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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 <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
137static int __xsk_rcv_zc(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len)
138{
139 struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp);
140 u64 addr;
141 int err;
142
143 addr = xp_get_handle(xskb);
144 err = xskq_prod_reserve_desc(xs->rx, addr, len);
145 if (err) {
146 xs->rx_queue_full++;
147 return err;
148 }
149
150 xp_release(xskb);
151 return 0;
152}
153
154static void xsk_copy_xdp(struct xdp_buff *to, struct xdp_buff *from, u32 len)
155{
156 void *from_buf, *to_buf;
157 u32 metalen;
158
159 if (unlikely(xdp_data_meta_unsupported(from))) {
160 from_buf = from->data;
161 to_buf = to->data;
162 metalen = 0;
163 } else {
164 from_buf = from->data_meta;
165 metalen = from->data - from->data_meta;
166 to_buf = to->data - metalen;
167 }
168
169 memcpy(to_buf, from_buf, len + metalen);
170}
171
172static int __xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
173{
174 struct xdp_buff *xsk_xdp;
175 int err;
176 u32 len;
177
178 len = xdp->data_end - xdp->data;
179 if (len > xsk_pool_get_rx_frame_size(xs->pool)) {
180 xs->rx_dropped++;
181 return -ENOSPC;
182 }
183
184 xsk_xdp = xsk_buff_alloc(xs->pool);
185 if (!xsk_xdp) {
186 xs->rx_dropped++;
187 return -ENOMEM;
188 }
189
190 xsk_copy_xdp(xsk_xdp, xdp, len);
191 err = __xsk_rcv_zc(xs, xsk_xdp, len);
192 if (err) {
193 xsk_buff_free(xsk_xdp);
194 return err;
195 }
196 return 0;
197}
198
199static bool xsk_tx_writeable(struct xdp_sock *xs)
200{
201 if (xskq_cons_present_entries(xs->tx) > xs->tx->nentries / 2)
202 return false;
203
204 return true;
205}
206
207static bool xsk_is_bound(struct xdp_sock *xs)
208{
209 if (READ_ONCE(xs->state) == XSK_BOUND) {
210 /* Matches smp_wmb() in bind(). */
211 smp_rmb();
212 return true;
213 }
214 return false;
215}
216
217static int xsk_rcv_check(struct xdp_sock *xs, struct xdp_buff *xdp)
218{
219 if (!xsk_is_bound(xs))
220 return -ENXIO;
221
222 if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index)
223 return -EINVAL;
224
225 sk_mark_napi_id_once_xdp(&xs->sk, xdp);
226 return 0;
227}
228
229static void xsk_flush(struct xdp_sock *xs)
230{
231 xskq_prod_submit(xs->rx);
232 __xskq_cons_release(xs->pool->fq);
233 sock_def_readable(&xs->sk);
234}
235
236int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
237{
238 int err;
239
240 spin_lock_bh(&xs->rx_lock);
241 err = xsk_rcv_check(xs, xdp);
242 if (!err) {
243 err = __xsk_rcv(xs, xdp);
244 xsk_flush(xs);
245 }
246 spin_unlock_bh(&xs->rx_lock);
247 return err;
248}
249
250static int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
251{
252 int err;
253 u32 len;
254
255 err = xsk_rcv_check(xs, xdp);
256 if (err)
257 return err;
258
259 if (xdp->rxq->mem.type == MEM_TYPE_XSK_BUFF_POOL) {
260 len = xdp->data_end - xdp->data;
261 return __xsk_rcv_zc(xs, xdp, len);
262 }
263
264 err = __xsk_rcv(xs, xdp);
265 if (!err)
266 xdp_return_buff(xdp);
267 return err;
268}
269
270int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp)
271{
272 struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list);
273 int err;
274
275 err = xsk_rcv(xs, xdp);
276 if (err)
277 return err;
278
279 if (!xs->flush_node.prev)
280 list_add(&xs->flush_node, flush_list);
281
282 return 0;
283}
284
285void __xsk_map_flush(void)
286{
287 struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list);
288 struct xdp_sock *xs, *tmp;
289
290 list_for_each_entry_safe(xs, tmp, flush_list, flush_node) {
291 xsk_flush(xs);
292 __list_del_clearprev(&xs->flush_node);
293 }
294}
295
296void xsk_tx_completed(struct xsk_buff_pool *pool, u32 nb_entries)
297{
298 xskq_prod_submit_n(pool->cq, nb_entries);
299}
300EXPORT_SYMBOL(xsk_tx_completed);
301
302void xsk_tx_release(struct xsk_buff_pool *pool)
303{
304 struct xdp_sock *xs;
305
306 rcu_read_lock();
307 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) {
308 __xskq_cons_release(xs->tx);
309 if (xsk_tx_writeable(xs))
310 xs->sk.sk_write_space(&xs->sk);
311 }
312 rcu_read_unlock();
313}
314EXPORT_SYMBOL(xsk_tx_release);
315
316bool xsk_tx_peek_desc(struct xsk_buff_pool *pool, struct xdp_desc *desc)
317{
318 struct xdp_sock *xs;
319
320 rcu_read_lock();
321 list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) {
322 if (!xskq_cons_peek_desc(xs->tx, desc, pool)) {
323 xs->tx->queue_empty_descs++;
324 continue;
325 }
326
327 /* This is the backpressure mechanism for the Tx path.
328 * Reserve space in the completion queue and only proceed
329 * if there is space in it. This avoids having to implement
330 * any buffering in the Tx path.
