tun: Fix TUN_PKT_STRIP setting

commit 2eb783c43e7cf807a45899c10ed556b6dc116625 upstream.

We set the flag TUN_PKT_STRIP if the user buffer provided is too
small to contain the entire packet plus meta-data.  However, this
has been broken ever since we added GSO meta-data.  VLAN acceleration
also has the same problem.

This patch fixes this by taking both into account when setting the
TUN_PKT_STRIP flag.

The fact that this has been broken for six years without anyone
realising means that nobody actually uses this flag.

Fixes: f43798c276 ("tun: Allow GSO using virtio_net_hdr")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
[wt: no tuntap VLAN offloading in 3.10]
Signed-off-by: Willy Tarreau <w@1wt.eu>
This commit is contained in:
Herbert Xu 2014-11-03 04:30:14 +08:00 committed by syphyr
parent 6f1310e018
commit b8d65ae0ed
1 changed files with 8 additions and 4 deletions

View File

@ -1379,12 +1379,16 @@ static ssize_t tun_put_user(struct tun_struct *tun,
{
struct tun_pi pi = { 0, skb->protocol };
ssize_t total = 0;
int vnet_hdr_sz = 0;
if (tun->flags & TUN_VNET_HDR)
vnet_hdr_sz = tun->vnet_hdr_sz;
if (!(tun->flags & TUN_NO_PI)) {
if ((len -= sizeof(pi)) < 0)
return -EINVAL;
if (len < skb->len) {
if (len < skb->len + vnet_hdr_sz) {
/* Packet will be striped */
pi.flags |= TUN_PKT_STRIP;
}
@ -1394,9 +1398,9 @@ static ssize_t tun_put_user(struct tun_struct *tun,
total += sizeof(pi);
}
if (tun->flags & TUN_VNET_HDR) {
if (vnet_hdr_sz) {
struct virtio_net_hdr gso = { 0 }; /* no info leak */
if ((len -= tun->vnet_hdr_sz) < 0)
if ((len -= vnet_hdr_sz) < 0)
return -EINVAL;
if (skb_is_gso(skb)) {
@ -1439,7 +1443,7 @@ static ssize_t tun_put_user(struct tun_struct *tun,
if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
sizeof(gso))))
return -EFAULT;
total += tun->vnet_hdr_sz;
total += vnet_hdr_sz;
}
// ------------- START of KNOX_VPN ------------------//