From 53531e6a644a48c2d5a9423f084ae4e91ec6019a Mon Sep 17 00:00:00 2001 From: Jack Ma Date: Fri, 24 Jul 2026 00:26:16 +0000 Subject: net: nexthop: add NHA_DST_PORT for fdb nexthops Commit 1274e1cc4226 ("vxlan: ecmp support for mac fdb entries") lets a single inner MAC be reached through a group of remote VTEPs, with the kernel flow-hashing across the group members. Each member carries its own remote IP, but the UDP destination port is always taken from the VXLAN device (vxlan->cfg.dst_port) and cannot be set per member. Some deployments pack several receivers behind one underlay IP and tell them apart by UDP port, so they need a per-nexthop destination port to spread flows across (IP, port) tuples rather than IP alone. Add a netlink attribute NHA_DST_PORT (__be16, mirroring NDA_PORT) that carries an optional UDP destination port on an fdb nexthop. It is only accepted together with NHA_FDB and NHA_GATEWAY; it is stored in struct nh_info and echoed back on dump. The attribute is named generically rather than fdb-specific so it can be reused should another nexthop type ever need a destination port. This patch is control-plane plumbing only; the VXLAN datapath is wired up in a follow-up patch, so behaviour is unchanged for now. Signed-off-by: Jack Ma Reviewed-by: Ido Schimmel Reviewed-by: David Ahern Link: https://patch.msgid.link/20260724-b4-vxlan-fdb-port-v5-1-cd1c6aeee058@gmail.com Signed-off-by: Jakub Kicinski --- include/uapi/linux/nexthop.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/nexthop.h b/include/uapi/linux/nexthop.h index bc49baf4a267..59cf1cee93bd 100644 --- a/include/uapi/linux/nexthop.h +++ b/include/uapi/linux/nexthop.h @@ -83,6 +83,9 @@ enum { /* u32; read-only; whether any driver collects HW stats */ NHA_HW_STATS_USED, + /* be16; UDP destination port for an fdb nexthop (e.g. VXLAN) */ + NHA_DST_PORT, + __NHA_MAX, }; -- cgit v1.2.3