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 #define MACVTAP_FEATURES (IFF_VNET_HDR | IFF_VNET_LE | IFF_MULTI_QUEUE)
50 static inline u16 macvtap16_to_cpu(struct macvtap_queue *q, __virtio16 val)
52 return __virtio16_to_cpu(q->flags & IFF_VNET_LE, val);
55 static inline __virtio16 cpu_to_macvtap16(struct macvtap_queue *q, u16 val)
57 return __cpu_to_virtio16(q->flags & IFF_VNET_LE, val);
60 static struct proto macvtap_proto = {
63 .obj_size = sizeof (struct macvtap_queue),
67 * Variables for dealing with macvtaps device numbers.
69 static dev_t macvtap_major;
70 #define MACVTAP_NUM_DEVS (1U << MINORBITS)
71 static DEFINE_MUTEX(minor_lock);
72 static DEFINE_IDR(minor_idr);
74 #define GOODCOPY_LEN 128
75 static struct class *macvtap_class;
76 static struct cdev macvtap_cdev;
78 static const struct proto_ops macvtap_socket_ops;
80 #define TUN_OFFLOADS (NETIF_F_HW_CSUM | NETIF_F_TSO_ECN | NETIF_F_TSO | \
82 #define RX_OFFLOADS (NETIF_F_GRO | NETIF_F_LRO)
83 #define TAP_FEATURES (NETIF_F_GSO | NETIF_F_SG)
85 static struct macvlan_dev *macvtap_get_vlan_rcu(const struct net_device *dev)
87 return rcu_dereference(dev->rx_handler_data);
92 * The macvtap_queue and the macvlan_dev are loosely coupled, the
93 * pointers from one to the other can only be read while rcu_read_lock
96 * Both the file and the macvlan_dev hold a reference on the macvtap_queue
97 * through sock_hold(&q->sk). When the macvlan_dev goes away first,
98 * q->vlan becomes inaccessible. When the files gets closed,
99 * macvtap_get_queue() fails.
101 * There may still be references to the struct sock inside of the
102 * queue from outbound SKBs, but these never reference back to the
103 * file or the dev. The data structure is freed through __sk_free
104 * when both our references and any pending SKBs are gone.
107 static int macvtap_enable_queue(struct net_device *dev, struct file *file,
108 struct macvtap_queue *q)
110 struct macvlan_dev *vlan = netdev_priv(dev);
119 rcu_assign_pointer(vlan->taps[vlan->numvtaps], q);
120 q->queue_index = vlan->numvtaps;
129 static int macvtap_set_queue(struct net_device *dev, struct file *file,
130 struct macvtap_queue *q)
132 struct macvlan_dev *vlan = netdev_priv(dev);
134 if (vlan->numqueues == MAX_MACVTAP_QUEUES)
137 rcu_assign_pointer(q->vlan, vlan);
138 rcu_assign_pointer(vlan->taps[vlan->numvtaps], q);
142 q->queue_index = vlan->numvtaps;
144 file->private_data = q;
145 list_add_tail(&q->next, &vlan->queue_list);
153 static int macvtap_disable_queue(struct macvtap_queue *q)
155 struct macvlan_dev *vlan;
156 struct macvtap_queue *nq;
162 vlan = rtnl_dereference(q->vlan);
165 int index = q->queue_index;
166 BUG_ON(index >= vlan->numvtaps);
167 nq = rtnl_dereference(vlan->taps[vlan->numvtaps - 1]);
168 nq->queue_index = index;
170 rcu_assign_pointer(vlan->taps[index], nq);
171 RCU_INIT_POINTER(vlan->taps[vlan->numvtaps - 1], NULL);
181 * The file owning the queue got closed, give up both
182 * the reference that the files holds as well as the
183 * one from the macvlan_dev if that still exists.
185 * Using the spinlock makes sure that we don't get
186 * to the queue again after destroying it.
