On Thu, Jun 28, 2018 at 8:20 AM, Yifeng Sun <pkusunyif...@gmail.com> wrote:
> Add 'clone' action to kernel datapath by using existing functions.
> When actions within clone don't modify the current flow, the flow
> key is not cloned before executing clone actions.
>
> This is a follow up patch for this incomplete work:
> https://patchwork.ozlabs.org/patch/722096/
>
> Signed-off-by: Yifeng Sun <pkusunyif...@gmail.com>
> Signed-off-by: Andy Zhou <az...@ovn.org>
> ---
> include/uapi/linux/openvswitch.h | 8 +++++
> net/openvswitch/actions.c | 33 ++++++++++++++++++
> net/openvswitch/flow_netlink.c | 73
> ++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 114 insertions(+)
>
> diff --git a/include/uapi/linux/openvswitch.h
> b/include/uapi/linux/openvswitch.h
> index 863aaba..5de8583 100644
> --- a/include/uapi/linux/openvswitch.h
> +++ b/include/uapi/linux/openvswitch.h
> @@ -625,6 +625,11 @@ struct sample_arg {
> * 'OVS_SAMPLE_ATTR_PROBABILITY'.
> */
> };
> +
> +#define OVS_CLONE_ATTR_EXEC 0 /* Specify an u32 value. When nonzero,
> + * actions in clone will not change flow
> + * keys. False otherwise.
> + */
> #endif
This symbol is used only in datapath, so we can move it to kernel
headers from uapi.
> diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c
> index 30a5df2..4444e31 100644
> --- a/net/openvswitch/actions.c
> +++ b/net/openvswitch/actions.c
> @@ -1057,6 +1057,28 @@ static int sample(struct datapath *dp, struct sk_buff
> *skb,
> clone_flow_key);
> }
>
> +/* When 'last' is true, clone() should always consume the 'skb'.
> + * Otherwise, clone() should keep 'skb' intact regardless what
> + * actions are executed within clone().
> + */
> +static int clone(struct datapath *dp, struct sk_buff *skb,
> + struct sw_flow_key *key, const struct nlattr *attr,
> + bool last)
> +{
> + struct nlattr *actions;
> + struct nlattr *clone_arg;
> + int rem = nla_len(attr);
> + bool clone_flow_key;
> +
> + /* The first action is always 'OVS_CLONE_ATTR_ARG'. */
> + clone_arg = nla_data(attr);
> + clone_flow_key = !nla_get_u32(clone_arg);
> + actions = nla_next(clone_arg, &rem);
> +
Since OVS_CLONE_ATTR_EXEC means do not clone the key, it can be named
accordingly.
