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/init.h>
15#include <linux/wait.h>
16#include <linux/cdev.h>
17#include <linux/idr.h>
18#include <linux/fs.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
25
26
27
28
29
30
31
32
33
34
35struct macvtap_queue {
36 struct sock sk;
37 struct socket sock;
38 struct socket_wq wq;
39 int vnet_hdr_sz;
40 struct macvlan_dev __rcu *vlan;
41 struct file *file;
42 unsigned int flags;
43 u16 queue_index;
44 bool enabled;
45 struct list_head next;
46};
47
48static struct proto macvtap_proto = {
49 .name = "macvtap",
50 .owner = THIS_MODULE,
51 .obj_size = sizeof (struct macvtap_queue),
52};
53
54
55
56
57static dev_t macvtap_major;
58#define MACVTAP_NUM_DEVS (1U << MINORBITS)
59static DEFINE_MUTEX(minor_lock);
60static DEFINE_IDR(minor_idr);
61
62#define GOODCOPY_LEN 128
63static struct class *macvtap_class;
64static struct cdev macvtap_cdev;
65
66static const struct proto_ops macvtap_socket_ops;
67
68#define TUN_OFFLOADS (NETIF_F_HW_CSUM | NETIF_F_TSO_ECN | NETIF_F_TSO | \
69 NETIF_F_TSO6 | NETIF_F_UFO)
70#define RX_OFFLOADS (NETIF_F_GRO | NETIF_F_LRO)
71#define TAP_FEATURES (NETIF_F_GSO | NETIF_F_SG)
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90static int macvtap_enable_queue(struct net_device *dev, struct file *file,
91 struct macvtap_queue *q)
92{
93 struct macvlan_dev *vlan = netdev_priv(dev);
94 int err = -EINVAL;
95
96 ASSERT_RTNL();
97
98 if (q->enabled)
99 goto out;
100
101 err = 0;
102 rcu_assign_pointer(vlan->taps[vlan->numvtaps], q);
103 q->queue_index = vlan->numvtaps;
104 q->enabled = true;
105
106 vlan->numvtaps++;
107out:
108 return err;
109}
110
111static int macvtap_set_queue(struct net_device *dev, struct file *file,
112 struct macvtap_queue *q)
113{
114 struct macvlan_dev *vlan = netdev_priv(dev);
115 int err = -EBUSY;
116
117 rtnl_lock();
118 if (vlan->numqueues == MAX_MACVTAP_QUEUES)
119 goto out;
120
121 err = 0;
122 rcu_assign_pointer(q->vlan, vlan);
123 rcu_assign_pointer(vlan->taps[vlan->numvtaps], q);
124 sock_hold(&q->sk);
125
126 q->file = file;
127 q->queue_index = vlan->numvtaps;
128 q->enabled = true;
129 file->private_data = q;
130 list_add_tail(&q->next, &vlan->queue_list);
131
132 vlan->numvtaps++;
133 vlan->numqueues++;
134
135out:
136 rtnl_unlock();
137 return err;
138}
139
140static int macvtap_disable_queue(struct macvtap_queue *q)
141{
142 struct macvlan_dev *vlan;
143 struct macvtap_queue *nq;
144
145 ASSERT_RTNL();
146 if (!q->enabled)
147 return -EINVAL;
148
149 vlan = rtnl_dereference(q->vlan);
150
151 if (vlan) {
152 int index = q->queue_index;
153 BUG_ON(index >= vlan->numvtaps);
154 nq = rtnl_dereference(vlan->taps[vlan->numvtaps - 1]);
155 nq->queue_index = index;
156
157 rcu_assign_pointer(vlan->taps[index], nq);
158 RCU_INIT_POINTER(vlan->taps[vlan->numvtaps - 1], NULL);
159 q->enabled = false;
160
161 vlan->numvtaps--;
162 }
163
164 return 0;
165}
166
167
168
169
170
171
172
173
174
175static void macvtap_put_queue(struct macvtap_queue *q)
176{
177 struct macvlan_dev *vlan;
178
179 rtnl_lock();
180 vlan = rtnl_dereference(q->vlan);
181
182 if (vlan) {
183 if (q->enabled)
184 BUG_ON(macvtap_disable_queue(q));
185
186 vlan->numqueues--;
187 RCU_INIT_POINTER(q->vlan, NULL);
188 sock_put(&q->sk);
189 list_del_init(&q->next);
190 }
191
192 rtnl_unlock();
193
194 synchronize_rcu();
195 sock_put(&q->sk);
196}
197
198
199
200
201
202
203
204
205static struct macvtap_queue *macvtap_get_queue(struct net_device *dev,
206 struct sk_buff *skb)
207{
208 struct macvlan_dev *vlan = netdev_priv(dev);
209 struct macvtap_queue *tap = NULL;
210
211
212
213
214
215 int numvtaps = ACCESS_ONCE(vlan->numvtaps);
216 __u32 rxq;
217
218 if (!numvtaps)
219 goto out;
220
221
222 rxq = skb_get_rxhash(skb);
223 if (rxq) {
224 tap = rcu_dereference(vlan->taps[rxq % numvtaps]);
225 goto out;
226 }
227
228 if (likely(skb_rx_queue_recorded(skb))) {
229 rxq = skb_get_rx_queue(skb);
230
231 while (unlikely(rxq >= numvtaps))
232 rxq -= numvtaps;
233
234 tap = rcu_dereference(vlan->taps[rxq]);
235 goto out;
236 }
237
238 tap = rcu_dereference(vlan->taps[0]);
239out:
240 return tap;
241}
242
243
244
245
246
247
248static void macvtap_del_queues(struct net_device *dev)
249{
250 struct macvlan_dev *vlan = netdev_priv(dev);
251 struct macvtap_queue *q, *tmp, *qlist[MAX_MACVTAP_QUEUES];
252 int i, j = 0;
253
254 ASSERT_RTNL();
255 list_for_each_entry_safe(q, tmp, &vlan->queue_list, next) {
256 list_del_init(&q->next);
257 qlist[j++] = q;
258 RCU_INIT_POINTER(q->vlan, NULL);
259 if (q->enabled)
260 vlan->numvtaps--;
261 vlan->numqueues--;
262 }
263 for (i = 0; i < vlan->numvtaps; i++)
264 RCU_INIT_POINTER(vlan->taps[i], NULL);
265 BUG_ON(vlan->numvtaps);
266 BUG_ON(vlan->numqueues);
267
268 vlan->numvtaps = MAX_MACVTAP_QUEUES;
269
270 for (--j; j >= 0; j--)
271 sock_put(&qlist[j]->sk);
272}
273
274
275
276
277
278
279static int macvtap_forward(struct net_device *dev, struct sk_buff *skb)
280{
281 struct macvlan_dev *vlan = netdev_priv(dev);
282 struct macvtap_queue *q = macvtap_get_queue(dev, skb);
283 netdev_features_t features = TAP_FEATURES;
284
285 if (!q)
286 goto drop;
287
288 if (skb_queue_len(&q->sk.sk_receive_queue) >= dev->tx_queue_len)
289 goto drop;
290
291 skb->dev = dev;
292
293
294
295
296 if (q->flags & IFF_VNET_HDR)
297 features |= vlan->tap_features;
298 if (netif_needs_gso(skb, features)) {
299 struct sk_buff *segs = __skb_gso_segment(skb, features, false);
300
301 if (IS_ERR(segs))
302 goto drop;
303
304 if (!segs) {
305 skb_queue_tail(&q->sk.sk_receive_queue, skb);
306 goto wake_up;
307 }
308
309 kfree_skb(skb);
310 while (segs) {
311 struct sk_buff *nskb = segs->next;
312
313 segs->next = NULL;
314 skb_queue_tail(&q->sk.sk_receive_queue, segs);
315 segs = nskb;
316 }
317 } else {
318 skb_queue_tail(&q->sk.sk_receive_queue, skb);
319 }
320
321wake_up:
322 wake_up_interruptible_poll(sk_sleep(&q->sk), POLLIN | POLLRDNORM | POLLRDBAND);
323 return NET_RX_SUCCESS;
324
325drop:
326 kfree_skb(skb);
327 return NET_RX_DROP;
328}
329
330
331
332
333
334
335static int macvtap_receive(struct sk_buff *skb)
336{
337 skb_push(skb, ETH_HLEN);
338 return macvtap_forward(skb->dev, skb);
339}
340
341static int macvtap_get_minor(struct macvlan_dev *vlan)
342{
343 int retval = -ENOMEM;
344
345 mutex_lock(&minor_lock);
346 retval = idr_alloc(&minor_idr, vlan, 1, MACVTAP_NUM_DEVS, GFP_KERNEL);
347 if (retval >= 0) {
348 vlan->minor = retval;
349 } else if (retval == -ENOSPC) {
350 printk(KERN_ERR "too many macvtap devices\n");
351 retval = -EINVAL;
352 }
353 mutex_unlock(&minor_lock);
354 return retval < 0 ? retval : 0;
355}
356
357static void macvtap_free_minor(struct macvlan_dev *vlan)
358{
359 mutex_lock(&minor_lock);
360 if (vlan->minor) {
361 idr_remove(&minor_idr, vlan->minor);
362 vlan->minor = 0;
363 }
364 mutex_unlock(&minor_lock);
365}
366
367static struct net_device *dev_get_by_macvtap_minor(int minor)
368{
369 struct net_device *dev = NULL;
370 struct macvlan_dev *vlan;
371
372 mutex_lock(&minor_lock);
373 vlan = idr_find(&minor_idr, minor);
374 if (vlan) {
375 dev = vlan->dev;
376 dev_hold(dev);
377 }
378 mutex_unlock(&minor_lock);
379 return dev;
380}
381
382static int macvtap_newlink(struct net *src_net,
383 struct net_device *dev,
384 struct nlattr *tb[],
385 struct nlattr *data[])
386{
387 struct macvlan_dev *vlan = netdev_priv(dev);
388 INIT_LIST_HEAD(&vlan->queue_list);
389
390
391
392
393 vlan->tap_features = TUN_OFFLOADS;
394
395
396
397
398 return macvlan_common_newlink(src_net, dev, tb, data,
399 macvtap_receive, macvtap_forward);
400}
401
402static void macvtap_dellink(struct net_device *dev,
403 struct list_head *head)
404{
405 macvtap_del_queues(dev);
406 macvlan_dellink(dev, head);
407}
408
409static void macvtap_setup(struct net_device *dev)
410{
411 macvlan_common_setup(dev);
412 dev->tx_queue_len = TUN_READQ_SIZE;
413}
414
415static struct rtnl_link_ops macvtap_link_ops __read_mostly = {
416 .kind = "macvtap",
417 .setup = macvtap_setup,
418 .newlink = macvtap_newlink,
419 .dellink = macvtap_dellink,
420};
421
422
423static void macvtap_sock_write_space(struct sock *sk)
424{
425 wait_queue_head_t *wqueue;
426
427 if (!sock_writeable(sk) ||
428 !test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
429 return;
430
431 wqueue = sk_sleep(sk);
432 if (wqueue && waitqueue_active(wqueue))
433 wake_up_interruptible_poll(wqueue, POLLOUT | POLLWRNORM | POLLWRBAND);
434}
435
436static void macvtap_sock_destruct(struct sock *sk)
437{
438 skb_queue_purge(&sk->sk_receive_queue);
439}
440
441static int macvtap_open(struct inode *inode, struct file *file)
442{
443 struct net *net = current->nsproxy->net_ns;
444 struct net_device *dev = dev_get_by_macvtap_minor(iminor(inode));
445 struct macvtap_queue *q;
446 int err;
447
448 err = -ENODEV;
449 if (!dev)
450 goto out;
451
452 err = -ENOMEM;
453 q = (struct macvtap_queue *)sk_alloc(net, AF_UNSPEC, GFP_KERNEL,
454 &macvtap_proto);
455 if (!q)
456 goto out;
457
458 RCU_INIT_POINTER(q->sock.wq, &q->wq);
459 init_waitqueue_head(&q->wq.wait);
460 q->sock.type = SOCK_RAW;
461 q->sock.state = SS_CONNECTED;
462 q->sock.file = file;
463 q->sock.ops = &macvtap_socket_ops;
464 sock_init_data(&q->sock, &q->sk);
465 q->sk.sk_write_space = macvtap_sock_write_space;
466 q->sk.sk_destruct = macvtap_sock_destruct;
467 q->flags = IFF_VNET_HDR | IFF_NO_PI | IFF_TAP;
468 q->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
469
470
471
472
473
474
475
476
477 if ((dev->features & NETIF_F_HIGHDMA) && (dev->features & NETIF_F_SG))
478 sock_set_flag(&q->sk, SOCK_ZEROCOPY);
479
480 err = macvtap_set_queue(dev, file, q);
481 if (err)
482 sock_put(&q->sk);
483
484out:
485 if (dev)
486 dev_put(dev);
487
488 return err;
489}
490
491static int macvtap_release(struct inode *inode, struct file *file)
492{
493 struct macvtap_queue *q = file->private_data;
494 macvtap_put_queue(q);
495 return 0;
496}
497
498static unsigned int macvtap_poll(struct file *file, poll_table * wait)
499{
500 struct macvtap_queue *q = file->private_data;
501 unsigned int mask = POLLERR;
502
503 if (!q)
504 goto out;
505
506 mask = 0;
507 poll_wait(file, &q->wq.wait, wait);
508
509 if (!skb_queue_empty(&q->sk.sk_receive_queue))
510 mask |= POLLIN | POLLRDNORM;
511
512 if (sock_writeable(&q->sk) ||
513 (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &q->sock.flags) &&
514 sock_writeable(&q->sk)))
515 mask |= POLLOUT | POLLWRNORM;
516
517out:
518 return mask;
519}
520
521static inline struct sk_buff *macvtap_alloc_skb(struct sock *sk, size_t prepad,
522 size_t len, size_t linear,
523 int noblock, int *err)
524{
525 struct sk_buff *skb;
526
527
528 if (prepad + len < PAGE_SIZE || !linear)
529 linear = len;
530
531 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
532 err);
533 if (!skb)
534 return NULL;
535
536 skb_reserve(skb, prepad);
537 skb_put(skb, linear);
538 skb->data_len = len - linear;
539 skb->len += len - linear;
540
541 return skb;
542}
543
544
545static int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *from,
546 int offset, size_t count)
547{
548 int len = iov_length(from, count) - offset;
549 int copy = skb_headlen(skb);
550 int size, offset1 = 0;
551 int i = 0;
552
553
554 while (count && (offset >= from->iov_len)) {
555 offset -= from->iov_len;
556 ++from;
557 --count;
558 }
559
560
561 while (count && (copy > 0)) {
562 size = min_t(unsigned int, copy, from->iov_len - offset);
563 if (copy_from_user(skb->data + offset1, from->iov_base + offset,
564 size))
565 return -EFAULT;
566 if (copy > size) {
567 ++from;
568 --count;
569 offset = 0;
570 } else
571 offset += size;
572 copy -= size;
573 offset1 += size;
574 }
575
576 if (len == offset1)
577 return 0;
578
579 while (count--) {
580 struct page *page[MAX_SKB_FRAGS];
581 int num_pages;
582 unsigned long base;
583 unsigned long truesize;
584
585 len = from->iov_len - offset;
586 if (!len) {
587 offset = 0;
588 ++from;
589 continue;
590 }
591 base = (unsigned long)from->iov_base + offset;
592 size = ((base & ~PAGE_MASK) + len + ~PAGE_MASK) >> PAGE_SHIFT;
593 if (i + size > MAX_SKB_FRAGS)
594 return -EMSGSIZE;
595 num_pages = get_user_pages_fast(base, size, 0, &page[i]);
596 if (num_pages != size) {
597 int j;
598
599 for (j = 0; j < num_pages; j++)
600 put_page(page[i + j]);
601 return -EFAULT;
602 }
603 truesize = size * PAGE_SIZE;
604 skb->data_len += len;
605 skb->len += len;
606 skb->truesize += truesize;
607 atomic_add(truesize, &skb->sk->sk_wmem_alloc);
608 while (len) {
609 int off = base & ~PAGE_MASK;
610 int size = min_t(int, len, PAGE_SIZE - off);
611 __skb_fill_page_desc(skb, i, page[i], off, size);
612 skb_shinfo(skb)->nr_frags++;
613
614 base += size;
615 len -= size;
616 i++;
617 }
618 offset = 0;
619 ++from;
620 }
621 return 0;
622}
623
624
625
626
627
628static int macvtap_skb_from_vnet_hdr(struct sk_buff *skb,
629 struct virtio_net_hdr *vnet_hdr)
630{
631 unsigned short gso_type = 0;
632 if (vnet_hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
633 switch (vnet_hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
634 case VIRTIO_NET_HDR_GSO_TCPV4:
635 gso_type = SKB_GSO_TCPV4;
636 break;
637 case VIRTIO_NET_HDR_GSO_TCPV6:
638 gso_type = SKB_GSO_TCPV6;
639 break;
640 case VIRTIO_NET_HDR_GSO_UDP:
641 gso_type = SKB_GSO_UDP;
642 break;
643 default:
644 return -EINVAL;
645 }
646
647 if (vnet_hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN)
648 gso_type |= SKB_GSO_TCP_ECN;
649
650 if (vnet_hdr->gso_size == 0)
651 return -EINVAL;
652 }
653
654 if (vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
655 if (!skb_partial_csum_set(skb, vnet_hdr->csum_start,
656 vnet_hdr->csum_offset))
657 return -EINVAL;
658 }
659
660 if (vnet_hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
661 skb_shinfo(skb)->gso_size = vnet_hdr->gso_size;
662 skb_shinfo(skb)->gso_type = gso_type;
663
664
665 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
666 skb_shinfo(skb)->gso_segs = 0;
667 }
668 return 0;
669}
670
671static int macvtap_skb_to_vnet_hdr(const struct sk_buff *skb,
672 struct virtio_net_hdr *vnet_hdr)
673{
674 memset(vnet_hdr, 0, sizeof(*vnet_hdr));
675
676 if (skb_is_gso(skb)) {
677 struct skb_shared_info *sinfo = skb_shinfo(skb);
678
679
680 vnet_hdr->hdr_len = skb_headlen(skb);
681 vnet_hdr->gso_size = sinfo->gso_size;
682 if (sinfo->gso_type & SKB_GSO_TCPV4)
683 vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
684 else if (sinfo->gso_type & SKB_GSO_TCPV6)
685 vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
686 else if (sinfo->gso_type & SKB_GSO_UDP)
687 vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP;
688 else
689 BUG();
690 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
691 vnet_hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN;
692 } else
693 vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
694
695 if (skb->ip_summed == CHECKSUM_PARTIAL) {
696 vnet_hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
697 vnet_hdr->csum_start = skb_checksum_start_offset(skb);
698 vnet_hdr->csum_offset = skb->csum_offset;
699 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
700 vnet_hdr->flags = VIRTIO_NET_HDR_F_DATA_VALID;
701 }
702
703 return 0;
704}
705
706static unsigned long iov_pages(const struct iovec *iv, int offset,
707 unsigned long nr_segs)
708{
709 unsigned long seg, base;
710 int pages = 0, len, size;
711
712 while (nr_segs && (offset >= iv->iov_len)) {
713 offset -= iv->iov_len;
714 ++iv;
715 --nr_segs;
716 }
717
718 for (seg = 0; seg < nr_segs; seg++) {
719 base = (unsigned long)iv[seg].iov_base + offset;
720 len = iv[seg].iov_len - offset;
721 size = ((base & ~PAGE_MASK) + len + ~PAGE_MASK) >> PAGE_SHIFT;
722 pages += size;
723 offset = 0;
724 }
725
726 return pages;
727}
728
729
730static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m,
731 const struct iovec *iv, unsigned long total_len,
732 size_t count, int noblock)
733{
734 struct sk_buff *skb;
735 struct macvlan_dev *vlan;
736 unsigned long len = total_len;
737 int err;
738 struct virtio_net_hdr vnet_hdr = { 0 };
739 int vnet_hdr_len = 0;
740 int copylen = 0;
741 bool zerocopy = false;
742 size_t linear;
743
744 if (q->flags & IFF_VNET_HDR) {
745 vnet_hdr_len = q->vnet_hdr_sz;
746
747 err = -EINVAL;
748 if (len < vnet_hdr_len)
749 goto err;
750 len -= vnet_hdr_len;
751
752 err = memcpy_fromiovecend((void *)&vnet_hdr, iv, 0,
753 sizeof(vnet_hdr));
754 if (err < 0)
755 goto err;
756 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
757 vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 >
758 vnet_hdr.hdr_len)
759 vnet_hdr.hdr_len = vnet_hdr.csum_start +
760 vnet_hdr.csum_offset + 2;
761 err = -EINVAL;
762 if (vnet_hdr.hdr_len > len)
763 goto err;
764 }
765
766 err = -EINVAL;
767 if (unlikely(len < ETH_HLEN))
768 goto err;
769
770 err = -EMSGSIZE;
771 if (unlikely(count > UIO_MAXIOV))
772 goto err;
773
774 if (m && m->msg_control && sock_flag(&q->sk, SOCK_ZEROCOPY)) {
775 copylen = vnet_hdr.hdr_len ? vnet_hdr.hdr_len : GOODCOPY_LEN;
776 linear = copylen;
777 if (iov_pages(iv, vnet_hdr_len + copylen, count)
778 <= MAX_SKB_FRAGS)
779 zerocopy = true;
780 }
781
782 if (!zerocopy) {
783 copylen = len;
784 linear = vnet_hdr.hdr_len;
785 }
786
787 skb = macvtap_alloc_skb(&q->sk, NET_IP_ALIGN, copylen,
788 linear, noblock, &err);
789 if (!skb)
790 goto err;
791
792 if (zerocopy)
793 err = zerocopy_sg_from_iovec(skb, iv, vnet_hdr_len, count);
794 else {
795 err = skb_copy_datagram_from_iovec(skb, 0, iv, vnet_hdr_len,
796 len);
797 if (!err && m && m->msg_control) {
798 struct ubuf_info *uarg = m->msg_control;
799 uarg->callback(uarg, false);
800 }
801 }
802
803 if (err)
804 goto err_kfree;
805
806 skb_set_network_header(skb, ETH_HLEN);
807 skb_reset_mac_header(skb);
808 skb->protocol = eth_hdr(skb)->h_proto;
809
810 if (vnet_hdr_len) {
811 err = macvtap_skb_from_vnet_hdr(skb, &vnet_hdr);
812 if (err)
813 goto err_kfree;
814 }
815
816 skb_probe_transport_header(skb, ETH_HLEN);
817
818 rcu_read_lock();
819 vlan = rcu_dereference(q->vlan);
820
821 if (zerocopy) {
822 skb_shinfo(skb)->destructor_arg = m->msg_control;
823 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
824 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
825 }
826 if (vlan) {
827 local_bh_disable();
828 macvlan_start_xmit(skb, vlan->dev);
829 local_bh_enable();
830 } else {
831 kfree_skb(skb);
832 }
833 rcu_read_unlock();
834
835 return total_len;
836
837err_kfree:
838 kfree_skb(skb);
839
840err:
841 rcu_read_lock();
842 vlan = rcu_dereference(q->vlan);
843 if (vlan)
844 vlan->dev->stats.tx_dropped++;
845 rcu_read_unlock();
846
847 return err;
848}
849
850static ssize_t macvtap_aio_write(struct kiocb *iocb, const struct iovec *iv,
851 unsigned long count, loff_t pos)
852{
853 struct file *file = iocb->ki_filp;
854 ssize_t result = -ENOLINK;
855 struct macvtap_queue *q = file->private_data;
856
857 result = macvtap_get_user(q, NULL, iv, iov_length(iv, count), count,
858 file->f_flags & O_NONBLOCK);
859 return result;
860}
861
862
863static ssize_t macvtap_put_user(struct macvtap_queue *q,
864 const struct sk_buff *skb,
865 const struct iovec *iv, int len)
866{
867 struct macvlan_dev *vlan;
868 int ret;
869 int vnet_hdr_len = 0;
870 int vlan_offset = 0;
871 int copied;
872
873 if (q->flags & IFF_VNET_HDR) {
874 struct virtio_net_hdr vnet_hdr;
875 vnet_hdr_len = q->vnet_hdr_sz;
876 if ((len -= vnet_hdr_len) < 0)
877 return -EINVAL;
878
879 ret = macvtap_skb_to_vnet_hdr(skb, &vnet_hdr);
880 if (ret)
881 return ret;
882
883 if (memcpy_toiovecend(iv, (void *)&vnet_hdr, 0, sizeof(vnet_hdr)))
884 return -EFAULT;
885 }
886 copied = vnet_hdr_len;
887
888 if (!vlan_tx_tag_present(skb))
889 len = min_t(int, skb->len, len);
890 else {
891 int copy;
892 struct {
893 __be16 h_vlan_proto;
894 __be16 h_vlan_TCI;
895 } veth;
896 veth.h_vlan_proto = skb->vlan_proto;
897 veth.h_vlan_TCI = htons(vlan_tx_tag_get(skb));
898
899 vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);
900 len = min_t(int, skb->len + VLAN_HLEN, len);
901
902 copy = min_t(int, vlan_offset, len);
903 ret = skb_copy_datagram_const_iovec(skb, 0, iv, copied, copy);
904 len -= copy;
905 copied += copy;
906 if (ret || !len)
907 goto done;
908
909 copy = min_t(int, sizeof(veth), len);
910 ret = memcpy_toiovecend(iv, (void *)&veth, copied, copy);
911 len -= copy;
912 copied += copy;
913 if (ret || !len)
914 goto done;
915 }
916
917 ret = skb_copy_datagram_const_iovec(skb, vlan_offset, iv, copied, len);
918 copied += len;
919
920done:
921 rcu_read_lock();
922 vlan = rcu_dereference(q->vlan);
923 if (vlan) {
924 preempt_disable();
925 macvlan_count_rx(vlan, copied - vnet_hdr_len, ret == 0, 0);
926 preempt_enable();
927 }
928 rcu_read_unlock();
929
930 return ret ? ret : copied;
931}
932
933static ssize_t macvtap_do_read(struct macvtap_queue *q, struct kiocb *iocb,
934 const struct iovec *iv, unsigned long len,
935 int noblock)
936{
937 DEFINE_WAIT(wait);
938 struct sk_buff *skb;
939 ssize_t ret = 0;
940
941 while (len) {
942 if (!noblock)
943 prepare_to_wait(sk_sleep(&q->sk), &wait,
944 TASK_INTERRUPTIBLE);
945
946
947 skb = skb_dequeue(&q->sk.sk_receive_queue);
948 if (!skb) {
949 if (noblock) {
950 ret = -EAGAIN;
951 break;
952 }
953 if (signal_pending(current)) {
954 ret = -ERESTARTSYS;
955 break;
956 }
957
958 schedule();
959 continue;
960 }
961 ret = macvtap_put_user(q, skb, iv, len);
962 kfree_skb(skb);
963 break;
964 }
965
966 if (!noblock)
967 finish_wait(sk_sleep(&q->sk), &wait);
968 return ret;
969}
970
971static ssize_t macvtap_aio_read(struct kiocb *iocb, const struct iovec *iv,
972 unsigned long count, loff_t pos)
973{
974 struct file *file = iocb->ki_filp;
975 struct macvtap_queue *q = file->private_data;
976 ssize_t len, ret = 0;
977
978 len = iov_length(iv, count);
979 if (len < 0) {
980 ret = -EINVAL;
981 goto out;
982 }
983
984 ret = macvtap_do_read(q, iocb, iv, len, file->f_flags & O_NONBLOCK);
985 ret = min_t(ssize_t, ret, len);
986out:
987 return ret;
988}
989
990static struct macvlan_dev *macvtap_get_vlan(struct macvtap_queue *q)
991{
992 struct macvlan_dev *vlan;
993
994 ASSERT_RTNL();
995 vlan = rtnl_dereference(q->vlan);
996 if (vlan)
997 dev_hold(vlan->dev);
998
999 return vlan;
1000}
1001
1002static void macvtap_put_vlan(struct macvlan_dev *vlan)
1003{
1004 dev_put(vlan->dev);
1005}
1006
1007static int macvtap_ioctl_set_queue(struct file *file, unsigned int flags)
1008{
1009 struct macvtap_queue *q = file->private_data;
1010 struct macvlan_dev *vlan;
1011 int ret;
1012
1013 vlan = macvtap_get_vlan(q);
1014 if (!vlan)
1015 return -EINVAL;
1016
1017 if (flags & IFF_ATTACH_QUEUE)
1018 ret = macvtap_enable_queue(vlan->dev, file, q);
1019 else if (flags & IFF_DETACH_QUEUE)
1020 ret = macvtap_disable_queue(q);
1021 else
1022 ret = -EINVAL;
1023
1024 macvtap_put_vlan(vlan);
1025 return ret;
1026}
1027
1028static int set_offload(struct macvtap_queue *q, unsigned long arg)
1029{
1030 struct macvlan_dev *vlan;
