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	macvtap: restore vlan header on user read
Ethernet vlan header is not on the packet and kept in the skb->vlan_tci when it comes from lower dev. This patch inserts vlan header in user buffer during skb copy on user read. Signed-off-by: Basil Gor <basil.gor@gmail.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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					 1 changed files with 37 additions and 4 deletions
				
			
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			@ -1,5 +1,6 @@
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#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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			@ -759,6 +760,8 @@ static ssize_t macvtap_put_user(struct macvtap_queue *q,
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	struct macvlan_dev *vlan;
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	int ret;
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	int vnet_hdr_len = 0;
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	int vlan_offset = 0;
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	int copied;
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	if (q->flags & IFF_VNET_HDR) {
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		struct virtio_net_hdr vnet_hdr;
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			@ -773,18 +776,48 @@ static ssize_t macvtap_put_user(struct macvtap_queue *q,
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		if (memcpy_toiovecend(iv, (void *)&vnet_hdr, 0, sizeof(vnet_hdr)))
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			return -EFAULT;
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	}
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	copied = vnet_hdr_len;
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	if (!vlan_tx_tag_present(skb))
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		len = min_t(int, skb->len, len);
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	else {
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		int copy;
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		struct {
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			__be16 h_vlan_proto;
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			__be16 h_vlan_TCI;
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		} veth;
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		veth.h_vlan_proto = htons(ETH_P_8021Q);
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		veth.h_vlan_TCI = htons(vlan_tx_tag_get(skb));
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	ret = skb_copy_datagram_const_iovec(skb, 0, iv, vnet_hdr_len, len);
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		vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);
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		len = min_t(int, skb->len + VLAN_HLEN, len);
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		copy = min_t(int, vlan_offset, len);
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		ret = skb_copy_datagram_const_iovec(skb, 0, iv, copied, copy);
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		len -= copy;
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		copied += copy;
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		if (ret || !len)
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			goto done;
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		copy = min_t(int, sizeof(veth), len);
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		ret = memcpy_toiovecend(iv, (void *)&veth, copied, copy);
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		len -= copy;
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		copied += copy;
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		if (ret || !len)
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			goto done;
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	}
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	ret = skb_copy_datagram_const_iovec(skb, vlan_offset, iv, copied, len);
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	copied += len;
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done:
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	rcu_read_lock_bh();
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	vlan = rcu_dereference_bh(q->vlan);
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	if (vlan)
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		macvlan_count_rx(vlan, len, ret == 0, 0);
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		macvlan_count_rx(vlan, copied - vnet_hdr_len, ret == 0, 0);
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	rcu_read_unlock_bh();
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	return ret ? ret : (len + vnet_hdr_len);
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	return ret ? ret : copied;
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}
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static ssize_t macvtap_do_read(struct macvtap_queue *q, struct kiocb *iocb,
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