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>
19 #include <net/net_namespace.h>
20 #include <net/rtnetlink.h>
22 #include <linux/virtio_net.h>
25 * A macvtap queue is the central object of this driver, it connects
26 * an open character device to a macvlan interface. There can be
27 * multiple queues on one interface, which map back to queues
28 * implemented in hardware on the underlying device.
30 * macvtap_proto is used to allocate queues through the sock allocation
34 struct macvtap_queue
{
39 struct macvlan_dev __rcu
*vlan
;
44 struct list_head next
;
47 static struct proto macvtap_proto
= {
50 .obj_size
= sizeof (struct macvtap_queue
),
54 * Variables for dealing with macvtaps device numbers.
56 static dev_t macvtap_major
;
57 #define MACVTAP_NUM_DEVS (1U << MINORBITS)
58 static DEFINE_MUTEX(minor_lock
);
59 static DEFINE_IDR(minor_idr
);
61 #define GOODCOPY_LEN 128
62 static struct class *macvtap_class
;
63 static struct cdev macvtap_cdev
;
65 static const struct proto_ops macvtap_socket_ops
;
67 #define TUN_OFFLOADS (NETIF_F_HW_CSUM | NETIF_F_TSO_ECN | NETIF_F_TSO | \
68 NETIF_F_TSO6 | NETIF_F_UFO)
69 #define RX_OFFLOADS (NETIF_F_GRO | NETIF_F_LRO)
70 #define TAP_FEATURES (NETIF_F_GSO | NETIF_F_SG)
72 static struct macvlan_dev
*macvtap_get_vlan_rcu(const struct net_device
*dev
)
74 return rcu_dereference(dev
->rx_handler_data
);
79 * The macvtap_queue and the macvlan_dev are loosely coupled, the
80 * pointers from one to the other can only be read while rcu_read_lock
83 * Both the file and the macvlan_dev hold a reference on the macvtap_queue
84 * through sock_hold(&q->sk). When the macvlan_dev goes away first,
85 * q->vlan becomes inaccessible. When the files gets closed,
86 * macvtap_get_queue() fails.
88 * There may still be references to the struct sock inside of the
89 * queue from outbound SKBs, but these never reference back to the
90 * file or the dev. The data structure is freed through __sk_free
91 * when both our references and any pending SKBs are gone.
94 static int macvtap_enable_queue(struct net_device
*dev
, struct file
*file
,
95 struct macvtap_queue
*q
)
97 struct macvlan_dev
*vlan
= netdev_priv(dev
);
106 rcu_assign_pointer(vlan
->taps
[vlan
->numvtaps
], q
);
107 q
->queue_index
= vlan
->numvtaps
;
116 static int macvtap_set_queue(struct net_device
*dev
, struct file
*file
,
117 struct macvtap_queue
*q
)
119 struct macvlan_dev
*vlan
= netdev_priv(dev
);
121 if (vlan
->numqueues
== MAX_MACVTAP_QUEUES
)
124 rcu_assign_pointer(q
->vlan
, vlan
);
125 rcu_assign_pointer(vlan
->taps
[vlan
->numvtaps
], q
);
129 q
->queue_index
= vlan
->numvtaps
;
131 file
->private_data
= q
;
132 list_add_tail(&q
->next
, &vlan
->queue_list
);
140 static int macvtap_disable_queue(struct macvtap_queue
*q
)
142 struct macvlan_dev
*vlan
;
143 struct macvtap_queue
*nq
;
149 vlan
= rtnl_dereference(q
->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
;
157 rcu_assign_pointer(vlan
->taps
[index
], nq
);
158 RCU_INIT_POINTER(vlan
->taps
[vlan
->numvtaps
- 1], NULL
);
168 * The file owning the queue got closed, give up both
169 * the reference that the files holds as well as the
170 * one from the macvlan_dev if that still exists.
172 * Using the spinlock makes sure that we don't get
173 * to the queue again after destroying it.
175 static void macvtap_put_queue(struct macvtap_queue
*q
)
177 struct macvlan_dev
*vlan
;
180 vlan
= rtnl_dereference(q
->vlan
);
184 BUG_ON(macvtap_disable_queue(q
));
187 RCU_INIT_POINTER(q
->vlan
, NULL
);
189 list_del_init(&q
->next
);
199 * Select a queue based on the rxq of the device on which this packet
200 * arrived. If the incoming device is not mq, calculate a flow hash
201 * to select a queue. If all fails, find the first available queue.
