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
;
630 /* Neighbour code has some assumptions on HH_DATA_MOD alignment */
631 #define MACVTAP_RESERVE HH_DATA_OFF(ETH_HLEN)
633 /* Get packet from user space buffer */
634 static ssize_t
macvtap_get_user(struct macvtap_queue
*q
, struct msghdr
*m
,
635 struct iov_iter
*from
, int noblock
)
637 int good_linear
= SKB_MAX_HEAD(MACVTAP_RESERVE
);
639 struct macvlan_dev
*vlan
;
640 unsigned long total_len
= iov_iter_count(from
);
641 unsigned long len
= total_len
;
643 struct virtio_net_hdr vnet_hdr
= { 0 };
644 int vnet_hdr_len
= 0;
647 bool zerocopy
= false;
651 if (q
->flags
& IFF_VNET_HDR
) {
652 vnet_hdr_len
= q
->vnet_hdr_sz
;
655 if (len
< vnet_hdr_len
)
660 n
= copy_from_iter(&vnet_hdr
, sizeof(vnet_hdr
), from
);
661 if (n
!= sizeof(vnet_hdr
))
663 iov_iter_advance(from
, vnet_hdr_len
- sizeof(vnet_hdr
));
664 if ((vnet_hdr
.flags
& VIRTIO_NET_HDR_F_NEEDS_CSUM
) &&
665 macvtap16_to_cpu(q
, vnet_hdr
.csum_start
) +
666 macvtap16_to_cpu(q
, vnet_hdr
.csum_offset
) + 2 >
667 macvtap16_to_cpu(q
, vnet_hdr
.hdr_len
))
668 vnet_hdr
.hdr_len
= cpu_to_macvtap16(q
,
669 macvtap16_to_cpu(q
, vnet_hdr
.csum_start
) +
670 macvtap16_to_cpu(q
, vnet_hdr
.csum_offset
) + 2);
672 if (macvtap16_to_cpu(q
, vnet_hdr
.hdr_len
) > len
)
677 if (unlikely(len
< ETH_HLEN
))
680 if (m
&& m
->msg_control
&& sock_flag(&q
->sk
, SOCK_ZEROCOPY
)) {
683 copylen
= vnet_hdr
.hdr_len
?
684 macvtap16_to_cpu(q
, vnet_hdr
.hdr_len
) : GOODCOPY_LEN
;
685 if (copylen
> good_linear
)
686 copylen
= good_linear
;
687 else if (copylen
< ETH_HLEN
)
691 iov_iter_advance(&i
, copylen
);
692 if (iov_iter_npages(&i
, INT_MAX
) <= MAX_SKB_FRAGS
)
698 linear
= macvtap16_to_cpu(q
, vnet_hdr
.hdr_len
);
699 if (linear
> good_linear
)
700 linear
= good_linear
;
701 else if (linear
< ETH_HLEN
)
705 skb
= macvtap_alloc_skb(&q
->sk
, MACVTAP_RESERVE
, copylen
,
706 linear
, noblock
, &err
);
711 err
= zerocopy_sg_from_iter(skb
, from
);
713 err
= skb_copy_datagram_from_iter(skb
, 0, from
, 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
= virtio_net_hdr_to_skb(skb
, &vnet_hdr
,
729 macvtap_is_little_endian(q
));
734 skb_probe_transport_header(skb
, ETH_HLEN
);
736 /* Move network header to the right position for VLAN tagged packets */
737 if ((skb
->protocol
== htons(ETH_P_8021Q
) ||
738 skb
->protocol
== htons(ETH_P_8021AD
)) &&
739 __vlan_get_protocol(skb
, skb
->protocol
, &depth
) != 0)
740 skb_set_network_header(skb
, depth
);
743 vlan
= rcu_dereference(q
->vlan
);
744 /* copy skb_ubuf_info for callback when skb has no error */
746 skb_shinfo(skb
)->destructor_arg
= m
->msg_control
;
747 skb_shinfo(skb
)->tx_flags
|= SKBTX_DEV_ZEROCOPY
;
748 skb_shinfo(skb
)->tx_flags
|= SKBTX_SHARED_FRAG
;
751 skb
->dev
= vlan
->dev
;
765 vlan
= rcu_dereference(q
->vlan
);
767 this_cpu_inc(vlan
->pcpu_stats
->tx_dropped
);
773 static ssize_t
macvtap_write_iter(struct kiocb
*iocb
, struct iov_iter
*from
)
775 struct file
*file
= iocb
->ki_filp
;
776 struct macvtap_queue
*q
= file
->private_data
;
778 return macvtap_get_user(q
, NULL
, from
, file
->f_flags
& O_NONBLOCK
);
781 /* Put packet to the user space buffer */
782 static ssize_t
macvtap_put_user(struct macvtap_queue
*q
,
783 const struct sk_buff
*skb
,
784 struct iov_iter
*iter
)
787 int vnet_hdr_len
= 0;
791 if (q
->flags
& IFF_VNET_HDR
) {
792 struct virtio_net_hdr vnet_hdr
;
793 vnet_hdr_len
= q
->vnet_hdr_sz
;
794 if (iov_iter_count(iter
) < vnet_hdr_len
)
797 ret
= virtio_net_hdr_from_skb(skb
, &vnet_hdr
,
798 macvtap_is_little_endian(q
));
802 if (copy_to_iter(&vnet_hdr
, sizeof(vnet_hdr
), iter
) !=
806 iov_iter_advance(iter
, vnet_hdr_len
- sizeof(vnet_hdr
));
808 total
= vnet_hdr_len
;
811 if (skb_vlan_tag_present(skb
)) {
816 veth
.h_vlan_proto
= skb
->vlan_proto
;
817 veth
.h_vlan_TCI
= htons(skb_vlan_tag_get(skb
));
819 vlan_offset
= offsetof(struct vlan_ethhdr
, h_vlan_proto
);
822 ret
= skb_copy_datagram_iter(skb
, 0, iter
, vlan_offset
);
823 if (ret
|| !iov_iter_count(iter
))
826 ret
= copy_to_iter(&veth
, sizeof(veth
), iter
);
827 if (ret
!= sizeof(veth
) || !iov_iter_count(iter
))
831 ret
= skb_copy_datagram_iter(skb
, vlan_offset
, iter
,
832 skb
->len
- vlan_offset
);
835 return ret
? ret
: total
;
838 static ssize_t
macvtap_do_read(struct macvtap_queue
*q
,
846 if (!iov_iter_count(to
))
851 prepare_to_wait(sk_sleep(&q
->sk
), &wait
,
854 /* Read frames from the queue */
855 skb
= skb_dequeue(&q
->sk
.sk_receive_queue
);
862 if (signal_pending(current
)) {
866 /* Nothing to read, let's sleep */
870 finish_wait(sk_sleep(&q
->sk
), &wait
);
873 ret
= macvtap_put_user(q
, skb
, to
);
874 if (unlikely(ret
< 0))
882 static ssize_t
macvtap_read_iter(struct kiocb
*iocb
, struct iov_iter
*to
)
884 struct file
*file
= iocb
->ki_filp
;
885 struct macvtap_queue
*q
= file
->private_data
;
886 ssize_t len
= iov_iter_count(to
), ret
;
888 ret
= macvtap_do_read(q
, to
, file
->f_flags
& O_NONBLOCK
);
889 ret
= min_t(ssize_t
, ret
, len
);
895 static struct macvlan_dev
*macvtap_get_vlan(struct macvtap_queue
*q
)
897 struct macvlan_dev
*vlan
;
900 vlan
= rtnl_dereference(q
->vlan
);
907 static void macvtap_put_vlan(struct macvlan_dev
*vlan
)
912 static int macvtap_ioctl_set_queue(struct file
*file
, unsigned int flags
)
914 struct macvtap_queue
*q
= file
->private_data
;
915 struct macvlan_dev
*vlan
;
918 vlan
= macvtap_get_vlan(q
);
922 if (flags
& IFF_ATTACH_QUEUE
)
923 ret
= macvtap_enable_queue(vlan
->dev
, file
, q
);
924 else if (flags
& IFF_DETACH_QUEUE
)
925 ret
= macvtap_disable_queue(q
);
929 macvtap_put_vlan(vlan
);
933 static int set_offload(struct macvtap_queue
*q
, unsigned long arg
)
935 struct macvlan_dev
*vlan
;
936 netdev_features_t features
;
937 netdev_features_t feature_mask
= 0;
939 vlan
= rtnl_dereference(q
->vlan
);
943 features
= vlan
->dev
->features
;
945 if (arg
& TUN_F_CSUM
) {
946 feature_mask
= NETIF_F_HW_CSUM
;
948 if (arg
& (TUN_F_TSO4
| TUN_F_TSO6
)) {
949 if (arg
& TUN_F_TSO_ECN
)
950 feature_mask
|= NETIF_F_TSO_ECN
;
951 if (arg
& TUN_F_TSO4
)
952 feature_mask
|= NETIF_F_TSO
;
953 if (arg
& TUN_F_TSO6
)
954 feature_mask
|= NETIF_F_TSO6
;
958 feature_mask
|= NETIF_F_UFO
;
961 /* tun/tap driver inverts the usage for TSO offloads, where
962 * setting the TSO bit means that the userspace wants to
963 * accept TSO frames and turning it off means that user space
964 * does not support TSO.
965 * For macvtap, we have to invert it to mean the same thing.
966 * When user space turns off TSO, we turn off GSO/LRO so that
967 * user-space will not receive TSO frames.
969 if (feature_mask
& (NETIF_F_TSO
| NETIF_F_TSO6
| NETIF_F_UFO
))
970 features
|= RX_OFFLOADS
;
972 features
&= ~RX_OFFLOADS
;
974 /* tap_features are the same as features on tun/tap and
975 * reflect user expectations.
977 vlan
->tap_features
= feature_mask
;
978 vlan
->set_features
= features
;
979 netdev_update_features(vlan
->dev
);
985 * provide compatibility with generic tun/tap interface
987 static long macvtap_ioctl(struct file
*file
, unsigned int cmd
,
990 struct macvtap_queue
*q
= file
->private_data
;
991 struct macvlan_dev
*vlan
;
992 void __user
*argp
= (void __user
*)arg
;
993 struct ifreq __user
*ifr
= argp
;
994 unsigned int __user
*up
= argp
;
996 int __user
*sp
= argp
;
1003 /* ignore the name, just look at flags */
1004 if (get_user(u
, &ifr
->ifr_flags
))
1008 if ((u
& ~MACVTAP_FEATURES
) != (IFF_NO_PI
| IFF_TAP
))
1011 q
->flags
= (q
->flags
& ~MACVTAP_FEATURES
) | u
;
1017 vlan
= macvtap_get_vlan(q
);
1025 if (copy_to_user(&ifr
->ifr_name
, vlan
->dev
->name
, IFNAMSIZ
) ||
1026 put_user(u
, &ifr
->ifr_flags
))
1028 macvtap_put_vlan(vlan
);
1033 if (get_user(u
, &ifr
->ifr_flags
))
1036 ret
= macvtap_ioctl_set_queue(file
, u
);
1040 case TUNGETFEATURES
:
1041 if (put_user(IFF_TAP
| IFF_NO_PI
| MACVTAP_FEATURES
, up
))
1046 if (get_user(s
, sp
))
1049 q
->sk
.sk_sndbuf
= s
;
1052 case TUNGETVNETHDRSZ
:
1054 if (put_user(s
, sp
))
1058 case TUNSETVNETHDRSZ
:
1059 if (get_user(s
, sp
))
1061 if (s
< (int)sizeof(struct virtio_net_hdr
))
1068 s
= !!(q
->flags
