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net: Add MDIO bus driver for the Hisilicon FEMAC
[deliverable/linux.git] / drivers / net / macvtap.c
1 #include <linux/etherdevice.h>
2 #include <linux/if_macvlan.h>
3 #include <linux/if_vlan.h>
4 #include <linux/interrupt.h>
5 #include <linux/nsproxy.h>
6 #include <linux/compat.h>
7 #include <linux/if_tun.h>
8 #include <linux/module.h>
9 #include <linux/skbuff.h>
10 #include <linux/cache.h>
11 #include <linux/sched.h>
12 #include <linux/types.h>
13 #include <linux/slab.h>
14 #include <linux/wait.h>
15 #include <linux/cdev.h>
16 #include <linux/idr.h>
17 #include <linux/fs.h>
18 #include <linux/uio.h>
19
20 #include <net/net_namespace.h>
21 #include <net/rtnetlink.h>
22 #include <net/sock.h>
23 #include <linux/virtio_net.h>
24 #include <linux/skb_array.h>
25
26 /*
27 * A macvtap queue is the central object of this driver, it connects
28 * an open character device to a macvlan interface. There can be
29 * multiple queues on one interface, which map back to queues
30 * implemented in hardware on the underlying device.
31 *
32 * macvtap_proto is used to allocate queues through the sock allocation
33 * mechanism.
34 *
35 */
36 struct macvtap_queue {
37 struct sock sk;
38 struct socket sock;
39 struct socket_wq wq;
40 int vnet_hdr_sz;
41 struct macvlan_dev __rcu *vlan;
42 struct file *file;
43 unsigned int flags;
44 u16 queue_index;
45 bool enabled;
46 struct list_head next;
47 struct skb_array skb_array;
48 };
49
50 #define MACVTAP_FEATURES (IFF_VNET_HDR | IFF_MULTI_QUEUE)
51
52 #define MACVTAP_VNET_LE 0x80000000
53 #define MACVTAP_VNET_BE 0x40000000
54
55 #ifdef CONFIG_TUN_VNET_CROSS_LE
56 static inline bool macvtap_legacy_is_little_endian(struct macvtap_queue *q)
57 {
58 return q->flags & MACVTAP_VNET_BE ? false :
59 virtio_legacy_is_little_endian();
60 }
61
62 static long macvtap_get_vnet_be(struct macvtap_queue *q, int __user *sp)
63 {
64 int s = !!(q->flags & MACVTAP_VNET_BE);
65
66 if (put_user(s, sp))
67 return -EFAULT;
68
69 return 0;
70 }
71
72 static long macvtap_set_vnet_be(struct macvtap_queue *q, int __user *sp)
73 {
74 int s;
75
76 if (get_user(s, sp))
77 return -EFAULT;
78
79 if (s)
80 q->flags |= MACVTAP_VNET_BE;
81 else
82 q->flags &= ~MACVTAP_VNET_BE;
83
84 return 0;
85 }
86 #else
87 static inline bool macvtap_legacy_is_little_endian(struct macvtap_queue *q)
88 {
89 return virtio_legacy_is_little_endian();
90 }
91
92 static long macvtap_get_vnet_be(struct macvtap_queue *q, int __user *argp)
93 {
94 return -EINVAL;
95 }
96
97 static long macvtap_set_vnet_be(struct macvtap_queue *q, int __user *argp)
98 {
99 return -EINVAL;
100 }
101 #endif /* CONFIG_TUN_VNET_CROSS_LE */
102
103 static inline bool macvtap_is_little_endian(struct macvtap_queue *q)
104 {
105 return q->flags & MACVTAP_VNET_LE ||
106 macvtap_legacy_is_little_endian(q);
107 }
108
109 static inline u16 macvtap16_to_cpu(struct macvtap_queue *q, __virtio16 val)
110 {
111 return __virtio16_to_cpu(macvtap_is_little_endian(q), val);
112 }
113
114 static inline __virtio16 cpu_to_macvtap16(struct macvtap_queue *q, u16 val)
115 {
116 return __cpu_to_virtio16(macvtap_is_little_endian(q), val);
117 }
118
119 static struct proto macvtap_proto = {
120 .name = "macvtap",
121 .owner = THIS_MODULE,
122 .obj_size = sizeof (struct macvtap_queue),
123 };
124
125 /*
126 * Variables for dealing with macvtaps device numbers.
127 */
128 static dev_t macvtap_major;
129 #define MACVTAP_NUM_DEVS (1U << MINORBITS)
130 static DEFINE_MUTEX(minor_lock);
131 static DEFINE_IDR(minor_idr);
132
133 #define GOODCOPY_LEN 128
134 static const void *macvtap_net_namespace(struct device *d)
135 {
136 struct net_device *dev = to_net_dev(d->parent);
137 return dev_net(dev);
138 }
139
140 static struct class macvtap_class = {
141 .name = "macvtap",
142 .owner = THIS_MODULE,
143 .ns_type = &net_ns_type_operations,
144 .namespace = macvtap_net_namespace,
145 };
146 static struct cdev macvtap_cdev;
147
148 static const struct proto_ops macvtap_socket_ops;
149
150 #define TUN_OFFLOADS (NETIF_F_HW_CSUM | NETIF_F_TSO_ECN | NETIF_F_TSO | \
151 NETIF_F_TSO6 | NETIF_F_UFO)
152 #define RX_OFFLOADS (NETIF_F_GRO | NETIF_F_LRO)
153 #define TAP_FEATURES (NETIF_F_GSO | NETIF_F_SG | NETIF_F_FRAGLIST)
154
155 static struct macvlan_dev *macvtap_get_vlan_rcu(const struct net_device *dev)
156 {
157 return rcu_dereference(dev->rx_handler_data);
158 }
159
160 /*
161 * RCU usage:
162 * The macvtap_queue and the macvlan_dev are loosely coupled, the
163 * pointers from one to the other can only be read while rcu_read_lock
164 * or rtnl is held.