202 * Cache vlan->numvtaps since it can become zero during the execution
205 static struct macvtap_queue
*macvtap_get_queue(struct net_device
*dev
,
208 struct macvlan_dev
*vlan
= netdev_priv(dev
);
209 struct macvtap_queue
*tap
= NULL
;
210 /* Access to taps array is protected by rcu, but access to numvtaps
211 * isn't. Below we use it to lookup a queue, but treat it as a hint
212 * and validate that the result isn't NULL - in case we are
213 * racing against queue removal.
215 int numvtaps
= ACCESS_ONCE(vlan
->numvtaps
);
221 /* Check if we can use flow to select a queue */
222 rxq
= skb_get_hash(skb
);
224 tap
= rcu_dereference(vlan
->taps
[rxq
% numvtaps
]);
228 if (likely(skb_rx_queue_recorded(skb
))) {
229 rxq
= skb_get_rx_queue(skb
);
231 while (unlikely(rxq
>= numvtaps
))
234 tap
= rcu_dereference(vlan
->taps
[rxq
]);
238 tap
= rcu_dereference(vlan
->taps
[0]);
244 * The net_device is going away, give up the reference
245 * that it holds on all queues and safely set the pointer
246 * from the queues to NULL.
248 static void macvtap_del_queues(struct net_device
*dev
)
250 struct macvlan_dev
*vlan
= netdev_priv(dev
);
251 struct macvtap_queue
*q
, *tmp
, *qlist
[MAX_MACVTAP_QUEUES
];
255 list_for_each_entry_safe(q
, tmp
, &vlan
->queue_list
, next
) {
256 list_del_init(&q
->next
);
258 RCU_INIT_POINTER(q
->vlan
, NULL
);
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 /* guarantee that any future macvtap_set_queue will fail */
268 vlan
->numvtaps
= MAX_MACVTAP_QUEUES
;
270 for (--j
; j
>= 0; j
--)
271 sock_put(&qlist
[j
]->sk
);
274 static rx_handler_result_t
macvtap_handle_frame(struct sk_buff
**pskb
)
276 struct sk_buff
*skb
= *pskb
;
277 struct net_device
*dev
= skb
->dev
;
278 struct macvlan_dev
*vlan
;
279 struct macvtap_queue
*q
;
280 netdev_features_t features
= TAP_FEATURES
;
282 vlan
= macvtap_get_vlan_rcu(dev
);
284 return RX_HANDLER_PASS
;
286 q
= macvtap_get_queue(dev
, skb
);
288 return RX_HANDLER_PASS
;
290 if (skb_queue_len(&q
->sk
.sk_receive_queue
) >= dev
->tx_queue_len
)
293 skb_push(skb
, ETH_HLEN
);
295 /* Apply the forward feature mask so that we perform segmentation
296 * according to users wishes. This only works if VNET_HDR is
299 if (q
->flags
& IFF_VNET_HDR
)
300 features
|= vlan
->tap_features
;
301 if (netif_needs_gso(dev
, skb
, features
)) {
302 struct sk_buff
*segs
= __skb_gso_segment(skb
, features
, false);
308 skb_queue_tail(&q
->sk
.sk_receive_queue
, skb
);
314 struct sk_buff
*nskb
= segs
->next
;
317 skb_queue_tail(&q
->sk
.sk_receive_queue
, segs
);
321 /* If we receive a partial checksum and the tap side
322 * doesn't support checksum offload, compute the checksum.
323 * Note: it doesn't matter which checksum feature to
324 * check, we either support them all or none.
326 if (skb
->ip_summed
== CHECKSUM_PARTIAL
&&
327 !(features
& NETIF_F_ALL_CSUM
) &&
328 skb_checksum_help(skb
))
330 skb_queue_tail(&q
->sk
.sk_receive_queue
, skb
);
334 wake_up_interruptible_poll(sk_sleep(&q
->sk
), POLLIN
| POLLRDNORM
| POLLRDBAND
);
335 return RX_HANDLER_CONSUMED
;
338 /* Count errors/drops only here, thus don't care about args. */
339 macvlan_count_rx(vlan
, 0, 0, 0);
341 return RX_HANDLER_CONSUMED
;
344 static int macvtap_get_minor(struct macvlan_dev
*vlan
)
346 int retval
= -ENOMEM
;
348 mutex_lock(&minor_lock
);
349 retval
= idr_alloc(&minor_idr
, vlan
, 1, MACVTAP_NUM_DEVS
, GFP_KERNEL
);
351 vlan
->minor
= retval
;
352 } else if (retval
== -ENOSPC
) {
353 printk(KERN_ERR
"too many macvtap devices\n");
356 mutex_unlock(&minor_lock
);
357 return retval
< 0 ? retval
: 0;
360 static void macvtap_free_minor(struct macvlan_dev
*vlan
)
362 mutex_lock(&minor_lock
);
364 idr_remove(&minor_idr
, vlan
->minor
);
367 mutex_unlock(&minor_lock
);
370 static struct net_device
*dev_get_by_macvtap_minor(int minor
)
372 struct net_device
*dev
= NULL
;
373 struct macvlan_dev
*vlan
;
375 mutex_lock(&minor_lock
);
376 vlan
= idr_find(&minor_idr
, minor
);
381 mutex_unlock(&minor_lock
);
385 static int macvtap_newlink(struct net
*src_net
,
386 struct net_device
*dev
,
388 struct nlattr
*data
[])
390 struct macvlan_dev
*vlan
= netdev_priv(dev
);
393 INIT_LIST_HEAD(&vlan
->queue_list
);
395 /* Since macvlan supports all offloads by default, make
396 * tap support all offloads also.
