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
52 static inline u16
macvtap16_to_cpu(struct macvtap_queue
*q
, __virtio16 val
)
54 return __virtio16_to_cpu(q
->flags
& MACVTAP_VNET_LE
, val
);
57 static inline __virtio16
cpu_to_macvtap16(struct macvtap_queue
*q
, u16 val
)
59 return __cpu_to_virtio16(q
->flags
& MACVTAP_VNET_LE
, val
);
62 static struct proto macvtap_proto
= {
65 .obj_size
= sizeof (struct macvtap_queue
),
69 * Variables for dealing with macvtaps device numbers.
71 static dev_t macvtap_major
;
72 #define MACVTAP_NUM_DEVS (1U << MINORBITS)
73 static DEFINE_MUTEX(minor_lock
);
74 static DEFINE_IDR(minor_idr
);
76 #define GOODCOPY_LEN 128
77 static struct class *macvtap_class
;
78 static struct cdev macvtap_cdev
;
80 static const struct proto_ops macvtap_socket_ops
;
82 #define TUN_OFFLOADS (NETIF_F_HW_CSUM | NETIF_F_TSO_ECN | NETIF_F_TSO | \
83 NETIF_F_TSO6 | NETIF_F_UFO)
84 #define RX_OFFLOADS (NETIF_F_GRO | NETIF_F_LRO)
85 #define TAP_FEATURES (NETIF_F_GSO | NETIF_F_SG)
87 static struct macvlan_dev
*macvtap_get_vlan_rcu(const struct net_device
*dev
)
89 return rcu_dereference(dev
->rx_handler_data
);
94 * The macvtap_queue and the macvlan_dev are loosely coupled, the
95 * pointers from one to the other can only be read while rcu_read_lock
98 * Both the file and the macvlan_dev hold a reference on the macvtap_queue
99 * through sock_hold(&q->sk). When the macvlan_dev goes away first,
100 * q->vlan becomes inaccessible. When the files gets closed,
101 * macvtap_get_queue() fails.
103 * There may still be references to the struct sock inside of the
104 * queue from outbound SKBs, but these never reference back to the
105 * file or the dev. The data structure is freed through __sk_free
106 * when both our references and any pending SKBs are gone.
109 static int macvtap_enable_queue(struct net_device
*dev
, struct file
*file
,
110 struct macvtap_queue
*q
)
112 struct macvlan_dev
*vlan
= netdev_priv(dev
);
121 rcu_assign_pointer(vlan
->taps
[vlan
->numvtaps
], q
);
122 q
->queue_index
= vlan
->numvtaps
;
131 static int macvtap_set_queue(struct net_device
*dev
, struct file
*file
,
132 struct macvtap_queue
*q
)
134 struct macvlan_dev
*vlan
= netdev_priv(dev
);
136 if (vlan
->numqueues
== MAX_MACVTAP_QUEUES
)
139 rcu_assign_pointer(q
->vlan
, vlan
);
140 rcu_assign_pointer(vlan
->taps
[vlan
->numvtaps
], q
);
144 q
->queue_index
= vlan
->numvtaps
;
146 file
->private_data
= q
;
147 list_add_tail(&q
->next
, &vlan
->queue_list
);
155 static int macvtap_disable_queue(struct macvtap_queue
*q
)
157 struct macvlan_dev
*vlan
;
158 struct macvtap_queue
*nq
;
164 vlan
= rtnl_dereference(q
->vlan
);
167 int index
= q
->queue_index
;
168 BUG_ON(index
>= vlan
->numvtaps
);
169 nq
= rtnl_dereference(vlan
->taps
[vlan
->numvtaps
- 1]);
170 nq
->queue_index
= index
;
172 rcu_assign_pointer(vlan
->taps
[index
], nq
);
173 RCU_INIT_POINTER(vlan
->taps
[vlan
->numvtaps
- 1], NULL
);
183 * The file owning the queue got closed, give up both
184 * the reference that the files holds as well as the
185 * one from the macvlan_dev if that still exists.
187 * Using the spinlock makes sure that we don't get
188 * to the queue again after destroying it.
190 static void macvtap_put_queue(struct macvtap_queue
*q
)
192 struct macvlan_dev
*vlan
;
195 vlan
= rtnl_dereference(q
->vlan
);
199 BUG_ON(macvtap_disable_queue(q
));
202 RCU_INIT_POINTER(q
->vlan
, NULL
);
204 list_del_init(&q
->next
);
214 * Select a queue based on the rxq of the device on which this packet
215 * arrived. If the incoming device is not mq, calculate a flow hash
216 * to select a queue. If all fails, find the first available queue.
217 * Cache vlan->numvtaps since it can become zero during the execution
220 static struct macvtap_queue
*macvtap_get_queue(struct net_device
*dev
,
223 struct macvlan_dev
*vlan
= netdev_priv(dev
);
224 struct macvtap_queue
*tap
= NULL
;
225 /* Access to taps array is protected by rcu, but access to numvtaps
226 * isn't. Below we use it to lookup a queue, but treat it as a hint
227 * and validate that the result isn't NULL - in case we are
228 * racing against queue removal.
230 int numvtaps
= ACCESS_ONCE(vlan
->numvtaps
);
236 /* Check if we can use flow to select a queue */
237 rxq
= skb_get_hash(skb
);
239 tap
= rcu_dereference(vlan
->taps
[rxq
% numvtaps
]);
243 if (likely(skb_rx_queue_recorded(skb
))) {
244 rxq
= skb_get_rx_queue(skb
);
246 while (unlikely(rxq
>= numvtaps
))
249 tap
= rcu_dereference(vlan
->taps
[rxq
]);
253 tap
= rcu_dereference(vlan
->taps
[0]);
259 * The net_device is going away, give up the reference
260 * that it holds on all queues and safely set the pointer
261 * from the queues to NULL.
263 static void macvtap_del_queues(struct net_device
*dev
)
265 struct macvlan_dev
*vlan
= netdev_priv(dev
);
266 struct macvtap_queue
*q
, *tmp
, *qlist
[MAX_MACVTAP_QUEUES
];
270 list_for_each_entry_safe(q
, tmp
, &vlan
->queue_list
, next
) {
271 list_del_init(&q
->next
);
273 RCU_INIT_POINTER(q
->vlan
, NULL
);
278 for (i
= 0; i
< vlan
->numvtaps
; i
++)
279 RCU_INIT_POINTER(vlan
->taps
[i
], NULL
);
280 BUG_ON(vlan
->numvtaps
);
281 BUG_ON(vlan
->numqueues
);
282 /* guarantee that any future macvtap_set_queue will fail */
283 vlan
->numvtaps
= MAX_MACVTAP_QUEUES
;
285 for (--j
; j
>= 0; j
--)
286 sock_put(&qlist
[j
]->sk
);
289 static rx_handler_result_t
macvtap_handle_frame(struct sk_buff
**pskb
)
291 struct sk_buff
*skb
= *pskb
;
292 struct net_device
*dev
= skb
->dev
;
293 struct macvlan_dev
*vlan
;
294 struct macvtap_queue
*q
;
295 netdev_features_t features
= TAP_FEATURES
;
297 vlan
= macvtap_get_vlan_rcu(dev
);
299 return RX_HANDLER_PASS
;
301 q
= macvtap_get_queue(dev
, skb
);
303 return RX_HANDLER_PASS
;
305 if (skb_queue_len(&q
->sk
.sk_receive_queue
) >= dev
->tx_queue_len
)
308 skb_push(skb
, ETH_HLEN
);
310 /* Apply the forward feature mask so that we perform segmentation
311 * according to users wishes. This only works if VNET_HDR is
314 if (q
->flags
& IFF_VNET_HDR
)
315 features
|= vlan
->tap_features
;
316 if (netif_needs_gso(skb
, features
)) {
317 struct sk_buff
*segs
= __skb_gso_segment(skb
, features
, false);
323 skb_queue_tail(&q
->sk
.sk_receive_queue
, skb
);
329 struct sk_buff
*nskb
= segs
->next
;
332 skb_queue_tail(&q
->sk
.sk_receive_queue
, segs
);
336 /* If we receive a partial checksum and the tap side
337 * doesn't support checksum offload, compute the checksum.
338 * Note: it doesn't matter which checksum feature to
339 * check, we either support them all or none.
341 if (skb
->ip_summed
== CHECKSUM_PARTIAL
&&
342 !(features
& NETIF_F_ALL_CSUM
) &&
343 skb_checksum_help(skb
))
345 skb_queue_tail(&q
->sk
.sk_receive_queue
, skb
);
349 wake_up_interruptible_poll(sk_sleep(&q
->sk
), POLLIN
| POLLRDNORM
| POLLRDBAND
);
350 return RX_HANDLER_CONSUMED
;
353 /* Count errors/drops only here, thus don't care about args. */
354 macvlan_count_rx(vlan
, 0, 0, 0);
356 return RX_HANDLER_CONSUMED
;
359 static int macvtap_get_minor(struct macvlan_dev
*vlan
)
361 int retval
= -ENOMEM
;
363 mutex_lock(&minor_lock
);
364 retval
= idr_alloc(&minor_idr
, vlan
, 1, MACVTAP_NUM_DEVS
, GFP_KERNEL
);
366 vlan
->minor
= retval
;
367 } else if (retval
== -ENOSPC
) {
368 printk(KERN_ERR
"too many macvtap devices\n");
371 mutex_unlock(&minor_lock
);
372 return retval
< 0 ? retval
: 0;
375 static void macvtap_free_minor(struct macvlan_dev
*vlan
)
377 mutex_lock(&minor_lock
);
379 idr_remove(&minor_idr
, vlan
->minor
);
382 mutex_unlock(&minor_lock
);
385 static struct net_device
*dev_get_by_macvtap_minor(int minor
)
387 struct net_device
*dev
= NULL
;
388 struct macvlan_dev
*vlan
;
390 mutex_lock(&minor_lock
);
391 vlan
= idr_find(&minor_idr
, minor
);
396 mutex_unlock(&minor_lock
);
400 static int macvtap_newlink(struct net
*src_net
,
401 struct net_device
*dev
,
403 struct nlattr
*data
[])
405 struct macvlan_dev
*vlan
= netdev_priv(dev
);
408 INIT_LIST_HEAD(&vlan
->queue_list
);
410 /* Since macvlan supports all offloads by default, make
411 * tap support all offloads also.
