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>
18 #include <linux/uio.h>
20 #include <net/net_namespace.h>
21 #include <net/rtnetlink.h>
23 #include <linux/virtio_net.h>
26 * A macvtap queue is the central object of this driver, it connects
27 * an open character device to a macvlan interface. There can be
28 * multiple queues on one interface, which map back to queues
29 * implemented in hardware on the underlying device.
31 * macvtap_proto is used to allocate queues through the sock allocation
35 struct macvtap_queue
{
40 struct macvlan_dev __rcu
*vlan
;
45 struct list_head next
;
48 #define MACVTAP_FEATURES (IFF_VNET_HDR | IFF_MULTI_QUEUE)
50 #define MACVTAP_VNET_LE 0x80000000
51 #define MACVTAP_VNET_BE 0x40000000
53 #ifdef CONFIG_TUN_VNET_CROSS_LE
54 static inline bool macvtap_legacy_is_little_endian(struct macvtap_queue
*q
)
56 return q
->flags
& MACVTAP_VNET_BE
? false :
57 virtio_legacy_is_little_endian();
60 static long macvtap_get_vnet_be(struct macvtap_queue
*q
, int __user
*sp
)
62 int s
= !!(q
->flags
& MACVTAP_VNET_BE
);
70 static long macvtap_set_vnet_be(struct macvtap_queue
*q
, int __user
*sp
)
78 q
->flags
|= MACVTAP_VNET_BE
;
80 q
->flags
&= ~MACVTAP_VNET_BE
;
85 static inline bool macvtap_legacy_is_little_endian(struct macvtap_queue
*q
)
87 return virtio_legacy_is_little_endian();
90 static long macvtap_get_vnet_be(struct macvtap_queue
*q
, int __user
*argp
)
95 static long macvtap_set_vnet_be(struct macvtap_queue
*q
, int __user
*argp
)
99 #endif /* CONFIG_TUN_VNET_CROSS_LE */
101 static inline bool macvtap_is_little_endian(struct macvtap_queue
*q
)
103 return q
->flags
& MACVTAP_VNET_LE
||
104 macvtap_legacy_is_little_endian(q
);
107 static inline u16
macvtap16_to_cpu(struct macvtap_queue
*q
, __virtio16 val
)
109 return __virtio16_to_cpu(macvtap_is_little_endian(q
), val
);
112 static inline __virtio16
cpu_to_macvtap16(struct macvtap_queue
*q
, u16 val
)
114 return __cpu_to_virtio16(macvtap_is_little_endian(q
), val
);
117 static struct proto macvtap_proto
= {
119 .owner
= THIS_MODULE
,
120 .obj_size
= sizeof (struct macvtap_queue
),
124 * Variables for dealing with macvtaps device numbers.
126 static dev_t macvtap_major
;
127 #define MACVTAP_NUM_DEVS (1U << MINORBITS)
128 static DEFINE_MUTEX(minor_lock
);
129 static DEFINE_IDR(minor_idr
);
131 #define GOODCOPY_LEN 128
132 static const void *macvtap_net_namespace(struct device
*d
)
134 struct net_device
*dev
= to_net_dev(d
->parent
);
138 static struct class macvtap_class
= {
140 .owner
= THIS_MODULE
,
141 .ns_type
= &net_ns_type_operations
,
142 .namespace = macvtap_net_namespace
,
144 static struct cdev macvtap_cdev
;
146 static const struct proto_ops macvtap_socket_ops
;
148 #define TUN_OFFLOADS (NETIF_F_HW_CSUM | NETIF_F_TSO_ECN | NETIF_F_TSO | \
149 NETIF_F_TSO6 | NETIF_F_UFO)
150 #define RX_OFFLOADS (NETIF_F_GRO | NETIF_F_LRO)
151 #define TAP_FEATURES (NETIF_F_GSO | NETIF_F_SG | NETIF_F_FRAGLIST)
153 static struct macvlan_dev
*macvtap_get_vlan_rcu(const struct net_device
*dev
)
155 return rcu_dereference(dev
->rx_handler_data
);
160 * The macvtap_queue and the macvlan_dev are loosely coupled, the
161 * pointers from one to the other can only be read while rcu_read_lock
164 * Both the file and the macvlan_dev hold a reference on the macvtap_queue
165 * through sock_hold(&q->sk). When the macvlan_dev goes away first,
166 * q->vlan becomes inaccessible. When the files gets closed,
167 * macvtap_get_queue() fails.
169 * There may still be references to the struct sock inside of the
170 * queue from outbound SKBs, but these never reference back to the
171 * file or the dev. The data structure is freed through __sk_free
172 * when both our references and any pending SKBs are gone.