398 vlan
->tap_features
= TUN_OFFLOADS
;
400 err
= netdev_rx_handler_register(dev
, macvtap_handle_frame
, vlan
);
404 /* Don't put anything that may fail after macvlan_common_newlink
405 * because we can't undo what it does.
407 return macvlan_common_newlink(src_net
, dev
, tb
, data
);
410 static void macvtap_dellink(struct net_device
*dev
,
411 struct list_head
*head
)
413 netdev_rx_handler_unregister(dev
);
414 macvtap_del_queues(dev
);
415 macvlan_dellink(dev
, head
);
418 static void macvtap_setup(struct net_device
*dev
)
420 macvlan_common_setup(dev
);
421 dev
->tx_queue_len
= TUN_READQ_SIZE
;
424 static struct rtnl_link_ops macvtap_link_ops __read_mostly
= {
426 .setup
= macvtap_setup
,
427 .newlink
= macvtap_newlink
,
428 .dellink
= macvtap_dellink
,
432 static void macvtap_sock_write_space(struct sock
*sk
)
434 wait_queue_head_t
*wqueue
;
436 if (!sock_writeable(sk
) ||
437 !test_and_clear_bit(SOCK_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
))
440 wqueue
= sk_sleep(sk
);
441 if (wqueue
&& waitqueue_active(wqueue
))
442 wake_up_interruptible_poll(wqueue
, POLLOUT
| POLLWRNORM
| POLLWRBAND
);
445 static void macvtap_sock_destruct(struct sock
*sk
)
447 skb_queue_purge(&sk
->sk_receive_queue
);
450 static int macvtap_open(struct inode
*inode
, struct file
*file
)
452 struct net
*net
= current
->nsproxy
->net_ns
;
453 struct net_device
*dev
;
454 struct macvtap_queue
*q
;
458 dev
= dev_get_by_macvtap_minor(iminor(inode
));
463 q
= (struct macvtap_queue
*)sk_alloc(net
, AF_UNSPEC
, GFP_KERNEL
,
468 RCU_INIT_POINTER(q
->sock
.wq
, &q
->wq
);
469 init_waitqueue_head(&q
->wq
.wait
);
470 q
->sock
.type
= SOCK_RAW
;
471 q
->sock
.state
= SS_CONNECTED
;
473 q
->sock
.ops
= &macvtap_socket_ops
;
474 sock_init_data(&q
->sock
, &q
->sk
);
475 q
->sk
.sk_write_space
= macvtap_sock_write_space
;
476 q
->sk
.sk_destruct
= macvtap_sock_destruct
;
477 q
->flags
= IFF_VNET_HDR
| IFF_NO_PI
| IFF_TAP
;
478 q
->vnet_hdr_sz
= sizeof(struct virtio_net_hdr
);
481 * so far only KVM virtio_net uses macvtap, enable zero copy between
482 * guest kernel and host kernel when lower device supports zerocopy
484 * The macvlan supports zerocopy iff the lower device supports zero
485 * copy so we don't have to look at the lower device directly.
