[PATCH net-next v3 0/6] netlink: add lwtunnel encap sub-message support to rt-route
From: Hangbin Liu
Date: Tue Sep 29 2026 - 21:52:16 EST
This series adds YNL sub-message support for lwtunnel encap data in
the rt-route netlink family, and describes the tunnel-specific
attribute sets that were previously opaque binary blobs.
The kernel currently emits encap_type after the encap payload nest,
but YNL sub-message parsing needs the selector (encap_type) first to
dispatch on the correct attribute set. Patch 1 reorders the kernel
output, and patch 2 teaches the YNL C code generator to convert enum
selectors to their string form for sub-message dispatch.
Patches 3-6 extend the rt-route YAML spec.
Tested with ynl selftest and checked with following cmds
# modprobe ila
# modprobe xfrm_interface
# ip addr add 10.1.0.1/24 dev lo
# ip route add 10.1.0.0/24 dev lo encap mpls 100 via 10.1.0.254
# ip route add 10.2.0.0/24 dev lo encap ip id 1 dst 127.0.0.1 src 127.0.0.1
# ip route add 2001:db8:3::/64 dev lo encap ila 1:2:3:4 csum-mode no-action ident-type luid hook-type output
# ip route add 2001:db8:4::/64 dev lo encap ip6 id 1 dst 2001:db8::5 src 2001:db8::1 hoplimit 64
# ip route add 2001:db8:5::/64 dev lo encap seg6 mode inline segs 2001:db8::1
# ip route add 2001:db8:6::/65 dev lo encap seg6local action End flavors psp,next-csid lblen 32 nflen 16
# ip route add 2001:db8:7::/65 dev lo encap bpf in ob /tmp/kself/net/lib/xdp_dummy.bpf.o sec xdp
# ip route add 2001:db8:8::/64 dev lo encap rpl segs 2001:db8::1
# ip route add 2001:db8:9::/64 encap ioam6 trace prealloc type 0x800000 ns 0 size 4 dev lo
# ip route add 2001:db8:10::/64 dev lo encap xfrm if_id 100
# ip route show
10.1.0.0/24 encap mpls 100 via 10.1.0.254 dev lo
10.2.0.0/24 encap ip id 1 src 127.0.0.1 dst 127.0.0.1 ttl 0 tos 0 dev lo scope link
# ip -6 route show
2001:db8:3::/64 encap ila 1:2:3:4 csum-mode no-action ident-type luid hook-type output dev lo metric 1024 pref medium
2001:db8:4::/64 encap ip6 id 1 src 2001:db8::1 dst 2001:db8::5 hoplimit 64 tc 0 dev lo metric 1024 pref medium
2001:db8:5::/64 encap seg6 mode inline segs 2 [ 2001:db8::1 :: ] dev lo metric 1024 pref medium
2001:db8:6::/65 encap seg6local action End flavors psp,next-csid lblen 32 nflen 16 dev lo metric 1024 pref medium
2001:db8:7::/65 encap bpf in xdp_dummy.bpf.o:[xdp] dev lo metric 1024 pref medium
2001:db8:8::/64 encap rpl segs 1 [ 2001:db8::1 ] dev lo metric 1024 pref medium
2001:db8:9::/64 encap ioam6 freq 1/1 mode inline trace prealloc type 0x800000 ns 0 size 4 dev lo metric 1024 pref medium
2001:db8:10::/64 encap xfrm if_id 100 dev lo metric 1024 pref medium
# ./tools/net/ynl/pyynl/cli.py --family rt-route --dump getroute > /tmp/route_dump.json
All the result looks good.
Signed-off-by: Hangbin Liu <liuhangbin@xxxxxxxxxx>
---
Changes in v3:
- patch 02: return local_vars and define new helpers is_enum_val and
get_enum_name (Jakub Kicinski)
- patch 03: alphabet order for header files in Makefile (Jakub Kicinski)
set byte-order for ila-attrs. ILA_ATTR_IDENTIFIER is not used, so no
need to set byte-order. (sashiko)
- patch 04: add multi-attr: true for geneve opts (sashiko)
- patch 05: remove lwt-bpf-prog from seg6 local, add a seg6 specific one
in patch 06 (sashiko)
- patch 06: add seg6-local-bpf and seg6-local-flv-ops. Set enum-as-flags
for seg6-local-flv-ops, set max-len for seg6-local-bpf-prog-name (sashiko)
- Link to v2: https://lore.kernel.org/r/20260920-ynl_rt_encap-v2-0-c664a3e726f6@xxxxxxxxxx
Changes in v2:
- Patch 1: Check ops->fill_encap before setting encap_type_attr
- Patch 2: Get string in generated sub-message parser and check it before reference
- Patch 3-4: set byte-orders and max-len
- Patch 5: include lwtunnel.h
- Link to v1: https://lore.kernel.org/r/20260917-ynl_rt_encap-v1-0-fbbe6e680571@xxxxxxxxxx
---
Hangbin Liu (6):
net: lwtunnel: change encap fill order
tools: ynl: convert enum selector to string for sub-message parsing
netlink: specs: rt-route: add lwtunnel encap sub-message support
netlink: specs: rt-route: describe lwtunnel IP options
netlink: specs: rt-route: describe lwt BPF program options
netlink: specs: rt-route: describe seg6-local attrs
Documentation/netlink/specs/rt-route.yaml | 446 +++++++++++++++++++++++++++++-
net/core/lwtunnel.c | 35 +--
tools/net/ynl/Makefile.deps | 9 +-
tools/net/ynl/pyynl/ynl_gen_c.py | 34 ++-
4 files changed, 500 insertions(+), 24 deletions(-)
---
base-commit: 806487df0088ff5f87890fadf95594d2afc00ff5
change-id: 20260908-ynl_rt_encap-3140103b368a
Best regards,
--
Hangbin Liu <liuhangbin@xxxxxxxxxx>