188 static void macvtap_put_queue(struct macvtap_queue *q)
190 struct macvlan_dev *vlan;
193 vlan = rtnl_dereference(q->vlan);
197 BUG_ON(macvtap_disable_queue(q));
200 RCU_INIT_POINTER(q->vlan, NULL);
202 list_del_init(&q->next);
212 * Select a queue based on the rxq of the device on which this packet
213 * arrived. If the incoming device is not mq, calculate a flow hash
214 * to select a queue. If all fails, find the first available queue.
215 * Cache vlan->numvtaps since it can become zero during the execution
218 static struct macvtap_queue *macvtap_get_queue(struct net_device *dev,
221 struct macvlan_dev *vlan = netdev_priv(dev);
222 struct macvtap_queue *tap = NULL;
223 /* Access to taps array is protected by rcu, but access to numvtaps
224 * isn't. Below we use it to lookup a queue, but treat it as a hint
225 * and validate that the result isn't NULL - in case we are
226 * racing against queue removal.
228 int numvtaps = ACCESS_ONCE(vlan->numvtaps);
234 /* Check if we can use flow to select a queue */
235 rxq = skb_get_hash(skb);
237 tap = rcu_dereference(vlan->taps[rxq % numvtaps]);
241 if (likely(skb_rx_queue_recorded(skb))) {
242 rxq = skb_get_rx_queue(skb);
244 while (unlikely(rxq >= numvtaps))
247 tap = rcu_dereference(vlan->taps[rxq]);
251 tap = rcu_dereference(vlan->taps[0]);
257 * The net_device is going away, give up the reference
258 * that it holds on all queues and safely set the pointer
259 * from the queues to NULL.
261 static void macvtap_del_queues(struct net_device *dev)
263 struct macvlan_dev *vlan = netdev_priv(dev);
264 struct macvtap_queue *q, *tmp, *qlist[MAX_MACVTAP_QUEUES];
268 list_for_each_entry_safe(q, tmp, &vlan->queue_list, next) {
269 list_del_init(&q->next);
271 RCU_INIT_POINTER(q->vlan, NULL);
276 for (i = 0; i < vlan->numvtaps; i++)
277 RCU_INIT_POINTER(vlan->taps[i], NULL);
278 BUG_ON(vlan->numvtaps);
279 BUG_ON(vlan->numqueues);
280 /* guarantee that any future macvtap_set_queue will fail */
281 vlan->numvtaps = MAX_MACVTAP_QUEUES;
283 for (--j; j >= 0; j--)
284 sock_put(&qlist[j]->sk);
287 static rx_handler_result_t macvtap_handle_frame(struct sk_buff **pskb)
289 struct sk_buff *skb = *pskb;
290 struct net_device *dev = skb->dev;
291 struct macvlan_dev *vlan;
292 struct macvtap_queue *q;
293 netdev_features_t features = TAP_FEATURES;
295 vlan = macvtap_get_vlan_rcu(dev);
297 return RX_HANDLER_PASS;
299 q = macvtap_get_queue(dev, skb);
301 return RX_HANDLER_PASS;
303 if (skb_queue_len(&q->sk.sk_receive_queue) >= dev->tx_queue_len)
306 skb_push(skb, ETH_HLEN);
308 /* Apply the forward feature mask so that we perform segmentation
309 * according to users wishes. This only works if VNET_HDR is
312 if (q->flags & IFF_VNET_HDR)
313 features |= vlan->tap_features;
314 if (netif_needs_gso(dev, skb, features)) {
315 struct sk_buff *segs = __skb_gso_segment(skb, features, false);
321 skb_queue_tail(&q->sk.sk_receive_queue, skb);
327 struct sk_buff *nskb = segs->next;
330 skb_queue_tail(&q->sk.sk_receive_queue, segs);
334 /* If we receive a partial checksum and the tap side
335 * doesn't support checksum offload, compute the checksum.
336 * Note: it doesn't matter which checksum feature to
337 * check, we either support them all or none.
339 if (skb->ip_summed == CHECKSUM_PARTIAL &&
340 !(features & NETIF_F_ALL_CSUM) &&
341 skb_checksum_help(skb))
343 skb_queue_tail(&q->sk.sk_receive_queue, skb);
347 wake_up_interruptible_poll(sk_sleep(&q->sk), POLLIN | POLLRDNORM | POLLRDBAND);
348 return RX_HANDLER_CONSUMED;
351 /* Count errors/drops only here, thus don't care about args. */
352 macvlan_count_rx(vlan, 0, 0, 0);
354 return RX_HANDLER_CONSUMED;
357 static int macvtap_get_minor(struct macvlan_dev *vlan)
359 int retval = -ENOMEM;
361 mutex_lock(&minor_lock);
362 retval = idr_alloc(&minor_idr, vlan, 1, MACVTAP_NUM_DEVS, GFP_KERNEL);
364 vlan->minor = retval;
365 } else if (retval == -ENOSPC) {
366 printk(KERN_ERR "too many macvtap devices\n");
369 mutex_unlock(&minor_lock);
370 return retval < 0 ? retval : 0;
373 static void macvtap_free_minor(struct macvlan_dev *vlan)
375 mutex_lock(&minor_lock);
377 idr_remove(&minor_idr, vlan->minor);
380 mutex_unlock(&minor_lock);
383 static struct net_device *dev_get_by_macvtap_minor(int minor)
385 struct net_device *dev = NULL;
386 struct macvlan_dev *vlan;
388 mutex_lock(&minor_lock);
389 vlan = idr_find(&minor_idr, minor);
394 mutex_unlock(&minor_lock);
398 static int macvtap_newlink(struct net *src_net,
399 struct net_device *dev,
401 struct nlattr *data[])
403 struct macvlan_dev *vlan = netdev_priv(dev);
406 INIT_LIST_HEAD(&vlan->queue_list);
408 /* Since macvlan supports all offloads by default, make
409 * tap support all offloads also.
411 vlan->tap_features = TUN_OFFLOADS;
413 err = netdev_rx_handler_register(dev, macvtap_handle_frame, vlan);
417 /* Don't put anything that may fail after macvlan_common_newlink
418 * because we can't undo what it does.
420 return macvlan_common_newlink(src_net, dev, tb, data);
423 static void macvtap_dellink(struct net_device *dev,
424 struct list_head *head)
426 netdev_rx_handler_unregister(dev);
427 macvtap_del_queues(dev);
428 macvlan_dellink(dev, head);
431 static void macvtap_setup(struct net_device *dev)
433 macvlan_common_setup(dev);
434 dev->tx_queue_len = TUN_READQ_SIZE;
437 static struct rtnl_link_ops macvtap_link_ops __read_mostly = {
439 .setup = macvtap_setup,
440 .newlink = macvtap_newlink,
441 .dellink = macvtap_dellink,
445 static void macvtap_sock_write_space(struct sock *sk)
447 wait_queue_head_t *wqueue;
449 if (!sock_writeable(sk) ||
450 !test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
453 wqueue = sk_sleep(sk);
454 if (wqueue && waitqueue_active(wqueue))
455 wake_up_interruptible_poll(wqueue, POLLOUT | POLLWRNORM | POLLWRBAND);
458 static void macvtap_sock_destruct(struct sock *sk)
460 skb_queue_purge(&sk->sk_receive_queue);
463 static int macvtap_open(struct inode *inode, struct file *file)
465 struct net *net = current->nsproxy->net_ns;
466 struct net_device *dev;
467 struct macvtap_queue *q;
471 dev = dev_get_by_macvtap_minor(iminor(inode));
476 q = (struct macvtap_queue *)sk_alloc(net, AF_UNSPEC, GFP_KERNEL,
481 RCU_INIT_POINTER(q->sock.wq, &q->wq);
482 init_waitqueue_head(&q->wq.wait);
483 q->sock.type = SOCK_RAW;
484 q->sock.state = SS_CONNECTED;
486 q->sock.ops = &macvtap_socket_ops;
487 sock_init_data(&q->sock, &q->sk);
488 q->sk.sk_write_space = macvtap_sock_write_space;
489 q->sk.sk_destruct = macvtap_sock_destruct;
490 q->flags = IFF_VNET_HDR | IFF_NO_PI | IFF_TAP;
491 q->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
494 * so far only KVM virtio_net uses macvtap, enable zero copy between
495 * guest kernel and host kernel when lower device supports zerocopy
497 * The macvlan supports zerocopy iff the lower device supports zero
498 * copy so we don't have to look at the lower device directly.
