diff --git a/Documentation/netlink/genetlink.yaml b/Documentation/netlink/genetlink.yaml
new file mode 100644
index 000000000000..3283bf458ff1
--- /dev/null
+++ b/Documentation/netlink/genetlink.yaml
@@ -0,0 +1,330 @@
+# SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)
+%YAML 1.2
+---
+$id: http://kernel.org/schemas/netlink/genetlink-legacy.yaml#
+$schema: https://json-schema.org/draft-07/schema
+
+# Common defines
+$defs:
+  uint:
+    type: integer
+    minimum: 0
+  len-or-define:
+    type: [ string, integer ]
+    pattern: ^[0-9A-Za-z_]+( - 1)?$
+    minimum: 0
+  len-or-limit:
+    # literal int or limit based on fixed-width type e.g. u8-min, u16-max, etc.
+    type: [ string, integer ]
+    pattern: ^[su](8|16|32|64)-(min|max)$
+    minimum: 0
+
+# Schema for specs
+title: Protocol
+description: Specification of a genetlink protocol
+type: object
+required: [ name, doc, attribute-sets, operations ]
+additionalProperties: False
+properties:
+  name:
+    description: Name of the genetlink family.
+    type: string
+  doc:
+    type: string
+  protocol:
+    description: Schema compatibility level. Default is "genetlink".
+    enum: [ genetlink ]
+  uapi-header:
+    description: Path to the uAPI header, default is linux/${family-name}.h
+    type: string
+
+  definitions:
+    description: List of type and constant definitions (enums, flags, defines).
+    type: array
+    items:
+      type: object
+      required: [ type, name ]
+      additionalProperties: False
+      properties:
+        name:
+          type: string
+        header:
+          description: For C-compatible languages, header which already defines this value.
+          type: string
+        type:
+          enum: [ const, enum, flags ]
+        doc:
+          type: string
+        # For const
+        value:
+          description: For const - the value.
+          type: [ string, integer ]
+        # For enum and flags
+        value-start:
+          description: For enum or flags the literal initializer for the first value.
+          type: [ string, integer ]
+        entries:
+          description: For enum or flags array of values.
+          type: array
+          items:
+            oneOf:
+              - type: string
+              - type: object
+                required: [ name ]
+                additionalProperties: False
+                properties:
+                  name:
+                    type: string
+                  value:
+                    type: integer
+                  doc:
+                    type: string
+        render-max:
+          description: Render the max members for this enum.
+          type: boolean
+
+  attribute-sets:
+    description: Definition of attribute spaces for this family.
+    type: array
+    items:
+      description: Definition of a single attribute space.
+      type: object
+      required: [ name, attributes ]
+      additionalProperties: False
+      properties:
+        name:
+          description: |
+            Name used when referring to this space in other definitions, not used outside of the spec.
+          type: string
+        name-prefix:
+          description: |
+            Prefix for the C enum name of the attributes. Default family[name]-set[name]-a-
+          type: string
+        enum-name:
+          description: Name for the enum type of the attribute.
+          type: string
+        doc:
+          description: Documentation of the space.
+          type: string
+        subset-of:
+          description: |
+            Name of another space which this is a logical part of. Sub-spaces can be used to define
+            a limited group of attributes which are used in a nest.
+          type: string
+        attributes:
+          description: List of attributes in the space.
+          type: array
+          items:
+            type: object
+            required: [ name ]
+            additionalProperties: False
+            properties:
+              name:
+                type: string
+              type: &attr-type
+                enum: [ unused, pad, flag, binary,
+                        uint, sint, u8, u16, u32, u64, s32, s64,
+                        string, nest, array-nest, nest-type-value ]
+              doc:
+                description: Documentation of the attribute.
+                type: string
+              value:
+                description: Value for the enum item representing this attribute in the uAPI.
+                $ref: '#/$defs/uint'
+              type-value:
+                description: Name of the value extracted from the type of a nest-type-value attribute.
+                type: array
+                items:
+                  type: string
+              byte-order:
+                enum: [ little-endian, big-endian ]
+              multi-attr:
+                type: boolean
+              nested-attributes:
+                description: Name of the space (sub-space) used inside the attribute.
+                type: string
+              enum:
+                description: Name of the enum type used for the attribute.
+                type: string
+              enum-as-flags:
+                description: |
+                  Treat the enum as flags. In most cases enum is either used as flags or as values.
+                  Sometimes, however, both forms are necessary, in which case header contains the enum
+                  form while specific attributes may request to convert the values into a bitfield.
+                type: boolean
+              checks:
+                description: Kernel input validation.
+                type: object
+                additionalProperties: False
+                properties:
+                  flags-mask:
+                    description: Name of the flags constant on which to base mask (unsigned scalar types only).
+                    type: string
+                  min:
+                    description: Min value for an integer attribute.
+                    $ref: '#/$defs/len-or-limit'
+                  max:
+                    description: Max value for an integer attribute.
+                    $ref: '#/$defs/len-or-limit'
+                  min-len:
+                    description: Min length for a binary attribute.
+                    $ref: '#/$defs/len-or-define'
+                  max-len:
+                    description: Max length for a string or a binary attribute.
+                    $ref: '#/$defs/len-or-define'
+                  exact-len:
+                    description: Exact length for a string or a binary attribute.
+                    $ref: '#/$defs/len-or-define'
+              sub-type: *attr-type
+              display-hint: &display-hint
+                description: |
+                  Optional format indicator that is intended only for choosing
+                  the right formatting mechanism when displaying values of this
+                  type.
+                enum: [ hex, mac, fddi, ipv4, ipv6, uuid ]
+
+      # Make sure name-prefix does not appear in subsets (subsets inherit naming)
+      dependencies:
+        name-prefix:
+          not:
+            required: [ subset-of ]
+        subset-of:
+          not:
+            required: [ name-prefix ]
+
+      # type property is only required if not in subset definition
+      if:
+        properties:
+          subset-of:
+            not:
+              type: string
+      then:
+        properties:
+          attributes:
+            items:
+              required: [ type ]
+
+  operations:
+    description: Operations supported by the protocol.
+    type: object
+    required: [ list ]
+    additionalProperties: False
+    properties:
+      enum-model:
+        description: |
+          The model of assigning values to the operations.
+          "unified" is the recommended model where all message types belong
+          to a single enum.
+          "directional" has the messages sent to the kernel and from the kernel
+          enumerated separately.
+        enum: [ unified ]
+      name-prefix:
+        description: |
+          Prefix for the C enum name of the command. The name is formed by concatenating
+          the prefix with the upper case name of the command, with dashes replaced by underscores.
+        type: string
+      enum-name:
+        description: Name for the enum type with commands.
+        type: string
+      async-prefix:
+        description: Same as name-prefix but used to render notifications and events to separate enum.
+        type: string
+      async-enum:
+        description: Name for the enum type with notifications/events.
+        type: string
+      list:
+        description: List of commands
+        type: array
+        items:
+          type: object
+          additionalProperties: False
+          required: [ name, doc ]
+          properties:
+            name:
+              description: Name of the operation, also defining its C enum value in uAPI.
+              type: string
+            doc:
+              description: Documentation for the command.
+              type: string
+            value:
+              description: Value for the enum in the uAPI.
+              $ref: '#/$defs/uint'
+            attribute-set:
+              description: |
+                Attribute space from which attributes directly in the requests and replies
+                to this command are defined.
+              type: string
+            flags: &cmd_flags
+              description: Command flags.
+              type: array
+              items:
+                enum: [ admin-perm ]
+            dont-validate:
+              description: Kernel attribute validation flags.
+              type: array
+              items:
+                enum: [ strict, dump, dump-strict ]
+            config-cond:
+              description: |
+                Name of the kernel config option gating the presence of
+                the operation, without the 'CONFIG_' prefix.
+              type: string
+            do: &subop-type
+              description: Main command handler.
+              type: object
+              additionalProperties: False
+              properties:
+                request: &subop-attr-list
+                  description: Definition of the request message for a given command.
