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WIP FPC-III support
[linux/fpc-iii.git] / net / xdp / xsk.c
blob8037b04a9edd11cad8845d95a06b2d442c29f8f5
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 16
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->real_num_rx_queues)
112 dev->_rx[queue_id].pool = NULL;
113 if (queue_id < dev->real_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, u32 len,
188 bool explicit_free)
189 {
190 struct xdp_buff *xsk_xdp;
191 int err;
192
193 if (len > xsk_pool_get_rx_frame_size(xs->pool)) {
194 xs->rx_dropped++;
195 return -ENOSPC;
196 }
197
198 xsk_xdp = xsk_buff_alloc(xs->pool);
199 if (!xsk_xdp) {
200 xs->rx_dropped++;
201 return -ENOSPC;
202 }
203
204 xsk_copy_xdp(xsk_xdp, xdp, len);
205 err = __xsk_rcv_zc(xs, xsk_xdp, len);
206 if (err) {
207 xsk_buff_free(xsk_xdp);
208 return err;
209 }
210 if (explicit_free)
211 xdp_return_buff(xdp);
212 return 0;
213 }
214
215 static bool xsk_tx_writeable(struct xdp_sock *xs)
216 {
217 if (xskq_cons_present_entries(xs->tx) > xs->tx->nentries / 2)
218 return false;
219
220 return true;
221 }
222
223 static bool xsk_is_bound(struct xdp_sock *xs)
224 {
225 if (READ_ONCE(xs->state) == XSK_BOUND) {
226 /* Matches smp_wmb() in bind(). */
227 smp_rmb();
228 return true;
229 }
230 return false;
231 }
232
233 static int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp,
234 bool explicit_free)
235 {
236 u32 len;
237
238 if (!xsk_is_bound(xs))
239 return -EINVAL;
240
241 if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index)
242 return -EINVAL;
243
244 sk_mark_napi_id_once_xdp(&xs->sk, xdp);
245 len = xdp->data_end - xdp->data;
246
247 return xdp->rxq->mem.type == MEM_TYPE_XSK_BUFF_POOL ?
248 __xsk_rcv_zc(xs, xdp, len) :
249 __xsk_rcv(xs, xdp, len, explicit_free);
250 }
251
252 static void xsk_flush(struct xdp_sock *xs)
253 {
254 xskq_prod_submit(xs->rx);
255 __xskq_cons_release(xs->pool->fq);
256 sock_def_readable(&xs->sk);
257 }
258
259 int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
260 {
261 int err;
262
263 spin_lock_bh(&xs->rx_lock);
264 err = xsk_rcv(xs, xdp, false);
265 xsk_flush(xs);
266 spin_unlock_bh(&xs->rx_lock);
267 return err;
268 }
269
270 int __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, true);
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
285 void __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
296 void xsk_tx_completed(struct xsk_buff_pool *pool, u32 nb_entries)
297 {
298 xskq_prod_submit_n(pool->cq, nb_entries);
299 }
300 EXPORT_SYMBOL(xsk_tx_completed);
301
302 void 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 }
314 EXPORT_SYMBOL(xsk_tx_release);
315
316 bool 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
340 out:
341 rcu_read_unlock();
342 return false;
343 }
344 EXPORT_SYMBOL(xsk_tx_peek_desc);
345
346 static u32 xsk_tx_peek_release_fallback(struct xsk_buff_pool *pool, struct xdp_desc *descs,
347 u32 max_entries)
348 {
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
358 u32 xsk_tx_peek_release_desc_batch(struct xsk_buff_pool *pool, struct xdp_desc *descs,
359 u32 max_entries)
360 {
361 struct xdp_sock *xs;
362 u32 nb_pkts;
363
364 rcu_read_lock();
365 if (!list_is_singular(&pool->xsk_tx_list)) {
366 /* Fallback to the non-batched version */
367 rcu_read_unlock();
368 return xsk_tx_peek_release_fallback(pool, descs, max_entries);
369 }
370
371 xs = list_first_or_null_rcu(&pool->xsk_tx_list, struct xdp_sock, tx_list);
372 if (!xs) {
373 nb_pkts = 0;
374 goto out;
375 }
376
377 nb_pkts = xskq_cons_peek_desc_batch(xs->tx, descs, pool, max_entries);
378 if (!nb_pkts) {
379 xs->tx->queue_empty_descs++;
380 goto out;
381 }
382
383 /* This is the backpressure mechanism for the Tx path. Try to
384 * reserve space in the completion queue for all packets, but
385 * if there are fewer slots available, just process that many
386 * packets. This avoids having to implement any buffering in
387 * the Tx path.
