![Jason Wang](/assets/img/avatar_default.png)
Switch to use the new help skb_probe_transport_header() to do the l4 header probing for untrusted sources. For packets with partial csum, the header should already been set by skb_partial_csum_set(). Cc: Eric Dumazet <edumazet@google.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1155 lines
28 KiB
C
1155 lines
28 KiB
C
#include <linux/etherdevice.h>
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#include <linux/if_macvlan.h>
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#include <linux/if_vlan.h>
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#include <linux/interrupt.h>
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#include <linux/nsproxy.h>
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#include <linux/compat.h>
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#include <linux/if_tun.h>
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#include <linux/module.h>
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#include <linux/skbuff.h>
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#include <linux/cache.h>
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#include <linux/sched.h>
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#include <linux/types.h>
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#include <linux/slab.h>
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#include <linux/init.h>
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#include <linux/wait.h>
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#include <linux/cdev.h>
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#include <linux/idr.h>
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#include <linux/fs.h>
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#include <net/net_namespace.h>
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#include <net/rtnetlink.h>
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#include <net/sock.h>
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#include <linux/virtio_net.h>
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/*
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* A macvtap queue is the central object of this driver, it connects
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* an open character device to a macvlan interface. There can be
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* multiple queues on one interface, which map back to queues
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* implemented in hardware on the underlying device.
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*
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* macvtap_proto is used to allocate queues through the sock allocation
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* mechanism.
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*
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* TODO: multiqueue support is currently not implemented, even though
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* macvtap is basically prepared for that. We will need to add this
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* here as well as in virtio-net and qemu to get line rate on 10gbit
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* adapters from a guest.
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*/
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struct macvtap_queue {
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struct sock sk;
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struct socket sock;
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struct socket_wq wq;
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int vnet_hdr_sz;
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struct macvlan_dev __rcu *vlan;
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struct file *file;
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unsigned int flags;
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};
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static struct proto macvtap_proto = {
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.name = "macvtap",
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.owner = THIS_MODULE,
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.obj_size = sizeof (struct macvtap_queue),
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};
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/*
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* Variables for dealing with macvtaps device numbers.
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*/
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static dev_t macvtap_major;
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#define MACVTAP_NUM_DEVS (1U << MINORBITS)
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static DEFINE_MUTEX(minor_lock);
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static DEFINE_IDR(minor_idr);
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#define GOODCOPY_LEN 128
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static struct class *macvtap_class;
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static struct cdev macvtap_cdev;
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static const struct proto_ops macvtap_socket_ops;
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/*
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* RCU usage:
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* The macvtap_queue and the macvlan_dev are loosely coupled, the
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* pointers from one to the other can only be read while rcu_read_lock
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* or macvtap_lock is held.
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*
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* Both the file and the macvlan_dev hold a reference on the macvtap_queue
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* through sock_hold(&q->sk). When the macvlan_dev goes away first,
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* q->vlan becomes inaccessible. When the files gets closed,
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* macvtap_get_queue() fails.
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*
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* There may still be references to the struct sock inside of the
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* queue from outbound SKBs, but these never reference back to the
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* file or the dev. The data structure is freed through __sk_free
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* when both our references and any pending SKBs are gone.
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*/
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static DEFINE_SPINLOCK(macvtap_lock);
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/*
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* get_slot: return a [unused/occupied] slot in vlan->taps[]:
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* - if 'q' is NULL, return the first empty slot;
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* - otherwise, return the slot this pointer occupies.
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*/
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static int get_slot(struct macvlan_dev *vlan, struct macvtap_queue *q)
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{
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int i;
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for (i = 0; i < MAX_MACVTAP_QUEUES; i++) {
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if (rcu_dereference_protected(vlan->taps[i],
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lockdep_is_held(&macvtap_lock)) == q)
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return i;
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}
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/* Should never happen */
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BUG_ON(1);
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}
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static int macvtap_set_queue(struct net_device *dev, struct file *file,
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struct macvtap_queue *q)
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{
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struct macvlan_dev *vlan = netdev_priv(dev);
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int index;
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int err = -EBUSY;
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spin_lock(&macvtap_lock);
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if (vlan->numvtaps == MAX_MACVTAP_QUEUES)
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goto out;
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err = 0;
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index = get_slot(vlan, NULL);
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rcu_assign_pointer(q->vlan, vlan);
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rcu_assign_pointer(vlan->taps[index], q);
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sock_hold(&q->sk);
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q->file = file;
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file->private_data = q;
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vlan->numvtaps++;
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out:
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spin_unlock(&macvtap_lock);
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return err;
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}
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/*
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* The file owning the queue got closed, give up both
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* the reference that the files holds as well as the
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* one from the macvlan_dev if that still exists.
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*
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* Using the spinlock makes sure that we don't get
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* to the queue again after destroying it.
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*/
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static void macvtap_put_queue(struct macvtap_queue *q)
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{
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struct macvlan_dev *vlan;
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spin_lock(&macvtap_lock);
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vlan = rcu_dereference_protected(q->vlan,
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lockdep_is_held(&macvtap_lock));
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if (vlan) {
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int index = get_slot(vlan, q);
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RCU_INIT_POINTER(vlan->taps[index], NULL);
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RCU_INIT_POINTER(q->vlan, NULL);
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sock_put(&q->sk);
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--vlan->numvtaps;
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}
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spin_unlock(&macvtap_lock);
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synchronize_rcu();
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sock_put(&q->sk);
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}
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/*
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* Select a queue based on the rxq of the device on which this packet
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* arrived. If the incoming device is not mq, calculate a flow hash
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* to select a queue. If all fails, find the first available queue.
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* Cache vlan->numvtaps since it can become zero during the execution
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* of this function.
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*/
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static struct macvtap_queue *macvtap_get_queue(struct net_device *dev,
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struct sk_buff *skb)
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{
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struct macvlan_dev *vlan = netdev_priv(dev);
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struct macvtap_queue *tap = NULL;
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int numvtaps = vlan->numvtaps;
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__u32 rxq;
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if (!numvtaps)
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goto out;
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/* Check if we can use flow to select a queue */
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rxq = skb_get_rxhash(skb);
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if (rxq) {
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tap = rcu_dereference(vlan->taps[rxq % numvtaps]);
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if (tap)
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goto out;
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}
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if (likely(skb_rx_queue_recorded(skb))) {
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rxq = skb_get_rx_queue(skb);
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while (unlikely(rxq >= numvtaps))
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rxq -= numvtaps;
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tap = rcu_dereference(vlan->taps[rxq]);
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if (tap)
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goto out;
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}
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/* Everything failed - find first available queue */
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for (rxq = 0; rxq < MAX_MACVTAP_QUEUES; rxq++) {
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tap = rcu_dereference(vlan->taps[rxq]);
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if (tap)
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break;
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}
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out:
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return tap;
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}
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/*
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* The net_device is going away, give up the reference
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* that it holds on all queues and safely set the pointer
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* from the queues to NULL.
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*/
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static void macvtap_del_queues(struct net_device *dev)
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{
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struct macvlan_dev *vlan = netdev_priv(dev);
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struct macvtap_queue *q, *qlist[MAX_MACVTAP_QUEUES];
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int i, j = 0;
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/* macvtap_put_queue can free some slots, so go through all slots */
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spin_lock(&macvtap_lock);
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for (i = 0; i < MAX_MACVTAP_QUEUES && vlan->numvtaps; i++) {
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q = rcu_dereference_protected(vlan->taps[i],
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lockdep_is_held(&macvtap_lock));
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if (q) {
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qlist[j++] = q;
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RCU_INIT_POINTER(vlan->taps[i], NULL);
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RCU_INIT_POINTER(q->vlan, NULL);
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vlan->numvtaps--;
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}
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}
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BUG_ON(vlan->numvtaps != 0);
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/* guarantee that any future macvtap_set_queue will fail */
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vlan->numvtaps = MAX_MACVTAP_QUEUES;
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spin_unlock(&macvtap_lock);
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synchronize_rcu();
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for (--j; j >= 0; j--)
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sock_put(&qlist[j]->sk);
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}
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/*
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* Forward happens for data that gets sent from one macvlan
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* endpoint to another one in bridge mode. We just take
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* the skb and put it into the receive queue.
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*/
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static int macvtap_forward(struct net_device *dev, struct sk_buff *skb)
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{
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struct macvtap_queue *q = macvtap_get_queue(dev, skb);
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if (!q)
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goto drop;
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if (skb_queue_len(&q->sk.sk_receive_queue) >= dev->tx_queue_len)
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goto drop;
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skb_queue_tail(&q->sk.sk_receive_queue, skb);
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wake_up_interruptible_poll(sk_sleep(&q->sk), POLLIN | POLLRDNORM | POLLRDBAND);
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return NET_RX_SUCCESS;
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drop:
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kfree_skb(skb);
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return NET_RX_DROP;
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}
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/*
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* Receive is for data from the external interface (lowerdev),
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* in case of macvtap, we can treat that the same way as
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* forward, which macvlan cannot.
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*/
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static int macvtap_receive(struct sk_buff *skb)
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{
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skb_push(skb, ETH_HLEN);
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return macvtap_forward(skb->dev, skb);
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}
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static int macvtap_get_minor(struct macvlan_dev *vlan)
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{
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int retval = -ENOMEM;
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mutex_lock(&minor_lock);
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retval = idr_alloc(&minor_idr, vlan, 1, MACVTAP_NUM_DEVS, GFP_KERNEL);
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if (retval >= 0) {
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vlan->minor = retval;
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} else if (retval == -ENOSPC) {
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printk(KERN_ERR "too many macvtap devices\n");
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retval = -EINVAL;
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}
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mutex_unlock(&minor_lock);
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return retval < 0 ? retval : 0;
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}
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static void macvtap_free_minor(struct macvlan_dev *vlan)
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{
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mutex_lock(&minor_lock);
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if (vlan->minor) {
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idr_remove(&minor_idr, vlan->minor);
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vlan->minor = 0;
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}
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mutex_unlock(&minor_lock);
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}
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static struct net_device *dev_get_by_macvtap_minor(int minor)
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{
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struct net_device *dev = NULL;
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struct macvlan_dev *vlan;
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mutex_lock(&minor_lock);
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vlan = idr_find(&minor_idr, minor);
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if (vlan) {
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dev = vlan->dev;
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dev_hold(dev);
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}
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mutex_unlock(&minor_lock);
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return dev;
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}
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static int macvtap_newlink(struct net *src_net,
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struct net_device *dev,
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struct nlattr *tb[],
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struct nlattr *data[])
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{
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/* Don't put anything that may fail after macvlan_common_newlink
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* because we can't undo what it does.
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*/
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return macvlan_common_newlink(src_net, dev, tb, data,
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macvtap_receive, macvtap_forward);
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}
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static void macvtap_dellink(struct net_device *dev,
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struct list_head *head)
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{
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macvtap_del_queues(dev);
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macvlan_dellink(dev, head);
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}
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static void macvtap_setup(struct net_device *dev)
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{
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macvlan_common_setup(dev);
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dev->tx_queue_len = TUN_READQ_SIZE;
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}
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static struct rtnl_link_ops macvtap_link_ops __read_mostly = {
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.kind = "macvtap",
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.setup = macvtap_setup,
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.newlink = macvtap_newlink,
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.dellink = macvtap_dellink,
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};
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static void macvtap_sock_write_space(struct sock *sk)
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{
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wait_queue_head_t *wqueue;
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if (!sock_writeable(sk) ||
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!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
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return;
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wqueue = sk_sleep(sk);
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if (wqueue && waitqueue_active(wqueue))
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wake_up_interruptible_poll(wqueue, POLLOUT | POLLWRNORM | POLLWRBAND);
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}
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static void macvtap_sock_destruct(struct sock *sk)
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{
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skb_queue_purge(&sk->sk_receive_queue);
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}
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static int macvtap_open(struct inode *inode, struct file *file)
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{
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struct net *net = current->nsproxy->net_ns;
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struct net_device *dev = dev_get_by_macvtap_minor(iminor(inode));
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struct macvtap_queue *q;
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int err;
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err = -ENODEV;
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if (!dev)
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goto out;
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err = -ENOMEM;
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q = (struct macvtap_queue *)sk_alloc(net, AF_UNSPEC, GFP_KERNEL,
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&macvtap_proto);
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if (!q)
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goto out;
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q->sock.wq = &q->wq;
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init_waitqueue_head(&q->wq.wait);
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q->sock.type = SOCK_RAW;
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q->sock.state = SS_CONNECTED;
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q->sock.file = file;
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q->sock.ops = &macvtap_socket_ops;
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sock_init_data(&q->sock, &q->sk);
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q->sk.sk_write_space = macvtap_sock_write_space;
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q->sk.sk_destruct = macvtap_sock_destruct;
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q->flags = IFF_VNET_HDR | IFF_NO_PI | IFF_TAP;
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q->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
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/*
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* so far only KVM virtio_net uses macvtap, enable zero copy between
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* guest kernel and host kernel when lower device supports zerocopy
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*
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* The macvlan supports zerocopy iff the lower device supports zero
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* copy so we don't have to look at the lower device directly.