413 vlan
->tap_features
= TUN_OFFLOADS
;
415 err
= netdev_rx_handler_register(dev
, macvtap_handle_frame
, vlan
);
419 /* Don't put anything that may fail after macvlan_common_newlink
420 * because we can't undo what it does.
422 return macvlan_common_newlink(src_net
, dev
, tb
, data
);
425 static void macvtap_dellink(struct net_device
*dev
,
426 struct list_head
*head
)
428 netdev_rx_handler_unregister(dev
);
429 macvtap_del_queues(dev
);
430 macvlan_dellink(dev
, head
);
433 static void macvtap_setup(struct net_device
*dev
)
435 macvlan_common_setup(dev
);
436 dev
->tx_queue_len
= TUN_READQ_SIZE
;
439 static struct rtnl_link_ops macvtap_link_ops __read_mostly
= {
441 .setup
= macvtap_setup
,
442 .newlink
= macvtap_newlink
,
443 .dellink
= macvtap_dellink
,
447 static void macvtap_sock_write_space(struct sock
*sk
)
449 wait_queue_head_t
*wqueue
;
451 if (!sock_writeable(sk
) ||
452 !test_and_clear_bit(SOCK_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
))
455 wqueue
= sk_sleep(sk
);
456 if (wqueue
&& waitqueue_active(wqueue
))
457 wake_up_interruptible_poll(wqueue
, POLLOUT
| POLLWRNORM
| POLLWRBAND
);
460 static void macvtap_sock_destruct(struct sock
*sk
)
462 skb_queue_purge(&sk
->sk_receive_queue
);
465 static int macvtap_open(struct inode
*inode
, struct file
*file
)
467 struct net
*net
= current
->nsproxy
->net_ns
;
468 struct net_device
*dev
;
469 struct macvtap_queue
*q
;
473 dev
= dev_get_by_macvtap_minor(iminor(inode
));
478 q
= (struct macvtap_queue
*)sk_alloc(net
, AF_UNSPEC
, GFP_KERNEL
,
483 RCU_INIT_POINTER(q
->sock
.wq
, &q
->wq
);
484 init_waitqueue_head(&q
->wq
.wait
);
485 q
->sock
.type
= SOCK_RAW
;
486 q
->sock
.state
= SS_CONNECTED
;
488 q
->sock
.ops
= &macvtap_socket_ops
;
489 sock_init_data(&q
->sock
, &q
->sk
);
490 q
->sk
.sk_write_space
= macvtap_sock_write_space
;
491 q
->sk
.sk_destruct
= macvtap_sock_destruct
;
492 q
->flags
= IFF_VNET_HDR
| IFF_NO_PI
| IFF_TAP
;
493 q
->vnet_hdr_sz
= sizeof(struct virtio_net_hdr
);
496 * so far only KVM virtio_net uses macvtap, enable zero copy between
497 * guest kernel and host kernel when lower device supports zerocopy
499 * The macvlan supports zerocopy iff the lower device supports zero
500 * copy so we don't have to look at the lower device directly.
