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Commit 730054da 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 truncated
checking work.

Cc: Vlad Yasevich <vyasevich@gmail.com>
Cc: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 923347bb

drivers/net/macvtap.c

+14 −13
Original line number Diff line number Diff line
@@ -767,10 +767,14 @@ static ssize_t macvtap_put_user(struct macvtap_queue *q, 
				const struct sk_buff *skb,

				const struct iovec *iv, int len)

{

	int ret;

	int ret, off;

	int vnet_hdr_len = 0;

	int vlan_offset = 0;

	int copied;

	struct {

		__be16 h_vlan_proto;

		__be16 h_vlan_TCI;

	} veth;



	if (q->flags & IFF_VNET_HDR) {

		struct virtio_net_hdr vnet_hdr;
@@ -785,16 +789,13 @@ 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;

	off = 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 = skb->vlan_proto;

		veth.h_vlan_TCI = htons(vlan_tx_tag_get(skb));
@@ -802,22 +803,22 @@ static ssize_t macvtap_put_user(struct macvtap_queue *q, 
		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);

		ret = skb_copy_datagram_const_iovec(skb, 0, iv, off, copy);

		len -= copy;

		copied += copy;

		off += copy;

		if (ret || !len)

			goto done;



		copy = min_t(int, sizeof(veth), len);

		ret = memcpy_toiovecend(iv, (void *)&veth, copied, copy);

		ret = memcpy_toiovecend(iv, (void *)&veth, off, copy);

		len -= copy;

		copied += copy;

		off += copy;

		if (ret || !len)

			goto done;

	}



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

	copied += len;

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

	copied += skb->len + (vlan_offset ? sizeof(veth) : 0);



done:

	return ret ? ret : copied;
@@ -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: