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xsk: Inherit need_wakeup flag for shared sockets
[mirror_ubuntu-jammy-kernel.git] / net / xdp / xsk.c
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
35 static DEFINE_PER_CPU(struct list_head, xskmap_flush_list);
36
37 void 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 }
45 EXPORT_SYMBOL(xsk_set_rx_need_wakeup);
46
47 void 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 }
62 EXPORT_SYMBOL(xsk_set_tx_need_wakeup);
63
64 void 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 }
72 EXPORT_SYMBOL(xsk_clear_rx_need_wakeup);
73
74 void 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 }
89 EXPORT_SYMBOL(xsk_clear_tx_need_wakeup);
90
91 bool xsk_uses_need_wakeup(struct xsk_buff_pool *pool)
92 {
93 return pool->uses_need_wakeup;
94 }
95 EXPORT_SYMBOL(xsk_uses_need_wakeup);
96
97 struct 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 }
107 EXPORT_SYMBOL(xsk_get_pool_from_qid);
108
109 void 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 */
121 int 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
137 void xp_release(struct xdp_buff_xsk *xskb)
138 {
139 xskb->pool->free_heads[xskb->pool->free_heads_cnt++] = xskb;
140 }
141
142 static 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
152 static 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
169 static 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
187 static 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
214 static 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
222 static 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
232 static 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
244 static 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
251 int 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
265 static 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
285 int __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
300 void __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
311 void xsk_tx_completed(struct xsk_buff_pool *pool, u32 nb_entries)
312 {
313 xskq_prod_submit_n(pool->cq, nb_entries);
314 }
315 EXPORT_SYMBOL(xsk_tx_completed);
316
317 void 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 }
329 EXPORT_SYMBOL(xsk_tx_release);
330
331 bool 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
355 out:
356 rcu_read_unlock();
357 return false;
358 }
359 EXPORT_SYMBOL(xsk_tx_peek_desc);
360
361 static u32 xsk_tx_peek_release_fallback(struct xsk_buff_pool *pool, u32 max_entries)
362 {
363 struct xdp_desc *descs = pool->tx_descs;
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
373 u32 xsk_tx_peek_release_desc_batch(struct xsk_buff_pool *pool, u32 max_entries)
374 {
375 struct xdp_sock *xs;
376 u32 nb_pkts;
377
378 rcu_read_lock();
379 if (!list_is_singular(&pool->xsk_tx_list)) {
380 /* Fallback to the non-batched version */
381 rcu_read_unlock();
382 return xsk_tx_peek_release_fallback(pool, max_entries);
383 }
384
385 xs = list_first_or_null_rcu(&pool->xsk_tx_list, struct xdp_sock, tx_list);
386 if (!xs) {
387 nb_pkts = 0;
388 goto out;
389 }
390
391 max_entries = xskq_cons_nb_entries(xs->tx, max_entries);
392 nb_pkts = xskq_cons_read_desc_batch(xs->tx, 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, pool->tx_descs, nb_pkts);
405 if (!nb_pkts)
406 goto out;
407
408 xskq_cons_release_n(xs->tx, max_entries);
409 __xskq_cons_release(xs->tx);
410 xs->sk.sk_write_space(&xs->sk);
411
412 out:
413 rcu_read_unlock();
414 return nb_pkts;
415 }
416 EXPORT_SYMBOL(xsk_tx_peek_release_desc_batch);
417
418 static int xsk_wakeup(struct xdp_sock *xs, u8 flags)
419 {
420 struct net_device *dev = xs->dev;
421
422 return dev->netdev_ops->ndo_xsk_wakeup(dev, xs->queue_id, flags);
423 }
424
425 static void xsk_destruct_skb(struct sk_buff *skb)
426 {
427 u64 addr = (u64)(long)skb_shinfo(skb)->destructor_arg;
428 struct xdp_sock *xs = xdp_sk(skb->sk);
429 unsigned long flags;
430
431 spin_lock_irqsave(&xs->pool->cq_lock, flags);
432 xskq_prod_submit_addr(xs->pool->cq, addr);
433 spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
434
435 sock_wfree(skb);
436 }
437
438 static struct sk_buff *xsk_build_skb_zerocopy(struct xdp_sock *xs,
439 struct xdp_desc *desc)
440 {
441 struct xsk_buff_pool *pool = xs->pool;
442 u32 hr, len, ts, offset, copy, copied;
443 struct sk_buff *skb;
444 struct page *page;
445 void *buffer;
446 int err, i;
447 u64 addr;
448
449 hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(xs->dev->needed_headroom));
450
451 skb = sock_alloc_send_skb(&xs->sk, hr, 1, &err);
452 if (unlikely(!skb))
453 return ERR_PTR(err);
454
455 skb_reserve(skb, hr);
456
457 addr = desc->addr;
458 len = desc->len;
459 ts = pool->unaligned ? len : pool->chunk_size;