500 if ((dev->features & NETIF_F_HIGHDMA) && (dev->features & NETIF_F_SG))
501 sock_set_flag(&q->sk, SOCK_ZEROCOPY);
503 err = macvtap_set_queue(dev, file, q);
515 static int macvtap_release(struct inode *inode, struct file *file)
517 struct macvtap_queue *q = file->private_data;
518 macvtap_put_queue(q);
522 static unsigned int macvtap_poll(struct file *file, poll_table * wait)
524 struct macvtap_queue *q = file->private_data;
525 unsigned int mask = POLLERR;
531 poll_wait(file, &q->wq.wait, wait);
533 if (!skb_queue_empty(&q->sk.sk_receive_queue))
534 mask |= POLLIN | POLLRDNORM;
536 if (sock_writeable(&q->sk) ||
537 (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &q->sock.flags) &&
538 sock_writeable(&q->sk)))
539 mask |= POLLOUT | POLLWRNORM;
545 static inline struct sk_buff *macvtap_alloc_skb(struct sock *sk, size_t prepad,
546 size_t len, size_t linear,
547 int noblock, int *err)
551 /* Under a page? Don't bother with paged skb. */
552 if (prepad + len < PAGE_SIZE || !linear)
555 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
560 skb_reserve(skb, prepad);
561 skb_put(skb, linear);
562 skb->data_len = len - linear;
563 skb->len += len - linear;
569 * macvtap_skb_from_vnet_hdr and macvtap_skb_to_vnet_hdr should
570 * be shared with the tun/tap driver.
572 static int macvtap_skb_from_vnet_hdr(struct macvtap_queue *q,
574 struct virtio_net_hdr *vnet_hdr)
576 unsigned short gso_type = 0;
577 if (vnet_hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
578 switch (vnet_hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
579 case VIRTIO_NET_HDR_GSO_TCPV4:
580 gso_type = SKB_GSO_TCPV4;
582 case VIRTIO_NET_HDR_GSO_TCPV6:
583 gso_type = SKB_GSO_TCPV6;
585 case VIRTIO_NET_HDR_GSO_UDP:
586 pr_warn_once("macvtap: %s: using disabled UFO feature; please fix this program\n",
588 gso_type = SKB_GSO_UDP;
589 if (skb->protocol == htons(ETH_P_IPV6))
590 ipv6_proxy_select_ident(skb);
596 if (vnet_hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN)
597 gso_type |= SKB_GSO_TCP_ECN;
599 if (vnet_hdr->gso_size == 0)
603 if (vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
604 if (!skb_partial_csum_set(skb, macvtap16_to_cpu(q, vnet_hdr->csum_start),
605 macvtap16_to_cpu(q, vnet_hdr->csum_offset)))
609 if (vnet_hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
610 skb_shinfo(skb)->gso_size = macvtap16_to_cpu(q, vnet_hdr->gso_size);
611 skb_shinfo(skb)->gso_type = gso_type;
613 /* Header must be checked, and gso_segs computed. */
614 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
615 skb_shinfo(skb)->gso_segs = 0;
620 static void macvtap_skb_to_vnet_hdr(struct macvtap_queue *q,
621 const struct sk_buff *skb,
622 struct virtio_net_hdr *vnet_hdr)
624 memset(vnet_hdr, 0, sizeof(*vnet_hdr));
626 if (skb_is_gso(skb)) {
627 struct skb_shared_info *sinfo = skb_shinfo(skb);
629 /* This is a hint as to how much should be linear. */
630 vnet_hdr->hdr_len = cpu_to_macvtap16(q, skb_headlen(skb));
631 vnet_hdr->gso_size = cpu_to_macvtap16(q, sinfo->gso_size);
632 if (sinfo->gso_type & SKB_GSO_TCPV4)