487 if ((dev
->features
& NETIF_F_HIGHDMA
) && (dev
->features
& NETIF_F_SG
))
488 sock_set_flag(&q
->sk
, SOCK_ZEROCOPY
);
490 err
= macvtap_set_queue(dev
, file
, q
);
502 static int macvtap_release(struct inode
*inode
, struct file
*file
)
504 struct macvtap_queue
*q
= file
->private_data
;
505 macvtap_put_queue(q
);
509 static unsigned int macvtap_poll(struct file
*file
, poll_table
* wait
)
511 struct macvtap_queue
*q
= file
->private_data
;
512 unsigned int mask
= POLLERR
;
518 poll_wait(file
, &q
->wq
.wait
, wait
);
520 if (!skb_queue_empty(&q
->sk
.sk_receive_queue
))
521 mask
|= POLLIN
| POLLRDNORM
;
523 if (sock_writeable(&q
->sk
) ||
524 (!test_and_set_bit(SOCK_ASYNC_NOSPACE
, &q
->sock
.flags
) &&
525 sock_writeable(&q
->sk
)))
526 mask
|= POLLOUT
| POLLWRNORM
;
532 static inline struct sk_buff
*macvtap_alloc_skb(struct sock
*sk
, size_t prepad
,
533 size_t len
, size_t linear
,
534 int noblock
, int *err
)
538 /* Under a page? Don't bother with paged skb. */
539 if (prepad
+ len
< PAGE_SIZE
|| !linear
)
542 skb
= sock_alloc_send_pskb(sk
, prepad
+ linear
, len
- linear
, noblock
,
547 skb_reserve(skb
, prepad
);
548 skb_put(skb
, linear
);
549 skb
->data_len
= len
- linear
;
550 skb
->len
+= len
- linear
;
556 * macvtap_skb_from_vnet_hdr and macvtap_skb_to_vnet_hdr should
557 * be shared with the tun/tap driver.
559 static int macvtap_skb_from_vnet_hdr(struct sk_buff
*skb
,
560 struct virtio_net_hdr
*vnet_hdr
)
562 unsigned short gso_type
= 0;
563 if (vnet_hdr
->gso_type
!= VIRTIO_NET_HDR_GSO_NONE
) {
564 switch (vnet_hdr
->gso_type
& ~VIRTIO_NET_HDR_GSO_ECN
) {
565 case VIRTIO_NET_HDR_GSO_TCPV4
:
566 gso_type
= SKB_GSO_TCPV4
;
568 case VIRTIO_NET_HDR_GSO_TCPV6
:
569 gso_type
= SKB_GSO_TCPV6
;
571 case VIRTIO_NET_HDR_GSO_UDP
:
572 gso_type
= SKB_GSO_UDP
;
578 if (vnet_hdr
->gso_type
& VIRTIO_NET_HDR_GSO_ECN
)
579 gso_type
|= SKB_GSO_TCP_ECN
;
581 if (vnet_hdr
->gso_size
== 0)
585 if (vnet_hdr
->flags
& VIRTIO_NET_HDR_F_NEEDS_CSUM
) {
586 if (!skb_partial_csum_set(skb
, vnet_hdr
->csum_start
,
587 vnet_hdr
->csum_offset
))
591 if (vnet_hdr
->gso_type
!= VIRTIO_NET_HDR_GSO_NONE
) {
592 skb_shinfo(skb
)->gso_size
= vnet_hdr
->gso_size
;
593 skb_shinfo(skb
)->gso_type
= gso_type
;
595 /* Header must be checked, and gso_segs computed. */
596 skb_shinfo(skb
)->gso_type
|= SKB_GSO_DODGY
;
597 skb_shinfo(skb
)->gso_segs
= 0;
602 static void macvtap_skb_to_vnet_hdr(const struct sk_buff
*skb
,
603 struct virtio_net_hdr
*vnet_hdr
)
605 memset(vnet_hdr
, 0, sizeof(*vnet_hdr
));
607 if (skb_is_gso(skb
)) {
608 struct skb_shared_info
*sinfo
= skb_shinfo(skb
);
610 /* This is a hint as to how much should be linear. */
611 vnet_hdr
->hdr_len
= skb_headlen(skb
);
612 vnet_hdr
->gso_size
= sinfo
->gso_size
;
613 if (sinfo
->gso_type
& SKB_GSO_TCPV4
)
614 vnet_hdr
->gso_type
= VIRTIO_NET_HDR_GSO_TCPV4
;
615 else if (sinfo
->gso_type
& SKB_GSO_TCPV6
)
616 vnet_hdr
->gso_type
= VIRTIO_NET_HDR_GSO_TCPV6
;
617 else if (sinfo
->gso_type
& SKB_GSO_UDP
)
618 vnet_hdr
->gso_type
= VIRTIO_NET_HDR_GSO_UDP
;
621 if (sinfo
->gso_type
& SKB_GSO_TCP_ECN
)
622 vnet_hdr
->gso_type
|= VIRTIO_NET_HDR_GSO_ECN
;
624 vnet_hdr