165 *
166 * Both the file and the macvlan_dev hold a reference on the macvtap_queue
167 * through sock_hold(&q->sk). When the macvlan_dev goes away first,
168 * q->vlan becomes inaccessible. When the files gets closed,
169 * macvtap_get_queue() fails.
170 *
171 * There may still be references to the struct sock inside of the
172 * queue from outbound SKBs, but these never reference back to the
173 * file or the dev. The data structure is freed through __sk_free
174 * when both our references and any pending SKBs are gone.
175 */
176
177 static int macvtap_enable_queue(struct net_device *dev, struct file *file,
178 struct macvtap_queue *q)
179 {
180 struct macvlan_dev *vlan = netdev_priv(dev);
181 int err = -EINVAL;
182
183 ASSERT_RTNL();
184
185 if (q->enabled)
186 goto out;
187
188 err = 0;
189 rcu_assign_pointer(vlan->taps[vlan->numvtaps], q);
190 q->queue_index = vlan->numvtaps;
191 q->enabled = true;
192
193 vlan->numvtaps++;
194 out:
195 return err;
196 }
197
198 /* Requires RTNL */
199 static int macvtap_set_queue(struct net_device *dev, struct file *file,
200 struct macvtap_queue *q)
201 {
202 struct macvlan_dev *vlan = netdev_priv(dev);
203
204 if (vlan->numqueues == MAX_MACVTAP_QUEUES)
205 return -EBUSY;
206
207 rcu_assign_pointer(q->vlan, vlan);
208 rcu_assign_pointer(vlan->taps[vlan->numvtaps], q);
209 sock_hold(&q->sk);
210
211 q->file = file;
212 q->queue_index = vlan->numvtaps;
213 q->enabled = true;
214 file->private_data = q;
215 list_add_tail(&q->next, &vlan->queue_list);
216
217 vlan->numvtaps++;
218 vlan->numqueues++;
219
220 return 0;
221 }
222
223 static int macvtap_disable_queue(struct macvtap_queue *q)
224 {
225 struct macvlan_dev *vlan;
226 struct macvtap_queue *nq;
227
228 ASSERT_RTNL();
229 if (!q->enabled)
230 return -EINVAL;
231
232 vlan = rtnl_dereference(q->vlan);
233
234 if (vlan) {
235 int index = q->queue_index;
236 BUG_ON(index >= vlan->numvtaps);
237 nq = rtnl_dereference(vlan->taps[vlan->numvtaps - 1]);
238 nq->queue_index = index;
239
240 rcu_assign_pointer(vlan->taps[index], nq);
241 RCU_INIT_POINTER(vlan->taps[vlan->numvtaps - 1], NULL);
242 q->enabled = false;
243
244 vlan->numvtaps--;
245 }
246
247 return 0;
248 }
249
250 /*
251 * The file owning the queue got closed, give up both
252 * the reference that the files holds as well as the
253 * one from the macvlan_dev if that still exists.
254 *
255 * Using the spinlock makes sure that we don't get
256 * to the queue again after destroying it.
257 */
258 static void macvtap_put_queue(struct macvtap_queue *q)
259 {
260 struct macvlan_dev *vlan;
261
262 rtnl_lock();
263 vlan = rtnl_dereference(q->vlan);
264
265 if (vlan) {
266 if (q->enabled)
267 BUG_ON(macvtap_disable_queue(q));
268
269 vlan->numqueues--;
270 RCU_INIT_POINTER(q->vlan, NULL);
271 sock_put(&q->sk);
272 list_del_init(&q->next);
273 }
274
275 rtnl_unlock();
276
277 synchronize_rcu();
278 skb_array_cleanup(&q->skb_array);
279 sock_put(&q->sk);
280 }
281
282 /*
283 * Select a queue based on the rxq of the device on which this packet
284 * arrived. If the incoming device is not mq, calculate a flow hash
285 * to select a queue. If all fails, find the first available queue.
286 * Cache vlan->numvtaps since it can become zero during the execution
287 * of this function.
288 */
289 static struct macvtap_queue *macvtap_get_queue(struct net_device *dev,
290 struct sk_buff *skb)
291 {
292 struct macvlan_dev *vlan = netdev_priv(dev);
293 struct macvtap_queue *tap = NULL;
294 /* Access to taps array is protected by rcu, but access to numvtaps
295 * isn't. Below we use it to lookup a queue, but treat it as a hint
296 * and validate that the result isn't NULL - in case we are
297 * racing against queue removal.
298 */
299 int numvtaps = ACCESS_ONCE(vlan->numvtaps);
300 __u32 rxq;
301
302 if (!numvtaps)
303 goto out;
304
305 if (numvtaps == 1)
306 goto single;
307
308 /* Check if we can use flow to select a queue */
309 rxq = skb_get_hash(skb);
310 if (rxq) {
311 tap = rcu_dereference(vlan->taps[rxq % numvtaps]);
312 goto out;
313 }
314
315 if (likely(skb_rx_queue_recorded(skb))) {
316 rxq = skb_get_rx_queue(skb);
317
318 while (unlikely(rxq >= numvtaps))
319 rxq -= numvtaps;
320
321 tap = rcu_dereference(vlan->taps[rxq]);
322 goto out;
323 }
324
325 single:
326 tap = rcu_dereference(vlan->taps[0]);
327 out:
328 return tap;
329 }
330
331 /*
332 * The net_device is going away, give up the reference
333 * that it holds on all queues and safely set the pointer
334 * from the queues to NULL.
