[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit
Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/os/linux/linux-3.4.x/drivers/net/macvtap.c b/ap/os/linux/linux-3.4.x/drivers/net/macvtap.c
new file mode 100644
index 0000000..c19f944
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/drivers/net/macvtap.c
@@ -0,0 +1,1181 @@
+#include <linux/etherdevice.h>
+#include <linux/if_macvlan.h>
+#include <linux/if_vlan.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/idr.h>
+#include <linux/fs.h>
+
+#include <net/ipv6.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),
+};
+
+/*
+ * 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;
+
+/*
+ * 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_INIT_POINTER(vlan->taps[index], NULL);
+ RCU_INIT_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;
+
+ /* 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;
+ }
+
+ 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;
+ }
+
+ /* 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_INIT_POINTER(vlan->taps[i], NULL);
+ RCU_INIT_POINTER(q->vlan, NULL);
+ vlan->numvtaps--;
+ }
+ }
+ BUG_ON(vlan->numvtaps != 0);
+ /* guarantee that any future macvtap_set_queue will fail */
+ vlan->numvtaps = MAX_MACVTAP_QUEUES;
+ 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_get_minor(struct macvlan_dev *vlan)
+{
+ int retval = -ENOMEM;
+ int id;
+
+ mutex_lock(&minor_lock);
+ if (idr_pre_get(&minor_idr, GFP_KERNEL) == 0)
+ goto exit;
+
+ retval = idr_get_new_above(&minor_idr, vlan, 1, &id);
+ if (retval < 0) {
+ if (retval == -EAGAIN)
+ retval = -ENOMEM;
+ goto exit;
+ }
+ if (id < MACVTAP_NUM_DEVS) {
+ vlan->minor = id;
+ } else {
+ printk(KERN_ERR "too many macvtap devices\n");
+ retval = -EINVAL;
+ idr_remove(&minor_idr, id);
+ }
+exit:
+ mutex_unlock(&minor_lock);
+ return retval;
+}
+
+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);
+}
+
+static struct net_device *dev_get_by_macvtap_minor(int minor)
+{
+ 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;
+}
+
+static int macvtap_newlink(struct net *src_net,
+ struct net_device *dev,
+ struct nlattr *tb[],
+ struct nlattr *data[])
+{
+ /* 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);
+}
+
+static void macvtap_dellink(struct net_device *dev,
+ struct list_head *head)
+{
+ 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 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;
+
+ 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]);
+ }
+ 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;
+ if (skb->protocol == htons(ETH_P_IPV6))
+ ipv6_proxy_select_ident(skb);
+ 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);
+ if (vlan_tx_tag_present(skb))
+ vnet_hdr->csum_start += VLAN_HLEN;
+ 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;
+}
+
+static unsigned long iov_pages(const struct iovec *iv, int offset,
+ unsigned long nr_segs)
+{
+ unsigned long seg, base;
+ int pages = 0, len, size;
+
+ while (nr_segs && (offset >= iv->iov_len)) {
+ offset -= iv->iov_len;
+ ++iv;
+ --nr_segs;
+ }
+
+ for (seg = 0; seg < nr_segs; seg++) {
+ base = (unsigned long)iv[seg].iov_base + offset;
+ len = iv[seg].iov_len - offset;
+ size = ((base & ~PAGE_MASK) + len + ~PAGE_MASK) >> PAGE_SHIFT;
+ pages += size;
+ offset = 0;
+ }
+
+ return pages;
+}
+
+/* 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)) {
+ copylen = vnet_hdr.hdr_len ? vnet_hdr.hdr_len : GOODCOPY_LEN;
+ linear = copylen;
+ if (iov_pages(iv, vnet_hdr_len + copylen, count)
+ <= MAX_SKB_FRAGS)
+ zerocopy = true;
+ }
+
+ if (!zerocopy) {
+ 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 && m && m->msg_control) {
+ struct ubuf_info *uarg = m->msg_control;
+ uarg->callback(uarg);
+ }
+ }
+
+ 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);
+ /* 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;
+ }
+ if (vlan)
+ macvlan_start_xmit(skb, vlan->dev);
+ else
+ kfree_skb(skb);
+ rcu_read_unlock_bh();
+
+ return total_len;
+
+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, 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)
+{
+ int ret;
+ int vnet_hdr_len = 0;
+ int vlan_offset = 0;
+ int copied, total;
+
+ 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;
+ }
+ total = copied = vnet_hdr_len;
+ total += skb->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);
+ total += VLAN_HLEN;
+
+ 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);
+
+done:
+ return ret ? ret : total;
+}
+
+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);
+ if (ret > 0)
+ iocb->ki_pos = ret;
+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, 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 = ptr;
+ struct macvlan_dev *vlan;
+ struct device *classdev;
+ dev_t devt;
+ int err;
+
+ if (dev->rtnl_link_ops != &macvtap_link_ops)
+ return NOTIFY_DONE;
+
+ vlan = netdev_priv(dev);
+
+ switch (event) {
+ case NETDEV_REGISTER:
+ /* Create the device node here after the network device has
+ * been registered but before register_netdevice has
+ * finished running.
+ */
+ err = macvtap_get_minor(vlan);
+ 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);
+ if (IS_ERR(classdev)) {
+ macvtap_free_minor(vlan);
+ return notifier_from_errno(PTR_ERR(classdev));
+ }
+ break;
+ case NETDEV_UNREGISTER:
+ devt = MKDEV(MAJOR(macvtap_major), vlan->minor);
+ device_destroy(macvtap_class, devt);
+ macvtap_free_minor(vlan);
+ break;
+ }
+
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block macvtap_notifier_block __read_mostly = {
+ .notifier_call = macvtap_device_event,
+};
+
+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 = register_netdevice_notifier(&macvtap_notifier_block);
+ if (err)
+ goto out4;
+
+ err = macvlan_link_register(&macvtap_link_ops);
+ if (err)
+ goto out5;
+
+ return 0;
+
+out5:
+ unregister_netdevice_notifier(&macvtap_notifier_block);
+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);
+ unregister_netdevice_notifier(&macvtap_notifier_block);
+ 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");