388 */
389 nb_pkts = xskq_prod_reserve_addr_batch(pool->cq, descs, nb_pkts);
390 if (!nb_pkts)
391 goto out;
392
393 xskq_cons_release_n(xs->tx, nb_pkts);
394 __xskq_cons_release(xs->tx);
395 xs->sk.sk_write_space(&xs->sk);
396
397 out:
398 rcu_read_unlock();
399 return nb_pkts;
400 }
401 EXPORT_SYMBOL(xsk_tx_peek_release_desc_batch);
402
403 static int xsk_wakeup(struct xdp_sock *xs, u8 flags)
404 {
405 struct net_device *dev = xs->dev;
406 int err;
407
408 rcu_read_lock();
409 err = dev->netdev_ops->ndo_xsk_wakeup(dev, xs->queue_id, flags);
410 rcu_read_unlock();
411
412 return err;
413 }
414
415 static int xsk_zc_xmit(struct xdp_sock *xs)
416 {
417 return xsk_wakeup(xs, XDP_WAKEUP_TX);
418 }
419
420 static void xsk_destruct_skb(struct sk_buff *skb)
421 {
422 u64 addr = (u64)(long)skb_shinfo(skb)->destructor_arg;
423 struct xdp_sock *xs = xdp_sk(skb->sk);
424 unsigned long flags;
425
426 spin_lock_irqsave(&xs->pool->cq_lock, flags);
427 xskq_prod_submit_addr(xs->pool->cq, addr);
428 spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
429
430 sock_wfree(skb);
431 }
432
433 static int xsk_generic_xmit(struct sock *sk)
434 {
435 struct xdp_sock *xs = xdp_sk(sk);
436 u32 max_batch = TX_BATCH_SIZE;
437 bool sent_frame = false;
438 struct xdp_desc desc;
439 struct sk_buff *skb;
440 unsigned long flags;
441 int err = 0;
442
443 mutex_lock(&xs->mutex);
444
445 if (xs->queue_id >= xs->dev->real_num_tx_queues)
446 goto out;
447
448 while (xskq_cons_peek_desc(xs->tx, &desc, xs->pool)) {
449 char *buffer;
450 u64 addr;
451 u32 len;
452
453 if (max_batch-- == 0) {
454 err = -EAGAIN;
455 goto out;
456 }
457
458 len = desc.len;
459 skb = sock_alloc_send_skb(sk, len, 1, &err);
460 if (unlikely(!skb))
461 goto out;
462
463 skb_put(skb, len);
464 addr = desc.addr;
465 buffer = xsk_buff_raw_get_data(xs->pool, addr);
466 err = skb_store_bits(skb, 0, buffer, len);
467 /* This is the backpressure mechanism for the Tx path.
468 * Reserve space in the completion queue and only proceed
469 * if there is space in it. This avoids having to implement
470 * any buffering in the Tx path.
471 */
472 spin_lock_irqsave(&xs->pool->cq_lock, flags);
473 if (unlikely(err) || xskq_prod_reserve(xs->pool->cq)) {
474 spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
475 kfree_skb(skb);
476 goto out;
477 }
478 spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
479
480 skb->dev = xs->dev;
481 skb->priority = sk->sk_priority;
482 skb->mark = sk->sk_mark;
483 skb_shinfo(skb)->destructor_arg = (void *)(long)desc.addr;
484 skb->destructor = xsk_destruct_skb;
485
486 err = __dev_direct_xmit(skb, xs->queue_id);
487 if (err == NETDEV_TX_BUSY) {
488 /* Tell user-space to retry the send */
489 skb->destructor = sock_wfree;
490 spin_lock_irqsave(&xs->pool->cq_lock, flags);
491 xskq_prod_cancel(xs->pool->cq);
492 spin_unlock_irqrestore(&xs->pool->cq_lock, flags);
493 /* Free skb without triggering the perf drop trace */
494 consume_skb(skb);
495 err = -EAGAIN;
496 goto out;
497 }
498
499 xskq_cons_release(xs->tx);
500 /* Ignore NET_XMIT_CN as packet might have been sent */
501 if (err == NET_XMIT_DROP) {
502 /* SKB completed but not sent */
503 err = -EBUSY;
504 goto out;
505 }
506
507 sent_frame = true;
508 }
509
510 xs->tx->queue_empty_descs++;
511
512 out:
513 if (sent_frame)
514 if (xsk_tx_writeable(xs))
515 sk->sk_write_space(sk);
516
517 mutex_unlock(&xs->mutex);
518 return err;
519 }
520
521 static int __xsk_sendmsg(struct sock *sk)
522 {
523 struct xdp_sock *xs = xdp_sk(sk);
524
525 if (unlikely(!(xs->dev->flags & IFF_UP)))
526 return -ENETDOWN;
527 if (unlikely(!xs->tx))
528 return -ENOBUFS;
529
530 return xs->zc ? xsk_zc_xmit(xs) : xsk_generic_xmit(sk);
531 }
532
533 static bool xsk_no_wakeup(struct sock *sk)
534 {
535 #ifdef CONFIG_NET_RX_BUSY_POLL
536 /* Prefer busy-polling, skip the wakeup. */
537 return READ_ONCE(sk->sk_prefer_busy_poll) && READ_ONCE(sk->sk_ll_usec) &&
538 READ_ONCE(sk->sk_napi_id) >= MIN_NAPI_ID;
539 #else
540 return false;
541 #endif
542 }
543
544 static int xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
545 {
546 bool need_wait = !(m->msg_flags & MSG_DONTWAIT);