460
461 buffer = xsk_buff_raw_get_data(pool, addr);
462 offset = offset_in_page(buffer);
463 addr = buffer - pool->addrs;
464
465 for (copied = 0, i = 0; copied < len; i++) {
466 page = pool->umem->pgs[addr >> PAGE_SHIFT];
467 get_page(page);
468
469 copy = min_t(u32, PAGE_SIZE - offset, len - copied);
470 skb_fill_page_desc(skb, i, page, offset, copy);
471
472 copied += copy;
473 addr += copy;
474 offset = 0;
475 }
476
477 skb->len += len;
478 skb->data_len += len;
479 skb->truesize += ts;
480
481 refcount_add(ts, &xs->sk.sk_wmem_alloc);
482
483 return skb;
484 }
485
486 static struct sk_buff *xsk_build_skb(struct xdp_sock *xs,
487 struct xdp_desc *desc)
488 {
489 struct net_device *dev = xs->dev;
490 struct sk_buff *skb;
491
492 if (dev->priv_flags & IFF_TX_SKB_NO_LINEAR) {
493 skb = xsk_build_skb_zerocopy(xs, desc);
494 if (IS_ERR(skb))
495 return skb;
496 } else {
497 u32 hr, tr, len;
498 void *buffer;
499 int err;
500
501 hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(dev->needed_headroom));
502 tr = dev->needed_tailroom;
503 len = desc->len;
504
505 skb = sock_alloc_send_skb(&xs->sk, hr + len + tr, 1, &err);
506 if (unlikely(!skb))
507 return ERR_PTR(err);
508
509 skb_reserve(skb, hr);
510 skb_put(skb, len);
511
512 buffer = xsk_buff_raw_get_data(xs->pool, desc->addr);
513 err = skb_store_bits(skb, 0, buffer, len);
514 if (unlikely(err)) {
515 kfree_skb(skb);
516 return ERR_PTR(err);
517 }
518 }
519
520 skb->dev = dev;
521 skb->priority = xs->sk.sk_priority;
522 skb->mark = xs->sk.sk_mark;
523 skb_shinfo(skb)->destructor_arg = (void *)(long)desc->addr;
524 skb->destructor = xsk_destruct_skb;
525
526 return skb;
527 }
528
529 static int xsk_generic_xmit(struct sock *sk)
530 {
531 struct xdp_sock *xs = xdp_sk(sk);
532 u32 max_batch = TX_BATCH_SIZE;
533 bool sent_frame = false;
534 struct xdp_desc desc;
535 struct sk_buff *skb;
536 unsigned long flags;
537 int err = 0;
538
539 mutex_lock(&xs->mutex);
540
541 /* Since we dropped the RCU read lock, the socket state might have changed. */
542 if (unlikely(!xsk_is_bound(xs))) {
543 err = -ENXIO;
544 goto out;
545 }
546
547 if (xs->queue_id >= xs->dev->real_num_tx_queues)
548 goto out;
549
550 while (xskq_cons_peek_desc(xs->tx, &desc, xs->pool)) {
551 if (max_batch-- == 0) {
552 err = -EAGAIN;
553 goto out;
554 }
555
556 /* This is the backpressure mechanism for the Tx path.
557 * Reserve space in the completion queue and only proceed
558 * if there is space in it. This avoids having to implement
559 * any buffering in the Tx path.
560 */
561 spin_lock_irqsave(&xs->pool->cq_lock, flags);
562 if (xskq_prod_reserve(xs->pool->cq)) {
563 spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
564 goto out;
565 }
566 spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
567
568 skb = xsk_build_skb(xs, &desc);
569 if (IS_ERR(skb)) {
570 err = PTR_ERR(skb);
571 spin_lock_irqsave(&xs->pool->cq_lock, flags);
572 xskq_prod_cancel(xs->pool->cq);
573 spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
574 goto out;
575 }
576
577 err = __dev_direct_xmit(skb, xs->queue_id);
578 if (err == NETDEV_TX_BUSY) {
579 /* Tell user-space to retry the send */
580 skb->destructor = sock_wfree;
581 spin_lock_irqsave(&xs->pool->cq_lock, flags);
582 xskq_prod_cancel(xs->pool->cq);
583 spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
584 /* Free skb without triggering the perf drop trace */
585 consume_skb(skb);
586 err = -EAGAIN;
587 goto out;
588 }
589
590 xskq_cons_release(xs->tx);
591 /* Ignore NET_XMIT_CN as packet might have been sent */
592 if (err == NET_XMIT_DROP) {
593 /* SKB completed but not sent */
594 err = -EBUSY;
595 goto out;
596 }
597
598 sent_frame = true;
599 }
600
601 xs->tx->queue_empty_descs++;
602
603 out:
604 if (sent_frame)
605 if (xsk_tx_writeable(xs))
606 sk->sk_write_space(sk);
607
608 mutex_unlock(&xs->mutex);
609 return err;
610 }
611
612 static int xsk_xmit(struct sock *sk)
613 {
614 struct xdp_sock *xs = xdp_sk(sk);
615 int ret;
616
617 if (unlikely(!(xs->dev->flags & IFF_UP)))
618 return -ENETDOWN;
619 if (unlikely(!xs->tx))
620 return -ENOBUFS;
621
622 if (xs->zc)
623 return xsk_wakeup(xs, XDP_WAKEUP_TX);
624
625 /* Drop the RCU lock since the SKB path might sleep. */
626 rcu_read_unlock();
627 ret = xsk_generic_xmit(sk);
628 /* Reaquire RCU lock before going into common code. */
629 rcu_read_lock();
630
631 return ret;
632 }
633
634 static bool xsk_no_wakeup(struct sock *sk)
635 {
636 #ifdef CONFIG_NET_RX_BUSY_POLL
637 /* Prefer busy-polling, skip the wakeup. */
638 return READ_ONCE(sk->sk_prefer_busy_poll) && READ_ONCE(sk->sk_ll_usec) &&
639 READ_ONCE(sk->sk_napi_id) >= MIN_NAPI_ID;
640 #else
641 return false;
642 #endif
643 }
644
645 static int __xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
646 {
647 bool need_wait = !(m->msg_flags & MSG_DONTWAIT);
648 struct sock *sk = sock->sk;
649 struct xdp_sock *xs = xdp_sk(sk);
650 struct xsk_buff_pool *pool;
651
652 if (unlikely(!xsk_is_bound(xs)))
653 return -ENXIO;
654 if (unlikely(need_wait))
655 return -EOPNOTSUPP;
656
657 if (sk_can_busy_loop(sk))
658 sk_busy_loop(sk, 1); /* only support non-blocking sockets */
659
660 if (xs->zc && xsk_no_wakeup(sk))
661 return 0;
662
663 pool = xs->pool;
664 if (pool->cached_need_wakeup & XDP_WAKEUP_TX)
665 return xsk_xmit(sk);
666 return 0;
667 }
668
669 static int xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
670 {
671 int ret;
672
673 rcu_read_lock();
674 ret = __xsk_sendmsg(sock, m, total_len);
675 rcu_read_unlock();
676
677 return ret;
678 }
679
680 static int __xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int flags)
681 {
682 bool need_wait = !(flags & MSG_DONTWAIT);
683 struct sock *sk = sock->sk;
684 struct xdp_sock *xs = xdp_sk(sk);
685
686 if (unlikely(!xsk_is_bound(xs)))
687 return -ENXIO;
688 if (unlikely(!(xs->dev->flags & IFF_UP)))
689 return -ENETDOWN;
690 if (unlikely(!xs->rx))
691 return -ENOBUFS;
692 if (unlikely(need_wait))
693 return -EOPNOTSUPP;
694
695 if (sk_can_busy_loop(sk))
696 sk_busy_loop(sk, 1); /* only support non-blocking sockets */
697
698 if (xsk_no_wakeup(sk))
699 return 0;
700
701 if (xs->pool->cached_need_wakeup & XDP_WAKEUP_RX && xs->zc)
702 return xsk_wakeup(xs, XDP_WAKEUP_RX);
703 return 0;
704 }
705
706 static int xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int flags)
707 {
708 int ret;
709
710 rcu_read_lock();
711 ret = __xsk_recvmsg(sock, m, len, flags);
712 rcu_read_unlock();
713
714 return ret;
715 }
716
717 static __poll_t xsk_poll(struct file *file, struct socket *sock,
718 struct poll_table_struct *wait)
719 {
720 __poll_t mask = 0;
721 struct sock *sk = sock->sk;
722 struct xdp_sock *xs = xdp_sk(sk);
723 struct xsk_buff_pool *pool;
724
725 sock_poll_wait(file, sock, wait);
726
727 rcu_read_lock();
728 if (unlikely(!xsk_is_bound(xs))) {
729 rcu_read_unlock();
730 return mask;
731 }
732
733 pool = xs->pool;
734
735 if (pool->cached_need_wakeup) {
736 if (xs->zc)
737 xsk_wakeup(xs, pool->cached_need_wakeup);
738 else
739 /* Poll needs to drive Tx also in copy mode */
740 xsk_xmit(sk);
741 }
742
743 if (xs->rx && !xskq_prod_is_empty(xs->rx))
744 mask |= EPOLLIN | EPOLLRDNORM;
745 if (xs->tx && xsk_tx_writeable(xs))
746 mask |= EPOLLOUT | EPOLLWRNORM;
747
748 rcu_read_unlock();
749 return mask;
750 }
751
752 static int xsk_init_queue(u32 entries, struct xsk_queue **queue,
753 bool umem_queue)
754 {
755 struct xsk_queue *q;
756
757 if (entries == 0 || *queue || !is_power_of_2(entries))
758 return -EINVAL;
759
760 q = xskq_create(entries, umem_queue);
761 if (!q)
762 return -ENOMEM;
763
764 /* Make sure queue is ready before it can be seen by others */
765 smp_wmb();
766 WRITE_ONCE(*queue, q);
767 return 0;
768 }
769
770 static void xsk_unbind_dev(struct xdp_sock *xs)
771 {
772 struct net_device *dev = xs->dev;
773
774 if (xs->state != XSK_BOUND)
775 return;
776 WRITE_ONCE(xs->state, XSK_UNBOUND);
777
778 /* Wait for driver to stop using the xdp socket. */
779 xp_del_xsk(xs->pool, xs);
780 synchronize_net();
781 dev_put(dev);
782 }
783
784 static struct xsk_map *xsk_get_map_list_entry(struct xdp_sock *xs,
785 struct xdp_sock __rcu ***map_entry)
786 {
787 struct xsk_map *map = NULL;
788 struct xsk_map_node *node;
789
790 *map_entry = NULL;
791
792 spin_lock_bh(&xs->map_list_lock);
793 node = list_first_entry_or_null(&xs->map_list, struct xsk_map_node,
794 node);
795 if (node) {
796 bpf_map_inc(&node->map->map);
797 map = node->map;
798 *map_entry = node->map_entry;
799 }
800 spin_unlock_bh(&xs->map_list_lock);
801 return map;
802 }
803
804 static void xsk_delete_from_maps(struct xdp_sock *xs)
805 {
806 /* This function removes the current XDP socket from all the
807 * maps it resides in. We need to take extra care here, due to
808 * the two locks involved. Each map has a lock synchronizing
809 * updates to the entries, and each socket has a lock that
810 * synchronizes access to the list of maps (map_list). For
811 * deadlock avoidance the locks need to be taken in the order
812 * "map lock"->"socket map list lock". We start off by
813 * accessing the socket map list, and take a reference to the
814 * map to guarantee existence between the
815 * xsk_get_map_list_entry() and xsk_map_try_sock_delete()
816 * calls. Then we ask the map to remove the socket, which
817 * tries to remove the socket from the map. Note that there
818 * might be updates to the map between
819 * xsk_get_map_list_entry() and xsk_map_try_sock_delete().
820 */
821 struct xdp_sock __rcu **map_entry = NULL;
822 struct xsk_map *map;
823
824 while ((map = xsk_get_map_list_entry(xs, &map_entry))) {
825 xsk_map_try_sock_delete(map, xs, map_entry);
826 bpf_map_put(&map->map);
827 }
828 }
829
830 static int xsk_release(struct socket *sock)
831 {
832 struct sock *sk = sock->sk;
833 struct xdp_sock *xs = xdp_sk(sk);
834 struct net *net;
835
836 if (!sk)
837 return 0;
838
839 net = sock_net(sk);
840
841 mutex_lock(&net->xdp.lock);
842 sk_del_node_init_rcu(sk);
843 mutex_unlock(&net->xdp.lock);
844
845 local_bh_disable();
846 sock_prot_inuse_add(net, sk->sk_prot, -1);
847 local_bh_enable();
848
849 xsk_delete_from_maps(xs);
850 mutex_lock(&xs->mutex);
851 xsk_unbind_dev(xs);
852 mutex_unlock(&xs->mutex);
853
854 xskq_destroy(xs->rx);
855 xskq_destroy(xs->tx);
856 xskq_destroy(xs->fq_tmp);
857 xskq_destroy(xs->cq_tmp);
858
859 sock_orphan(sk);
860 sock->sk = NULL;
861
862 sk_refcnt_debug_release(sk);
863 sock_put(sk);
864
865 return 0;
866 }
867
868 static struct socket *xsk_lookup_xsk_from_fd(int fd)
869 {
870 struct socket *sock;
871 int err;
872
873 sock = sockfd_lookup(fd, &err);
874 if (!sock)
875 return ERR_PTR(-ENOTSOCK);
876
877 if (sock->sk->sk_family != PF_XDP) {
878 sockfd_put(sock);
879 return ERR_PTR(-ENOPROTOOPT);
880 }
881
882 return sock;
883 }
884
885 static bool xsk_validate_queues(struct xdp_sock *xs)
886 {
887 return xs->fq_tmp && xs->cq_tmp;
888 }
889
890 static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
891 {
892 struct sockaddr_xdp *sxdp = (struct sockaddr_xdp *)addr;
893 struct sock *sk = sock->sk;
894 struct xdp_sock *xs = xdp_sk(sk);
895 struct net_device *dev;
896 u32 flags, qid;
897 int err = 0;
898
899 if (addr_len < sizeof(struct sockaddr_xdp))
900 return -EINVAL;
901 if (sxdp->sxdp_family != AF_XDP)
902 return -EINVAL;
903
904 flags = sxdp->sxdp_flags;
905 if (flags & ~(XDP_SHARED_UMEM | XDP_COPY | XDP_ZEROCOPY |
906 XDP_USE_NEED_WAKEUP))
907 return -EINVAL;
908
909 rtnl_lock();
910 mutex_lock(&xs->mutex);
911 if (xs->state != XSK_READY) {
912 err = -EBUSY;
913 goto out_release;
914 }
915
916 dev = dev_get_by_index(sock_net(sk), sxdp->sxdp_ifindex);
917 if (!dev) {
918 err = -ENODEV;
919 goto out_release;
920 }
921
922 if (!xs->rx && !xs->tx) {
923 err = -EINVAL;
924 goto out_unlock;
925 }
926
927 qid = sxdp->sxdp_queue_id;
928
929 if (flags & XDP_SHARED_UMEM) {
930 struct xdp_sock *umem_xs;
931 struct socket *sock;
932
933 if ((flags & XDP_COPY) || (flags & XDP_ZEROCOPY) ||
934 (flags & XDP_USE_NEED_WAKEUP)) {
935 /* Cannot specify flags for shared sockets. */
936 err = -EINVAL;
937 goto out_unlock;
938 }
939
940 if (xs->umem) {
941 /* We have already our own. */
942 err = -EINVAL;
943 goto out_unlock;
944 }
945
946 sock = xsk_lookup_xsk_from_fd(sxdp->sxdp_shared_umem_fd);
947 if (IS_ERR(sock)) {
948 err = PTR_ERR(sock);
949 goto out_unlock;
950 }
951
952 umem_xs = xdp_sk(sock->sk);
953 if (!xsk_is_bound(umem_xs)) {
954 err = -EBADF;
955 sockfd_put(sock);
956 goto out_unlock;
957 }
958
959 if (umem_xs->queue_id != qid || umem_xs->dev != dev) {
960 /* Share the umem with another socket on another qid
961 * and/or device.
962 */
963 xs->pool = xp_create_and_assign_umem(xs,
964 umem_xs->umem);
965 if (!xs->pool) {
966 err = -ENOMEM;
967 sockfd_put(sock);
968 goto out_unlock;
969 }
970
971 err = xp_assign_dev_shared(xs->pool, umem_xs, dev,
972 qid);
973 if (err) {
974 xp_destroy(xs->pool);
975 xs->pool = NULL;
976 sockfd_put(sock);
977 goto out_unlock;
978 }
979 } else {
980 /* Share the buffer pool with the other socket. */
981 if (xs->fq_tmp || xs->cq_tmp) {
982 /* Do not allow setting your own fq or cq. */
983 err = -EINVAL;
984 sockfd_put(sock);
985 goto out_unlock;
986 }
987
988 xp_get_pool(umem_xs->pool);
989 xs->pool = umem_xs->pool;
990
991 /* If underlying shared umem was created without Tx
992 * ring, allocate Tx descs array that Tx batching API
993 * utilizes
994 */
995 if (xs->tx && !xs->pool->tx_descs) {
996 err = xp_alloc_tx_descs(xs->pool, xs);
997 if (err) {
998 xp_put_pool(xs->pool);
999 sockfd_put(sock);
1000 goto out_unlock;
1001 }
1002 }
1003 }
1004
1005 xdp_get_umem(umem_xs->umem);
1006 WRITE_ONCE(xs->umem, umem_xs->umem);
1007 sockfd_put(sock);
1008 } else if (!xs->umem || !xsk_validate_queues(xs)) {
1009 err = -EINVAL;
1010 goto out_unlock;
1011 } else {
1012 /* This xsk has its own umem. */
1013 xs->pool = xp_create_and_assign_umem(xs, xs->umem);
1014 if (!xs->pool) {
1015 err = -ENOMEM;
1016 goto out_unlock;
1017 }
1018
1019 err = xp_assign_dev(xs->pool, dev, qid, flags);
1020 if (err) {
1021 xp_destroy(xs->pool);
1022 xs->pool = NULL;
1023 goto out_unlock;
1024 }
1025 }
1026
1027 /* FQ and CQ are now owned by the buffer pool and cleaned up with it. */
1028 xs->fq_tmp = NULL;
1029 xs->cq_tmp = NULL;
1030
1031 xs->dev = dev;
1032 xs->zc = xs->umem->zc;
1033 xs->queue_id = qid;
1034 xp_add_xsk(xs->pool, xs);
1035
1036 out_unlock:
1037 if (err) {
1038 dev_put(dev);
1039 } else {
1040 /* Matches smp_rmb() in bind() for shared umem
1041 * sockets, and xsk_is_bound().
1042 */
1043 smp_wmb();
1044 WRITE_ONCE(xs->state, XSK_BOUND);
1045 }
1046 out_release:
1047 mutex_unlock(&xs->mutex);
1048 rtnl_unlock();
1049 return err;
1050 }
1051
1052 struct xdp_umem_reg_v1 {
1053 __u64 addr; /* Start of packet data area */
1054 __u64 len; /* Length of packet data area */
1055 __u32 chunk_size;
1056 __u32 headroom;
1057 };
1058
1059 static int xsk_setsockopt(struct socket *sock, int level, int optname,
1060 sockptr_t optval, unsigned int optlen)
1061 {
1062 struct sock *sk = sock->sk;
1063 struct xdp_sock *xs = xdp_sk(sk);
1064 int err;
1065
1066 if (level != SOL_XDP)
1067 return -ENOPROTOOPT;
1068
1069 switch (optname) {
1070 case XDP_RX_RING:
1071 case XDP_TX_RING:
1072 {
1073 struct xsk_queue **q;
1074 int entries;
1075
1076 if (optlen < sizeof(entries))
1077 return -EINVAL;
1078 if (copy_from_sockptr(&entries, optval, sizeof(entries)))
1079 return -EFAULT;
1080
1081 mutex_lock(&xs->mutex);
1082 if (xs->state != XSK_READY) {
1083 mutex_unlock(&xs->mutex);
1084 return -EBUSY;
1085 }
1086 q = (optname == XDP_TX_RING) ? &xs->tx : &xs->rx;
1087 err = xsk_init_queue(entries, q, false);
1088 if (!err && optname == XDP_TX_RING)
1089 /* Tx needs to be explicitly woken up the first time */
1090 xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP;
1091 mutex_unlock(&xs->mutex);
1092 return err;
1093 }
1094 case XDP_UMEM_REG:
1095 {
1096 size_t mr_size = sizeof(struct xdp_umem_reg);
1097 struct xdp_umem_reg mr = {};
1098 struct xdp_umem *umem;
1099
1100 if (optlen < sizeof(struct xdp_umem_reg_v1))
1101 return -EINVAL;
1102 else if (optlen < sizeof(mr))
1103 mr_size = sizeof(struct xdp_umem_reg_v1);
1104
1105 if (copy_from_sockptr(&mr, optval, mr_size))
1106 return -EFAULT;