175 static int macvtap_enable_queue(struct net_device
*dev
, struct file
*file
,
176 struct macvtap_queue
*q
)
178 struct macvlan_dev
*vlan
= netdev_priv(dev
);
187 rcu_assign_pointer(vlan
->taps
[vlan
->numvtaps
], q
);
188 q
->queue_index
= vlan
->numvtaps
;
197 static int macvtap_set_queue(struct net_device
*dev
, struct file
*file
,
198 struct macvtap_queue
*q
)
200 struct macvlan_dev
*vlan
= netdev_priv(dev
);
202 if (vlan
->numqueues
== MAX_MACVTAP_QUEUES
)
205 rcu_assign_pointer(q
->vlan
, vlan
);
206 rcu_assign_pointer(vlan
->taps
[vlan
->numvtaps
], q
);
210 q
->queue_index
= vlan
->numvtaps
;
212 file
->private_data
= q
;
213 list_add_tail(&q
->next
, &vlan
->queue_list
);
221 static int macvtap_disable_queue(struct macvtap_queue
*q
)
223 struct macvlan_dev
*vlan
;
224 struct macvtap_queue
*nq
;
230 vlan
= rtnl_dereference(q
->vlan
);
233 int index
= q
->queue_index
;
234 BUG_ON(index
>= vlan
->numvtaps
);
235 nq
= rtnl_dereference(vlan
->taps
[vlan
->numvtaps
- 1]);
236 nq
->queue_index
= index
;
238 rcu_assign_pointer(vlan
->taps
[index
], nq
);
239 RCU_INIT_POINTER(vlan
->taps
[vlan
->numvtaps
- 1], NULL
);
249 * The file owning the queue got closed, give up both
250 * the reference that the files holds as well as the
251 * one from the macvlan_dev if that still exists.
253 * Using the spinlock makes sure that we don't get
254 * to the queue again after destroying it.
256 static void macvtap_put_queue(struct macvtap_queue
*q
)
258 struct macvlan_dev
*vlan
;
261 vlan
= rtnl_dereference(q
->vlan
);
265 BUG_ON(macvtap_disable_queue(q
));
268 RCU_INIT_POINTER(q
->vlan
, NULL
);
270 list_del_init(&q
->next
);
280 * Select a queue based on the rxq of the device on which this packet
281 * arrived. If the incoming device is not mq, calculate a flow hash
282 * to select a queue. If all fails, find the first available queue.
283 * Cache vlan->numvtaps since it can become zero during the execution
286 static struct macvtap_queue
*macvtap_get_queue(struct net_device
*dev
,
289 struct macvlan_dev
*vlan
= netdev_priv(dev
);
290 struct macvtap_queue
*tap
= NULL
;
291 /* Access to taps array is protected by rcu, but access to numvtaps
292 * isn't. Below we use it to lookup a queue, but treat it as a hint
293 * and validate that the result isn't NULL - in case we are
294 * racing against queue removal.
296 int numvtaps
= ACCESS_ONCE(vlan
->numvtaps
);
302 /* Check if we can use flow to select a queue */
303 rxq
= skb_get_hash(skb
);
305 tap
= rcu_dereference(vlan
->taps
[rxq
% numvtaps
]);
309 if (likely(skb_rx_queue_recorded(skb
))) {
310 rxq
= skb_get_rx_queue(skb
);
312 while (unlikely(rxq
>= numvtaps
))
315 tap
= rcu_dereference(vlan
->taps
[rxq
]);
319 tap
= rcu_dereference(vlan
->taps
[0]);
325 * The net_device is going away, give up the reference
326 * that it holds on all queues and safely set the pointer
327 * from the queues to NULL.
329 static void macvtap_del_queues(struct net_device
*dev
)
331 struct macvlan_dev
*vlan
= netdev_priv(dev
);
332 struct macvtap_queue
*q
, *tmp
;
335 list_for_each_entry_safe(q
, tmp
, &vlan
->queue_list
, next
) {
336 list_del_init(&q
->next
);
337 RCU_INIT_POINTER(q
->vlan
, NULL
);
343 BUG_ON(vlan
->numvtaps
);
344 BUG_ON(vlan
->numqueues
);
345 /* guarantee that any future macvtap_set_queue will fail */
346 vlan
->numvtaps
= MAX_MACVTAP_QUEUES
;
349 static rx_handler_result_t
macvtap_handle_frame(struct sk_buff
**pskb
)
351 struct sk_buff
*skb
= *pskb
;
352 struct net_device
*dev
= skb
->dev
;
353 struct macvlan_dev
*vlan
;
354 struct macvtap_queue
*q
;
355 netdev_features_t features
= TAP_FEATURES
;
357 vlan
= macvtap_get_vlan_rcu(dev
);
359 return RX_HANDLER_PASS
;
361 q
= macvtap_get_queue(dev
, skb
);
363 return RX_HANDLER_PASS
;
365 if (skb_queue_len(&q
->sk
.sk_receive_queue
) >= dev
->tx_queue_len
)
368 skb_push(skb
, ETH_HLEN
);
370 /* Apply the forward feature mask so that we perform segmentation
371 * according to users wishes. This only works if VNET_HDR is
374 if (q
->flags
& IFF_VNET_HDR
)
375 features
|= vlan
->tap_features
;
376 if (netif_needs_gso(skb
, features
)) {
377 struct sk_buff
*segs
= __skb_gso_segment(skb
, features
, false);
383 skb_queue_tail(&q
->sk
.sk_receive_queue
, skb
);
389 struct sk_buff
*nskb
= segs
->next
;
392 skb_queue_tail(&q
->sk
.sk_receive_queue
, segs
);
396 /* If we receive a partial checksum and the tap side
397 * doesn't support checksum offload, compute the checksum.
398 * Note: it doesn't matter which checksum feature to
399 * check, we either support them all or none.
401 if (skb
->ip_summed
== CHECKSUM_PARTIAL
&&
402 !(features
& NETIF_F_CSUM_MASK
) &&
403 skb_checksum_help(skb
))
405 skb_queue_tail(&q
->sk
.sk_receive_queue
, skb
);
409 wake_up_interruptible_poll(sk_sleep(&q
->sk
), POLLIN
| POLLRDNORM
| POLLRDBAND
);
410 return RX_HANDLER_CONSUMED
;
413 /* Count errors/drops only here, thus don't care about args. */
414 macvlan_count_rx(vlan
, 0, 0, 0);
416 return RX_HANDLER_CONSUMED
;
419 static int macvtap_get_minor(struct macvlan_dev
*vlan
)
421 int retval
= -ENOMEM
;
423 mutex_lock(&minor_lock
);
424 retval
= idr_alloc(&minor_idr
, vlan
, 1, MACVTAP_NUM_DEVS
, GFP_KERNEL
);
426 vlan
->minor
= retval
;
427 } else if (retval
== -ENOSPC
) {
428 printk(KERN_ERR
"too many macvtap devices\n");
431 mutex_unlock(&minor_lock
);
432 return retval
< 0 ? retval
: 0;
435 static void macvtap_free_minor(struct macvlan_dev
*vlan
)
437 mutex_lock(&minor_lock
);
439 idr_remove(&minor_idr
, vlan
->minor
);
442 mutex_unlock(&minor_lock
);
445 static struct net_device
*dev_get_by_macvtap_minor(int minor
)
447 struct net_device
*dev
= NULL
;
448 struct macvlan_dev
*vlan
;
450 mutex_lock(&minor_lock
);
451 vlan
= idr_find(&minor_idr
, minor
);
456 mutex_unlock(&minor_lock
);
460 static int macvtap_newlink(struct net
*src_net
,
461 struct net_device
*dev
,
463 struct nlattr
*data
[])
465 struct macvlan_dev
*vlan
= netdev_priv(dev
);
468 INIT_LIST_HEAD(&vlan
->queue_list
);
470 /* Since macvlan supports all offloads by default, make
471 * tap support all offloads also.
473 vlan
->tap_features
= TUN_OFFLOADS
;
475 err
= netdev_rx_handler_register(dev
, macvtap_handle_frame
, vlan
);
479 /* Don't put anything that may fail after macvlan_common_newlink
480 * because we can't undo what it does.
482 return macvlan_common_newlink(src_net
, dev
, tb
, data
);
485 static void macvtap_dellink(struct net_device
*dev
,
486 struct list_head
*head
)
488 netdev_rx_handler_unregister(dev
);
489 macvtap_del_queues(dev
);
490 macvlan_dellink(dev
, head
);
493 static void macvtap_setup(struct net_device
*dev
)
495 macvlan_common_setup(dev
);
496 dev
->tx_queue_len
= TUN_READQ_SIZE
;
499 static struct rtnl_link_ops macvtap_link_ops __read_mostly
= {
501 .setup
= macvtap_setup
,
502 .newlink
= macvtap_newlink
,
503 .dellink
= macvtap_dellink
,
507 static void macvtap_sock_write_space(struct sock
*sk
)
509 wait_queue_head_t
*wqueue
;
511 if (!sock_writeable(sk
) ||
512 !test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
))
515 wqueue
= sk_sleep(sk
);
516 if (wqueue
&& waitqueue_active(wqueue
))
517 wake_up_interruptible_poll(wqueue
, POLLOUT
| POLLWRNORM
| POLLWRBAND
);
520 static void macvtap_sock_destruct(struct sock
*sk
)
522 skb_queue_purge(&sk
->sk_receive_queue
);
525 static int macvtap_open(struct inode
*inode
, struct file
*file
)
527 struct net
*net
= current
->nsproxy
->net_ns
;
528 struct net_device
*dev
;
529 struct macvtap_queue
*q
;
533 dev
= dev_get_by_macvtap_minor(iminor(inode
));
538 q
= (struct macvtap_queue
*)sk_alloc(net
, AF_UNSPEC
, GFP_KERNEL
,
543 RCU_INIT_POINTER(q
->sock
.wq
, &q
->wq
);
544 init_waitqueue_head(&q
->wq
.wait
);
545 q
->sock
.type
= SOCK_RAW
;
546 q
->sock
.state
= SS_CONNECTED
;
548 q
->sock
.ops
= &macvtap_socket_ops
;
549 sock_init_data(&q
->sock
, &q
->sk
);
550 q
->sk
.sk_write_space
= macvtap_sock_write_space
;
551 q
->sk
.sk_destruct
= macvtap_sock_destruct
;
552 q
->flags
= IFF_VNET_HDR
| IFF_NO_PI
| IFF_TAP
;
553 q
->vnet_hdr_sz
= sizeof(struct virtio_net_hdr
);
556 * so far only KVM virtio_net uses macvtap, enable zero copy between
557 * guest kernel and host kernel when lower device supports zerocopy
559 * The macvlan supports zerocopy iff the lower device supports zero
560 * copy so we don't have to look at the lower device directly.
562 if ((dev
->features
& NETIF_F_HIGHDMA
) && (dev
->features
& NETIF_F_SG
))
563 sock_set_flag(&q
->sk
, SOCK_ZEROCOPY
);
565 err
= macvtap_set_queue(dev
, file
, q
);
577 static int macvtap_release(struct inode
*inode
, struct file
*file
)
579 struct macvtap_queue
*q
= file
->private_data
;
580 macvtap_put_queue(q
);
584 static unsigned int macvtap_poll(struct file
*file
, poll_table
* wait
)
586 struct macvtap_queue
*q
= file
->private_data
;
587 unsigned int mask
= POLLERR
;
593 poll_wait(file
, &q
->wq
.wait
, wait
);
595 if (!skb_queue_empty(&q
->sk
.sk_receive_queue
))
596 mask
|= POLLIN
| POLLRDNORM
;
598 if (sock_writeable(&q
->sk
) ||
599 (!test_and_set_bit(SOCKWQ_ASYNC_NOSPACE
, &q
->sock
.flags
) &&
600 sock_writeable(&q
->sk
)))
601 mask
|= POLLOUT
| POLLWRNORM
;
607 static inline struct sk_buff
*macvtap_alloc_skb(struct sock
*sk
, size_t prepad
,
608 size_t len
, size_t linear
,
609 int noblock
, int *err
)
613 /* Under a page? Don't bother with paged skb. */
614 if (prepad
+ len
< PAGE_SIZE
|| !linear
)
617 skb
= sock_alloc_send_pskb(sk
, prepad
+ linear
, len
- linear
, noblock
,
622 skb_reserve(skb
, prepad
);
623 skb_put(skb
, linear
);
624 skb
->data_len
= len
- linear
;
625 skb
->len
+= len
- linear
;
631 * macvtap_skb_from_vnet_hdr and macvtap_skb_to_vnet_hdr should
632 * be shared with the tun/tap driver.
634 static int macvtap_skb_from_vnet_hdr(struct macvtap_queue
*q
,
636 struct virtio_net_hdr
*vnet_hdr
)
638 unsigned short gso_type
= 0;
639 if (vnet_hdr
->gso_type
!= VIRTIO_NET_HDR_GSO_NONE
) {
640 switch (vnet_hdr
->gso_type
& ~VIRTIO_NET_HDR_GSO_ECN
) {
641 case VIRTIO_NET_HDR_GSO_TCPV4
:
642 gso_type
= SKB_GSO_TCPV4
;
644 case VIRTIO_NET_HDR_GSO_TCPV6
:
645 gso_type
= SKB_GSO_TCPV6
;
647 case VIRTIO_NET_HDR_GSO_UDP
:
648 gso_type
= SKB_GSO_UDP
;
654 if (vnet_hdr
->gso_type
& VIRTIO_NET_HDR_GSO_ECN
)
655 gso_type
|= SKB_GSO_TCP_ECN
;
657 if (vnet_hdr
->gso_size
== 0)
661 if (vnet_hdr
->flags
& VIRTIO_NET_HDR_F_NEEDS_CSUM
) {
662 if (!skb_partial_csum_set(skb
, macvtap16_to_cpu(q
, vnet_hdr
->csum_start
),
663 macvtap16_to_cpu(q
, vnet_hdr
->csum_offset
)))
667 if (vnet_hdr
->gso_type
!= VIRTIO_NET_HDR_GSO_NONE
) {
668 skb_shinfo(skb
)->gso_size
= macvtap16_to_cpu(q
, vnet_hdr
->gso_size
);
669 skb_shinfo(skb
)->gso_type
= gso_type
;
671 /* Header must be checked, and gso_segs computed. */
672 skb_shinfo(skb
)->gso_type
|= SKB_GSO_DODGY
;
673 skb_shinfo(skb
)->gso_segs
= 0;
678 static void macvtap_skb_to_vnet_hdr(struct macvtap_queue
*q
,
679 const struct sk_buff
*skb
,
680 struct virtio_net_hdr
*vnet_hdr
)
682 memset(vnet_hdr
, 0, sizeof(*vnet_hdr
));
684 if (skb_is_gso(skb
)) {
685 struct skb_shared_info
*sinfo
= skb_shinfo(skb
);
687 /* This is a hint as to how much should be linear. */
688 vnet_hdr
->hdr_len
= cpu_to_macvtap16(q
, skb_headlen(skb
));
689 vnet_hdr
->gso_size
= cpu_to_macvtap16(q
, sinfo
->gso_size
);
690 if (sinfo
->gso_type
& SKB_GSO_TCPV4
)
691 vnet_hdr
->gso_type
= VIRTIO_NET_HDR_GSO_TCPV4
;
692 else if (sinfo
->gso_type
& SKB_GSO_TCPV6
)
693 vnet_hdr
->gso_type
= VIRTIO_NET_HDR_GSO_TCPV6
;
694 else if (sinfo
->gso_type
& SKB_GSO_UDP
)
695 vnet_hdr
->gso_type
= VIRTIO_NET_HDR_GSO_UDP
;
698 if (sinfo
->gso_type
& SKB_GSO_TCP_ECN
)
699 vnet_hdr
->gso_type
|= VIRTIO_NET_HDR_GSO_ECN
;
701 vnet_hdr
->gso_type
= VIRTIO_NET_HDR_GSO_NONE
;
703 if (skb
->ip_summed
== CHECKSUM_PARTIAL
) {
704 vnet_hdr
->flags
= VIRTIO_NET_HDR_F_NEEDS_CSUM
;
705 if (skb_vlan_tag_present(skb
))
706 vnet_hdr
->csum_start
= cpu_to_macvtap16(q
,
707 skb_checksum_start_offset(skb
) + VLAN_HLEN
);
709 vnet_hdr
->csum_start
= cpu_to_macvtap16(q
,
710 skb_checksum_start_offset(skb
));
711 vnet_hdr
->csum_offset
= cpu_to_macvtap16(q
, skb
->csum_offset
);
712 } else if (skb
->ip_summed
== CHECKSUM_UNNECESSARY
) {
713 vnet_hdr
->flags
= VIRTIO_NET_HDR_F_DATA_VALID
;
714 } /* else everything is zero */
717 /* Neighbour code has some assumptions on HH_DATA_MOD alignment */
718 #define MACVTAP_RESERVE HH_DATA_OFF(ETH_HLEN)
720 /* Get packet from user space buffer */
721 static ssize_t
macvtap_get_user(struct macvtap_queue
*q
, struct msghdr
*m
,
722 struct iov_iter
*from
, int noblock
)
724 int good_linear
= SKB_MAX_HEAD(MACVTAP_RESERVE
);
726 struct macvlan_dev
*vlan
;
727 unsigned long total_len
= iov_iter_count(from
);
728 unsigned long len
= total_len
;
730 struct virtio_net_hdr vnet_hdr
= { 0 };
731 int vnet_hdr_len
= 0;
734 bool zerocopy
= false;
738 if (q
->flags
& IFF_VNET_HDR
) {
739 vnet_hdr_len
= q
->vnet_hdr_sz
;
742 if (len
< vnet_hdr_len
)
747 n
= copy_from_iter(&vnet_hdr
, sizeof(vnet_hdr
), from
);
748 if (n
!= sizeof(vnet_hdr
))
750 iov_iter_advance(from
, vnet_hdr_len
- sizeof(vnet_hdr
));
751 if ((vnet_hdr
.flags
& VIRTIO_NET_HDR_F_NEEDS_CSUM
) &&
752 macvtap16_to_cpu(q
, vnet_hdr
.csum_start
) +
753 macvtap16_to_cpu(q
, vnet_hdr
.csum_offset
) + 2 >
754 macvtap16_to_cpu(q
, vnet_hdr
.hdr_len
))
755 vnet_hdr
.hdr_len
= cpu_to_macvtap16(q
,
756 macvtap16_to_cpu(q
, vnet_hdr
.csum_start
) +
757 macvtap16_to_cpu(q
, vnet_hdr
.csum_offset
) + 2);
759 if (macvtap16_to_cpu(q
, vnet_hdr
.hdr_len
) > len
)
764 if (unlikely(len
< ETH_HLEN
))
767 if (m
&& m
->msg_control
&& sock_flag(&q
->sk
, SOCK_ZEROCOPY
)) {
770 copylen
= vnet_hdr
.hdr_len
?
771 macvtap16_to_cpu(q
, vnet_hdr
.hdr_len
) : GOODCOPY_LEN
;
772 if (copylen
> good_linear
)
773 copylen
= good_linear
;
774 else if (copylen
< ETH_HLEN
)
778 iov_iter_advance(&i
, copylen
);
779 if (iov_iter_npages(&i
, INT_MAX
) <= MAX_SKB_FRAGS
)
785 linear
= macvtap16_to_cpu(q
, vnet_hdr
.hdr_len
);
786 if (linear
> good_linear
)
787 linear
= good_linear
;
788 else if (linear
< ETH_HLEN
)
792 skb
= macvtap_alloc_skb(&q
->sk
, MACVTAP_RESERVE
, copylen
,
793 linear
, noblock
, &err
);
798 err
= zerocopy_sg_from_iter(skb
, from
);
800 err
= skb_copy_datagram_from_iter(skb
, 0, from
, len
);
801 if (!err
&& m
&& m
->msg_control
) {
802 struct ubuf_info
*uarg
= m
->msg_control
;
803 uarg
->callback(uarg
, false);
810 skb_set_network_header(skb
, ETH_HLEN
);
811 skb_reset_mac_header(skb
);
812 skb
->protocol
= eth_hdr(skb
)->h_proto
;
815 err
= macvtap_skb_from_vnet_hdr(q
, skb
, &vnet_hdr
);
820 skb_probe_transport_header(skb
, ETH_HLEN
);
822 /* Move network header to the right position for VLAN tagged packets */
823 if ((skb
->protocol
== htons(ETH_P_8021Q
) ||
824 skb
->protocol
== htons(ETH_P_8021AD
)) &&
825 __vlan_get_protocol(skb
, skb
->protocol
, &depth
) != 0)
826 skb_set_network_header(skb
, depth
);
829 vlan
= rcu_dereference(q
->vlan
);
830 /* copy skb_ubuf_info for callback when skb has no error */
832 skb_shinfo(skb
)->destructor_arg
= m
->msg_control
;
833 skb_shinfo(skb
)->tx_flags
|= SKBTX_DEV_ZEROCOPY
;
834 skb_shinfo(skb
)->tx_flags
|= SKBTX_SHARED_FRAG
;
837 skb
->dev
= vlan
->dev
;
851 vlan
= rcu_dereference(q
->vlan
);
853 this_cpu_inc(vlan
->pcpu_stats
->tx_dropped
);
859 static ssize_t
macvtap_write_iter(struct kiocb
*iocb
, struct iov_iter
*from
)
861 struct file
*file
= iocb
->ki_filp
;
862 struct macvtap_queue
*q
= file
->private_data
;
864 return macvtap_get_user(q
, NULL
, from
, file
->f_flags
& O_NONBLOCK
);
867 /* Put packet to the user space buffer */
868 static ssize_t
macvtap_put_user(struct macvtap_queue
*q
,
869 const struct sk_buff
*skb
,
870 struct iov_iter
*iter
)
873 int vnet_hdr_len
= 0;
877 if (q
->flags
& IFF_VNET_HDR
) {
878 struct virtio_net_hdr vnet_hdr
;
879 vnet_hdr_len
= q
->vnet_hdr_sz
;
880 if (iov_iter_count(iter
) < vnet_hdr_len
)
883 macvtap_skb_to_vnet_hdr(q
, skb
, &vnet_hdr
);
885 if (copy_to_iter(&vnet_hdr
, sizeof(vnet_hdr
), iter
) !=
889 iov_iter_advance(iter
, vnet_hdr_len
- sizeof(vnet_hdr
));
891 total
= vnet_hdr_len
;
894 if (skb_vlan_tag_present(skb
)) {
899 veth
.h_vlan_proto
= skb
->vlan_proto
;
900 veth
.h_vlan_TCI
= htons(skb_vlan_tag_get(skb
));
902 vlan_offset
= offsetof(struct vlan_ethhdr
, h_vlan_proto
);
905 ret
= skb_copy_datagram_iter(skb
, 0, iter
, vlan_offset
);
906 if (ret
|| !iov_iter_count(iter
))
909 ret
= copy_to_iter(&veth
, sizeof(veth
), iter
);
910 if (ret
!= sizeof(veth
) || !iov_iter_count(iter
))
914 ret
= skb_copy_datagram_iter(skb
, vlan_offset
, iter
,
915 skb
->len
- vlan_offset
);
918 return ret
? ret
: total
;
921 static ssize_t
macvtap_do_read(struct macvtap_queue
*q
,
929 if (!iov_iter_count(to
))
934 prepare_to_wait(sk_sleep(&q
->sk
), &wait
,
937 /* Read frames from the queue */
938 skb
= skb_dequeue(&q
->sk
.sk_receive_queue
);
945 if (signal_pending(current
)) {
949 /* Nothing to read, let's sleep */
953 finish_wait(sk_sleep(&q
->sk
), &wait
);
956 ret
= macvtap_put_user(q
, skb
, to
);
957 if (unlikely(ret
< 0))
965 static ssize_t
macvtap_read_iter(struct kiocb
*iocb
, struct iov_iter
*to
)
967 struct file
*file
= iocb
->ki_filp
;
968 struct macvtap_queue
*q
= file
->private_data
;
969 ssize_t len
= iov_iter_count(to
), ret
;
971 ret
= macvtap_do_read(q
, to
, file
->f_flags
& O_NONBLOCK
);
972 ret
= min_t(ssize_t
, ret
, len
);
978 static struct macvlan_dev
*macvtap_get_vlan(struct macvtap_queue
*q
)
980 struct macvlan_dev
*vlan
;
983 vlan
= rtnl_dereference(q
->vlan
);
990 static void macvtap_put_vlan(struct macvlan_dev
*vlan
)
995 static int macvtap_ioctl_set_queue(struct file
*file
, unsigned int flags
)
997 struct macvtap_queue
*q
= file
->private_data
;
998 struct macvlan_dev
*vlan
;
1001 vlan
= macvtap_get_vlan(q
);
1005 if (flags
& IFF_ATTACH_QUEUE
)
1006 ret
= macvtap_enable_queue(vlan
->dev
, file
, q
);
1007 else if (flags
& IFF_DETACH_QUEUE
)
1008 ret
= macvtap_disable_queue(q
);
1012 macvtap_put_vlan(vlan
);
1016 static int set_offload(struct macvtap_queue
*q
, unsigned long arg
)
1018 struct macvlan_dev
*vlan
;
1019 netdev_features_t features
;
1020 netdev_features_t feature_mask
= 0;
1022 vlan
= rtnl_dereference(q
->vlan
);
1026 features
= vlan
->dev
->features
;
1028 if (arg
& TUN_F_CSUM
) {
1029 feature_mask
= NETIF_F_HW_CSUM
;
1031 if (arg
& (TUN_F_TSO4
| TUN_F_TSO6
)) {
1032 if (arg
& TUN_F_TSO_ECN
)
1033 feature_mask
|= NETIF_F_TSO_ECN
;
1034 if (arg
& TUN_F_TSO4
)
1035 feature_mask
|= NETIF_F_TSO
;
1036 if (arg
& TUN_F_TSO6
)
1037 feature_mask
|= NETIF_F_TSO6
;
1040 if (arg
& TUN_F_UFO
)
1041 feature_mask
|= NETIF_F_UFO
;
1044 /* tun/tap driver inverts the usage for TSO offloads, where
1045 * setting the TSO bit means that the userspace wants to
1046 * accept TSO frames and turning it off means that user space
1047 * does not support TSO.
