?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
ARM: dma-api: fix max_pfn off-by-one error in __dma_supported()
[linux/fpc-iii.git] / net / xdp / xsk.c
blobdf600487a68d513c3f7abcb1b584d2f4c229a7dd
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.h>
26 #include <net/xdp.h>
27
28 #include "xsk_queue.h"
29 #include "xdp_umem.h"
30 #include "xsk.h"
31
32 #define TX_BATCH_SIZE 16
33
34 static DEFINE_PER_CPU(struct list_head, xskmap_flush_list);
35
36 bool xsk_is_setup_for_bpf_map(struct xdp_sock *xs)
37 {
38 return READ_ONCE(xs->rx) && READ_ONCE(xs->umem) &&
39 READ_ONCE(xs->umem->fq);
40 }
41
42 bool xsk_umem_has_addrs(struct xdp_umem *umem, u32 cnt)
43 {
44 return xskq_cons_has_entries(umem->fq, cnt);
45 }
46 EXPORT_SYMBOL(xsk_umem_has_addrs);
47
48 bool xsk_umem_peek_addr(struct xdp_umem *umem, u64 *addr)
49 {
50 return xskq_cons_peek_addr(umem->fq, addr, umem);
51 }
52 EXPORT_SYMBOL(xsk_umem_peek_addr);
53
54 void xsk_umem_release_addr(struct xdp_umem *umem)
55 {
56 xskq_cons_release(umem->fq);
57 }
58 EXPORT_SYMBOL(xsk_umem_release_addr);
59
60 void xsk_set_rx_need_wakeup(struct xdp_umem *umem)
61 {
62 if (umem->need_wakeup & XDP_WAKEUP_RX)
63 return;
64
65 umem->fq->ring->flags |= XDP_RING_NEED_WAKEUP;
66 umem->need_wakeup |= XDP_WAKEUP_RX;
67 }
68 EXPORT_SYMBOL(xsk_set_rx_need_wakeup);
69
70 void xsk_set_tx_need_wakeup(struct xdp_umem *umem)
71 {
72 struct xdp_sock *xs;
73
74 if (umem->need_wakeup & XDP_WAKEUP_TX)
75 return;
76
77 rcu_read_lock();
78 list_for_each_entry_rcu(xs, &umem->xsk_list, list) {
79 xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP;
80 }
81 rcu_read_unlock();
82
83 umem->need_wakeup |= XDP_WAKEUP_TX;
84 }
85 EXPORT_SYMBOL(xsk_set_tx_need_wakeup);
86
87 void xsk_clear_rx_need_wakeup(struct xdp_umem *umem)
88 {
89 if (!(umem->need_wakeup & XDP_WAKEUP_RX))
90 return;
91
92 umem->fq->ring->flags &= ~XDP_RING_NEED_WAKEUP;
93 umem->need_wakeup &= ~XDP_WAKEUP_RX;
94 }
95 EXPORT_SYMBOL(xsk_clear_rx_need_wakeup);
96
97 void xsk_clear_tx_need_wakeup(struct xdp_umem *umem)
98 {
99 struct xdp_sock *xs;
100
101 if (!(umem->need_wakeup & XDP_WAKEUP_TX))
102 return;
103
104 rcu_read_lock();
105 list_for_each_entry_rcu(xs, &umem->xsk_list, list) {
106 xs->tx->ring->flags &= ~XDP_RING_NEED_WAKEUP;
107 }
108 rcu_read_unlock();
109
110 umem->need_wakeup &= ~XDP_WAKEUP_TX;
111 }
112 EXPORT_SYMBOL(xsk_clear_tx_need_wakeup);
113
114 bool xsk_umem_uses_need_wakeup(struct xdp_umem *umem)
115 {
116 return umem->flags & XDP_UMEM_USES_NEED_WAKEUP;
117 }
118 EXPORT_SYMBOL(xsk_umem_uses_need_wakeup);
119
120 /* If a buffer crosses a page boundary, we need to do 2 memcpy's, one for
121 * each page. This is only required in copy mode.
122 */
123 static void __xsk_rcv_memcpy(struct xdp_umem *umem, u64 addr, void *from_buf,
124 u32 len, u32 metalen)
125 {
126 void *to_buf = xdp_umem_get_data(umem, addr);
127
128 addr = xsk_umem_add_offset_to_addr(addr);
129 if (xskq_cons_crosses_non_contig_pg(umem, addr, len + metalen)) {
130 void *next_pg_addr = umem->pages[(addr >> PAGE_SHIFT) + 1].addr;
131 u64 page_start = addr & ~(PAGE_SIZE - 1);
132 u64 first_len = PAGE_SIZE - (addr - page_start);
133
134 memcpy(to_buf, from_buf, first_len + metalen);
135 memcpy(next_pg_addr, from_buf + first_len, len - first_len);
136
137 return;
138 }
139
140 memcpy(to_buf, from_buf, len + metalen);
141 }
142
143 static int __xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len)
144 {
145 u64 offset = xs->umem->headroom;
146 u64 addr, memcpy_addr;
147 void *from_buf;
148 u32 metalen;
149 int err;
150
151 if (!xskq_cons_peek_addr(xs->umem->fq, &addr, xs->umem) ||
152 len > xs->umem->chunk_size_nohr - XDP_PACKET_HEADROOM) {
153 xs->rx_dropped++;
154 return -ENOSPC;
155 }
156
157 if (unlikely(xdp_data_meta_unsupported(xdp))) {
158 from_buf = xdp->data;
159 metalen = 0;
160 } else {
161 from_buf = xdp->data_meta;
162 metalen = xdp->data - xdp->data_meta;
163 }
164
165 memcpy_addr = xsk_umem_adjust_offset(xs->umem, addr, offset);
166 __xsk_rcv_memcpy(xs->umem, memcpy_addr, from_buf, len, metalen);
167
168 offset += metalen;
169 addr = xsk_umem_adjust_offset(xs->umem, addr, offset);
170 err = xskq_prod_reserve_desc(xs->rx, addr, len);
171 if (!err) {
172 xskq_cons_release(xs->umem->fq);
173 xdp_return_buff(xdp);
174 return 0;
175 }
176
177 xs->rx_dropped++;
178 return err;
179 }
180
181 static int __xsk_rcv_zc(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len)
182 {
183 int err = xskq_prod_reserve_desc(xs->rx, xdp->handle, len);
184
185 if (err)
186 xs->rx_dropped++;
187
188 return err;
189 }
190
191 static bool xsk_is_bound(struct xdp_sock *xs)
192 {
193 if (READ_ONCE(xs->state) == XSK_BOUND) {
194 /* Matches smp_wmb() in bind(). */
195 smp_rmb();
196 return true;
197 }
198 return false;
199 }
200
201 static int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
202 {
203 u32 len;
204
205 if (!xsk_is_bound(xs))
206 return -EINVAL;
207
208 if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index)
209 return -EINVAL;
210
211 len = xdp->data_end - xdp->data;
212
213 return (xdp->rxq->mem.type == MEM_TYPE_ZERO_COPY) ?
214 __xsk_rcv_zc(xs, xdp, len) : __xsk_rcv(xs, xdp, len);
215 }
216
217 static void xsk_flush(struct xdp_sock *xs)
218 {
219 xskq_prod_submit(xs->rx);
220 sock_def_readable(&xs->sk);
221 }
222
223 int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
224 {
225 u32 metalen = xdp->data - xdp->data_meta;
226 u32 len = xdp->data_end - xdp->data;
227 u64 offset = xs->umem->headroom;
228 void *buffer;
229 u64 addr;
230 int err;
231
232 spin_lock_bh(&xs->rx_lock);
233
234 if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index) {
235 err = -EINVAL;
236 goto out_unlock;
237 }
238
239 if (!xskq_cons_peek_addr(xs->umem->fq, &addr, xs->umem) ||
240 len > xs->umem->chunk_size_nohr - XDP_PACKET_HEADROOM) {
241 err = -ENOSPC;
242 goto out_drop;
243 }
244
245 addr = xsk_umem_adjust_offset(xs->umem, addr, offset);
246 buffer = xdp_umem_get_data(xs->umem, addr);
247 memcpy(buffer, xdp->data_meta, len + metalen);
248
249 addr = xsk_umem_adjust_offset(xs->umem, addr, metalen);
250 err = xskq_prod_reserve_desc(xs->rx, addr, len);
251 if (err)
252 goto out_drop;
253
254 xskq_cons_release(xs->umem->fq);
255 xskq_prod_submit(xs->rx);
256
257 spin_unlock_bh(&xs->rx_lock);
258
259 xs->sk.sk_data_ready(&xs->sk);
260 return 0;
261
262 out_drop:
263 xs->rx_dropped++;
264 out_unlock:
265 spin_unlock_bh(&xs->rx_lock);
266 return err;
267 }
268
269 int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp)
270 {
271 struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list);
272 int err;
273
274 err = xsk_rcv(xs, xdp);
275 if (err)
276 return err;
277
278 if (!xs->flush_node.prev)
279 list_add(&xs->flush_node, flush_list);
280
281 return 0;
282 }
283
284 void __xsk_map_flush(void)
285 {
286 struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list);
287 struct xdp_sock *xs, *tmp;
288
289 list_for_each_entry_safe(xs, tmp, flush_list, flush_node) {
290 xsk_flush(xs);
291 __list_del_clearprev(&xs->flush_node);
292 }
293 }
294
295 void xsk_umem_complete_tx(struct xdp_umem *umem, u32 nb_entries)
296 {
297 xskq_prod_submit_n(umem->cq, nb_entries);
298 }
299 EXPORT_SYMBOL(xsk_umem_complete_tx);
300
301 void xsk_umem_consume_tx_done(struct xdp_umem *umem)
302 {
303 struct xdp_sock *xs;
304
305 rcu_read_lock();
306 list_for_each_entry_rcu(xs, &umem->xsk_list, list) {
307 xs->sk.sk_write_space(&xs->sk);
308 }
309 rcu_read_unlock();
310 }
311 EXPORT_SYMBOL(xsk_umem_consume_tx_done);
312
313 bool xsk_umem_consume_tx(struct xdp_umem *umem, struct xdp_desc *desc)
314 {
315 struct xdp_sock *xs;
316
317 rcu_read_lock();
318 list_for_each_entry_rcu(xs, &umem->xsk_list, list) {
319 if (!xskq_cons_peek_desc(xs->tx, desc, umem))
320 continue;
321
322 /* This is the backpreassure mechanism for the Tx path.
323 * Reserve space in the completion queue and only proceed
324 * if there is space in it. This avoids having to implement
325 * any buffering in the Tx path.
326 */
327 if (xskq_prod_reserve_addr(umem->cq, desc->addr))
328 goto out;
329
330 xskq_cons_release(xs->tx);
331 rcu_read_unlock();
332 return true;
333 }
334
335 out:
336 rcu_read_unlock();
337 return false;
338 }
339 EXPORT_SYMBOL(xsk_umem_consume_tx);
340
341 static int xsk_wakeup(struct xdp_sock *xs, u8 flags)
342 {
343 struct net_device *dev = xs->dev;
344 int err;
345
346 rcu_read_lock();
347 err = dev->netdev_ops->ndo_xsk_wakeup(dev, xs->queue_id, flags);
348 rcu_read_unlock();
349
350 return err;
351 }
352
353 static int xsk_zc_xmit(struct xdp_sock *xs)
354 {
355 return xsk_wakeup(xs, XDP_WAKEUP_TX);
356 }
357
358 static void xsk_destruct_skb(struct sk_buff *skb)
359 {
360 u64 addr = (u64)(long)skb_shinfo(skb)->destructor_arg;
361 struct xdp_sock *xs = xdp_sk(skb->sk);
362 unsigned long flags;
363
364 spin_lock_irqsave(&xs->tx_completion_lock, flags);
365 xskq_prod_submit_addr(xs->umem->cq, addr);
366 spin_unlock_irqrestore(&xs->tx_completion_lock, flags);
367
368 sock_wfree(skb);
369 }
370
371 static int xsk_generic_xmit(struct sock *sk)
372 {
373 struct xdp_sock *xs = xdp_sk(sk);
374 u32 max_batch = TX_BATCH_SIZE;
375 bool sent_frame = false;
376 struct xdp_desc desc;
377 struct sk_buff *skb;
378 int err = 0;
379
380 mutex_lock(&xs->mutex);
381
382 if (xs->queue_id >= xs->dev->real_num_tx_queues)
383 goto out;
384
385 while (xskq_cons_peek_desc(xs->tx, &desc, xs->umem)) {
386 char *buffer;
387 u64 addr;
388 u32 len;
389
390 if (max_batch-- == 0) {
391 err = -EAGAIN;
392 goto out;
393 }
394
395 len = desc.len;
396 skb = sock_alloc_send_skb(sk, len, 1, &err);
397 if (unlikely(!skb)) {
398 err = -EAGAIN;
399 goto out;
400 }
401
402 skb_put(skb, len);
403 addr = desc.addr;
404 buffer = xdp_umem_get_data(xs->umem, addr);
405 err = skb_store_bits(skb, 0, buffer, len);
406 /* This is the backpreassure mechanism for the Tx path.
407 * Reserve space in the completion queue and only proceed
408 * if there is space in it. This avoids having to implement
409 * any buffering in the Tx path.
410 */
411 if (unlikely(err) || xskq_prod_reserve(xs->umem->cq)) {
412 kfree_skb(skb);
413 goto out;
414 }
415
416 skb->dev = xs->dev;
417 skb->priority = sk->sk_priority;
418 skb->mark = sk->sk_mark;
419 skb_shinfo(skb)->destructor_arg = (void *)(long)desc.addr;
420 skb->destructor = xsk_destruct_skb;
421
422 err = dev_direct_xmit(skb, xs->queue_id);
423 xskq_cons_release(xs->tx);
424 /* Ignore NET_XMIT_CN as packet might have been sent */
425 if (err == NET_XMIT_DROP || err == NETDEV_TX_BUSY) {
426 /* SKB completed but not sent */
427 err = -EBUSY;
428 goto out;
429 }
430
431 sent_frame = true;
432 }
433
434 out:
435 if (sent_frame)
436 sk->sk_write_space(sk);
437
438 mutex_unlock(&xs->mutex);
439 return err;
440 }
441
442 static int __xsk_sendmsg(struct sock *sk)
443 {
444 struct xdp_sock *xs = xdp_sk(sk);
445
446 if (unlikely(!(xs->dev->flags & IFF_UP)))
447 return -ENETDOWN;
448 if (unlikely(!xs->tx))
449 return -ENOBUFS;
450
451 return xs->zc ? xsk_zc_xmit(xs) : xsk_generic_xmit(sk);
452 }
453
454 static int xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
455 {
456 bool need_wait = !(m->msg_flags & MSG_DONTWAIT);
457 struct sock *sk = sock->sk;
458 struct xdp_sock *xs = xdp_sk(sk);
459
460 if (unlikely(!xsk_is_bound(xs)))
461 return -ENXIO;
462 if (unlikely(need_wait))
463 return -EOPNOTSUPP;
464
465 return __xsk_sendmsg(sk);
466 }
467
468 static __poll_t xsk_poll(struct file *file, struct socket *sock,
469 struct poll_table_struct *wait)
470 {
471 __poll_t mask = datagram_poll(file, sock, wait);
472 struct sock *sk = sock->sk;
473 struct xdp_sock *xs = xdp_sk(sk);
474 struct xdp_umem *umem;
475
476 if (unlikely(!xsk_is_bound(xs)))
477 return mask;
478
479 umem = xs->umem;
480
481 if (umem->need_wakeup) {
482 if (xs->zc)
483 xsk_wakeup(xs, umem->need_wakeup);
484 else
485 /* Poll needs to drive Tx also in copy mode */
486 __xsk_sendmsg(sk);
487 }
488
489 if (xs->rx && !xskq_prod_is_empty(xs->rx))
490 mask |= EPOLLIN | EPOLLRDNORM;
491 if (xs->tx && !xskq_cons_is_full(xs->tx))
492 mask |= EPOLLOUT | EPOLLWRNORM;
493
494 return mask;
495 }
496
497 static int xsk_init_queue(u32 entries, struct xsk_queue **queue,
498 bool umem_queue)
499 {
500 struct xsk_queue *q;
501
502 if (entries == 0 || *queue || !is_power_of_2(entries))
503 return -EINVAL;
504
505 q = xskq_create(entries, umem_queue);
506 if (!q)
507 return -ENOMEM;
508
509 /* Make sure queue is ready before it can be seen by others */
510 smp_wmb();
511 WRITE_ONCE(*queue, q);
512 return 0;
513 }
514
515 static void xsk_unbind_dev(struct xdp_sock *xs)
516 {
517 struct net_device *dev = xs->dev;
518
519 if (xs->state != XSK_BOUND)
520 return;
521 WRITE_ONCE(xs->state, XSK_UNBOUND);
522
523 /* Wait for driver to stop using the xdp socket. */
524 xdp_del_sk_umem(xs->umem, xs);
525 xs->dev = NULL;
526 synchronize_net();
527 dev_put(dev);
528 }
529
530 static struct xsk_map *xsk_get_map_list_entry(struct xdp_sock *xs,
531 struct xdp_sock ***map_entry)
532 {
533 struct xsk_map *map = NULL;
534 struct xsk_map_node *node;
535
536 *map_entry = NULL;
537
538 spin_lock_bh(&xs->map_list_lock);
539 node = list_first_entry_or_null(&xs->map_list, struct xsk_map_node,
540 node);
541 if (node) {
542 WARN_ON(xsk_map_inc(node->map));
543 map = node->map;
544 *map_entry = node->map_entry;
545 }
546 spin_unlock_bh(&xs->map_list_lock);
547 return map;
548 }
549
550 static void xsk_delete_from_maps(struct xdp_sock *xs)
551 {
552 /* This function removes the current XDP socket from all the
553 * maps it resides in. We need to take extra care here, due to
554 * the two locks involved. Each map has a lock synchronizing
555 * updates to the entries, and each socket has a lock that
556 * synchronizes access to the list of maps (map_list). For
557 * deadlock avoidance the locks need to be taken in the order
558 * "map lock"->"socket map list lock". We start off by
559 * accessing the socket map list, and take a reference to the
560 * map to guarantee existence between the
561 * xsk_get_map_list_entry() and xsk_map_try_sock_delete()
562 * calls. Then we ask the map to remove the socket, which
563 * tries to remove the socket from the map. Note that there
564 * might be updates to the map between
565 * xsk_get_map_list_entry() and xsk_map_try_sock_delete().
566 */
567 struct xdp_sock **map_entry = NULL;
568 struct xsk_map *map;
569
570 while ((map = xsk_get_map_list_entry(xs, &map_entry))) {
571 xsk_map_try_sock_delete(map, xs, map_entry);
572 xsk_map_put(map);
573 }
574 }
575
576 static int xsk_release(struct socket *sock)
577 {
578 struct sock *sk = sock->sk;
579 struct xdp_sock *xs = xdp_sk(sk);
580 struct net *net;
581
582 if (!sk)
583 return 0;
584
585 net = sock_net(sk);
586
587 mutex_lock(&net->xdp.lock);
588 sk_del_node_init_rcu(sk);
589 mutex_unlock(&net->xdp.lock);
590
591 local_bh_disable();
592 sock_prot_inuse_add(net, sk->sk_prot, -1);
593 local_bh_enable();
594
595 xsk_delete_from_maps(xs);
596 mutex_lock(&xs->mutex);
597 xsk_unbind_dev(xs);
598 mutex_unlock(&xs->mutex);
599
600 xskq_destroy(xs->rx);
601 xskq_destroy(xs->tx);
602
603 sock_orphan(sk);
604 sock->sk = NULL;
605
606 sk_refcnt_debug_release(sk);
607 sock_put(sk);
608
609 return 0;
610 }
611
612 static struct socket *xsk_lookup_xsk_from_fd(int fd)
613 {
614 struct socket *sock;
615 int err;
616
617 sock = sockfd_lookup(fd, &err);
618 if (!sock)
619 return ERR_PTR(-ENOTSOCK);
620
621 if (sock->sk->sk_family != PF_XDP) {
622 sockfd_put(sock);
623 return ERR_PTR(-ENOPROTOOPT);
624 }
625
626 return sock;
627 }
628
629 /* Check if umem pages are contiguous.
630 * If zero-copy mode, use the DMA address to do the page contiguity check
631 * For all other modes we use addr (kernel virtual address)
632 * Store the result in the low bits of addr.
633 */
634 static void xsk_check_page_contiguity(struct xdp_umem *umem, u32 flags)
635 {
636 struct xdp_umem_page *pgs = umem->pages;
637 int i, is_contig;
638
639 for (i = 0; i < umem->npgs - 1; i++) {
640 is_contig = (flags & XDP_ZEROCOPY) ?
641 (pgs[i].dma + PAGE_SIZE == pgs[i + 1].dma) :
642 (pgs[i].addr + PAGE_SIZE == pgs[i + 1].addr);
643 pgs[i].addr += is_contig << XSK_NEXT_PG_CONTIG_SHIFT;
644 }
645 }
646
647 static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
648 {
649 struct sockaddr_xdp *sxdp = (struct sockaddr_xdp *)addr;
650 struct sock *sk = sock->sk;
651 struct xdp_sock *xs = xdp_sk(sk);
652 struct net_device *dev;
653 u32 flags, qid;
654 int err = 0;
655
656 if (addr_len < sizeof(struct sockaddr_xdp))
657 return -EINVAL;
658 if (sxdp->sxdp_family != AF_XDP)
659 return -EINVAL;
660
661 flags = sxdp->sxdp_flags;
662 if (flags & ~(XDP_SHARED_UMEM | XDP_COPY | XDP_ZEROCOPY |
663 XDP_USE_NEED_WAKEUP))
664 return -EINVAL;
665
666 rtnl_lock();
667 mutex_lock(&xs->mutex);
668 if (xs->state != XSK_READY) {
669 err = -EBUSY;
670 goto out_release;
671 }
672
673 dev = dev_get_by_index(sock_net(sk), sxdp->sxdp_ifindex);
674 if (!dev) {
675 err = -ENODEV;
676 goto out_release;
677 }
678
679 if (!xs->rx && !xs->tx) {
680 err = -EINVAL;
681 goto out_unlock;
682 }
683
684 qid = sxdp->sxdp_queue_id;
685
686 if (flags & XDP_SHARED_UMEM) {
687 struct xdp_sock *umem_xs;
688 struct socket *sock;
689
690 if ((flags & XDP_COPY) || (flags & XDP_ZEROCOPY) ||
691 (flags & XDP_USE_NEED_WAKEUP)) {
692 /* Cannot specify flags for shared sockets. */
693 err = -EINVAL;
694 goto out_unlock;
695 }
696
697 if (xs->umem) {
698 /* We have already our own. */
699 err = -EINVAL;
700 goto out_unlock;
701 }
702
703 sock = xsk_lookup_xsk_from_fd(sxdp->sxdp_shared_umem_fd);
704 if (IS_ERR(sock)) {
705 err = PTR_ERR(sock);
706 goto out_unlock;
707 }
708
709 umem_xs = xdp_sk(sock->sk);
710 if (!xsk_is_bound(umem_xs)) {
711 err = -EBADF;
712 sockfd_put(sock);
713 goto out_unlock;
714 }
715 if (umem_xs->dev != dev || umem_xs->queue_id != qid) {
716 err = -EINVAL;
717 sockfd_put(sock);
718 goto out_unlock;
719 }
720
721 xdp_get_umem(umem_xs->umem);
722 WRITE_ONCE(xs->umem, umem_xs->umem);
723 sockfd_put(sock);
724 } else if (!xs->umem || !xdp_umem_validate_queues(xs->umem)) {
725 err = -EINVAL;
726 goto out_unlock;
727 } else {
728 /* This xsk has its own umem. */
729 xskq_set_umem(xs->umem->fq, xs->umem->size,
730 xs->umem->chunk_mask);
731 xskq_set_umem(xs->umem->cq, xs->umem->size,
732 xs->umem->chunk_mask);
733
734 err = xdp_umem_assign_dev(xs->umem, dev, qid, flags);
735 if (err)
736 goto out_unlock;
737
738 xsk_check_page_contiguity(xs->umem, flags);
739 }
740
741 xs->dev = dev;
742 xs->zc = xs->umem->zc;
743 xs->queue_id = qid;
744 xskq_set_umem(xs->rx, xs->umem->size, xs->umem->chunk_mask);
745 xskq_set_umem(xs->tx, xs->umem->size, xs->umem->chunk_mask);
746 xdp_add_sk_umem(xs->umem, xs);
747
748 out_unlock:
749 if (err) {
750 dev_put(dev);
751 } else {
752 /* Matches smp_rmb() in bind() for shared umem
753 * sockets, and xsk_is_bound().