& MACVTAP_VNET_LE
);
1069 if (put_user(s
, sp
))
1074 if (get_user(s
, sp
))
1077 q
->flags
|= MACVTAP_VNET_LE
;
1079 q
->flags
&= ~MACVTAP_VNET_LE
;
1083 return macvtap_get_vnet_be(q
, sp
);
1086 return macvtap_set_vnet_be(q
, sp
);
1089 /* let the user check for future flags */
1090 if (arg
& ~(TUN_F_CSUM
| TUN_F_TSO4
| TUN_F_TSO6
|
1091 TUN_F_TSO_ECN
| TUN_F_UFO
))
1095 ret
= set_offload(q
, arg
);
1101 vlan
= macvtap_get_vlan(q
);
1107 u
= vlan
->dev
->type
;
1108 if (copy_to_user(&ifr
->ifr_name
, vlan
->dev
->name
, IFNAMSIZ
) ||
1109 copy_to_user(&ifr
->ifr_hwaddr
.sa_data
, vlan
->dev
->dev_addr
, ETH_ALEN
) ||
1110 put_user(u
, &ifr
->ifr_hwaddr
.sa_family
))
1112 macvtap_put_vlan(vlan
);
1117 if (copy_from_user(&sa
, &ifr
->ifr_hwaddr
, sizeof(sa
)))
1120 vlan
= macvtap_get_vlan(q
);
1125 ret
= dev_set_mac_address(vlan
->dev
, &sa
);
1126 macvtap_put_vlan(vlan
);
1135 #ifdef CONFIG_COMPAT
1136 static long macvtap_compat_ioctl(struct file
*file
, unsigned int cmd
,
1139 return macvtap_ioctl(file
, cmd
, (unsigned long)compat_ptr(arg
));
1143 static const struct file_operations macvtap_fops
= {
1144 .owner
= THIS_MODULE
,
1145 .open
= macvtap_open
,
1146 .release
= macvtap_release
,
1147 .read_iter
= macvtap_read_iter
,
1148 .write_iter
= macvtap_write_iter
,
1149 .poll
= macvtap_poll
,
1150 .llseek
= no_llseek
,
1151 .unlocked_ioctl
= macvtap_ioctl
,
1152 #ifdef CONFIG_COMPAT
1153 .compat_ioctl
= macvtap_compat_ioctl
,
1157 static int macvtap_sendmsg(struct socket
*sock
, struct msghdr
*m
,
1160 struct macvtap_queue
*q
= container_of(sock
, struct macvtap_queue
, sock
);
1161 return macvtap_get_user(q
, m
, &m
->msg_iter
, m
->msg_flags
& MSG_DONTWAIT
);
1164 static int macvtap_recvmsg(struct socket
*sock
, struct msghdr
*m
,
1165 size_t total_len
, int flags
)
1167 struct macvtap_queue
*q
= container_of(sock
, struct macvtap_queue
, sock
);
1169 if (flags
& ~(MSG_DONTWAIT
|MSG_TRUNC
))
1171 ret
= macvtap_do_read(q
, &m
->msg_iter
, flags
& MSG_DONTWAIT
);
1172 if (ret
> total_len
) {
1173 m
->msg_flags
|= MSG_TRUNC
;
1174 ret
= flags
& MSG_TRUNC
? ret
: total_len
;
1179 /* Ops structure to mimic raw sockets with tun */
1180 static const struct proto_ops macvtap_socket_ops
= {
1181 .sendmsg
= macvtap_sendmsg
,
1182 .recvmsg
= macvtap_recvmsg
,
1185 /* Get an underlying socket object from tun file. Returns error unless file is
1186 * attached to a device. The returned object works like a packet socket, it
1187 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
1188 * holding a reference to the file for as long as the socket is in use. */
1189 struct socket
*macvtap_get_socket(struct file
*file
)
1191 struct macvtap_queue
*q
;
1192 if (file
