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>
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 static struct proto macvtap_proto
= {
51 .obj_size
= sizeof (struct macvtap_queue
),
55 * Variables for dealing with macvtaps device numbers.
57 static dev_t macvtap_major
;
58 #define MACVTAP_NUM_DEVS (1U << MINORBITS)
59 static DEFINE_MUTEX(minor_lock
);
60 static DEFINE_IDR(minor_idr
);
62 #define GOODCOPY_LEN 128
63 static struct class *macvtap_class
;
64 static struct cdev macvtap_cdev
;
66 static const struct proto_ops macvtap_socket_ops
;
68 #define TUN_OFFLOADS (NETIF_F_HW_CSUM | NETIF_F_TSO_ECN | NETIF_F_TSO | \
70 #define RX_OFFLOADS (NETIF_F_GRO | NETIF_F_LRO)
71 #define TAP_FEATURES (NETIF_F_GSO | NETIF_F_SG)
73 static struct macvlan_dev
*macvtap_get_vlan_rcu(const struct net_device
*dev
)
75 return rcu_dereference(dev
->rx_handler_data
);
80 * The macvtap_queue and the macvlan_dev are loosely coupled, the
81 * pointers from one to the other can only be read while rcu_read_lock
84 * Both the file and the macvlan_dev hold a reference on the macvtap_queue
85 * through sock_hold(&q->sk). When the macvlan_dev goes away first,
86 * q->vlan becomes inaccessible. When the files gets closed,
87 * macvtap_get_queue() fails.
89 * There may still be references to the struct sock inside of the
90 * queue from outbound SKBs, but these never reference back to the
91 * file or the dev. The data structure is freed through __sk_free
92 * when both our references and any pending SKBs are gone.
95 static int macvtap_enable_queue(struct net_device
*dev
, struct file
*file
,
96 struct macvtap_queue
*q
)
98 struct macvlan_dev
*vlan
= netdev_priv(dev
);
107 rcu_assign_pointer(vlan
->taps
[vlan
->numvtaps
], q
);
108 q
->queue_index
= vlan
->numvtaps
;
117 static int macvtap_set_queue(struct net_device
*dev
, struct file
*file
,
118 struct macvtap_queue
*q
)
120 struct macvlan_dev
*vlan
= netdev_priv(dev
);
122 if (vlan
->numqueues
== MAX_MACVTAP_QUEUES
)
125 rcu_assign_pointer(q
->vlan
, vlan
);
126 rcu_assign_pointer(vlan
->taps
[vlan
->numvtaps
], q
);
130 q
->queue_index
= vlan
->numvtaps
;
132 file
->private_data
= q
;
133 list_add_tail(&q
->next
, &vlan
->queue_list
);
141 static int macvtap_disable_queue(struct macvtap_queue
*q
)
143 struct macvlan_dev
*vlan
;
144 struct macvtap_queue
*nq
;
150 vlan
= rtnl_dereference(q
->vlan
);
153 int index
= q
->queue_index
;
154 BUG_ON(index
>= vlan
->numvtaps
);
155 nq
= rtnl_dereference(vlan
->taps
[vlan
->numvtaps
- 1]);
156 nq
->queue_index
= index
;
158 rcu_assign_pointer(vlan
->taps
[index
], nq
);
159 RCU_INIT_POINTER(vlan
->taps
[vlan
->numvtaps
- 1], NULL
);
169 * The file owning the queue got closed, give up both
170 * the reference that the files holds as well as the
171 * one from the macvlan_dev if that still exists.
173 * Using the spinlock makes sure that we don't get
174 * to the queue again after destroying it.
176 static void macvtap_put_queue(struct macvtap_queue
*q
)
178 struct macvlan_dev
*vlan
;
181 vlan
= rtnl_dereference(q
->vlan
);
185 BUG_ON(macvtap_disable_queue(q
));
188 RCU_INIT_POINTER(q
->vlan
, NULL
);
190 list_del_init(&q
->next
);
200 * Select a queue based on the rxq of the device on which this packet
201 * arrived. If the incoming device is not mq, calculate a flow hash
202 * to select a queue. If all fails, find the first available queue.
203 * Cache vlan->numvtaps since it can become zero during the execution
206 static struct macvtap_queue
*macvtap_get_queue(struct net_device
*dev
,
209 struct macvlan_dev
*vlan
= netdev_priv(dev
);
210 struct macvtap_queue
*tap
= NULL
;
211 /* Access to taps array is protected by rcu, but access to numvtaps
212 * isn't. Below we use it to lookup a queue, but treat it as a hint
213 * and validate that the result isn't NULL - in case we are
214 * racing against queue removal.
216 int numvtaps
= ACCESS_ONCE(vlan
->numvtaps
);
222 /* Check if we can use flow to select a queue */
223 rxq
= skb_get_hash(skb
);
225 tap
= rcu_dereference(vlan
->taps
[rxq
% numvtaps
]);
229 if (likely(skb_rx_queue_recorded(skb
))) {
230 rxq
= skb_get_rx_queue(skb
);
232 while (unlikely(rxq
>= numvtaps
))
235 tap
= rcu_dereference(vlan
->taps
[rxq
]);
239 tap
= rcu_dereference(vlan
->taps
[0]);
245 * The net_device is going away, give up the reference
246 * that it holds on all queues and safely set the pointer
247 * from the queues to NULL.
249 static void macvtap_del_queues(struct net_device
*dev
)
251 struct macvlan_dev
*vlan
= netdev_priv(dev
);
252 struct macvtap_queue
*q
, *tmp
, *qlist
[MAX_MACVTAP_QUEUES
];
256 list_for_each_entry_safe(q
, tmp
, &vlan
->queue_list
, next
) {
257 list_del_init(&q
->next
);
259 RCU_INIT_POINTER(q
->vlan
, NULL
);
264 for (i
= 0; i
< vlan
->numvtaps
; i
++)
265 RCU_INIT_POINTER(vlan
->taps
[i
], NULL
);
266 BUG_ON(vlan
->numvtaps
);
267 BUG_ON(vlan
->numqueues
);
268 /* guarantee that any future macvtap_set_queue will fail */
269 vlan
->numvtaps
= MAX_MACVTAP_QUEUES
;
271 for (--j
; j
>= 0; j
--)
272 sock_put(&qlist
[j
]->sk
);
275 static rx_handler_result_t
macvtap_handle_frame(struct sk_buff
**pskb
)
277 struct sk_buff
*skb
= *pskb
;
278 struct net_device
*dev
= skb
->dev
;
279 struct macvlan_dev
*vlan
;
280 struct macvtap_queue
*q
;
281 netdev_features_t features
= TAP_FEATURES
;
283 vlan
= macvtap_get_vlan_rcu(dev
);
285 return RX_HANDLER_PASS
;
287 q
= macvtap_get_queue(dev
, skb
);
289 return RX_HANDLER_PASS
;
291 if (skb_queue_len(&q
->sk
.sk_receive_queue
) >= dev
->tx_queue_len
)
294 skb_push(skb
, ETH_HLEN
);
296 /* Apply the forward feature mask so that we perform segmentation
297 * according to users wishes. This only works if VNET_HDR is
300 if (q
->flags
& IFF_VNET_HDR
)
301 features
|= vlan
->tap_features
;
302 if (netif_needs_gso(dev
, skb
, features
)) {
303 struct sk_buff
*segs
= __skb_gso_segment(skb
, features
, false);
309 skb_queue_tail(&q
->sk
.sk_receive_queue
, skb
);
315 struct sk_buff
*nskb
= segs
->next
;
318 skb_queue_tail(&q
->sk
.sk_receive_queue
, segs
);
322 /* If we receive a partial checksum and the tap side
323 * doesn't support checksum offload, compute the checksum.
324 * Note: it doesn't matter which checksum feature to
325 * check, we either support them all or none.
327 if (skb
->ip_summed
== CHECKSUM_PARTIAL
&&
328 !(features
& NETIF_F_ALL_CSUM
) &&
329 skb_checksum_help(skb
))
331 skb_queue_tail(&q
->sk
.sk_receive_queue
, skb
);
335 wake_up_interruptible_poll(sk_sleep(&q
->sk
), POLLIN
| POLLRDNORM
| POLLRDBAND
);
336 return RX_HANDLER_CONSUMED
;
339 /* Count errors/drops only here, thus don't care about args. */
340 macvlan_count_rx(vlan
, 0, 0, 0);
342 return RX_HANDLER_CONSUMED
;
345 static int macvtap_get_minor(struct macvlan_dev
*vlan
)
347 int retval
= -ENOMEM
;
349 mutex_lock(&minor_lock
);
350 retval
= idr_alloc(&minor_idr
, vlan
, 1, MACVTAP_NUM_DEVS
, GFP_KERNEL
);
352 vlan
->minor
= retval
;
353 } else if (retval
== -ENOSPC
) {
354 printk(KERN_ERR
"too many macvtap devices\n");
357 mutex_unlock(&minor_lock
);
358 return retval
< 0 ? retval
: 0;
361 static void macvtap_free_minor(struct macvlan_dev
*vlan
)
363 mutex_lock(&minor_lock
);
365 idr_remove(&minor_idr
, vlan
->minor
);
368 mutex_unlock(&minor_lock
);
371 static struct net_device
*dev_get_by_macvtap_minor(int minor
)
373 struct net_device
*dev
= NULL
;
374 struct macvlan_dev
*vlan
;
376 mutex_lock(&minor_lock
);
377 vlan
= idr_find(&minor_idr
, minor
);
382 mutex_unlock(&minor_lock
);
386 static int macvtap_newlink(struct net
*src_net
,
387 struct net_device
*dev
,
389 struct nlattr
*data
[])
391 struct macvlan_dev
*vlan
= netdev_priv(dev
);
394 INIT_LIST_HEAD(&vlan
->queue_list
);
396 /* Since macvlan supports all offloads by default, make
397 * tap support all offloads also.
399 vlan
->tap_features
= TUN_OFFLOADS
;
401 err
= netdev_rx_handler_register(dev
, macvtap_handle_frame
, vlan
);
405 /* Don't put anything that may fail after macvlan_common_newlink
406 * because we can't undo what it does.
408 return macvlan_common_newlink(src_net
, dev
, tb
, data
);
411 static void macvtap_dellink(struct net_device
*dev
,
412 struct list_head
*head
)
414 netdev_rx_handler_unregister(dev
);
415 macvtap_del_queues(dev
);
416 macvlan_dellink(dev
, head
);
419 static void macvtap_setup(struct net_device
*dev
)
421 macvlan_common_setup(dev
);
422 dev
->tx_queue_len
= TUN_READQ_SIZE
;
425 static struct rtnl_link_ops macvtap_link_ops __read_mostly
= {
427 .setup
= macvtap_setup
,
428 .newlink
= macvtap_newlink
,
429 .dellink
= macvtap_dellink
,
433 static void macvtap_sock_write_space(struct sock
*sk
)
435 wait_queue_head_t
*wqueue
;
437 if (!sock_writeable(sk
) ||
438 !test_and_clear_bit(SOCK_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
))
441 wqueue
= sk_sleep(sk
);
442 if (wqueue
&& waitqueue_active(wqueue
))
443 wake_up_interruptible_poll(wqueue
, POLLOUT
| POLLWRNORM
| POLLWRBAND
);
446 static void macvtap_sock_destruct(struct sock
*sk
)
448 skb_queue_purge(&sk
->sk_receive_queue
);
451 static int macvtap_open(struct inode
*inode
, struct file
*file
)
453 struct net
*net
= current
->nsproxy
->net_ns
;
454 struct net_device
*dev
;
455 struct macvtap_queue
*q
;
459 dev
= dev_get_by_macvtap_minor(iminor(inode
));
464 q
= (struct macvtap_queue
*)sk_alloc(net
, AF_UNSPEC
, GFP_KERNEL
,
469 RCU_INIT_POINTER(q
->sock
.wq
, &q
->wq
);
470 init_waitqueue_head(&q
->wq
.wait
);
471 q
->sock
.type
= SOCK_RAW
;
472 q
->sock
.state
= SS_CONNECTED
;
474 q
->sock
.ops
= &macvtap_socket_ops
;
475 sock_init_data(&q
->sock
, &q
->sk
);
476 q
->sk
.sk_write_space
= macvtap_sock_write_space
;
477 q
->sk
.sk_destruct
= macvtap_sock_destruct
;
478 q
->flags
= IFF_VNET_HDR
| IFF_NO_PI
| IFF_TAP
;
479 q
->vnet_hdr_sz
= sizeof(struct virtio_net_hdr
);
482 * so far only KVM virtio_net uses macvtap, enable zero copy between
483 * guest kernel and host kernel when lower device supports zerocopy
485 * The macvlan supports zerocopy iff the lower device supports zero
486 * copy so we don't have to look at the lower device directly.
488 if ((dev
->features
& NETIF_F_HIGHDMA
) && (dev
->features
& NETIF_F_SG
))
489 sock_set_flag(&q
->sk
, SOCK_ZEROCOPY
);
491 err
= macvtap_set_queue(dev
, file
, q
);
503 static int macvtap_release(struct inode
*inode
, struct file
*file
)
505 struct macvtap_queue
*q
= file
->private_data
;
506 macvtap_put_queue(q
);
510 static unsigned int macvtap_poll(struct file
*file
, poll_table
* wait
)
512 struct macvtap_queue
*q
= file
->private_data
;
513 unsigned int mask
= POLLERR
;
519 poll_wait(file
, &q
->wq
.wait
, wait
);
521 if (!skb_queue_empty(&q
->sk
.sk_receive_queue
))
522 mask
|= POLLIN
| POLLRDNORM
;
524 if (sock_writeable(&q
->sk
) ||
525 (!test_and_set_bit(SOCK_ASYNC_NOSPACE
, &q
->sock
.flags
) &&
526 sock_writeable(&q
->sk
)))
527 mask
|= POLLOUT
| POLLWRNORM
;
533 static inline struct sk_buff
*macvtap_alloc_skb(struct sock
*sk
, size_t prepad
,
534 size_t len
, size_t linear
,
535 int noblock
, int *err
)
539 /* Under a page? Don't bother with paged skb. */
540 if (prepad
+ len
< PAGE_SIZE
|| !linear
)
543 skb
= sock_alloc_send_pskb(sk
, prepad
+ linear
, len
- linear
, noblock
,
548 skb_reserve(skb
, prepad
);
549 skb_put(skb
, linear
);
550 skb
->data_len
= len
- linear
;
551 skb
->len
+= len
- linear
;
557 * macvtap_skb_from_vnet_hdr and macvtap_skb_to_vnet_hdr should
558 * be shared with the tun/tap driver.
560 static int macvtap_skb_from_vnet_hdr(struct sk_buff
*skb
,
561 struct virtio_net_hdr
*vnet_hdr
)
563 unsigned short gso_type
= 0;
564 if (vnet_hdr
->gso_type
!= VIRTIO_NET_HDR_GSO_NONE
) {
565 switch (vnet_hdr
->gso_type
& ~VIRTIO_NET_HDR_GSO_ECN
) {
566 case VIRTIO_NET_HDR_GSO_TCPV4
:
567 gso_type
= SKB_GSO_TCPV4
;
569 case VIRTIO_NET_HDR_GSO_TCPV6
:
570 gso_type
= SKB_GSO_TCPV6
;
572 case VIRTIO_NET_HDR_GSO_UDP
:
573 pr_warn_once("macvtap: %s: using disabled UFO feature; please fix this program\n",
575 gso_type
= SKB_GSO_UDP
;
576 if (skb
->protocol
== htons(ETH_P_IPV6
))
577 ipv6_proxy_select_ident(skb
);
583 if (vnet_hdr
->gso_type
& VIRTIO_NET_HDR_GSO_ECN
)
584 gso_type
|= SKB_GSO_TCP_ECN
;
586 if (vnet_hdr
->gso_size
== 0)
590 if (vnet_hdr
->flags
& VIRTIO_NET_HDR_F_NEEDS_CSUM
) {
591 if (!skb_partial_csum_set(skb
, vnet_hdr
->csum_start
,
592 vnet_hdr
->csum_offset
))
596 if (vnet_hdr
->gso_type
!= VIRTIO_NET_HDR_GSO_NONE
) {
597 skb_shinfo(skb
)->gso_size
= vnet_hdr
->gso_size
;
598 skb_shinfo(skb
)->gso_type
= gso_type
;
600 /* Header must be checked, and gso_segs computed. */
601 skb_shinfo(skb
)->gso_type
|= SKB_GSO_DODGY
;
602 skb_shinfo(skb
)->gso_segs
= 0;
607 static void macvtap_skb_to_vnet_hdr(const struct sk_buff
*skb
,
608 struct virtio_net_hdr
*vnet_hdr
)
610 memset(vnet_hdr
, 0, sizeof(*vnet_hdr
));
612 if (skb_is_gso(skb
)) {
613 struct skb_shared_info
*sinfo
= skb_shinfo(skb
);
615 /* This is a hint as to how much should be linear. */
616 vnet_hdr
->hdr_len
= skb_headlen(skb
);
617 vnet_hdr
->gso_size
= sinfo
->gso_size
;
618 if (sinfo
->gso_type
& SKB_GSO_TCPV4
)
619 vnet_hdr
->gso_type
= VIRTIO_NET_HDR_GSO_TCPV4
;
620 else if (sinfo
->gso_type
& SKB_GSO_TCPV6
)
621 vnet_hdr
->gso_type
= VIRTIO_NET_HDR_GSO_TCPV6
;
624 if (sinfo
->gso_type
& SKB_GSO_TCP_ECN
)
625 vnet_hdr
->gso_type