+                  type: object
+                  additionalProperties: False
+                  properties:
+                    attributes:
+                      description: |
+                        Names of attributes from the attribute-set (not full attribute
+                        definitions, just names).
+                      type: array
+                      items:
+                        type: string
+                reply: *subop-attr-list
+                pre:
+                  description: Hook for a function to run before the main callback (pre_doit or start).
+                  type: string
+                post:
+                  description: Hook for a function to run after the main callback (post_doit or done).
+                  type: string
+            dump: *subop-type
+            notify:
+              description: Name of the command sharing the reply type with this notification.
+              type: string
+            event:
+              type: object
+              additionalProperties: False
+              properties:
+                attributes:
+                  description: Explicit list of the attributes for the notification.
+                  type: array
+                  items:
+                    type: string
+            mcgrp:
+              description: Name of the multicast group generating given notification.
+              type: string
+  mcast-groups:
+    description: List of multicast groups.
+    type: object
+    required: [ list ]
+    additionalProperties: False
+    properties:
+      list:
+        description: List of groups.
+        type: array
+        items:
+          type: object
+          required: [ name ]
+          additionalProperties: False
+          properties:
+            name:
+              description: |
+                The name for the group, used to form the define and the value of the define.
+              type: string
+            flags: *cmd_flags
diff --git a/tools/net/ynl/cli.py b/tools/net/ynl/cli.py
new file mode 100644
index 000000000000..0f8239979670
--- /dev/null
+++ b/tools/net/ynl/cli.py
@@ -0,0 +1,77 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+
+import argparse
+import json
+import pprint
+import time
+
+from lib import YnlFamily, Netlink
+
+
+class YnlEncoder(json.JSONEncoder):
+    def default(self, obj):
+        if isinstance(obj, bytes):
+            return bytes.hex(obj)
+        if isinstance(obj, set):
+            return list(obj)
+        return json.JSONEncoder.default(self, obj)
+
+
+def main():
+    parser = argparse.ArgumentParser(description='YNL CLI sample')
+    parser.add_argument('--spec', dest='spec', type=str, required=True)
+    parser.add_argument('--schema', dest='schema', type=str)
+    parser.add_argument('--no-schema', action='store_true')
+    parser.add_argument('--json', dest='json_text', type=str)
+    parser.add_argument('--do', dest='do', type=str)
+    parser.add_argument('--dump', dest='dump', type=str)
+    parser.add_argument('--sleep', dest='sleep', type=int)
+    parser.add_argument('--subscribe', dest='ntf', type=str)
+    parser.add_argument('--replace', dest='flags', action='append_const',
+                        const=Netlink.NLM_F_REPLACE)
+    parser.add_argument('--excl', dest='flags', action='append_const',
+                        const=Netlink.NLM_F_EXCL)
+    parser.add_argument('--create', dest='flags', action='append_const',
+                        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)
+    parser.add_argument('--output-json', action='store_true')
+    args = parser.parse_args()
+
+    def output(msg):
+        if args.output_json:
+            print(json.dumps(msg, cls=YnlEncoder))
+        else:
+            pprint.PrettyPrinter().pprint(msg)
+
+    if args.no_schema:
+        args.schema = ''
+
+    attrs = {}
+    if args.json_text:
+        attrs = json.loads(args.json_text)
+
+    ynl = YnlFamily(args.spec, args.schema, args.process_unknown)
+
+    if args.ntf:
+        ynl.ntf_subscribe(args.ntf)
+
+    if args.sleep:
+        time.sleep(args.sleep)
+
+    if args.do:
+        reply = ynl.do(args.do, attrs, args.flags)
+        output(reply)
+    if args.dump:
+        reply = ynl.dump(args.dump, attrs)
+        output(reply)
+
+    if args.ntf:
+        ynl.check_ntf()
+        output(ynl.async_msg_queue)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/tools/net/ynl/lib/__init__.py b/tools/net/ynl/lib/__init__.py
new file mode 100644
index 000000000000..f7eaa07783e7
--- /dev/null
+++ b/tools/net/ynl/lib/__init__.py
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+
+from .nlspec import SpecAttr, SpecAttrSet, SpecEnumEntry, SpecEnumSet, \
+    SpecFamily, SpecOperation
+from .ynl import YnlFamily, Netlink
+
+__all__ = ["SpecAttr", "SpecAttrSet", "SpecEnumEntry", "SpecEnumSet",
+           "SpecFamily", "SpecOperation", "YnlFamily", "Netlink"]
diff --git a/tools/net/ynl/lib/nlspec.py b/tools/net/ynl/lib/nlspec.py
new file mode 100644
index 000000000000..fbce52395b3b
--- /dev/null
+++ b/tools/net/ynl/lib/nlspec.py
@@ -0,0 +1,607 @@
+# SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+
+import collections
+import importlib
+import os
+import yaml
+
+
+# To be loaded dynamically as needed
+jsonschema = None
+
+
+class SpecElement:
+    """Netlink spec element.
+
+    Abstract element of the Netlink spec. Implements the dictionary interface
+    for access to the raw spec. Supports iterative resolution of dependencies
+    across elements and class inheritance levels. The elements of the spec
+    may refer to each other, and although loops should be very rare, having
+    to maintain correct ordering of instantiation is painful, so the resolve()
+    method should be used to perform parts of init which require access to
+    other parts of the spec.
+
+    Attributes:
+        yaml        raw spec as loaded from the spec file
+        family      back reference to the full family
+
+        name        name of the entity as listed in the spec (optional)
+        ident_name  name which can be safely used as identifier in code (optional)
+    """
+    def __init__(self, family, yaml):
+        self.yaml = yaml
+        self.family = family
+
+        if 'name' in self.yaml:
+            self.name = self.yaml['name']
+            self.ident_name = self.name.replace('-', '_')
+
+        self._super_resolved = False
+        family.add_unresolved(self)
+
+    def __getitem__(self, key):
+        return self.yaml[key]
+
+    def __contains__(self, key):
+        return key in self.yaml
+
+    def get(self, key, default=None):
+        return self.yaml.get(key, default)
+
+    def resolve_up(self, up):
+        if not self._super_resolved:
+            up.resolve()
+            self._super_resolved = True
+
+    def resolve(self):
+        pass
+
+
+class SpecEnumEntry(SpecElement):
+    """ Entry within an enum declared in the Netlink spec.
+
+    Attributes:
+        doc         documentation string
+        enum_set    back reference to the enum
+        value       numerical value of this enum (use accessors in most situations!)
+
+    Methods:
+        raw_value   raw value, i.e. the id in the enum, unlike user value which is a mask for flags
+        user_value   user value, same as raw value for enums, for flags it's the mask
+    """
+    def __init__(self, enum_set, yaml, prev, value_start):
+        if isinstance(yaml, str):
+            yaml = {'name': yaml}
+        super().__init__(enum_set.family, yaml)
+
+        self.doc = yaml.get('doc', '')
+        self.enum_set = enum_set
+
+        if 'value' in yaml:
+            self.value = yaml['value']
+        elif prev:
+            self.value = prev.value + 1
+        else:
+            self.value = value_start
+
+    def has_doc(self):
+        return bool(self.doc)
+
+    def raw_value(self):
+        return self.value
+
+    def user_value(self, as_flags=None):
+        if self.enum_set['type'] == 'flags' or as_flags:
+            return 1 << self.value
+        else:
+            return self.value
+
+
+class SpecEnumSet(SpecElement):
+    """ Enum type
+
+    Represents an enumeration (list of numerical constants)
+    as declared in the "definitions" section of the spec.