1048 * For macvtap, we have to invert it to mean the same thing.
1049 * When user space turns off TSO, we turn off GSO/LRO so that
1050 * user-space will not receive TSO frames.
1052 if (feature_mask
& (NETIF_F_TSO
| NETIF_F_TSO6
| NETIF_F_UFO
))
1053 features
|= RX_OFFLOADS
;
1055 features
&= ~RX_OFFLOADS
;
1057 /* tap_features are the same as features on tun/tap and
1058 * reflect user expectations.
1060 vlan
->tap_features
= feature_mask
;
1061 vlan
->set_features
= features
;
1062 netdev_update_features(vlan
->dev
);
1068 * provide compatibility with generic tun/tap interface
1070 static long macvtap_ioctl(struct file
*file
, unsigned int cmd
,
1073 struct macvtap_queue
*q
= file
->private_data
;
1074 struct macvlan_dev
*vlan
;
1075 void __user
*argp
= (void __user
*)arg
;
1076 struct ifreq __user
*ifr
= argp
;
1077 unsigned int __user
*up
= argp
;
1079 int __user
*sp
= argp
;
1086 /* ignore the name, just look at flags */
1087 if (get_user(u
, &ifr
->ifr_flags
))
1091 if ((u
& ~MACVTAP_FEATURES
) != (IFF_NO_PI
| IFF_TAP
))
1094 q
->flags
= (q
->flags
& ~MACVTAP_FEATURES
) | u
;
1100 vlan
= macvtap_get_vlan(q
);
1108 if (copy_to_user(&ifr
->ifr_name
, vlan
->dev
->name
, IFNAMSIZ
) ||
1109 put_user(u
, &ifr
->ifr_flags
))
1111 macvtap_put_vlan(vlan
);
1116 if (get_user(u
, &ifr
->ifr_flags
))
1119 ret
= macvtap_ioctl_set_queue(file
, u
);
1123 case TUNGETFEATURES
:
1124 if (put_user(IFF_TAP
| IFF_NO_PI
| MACVTAP_FEATURES
, up
))
1129 if (get_user(s
, sp
))
1132 q
->sk
.sk_sndbuf
= s
;
1135 case TUNGETVNETHDRSZ
:
1137 if (put_user(s
, sp
))
1141 case TUNSETVNETHDRSZ
:
1142 if (get_user(s
, sp
))
1144 if (s
< (int)sizeof(struct virtio_net_hdr
))
1151 s
= !!(q
->flags
& MACVTAP_VNET_LE
);
1152 if (put_user(s
, sp
))
1157 if (get_user(s
, sp
))
1160 q
->flags
|= MACVTAP_VNET_LE
;
1162 q
->flags
&= ~MACVTAP_VNET_LE
;
1166 return macvtap_get_vnet_be(q
, sp
);
1169 return macvtap_set_vnet_be(q
, sp
);
1172 /* let the user check for future flags */
1173 if (arg
& ~(TUN_F_CSUM
| TUN_F_TSO4
| TUN_F_TSO6
|
1174 TUN_F_TSO_ECN
| TUN_F_UFO
))
1178 ret
= set_offload(q
, arg
);
1184 vlan
= macvtap_get_vlan(q
);
1190 u
= vlan
->dev
->type
;
1191 if (copy_to_user(&ifr
->ifr_name
, vlan
->dev
->name
, IFNAMSIZ
) ||
1192 copy_to_user(&ifr
->ifr_hwaddr
.sa_data
, vlan
->dev
->dev_addr
, ETH_ALEN
) ||
1193 put_user(u
, &ifr
->ifr_hwaddr
.sa_family
))
1195 macvtap_put_vlan(vlan
);
1200 if (copy_from_user(&sa
, &ifr
->ifr_hwaddr
, sizeof(sa
)))
1203 vlan
= macvtap_get_vlan(q
);
1208 ret
= dev_set_mac_address(vlan
->dev
, &sa
);
1209 macvtap_put_vlan(vlan
);
1218 #ifdef CONFIG_COMPAT
1219 static long macvtap_compat_ioctl(struct file
*file
, unsigned int cmd
,
1222 return macvtap_ioctl(file
, cmd
, (unsigned long)compat_ptr(arg
));
1226 static const struct file_operations macvtap_fops
= {
1227 .owner
= THIS_MODULE
,
1228 .open
= macvtap_open
,
1229 .release
= macvtap_release
,
1230 .read_iter
= macvtap_read_iter
,
1231 .write_iter
= macvtap_write_iter
,
1232 .poll
= macvtap_poll
,
1233 .llseek
= no_llseek
,
1234 .unlocked_ioctl
= macvtap_ioctl
,
1235 #ifdef CONFIG_COMPAT
1236 .compat_ioctl
= macvtap_compat_ioctl
,
1240 static int macvtap_sendmsg(struct socket
*sock
, struct msghdr
*m
,
1243 struct macvtap_queue
*q
= container_of(sock
, struct macvtap_queue
, sock
);
1244 return macvtap_get_user(q
, m
, &m
->msg_iter
, m
->msg_flags
& MSG_DONTWAIT
);
1247 static int macvtap_recvmsg(struct socket
*sock
, struct msghdr
*m
,
1248 size_t total_len
, int flags
)
1250 struct macvtap_queue
*q
= container_of(sock
