Le 25/08/2022 à 17:46, 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
>
> Signed-off-by: Eyal Birger <eyal.birger@xxxxxxxxx>
>
> ----
>
> v3: netlink improvements as suggested by Nikolay Aleksandrov and
> Nicolas Dichtel
>
> v2:
> - move lwt_xfrm_info() helper to dst_metadata.h
> - add "link" property as suggested by Nicolas Dichtel
> ---
> include/net/dst_metadata.h | 11 +++++
> include/uapi/linux/lwtunnel.h | 10 +++++
> net/core/lwtunnel.c | 1 +
> net/xfrm/xfrm_interface.c | 85 +++++++++++++++++++++++++++++++++++
> 4 files changed, 107 insertions(+)
>
> diff --git a/include/net/dst_metadata.h b/include/net/dst_metadata.h
> index e4b059908cc7..57f75960fa28 100644
> --- a/include/net/dst_metadata.h
> +++ b/include/net/dst_metadata.h
> @@ -60,13 +60,24 @@ skb_tunnel_info(const struct sk_buff *skb)
> return NULL;
> }
>
> +static inline struct xfrm_md_info *lwt_xfrm_info(struct lwtunnel_state *lwt)
> +{
> + return (struct xfrm_md_info *)lwt->data;
> +}
> +
> static inline struct xfrm_md_info *skb_xfrm_md_info(const struct sk_buff *skb)
> {
> struct metadata_dst *md_dst = skb_metadata_dst(skb);
> + struct dst_entry *dst;
>
> if (md_dst && md_dst->type == METADATA_XFRM)
> return &md_dst->u.xfrm_info;
>
> + dst = skb_dst(skb);
> + if (dst && dst->lwtstate &&
> + dst->lwtstate->type == LWTUNNEL_ENCAP_XFRM)
> + return lwt_xfrm_info(dst->lwtstate);
> +
> return NULL;
> }
>
> diff --git a/include/uapi/linux/lwtunnel.h b/include/uapi/linux/lwtunnel.h
> index 2e206919125c..229655ef792f 100644
> --- a/include/uapi/linux/lwtunnel.h
> +++ b/include/uapi/linux/lwtunnel.h
> @@ -15,6 +15,7 @@ enum lwtunnel_encap_types {
> LWTUNNEL_ENCAP_SEG6_LOCAL,
> LWTUNNEL_ENCAP_RPL,
> LWTUNNEL_ENCAP_IOAM6,
> + LWTUNNEL_ENCAP_XFRM,
> __LWTUNNEL_ENCAP_MAX,
> };
>
> @@ -111,4 +112,13 @@ enum {
>
> #define LWT_BPF_MAX_HEADROOM 256
>
> +enum {
> + LWT_XFRM_UNSPEC,
> + LWT_XFRM_IF_ID,
> + LWT_XFRM_LINK,
> + __LWT_XFRM_MAX,
> +};
> +
> +#define LWT_XFRM_MAX (__LWT_XFRM_MAX - 1)
> +
> #endif /* _UAPI_LWTUNNEL_H_ */
> diff --git a/net/core/lwtunnel.c b/net/core/lwtunnel.c
> index 9ccd64e8a666..6fac2f0ef074 100644
> --- a/net/core/lwtunnel.c
> +++ b/net/core/lwtunnel.c
> @@ -50,6 +50,7 @@ static const char *lwtunnel_encap_str(enum lwtunnel_encap_types encap_type)
> return "IOAM6";
> case LWTUNNEL_ENCAP_IP6:
> case LWTUNNEL_ENCAP_IP:
> + case LWTUNNEL_ENCAP_XFRM:
> case LWTUNNEL_ENCAP_NONE:
> case __LWTUNNEL_ENCAP_MAX:
> /* should not have got here */
> diff --git a/net/xfrm/xfrm_interface.c b/net/xfrm/xfrm_interface.c
> index e9a355047468..495dee8b0764 100644
> --- a/net/xfrm/xfrm_interface.c
> +++ b/net/xfrm/xfrm_interface.c
> @@ -60,6 +60,88 @@ struct xfrmi_net {
> struct xfrm_if __rcu *collect_md_xfrmi;
> };
>
> +static const struct nla_policy xfrm_lwt_policy[LWT_XFRM_MAX + 1] = {
> + [LWT_XFRM_IF_ID] = NLA_POLICY_MIN(NLA_U32, 1),
> + [LWT_XFRM_LINK] = NLA_POLICY_MIN(NLA_S32, 1),
IMHO, it would be better to keep consistency with IFLA_XFRM_LINK.
$ git grep _LINK.*NLA_U32 net/ drivers/net/
drivers/net/gtp.c: [GTPA_LINK] = { .type = NLA_U32, },
drivers/net/vxlan/vxlan_core.c: [IFLA_VXLAN_LINK] = { .type = NLA_U32 },
...
net/core/rtnetlink.c: [IFLA_LINK] = { .type = NLA_U32 },
...
net/ipv4/ip_gre.c: [IFLA_GRE_LINK] = { .type = NLA_U32 },
net/ipv4/ip_vti.c: [IFLA_VTI_LINK] = { .type = NLA_U32 },
net/ipv4/ipip.c: [IFLA_IPTUN_LINK] = { .type = NLA_U32 },
net/ipv6/ip6_gre.c: [IFLA_GRE_LINK] = { .type = NLA_U32 },
net/ipv6/ip6_tunnel.c: [IFLA_IPTUN_LINK] = { .type = NLA_U32 },
net/ipv6/ip6_vti.c: [IFLA_VTI_LINK] = { .type = NLA_U32 },
net/ipv6/sit.c: [IFLA_IPTUN_LINK] = { .type = NLA_U32 },
net/sched/cls_u32.c: [TCA_U32_LINK] = { .type = NLA_U32 },
...
net/xfrm/xfrm_interface.c: [IFLA_XFRM_LINK] = { .type = NLA_U32 },
$ git grep _LINK.*NLA_S32 net/ drivers/net/
net/core/rtnetlink.c: [IFLA_LINK_NETNSID] = { .type = NLA_S32 },
$
They all are U32. Adding one S32 would just add confusion.