502 if ((dev
->features
& NETIF_F_HIGHDMA
) && (dev
->features
& NETIF_F_SG
))
503 sock_set_flag(&q
->sk
, SOCK_ZEROCOPY
);
505 err
= macvtap_set_queue(dev
, file
, q
);
517 static int macvtap_release(struct inode
*inode
, struct file
*file
)
519 struct macvtap_queue
*q
= file
->private_data
;
520 macvtap_put_queue(q
);
524 static unsigned int macvtap_poll(struct file
*file
, poll_table
* wait
)
526 struct macvtap_queue
*q
= file
->private_data
;
527 unsigned int mask
= POLLERR
;
533 poll_wait(file
, &q
->wq
.wait
, wait
);
535 if (!skb_queue_empty(&q
->sk
.sk_receive_queue
))
536 mask
|= POLLIN
| POLLRDNORM
;
538 if (sock_writeable(&q
->sk
) ||
539 (!test_and_set_bit(SOCK_ASYNC_NOSPACE
, &q
->sock
.flags
) &&
540 sock_writeable(&q
->sk
)))
541 mask
|= POLLOUT
| POLLWRNORM
;
547 static inline struct sk_buff
*macvtap_alloc_skb(struct sock
*sk
, size_t prepad
,
548 size_t len
, size_t linear
,
549 int noblock
, int *err
)
553 /* Under a page? Don't bother with paged skb. */
554 if (prepad
+ len
< PAGE_SIZE
|| !linear
)
557 skb
= sock_alloc_send_pskb(sk
, prepad
+ linear
, len
- linear
, noblock
,
562 skb_reserve(skb
, prepad
);
563 skb_put(skb
, linear
);
564 skb
->data_len
= len
- linear
;
565 skb
->len
+= len
- linear
;
571 * macvtap_skb_from_vnet_hdr and macvtap_skb_to_vnet_hdr should
572 * be shared with the tun/tap driver.
574 static int macvtap_skb_from_vnet_hdr(struct macvtap_queue
*q
,
576 struct virtio_net_hdr
*vnet_hdr
)
578 unsigned short gso_type
= 0;
579 if (vnet_hdr
->gso_type
!= VIRTIO_NET_HDR_GSO_NONE
) {
580 switch (vnet_hdr
->gso_type
& ~VIRTIO_NET_HDR_GSO_ECN
) {
581 case VIRTIO_NET_HDR_GSO_TCPV4
:
582 gso_type
= SKB_GSO_TCPV4
;
584 case VIRTIO_NET_HDR_GSO_TCPV6
:
585 gso_type
= SKB_GSO_TCPV6
;
587 case VIRTIO_NET_HDR_GSO_UDP
:
588 gso_type
= SKB_GSO_UDP
;
594 if (vnet_hdr
->gso_type
& VIRTIO_NET_HDR_GSO_ECN
)
595 gso_type
|= SKB_GSO_TCP_ECN
;
597 if (vnet_hdr
->gso_size
== 0)
601 if (vnet_hdr
->flags
& VIRTIO_NET_HDR_F_NEEDS_CSUM
) {
602 if (!skb_partial_csum_set(skb
, macvtap16_to_cpu(q
, vnet_hdr
->csum_start
),
603 macvtap16_to_cpu(q
, vnet_hdr
->csum_offset
)))
607 if (vnet_hdr
->gso_type
!= VIRTIO_NET_HDR_GSO_NONE
) {
608 skb_shinfo(skb
)->gso_size
= macvtap16_to_cpu(q
, vnet_hdr
->gso_size
);
609 skb_shinfo(skb
)->gso_type
= gso_type
;
611 /* Header must be checked, and gso_segs computed. */
612 skb_shinfo(skb
)->gso_type
|= SKB_GSO_DODGY
;
613 skb_shinfo(skb
)->gso_segs
= 0;
618 static void macvtap_skb_to_vnet_hdr(struct macvtap_queue
*q
,
619 const struct sk_buff
*skb
,
620 struct virtio_net_hdr
*vnet_hdr
)
622 memset(vnet_hdr
, 0, sizeof(*vnet_hdr
));
624 if (skb_is_gso(skb
)) {
625 struct skb_shared_info
*sinfo
= skb_shinfo(skb
);
627 /* This is a hint as to how much should be linear. */
628 vnet_hdr
->hdr_len
= cpu_to_macvtap16(q
, skb_headlen(skb
));
629 vnet_hdr
->gso_size
= cpu_to_macvtap16(q
, sinfo
->gso_size
);
630 if (sinfo
->gso_type
& SKB_GSO_TCPV4
)
631 vnet_hdr
->gso_type
= VIRTIO_NET_HDR_GSO_TCPV4
;
632 else if (sinfo
->gso_type
& SKB_GSO_TCPV6
)
633 vnet_hdr
->gso_type
= VIRTIO_NET_HDR_GSO_TCPV6
;
634 else if (sinfo
->gso_type
& SKB_GSO_UDP
)
635 vnet_hdr
->gso_type
= VIRTIO_NET_HDR_GSO_UDP
;
638 if (sinfo
->gso_type
& SKB_GSO_TCP_ECN
)
639 vnet_hdr
->gso_type
|= VIRTIO_NET_HDR_GSO_ECN
;
641 vnet_hdr
->gso_type
= VIRTIO_NET_HDR_GSO_NONE
;
643 if (skb
->ip_summed
== CHECKSUM_PARTIAL
) {
644 vnet_hdr
->flags
= VIRTIO_NET_HDR_F_NEEDS_CSUM
;
645 if (skb_vlan_tag_present(skb
))
646 vnet_hdr
->csum_start
= cpu_to_macvtap16(q
,
647 skb_checksum_start_offset(skb
) + VLAN_HLEN
);
649 vnet_hdr
->csum_start
= cpu_to_macvtap16(q
,
650 skb_checksum_start_offset(skb
));
651 vnet_hdr
->csum_offset
= cpu_to_macvtap16(q
, skb
->csum_offset
);
652 } else if (skb
->ip_summed
== CHECKSUM_UNNECESSARY
) {
653 vnet_hdr
->flags
= VIRTIO_NET_HDR_F_DATA_VALID
;
654 } /* else everything is zero */
657 /* Neighbour code has some assumptions on HH_DATA_MOD alignment */
658 #define MACVTAP_RESERVE HH_DATA_OFF(ETH_HLEN)
660 /* Get packet from user space buffer */
661 static ssize_t
macvtap_get_user(struct macvtap_queue
*q
, struct msghdr
*m
,
662 struct iov_iter
*from
, int noblock
)
664 int good_linear
= SKB_MAX_HEAD(MACVTAP_RESERVE
);
666 struct macvlan_dev
*vlan
;
667 unsigned long total_len
= iov_iter_count(from
);
668 unsigned long len
= total_len
;
670 struct virtio_net_hdr vnet_hdr
= { 0 };
671 int vnet_hdr_len
= 0;
673 bool zerocopy
= false;
677 if (q
->flags
& IFF_VNET_HDR
) {
678 vnet_hdr_len
= q
->vnet_hdr_sz
;
681 if (len
< vnet_hdr_len
)
686 n
= copy_from_iter(&vnet_hdr
, sizeof(vnet_hdr
), from
);
687 if (n
!= sizeof(vnet_hdr
))
689 iov_iter_advance(from
, vnet_hdr_len
- sizeof(vnet_hdr
));
690 if ((vnet_hdr
.flags
& VIRTIO_NET_HDR_F_NEEDS_CSUM
) &&
691 macvtap16_to_cpu(q
, vnet_hdr
.csum_start
) +
692 macvtap16_to_cpu(q
, vnet_hdr
.csum_offset
) + 2 >
693 macvtap16_to_cpu(q
, vnet_hdr
.hdr_len
))
694 vnet_hdr
.hdr_len
= cpu_to_macvtap16(q
,
695 macvtap16_to_cpu(q
, vnet_hdr
.csum_start
) +
696 macvtap16_to_cpu(q
, vnet_hdr
.csum_offset
) + 2);
698 if (macvtap16_to_cpu(q
, vnet_hdr
.hdr_len
) > len
)
703 if (unlikely(len
< ETH_HLEN
))
706 if (m
&& m
->msg_control
&& sock_flag(&q
->sk
, SOCK_ZEROCOPY
)) {
709 copylen
= vnet_hdr
.hdr_len
?
710 macvtap16_to_cpu(q
, vnet_hdr
.hdr_len
) : GOODCOPY_LEN
;
711 if (copylen
> good_linear
)
712 copylen
= good_linear
;
715 iov_iter_advance(&i
, copylen
);
716 if (iov_iter_npages(&i
, INT_MAX
) <= MAX_SKB_FRAGS
)
722 if (macvtap16_to_cpu(q
, vnet_hdr
.hdr_len
) > good_linear
)
723 linear
= good_linear
;
725 linear
= macvtap16_to_cpu(q
, vnet_hdr
.hdr_len
);
728 skb
= macvtap_alloc_skb(&q
->sk
, MACVTAP_RESERVE
, copylen
,
729 linear
, noblock
, &err
);
734 err
= zerocopy_sg_from_iter(skb
, from
);
736 err
= skb_copy_datagram_from_iter(skb
, 0, from
, len
);
737 if (!err
&& m
&& m
->msg_control
) {
738 struct ubuf_info
*uarg
= m
->msg_control
;
739 uarg
->callback(uarg
, false);
746 skb_set_network_header(skb
, ETH_HLEN
);
747 skb_reset_mac_header(skb
);
748 skb
->protocol
= eth_hdr(skb
)->h_proto
;
751 err
= macvtap_skb_from_vnet_hdr(q
, skb
, &vnet_hdr
);
756 skb_probe_transport_header(skb
, ETH_HLEN
);
759 vlan
= rcu_dereference(q
->vlan
);
760 /* copy skb_ubuf_info for callback when skb has no error */
762 skb_shinfo(skb
)->destructor_arg
= m
->msg_control
;
763 skb_shinfo(skb
)->tx_flags
|= SKBTX_DEV_ZEROCOPY
;
764 skb_shinfo(skb
)->tx_flags
|= SKBTX_SHARED_FRAG
;
767 skb
->dev
= vlan
->dev
;
781 vlan
= rcu_dereference(q
->vlan
);
783 this_cpu_inc(vlan
->pcpu_stats
->tx_dropped
);
789 static ssize_t
macvtap_write_iter(struct kiocb
*iocb
, struct iov_iter
*from
)
791 struct file
*file
= iocb
->ki_filp
;
