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: Jason Wang <jasowang@redhat.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jason Wang 2013-12-11 13:08:34 +08:00 коммит произвёл David S. Miller
Родитель e6fd07c899
Коммит ce232ce01d
1 изменённых файлов: 6 добавлений и 5 удалений

Просмотреть файл

@ -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: