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Commit ce232ce0 authored by Jason Wang's avatar Jason Wang Committed by David S. Miller
Browse files

macvtap: signal truncated packets 



macvtap_put_user() never return a value grater than iov length, this in fact
bypasses the truncated checking in macvtap_recvmsg(). Fix this by always
returning the size of packet plus the possible vlan header to let the trunca
checking work.

Cc: Vlad Yasevich <vyasevich@gmail.com>
Cc: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Acked-by: default avatarVlad Yasevich <vyasevich@gmail.com>
Acked-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e6fd07c8

drivers/net/macvtap.c

+6 −5
Original line number Diff line number Diff line
@@ -770,7 +770,7 @@ static ssize_t macvtap_put_user(struct macvtap_queue *q, 
	int ret;

	int vnet_hdr_len = 0;

	int vlan_offset = 0;

	int copied;

	int copied, total;



	if (q->flags & IFF_VNET_HDR) {

		struct virtio_net_hdr vnet_hdr;
@@ -785,7 +785,8 @@ static ssize_t macvtap_put_user(struct macvtap_queue *q, 
		if (memcpy_toiovecend(iv, (void *)&vnet_hdr, 0, sizeof(vnet_hdr)))

			return -EFAULT;

	}

	copied = vnet_hdr_len;

	total = copied = vnet_hdr_len;

	total += skb->len;



	if (!vlan_tx_tag_present(skb))

		len = min_t(int, skb->len, len);
@@ -800,6 +801,7 @@ static ssize_t macvtap_put_user(struct macvtap_queue *q, 


		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);
@@ -817,10 +819,9 @@ static ssize_t macvtap_put_user(struct macvtap_queue *q, 
	}



	ret = skb_copy_datagram_const_iovec(skb, vlan_offset, iv, copied, len);

	copied += len;



done:

	return ret ? ret : copied;

	return ret ? ret : total;

}



static ssize_t macvtap_do_read(struct macvtap_queue *q, struct kiocb *iocb,
@@ -875,7 +876,7 @@ static ssize_t macvtap_aio_read(struct kiocb *iocb, const struct iovec *iv, 
	}



	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? */

	ret = min_t(ssize_t, ret, len);

	if (ret > 0)

		iocb->ki_pos = ret;

out: