[PATCH net-next v4 0/6] netlink: add lwtunnel encap sub-message support to rt-route

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 link add geneve1 type geneve id 1 remote 10.1.0.2 ttl 64
 # ip link set geneve1 up
 # ip route add 10.1.0.0/24 dev lo encap mpls 100 via 10.1.0.254
 # ip route add 1.1.1.0/24 encap ip id 1 geneve_opts 1:1:1212121234567891,2:2:1212121234567892,3:3:1212121234567893 dst 10.1.0.2 dev geneve1
 # 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
 1.1.1.0/24  encap ip id 1 src 0.0.0.0 dst 10.1.0.2 ttl 0 tos 0
        geneve_opts 1:1:1212121234567891,2:2:1212121234567892,3:3:1212121234567893 dev geneve1 scope link
 10.1.0.0/24  encap mpls  100 via 10.1.0.254 dev lo
 # 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 <redacted>
---
Changes in v4:
- patch 02: include check `not self.selector.is_external()` for enum selectors,
            return error when enum lookup failed. (sashiko, Jakub)
- patch 04: set geneve options to binary due to the different format between
            request and dump (sashiko)
- patch 05: set max-len for lwt-bpf-prog-name (sashiko)
- patch 06: fix seg6-local-flv-ops type and name prefix (sashiko)
- Link to v3: https://lore.kernel.org/r/20260930-ynl_rt_encap-v3-0-4106c21b9ee7@kylinos.cn (local)

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@kylinos.cn (local)

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@kylinos.cn (local)

---
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 | 430 +++++++++++++++++++++++++++++-
 net/core/lwtunnel.c                       |  35 +--
 tools/net/ynl/Makefile.deps               |   9 +-
 tools/net/ynl/pyynl/ynl_gen_c.py          |  34 ++-
 4 files changed, 484 insertions(+), 24 deletions(-)
---
base-commit: 8df0638138d3e0344fd1fb36cf2d1ca1cf5028f0
change-id: 20260908-ynl_rt_encap-3140103b368a

Best regards,
-- 
Hangbin Liu [off-list ref]