1107
1108 mutex_lock(&xs->mutex);
1109 if (xs->state != XSK_READY || xs->umem) {
1110 mutex_unlock(&xs->mutex);
1111 return -EBUSY;
1112 }
1113
1114 umem = xdp_umem_create(&mr);
1115 if (IS_ERR(umem)) {
1116 mutex_unlock(&xs->mutex);
1117 return PTR_ERR(umem);
1118 }
1119
1120 /* Make sure umem is ready before it can be seen by others */
1121 smp_wmb();
1122 WRITE_ONCE(xs->umem, umem);
1123 mutex_unlock(&xs->mutex);
1124 return 0;
1125 }
1126 case XDP_UMEM_FILL_RING:
1127 case XDP_UMEM_COMPLETION_RING:
1128 {
1129 struct xsk_queue **q;
1130 int entries;
1131
1132 if (copy_from_sockptr(&entries, optval, sizeof(entries)))
1133 return -EFAULT;
1134
1135 mutex_lock(&xs->mutex);
1136 if (xs->state != XSK_READY) {
1137 mutex_unlock(&xs->mutex);
1138 return -EBUSY;
1139 }
1140
1141 q = (optname == XDP_UMEM_FILL_RING) ? &xs->fq_tmp :
1142 &xs->cq_tmp;
1143 err = xsk_init_queue(entries, q, true);
1144 mutex_unlock(&xs->mutex);
1145 return err;
1146 }
1147 default:
1148 break;
1149 }
1150
1151 return -ENOPROTOOPT;
1152 }
1153
1154 static void xsk_enter_rxtx_offsets(struct xdp_ring_offset_v1 *ring)
1155 {
1156 ring->producer = offsetof(struct xdp_rxtx_ring, ptrs.producer);
1157 ring->consumer = offsetof(struct xdp_rxtx_ring, ptrs.consumer);
1158 ring->desc = offsetof(struct xdp_rxtx_ring, desc);
1159 }
1160
1161 static void xsk_enter_umem_offsets(struct xdp_ring_offset_v1 *ring)
1162 {
1163 ring->producer = offsetof(struct xdp_umem_ring, ptrs.producer);
1164 ring->consumer = offsetof(struct xdp_umem_ring, ptrs.consumer);
1165 ring->desc = offsetof(struct xdp_umem_ring, desc);
1166 }
1167
1168 struct xdp_statistics_v1 {
1169 __u64 rx_dropped;
1170 __u64 rx_invalid_descs;
1171 __u64 tx_invalid_descs;
1172 };
1173
1174 static int xsk_getsockopt(struct socket *sock, int level, int optname,
1175 char __user *optval, int __user *optlen)
1176 {
1177 struct sock *sk = sock->sk;
1178 struct xdp_sock *xs = xdp_sk(sk);
1179 int len;
1180
1181 if (level != SOL_XDP)
1182 return -ENOPROTOOPT;
1183
1184 if (get_user(len, optlen))
1185 return -EFAULT;
1186 if (len < 0)
1187 return -EINVAL;
1188
1189 switch (optname) {
1190 case XDP_STATISTICS:
1191 {
1192 struct xdp_statistics stats = {};
1193 bool extra_stats = true;
1194 size_t stats_size;
1195
1196 if (len < sizeof(struct xdp_statistics_v1)) {
1197 return -EINVAL;
1198 } else if (len < sizeof(stats)) {
1199 extra_stats = false;
1200 stats_size = sizeof(struct xdp_statistics_v1);
1201 } else {
1202 stats_size = sizeof(stats);
1203 }
1204
1205 mutex_lock(&xs->mutex);
1206 stats.rx_dropped = xs->rx_dropped;
1207 if (extra_stats) {
1208 stats.rx_ring_full = xs->rx_queue_full;
1209 stats.rx_fill_ring_empty_descs =
1210 xs->pool ? xskq_nb_queue_empty_descs(xs->pool->fq) : 0;
1211 stats.tx_ring_empty_descs = xskq_nb_queue_empty_descs(xs->tx);
1212 } else {
1213 stats.rx_dropped += xs->rx_queue_full;
1214 }
1215 stats.rx_invalid_descs = xskq_nb_invalid_descs(xs->rx);
1216 stats.tx_invalid_descs = xskq_nb_invalid_descs(xs->tx);
1217 mutex_unlock(&xs->mutex);
1218
1219 if (copy_to_user(optval, &stats, stats_size))
1220 return -EFAULT;
1221 if (put_user(stats_size, optlen))
1222 return -EFAULT;
1223
1224 return 0;
1225 }
1226 case XDP_MMAP_OFFSETS:
1227 {
1228 struct xdp_mmap_offsets off;
1229 struct xdp_mmap_offsets_v1 off_v1;
1230 bool flags_supported = true;
1231 void *to_copy;
1232
1233 if (len < sizeof(off_v1))
1234 return -EINVAL;
1235 else if (len < sizeof(off))
1236 flags_supported = false;
1237
1238 if (flags_supported) {
1239 /* xdp_ring_offset is identical to xdp_ring_offset_v1
1240 * except for the flags field added to the end.