|= VIRTIO_NET_HDR_GSO_ECN
;
627 vnet_hdr
->gso_type
= VIRTIO_NET_HDR_GSO_NONE
;
629 if (skb
->ip_summed
== CHECKSUM_PARTIAL
) {
630 vnet_hdr
->flags
= VIRTIO_NET_HDR_F_NEEDS_CSUM
;
631 vnet_hdr
->csum_start
= skb_checksum_start_offset(skb
);
632 if (vlan_tx_tag_present(skb
))
633 vnet_hdr
->csum_start
+= VLAN_HLEN
;
634 vnet_hdr
->csum_offset
= skb
->csum_offset
;
635 } else if (skb
->ip_summed
== CHECKSUM_UNNECESSARY
) {
636 vnet_hdr
->flags
= VIRTIO_NET_HDR_F_DATA_VALID
;
637 } /* else everything is zero */
640 /* Get packet from user space buffer */
641 static ssize_t
macvtap_get_user(struct macvtap_queue
*q
, struct msghdr
*m
,
642 const struct iovec
*iv
, unsigned long total_len
,
643 size_t count
, int noblock
)
645 int good_linear
= SKB_MAX_HEAD(NET_IP_ALIGN
);
647 struct macvlan_dev
*vlan
;
648 unsigned long len
= total_len
;
650 struct virtio_net_hdr vnet_hdr
= { 0 };
651 int vnet_hdr_len
= 0;
653 bool zerocopy
= false;
656 if (q
->flags
& IFF_VNET_HDR
) {
657 vnet_hdr_len
= q
->vnet_hdr_sz
;
660 if (len
< vnet_hdr_len
)
664 err
= memcpy_fromiovecend((void *)&vnet_hdr
, iv
, 0,
668 if ((vnet_hdr
.flags
& VIRTIO_NET_HDR_F_NEEDS_CSUM
) &&
669 vnet_hdr
.csum_start
+ vnet_hdr
.csum_offset
+ 2 >
671 vnet_hdr
.hdr_len
= vnet_hdr
.csum_start
+
672 vnet_hdr
.csum_offset
+ 2;
674 if (vnet_hdr
.hdr_len
> len
)
679 if (unlikely(len
< ETH_HLEN
))
683 if (unlikely(count
> UIO_MAXIOV
))
686 if (m
&& m
->msg_control
&& sock_flag(&q
->sk
, SOCK_ZEROCOPY
)) {
687 copylen
= vnet_hdr
.hdr_len
? vnet_hdr
.hdr_len
: GOODCOPY_LEN
;
688 if (copylen
> good_linear
)
689 copylen
= good_linear
;
691 if (iov_pages(iv
, vnet_hdr_len
+ copylen
, count
)
698 if (vnet_hdr
.hdr_len
> good_linear
)
699 linear
= good_linear
;
701 linear
= vnet_hdr
.hdr_len
;
704 skb
= macvtap_alloc_skb(&q
->sk
, NET_IP_ALIGN
, copylen
,
705 linear
, noblock
, &err
);
710 err
= zerocopy_sg_from_iovec(skb
, iv
, vnet_hdr_len
, count
);
712 err
= skb_copy_datagram_from_iovec(skb
, 0, iv
, vnet_hdr_len
,
714 if (!err
&& m
&& m
->msg_control
) {
715 struct ubuf_info
*uarg
= m
->msg_control
;
716 uarg
->callback(uarg
, false);
723 skb_set_network_header(skb
, ETH_HLEN
);
724 skb_reset_mac_header(skb
);
725 skb
->protocol
= eth_hdr(skb
)->h_proto
;
728 err
= macvtap_skb_from_vnet_hdr(skb
, &vnet_hdr
);
733 skb_probe_transport_header(skb
, ETH_HLEN
);
736 vlan
= rcu_dereference(q
->vlan
);
737 /* copy skb_ubuf_info for callback when skb has no error */
739 skb_shinfo(skb
)->destructor_arg
= m
->msg_control
;
740 skb_shinfo(skb
)->tx_flags
|= SKBTX_DEV_ZEROCOPY
;
741 skb_shinfo(skb
)->tx_flags
|= SKBTX_SHARED_FRAG
;
744 skb
->dev
= vlan
->dev
;
758 vlan
= rcu_dereference(q
->vlan
);
760 this_cpu_inc(vlan
->pcpu_stats
->tx_dropped
);
766 static ssize_t
macvtap_aio_write(struct kiocb
*iocb
, const struct iovec
*iv
,
767 unsigned long count
, loff_t pos
)
769 struct file
*file
= iocb
->ki_filp
;
770 ssize_t result
= -ENOLINK
;
771 struct macvtap_queue
*q
= file
->private_data
;
773 result
= macvtap_get_user(q
, NULL
, iv
, iov_length(iv
, count
), count
,
774 file
->f_flags
& O_NONBLOCK
);
778 /* Put packet to the user space buffer */
779 static ssize_t
macvtap_put_user(struct macvtap_queue
*q
,