->gso_type
= VIRTIO_NET_HDR_GSO_NONE
;
626 if (skb
->ip_summed
== CHECKSUM_PARTIAL
) {
627 vnet_hdr
->flags
= VIRTIO_NET_HDR_F_NEEDS_CSUM
;
628 vnet_hdr
->csum_start
= skb_checksum_start_offset(skb
);
629 vnet_hdr
->csum_offset
= skb
->csum_offset
;
630 } else if (skb
->ip_summed
== CHECKSUM_UNNECESSARY
) {
631 vnet_hdr
->flags
= VIRTIO_NET_HDR_F_DATA_VALID
;
632 } /* else everything is zero */
635 /* Get packet from user space buffer */
636 static ssize_t
macvtap_get_user(struct macvtap_queue
*q
, struct msghdr
*m
,
637 const struct iovec
*iv
, unsigned long total_len
,
638 size_t count
, int noblock
)
640 int good_linear
= SKB_MAX_HEAD(NET_IP_ALIGN
);
642 struct macvlan_dev
*vlan
;
643 unsigned long len
= total_len
;
645 struct virtio_net_hdr vnet_hdr
= { 0 };
646 int vnet_hdr_len
= 0;
648 bool zerocopy
= false;
651 if (q
->flags
& IFF_VNET_HDR
) {
652 vnet_hdr_len
= q
->vnet_hdr_sz
;
655 if (len
< vnet_hdr_len
)
659 err
= memcpy_fromiovecend((void *)&vnet_hdr
, iv
, 0,
663 if ((vnet_hdr
.flags
& VIRTIO_NET_HDR_F_NEEDS_CSUM
) &&
664 vnet_hdr
.csum_start
+ vnet_hdr
.csum_offset
+ 2 >
666 vnet_hdr
.hdr_len
= vnet_hdr
.csum_start
+
667 vnet_hdr
.csum_offset
+ 2;
669 if (vnet_hdr
.hdr_len
> len
)
674 if (unlikely(len
< ETH_HLEN
))
678 if (unlikely(count
> UIO_MAXIOV
))
681 if (m
&& m
->msg_control
&& sock_flag(&q
->sk
, SOCK_ZEROCOPY
)) {
682 copylen
= vnet_hdr
.hdr_len
? vnet_hdr
.hdr_len
: GOODCOPY_LEN
;
683 if (copylen
> good_linear
)
684 copylen
= good_linear
;
686 if (iov_pages(iv
, vnet_hdr_len
+ copylen
, count
)
693 if (vnet_hdr
.hdr_len
> good_linear
)
694 linear
= good_linear
;
696 linear
= vnet_hdr
.hdr_len
;
699 skb
= macvtap_alloc_skb(&q
->sk
, NET_IP_ALIGN
, copylen
,
700 linear
, noblock
, &err
);
705 err
= zerocopy_sg_from_iovec(skb
, iv
, vnet_hdr_len
, count
);
707 err
= skb_copy_datagram_from_iovec(skb
, 0, iv
, vnet_hdr_len
,
709 if (!err
&& m
&& m
->msg_control
) {
710 struct ubuf_info
*uarg
= m
->msg_control
;
711 uarg
->callback(uarg
, false);
718 skb_set_network_header(skb
, ETH_HLEN
);
719 skb_reset_mac_header(skb
);
720 skb
->protocol
= eth_hdr(skb
)->h_proto
;
723 err
= macvtap_skb_from_vnet_hdr(skb
, &vnet_hdr
);
728 skb_probe_transport_header(skb
, ETH_HLEN
);
731 vlan
= rcu_dereference(q
->vlan
);
732 /* copy skb_ubuf_info for callback when skb has no error */
734 skb_shinfo(skb
)->destructor_arg
= m
->msg_control
;
735 skb_shinfo(skb
)->tx_flags
|= SKBTX_DEV_ZEROCOPY
;
736 skb_shinfo(skb
)->tx_flags
|= SKBTX_SHARED_FRAG
;
739 skb
->dev
= vlan
->dev
;
753 vlan
= rcu_dereference(q
->vlan
);
755 this_cpu_inc(vlan
->pcpu_stats
->tx_dropped
);
761 static ssize_t
macvtap_aio_write(struct kiocb
*iocb
, const struct iovec
*iv
,
762 unsigned long count
, loff_t pos
)
764 struct file
*file
= iocb
->ki_filp
;
765 ssize_t result
= -ENOLINK
;
766 struct macvtap_queue
*q
= file
->private_data
;
768 result
= macvtap_get_user(q
, NULL
, iv
, iov_length(iv
, count
), count
,
769 file
->f_flags
& O_NONBLOCK
);
773 /* Put packet to the user space buffer */
774 static ssize_t
macvtap_put_user(struct macvtap_queue
*q
,
775 const struct sk_buff
*skb
,
776 const struct iovec
*iv
, int len
)
