diff options
Diffstat (limited to 'drivers/net/macvtap.c')
| -rw-r--r-- | drivers/net/macvtap.c | 1290 |
1 files changed, 108 insertions, 1182 deletions
diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c index 876c72246ae9..b391a0f740a3 100644 --- a/drivers/net/macvtap.c +++ b/drivers/net/macvtap.c @@ -1,5 +1,7 @@ +// SPDX-License-Identifier: GPL-2.0-only #include <linux/etherdevice.h> #include <linux/if_macvlan.h> +#include <linux/if_tap.h> #include <linux/if_vlan.h> #include <linux/interrupt.h> #include <linux/nsproxy.h> @@ -8,396 +10,119 @@ #include <linux/module.h> #include <linux/skbuff.h> #include <linux/cache.h> -#include <linux/sched.h> +#include <linux/sched/signal.h> #include <linux/types.h> #include <linux/slab.h> -#include <linux/init.h> #include <linux/wait.h> #include <linux/cdev.h> #include <linux/idr.h> #include <linux/fs.h> +#include <linux/uio.h> #include <net/net_namespace.h> #include <net/rtnetlink.h> #include <net/sock.h> #include <linux/virtio_net.h> +#include <linux/skb_array.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. - * - */ -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; - u16 queue_index; - bool enabled; - struct list_head next; -}; - -static struct proto macvtap_proto = { - .name = "macvtap", - .owner = THIS_MODULE, - .obj_size = sizeof (struct macvtap_queue), +struct macvtap_dev { + struct macvlan_dev vlan; + struct tap_dev tap; }; /* * Variables for dealing with macvtaps device numbers. */ static dev_t macvtap_major; -#define MACVTAP_NUM_DEVS (1U << MINORBITS) -static DEFINE_MUTEX(minor_lock); -static DEFINE_IDR(minor_idr); - -#define GOODCOPY_LEN 128 -static struct class *macvtap_class; -static struct cdev macvtap_cdev; - -static const struct proto_ops macvtap_socket_ops; - -#define TUN_OFFLOADS (NETIF_F_HW_CSUM | NETIF_F_TSO_ECN | NETIF_F_TSO | \ - NETIF_F_TSO6 | NETIF_F_UFO) -#define RX_OFFLOADS (NETIF_F_GRO | NETIF_F_LRO) -/* - * 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 rtnl 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 int macvtap_enable_queue(struct net_device *dev, struct file *file, - struct macvtap_queue *q) +static const void *macvtap_net_namespace(const struct device *d) { - struct macvlan_dev *vlan = netdev_priv(dev); - int err = -EINVAL; - - ASSERT_RTNL(); - - if (q->enabled) - goto out; - - err = 0; - rcu_assign_pointer(vlan->taps[vlan->numvtaps], q); - q->queue_index = vlan->numvtaps; - q->enabled = true; - - vlan->numvtaps++; -out: - return err; -} - -static int macvtap_set_queue(struct net_device *dev, struct file *file, - struct macvtap_queue *q) -{ - struct macvlan_dev *vlan = netdev_priv(dev); - int err = -EBUSY; - - rtnl_lock(); - if (vlan->numqueues == MAX_MACVTAP_QUEUES) - goto out; - - err = 0; - rcu_assign_pointer(q->vlan, vlan); - rcu_assign_pointer(vlan->taps[vlan->numvtaps], q); - sock_hold(&q->sk); - - q->file = file; - q->queue_index = vlan->numvtaps; - q->enabled = true; - file->private_data = q; - list_add_tail(&q->next, &vlan->queue_list); - - vlan->numvtaps++; - vlan->numqueues++; - -out: - rtnl_unlock(); - return err; -} - -static int macvtap_disable_queue(struct macvtap_queue *q) -{ - struct macvlan_dev *vlan; - struct macvtap_queue *nq; - - ASSERT_RTNL(); - if (!q->enabled) - return -EINVAL; - - vlan = rtnl_dereference(q->vlan); - - if (vlan) { - int index = q->queue_index; - BUG_ON(index >= vlan->numvtaps); - nq = rtnl_dereference(vlan->taps[vlan->numvtaps - 1]); - nq->queue_index = index; - - rcu_assign_pointer(vlan->taps[index], nq); - RCU_INIT_POINTER(vlan->taps[vlan->numvtaps - 1], NULL); - q->enabled = false; - - vlan->numvtaps--; - } - - return 0; -} - -/* - * 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; - - rtnl_lock(); - vlan = rtnl_dereference(q->vlan); - - if (vlan) { - if (q->enabled) - BUG_ON(macvtap_disable_queue(q)); - - vlan->numqueues--; - RCU_INIT_POINTER(q->vlan, NULL); - sock_put(&q->sk); - list_del_init(&q->next); - } - - rtnl_unlock(); - - synchronize_rcu(); - sock_put(&q->sk); + const struct net_device *dev = to_net_dev(d->parent); + return dev_net(dev); } -/* - * 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; - /* Access to taps array is protected by rcu, but access to numvtaps - * isn't. Below we use it to lookup a queue, but treat it as a hint - * and validate that the result isn't NULL - in case we are - * racing against queue removal. - */ - int numvtaps = ACCESS_ONCE(vlan->numvtaps); - __u32 rxq; - - if (!numvtaps) - 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]); - 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]); - goto out; - } +static struct class macvtap_class = { + .name = "macvtap", + .ns_type = &net_ns_type_operations, + .namespace = macvtap_net_namespace, +}; +static struct cdev macvtap_cdev; - tap = rcu_dereference(vlan->taps[0]); -out: - return tap; -} +#define TUN_OFFLOADS (NETIF_F_HW_CSUM | NETIF_F_TSO_ECN | NETIF_F_TSO | \ + NETIF_F_TSO6) -/* - * 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) +static void macvtap_count_tx_dropped(struct tap_dev *tap) { - struct macvlan_dev *vlan = netdev_priv(dev); - struct macvtap_queue *q, *tmp, *qlist[MAX_MACVTAP_QUEUES]; - int i, j = 0; - - ASSERT_RTNL(); - list_for_each_entry_safe(q, tmp, &vlan->queue_list, next) { - list_del_init(&q->next); - qlist[j++] = q; - RCU_INIT_POINTER(q->vlan, NULL); - if (q->enabled) - vlan->numvtaps--; - vlan->numqueues--; - } - for (i = 0; i < vlan->numvtaps; i++) - RCU_INIT_POINTER(vlan->taps[i], NULL); - BUG_ON(vlan->numvtaps); - BUG_ON(vlan->numqueues); - /* guarantee that any future macvtap_set_queue will fail */ - vlan->numvtaps = MAX_MACVTAP_QUEUES; + struct macvtap_dev *vlantap = container_of(tap, struct macvtap_dev, tap); + struct macvlan_dev *vlan = &vlantap->vlan; - for (--j; j >= 0; j--) - sock_put(&qlist[j]->sk); + this_cpu_inc(vlan->pcpu_stats->tx_dropped); } -/* - * 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) +static void macvtap_count_rx_dropped(struct tap_dev *tap) { - struct macvlan_dev *vlan = netdev_priv(dev); - struct macvtap_queue *q = macvtap_get_queue(dev, skb); - netdev_features_t features; - if (!q) - goto drop; - - if (skb_queue_len(&q->sk.sk_receive_queue) >= dev->tx_queue_len) - goto drop; - - skb->dev = dev; - /* Apply the forward feature mask so that we perform segmentation - * according to users wishes. - */ - features = netif_skb_features(skb) & vlan->tap_features; - if (netif_needs_gso(skb, features)) { - struct sk_buff *segs = __skb_gso_segment(skb, features, false); - - if (IS_ERR(segs)) - goto drop; - - if (!segs) { - skb_queue_tail(&q->sk.sk_receive_queue, skb); - goto wake_up; - } + struct macvtap_dev *vlantap = container_of(tap, struct macvtap_dev, tap); + struct macvlan_dev *vlan = &vlantap->vlan; - kfree_skb(skb); - while (segs) { - struct sk_buff *nskb = segs->next; - - segs->next = NULL; - skb_queue_tail(&q->sk.sk_receive_queue, segs); - segs = nskb; - } - } else { - skb_queue_tail(&q->sk.sk_receive_queue, skb); - } - -wake_up: - 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); + macvlan_count_rx(vlan, 0, 0, 0); } -static int macvtap_get_minor(struct macvlan_dev *vlan) +static void macvtap_update_features(struct tap_dev *tap, + netdev_features_t features) { - int retval = -ENOMEM; + struct macvtap_dev *vlantap = container_of(tap, struct macvtap_dev, tap); + struct macvlan_dev *vlan = &vlantap->vlan; - mutex_lock(&minor_lock); - retval = idr_alloc(&minor_idr, vlan, 1, MACVTAP_NUM_DEVS, GFP_KERNEL); - if (retval >= 0) { - vlan->minor = retval; - } else if (retval == -ENOSPC) { - printk(KERN_ERR "too many macvtap devices\n"); - retval = -EINVAL; - } - mutex_unlock(&minor_lock); - return retval < 0 ? retval : 0; -} - -static void macvtap_free_minor(struct macvlan_dev *vlan) -{ - mutex_lock(&minor_lock); - if (vlan->minor) { - idr_remove(&minor_idr, vlan->minor); - vlan->minor = 0; - } - mutex_unlock(&minor_lock); + vlan->set_features = features; + netdev_update_features(vlan->dev); } -static struct net_device *dev_get_by_macvtap_minor(int minor) +static int macvtap_newlink(struct net_device *dev, + struct rtnl_newlink_params *params, + struct netlink_ext_ack *extack) { - struct net_device *dev = NULL; - struct macvlan_dev *vlan; - - mutex_lock(&minor_lock); - vlan = idr_find(&minor_idr, minor); - if (vlan) { - dev = vlan->dev; - dev_hold(dev); - } - mutex_unlock(&minor_lock); - return dev; -} + struct macvtap_dev *vlantap = netdev_priv(dev); + int err; -static int macvtap_newlink(struct net *src_net, - struct net_device *dev, - struct nlattr *tb[], - struct nlattr *data[]) -{ - struct macvlan_dev *vlan = netdev_priv(dev); - INIT_LIST_HEAD(&vlan->queue_list); + INIT_LIST_HEAD(&vlantap->tap.queue_list); /* Since macvlan supports all offloads by default, make * tap support all offloads also. */ - vlan->tap_features = TUN_OFFLOADS; + vlantap->tap.tap_features = TUN_OFFLOADS; + + /* Register callbacks for rx/tx drops accounting and updating + * net_device features + */ + vlantap->tap.count_tx_dropped = macvtap_count_tx_dropped; + vlantap->tap.count_rx_dropped = macvtap_count_rx_dropped; + vlantap->tap.update_features = macvtap_update_features; + + err = netdev_rx_handler_register(dev, tap_handle_frame, &vlantap->tap); + if (err) + return err; /* Don't put anything that may fail after macvlan_common_newlink * because we can't undo what it does. */ - return macvlan_common_newlink(src_net, dev, tb, data, - macvtap_receive, macvtap_forward); + err = macvlan_common_newlink(dev, params, extack); + if (err) { + netdev_rx_handler_unregister(dev); + return err; + } + + vlantap->tap.dev = vlantap->vlan.dev; + + return 0; } static void macvtap_dellink(struct net_device *dev, struct list_head *head) { - macvtap_del_queues(dev); + struct macvtap_dev *vlantap = netdev_priv(dev); + + netdev_rx_handler_unregister(dev); + tap_del_queues(&vlantap->tap); macvlan_dellink(dev, head); } @@ -407,837 +132,35 @@ static void macvtap_setup(struct net_device *dev) dev->tx_queue_len = TUN_READQ_SIZE; } +static struct net *macvtap_link_net(const struct net_device *dev) +{ + return dev_net(macvlan_dev_real_dev(dev)); +} + static struct rtnl_link_ops macvtap_link_ops __read_mostly = { .kind = "macvtap", .setup = macvtap_setup, .newlink = macvtap_newlink, .dellink = macvtap_dellink, + .get_link_net = macvtap_link_net, + .priv_size = sizeof(struct macvtap_dev), }; - -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 void macvtap_sock_destruct(struct sock *sk) -{ - skb_queue_purge(&sk->sk_receive_queue); -} - -static int macvtap_open(struct inode *inode, struct file *file) -{ - struct net *net = current->nsproxy->net_ns; - struct net_device *dev = dev_get_by_macvtap_minor(iminor(inode)); - struct macvtap_queue *q; - int err; - - err = -ENODEV; - if (!dev) - goto out; - - err = -ENOMEM; - q = (struct macvtap_queue *)sk_alloc(net, AF_UNSPEC, GFP_KERNEL, - &macvtap_proto); - if (!q) - goto out; - - RCU_INIT_POINTER(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->sk.sk_destruct = macvtap_sock_destruct; - q->flags = IFF_VNET_HDR | IFF_NO_PI | IFF_TAP; - q->vnet_hdr_sz = sizeof(struct virtio_net_hdr); - - /* - * so far only KVM virtio_net uses macvtap, enable zero copy between - * guest kernel and host kernel when lower device supports zerocopy - * - * The macvlan supports zerocopy iff the lower device supports zero - * copy so we don't have to look at the lower device directly. - */ - if ((dev->features & NETIF_F_HIGHDMA) && (dev->features & NETIF_F_SG)) - sock_set_flag(&q->sk, SOCK_ZEROCOPY); - - 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; -} - -/* set skb frags from iovec, this can move to core network code for reuse */ -static int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *from, - int offset, size_t count) -{ - int len = iov_length(from, count) - offset; - int copy = skb_headlen(skb); - int size, offset1 = 0; - int i = 0; - - /* Skip over from offset */ - while (count && (offset >= from->iov_len)) { - offset -= from->iov_len; - ++from; - --count; - } - - /* copy up to skb headlen */ - while (count && (copy > 0)) { - size = min_t(unsigned int, copy, from->iov_len - offset); - if (copy_from_user(skb->data + offset1, from->iov_base + offset, - size)) - return -EFAULT; - if (copy > size) { - ++from; - --count; - offset = 0; - } else - offset += size; - copy -= size; - offset1 += size; - } - - if (len == offset1) - return 0; - - while (count--) { - struct page *page[MAX_SKB_FRAGS]; - int num_pages; - unsigned long base; - unsigned long truesize; - - len = from->iov_len - offset; - if (!len) { - offset = 0; - ++from; - continue; - } - base = (unsigned long)from->iov_base + offset; - size = ((base & ~PAGE_MASK) + len + ~PAGE_MASK) >> PAGE_SHIFT; - if (i + size > MAX_SKB_FRAGS) - return -EMSGSIZE; - num_pages = get_user_pages_fast(base, size, 0, &page[i]); - if (num_pages != size) { - int j; - - for (j = 0; j < num_pages; j++) - put_page(page[i + j]); - return -EFAULT; - } - truesize = size * PAGE_SIZE; - skb->data_len += len; - skb->len += len; - skb->truesize += truesize; - atomic_add(truesize, &skb->sk->sk_wmem_alloc); - while (len) { - int off = base & ~PAGE_MASK; - int size = min_t(int, len, PAGE_SIZE - off); - __skb_fill_page_desc(skb, i, page[i], off, size); - skb_shinfo(skb)->nr_frags++; - /* increase sk_wmem_alloc */ - base += size; - len -= size; - i++; - } - offset = 0; - ++from; - } - return 0; -} - -/* - * 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 if (skb->ip_summed == CHECKSUM_UNNECESSARY) { - vnet_hdr->flags = VIRTIO_NET_HDR_F_DATA_VALID; - } /* else everything is zero */ - - return 0; -} - - -/* Get packet from user space buffer */ -static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m, - const struct iovec *iv, unsigned long total_len, - size_t count, int noblock) -{ - struct sk_buff *skb; - struct macvlan_dev *vlan; - unsigned long len = total_len; - int err; - struct virtio_net_hdr vnet_hdr = { 0 }; - int vnet_hdr_len = 0; - int copylen = 0; - bool zerocopy = false; - size_t linear; - - 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; - - if (m && m->msg_control && sock_flag(&q->sk, SOCK_ZEROCOPY)) - zerocopy = true; - - if (zerocopy) { - /* Userspace may produce vectors with count greater than - * MAX_SKB_FRAGS, so we need to linearize parts of the skb - * to let the rest of data to be fit in the frags. - */ - if (count > MAX_SKB_FRAGS) { - copylen = iov_length(iv, count - MAX_SKB_FRAGS); - if (copylen < vnet_hdr_len) - copylen = 0; - else - copylen -= vnet_hdr_len; - } - /* There are 256 bytes to be copied in skb, so there is enough - * room for skb expand head in case it is used. - * The rest buffer is mapped from userspace. - */ - if (copylen < vnet_hdr.hdr_len) - copylen = vnet_hdr.hdr_len; - if (!copylen) - copylen = GOODCOPY_LEN; - linear = copylen; - } else { - copylen = len; - linear = vnet_hdr.hdr_len; - } - - skb = macvtap_alloc_skb(&q->sk, NET_IP_ALIGN, copylen, - linear, noblock, &err); - if (!skb) - goto err; - - if (zerocopy) - err = zerocopy_sg_from_iovec(skb, iv, vnet_hdr_len, count); - else - 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; - } - - skb_probe_transport_header(skb, ETH_HLEN); - - rcu_read_lock(); - vlan = rcu_dereference(q->vlan); - /* copy skb_ubuf_info for callback when skb has no error */ - if (zerocopy) { - skb_shinfo(skb)->destructor_arg = m->msg_control; - skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY; - skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG; - } - if (vlan) - macvlan_start_xmit(skb, vlan->dev); - else - kfree_skb(skb); - rcu_read_unlock(); - - return total_len; - -err_kfree: - kfree_skb(skb); - -err: - rcu_read_lock(); - vlan = rcu_dereference(q->vlan); - if (vlan) - vlan->dev->stats.tx_dropped++; - rcu_read_unlock(); - - 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, NULL, iv, iov_length(iv, count), 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; - int vlan_offset = 0; - int copied; - - 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; - } - copied = vnet_hdr_len; - - if (!vlan_tx_tag_present(skb)) - len = min_t(int, skb->len, len); - else { - int copy; - struct { - __be16 h_vlan_proto; - __be16 h_vlan_TCI; - } veth; - veth.h_vlan_proto = htons(ETH_P_8021Q); - veth.h_vlan_TCI = htons(vlan_tx_tag_get(skb)); - - vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto); - len = min_t(int, skb->len + VLAN_HLEN, len); - - copy = min_t(int, vlan_offset, len); - ret = skb_copy_datagram_const_iovec(skb, 0, iv, copied, copy); - len -= copy; - copied += copy; - if (ret || !len) - goto done; - - copy = min_t(int, sizeof(veth), len); - ret = memcpy_toiovecend(iv, (void *)&veth, copied, copy); - len -= copy; - copied += copy; - if (ret || !len) - goto done; - } - - ret = skb_copy_datagram_const_iovec(skb, vlan_offset, iv, copied, len); - copied += len; - -done: - rcu_read_lock(); - vlan = rcu_dereference(q->vlan); - if (vlan) - macvlan_count_rx(vlan, copied - vnet_hdr_len, ret == 0, 0); - rcu_read_unlock(); - - return ret ? ret : copied; -} - -static ssize_t macvtap_do_read(struct macvtap_queue *q, struct kiocb *iocb, - const struct iovec *iv, unsigned long len, - int noblock) -{ - DEFINE_WAIT(wait); - struct sk_buff *skb; - ssize_t ret = 0; - - while (len) { - if (!noblock) - prepare_to_wait(sk_sleep(&q->sk), &wait, - 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; - } - - if (!noblock) - finish_wait(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; -} - -static struct macvlan_dev *macvtap_get_vlan(struct macvtap_queue *q) -{ - struct macvlan_dev *vlan; - - ASSERT_RTNL(); - vlan = rtnl_dereference(q->vlan); - if (vlan) - dev_hold(vlan->dev); - - return vlan; -} - -static void macvtap_put_vlan(struct macvlan_dev *vlan) -{ - dev_put(vlan->dev); -} - -static int macvtap_ioctl_set_queue(struct file *file, unsigned int flags) -{ - struct macvtap_queue *q = file->private_data; - struct macvlan_dev *vlan; - int ret; - - vlan = macvtap_get_vlan(q); - if (!vlan) - return -EINVAL; - - if (flags & IFF_ATTACH_QUEUE) - ret = macvtap_enable_queue(vlan->dev, file, q); - else if (flags & IFF_DETACH_QUEUE) - ret = macvtap_disable_queue(q); - else - ret = -EINVAL; - - macvtap_put_vlan(vlan); - return ret; -} - -static int set_offload(struct macvtap_queue *q, unsigned long arg) -{ - struct macvlan_dev *vlan; - netdev_features_t features; - netdev_features_t feature_mask = 0; - - vlan = rtnl_dereference(q->vlan); - if (!vlan) - return -ENOLINK; - - features = vlan->dev->features; - - if (arg & TUN_F_CSUM) { - feature_mask = NETIF_F_HW_CSUM; - - if (arg & (TUN_F_TSO4 | TUN_F_TSO6)) { - if (arg & TUN_F_TSO_ECN) - feature_mask |= NETIF_F_TSO_ECN; - if (arg & TUN_F_TSO4) - feature_mask |= NETIF_F_TSO; - if (arg & TUN_F_TSO6) - feature_mask |= NETIF_F_TSO6; - } - - if (arg & TUN_F_UFO) - feature_mask |= NETIF_F_UFO; - } - - /* tun/tap driver inverts the usage for TSO offloads, where - * setting the TSO bit means that the userspace wants to - * accept TSO frames and turning it off means that user space - * does not support TSO. - * For macvtap, we have to invert it to mean the same thing. - * When user space turns off TSO, we turn off GSO/LRO so that - * user-space will not receive TSO frames. - */ - if (feature_mask & (NETIF_F_TSO | NETIF_F_TSO6 | NETIF_F_UFO)) - features |= RX_OFFLOADS; - else - features &= ~RX_OFFLOADS; - - /* tap_features are the same as features on tun/tap and - * reflect user expectations. - */ - vlan->tap_features = vlan->dev->features & - (feature_mask | ~TUN_OFFLOADS); - vlan->set_features = features; - netdev_update_features(vlan->dev); - - return 0; -} - -/* - * 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_MULTI_QUEUE)) != - (IFF_NO_PI | IFF_TAP)) - ret = -EINVAL; - else - q->flags = u; - - return ret; - - case TUNGETIFF: - rtnl_lock(); - vlan = macvtap_get_vlan(q); - if (!vlan) { - rtnl_unlock(); - return -ENOLINK; - } - - ret = 0; - if (copy_to_user(&ifr->ifr_name, vlan->dev->name, IFNAMSIZ) || - put_user(q->flags, &ifr->ifr_flags)) - ret = -EFAULT; - macvtap_put_vlan(vlan); - rtnl_unlock(); - return ret; - - case TUNSETQUEUE: - if (get_user(u, &ifr->ifr_flags)) - return -EFAULT; - rtnl_lock(); - ret = macvtap_ioctl_set_queue(file, u); - rtnl_unlock(); - - case TUNGETFEATURES: - if (put_user(IFF_TAP | IFF_NO_PI | IFF_VNET_HDR | - IFF_MULTI_QUEUE, 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; - rtnl_lock(); - ret = set_offload(q, arg); - rtnl_unlock(); - return ret; - - 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, m->msg_iov, total_len, m->msg_iovlen, - 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_device_event(struct notifier_block *unused, unsigned long event, void *ptr) { struct net_device *dev = netdev_notifier_info_to_dev(ptr); - struct macvlan_dev *vlan; + struct macvtap_dev *vlantap; struct device *classdev; dev_t devt; int err; + char tap_name[IFNAMSIZ]; if (dev->rtnl_link_ops != &macvtap_link_ops) return NOTIFY_DONE; - vlan = netdev_priv(dev); + snprintf(tap_name, IFNAMSIZ, "tap%d", dev->ifindex); + vlantap = netdev_priv(dev); switch (event) { case NETDEV_REGISTER: @@ -1245,22 +168,34 @@ static int macvtap_device_event(struct notifier_block *unused, * been registered but before register_netdevice has * finished running. */ - err = macvtap_get_minor(vlan); + err = tap_get_minor(macvtap_major, &vlantap->tap); if (err) return notifier_from_errno(err); - devt = MKDEV(MAJOR(macvtap_major), vlan->minor); - classdev = device_create(macvtap_class, &dev->dev, devt, - dev, "tap%d", dev->ifindex); + devt = MKDEV(MAJOR(macvtap_major), vlantap->tap.minor); + classdev = device_create(&macvtap_class, &dev->dev, devt, + dev, "%s", tap_name); if (IS_ERR(classdev)) { - macvtap_free_minor(vlan); + tap_free_minor(macvtap_major, &vlantap->tap); return notifier_from_errno(PTR_ERR(classdev)); } + err = sysfs_create_link(&dev->dev.kobj, &classdev->kobj, + tap_name); + if (err) + return notifier_from_errno(err); break; case NETDEV_UNREGISTER: - devt = MKDEV(MAJOR(macvtap_major), vlan->minor); - device_destroy(macvtap_class, devt); - macvtap_free_minor(vlan); + /* vlan->minor == 0 if NETDEV_REGISTER above failed */ + if (vlantap->tap.minor == 0) + break; + sysfs_remove_link(&dev->dev.kobj, tap_name); + devt = MKDEV(MAJOR(macvtap_major), vlantap->tap.minor); + device_destroy(&macvtap_class, devt); + tap_free_minor(macvtap_major, &vlantap->tap); + break; + case NETDEV_CHANGE_TX_QUEUE_LEN: + if (tap_queue_resize(&vlantap->tap)) + return NOTIFY_BAD; break; } @@ -1271,59 +206,50 @@ static struct notifier_block macvtap_notifier_block __read_mostly = { .notifier_call = macvtap_device_event, }; -static int macvtap_init(void) +static int __init macvtap_init(void) { int err; - err = alloc_chrdev_region(&macvtap_major, 0, - MACVTAP_NUM_DEVS, "macvtap"); + err = tap_create_cdev(&macvtap_cdev, &macvtap_major, "macvtap", + THIS_MODULE); if (err) goto out1; - cdev_init(&macvtap_cdev, &macvtap_fops); - err = cdev_add(&macvtap_cdev, macvtap_major, MACVTAP_NUM_DEVS); + err = class_register(&macvtap_class); if (err) goto out2; - macvtap_class = class_create(THIS_MODULE, "macvtap"); - if (IS_ERR(macvtap_class)) { - err = PTR_ERR(macvtap_class); - goto out3; - } - err = register_netdevice_notifier(&macvtap_notifier_block); if (err) - goto out4; + goto out3; err = macvlan_link_register(&macvtap_link_ops); if (err) - goto out5; + goto out4; return 0; -out5: - unregister_netdevice_notifier(&macvtap_notifier_block); out4: - class_unregister(macvtap_class); + unregister_netdevice_notifier(&macvtap_notifier_block); out3: - cdev_del(&macvtap_cdev); + class_unregister(&macvtap_class); out2: - unregister_chrdev_region(macvtap_major, MACVTAP_NUM_DEVS); + tap_destroy_cdev(macvtap_major, &macvtap_cdev); out1: return err; } module_init(macvtap_init); -static void macvtap_exit(void) +static void __exit macvtap_exit(void) { rtnl_link_unregister(&macvtap_link_ops); unregister_netdevice_notifier(&macvtap_notifier_block); - class_unregister(macvtap_class); - cdev_del(&macvtap_cdev); - unregister_chrdev_region(macvtap_major, MACVTAP_NUM_DEVS); + class_unregister(&macvtap_class); + tap_destroy_cdev(macvtap_major, &macvtap_cdev); } module_exit(macvtap_exit); MODULE_ALIAS_RTNL_LINK("macvtap"); +MODULE_DESCRIPTION("MAC-VLAN based tap driver"); MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>"); MODULE_LICENSE("GPL"); |