Re: [PATCH ipsec-next,v4 3/3] xfrm: lwtunnel: add lwtunnel support for xfrm interfaces in collect_md mode

[Nicolas Dichtel <nicolas.dichtel@6wind.com>]

Le 26/08/2022 à 13:47, Eyal Birger a écrit :
> Allow specifying the xfrm interface if_id and link as part of a route
> metadata using the lwtunnel infrastructure.
> 
> This allows for example using a single xfrm interface in collect_md
> mode as the target of multiple routes each specifying a different if_id.
> 
> With the appropriate changes to iproute2, considering an xfrm device
> ipsec1 in collect_md mode one can for example add a route specifying
> an if_id like so:
> 
> ip route add <SUBNET> dev ipsec1 encap xfrm if_id 1
> 
> In which case traffic routed to the device via this route would use
> if_id in the xfrm interface policy lookup.
> 
> Or in the context of vrf, one can also specify the "link" property:
> 
> ip route add <SUBNET> dev ipsec1 encap xfrm if_id 1 link_dev eth15
> 
> Note: LWT_XFRM_LINK uses NLA_U32 similar to IFLA_XFRM_LINK even though
> internally "link" is signed. This is consistent with other _LINK
> attributes in other devices as well as in bpf and should not have an
> effect as device indexes can't be negative.
> 
> Signed-off-by: Eyal Birger <eyal.birger@gmail.com>
Reviewed-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>