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1// SPDX-License-Identifier: GPL-2.0
2/* XDP sockets
3 *
4 * AF_XDP sockets allows a channel between XDP programs and userspace
5 * applications.
6 * Copyright(c) 2018 Intel Corporation.
7 *
8 * Author(s): Björn Töpel <bjorn.topel@intel.com>
9 * Magnus Karlsson <magnus.karlsson@intel.com>
10 */
11
12#define pr_fmt(fmt) "AF_XDP: %s: " fmt, __func__
13
14#include <linux/if_xdp.h>
15#include <linux/init.h>
16#include <linux/sched/mm.h>
17#include <linux/sched/signal.h>
18#include <linux/sched/task.h>
19#include <linux/socket.h>
20#include <linux/file.h>
21#include <linux/uaccess.h>
22#include <linux/net.h>
23#include <linux/netdevice.h>
24#include <linux/rculist.h>
25#include <linux/vmalloc.h>
26#include <net/xdp_sock_drv.h>
27#include <net/busy_poll.h>
28#include <net/netdev_rx_queue.h>
29#include <net/xdp.h>
30
31#include "xsk_queue.h"
32#include "xdp_umem.h"
33#include "xsk.h"
34
35#define TX_BATCH_SIZE 32
36#define MAX_PER_SOCKET_BUDGET (TX_BATCH_SIZE)
37
38static DEFINE_PER_CPU(struct list_head, xskmap_flush_list);
39
40void xsk_set_rx_need_wakeup(struct xsk_buff_pool *pool)
41{
42 if (pool->cached_need_wakeup & XDP_WAKEUP_RX)
43 return;
44
45 pool->fq->ring->flags |= XDP_RING_NEED_WAKEUP;
46 pool->cached_need_wakeup |= XDP_WAKEUP_RX;
47}
48EXPORT_SYMBOL(xsk_set_rx_need_wakeup);
49
50void xsk_set_tx_need_wakeup(struct xsk_buff_pool *pool)
51{
52 struct xdp_sock *xs;
53
54 if (pool->cached_need_wakeup & XDP_WAKEUP_TX)
55 return;
56
57 rcu_read_lock();
58 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) {
59 xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP;
60 }
61 rcu_read_unlock();
62
63 pool->cached_need_wakeup |= XDP_WAKEUP_TX;
64}
65EXPORT_SYMBOL(xsk_set_tx_need_wakeup);
66
67void xsk_clear_rx_need_wakeup(struct xsk_buff_pool *pool)
68{
69 if (!(pool->cached_need_wakeup & XDP_WAKEUP_RX))
70 return;
71
72 pool->fq->ring->flags &= ~XDP_RING_NEED_WAKEUP;
73 pool->cached_need_wakeup &= ~XDP_WAKEUP_RX;
74}
75EXPORT_SYMBOL(xsk_clear_rx_need_wakeup);
76
77void xsk_clear_tx_need_wakeup(struct xsk_buff_pool *pool)
78{
79 struct xdp_sock *xs;
80
81 if (!(pool->cached_need_wakeup & XDP_WAKEUP_TX))
82 return;
83
84 rcu_read_lock();
85 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) {
86 xs->tx->ring->flags &= ~XDP_RING_NEED_WAKEUP;
87 }
88 rcu_read_unlock();
89
90 pool->cached_need_wakeup &= ~XDP_WAKEUP_TX;
91}
92EXPORT_SYMBOL(xsk_clear_tx_need_wakeup);
93
94bool xsk_uses_need_wakeup(struct xsk_buff_pool *pool)
95{
96 return pool->uses_need_wakeup;
97}
98EXPORT_SYMBOL(xsk_uses_need_wakeup);
99
100struct xsk_buff_pool *xsk_get_pool_from_qid(struct net_device *dev,
101 u16 queue_id)
102{
103 if (queue_id < dev->real_num_rx_queues)
104 return dev->_rx[queue_id].pool;
105 if (queue_id < dev->real_num_tx_queues)
106 return dev->_tx[queue_id].pool;
107
108 return NULL;
109}
110EXPORT_SYMBOL(xsk_get_pool_from_qid);
111
112void xsk_clear_pool_at_qid(struct net_device *dev, u16 queue_id)
113{
114 if (queue_id < dev->num_rx_queues)
115 dev->_rx[queue_id].pool = NULL;
116 if (queue_id < dev->num_tx_queues)
117 dev->_tx[queue_id].pool = NULL;
118}
119
120/* The buffer pool is stored both in the _rx struct and the _tx struct as we do
121 * not know if the device has more tx queues than rx, or the opposite.
122 * This might also change during run time.
123 */
124int xsk_reg_pool_at_qid(struct net_device *dev, struct xsk_buff_pool *pool,
125 u16 queue_id)
126{
127 if (queue_id >= max_t(unsigned int,
128 dev->real_num_rx_queues,
129 dev->real_num_tx_queues))
130 return -EINVAL;
131
132 if (queue_id < dev->real_num_rx_queues)
133 dev->_rx[queue_id].pool = pool;
134 if (queue_id < dev->real_num_tx_queues)
135 dev->_tx[queue_id].pool = pool;
136
137 return 0;
138}
139
140static int __xsk_rcv_zc(struct xdp_sock *xs, struct xdp_buff_xsk *xskb, u32 len,
141 u32 flags)
142{
143 u64 addr;
144 int err;
145
146 addr = xp_get_handle(xskb);
147 err = xskq_prod_reserve_desc(xs->rx, addr, len, flags);
148 if (err) {
149 xs->rx_queue_full++;
150 return err;
151 }
152
153 xp_release(xskb);
154 return 0;
155}
156
157static int xsk_rcv_zc(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len)
158{
159 struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp);
160 u32 frags = xdp_buff_has_frags(xdp);
161 struct xdp_buff_xsk *pos, *tmp;
162 struct list_head *xskb_list;
163 u32 contd = 0;
164 int err;
165
166 if (frags)
167 contd = XDP_PKT_CONTD;
168
169 err = __xsk_rcv_zc(xs, xskb, len, contd);
170 if (err)
171 goto err;
172 if (likely(!frags))
173 return 0;
174
175 xskb_list = &xskb->pool->xskb_list;
176 list_for_each_entry_safe(pos, tmp, xskb_list, xskb_list_node) {
177 if (list_is_singular(xskb_list))
178 contd = 0;
179 len = pos->xdp.data_end - pos->xdp.data;
180 err = __xsk_rcv_zc(xs, pos, len, contd);
181 if (err)
182 goto err;
183 list_del(&pos->xskb_list_node);
184 }
185
186 return 0;
187err:
188 xsk_buff_free(xdp);
189 return err;
190}
191
192static void *xsk_copy_xdp_start(struct xdp_buff *from)
193{
194 if (unlikely(xdp_data_meta_unsupported(from)))
195 return from->data;
196 else
197 return from->data_meta;
198}
199
200static u32 xsk_copy_xdp(void *to, void **from, u32 to_len,
201 u32 *from_len, skb_frag_t **frag, u32 rem)
202{
203 u32 copied = 0;
204
205 while (1) {
206 u32 copy_len = min_t(u32, *from_len, to_len);
207
208 memcpy(to, *from, copy_len);
209 copied += copy_len;
210 if (rem == copied)
211 return copied;
212
213 if (*from_len == copy_len) {
214 *from = skb_frag_address(*frag);
215 *from_len = skb_frag_size((*frag)++);
216 } else {
217 *from += copy_len;
218 *from_len -= copy_len;
219 }
220 if (to_len == copy_len)
221 return copied;
222
223 to_len -= copy_len;
224 to += copy_len;
225 }
226}
227
228static int __xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len)
229{
230 u32 frame_size = xsk_pool_get_rx_frame_size(xs->pool);
231 void *copy_from = xsk_copy_xdp_start(xdp), *copy_to;
232 u32 from_len, meta_len, rem, num_desc;
233 struct xdp_buff_xsk *xskb;
234 struct xdp_buff *xsk_xdp;
235 skb_frag_t *frag;
236
237 from_len = xdp->data_end - copy_from;
238 meta_len = xdp->data - copy_from;
239 rem = len + meta_len;
240
241 if (len <= frame_size && !xdp_buff_has_frags(xdp)) {
242 int err;
243
244 xsk_xdp = xsk_buff_alloc(xs->pool);
245 if (!xsk_xdp) {
246 xs->rx_dropped++;
247 return -ENOMEM;
248 }
249 memcpy(xsk_xdp->data - meta_len, copy_from, rem);
250 xskb = container_of(xsk_xdp, struct xdp_buff_xsk, xdp);
251 err = __xsk_rcv_zc(xs, xskb, len, 0);
252 if (err) {
253 xsk_buff_free(xsk_xdp);
254 return err;
255 }
256
257 return 0;
258 }
259
260 num_desc = (len - 1) / frame_size + 1;
261
262 if (!xsk_buff_can_alloc(xs->pool, num_desc)) {
263 xs->rx_dropped++;
264 return -ENOMEM;
265 }
266 if (xskq_prod_nb_free(xs->rx, num_desc) < num_desc) {
267 xs->rx_queue_full++;
268 return -ENOBUFS;
269 }
270
271 if (xdp_buff_has_frags(xdp)) {
272 struct skb_shared_info *sinfo;
273
274 sinfo = xdp_get_shared_info_from_buff(xdp);
275 frag = &sinfo->frags[0];
276 }
277
278 do {
279 u32 to_len = frame_size + meta_len;
280 u32 copied;
281
282 xsk_xdp = xsk_buff_alloc(xs->pool);
283 copy_to = xsk_xdp->data - meta_len;
284
285 copied = xsk_copy_xdp(copy_to, ©_from, to_len, &from_len, &frag, rem);
286 rem -= copied;
287
288 xskb = container_of(xsk_xdp, struct xdp_buff_xsk, xdp);
289 __xsk_rcv_zc(xs, xskb, copied - meta_len, rem ? XDP_PKT_CONTD : 0);
290 meta_len = 0;
291 } while (rem);
292
293 return 0;
294}
295
296static bool xsk_tx_writeable(struct xdp_sock *xs)
297{
298 if (xskq_cons_present_entries(xs->tx) > xs->tx->nentries / 2)
299 return false;
300
301 return true;
302}
303
304static bool xsk_is_bound(struct xdp_sock *xs)
305{
306 if (READ_ONCE(xs->state) == XSK_BOUND) {
307 /* Matches smp_wmb() in bind(). */
308 smp_rmb();
309 return true;
310 }
311 return false;
312}
313
314static int xsk_rcv_check(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len)
315{
316 if (!xsk_is_bound(xs))
317 return -ENXIO;
318
319 if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index)
320 return -EINVAL;
321
322 if (len > xsk_pool_get_rx_frame_size(xs->pool) && !xs->sg) {
323 xs->rx_dropped++;
324 return -ENOSPC;
325 }
326
327 sk_mark_napi_id_once_xdp(&xs->sk, xdp);
328 return 0;
329}
330
331static void xsk_flush(struct xdp_sock *xs)
332{
333 xskq_prod_submit(xs->rx);
334 __xskq_cons_release(xs->pool->fq);
335 sock_def_readable(&xs->sk);
336}
337
338int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
339{
340 u32 len = xdp_get_buff_len(xdp);
341 int err;
342
343 spin_lock_bh(&xs->rx_lock);
344 err = xsk_rcv_check(xs, xdp, len);
345 if (!err) {
346 err = __xsk_rcv(xs, xdp, len);
347 xsk_flush(xs);
348 }
349 spin_unlock_bh(&xs->rx_lock);
350 return err;
351}
352
353static int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
354{
355 u32 len = xdp_get_buff_len(xdp);
356 int err;
357
358 err = xsk_rcv_check(xs, xdp, len);
359 if (err)
360 return err;
361
362 if (xdp->rxq->mem.type == MEM_TYPE_XSK_BUFF_POOL) {
363 len = xdp->data_end - xdp->data;
364 return xsk_rcv_zc(xs, xdp, len);
365 }
366
367 err = __xsk_rcv(xs, xdp, len);
368 if (!err)
369 xdp_return_buff(xdp);
370 return err;
371}
372
373int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp)
374{
375 struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list);
376 int err;
377
378 err = xsk_rcv(xs, xdp);
379 if (err)
380 return err;
381
382 if (!xs->flush_node.prev)
383 list_add(&xs->flush_node, flush_list);
384
385 return 0;
386}
387
388void __xsk_map_flush(void)
389{
390 struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list);
391 struct xdp_sock *xs, *tmp;
392
393 list_for_each_entry_safe(xs, tmp, flush_list, flush_node) {
394 xsk_flush(xs);
395 __list_del_clearprev(&xs->flush_node);
396 }
397}
398
399#ifdef CONFIG_DEBUG_NET
400bool xsk_map_check_flush(void)
401{
402 if (list_empty(this_cpu_ptr(&xskmap_flush_list)))
403 return false;
404 __xsk_map_flush();
405 return true;
406}
407#endif
408
409void xsk_tx_completed(struct xsk_buff_pool *pool, u32 nb_entries)
410{
411 xskq_prod_submit_n(pool->cq, nb_entries);
412}
413EXPORT_SYMBOL(xsk_tx_completed);
414
415void xsk_tx_release(struct xsk_buff_pool *pool)
416{
417 struct xdp_sock *xs;
418
419 rcu_read_lock();
420 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) {
421 __xskq_cons_release(xs->tx);
422 if (xsk_tx_writeable(xs))
423 xs->sk.sk_write_space(&xs->sk);
424 }
425 rcu_read_unlock();
426}
427EXPORT_SYMBOL(xsk_tx_release);
428
429bool xsk_tx_peek_desc(struct xsk_buff_pool *pool, struct xdp_desc *desc)
430{
431 bool budget_exhausted = false;
432 struct xdp_sock *xs;
433
434 rcu_read_lock();
435again:
436 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) {
437 if (xs->tx_budget_spent >= MAX_PER_SOCKET_BUDGET) {
438 budget_exhausted = true;
439 continue;
440 }
441
442 if (!xskq_cons_peek_desc(xs->tx, desc, pool)) {
443 if (xskq_has_descs(xs->tx))
444 xskq_cons_release(xs->tx);
445 continue;
446 }
447
448 xs->tx_budget_spent++;
449
450 /* This is the backpressure mechanism for the Tx path.