547 struct sock *sk = sock->sk;
548 struct xdp_sock *xs = xdp_sk(sk);
549 struct xsk_buff_pool *pool;
550
551 if (unlikely(!xsk_is_bound(xs)))
552 return -ENXIO;
553 if (unlikely(need_wait))
554 return -EOPNOTSUPP;
555
556 if (sk_can_busy_loop(sk))
557 sk_busy_loop(sk, 1); /* only support non-blocking sockets */
558
559 if (xsk_no_wakeup(sk))
560 return 0;
561
562 pool = xs->pool;
563 if (pool->cached_need_wakeup & XDP_WAKEUP_TX)
564 return __xsk_sendmsg(sk);
565 return 0;
566 }
567
568 static int xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int flags)
569 {
570 bool need_wait = !(flags & MSG_DONTWAIT);
571 struct sock *sk = sock->sk;
572 struct xdp_sock *xs = xdp_sk(sk);
573
574 if (unlikely(!xsk_is_bound(xs)))
575 return -ENXIO;
576 if (unlikely(!(xs->dev->flags & IFF_UP)))
577 return -ENETDOWN;
578 if (unlikely(!xs->rx))
579 return -ENOBUFS;
580 if (unlikely(need_wait))
581 return -EOPNOTSUPP;
582
583 if (sk_can_busy_loop(sk))
584 sk_busy_loop(sk, 1); /* only support non-blocking sockets */
585
586 if (xsk_no_wakeup(sk))
587 return 0;
588
589 if (xs->pool->cached_need_wakeup & XDP_WAKEUP_RX && xs->zc)
590 return xsk_wakeup(xs, XDP_WAKEUP_RX);
591 return 0;
592 }
593
594 static __poll_t xsk_poll(struct file *file, struct socket *sock,
595 struct poll_table_struct *wait)
596 {
597 __poll_t mask = 0;
598 struct sock *sk = sock->sk;
599 struct xdp_sock *xs = xdp_sk(sk);
600 struct xsk_buff_pool *pool;
601
602 sock_poll_wait(file, sock, wait);
603
604 if (unlikely(!xsk_is_bound(xs)))
605 return mask;
606
607 pool = xs->pool;
608
609 if (pool->cached_need_wakeup) {
610 if (xs->zc)
611 xsk_wakeup(xs, pool->cached_need_wakeup);
612 else
613 /* Poll needs to drive Tx also in copy mode */
614 __xsk_sendmsg(sk);
615 }
616
617 if (xs->rx && !xskq_prod_is_empty(xs->rx))
618 mask |= EPOLLIN | EPOLLRDNORM;
619 if (xs->tx && xsk_tx_writeable(xs))
620 mask |= EPOLLOUT | EPOLLWRNORM;
621
622 return mask;
623 }
624
625 static int xsk_init_queue(u32 entries, struct xsk_queue **queue,
626 bool umem_queue)
627 {
628 struct xsk_queue *q;
629
630 if (entries == 0 || *queue || !is_power_of_2(entries))
631 return -EINVAL;
632
633 q = xskq_create(entries, umem_queue);
634 if (!q)
635 return -ENOMEM;
636
637 /* Make sure queue is ready before it can be seen by others */
638 smp_wmb();
639 WRITE_ONCE(*queue, q);
640 return 0;
641 }
642
643 static void xsk_unbind_dev(struct xdp_sock *xs)
644 {
645 struct net_device *dev = xs->dev;
646
647 if (xs->state != XSK_BOUND)
648 return;
649 WRITE_ONCE(xs->state, XSK_UNBOUND);
650
651 /* Wait for driver to stop using the xdp socket. */
652 xp_del_xsk(xs->pool, xs);
653 xs->dev = NULL;
654 synchronize_net();
655 dev_put(dev);
656 }
657
658 static struct xsk_map *xsk_get_map_list_entry(struct xdp_sock *xs,
659 struct xdp_sock ***map_entry)
660 {
661 struct xsk_map *map = NULL;
662 struct xsk_map_node *node;
663
664 *map_entry = NULL;
665
666 spin_lock_bh(&xs->map_list_lock);
667 node = list_first_entry_or_null(&xs->map_list, struct xsk_map_node,
668 node);
669 if (node) {
670 bpf_map_inc(&node->map->map);
671 map = node->map;
672 *map_entry = node->map_entry;
673 }
674 spin_unlock_bh(&xs->map_list_lock);
675 return map;
676 }
677
678 static void xsk_delete_from_maps(struct xdp_sock *xs)
679 {
680 /* This function removes the current XDP socket from all the
681 * maps it resides in. We need to take extra care here, due to
682 * the two locks involved. Each map has a lock synchronizing
683 * updates to the entries, and each socket has a lock that
684 * synchronizes access to the list of maps (map_list). For
685 * deadlock avoidance the locks need to be taken in the order
686 * "map lock"->"socket map list lock". We start off by
687 * accessing the socket map list, and take a reference to the
688 * map to guarantee existence between the
689 * xsk_get_map_list_entry() and xsk_map_try_sock_delete()
690 * calls. Then we ask the map to remove the socket, which
691 * tries to remove the socket from the map. Note that there
692 * might be updates to the map between
693 * xsk_get_map_list_entry() and xsk_map_try_sock_delete().
694 */
695 struct xdp_sock **map_entry = NULL;
696 struct xsk_map *map;
697
698 while ((map = xsk_get_map_list_entry(xs, &map_entry))) {
699 xsk_map_try_sock_delete(map, xs, map_entry);
700 bpf_map_put(&map->map);
701 }
702 }
703
704 static int xsk_release(struct socket *sock)
705 {
706 struct sock *sk = sock->sk;
707 struct xdp_sock *xs = xdp_sk(sk);
708 struct net *net;
709
710 if (!sk)
711 return 0;
712
713 net = sock_net(sk);
714
715 mutex_lock(&net->xdp.lock);
716 sk_del_node_init_rcu(sk);
717 mutex_unlock(&net->xdp.lock);
718
719 local_bh_disable();
720 sock_prot_inuse_add(net, sk->sk_prot, -1);
721 local_bh_enable();
722
723 xsk_delete_from_maps(xs);
724 mutex_lock(&xs->mutex);
725 xsk_unbind_dev(xs);
726 mutex_unlock(&xs->mutex);
727
728 xskq_destroy(xs->rx);
729 xskq_destroy(xs->tx);
730 xskq_destroy(xs->fq_tmp);
731 xskq_destroy(xs->cq_tmp);
732
733 sock_orphan(sk);
734 sock->sk = NULL;
735
736 sk_refcnt_debug_release(sk);
737 sock_put(sk);
738
739 return 0;
740 }
741
742 static struct socket *xsk_lookup_xsk_from_fd(int fd)
743 {
744 struct socket *sock;
745 int err;
746
747 sock = sockfd_lookup(fd, &err);
748 if (!sock)
749 return ERR_PTR(-ENOTSOCK);
750
751 if (sock->sk->sk_family != PF_XDP) {
752 sockfd_put(sock);
753 return ERR_PTR(-ENOPROTOOPT);
754 }
755
756 return sock;
757 }
758
759 static bool xsk_validate_queues(struct xdp_sock *xs)
760 {
761 return xs->fq_tmp && xs->cq_tmp;
762 }
763
764 static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
765 {
766 struct sockaddr_xdp *sxdp = (struct sockaddr_xdp *)addr;
767 struct sock *sk = sock->sk;
768 struct xdp_sock *xs = xdp_sk(sk);
769 struct net_device *dev;
770 u32 flags, qid;
771 int err = 0;
772
773 if (addr_len < sizeof(struct sockaddr_xdp))
774 return -EINVAL;
775 if (sxdp->sxdp_family != AF_XDP)
776 return -EINVAL;
777
778 flags = sxdp->sxdp_flags;
779 if (flags & ~(XDP_SHARED_UMEM | XDP_COPY | XDP_ZEROCOPY |
780 XDP_USE_NEED_WAKEUP))
781 return -EINVAL;
782
783 rtnl_lock();
784 mutex_lock(&xs->mutex);
785 if (xs->state != XSK_READY) {
786 err = -EBUSY;
787 goto out_release;
788 }
789
790 dev = dev_get_by_index(sock_net(sk), sxdp->sxdp_ifindex);
791 if (!dev) {
792 err = -ENODEV;
793 goto out_release;
794 }
795
796 if (!xs->rx && !xs->tx) {
797 err = -EINVAL;
798 goto out_unlock;
799 }
800
801 qid = sxdp->sxdp_queue_id;
802
803 if (flags & XDP_SHARED_UMEM) {
804 struct xdp_sock *umem_xs;
805 struct socket *sock;
806
807 if ((flags & XDP_COPY) || (flags & XDP_ZEROCOPY) ||
808 (flags & XDP_USE_NEED_WAKEUP)) {
809 /* Cannot specify flags for shared sockets. */
810 err = -EINVAL;
811 goto out_unlock;
812 }
813
814 if (xs->umem) {
815 /* We have already our own. */
816 err = -EINVAL;
817 goto out_unlock;
818 }
819
820 sock = xsk_lookup_xsk_from_fd(sxdp->sxdp_shared_umem_fd);
821 if (IS_ERR(sock)) {
822 err = PTR_ERR(sock);
823 goto out_unlock;
824 }
825
826 umem_xs = xdp_sk(sock->sk);
827 if (!xsk_is_bound(umem_xs)) {
828 err = -EBADF;
829 sockfd_put(sock);
830 goto out_unlock;
831 }
832
833 if (umem_xs->queue_id != qid || umem_xs->dev != dev) {
834 /* Share the umem with another socket on another qid
835 * and/or device.