754 */
755 smp_wmb();
756 WRITE_ONCE(xs->state, XSK_BOUND);
757 }
758 out_release:
759 mutex_unlock(&xs->mutex);
760 rtnl_unlock();
761 return err;
762 }
763
764 struct xdp_umem_reg_v1 {
765 __u64 addr; /* Start of packet data area */
766 __u64 len; /* Length of packet data area */
767 __u32 chunk_size;
768 __u32 headroom;
769 };
770
771 static int xsk_setsockopt(struct socket *sock, int level, int optname,
772 char __user *optval, unsigned int optlen)
773 {
774 struct sock *sk = sock->sk;
775 struct xdp_sock *xs = xdp_sk(sk);
776 int err;
777
778 if (level != SOL_XDP)
779 return -ENOPROTOOPT;
780
781 switch (optname) {
782 case XDP_RX_RING:
783 case XDP_TX_RING:
784 {
785 struct xsk_queue **q;
786 int entries;
787
788 if (optlen < sizeof(entries))
789 return -EINVAL;
790 if (copy_from_user(&entries, optval, sizeof(entries)))
791 return -EFAULT;
792
793 mutex_lock(&xs->mutex);
794 if (xs->state != XSK_READY) {
795 mutex_unlock(&xs->mutex);
796 return -EBUSY;
797 }
798 q = (optname == XDP_TX_RING) ? &xs->tx : &xs->rx;
799 err = xsk_init_queue(entries, q, false);
800 if (!err && optname == XDP_TX_RING)
801 /* Tx needs to be explicitly woken up the first time */
802 xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP;
803 mutex_unlock(&xs->mutex);
804 return err;
805 }
806 case XDP_UMEM_REG:
807 {
808 size_t mr_size = sizeof(struct xdp_umem_reg);
809 struct xdp_umem_reg mr = {};
810 struct xdp_umem *umem;
811
812 if (optlen < sizeof(struct xdp_umem_reg_v1))
813 return -EINVAL;
814 else if (optlen < sizeof(mr))
815 mr_size = sizeof(struct xdp_umem_reg_v1);
816
817 if (copy_from_user(&mr, optval, mr_size))
818 return -EFAULT;
819
820 mutex_lock(&xs->mutex);
821 if (xs->state != XSK_READY || xs->umem) {
822 mutex_unlock(&xs->mutex);
823 return -EBUSY;
824 }
825
826 umem = xdp_umem_create(&mr);
827 if (IS_ERR(umem)) {
828 mutex_unlock(&xs->mutex);
829 return PTR_ERR(umem);
830 }
831
832 /* Make sure umem is ready before it can be seen by others */
833 smp_wmb();
834 WRITE_ONCE(xs->umem, umem);
835 mutex_unlock(&xs->mutex);
836 return 0;
837 }
838 case XDP_UMEM_FILL_RING:
839 case XDP_UMEM_COMPLETION_RING:
840 {
841 struct xsk_queue **q;
842 int entries;
843
844 if (copy_from_user(&entries, optval, sizeof(entries)))
845 return -EFAULT;
846
847 mutex_lock(&xs->mutex);
848 if (xs->state != XSK_READY) {
849 mutex_unlock(&xs->mutex);
850 return -EBUSY;
851 }
852 if (!xs->umem) {
853 mutex_unlock(&xs->mutex);
854 return -EINVAL;
855 }
856
857 q = (optname == XDP_UMEM_FILL_RING) ? &xs->umem->fq :
858 &xs->umem->cq;
859 err = xsk_init_queue(entries, q, true);
860 mutex_unlock(&xs->mutex);
861 return err;
862 }
863 default:
864 break;
865 }
866
867 return -ENOPROTOOPT;
868 }
869
870 static void xsk_enter_rxtx_offsets(struct xdp_ring_offset_v1 *ring)
871 {
872 ring->producer = offsetof(struct xdp_rxtx_ring, ptrs.producer);
873 ring->consumer = offsetof(struct xdp_rxtx_ring, ptrs.consumer);
874 ring->desc = offsetof(struct xdp_rxtx_ring, desc);
875 }
876
877 static void xsk_enter_umem_offsets(struct xdp_ring_offset_v1 *ring)
878 {
879 ring->producer = offsetof(struct xdp_umem_ring, ptrs.producer);
880 ring->consumer = offsetof(struct xdp_umem_ring, ptrs.consumer);
881 ring->desc = offsetof(struct xdp_umem_ring, desc);
882 }
883
884 static int xsk_getsockopt(struct socket *sock, int level, int optname,
885 char __user *optval, int __user *optlen)
886 {
887 struct sock *sk = sock->sk;
888 struct xdp_sock *xs = xdp_sk(sk);
889 int len;
890
891 if (level != SOL_XDP)
892 return -ENOPROTOOPT;
893
894 if (get_user(len, optlen))
895 return -EFAULT;
896 if (len < 0)
897 return -EINVAL;
898
899 switch (optname) {
900 case XDP_STATISTICS:
901 {
902 struct xdp_statistics stats;
903
904 if (len < sizeof(stats))
905 return -EINVAL;
906
907 mutex_lock(&xs->mutex);
908 stats.rx_dropped = xs->rx_dropped;
909 stats.rx_invalid_descs = xskq_nb_invalid_descs(xs->rx);
910 stats.tx_invalid_descs = xskq_nb_invalid_descs(xs->tx);
911 mutex_unlock(&xs->mutex);
912
913 if (copy_to_user(optval, &stats, sizeof(stats)))
914 return -EFAULT;
915 if (put_user(sizeof(stats), optlen))
916 return -EFAULT;
917
918 return 0;
919 }
920 case XDP_MMAP_OFFSETS:
921 {
922 struct xdp_mmap_offsets off;
923 struct xdp_mmap_offsets_v1 off_v1;
924 bool flags_supported = true;
925 void *to_copy;
926
927 if (len < sizeof(off_v1))
928 return -EINVAL;
929 else if (len < sizeof(off))
930 flags_supported = false;
931
932 if (flags_supported) {
933 /* xdp_ring_offset is identical to xdp_ring_offset_v1
934 * except for the flags field added to the end.
935 */
936 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *)
937 &off.rx);
938 xsk_enter_rxtx_offsets((struct xdp_ring_offset_v1 *)
939 &off.tx);
940 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *)
941 &off.fr);
942 xsk_enter_umem_offsets((struct xdp_ring_offset_v1 *)
943 &off.cr);
944 off.rx.flags = offsetof(struct xdp_rxtx_ring,
945 ptrs.flags);
946 off.tx.flags = offsetof(struct xdp_rxtx_ring,
947 ptrs.flags);
948 off.fr.flags = offsetof(struct xdp_umem_ring,
949 ptrs.flags);
950 off.cr.flags = offsetof(struct xdp_umem_ring,
951 ptrs.flags);
952
953 len = sizeof(off);
954 to_copy = &off;
955 } else {
956 xsk_enter_rxtx_offsets(&off_v1.rx);
957 xsk_enter_rxtx_offsets(&off_v1.tx);
958 xsk_enter_umem_offsets(&off_v1.fr);
959 xsk_enter_umem_offsets(&off_v1.cr);
960
961 len = sizeof(off_v1);
962 to_copy = &off_v1;
963 }
964
965 if (copy_to_user(optval, to_copy, len))
966 return -EFAULT;
967 if (put_user(len, optlen))
968 return -EFAULT;
969
970 return 0;
971 }
972 case XDP_OPTIONS:
973 {
974 struct xdp_options opts = {};
975
976 if (len < sizeof(opts))
977 return -EINVAL;
978
979 mutex_lock(&xs->mutex);
980 if (xs->zc)
981 opts.flags |= XDP_OPTIONS_ZEROCOPY;
982 mutex_unlock(&xs->mutex);
983
984 len = sizeof(opts);
985 if (copy_to_user(optval, &opts, len))
986 return -EFAULT;
987 if (put_user(len, optlen))
988 return -EFAULT;
989
990 return 0;
991 }
992 default:
993 break;
994 }
995
996 return -EOPNOTSUPP;
997 }
998
999 static int xsk_mmap(struct file *file, struct socket *sock,
1000 struct vm_area_struct *vma)
1001 {
1002 loff_t offset = (loff_t)vma->vm_pgoff << PAGE_SHIFT;
1003 unsigned long size = vma->vm_end - vma->vm_start;
1004 struct xdp_sock *xs = xdp_sk(sock->sk);
1005 struct xsk_queue *q = NULL;
1006 struct xdp_umem *umem;
1007 unsigned long pfn;
1008 struct page *qpg;
1009
1010 if (READ_ONCE(xs->state) != XSK_READY)
1011 return -EBUSY;
1012
1013 if (offset == XDP_PGOFF_RX_RING) {
1014 q = READ_ONCE(xs->rx);
1015 } else if (offset == XDP_PGOFF_TX_RING) {
1016 q = READ_ONCE(xs->tx);
1017 } else {
1018 umem = READ_ONCE(xs->umem);
1019 if (!umem)
1020 return -EINVAL;
1021
1022 /* Matches the smp_wmb() in XDP_UMEM_REG */
1023 smp_rmb();
1024 if (offset == XDP_UMEM_PGOFF_FILL_RING)
1025 q = READ_ONCE(umem->fq);
1026 else if (offset == XDP_UMEM_PGOFF_COMPLETION_RING)
1027 q = READ_ONCE(umem->cq);
1028 }
1029
1030 if (!q)
1031 return -EINVAL;
1032
1033 /* Matches the smp_wmb() in xsk_init_queue */
1034 smp_rmb();
1035 qpg = virt_to_head_page(q->ring);
1036 if (size > page_size(qpg))
1037 return -EINVAL;
1038
1039 pfn = virt_to_phys(q->ring) >> PAGE_SHIFT;
1040 return remap_pfn_range(vma, vma->vm_start, pfn,
1041 size, vma->vm_page_prot);
1042 }
1043
1044 static int xsk_notifier(struct notifier_block *this,
1045 unsigned long msg, void *ptr)
1046 {
1047 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1048 struct net *net = dev_net(dev);
1049 struct sock *sk;
1050
1051 switch (msg) {
1052 case NETDEV_UNREGISTER:
1053 mutex_lock(&net->xdp.lock);
1054 sk_for_each(sk, &net->xdp.list) {
1055 struct xdp_sock *xs = xdp_sk(sk);
1056
1057 mutex_lock(&xs->mutex);
1058 if (xs->dev == dev) {
1059 sk->sk_err = ENETDOWN;
1060 if (!sock_flag(sk, SOCK_DEAD))
1061 sk->sk_error_report(sk);
1062
1063 xsk_unbind_dev(xs);
1064
1065 /* Clear device references in umem. */
1066 xdp_umem_clear_dev(xs->umem);
1067 }
1068 mutex_unlock(&xs->mutex);
1069 }
1070 mutex_unlock(&net->xdp.lock);
1071 break;
1072 }
1073 return NOTIFY_DONE;
1074 }
1075
1076 static struct proto xsk_proto = {
1077 .name = "XDP",