335 */
336 static void macvtap_del_queues(struct net_device *dev)
337 {
338 struct macvlan_dev *vlan = netdev_priv(dev);
339 struct macvtap_queue *q, *tmp;
340
341 ASSERT_RTNL();
342 list_for_each_entry_safe(q, tmp, &vlan->queue_list, next) {
343 list_del_init(&q->next);
344 RCU_INIT_POINTER(q->vlan, NULL);
345 if (q->enabled)
346 vlan->numvtaps--;
347 vlan->numqueues--;
348 sock_put(&q->sk);
349 }
350 BUG_ON(vlan->numvtaps);
351 BUG_ON(vlan->numqueues);
352 /* guarantee that any future macvtap_set_queue will fail */
353 vlan->numvtaps = MAX_MACVTAP_QUEUES;
354 }
355
356 static rx_handler_result_t macvtap_handle_frame(struct sk_buff **pskb)
357 {
358 struct sk_buff *skb = *pskb;
359 struct net_device *dev = skb->dev;
360 struct macvlan_dev *vlan;
361 struct macvtap_queue *q;
362 netdev_features_t features = TAP_FEATURES;
363
364 vlan = macvtap_get_vlan_rcu(dev);
365 if (!vlan)
366 return RX_HANDLER_PASS;
367
368 q = macvtap_get_queue(dev, skb);
369 if (!q)
370 return RX_HANDLER_PASS;
371
372 if (__skb_array_full(&q->skb_array))
373 goto drop;
374
375 skb_push(skb, ETH_HLEN);
376
377 /* Apply the forward feature mask so that we perform segmentation
378 * according to users wishes. This only works if VNET_HDR is
379 * enabled.
380 */
381 if (q->flags & IFF_VNET_HDR)
382 features |= vlan->tap_features;
383 if (netif_needs_gso(skb, features)) {
384 struct sk_buff *segs = __skb_gso_segment(skb, features, false);
385
386 if (IS_ERR(segs))
387 goto drop;
388
389 if (!segs) {
390 if (skb_array_produce(&q->skb_array, skb))
391 goto drop;
392 goto wake_up;
393 }
394
395 consume_skb(skb);
396 while (segs) {
397 struct sk_buff *nskb = segs->next;
398
399 segs->next = NULL;
400 if (skb_array_produce(&q->skb_array, segs)) {
401 kfree_skb(segs);
402 kfree_skb_list(nskb);
403 break;
404 }
405 segs = nskb;
406 }
407 } else {
408 /* If we receive a partial checksum and the tap side
409 * doesn't support checksum offload, compute the checksum.
410 * Note: it doesn't matter which checksum feature to
411 * check, we either support them all or none.
412 */
413 if (skb->ip_summed == CHECKSUM_PARTIAL &&
414 !(features & NETIF_F_CSUM_MASK) &&
415 skb_checksum_help(skb))
416 goto drop;
417 if (skb_array_produce(&q->skb_array, skb))
418 goto drop;
419 }
420
421 wake_up:
422 wake_up_interruptible_poll(sk_sleep(&q->sk), POLLIN | POLLRDNORM | POLLRDBAND);
423 return RX_HANDLER_CONSUMED;
424
425 drop:
426 /* Count errors/drops only here, thus don't care about args. */
427 macvlan_count_rx(vlan, 0, 0, 0);
428 kfree_skb(skb);
429 return RX_HANDLER_CONSUMED;
430 }
431
432 static int macvtap_get_minor(struct macvlan_dev *vlan)
433 {
434 int retval = -ENOMEM;
435
436 mutex_lock(&minor_lock);
437 retval = idr_alloc(&minor_idr, vlan, 1, MACVTAP_NUM_DEVS, GFP_KERNEL);
438 if (retval >= 0) {
439 vlan->minor = retval;
440 } else if (retval == -ENOSPC) {
441 printk(KERN_ERR "too many macvtap devices\n");
442 retval = -EINVAL;
443 }
444 mutex_unlock(&minor_lock);
445 return retval < 0 ? retval : 0;
446 }
447
448 static void macvtap_free_minor(struct macvlan_dev *vlan)
449 {
450 mutex_lock(&minor_lock);
451 if (vlan->minor) {
452 idr_remove(&minor_idr, vlan->minor);
453 vlan->minor = 0;
454 }
455 mutex_unlock(&minor_lock);
456 }
457
458 static struct net_device *dev_get_by_macvtap_minor(int minor)
459 {
460 struct net_device *dev = NULL;
461 struct macvlan_dev *vlan;
462
463 mutex_lock(&minor_lock);
464 vlan = idr_find(&minor_idr, minor);
465 if (vlan) {
466 dev = vlan->dev;
467 dev_hold(dev);
468 }
469 mutex_unlock(&minor_lock);
470 return dev;
471 }
472
473 static int macvtap_newlink(struct net *src_net,
474 struct net_device *dev,
475 struct nlattr *tb[],
476 struct nlattr *data[])
477 {
478 struct macvlan_dev *vlan = netdev_priv(dev);
479 int err;
480
481 INIT_LIST_HEAD(&vlan->queue_list);
482
483 /* Since macvlan supports all offloads by default, make
484 * tap support all offloads also.
485 */
486 vlan->tap_features = TUN_OFFLOADS;
487
488 err = netdev_rx_handler_register(dev, macvtap_handle_frame, vlan);
489 if (err)
490 return err;
491
492 /* Don't put anything that may fail after macvlan_common_newlink
493 * because we can't undo what it does.
494 */
495 return macvlan_common_newlink(src_net, dev, tb, data);
496 }
497
498 static void macvtap_dellink(struct net_device *dev,
499 struct list_head *head)
500 {
501 netdev_rx_handler_unregister(dev);
502 macvtap_del_queues(dev);
503 macvlan_dellink(dev, head);
504 }
505
506 static void macvtap_setup(struct net_device *dev)
507 {
508 macvlan_common_setup(dev);
509 dev->tx_queue_len = TUN_READQ_SIZE;
510 }
511
512 static struct rtnl_link_ops macvtap_link_ops __read_mostly = {
513 .kind = "macvtap",
514 .setup = macvtap_setup,
515 .newlink = macvtap_newlink,
516 .dellink = macvtap_dellink,
517 };
518
519
520 static void macvtap_sock_write_space(struct sock *sk)
521 {
522 wait_queue_head_t *wqueue;
523
524 if (!sock_writeable(sk) ||
525 !test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags))
526 return;
527
528 wqueue = sk_sleep(sk);
529 if (wqueue && waitqueue_active(wqueue))
530 wake_up_interruptible_poll(wqueue, POLLOUT | POLLWRNORM | POLLWRBAND);
531 }
532
533 static void macvtap_sock_destruct(struct sock *sk)
534 {
535 struct macvtap_queue *q = container_of(sk, struct macvtap_queue, sk);
536 struct sk_buff *skb;
537
538 while ((skb = skb_array_consume(&q->skb_array)) != NULL)
539 kfree(skb);
540 }
541
542 static int macvtap_open(struct inode *inode, struct file *file)
543 {
544 struct net *net = current->nsproxy->net_ns;
545 struct net_device *dev;
546 struct macvtap_queue *q;
547 int err = -ENODEV;
548
549 rtnl_lock();
550 dev = dev_get_by_macvtap_minor(iminor(inode));
551 if (!dev)
552 goto err;
553
554 err = -ENOMEM;
555 q = (struct macvtap_queue *)sk_alloc(net, AF_UNSPEC, GFP_KERNEL,
556 &macvtap_proto, 0);
557 if (!q)
558 goto err;
559
560 RCU_INIT_POINTER(q->sock.wq, &q->wq);
561 init_waitqueue_head(&q->wq.wait);
562 q->sock.type = SOCK_RAW;
563 q->sock.state = SS_CONNECTED;
564 q->sock.file = file;
565 q->sock.ops = &macvtap_socket_ops;
566 sock_init_data(&q->sock, &q->sk);
567 q->sk.sk_write_space = macvtap_sock_write_space;
568 q->sk.sk_destruct = macvtap_sock_destruct;
569 q->flags = IFF_VNET_HDR | IFF_NO_PI | IFF_TAP;
570 q->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
571
572 /*
573 * so far only KVM virtio_net uses macvtap, enable zero copy between
574 * guest kernel and host kernel when lower device supports zerocopy
575 *
576 * The macvlan supports zerocopy iff the lower device supports zero
577 * copy so we don't have to look at the lower device directly.
578 */
579 if ((dev->features & NETIF_F_HIGHDMA) && (dev->features & NETIF_F_SG))
580 sock_set_flag(&q->sk, SOCK_ZEROCOPY);
581
582 err = -ENOMEM;
583 if (skb_array_init(&q->skb_array, dev->tx_queue_len, GFP_KERNEL))
584 goto err_array;
585
586 err = macvtap_set_queue(dev, file, q);
587 if (err)
588 goto err_queue;
589
590 dev_put(dev);
591
592 rtnl_unlock();
593 return err;
594
595 err_queue:
596 skb_array_cleanup(&q->skb_array);
597 err_array:
598 sock_put(&q->sk);
599 err:
600 if (dev)
601 dev_put(dev);
602
603 rtnl_unlock();
604 return err;
605 }
606
607 static int macvtap_release(struct inode *inode, struct file *file)
608 {
609 struct macvtap_queue *q = file->private_data;
610 macvtap_put_queue(q);
611 return 0;
612 }
613
614 static unsigned int macvtap_poll(struct file *file, poll_table * wait)
615 {
616 struct macvtap_queue *q = file->private_data;
617 unsigned int mask = POLLERR;
618
619 if (!q)
620 goto out;
621
622 mask = 0;
623 poll_wait(file, &q->wq.wait, wait);
624
625 if (!skb_array_empty(&q->skb_array))
626 mask |= POLLIN | POLLRDNORM;
627
628 if (sock_writeable(&q->sk) ||
629 (!test_and_set_bit(SOCKWQ_ASYNC_NOSPACE, &q->sock.flags) &&
630 sock_writeable(&q->sk)))
631 mask |= POLLOUT | POLLWRNORM;
632
633 out:
634 return mask;
635 }
636
637 static inline struct sk_buff *macvtap_alloc_skb(struct sock *sk, size_t prepad,
638 size_t len, size_t linear,
639 int noblock, int *err)
640 {
641 struct sk_buff *skb;
642
643 /* Under a page? Don't bother with paged skb. */
644 if (prepad + len < PAGE_SIZE || !linear)
645 linear = len;
646
647 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
648 err, 0);
649 if (!skb)
650 return NULL;
651
652 skb_reserve(skb, prepad);
653 skb_put(skb, linear);
654 skb->data_len = len - linear;
655 skb->len += len - linear;
656
657 return skb;
658 }
659
660 /* Neighbour code has some assumptions on HH_DATA_MOD alignment */
661 #define MACVTAP_RESERVE HH_DATA_OFF(ETH_HLEN)
662
663 /* Get packet from user space buffer */
664 static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m,
665 struct iov_iter *from, int noblock)
666 {
667 int good_linear = SKB_MAX_HEAD(MACVTAP_RESERVE);
668 struct sk_buff *skb;
669 struct macvlan_dev *vlan;
670 unsigned long total_len = iov_iter_count(from);
671 unsigned long len = total_len;
672 int err;
673 struct virtio_net_hdr vnet_hdr = { 0 };
674 int vnet_hdr_len = 0;
675 int copylen = 0;
676 int depth;
677 bool zerocopy = false;
678 size_t linear;
679 ssize_t n;
680
681 if (q->flags & IFF_VNET_HDR) {
682 vnet_hdr_len = q->vnet_hdr_sz;
683
684 err = -EINVAL;
685 if (len < vnet_hdr_len)
686 goto err;
687 len -= vnet_hdr_len;
688
689 err = -EFAULT;
690 n = copy_from_iter(&vnet_hdr, sizeof(vnet_hdr), from);
691 if (n != sizeof(vnet_hdr))
692 goto err;
693 iov_iter_advance(from, vnet_hdr_len - sizeof(vnet_hdr));
694 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
695 macvtap16_to_cpu(q, vnet_hdr.csum_start) +
696 macvtap16_to_cpu(q, vnet_hdr.csum_offset) + 2 >
697 macvtap16_to_cpu(q, vnet_hdr.hdr_len))
698 vnet_hdr.hdr_len = cpu_to_macvtap16(q,
699 macvtap16_to_cpu(q, vnet_hdr.csum_start) +
700 macvtap16_to_cpu(q, vnet_hdr.csum_offset) + 2);
701 err = -EINVAL;
702 if (macvtap16_to_cpu(q, vnet_hdr.hdr_len) > len)
703 goto err;
704 }
705
706 err = -EINVAL;
707 if (unlikely(len < ETH_HLEN))
708 goto err;
709
710 if (m && m->msg_control && sock_flag(&q->sk, SOCK_ZEROCOPY)) {
711 struct iov_iter i;
712
713 copylen = vnet_hdr.hdr_len ?
714 macvtap16_to_cpu(q, vnet_hdr.hdr_len) : GOODCOPY_LEN;
715 if (copylen > good_linear)
716 copylen = good_linear;
717 else if (copylen < ETH_HLEN)
718 copylen = ETH_HLEN;
719 linear = copylen;
720 i = *from;
721 iov_iter_advance(&i, copylen);
722 if (iov_iter_npages(&i, INT_MAX) <= MAX_SKB_FRAGS)
723 zerocopy = true;
724 }
725
726 if (!zerocopy) {
727 copylen = len;
728 linear = macvtap16_to_cpu(q, vnet_hdr.hdr_len);
729 if (linear > good_linear)
730 linear = good_linear;
731 else if (linear < ETH_HLEN)
732 linear = ETH_HLEN;
733 }
734
735 skb = macvtap_alloc_skb(&q->sk, MACVTAP_RESERVE, copylen,
736 linear, noblock, &err);
737 if (!skb)
738 goto err;
739
740 if (zerocopy)
741 err = zerocopy_sg_from_iter(skb, from);
742 else {
743 err = skb_copy_datagram_from_iter(skb, 0, from, len);
744 if (!err && m && m->msg_control) {
745 struct ubuf_info *uarg = m->msg_control;
746 uarg->callback(uarg, false);
747 }
748 }
749
750 if (err)
751 goto err_kfree;
752
753 skb_set_network_header(skb, ETH_HLEN);
754 skb_reset_mac_header(skb);
755 skb->protocol = eth_hdr(skb)->h_proto;
756
757 if (vnet_hdr_len) {
758 err = virtio_net_hdr_to_skb(skb, &vnet_hdr,
759 macvtap_is_little_endian(q));
760 if (err)
761 goto err_kfree;
762 }
763
764 skb_probe_transport_header(skb, ETH_HLEN);
765
766 /* Move network header to the right position for VLAN tagged packets */
767 if ((skb->protocol == htons(ETH_P_8021Q) ||
768 skb->protocol == htons(ETH_P_8021AD)) &&
769 __vlan_get_protocol(skb, skb->protocol, &depth) != 0)
770 skb_set_network_header(skb, depth);
771
772 rcu_read_lock();
773 vlan = rcu_dereference(q->vlan);
774 /* copy skb_ubuf_info for callback when skb has no error */
775 if (zerocopy) {
776 skb_shinfo(skb)->destructor_arg = m->msg_control;
777 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
778 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
779 }
780 if (vlan) {
781 skb->dev = vlan->dev;
782 dev_queue_xmit(skb);
783 } else {
784 kfree_skb(skb);
785 }
786 rcu_read_unlock();
787
788 return total_len;
789
790 err_kfree:
791 kfree_skb(skb);
792
793 err:
794 rcu_read_lock();
795 vlan = rcu_dereference(q->vlan);
796 if (vlan)
797 this_cpu_inc(vlan->pcpu_stats->tx_dropped);
798 rcu_read_unlock();
799
800 return err;
801 }
802
803 static ssize_t macvtap_write_iter(struct kiocb *iocb, struct iov_iter *from)
804 {
805 struct file *file = iocb->ki_filp;
806 struct macvtap_queue *q = file->private_data;
807
808 return macvtap_get_user(q, NULL, from, file->f_flags & O_NONBLOCK);
809 }
810
811 /* Put packet to the user space buffer */
812 static ssize_t macvtap_put_user(struct macvtap_queue *q,
813 const struct sk_buff *skb,
814 struct iov_iter *iter)
815 {
816 int ret;
817 int vnet_hdr_len = 0;
818 int vlan_offset = 0;
819 int total;
820
821 if (q->flags & IFF_VNET_HDR) {
822 struct virtio_net_hdr vnet_hdr;
823 vnet_hdr_len = q->vnet_hdr_sz;
824 if (iov_iter_count(iter) < vnet_hdr_len)
825 return -EINVAL;
826
827 ret = virtio_net_hdr_from_skb(skb, &vnet_hdr,
828 macvtap_is_little_endian(q));
829 if (ret)
830 BUG();
831
832 if (copy_to_iter(&vnet_hdr, sizeof(vnet_hdr), iter) !=
833 sizeof(vnet_hdr))
834 return -EFAULT;
835
836 iov_iter_advance(iter, vnet_hdr_len - sizeof(vnet_hdr));
837 }
838 total = vnet_hdr_len;
839 total += skb->len;
840
841 if (skb_vlan_tag_present(skb)) {
842 struct {
843 __be16 h_vlan_proto;
844 __be16 h_vlan_TCI;
845 } veth;
846 veth.h_vlan_proto = skb->vlan_proto;
847 veth.h_vlan_TCI = htons(skb_vlan_tag_get(skb));
848
849 vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);
850 total += VLAN_HLEN;
851
852 ret = skb_copy_datagram_iter(skb, 0, iter, vlan_offset);
853 if (ret || !iov_iter_count(iter))
854 goto done;
855
856 ret = copy_to_iter(&veth, sizeof(veth), iter);
857 if (ret != sizeof(veth) || !iov_iter_count(iter))
858 goto done;
859 }
860
861 ret = skb_copy_datagram_iter(skb, vlan_offset, iter,
862 skb->len - vlan_offset);
863
864 done:
865 return ret ? ret : total;
866 }
867
868 static ssize_t macvtap_do_read(struct macvtap_queue *q,
869 struct iov_iter *to,
870 int noblock)
871 {
872 DEFINE_WAIT(wait);
873 struct sk_buff *skb;
874 ssize_t ret = 0;
875
876 if (!iov_iter_count(to))
877 return 0;
878
879 while (1) {
880 if (!noblock)
881 prepare_to_wait(sk_sleep(&q->sk), &wait,
882 TASK_INTERRUPTIBLE);
883
884 /* Read frames from the queue */
885 skb = skb_array_consume(&q->skb_array);
886 if (skb)
887 break;
888 if (noblock) {
889 ret = -EAGAIN;
890 break;
891 }
892 if (signal_pending(current)) {
893 ret = -ERESTARTSYS;
894 break;
895 }
896 /* Nothing to read, let's sleep */
897 schedule();
898 }
899 if (!noblock)
900 finish_wait(sk_sleep(&q->sk), &wait);
901
902 if (skb) {
903 ret = macvtap_put_user(q, skb, to);
904 if (unlikely(ret < 0))
905 kfree_skb(skb);
906 else
907 consume_skb(skb);
908 }
909 return ret;
910 }
911
912 static ssize_t macvtap_read_iter(struct kiocb *iocb, struct iov_iter *to)
913 {
914 struct file *file = iocb->ki_filp;
915 struct macvtap_queue *q = file->private_data;
916 ssize_t len = iov_iter_count(to), ret;
917
918 ret = macvtap_do_read(q, to, file->f_flags & O_NONBLOCK);
919 ret = min_t(ssize_t, ret, len);
920 if (ret > 0)
921 iocb->ki_pos = ret;
922 return ret;
923 }
924
925 static struct macvlan_dev *macvtap_get_vlan(struct macvtap_queue *q)
926 {
927 struct macvlan_dev *vlan;
928
929 ASSERT_RTNL();
930 vlan = rtnl_dereference(q->vlan);
931 if (vlan)
932 dev_hold(vlan->dev);
933
934 return vlan;
935 }
936
937 static void macvtap_put_vlan(struct macvlan_dev *vlan)
938 {
939 dev_put(vlan->dev);
940 }
941
942 static int macvtap_ioctl_set_queue(struct file *file, unsigned int flags)
943 {
944 struct macvtap_queue *q = file->private_data;
945 struct macvlan_dev *vlan;
946 int ret;
947
948 vlan = macvtap_get_vlan(q);
949 if (!vlan)
950 return -EINVAL;
951
952 if (flags & IFF_ATTACH_QUEUE)
953 ret = macvtap_enable_queue(vlan->dev, file, q);
954 else if (flags & IFF_DETACH_QUEUE)
955 ret = macvtap_disable_queue(q);
956 else
957 ret = -EINVAL;
958
959 macvtap_put_vlan(vlan);
960 return ret;
961 }
962
963 static int set_offload(struct macvtap_queue *q, unsigned long arg)
964 {
965 struct macvlan_dev *vlan;
966 netdev_features_t features;
967 netdev_features_t feature_mask = 0;
968
969 vlan = rtnl_dereference(q->vlan);
970 if (!vlan)
971 return -ENOLINK;
972
973 features = vlan->dev->features;
974
975 if (arg & TUN_F_CSUM) {
976 feature_mask = NETIF_F_HW_CSUM;
977
978 if (arg & (TUN_F_TSO4 | TUN_F_TSO6)) {
979 if (arg & TUN_F_TSO_ECN)
980 feature_mask |= NETIF_F_TSO_ECN;
981 if (arg & TUN_F_TSO4)
982 feature_mask |= NETIF_F_TSO;
983 if (arg & TUN_F_TSO6)
984 feature_mask |= NETIF_F_TSO6;
985 }
986
987 if (arg & TUN_F_UFO)
988 feature_mask |= NETIF_F_UFO;
989 }
990
991 /* tun/tap driver inverts the usage for TSO offloads, where
992 * setting the TSO bit means that the userspace wants to
993 * accept TSO frames and turning it off means that user space
994 * does not support TSO.
995 * For macvtap, we have to invert it to mean the same thing.
996 * When user space turns off TSO, we turn off GSO/LRO so that
997 * user-space will not receive TSO frames.
998 */
999 if (feature_mask & (NETIF_F_TSO | NETIF_F_TSO6 | NETIF_F_UFO))
1000 features |= RX_OFFLOADS;
1001 else
1002 features &= ~RX_OFFLOADS;
1003
1004 /* tap_features are the same as features on tun/tap and
1005 * reflect user expectations.
1006 */
1007 vlan->tap_features = feature_mask;
1008 vlan->set_features = features;
1009 netdev_update_features(vlan->dev);
1010
1011 return 0;
1012 }
1013
1014 /*
1015 * provide compatibility with generic tun/tap interface
1016 */
1017 static long macvtap_ioctl(struct file *file, unsigned int cmd,
1018 unsigned long arg)
1019 {
1020 struct macvtap_queue *q = file->private_data;
1021 struct macvlan_dev *vlan;
1022 void __user *argp = (void __user *)arg;
1023 struct ifreq __user *ifr = argp;
1024 unsigned int __user *up = argp;
1025 unsigned short u;
1026 int __user *sp = argp;
1027 struct sockaddr sa;
1028 int s;
1029 int ret;
1030
1031 switch (cmd) {
1032 case TUNSETIFF:
1033 /* ignore the name, just look at flags */
1034 if (get_user(u, &ifr->ifr_flags))
1035 return -EFAULT;
1036
1037 ret = 0;
1038 if ((u & ~MACVTAP_FEATURES) != (IFF_NO_PI | IFF_TAP))
1039 ret = -EINVAL;
1040 else
1041 q->flags = (q->flags & ~MACVTAP_FEATURES) | u;
1042
1043 return ret;
1044
1045 case TUNGETIFF:
1046 rtnl_lock();
1047 vlan = macvtap_get_vlan(q);
1048 if (!vlan) {
1049 rtnl_unlock();
1050 return -ENOLINK;
1051 }
1052
1053 ret = 0;
1054 u = q->flags;
1055 if (copy_to_user(&ifr->ifr_name, vlan->dev->name, IFNAMSIZ) ||
1056 put_user(u, &ifr->ifr_flags))
1057 ret = -EFAULT;
1058 macvtap_put_vlan(vlan);
1059 rtnl_unlock();
1060 return ret;
1061
1062 case TUNSETQUEUE:
1063 if (get_user(u, &ifr->ifr_flags))
1064 return -EFAULT;
1065 rtnl_lock();
1066 ret = macvtap_ioctl_set_queue(file, u);
1067 rtnl_unlock();
1068 return ret;
1069
1070 case TUNGETFEATURES:
1071 if (put_user(IFF_TAP | IFF_NO_PI | MACVTAP_FEATURES, up))
1072 return -EFAULT;
1073 return 0;
1074
1075 case TUNSETSNDBUF:
1076 if (get_user(s, sp))
1077 return -EFAULT;
1078
1079 q->sk.sk_sndbuf = s;
1080 return 0;
1081
1082 case TUNGETVNETHDRSZ:
1083 s = q->vnet_hdr_sz;
1084 if (put_user(s, sp))
1085 return -EFAULT;
1086 return 0;
1087
1088 case TUNSETVNETHDRSZ:
1089 if (get_user(s, sp))
1090 return -EFAULT;
1091 if (s < (int)sizeof(struct virtio_net_hdr))
1092 return -EINVAL;
1093
1094 q->vnet_hdr_sz = s;
1095 return 0;
1096
1097 case TUNGETVNETLE:
1098 s = !!(q->flags & MACVTAP_VNET_LE);
1099 if (put_user(s, sp))
1100 return -EFAULT;
1101 return 0;
1102
1103 case TUNSETVNETLE:
1104 if (get_user(s, sp))
1105 return -EFAULT;
1106 if (s)
1107 q->flags |= MACVTAP_VNET_LE;
1108 else
1109 q->flags &= ~MACVTAP_VNET_LE;
1110 return 0;
1111
1112 case TUNGETVNETBE:
1113 return macvtap_get_vnet_be(q, sp);
1114
1115 case TUNSETVNETBE:
1116 return macvtap_set_vnet_be(q, sp);
1117
1118 case TUNSETOFFLOAD:
1119 /* let the user check for future flags */
1120 if (arg & ~(TUN_F_CSUM | TUN_F_TSO4 | TUN_F_TSO6 |
1121 TUN_F_TSO_ECN | TUN_F_UFO))
1122 return -EINVAL;
1123
1124 rtnl_lock();
1125 ret = set_offload(q, arg);
1126 rtnl_unlock();
1127 return ret;
1128
1129 case SIOCGIFHWADDR:
1130 rtnl_lock();
1131 vlan = macvtap_get_vlan(q);
1132 if (!vlan) {
1133 rtnl_unlock();
1134 return -ENOLINK;
1135 }
1136 ret = 0;
1137 u = vlan->dev->type;
1138 if (copy_to_user(&ifr->ifr_name, vlan->dev->name, IFNAMSIZ) ||
1139 copy_to_user(&ifr->ifr_hwaddr.sa_data, vlan->dev->dev_addr, ETH_ALEN) ||
1140 put_user(u, &ifr->ifr_hwaddr.sa_family))
1141 ret = -EFAULT;
1142 macvtap_put_vlan(vlan);
1143 rtnl_unlock();
1144 return ret;
1145
1146 case SIOCSIFHWADDR:
1147 if (copy_from_user(&sa, &ifr->ifr_hwaddr, sizeof(sa)))
1148 return -EFAULT;
1149 rtnl_lock();
1150 vlan = macvtap_get_vlan(q);
1151 if (!vlan) {
1152 rtnl_unlock();
1153 return -ENOLINK;
1154 }
1155 ret = dev_set_mac_address(vlan->dev, &sa);
1156 macvtap_put_vlan(vlan);
1157 rtnl_unlock();
1158 return ret;
1159
1160 default:
1161 return -EINVAL;
1162 }
1163 }
1164
1165 #ifdef CONFIG_COMPAT
1166 static long macvtap_compat_ioctl(struct file *file, unsigned int cmd,
1167 unsigned long arg)
1168 {
1169 return macvtap_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
1170 }
1171 #endif
1172
1173 static const struct file_operations macvtap_fops = {
1174 .owner = THIS_MODULE,
1175 .open = macvtap_open,
1176 .release = macvtap_release,
1177 .read_iter = macvtap_read_iter,
1178 .write_iter = macvtap_write_iter,
1179 .poll = macvtap_poll,
1180 .llseek = no_llseek,
1181 .unlocked_ioctl = macvtap_ioctl,
1182 #ifdef CONFIG_COMPAT
1183 .compat_ioctl = macvtap_compat_ioctl,
1184 #endif
1185 };
1186
1187 static int macvtap_sendmsg(struct socket *sock, struct msghdr *m,
1188 size_t total_len)
1189 {
1190 struct macvtap_queue *q = container_of(sock, struct macvtap_queue, sock);
1191 return macvtap_get_user(q, m, &m->msg_iter, m->msg_flags & MSG_DONTWAIT);
1192 }
1193
1194 static int macvtap_recvmsg(struct socket *sock, struct msghdr *m,
1195 size_t total_len, int flags)
1196 {
1197 struct macvtap_queue *q = container_of(sock, struct macvtap_queue, sock);
1198 int ret;
1199 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC))
1200 return -EINVAL;
1201 ret = macvtap_do_read(q, &m->msg_iter, flags & MSG_DONTWAIT);
1202 if (ret > total_len) {