451 * Reserve space in the completion queue and only proceed
452 * if there is space in it. This avoids having to implement
453 * any buffering in the Tx path.
454 */
455 if (xskq_prod_reserve_addr(pool->cq, desc->addr))
456 goto out;
457
458 xskq_cons_release(xs->tx);
459 rcu_read_unlock();
460 return true;
461 }
462
463 if (budget_exhausted) {
464 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list)
465 xs->tx_budget_spent = 0;
466
467 budget_exhausted = false;
468 goto again;
469 }
470
471out:
472 rcu_read_unlock();
473 return false;
474}
475EXPORT_SYMBOL(xsk_tx_peek_desc);
476
477static u32 xsk_tx_peek_release_fallback(struct xsk_buff_pool *pool, u32 max_entries)
478{
479 struct xdp_desc *descs = pool->tx_descs;
480 u32 nb_pkts = 0;
481
482 while (nb_pkts < max_entries && xsk_tx_peek_desc(pool, &descs[nb_pkts]))
483 nb_pkts++;
484
485 xsk_tx_release(pool);
486 return nb_pkts;
487}
488
489u32 xsk_tx_peek_release_desc_batch(struct xsk_buff_pool *pool, u32 nb_pkts)
490{
491 struct xdp_sock *xs;
492
493 rcu_read_lock();
494 if (!list_is_singular(&pool->xsk_tx_list)) {
495 /* Fallback to the non-batched version */
496 rcu_read_unlock();
497 return xsk_tx_peek_release_fallback(pool, nb_pkts);
498 }
499
500 xs = list_first_or_null_rcu(&pool->xsk_tx_list, struct xdp_sock, tx_list);
501 if (!xs) {
502 nb_pkts = 0;
503 goto out;
504 }
505
506 nb_pkts = xskq_cons_nb_entries(xs->tx, nb_pkts);
507
508 /* This is the backpressure mechanism for the Tx path. Try to
509 * reserve space in the completion queue for all packets, but
510 * if there are fewer slots available, just process that many
511 * packets. This avoids having to implement any buffering in
512 * the Tx path.
513 */
514 nb_pkts = xskq_prod_nb_free(pool->cq, nb_pkts);
515 if (!nb_pkts)
516 goto out;
517
518 nb_pkts = xskq_cons_read_desc_batch(xs->tx, pool, nb_pkts);
519 if (!nb_pkts) {
520 xs->tx->queue_empty_descs++;
521 goto out;
522 }
523
524 __xskq_cons_release(xs->tx);
525 xskq_prod_write_addr_batch(pool->cq, pool->tx_descs, nb_pkts);
526 xs->sk.sk_write_space(&xs->sk);
527
528out:
529 rcu_read_unlock();
530 return nb_pkts;
531}
532EXPORT_SYMBOL(xsk_tx_peek_release_desc_batch);
533
534static int xsk_wakeup(struct xdp_sock *xs, u8 flags)
535{
536 struct net_device *dev = xs->dev;
537
538 return dev->netdev_ops->ndo_xsk_wakeup(dev, xs->queue_id, flags);
539}
540
541static int xsk_cq_reserve_addr_locked(struct xdp_sock *xs, u64 addr)
542{
543 unsigned long flags;
544 int ret;
545
546 spin_lock_irqsave(&xs->pool->cq_lock, flags);
547 ret = xskq_prod_reserve_addr(xs->pool->cq, addr);
548 spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
549
550 return ret;
551}
552
553static void xsk_cq_submit_locked(struct xdp_sock *xs, u32 n)
554{
555 unsigned long flags;
556
557 spin_lock_irqsave(&xs->pool->cq_lock, flags);
558 xskq_prod_submit_n(xs->pool->cq, n);
559 spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
560}
561
562static void xsk_cq_cancel_locked(struct xdp_sock *xs, u32 n)
563{
564 unsigned long flags;
565
566 spin_lock_irqsave(&xs->pool->cq_lock, flags);
567 xskq_prod_cancel_n(xs->pool->cq, n);
568 spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
569}
570
571static u32 xsk_get_num_desc(struct sk_buff *skb)
572{
573 return skb ? (long)skb_shinfo(skb)->destructor_arg : 0;
574}
575
576static void xsk_destruct_skb(struct sk_buff *skb)
577{
578 struct xsk_tx_metadata_compl *compl = &skb_shinfo(skb)->xsk_meta;
579
580 if (compl->tx_timestamp) {
581 /* sw completion timestamp, not a real one */
582 *compl->tx_timestamp = ktime_get_tai_fast_ns();
583 }
584
585 xsk_cq_submit_locked(xdp_sk(skb->sk), xsk_get_num_desc(skb));
586 sock_wfree(skb);
587}
588
589static void xsk_set_destructor_arg(struct sk_buff *skb)
590{
591 long num = xsk_get_num_desc(xdp_sk(skb->sk)->skb) + 1;
592
593 skb_shinfo(skb)->destructor_arg = (void *)num;
594}
595
596static void xsk_consume_skb(struct sk_buff *skb)
597{
598 struct xdp_sock *xs = xdp_sk(skb->sk);
599
600 skb->destructor = sock_wfree;
601 xsk_cq_cancel_locked(xs, xsk_get_num_desc(skb));
602 /* Free skb without triggering the perf drop trace */
603 consume_skb(skb);
604 xs->skb = NULL;
605}
606
607static void xsk_drop_skb(struct sk_buff *skb)
608{
609 xdp_sk(skb->sk)->tx->invalid_descs += xsk_get_num_desc(skb);
610 xsk_consume_skb(skb);
611}
612
613static struct sk_buff *xsk_build_skb_zerocopy(struct xdp_sock *xs,
614 struct xdp_desc *desc)
615{
616 struct xsk_buff_pool *pool = xs->pool;
617 u32 hr, len, ts, offset, copy, copied;
618 struct sk_buff *skb = xs->skb;
619 struct page *page;
620 void *buffer;
621 int err, i;
622 u64 addr;
623
624 if (!skb) {
625 hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(xs->dev->needed_headroom));
626
627 skb = sock_alloc_send_skb(&xs->sk, hr, 1, &err);
628 if (unlikely(!skb))
629 return ERR_PTR(err);
630
631 skb_reserve(skb, hr);
632 }
633
634 addr = desc->addr;
635 len = desc->len;
636 ts = pool->unaligned ? len : pool->chunk_size;
637
638 buffer = xsk_buff_raw_get_data(pool, addr);
639 offset = offset_in_page(buffer);
640 addr = buffer - pool->addrs;
641
642 for (copied = 0, i = skb_shinfo(skb)->nr_frags; copied < len; i++) {
643 if (unlikely(i >= MAX_SKB_FRAGS))
644 return ERR_PTR(-EOVERFLOW);
645
646 page = pool->umem->pgs[addr >> PAGE_SHIFT];
647 get_page(page);
648
649 copy = min_t(u32, PAGE_SIZE - offset, len - copied);
650 skb_fill_page_desc(skb, i, page, offset, copy);
651
652 copied += copy;
653 addr += copy;
654 offset = 0;
655 }
656
657 skb->len += len;
658 skb->data_len += len;
659 skb->truesize += ts;
660
661 refcount_add(ts, &xs->sk.sk_wmem_alloc);
662
663 return skb;
664}
665
666static struct sk_buff *xsk_build_skb(struct xdp_sock *xs,
667 struct xdp_desc *desc)
668{
669 struct xsk_tx_metadata *meta = NULL;
670 struct net_device *dev = xs->dev;
671 struct sk_buff *skb = xs->skb;
672 bool first_frag = false;
673 int err;
674
675 if (dev->priv_flags & IFF_TX_SKB_NO_LINEAR) {
676 skb = xsk_build_skb_zerocopy(xs, desc);
677 if (IS_ERR(skb)) {
678 err = PTR_ERR(skb);
679 goto free_err;
680 }
681 } else {
682 u32 hr, tr, len;
683 void *buffer;
684
685 buffer = xsk_buff_raw_get_data(xs->pool, desc->addr);
686 len = desc->len;
687
688 if (!skb) {
689 hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(dev->needed_headroom));
690 tr = dev->needed_tailroom;
691 skb = sock_alloc_send_skb(&xs->sk, hr + len + tr, 1, &err);
692 if (unlikely(!skb))
693 goto free_err;
694
695 skb_reserve(skb, hr);
696 skb_put(skb, len);
697
698 err = skb_store_bits(skb, 0, buffer, len);
699 if (unlikely(err)) {
700 kfree_skb(skb);
701 goto free_err;
702 }
703
704 first_frag = true;
705 } else {
706 int nr_frags = skb_shinfo(skb)->nr_frags;
707 struct page *page;
708 u8 *vaddr;
709
710 if (unlikely(nr_frags == (MAX_SKB_FRAGS - 1) && xp_mb_desc(desc))) {
711 err = -EOVERFLOW;
712 goto free_err;
713 }
714
715 page = alloc_page(xs->sk.sk_allocation);
716 if (unlikely(!page)) {
717 err = -EAGAIN;
718 goto free_err;
719 }
720
721 vaddr = kmap_local_page(page);
722 memcpy(vaddr, buffer, len);
723 kunmap_local(vaddr);
724
725 skb_add_rx_frag(skb, nr_frags, page, 0, len, PAGE_SIZE);
726 refcount_add(PAGE_SIZE, &xs->sk.sk_wmem_alloc);
727 }
728
729 if (first_frag && desc->options & XDP_TX_METADATA) {
730 if (unlikely(xs->pool->tx_metadata_len == 0)) {
731 err = -EINVAL;
732 goto free_err;
733 }
734
735 meta = buffer - xs->pool->tx_metadata_len;
736 if (unlikely(!xsk_buff_valid_tx_metadata(meta))) {
737 err = -EINVAL;
738 goto free_err;
739 }
740
741 if (meta->flags & XDP_TXMD_FLAGS_CHECKSUM) {
742 if (unlikely(meta->request.csum_start +
743 meta->request.csum_offset +
744 sizeof(__sum16) > len)) {
745 err = -EINVAL;
746 goto free_err;
747 }
748
749 skb->csum_start = hr + meta->request.csum_start;
750 skb->csum_offset = meta->request.csum_offset;
751 skb->ip_summed = CHECKSUM_PARTIAL;
752
753 if (unlikely(xs->pool->tx_sw_csum)) {
754 err = skb_checksum_help(skb);
755 if (err)
756 goto free_err;
757 }
758 }
759 }
760 }
761
762 skb->dev = dev;
763 skb->priority = READ_ONCE(xs->sk.sk_priority);
764 skb->mark = READ_ONCE(xs->sk.sk_mark);
765 skb->destructor = xsk_destruct_skb;
766 xsk_tx_metadata_to_compl(meta, &skb_shinfo(skb)->xsk_meta);
767 xsk_set_destructor_arg(skb);
768
769 return skb;
770
771free_err:
772 if (err == -EOVERFLOW) {
773 /* Drop the packet */
774 xsk_set_destructor_arg(xs->skb);
775 xsk_drop_skb(xs->skb);
776 xskq_cons_release(xs->tx);
777 } else {
778 /* Let application retry */
779 xsk_cq_cancel_locked(xs, 1);
780 }
781
782 return ERR_PTR(err);
783}
784
785static int __xsk_generic_xmit(struct sock *sk)
786{
787 struct xdp_sock *xs = xdp_sk(sk);
788 u32 max_batch = TX_BATCH_SIZE;
789 bool sent_frame = false;
790 struct xdp_desc desc;
791 struct sk_buff *skb;
792 int err = 0;
793
794 mutex_lock(&xs->mutex);
795
796 /* Since we dropped the RCU read lock, the socket state might have changed. */
797 if (unlikely(!xsk_is_bound(xs))) {
798 err = -ENXIO;
799 goto out;
800 }
801
802 if (xs->queue_id >= xs->dev->real_num_tx_queues)
803 goto out;
804
805 while (xskq_cons_peek_desc(xs->tx, &desc, xs->pool)) {
806 if (max_batch-- == 0) {
807 err = -EAGAIN;
808 goto out;
809 }
810
811 /* This is the backpressure mechanism for the Tx path.
812 * Reserve space in the completion queue and only proceed
813 * if there is space in it. This avoids having to implement
814 * any buffering in the Tx path.