836 */
837 xs->pool = xp_create_and_assign_umem(xs,
838 umem_xs->umem);
839 if (!xs->pool) {
840 err = -ENOMEM;
841 sockfd_put(sock);
842 goto out_unlock;
843 }
844
845 err = xp_assign_dev_shared(xs->pool, umem_xs->umem,
846 dev, qid);
847 if (err) {
848 xp_destroy(xs->pool);
849 xs->pool = NULL;
850 sockfd_put(sock);
851 goto out_unlock;
852 }
853 } else {
854 /* Share the buffer pool with the other socket. */
855 if (xs->fq_tmp || xs->cq_tmp) {
856 /* Do not allow setting your own fq or cq. */
857 err = -EINVAL;
858 sockfd_put(sock);
859 goto out_unlock;
860 }
861
862 xp_get_pool(umem_xs->pool);
863 xs->pool = umem_xs->pool;
864 }
865
866 xdp_get_umem(umem_xs->umem);
867 WRITE_ONCE(xs->umem, umem_xs->umem);
868 sockfd_put(sock);
869 } else if (!xs->umem || !xsk_validate_queues(xs)) {
870 err = -EINVAL;
871 goto out_unlock;
872 } else {
873 /* This xsk has its own umem. */
874 xs->pool = xp_create_and_assign_umem(xs, xs->umem);
875 if (!xs->pool) {
876 err = -ENOMEM;
877 goto out_unlock;
878 }
879
880 err = xp_assign_dev(xs->pool, dev, qid, flags);
881 if (err) {
882 xp_destroy(xs->pool);
883 xs->pool = NULL;
884 goto out_unlock;
885 }
886 }
887
888 /* FQ and CQ are now owned by the buffer pool and cleaned up with it. */
889 xs->fq_tmp = NULL;
890 xs->cq_tmp = NULL;
891
892 xs->dev = dev;
893 xs->zc = xs->umem->zc;
894 xs->queue_id = qid;
895 xp_add_xsk(xs->pool, xs);
896
897 out_unlock:
898 if (err) {
899 dev_put(dev);
900 } else {
901 /* Matches smp_rmb() in bind() for shared umem
902 * sockets, and xsk_is_bound().
903 */
904 smp_wmb();
905 WRITE_ONCE(xs->state, XSK_BOUND);
906 }
907 out_release:
908 mutex_unlock(&xs->mutex);
909 rtnl_unlock();
910 return err;
911 }
912
913 struct xdp_umem_reg_v1 {
914 __u64 addr; /* Start of packet data area */
915 __u64 len; /* Length of packet data area */
916 __u32 chunk_size;
917 __u32 headroom;
918 };
919
920 static int xsk_setsockopt(struct socket *sock, int level, int optname,
921 sockptr_t optval, unsigned int optlen)
922 {
923 struct sock *sk = sock->sk;
924 struct xdp_sock *xs = xdp_sk(sk);
925 int err;
926
927 if (level != SOL_XDP)
928 return -ENOPROTOOPT;
929
930 switch (optname) {
931 case XDP_RX_RING:
932 case XDP_TX_RING:
933 {
934 struct xsk_queue **q;
935 int entries;
936
937 if (optlen < sizeof(entries))
938 return -EINVAL;
939 if (copy_from_sockptr(&entries, optval, sizeof(entries)))
940 return -EFAULT;
941
942 mutex_lock(&xs->mutex);
943 if (xs->state != XSK_READY) {
944 mutex_unlock(&xs->mutex);
945 return -EBUSY;
946 }
947 q = (optname == XDP_TX_RING) ? &xs->tx : &xs->rx;
948 err = xsk_init_queue(entries, q, false);
949 if (!err && optname == XDP_TX_RING)
950 /* Tx needs to be explicitly woken up the first time */
951 xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP;
952 mutex_unlock(&xs->mutex);
953 return err;
954 }
955 case XDP_UMEM_REG:
956 {
957 size_t mr_size = sizeof(struct xdp_umem_reg);
958 struct xdp_umem_reg mr = {};
959 struct xdp_umem *umem;
960
961 if (optlen < sizeof(struct xdp_umem_reg_v1))
962 return -EINVAL;
963 else if (optlen < sizeof(mr))
964 mr_size = sizeof(struct xdp_umem_reg_v1);
965
966 if (copy_from_sockptr(&mr, optval, mr_size))
967 return -EFAULT;
968
969 mutex_lock(&xs->mutex);
970 if (xs->state != XSK_READY || xs->umem) {
971 mutex_unlock(&xs->mutex);
972 return -EBUSY;
973 }
974
975 umem = xdp_umem_create(&mr);
976 if (IS_ERR(umem)) {
977 mutex_unlock(&xs->mutex);
978 return PTR_ERR(umem);
979 }
980
981 /* Make sure umem is ready before it can be seen by others */
982 smp_wmb();
983 WRITE_ONCE(xs->umem, umem);
984 mutex_unlock(&xs->mutex);
985 return 0;
986 }
987 case XDP_UMEM_FILL_RING:
988 case XDP_UMEM_COMPLETION_RING:
989 {
990 struct xsk_queue **q;
991 int entries;
992
993 if (copy_from_sockptr(&entries, optval, sizeof(entries)))
994 return -EFAULT;
995
996 mutex_lock(&xs->mutex);
997 if (xs->state != XSK_READY) {
998 mutex_unlock(&xs->mutex);
999 return -EBUSY;
1000 }
1001
1002 q = (optname == XDP_UMEM_FILL_RING) ? &xs->fq_tmp :
1003 &xs->cq_tmp;
1004 err = xsk_init_queue(entries, q, true);
1005 mutex_unlock(&xs->mutex);
1006 return err;
1007 }
1008 default:
1009 break;
1010 }
1011
1012 return -ENOPROTOOPT;
1013 }
1014
1015 static void xsk_enter_rxtx_offsets(struct xdp_ring_offset_v1 *ring)
1016 {
1017 ring->producer = offsetof(struct xdp_rxtx_ring, ptrs.producer);
1018 ring->consumer = offsetof(struct xdp_rxtx_ring, ptrs.consumer);
1019 ring->desc = offsetof(struct xdp_rxtx_ring, desc);
1020 }
1021
1022 static void xsk_enter_umem_offsets(struct xdp_ring_offset_v1 *ring)
1023 {
1024 ring->producer = offsetof(struct xdp_umem_ring, ptrs.producer);
1025 ring->consumer = offsetof(struct xdp_umem_ring, ptrs.consumer);
1026 ring->desc = offsetof(struct xdp_umem_ring, desc);
1027 }
1028
1029 struct xdp_statistics_v1 {
1030 __u64 rx_dropped;
1031 __u64 rx_invalid_descs;
1032 __u64 tx_invalid_descs;
1033 };
1034
1035 static int xsk_getsockopt(struct socket *sock, int level, int optname,
1036 char __user *optval, int __user *optlen)
1037 {
1038 struct sock *sk = sock->sk;
1039 struct xdp_sock *xs = xdp_sk(sk);
1040 int len;
1041
1042 if (level != SOL_XDP)
1043 return -ENOPROTOOPT;
1044
1045 if (get_user(len, optlen))
1046 return -EFAULT;
1047 if (len < 0)
1048 return -EINVAL;
1049
1050 switch (optname) {
1051 case XDP_STATISTICS:
1052 {
1053 struct xdp_statistics stats = {};
1054 bool extra_stats = true;
1055 size_t stats_size;
1056
1057 if (len < sizeof(struct xdp_statistics_v1)) {
1058 return -EINVAL;
1059 } else if (len < sizeof(stats)) {
1060 extra_stats = false;
1061 stats_size = sizeof(struct xdp_statistics_v1);
1062 } else {
1063 stats_size = sizeof(stats);
1064 }
1065
1066 mutex_lock(&xs->mutex);
1067 stats.rx_dropped = xs->rx_dropped;
1068 if (extra_stats) {
1069 stats.rx_ring_full = xs->rx_queue_full;
1070 stats.rx_fill_ring_empty_descs =
1071 xs->pool ? xskq_nb_queue_empty_descs(xs->pool->fq) : 0;
1072 stats.tx_ring_empty_descs = xskq_nb_queue_empty_descs(xs->tx);
1073 } else {
1074 stats.rx_dropped += xs->rx_queue_full;
1075 }
1076 stats.rx_invalid_descs = xskq_nb_invalid_descs(xs->rx);
1077 stats.tx_invalid_descs = xskq_nb_invalid_descs(xs->tx);
1078 mutex_unlock(&xs->mutex);
1079
1080 if (copy_to_user(optval, &stats, stats_size))
1081 return -EFAULT;
1082 if (put_user(stats_size, optlen))
1083 return -EFAULT;
1084
1085 return 0;
1086 }
1087 case XDP_MMAP_OFFSETS:
1088 {
1089 struct xdp_mmap_offsets off;
1090 struct xdp_mmap_offsets_v1 off_v1;
1091 bool flags_supported = true;
1092 void *to_copy;
1093
1094 if (len < sizeof(off_v1))
1095 return -EINVAL;
1096 else if (len < sizeof(off))
1097 flags_supported = false;
1098
1099 if (flags_supported) {
1100 /* xdp_ring_offset is identical to xdp_ring_offset_v1
1101 * except for the flags field added to the end.
1102 */
1103 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *)
1104 &off.rx);
1105 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *)
1106 &off.tx);
1107 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *)
1108 &off.fr);
1109 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *)
1110 &off.cr);
1111 off.rx.flags = offsetof(struct xdp_rxtx_ring,
1112 ptrs.flags);
1113 off.tx.flags = offsetof(struct xdp_rxtx_ring,
1114 ptrs.flags);
1115 off.fr.flags = offsetof(struct xdp_umem_ring,
1116 ptrs.flags);
1117 off.cr.flags = offsetof(struct xdp_umem_ring,
1118 ptrs.flags);
1119
1120 len = sizeof(off);
1121 to_copy = &off;
1122 } else {
1123 xsk_enter_rxtx_offsets(&off_v1.rx);
1124 xsk_enter_rxtx_offsets(&off_v1.tx);
1125 xsk_enter_umem_offsets(&off_v1.fr);
1126 xsk_enter_umem_offsets(&off_v1.cr);
1127
1128 len = sizeof(off_v1);
1129 to_copy = &off_v1;
1130 }
1131
1132 if (copy_to_user(optval, to_copy, len))
1133 return -EFAULT;
1134 if (put_user(len, optlen))
1135 return -EFAULT;
1136
1137 return 0;
1138 }
1139 case XDP_OPTIONS:
1140 {
1141 struct xdp_options opts = {};
1142
1143 if (len < sizeof(opts))
1144 return -EINVAL;
1145
1146 mutex_lock(&xs->mutex);
1147 if (xs->zc)
1148 opts.flags |= XDP_OPTIONS_ZEROCOPY;
1149 mutex_unlock(&xs->mutex);
1150
1151 len = sizeof(opts);
1152 if (copy_to_user(optval, &opts, len))
1153 return -EFAULT;
1154 if (put_user(len, optlen))
1155 return -EFAULT;
1156
1157 return 0;
1158 }
1159 default:
1160 break;
1161 }
1162
1163 return -EOPNOTSUPP;
1164 }
1165
1166 static int xsk_mmap(struct file *file, struct socket *sock,
1167 struct vm_area_struct *vma)
1168 {
1169 loff_t offset = (loff_t)vma->vm_pgoff << PAGE_SHIFT;
1170 unsigned long size = vma->vm_end - vma->vm_start;
1171 struct xdp_sock *xs = xdp_sk(sock->sk);
1172 struct xsk_queue *q = NULL;
1173 unsigned long pfn;
1174 struct page *qpg;
1175
1176 if (READ_ONCE(xs->state) != XSK_READY)
1177 return -EBUSY;
1178
1179 if (offset == XDP_PGOFF_RX_RING) {
1180 q = READ_ONCE(xs->rx);
1181 } else if (offset == XDP_PGOFF_TX_RING) {
1182 q = READ_ONCE(xs->tx);
1183 } else {
1184 /* Matches the smp_wmb() in XDP_UMEM_REG */
1185 smp_rmb();
1186 if (offset == XDP_UMEM_PGOFF_FILL_RING)
1187 q = READ_ONCE(xs->fq_tmp);
1188 else if (offset == XDP_UMEM_PGOFF_COMPLETION_RING)
1189 q = READ_ONCE(xs->cq_tmp);
1190 }
1191
1192 if (!q)
1193 return -EINVAL;
1194
1195 /* Matches the smp_wmb() in xsk_init_queue */
1196 smp_rmb();
1197 qpg = virt_to_head_page(q->ring);
1198 if (size > page_size(qpg))
1199 return -EINVAL;
1200
1201 pfn = virt_to_phys(q->ring) >> PAGE_SHIFT;
1202 return remap_pfn_range(vma, vma->vm_start, pfn,
1203 size, vma->vm_page_prot);
1204 }
1205
1206 static int xsk_notifier(struct notifier_block *this,
1207 unsigned long msg, void *ptr)
1208 {
1209 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1210 struct net *net = dev_net(dev);
1211 struct sock *sk;
1212
1213 switch (msg) {
1214 case NETDEV_UNREGISTER:
1215 mutex_lock(&net->xdp.lock);
1216 sk_for_each(sk, &net->xdp.list) {
1217 struct xdp_sock *xs = xdp_sk(sk);
1218
1219 mutex_lock(&xs->mutex);
1220 if (xs->dev == dev) {
1221 sk->sk_err = ENETDOWN;
1222 if (!sock_flag(sk, SOCK_DEAD))
1223 sk->sk_error_report(sk);
1224
1225 xsk_unbind_dev(xs);
1226
1227 /* Clear device references. */
1228 xp_clear_dev(xs->pool);
1229 }
1230 mutex_unlock(&xs->mutex);
1231 }
1232 mutex_unlock(&net->xdp.lock);
1233 break;
1234 }
1235 return NOTIFY_DONE;
1236 }
1237
1238 static struct proto xsk_proto = {
1239 .name = "XDP",
1240 .owner = THIS_MODULE,
