linux-stable.git/tools/net/ynl, branch v6.16

tools: ynl: fix mixing ops and notifications on one socket

2025-06-19T15:37:39+00:00

The multi message support loosened the connection between the request
and response handling, as we can now submit multiple requests before
we start processing responses. Passing the attr set to NlMsgs decoding
no longer makes sense (if it ever did), attr set may differ message
by messsage. Isolate the part of decoding responsible for attr-set
specific interpretation and call it once we identified the correct op.

Without this fix performing SET operation on an ethtool socket, while
being subscribed to notifications causes:

 # File "tools/net/ynl/pyynl/lib/ynl.py", line 1096, in _op
 # Exception|     return self._ops(ops)[0]
 # Exception|            ~~~~~~~~~^^^^^
 # File "tools/net/ynl/pyynl/lib/ynl.py", line 1040, in _ops
 # Exception|     nms = NlMsgs(reply, attr_space=op.attr_set)
 # Exception|                                    ^^^^^^^^^^^

The value of op we use on line 1040 is stale, it comes form the previous
loop. If a notification comes before a response we will update op to None
and the next iteration thru the loop will break with the trace above.

Fixes: 6fda63c45fe8 ("tools/net/ynl: fix cli.py --subscribe feature")
Fixes: ba8be00f68f5 ("tools/net/ynl: Add multi message support to ynl")
Reviewed-by: Donald Hunter 
Link: https://patch.msgid.link/20250618171746.1201403-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski

tools: ynl: parse extack for sub-messages

2025-05-28T00:31:42+00:00

Extend the Python YNL extack decoding to handle sub-messages in the same
way that YNL C does. This involves retaining the input values so that
they are available during extack decoding.

./tools/net/ynl/pyynl/cli.py --family rt-link --do newlink --create \
    --json '{
        "linkinfo": {"kind": "netkit", "data": {"policy": 10} }
    }'
Netlink error: Invalid argument
nl_len = 92 (76) nl_flags = 0x300 nl_type = 2
	error: -22
	extack: {'msg': 'Provided default xmit policy not supported', 'bad-attr': '.linkinfo.data(netkit).policy'}

Signed-off-by: Donald Hunter 
Link: https://patch.msgid.link/20250523103031.80236-1-donald.hunter@gmail.com
Signed-off-by: Jakub Kicinski

tools: ynl: add a sample for TC

2025-05-21T19:38:23+00:00

Add a very simple TC dump sample with decoding of fq_codel attrs:

  # ./tools/net/ynl/samples/tc
        dummy0: fq_codel  limit: 10240p target: 5ms new_flow_cnt: 0

proving that selector passing (for stats) works.

Reviewed-by: Donald Hunter 
Link: https://patch.msgid.link/20250520161916.413298-13-kuba@kernel.org
Signed-off-by: Jakub Kicinski

tools: ynl: enable codegen for TC

2025-05-21T19:38:23+00:00

We are ready to support most of TC. Enable C code gen.

Reviewed-by: Donald Hunter 
Link: https://patch.msgid.link/20250520161916.413298-11-kuba@kernel.org
Signed-off-by: Jakub Kicinski

tools: ynl-gen: support weird sub-message formats

2025-05-21T19:38:23+00:00

TC uses all possible sub-message formats:
 - nested attrs
 - fixed headers + nested attrs
 - fixed headers
 - empty

Nested attrs are already supported for rt-link. Add support
for remaining 3. The empty and fixed headers ones are fairly
trivial, we can fake a Binary or Flags type instead of a Nest.

For fixed headers + nest we need to teach nest parsing and
nest put to handle fixed headers.

Reviewed-by: Donald Hunter 
Link: https://patch.msgid.link/20250520161916.413298-10-kuba@kernel.org
Signed-off-by: Jakub Kicinski

tools: ynl-gen: support local attrs in _multi_parse

2025-05-21T19:38:22+00:00

The _multi_parse() helper calls the _attr_get() method of each attr,
but it only respects what code the helper wants to emit, not what
local variables it needs. Local variables will soon be needed,
support them.

Reviewed-by: Donald Hunter 
Link: https://patch.msgid.link/20250520161916.413298-9-kuba@kernel.org
Signed-off-by: Jakub Kicinski

tools: ynl-gen: move fixed header info from RenderInfo to Struct

2025-05-21T19:38:22+00:00

RenderInfo describes a request-response exchange. Struct describes
a parsed attribute set. For ease of parsing sub-messages with
fixed headers move fixed header info from RenderInfo to Struct.
No functional changes.

Reviewed-by: Donald Hunter 
Link: https://patch.msgid.link/20250520161916.413298-8-kuba@kernel.org
Signed-off-by: Jakub Kicinski

tools: ynl-gen: support passing selector to a nest

2025-05-21T19:38:22+00:00

In rtnetlink all submessages had the selector at the same level
of nesting as the submessage. We could refer to the relevant
attribute from the current struct. In TC, stats are one level
of nesting deeper than "kind". Teach the code-gen about structs
which need to be passed a selector by the caller for parsing.

Because structs are "topologically sorted" one pass of propagating
the selectors down is enough.

For generating netlink message we depend on the presence bits
so no selector passing needed there.

Reviewed-by: Donald Hunter 
Link: https://patch.msgid.link/20250520161916.413298-7-kuba@kernel.org
Signed-off-by: Jakub Kicinski

tools: ynl-gen: add makefile deps for neigh

2025-05-21T19:38:20+00:00

Kory is reporting build issues after recent additions to YNL
if the system headers are old.

Link: https://lore.kernel.org/20250519164949.597d6e92@kmaincent-XPS-13-7390
Reported-by: Kory Maincent 
Fixes: 0939a418b3b0 ("tools: ynl: submsg: reverse parse / error reporting")
Tested-by: Kory Maincent 
Link: https://patch.msgid.link/20250520161916.413298-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski

tools: ynl: add a sample for rt-link

2025-05-16T23:32:06+00:00

Add a fairly complete example of rt-link usage. If run without any
arguments it simply lists the interfaces and some of their attrs.
If run with an arg it tries to create and delete a netkit device.

1 # ./tools/net/ynl/samples/rt-link 1
2 Trying to create a Netkit interface
3 Testing error message for policy being bad:
4 Kernel error: 'Provided default xmit policy not supported' (bad attribute: .linkinfo.data(netkit).policy)
5 1: lo: mtu 65536
6 2: wlp0s1: mtu 1500
7 3: enp0s13: mtu 1500
8 4: dummy0: mtu 1500 kind dummy altname one two
9 5: nk0: mtu 1500 kind netkit primary 0 policy forward
10 6: nk1: mtu 1500 kind netkit primary 1 policy blackhole
11 Trying to delete a Netkit interface (ifindex 6)

Sample creates the device first, it sets an invalid value for a netkit
attribute to trigger reverse parsing. Line 4 shows the error with the
attribute path correctly generated by YNL.

Then sample fixes the bad attribute and re-issues the request, with
NLM_F_ECHO set. This flag causes the notification to be looped back
to the initiating socket (our socket). Sample parses this notification
to save the ifindex of the created netkit.

Sample then proceeds to list the devices. Line 8 above shows a dummy
device with two alt names. Lines 9 and 10 show the netkit devices
the sample itself created.

The "primary" and "policy" attrs are from inside the netkit submsg.
The string values are auto-generated for the enums by YNL.

To clean up sample deletes the interface it created (line 11).

Reviewed-by: Donald Hunter
Link: https://patch.msgid.link/20250515231650.1325372-10-kuba@kernel.org
Signed-off-by: Jakub Kicinski