#include <linux/etherdevice.h> #include <linux/if_macvlan.h> #include <linux/interrupt.h> #include <linux/nsproxy.h> #include <linux/compat.h> #include <linux/if_tun.h> #include <linux/module.h> #include <linux/skbuff.h> #include <linux/cache.h> #include <linux/sched.h> #include <linux/types.h> #include <linux/slab.h> #include <linux/init.h> #include <linux/wait.h> #include <linux/cdev.h> #include <linux/fs.h> #include <net/net_namespace.h> #include <net/rtnetlink.h> #include <net/sock.h> #include <linux/virtio_net.h> /* * A macvtap queue is the central object of this driver, it connects * an open character device to a macvlan interface. There can be * multiple queues on one interface, which map back to queues * implemented in hardware on the underlying device. * * macvtap_proto is used to allocate queues through the sock allocation * mechanism. * * TODO: multiqueue support is currently not implemented, even though * macvtap is basically prepared for that. We will need to add this * here as well as in virtio-net and qemu to get line rate on 10gbit * adapters from a guest. */ struct macvtap_queue { struct sock sk; struct socket sock; struct socket_wq wq; int vnet_hdr_sz; struct macvlan_dev __rcu *vlan; struct file *file; unsigned int flags; }; static struct proto macvtap_proto = { .name = "macvtap", .owner = THIS_MODULE, .obj_size = sizeof (struct macvtap_queue), }; /* * Minor number matches netdev->ifindex, so need a potentially * large value. This also makes it possible to split the * tap functionality out again in the future by offering it * from other drivers besides macvtap. As long as every device * only has one tap, the interface numbers assure that the * device nodes are unique. */ static dev_t macvtap_major; #define MACVTAP_NUM_DEVS 65536 static struct class *macvtap_class; static struct cdev macvtap_cdev; static const struct proto_ops macvtap_socket_ops; /* * RCU usage: * The macvtap_queue and the macvlan_dev are loosely coupled, the * pointers from one to the other can only be read while rcu_read_lock * or macvtap_lock is held. * * Both the file and the macvlan_dev hold a reference on the macvtap_queue * through sock_hold(&q->sk). When the macvlan_dev goes away first, * q->vlan becomes inaccessible. When the files gets closed, * macvtap_get_queue() fails. * * There may still be references to the struct sock inside of the * queue from outbound SKBs, but these never reference back to the * file or the dev. The data structure is freed through __sk_free * when both our references and any pending SKBs are gone. */ static DEFINE_SPINLOCK(macvtap_lock); /* * get_slot: return a [unused/occupied] slot in vlan->taps[]: * - if 'q' is NULL, return the first empty slot; * - otherwise, return the slot this pointer occupies. */ static int get_slot(struct macvlan_dev *vlan, struct macvtap_queue *q) { int i; for (i = 0; i < MAX_MACVTAP_QUEUES; i++) { if (rcu_dereference(vlan->taps[i]) == q) return i; } /* Should never happen */ BUG_ON(1); } static int macvtap_set_queue(struct net_device *dev, struct file *file, struct macvtap_queue *q) { struct macvlan_dev *vlan = netdev_priv(dev); int index; int err = -EBUSY; spin_lock(&macvtap_lock); if (vlan->numvtaps == MAX_MACVTAP_QUEUES) goto out; err = 0; index = get_slot(vlan, NULL); rcu_assign_pointer(q->vlan, vlan); rcu_assign_pointer(vlan->taps[index], q); sock_hold(&q->sk); q->file = file; file->private_data = q; vlan->numvtaps++; out: spin_unlock(&macvtap_lock); return err; } /* * The file owning the queue got closed, give up both * the reference that the files holds as well as the * one from the macvlan_dev if that still exists. * * Using the spinlock makes sure that we don't get * to the queue again after destroying it. */ static void macvtap_put_queue(struct macvtap_queue *q) { struct macvlan_dev *vlan; spin_lock(&macvtap_lock); vlan = rcu_dereference_protected(q->vlan, lockdep_is_held(&macvtap_lock)); if (vlan) { int index = get_slot(vlan, q); rcu_assign_pointer(vlan->taps[index], NULL); rcu_assign_pointer(q->vlan, NULL); sock_put(&q->sk); --vlan->numvtaps; } spin_unlock(&macvtap_lock); synchronize_rcu(); sock_put(&q->sk); } /* * Select a queue based on the rxq of the device on which this packet * arrived. If the incoming device is not mq, calculate a flow hash * to select a queue. If all fails, find the first available queue. * Cache vlan->numvtaps since it can become zero during the execution * of this function. */ static struct macvtap_queue *macvtap_get_queue(struct net_device *dev, struct sk_buff *skb) { struct macvlan_dev *vlan = netdev_priv(dev); struct macvtap_queue *tap = NULL; int numvtaps = vlan->numvtaps; __u32 rxq; if (!numvtaps) goto out; if (likely(skb_rx_queue_recorded(skb))) { rxq = skb_get_rx_queue(skb); while (unlikely(rxq >= numvtaps)) rxq -= numvtaps; tap = rcu_dereference(vlan->taps[rxq]); if (tap) goto out; } /* Check if we can use flow to select a queue */ rxq = skb_get_rxhash(skb); if (rxq) { tap = rcu_dereference(vlan->taps[rxq % numvtaps]); if (tap) goto out; } /* Everything failed - find first available queue */ for (rxq = 0; rxq < MAX_MACVTAP_QUEUES; rxq++) { tap = rcu_dereference(vlan->taps[rxq]); if (tap) break; } out: return tap; } /* * The net_device is going away, give up the reference * that it holds on all queues and safely set the pointer * from the queues to NULL. */ static void macvtap_del_queues(struct net_device *dev) { struct macvlan_dev *vlan = netdev_priv(dev); struct macvtap_queue *q, *qlist[MAX_MACVTAP_QUEUES]; int i, j = 0; /* macvtap_put_queue can free some slots, so go through all slots */ spin_lock(&macvtap_lock); for (i = 0; i < MAX_MACVTAP_QUEUES && vlan->numvtaps; i++) { q = rcu_dereference_protected(vlan->taps[i], lockdep_is_held(&macvtap_lock)); if (q) { qlist[j++] = q; rcu_assign_pointer(vlan->taps[i], NULL); rcu_assign_pointer(q->vlan, NULL); vlan->numvtaps--; } } BUG_ON(vlan->numvtaps != 0); spin_unlock(&macvtap_lock); synchronize_rcu(); for (--j; j >= 0; j--) sock_put(&qlist[j]->sk); } /* * Forward happens for data that gets sent from one macvlan * endpoint to another one in bridge mode. We just take * the skb and put it into the receive queue. */ static int macvtap_forward(struct net_device *dev, struct sk_buff *skb) { struct macvtap_queue *q = macvtap_get_queue(dev, skb); if (!q) goto drop; if (skb_queue_len(&q->sk.sk_receive_queue) >= dev->tx_queue_len) goto drop; skb_queue_tail(&q->sk.sk_receive_queue, skb); wake_up_interruptible_poll(sk_sleep(&q->sk), POLLIN | POLLRDNORM | POLLRDBAND); return NET_RX_SUCCESS; drop: kfree_skb(skb); return NET_RX_DROP; } /* * Receive is for data from the external interface (lowerdev), * in case of macvtap, we can treat that the same way as * forward, which macvlan cannot. */ static int macvtap_receive(struct sk_buff *skb) { skb_push(skb, ETH_HLEN); return macvtap_forward(skb->dev, skb); } static int macvtap_newlink(struct net *src_net, struct