On 12/10/2013 11:29 PM, Michael S. Tsirkin wrote:
> On Tue, Dec 10, 2013 at 01:49:46PM +0800, Jason Wang wrote:
>> > 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 <vyasev...@gmail.com>
>> > Cc: Zhi Yong Wu <wu...@linux.vnet.ibm.com>
>> > Cc: Michael S. Tsirkin <m...@redhat.com>
>> > Signed-off-by: Jason Wang <jasow...@redhat.com>
>> > ---
>> > Changes from v1:
>> > - increase total unconditionally
>> > - do not move the structure veth out of the vlan handling block
>> > ---
>> > drivers/net/macvtap.c | 19 ++++++++++---------
>> > 1 file changed, 10 insertions(+), 9 deletions(-)
>> >
>> > diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
>> > index 957cc5c..ded4b2c 100644
>> > --- a/drivers/net/macvtap.c
>> > +++ b/drivers/net/macvtap.c
>> > @@ -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, offset;
>> >
>> > 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;
>> > + offset = copied = vnet_hdr_len;
>> > + copied += skb->len;
>> >
>> > if (!vlan_tx_tag_present(skb))
>> > len = min_t(int, skb->len, len);
>> > @@ -800,24 +801,24 @@ 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);
>> > + copied += VLAN_HLEN;
>> >
>> > 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, offset, copy);
>> > len -= copy;
>> > - copied += copy;
>> > + offset += 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, offset, copy);
>> > len -= copy;
>> > - copied += copy;
>> > + offset += 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, offset, len);
>> >
>> > done:
>> > return ret ? ret : copied;
> I commented on this already. copied is how much we copied,
> so its value is correct.
> You want to name the new one total_len or something along
> these lines and return it.
>
Ok, to be same with tun, I will use "total" in V3.
Thanks
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