815 */
816 if (xsk_cq_reserve_addr_locked(xs, desc.addr))
817 goto out;
818
819 skb = xsk_build_skb(xs, &desc);
820 if (IS_ERR(skb)) {
821 err = PTR_ERR(skb);
822 if (err != -EOVERFLOW)
823 goto out;
824 err = 0;
825 continue;
826 }
827
828 xskq_cons_release(xs->tx);
829
830 if (xp_mb_desc(&desc)) {
831 xs->skb = skb;
832 continue;
833 }
834
835 err = __dev_direct_xmit(skb, xs->queue_id);
836 if (err == NETDEV_TX_BUSY) {
837 /* Tell user-space to retry the send */
838 xskq_cons_cancel_n(xs->tx, xsk_get_num_desc(skb));
839 xsk_consume_skb(skb);
840 err = -EAGAIN;
841 goto out;
842 }
843
844 /* Ignore NET_XMIT_CN as packet might have been sent */
845 if (err == NET_XMIT_DROP) {
846 /* SKB completed but not sent */
847 err = -EBUSY;
848 xs->skb = NULL;
849 goto out;
850 }
851
852 sent_frame = true;
853 xs->skb = NULL;
854 }
855
856 if (xskq_has_descs(xs->tx)) {
857 if (xs->skb)
858 xsk_drop_skb(xs->skb);
859 xskq_cons_release(xs->tx);
860 }
861
862out:
863 if (sent_frame)
864 if (xsk_tx_writeable(xs))
865 sk->sk_write_space(sk);
866
867 mutex_unlock(&xs->mutex);
868 return err;
869}
870
871static int xsk_generic_xmit(struct sock *sk)
872{
873 int ret;
874
875 /* Drop the RCU lock since the SKB path might sleep. */
876 rcu_read_unlock();
877 ret = __xsk_generic_xmit(sk);
878 /* Reaquire RCU lock before going into common code. */
879 rcu_read_lock();
880
881 return ret;
882}
883
884static bool xsk_no_wakeup(struct sock *sk)
885{
886#ifdef CONFIG_NET_RX_BUSY_POLL
887 /* Prefer busy-polling, skip the wakeup. */
888 return READ_ONCE(sk->sk_prefer_busy_poll) && READ_ONCE(sk->sk_ll_usec) &&
889 READ_ONCE(sk->sk_napi_id) >= MIN_NAPI_ID;
890#else
891 return false;
892#endif
893}
894
895static int xsk_check_common(struct xdp_sock *xs)
896{
897 if (unlikely(!xsk_is_bound(xs)))
898 return -ENXIO;
899 if (unlikely(!(xs->dev->flags & IFF_UP)))
900 return -ENETDOWN;
901
902 return 0;
903}
904
905static int __xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
906{
907 bool need_wait = !(m->msg_flags & MSG_DONTWAIT);
908 struct sock *sk = sock->sk;
909 struct xdp_sock *xs = xdp_sk(sk);
910 struct xsk_buff_pool *pool;
911 int err;
912
913 err = xsk_check_common(xs);
914 if (err)
915 return err;
916 if (unlikely(need_wait))
917 return -EOPNOTSUPP;
918 if (unlikely(!xs->tx))
919 return -ENOBUFS;
920
921 if (sk_can_busy_loop(sk)) {
922 if (xs->zc)
923 __sk_mark_napi_id_once(sk, xsk_pool_get_napi_id(xs->pool));
924 sk_busy_loop(sk, 1); /* only support non-blocking sockets */
925 }
926
927 if (xs->zc && xsk_no_wakeup(sk))
928 return 0;
929
930 pool = xs->pool;
931 if (pool->cached_need_wakeup & XDP_WAKEUP_TX) {
932 if (xs->zc)
933 return xsk_wakeup(xs, XDP_WAKEUP_TX);
934 return xsk_generic_xmit(sk);
935 }
936 return 0;
937}
938
939static int xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
940{
941 int ret;
942
943 rcu_read_lock();
944 ret = __xsk_sendmsg(sock, m, total_len);
945 rcu_read_unlock();
946
947 return ret;
948}
949
950static int __xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int flags)
951{
952 bool need_wait = !(flags & MSG_DONTWAIT);
953 struct sock *sk = sock->sk;
954 struct xdp_sock *xs = xdp_sk(sk);
955 int err;
956
957 err = xsk_check_common(xs);
958 if (err)
959 return err;
960 if (unlikely(!xs->rx))
961 return -ENOBUFS;
962 if (unlikely(need_wait))
963 return -EOPNOTSUPP;
964
965 if (sk_can_busy_loop(sk))
966 sk_busy_loop(sk, 1); /* only support non-blocking sockets */
967
968 if (xsk_no_wakeup(sk))
969 return 0;
970
971 if (xs->pool->cached_need_wakeup & XDP_WAKEUP_RX && xs->zc)
972 return xsk_wakeup(xs, XDP_WAKEUP_RX);
973 return 0;
974}
975
976static int xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int flags)
977{
978 int ret;
979
980 rcu_read_lock();
981 ret = __xsk_recvmsg(sock, m, len, flags);
982 rcu_read_unlock();
983
984 return ret;
985}
986
987static __poll_t xsk_poll(struct file *file, struct socket *sock,
988 struct poll_table_struct *wait)
989{
990 __poll_t mask = 0;
991 struct sock *sk = sock->sk;
992 struct xdp_sock *xs = xdp_sk(sk);
993 struct xsk_buff_pool *pool;
994
995 sock_poll_wait(file, sock, wait);
996
997 rcu_read_lock();
998 if (xsk_check_common(xs))
999 goto out;
1000
1001 pool = xs->pool;
1002
1003 if (pool->cached_need_wakeup) {
1004 if (xs->zc)
1005 xsk_wakeup(xs, pool->cached_need_wakeup);
1006 else if (xs->tx)
1007 /* Poll needs to drive Tx also in copy mode */
1008 xsk_generic_xmit(sk);
1009 }
1010
1011 if (xs->rx && !xskq_prod_is_empty(xs->rx))
1012 mask |= EPOLLIN | EPOLLRDNORM;
1013 if (xs->tx && xsk_tx_writeable(xs))
1014 mask |= EPOLLOUT | EPOLLWRNORM;
1015out:
1016 rcu_read_unlock();
1017 return mask;
1018}
1019
1020static int xsk_init_queue(u32 entries, struct xsk_queue **queue,
1021 bool umem_queue)
1022{
1023 struct xsk_queue *q;
1024
1025 if (entries == 0 || *queue || !is_power_of_2(entries))
1026 return -EINVAL;
1027
1028 q = xskq_create(entries, umem_queue);
1029 if (!q)
1030 return -ENOMEM;
1031
1032 /* Make sure queue is ready before it can be seen by others */
1033 smp_wmb();
1034 WRITE_ONCE(*queue, q);
1035 return 0;
1036}
1037
1038static void xsk_unbind_dev(struct xdp_sock *xs)
1039{
1040 struct net_device *dev = xs->dev;
1041
1042 if (xs->state != XSK_BOUND)
1043 return;
1044 WRITE_ONCE(xs->state, XSK_UNBOUND);
1045
1046 /* Wait for driver to stop using the xdp socket. */
1047 xp_del_xsk(xs->pool, xs);
1048 synchronize_net();
1049 dev_put(dev);
1050}
1051
1052static struct xsk_map *xsk_get_map_list_entry(struct xdp_sock *xs,
1053 struct xdp_sock __rcu ***map_entry)
1054{
1055 struct xsk_map *map = NULL;
1056 struct xsk_map_node *node;
1057
1058 *map_entry = NULL;
1059
1060 spin_lock_bh(&xs->map_list_lock);
1061 node = list_first_entry_or_null(&xs->map_list, struct xsk_map_node,
1062 node);
1063 if (node) {
1064 bpf_map_inc(&node->map->map);
1065 map = node->map;
1066 *map_entry = node->map_entry;
1067 }
1068 spin_unlock_bh(&xs->map_list_lock);
1069 return map;
1070}
1071
1072static void xsk_delete_from_maps(struct xdp_sock *xs)
1073{
1074 /* This function removes the current XDP socket from all the
1075 * maps it resides in. We need to take extra care here, due to
1076 * the two locks involved. Each map has a lock synchronizing
1077 * updates to the entries, and each socket has a lock that
1078 * synchronizes access to the list of maps (map_list). For
1079 * deadlock avoidance the locks need to be taken in the order
1080 * "map lock"->"socket map list lock". We start off by
1081 * accessing the socket map list, and take a reference to the
1082 * map to guarantee existence between the
1083 * xsk_get_map_list_entry() and xsk_map_try_sock_delete()
1084 * calls. Then we ask the map to remove the socket, which
1085 * tries to remove the socket from the map. Note that there
1086 * might be updates to the map between
1087 * xsk_get_map_list_entry() and xsk_map_try_sock_delete().
1088 */
1089 struct xdp_sock __rcu **map_entry = NULL;
1090 struct xsk_map *map;
1091
1092 while ((map = xsk_get_map_list_entry(xs, &map_entry))) {
1093 xsk_map_try_sock_delete(map, xs, map_entry);
1094 bpf_map_put(&map->map);
1095 }
1096}
1097
1098static int xsk_release(struct socket *sock)
1099{
1100 struct sock *sk = sock->sk;
1101 struct xdp_sock *xs = xdp_sk(sk);
1102 struct net *net;
1103
1104 if (!sk)
1105 return 0;
1106
1107 net = sock_net(sk);
1108
1109 if (xs->skb)
1110 xsk_drop_skb(xs->skb);
1111
1112 mutex_lock(&net->xdp.lock);
1113 sk_del_node_init_rcu(sk);
1114 mutex_unlock(&net->xdp.lock);
1115
1116 sock_prot_inuse_add(net, sk->sk_prot, -1);
1117
1118 xsk_delete_from_maps(xs);
1119 mutex_lock(&xs->mutex);
1120 xsk_unbind_dev(xs);
1121 mutex_unlock(&xs->mutex);
1122
1123 xskq_destroy(xs->rx);
1124 xskq_destroy(xs->tx);
1125 xskq_destroy(xs->fq_tmp);
1126 xskq_destroy(xs->cq_tmp);
1127
1128 sock_orphan(sk);
1129 sock->sk = NULL;
1130
1131 sock_put(sk);
1132
1133 return 0;
1134}
1135
1136static struct socket *xsk_lookup_xsk_from_fd(int fd)
1137{
1138 struct socket *sock;
1139 int err;
1140
1141 sock = sockfd_lookup(fd, &err);
1142 if (!sock)
1143 return ERR_PTR(-ENOTSOCK);
1144
1145 if (sock->sk->sk_family != PF_XDP) {
1146 sockfd_put(sock);
1147 return ERR_PTR(-ENOPROTOOPT);
1148 }
1149
1150 return sock;
1151}
1152
1153static bool xsk_validate_queues(struct xdp_sock *xs)
1154{
1155 return xs->fq_tmp && xs->cq_tmp;
1156}
1157
1158static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
1159{
1160 struct sockaddr_xdp *sxdp = (struct sockaddr_xdp *)addr;
1161 struct sock *sk = sock->sk;
1162 struct xdp_sock *xs = xdp_sk(sk);
1163 struct net_device *dev;
1164 int bound_dev_if;
1165 u32 flags, qid;
1166 int err = 0;
1167
1168 if (addr_len < sizeof(struct sockaddr_xdp))
1169 return -EINVAL;
1170 if (sxdp->sxdp_family != AF_XDP)
1171 return -EINVAL;
1172
1173 flags = sxdp->sxdp_flags;
1174 if (flags & ~(XDP_SHARED_UMEM | XDP_COPY | XDP_ZEROCOPY |
1175 XDP_USE_NEED_WAKEUP | XDP_USE_SG))
1176 return -EINVAL;
1177
1178 bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
1179 if (bound_dev_if && bound_dev_if != sxdp->sxdp_ifindex)
1180 return -EINVAL;
1181
1182 rtnl_lock();
1183 mutex_lock(&xs->mutex);
1184 if (xs->state != XSK_READY) {
1185 err = -EBUSY;
1186 goto out_release;
1187 }
1188
1189 dev = dev_get_by_index(sock_net(sk), sxdp->sxdp_ifindex);
1190 if (!dev) {
1191 err = -ENODEV;
1192 goto out_release;
1193 }
1194
1195 if (!xs->rx && !xs->tx) {
1196 err = -EINVAL;
1197 goto out_unlock;
1198 }
1199
1200 qid = sxdp->sxdp_queue_id;
1201
1202 if (flags & XDP_SHARED_UMEM) {
1203 struct xdp_sock *umem_xs;
1204 struct socket *sock;
1205
1206 if ((flags & XDP_COPY) || (flags & XDP_ZEROCOPY) ||
1207 (flags & XDP_USE_NEED_WAKEUP) || (flags & XDP_USE_SG)) {
1208 /* Cannot specify flags for shared sockets. */
1209 err = -EINVAL;
1210 goto out_unlock;
1211 }
1212
1213 if (xs->umem) {
1214 /* We have already our own. */
1215 err = -EINVAL;
1216 goto out_unlock;
1217 }
1218
1219 sock = xsk_lookup_xsk_from_fd(sxdp->sxdp_shared_umem_fd);
1220 if (IS_ERR(sock)) {
1221 err = PTR_ERR(sock);
1222 goto out_unlock;
1223 }
1224
1225 umem_xs = xdp_sk(sock->sk);
1226 if (!xsk_is_bound(umem_xs)) {
1227 err = -EBADF;
1228 sockfd_put(sock);
1229 goto out_unlock;
1230 }
1231
1232 if (umem_xs->queue_id != qid || umem_xs->dev != dev) {
1233 /* Share the umem with another socket on another qid
1234 * and/or device.
