Commit d96e48a3 authored by Jiri Pirko's avatar Jiri Pirko Committed by Jakub Kicinski
Browse files

tools: ynl: introduce option to process unknown attributes or types 



In case the kernel sends message back containing attribute not defined
in family spec, following exception is raised to the user:

$ sudo ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/devlink.yaml --do trap-get --json '{"bus-name": "netdevsim", "dev-name": "netdevsim1", "trap-name": "source_mac_is_multicast"}'
Traceback (most recent call last):
  File "/home/jiri/work/linux/tools/net/ynl/lib/ynl.py", line 521, in _decode
    attr_spec = attr_space.attrs_by_val[attr.type]
                ~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^
KeyError: 132

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/jiri/work/linux/./tools/net/ynl/cli.py", line 61, in <module>
    main()
  File "/home/jiri/work/linux/./tools/net/ynl/cli.py", line 49, in main
    reply = ynl.do(args.do, attrs, args.flags)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/jiri/work/linux/tools/net/ynl/lib/ynl.py", line 731, in do
    return self._op(method, vals, flags)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/jiri/work/linux/tools/net/ynl/lib/ynl.py", line 719, in _op
    rsp_msg = self._decode(decoded.raw_attrs, op.attr_set.name)
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/jiri/work/linux/tools/net/ynl/lib/ynl.py", line 525, in _decode
    raise Exception(f"Space '{space}' has no attribute with value '{attr.type}'")
Exception: Space 'devlink' has no attribute with value '132'

Introduce a command line option "process-unknown" and pass it down to
YnlFamily class constructor to allow user to process unknown
attributes and types and print them as binaries.

$ sudo ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/devlink.yaml --do trap-get --json '{"bus-name": "netdevsim", "dev-name": "netdevsim1", "trap-name": "source_mac_is_multicast"}' --process-unknown
{'UnknownAttr(129)': {'UnknownAttr(0)': b'\x00\x00\x00\x00\x00\x00\x00\x00',
                      'UnknownAttr(1)': b'\x00\x00\x00\x00\x00\x00\x00\x00',
                      'UnknownAttr(2)': b'\x0e\x00\x00\x00\x00\x00\x00\x00'},
 'UnknownAttr(132)': b'\x00',
 'UnknownAttr(133)': b'',
 'UnknownAttr(134)': {'UnknownAttr(0)': b''},
 'bus-name': 'netdevsim',
 'dev-name': 'netdevsim1',
 'trap-action': 'drop',
 'trap-group-name': 'l2_drops',
 'trap-name': 'source_mac_is_multicast'}

Signed-off-by: default avatarJiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20231027092525.956172-1-jiri@resnulli.us


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent ff672b9f

tools/net/ynl/cli.py

+2 −1
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ def main(): 
                        const=Netlink.NLM_F_CREATE)

    parser.add_argument('--append', dest='flags', action='append_const',

                        const=Netlink.NLM_F_APPEND)

    parser.add_argument('--process-unknown', action=argparse.BooleanOptionalAction)

    args = parser.parse_args()



    if args.no_schema:
@@ -36,7 +37,7 @@ def main(): 
    if args.json_text:

        attrs = json.loads(args.json_text)



    ynl = YnlFamily(args.spec, args.schema)

    ynl = YnlFamily(args.spec, args.schema, args.process_unknown)



    if args.ntf:

        ynl.ntf_subscribe(args.ntf)

tools/net/ynl/lib/ynl.py

+37 −11
Original line number Diff line number Diff line
@@ -100,6 +100,7 @@ class NlAttr: 
    def __init__(self, raw, offset):

        self._len, self._type = struct.unpack("HH", raw[offset:offset + 4])

        self.type = self._type & ~Netlink.NLA_TYPE_MASK

        self.is_nest = self._type & Netlink.NLA_F_NESTED

        self.payload_len = self._len

        self.full_len = (self.payload_len + 3) & ~3

        self.raw = raw[offset + 4:offset + self.payload_len]
@@ -411,10 +412,11 @@ class GenlProtocol(NetlinkProtocol): 




class YnlFamily(SpecFamily):

    def __init__(self, def_path, schema=None):

    def __init__(self, def_path, schema=None, process_unknown=False):

        super().__init__(def_path, schema)



        self.include_raw = False

        self.process_unknown = process_unknown



        try:

            if self.proto == "netlink-raw":
@@ -526,14 +528,41 @@ class YnlFamily(SpecFamily): 
            decoded.append({ item.type: subattrs })

        return decoded



    def _decode_unknown(self, attr):

        if attr.is_nest:

            return self._decode(NlAttrs(attr.raw), None)

        else:

            return attr.as_bin()



    def _rsp_add(self, rsp, name, is_multi, decoded):

        if is_multi == None:

            if name in rsp and type(rsp[name]) is not list:

                rsp[name] = [rsp[name]]

                is_multi = True

            else:

                is_multi = False



        if not is_multi:

            rsp[name] = decoded

        elif name in rsp:

            rsp[name].append(decoded)

        else:

            rsp[name] = [decoded]



    def _decode(self, attrs, space):

        if space:

            attr_space = self.attr_sets[space]

        rsp = dict()

        for attr in attrs:

            try:

                attr_spec = attr_space.attrs_by_val[attr.type]

            except KeyError:

            except (KeyError, UnboundLocalError):

                if not self.process_unknown:

                    raise Exception(f"Space '{space}' has no attribute with value '{attr.type}'")

                attr_name = f"UnknownAttr({attr.type})"

                self._rsp_add(rsp, attr_name, None, self._decode_unknown(attr))

                continue



            if attr_spec["type"] == 'nest':

                subdict = self._decode(NlAttrs(attr.raw), attr_spec['nested-attributes'])

                decoded = subdict
@@ -558,14 +587,11 @@ class YnlFamily(SpecFamily): 
                    selector = self._decode_enum(selector, attr_spec)

                decoded = {"value": value, "selector": selector}

            else:

                if not self.process_unknown:

                    raise Exception(f'Unknown {attr_spec["type"]} with name {attr_spec["name"]}')

                decoded = self._decode_unknown(attr)



            if not attr_spec.is_multi:

                rsp[attr_spec['name']] = decoded

            elif attr_spec.name in rsp:

                rsp[attr_spec.name].append(decoded)

            else:

                rsp[attr_spec.name] = [decoded]

            self._rsp_add(rsp, attr_spec["name"], attr_spec.is_multi, decoded)



        return rsp