Messages in this thread | | | Date | Wed, 11 Dec 2013 16:32:35 +0200 | From | "Michael S. Tsirkin" <> | Subject | Re: [PATCH net V3 1/2] tun: unbreak truncated packet signalling |
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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
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