331 */
332 if (xskq_prod_reserve_addr(pool->cq, desc->addr))
333 goto out;
334
335 xskq_cons_release(xs->tx);
336 rcu_read_unlock();
337 return true;
338 }
339
340out:
341 rcu_read_unlock();
342 return false;
343}
344EXPORT_SYMBOL(xsk_tx_peek_desc);
345
346static u32 xsk_tx_peek_release_fallback(struct xsk_buff_pool *pool, u32 max_entries)
347{
348 struct xdp_desc *descs = pool->tx_descs;
349 u32 nb_pkts = 0;
350
351 while (nb_pkts < max_entries && xsk_tx_peek_desc(pool, &descs[nb_pkts]))
352 nb_pkts++;
353
354 xsk_tx_release(pool);
355 return nb_pkts;
356}
357
358u32 xsk_tx_peek_release_desc_batch(struct xsk_buff_pool *pool, u32 nb_pkts)
359{
360 struct xdp_sock *xs;
361
362 rcu_read_lock();
363 if (!list_is_singular(&pool->xsk_tx_list)) {
364 /* Fallback to the non-batched version */
365 rcu_read_unlock();
366 return xsk_tx_peek_release_fallback(pool, nb_pkts);
367 }
368
369 xs = list_first_or_null_rcu(&pool->xsk_tx_list, struct xdp_sock, tx_list);
370 if (!xs) {
371 nb_pkts = 0;
372 goto out;
373 }
374
375 nb_pkts = xskq_cons_nb_entries(xs->tx, nb_pkts);
376
377 /* This is the backpressure mechanism for the Tx path. Try to
378 * reserve space in the completion queue for all packets, but
379 * if there are fewer slots available, just process that many
380 * packets. This avoids having to implement any buffering in
381 * the Tx path.
382 */
383 nb_pkts = xskq_prod_nb_free(pool->cq, nb_pkts);
384 if (!nb_pkts)
385 goto out;
386
387 nb_pkts = xskq_cons_read_desc_batch(xs->tx, pool, nb_pkts);
388 if (!nb_pkts) {
389 xs->tx->queue_empty_descs++;
390 goto out;
391 }
392
393 __xskq_cons_release(xs->tx);
394 xskq_prod_write_addr_batch(pool->cq, pool->tx_descs, nb_pkts);
395 xs->sk.sk_write_space(&xs->sk);
396
397out:
398 rcu_read_unlock();
399 return nb_pkts;
400}
401EXPORT_SYMBOL(xsk_tx_peek_release_desc_batch);
402
403static int xsk_wakeup(struct xdp_sock *xs, u8 flags)
404{
405 struct net_device *dev = xs->dev;
406
407 return dev->netdev_ops->ndo_xsk_wakeup(dev, xs->queue_id, flags);
408}
409
410static void xsk_destruct_skb(struct sk_buff *skb)
411{
412 u64 addr = (u64)(long)skb_shinfo(skb)->destructor_arg;
413 struct xdp_sock *xs = xdp_sk(skb->sk);
414 unsigned long flags;
415
416 spin_lock_irqsave(&xs->pool->cq_lock, flags);
417 xskq_prod_submit_addr(xs->pool->cq, addr);
418 spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
419
420 sock_wfree(skb);
421}
422
423static struct sk_buff *xsk_build_skb_zerocopy(struct xdp_sock *xs,
424 struct xdp_desc *desc)
425{
426 struct xsk_buff_pool *pool = xs->pool;
427 u32 hr, len, ts, offset, copy, copied;
428 struct sk_buff *skb;
429 struct page *page;
430 void *buffer;
431 int err, i;
432 u64 addr;
433
434 hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(xs->dev->needed_headroom));
435
436 skb = sock_alloc_send_skb(&xs->sk, hr, 1, &err);
437 if (unlikely(!skb))
438 return ERR_PTR(err);
439
440 skb_reserve(skb, hr);
441
442 addr = desc->addr;
443 len = desc->len;
444 ts = pool->unaligned ? len : pool->chunk_size;
445
446 buffer = xsk_buff_raw_get_data(pool, addr);
447 offset = offset_in_page(buffer);
448 addr = buffer - pool->addrs;
449
450 for (copied = 0, i = 0; copied < len; i++) {
451 page = pool->umem->pgs[addr >> PAGE_SHIFT];
452 get_page(page);
453
454 copy = min_t(u32, PAGE_SIZE - offset, len - copied);
455 skb_fill_page_desc(skb, i, page, offset, copy);
456
457 copied += copy;
458 addr += copy;
459 offset = 0;
460 }
461
462 skb->len += len;
463 skb->data_len += len;
464 skb->truesize += ts;
465
466 refcount_add(ts, &xs->sk.sk_wmem_alloc);
467
468 return skb;
469}
470
471static struct sk_buff *xsk_build_skb(struct xdp_sock *xs,
472 struct xdp_desc *desc)
473{
474 struct net_device *dev = xs->dev;
475 struct sk_buff *skb;
476
477 if (dev->priv_flags & IFF_TX_SKB_NO_LINEAR) {
478 skb = xsk_build_skb_zerocopy(xs, desc);
479 if (IS_ERR(skb))
480 return skb;
481 } else {
482 u32 hr, tr, len;
483 void *buffer;
484 int err;
485
486 hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(dev->needed_headroom));
487 tr = dev->needed_tailroom;
488 len = desc->len;
489
490 skb = sock_alloc_send_skb(&xs->sk, hr + len + tr, 1, &err);
491 if (unlikely(!skb))
492 return ERR_PTR(err);
493
494 skb_reserve(skb, hr);
495 skb_put(skb, len);
496
497 buffer = xsk_buff_raw_get_data(xs->pool, desc->addr);
498 err = skb_store_bits(skb, 0, buffer, len);
499 if (unlikely(err)) {
500 kfree_skb(skb);
501 return ERR_PTR(err);
502 }
503 }
504
505 skb->dev = dev;
506 skb->priority = xs->sk.sk_priority;
507 skb->mark = xs->sk.sk_mark;
508 skb_shinfo(skb)->destructor_arg = (void *)(long)desc->addr;
509 skb->destructor = xsk_destruct_skb;
510
511 return skb;
512}
513
514static int xsk_generic_xmit(struct sock *sk)
515{
516 struct xdp_sock *xs = xdp_sk(sk);
517 u32 max_batch = TX_BATCH_SIZE;
518 bool sent_frame = false;
519 struct xdp_desc desc;
520 struct sk_buff *skb;
521 unsigned long flags;
522 int err = 0;
523
524 mutex_lock(&xs->mutex);
525
526 /* Since we dropped the RCU read lock, the socket state might have changed. */
527 if (unlikely(!xsk_is_bound(xs))) {
528 err = -ENXIO;
529 goto out;
530 }
531
532 if (xs->queue_id >= xs->dev->real_num_tx_queues)
533 goto out;
534
535 while (xskq_cons_peek_desc(xs->tx, &desc, xs->pool)) {
536 if (max_batch-- == 0) {
537 err = -EAGAIN;
538 goto out;
539 }
540
541 /* This is the backpressure mechanism for the Tx path.
542 * Reserve space in the completion queue and only proceed
543 * if there is space in it. This avoids having to implement
544 * any buffering in the Tx path.
545 */
546 spin_lock_irqsave(&xs->pool->cq_lock, flags);
547 if (xskq_prod_reserve(xs->pool->cq)) {
548 spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
549 goto out;
550 }
551 spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
552
553 skb = xsk_build_skb(xs, &desc);
554 if (IS_ERR(skb)) {
555 err = PTR_ERR(skb);
556 spin_lock_irqsave(&xs->pool->cq_lock, flags);
557 xskq_prod_cancel(xs->pool->cq);
558 spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
559 goto out;
560 }
561
562 err = __dev_direct_xmit(skb, xs->queue_id);
563 if (err == NETDEV_TX_BUSY) {
564 /* Tell user-space to retry the send */
565 skb->destructor = sock_wfree;
566 spin_lock_irqsave(&xs->pool->cq_lock, flags);
567 xskq_prod_cancel(xs->pool->cq);
568 spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
569 /* Free skb without triggering the perf drop trace */
570 consume_skb(skb);
571 err = -EAGAIN;
572 goto out;
573 }
574
575 xskq_cons_release(xs->tx);
576 /* Ignore NET_XMIT_CN as packet might have been sent */
577 if (err == NET_XMIT_DROP) {
578 /* SKB completed but not sent */
579 err = -EBUSY;
580 goto out;
581 }
582
583 sent_frame = true;
584 }
585
586 xs->tx->queue_empty_descs++;
587
588out:
589 if (sent_frame)
590 if (xsk_tx_writeable(xs))
591 sk->sk_write_space(sk);
592
593 mutex_unlock(&xs->mutex);
594 return err;
595}
596
597static int xsk_xmit(struct sock *sk)
598{
599 struct xdp_sock *xs = xdp_sk(sk);
600 int ret;
601
602 if (unlikely(!(xs->dev->flags & IFF_UP)))
603 return -ENETDOWN;
604 if (unlikely(!xs->tx))
605 return -ENOBUFS;
606
607 if (xs->zc)
608 return xsk_wakeup(xs, XDP_WAKEUP_TX);
609
610 /* Drop the RCU lock since the SKB path might sleep. */
611 rcu_read_unlock();
612 ret = xsk_generic_xmit(sk);
613 /* Reaquire RCU lock before going into common code. */
614 rcu_read_lock();
615
616 return ret;
617}
618
619static bool xsk_no_wakeup(struct sock *sk)
620{
621#ifdef CONFIG_NET_RX_BUSY_POLL
622 /* Prefer busy-polling, skip the wakeup. */
623 return READ_ONCE(sk->sk_prefer_busy_poll) && READ_ONCE(sk->sk_ll_usec) &&
624 READ_ONCE(sk->sk_napi_id) >= MIN_NAPI_ID;
625#else
626 return false;
627#endif
628}
629
630static int __xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
631{
632 bool need_wait = !(m->msg_flags & MSG_DONTWAIT);
633 struct sock *sk = sock->sk;
634 struct xdp_sock *xs = xdp_sk(sk);
635 struct xsk_buff_pool *pool;
636
637 if (unlikely(!xsk_is_bound(xs)))
638 return -ENXIO;
639 if (unlikely(need_wait))
640 return -EOPNOTSUPP;
641
642 if (sk_can_busy_loop(sk)) {
643 if (xs->zc)
644 __sk_mark_napi_id_once(sk, xsk_pool_get_napi_id(xs->pool));
645 sk_busy_loop(sk, 1); /* only support non-blocking sockets */
646 }
647
648 if (xs->zc && xsk_no_wakeup(sk))
649 return 0;
650
651 pool = xs->pool;
652 if (pool->cached_need_wakeup & XDP_WAKEUP_TX)
653 return xsk_xmit(sk);
654 return 0;
655}
656
657static int xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
658{
659 int ret;
660
661 rcu_read_lock();
662 ret = __xsk_sendmsg(sock, m, total_len);
663 rcu_read_unlock();
664
665 return ret;
666}
667
668static int __xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int flags)
669{
670 bool need_wait = !(flags & MSG_DONTWAIT);
671 struct sock *sk = sock->sk;
672 struct xdp_sock *xs = xdp_sk(sk);
673
674 if (unlikely(!xsk_is_bound(xs)))
675 return -ENXIO;
676 if (unlikely(!(xs->dev->flags & IFF_UP)))
677 return -ENETDOWN;