1235 */
1236 xs->pool = xp_create_and_assign_umem(xs,
1237 umem_xs->umem);
1238 if (!xs->pool) {
1239 err = -ENOMEM;
1240 sockfd_put(sock);
1241 goto out_unlock;
1242 }
1243
1244 err = xp_assign_dev_shared(xs->pool, umem_xs, dev,
1245 qid);
1246 if (err) {
1247 xp_destroy(xs->pool);
1248 xs->pool = NULL;
1249 sockfd_put(sock);
1250 goto out_unlock;
1251 }
1252 } else {
1253 /* Share the buffer pool with the other socket. */
1254 if (xs->fq_tmp || xs->cq_tmp) {
1255 /* Do not allow setting your own fq or cq. */
1256 err = -EINVAL;
1257 sockfd_put(sock);
1258 goto out_unlock;
1259 }
1260
1261 xp_get_pool(umem_xs->pool);
1262 xs->pool = umem_xs->pool;
1263
1264 /* If underlying shared umem was created without Tx
1265 * ring, allocate Tx descs array that Tx batching API
1266 * utilizes
1267 */
1268 if (xs->tx && !xs->pool->tx_descs) {
1269 err = xp_alloc_tx_descs(xs->pool, xs);
1270 if (err) {
1271 xp_put_pool(xs->pool);
1272 xs->pool = NULL;
1273 sockfd_put(sock);
1274 goto out_unlock;
1275 }
1276 }
1277 }
1278
1279 xdp_get_umem(umem_xs->umem);
1280 WRITE_ONCE(xs->umem, umem_xs->umem);
1281 sockfd_put(sock);
1282 } else if (!xs->umem || !xsk_validate_queues(xs)) {
1283 err = -EINVAL;
1284 goto out_unlock;
1285 } else {
1286 /* This xsk has its own umem. */
1287 xs->pool = xp_create_and_assign_umem(xs, xs->umem);
1288 if (!xs->pool) {
1289 err = -ENOMEM;
1290 goto out_unlock;
1291 }
1292
1293 err = xp_assign_dev(xs->pool, dev, qid, flags);
1294 if (err) {
1295 xp_destroy(xs->pool);
1296 xs->pool = NULL;
1297 goto out_unlock;
1298 }
1299 }
1300
1301 /* FQ and CQ are now owned by the buffer pool and cleaned up with it. */
1302 xs->fq_tmp = NULL;
1303 xs->cq_tmp = NULL;
1304
1305 xs->dev = dev;
1306 xs->zc = xs->umem->zc;
1307 xs->sg = !!(xs->umem->flags & XDP_UMEM_SG_FLAG);
1308 xs->queue_id = qid;
1309 xp_add_xsk(xs->pool, xs);
1310
1311out_unlock:
1312 if (err) {
1313 dev_put(dev);
1314 } else {
1315 /* Matches smp_rmb() in bind() for shared umem
1316 * sockets, and xsk_is_bound().
1317 */
1318 smp_wmb();
1319 WRITE_ONCE(xs->state, XSK_BOUND);
1320 }
1321out_release:
1322 mutex_unlock(&xs->mutex);
1323 rtnl_unlock();
1324 return err;
1325}
1326
1327struct xdp_umem_reg_v1 {
1328 __u64 addr; /* Start of packet data area */
1329 __u64 len; /* Length of packet data area */
1330 __u32 chunk_size;
1331 __u32 headroom;
1332};
1333
1334struct xdp_umem_reg_v2 {
1335 __u64 addr; /* Start of packet data area */
1336 __u64 len; /* Length of packet data area */
1337 __u32 chunk_size;
1338 __u32 headroom;
1339 __u32 flags;
1340};
1341
1342static int xsk_setsockopt(struct socket *sock, int level, int optname,
1343 sockptr_t optval, unsigned int optlen)
1344{
1345 struct sock *sk = sock->sk;
1346 struct xdp_sock *xs = xdp_sk(sk);
1347 int err;
1348
1349 if (level != SOL_XDP)
1350 return -ENOPROTOOPT;
1351
1352 switch (optname) {
1353 case XDP_RX_RING:
1354 case XDP_TX_RING:
1355 {
1356 struct xsk_queue **q;
1357 int entries;
1358
1359 if (optlen < sizeof(entries))
1360 return -EINVAL;
1361 if (copy_from_sockptr(&entries, optval, sizeof(entries)))
1362 return -EFAULT;
1363
1364 mutex_lock(&xs->mutex);
1365 if (xs->state != XSK_READY) {
1366 mutex_unlock(&xs->mutex);
1367 return -EBUSY;
1368 }
1369 q = (optname == XDP_TX_RING) ? &xs->tx : &xs->rx;
1370 err = xsk_init_queue(entries, q, false);
1371 if (!err && optname == XDP_TX_RING)
1372 /* Tx needs to be explicitly woken up the first time */
1373 xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP;
1374 mutex_unlock(&xs->mutex);
1375 return err;
1376 }
1377 case XDP_UMEM_REG:
1378 {
1379 size_t mr_size = sizeof(struct xdp_umem_reg);
1380 struct xdp_umem_reg mr = {};
1381 struct xdp_umem *umem;
1382
1383 if (optlen < sizeof(struct xdp_umem_reg_v1))
1384 return -EINVAL;
1385 else if (optlen < sizeof(struct xdp_umem_reg_v2))
1386 mr_size = sizeof(struct xdp_umem_reg_v1);
1387 else if (optlen < sizeof(mr))
1388 mr_size = sizeof(struct xdp_umem_reg_v2);
1389
1390 if (copy_from_sockptr(&mr, optval, mr_size))
1391 return -EFAULT;
1392
1393 mutex_lock(&xs->mutex);
1394 if (xs->state != XSK_READY || xs->umem) {
1395 mutex_unlock(&xs->mutex);
1396 return -EBUSY;
1397 }
1398
1399 umem = xdp_umem_create(&mr);
1400 if (IS_ERR(umem)) {
1401 mutex_unlock(&xs->mutex);
1402 return PTR_ERR(umem);
1403 }
1404
1405 /* Make sure umem is ready before it can be seen by others */
1406 smp_wmb();
1407 WRITE_ONCE(xs->umem, umem);
1408 mutex_unlock(&xs->mutex);
1409 return 0;
1410 }
1411 case XDP_UMEM_FILL_RING:
1412 case XDP_UMEM_COMPLETION_RING:
1413 {
1414 struct xsk_queue **q;
1415 int entries;
1416
1417 if (copy_from_sockptr(&entries, optval, sizeof(entries)))
1418 return -EFAULT;
1419
1420 mutex_lock(&xs->mutex);
1421 if (xs->state != XSK_READY) {
1422 mutex_unlock(&xs->mutex);
1423 return -EBUSY;
1424 }
1425
1426 q = (optname == XDP_UMEM_FILL_RING) ? &xs->fq_tmp :
1427 &xs->cq_tmp;
1428 err = xsk_init_queue(entries, q, true);
1429 mutex_unlock(&xs->mutex);
1430 return err;
1431 }
1432 default:
1433 break;
1434 }
1435
1436 return -ENOPROTOOPT;
1437}
1438
1439static void xsk_enter_rxtx_offsets(struct xdp_ring_offset_v1 *ring)
1440{
1441 ring->producer = offsetof(struct xdp_rxtx_ring, ptrs.producer);
1442 ring->consumer = offsetof(struct xdp_rxtx_ring, ptrs.consumer);
1443 ring->desc = offsetof(struct xdp_rxtx_ring, desc);
1444}
1445
1446static void xsk_enter_umem_offsets(struct xdp_ring_offset_v1 *ring)
1447{
1448 ring->producer = offsetof(struct xdp_umem_ring, ptrs.producer);
1449 ring->consumer = offsetof(struct xdp_umem_ring, ptrs.consumer);
1450 ring->desc = offsetof(struct xdp_umem_ring, desc);
1451}
1452
1453struct xdp_statistics_v1 {
1454 __u64 rx_dropped;
1455 __u64 rx_invalid_descs;
1456 __u64 tx_invalid_descs;
1457};
1458
1459static int xsk_getsockopt(struct socket *sock, int level, int optname,
1460 char __user *optval, int __user *optlen)
1461{
1462 struct sock *sk = sock->sk;
1463 struct xdp_sock *xs = xdp_sk(sk);
1464 int len;
1465
1466 if (level != SOL_XDP)
1467 return -ENOPROTOOPT;
1468
1469 if (get_user(len, optlen))
1470 return -EFAULT;
1471 if (len < 0)
1472 return -EINVAL;
1473
1474 switch (optname) {
1475 case XDP_STATISTICS:
1476 {
1477 struct xdp_statistics stats = {};
1478 bool extra_stats = true;
1479 size_t stats_size;
1480
1481 if (len < sizeof(struct xdp_statistics_v1)) {
1482 return -EINVAL;
1483 } else if (len < sizeof(stats)) {
1484 extra_stats = false;
1485 stats_size = sizeof(struct xdp_statistics_v1);
1486 } else {
1487 stats_size = sizeof(stats);
1488 }
1489
1490 mutex_lock(&xs->mutex);
1491 stats.rx_dropped = xs->rx_dropped;
1492 if (extra_stats) {
1493 stats.rx_ring_full = xs->rx_queue_full;
1494 stats.rx_fill_ring_empty_descs =
1495 xs->pool ? xskq_nb_queue_empty_descs(xs->pool->fq) : 0;
1496 stats.tx_ring_empty_descs = xskq_nb_queue_empty_descs(xs->tx);
1497 } else {
1498 stats.rx_dropped += xs->rx_queue_full;
1499 }
1500 stats.rx_invalid_descs = xskq_nb_invalid_descs(xs->rx);
1501 stats.tx_invalid_descs = xskq_nb_invalid_descs(xs->tx);
1502 mutex_unlock(&xs->mutex);
1503
1504 if (copy_to_user(optval, &stats, stats_size))
1505 return -EFAULT;
1506 if (put_user(stats_size, optlen))
1507 return -EFAULT;
1508
1509 return 0;
1510 }
1511 case XDP_MMAP_OFFSETS:
1512 {
1513 struct xdp_mmap_offsets off;
1514 struct xdp_mmap_offsets_v1 off_v1;
1515 bool flags_supported = true;
1516 void *to_copy;
1517
1518 if (len < sizeof(off_v1))
1519 return -EINVAL;
1520 else if (len < sizeof(off))
1521 flags_supported = false;
1522
1523 if (flags_supported) {
1524 /* xdp_ring_offset is identical to xdp_ring_offset_v1
1525 * except for the flags field added to the end.