1241 */
1242 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *)
1243 &off.rx);
1244 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *)
1245 &off.tx);
1246 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *)
1247 &off.fr);
1248 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *)
1249 &off.cr);
1250 off.rx.flags = offsetof(struct xdp_rxtx_ring,
1251 ptrs.flags);
1252 off.tx.flags = offsetof(struct xdp_rxtx_ring,
1253 ptrs.flags);
1254 off.fr.flags = offsetof(struct xdp_umem_ring,
1255 ptrs.flags);
1256 off.cr.flags = offsetof(struct xdp_umem_ring,
1257 ptrs.flags);
1258
1259 len = sizeof(off);
1260 to_copy = &off;
1261 } else {
1262 xsk_enter_rxtx_offsets(&off_v1.rx);
1263 xsk_enter_rxtx_offsets(&off_v1.tx);
1264 xsk_enter_umem_offsets(&off_v1.fr);
1265 xsk_enter_umem_offsets(&off_v1.cr);
1266
1267 len = sizeof(off_v1);
1268 to_copy = &off_v1;
1269 }
1270
1271 if (copy_to_user(optval, to_copy, len))
1272 return -EFAULT;
1273 if (put_user(len, optlen))
1274 return -EFAULT;
1275
1276 return 0;
1277 }
1278 case XDP_OPTIONS:
1279 {
1280 struct xdp_options opts = {};
1281
1282 if (len < sizeof(opts))
1283 return -EINVAL;
1284
1285 mutex_lock(&xs->mutex);
1286 if (xs->zc)
1287 opts.flags |= XDP_OPTIONS_ZEROCOPY;
1288 mutex_unlock(&xs->mutex);
1289
1290 len = sizeof(opts);
1291 if (copy_to_user(optval, &opts, len))
1292 return -EFAULT;
1293 if (put_user(len, optlen))
1294 return -EFAULT;
1295
1296 return 0;
1297 }
1298 default:
1299 break;
1300 }
1301
1302 return -EOPNOTSUPP;
1303 }
1304
1305 static int xsk_mmap(struct file *file, struct socket *sock,
1306 struct vm_area_struct *vma)
1307 {
1308 loff_t offset = (loff_t)vma->vm_pgoff << PAGE_SHIFT;
1309 unsigned long size = vma->vm_end - vma->vm_start;
1310 struct xdp_sock *xs = xdp_sk(sock->sk);
1311 struct xsk_queue *q = NULL;
1312 unsigned long pfn;
1313 struct page *qpg;
1314
1315 if (READ_ONCE(xs->state) != XSK_READY)
1316 return -EBUSY;
1317
1318 if (offset == XDP_PGOFF_RX_RING) {
1319 q = READ_ONCE(xs->rx);
1320 } else if (offset == XDP_PGOFF_TX_RING) {
1321 q = READ_ONCE(xs->tx);
1322 } else {
1323 /* Matches the smp_wmb() in XDP_UMEM_REG */
1324 smp_rmb();
1325 if (offset == XDP_UMEM_PGOFF_FILL_RING)
1326 q = READ_ONCE(xs->fq_tmp);
1327 else if (offset == XDP_UMEM_PGOFF_COMPLETION_RING)
1328 q = READ_ONCE(xs->cq_tmp);
1329 }
1330
1331 if (!q)
1332 return -EINVAL;
1333
1334 /* Matches the smp_wmb() in xsk_init_queue */
1335 smp_rmb();
1336 qpg = virt_to_head_page(q->ring);
1337 if (size > page_size(qpg))
1338 return -EINVAL;
1339
1340 pfn = virt_to_phys(q->ring) >> PAGE_SHIFT;
1341 return remap_pfn_range(vma, vma->vm_start, pfn,
1342 size, vma->vm_page_prot);
1343 }
1344
1345 static int xsk_notifier(struct notifier_block *this,
1346 unsigned long msg, void *ptr)
1347 {
1348 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1349 struct net *net = dev_net(dev);
1350 struct sock *sk;
1351
1352 switch (msg) {
1353 case NETDEV_UNREGISTER:
1354 mutex_lock(&net->xdp.lock);
1355 sk_for_each(sk, &net->xdp.list) {
1356 struct xdp_sock *xs = xdp_sk(sk);
1357
1358 mutex_lock(&xs->mutex);
1359 if (xs->dev == dev) {
1360 sk->sk_err = ENETDOWN;
1361 if (!sock_flag(sk, SOCK_DEAD))
1362 sk_error_report(sk);
1363
1364 xsk_unbind_dev(xs);
1365
1366 /* Clear device references. */
1367 xp_clear_dev(xs->pool);
1368 }
1369 mutex_unlock(&xs->mutex);
1370 }
1371 mutex_unlock(&net->xdp.lock);
1372 break;
1373 }
1374 return NOTIFY_DONE;
1375 }
1376
1377 static struct proto xsk_proto = {
1378 .name = "XDP",
1379 .owner = THIS_MODULE,