633 vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
634 else if (sinfo->gso_type & SKB_GSO_TCPV6)
635 vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
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 (vlan_tx_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 /* Get packet from user space buffer */
658 static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m,
659 const struct iovec *iv, unsigned long total_len,
660 size_t count, int noblock)
662 int good_linear = SKB_MAX_HEAD(NET_IP_ALIGN);
664 struct macvlan_dev *vlan;
665 unsigned long len = total_len;
667 struct virtio_net_hdr vnet_hdr = { 0 };
668 int vnet_hdr_len = 0;
670 bool zerocopy = false;
673 if (q->flags & IFF_VNET_HDR) {
674 vnet_hdr_len = q->vnet_hdr_sz;
677 if (len < vnet_hdr_len)
681 err = memcpy_fromiovecend((void *)&vnet_hdr, iv, 0,
685 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
686 macvtap16_to_cpu(q, vnet_hdr.csum_start) +
687 macvtap16_to_cpu(q, vnet_hdr.csum_offset) + 2 >
688 macvtap16_to_cpu(q, vnet_hdr.hdr_len))
689 vnet_hdr.hdr_len = cpu_to_macvtap16(q,
690 macvtap16_to_cpu(q, vnet_hdr.csum_start) +
691 macvtap16_to_cpu(q, vnet_hdr.csum_offset) + 2);
693 if (macvtap16_to_cpu(q, vnet_hdr.hdr_len) > len)
698 if (unlikely(len < ETH_HLEN))
702 if (unlikely(count > UIO_MAXIOV))
705 if (m && m->msg_control && sock_flag(&q->sk, SOCK_ZEROCOPY)) {
706 copylen = vnet_hdr.hdr_len ?
707 macvtap16_to_cpu(q, vnet_hdr.hdr_len) : GOODCOPY_LEN;
708 if (copylen > good_linear)
709 copylen = good_linear;
711 if (iov_pages(iv, vnet_hdr_len + copylen, count)
718 if (macvtap16_to_cpu(q, vnet_hdr.hdr_len) > good_linear)
719 linear = good_linear;
721 linear = macvtap16_to_cpu(q, vnet_hdr.hdr_len);
724 skb = macvtap_alloc_skb(&q->sk, NET_IP_ALIGN, copylen,
725 linear, noblock, &err);
730 err = zerocopy_sg_from_iovec(skb, iv, vnet_hdr_len, count);
732 err = skb_copy_datagram_from_iovec(skb, 0, iv, vnet_hdr_len,
734 if (!err && m && m->msg_control) {
735 struct ubuf_info *uarg = m->msg_control;
736 uarg->callback(uarg, false);
743 skb_set_network_header(skb, ETH_HLEN);
744 skb_reset_mac_header(skb);
745 skb->protocol = eth_hdr(skb)->h_proto;
748 err = macvtap_skb_from_vnet_hdr(q, skb, &vnet_hdr);
753 skb_probe_transport_header(skb, ETH_HLEN);
756 vlan = rcu_dereference(q->vlan);
757 /* copy skb_ubuf_info for callback when skb has no error */
759 skb_shinfo(skb)->destructor_arg = m->msg_control;
760 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
761 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
764 skb->dev = vlan->dev;
778 vlan = rcu_dereference(q->vlan);
780 this_cpu_inc(vlan->pcpu_stats->tx_dropped);
786 static ssize_t macvtap_aio_write(struct kiocb *iocb, const struct iovec *iv,
787 unsigned long count, loff_t pos)
789 struct file *file = iocb->ki_filp;
790 ssize_t result = -ENOLINK;
791 struct macvtap_queue *q = file->private_data;
793 result = macvtap_get_user(q, NULL, iv, iov_length(iv, count), count,
794 file->f_flags & O_NONBLOCK);
798 /* Put packet to the user space buffer */
799 static ssize_t macvtap_put_user(struct macvtap_queue *q,
