Messages in this thread | | | Date | Wed, 11 Dec 2013 11:28:13 +0800 | From | Jason Wang <> | Subject | Re: [PATCH net V2 1/2] tun: unbreak truncated packet signalling |
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On 12/10/2013 11:32 PM, Michael S. Tsirkin wrote: > On Tue, Dec 10, 2013 at 01:49:45PM +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> >> > --- >> > 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..cd142134 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, offset; >> > >> > 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; >> > } >> > >> > + offset = 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, offset, copy); >> > len -= copy; >> > - total += copy; >> > + offset += 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, offset, copy); >> > len -= copy; >> > - total += copy; >> > + offset += 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, offset, len); >> > >> > done: >> > tun->dev->stats.tx_packets++; > offset is not descriptive. I would call new variable "copied", > and change all code to use that, do > total = copied + skb->len, total is then the total length. >
Ok, will do it in v3.
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