+
+    Attributes:
+        type            enum or flags
+        entries         entries by name
+        entries_by_val  entries by value
+    Methods:
+        get_mask      for flags compute the mask of all defined values
+    """
+    def __init__(self, family, yaml):
+        super().__init__(family, yaml)
+
+        self.type = yaml['type']
+
+        prev_entry = None
+        value_start = self.yaml.get('value-start', 0)
+        self.entries = dict()
+        self.entries_by_val = dict()
+        for entry in self.yaml['entries']:
+            e = self.new_entry(entry, prev_entry, value_start)
+            self.entries[e.name] = e
+            self.entries_by_val[e.raw_value()] = e
+            prev_entry = e
+
+    def new_entry(self, entry, prev_entry, value_start):
+        return SpecEnumEntry(self, entry, prev_entry, value_start)
+
+    def has_doc(self):
+        if 'doc' in self.yaml:
+            return True
+        for entry in self.entries.values():
+            if entry.has_doc():
+                return True
+        return False
+
+    def get_mask(self, as_flags=None):
+        mask = 0
+        for e in self.entries.values():
+            mask += e.user_value(as_flags)
+        return mask
+
+
+class SpecAttr(SpecElement):
+    """ Single Netlink attribute type
+
+    Represents a single attribute type within an attr space.
+
+    Attributes:
+        type          string, attribute type
+        value         numerical ID when serialized
+        attr_set      Attribute Set containing this attr
+        is_multi      bool, attr may repeat multiple times
+        struct_name   string, name of struct definition
+        sub_type      string, name of sub type
+        len           integer, optional byte length of binary types
+        display_hint  string, hint to help choose format specifier
+                      when displaying the value
+        sub_message   string, name of sub message type
+        selector      string, name of attribute used to select
+                      sub-message type
+
+        is_auto_scalar bool, attr is a variable-size scalar
+    """
+    def __init__(self, family, attr_set, yaml, value):
+        super().__init__(family, yaml)
+
+        self.type = yaml['type']
+        self.value = value
+        self.attr_set = attr_set
+        self.is_multi = yaml.get('multi-attr', False)
+        self.struct_name = yaml.get('struct')
+        self.sub_type = yaml.get('sub-type')
+        self.byte_order = yaml.get('byte-order')
+        self.len = yaml.get('len')
+        self.display_hint = yaml.get('display-hint')
+        self.sub_message = yaml.get('sub-message')
+        self.selector = yaml.get('selector')
+
+        self.is_auto_scalar = self.type == "sint" or self.type == "uint"
+
+
+class SpecAttrSet(SpecElement):
+    """ Netlink Attribute Set class.
+
+    Represents a ID space of attributes within Netlink.
+
+    Note that unlike other elements, which expose contents of the raw spec
+    via the dictionary interface Attribute Set exposes attributes by name.
+
+    Attributes:
+        attrs      ordered dict of all attributes (indexed by name)
+        attrs_by_val  ordered dict of all attributes (indexed by value)
+        subset_of  parent set if this is a subset, otherwise None
+    """
+    def __init__(self, family, yaml):
+        super().__init__(family, yaml)
+
+        self.subset_of = self.yaml.get('subset-of', None)
+
+        self.attrs = collections.OrderedDict()
+        self.attrs_by_val = collections.OrderedDict()
+
+        if self.subset_of is None:
+            val = 1
+            for elem in self.yaml['attributes']:
+                if 'value' in elem:
+                    val = elem['value']
+
+                attr = self.new_attr(elem, val)
+                self.attrs[attr.name] = attr
+                self.attrs_by_val[attr.value] = attr
+                val += 1
+        else:
+            real_set = family.attr_sets[self.subset_of]
+            for elem in self.yaml['attributes']:
+                attr = real_set[elem['name']]
+                self.attrs[attr.name] = attr
+                self.attrs_by_val[attr.value] = attr
+
+    def new_attr(self, elem, value):
+        return SpecAttr(self.family, self, elem, value)
+
+    def __getitem__(self, key):
+        return self.attrs[key]
+
+    def __contains__(self, key):
+        return key in self.attrs
+
+    def __iter__(self):
+        yield from self.attrs
+
+    def items(self):
+        return self.attrs.items()
+
+
+class SpecStructMember(SpecElement):
+    """Struct member attribute
+
+    Represents a single struct member attribute.
+
+    Attributes:
+        type        string, type of the member attribute
+        byte_order  string or None for native byte order
+        enum        string, name of the enum definition
+        len         integer, optional byte length of binary types
+        display_hint  string, hint to help choose format specifier
+                      when displaying the value
+        struct      string, name of nested struct type
+    """
+    def __init__(self, family, yaml):
+        super().__init__(family, yaml)
+        self.type = yaml['type']
+        self.byte_order = yaml.get('byte-order')
+        self.enum = yaml.get('enum')
+        self.len = yaml.get('len')
+        self.display_hint = yaml.get('display-hint')
+        self.struct = yaml.get('struct')
+
+
+class SpecStruct(SpecElement):
+    """Netlink struct type
+
+    Represents a C struct definition.
+
+    Attributes:
+        members   ordered list of struct members
+    """
+    def __init__(self, family, yaml):
+        super().__init__(family, yaml)
+
+        self.members = []
+        for member in yaml.get('members', []):
+            self.members.append(self.new_member(family, member))
+
+    def new_member(self, family, elem):
+        return SpecStructMember(family, elem)
+
+    def __iter__(self):
+        yield from self.members
+
+    def items(self):
+        return self.members.items()
+
+
+class SpecSubMessage(SpecElement):
+    """ Netlink sub-message definition
+
+    Represents a set of sub-message formats for polymorphic nlattrs
+    that contain type-specific sub messages.
+
+    Attributes:
+        name     string, name of sub-message definition
+        formats  dict of sub-message formats indexed by match value
+    """
+    def __init__(self, family, yaml):
+        super().__init__(family, yaml)
+
+        self.formats = collections.OrderedDict()
+        for elem in self.yaml['formats']:
+            format = self.new_format(family, elem)
+            self.formats[format.value] = format
+
+    def new_format(self, family, format):
+        return SpecSubMessageFormat(family, format)
+
+
+class SpecSubMessageFormat(SpecElement):
+    """ Netlink sub-message format definition
+
+    Represents a single format for a sub-message.
+
+    Attributes:
+        value         attribute value to match against type selector
+        fixed_header  string, name of fixed header, or None
+        attr_set      string, name of attribute set, or None
+    """
+    def __init__(self, family, yaml):
+        super().__init__(family, yaml)
+
+        self.value = yaml.get('value')
+        self.fixed_header = yaml.get('fixed-header')
+        self.attr_set = yaml.get('attribute-set')
+
+
+class SpecOperation(SpecElement):
+    """Netlink Operation
+
+    Information about a single Netlink operation.
+
+    Attributes:
+        value           numerical ID when serialized, None if req/rsp values differ
+
+        req_value       numerical ID when serialized, user -> kernel
+        rsp_value       numerical ID when serialized, user <- kernel
+        is_call         bool, whether the operation is a call
+        is_async        bool, whether the operation is a notification
+        is_resv         bool, whether the operation does not exist (it's just a reserved ID)
+        attr_set        attribute set name
+        fixed_header    string, optional name of fixed header struct
+
+        yaml            raw spec as loaded from the spec file
+    """
+    def __init__(self, family, yaml, req_value, rsp_value):
+        super().__init__(family, yaml)
+
+        self.value = req_value if req_value == rsp_value else None
+        self.req_value = req_value
+        self.rsp_value = rsp_value
+
+        self.is_call = 'do' in yaml or 'dump' in yaml
+        self.is_async = 'notify' in yaml or 'event' in yaml
+        self.is_resv = not self.is_async and not self.is_call
+        self.fixed_header = self.yaml.get('fixed-header', family.fixed_header)
+
+        # Added by resolve:
+        self.attr_set = None
+        delattr(self, "attr_set")
+
+    def resolve(self):
+        self.resolve_up(super())
+
+        if 'attribute-set' in self.yaml:
+            attr_set_name = self.yaml['attribute-set']
+        elif 'notify' in self.yaml:
+            msg = self.family.msgs[self.yaml['notify']]
+            attr_set_name = msg['attribute-set']
+        elif self.is_resv:
+            attr_set_name = ''
+        else:
+            raise Exception(f"Can't resolve attribute set for op '{self.name}'")
+        if attr_set_name:
+            self.attr_set = self.family.attr_sets[attr_set_name]
+
+
+class SpecMcastGroup(SpecElement):
+    """Netlink Multicast Group
+
+    Information about a multicast group.
