lkml.org 
[lkml]   [2013]   [Dec]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH net V3 1/2] tun: unbreak truncated packet signalling
On Wed, Dec 11, 2013 at 01:08:33PM +0800, Jason Wang wrote:
> Commit 6680ec68eff47d36f67b4351bc9836fd6cba9532
> (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>

> ---
> Changes from V2:
> - use "copied" as the variable name instead to be more descriptive
> Changes from v1:
> - increase total unconditionally
> - do not move veth structure out of the vlan handing block
> ---
> drivers/net/tun.c | 16 +++++++++-------
> 1 file changed, 9 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> index e26cbea..7c8343a 100644
> --- a/drivers/net/tun.c
> +++ b/drivers/net/tun.c
> @@ -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++;
> --
> 1.8.3.2


\
 
 \ /
  Last update: 2013-12-11 16:01    [W:0.053 / U:0.092 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site