or ``-errno`` on error.
730 * * ``-EOPNOTSUPP`` : means device driver doesn't implement kfunc
731 * * ``-ENODATA``    : means no RX-hash available for this frame
732 */
733__bpf_kfunc int bpf_xdp_metadata_rx_hash(const struct xdp_md *ctx, u32 *hash,
734					 enum xdp_rss_hash_type *rss_type)
735{
736	return -EOPNOTSUPP;
737}
738
739/**
740 * bpf_xdp_metadata_rx_vlan_tag - Get XDP packet outermost VLAN tag
741 * @ctx: XDP context pointer.
742 * @vlan_proto: Destination pointer for VLAN Tag protocol identifier (TPID).
743 * @vlan_tci: Destination pointer for VLAN TCI (VID + DEI + PCP)
744 *
745 * In case of success, ``vlan_proto`` contains *Tag protocol identifier (TPID)*,
746 * usually ``ETH_P_8021Q`` or ``ETH_P_8021AD``, but some networks can use
747 * custom TPIDs. ``vlan_proto`` is stored in **network byte order (BE)**
748 * and should be used as follows:
749 * ``if (vlan_proto == bpf_htons(ETH_P_8021Q)) do_something();``
750 *
751 * ``vlan_tci`` contains the remaining 16 bits of a VLAN tag.
752 * Driver is expected to provide those in **host byte order (usually LE)**,
753 * so the bpf program should not perform byte conversion.
754 * According to 802.1Q standard, *VLAN TCI (Tag control information)*
755 * is a bit field that contains:
756 * *VLAN identifier (VID)* that can be read with ``vlan_tci & 0xfff``,
757 * *Drop eligible indicator (DEI)* - 1 bit,
758 * *Priority code point (PCP)* - 3 bits.
759 * For detailed meaning of DEI and PCP, please refer to other sources.
760 *
761 * Return:
762 * * Returns 0 on success or ``-errno`` on error.
763 * * ``-EOPNOTSUPP`` : device driver doesn't implement kfunc
764 * * ``-ENODATA``    : VLAN tag was not stripped or is not available
765 */
766__bpf_kfunc int bpf_xdp_metadata_rx_vlan_tag(const struct xdp_md *ctx,
767					     __be16 *vlan_proto, u16 *vlan_tci)
768{
769	return -EOPNOTSUPP;
770}
771
772__bpf_kfunc_end_defs();
773
774BTF_SET8_START(xdp_metadata_kfunc_ids)
775#define XDP_METADATA_KFUNC(_, __, name, ___) BTF_ID_FLAGS(func, name, KF_TRUSTED_ARGS)
776XDP_METADATA_KFUNC_xxx
777#undef XDP_METADATA_KFUNC
778BTF_SET8_END(xdp_metadata_kfunc_ids)
779
780static const struct btf_kfunc_id_set xdp_metadata_kfunc_set = {
781	.owner = THIS_MODULE,
782	.set   = &xdp_metadata_kfunc_ids,
783};
784
785BTF_ID_LIST(xdp_metadata_kfunc_ids_unsorted)
786#define XDP_METADATA_KFUNC(name, _, str, __) BTF_ID(func, str)
787XDP_METADATA_KFUNC_xxx
788#undef XDP_METADATA_KFUNC
789
790u32 bpf_xdp_metadata_kfunc_id(int id)
791{
792	/* xdp_metadata_kfunc_ids is sorted and can't be used */
793	return xdp_metadata_kfunc_ids_unsorted[id];
794}
795
796bool bpf_dev_bound_kfunc_id(u32 btf_id)
797{
798	return btf_id_set8_contains(&xdp_metadata_kfunc_ids, btf_id);
799}
800
801static int __init xdp_metadata_init(void)
802{
803	return register_btf_kfunc_id_set(BPF_PROG_TYPE_XDP, &xdp_metadata_kfunc_set);
804}
805late_initcall(xdp_metadata_init);
806
807void xdp_set_features_flag(struct net_device *dev, xdp_features_t val)
808{
809	val &= NETDEV_XDP_ACT_MASK;
810	if (dev->xdp_features == val)
811		return;
812
813	dev->xdp_features = val;
814
815	if (dev->reg_state == NETREG_REGISTERED)
816		call_netdevice_notifiers(NETDEV_XDP_FEAT_CHANGE, dev);
817}
818EXPORT_SYMBOL_GPL(xdp_set_features_flag);
819
820void xdp_features_set_redirect_target(struct net_device *dev, bool support_sg)
821{
822	xdp_features_t val = (dev->xdp_features | NETDEV_XDP_ACT_NDO_XMIT);
823
824	if (support_sg)
825		val |= NETDEV_XDP_ACT_NDO_XMIT_SG;
826	xdp_set_features_flag(dev, val);
827}
828EXPORT_SYMBOL_GPL(xdp_features_set_redirect_target);
829
830void xdp_features_clear_redirect_target(struct net_device *dev)
831{
832	xdp_features_t val = dev->xdp_features;
833
834	val &= ~(NETDEV_XDP_ACT_NDO_XMIT | NETDEV_XDP_ACT_NDO_XMIT_SG);
835	xdp_set_features_flag(dev, val);
836}
837EXPORT_SYMBOL_GPL(xdp_features_clear_redirect_target);