780 const struct sk_buff
*skb
,
781 const struct iovec
*iv
, int len
)
784 int vnet_hdr_len
= 0;
788 if (q
->flags
& IFF_VNET_HDR
) {
789 struct virtio_net_hdr vnet_hdr
;
790 vnet_hdr_len
= q
->vnet_hdr_sz
;
791 if ((len
-= vnet_hdr_len
) < 0)
794 macvtap_skb_to_vnet_hdr(skb
, &vnet_hdr
);
796 if (memcpy_toiovecend(iv
, (void *)&vnet_hdr
, 0, sizeof(vnet_hdr
)))
799 total
= copied
= vnet_hdr_len
;
802 if (!vlan_tx_tag_present(skb
))
803 len
= min_t(int, skb
->len
, len
);
810 veth
.h_vlan_proto
= skb
->vlan_proto
;
811 veth
.h_vlan_TCI
= htons(vlan_tx_tag_get(skb
));
813 vlan_offset
= offsetof(struct vlan_ethhdr
, h_vlan_proto
);
814 len
= min_t(int, skb
->len
+ VLAN_HLEN
, len
);
817 copy
= min_t(int, vlan_offset
, len
);
818 ret
= skb_copy_datagram_const_iovec(skb
, 0, iv
, copied
, copy
);
824 copy
= min_t(int, sizeof(veth
), len
);
825 ret
= memcpy_toiovecend(iv
, (void *)&veth
, copied
, copy
);
832 ret
= skb_copy_datagram_const_iovec(skb
, vlan_offset
, iv
, copied
, len
);
835 return ret
? ret
: total
;
838 static ssize_t
macvtap_do_read(struct macvtap_queue
*q
,
839 const struct iovec
*iv
, unsigned long len
,
848 prepare_to_wait(sk_sleep(&q
->sk
), &wait
,
851 /* Read frames from the queue */
852 skb
= skb_dequeue(&q
->sk
.sk_receive_queue
);
858 if (signal_pending(current
)) {
862 /* Nothing to read, let's sleep */
866 ret
= macvtap_put_user(q
, skb
, iv
, len
);
872 finish_wait(sk_sleep(&q
->sk
), &wait
);
876 static ssize_t
macvtap_aio_read(struct kiocb
*iocb
, const struct iovec
*iv
,
877 unsigned long count
, loff_t pos
)
879 struct file
*file
= iocb
->ki_filp
;
880 struct macvtap_queue
*q
= file
->private_data
;
881 ssize_t len
, ret
= 0;
883 len
= iov_length(iv
, count
);
889 ret
= macvtap_do_read(q
, iv
, len
, file
->f_flags
& O_NONBLOCK
);
890 ret
= min_t(ssize_t
, ret
, len
);
897 static struct macvlan_dev
*macvtap_get_vlan(struct macvtap_queue
*q
)
899 struct macvlan_dev
*vlan
;
902 vlan
= rtnl_dereference(q
->vlan
);
909 static void macvtap_put_vlan(struct macvlan_dev
*vlan
)
914 static int macvtap_ioctl_set_queue(struct file
*file
, unsigned int flags
)
916 struct macvtap_queue
*q
= file
->private_data
;
917 struct macvlan_dev
*vlan
;
920 vlan
= macvtap_get_vlan(q
);
924 if (flags
& IFF_ATTACH_QUEUE
)
925 ret
= macvtap_enable_queue(vlan
->dev
, file
, q
);
926 else if (flags
& IFF_DETACH_QUEUE
)
927 ret
= macvtap_disable_queue(q
);
931 macvtap_put_vlan(vlan
);
935 static int set_offload(struct macvtap_queue
*q
, unsigned long arg
)
937 struct macvlan_dev
*vlan
;
938 netdev_features_t features
;
939 netdev_features_t feature_mask
= 0;
941 vlan
= rtnl_dereference(q
->vlan
);
945 features
= vlan
->dev
->features
;
947 if (arg
& TUN_F_CSUM
) {
948 feature_mask
= NETIF_F_HW_CSUM
;
950 if (arg
& (TUN_F_TSO4
| TUN_F_TSO6
)) {
951 if (arg
& TUN_F_TSO_ECN
)
952 feature_mask
|= NETIF_F_TSO_ECN
;
953 if (arg
& TUN_F_TSO4
)
954 feature_mask
|= NETIF_F_TSO
;
955 if (arg
& TUN_F_TSO6
)
956 feature_mask
|= NETIF_F_TSO6
;
960 /* tun/tap driver inverts the usage for TSO offloads, where
961 * setting the TSO bit means that the userspace wants to
962 * accept TSO frames and turning it off means that user space
963 * does not support TSO.