800 const struct sk_buff *skb,
801 const struct iovec *iv, int len)
804 int vnet_hdr_len = 0;
808 if (q->flags & IFF_VNET_HDR) {
809 struct virtio_net_hdr vnet_hdr;
810 vnet_hdr_len = q->vnet_hdr_sz;
811 if ((len -= vnet_hdr_len) < 0)
814 macvtap_skb_to_vnet_hdr(q, skb, &vnet_hdr);
816 if (memcpy_toiovecend(iv, (void *)&vnet_hdr, 0, sizeof(vnet_hdr)))
819 total = copied = vnet_hdr_len;
822 if (!vlan_tx_tag_present(skb))
823 len = min_t(int, skb->len, len);
830 veth.h_vlan_proto = skb->vlan_proto;
831 veth.h_vlan_TCI = htons(vlan_tx_tag_get(skb));
833 vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);
834 len = min_t(int, skb->len + VLAN_HLEN, len);
837 copy = min_t(int, vlan_offset, len);
838 ret = skb_copy_datagram_const_iovec(skb, 0, iv, copied, copy);
844 copy = min_t(int, sizeof(veth), len);
845 ret = memcpy_toiovecend(iv, (void *)&veth, copied, copy);
852 ret = skb_copy_datagram_const_iovec(skb, vlan_offset, iv, copied, len);
855 return ret ? ret : total;
858 static ssize_t macvtap_do_read(struct macvtap_queue *q,
859 const struct iovec *iv, unsigned long len,
868 prepare_to_wait(sk_sleep(&q->sk), &wait,
871 /* Read frames from the queue */
872 skb = skb_dequeue(&q->sk.sk_receive_queue);
878 if (signal_pending(current)) {
882 /* Nothing to read, let's sleep */
886 ret = macvtap_put_user(q, skb, iv, len);
892 finish_wait(sk_sleep(&q->sk), &wait);
896 static ssize_t macvtap_aio_read(struct kiocb *iocb, const struct iovec *iv,
897 unsigned long count, loff_t pos)
899 struct file *file = iocb->ki_filp;
900 struct macvtap_queue *q = file->private_data;
901 ssize_t len, ret = 0;
903 len = iov_length(iv, count);
909 ret = macvtap_do_read(q, iv, len, file->f_flags & O_NONBLOCK);
910 ret = min_t(ssize_t, ret, len);
917 static struct macvlan_dev *macvtap_get_vlan(struct macvtap_queue *q)
919 struct macvlan_dev *vlan;
922 vlan = rtnl_dereference(q->vlan);
929 static void macvtap_put_vlan(struct macvlan_dev *vlan)
934 static int macvtap_ioctl_set_queue(struct file *file, unsigned int flags)
936 struct macvtap_queue *q = file->private_data;
937 struct macvlan_dev *vlan;
940 vlan = macvtap_get_vlan(q);
944 if (flags & IFF_ATTACH_QUEUE)
945 ret = macvtap_enable_queue(vlan->dev, file, q);
946 else if (flags & IFF_DETACH_QUEUE)
947 ret = macvtap_disable_queue(q);
951 macvtap_put_vlan(vlan);
955 static int set_offload(struct macvtap_queue *q, unsigned long arg)
957 struct macvlan_dev *vlan;
958 netdev_features_t features;
959 netdev_features_t feature_mask = 0;
961 vlan = rtnl_dereference(q->vlan);
965 features = vlan->dev->features;
967 if (arg & TUN_F_CSUM) {
968 feature_mask = NETIF_F_HW_CSUM;
970 if (arg & (TUN_F_TSO4 | TUN_F_TSO6)) {
971 if (arg & TUN_F_TSO_ECN)
972 feature_mask |= NETIF_F_TSO_ECN;
973 if (arg & TUN_F_TSO4)
974 feature_mask |= NETIF_F_TSO;
975 if (arg & TUN_F_TSO6)
976 feature_mask |= NETIF_F_TSO6;
980 /* tun/tap driver inverts the usage for TSO offloads, where
981 * setting the TSO bit means that the userspace wants to
982 * accept TSO frames and turning it off means that user space
983 * does not support TSO.
