From: Tonghao Zhang <[email protected]> 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 <[email protected]> Cc: William Tu <[email protected]> Signed-off-by: Tonghao Zhang <[email protected]> --- net/openvswitch/datapath.c | 22 ++++++++-------------- 1 file changed, 8 insertions(+), 14 deletions(-) diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c index 8ce1f773378d..93d4991ddc1f 100644 --- a/net/openvswitch/datapath.c +++ b/net/openvswitch/datapath.c @@ -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 */ -- 2.23.0 _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