779 int vnet_hdr_len
= 0;
783 if (q
->flags
& IFF_VNET_HDR
) {
784 struct virtio_net_hdr vnet_hdr
;
785 vnet_hdr_len
= q
->vnet_hdr_sz
;
786 if ((len
-= vnet_hdr_len
) < 0)
789 macvtap_skb_to_vnet_hdr(skb
, &vnet_hdr
);
791 if (memcpy_toiovecend(iv
, (void *)&vnet_hdr
, 0, sizeof(vnet_hdr
)))
794 total
= copied
= vnet_hdr_len
;
797 if (!vlan_tx_tag_present(skb
))
798 len
= min_t(int, skb
->len
, len
);
805 veth
.h_vlan_proto
= skb
->vlan_proto
;
806 veth
.h_vlan_TCI
= htons(vlan_tx_tag_get(skb
));
808 vlan_offset
= offsetof(struct vlan_ethhdr
, h_vlan_proto
);
809 len
= min_t(int, skb
->len
+ VLAN_HLEN
, len
);
812 copy
= min_t(int, vlan_offset
, len
);
813 ret
= skb_copy_datagram_const_iovec(skb
, 0, iv
, copied
, copy
);
819 copy
= min_t(int, sizeof(veth
), len
);
820 ret
= memcpy_toiovecend(iv
, (void *)&veth
, copied
, copy
);
827 ret
= skb_copy_datagram_const_iovec(skb
, vlan_offset
, iv
, copied
, len
);
830 return ret
? ret
: total
;
833 static ssize_t
macvtap_do_read(struct macvtap_queue
*q
,
834 const struct iovec
*iv
, unsigned long len
,
843 prepare_to_wait(sk_sleep(&q
->sk
), &wait
,
846 /* Read frames from the queue */
847 skb
= skb_dequeue(&q
->sk
.sk_receive_queue
);
853 if (signal_pending(current
)) {
857 /* Nothing to read, let's sleep */
861 ret
= macvtap_put_user(q
, skb
, iv
, len
);
867 finish_wait(sk_sleep(&q
->sk
), &wait
);
871 static ssize_t
macvtap_aio_read(struct kiocb
*iocb
, const struct iovec
*iv
,
872 unsigned long count
, loff_t pos
)
874 struct file
*file
= iocb
->ki_filp
;
875 struct macvtap_queue
*q
= file
->private_data
;
876 ssize_t len
, ret
= 0;
878 len
= iov_length(iv
, count
);
884 ret
= macvtap_do_read(q
, iv
, len
, file
->f_flags
& O_NONBLOCK
);
885 ret
= min_t(ssize_t
, ret
, len
);
892 static struct macvlan_dev
*macvtap_get_vlan(struct macvtap_queue
*q
)
894 struct macvlan_dev
*vlan
;
897 vlan
= rtnl_dereference(q
->vlan
);
904 static void macvtap_put_vlan(struct macvlan_dev
*vlan
)
909 static int macvtap_ioctl_set_queue(struct file
*file
, unsigned int flags
)
911 struct macvtap_queue
*q
= file
->private_data
;
912 struct macvlan_dev
*vlan
;
915 vlan
= macvtap_get_vlan(q
);
919 if (flags
& IFF_ATTACH_QUEUE
)
920 ret
= macvtap_enable_queue(vlan
->dev
, file
, q
);
921 else if (flags
& IFF_DETACH_QUEUE
)
922 ret
= macvtap_disable_queue(q
);
926 macvtap_put_vlan(vlan
);
930 static int set_offload(struct macvtap_queue
*q
, unsigned long arg
)
932 struct macvlan_dev
*vlan
;
933 netdev_features_t features
;
934 netdev_features_t feature_mask
= 0;
936 vlan
= rtnl_dereference(q
->vlan
);
940 features
= vlan
->dev
->features
;
942 if (arg
& TUN_F_CSUM
) {
943 feature_mask
= NETIF_F_HW_CSUM
;
945 if (arg
& (TUN_F_TSO4
| TUN_F_TSO6
)) {
946 if (arg
& TUN_F_TSO_ECN
)
947 feature_mask
|= NETIF_F_TSO_ECN
;
948 if (arg
& TUN_F_TSO4
)
949 feature_mask
|= NETIF_F_TSO
;
950 if (arg
& TUN_F_TSO6
)
951 feature_mask
|= NETIF_F_TSO6
;
955 feature_mask
|= NETIF_F_UFO
;
958 /* tun/tap driver inverts the usage for TSO offloads, where
959 * setting the TSO bit means that the userspace wants to
960 * accept TSO frames and turning it off means that user space
961 * does not support TSO.