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*/
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if ((dev->features & NETIF_F_HIGHDMA) && (dev->features & NETIF_F_SG))
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sock_set_flag(&q->sk, SOCK_ZEROCOPY);
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err = macvtap_set_queue(dev, file, q);
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if (err)
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sock_put(&q->sk);
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out:
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if (dev)
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dev_put(dev);
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return err;
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}
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static int macvtap_release(struct inode *inode, struct file *file)
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{
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struct macvtap_queue *q = file->private_data;
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macvtap_put_queue(q);
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return 0;
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}
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|
|
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static unsigned int macvtap_poll(struct file *file, poll_table * wait)
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{
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struct macvtap_queue *q = file->private_data;
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unsigned int mask = POLLERR;
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if (!q)
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goto out;
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mask = 0;
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poll_wait(file, &q->wq.wait, wait);
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if (!skb_queue_empty(&q->sk.sk_receive_queue))
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mask |= POLLIN | POLLRDNORM;
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if (sock_writeable(&q->sk) ||
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(!test_and_set_bit(SOCK_ASYNC_NOSPACE, &q->sock.flags) &&
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sock_writeable(&q->sk)))
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mask |= POLLOUT | POLLWRNORM;
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out:
|
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return mask;
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}
|
|
|
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static inline struct sk_buff *macvtap_alloc_skb(struct sock *sk, size_t prepad,
|
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size_t len, size_t linear,
|
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int noblock, int *err)
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|
{
|
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struct sk_buff *skb;
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|
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/* Under a page? Don't bother with paged skb. */
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if (prepad + len < PAGE_SIZE || !linear)
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linear = len;
|
|
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skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
|
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err);
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if (!skb)
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return NULL;
|
|
|
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skb_reserve(skb, prepad);
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skb_put(skb, linear);
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skb->data_len = len - linear;
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skb->len += len - linear;
|
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|
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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,
|
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int offset, size_t count)
|
|
{
|
|
int len = iov_length(from, count) - offset;
|
|
int copy = skb_headlen(skb);
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int size, offset1 = 0;
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int i = 0;
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|
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/* Skip over from offset */
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while (count && (offset >= from->iov_len)) {
|
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offset -= from->iov_len;
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++from;
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--count;
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}
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|
|
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/* copy up to skb headlen */
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|
while (count && (copy > 0)) {
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|
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
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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) {
|
|
for (i = 0; i < num_pages; i++)
|
|
put_page(page[i]);
|
|
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;
|
|
|
|
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;
|
|
} else
|
|
copylen = len;
|
|
|
|
skb = macvtap_alloc_skb(&q->sk, NET_IP_ALIGN, copylen,
|
|
vnet_hdr.hdr_len, 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_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;
|
|
skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
|
|
}
|
|
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)
|
|
{
|
|
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_bh();
|
|
vlan = rcu_dereference_bh(q->vlan);
|
|
if (vlan)
|
|
macvlan_count_rx(vlan, copied - vnet_hdr_len, ret == 0, 0);
|
|
rcu_read_unlock_bh();
|
|
|
|
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) {
|
|
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;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* 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");
|