1203 m->msg_flags |= MSG_TRUNC;
1204 ret = flags & MSG_TRUNC ? ret : total_len;
1205 }
1206 return ret;
1207 }
1208
1209 static int macvtap_peek_len(struct socket *sock)
1210 {
1211 struct macvtap_queue *q = container_of(sock, struct macvtap_queue,
1212 sock);
1213 return skb_array_peek_len(&q->skb_array);
1214 }
1215
1216 /* Ops structure to mimic raw sockets with tun */
1217 static const struct proto_ops macvtap_socket_ops = {
1218 .sendmsg = macvtap_sendmsg,
1219 .recvmsg = macvtap_recvmsg,
1220 .peek_len = macvtap_peek_len,
1221 };
1222
1223 /* Get an underlying socket object from tun file. Returns error unless file is
1224 * attached to a device. The returned object works like a packet socket, it
1225 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
1226 * holding a reference to the file for as long as the socket is in use. */
1227 struct socket *macvtap_get_socket(struct file *file)
1228 {
1229 struct macvtap_queue *q;
1230 if (file->f_op != &macvtap_fops)
1231 return ERR_PTR(-EINVAL);
1232 q = file->private_data;
1233 if (!q)
1234 return ERR_PTR(-EBADFD);
1235 return &q->sock;
1236 }
1237 EXPORT_SYMBOL_GPL(macvtap_get_socket);
1238
1239 static int macvtap_queue_resize(struct macvlan_dev *vlan)
1240 {
1241 struct net_device *dev = vlan->dev;
1242 struct macvtap_queue *q;
1243 struct skb_array **arrays;
1244 int n = vlan->numqueues;
1245 int ret, i = 0;
1246
1247 arrays = kmalloc(sizeof *arrays * n, GFP_KERNEL);
1248 if (!arrays)
1249 return -ENOMEM;
1250
1251 list_for_each_entry(q, &vlan->queue_list, next)
1252 arrays[i++] = &q->skb_array;
1253
1254 ret = skb_array_resize_multiple(arrays, n,
1255 dev->tx_queue_len, GFP_KERNEL);
1256
1257 kfree(arrays);
1258 return ret;
1259 }
1260
1261 static int macvtap_device_event(struct notifier_block *unused,
1262 unsigned long event, void *ptr)
1263 {
1264 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1265 struct macvlan_dev *vlan;
1266 struct device *classdev;
1267 dev_t devt;
1268 int err;
1269 char tap_name[IFNAMSIZ];
1270
1271 if (dev->rtnl_link_ops != &macvtap_link_ops)
1272 return NOTIFY_DONE;
1273
1274 snprintf(tap_name, IFNAMSIZ, "tap%d", dev->ifindex);
1275 vlan = netdev_priv(dev);
1276
1277 switch (event) {
1278 case NETDEV_REGISTER:
1279 /* Create the device node here after the network device has
1280 * been registered but before register_netdevice has
1281 * finished running.
1282 */
1283 err = macvtap_get_minor(vlan);
1284 if (err)
1285 return notifier_from_errno(err);
1286
1287 devt = MKDEV(MAJOR(macvtap_major), vlan->minor);
1288 classdev = device_create(&macvtap_class, &dev->dev, devt,
1289 dev, tap_name);
1290 if (IS_ERR(classdev)) {
1291 macvtap_free_minor(vlan);
1292 return notifier_from_errno(PTR_ERR(classdev));
1293 }
1294 err = sysfs_create_link(&dev->dev.kobj, &classdev->kobj,
1295 tap_name);
1296 if (err)
1297 return notifier_from_errno(err);
1298 break;
1299 case NETDEV_UNREGISTER:
1300 /* vlan->minor == 0 if NETDEV_REGISTER above failed */
1301 if (vlan->minor == 0)
1302 break;
1303 sysfs_remove_link(&dev->dev.kobj, tap_name);
1304 devt = MKDEV(MAJOR(macvtap_major), vlan->minor);
1305 device_destroy(&macvtap_class, devt);
1306 macvtap_free_minor(vlan);
1307 break;
1308 case NETDEV_CHANGE_TX_QUEUE_LEN:
1309 if (macvtap_queue_resize(vlan))
1310 return NOTIFY_BAD;
1311 break;
1312 }
1313
1314 return NOTIFY_DONE;
1315 }
1316
1317 static struct notifier_block macvtap_notifier_block __read_mostly = {
1318 .notifier_call = macvtap_device_event,
1319 };
1320
1321 static int macvtap_init(void)
1322 {
1323 int err;
1324
1325 err = alloc_chrdev_region(&macvtap_major, 0,
1326 MACVTAP_NUM_DEVS, "macvtap");
1327 if (err)
1328 goto out1;
1329
1330 cdev_init(&macvtap_cdev, &macvtap_fops);
1331 err = cdev_add(&macvtap_cdev, macvtap_major, MACVTAP_NUM_DEVS);
1332 if (err)
1333 goto out2;
1334
1335 err = class_register(&macvtap_class);
1336 if (err)
1337 goto out3;
1338
1339 err = register_netdevice_notifier(&macvtap_notifier_block);
1340 if (err)
1341 goto out4;
1342
1343 err = macvlan_link_register(&macvtap_link_ops);
1344 if (err)
1345 goto out5;
1346
1347 return 0;
1348
1349 out5:
1350 unregister_netdevice_notifier(&macvtap_notifier_block);
1351 out4:
1352 class_unregister(&macvtap_class);
1353 out3:
1354 cdev_del(&macvtap_cdev);
1355 out2:
1356 unregister_chrdev_region(macvtap_major, MACVTAP_NUM_DEVS);
1357 out1:
1358 return err;
1359 }
1360 module_init(macvtap_init);
1361
1362 static void macvtap_exit(void)
1363 {
1364 rtnl_link_unregister(&macvtap_link_ops);
1365 unregister_netdevice_notifier(&macvtap_notifier_block);
1366 class_unregister(&macvtap_class);
1367 cdev_del(&macvtap_cdev);
1368 unregister_chrdev_region(macvtap_major, MACVTAP_NUM_DEVS);
1369 idr_destroy(&minor_idr);
1370 }
1371 module_exit(macvtap_exit);
1372
1373 MODULE_ALIAS_RTNL_LINK("macvtap");
1374 MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>");
1375 MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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