962 * For macvtap, we have to invert it to mean the same thing.
963 * When user space turns off TSO, we turn off GSO/LRO so that
964 * user-space will not receive TSO frames.
966 if (feature_mask
& (NETIF_F_TSO
| NETIF_F_TSO6
| NETIF_F_UFO
))
967 features
|= RX_OFFLOADS
;
969 features
&= ~RX_OFFLOADS
;
971 /* tap_features are the same as features on tun/tap and
972 * reflect user expectations.
974 vlan
->tap_features
= feature_mask
;
975 vlan
->set_features
= features
;
976 netdev_update_features(vlan
->dev
);
982 * provide compatibility with generic tun/tap interface
984 static long macvtap_ioctl(struct file
*file
, unsigned int cmd
,
987 struct macvtap_queue
*q
= file
->private_data
;
988 struct macvlan_dev
*vlan
;
989 void __user
*argp
= (void __user
*)arg
;
990 struct ifreq __user
*ifr
= argp
;
991 unsigned int __user
*up
= argp
;
993 int __user
*sp
= argp
;
999 /* ignore the name, just look at flags */
1000 if (get_user(u
, &ifr
->ifr_flags
))
1004 if ((u
& ~(IFF_VNET_HDR
| IFF_MULTI_QUEUE
)) !=
1005 (IFF_NO_PI
| IFF_TAP
))
1014 vlan
= macvtap_get_vlan(q
);
1021 if (copy_to_user(&ifr
->ifr_name
, vlan
->dev
->name
, IFNAMSIZ
) ||
1022 put_user(q
->flags
, &ifr
->ifr_flags
))
1024 macvtap_put_vlan(vlan
);
1029 if (get_user(u
, &ifr
->ifr_flags
))
1032 ret
= macvtap_ioctl_set_queue(file
, u
);
1036 case TUNGETFEATURES
:
1037 if (put_user(IFF_TAP
| IFF_NO_PI
| IFF_VNET_HDR
|
1038 IFF_MULTI_QUEUE
, up
))
1043 if (get_user(u
, up
))
1046 q
->sk
.sk_sndbuf
= u
;
1049 case TUNGETVNETHDRSZ
:
1051 if (put_user(s
, sp
))
1055 case TUNSETVNETHDRSZ
:
1056 if (get_user(s
, sp
))
1058 if (s
< (int)sizeof(struct virtio_net_hdr
))
1065 /* let the user check for future flags */
1066 if (arg
& ~(TUN_F_CSUM
| TUN_F_TSO4
| TUN_F_TSO6
|
1067 TUN_F_TSO_ECN
| TUN_F_UFO
))
1071 ret
= set_offload(q
, arg
);
1080 #ifdef CONFIG_COMPAT
1081 static long macvtap_compat_ioctl(struct file
*file
, unsigned int cmd
,
1084 return macvtap_ioctl(file
, cmd
, (unsigned long)compat_ptr(arg
));
1088 static const struct file_operations macvtap_fops
= {
1089 .owner
= THIS_MODULE
,
1090 .open
= macvtap_open
,
1091 .release
= macvtap_release
,
1092 .aio_read
= macvtap_aio_read
,
1093 .aio_write
= macvtap_aio_write
,
1094 .poll
= macvtap_poll
,
1095 .llseek
= no_llseek
,
1096 .unlocked_ioctl
= macvtap_ioctl
,
1097 #ifdef CONFIG_COMPAT
1098 .compat_ioctl
= macvtap_compat_ioctl
,
1102 static int macvtap_sendmsg(struct kiocb
*iocb
, struct socket
*sock
,
1103 struct msghdr
*m
, size_t total_len
)
1105 struct macvtap_queue
*q
= container_of(sock
, struct macvtap_queue
, sock
);
1106 return macvtap_get_user(q
, m
, m
->msg_iov
, total_len
, m
->msg_iovlen
,
1107 m
->msg_flags
& MSG_DONTWAIT
);
1110 static int macvtap_recvmsg(struct kiocb
*iocb
, struct socket
*sock
,
1111 struct msghdr
*m
, size_t total_len
,
1114 struct macvtap_queue
*q
= container_of(sock
, struct macvtap_queue
, sock
);
1116 if (flags
& ~(MSG_DONTWAIT
|MSG_TRUNC
))
1118 ret
= macvtap_do_read(q
, m
->msg_iov
, total_len
,
1119 flags
& MSG_DONTWAIT
);
1120 if (ret
> total_len
) {
1121 m
->msg_flags