net_device *dev, struct nlattr *tb[], struct nlattr *data[]) { struct device *classdev; dev_t devt; int err; err = macvlan_common_newlink(src_net, dev, tb, data, macvtap_receive, macvtap_forward); if (err) goto out; devt = MKDEV(MAJOR(macvtap_major), dev->ifindex); classdev = device_create(macvtap_class, &dev->dev, devt, dev, "tap%d", dev->ifindex); if (IS_ERR(classdev)) { err = PTR_ERR(classdev); macvtap_del_queues(dev); } out: return err; } static void macvtap_dellink(struct net_device *dev, struct list_head *head) { device_destroy(macvtap_class, MKDEV(MAJOR(macvtap_major), dev->ifindex)); macvtap_del_queues(dev); macvlan_dellink(dev, head); } static void macvtap_setup(struct net_device *dev) { macvlan_common_setup(dev); dev->tx_queue_len = TUN_READQ_SIZE; } static struct rtnl_link_ops macvtap_link_ops __read_mostly = { .kind = "macvtap", .setup = macvtap_setup, .newlink = macvtap_newlink, .dellink = macvtap_dellink, }; static void macvtap_sock_write_space(struct sock *sk) { wait_queue_head_t *wqueue; if (!sock_writeable(sk) || !test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags)) return; wqueue = sk_sleep(sk); if (wqueue && waitqueue_active(wqueue)) wake_up_interruptible_poll(wqueue, POLLOUT | POLLWRNORM | POLLWRBAND); } static int macvtap_open(struct inode *inode, struct file *file) { struct net *net = current->nsproxy->net_ns; struct net_device *dev = dev_get_by_index(net, iminor(inode)); struct macvtap_queue *q; int err; err = -ENODEV; if (!dev) goto out; /* check if this is a macvtap device */ err = -EINVAL; if (dev->rtnl_link_ops != &macvtap_link_ops) goto out; err = -ENOMEM; q = (struct macvtap_queue *)sk_alloc(net, AF_UNSPEC, GFP_KERNEL, &macvtap_proto); if (!q) goto out; q->sock.wq = &q->wq; init_waitqueue_head(&q->wq.wait); q->sock.type = SOCK_RAW; q->sock.state = SS_CONNECTED; q->sock.file = file; q->sock.ops = &macvtap_socket_ops; sock_init_data(&q->sock, &q->sk); q->sk.sk_write_space = macvtap_sock_write_space; q->flags = IFF_VNET_HDR | IFF_NO_PI | IFF_TAP; q->vnet_hdr_sz = sizeof(struct virtio_net_hdr); err = macvtap_set_queue(dev, file, q); if (err) sock_put(&q->sk); out: if (dev) dev_put(dev); return err; } static int macvtap_release(struct inode *inode, struct file *file) { struct macvtap_queue *q = file->private_data; macvtap_put_queue(q); return 0; } static unsigned int macvtap_poll(struct file *file, poll_table * wait) { struct macvtap_queue *q = file->private_data; unsigned int mask = POLLERR; if (!q) goto out; mask = 0; poll_wait(file, &q->wq.wait, wait); if (!skb_queue_empty(&q->sk.sk_receive_queue)) mask |= POLLIN | POLLRDNORM; if (sock_writeable(&q->sk) || (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &q->sock.flags) && sock_writeable(&q->sk))) mask |= POLLOUT | POLLWRNORM; out: return mask; } static inline struct sk_buff *macvtap_alloc_skb(struct sock *sk, size_t prepad, size_t len, size_t linear, int noblock, int *err) { struct sk_buff *skb; /* Under a page? Don't bother with paged skb. */ if (prepad + len < PAGE_SIZE || !linear) linear = len; skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, err); if (!skb) return NULL; skb_reserve(skb, prepad); skb_put(skb, linear); skb->data_len = len - linear; skb->len += len - linear; return skb; } /* * macvtap_skb_from_vnet_hdr and macvtap_skb_to_vnet_hdr should * be shared with the tun/tap driver. */ static int macvtap_skb_from_vnet_hdr(struct sk_buff *skb, struct virtio_net_hdr *vnet_hdr) { unsigned short gso_type = 0; if (vnet_hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) { switch (vnet_hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { case VIRTIO_NET_HDR_GSO_TCPV4: gso_type = SKB_GSO_TCPV4; break; case VIRTIO_NET_HDR_GSO_TCPV6: gso_type = SKB_GSO_TCPV6; break; case VIRTIO_NET_HDR_GSO_UDP: gso_type = SKB_GSO_UDP; break; default: return -EINVAL; } if (vnet_hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN) gso_type |= SKB_GSO_TCP_ECN; if (vnet_hdr->gso_size == 0) return -EINVAL; } if (vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { if (!skb_partial_csum_set(skb, vnet_hdr->csum_start, vnet_hdr->csum_offset)) return -EINVAL; } if (vnet_hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) { skb_shinfo(skb)->gso_size = vnet_hdr->gso_size; skb_shinfo(skb)->gso_type = gso_type; /* Header must be checked, and gso_segs computed. */ skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; skb_shinfo(skb)->gso_segs = 0; } return 0; } static int macvtap_skb_to_vnet_hdr(const struct sk_buff *skb, struct virtio_net_hdr *vnet_hdr) { memset(vnet_hdr, 0, sizeof(*vnet_hdr)); if (skb_is_gso(skb)) { struct skb_shared_info *sinfo = skb_shinfo(skb); /* This is a hint as to how much should be linear. */ vnet_hdr->hdr_len = skb_headlen(skb); vnet_hdr->gso_size = sinfo->gso_size; if (sinfo->gso_type & SKB_GSO_TCPV4) vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4; else if (sinfo->gso_type & SKB_GSO_TCPV6) vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6; else if (sinfo->gso_type & SKB_GSO_UDP) vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP; else BUG(); if (sinfo->gso_type & SKB_GSO_TCP_ECN) vnet_hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN; } else vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE; if (skb->ip_summed == CHECKSUM_PARTIAL) { vnet_hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; vnet_hdr->csum_start = skb_checksum_start_offset(skb); vnet_hdr->csum_offset = skb->csum_offset; } /* else everything is zero */ return 0; } /* Get packet from user space buffer */ static ssize_t macvtap_get_user(struct macvtap_queue *q, const struct iovec *iv, size_t count, int noblock) { struct sk_buff *skb; struct macvlan_dev *vlan; size_t len = count; int err; struct virtio_net_hdr vnet_hdr = { 0 }; int vnet_hdr_len = 0; if (q->flags & IFF_VNET_HDR) { vnet_hdr_len = q->vnet_hdr_sz; err = -EINVAL; if (len < vnet_hdr_len) goto err; len -= vnet_hdr_len; err = memcpy_fromiovecend((void *)&vnet_hdr, iv, 0, sizeof(vnet_hdr)); if (err < 0) goto err; if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 > vnet_hdr.hdr_len) vnet_hdr.hdr_len = vnet_hdr.csum_start + vnet_hdr.csum_offset + 2; err = -EINVAL; if (vnet_hdr.hdr_len > len) goto err; } err = -EINVAL; if (unlikely(len < ETH_HLEN)) goto err; err = -EMSGSIZE; if (unlikely(count > UIO_MAXIOV)) goto err; skb = macvtap_alloc_skb(&q->sk, NET_IP_ALIGN, len, vnet_hdr.hdr_len, noblock, &err); if (!skb) goto err; err = skb_copy_datagram_from_iovec(skb, 0, iv, vnet_hdr_len, len); if (err) goto err_kfree; skb_set_network_header(skb, ETH_HLEN); skb_reset_mac_header(skb); skb->protocol = eth_hdr(skb)->h_proto; if (vnet_hdr_len) { err = macvtap_skb_from_vnet_hdr(skb, &vnet_hdr); if (err) goto err_kfree; } rcu_read_lock_bh(); vlan = rcu_dereference_bh(q->vlan); if (vlan) macvlan_start_xmit(skb, vlan->dev); else kfree_skb(skb); rcu_read_unlock_bh(); return count; err_kfree: kfree_skb(skb); err: rcu_read_lock_bh(); vlan = rcu_dereference_bh(q->vlan); if (vlan) vlan->dev->stats.tx_dropped++; rcu_read_unlock_bh(); return err; } static ssize_t macvtap_aio_write(struct kiocb *iocb, const struct iovec *iv, unsigned long count, loff_t pos) { struct file *file = iocb->ki_filp; ssize_t result = -ENOLINK; struct macvtap_queue *q = file->private_data; result = macvtap_get_user(q, iv, iov_length(iv, count), file->f_flags & O_NONBLOCK); return result; } /* Put packet to the user space buffer */ static ssize_t macvtap_put_user(struct macvtap_queue *q, const struct sk_buff *skb, const struct iovec *iv, int len) { struct macvlan_dev *vlan; int ret; int vnet_hdr_len = 0; if (q->flags & IFF_VNET_HDR) { struct virtio_net_hdr vnet_hdr; vnet_hdr_len = q->vnet_hdr_sz; if ((len -= vnet_hdr_len) < 0) return -EINVAL; ret = macvtap_skb_to_vnet_hdr(skb, &vnet_hdr); if (ret) return ret; if (memcpy_toiovecend(iv, (void *)&vnet_hdr, 0, sizeof(vnet_hdr))) return -EFAULT; } len = min_t(int, skb->len, len); ret = skb_copy_datagram_const_iovec(skb, 0, iv, vnet_hdr_len, len); rcu_read_lock_bh(); vlan = rcu_dereference_bh(q->vlan); if (vlan) macvlan_count_rx(vlan, len, ret == 0, 0); rcu_read_unlock_bh(); return ret ? ret : (len + vnet_hdr_len); } static ssize_t macvtap_do_read(struct macvtap_queue *q, struct kiocb *iocb, const struct iovec *iv, unsigned long len, int noblock) { DECLARE_WAITQUEUE(wait, current); struct sk_buff *skb; ssize_t ret = 0; add_wait_queue(sk_sleep(&q->sk), &wait); while (len) { current->state = TASK_INTERRUPTIBLE; /* Read frames from the queue */ skb = skb_dequeue(&q->sk.sk_receive_queue); if (!skb) { if (noblock) { ret = -EAGAIN; break; } if (signal_pending(current)) { ret = -ERESTARTSYS; break; } /* Nothing to read, let's sleep */ schedule(); continue; } ret = macvtap_put_user(q, skb, iv, len); kfree_skb(skb); break; } current->state = TASK_RUNNING; remove_wait_queue(sk_sleep(&q->sk), &wait); return ret; } static ssize_t macvtap_aio_read(struct kiocb *iocb, const struct iovec *iv, unsigned long count, loff_t pos) { struct file *file = iocb->ki_filp; struct macvtap_queue *q = file->private_data; ssize_t len, ret = 0; len = iov_length(iv, count); if (len < 0) { ret = -EINVAL; goto out; } ret = macvtap_do_read(q, iocb, iv, len, file->f_flags & O_NONBLOCK); ret = min_t(ssize_t, ret, len); /* XXX copied from tun.c. Why? */ out: return ret; } /* * provide compatibility with generic tun/tap interface */ static long macvtap_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { struct macvtap_queue *q = file->private_data; struct macvlan_dev *vlan; void __user *argp = (void __user *)arg; struct ifreq __user *ifr = argp; unsigned int __user *up = argp; unsigned int u; int __user *sp = argp; int s; int ret; switch (cmd) { case TUNSETIFF: /* ignore the name, just look at flags */ if (get_user(u, &ifr->ifr_flags)) return -EFAULT; ret = 0; if ((u & ~IFF_VNET_HDR) != (IFF_NO_PI | IFF_TAP)) ret = -EINVAL; else q->flags = u; return ret; case TUNGETIFF: rcu_read_lock_bh(); vlan = rcu_dereference_bh(q->vlan); if (vlan) dev_hold(vlan->dev); rcu_read_unlock_bh(); if (!vlan) return -ENOLINK; ret = 0; if (copy_to_user(&ifr->ifr_name, vlan->dev->name, IFNAMSIZ) || put_user(q->flags, &ifr->ifr_flags)) ret = -EFAULT; dev_put(vlan->dev); return ret; case TUNGETFEATURES: if (put_user(IFF_TAP | IFF_NO_PI | IFF_VNET_HDR, up)) return -EFAULT; return 0; case TUNSETSNDBUF: if (get_user(u, up)) return -EFAULT; q->sk.sk_sndbuf = u; return 0; case TUNGETVNETHDRSZ: s = q->vnet_hdr_sz; if (put_user(s, sp)) return -EFAULT; return 0; case TUNSETVNETHDRSZ: if (get_user(s, sp)) return -EFAULT; if (s < (int)sizeof(struct virtio_net_hdr)) return -EINVAL; q->vnet_hdr_sz = s; return 0; case TUNSETOFFLOAD: /* let the user check for future flags */ if (arg & ~(TUN_F_CSUM | TUN_F_TSO4 | TUN_F_TSO6 | TUN_F_TSO_ECN | TUN_F_UFO)) return -EINVAL; /* TODO: only accept frames with the features that got enabled for forwarded frames */ if (!(q->flags & IFF_VNET_HDR)) return -EINVAL; return 0; default: return -EINVAL; } } #ifdef CONFIG_COMPAT static long macvtap_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { return macvtap_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); } #endif static const struct file_operations macvtap_fops = { .owner = THIS_MODULE, .open = macvtap_open, .release = macvtap_release, .aio_read = macvtap_aio_read, .aio_write = macvtap_aio_write, .poll = macvtap_poll, .llseek = no_llseek, .unlocked_ioctl = macvtap_ioctl, #ifdef CONFIG_COMPAT .compat_ioctl = macvtap_compat_ioctl, #endif }; static int macvtap_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m, size_t total_len) { struct macvtap_queue *q = container_of(sock, struct macvtap_queue, sock); return macvtap_get_user(q, m->msg_iov, total_len, m->msg_flags & MSG_DONTWAIT); } static int macvtap_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m, size_t total_len, int flags) { struct macvtap_queue *q = container_of(sock, struct macvtap_queue, sock); int ret; if (flags & ~(MSG_DONTWAIT|MSG_TRUNC)) return -EINVAL; ret = macvtap_do_read(q, iocb, m->msg_iov, total_len, flags & MSG_DONTWAIT); if (ret > total_len) { m->msg_flags |= MSG_TRUNC; ret = flags & MSG_TRUNC ? ret : total_len; } return ret; } /* Ops structure to mimic raw sockets with tun */ static const struct proto_ops macvtap_socket_ops = { .sendmsg = macvtap_sendmsg, .recvmsg = macvtap_recvmsg, }; /* Get an underlying socket object from tun file. Returns error unless file is * attached to a device. The returned object works like a packet socket, it * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for * holding a reference to the file for as long as the socket is in use. */ struct socket *macvtap_get_socket(struct file *file) { struct macvtap_queue *q; if (file->f_op != &macvtap_fops) return ERR_PTR(-EINVAL); q = file->private_data; if (!q) return ERR_PTR(-EBADFD); return &q->sock; } EXPORT_SYMBOL_GPL(macvtap_get_socket); static int macvtap_init(void) { int err; err = alloc_chrdev_region(&macvtap_major, 0, MACVTAP_NUM_DEVS, "macvtap"); if (err) goto out1; cdev_init(&macvtap_cdev, &macvtap_fops); err = cdev_add(&macvtap_cdev, macvtap_major, MACVTAP_NUM_DEVS); if (err) goto out2; macvtap_class = class_create(THIS_MODULE, "macvtap"); if (IS_ERR(macvtap_class)) { err = PTR_ERR(macvtap_class); goto out3; } err = macvlan_link_register(&macvtap_link_ops); if (err) goto out4; return 0; out4: class_unregister(macvtap_class); out3: cdev_del(&macvtap_cdev); out2: unregister_chrdev_region(macvtap_major, MACVTAP_NUM_DEVS); out1: return err; } module_init(macvtap_init); static void macvtap_exit(void) { rtnl_link_unregister(&macvtap_link_ops); class_unregister(macvtap_class); cdev_del(&macvtap_cdev); unregister_chrdev_region(macvtap_major, MACVTAP_NUM_DEVS); } module_exit(macvtap_exit); MODULE_ALIAS_RTNL_LINK("macvtap"); MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>"); MODULE_LICENSE("GPL");