792 struct macvtap_queue
*q
= file
->private_data
;
794 return macvtap_get_user(q
, NULL
, from
, file
->f_flags
& O_NONBLOCK
);
797 /* Put packet to the user space buffer */
798 static ssize_t
macvtap_put_user(struct macvtap_queue
*q
,
799 const struct sk_buff
*skb
,
800 struct iov_iter
*iter
)
803 int vnet_hdr_len
= 0;
807 if (q
->flags
& IFF_VNET_HDR
) {
808 struct virtio_net_hdr vnet_hdr
;
809 vnet_hdr_len
= q
->vnet_hdr_sz
;
810 if (iov_iter_count(iter
) < vnet_hdr_len
)
813 macvtap_skb_to_vnet_hdr(q
, skb
, &vnet_hdr
);
815 if (copy_to_iter(&vnet_hdr
, sizeof(vnet_hdr
), iter
) !=
819 iov_iter_advance(iter
, vnet_hdr_len
- sizeof(vnet_hdr
));
821 total
= vnet_hdr_len
;
824 if (skb_vlan_tag_present(skb
)) {
829 veth
.h_vlan_proto
= skb
->vlan_proto
;
830 veth
.h_vlan_TCI
= htons(skb_vlan_tag_get(skb
));
832 vlan_offset
= offsetof(struct vlan_ethhdr
, h_vlan_proto
);
835 ret
= skb_copy_datagram_iter(skb
, 0, iter
, vlan_offset
);
836 if (ret
|| !iov_iter_count(iter
))
839 ret
= copy_to_iter(&veth
, sizeof(veth
), iter
);
840 if (ret
!= sizeof(veth
) || !iov_iter_count(iter
))
844 ret
= skb_copy_datagram_iter(skb
, vlan_offset
, iter
,
845 skb
->len
- vlan_offset
);
848 return ret
? ret
: total
;
851 static ssize_t
macvtap_do_read(struct macvtap_queue
*q
,
859 if (!iov_iter_count(to
))
864 prepare_to_wait(sk_sleep(&q
->sk
), &wait
,
867 /* Read frames from the queue */
868 skb
= skb_dequeue(&q
->sk
.sk_receive_queue
);
875 if (signal_pending(current
)) {
879 /* Nothing to read, let's sleep */
883 ret
= macvtap_put_user(q
, skb
, to
);
884 if (unlikely(ret
< 0))
890 finish_wait(sk_sleep(&q
->sk
), &wait
);
894 static ssize_t
macvtap_read_iter(struct kiocb
*iocb
, struct iov_iter
*to
)
896 struct file
*file
= iocb
->ki_filp
;
897 struct macvtap_queue
*q
= file
->private_data
;
898 ssize_t len
= iov_iter_count(to
), ret
;
900 ret
= macvtap_do_read(q
, to
, file
->f_flags
& O_NONBLOCK
);
901 ret
= min_t(ssize_t
, ret
, len
);
907 static struct macvlan_dev
*macvtap_get_vlan(struct macvtap_queue
*q
)
909 struct macvlan_dev
*vlan
;
912 vlan
= rtnl_dereference(q
->vlan
);
919 static void macvtap_put_vlan(struct macvlan_dev
*vlan
)
924 static int macvtap_ioctl_set_queue(struct file
*file
, unsigned int flags
)
926 struct macvtap_queue
*q
= file
->private_data
;
927 struct macvlan_dev
*vlan
;
930 vlan
= macvtap_get_vlan(q
);
934 if (flags
& IFF_ATTACH_QUEUE
)
935 ret
= macvtap_enable_queue(vlan
->dev
, file
, q
);
936 else if (flags
& IFF_DETACH_QUEUE
)
937 ret
= macvtap_disable_queue(q
);
941 macvtap_put_vlan(vlan
);
945 static int set_offload(struct macvtap_queue
*q
, unsigned long arg
)
947 struct macvlan_dev
*vlan
;
948 netdev_features_t features
;
949 netdev_features_t feature_mask
= 0;
951 vlan
= rtnl_dereference(q
->vlan
);
955 features
= vlan
->dev
->features
;
957 if (arg
& TUN_F_CSUM
) {
958 feature_mask
= NETIF_F_HW_CSUM
;
960 if (arg
& (TUN_F_TSO4
| TUN_F_TSO6
)) {
961 if (arg
& TUN_F_TSO_ECN
)
962 feature_mask
|= NETIF_F_TSO_ECN
;
963 if (arg
& TUN_F_TSO4
)
964 feature_mask
|= NETIF_F_TSO
;
965 if (arg
& TUN_F_TSO6
)
966 feature_mask
|= NETIF_F_TSO6
;
970 feature_mask
|= NETIF_F_UFO
;
973 /* tun/tap driver inverts the usage for TSO offloads, where
974 * setting the TSO bit means that the userspace wants to
975 * accept TSO frames and turning it off means that user space
976 * does not support TSO.