|= MSG_TRUNC
;
1122 ret
= flags
& MSG_TRUNC
? ret
: total_len
;
1127 /* Ops structure to mimic raw sockets with tun */
1128 static const struct proto_ops macvtap_socket_ops
= {
1129 .sendmsg
= macvtap_sendmsg
,
1130 .recvmsg
= macvtap_recvmsg
,
1133 /* Get an underlying socket object from tun file. Returns error unless file is
1134 * attached to a device. The returned object works like a packet socket, it
1135 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
1136 * holding a reference to the file for as long as the socket is in use. */
1137 struct socket
*macvtap_get_socket(struct file
*file
)
1139 struct macvtap_queue
*q
;
1140 if (file
->f_op
!= &macvtap_fops
)
1141 return ERR_PTR(-EINVAL
);
1142 q
= file
->private_data
;
1144 return ERR_PTR(-EBADFD
);
1147 EXPORT_SYMBOL_GPL(macvtap_get_socket
);
1149 static int macvtap_device_event(struct notifier_block
*unused
,
1150 unsigned long event
, void *ptr
)
1152 struct net_device
*dev
= netdev_notifier_info_to_dev(ptr
);
1153 struct macvlan_dev
*vlan
;
1154 struct device
*classdev
;
1158 if (dev
->rtnl_link_ops
!= &macvtap_link_ops
)
1161 vlan
= netdev_priv(dev
);
1164 case NETDEV_REGISTER
:
1165 /* Create the device node here after the network device has
1166 * been registered but before register_netdevice has
1169 err
= macvtap_get_minor(vlan
);
1171 return notifier_from_errno(err
);
1173 devt
= MKDEV(MAJOR(macvtap_major
), vlan
->minor
);
1174 classdev
= device_create(macvtap_class
, &dev
->dev
, devt
,
1175 dev
, "tap%d", dev
->ifindex
);
1176 if (IS_ERR(classdev
)) {
1177 macvtap_free_minor(vlan
);
1178 return notifier_from_errno(PTR_ERR(classdev
));
1181 case NETDEV_UNREGISTER
:
1182 devt
= MKDEV(MAJOR(macvtap_major
), vlan
->minor
);
1183 device_destroy(macvtap_class
, devt
);
1184 macvtap_free_minor(vlan
);
1191 static struct notifier_block macvtap_notifier_block __read_mostly
= {
1192 .notifier_call
= macvtap_device_event
,
1195 static int macvtap_init(void)
1199 err
= alloc_chrdev_region(&macvtap_major
, 0,
1200 MACVTAP_NUM_DEVS
, "macvtap");
1204 cdev_init(&macvtap_cdev
, &macvtap_fops
);
1205 err
= cdev_add(&macvtap_cdev
, macvtap_major
, MACVTAP_NUM_DEVS
);
1209 macvtap_class
= class_create(THIS_MODULE
, "macvtap");
1210 if (IS_ERR(macvtap_class
)) {
1211 err
= PTR_ERR(macvtap_class
);
1215 err
= register_netdevice_notifier(&macvtap_notifier_block
);
1219 err
= macvlan_link_register(&macvtap_link_ops
);
1226 unregister_netdevice_notifier(&macvtap_notifier_block
);
1228 class_unregister(macvtap_class
);
1230 cdev_del(&macvtap_cdev
);
1232 unregister_chrdev_region(macvtap_major
, MACVTAP_NUM_DEVS
);
1236 module_init(macvtap_init
);
1238 static void macvtap_exit(void)
1240 rtnl_link_unregister(&macvtap_link_ops
);
1241 unregister_netdevice_notifier(&macvtap_notifier_block
);
1242 class_unregister(macvtap_class
);
1243 cdev_del(&macvtap_cdev
);
1244 unregister_chrdev_region(macvtap_major
, MACVTAP_NUM_DEVS
);
1246 module_exit(macvtap_exit
);
1248 MODULE_ALIAS_RTNL_LINK("macvtap");
1249 MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>");
1250 MODULE_LICENSE("GPL");