964 * For macvtap, we have to invert it to mean the same thing.
965 * When user space turns off TSO, we turn off GSO/LRO so that
966 * user-space will not receive TSO frames.
968 if (feature_mask
& (NETIF_F_TSO
| NETIF_F_TSO6
))
969 features
|= RX_OFFLOADS
;
971 features
&= ~RX_OFFLOADS
;
973 /* tap_features are the same as features on tun/tap and
974 * reflect user expectations.
976 vlan
->tap_features
= feature_mask
;
977 vlan
->set_features
= features
;
978 netdev_update_features(vlan
->dev
);
984 * provide compatibility with generic tun/tap interface
986 static long macvtap_ioctl(struct file
*file
, unsigned int cmd
,
989 struct macvtap_queue
*q
= file
->private_data
;
990 struct macvlan_dev
*vlan
;
991 void __user
*argp
= (void __user
*)arg
;
992 struct ifreq __user
*ifr
= argp
;
993 unsigned int __user
*up
= argp
;
995 int __user
*sp
= argp
;
1001 /* ignore the name, just look at flags */
1002 if (get_user(u
, &ifr
->ifr_flags
))
1006 if ((u
& ~(IFF_VNET_HDR
| IFF_MULTI_QUEUE
)) !=
1007 (IFF_NO_PI
| IFF_TAP
))
1016 vlan
= macvtap_get_vlan(q
);
1023 if (copy_to_user(&ifr
->ifr_name
, vlan
->dev
->name
, IFNAMSIZ
) ||
1024 put_user(q
->flags
, &ifr
->ifr_flags
))
1026 macvtap_put_vlan(vlan
);
1031 if (get_user(u
, &ifr
->ifr_flags
))
1034 ret
= macvtap_ioctl_set_queue(file
, u
);
1038 case TUNGETFEATURES
:
1039 if (put_user(IFF_TAP
| IFF_NO_PI
| IFF_VNET_HDR
|
1040 IFF_MULTI_QUEUE
, up
))
1045 if (get_user(u
, up
))
1048 q
->sk
.sk_sndbuf
= u
;
1051 case TUNGETVNETHDRSZ
:
1053 if (put_user(s
, sp
))
1057 case TUNSETVNETHDRSZ
:
1058 if (get_user(s
, sp
))
1060 if (s
< (int)sizeof(struct virtio_net_hdr
))
1067 /* let the user check for future flags */
1068 if (arg
& ~(TUN_F_CSUM
| TUN_F_TSO4
| TUN_F_TSO6
|
1073 ret
= set_offload(q
, arg
);
1082 #ifdef CONFIG_COMPAT
1083 static long macvtap_compat_ioctl(struct file
*file
, unsigned int cmd
,
1086 return macvtap_ioctl(file
, cmd
, (unsigned long)compat_ptr(arg
));
1090 static const struct file_operations macvtap_fops
= {
1091 .owner
= THIS_MODULE
,
1092 .open
= macvtap_open
,
1093 .release
= macvtap_release
,
1094 .aio_read
= macvtap_aio_read
,
1095 .aio_write
= macvtap_aio_write
,
1096 .poll
= macvtap_poll
,
1097 .llseek
= no_llseek
,
1098 .unlocked_ioctl
= macvtap_ioctl
,
1099 #ifdef CONFIG_COMPAT
1100 .compat_ioctl
= macvtap_compat_ioctl
,
1104 static int macvtap_sendmsg(struct kiocb
*iocb
, struct socket
*sock
,
1105 struct msghdr
*m
, size_t total_len
)
1107 struct macvtap_queue
*q
= container_of(sock
, struct macvtap_queue
, sock
);
1108 return macvtap_get_user(q
, m
, m
->msg_iov
, total_len
, m
->msg_iovlen
,
1109 m
->msg_flags
& MSG_DONTWAIT
);
1112 static int macvtap_recvmsg(struct kiocb
*iocb
, struct socket
*sock
,
1113 struct msghdr
*m
, size_t total_len
,
1116 struct macvtap_queue
*q
= container_of(sock
, struct macvtap_queue
, sock
);
1118 if (flags
& ~(MSG_DONTWAIT
|MSG_TRUNC
))
1120 ret
= macvtap_do_read(q
, m
->msg_iov
, total_len
,
1121 flags
& MSG_DONTWAIT
);
1122 if (ret
> total_len
) {
1123 m
->msg_flags
|= MSG_TRUNC
;
1124 ret