977 * For macvtap, we have to invert it to mean the same thing.
978 * When user space turns off TSO, we turn off GSO/LRO so that
979 * user-space will not receive TSO frames.
981 if (feature_mask
& (NETIF_F_TSO
| NETIF_F_TSO6
| NETIF_F_UFO
))
982 features
|= RX_OFFLOADS
;
984 features
&= ~RX_OFFLOADS
;
986 /* tap_features are the same as features on tun/tap and
987 * reflect user expectations.
989 vlan
->tap_features
= feature_mask
;
990 vlan
->set_features
= features
;
991 netdev_update_features(vlan
->dev
);
997 * provide compatibility with generic tun/tap interface
999 static long macvtap_ioctl(struct file
*file
, unsigned int cmd
,
1002 struct macvtap_queue
*q
= file
->private_data
;
1003 struct macvlan_dev
*vlan
;
1004 void __user
*argp
= (void __user
*)arg
;
1005 struct ifreq __user
*ifr
= argp
;
1006 unsigned int __user
*up
= argp
;
1008 int __user
*sp
= argp
;
1015 /* ignore the name, just look at flags */
1016 if (get_user(u
, &ifr
->ifr_flags
))
1020 if ((u
& ~MACVTAP_FEATURES
) != (IFF_NO_PI
| IFF_TAP
))
1023 q
->flags
= (q
->flags
& ~MACVTAP_FEATURES
) | u
;
1029 vlan
= macvtap_get_vlan(q
);
1037 if (copy_to_user(&ifr
->ifr_name
, vlan
->dev
->name
, IFNAMSIZ
) ||
1038 put_user(u
, &ifr
->ifr_flags
))
1040 macvtap_put_vlan(vlan
);
1045 if (get_user(u
, &ifr
->ifr_flags
))
1048 ret
= macvtap_ioctl_set_queue(file
, u
);
1052 case TUNGETFEATURES
:
1053 if (put_user(IFF_TAP
| IFF_NO_PI
| MACVTAP_FEATURES
, up
))
1058 if (get_user(u
, up
))
1061 q
->sk
.sk_sndbuf
= u
;
1064 case TUNGETVNETHDRSZ
:
1066 if (put_user(s
, sp
))
1070 case TUNSETVNETHDRSZ
:
1071 if (get_user(s
, sp
))
1073 if (s
< (int)sizeof(struct virtio_net_hdr
))
1080 s
= !!(q
->flags
& MACVTAP_VNET_LE
);
1081 if (put_user(s
, sp
))
1086 if (get_user(s
, sp
))
1089 q
->flags
|= MACVTAP_VNET_LE
;
1091 q
->flags
&= ~MACVTAP_VNET_LE
;
1095 /* let the user check for future flags */
1096 if (arg
& ~(TUN_F_CSUM
| TUN_F_TSO4
| TUN_F_TSO6
|
1097 TUN_F_TSO_ECN
| TUN_F_UFO
))
1101 ret
= set_offload(q
, arg
);
1107 vlan
= macvtap_get_vlan(q
);
1113 u
= vlan
->dev
->type
;
1114 if (copy_to_user(&ifr
->ifr_name
, vlan
->dev
->name
, IFNAMSIZ
) ||
1115 copy_to_user(&ifr
->ifr_hwaddr
.sa_data
, vlan
->dev
->dev_addr
, ETH_ALEN
) ||
1116 put_user(u
, &ifr
->ifr_hwaddr
.sa_family
))
1118 macvtap_put_vlan(vlan
);
1123 if (copy_from_user(&sa
, &ifr
->ifr_hwaddr
, sizeof(sa
)))
1126 vlan
= macvtap_get_vlan(q
);
1131 ret
= dev_set_mac_address(vlan
->dev
, &sa
);
1132 macvtap_put_vlan(vlan
);
1141 #ifdef CONFIG_COMPAT
1142 static long macvtap_compat_ioctl(struct file
*file
, unsigned int cmd
,
1145 return macvtap_ioctl(file
, cmd
, (unsigned long)compat_ptr(arg
));
1149 static const struct file_operations macvtap_fops
= {
1150 .owner
= THIS_MODULE
,
1151 .open
= macvtap_open
,
1152 .release
= macvtap_release
,
1153 .read_iter
= macvtap_read_iter
,
1154 .write_iter
= macvtap_write_iter
,
1155 .poll
= macvtap_poll
,
1156 .llseek
= no_llseek
,
1157 .unlocked_ioctl
= macvtap_ioctl
,
1158 #ifdef CONFIG_COMPAT
1159 .compat_ioctl
= macvtap_compat_ioctl
,
1163 static int macvtap_sendmsg(struct socket
*sock
, struct msghdr
*m
,
1166 struct macvtap_queue
*q
= container_of(sock
, struct macvtap_queue
, sock
);
1167 return macvtap_get_user(q
, m
, &m
->msg_iter
, m
->msg_flags
& MSG_DONTWAIT
);
1170 static int macvtap_recvmsg(struct socket
*sock
, struct msghdr
*m
,