1526 */
1527 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *)
1528 &off.rx);
1529 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *)
1530 &off.tx);
1531 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *)
1532 &off.fr);
1533 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *)
1534 &off.cr);
1535 off.rx.flags = offsetof(struct xdp_rxtx_ring,
1536 ptrs.flags);
1537 off.tx.flags = offsetof(struct xdp_rxtx_ring,
1538 ptrs.flags);
1539 off.fr.flags = offsetof(struct xdp_umem_ring,
1540 ptrs.flags);
1541 off.cr.flags = offsetof(struct xdp_umem_ring,
1542 ptrs.flags);
1543
1544 len = sizeof(off);
1545 to_copy = &off;
1546 } else {
1547 xsk_enter_rxtx_offsets(&off_v1.rx);
1548 xsk_enter_rxtx_offsets(&off_v1.tx);
1549 xsk_enter_umem_offsets(&off_v1.fr);
1550 xsk_enter_umem_offsets(&off_v1.cr);
1551
1552 len = sizeof(off_v1);
1553 to_copy = &off_v1;
1554 }
1555
1556 if (copy_to_user(optval, to_copy, len))
1557 return -EFAULT;
1558 if (put_user(len, optlen))
1559 return -EFAULT;
1560
1561 return 0;
1562 }
1563 case XDP_OPTIONS:
1564 {
1565 struct xdp_options opts = {};
1566
1567 if (len < sizeof(opts))
1568 return -EINVAL;
1569
1570 mutex_lock(&xs->mutex);
1571 if (xs->zc)
1572 opts.flags |= XDP_OPTIONS_ZEROCOPY;
1573 mutex_unlock(&xs->mutex);
1574
1575 len = sizeof(opts);
1576 if (copy_to_user(optval, &opts, len))
1577 return -EFAULT;
1578 if (put_user(len, optlen))
1579 return -EFAULT;
1580
1581 return 0;
1582 }
1583 default:
1584 break;
1585 }
1586
1587 return -EOPNOTSUPP;
1588}
1589
1590static int xsk_mmap(struct file *file, struct socket *sock,
1591 struct vm_area_struct *vma)
1592{
1593 loff_t offset = (loff_t)vma->vm_pgoff << PAGE_SHIFT;
1594 unsigned long size = vma->vm_end - vma->vm_start;
1595 struct xdp_sock *xs = xdp_sk(sock->sk);
1596 int state = READ_ONCE(xs->state);
1597 struct xsk_queue *q = NULL;
1598
1599 if (state != XSK_READY && state != XSK_BOUND)
1600 return -EBUSY;
1601
1602 if (offset == XDP_PGOFF_RX_RING) {
1603 q = READ_ONCE(xs->rx);
1604 } else if (offset == XDP_PGOFF_TX_RING) {
1605 q = READ_ONCE(xs->tx);
1606 } else {
1607 /* Matches the smp_wmb() in XDP_UMEM_REG */
1608 smp_rmb();
1609 if (offset == XDP_UMEM_PGOFF_FILL_RING)
1610 q = state == XSK_READY ? READ_ONCE(xs->fq_tmp) :
1611 READ_ONCE(xs->pool->fq);
1612 else if (offset == XDP_UMEM_PGOFF_COMPLETION_RING)
1613 q = state == XSK_READY ? READ_ONCE(xs->cq_tmp) :
1614 READ_ONCE(xs->pool->cq);
1615 }
1616
1617 if (!q)
1618 return -EINVAL;
1619
1620 /* Matches the smp_wmb() in xsk_init_queue */
1621 smp_rmb();
1622 if (size > q->ring_vmalloc_size)
1623 return -EINVAL;
1624
1625 return remap_vmalloc_range(vma, q->ring, 0);
1626}
1627
1628static int xsk_notifier(struct notifier_block *this,
1629 unsigned long msg, void *ptr)
1630{
1631 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1632 struct net *net = dev_net(dev);
1633 struct sock *sk;
1634
1635 switch (msg) {
1636 case NETDEV_UNREGISTER:
1637 mutex_lock(&net->xdp.lock);
1638 sk_for_each(sk, &net->xdp.list) {
1639 struct xdp_sock *xs = xdp_sk(sk);
1640
1641 mutex_lock(&xs->mutex);
1642 if (xs->dev == dev) {
1643 sk->sk_err = ENETDOWN;
1644 if (!sock_flag(sk, SOCK_DEAD))
1645 sk_error_report(sk);
1646
1647 xsk_unbind_dev(xs);
1648
1649 /* Clear device references. */
1650 xp_clear_dev(xs->pool);
1651 }
1652 mutex_unlock(&xs->mutex);
1653 }
1654 mutex_unlock(&net->xdp.lock);
1655 break;
1656 }
1657 return NOTIFY_DONE;
1658}
1659
1660static struct proto xsk_proto = {
1661 .name = "XDP",
1662 .owner = THIS_MODULE,
1663 .obj_size = sizeof(struct xdp_sock),
1664};
1665
1666static const struct proto_ops xsk_proto_ops = {
1667 .family = PF_XDP,
1668 .owner = THIS_MODULE,
1669 .release = xsk_release,
1670 .bind = xsk_bind,
1671 .connect = sock_no_connect,
1672 .socketpair = sock_no_socketpair,
1673 .accept = sock_no_accept,
1674 .getname = sock_no_getname,
1675 .poll = xsk_poll,
1676 .ioctl = sock_no_ioctl,
1677 .listen = sock_no_listen,
1678 .shutdown = sock_no_shutdown,
1679 .setsockopt = xsk_setsockopt,
1680 .getsockopt = xsk_getsockopt,
1681 .sendmsg = xsk_sendmsg,
1682 .recvmsg = xsk_recvmsg,
1683 .mmap = xsk_mmap,
1684};
1685
1686static void xsk_destruct(struct sock *sk)
1687{
1688 struct xdp_sock *xs = xdp_sk(sk);
1689
1690 if (!sock_flag(sk, SOCK_DEAD))
1691 return;
1692
1693 if (!xp_put_pool(xs->pool))
1694 xdp_put_umem(xs->umem, !xs->pool);
1695}
1696
1697static int xsk_create(struct net *net, struct socket *sock, int protocol,
1698 int kern)
1699{
1700 struct xdp_sock *xs;
1701 struct sock *sk;
1702
1703 if (!ns_capable(net->user_ns, CAP_NET_RAW))
1704 return -EPERM;
1705 if (sock->type != SOCK_RAW)
1706 return -ESOCKTNOSUPPORT;
1707
1708 if (protocol)
1709 return -EPROTONOSUPPORT;
1710
1711 sock->state = SS_UNCONNECTED;
1712
1713 sk = sk_alloc(net, PF_XDP, GFP_KERNEL, &xsk_proto, kern);
1714 if (!sk)
1715 return -ENOBUFS;
1716
1717 sock->ops = &xsk_proto_ops;
1718
1719 sock_init_data(sock, sk);
1720
1721 sk->sk_family = PF_XDP;
1722
1723 sk->sk_destruct = xsk_destruct;
1724
1725 sock_set_flag(sk, SOCK_RCU_FREE);
1726
1727 xs = xdp_sk(sk);
1728 xs->state = XSK_READY;
1729 mutex_init(&xs->mutex);
1730 spin_lock_init(&xs->rx_lock);
1731
1732 INIT_LIST_HEAD(&xs->map_list);
1733 spin_lock_init(&xs->map_list_lock);
1734
1735 mutex_lock(&net->xdp.lock);
1736 sk_add_node_rcu(sk, &net->xdp.list);
1737 mutex_unlock(&net->xdp.lock);
1738
1739 sock_prot_inuse_add(net, &xsk_proto, 1);
1740
1741 return 0;
1742}
1743
1744static const struct net_proto_family xsk_family_ops = {
1745 .family = PF_XDP,
1746 .create = xsk_create,
1747 .owner = THIS_MODULE,
1748};
1749
1750static struct notifier_block xsk_netdev_notifier = {
1751 .notifier_call = xsk_notifier,
1752};
1753
1754static int __net_init xsk_net_init(struct net *net)
1755{
1756 mutex_init(&net->xdp.lock);
1757 INIT_HLIST_HEAD(&net->xdp.list);
1758 return 0;
1759}
1760
1761static void __net_exit xsk_net_exit(struct net *net)
1762{
1763 WARN_ON_ONCE(!hlist_empty(&net->xdp.list));
1764}
1765
1766static struct pernet_operations xsk_net_ops = {
1767 .init = xsk_net_init,
1768 .exit = xsk_net_exit,
1769};
1770
1771static int __init xsk_init(void)
1772{
1773 int err, cpu;
1774
1775 err = proto_register(&xsk_proto, 0 /* no slab */);
1776 if (err)
1777 goto out;
1778
1779 err = sock_register(&xsk_family_ops);
1780 if (err)
1781 goto out_proto;
1782
1783 err = register_pernet_subsys(&xsk_net_ops);
1784 if (err)
1785 goto out_sk;
1786
1787 err = register_netdevice_notifier(&xsk_netdev_notifier);
1788 if (err)
1789 goto out_pernet;
1790
1791 for_each_possible_cpu(cpu)
1792 INIT_LIST_HEAD(&per_cpu(xskmap_flush_list, cpu));
1793 return 0;
1794
1795out_pernet:
1796 unregister_pernet_subsys(&xsk_net_ops);
1797out_sk:
1798 sock_unregister(PF_XDP);
1799out_proto:
1800 proto_unregister(&xsk_proto);
1801out:
1802 return err;
1803}
1804
1805fs_initcall(xsk_init);
1// SPDX-License-Identifier: GPL-2.0
2/* XDP sockets
3 *
4 * AF_XDP sockets allows a channel between XDP programs and userspace
5 * applications.
6 * Copyright(c) 2018 Intel Corporation.
7 *
8 * Author(s): Björn Töpel <bjorn.topel@intel.com>
9 * Magnus Karlsson <magnus.karlsson@intel.com>
10 */
11
12#define pr_fmt(fmt) "AF_XDP: %s: " fmt, __func__
13
14#include <linux/if_xdp.h>
15#include <linux/init.h>
16#include <linux/sched/mm.h>
17#include <linux/sched/signal.h>
18#include <linux/sched/task.h>
19#include <linux/socket.h>
20#include <linux/file.h>
21#include <linux/uaccess.h>
22#include <linux/net.h>
23#include <linux/netdevice.h>
24#include <linux/rculist.h>
25#include <net/xdp_sock_drv.h>
26#include <net/busy_poll.h>
27#include <net/xdp.h>
28
29#include "xsk_queue.h"
30#include "xdp_umem.h"
31#include "xsk.h"
32
33#define TX_BATCH_SIZE 32
34
35static DEFINE_PER_CPU(struct list_head, xskmap_flush_list);
36
37void xsk_set_rx_need_wakeup(struct xsk_buff_pool *pool)
38{
39 if (pool->cached_need_wakeup & XDP_WAKEUP_RX)
40 return;
41
42 pool->fq->ring->flags |= XDP_RING_NEED_WAKEUP;
43 pool->cached_need_wakeup |= XDP_WAKEUP_RX;
44}
45EXPORT_SYMBOL(xsk_set_rx_need_wakeup);
46
47void xsk_set_tx_need_wakeup(struct xsk_buff_pool *pool)
48{
49 struct xdp_sock *xs;
50
51 if (pool->cached_need_wakeup & XDP_WAKEUP_TX)
52 return;
53
54 rcu_read_lock();
55 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) {
56 xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP;
57 }
58 rcu_read_unlock();
59
60 pool->cached_need_wakeup |= XDP_WAKEUP_TX;
61}
62EXPORT_SYMBOL(xsk_set_tx_need_wakeup);
63
64void xsk_clear_rx_need_wakeup(struct xsk_buff_pool *pool)
65{
66 if (!(pool->cached_need_wakeup & XDP_WAKEUP_RX))
67 return;
68
69 pool->fq->ring->flags &= ~XDP_RING_NEED_WAKEUP;
70 pool->cached_need_wakeup &= ~XDP_WAKEUP_RX;
71}
72EXPORT_SYMBOL(xsk_clear_rx_need_wakeup);
73
74void xsk_clear_tx_need_wakeup(struct xsk_buff_pool *pool)
75{
76 struct xdp_sock *xs;
77
78 if (!(pool->cached_need_wakeup & XDP_WAKEUP_TX))
79 return;
80
81 rcu_read_lock();
82 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) {
83 xs->tx->ring->flags &= ~XDP_RING_NEED_WAKEUP;
84 }
85 rcu_read_unlock();
86
87 pool->cached_need_wakeup &= ~XDP_WAKEUP_TX;
88}
89EXPORT_SYMBOL(xsk_clear_tx_need_wakeup);
90
91bool xsk_uses_need_wakeup(struct xsk_buff_pool *pool)
92{
93 return pool->uses_need_wakeup;
94}
95EXPORT_SYMBOL(xsk_uses_need_wakeup);
96
97struct xsk_buff_pool *xsk_get_pool_from_qid(struct net_device *dev,
98 u16 queue_id)
99{
100 if (queue_id < dev->real_num_rx_queues)
101 return dev->_rx[queue_id].pool;
102 if (queue_id < dev->real_num_tx_queues)
103 return dev->_tx[queue_id].pool;
104
105 return NULL;
106}
107EXPORT_SYMBOL(xsk_get_pool_from_qid);
108
109void xsk_clear_pool_at_qid(struct net_device *dev, u16 queue_id)
110{
111 if (queue_id < dev->num_rx_queues)
112 dev->_rx[queue_id].pool = NULL;
113 if (queue_id < dev->num_tx_queues)
114 dev->_tx[queue_id].pool = NULL;
115}
116
117/* The buffer pool is stored both in the _rx struct and the _tx struct as we do
118 * not know if the device has more tx queues than rx, or the opposite.
119 * This might also change during run time.
120 */
121int xsk_reg_pool_at_qid(struct net_device *dev, struct xsk_buff_pool *pool,
122 u16 queue_id)
123{
124 if (queue_id >= max_t(unsigned int,
125 dev->real_num_rx_queues,
126 dev->real_num_tx_queues))
127 return -EINVAL;
128
129 if (queue_id < dev->real_num_rx_queues)
130 dev->_rx[queue_id].pool = pool;
131 if (queue_id < dev->real_num_tx_queues)
132 dev->_tx[queue_id].pool = pool;
133
134 return 0;
135}
136
137void xp_release(struct xdp_buff_xsk *xskb)
138{
139 xskb->pool->free_heads[xskb->pool->free_heads_cnt++] = xskb;
140}
141
142static u64 xp_get_handle(struct xdp_buff_xsk *xskb)
143{
144 u64 offset = xskb->xdp.data - xskb->xdp.data_hard_start;
145
146 offset += xskb->pool->headroom;
147 if (!xskb->pool->unaligned)
148 return xskb->orig_addr + offset;
149 return xskb->orig_addr + (offset << XSK_UNALIGNED_BUF_OFFSET_SHIFT);
150}
151
152static int __xsk_rcv_zc(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len)
153{
154 struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp);
155 u64 addr;
156 int err;
157
158 addr = xp_get_handle(xskb);
159 err = xskq_prod_reserve_desc(xs->rx, addr, len);
160 if (err) {
161 xs->rx_queue_full++;
162 return err;
163 }
164
165 xp_release(xskb);
166 return 0;
167}
168
169static void xsk_copy_xdp(struct xdp_buff *to, struct xdp_buff *from, u32 len)
170{
171 void *from_buf, *to_buf;
172 u32 metalen;
173
174 if (unlikely(xdp_data_meta_unsupported(from))) {
175 from_buf = from->data;
176 to_buf = to->data;
177 metalen = 0;
178 } else {
179 from_buf = from->data_meta;
180 metalen = from->data - from->data_meta;
181 to_buf = to->data - metalen;
182 }
183
184 memcpy(to_buf, from_buf, len + metalen);
185}
186
187static int __xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
188{
189 struct xdp_buff *xsk_xdp;
190 int err;
191 u32 len;
192
193 len = xdp->data_end - xdp->data;
194 if (len > xsk_pool_get_rx_frame_size(xs->pool)) {
195 xs->rx_dropped++;
196 return -ENOSPC;
197 }
198
199 xsk_xdp = xsk_buff_alloc(xs->pool);
200 if (!xsk_xdp) {
201 xs->rx_dropped++;
202 return -ENOSPC;
203 }
204
205 xsk_copy_xdp(xsk_xdp, xdp, len);
206 err = __xsk_rcv_zc(xs, xsk_xdp, len);
207 if (err) {
208 xsk_buff_free(xsk_xdp);
209 return err;
210 }
211 return 0;
212}
213
214static bool xsk_tx_writeable(struct xdp_sock *xs)
215{
216 if (xskq_cons_present_entries(xs->tx) > xs->tx->nentries / 2)
217 return false;
218
219 return true;
220}
221
222static bool xsk_is_bound(struct xdp_sock *xs)
223{
224 if (READ_ONCE(xs->state) == XSK_BOUND) {
225 /* Matches smp_wmb() in bind(). */
226 smp_rmb();
227 return true;
228 }
229 return false;
230}
231
232static int xsk_rcv_check(struct xdp_sock *xs, struct xdp_buff *xdp)
233{
234 if (!xsk_is_bound(xs))
235 return -EINVAL;
236
237 if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index)
238 return -EINVAL;
239
240 sk_mark_napi_id_once_xdp(&xs->sk, xdp);
241 return 0;
242}
243
244static void xsk_flush(struct xdp_sock *xs)
245{
246 xskq_prod_submit(xs->rx);
247 __xskq_cons_release(xs->pool->fq);
248 sock_def_readable(&xs->sk);
249}
250
251int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
252{
253 int err;
254
255 spin_lock_bh(&xs->rx_lock);
256 err = xsk_rcv_check(xs, xdp);
257 if (!err) {
258 err = __xsk_rcv(xs, xdp);
259 xsk_flush(xs);
260 }
261 spin_unlock_bh(&xs->rx_lock);
262 return err;
263}
264
265static int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
266{
267 int err;
268 u32 len;
269
270 err = xsk_rcv_check(xs, xdp);
271 if (err)
272 return err;
273
274 if (xdp->rxq->mem.type == MEM_TYPE_XSK_BUFF_POOL) {
275 len = xdp->data_end - xdp->data;
276 return __xsk_rcv_zc(xs, xdp, len);
277 }
278
279 err = __xsk_rcv(xs, xdp);
280 if (!err)
281 xdp_return_buff(xdp);
282 return err;
283}
284
285int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp)
286{
287 struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list);
288 int err;
289
290 err = xsk_rcv(xs, xdp);
291 if (err)
292 return err;
293
294 if (!xs->flush_node.prev)
295 list_add(&xs->flush_node, flush_list);
296
297 return 0;
298}
299
300void __xsk_map_flush(void)
301{
302 struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list);
303 struct xdp_sock *xs, *tmp;
304
305 list_for_each_entry_safe(xs, tmp, flush_list, flush_node) {
306 xsk_flush(xs);
307 __list_del_clearprev(&xs->flush_node);
308 }
309}
310
311void xsk_tx_completed(struct xsk_buff_pool *pool, u32 nb_entries)
312{
313 xskq_prod_submit_n(pool->cq, nb_entries);
314}
315EXPORT_SYMBOL(xsk_tx_completed);
316
317void xsk_tx_release(struct xsk_buff_pool *pool)
318{
319 struct xdp_sock *xs;
320
321 rcu_read_lock();
322 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) {
323 __xskq_cons_release(xs->tx);
324 if (xsk_tx_writeable(xs))
325 xs->sk.sk_write_space(&xs->sk);
326 }
327 rcu_read_unlock();
328}
329EXPORT_SYMBOL(xsk_tx_release);
330
331bool xsk_tx_peek_desc(struct xsk_buff_pool *pool, struct xdp_desc *desc)
332{
333 struct xdp_sock *xs;
334
335 rcu_read_lock();
336 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) {
337 if (!xskq_cons_peek_desc(xs->tx, desc, pool)) {
338 xs->tx->queue_empty_descs++;
339 continue;
340 }
341
342 /* This is the backpressure mechanism for the Tx path.