1241 .obj_size = sizeof(struct xdp_sock),
1242 };
1243
1244 static const struct proto_ops xsk_proto_ops = {
1245 .family = PF_XDP,
1246 .owner = THIS_MODULE,
1247 .release = xsk_release,
1248 .bind = xsk_bind,
1249 .connect = sock_no_connect,
1250 .socketpair = sock_no_socketpair,
1251 .accept = sock_no_accept,
1252 .getname = sock_no_getname,
1253 .poll = xsk_poll,
1254 .ioctl = sock_no_ioctl,
1255 .listen = sock_no_listen,
1256 .shutdown = sock_no_shutdown,
1257 .setsockopt = xsk_setsockopt,
1258 .getsockopt = xsk_getsockopt,
1259 .sendmsg = xsk_sendmsg,
1260 .recvmsg = xsk_recvmsg,
1261 .mmap = xsk_mmap,
1262 .sendpage = sock_no_sendpage,
1263 };
1264
1265 static void xsk_destruct(struct sock *sk)
1266 {
1267 struct xdp_sock *xs = xdp_sk(sk);
1268
1269 if (!sock_flag(sk, SOCK_DEAD))
1270 return;
1271
1272 if (!xp_put_pool(xs->pool))
1273 xdp_put_umem(xs->umem, !xs->pool);
1274
1275 sk_refcnt_debug_dec(sk);
1276 }
1277
1278 static int xsk_create(struct net *net, struct socket *sock, int protocol,
1279 int kern)
1280 {
1281 struct xdp_sock *xs;
1282 struct sock *sk;
1283
1284 if (!ns_capable(net->user_ns, CAP_NET_RAW))
1285 return -EPERM;
1286 if (sock->type != SOCK_RAW)
1287 return -ESOCKTNOSUPPORT;
1288
1289 if (protocol)
1290 return -EPROTONOSUPPORT;
1291
1292 sock->state = SS_UNCONNECTED;
1293
1294 sk = sk_alloc(net, PF_XDP, GFP_KERNEL, &xsk_proto, kern);
1295 if (!sk)
1296 return -ENOBUFS;
1297
1298 sock->ops = &xsk_proto_ops;
1299
1300 sock_init_data(sock, sk);
1301
1302 sk->sk_family = PF_XDP;
1303
1304 sk->sk_destruct = xsk_destruct;
1305 sk_refcnt_debug_inc(sk);
1306
1307 sock_set_flag(sk, SOCK_RCU_FREE);
1308
1309 xs = xdp_sk(sk);
1310 xs->state = XSK_READY;
1311 mutex_init(&xs->mutex);
1312 spin_lock_init(&xs->rx_lock);
1313
1314 INIT_LIST_HEAD(&xs->map_list);
1315 spin_lock_init(&xs->map_list_lock);
1316
1317 mutex_lock(&net->xdp.lock);
1318 sk_add_node_rcu(sk, &net->xdp.list);
1319 mutex_unlock(&net->xdp.lock);
1320
1321 local_bh_disable();
1322 sock_prot_inuse_add(net, &xsk_proto, 1);
1323 local_bh_enable();
1324
1325 return 0;
1326 }
1327
1328 static const struct net_proto_family xsk_family_ops = {
1329 .family = PF_XDP,
1330 .create = xsk_create,
1331 .owner = THIS_MODULE,
1332 };
1333
1334 static struct notifier_block xsk_netdev_notifier = {
1335 .notifier_call = xsk_notifier,
1336 };
1337
1338 static int __net_init xsk_net_init(struct net *net)
1339 {
1340 mutex_init(&net->xdp.lock);
1341 INIT_HLIST_HEAD(&net->xdp.list);
1342 return 0;
1343 }
1344
1345 static void __net_exit xsk_net_exit(struct net *net)
1346 {
1347 WARN_ON_ONCE(!hlist_empty(&net->xdp.list));
1348 }
1349
1350 static struct pernet_operations xsk_net_ops = {
1351 .init = xsk_net_init,
1352 .exit = xsk_net_exit,
1353 };
1354
1355 static int __init xsk_init(void)
1356 {
1357 int err, cpu;
1358
1359 err = proto_register(&xsk_proto, 0 /* no slab */);
1360 if (err)
1361 goto out;
1362
1363 err = sock_register(&xsk_family_ops);
1364 if (err)
1365 goto out_proto;
1366
1367 err = register_pernet_subsys(&xsk_net_ops);
1368 if (err)
1369 goto out_sk;
1370
1371 err = register_netdevice_notifier(&xsk_netdev_notifier);
1372 if (err)
1373 goto out_pernet;
1374
1375 for_each_possible_cpu(cpu)
1376 INIT_LIST_HEAD(&per_cpu(xskmap_flush_list, cpu));
1377 return 0;
1378
1379 out_pernet:
1380 unregister_pernet_subsys(&xsk_net_ops);
1381 out_sk:
1382 sock_unregister(PF_XDP);
1383 out_proto:
1384 proto_unregister(&xsk_proto);
1385 out:
1386 return err;
1387 }
1388
1389 fs_initcall(xsk_init);
Linux with added FPC-III support