= flags
& MSG_TRUNC
? ret
: total_len
;
1129 /* Ops structure to mimic raw sockets with tun */
1130 static const struct proto_ops macvtap_socket_ops
= {
1131 .sendmsg
= macvtap_sendmsg
,
1132 .recvmsg
= macvtap_recvmsg
,
1135 /* Get an underlying socket object from tun file. Returns error unless file is
1136 * attached to a device. The returned object works like a packet socket, it
1137 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
1138 * holding a reference to the file for as long as the socket is in use. */
1139 struct socket
*macvtap_get_socket(struct file
*file
)
1141 struct macvtap_queue
*q
;
1142 if (file
->f_op
!= &macvtap_fops
)
1143 return ERR_PTR(-EINVAL
);
1144 q
= file
->private_data
;
1146 return ERR_PTR(-EBADFD
);
1149 EXPORT_SYMBOL_GPL(macvtap_get_socket
);
1151 static int macvtap_device_event(struct notifier_block
*unused
,
1152 unsigned long event
, void *ptr
)
1154 struct net_device
*dev
= netdev_notifier_info_to_dev(ptr
);
1155 struct macvlan_dev
*vlan
;
1156 struct device
*classdev
;
1160 if (dev
->rtnl_link_ops
!= &macvtap_link_ops
)
1163 vlan
= netdev_priv(dev
);
1166 case NETDEV_REGISTER
:
1167 /* Create the device node here after the network device has
1168 * been registered but before register_netdevice has
1171 err
= macvtap_get_minor(vlan
);
1173 return notifier_from_errno(err
);
1175 devt
= MKDEV(MAJOR(macvtap_major
), vlan
->minor
);
1176 classdev
= device_create(macvtap_class
, &dev
->dev
, devt
,
1177 dev
, "tap%d", dev
->ifindex
);
1178 if (IS_ERR(classdev
)) {
1179 macvtap_free_minor(vlan
);
1180 return notifier_from_errno(PTR_ERR(classdev
));
1183 case NETDEV_UNREGISTER
:
1184 devt
= MKDEV(MAJOR(macvtap_major
), vlan
->minor
);
1185 device_destroy(macvtap_class
, devt
);
1186 macvtap_free_minor(vlan
);
1193 static struct notifier_block macvtap_notifier_block __read_mostly
= {
1194 .notifier_call
= macvtap_device_event
,
1197 static int macvtap_init(void)
1201 err
= alloc_chrdev_region(&macvtap_major
, 0,
1202 MACVTAP_NUM_DEVS
, "macvtap");
1206 cdev_init(&macvtap_cdev
, &macvtap_fops
);
1207 err
= cdev_add(&macvtap_cdev
, macvtap_major
, MACVTAP_NUM_DEVS
);
1211 macvtap_class
= class_create(THIS_MODULE
, "macvtap");
1212 if (IS_ERR(macvtap_class
)) {
1213 err
= PTR_ERR(macvtap_class
);
1217 err
= register_netdevice_notifier(&macvtap_notifier_block
);
1221 err
= macvlan_link_register(&macvtap_link_ops
);
1228 unregister_netdevice_notifier(&macvtap_notifier_block
);
1230 class_unregister(macvtap_class
);
1232 cdev_del(&macvtap_cdev
);
1234 unregister_chrdev_region(macvtap_major
, MACVTAP_NUM_DEVS
);
1238 module_init(macvtap_init
);
1240 static void macvtap_exit(void)
1242 rtnl_link_unregister(&macvtap_link_ops
);
1243 unregister_netdevice_notifier(&macvtap_notifier_block
);
1244 class_unregister(macvtap_class
);
1245 cdev_del(&macvtap_cdev
);
1246 unregister_chrdev_region(macvtap_major
, MACVTAP_NUM_DEVS
);
1248 module_exit(macvtap_exit
);
1250 MODULE_ALIAS_RTNL_LINK("macvtap");
1251 MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>");
1252 MODULE_LICENSE("GPL");