343 * Reserve space in the completion queue and only proceed
344 * if there is space in it. This avoids having to implement
345 * any buffering in the Tx path.
346 */
347 if (xskq_prod_reserve_addr(pool->cq, desc->addr))
348 goto out;
349
350 xskq_cons_release(xs->tx);
351 rcu_read_unlock();
352 return true;
353 }
354
355out:
356 rcu_read_unlock();
357 return false;
358}
359EXPORT_SYMBOL(xsk_tx_peek_desc);
360
361static u32 xsk_tx_peek_release_fallback(struct xsk_buff_pool *pool, struct xdp_desc *descs,
362 u32 max_entries)
363{
364 u32 nb_pkts = 0;
365
366 while (nb_pkts < max_entries && xsk_tx_peek_desc(pool, &descs[nb_pkts]))
367 nb_pkts++;
368
369 xsk_tx_release(pool);
370 return nb_pkts;
371}
372
373u32 xsk_tx_peek_release_desc_batch(struct xsk_buff_pool *pool, struct xdp_desc *descs,
374 u32 max_entries)
375{
376 struct xdp_sock *xs;
377 u32 nb_pkts;
378
379 rcu_read_lock();
380 if (!list_is_singular(&pool->xsk_tx_list)) {
381 /* Fallback to the non-batched version */
382 rcu_read_unlock();
383 return xsk_tx_peek_release_fallback(pool, descs, max_entries);
384 }
385
386 xs = list_first_or_null_rcu(&pool->xsk_tx_list, struct xdp_sock, tx_list);
387 if (!xs) {
388 nb_pkts = 0;
389 goto out;
390 }
391
392 nb_pkts = xskq_cons_peek_desc_batch(xs->tx, descs, pool, max_entries);
393 if (!nb_pkts) {
394 xs->tx->queue_empty_descs++;
395 goto out;
396 }
397
398 /* This is the backpressure mechanism for the Tx path. Try to
399 * reserve space in the completion queue for all packets, but
400 * if there are fewer slots available, just process that many
401 * packets. This avoids having to implement any buffering in
402 * the Tx path.
403 */
404 nb_pkts = xskq_prod_reserve_addr_batch(pool->cq, descs, nb_pkts);
405 if (!nb_pkts)
406 goto out;
407
408 xskq_cons_release_n(xs->tx, nb_pkts);
409 __xskq_cons_release(xs->tx);
410 xs->sk.sk_write_space(&xs->sk);
411
412out:
413 rcu_read_unlock();
414 return nb_pkts;
415}
416EXPORT_SYMBOL(xsk_tx_peek_release_desc_batch);
417
418static int xsk_wakeup(struct xdp_sock *xs, u8 flags)
419{
420 struct net_device *dev = xs->dev;
421 int err;
422
423 rcu_read_lock();
424 err = dev->netdev_ops->ndo_xsk_wakeup(dev, xs->queue_id, flags);
425 rcu_read_unlock();
426
427 return err;
428}
429
430static int xsk_zc_xmit(struct xdp_sock *xs)
431{
432 return xsk_wakeup(xs, XDP_WAKEUP_TX);
433}
434
435static void xsk_destruct_skb(struct sk_buff *skb)
436{
437 u64 addr = (u64)(long)skb_shinfo(skb)->destructor_arg;
438 struct xdp_sock *xs = xdp_sk(skb->sk);
439 unsigned long flags;
440
441 spin_lock_irqsave(&xs->pool->cq_lock, flags);
442 xskq_prod_submit_addr(xs->pool->cq, addr);
443 spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
444
445 sock_wfree(skb);
446}
447
448static struct sk_buff *xsk_build_skb_zerocopy(struct xdp_sock *xs,
449 struct xdp_desc *desc)
450{
451 struct xsk_buff_pool *pool = xs->pool;
452 u32 hr, len, ts, offset, copy, copied;
453 struct sk_buff *skb;
454 struct page *page;
455 void *buffer;
456 int err, i;
457 u64 addr;
458
459 hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(xs->dev->needed_headroom));
460
461 skb = sock_alloc_send_skb(&xs->sk, hr, 1, &err);
462 if (unlikely(!skb))
463 return ERR_PTR(err);
464
465 skb_reserve(skb, hr);
466
467 addr = desc->addr;
468 len = desc->len;
469 ts = pool->unaligned ? len : pool->chunk_size;
470
471 buffer = xsk_buff_raw_get_data(pool, addr);
472 offset = offset_in_page(buffer);
473 addr = buffer - pool->addrs;
474
475 for (copied = 0, i = 0; copied < len; i++) {
476 page = pool->umem->pgs[addr >> PAGE_SHIFT];
477 get_page(page);
478
479 copy = min_t(u32, PAGE_SIZE - offset, len - copied);
480 skb_fill_page_desc(skb, i, page, offset, copy);
481
482 copied += copy;
483 addr += copy;
484 offset = 0;
485 }
486
487 skb->len += len;
488 skb->data_len += len;
489 skb->truesize += ts;
490
491 refcount_add(ts, &xs->sk.sk_wmem_alloc);
492
493 return skb;
494}
495
496static struct sk_buff *xsk_build_skb(struct xdp_sock *xs,
497 struct xdp_desc *desc)
498{
499 struct net_device *dev = xs->dev;
500 struct sk_buff *skb;
501
502 if (dev->priv_flags & IFF_TX_SKB_NO_LINEAR) {
503 skb = xsk_build_skb_zerocopy(xs, desc);
504 if (IS_ERR(skb))
505 return skb;
506 } else {
507 u32 hr, tr, len;
508 void *buffer;
509 int err;
510
511 hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(dev->needed_headroom));
512 tr = dev->needed_tailroom;
513 len = desc->len;
514
515 skb = sock_alloc_send_skb(&xs->sk, hr + len + tr, 1, &err);
516 if (unlikely(!skb))
517 return ERR_PTR(err);
518
519 skb_reserve(skb, hr);
520 skb_put(skb, len);
521
522 buffer = xsk_buff_raw_get_data(xs->pool, desc->addr);
523 err = skb_store_bits(skb, 0, buffer, len);
524 if (unlikely(err)) {
525 kfree_skb(skb);
526 return ERR_PTR(err);
527 }
528 }
529
530 skb->dev = dev;
531 skb->priority = xs->sk.sk_priority;
532 skb->mark = xs->sk.sk_mark;
533 skb_shinfo(skb)->destructor_arg = (void *)(long)desc->addr;
534 skb->destructor = xsk_destruct_skb;
535
536 return skb;
537}
538
539static int xsk_generic_xmit(struct sock *sk)
540{
541 struct xdp_sock *xs = xdp_sk(sk);
542 u32 max_batch = TX_BATCH_SIZE;
543 bool sent_frame = false;
544 struct xdp_desc desc;
545 struct sk_buff *skb;
546 unsigned long flags;
547 int err = 0;
548
549 mutex_lock(&xs->mutex);
550
551 if (xs->queue_id >= xs->dev->real_num_tx_queues)
552 goto out;
553
554 while (xskq_cons_peek_desc(xs->tx, &desc, xs->pool)) {
555 if (max_batch-- == 0) {
556 err = -EAGAIN;
557 goto out;
558 }
559
560 skb = xsk_build_skb(xs, &desc);
561 if (IS_ERR(skb)) {
562 err = PTR_ERR(skb);
563 goto out;
564 }
565
566 /* This is the backpressure mechanism for the Tx path.
567 * Reserve space in the completion queue and only proceed
568 * if there is space in it. This avoids having to implement
569 * any buffering in the Tx path.
570 */
571 spin_lock_irqsave(&xs->pool->cq_lock, flags);
572 if (xskq_prod_reserve(xs->pool->cq)) {
573 spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
574 kfree_skb(skb);
575 goto out;
576 }
577 spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
578
579 err = __dev_direct_xmit(skb, xs->queue_id);
580 if (err == NETDEV_TX_BUSY) {
581 /* Tell user-space to retry the send */
582 skb->destructor = sock_wfree;
583 spin_lock_irqsave(&xs->pool->cq_lock, flags);
584 xskq_prod_cancel(xs->pool->cq);
585 spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
586 /* Free skb without triggering the perf drop trace */
587 consume_skb(skb);
588 err = -EAGAIN;
589 goto out;
590 }
591
592 xskq_cons_release(xs->tx);
593 /* Ignore NET_XMIT_CN as packet might have been sent */
594 if (err == NET_XMIT_DROP) {
595 /* SKB completed but not sent */
596 err = -EBUSY;
597 goto out;
598 }
599
600 sent_frame = true;
601 }
602
603 xs->tx->queue_empty_descs++;
604
605out:
606 if (sent_frame)
607 if (xsk_tx_writeable(xs))
608 sk->sk_write_space(sk);
609
610 mutex_unlock(&xs->mutex);
611 return err;
612}
613
614static int __xsk_sendmsg(struct sock *sk)
615{
616 struct xdp_sock *xs = xdp_sk(sk);
617
618 if (unlikely(!(xs->dev->flags & IFF_UP)))
619 return -ENETDOWN;
620 if (unlikely(!xs->tx))
621 return -ENOBUFS;
622
623 return xs->zc ? xsk_zc_xmit(xs) : xsk_generic_xmit(sk);
624}
625
626static bool xsk_no_wakeup(struct sock *sk)
627{
628#ifdef CONFIG_NET_RX_BUSY_POLL
629 /* Prefer busy-polling, skip the wakeup. */
630 return READ_ONCE(sk->sk_prefer_busy_poll) && READ_ONCE(sk->sk_ll_usec) &&
631 READ_ONCE(sk->sk_napi_id) >= MIN_NAPI_ID;
632#else
633 return false;
634#endif
635}
636
637static int xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
638{
639 bool need_wait = !(m->msg_flags & MSG_DONTWAIT);
640 struct sock *sk = sock->sk;
641 struct xdp_sock *xs = xdp_sk(sk);
642 struct xsk_buff_pool *pool;
643
644 if (unlikely(!xsk_is_bound(xs)))
645 return -ENXIO;
646 if (unlikely(need_wait))
647 return -EOPNOTSUPP;
648
649 if (sk_can_busy_loop(sk))
650 sk_busy_loop(sk, 1); /* only support non-blocking sockets */
651
652 if (xsk_no_wakeup(sk))
653 return 0;
654
655 pool = xs->pool;
656 if (pool->cached_need_wakeup & XDP_WAKEUP_TX)
657 return __xsk_sendmsg(sk);
658 return 0;
659}
660
661static int xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int flags)
662{
663 bool need_wait = !(flags & MSG_DONTWAIT);
664 struct sock *sk = sock->sk;
665 struct xdp_sock *xs = xdp_sk(sk);
666
667 if (unlikely(!xsk_is_bound(xs)))
668 return -ENXIO;
669 if (unlikely(!(xs->dev->flags & IFF_UP)))
670 return -ENETDOWN;
671 if (unlikely(!xs->rx))
672 return -ENOBUFS;
673 if (unlikely(need_wait))
674 return -EOPNOTSUPP;
675
676 if (sk_can_busy_loop(sk))
677 sk_busy_loop(sk, 1); /* only support non-blocking sockets */
678
679 if (xsk_no_wakeup(sk))
680 return 0;
681
682 if (xs->pool->cached_need_wakeup & XDP_WAKEUP_RX && xs->zc)
683 return xsk_wakeup(xs, XDP_WAKEUP_RX);
684 return 0;
685}
686
687static __poll_t xsk_poll(struct file *file, struct socket *sock,
688 struct poll_table_struct *wait)
689{
690 __poll_t mask = 0;
691 struct sock *sk = sock->sk;
692 struct xdp_sock *xs = xdp_sk(sk);
693 struct xsk_buff_pool *pool;
694
695 sock_poll_wait(file, sock, wait);
696
697 if (unlikely(!xsk_is_bound(xs)))
698 return mask;
699
700 pool = xs->pool;
701
702 if (pool->cached_need_wakeup) {
703 if (xs->zc)
704 xsk_wakeup(xs, pool->cached_need_wakeup);
705 else
706 /* Poll needs to drive Tx also in copy mode */
707 __xsk_sendmsg(sk);
708 }
709
710 if (xs->rx && !xskq_prod_is_empty(xs->rx))
711 mask |= EPOLLIN | EPOLLRDNORM;
712 if (xs->tx && xsk_tx_writeable(xs))
713 mask |= EPOLLOUT | EPOLLWRNORM;
714
715 return mask;
716}
717
718static int xsk_init_queue(u32 entries, struct xsk_queue **queue,
719 bool umem_queue)
720{
721 struct xsk_queue *q;
722
723 if (entries == 0 || *queue || !is_power_of_2(entries))
724 return -EINVAL;
725
726 q = xskq_create(entries, umem_queue);
727 if (!q)
728 return -ENOMEM;
729
730 /* Make sure queue is ready before it can be seen by others */
731 smp_wmb();
732 WRITE_ONCE(*queue, q);
733 return 0;
734}
735
736static void xsk_unbind_dev(struct xdp_sock *xs)
737{
738 struct net_device *dev = xs->dev;
739
740 if (xs->state != XSK_BOUND)
741 return;
742 WRITE_ONCE(xs->state, XSK_UNBOUND);
743
744 /* Wait for driver to stop using the xdp socket. */
745 xp_del_xsk(xs->pool, xs);
746 xs->dev = NULL;
747 synchronize_net();
748 dev_put(dev);
749}
750
751static struct xsk_map *xsk_get_map_list_entry(struct xdp_sock *xs,
752 struct xdp_sock __rcu ***map_entry)
753{
754 struct xsk_map *map = NULL;
755 struct xsk_map_node *node;
756
757 *map_entry = NULL;
758
759 spin_lock_bh(&xs->map_list_lock);
760 node = list_first_entry_or_null(&xs->map_list, struct xsk_map_node,
761 node);
762 if (node) {
763 bpf_map_inc(&node->map->map);
764 map = node->map;
765 *map_entry = node->map_entry;
766 }
767 spin_unlock_bh(&xs->map_list_lock);
768 return map;
769}
770
771static void xsk_delete_from_maps(struct xdp_sock *xs)
772{
773 /* This function removes the current XDP socket from all the
774 * maps it resides in. We need to take extra care here, due to
775 * the two locks involved. Each map has a lock synchronizing
776 * updates to the entries, and each socket has a lock that
777 * synchronizes access to the list of maps (map_list). For
778 * deadlock avoidance the locks need to be taken in the order
779 * "map lock"->"socket map list lock". We start off by
780 * accessing the socket map list, and take a reference to the
781 * map to guarantee existence between the
782 * xsk_get_map_list_entry() and xsk_map_try_sock_delete()
783 * calls. Then we ask the map to remove the socket, which
784 * tries to remove the socket from the map. Note that there
785 * might be updates to the map between
786 * xsk_get_map_list_entry() and xsk_map_try_sock_delete().
787 */
788 struct xdp_sock __rcu **map_entry = NULL;
789 struct xsk_map *map;
790
791 while ((map = xsk_get_map_list_entry(xs, &map_entry))) {
792 xsk_map_try_sock_delete(map, xs, map_entry);
793 bpf_map_put(&map->map);
794 }
795}
796
797static int xsk_release(struct socket *sock)
798{
799 struct sock *sk = sock->sk;
800 struct xdp_sock *xs = xdp_sk(sk);
801 struct net *net;
802
803 if (!sk)
804 return 0;
805
806 net = sock_net(sk);
807
808 mutex_lock(&net->xdp.lock);
809 sk_del_node_init_rcu(sk);
810 mutex_unlock(&net->xdp.lock);
811
812 local_bh_disable();
813 sock_prot_inuse_add(net, sk->sk_prot, -1);
814 local_bh_enable();
815
816 xsk_delete_from_maps(xs);
817 mutex_lock(&xs->mutex);
818 xsk_unbind_dev(xs);
819 mutex_unlock(&xs->mutex);
820
821 xskq_destroy(xs->rx);
822 xskq_destroy(xs->tx);
823 xskq_destroy(xs->fq_tmp);
824 xskq_destroy(xs->cq_tmp);
825
826 sock_orphan(sk);
827 sock->sk = NULL;
828
829 sk_refcnt_debug_release(sk);
830 sock_put(sk);
831
832 return 0;
833}
834
835static struct socket *xsk_lookup_xsk_from_fd(int fd)
836{
837 struct socket *sock;
838 int err;
839
840 sock = sockfd_lookup(fd, &err);
841 if (!sock)
842 return ERR_PTR(-ENOTSOCK);
843
844 if (sock->sk->sk_family != PF_XDP) {
845 sockfd_put(sock);
846 return ERR_PTR(-ENOPROTOOPT);
847 }
848
849 return sock;
850}
851
852static bool xsk_validate_queues(struct xdp_sock *xs)
853{
854 return xs->fq_tmp && xs->cq_tmp;
855}
856
857static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
858{
859 struct sockaddr_xdp *sxdp = (struct sockaddr_xdp *)addr;
860 struct sock *sk = sock->sk;
861 struct xdp_sock *xs = xdp_sk(sk);
862 struct net_device *dev;
863 u32 flags, qid;
864 int err = 0;
865
866 if (addr_len < sizeof(struct sockaddr_xdp))
867 return -EINVAL;
868 if (sxdp->sxdp_family != AF_XDP)
869 return -EINVAL;
870
871 flags = sxdp->sxdp_flags;
872 if (flags & ~(XDP_SHARED_UMEM | XDP_COPY | XDP_ZEROCOPY |
873 XDP_USE_NEED_WAKEUP))
874 return -EINVAL;
875
876 rtnl_lock();
877 mutex_lock(&xs->mutex);
878 if (xs->state != XSK_READY) {
879 err = -EBUSY;
880 goto out_release;
881 }
882
883 dev = dev_get_by_index(sock_net(sk), sxdp->sxdp_ifindex);
884 if (!dev) {
885 err = -ENODEV;
886 goto out_release;
887 }
888
889 if (!xs->rx && !xs->tx) {
890 err = -EINVAL;
891 goto out_unlock;
892 }
893
894 qid = sxdp->sxdp_queue_id;
895
896 if (flags & XDP_SHARED_UMEM) {
897 struct xdp_sock *umem_xs;
898 struct socket *sock;
899
900 if ((flags & XDP_COPY) || (flags & XDP_ZEROCOPY) ||
901 (flags & XDP_USE_NEED_WAKEUP)) {
902 /* Cannot specify flags for shared sockets. */
903 err = -EINVAL;
904 goto out_unlock;
905 }
906
907 if (xs->umem) {
908 /* We have already our own. */
909 err = -EINVAL;
910 goto out_unlock;
911 }
912
913 sock = xsk_lookup_xsk_from_fd(sxdp->sxdp_shared_umem_fd);
914 if (IS_ERR(sock)) {
915 err = PTR_ERR(sock);
916 goto out_unlock;
917 }
918
919 umem_xs = xdp_sk(sock->sk);
920 if (!xsk_is_bound(umem_xs)) {
921 err = -EBADF;
922 sockfd_put(sock);
923 goto out_unlock;
924 }
925
926 if (umem_xs->queue_id != qid || umem_xs->dev != dev) {
927 /* Share the umem with another socket on another qid
928 * and/or device.
929 */
930 xs->pool = xp_create_and_assign_umem(xs,
931 umem_xs->umem);
932 if (!xs->pool) {
933 err = -ENOMEM;
934 sockfd_put(sock);
935 goto out_unlock;
936 }
937
938 err = xp_assign_dev_shared(xs->pool, umem_xs->umem,
939 dev, qid);
940 if (err) {
941 xp_destroy(xs->pool);
942 xs->pool = NULL;
943 sockfd_put(sock);
944 goto out_unlock;
945 }
946 } else {
947 /* Share the buffer pool with the other socket. */
948 if (xs->fq_tmp || xs->cq_tmp) {
949 /* Do not allow setting your own fq or cq. */
950 err = -EINVAL;
951 sockfd_put(sock);
952 goto out_unlock;
953 }
954
955 xp_get_pool(umem_xs->pool);
956 xs->pool = umem_xs->pool;
957 }
958
959 xdp_get_umem(umem_xs->umem);
960 WRITE_ONCE(xs->umem, umem_xs->umem);
961 sockfd_put(sock);
962 } else if (!xs->umem || !xsk_validate_queues(xs)) {
963 err = -EINVAL;
964 goto out_unlock;
965 } else {
966 /* This xsk has its own umem. */
967 xs->pool = xp_create_and_assign_umem(xs, xs->umem);
968 if (!xs->pool) {
969 err = -ENOMEM;
970 goto out_unlock;
971 }
972
973 err = xp_assign_dev(xs->pool, dev, qid, flags);
974 if (err) {
975 xp_destroy(xs->pool);
976 xs->pool = NULL;
977 goto out_unlock;
978 }
979 }
980
981 /* FQ and CQ are now owned by the buffer pool and cleaned up with it. */
982 xs->fq_tmp = NULL;
983 xs->cq_tmp = NULL;
984
985 xs->dev = dev;
986 xs->zc = xs->umem->zc;
987 xs->queue_id = qid;
988 xp_add_xsk(xs->pool, xs);
989
990out_unlock:
991 if (err) {
992 dev_put(dev);
993 } else {
994 /* Matches smp_rmb() in bind() for shared umem
995 * sockets, and xsk_is_bound().
996 */
997 smp_wmb();
998 WRITE_ONCE(xs->state, XSK_BOUND);
999 }
1000out_release:
1001 mutex_unlock(&xs->mutex);
1002 rtnl_unlock();
1003 return err;
1004}
1005
1006struct xdp_umem_reg_v1 {
1007 __u64 addr; /* Start of packet data area */
1008 __u64 len; /* Length of packet data area */
1009 __u32 chunk_size;
1010 __u32 headroom;
1011};
1012
1013static int xsk_setsockopt(struct socket *sock, int level, int optname,
1014 sockptr_t optval, unsigned int optlen)
1015{
1016 struct sock *sk = sock->sk;
1017 struct xdp_sock *xs = xdp_sk(sk);
1018 int err;
1019
1020 if (level != SOL_XDP)
1021 return -ENOPROTOOPT;
1022
1023 switch (optname) {
1024 case XDP_RX_RING:
1025 case XDP_TX_RING:
1026 {
1027 struct xsk_queue **q;
1028 int entries;
1029
1030 if (optlen < sizeof(entries))
1031 return -EINVAL;
1032 if (copy_from_sockptr(&entries, optval, sizeof(entries)))
1033 return -EFAULT;
1034
1035 mutex_lock(&xs->mutex);
1036 if (xs->state != XSK_READY) {
1037 mutex_unlock(&xs->mutex);
1038 return -EBUSY;
1039 }
1040 q = (optname == XDP_TX_RING) ? &xs->tx : &xs->rx;
1041 err = xsk_init_queue(entries, q, false);
1042 if (!err && optname == XDP_TX_RING)
1043 /* Tx needs to be explicitly woken up the first time */
1044 xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP;
1045 mutex_unlock(&xs->mutex);
1046 return err;
1047 }
1048 case XDP_UMEM_REG:
1049 {
1050 size_t mr_size = sizeof(struct xdp_umem_reg);
1051 struct xdp_umem_reg mr = {};
1052 struct xdp_umem *umem;
1053
1054 if (optlen < sizeof(struct xdp_umem_reg_v1))
1055 return -EINVAL;
1056 else if (optlen < sizeof(mr))
1057 mr_size = sizeof(struct xdp_umem_reg_v1);
1058
1059 if (copy_from_sockptr(&mr, optval, mr_size))
1060 return -EFAULT;
1061
1062 mutex_lock(&xs->mutex);
1063 if (xs->state != XSK_READY || xs->umem) {
1064 mutex_unlock(&xs->mutex);
1065 return -EBUSY;
1066 }
1067
1068 umem = xdp_umem_create(&mr);
1069 if (IS_ERR(umem)) {
1070 mutex_unlock(&xs->mutex);
1071 return PTR_ERR(umem);
1072 }
1073
1074 /* Make sure umem is ready before it can be seen by others */
1075 smp_wmb();
1076 WRITE_ONCE(xs->umem, umem);
1077 mutex_unlock(&xs->mutex);
1078 return 0;
1079 }
1080 case XDP_UMEM_FILL_RING:
1081 case XDP_UMEM_COMPLETION_RING:
1082 {
1083 struct xsk_queue **q;
1084 int entries;
1085
1086 if (copy_from_sockptr(&entries, optval, sizeof(entries)))
1087 return -EFAULT;
1088
1089 mutex_lock(&xs->mutex);
1090 if (xs->state != XSK_READY) {
1091 mutex_unlock(&xs->mutex);
1092 return -EBUSY;
1093 }
1094
1095 q = (optname == XDP_UMEM_FILL_RING) ? &xs->fq_tmp :
1096 &xs->cq_tmp;
1097 err = xsk_init_queue(entries, q, true);
1098 mutex_unlock(&xs->mutex);
1099 return err;
1100 }
1101 default:
1102 break;
1103 }
1104
1105 return -ENOPROTOOPT;
1106}
1107
1108static void xsk_enter_rxtx_offsets(struct xdp_ring_offset_v1 *ring)
1109{
1110 ring->producer = offsetof(struct xdp_rxtx_ring, ptrs.producer);
1111 ring->consumer = offsetof(struct xdp_rxtx_ring, ptrs.consumer);
1112 ring->desc = offsetof(struct xdp_rxtx_ring, desc);
1113}
1114
1115static void xsk_enter_umem_offsets(struct xdp_ring_offset_v1 *ring)
1116{
1117 ring->producer = offsetof(struct xdp_umem_ring, ptrs.producer);
1118 ring->consumer = offsetof(struct xdp_umem_ring, ptrs.consumer);
1119 ring->desc = offsetof(struct xdp_umem_ring, desc);
1120}
1121
1122struct xdp_statistics_v1 {
1123 __u64 rx_dropped;
1124 __u64 rx_invalid_descs;
1125 __u64 tx_invalid_descs;
1126};
1127
1128static int xsk_getsockopt(struct socket *sock, int level, int optname,
1129 char __user *optval, int __user *optlen)
1130{
1131 struct sock *sk = sock->sk;
1132 struct xdp_sock *xs = xdp_sk(sk);
1133 int len;
1134
1135 if (level != SOL_XDP)
1136 return -ENOPROTOOPT;
1137
1138 if (get_user(len, optlen))
1139 return -EFAULT;
1140 if (len < 0)
1141 return -EINVAL;
1142
1143 switch (optname) {
1144 case XDP_STATISTICS:
1145 {
1146 struct xdp_statistics stats = {};
1147 bool extra_stats = true;
1148 size_t stats_size;
1149
1150 if (len < sizeof(struct xdp_statistics_v1)) {
1151 return -EINVAL;
1152 } else if (len < sizeof(stats)) {
1153 extra_stats = false;
1154 stats_size = sizeof(struct xdp_statistics_v1);
1155 } else {
1156 stats_size = sizeof(stats);
1157 }
1158
1159 mutex_lock(&xs->mutex);
1160 stats.rx_dropped = xs->rx_dropped;
1161 if (extra_stats) {
1162 stats.rx_ring_full = xs->rx_queue_full;
1163 stats.rx_fill_ring_empty_descs =
1164 xs->pool ? xskq_nb_queue_empty_descs(xs->pool->fq) : 0;
1165 stats.tx_ring_empty_descs = xskq_nb_queue_empty_descs(xs->tx);
1166 } else {
1167 stats.rx_dropped += xs->rx_queue_full;
1168 }
1169 stats.rx_invalid_descs = xskq_nb_invalid_descs(xs->rx);
1170 stats.tx_invalid_descs = xskq_nb_invalid_descs(xs->tx);
1171 mutex_unlock(&xs->mutex);
1172
1173 if (copy_to_user(optval, &stats, stats_size))
1174 return -EFAULT;
1175 if (put_user(stats_size, optlen))
1176 return -EFAULT;
1177
1178 return 0;
1179 }
1180 case XDP_MMAP_OFFSETS:
1181 {
1182 struct xdp_mmap_offsets off;
1183 struct xdp_mmap_offsets_v1 off_v1;
1184 bool flags_supported = true;
1185 void *to_copy;
1186
1187 if (len < sizeof(off_v1))
1188 return -EINVAL;
1189 else if (len < sizeof(off))
1190 flags_supported = false;
1191
1192 if (flags_supported) {
1193 /* xdp_ring_offset is identical to xdp_ring_offset_v1
1194 * except for the flags field added to the end.
1195 */
1196 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *)
1197 &off.rx);
1198 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *)
1199 &off.tx);
1200 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *)
1201 &off.fr);
1202 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *)
1203 &off.cr);
1204 off.rx.flags = offsetof(struct xdp_rxtx_ring,
1205 ptrs.flags);
1206 off.tx.flags = offsetof(struct xdp_rxtx_ring,
1207 ptrs.flags);
1208 off.fr.flags = offsetof(struct xdp_umem_ring,
1209 ptrs.flags);
1210 off.cr.flags = offsetof(struct xdp_umem_ring,
1211 ptrs.flags);
1212
1213 len = sizeof(off);
1214 to_copy = &off;
1215 } else {
1216 xsk_enter_rxtx_offsets(&off_v1.rx);
1217 xsk_enter_rxtx_offsets(&off_v1.tx);
1218 xsk_enter_umem_offsets(&off_v1.fr);
1219 xsk_enter_umem_offsets(&off_v1.cr);
1220
1221 len = sizeof(off_v1);
1222 to_copy = &off_v1;
1223 }
1224
1225 if (copy_to_user(optval, to_copy, len))
1226 return -EFAULT;
1227 if (put_user(len, optlen))
1228 return -EFAULT;
1229
1230 return 0;
1231 }
1232 case XDP_OPTIONS:
1233 {
1234 struct xdp_options opts = {};
1235
1236 if (len < sizeof(opts))
1237 return -EINVAL;
1238
1239 mutex_lock(&xs->mutex);
1240 if (xs->zc)
1241 opts.flags |= XDP_OPTIONS_ZEROCOPY;
1242 mutex_unlock(&xs->mutex);
1243
1244 len = sizeof(opts);
1245 if (copy_to_user(optval, &opts, len))
1246 return -EFAULT;
1247 if (put_user(len, optlen))
1248 return -EFAULT;
1249
1250 return 0;
1251 }
1252 default:
1253 break;
1254 }
1255
1256 return -EOPNOTSUPP;
1257}
1258
1259static int xsk_mmap(struct file *file, struct socket *sock,
1260 struct vm_area_struct *vma)
1261{
1262 loff_t offset = (loff_t)vma->vm_pgoff << PAGE_SHIFT;
1263 unsigned long size = vma->vm_end - vma->vm_start;
1264 struct xdp_sock *xs = xdp_sk(sock->sk);
1265 struct xsk_queue *q = NULL;
1266 unsigned long pfn;
1267 struct page *qpg;
1268
1269 if (READ_ONCE(xs->state) != XSK_READY)
1270 return -EBUSY;
1271
1272 if (offset == XDP_PGOFF_RX_RING) {
1273 q = READ_ONCE(xs->rx);
1274 } else if (offset == XDP_PGOFF_TX_RING) {
1275 q = READ_ONCE(xs->tx);
1276 } else {
1277 /* Matches the smp_wmb() in XDP_UMEM_REG */
1278 smp_rmb();
1279 if (offset == XDP_UMEM_PGOFF_FILL_RING)
1280 q = READ_ONCE(xs->fq_tmp);
1281 else if (offset == XDP_UMEM_PGOFF_COMPLETION_RING)
1282 q = READ_ONCE(xs->cq_tmp);
1283 }
1284
1285 if (!q)
1286 return -EINVAL;
1287
1288 /* Matches the smp_wmb() in xsk_init_queue */
1289 smp_rmb();
1290 qpg = virt_to_head_page(q->ring);
1291 if (size > page_size(qpg))
1292 return -EINVAL;
1293
1294 pfn = virt_to_phys(q->ring) >> PAGE_SHIFT;
1295 return remap_pfn_range(vma, vma->vm_start, pfn,
1296 size, vma->vm_page_prot);
1297}
1298
1299static int xsk_notifier(struct notifier_block *this,
1300 unsigned long msg, void *ptr)
1301{
1302 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1303 struct net *net = dev_net(dev);
1304 struct sock *sk;
1305
1306 switch (msg) {
1307 case NETDEV_UNREGISTER:
1308 mutex_lock(&net->xdp.lock);
1309 sk_for_each(sk, &net->xdp.list) {
1310 struct xdp_sock *xs = xdp_sk(sk);
1311
1312 mutex_lock(&xs->mutex);
1313 if (xs->dev == dev) {
1314 sk->sk_err = ENETDOWN;
1315 if (!sock_flag(sk, SOCK_DEAD))
1316 sk_error_report(sk);
1317
1318 xsk_unbind_dev(xs);
1319
1320 /* Clear device references. */
1321 xp_clear_dev(xs->pool);
1322 }
1323 mutex_unlock(&xs->mutex);
1324 }
1325 mutex_unlock(&net->xdp.lock);
1326 break;
1327 }
1328 return NOTIFY_DONE;
1329}
1330
1331static struct proto xsk_proto = {
1332 .name = "XDP",
1333 .owner = THIS_MODULE,
1334 .obj_size = sizeof(struct xdp_sock),
1335};
1336
1337static const struct proto_ops xsk_proto_ops = {
1338 .family = PF_XDP,
1339 .owner = THIS_MODULE,
1340 .release = xsk_release,
1341 .bind = xsk_bind,
1342 .connect = sock_no_connect,
1343 .socketpair = sock_no_socketpair,
1344 .accept = sock_no_accept,
1345 .getname = sock_no_getname,
1346 .poll = xsk_poll,
1347 .ioctl = sock_no_ioctl,
1348 .listen = sock_no_listen,
1349 .shutdown = sock_no_shutdown,
1350 .setsockopt = xsk_setsockopt,
1351 .getsockopt = xsk_getsockopt,
1352 .sendmsg = xsk_sendmsg,
1353 .recvmsg = xsk_recvmsg,
1354 .mmap = xsk_mmap,
1355 .sendpage = sock_no_sendpage,
1356};
1357
1358static void xsk_destruct(struct sock *sk)
1359{
1360 struct xdp_sock *xs = xdp_sk(sk);
1361
1362 if (!sock_flag(sk, SOCK_DEAD))
1363 return;
1364
1365 if (!xp_put_pool(xs->pool))
1366 xdp_put_umem(xs->umem, !xs->pool);
1367
1368 sk_refcnt_debug_dec(sk);
1369}
1370
1371static int xsk_create(struct net *net, struct socket *sock, int protocol,
1372 int kern)
1373{
1374 struct xdp_sock *xs;
1375 struct sock *sk;
1376
1377 if (!ns_capable(net->user_ns, CAP_NET_RAW))
1378 return -EPERM;
1379 if (sock->type != SOCK_RAW)
1380 return -ESOCKTNOSUPPORT;
1381
1382 if (protocol)
1383 return -EPROTONOSUPPORT;
1384
1385 sock->state = SS_UNCONNECTED;
1386
1387 sk = sk_alloc(net, PF_XDP, GFP_KERNEL, &xsk_proto, kern);
1388 if (!sk)
1389 return -ENOBUFS;
1390
1391 sock->ops = &xsk_proto_ops;
1392
1393 sock_init_data(sock, sk);
1394
1395 sk->sk_family = PF_XDP;
1396
1397 sk->sk_destruct = xsk_destruct;
1398 sk_refcnt_debug_inc(sk);
1399
1400 sock_set_flag(sk, SOCK_RCU_FREE);
1401
1402 xs = xdp_sk(sk);
1403 xs->state = XSK_READY;
1404 mutex_init(&xs->mutex);
1405 spin_lock_init(&xs->rx_lock);
1406
1407 INIT_LIST_HEAD(&xs->map_list);
1408 spin_lock_init(&xs->map_list_lock);
1409
1410 mutex_lock(&net->xdp.lock);
1411 sk_add_node_rcu(sk, &net->xdp.list);
1412 mutex_unlock(&net->xdp.lock);
1413
1414 local_bh_disable();
1415 sock_prot_inuse_add(net, &xsk_proto, 1);
1416 local_bh_enable();
1417
1418 return 0;
1419}
1420
1421static const struct net_proto_family xsk_family_ops = {
1422 .family = PF_XDP,
1423 .create = xsk_create,
1424 .owner = THIS_MODULE,
1425};
1426
1427static struct notifier_block xsk_netdev_notifier = {
1428 .notifier_call = xsk_notifier,
1429};
1430
1431static int __net_init xsk_net_init(struct net *net)
1432{
1433 mutex_init(&net->xdp.lock);
1434 INIT_HLIST_HEAD(&net->xdp.list);
1435 return 0;
1436}
1437
1438static void __net_exit xsk_net_exit(struct net *net)
1439{
1440 WARN_ON_ONCE(!hlist_empty(&net->xdp.list));
1441}
1442
1443static struct pernet_operations xsk_net_ops = {
1444 .init = xsk_net_init,
1445 .exit = xsk_net_exit,
1446};
1447
1448static int __init xsk_init(void)
1449{
1450 int err, cpu;
1451
1452 err = proto_register(&xsk_proto, 0 /* no slab */);
1453 if (err)
1454 goto out;
1455
1456 err = sock_register(&xsk_family_ops);
1457 if (err)
1458 goto out_proto;
1459
1460 err = register_pernet_subsys(&xsk_net_ops);
1461 if (err)
1462 goto out_sk;
1463
1464 err = register_netdevice_notifier(&xsk_netdev_notifier);
1465 if (err)
1466 goto out_pernet;
1467
1468 for_each_possible_cpu(cpu)
1469 INIT_LIST_HEAD(&per_cpu(xskmap_flush_list, cpu));
1470 return 0;
1471
1472out_pernet:
1473 unregister_pernet_subsys(&xsk_net_ops);
1474out_sk:
1475 sock_unregister(PF_XDP);
1476out_proto:
1477 proto_unregister(&xsk_proto);
1478out:
1479 return err;
1480}
1481
1482fs_initcall(xsk_init);