[Devel] [PATCH RH7 3/3] net: openvswitch: add capability to specify ifindex of new links

[Vasily Averin]

On 8/14/20 8:01 PM, Andrey Zhadchenko wrote:
> Openvswitch creates several net devices, but unlike rtnetlink API there is
> no option to specify ifindex for link. This is crucial for criu during
> restore stage.
> Use ovs_header->dp_ifindex during OVS_DP_CMD_NEW as desired ifindex.
> Use OVS_VPORT_ATTR_IFINDEX during OVS_VPORT_CMD_NEW to specify new netdev
> ifindex. Both values were not relevant for corresponding requests, so
> existing software won't mess with it.
> 
> https://jira.sw.ru/browse/PSBM-105844
> Signed-off-by: Andrey Zhadchenko <andrey.zhadchenko at virtuozzo.com>
> ---
>  net/openvswitch/datapath.c           | 16 ++++++++++++++--
>  net/openvswitch/vport-internal_dev.c |  1 +
>  net/openvswitch/vport.h              |  2 ++
>  3 files changed, 17 insertions(+), 2 deletions(-)
> 
> diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
> index 6d63ace..47bf4db 100644
> --- a/net/openvswitch/datapath.c
> +++ b/net/openvswitch/datapath.c
> @@ -1582,6 +1582,7 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct genl_info *info)
>  	struct vport *vport;
>  	struct ovs_net *ovs_net;
>  	int err, i;
> +	struct ovs_header *ovs_header = info->userhdr;
>  
>  	err = -EINVAL;
>  	if (!a[OVS_DP_ATTR_NAME] || !a[OVS_DP_ATTR_UPCALL_PID])
> @@ -1626,6 +1627,7 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct genl_info *info)
>  	parms.dp = dp;
>  	parms.port_no = OVSP_LOCAL;
>  	parms.upcall_portids = a[OVS_DP_ATTR_UPCALL_PID];
> +	parms.desired_ifindex = ovs_header->dp_ifindex;
>  
>  	ovs_dp_change(dp, a);
>  
> @@ -2013,7 +2015,10 @@ static int ovs_vport_cmd_new(struct sk_buff *skb, struct genl_info *info)
>  	if (!a[OVS_VPORT_ATTR_NAME] || !a[OVS_VPORT_ATTR_TYPE] ||
>  	    !a[OVS_VPORT_ATTR_UPCALL_PID])
>  		return -EINVAL;
> -	if (a[OVS_VPORT_ATTR_IFINDEX])
> +
> +	parms.type = nla_get_u32(a[OVS_VPORT_ATTR_TYPE]);
> +
> +	if (a[OVS_VPORT_ATTR_IFINDEX] && parms.type != OVS_VPORT_TYPE_INTERNAL)
>  		return -EOPNOTSUPP;
>  
>  	port_no = a[OVS_VPORT_ATTR_PORT_NO]
> @@ -2050,12 +2055,19 @@ restart:
>  	}
>  
>  	parms.name = nla_data(a[OVS_VPORT_ATTR_NAME]);
> -	parms.type = nla_get_u32(a[OVS_VPORT_ATTR_TYPE]);
>  	parms.options = a[OVS_VPORT_ATTR_OPTIONS];
>  	parms.dp = dp;
>  	parms.port_no = port_no;
>  	parms.upcall_portids = a[OVS_VPORT_ATTR_UPCALL_PID];
>  
> +	if (parms.type == OVS_VPORT_TYPE_INTERNAL) {
> +		if (a[OVS_VPORT_ATTR_IFINDEX])
> +			parms.desired_ifindex =
> +				nla_get_u32(a[OVS_VPORT_ATTR_IFINDEX]);
> +		else
> +			parms.desired_ifindex = 0;
> +	}
> +
>  	vport = new_vport(&parms);
>  	err = PTR_ERR(vport);
>  	if (IS_ERR(vport)) {
> diff --git a/net/openvswitch/vport-internal_dev.c b/net/openvswitch/vport-internal_dev.c
> index 2757f21..8ec8ae5 100644
> --- a/net/openvswitch/vport-internal_dev.c
> +++ b/net/openvswitch/vport-internal_dev.c
> @@ -202,6 +202,7 @@ static struct vport *internal_dev_create(const struct vport_parms *parms)
>  	if (vport->port_no == OVSP_LOCAL)
>  		vport->dev->features |= NETIF_F_NETNS_LOCAL;
>  
> +	dev->ifindex = parms->desired_ifindex;   <<<<< VvS 

in my version of kernel sources dev is not used in this fuction

>  	rtnl_lock();
>  	err = register_netdevice(vport->dev);
>  	if (err)
> diff --git a/net/openvswitch/vport.h b/net/openvswitch/vport.h
> index cda66c2..c5281b5 100644
> --- a/net/openvswitch/vport.h
> +++ b/net/openvswitch/vport.h
> @@ -109,6 +109,8 @@ struct vport_parms {
>  	enum ovs_vport_type type;
>  	struct nlattr *options;
>  
> +	int desired_ifindex;
> +
>  	/* For ovs_vport_alloc(). */
>  	struct datapath *dp;
>  	u16 port_no;
>