, struct macvtap_queue
, sock
);
1252 if (flags
& ~(MSG_DONTWAIT
|MSG_TRUNC
))
1254 ret
= macvtap_do_read(q
, &m
->msg_iter
, flags
& MSG_DONTWAIT
);
1255 if (ret
> total_len
) {
1256 m
->msg_flags
|= MSG_TRUNC
;
1257 ret
= flags
& MSG_TRUNC
? ret
: total_len
;
1262 /* Ops structure to mimic raw sockets with tun */
1263 static const struct proto_ops macvtap_socket_ops
= {
1264 .sendmsg
= macvtap_sendmsg
,
1265 .recvmsg
= macvtap_recvmsg
,
1268 /* Get an underlying socket object from tun file. Returns error unless file is
1269 * attached to a device. The returned object works like a packet socket, it
1270 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
1271 * holding a reference to the file for as long as the socket is in use. */
1272 struct socket
*macvtap_get_socket(struct file
*file
)
1274 struct macvtap_queue
*q
;
1275 if (file
->f_op
!= &macvtap_fops
)
1276 return ERR_PTR(-EINVAL
);
1277 q
= file
->private_data
;
1279 return ERR_PTR(-EBADFD
);
1282 EXPORT_SYMBOL_GPL(macvtap_get_socket
);
1284 static int macvtap_device_event(struct notifier_block
*unused
,
1285 unsigned long event
, void *ptr
)
1287 struct net_device
*dev
= netdev_notifier_info_to_dev(ptr
);
1288 struct macvlan_dev
*vlan
;
1289 struct device
*classdev
;
1292 char tap_name
[IFNAMSIZ
];
1294 if (dev
->rtnl_link_ops
!= &macvtap_link_ops
)
1297 snprintf(tap_name
, IFNAMSIZ
, "tap%d", dev
->ifindex
);
1298 vlan
= netdev_priv(dev
);
1301 case NETDEV_REGISTER
:
1302 /* Create the device node here after the network device has
1303 * been registered but before register_netdevice has
1306 err
= macvtap_get_minor(vlan
);
1308 return notifier_from_errno(err
);
1310 devt
= MKDEV(MAJOR(macvtap_major
), vlan
->minor
);
1311 classdev
= device_create(&macvtap_class
, &dev
->dev
, devt
,
1313 if (IS_ERR(classdev
)) {
1314 macvtap_free_minor(vlan
);
1315 return notifier_from_errno(PTR_ERR(classdev
));
1317 err
= sysfs_create_link(&dev
->dev
.kobj
, &classdev
->kobj
,
1320 return notifier_from_errno(err
);
1322 case NETDEV_UNREGISTER
:
1323 /* vlan->minor == 0 if NETDEV_REGISTER above failed */
1324 if (vlan
->minor
== 0)
1326 sysfs_remove_link(&dev
->dev
.kobj
, tap_name
);
1327 devt
= MKDEV(MAJOR(macvtap_major
), vlan
->minor
);
1328 device_destroy(&macvtap_class
, devt
);
1329 macvtap_free_minor(vlan
);
1336 static struct notifier_block macvtap_notifier_block __read_mostly
= {
1337 .notifier_call
= macvtap_device_event
,
1340 static int macvtap_init(void)
1344 err
= alloc_chrdev_region(&macvtap_major
, 0,
1345 MACVTAP_NUM_DEVS
, "macvtap");
1349 cdev_init(&macvtap_cdev
, &macvtap_fops
);
1350 err
= cdev_add(&macvtap_cdev
, macvtap_major
, MACVTAP_NUM_DEVS
);
1354 err
= class_register(&macvtap_class
);
1358 err
= register_netdevice_notifier(&macvtap_notifier_block
);
1362 err
= macvlan_link_register(&macvtap_link_ops
);
1369 unregister_netdevice_notifier(&macvtap_notifier_block
);
1371 class_unregister(&macvtap_class
);
1373 cdev_del(&macvtap_cdev
);
1375 unregister_chrdev_region(macvtap_major
, MACVTAP_NUM_DEVS
);
1379 module_init(macvtap_init
);
1381 static void macvtap_exit(void)
1383 rtnl_link_unregister(&macvtap_link_ops
);
1384 unregister_netdevice_notifier(&macvtap_notifier_block
);
1385 class_unregister(&macvtap_class
);
1386 cdev_del(&macvtap_cdev
);
1387 unregister_chrdev_region(macvtap_major
, MACVTAP_NUM_DEVS
);
1388 idr_destroy(&minor_idr
);
1390 module_exit(macvtap_exit
);
1392 MODULE_ALIAS_RTNL_LINK("macvtap");
1393 MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>");
1394 MODULE_LICENSE("GPL");