1171 size_t total_len
, int flags
)
1173 struct macvtap_queue
*q
= container_of(sock
, struct macvtap_queue
, sock
);
1175 if (flags
& ~(MSG_DONTWAIT
|MSG_TRUNC
))
1177 ret
= macvtap_do_read(q
, &m
->msg_iter
, flags
& MSG_DONTWAIT
);
1178 if (ret
> total_len
) {
1179 m
->msg_flags
|= MSG_TRUNC
;
1180 ret
= flags
& MSG_TRUNC
? ret
: total_len
;
1185 /* Ops structure to mimic raw sockets with tun */
1186 static const struct proto_ops macvtap_socket_ops
= {
1187 .sendmsg
= macvtap_sendmsg
,
1188 .recvmsg
= macvtap_recvmsg
,
1191 /* Get an underlying socket object from tun file. Returns error unless file is
1192 * attached to a device. The returned object works like a packet socket, it
1193 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
1194 * holding a reference to the file for as long as the socket is in use. */
1195 struct socket
*macvtap_get_socket(struct file
*file
)
1197 struct macvtap_queue
*q
;
1198 if (file
->f_op
!= &macvtap_fops
)
1199 return ERR_PTR(-EINVAL
);
1200 q
= file
->private_data
;
1202 return ERR_PTR(-EBADFD
);
1205 EXPORT_SYMBOL_GPL(macvtap_get_socket
);
1207 static int macvtap_device_event(struct notifier_block
*unused
,
1208 unsigned long event
, void *ptr
)
1210 struct net_device
*dev
= netdev_notifier_info_to_dev(ptr
);
1211 struct macvlan_dev
*vlan
;
1212 struct device
*classdev
;
1216 if (dev
->rtnl_link_ops
!= &macvtap_link_ops
)
1219 vlan
= netdev_priv(dev
);
1222 case NETDEV_REGISTER
:
1223 /* Create the device node here after the network device has
1224 * been registered but before register_netdevice has
1227 err
= macvtap_get_minor(vlan
);
1229 return notifier_from_errno(err
);
1231 devt
= MKDEV(MAJOR(macvtap_major
), vlan
->minor
);
1232 classdev
= device_create(macvtap_class
, &dev
->dev
, devt
,
1233 dev
, "tap%d", dev
->ifindex
);
1234 if (IS_ERR(classdev
)) {
1235 macvtap_free_minor(vlan
);
1236 return notifier_from_errno(PTR_ERR(classdev
));
1239 case NETDEV_UNREGISTER
:
1240 devt
= MKDEV(MAJOR(macvtap_major
), vlan
->minor
);
1241 device_destroy(macvtap_class
, devt
);
1242 macvtap_free_minor(vlan
);
1249 static struct notifier_block macvtap_notifier_block __read_mostly
= {
1250 .notifier_call
= macvtap_device_event
,
1253 static int macvtap_init(void)
1257 err
= alloc_chrdev_region(&macvtap_major
, 0,
1258 MACVTAP_NUM_DEVS
, "macvtap");
1262 cdev_init(&macvtap_cdev
, &macvtap_fops
);
1263 err
= cdev_add(&macvtap_cdev
, macvtap_major
, MACVTAP_NUM_DEVS
);
1267 macvtap_class
= class_create(THIS_MODULE
, "macvtap");
1268 if (IS_ERR(macvtap_class
)) {
1269 err
= PTR_ERR(macvtap_class
);
1273 err
= register_netdevice_notifier(&macvtap_notifier_block
);
1277 err
= macvlan_link_register(&macvtap_link_ops
);
1284 unregister_netdevice_notifier(&macvtap_notifier_block
);
1286 class_unregister(macvtap_class
);
1288 cdev_del(&macvtap_cdev
);
1290 unregister_chrdev_region(macvtap_major
, MACVTAP_NUM_DEVS
);
1294 module_init(macvtap_init
);
1296 static void macvtap_exit(void)
1298 rtnl_link_unregister(&macvtap_link_ops
);
1299 unregister_netdevice_notifier(&macvtap_notifier_block
);
1300 class_unregister(macvtap_class
);
1301 cdev_del(&macvtap_cdev
);
1302 unregister_chrdev_region(macvtap_major
, MACVTAP_NUM_DEVS
);
1304 module_exit(macvtap_exit
);
1306 MODULE_ALIAS_RTNL_LINK("macvtap");
1307 MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>");
1308 MODULE_LICENSE("GPL");