net: openvswitch: don't call pad_packet if not necessary

The nla_put_u16/nla_put_u32 makes sure that
*attrlen is align. The call tree is that:

nla_put_u16/nla_put_u32
  -> nla_put		attrlen = sizeof(u16) or sizeof(u32)
  -> __nla_put		attrlen
  -> __nla_reserve	attrlen
  -> skb_put(skb, nla_total_size(attrlen))

nla_total_size returns the total length of attribute
including padding.

Cc: Joe Stringer <joe@ovn.org>
Cc: William Tu <u9012063@gmail.com>
Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Tonghao Zhang 2019-11-14 23:51:08 +08:00 committed by David S. Miller
parent 3bb884a4a0
commit 61ca533c0e
1 changed files with 8 additions and 14 deletions

View File

@ -487,23 +487,17 @@ static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb,
}
/* Add OVS_PACKET_ATTR_MRU */
if (upcall_info->mru) {
if (nla_put_u16(user_skb, OVS_PACKET_ATTR_MRU,
upcall_info->mru)) {
err = -ENOBUFS;
goto out;
}
pad_packet(dp, user_skb);
if (upcall_info->mru &&
nla_put_u16(user_skb, OVS_PACKET_ATTR_MRU, upcall_info->mru)) {
err = -ENOBUFS;
goto out;
}
/* Add OVS_PACKET_ATTR_LEN when packet is truncated */
if (cutlen > 0) {
if (nla_put_u32(user_skb, OVS_PACKET_ATTR_LEN,
skb->len)) {
err = -ENOBUFS;
goto out;
}
pad_packet(dp, user_skb);
if (cutlen > 0 &&
nla_put_u32(user_skb, OVS_PACKET_ATTR_LEN, skb->len)) {
err = -ENOBUFS;
goto out;
}
/* Add OVS_PACKET_ATTR_HASH */