678 if (unlikely(!xs->rx))
679 return -ENOBUFS;
680 if (unlikely(need_wait))
681 return -EOPNOTSUPP;
682
683 if (sk_can_busy_loop(sk))
684 sk_busy_loop(sk, 1); /* only support non-blocking sockets */
685
686 if (xsk_no_wakeup(sk))
687 return 0;
688
689 if (xs->pool->cached_need_wakeup & XDP_WAKEUP_RX && xs->zc)
690 return xsk_wakeup(xs, XDP_WAKEUP_RX);
691 return 0;
692}
693
694static int xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int flags)
695{
696 int ret;
697
698 rcu_read_lock();
699 ret = __xsk_recvmsg(sock, m, len, flags);
700 rcu_read_unlock();
701
702 return ret;
703}
704
705static __poll_t xsk_poll(struct file *file, struct socket *sock,
706 struct poll_table_struct *wait)
707{
708 __poll_t mask = 0;
709 struct sock *sk = sock->sk;
710 struct xdp_sock *xs = xdp_sk(sk);
711 struct xsk_buff_pool *pool;
712
713 sock_poll_wait(file, sock, wait);
714
715 rcu_read_lock();
716 if (unlikely(!xsk_is_bound(xs))) {
717 rcu_read_unlock();
718 return mask;
719 }
720
721 pool = xs->pool;
722
723 if (pool->cached_need_wakeup) {
724 if (xs->zc)
725 xsk_wakeup(xs, pool->cached_need_wakeup);
726 else
727 /* Poll needs to drive Tx also in copy mode */
728 xsk_xmit(sk);
729 }
730
731 if (xs->rx && !xskq_prod_is_empty(xs->rx))
732 mask |= EPOLLIN | EPOLLRDNORM;
733 if (xs->tx && xsk_tx_writeable(xs))
734 mask |= EPOLLOUT | EPOLLWRNORM;
735
736 rcu_read_unlock();
737 return mask;
738}
739
740static int xsk_init_queue(u32 entries, struct xsk_queue **queue,
741 bool umem_queue)
742{
743 struct xsk_queue *q;
744
745 if (entries == 0 || *queue || !is_power_of_2(entries))
746 return -EINVAL;
747
748 q = xskq_create(entries, umem_queue);
749 if (!q)
750 return -ENOMEM;
751
752 /* Make sure queue is ready before it can be seen by others */
753 smp_wmb();
754 WRITE_ONCE(*queue, q);
755 return 0;
756}
757
758static void xsk_unbind_dev(struct xdp_sock *xs)
759{
760 struct net_device *dev = xs->dev;
761
762 if (xs->state != XSK_BOUND)
763 return;
764 WRITE_ONCE(xs->state, XSK_UNBOUND);
765
766 /* Wait for driver to stop using the xdp socket. */
767 xp_del_xsk(xs->pool, xs);
768 synchronize_net();
769 dev_put(dev);
770}
771
772static struct xsk_map *xsk_get_map_list_entry(struct xdp_sock *xs,
773 struct xdp_sock __rcu ***map_entry)
774{
775 struct xsk_map *map = NULL;
776 struct xsk_map_node *node;
777
778 *map_entry = NULL;
779
780 spin_lock_bh(&xs->map_list_lock);
781 node = list_first_entry_or_null(&xs->map_list, struct xsk_map_node,
782 node);
783 if (node) {
784 bpf_map_inc(&node->map->map);
785 map = node->map;
786 *map_entry = node->map_entry;
787 }
788 spin_unlock_bh(&xs->map_list_lock);
789 return map;
790}
791
792static void xsk_delete_from_maps(struct xdp_sock *xs)
793{
794 /* This function removes the current XDP socket from all the
795 * maps it resides in. We need to take extra care here, due to
796 * the two locks involved. Each map has a lock synchronizing
797 * updates to the entries, and each socket has a lock that
798 * synchronizes access to the list of maps (map_list). For
799 * deadlock avoidance the locks need to be taken in the order
800 * "map lock"->"socket map list lock". We start off by
801 * accessing the socket map list, and take a reference to the
802 * map to guarantee existence between the
803 * xsk_get_map_list_entry() and xsk_map_try_sock_delete()
804 * calls. Then we ask the map to remove the socket, which
805 * tries to remove the socket from the map. Note that there
806 * might be updates to the map between
807 * xsk_get_map_list_entry() and xsk_map_try_sock_delete().
808 */
809 struct xdp_sock __rcu **map_entry = NULL;
810 struct xsk_map *map;
811
812 while ((map = xsk_get_map_list_entry(xs, &map_entry))) {
813 xsk_map_try_sock_delete(map, xs, map_entry);
814 bpf_map_put(&map->map);
815 }
816}
817
818static int xsk_release(struct socket *sock)
819{
820 struct sock *sk = sock->sk;
821 struct xdp_sock *xs = xdp_sk(sk);
822 struct net *net;
823
824 if (!sk)
825 return 0;
826
827 net = sock_net(sk);
828
829 mutex_lock(&net->xdp.lock);
830 sk_del_node_init_rcu(sk);
831 mutex_unlock(&net->xdp.lock);
832
833 sock_prot_inuse_add(net, sk->sk_prot, -1);
834
835 xsk_delete_from_maps(xs);
836 mutex_lock(&xs->mutex);
837 xsk_unbind_dev(xs);
838 mutex_unlock(&xs->mutex);
839
840 xskq_destroy(xs->rx);
841 xskq_destroy(xs->tx);
842 xskq_destroy(xs->fq_tmp);
843 xskq_destroy(xs->cq_tmp);
844
845 sock_orphan(sk);
846 sock->sk = NULL;
847
848 sk_refcnt_debug_release(sk);
849 sock_put(sk);
850
851 return 0;
852}
853
854static struct socket *xsk_lookup_xsk_from_fd(int fd)
855{
856 struct socket *sock;
857 int err;
858
859 sock = sockfd_lookup(fd, &err);
860 if (!sock)
861 return ERR_PTR(-ENOTSOCK);
862
863 if (sock->sk->sk_family != PF_XDP) {
864 sockfd_put(sock);
865 return ERR_PTR(-ENOPROTOOPT);
866 }
867
868 return sock;
869}
870
871static bool xsk_validate_queues(struct xdp_sock *xs)
872{
873 return xs->fq_tmp && xs->cq_tmp;
874}
875
876static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
877{
878 struct sockaddr_xdp *sxdp = (struct sockaddr_xdp *)addr;
879 struct sock *sk = sock->sk;
880 struct xdp_sock *xs = xdp_sk(sk);
881 struct net_device *dev;
882 u32 flags, qid;
883 int err = 0;
884
885 if (addr_len < sizeof(struct sockaddr_xdp))
886 return -EINVAL;
887 if (sxdp->sxdp_family != AF_XDP)
888 return -EINVAL;
889
890 flags = sxdp->sxdp_flags;
891 if (flags & ~(XDP_SHARED_UMEM | XDP_COPY | XDP_ZEROCOPY |
892 XDP_USE_NEED_WAKEUP))
893 return -EINVAL;
894
895 rtnl_lock();
896 mutex_lock(&xs->mutex);
897 if (xs->state != XSK_READY) {
898 err = -EBUSY;
899 goto out_release;
900 }
901
902 dev = dev_get_by_index(sock_net(sk), sxdp->sxdp_ifindex);
903 if (!dev) {
904 err = -ENODEV;
905 goto out_release;
906 }
907
908 if (!xs->rx && !xs->tx) {
909 err = -EINVAL;
910 goto out_unlock;
911 }
912
913 qid = sxdp->sxdp_queue_id;
914
915 if (flags & XDP_SHARED_UMEM) {
916 struct xdp_sock *umem_xs;
917 struct socket *sock;
918
919 if ((flags & XDP_COPY) || (flags & XDP_ZEROCOPY) ||
920 (flags & XDP_USE_NEED_WAKEUP)) {
921 /* Cannot specify flags for shared sockets. */
922 err = -EINVAL;
923 goto out_unlock;
924 }
925
926 if (xs->umem) {
927 /* We have already our own. */
928 err = -EINVAL;
929 goto out_unlock;
930 }
931
932 sock = xsk_lookup_xsk_from_fd(sxdp->sxdp_shared_umem_fd);
933 if (IS_ERR(sock)) {
934 err = PTR_ERR(sock);
935 goto out_unlock;
936 }
937
938 umem_xs = xdp_sk(sock->sk);
939 if (!xsk_is_bound(umem_xs)) {
940 err = -EBADF;
941 sockfd_put(sock);
942 goto out_unlock;
943 }
944
945 if (umem_xs->queue_id != qid || umem_xs->dev != dev) {
946 /* Share the umem with another socket on another qid
947 * and/or device.
948 */
949 xs->pool = xp_create_and_assign_umem(xs,
950 umem_xs->umem);
951 if (!xs->pool) {
952 err = -ENOMEM;
953 sockfd_put(sock);
954 goto out_unlock;
955 }
956
957 err = xp_assign_dev_shared(xs->pool, umem_xs, dev,
958 qid);
959 if (err) {
960 xp_destroy(xs->pool);
961 xs->pool = NULL;
962 sockfd_put(sock);
963 goto out_unlock;
964 }
965 } else {
966 /* Share the buffer pool with the other socket. */
967 if (xs->fq_tmp || xs->cq_tmp) {
968 /* Do not allow setting your own fq or cq. */
969 err = -EINVAL;
970 sockfd_put(sock);
971 goto out_unlock;
972 }
973
974 xp_get_pool(umem_xs->pool);
975 xs->pool = umem_xs->pool;
976
977 /* If underlying shared umem was created without Tx
978 * ring, allocate Tx descs array that Tx batching API
979 * utilizes
980 */
981 if (xs->tx && !xs->pool->tx_descs) {
982 err = xp_alloc_tx_descs(xs->pool, xs);
983 if (err) {
984 xp_put_pool(xs->pool);
985 sockfd_put(sock);
986 goto out_unlock;
987 }
988 }
989 }
990
991 xdp_get_umem(umem_xs->umem);
992 WRITE_ONCE(xs->umem, umem_xs->umem);
993 sockfd_put(sock);
994 } else if (!xs->umem || !xsk_validate_queues(xs)) {
995 err = -EINVAL;
996 goto out_unlock;
997 } else {
998 /* This xsk has its own umem. */
999 xs->pool = xp_create_and_assign_umem(xs, xs->umem);
1000 if (!xs->pool) {
1001 err = -ENOMEM;
1002 goto out_unlock;
1003 }
1004
1005 err = xp_assign_dev(xs->pool, dev, qid, flags);
1006 if (err) {
1007 xp_destroy(xs->pool);
1008 xs->pool = NULL;
1009 goto out_unlock;
1010 }
1011 }
1012
1013 /* FQ and CQ are now owned by the buffer pool and cleaned up with it. */
1014 xs->fq_tmp = NULL;
1015 xs->cq_tmp = NULL;
1016
1017 xs->dev = dev;
1018 xs->zc = xs->umem->zc;
1019 xs->queue_id = qid;
1020 xp_add_xsk(xs->pool, xs);
1021
1022out_unlock:
1023 if (err) {
1024 dev_put(dev);
1025 } else {
1026 /* Matches smp_rmb() in bind() for shared umem
1027 * sockets, and xsk_is_bound().
1028 */
1029 smp_wmb();
1030 WRITE_ONCE(xs->state, XSK_BOUND);
1031 }
1032out_release:
1033 mutex_unlock(&xs->mutex);
1034 rtnl_unlock();
1035 return err;
1036}
1037
1038struct xdp_umem_reg_v1 {
1039 __u64 addr; /* Start of packet data area */
1040 __u64 len; /* Length of packet data area */
1041 __u32 chunk_size;
1042 __u32 headroom;
1043};
1044
1045static int xsk_setsockopt(struct socket *sock, int level, int optname,
1046 sockptr_t optval, unsigned int optlen)
1047{
1048 struct sock *sk = sock->sk;
1049 struct xdp_sock *xs = xdp_sk(sk);
1050 int err;
1051
1052 if (level != SOL_XDP)
1053 return -ENOPROTOOPT;
1054
1055 switch (optname) {
1056 case XDP_RX_RING:
1057 case XDP_TX_RING:
1058 {
1059 struct xsk_queue **q;
1060 int entries;
1061
1062 if (optlen < sizeof(entries))
1063 return -EINVAL;
1064 if (copy_from_sockptr(&entries, optval, sizeof(entries)))
1065 return -EFAULT;
1066
1067 mutex_lock(&xs->mutex);
1068 if (xs->state != XSK_READY) {
1069 mutex_unlock(&xs->mutex);
1070 return -EBUSY;
1071 }
1072 q = (optname == XDP_TX_RING) ? &xs->tx : &xs->rx;
1073 err = xsk_init_queue(entries, q, false);
1074 if (!err && optname == XDP_TX_RING)
1075 /* Tx needs to be explicitly woken up the first time */
1076 xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP;
1077 mutex_unlock(&xs->mutex);
1078 return err;
1079 }
1080 case XDP_UMEM_REG:
1081 {
1082 size_t mr_size = sizeof(struct xdp_umem_reg);
1083 struct xdp_umem_reg mr = {};
1084 struct xdp_umem *umem;
1085
1086 if (optlen < sizeof(struct xdp_umem_reg_v1))
1087 return -EINVAL;
1088 else if (optlen < sizeof(mr))
1089 mr_size = sizeof(struct xdp_umem_reg_v1);
1090
1091 if (copy_from_sockptr(&mr, optval, mr_size))
1092 return -EFAULT;
1093
1094 mutex_lock(&xs->mutex);
1095 if (xs->state != XSK_READY || xs->umem) {
1096 mutex_unlock(&xs->mutex);
1097 return -EBUSY;
1098 }
1099
1100 umem = xdp_umem_create(&mr);
1101 if (IS_ERR(umem)) {
1102 mutex_unlock(&xs->mutex);
1103 return PTR_ERR(umem);
1104 }
1105
1106 /* Make sure umem is ready before it can be seen by others */
1107 smp_wmb();
1108 WRITE_ONCE(xs->umem, umem);
1109 mutex_unlock(&xs->mutex);
1110 return 0;
1111 }
1112 case XDP_UMEM_FILL_RING:
1113 case XDP_UMEM_COMPLETION_RING:
1114 {
1115 struct xsk_queue **q;
1116 int entries;
1117
1118 if (copy_from_sockptr(&entries, optval, sizeof(entries)))
1119 return -EFAULT;
1120
1121 mutex_lock(&xs->mutex);
1122 if (xs->state != XSK_READY) {
1123 mutex_unlock(&xs->mutex);
1124 return -EBUSY;
1125 }
1126
1127 q = (optname == XDP_UMEM_FILL_RING) ? &xs->fq_tmp :
1128 &xs->cq_tmp;
1129 err = xsk_init_queue(entries, q, true);
1130 mutex_unlock(&xs->mutex);
1131 return err;
1132 }
1133 default:
1134 break;
1135 }
1136
1137 return -ENOPROTOOPT;
1138}
1139
1140static void xsk_enter_rxtx_offsets(struct xdp_ring_offset_v1 *ring)
1141{
1142 ring->producer = offsetof(struct xdp_rxtx_ring, ptrs.producer);
1143 ring->consumer = offsetof(struct xdp_rxtx_ring, ptrs.consumer);
1144 ring->desc = offsetof(struct xdp_rxtx_ring, desc);
1145}
1146
1147static void xsk_enter_umem_offsets(struct xdp_ring_offset_v1 *ring)
1148{
1149 ring->producer = offsetof(struct xdp_umem_ring, ptrs.producer);
1150 ring->consumer = offsetof(struct xdp_umem_ring, ptrs.consumer);
1151 ring->desc = offsetof(struct xdp_umem_ring, desc);
1152}
1153
1154struct xdp_statistics_v1 {
1155 __u64 rx_dropped;
1156 __u64 rx_invalid_descs;
1157 __u64 tx_invalid_descs;
1158};
1159
1160static int xsk_getsockopt(struct socket *sock, int level, int optname,
1161 char __user *optval, int __user *optlen)
1162{
1163 struct sock *sk = sock->sk;
1164 struct xdp_sock *xs = xdp_sk(sk);
1165 int len;
1166
1167 if (level != SOL_XDP)
1168 return -ENOPROTOOPT;
1169
1170 if (get_user(len, optlen))
1171 return -EFAULT;
1172 if (len < 0)
1173 return -EINVAL;
1174
1175 switch (optname) {
1176 case XDP_STATISTICS:
1177 {
1178 struct xdp_statistics stats = {};
1179 bool extra_stats = true;
1180 size_t stats_size;
1181
1182 if (len < sizeof(struct xdp_statistics_v1)) {
1183 return -EINVAL;
1184 } else if (len < sizeof(stats)) {
1185 extra_stats = false;
1186 stats_size = sizeof(struct xdp_statistics_v1);
1187 } else {
1188 stats_size = sizeof(stats);
1189 }
1190
1191 mutex_lock(&xs->mutex);
1192 stats.rx_dropped = xs->rx_dropped;
1193 if (extra_stats) {
1194 stats.rx_ring_full = xs->rx_queue_full;
1195 stats.rx_fill_ring_empty_descs =
1196 xs->pool ? xskq_nb_queue_empty_descs(xs->pool->fq) : 0;
1197 stats.tx_ring_empty_descs = xskq_nb_queue_empty_descs(xs->tx);
1198 } else {
1199 stats.rx_dropped += xs->rx_queue_full;
1200 }
1201 stats.rx_invalid_descs = xskq_nb_invalid_descs(xs->rx);
1202 stats.tx_invalid_descs = xskq_nb_invalid_descs(xs->tx);
1203 mutex_unlock(&xs->mutex);
1204
1205 if (copy_to_user(optval, &stats, stats_size))
1206 return -EFAULT;
1207 if (put_user(stats_size, optlen))
1208 return -EFAULT;
1209
1210 return 0;
1211 }
1212 case XDP_MMAP_OFFSETS:
1213 {
1214 struct xdp_mmap_offsets off;
1215 struct xdp_mmap_offsets_v1 off_v1;
1216 bool flags_supported = true;
1217 void *to_copy;
1218
1219 if (len < sizeof(off_v1))
1220 return -EINVAL;
1221 else if (len < sizeof(off))
1222 flags_supported = false;
1223
1224 if (flags_supported) {
1225 /* xdp_ring_offset is identical to xdp_ring_offset_v1
1226 * except for the flags field added to the end.
1227 */
1228 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *)
1229 &off.rx);
1230 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *)
1231 &off.tx);
1232 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *)
1233 &off.fr);
1234 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *)
1235 &off.cr);
1236 off.rx.flags = offsetof(struct xdp_rxtx_ring,
1237 ptrs.flags);
1238 off.tx.flags = offsetof(struct xdp_rxtx_ring,
1239 ptrs.flags);
1240 off.fr.flags = offsetof(struct xdp_umem_ring,
1241 ptrs.flags);
1242 off.cr.flags = offsetof(struct xdp_umem_ring,
1243 ptrs.flags);
1244
1245 len = sizeof(off);
1246 to_copy = &off;
1247 } else {
1248 xsk_enter_rxtx_offsets(&off_v1.rx);
1249 xsk_enter_rxtx_offsets(&off_v1.tx);
1250 xsk_enter_umem_offsets(&off_v1.fr);
1251 xsk_enter_umem_offsets(&off_v1.cr);
1252
1253 len = sizeof(off_v1);
1254 to_copy = &off_v1;
1255 }
1256
1257 if (copy_to_user(optval, to_copy, len))
1258 return -EFAULT;
1259 if (put_user(len, optlen))
1260 return -EFAULT;
1261
1262 return 0;
1263 }
1264 case XDP_OPTIONS:
1265 {
1266 struct xdp_options opts = {};
1267
1268 if (len < sizeof(opts))
1269 return -EINVAL;
1270
1271 mutex_lock(&xs->mutex);
1272 if (xs->zc)
1273 opts.flags |= XDP_OPTIONS_ZEROCOPY;
1274 mutex_unlock(&xs->mutex);
1275
1276 len = sizeof(opts);
1277 if (copy_to_user(optval, &opts, len))
1278 return -EFAULT;
1279 if (put_user(len, optlen))
1280 return -EFAULT;
1281
1282 return 0;
1283 }
1284 default:
1285 break;
1286 }
1287
1288 return -EOPNOTSUPP;
1289}
1290
1291static int xsk_mmap(struct file *file, struct socket *sock,
1292 struct vm_area_struct *vma)
1293{
1294 loff_t offset = (loff_t)vma->vm_pgoff << PAGE_SHIFT;
1295 unsigned long size = vma->vm_end - vma->vm_start;
1296 struct xdp_sock *xs = xdp_sk(sock->sk);
1297 struct xsk_queue *q = NULL;
1298 unsigned long pfn;
1299 struct page *qpg;
1300
1301 if (READ_ONCE(xs->state) != XSK_READY)
1302 return -EBUSY;
1303
1304 if (offset == XDP_PGOFF_RX_RING) {
1305 q = READ_ONCE(xs->rx);
1306 } else if (offset == XDP_PGOFF_TX_RING) {
1307 q = READ_ONCE(xs->tx);
1308 } else {
1309 /* Matches the smp_wmb() in XDP_UMEM_REG */
1310 smp_rmb();
1311 if (offset == XDP_UMEM_PGOFF_FILL_RING)
1312 q = READ_ONCE(xs->fq_tmp);
1313 else if (offset == XDP_UMEM_PGOFF_COMPLETION_RING)
1314 q = READ_ONCE(xs->cq_tmp);
1315 }
1316
1317 if (!q)
1318 return -EINVAL;
1319
1320 /* Matches the smp_wmb() in xsk_init_queue */
1321 smp_rmb();
1322 qpg = virt_to_head_page(q->ring);
1323 if (size > page_size(qpg))
1324 return -EINVAL;
1325
1326 pfn = virt_to_phys(q->ring) >> PAGE_SHIFT;
1327 return remap_pfn_range(vma, vma->vm_start, pfn,
1328 size, vma->vm_page_prot);
1329}
1330
1331static int xsk_notifier(struct notifier_block *this,
1332 unsigned long msg, void *ptr)
1333{
1334 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1335 struct net *net = dev_net(dev);
1336 struct sock *sk;
1337
1338 switch (msg) {
1339 case NETDEV_UNREGISTER:
1340 mutex_lock(&net->xdp.lock);
1341 sk_for_each(sk, &net->xdp.list) {
1342 struct xdp_sock *xs = xdp_sk(sk);
1343
1344 mutex_lock(&xs->mutex);
1345 if (xs->dev == dev) {
1346 sk->sk_err = ENETDOWN;
1347 if (!sock_flag(sk, SOCK_DEAD))
1348 sk_error_report(sk);
1349
1350 xsk_unbind_dev(xs);
1351
1352 /* Clear device references. */
1353 xp_clear_dev(xs->pool);
1354 }
1355 mutex_unlock(&xs->mutex);
1356 }
1357 mutex_unlock(&net->xdp.lock);
1358 break;
1359 }
1360 return NOTIFY_DONE;
1361}
1362
1363static struct proto xsk_proto = {