984 * For macvtap, we have to invert it to mean the same thing.
985 * When user space turns off TSO, we turn off GSO/LRO so that
986 * user-space will not receive TSO frames.
988 if (feature_mask & (NETIF_F_TSO | NETIF_F_TSO6))
989 features |= RX_OFFLOADS;
991 features &= ~RX_OFFLOADS;
993 /* tap_features are the same as features on tun/tap and
994 * reflect user expectations.
996 vlan->tap_features = feature_mask;
997 vlan->set_features = features;
998 netdev_update_features(vlan->dev);
1004 * provide compatibility with generic tun/tap interface
1006 static long macvtap_ioctl(struct file *file, unsigned int cmd,
1009 struct macvtap_queue *q = file->private_data;
1010 struct macvlan_dev *vlan;
1011 void __user *argp = (void __user *)arg;
1012 struct ifreq __user *ifr = argp;
1013 unsigned int __user *up = argp;
1015 int __user *sp = argp;
1021 /* ignore the name, just look at flags */
1022 if (get_user(u, &ifr->ifr_flags))
1026 if ((u & ~MACVTAP_FEATURES) != (IFF_NO_PI | IFF_TAP))
1035 vlan = macvtap_get_vlan(q);
1042 if (copy_to_user(&ifr->ifr_name, vlan->dev->name, IFNAMSIZ) ||
1043 put_user(q->flags, &ifr->ifr_flags))
1045 macvtap_put_vlan(vlan);
1050 if (get_user(u, &ifr->ifr_flags))
1053 ret = macvtap_ioctl_set_queue(file, u);
1057 case TUNGETFEATURES:
1058 if (put_user(IFF_TAP | IFF_NO_PI | MACVTAP_FEATURES, up))
1063 if (get_user(u, up))
1066 q->sk.sk_sndbuf = u;
1069 case TUNGETVNETHDRSZ:
1071 if (put_user(s, sp))
1075 case TUNSETVNETHDRSZ:
1076 if (get_user(s, sp))
1078 if (s < (int)sizeof(struct virtio_net_hdr))
1085 /* let the user check for future flags */
1086 if (arg & ~(TUN_F_CSUM | TUN_F_TSO4 | TUN_F_TSO6 |
1091 ret = set_offload(q, arg);
1100 #ifdef CONFIG_COMPAT
1101 static long macvtap_compat_ioctl(struct file *file, unsigned int cmd,
1104 return macvtap_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
1108 static const struct file_operations macvtap_fops = {
1109 .owner = THIS_MODULE,
1110 .open = macvtap_open,
1111 .release = macvtap_release,
1112 .aio_read = macvtap_aio_read,
1113 .aio_write = macvtap_aio_write,
1114 .poll = macvtap_poll,
1115 .llseek = no_llseek,
1116 .unlocked_ioctl = macvtap_ioctl,
1117 #ifdef CONFIG_COMPAT
1118 .compat_ioctl = macvtap_compat_ioctl,
1122 static int macvtap_sendmsg(struct kiocb *iocb, struct socket *sock,
1123 struct msghdr *m, size_t total_len)
1125 struct macvtap_queue *q = container_of(sock, struct macvtap_queue, sock);
1126 return macvtap_get_user(q, m, m->msg_iov, total_len, m->msg_iovlen,
1127 m->msg_flags & MSG_DONTWAIT);
1130 static int macvtap_recvmsg(struct kiocb *iocb, struct socket *sock,
1131 struct msghdr *m, size_t total_len,
1134 struct macvtap_queue *q = container_of(sock, struct macvtap_queue, sock);
1136 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC))
1138 ret = macvtap_do_read(q, m->msg_iov, total_len,
1139 flags & MSG_DONTWAIT);
1140 if (ret > total_len) {
1141 m->msg_flags |= MSG_TRUNC;
1142 ret = flags & MSG_TRUNC ? ret : total_len;
1147 /* Ops structure to mimic raw sockets with tun */
1148 static const struct proto_ops macvtap_socket_ops = {
1149 .sendmsg = macvtap_sendmsg,
1150 .recvmsg = macvtap_recvmsg,
1153 /* Get an underlying socket object from tun file. Returns error unless file is
1154 * attached to a device. The returned object works like a packet socket, it
1155 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
1156 * holding a reference to the file for as long as the socket is in use. */
1157 struct socket *macvtap_get_socket(struct file *file)
1159 struct macvtap_queue *q;
1160 if (file->f_op != &macvtap_fops)
1161 return ERR_PTR(-EINVAL);
1162 q = file->private_data;
1164 return ERR_PTR(-EBADFD);
1167 EXPORT_SYMBOL_GPL(macvtap_get_socket);
1169 static int macvtap_device_event(struct notifier_block *unused,
1170 unsigned long event, void *ptr)
1172 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1173 struct macvlan_dev *vlan;
1174 struct device *classdev;
1178 if (dev->rtnl_link_ops != &macvtap_link_ops)
1181 vlan = netdev_priv(dev);
1184 case NETDEV_REGISTER:
1185 /* Create the device node here after the network device has
1186 * been registered but before register_netdevice has
1189 err = macvtap_get_minor(vlan);
1191 return notifier_from_errno(err);
1193 devt = MKDEV(MAJOR(macvtap_major), vlan->minor);
1194 classdev = device_create(macvtap_class, &dev->dev, devt,
1195 dev, "tap%d", dev->ifindex);
1196 if (IS_ERR(classdev)) {
1197 macvtap_free_minor(vlan);
1198 return notifier_from_errno(PTR_ERR(classdev));
1201 case NETDEV_UNREGISTER:
1202 devt = MKDEV(MAJOR(macvtap_major), vlan->minor);
1203 device_destroy(macvtap_class, devt);
1204 macvtap_free_minor(vlan);
1211 static struct notifier_block macvtap_notifier_block __read_mostly = {
1212 .notifier_call = macvtap_device_event,
1215 static int macvtap_init(void)
1219 err = alloc_chrdev_region(&macvtap_major, 0,
1220 MACVTAP_NUM_DEVS, "macvtap");
1224 cdev_init(&macvtap_cdev, &macvtap_fops);
1225 err = cdev_add(&macvtap_cdev, macvtap_major, MACVTAP_NUM_DEVS);
1229 macvtap_class = class_create(THIS_MODULE, "macvtap");
1230 if (IS_ERR(macvtap_class)) {
1231 err = PTR_ERR(macvtap_class);
1235 err = register_netdevice_notifier(&macvtap_notifier_block);
1239 err = macvlan_link_register(&macvtap_link_ops);
1246 unregister_netdevice_notifier(&macvtap_notifier_block);
1248 class_unregister(macvtap_class);
1250 cdev_del(&macvtap_cdev);
1252 unregister_chrdev_region(macvtap_major, MACVTAP_NUM_DEVS);
1256 module_init(macvtap_init);
1258 static void macvtap_exit(void)
1260 rtnl_link_unregister(&macvtap_link_ops);
1261 unregister_netdevice_notifier(&macvtap_notifier_block);
1262 class_unregister(macvtap_class);
1263 cdev_del(&macvtap_cdev);
1264 unregister_chrdev_region(macvtap_major, MACVTAP_NUM_DEVS);
1266 module_exit(macvtap_exit);
1268 MODULE_ALIAS_RTNL_LINK("macvtap");
1269 MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>");
1270 MODULE_LICENSE("GPL");