[PATCH net-next 2/3] vxlan: honor per-nexthop fdb destination port
From: Jack Ma <hidden>
Date: 2026-07-12 19:16:40
Also in:
linux-kselftest, lkml
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
When an fdb entry points at a nexthop group, vxlan_fdb_nh_path_select() resolves the selected leg's remote IP but leaves the UDP destination port at the device default (vxlan->cfg.dst_port). Extend nexthop_path_fdb_result() to also return the selected nexthop's NHA_FDB_PORT (0 when unset) and have vxlan_fdb_nh_path_select() store it in rdst->remote_port. vxlan_xmit_one() already prefers rdst->remote_port when non-zero and falls back to the device port otherwise, so nexthops without a port are unaffected. This lets one fdb nexthop group load-balance a flow across legs that share an underlay IP but differ in UDP destination port. Signed-off-by: Jack Ma <redacted> --- include/net/nexthop.h | 5 ++++- include/net/vxlan.h | 5 ++++- 2 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/include/net/nexthop.h b/include/net/nexthop.h
index 9c8227996..7fb612a73 100644
--- a/include/net/nexthop.h
+++ b/include/net/nexthop.h@@ -576,7 +576,8 @@ struct fib_nh_common *nexthop_fdb_nhc(struct nexthop *nh) } static inline struct fib_nh_common *nexthop_path_fdb_result(struct nexthop *nh, - int hash) + int hash, + __be16 *fdb_port) { struct nh_info *nhi; struct nexthop *nhp;
@@ -585,6 +586,8 @@ static inline struct fib_nh_common *nexthop_path_fdb_result(struct nexthop *nh, if (unlikely(!nhp)) return NULL; nhi = rcu_dereference(nhp->nh_info); + if (fdb_port) + *fdb_port = nhi->fdb_port; return &nhi->fib_nhc; } #endif
diff --git a/include/net/vxlan.h b/include/net/vxlan.h
index dfba89695..de41b3746 100644
--- a/include/net/vxlan.h
+++ b/include/net/vxlan.h@@ -567,8 +567,9 @@ static inline bool vxlan_fdb_nh_path_select(struct nexthop *nh, struct vxlan_rdst *rdst) { struct fib_nh_common *nhc; + __be16 fdb_port = 0; - nhc = nexthop_path_fdb_result(nh, hash >> 1); + nhc = nexthop_path_fdb_result(nh, hash >> 1, &fdb_port); if (unlikely(!nhc)) return false;
@@ -583,6 +584,8 @@ static inline bool vxlan_fdb_nh_path_select(struct nexthop *nh, break; } + rdst->remote_port = fdb_port; + return true; }
--
2.43.0