tun: unbreak truncated packet signalling

Commit 6680ec68ef
(tuntap: hardware vlan tx support) breaks the truncated packet signal by nev
return a length greater than iov length in tun_put_user(). This patch fixes
by always return the length of packet plus possible vlan header. Caller can
detect the truncated packet by comparing the return value and the size of io
length.

Cc: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: Jason Wang <jasowang@redhat.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 13:08:33 +08:00 committed by David S. Miller
parent 1598f7cb47
commit e6fd07c899
1 changed files with 9 additions and 7 deletions

View File

@ -1184,7 +1184,7 @@ static ssize_t tun_put_user(struct tun_struct *tun,
{
struct tun_pi pi = { 0, skb->protocol };
ssize_t total = 0;
int vlan_offset = 0;
int vlan_offset = 0, copied;
if (!(tun->flags & TUN_NO_PI)) {
if ((len -= sizeof(pi)) < 0)
@ -1248,6 +1248,8 @@ static ssize_t tun_put_user(struct tun_struct *tun,
total += tun->vnet_hdr_sz;
}
copied = total;
total += skb->len;
if (!vlan_tx_tag_present(skb)) {
len = min_t(int, skb->len, len);
} else {
@ -1262,24 +1264,24 @@ static ssize_t tun_put_user(struct tun_struct *tun,
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, total, copy);
ret = skb_copy_datagram_const_iovec(skb, 0, iv, copied, copy);
len -= copy;
total += copy;
copied += copy;
if (ret || !len)
goto done;
copy = min_t(int, sizeof(veth), len);
ret = memcpy_toiovecend(iv, (void *)&veth, total, copy);
ret = memcpy_toiovecend(iv, (void *)&veth, copied, copy);
len -= copy;
total += copy;
copied += copy;
if (ret || !len)
goto done;
}
skb_copy_datagram_const_iovec(skb, vlan_offset, iv, total, len);
total += len;
skb_copy_datagram_const_iovec(skb, vlan_offset, iv, copied, len);
done:
tun->dev->stats.tx_packets++;