+
+    Value is only used for classic netlink families that use the
+    netlink-raw schema. Genetlink families use dynamic ID allocation
+    where the ids of multicast groups get resolved at runtime. Value
+    will be None for genetlink families.
+
+    Attributes:
+        name      name of the mulitcast group
+        value     integer id of this multicast group for netlink-raw or None
+        yaml      raw spec as loaded from the spec file
+    """
+    def __init__(self, family, yaml):
+        super().__init__(family, yaml)
+        self.value = self.yaml.get('value')
+
+
+class SpecFamily(SpecElement):
+    """ Netlink Family Spec class.
+
+    Netlink family information loaded from a spec (e.g. in YAML).
+    Takes care of unfolding implicit information which can be skipped
+    in the spec itself for brevity.
+
+    The class can be used like a dictionary to access the raw spec
+    elements but that's usually a bad idea.
+
+    Attributes:
+        proto     protocol type (e.g. genetlink)
+        msg_id_model   enum-model for operations (unified, directional etc.)
+        license   spec license (loaded from an SPDX tag on the spec)
+
+        attr_sets  dict of attribute sets
+        msgs       dict of all messages (index by name)
+        sub_msgs   dict of all sub messages (index by name)
+        ops        dict of all valid requests / responses
+        ntfs       dict of all async events
+        consts     dict of all constants/enums
+        fixed_header  string, optional name of family default fixed header struct
+        mcast_groups  dict of all multicast groups (index by name)
+    """
+    def __init__(self, spec_path, schema_path=None, exclude_ops=None):
+        with open(spec_path, "r") as stream:
+            prefix = '# SPDX-License-Identifier: '
+            first = stream.readline().strip()
+            if not first.startswith(prefix):
+                raise Exception('SPDX license tag required in the spec')
+            self.license = first[len(prefix):]
+
+            stream.seek(0)
+            spec = yaml.safe_load(stream)
+
+        self._resolution_list = []
+
+        super().__init__(self, spec)
+
+        self._exclude_ops = exclude_ops if exclude_ops else []
+
+        self.proto = self.yaml.get('protocol', 'genetlink')
+        self.msg_id_model = self.yaml['operations'].get('enum-model', 'unified')
+
+        if schema_path is None:
+            schema_path = os.path.dirname(os.path.dirname(spec_path)) + f'/{self.proto}.yaml'
+        if schema_path:
+            global jsonschema
+
+            with open(schema_path, "r") as stream:
+                schema = yaml.safe_load(stream)
+
+            if jsonschema is None:
+                jsonschema = importlib.import_module("jsonschema")
+
+            jsonschema.validate(self.yaml, schema)
+
+        self.attr_sets = collections.OrderedDict()
+        self.sub_msgs = collections.OrderedDict()
+        self.msgs = collections.OrderedDict()
+        self.req_by_value = collections.OrderedDict()
+        self.rsp_by_value = collections.OrderedDict()
+        self.ops = collections.OrderedDict()
+        self.ntfs = collections.OrderedDict()
+        self.consts = collections.OrderedDict()
+        self.mcast_groups = collections.OrderedDict()
+
+        last_exception = None
+        while len(self._resolution_list) > 0:
+            resolved = []
+            unresolved = self._resolution_list
+            self._resolution_list = []
+
+            for elem in unresolved:
+                try:
+                    elem.resolve()
+                except (KeyError, AttributeError) as e:
+                    self._resolution_list.append(elem)
+                    last_exception = e
+                    continue
+
+                resolved.append(elem)
+
+            if len(resolved) == 0:
+                raise last_exception
+
+    def new_enum(self, elem):
+        return SpecEnumSet(self, elem)
+
+    def new_attr_set(self, elem):
+        return SpecAttrSet(self, elem)
+
+    def new_struct(self, elem):
+        return SpecStruct(self, elem)
+
+    def new_sub_message(self, elem):
+        return SpecSubMessage(self, elem);
+
+    def new_operation(self, elem, req_val, rsp_val):
+        return SpecOperation(self, elem, req_val, rsp_val)
+
+    def new_mcast_group(self, elem):
+        return SpecMcastGroup(self, elem)
+
+    def add_unresolved(self, elem):
+        self._resolution_list.append(elem)
+
+    def _dictify_ops_unified(self):
+        self.fixed_header = self.yaml['operations'].get('fixed-header')
+        val = 1
+        for elem in self.yaml['operations']['list']:
+            if 'value' in elem:
+                val = elem['value']
+
+            op = self.new_operation(elem, val, val)
+            val += 1
+
+            self.msgs[op.name] = op
+
+    def _dictify_ops_directional(self):
+        self.fixed_header = self.yaml['operations'].get('fixed-header')
+        req_val = rsp_val = 1
+        for elem in self.yaml['operations']['list']:
+            if 'notify' in elem or 'event' in elem:
+                if 'value' in elem:
+                    rsp_val = elem['value']
+                req_val_next = req_val
+                rsp_val_next = rsp_val + 1
+                req_val = None
+            elif 'do' in elem or 'dump' in elem:
+                mode = elem['do'] if 'do' in elem else elem['dump']
+
+                v = mode.get('request', {}).get('value', None)
+                if v:
+                    req_val = v
+                v = mode.get('reply', {}).get('value', None)
+                if v:
+                    rsp_val = v
+
+                rsp_inc = 1 if 'reply' in mode else 0
+                req_val_next = req_val + 1
+                rsp_val_next = rsp_val + rsp_inc
+            else:
+                raise Exception("Can't parse directional ops")
+
+            if req_val == req_val_next:
+                req_val = None
+            if rsp_val == rsp_val_next:
+                rsp_val = None
+
+            skip = False
+            for exclude in self._exclude_ops:
+                skip |= bool(exclude.match(elem['name']))
+            if not skip:
+                op = self.new_operation(elem, req_val, rsp_val)
+
+            req_val = req_val_next
+            rsp_val = rsp_val_next
+
+            self.msgs[op.name] = op
+
+    def find_operation(self, name):
+      """
+      For a given operation name, find and return operation spec.
+      """
+      for op in self.yaml['operations']['list']:
+        if name == op['name']:
+          return op
+      return None
+
+    def resolve(self):
+        self.resolve_up(super())
+
+        definitions = self.yaml.get('definitions', [])
+        for elem in definitions:
+            if elem['type'] == 'enum' or elem['type'] == 'flags':
+                self.consts[elem['name']] = self.new_enum(elem)
+            elif elem['type'] == 'struct':
+                self.consts[elem['name']] = self.new_struct(elem)
+            else:
+                self.consts[elem['name']] = elem
+
+        for elem in self.yaml['attribute-sets']:
+            attr_set = self.new_attr_set(elem)
+            self.attr_sets[elem['name']] = attr_set
+
+        for elem in self.yaml.get('sub-messages', []):
+            sub_message = self.new_sub_message(elem)
+            self.sub_msgs[sub_message.name] = sub_message
+
+        if self.msg_id_model == 'unified':
+            self._dictify_ops_unified()
+        elif self.msg_id_model == 'directional':
+            self._dictify_ops_directional()
+
+        for op in self.msgs.values():
+            if op.req_value is not None:
+                self.req_by_value[op.req_value] = op
+            if op.rsp_value is not None:
+                self.rsp_by_value[op.rsp_value] = op
+            if not op.is_async and 'attribute-set' in op:
+                self.ops[op.name] = op
+            elif op.is_async:
+                self.ntfs[op.name] = op
+
+        mcgs = self.yaml.get('mcast-groups')
+        if mcgs:
+            for elem in mcgs['list']:
+                mcg = self.new_mcast_group(elem)
+                self.mcast_groups[elem['name']] = mcg
diff --git a/tools/net/ynl/lib/ynl.py b/tools/net/ynl/lib/ynl.py
new file mode 100644
index 000000000000..03c7ca6aaae9
--- /dev/null
+++ b/tools/net/ynl/lib/ynl.py
@@ -0,0 +1,873 @@
+# SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+
+from collections import namedtuple
+import functools
+import os
+import random
+import socket
+import struct
+from struct import Struct
+import yaml
+import ipaddress
+import uuid
+
+from .nlspec import SpecFamily
+
+#
+# Generic Netlink code which should really be in some library, but I can't quickly find one.
+#
+
+
+class Netlink:
+    # Netlink socket
+    SOL_NETLINK = 270
+
+    NETLINK_ADD_MEMBERSHIP = 1
+    NETLINK_CAP_ACK = 10
+    NETLINK_EXT_ACK = 11
+    NETLINK_GET_STRICT_CHK = 12
+
+    # Netlink message
+    NLMSG_ERROR = 2
+    NLMSG_DONE = 3
+
+    NLM_F_REQUEST = 1
+    NLM_F_ACK = 4
+    NLM_F_ROOT = 0x100
+    NLM_F_MATCH = 0x200
+
+    NLM_F_REPLACE = 0x100
+    NLM_F_EXCL = 0x200
+    NLM_F_CREATE = 0x400
+    NLM_F_APPEND = 0x800
+
+    NLM_F_CAPPED = 0x100
+    NLM_F_ACK_TLVS = 0x200
+
+    NLM_F_DUMP = NLM_F_ROOT | NLM_F_MATCH
+
+    NLA_F_NESTED = 0x8000
+    NLA_F_NET_BYTEORDER = 0x4000
+
+    NLA_TYPE_MASK = NLA_F_NESTED | NLA_F_NET_BYTEORDER
+
+    # Genetlink defines
+    NETLINK_GENERIC = 16
+
+    GENL_ID_CTRL = 0x10
+
+    # nlctrl
+    CTRL_CMD_GETFAMILY = 3
+
+    CTRL_ATTR_FAMILY_ID = 1
+    CTRL_ATTR_FAMILY_NAME = 2
+    CTRL_ATTR_MAXATTR = 5
+    CTRL_ATTR_MCAST_GROUPS = 7
+
+    CTRL_ATTR_MCAST_GRP_NAME = 1
+    CTRL_ATTR_MCAST_GRP_ID = 2
+
+    # Extack types
+    NLMSGERR_ATTR_MSG = 1
+    NLMSGERR_ATTR_OFFS = 2
+    NLMSGERR_ATTR_COOKIE = 3
+    NLMSGERR_ATTR_POLICY = 4
+    NLMSGERR_ATTR_MISS_TYPE = 5
+    NLMSGERR_ATTR_MISS_NEST = 6
+
+
+class NlError(Exception):
+  def __init__(self, nl_msg):
+    self.nl_msg = nl_msg
+
+  def __str__(self):
+    return f"Netlink error: {os.strerror(-self.nl_msg.error)}\n{self.nl_msg}"
+
+
+class NlAttr:
+    ScalarFormat = namedtuple('ScalarFormat', ['native', 'big', 'little'])
+    type_formats = {
+        'u8' : ScalarFormat(Struct('B'), Struct("B"),  Struct("B")),
+        's8' : ScalarFormat(Struct('b'), Struct("b"),  Struct("b")),
+        'u16': ScalarFormat(Struct('H'), Struct(">H"), Struct("<H")),
+        's16': ScalarFormat(Struct('h'), Struct(">h"), Struct("<h")),
+        'u32': ScalarFormat(Struct('I'), Struct(">I"), Struct("<I")),
+        's32': ScalarFormat(Struct('i'), Struct(">i"), Struct("<i")),
+        'u64': ScalarFormat(Struct('Q'), Struct(">Q"), Struct("<Q")),
+        's64': ScalarFormat(Struct('q'), Struct(">q"), Struct("<q"))
+    }
+
+    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]
+
+    @classmethod
+    def get_format(cls, attr_type, byte_order=None):
+        format = cls.type_formats[attr_type]
+        if byte_order:
+            return format.big if byte_order == "big-endian" \
+                else format.little
+        return format.native
+
+    def as_scalar(self, attr_type, byte_order=None):
+        format = self.get_format(attr_type, byte_order)
+        return format.unpack(self.raw)[0]
+
+    def as_auto_scalar(self, attr_type, byte_order=None):
+        if len(self.raw) != 4 and len(self.raw) != 8:
+            raise Exception(f"Auto-scalar len payload be 4 or 8 bytes, got {len(self.raw)}")
+        real_type = attr_type[0] + str(len(self.raw) * 8)
+        format = self.get_format(real_type, byte_order)
+        return format.unpack(self.raw)[0]
+
+    def as_strz(self):
+        return self.raw.decode('ascii')[:-1]
+
+    def as_bin(self):
+        return self.raw
+
+    def as_c_array(self, type):
+        format = self.get_format(type)
+        return [ x[0] for x in format.iter_unpack(self.raw) ]
+
+    def __repr__(self):
+        return f"[type:{self.type} len:{self._len}] {self.raw}"
+
+
+class NlAttrs:
+    def __init__(self, msg, offset=0):
+        self.attrs = []
+
+        while offset < len(msg):
+            attr = NlAttr(msg, offset)
+            offset += attr.full_len
+            self.attrs.append(attr)
+
+    def __iter__(self):
+        yield from self.attrs
+
+    def __repr__(self):
+        msg = ''
+        for a in self.attrs:
+            if msg:
+                msg += '\n'
+            msg += repr(a)
+        return msg
+
+
+class NlMsg:
+    def __init__(self, msg, offset, attr_space=None):
+        self.hdr = msg[offset : offset + 16]
+
+        self.nl_len, self.nl_type, self.nl_flags, self.nl_seq, self.nl_portid = \
+            struct.unpack("IHHII", self.hdr)
+
+        self.raw = msg[offset + 16 : offset + self.nl_len]
+
+        self.error = 0
+        self.done = 0
+
+        extack_off = None
+        if self.nl_type == Netlink.NLMSG_ERROR:
+            self.error = struct.unpack("i", self.raw[0:4])[0]
+            self.done = 1
+            extack_off = 20
+        elif self.nl_type == Netlink.NLMSG_DONE:
+            self.done = 1
+            extack_off = 4
+
+        self.extack = None
+        if self.nl_flags & Netlink.NLM_F_ACK_TLVS and extack_off:
+            self.extack = dict()
+            extack_attrs = NlAttrs(self.raw[extack_off:])
+            for extack in extack_attrs:
+                if extack.type == Netlink.NLMSGERR_ATTR_MSG:
+                    self.extack['msg'] = extack.as_strz()
+                elif extack.type == Netlink.NLMSGERR_ATTR_MISS_TYPE:
+                    self.extack['miss-type'] = extack.as_scalar('u32')
+                elif extack.type == Netlink.NLMSGERR_ATTR_MISS_NEST:
+                    self.extack['miss-nest'] = extack.as_scalar('u32')
+                elif extack.type == Netlink.NLMSGERR_ATTR_OFFS:
+                    self.extack['bad-attr-offs'] = extack.as_scalar('u32')
+                else:
+                    if 'unknown' not in self.extack:
+                        self.extack['unknown'] = []
+                    self.extack['unknown'].append(extack)
+
+            if attr_space:
+                # We don't have the ability to parse nests yet, so only do global
+                if 'miss-type' in self.extack and 'miss-nest' not in self.extack:
+                    miss_type = self.extack['miss-type']
+                    if miss_type in attr_space.attrs_by_val:
+                        spec = attr_space.attrs_by_val[miss_type]
+                        desc = spec['name']
+                        if 'doc' in spec:
+                            desc += f" ({spec['doc']})"
+                        self.extack['miss-type'] = desc
+
+    def cmd(self):
+        return self.nl_type
+
+    def __repr__(self):
+        msg = f"nl_len = {self.nl_len} ({len(self.raw)}) nl_flags = 0x{self.nl_flags:x} nl_type = {self.nl_type}\n"
+        if self.error:
+            msg += '\terror: ' + str(self.error)
+        if self.extack:
+            msg += '\textack: ' + repr(self.extack)
+        return msg
+
+
+class NlMsgs:
+    def __init__(self, data, attr_space=None):
+        self.msgs = []
+
+        offset = 0
+        while offset < len(data):
+            msg = NlMsg(data, offset, attr_space=attr_space)
+            offset += msg.nl_len
+            self.msgs.append(msg)
+
+    def __iter__(self):
+        yield from self.msgs
+
+
+genl_family_name_to_id = None
+
+
+def _genl_msg(nl_type, nl_flags, genl_cmd, genl_version, seq=None):
+    # we prepend length in _genl_msg_finalize()
+    if seq is None:
+        seq = random.randint(1, 1024)
+    nlmsg = struct.pack("HHII", nl_type, nl_flags, seq, 0)
+    genlmsg = struct.pack("BBH", genl_cmd, genl_version, 0)
+    return nlmsg + genlmsg
+
+
+def _genl_msg_finalize(msg):
+    return struct.pack("I", len(msg) + 4) + msg
+
+
+def _genl_load_families():
+    with socket.socket(socket.AF_NETLINK, socket.SOCK_RAW, Netlink.NETLINK_GENERIC) as sock:
+        sock.setsockopt(Netlink.SOL_NETLINK, Netlink.NETLINK_CAP_ACK, 1)
+
+        msg = _genl_msg(Netlink.GENL_ID_CTRL,
+                        Netlink.NLM_F_REQUEST | Netlink.NLM_F_ACK | Netlink.NLM_F_DUMP,
+                        Netlink.CTRL_CMD_GETFAMILY, 1)
+        msg = _genl_msg_finalize(msg)
+
+        sock.send(msg, 0)
+
+        global genl_family_name_to_id
+        genl_family_name_to_id = dict()
+
+        while True:
+            reply = sock.recv(128 * 1024)
+            nms = NlMsgs(reply)
+            for nl_msg in nms:
+                if nl_msg.error:
+                    print("Netlink error:", nl_msg.error)
+                    return
+                if nl_msg.done:
+                    return
+
+                gm = GenlMsg(nl_msg)
+                fam = dict()
+                for attr in NlAttrs(gm.raw):
+                    if attr.type == Netlink.CTRL_ATTR_FAMILY_ID:
+                        fam['id'] = attr.as_scalar('u16')
+                    elif attr.type == Netlink.CTRL_ATTR_FAMILY_NAME:
+                        fam['name'] = attr.as_strz()
+                    elif attr.type == Netlink.CTRL_ATTR_MAXATTR:
+                        fam['maxattr'] = attr.as_scalar('u32')
+                    elif attr.type == Netlink.CTRL_ATTR_MCAST_GROUPS:
+                        fam['mcast'] = dict()
+                        for entry in NlAttrs(attr.raw):
+                            mcast_name = None
+                            mcast_id = None
+                            for entry_attr in NlAttrs(entry.raw):
+                                if entry_attr.type == Netlink.CTRL_ATTR_MCAST_GRP_NAME:
+                                    mcast_name = entry_attr.as_strz()
+                                elif entry_attr.type == Netlink.CTRL_ATTR_MCAST_GRP_ID:
+                                    mcast_id = entry_attr.as_scalar('u32')
+                            if mcast_name and mcast_id is not None:
+                                fam['mcast'][mcast_name] = mcast_id
+                if 'name' in fam and 'id' in fam:
+                    genl_family_name_to_id[fam['name']] = fam
+
+
+class GenlMsg:
+    def __init__(self, nl_msg):
+        self.nl = nl_msg
+        self.genl_cmd, self.genl_version, _ = struct.unpack_from("BBH", nl_msg.raw, 0)
+        self.raw = nl_msg.raw[4:]
+
+    def cmd(self):
+        return self.genl_cmd
+
+    def __repr__(self):
+        msg = repr(self.nl)
+        msg += f"\tgenl_cmd = {self.genl_cmd} genl_ver = {self.genl_version}\n"
+        for a in self.raw_attrs:
+            msg += '\t\t' + repr(a) + '\n'
+        return msg
+
+
+class NetlinkProtocol:
+    def __init__(self, family_name, proto_num):
+        self.family_name = family_name
+        self.proto_num = proto_num
+
+    def _message(self, nl_type, nl_flags, seq=None):
+        if seq is None:
+            seq = random.randint(1, 1024)
+        nlmsg = struct.pack("HHII", nl_type, nl_flags, seq, 0)
+        return nlmsg
+
+    def message(self, flags, command, version, seq=None):
+        return self._message(command, flags, seq)
+
+    def _decode(self, nl_msg):
+        return nl_msg
+
+    def decode(self, ynl, nl_msg):
+        msg = self._decode(nl_msg)
+        fixed_header_size = 0
+        if ynl:
+            op = ynl.rsp_by_value[msg.cmd()]
+            fixed_header_size = ynl._struct_size(op.fixed_header)
+        msg.raw_attrs = NlAttrs(msg.raw, fixed_header_size)
+        return msg
+
+    def get_mcast_id(self, mcast_name, mcast_groups):
+        if mcast_name not in mcast_groups:
+            raise Exception(f'Multicast group "{mcast_name}" not present in the spec')
+        return mcast_groups[mcast_name].value
+
+
+class GenlProtocol(NetlinkProtocol):
+    def __init__(self, family_name):
+        super().__init__(family_name, Netlink.NETLINK_GENERIC)
+
+        global genl_family_name_to_id
+        if genl_family_name_to_id is None:
+            _genl_load_families()
+
+        self.genl_family = genl_family_name_to_id[family_name]
+        self.family_id = genl_family_name_to_id[family_name]['id']
+
+    def message(self, flags, command, version, seq=None):
+        nlmsg = self._message(self.family_id, flags, seq)
+        genlmsg = struct.pack("BBH", command, version, 0)
+        return nlmsg + genlmsg
+
+    def _decode(self, nl_msg):
+        return GenlMsg(nl_msg)
+
+    def get_mcast_id(self, mcast_name, mcast_groups):
+        if mcast_name not in self.genl_family['mcast']:
+            raise Exception(f'Multicast group "{mcast_name}" not present in the family')
+        return self.genl_family['mcast'][mcast_name]
+
+
+
+class SpaceAttrs:
+    SpecValuesPair = namedtuple('SpecValuesPair', ['spec', 'values'])
+
+    def __init__(self, attr_space, attrs, outer = None):
+        outer_scopes = outer.scopes if outer else []
+        inner_scope = self.SpecValuesPair(attr_space, attrs)
+        self.scopes = [inner_scope] + outer_scopes
+
+    def lookup(self, name):
+        for scope in self.scopes:
+            if name in scope.spec:
+                if name in scope.values:
+                    return scope.values[name]
+                spec_name = scope.spec.yaml['name']
+                raise Exception(
+                    f"No value for '{name}' in attribute space '{spec_name}'")
+        raise Exception(f"Attribute '{name}' not defined in any attribute-set")
+
+
+#
+# YNL implementation details.
+#
+
+
+class YnlFamily(SpecFamily):
+    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":
+                self.nlproto = NetlinkProtocol(self.yaml['name'],
+                                               self.yaml['protonum'])
+            else:
+                self.nlproto = GenlProtocol(self.yaml['name'])
+        except KeyError:
+            raise Exception(f"Family '{self.yaml['name']}' not supported by the kernel")
+
+        self.sock = socket.socket(socket.AF_NETLINK, socket.SOCK_RAW, self.nlproto.proto_num)
+        self.sock.setsockopt(Netlink.SOL_NETLINK, Netlink.NETLINK_CAP_ACK, 1)
+        self.sock.setsockopt(Netlink.SOL_NETLINK, Netlink.NETLINK_EXT_ACK, 1)
+        self.sock.setsockopt(Netlink.SOL_NETLINK, Netlink.NETLINK_GET_STRICT_CHK, 1)
+
+        self.async_msg_ids = set()
+        self.async_msg_queue = []
+
+        for msg in self.msgs.values():
+            if msg.is_async:
+                self.async_msg_ids.add(msg.rsp_value)
+
+        for op_name, op in self.ops.items():
+            bound_f = functools.partial(self._op, op_name)
+            setattr(self, op.ident_name, bound_f)
+
+
+    def ntf_subscribe(self, mcast_name):
+        mcast_id = self.nlproto.get_mcast_id(mcast_name, self.mcast_groups)
+        self.sock.bind((0, 0))
+        self.sock.setsockopt(Netlink.SOL_NETLINK, Netlink.NETLINK_ADD_MEMBERSHIP,
+                             mcast_id)
+
+    def _add_attr(self, space, name, value, search_attrs):
+        try:
+            attr = self.attr_sets[space][name]
+        except KeyError:
+            raise Exception(f"Space '{space}' has no attribute '{name}'")
+        nl_type = attr.value
+
+        if attr.is_multi and isinstance(value, list):
+            attr_payload = b''
+            for subvalue in value:
+                attr_payload += self._add_attr(space, name, subvalue, search_attrs)
+            return attr_payload
+
+        if attr["type"] == 'nest':
+            nl_type |= Netlink.NLA_F_NESTED
+            attr_payload = b''
+            sub_attrs = SpaceAttrs(self.attr_sets[space], value, search_attrs)
+            for subname, subvalue in value.items():
+                attr_payload += self._add_attr(attr['nested-attributes'],
+                                               subname, subvalue, sub_attrs)
+        elif attr["type"] == 'flag':
+            attr_payload = b''
+        elif attr["type"] == 'string':
+            attr_payload = str(value).encode('ascii') + b'\x00'
+        elif attr["type"] == 'binary':
+            if isinstance(value, bytes):
+                attr_payload = value
+            elif isinstance(value, str):
+                attr_payload = bytes.fromhex(value)
+            elif isinstance(value, dict) and attr.struct_name:
+                attr_payload = self._encode_struct(attr.struct_name, value)
+            else:
+                raise Exception(f'Unknown type for binary attribute, value: {value}')
+        elif attr.is_auto_scalar:
+            scalar = int(value)
+            real_type = attr["type"][0] + ('32' if scalar.bit_length() <= 32 else '64')
+            format = NlAttr.get_format(real_type, attr.byte_order)
+            attr_payload = format.pack(int(value))
+        elif attr['type'] in NlAttr.type_formats:
+            format = NlAttr.get_format(attr['type'], attr.byte_order)
+            attr_payload = format.pack(int(value))
+        elif attr['type'] in "bitfield32":
+            attr_payload = struct.pack("II", int(value["value"]), int(value["selector"]))
+        elif attr['type'] == 'sub-message':
+            msg_format = self._resolve_selector(attr, search_attrs)
+            attr_payload = b''
+            if msg_format.fixed_header:
+                attr_payload += self._encode_struct(msg_format.fixed_header, value)
+            if msg_format.attr_set:
+                if msg_format.attr_set in self.attr_sets:
+                    nl_type |= Netlink.NLA_F_NESTED
+                    sub_attrs = SpaceAttrs(msg_format.attr_set, value, search_attrs)
+                    for subname, subvalue in value.items():
+                        attr_payload += self._add_attr(msg_format.attr_set,
+                                                       subname, subvalue, sub_attrs)
+                else:
+                    raise Exception(f"Unknown attribute-set '{msg_format.attr_set}'")
+        else:
+            raise Exception(f'Unknown type at {space} {name} {value} {attr["type"]}')
+
+        pad = b'\x00' * ((4 - len(attr_payload) % 4) % 4)
+        return struct.pack('HH', len(attr_payload) + 4, nl_type) + attr_payload + pad
+
+    def _decode_enum(self, raw, attr_spec):
+        enum = self.consts[attr_spec['enum']]
+        if enum.type == 'flags' or attr_spec.get('enum-as-flags', False):
+            i = 0
+            value = set()
+            while raw:
+                if raw & 1:
+                    value.add(enum.entries_by_val[i].name)
+                raw >>= 1
+                i += 1
+        else:
+            value = enum.entries_by_val[raw].name
+        return value
+
+    def _decode_binary(self, attr, attr_spec):
+        if attr_spec.struct_name:
+            decoded = self._decode_struct(attr.raw, attr_spec.struct_name)
+        elif attr_spec.sub_type:
+            decoded = attr.as_c_array(attr_spec.sub_type)
+        else:
+            decoded = attr.as_bin()
+            if attr_spec.display_hint:
+                decoded = self._formatted_string(decoded, attr_spec.display_hint)
+        return decoded
+
+    def _decode_array_nest(self, attr, attr_spec):
+        decoded = []
+        offset = 0
+        while offset < len(attr.raw):
+            item = NlAttr(attr.raw, offset)
+            offset += item.full_len
+
+            subattrs = self._decode(NlAttrs(item.raw), attr_spec['nested-attributes'])
+            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 _resolve_selector(self, attr_spec, search_attrs):
+        sub_msg = attr_spec.sub_message
+        if sub_msg not in self.sub_msgs:
+            raise Exception(f"No sub-message spec named {sub_msg} for {attr_spec.name}")
+        sub_msg_spec = self.sub_msgs[sub_msg]
+
+        selector = attr_spec.selector
+        value = search_attrs.lookup(selector)
+        if value not in sub_msg_spec.formats:
+            raise Exception(f"No message format for '{value}' in sub-message spec '{sub_msg}'")
+
+        spec = sub_msg_spec.formats[value]
+        return spec
+
+    def _decode_sub_msg(self, attr, attr_spec, search_attrs):
+        msg_format = self._resolve_selector(attr_spec, search_attrs)
+        decoded = {}
+        offset = 0
+        if msg_format.fixed_header:
+            decoded.update(self._decode_struct(attr.raw, msg_format.fixed_header));
+            offset = self._struct_size(msg_format.fixed_header)
+        if msg_format.attr_set:
+            if msg_format.attr_set in self.attr_sets:
+                subdict = self._decode(NlAttrs(attr.raw, offset), msg_format.attr_set)
+                decoded.update(subdict)
+            else:
+                raise Exception(f"Unknown attribute-set '{attr_space}' when decoding '{attr_spec.name}'")
+        return decoded
+
+    def _decode(self, attrs, space, outer_attrs = None):
+        if space:
+            attr_space = self.attr_sets[space]
+        rsp = dict()
+        search_attrs = SpaceAttrs(attr_space, rsp, outer_attrs)
+
+        for attr in attrs:
+            try:
+                attr_spec = attr_space.attrs_by_val[attr.type]
+            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'], search_attrs)
+                decoded = subdict
+            elif attr_spec["type"] == 'string':
+                decoded = attr.as_strz()
+            elif attr_spec["type"] == 'binary':
+                decoded = self._decode_binary(attr, attr_spec)
+            elif attr_spec["type"] == 'flag':
+                decoded = True
+            elif attr_spec.is_auto_scalar:
+                decoded = attr.as_auto_scalar(attr_spec['type'], attr_spec.byte_order)
+            elif attr_spec["type"] in NlAttr.type_formats:
+                decoded = attr.as_scalar(attr_spec['type'], attr_spec.byte_order)
+                if 'enum' in attr_spec:
+                    decoded = self._decode_enum(decoded, attr_spec)
+            elif attr_spec["type"] == 'array-nest':
+                decoded = self._decode_array_nest(attr, attr_spec)
+            elif attr_spec["type"] == 'bitfield32':
+                value, selector = struct.unpack("II", attr.raw)
+                if 'enum' in attr_spec:
+                    value = self._decode_enum(value, attr_spec)
+                    selector = self._decode_enum(selector, attr_spec)
+                decoded = {"value": value, "selector": selector}
+            elif attr_spec["type"] == 'sub-message':
+                decoded = self._decode_sub_msg(attr, attr_spec, search_attrs)
+            else:
+                if not self.process_unknown:
+                    raise Exception(f'Unknown {attr_spec["type"]} with name {attr_spec["name"]}')
+                decoded = self._decode_unknown(attr)
+
+            self._rsp_add(rsp, attr_spec["name"], attr_spec.is_multi, decoded)
+
+        return rsp
+
+    def _decode_extack_path(self, attrs, attr_set, offset, target):
+        for attr in attrs:
+            try:
+                attr_spec = attr_set.attrs_by_val[attr.type]
+            except KeyError:
+                raise Exception(f"Space '{attr_set.name}' has no attribute with value '{attr.type}'")
+            if offset > target:
+                break
+            if offset == target:
+                return '.' + attr_spec.name
+
+            if offset + attr.full_len <= target:
+                offset += attr.full_len
+                continue
+            if attr_spec['type'] != 'nest':
+                raise Exception(f"Can't dive into {attr.type} ({attr_spec['name']}) for extack")
+            offset += 4
+            subpath = self._decode_extack_path(NlAttrs(attr.raw),
+                                               self.attr_sets[attr_spec['nested-attributes']],
+                                               offset, target)
+            if subpath is None:
+                return None
+            return '.' + attr_spec.name + subpath
+
+        return None
+
+    def _decode_extack(self, request, op, extack):
+        if 'bad-attr-offs' not in extack:
+            return
+
+        msg = self.nlproto.decode(self, NlMsg(request, 0, op.attr_set))
+        offset = 20 + self._struct_size(op.fixed_header)
+        path = self._decode_extack_path(msg.raw_attrs, op.attr_set, offset,
+                                        extack['bad-attr-offs'])
+        if path:
+            del extack['bad-attr-offs']
+            extack['bad-attr'] = path
+
+    def _struct_size(self, name):
+        if name:
+            members = self.consts[name].members
+            size = 0
+            for m in members:
+                if m.type in ['pad', 'binary']:
+                    if m.struct:
+                        size += self._struct_size(m.struct)
+                    else:
+                        size += m.len
+                else:
+                    format = NlAttr.get_format(m.type, m.byte_order)
+                    size += format.size
+            return size
+        else:
+            return 0
+
+    def _decode_struct(self, data, name):
+        members = self.consts[name].members
+        attrs = dict()
+        offset = 0
+        for m in members:
+            value = None
+            if m.type == 'pad':
+                offset += m.len
+            elif m.type == 'binary':
+                if m.struct:
+                    len = self._struct_size(m.struct)
+                    value = self._decode_struct(data[offset : offset + len],
+                                                m.struct)
+                    offset += len
+                else:
+                    value = data[offset : offset + m.len]
+                    offset += m.len
+            else:
+                format = NlAttr.get_format(m.type, m.byte_order)
+                [ value ] = format.unpack_from(data, offset)
+                offset += format.size
+            if value is not None:
+                if m.enum:
+                    value = self._decode_enum(value, m)
+                elif m.display_hint:
+                    value = self._formatted_string(value, m.display_hint)
+                attrs[m.name] = value
+        return attrs
+
+    def _encode_struct(self, name, vals):
+        members = self.consts[name].members
+        attr_payload = b''
+        for m in members:
+            value = vals.pop(m.name) if m.name in vals else None
+            if m.type == 'pad':
+                attr_payload += bytearray(m.len)
+            elif m.type == 'binary':
+                if m.struct:
+                    if value is None:
+                        value = dict()
+                    attr_payload += self._encode_struct(m.struct, value)
+                else:
+                    if value is None:
+                        attr_payload += bytearray(m.len)
+                    else:
+                        attr_payload += bytes.fromhex(value)
+            else:
+                if value is None:
+                    value = 0
+                format = NlAttr.get_format(m.type, m.byte_order)
+                attr_payload += format.pack(value)
+        return attr_payload
+
+    def _formatted_string(self, raw, display_hint):
+        if display_hint == 'mac':
+            formatted = ':'.join('%02x' % b for b in raw)
+        elif display_hint == 'hex':
+            formatted = bytes.hex(raw, ' ')
+        elif display_hint in [ 'ipv4', 'ipv6' ]:
+            formatted = format(ipaddress.ip_address(raw))
+        elif display_hint == 'uuid':
+            formatted = str(uuid.UUID(bytes=raw))
+        else:
+            formatted = raw
+        return formatted
+
+    def handle_ntf(self, decoded):
+        msg = dict()
+        if self.include_raw:
+            msg['raw'] = decoded
+        op = self.rsp_by_value[decoded.cmd()]
+        attrs = self._decode(decoded.raw_attrs, op.attr_set.name)
+        if op.fixed_header:
+            attrs.update(self._decode_struct(decoded.raw, op.fixed_header))
+
+        msg['name'] = op['name']
+        msg['msg'] = attrs
+        self.async_msg_queue.append(msg)
+
+    def check_ntf(self):
+        while True:
+            try:
+                reply = self.sock.recv(128 * 1024, socket.MSG_DONTWAIT)
+            except BlockingIOError:
+                return
+
+            nms = NlMsgs(reply)
+            for nl_msg in nms:
+                if nl_msg.error:
+                    print("Netlink error in ntf!?", os.strerror(-nl_msg.error))
+                    print(nl_msg)
+                    continue
+                if nl_msg.done:
+                    print("Netlink done while checking for ntf!?")
+                    continue
+
+                decoded = self.nlproto.decode(self, nl_msg)
+                if decoded.cmd() not in self.async_msg_ids:
+                    print("Unexpected msg id done while checking for ntf", decoded)
+                    continue
+
+                self.handle_ntf(decoded)
+
+    def operation_do_attributes(self, name):
+      """
+      For a given operation name, find and return a supported
+      set of attributes (as a dict).
+      """
+      op = self.find_operation(name)
+      if not op:
+        return None
+
+      return op['do']['request']['attributes'].copy()
+
+    def _op(self, method, vals, flags=None, dump=False):
+        op = self.ops[method]
+
+        nl_flags = Netlink.NLM_F_REQUEST | Netlink.NLM_F_ACK
+        for flag in flags or []:
+            nl_flags |= flag
+        if dump:
+            nl_flags |= Netlink.NLM_F_DUMP
+
+        req_seq = random.randint(1024, 65535)
+        msg = self.nlproto.message(nl_flags, op.req_value, 1, req_seq)
+        if op.fixed_header:
+            msg += self._encode_struct(op.fixed_header, vals)
+        search_attrs = SpaceAttrs(op.attr_set, vals)
+        for name, value in vals.items():
+            msg += self._add_attr(op.attr_set.name, name, value, search_attrs)
+        msg = _genl_msg_finalize(msg)
+
+        self.sock.send(msg, 0)
+
+        done = False
+        rsp = []
+        while not done:
+            reply = self.sock.recv(128 * 1024)
+            nms = NlMsgs(reply, attr_space=op.attr_set)
+            for nl_msg in nms:
+                if nl_msg.extack:
+                    self._decode_extack(msg, op, nl_msg.extack)
+
+                if nl_msg.error:
+                    raise NlError(nl_msg)
+                if nl_msg.done:
+                    if nl_msg.extack:
+                        print("Netlink warning:")
+                        print(nl_msg)
+                    done = True
+                    break
+
+                decoded = self.nlproto.decode(self, nl_msg)
+
+                # Check if this is a reply to our request
+                if nl_msg.nl_seq != req_seq or decoded.cmd() != op.rsp_value:
+                    if decoded.cmd() in self.async_msg_ids:
+                        self.handle_ntf(decoded)
+                        continue
+                    else:
+                        print('Unexpected message: ' + repr(decoded))
+                        continue
+
+                rsp_msg = self._decode(decoded.raw_attrs, op.attr_set.name)
+                if op.fixed_header:
+                    rsp_msg.update(self._decode_struct(decoded.raw, op.fixed_header))
+                rsp.append(rsp_msg)
+
+        if not rsp:
+            return None
+        if not dump and len(rsp) == 1:
+            return rsp[0]
+        return rsp
+
+    def do(self, method, vals, flags=None):
+        return self._op(method, vals, flags)
+
+    def dump(self, method, vals):
+        return self._op(method, vals, [], dump=True)