1380 .obj_size = sizeof(struct xdp_sock),
1381 };
1382
1383 static const struct proto_ops xsk_proto_ops = {
1384 .family = PF_XDP,
1385 .owner = THIS_MODULE,
1386 .release = xsk_release,
1387 .bind = xsk_bind,
1388 .connect = sock_no_connect,
1389 .socketpair = sock_no_socketpair,
1390 .accept = sock_no_accept,
1391 .getname = sock_no_getname,
1392 .poll = xsk_poll,
1393 .ioctl = sock_no_ioctl,
1394 .listen = sock_no_listen,
1395 .shutdown = sock_no_shutdown,
1396 .setsockopt = xsk_setsockopt,
1397 .getsockopt = xsk_getsockopt,
1398 .sendmsg = xsk_sendmsg,
1399 .recvmsg = xsk_recvmsg,
1400 .mmap = xsk_mmap,
1401 .sendpage = sock_no_sendpage,
1402 };
1403
1404 static void xsk_destruct(struct sock *sk)
1405 {
1406 struct xdp_sock *xs = xdp_sk(sk);
1407
1408 if (!sock_flag(sk, SOCK_DEAD))
1409 return;
1410
1411 if (!xp_put_pool(xs->pool))
1412 xdp_put_umem(xs->umem, !xs->pool);
1413
1414 sk_refcnt_debug_dec(sk);
1415 }
1416
1417 static int xsk_create(struct net *net, struct socket *sock, int protocol,
1418 int kern)
1419 {
1420 struct xdp_sock *xs;
1421 struct sock *sk;
1422
1423 if (!ns_capable(net->user_ns, CAP_NET_RAW))
1424 return -EPERM;
1425 if (sock->type != SOCK_RAW)
1426 return -ESOCKTNOSUPPORT;
1427
1428 if (protocol)
1429 return -EPROTONOSUPPORT;
1430
1431 sock->state = SS_UNCONNECTED;
1432
1433 sk = sk_alloc(net, PF_XDP, GFP_KERNEL, &xsk_proto, kern);
1434 if (!sk)
1435 return -ENOBUFS;
1436
1437 sock->ops = &xsk_proto_ops;
1438
1439 sock_init_data(sock, sk);
1440
1441 sk->sk_family = PF_XDP;
1442
1443 sk->sk_destruct = xsk_destruct;
1444 sk_refcnt_debug_inc(sk);
1445
1446 sock_set_flag(sk, SOCK_RCU_FREE);
1447
1448 xs = xdp_sk(sk);
1449 xs->state = XSK_READY;
1450 mutex_init(&xs->mutex);
1451 spin_lock_init(&xs->rx_lock);
1452
1453 INIT_LIST_HEAD(&xs->map_list);
1454 spin_lock_init(&xs->map_list_lock);
1455
1456 mutex_lock(&net->xdp.lock);
1457 sk_add_node_rcu(sk, &net->xdp.list);
1458 mutex_unlock(&net->xdp.lock);
1459
1460 local_bh_disable();
1461 sock_prot_inuse_add(net, &xsk_proto, 1);
1462 local_bh_enable();
1463
1464 return 0;
1465 }
1466
1467 static const struct net_proto_family xsk_family_ops = {
1468 .family = PF_XDP,
1469 .create = xsk_create,
1470 .owner = THIS_MODULE,
1471 };
1472
1473 static struct notifier_block xsk_netdev_notifier = {
1474 .notifier_call = xsk_notifier,
1475 };
1476
1477 static int __net_init xsk_net_init(struct net *net)
1478 {
1479 mutex_init(&net->xdp.lock);
1480 INIT_HLIST_HEAD(&net->xdp.list);
1481 return 0;
1482 }
1483
1484 static void __net_exit xsk_net_exit(struct net *net)
1485 {
1486 WARN_ON_ONCE(!hlist_empty(&net->xdp.list));
1487 }
1488
1489 static struct pernet_operations xsk_net_ops = {
1490 .init = xsk_net_init,
1491 .exit = xsk_net_exit,
1492 };
1493
1494 static int __init xsk_init(void)
1495 {
1496 int err, cpu;
1497
1498 err = proto_register(&xsk_proto, 0 /* no slab */);
1499 if (err)
1500 goto out;
1501
1502 err = sock_register(&xsk_family_ops);
1503 if (err)
1504 goto out_proto;
1505
1506 err = register_pernet_subsys(&xsk_net_ops);
1507 if (err)
1508 goto out_sk;
1509
1510 err = register_netdevice_notifier(&xsk_netdev_notifier);
1511 if (err)
1512 goto out_pernet;
1513
1514 for_each_possible_cpu(cpu)
1515 INIT_LIST_HEAD(&per_cpu(xskmap_flush_list, cpu));
1516 return 0;
1517
1518 out_pernet:
1519 unregister_pernet_subsys(&xsk_net_ops);
1520 out_sk:
1521 sock_unregister(PF_XDP);
1522 out_proto:
1523 proto_unregister(&xsk_proto);
1524 out:
1525 return err;
1526 }
1527
1528 fs_initcall(xsk_init);
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