1364 .name = "XDP",
1365 .owner = THIS_MODULE,
1366 .obj_size = sizeof(struct xdp_sock),
1367};
1368
1369static const struct proto_ops xsk_proto_ops = {
1370 .family = PF_XDP,
1371 .owner = THIS_MODULE,
1372 .release = xsk_release,
1373 .bind = xsk_bind,
1374 .connect = sock_no_connect,
1375 .socketpair = sock_no_socketpair,
1376 .accept = sock_no_accept,
1377 .getname = sock_no_getname,
1378 .poll = xsk_poll,
1379 .ioctl = sock_no_ioctl,
1380 .listen = sock_no_listen,
1381 .shutdown = sock_no_shutdown,
1382 .setsockopt = xsk_setsockopt,
1383 .getsockopt = xsk_getsockopt,
1384 .sendmsg = xsk_sendmsg,
1385 .recvmsg = xsk_recvmsg,
1386 .mmap = xsk_mmap,
1387 .sendpage = sock_no_sendpage,
1388};
1389
1390static void xsk_destruct(struct sock *sk)
1391{
1392 struct xdp_sock *xs = xdp_sk(sk);
1393
1394 if (!sock_flag(sk, SOCK_DEAD))
1395 return;
1396
1397 if (!xp_put_pool(xs->pool))
1398 xdp_put_umem(xs->umem, !xs->pool);
1399
1400 sk_refcnt_debug_dec(sk);
1401}
1402
1403static int xsk_create(struct net *net, struct socket *sock, int protocol,
1404 int kern)
1405{
1406 struct xdp_sock *xs;
1407 struct sock *sk;
1408
1409 if (!ns_capable(net->user_ns, CAP_NET_RAW))
1410 return -EPERM;
1411 if (sock->type != SOCK_RAW)
1412 return -ESOCKTNOSUPPORT;
1413
1414 if (protocol)
1415 return -EPROTONOSUPPORT;
1416
1417 sock->state = SS_UNCONNECTED;
1418
1419 sk = sk_alloc(net, PF_XDP, GFP_KERNEL, &xsk_proto, kern);
1420 if (!sk)
1421 return -ENOBUFS;
1422
1423 sock->ops = &xsk_proto_ops;
1424
1425 sock_init_data(sock, sk);
1426
1427 sk->sk_family = PF_XDP;
1428
1429 sk->sk_destruct = xsk_destruct;
1430 sk_refcnt_debug_inc(sk);
1431
1432 sock_set_flag(sk, SOCK_RCU_FREE);
1433
1434 xs = xdp_sk(sk);
1435 xs->state = XSK_READY;
1436 mutex_init(&xs->mutex);
1437 spin_lock_init(&xs->rx_lock);
1438
1439 INIT_LIST_HEAD(&xs->map_list);
1440 spin_lock_init(&xs->map_list_lock);
1441
1442 mutex_lock(&net->xdp.lock);
1443 sk_add_node_rcu(sk, &net->xdp.list);
1444 mutex_unlock(&net->xdp.lock);
1445
1446 sock_prot_inuse_add(net, &xsk_proto, 1);
1447
1448 return 0;
1449}
1450
1451static const struct net_proto_family xsk_family_ops = {
1452 .family = PF_XDP,
1453 .create = xsk_create,
1454 .owner = THIS_MODULE,
1455};
1456
1457static struct notifier_block xsk_netdev_notifier = {
1458 .notifier_call = xsk_notifier,
1459};
1460
1461static int __net_init xsk_net_init(struct net *net)
1462{
1463 mutex_init(&net->xdp.lock);
1464 INIT_HLIST_HEAD(&net->xdp.list);
1465 return 0;
1466}
1467
1468static void __net_exit xsk_net_exit(struct net *net)
1469{
1470 WARN_ON_ONCE(!hlist_empty(&net->xdp.list));
1471}
1472
1473static struct pernet_operations xsk_net_ops = {
1474 .init = xsk_net_init,
1475 .exit = xsk_net_exit,
1476};
1477
1478static int __init xsk_init(void)
1479{
1480 int err, cpu;
1481
1482 err = proto_register(&xsk_proto, 0 /* no slab */);
1483 if (err)
1484 goto out;
1485
1486 err = sock_register(&xsk_family_ops);
1487 if (err)
1488 goto out_proto;
1489
1490 err = register_pernet_subsys(&xsk_net_ops);
1491 if (err)
1492 goto out_sk;
1493
1494 err = register_netdevice_notifier(&xsk_netdev_notifier);
1495 if (err)
1496 goto out_pernet;
1497
1498 for_each_possible_cpu(cpu)
1499 INIT_LIST_HEAD(&per_cpu(xskmap_flush_list, cpu));
1500 return 0;
1501
1502out_pernet:
1503 unregister_pernet_subsys(&xsk_net_ops);
1504out_sk:
1505 sock_unregister(PF_XDP);
1506out_proto:
1507 proto_unregister(&xsk_proto);
1508out:
1509 return err;
1510}
1511
1512fs_initcall(xsk_init);