1031 netdev_features_t features;
1032 netdev_features_t feature_mask = 0;
1033
1034 vlan = rtnl_dereference(q->vlan);
1035 if (!vlan)
1036 return -ENOLINK;
1037
1038 features = vlan->dev->features;
1039
1040 if (arg & TUN_F_CSUM) {
1041 feature_mask = NETIF_F_HW_CSUM;
1042
1043 if (arg & (TUN_F_TSO4 | TUN_F_TSO6)) {
1044 if (arg & TUN_F_TSO_ECN)
1045 feature_mask |= NETIF_F_TSO_ECN;
1046 if (arg & TUN_F_TSO4)
1047 feature_mask |= NETIF_F_TSO;
1048 if (arg & TUN_F_TSO6)
1049 feature_mask |= NETIF_F_TSO6;
1050 }
1051
1052 if (arg & TUN_F_UFO)
1053 feature_mask |= NETIF_F_UFO;
1054 }
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064 if (feature_mask & (NETIF_F_TSO | NETIF_F_TSO6 | NETIF_F_UFO))
1065 features |= RX_OFFLOADS;
1066 else
1067 features &= ~RX_OFFLOADS;
1068
1069
1070
1071
1072 vlan->tap_features = feature_mask;
1073 vlan->set_features = features;
1074 netdev_update_features(vlan->dev);
1075
1076 return 0;
1077}
1078
1079
1080
1081
1082static long macvtap_ioctl(struct file *file, unsigned int cmd,
1083 unsigned long arg)
1084{
1085 struct macvtap_queue *q = file->private_data;
1086 struct macvlan_dev *vlan;
1087 void __user *argp = (void __user *)arg;
1088 struct ifreq __user *ifr = argp;
1089 unsigned int __user *up = argp;
1090 unsigned int u;
1091 int __user *sp = argp;
1092 int s;
1093 int ret;
1094
1095 switch (cmd) {
1096 case TUNSETIFF:
1097
1098 if (get_user(u, &ifr->ifr_flags))
1099 return -EFAULT;
1100
1101 ret = 0;
1102 if ((u & ~(IFF_VNET_HDR | IFF_MULTI_QUEUE)) !=
1103 (IFF_NO_PI | IFF_TAP))
1104 ret = -EINVAL;
1105 else
1106 q->flags = u;
1107
1108 return ret;
1109
1110 case TUNGETIFF:
1111 rtnl_lock();
1112 vlan = macvtap_get_vlan(q);
1113 if (!vlan) {
1114 rtnl_unlock();
1115 return -ENOLINK;
1116 }
1117
1118 ret = 0;
1119 if (copy_to_user(&ifr->ifr_name, vlan->dev->name, IFNAMSIZ) ||
1120 put_user(q->flags, &ifr->ifr_flags))
1121 ret = -EFAULT;
1122 macvtap_put_vlan(vlan);
1123 rtnl_unlock();
1124 return ret;
1125
1126 case TUNSETQUEUE:
1127 if (get_user(u, &ifr->ifr_flags))
1128 return -EFAULT;
1129 rtnl_lock();
1130 ret = macvtap_ioctl_set_queue(file, u);
1131 rtnl_unlock();
1132 return ret;
1133
1134 case TUNGETFEATURES:
1135 if (put_user(IFF_TAP | IFF_NO_PI | IFF_VNET_HDR |
1136 IFF_MULTI_QUEUE, up))
1137 return -EFAULT;
1138 return 0;
1139
1140 case TUNSETSNDBUF:
1141 if (get_user(u, up))
1142 return -EFAULT;
1143
1144 q->sk.sk_sndbuf = u;
1145 return 0;
1146
1147 case TUNGETVNETHDRSZ:
1148 s = q->vnet_hdr_sz;
1149 if (put_user(s, sp))
1150 return -EFAULT;
1151 return 0;
1152
1153 case TUNSETVNETHDRSZ:
1154 if (get_user(s, sp))
1155 return -EFAULT;
1156 if (s < (int)sizeof(struct virtio_net_hdr))
1157 return -EINVAL;
1158
1159 q->vnet_hdr_sz = s;
1160 return 0;
1161
1162 case TUNSETOFFLOAD:
1163
1164 if (arg & ~(TUN_F_CSUM | TUN_F_TSO4 | TUN_F_TSO6 |
1165 TUN_F_TSO_ECN | TUN_F_UFO))
1166 return -EINVAL;
1167
1168 rtnl_lock();
1169 ret = set_offload(q, arg);
1170 rtnl_unlock();
1171 return ret;
1172
1173 default:
1174 return -EINVAL;
1175 }
1176}
1177
1178#ifdef CONFIG_COMPAT
1179static long macvtap_compat_ioctl(struct file *file, unsigned int cmd,
1180 unsigned long arg)
1181{
1182 return macvtap_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
1183}
1184#endif
1185
1186static const struct file_operations macvtap_fops = {
1187 .owner = THIS_MODULE,
1188 .open = macvtap_open,
1189 .release = macvtap_release,
1190 .aio_read = macvtap_aio_read,
1191 .aio_write = macvtap_aio_write,
1192 .poll = macvtap_poll,
1193 .llseek = no_llseek,
1194 .unlocked_ioctl = macvtap_ioctl,
1195#ifdef CONFIG_COMPAT
1196 .compat_ioctl = macvtap_compat_ioctl,
1197#endif
1198};
1199
1200static int macvtap_sendmsg(struct kiocb *iocb, struct socket *sock,
1201 struct msghdr *m, size_t total_len)
1202{
1203 struct macvtap_queue *q = container_of(sock, struct macvtap_queue, sock);
1204 return macvtap_get_user(q, m, m->msg_iov, total_len, m->msg_iovlen,
1205 m->msg_flags & MSG_DONTWAIT);
1206}
1207
1208static int macvtap_recvmsg(struct kiocb *iocb, struct socket *sock,
1209 struct msghdr *m, size_t total_len,
1210 int flags)
1211{
1212 struct macvtap_queue *q = container_of(sock, struct macvtap_queue, sock);
1213 int ret;
1214 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC))
1215 return -EINVAL;
1216 ret = macvtap_do_read(q, iocb, m->msg_iov, total_len,
1217 flags & MSG_DONTWAIT);
1218 if (ret > total_len) {
1219 m->msg_flags |= MSG_TRUNC;
1220 ret = flags & MSG_TRUNC ? ret : total_len;
1221 }
1222 return ret;
1223}
1224
1225
1226static const struct proto_ops macvtap_socket_ops = {
1227 .sendmsg = macvtap_sendmsg,
1228 .recvmsg = macvtap_recvmsg,
1229};
1230
1231
1232
1233
1234
1235struct socket *macvtap_get_socket(struct file *file)
1236{
1237 struct macvtap_queue *q;
1238 if (file->f_op != &macvtap_fops)
1239 return ERR_PTR(-EINVAL);
1240 q = file->private_data;
1241 if (!q)
1242 return ERR_PTR(-EBADFD);
1243 return &q->sock;
1244}
1245EXPORT_SYMBOL_GPL(macvtap_get_socket);
1246
1247static int macvtap_device_event(struct notifier_block *unused,
1248 unsigned long event, void *ptr)
1249{
1250 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1251 struct macvlan_dev *vlan;
1252 struct device *classdev;
1253 dev_t devt;
1254 int err;
1255
1256 if (dev->rtnl_link_ops != &macvtap_link_ops)
1257 return NOTIFY_DONE;
1258
1259 vlan = netdev_priv(dev);
1260
1261 switch (event) {
1262 case NETDEV_REGISTER:
1263
1264
1265
1266
1267 err = macvtap_get_minor(vlan);
1268 if (err)
1269 return notifier_from_errno(err);
1270
1271 devt = MKDEV(MAJOR(macvtap_major), vlan->minor);
1272 classdev = device_create(macvtap_class, &dev->dev, devt,
1273 dev, "tap%d", dev->ifindex);
1274 if (IS_ERR(classdev)) {
1275 macvtap_free_minor(vlan);
1276 return notifier_from_errno(PTR_ERR(classdev));
1277 }
1278 break;
1279 case NETDEV_UNREGISTER:
1280 devt = MKDEV(MAJOR(macvtap_major), vlan->minor);
1281 device_destroy(macvtap_class, devt);
1282 macvtap_free_minor(vlan);
1283 break;
1284 }
1285
1286 return NOTIFY_DONE;
1287}
1288
1289static struct notifier_block macvtap_notifier_block __read_mostly = {
1290 .notifier_call = macvtap_device_event,
1291};
1292
1293static int macvtap_init(void)
1294{
1295 int err;
1296
1297 err = alloc_chrdev_region(&macvtap_major, 0,
1298 MACVTAP_NUM_DEVS, "macvtap");
1299 if (err)
1300 goto out1;
1301
1302 cdev_init(&macvtap_cdev, &macvtap_fops);
1303 err = cdev_add(&macvtap_cdev, macvtap_major, MACVTAP_NUM_DEVS);
1304 if (err)
1305 goto out2;
1306
1307 macvtap_class = class_create(THIS_MODULE, "macvtap");
1308 if (IS_ERR(macvtap_class)) {
1309 err = PTR_ERR(macvtap_class);
1310 goto out3;
1311 }
1312
1313 err = register_netdevice_notifier(&macvtap_notifier_block);
1314 if (err)
1315 goto out4;
1316
1317 err = macvlan_link_register(&macvtap_link_ops);
1318 if (err)
1319 goto out5;
1320
1321 return 0;
1322
1323out5:
1324 unregister_netdevice_notifier(&macvtap_notifier_block);
1325out4:
1326 class_unregister(macvtap_class);
1327out3:
1328 cdev_del(&macvtap_cdev);
1329out2:
1330 unregister_chrdev_region(macvtap_major, MACVTAP_NUM_DEVS);
1331out1:
1332 return err;
1333}
1334module_init(macvtap_init);
1335
1336static void macvtap_exit(void)
1337{
1338 rtnl_link_unregister(&macvtap_link_ops);
1339 unregister_netdevice_notifier(&macvtap_notifier_block);
1340 class_unregister(macvtap_class);
1341 cdev_del(&macvtap_cdev);
1342 unregister_chrdev_region(macvtap_major, MACVTAP_NUM_DEVS);
1343}
1344module_exit(macvtap_exit);
1345
1346MODULE_ALIAS_RTNL_LINK("macvtap");
1347MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>");
1348MODULE_LICENSE("GPL");
1349