1078 .owner = THIS_MODULE,
1079 .obj_size = sizeof(struct xdp_sock),
1080 };
1081
1082 static const struct proto_ops xsk_proto_ops = {
1083 .family = PF_XDP,
1084 .owner = THIS_MODULE,
1085 .release = xsk_release,
1086 .bind = xsk_bind,
1087 .connect = sock_no_connect,
1088 .socketpair = sock_no_socketpair,
1089 .accept = sock_no_accept,
1090 .getname = sock_no_getname,
1091 .poll = xsk_poll,
1092 .ioctl = sock_no_ioctl,
1093 .listen = sock_no_listen,
1094 .shutdown = sock_no_shutdown,
1095 .setsockopt = xsk_setsockopt,
1096 .getsockopt = xsk_getsockopt,
1097 .sendmsg = xsk_sendmsg,
1098 .recvmsg = sock_no_recvmsg,
1099 .mmap = xsk_mmap,
1100 .sendpage = sock_no_sendpage,
1101 };
1102
1103 static void xsk_destruct(struct sock *sk)
1104 {
1105 struct xdp_sock *xs = xdp_sk(sk);
1106
1107 if (!sock_flag(sk, SOCK_DEAD))
1108 return;
1109
1110 xdp_put_umem(xs->umem);
1111
1112 sk_refcnt_debug_dec(sk);
1113 }
1114
1115 static int xsk_create(struct net *net, struct socket *sock, int protocol,
1116 int kern)
1117 {
1118 struct sock *sk;
1119 struct xdp_sock *xs;
1120
1121 if (!ns_capable(net->user_ns, CAP_NET_RAW))
1122 return -EPERM;
1123 if (sock->type != SOCK_RAW)
1124 return -ESOCKTNOSUPPORT;
1125
1126 if (protocol)
1127 return -EPROTONOSUPPORT;
1128
1129 sock->state = SS_UNCONNECTED;
1130
1131 sk = sk_alloc(net, PF_XDP, GFP_KERNEL, &xsk_proto, kern);
1132 if (!sk)
1133 return -ENOBUFS;
1134
1135 sock->ops = &xsk_proto_ops;
1136
1137 sock_init_data(sock, sk);
1138
1139 sk->sk_family = PF_XDP;
1140
1141 sk->sk_destruct = xsk_destruct;
1142 sk_refcnt_debug_inc(sk);
1143
1144 sock_set_flag(sk, SOCK_RCU_FREE);
1145
1146 xs = xdp_sk(sk);
1147 xs->state = XSK_READY;
1148 mutex_init(&xs->mutex);
1149 spin_lock_init(&xs->rx_lock);
1150 spin_lock_init(&xs->tx_completion_lock);
1151
1152 INIT_LIST_HEAD(&xs->map_list);
1153 spin_lock_init(&xs->map_list_lock);
1154
1155 mutex_lock(&net->xdp.lock);
1156 sk_add_node_rcu(sk, &net->xdp.list);
1157 mutex_unlock(&net->xdp.lock);
1158
1159 local_bh_disable();
1160 sock_prot_inuse_add(net, &xsk_proto, 1);
1161 local_bh_enable();
1162
1163 return 0;
1164 }
1165
1166 static const struct net_proto_family xsk_family_ops = {
1167 .family = PF_XDP,
1168 .create = xsk_create,
1169 .owner = THIS_MODULE,
1170 };
1171
1172 static struct notifier_block xsk_netdev_notifier = {
1173 .notifier_call = xsk_notifier,
1174 };
1175
1176 static int __net_init xsk_net_init(struct net *net)
1177 {
1178 mutex_init(&net->xdp.lock);
1179 INIT_HLIST_HEAD(&net->xdp.list);
1180 return 0;
1181 }
1182
1183 static void __net_exit xsk_net_exit(struct net *net)
1184 {
1185 WARN_ON_ONCE(!hlist_empty(&net->xdp.list));
1186 }
1187
1188 static struct pernet_operations xsk_net_ops = {
1189 .init = xsk_net_init,
1190 .exit = xsk_net_exit,
1191 };
1192
1193 static int __init xsk_init(void)
1194 {
1195 int err, cpu;
1196
1197 err = proto_register(&xsk_proto, 0 /* no slab */);
1198 if (err)
1199 goto out;
1200
1201 err = sock_register(&xsk_family_ops);
1202 if (err)
1203 goto out_proto;
1204
1205 err = register_pernet_subsys(&xsk_net_ops);
1206 if (err)
1207 goto out_sk;
1208
1209 err = register_netdevice_notifier(&xsk_netdev_notifier);
1210 if (err)
1211 goto out_pernet;
1212
1213 for_each_possible_cpu(cpu)
1214 INIT_LIST_HEAD(&per_cpu(xskmap_flush_list, cpu));
1215 return 0;
1216
1217 out_pernet:
1218 unregister_pernet_subsys(&xsk_net_ops);
1219 out_sk:
1220 sock_unregister(PF_XDP);
1221 out_proto:
1222 proto_unregister(&xsk_proto);
1223 out:
1224 return err;
1225 }
1226
1227 fs_initcall(xsk_init);
Linux with added FPC-III support