->f_op
!= &macvtap_fops
)
1193 return ERR_PTR(-EINVAL
);
1194 q
= file
->private_data
;
1196 return ERR_PTR(-EBADFD
);
1199 EXPORT_SYMBOL_GPL(macvtap_get_socket
);
1201 static int macvtap_device_event(struct notifier_block
*unused
,
1202 unsigned long event
, void *ptr
)
1204 struct net_device
*dev
= netdev_notifier_info_to_dev(ptr
);
1205 struct macvlan_dev
*vlan
;
1206 struct device
*classdev
;
1209 char tap_name
[IFNAMSIZ
];
1211 if (dev
->rtnl_link_ops
!= &macvtap_link_ops
)
1214 snprintf(tap_name
, IFNAMSIZ
, "tap%d", dev
->ifindex
);
1215 vlan
= netdev_priv(dev
);
1218 case NETDEV_REGISTER
:
1219 /* Create the device node here after the network device has
1220 * been registered but before register_netdevice has
1223 err
= macvtap_get_minor(vlan
);
1225 return notifier_from_errno(err
);
1227 devt
= MKDEV(MAJOR(macvtap_major
), vlan
->minor
);
1228 classdev
= device_create(&macvtap_class
, &dev
->dev
, devt
,
1230 if (IS_ERR(classdev
)) {
1231 macvtap_free_minor(vlan
);
1232 return notifier_from_errno(PTR_ERR(classdev
));
1234 err
= sysfs_create_link(&dev
->dev
.kobj
, &classdev
->kobj
,
1237 return notifier_from_errno(err
);
1239 case NETDEV_UNREGISTER
:
1240 /* vlan->minor == 0 if NETDEV_REGISTER above failed */
1241 if (vlan
->minor
== 0)
1243 sysfs_remove_link(&dev
->dev
.kobj
, tap_name
);
1244 devt
= MKDEV(MAJOR(macvtap_major
), vlan
->minor
);
1245 device_destroy(&macvtap_class
, devt
);
1246 macvtap_free_minor(vlan
);
1253 static struct notifier_block macvtap_notifier_block __read_mostly
= {
1254 .notifier_call
= macvtap_device_event
,
1257 static int macvtap_init(void)
1261 err
= alloc_chrdev_region(&macvtap_major
, 0,
1262 MACVTAP_NUM_DEVS
, "macvtap");
1266 cdev_init(&macvtap_cdev
, &macvtap_fops
);
1267 err
= cdev_add(&macvtap_cdev
, macvtap_major
, MACVTAP_NUM_DEVS
);
1271 err
= class_register(&macvtap_class
);
1275 err
= register_netdevice_notifier(&macvtap_notifier_block
);
1279 err
= macvlan_link_register(&macvtap_link_ops
);
1286 unregister_netdevice_notifier(&macvtap_notifier_block
);
1288 class_unregister(&macvtap_class
);
1290 cdev_del(&macvtap_cdev
);
1292 unregister_chrdev_region(macvtap_major
, MACVTAP_NUM_DEVS
);
1296 module_init(macvtap_init
);
1298 static void macvtap_exit(void)
1300 rtnl_link_unregister(&macvtap_link_ops
);
1301 unregister_netdevice_notifier(&macvtap_notifier_block
);
1302 class_unregister(&macvtap_class
);
1303 cdev_del(&macvtap_cdev
);
1304 unregister_chrdev_region(macvtap_major
, MACVTAP_NUM_DEVS
);
1305 idr_destroy(&minor_idr
);
1307 module_exit(macvtap_exit
);
1309 MODULE_ALIAS_RTNL_LINK("macvtap");
1310 MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>");
1311 MODULE_LICENSE("GPL");