Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

7 files changed, 2449 insertions, 0 deletions

diff --git a/tools/net/ynl/lib/.gitignore b/tools/net/ynl/lib/.gitignore
new file mode 100644
index 0000000000..c18dd8d83c
--- /dev/null
+++ b/tools/net/ynl/lib/.gitignore
@@ -0,0 +1 @@
+__pycache__/
diff --git a/tools/net/ynl/lib/Makefile b/tools/net/ynl/lib/Makefile
new file mode 100644
index 0000000000..d2e50fd0a5
--- /dev/null
+++ b/tools/net/ynl/lib/Makefile
@@ -0,0 +1,28 @@
+# SPDX-License-Identifier: GPL-2.0
+
+CC=gcc
+CFLAGS=-std=gnu11 -O2 -W -Wall -Wextra -Wno-unused-parameter -Wshadow
+ifeq ("$(DEBUG)","1")
+  CFLAGS += -g -fsanitize=address -fsanitize=leak -static-libasan
+endif
+
+SRCS=$(wildcard *.c)
+OBJS=$(patsubst %.c,%.o,${SRCS})
+
+include $(wildcard *.d)
+
+all: ynl.a
+
+ynl.a: $(OBJS)
+	ar rcs $@ $(OBJS)
+clean:
+	rm -f *.o *.d *~
+
+hardclean: clean
+	rm -f *.a
+
+%.o: %.c
+	$(COMPILE.c) -MMD -c -o $@ $<
+
+.PHONY: all clean
+.DEFAULT_GOAL=all
diff --git a/tools/net/ynl/lib/__init__.py b/tools/net/ynl/lib/__init__.py
new file mode 100644
index 0000000000..f7eaa07783
--- /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 0000000000..37bcb4d8b3
--- /dev/null
+++ b/tools/net/ynl/lib/nlspec.py
@@ -0,0 +1,545 @@
+# 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 atttribute type
+
+    Represents a single attribute type within an attr space.
+
+    Attributes:
+        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
+    """
+    def __init__(self, family, attr_set, yaml, value):
+        super().__init__(family, yaml)
+
+        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')
+
+
+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
+    """
+    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')
+
+
+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 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)
+        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.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_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
+
+        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.c b/tools/net/ynl/lib/ynl.c
new file mode 100644
index 0000000000..514e0d69e7
--- /dev/null
+++ b/tools/net/ynl/lib/ynl.c
@@ -0,0 +1,901 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+#include <errno.h>
+#include <poll.h>
+#include <string.h>
+#include <stdlib.h>
+#include <linux/types.h>
+
+#include <libmnl/libmnl.h>
+#include <linux/genetlink.h>
+
+#include "ynl.h"
+
+#define ARRAY_SIZE(arr)		(sizeof(arr) / sizeof(*arr))
+
+#define __yerr_msg(yse, _msg...)					\
+	({								\
+		struct ynl_error *_yse = (yse);				\
+									\
+		if (_yse) {						\
+			snprintf(_yse->msg, sizeof(_yse->msg) - 1,  _msg); \
+			_yse->msg[sizeof(_yse->msg) - 1] = 0;		\
+		}							\
+	})
+
+#define __yerr_code(yse, _code...)		\
+	({					\
+		struct ynl_error *_yse = (yse);	\
+						\
+		if (_yse) {			\
+			_yse->code = _code;	\
+		}				\
+	})
+
+#define __yerr(yse, _code, _msg...)		\
+	({					\
+		__yerr_msg(yse, _msg);		\
+		__yerr_code(yse, _code);	\
+	})
+
+#define __perr(yse, _msg)		__yerr(yse, errno, _msg)
+
+#define yerr_msg(_ys, _msg...)		__yerr_msg(&(_ys)->err, _msg)
+#define yerr(_ys, _code, _msg...)	__yerr(&(_ys)->err, _code, _msg)
+#define perr(_ys, _msg)			__yerr(&(_ys)->err, errno, _msg)
+
+/* -- Netlink boiler plate */
+static int
+ynl_err_walk_report_one(struct ynl_policy_nest *policy, unsigned int type,
+			char *str, int str_sz, int *n)
+{
+	if (!policy) {
+		if (*n < str_sz)
+			*n += snprintf(str, str_sz, "!policy");
+		return 1;
+	}
+
+	if (type > policy->max_attr) {
+		if (*n < str_sz)
+			*n += snprintf(str, str_sz, "!oob");
+		return 1;
+	}
+
+	if (!policy->table[type].name) {
+		if (*n < str_sz)
+			*n += snprintf(str, str_sz, "!name");
+		return 1;
+	}
+
+	if (*n < str_sz)
+		*n += snprintf(str, str_sz - *n,
+			       ".%s", policy->table[type].name);
+	return 0;
+}
+
+static int
+ynl_err_walk(struct ynl_sock *ys, void *start, void *end, unsigned int off,
+	     struct ynl_policy_nest *policy, char *str, int str_sz,
+	     struct ynl_policy_nest **nest_pol)
+{
+	unsigned int astart_off, aend_off;
+	const struct nlattr *attr;
+	unsigned int data_len;
+	unsigned int type;
+	bool found = false;
+	int n = 0;
+
+	if (!policy) {
+		if (n < str_sz)
+			n += snprintf(str, str_sz, "!policy");
+		return n;
+	}
+
+	data_len = end - start;
+
+	mnl_attr_for_each_payload(start, data_len) {
+		astart_off = (char *)attr - (char *)start;
+		aend_off = astart_off + mnl_attr_get_payload_len(attr);
+		if (aend_off <= off)
+			continue;
+
+		found = true;
+		break;
+	}
+	if (!found)
+		return 0;
+
+	off -= astart_off;
+
+	type = mnl_attr_get_type(attr);
+
+	if (ynl_err_walk_report_one(policy, type, str, str_sz, &n))
+		return n;
+
+	if (!off) {
+		if (nest_pol)
+			*nest_pol = policy->table[type].nest;
+		return n;
+	}
+
+	if (!policy->table[type].nest) {
+		if (n < str_sz)
+			n += snprintf(str, str_sz, "!nest");
+		return n;
+	}
+
+	off -= sizeof(struct nlattr);
+	start =  mnl_attr_get_payload(attr);
+	end = start + mnl_attr_get_payload_len(attr);
+
+	return n + ynl_err_walk(ys, start, end, off, policy->table[type].nest,
+				&str[n], str_sz - n, nest_pol);
+}
+
+#define NLMSGERR_ATTR_MISS_TYPE (NLMSGERR_ATTR_POLICY + 1)
+#define NLMSGERR_ATTR_MISS_NEST (NLMSGERR_ATTR_POLICY + 2)
+#define NLMSGERR_ATTR_MAX (NLMSGERR_ATTR_MAX + 2)
+
+static int
+ynl_ext_ack_check(struct ynl_sock *ys, const struct nlmsghdr *nlh,
+		  unsigned int hlen)
+{
+	const struct nlattr *tb[NLMSGERR_ATTR_MAX + 1] = {};
+	char miss_attr[sizeof(ys->err.msg)];
+	char bad_attr[sizeof(ys->err.msg)];
+	const struct nlattr *attr;
+	const char *str = NULL;
+
+	if (!(nlh->nlmsg_flags & NLM_F_ACK_TLVS))
+		return MNL_CB_OK;
+
+	mnl_attr_for_each(attr, nlh, hlen) {
+		unsigned int len, type;
+
+		len = mnl_attr_get_payload_len(attr);
+		type = mnl_attr_get_type(attr);
+
+		if (type > NLMSGERR_ATTR_MAX)
+			continue;
+
+		tb[type] = attr;
+
+		switch (type) {
+		case NLMSGERR_ATTR_OFFS:
+		case NLMSGERR_ATTR_MISS_TYPE:
+		case NLMSGERR_ATTR_MISS_NEST:
+			if (len != sizeof(__u32))
+				return MNL_CB_ERROR;
+			break;
+		case NLMSGERR_ATTR_MSG:
+			str = mnl_attr_get_payload(attr);
+			if (str[len - 1])
+				return MNL_CB_ERROR;
+			break;
+		default:
+			break;
+		}
+	}
+
+	bad_attr[0] = '\0';
+	miss_attr[0] = '\0';
+
+	if (tb[NLMSGERR_ATTR_OFFS]) {
+		unsigned int n, off;
+		void *start, *end;
+
+		ys->err.attr_offs = mnl_attr_get_u32(tb[NLMSGERR_ATTR_OFFS]);
+
+		n = snprintf(bad_attr, sizeof(bad_attr), "%sbad attribute: ",
+			     str ? " (" : "");
+
+		start = mnl_nlmsg_get_payload_offset(ys->nlh,
+						     sizeof(struct genlmsghdr));
+		end = mnl_nlmsg_get_payload_tail(ys->nlh);
+
+		off = ys->err.attr_offs;
+		off -= sizeof(struct nlmsghdr);
+		off -= sizeof(struct genlmsghdr);
+
+		n += ynl_err_walk(ys, start, end, off, ys->req_policy,
+				  &bad_attr[n], sizeof(bad_attr) - n, NULL);
+
+		if (n >= sizeof(bad_attr))
+			n = sizeof(bad_attr) - 1;
+		bad_attr[n] = '\0';
+	}
+	if (tb[NLMSGERR_ATTR_MISS_TYPE]) {
+		struct ynl_policy_nest *nest_pol = NULL;
+		unsigned int n, off, type;
+		void *start, *end;
+		int n2;
+
+		type = mnl_attr_get_u32(tb[NLMSGERR_ATTR_MISS_TYPE]);
+
+		n = snprintf(miss_attr, sizeof(miss_attr), "%smissing attribute: ",
+			     bad_attr[0] ? ", " : (str ? " (" : ""));
+
+		start = mnl_nlmsg_get_payload_offset(ys->nlh,
+						     sizeof(struct genlmsghdr));
+		end = mnl_nlmsg_get_payload_tail(ys->nlh);
+
+		nest_pol = ys->req_policy;
+		if (tb[NLMSGERR_ATTR_MISS_NEST]) {
+			off = mnl_attr_get_u32(tb[NLMSGERR_ATTR_MISS_NEST]);
+			off -= sizeof(struct nlmsghdr);
+			off -= sizeof(struct genlmsghdr);
+
+			n += ynl_err_walk(ys, start, end, off, ys->req_policy,
+					  &miss_attr[n], sizeof(miss_attr) - n,
+					  &nest_pol);
+		}
+
+		n2 = 0;
+		ynl_err_walk_report_one(nest_pol, type, &miss_attr[n],
+					sizeof(miss_attr) - n, &n2);
+		n += n2;
+
+		if (n >= sizeof(miss_attr))
+			n = sizeof(miss_attr) - 1;
+		miss_attr[n] = '\0';
+	}
+
+	/* Implicitly depend on ys->err.code already set */
+	if (str)
+		yerr_msg(ys, "Kernel %s: '%s'%s%s%s",
+			 ys->err.code ? "error" : "warning",
+			 str, bad_attr, miss_attr,
+			 bad_attr[0] || miss_attr[0] ? ")" : "");
+	else if (bad_attr[0] || miss_attr[0])
+		yerr_msg(ys, "Kernel %s: %s%s",
+			 ys->err.code ? "error" : "warning",
+			 bad_attr, miss_attr);
+
+	return MNL_CB_OK;
+}
+
+static int ynl_cb_error(const struct nlmsghdr *nlh, void *data)
+{
+	const struct nlmsgerr *err = mnl_nlmsg_get_payload(nlh);
+	struct ynl_parse_arg *yarg = data;
+	unsigned int hlen;
+	int code;
+
+	code = err->error >= 0 ? err->error : -err->error;
+	yarg->ys->err.code = code;
+	errno = code;
+
+	hlen = sizeof(*err);
+	if (!(nlh->nlmsg_flags & NLM_F_CAPPED))
+		hlen += mnl_nlmsg_get_payload_len(&err->msg);
+
+	ynl_ext_ack_check(yarg->ys, nlh, hlen);
+
+	return code ? MNL_CB_ERROR : MNL_CB_STOP;
+}
+
+static int ynl_cb_done(const struct nlmsghdr *nlh, void *data)
+{
+	struct ynl_parse_arg *yarg = data;
+	int err;
+
+	err = *(int *)NLMSG_DATA(nlh);
+	if (err < 0) {
+		yarg->ys->err.code = -err;
+		errno = -err;
+
+		ynl_ext_ack_check(yarg->ys, nlh, sizeof(int));
+
+		return MNL_CB_ERROR;
+	}
+	return MNL_CB_STOP;
+}
+
+static int ynl_cb_noop(const struct nlmsghdr *nlh, void *data)
+{
+	return MNL_CB_OK;
+}
+
+mnl_cb_t ynl_cb_array[NLMSG_MIN_TYPE] = {
+	[NLMSG_NOOP]	= ynl_cb_noop,
+	[NLMSG_ERROR]	= ynl_cb_error,
+	[NLMSG_DONE]	= ynl_cb_done,
+	[NLMSG_OVERRUN]	= ynl_cb_noop,
+};
+
+/* Attribute validation */
+
+int ynl_attr_validate(struct ynl_parse_arg *yarg, const struct nlattr *attr)
+{
+	struct ynl_policy_attr *policy;
+	unsigned int type, len;
+	unsigned char *data;
+
+	data = mnl_attr_get_payload(attr);
+	len = mnl_attr_get_payload_len(attr);
+	type = mnl_attr_get_type(attr);
+	if (type > yarg->rsp_policy->max_attr) {
+		yerr(yarg->ys, YNL_ERROR_INTERNAL,
+		     "Internal error, validating unknown attribute");
+		return -1;
+	}
+
+	policy = &yarg->rsp_policy->table[type];
+
+	switch (policy->type) {
+	case YNL_PT_REJECT:
+		yerr(yarg->ys, YNL_ERROR_ATTR_INVALID,
+		     "Rejected attribute (%s)", policy->name);
+		return -1;
+	case YNL_PT_IGNORE:
+		break;
+	case YNL_PT_U8:
+		if (len == sizeof(__u8))
+			break;
+		yerr(yarg->ys, YNL_ERROR_ATTR_INVALID,
+		     "Invalid attribute (u8 %s)", policy->name);
+		return -1;
+	case YNL_PT_U16:
+		if (len == sizeof(__u16))
+			break;
+		yerr(yarg->ys, YNL_ERROR_ATTR_INVALID,
+		     "Invalid attribute (u16 %s)", policy->name);
+		return -1;
+	case YNL_PT_U32:
+		if (len == sizeof(__u32))
+			break;
+		yerr(yarg->ys, YNL_ERROR_ATTR_INVALID,
+		     "Invalid attribute (u32 %s)", policy->name);
+		return -1;
+	case YNL_PT_U64:
+		if (len == sizeof(__u64))
+			break;
+		yerr(yarg->ys, YNL_ERROR_ATTR_INVALID,
+		     "Invalid attribute (u64 %s)", policy->name);
+		return -1;
+	case YNL_PT_FLAG:
+		/* Let flags grow into real attrs, why not.. */
+		break;
+	case YNL_PT_NEST:
+		if (!len || len >= sizeof(*attr))
+			break;
+		yerr(yarg->ys, YNL_ERROR_ATTR_INVALID,
+		     "Invalid attribute (nest %s)", policy->name);
+		return -1;
+	case YNL_PT_BINARY:
+		if (!policy->len || len == policy->len)
+			break;
+		yerr(yarg->ys, YNL_ERROR_ATTR_INVALID,
+		     "Invalid attribute (binary %s)", policy->name);
+		return -1;
+	case YNL_PT_NUL_STR:
+		if ((!policy->len || len <= policy->len) && !data[len - 1])
+			break;
+		yerr(yarg->ys, YNL_ERROR_ATTR_INVALID,
+		     "Invalid attribute (string %s)", policy->name);
+		return -1;
+	default:
+		yerr(yarg->ys, YNL_ERROR_ATTR_INVALID,
+		     "Invalid attribute (unknown %s)", policy->name);
+		return -1;
+	}
+
+	return 0;
+}
+
+/* Generic code */
+
+static void ynl_err_reset(struct ynl_sock *ys)
+{
+	ys->err.code = 0;
+	ys->err.attr_offs = 0;
+	ys->err.msg[0] = 0;
+}
+
+struct nlmsghdr *ynl_msg_start(struct ynl_sock *ys, __u32 id, __u16 flags)
+{
+	struct nlmsghdr *nlh;
+
+	ynl_err_reset(ys);
+
+	nlh = ys->nlh = mnl_nlmsg_put_header(ys->tx_buf);
+	nlh->nlmsg_type	= id;
+	nlh->nlmsg_flags = flags;
+	nlh->nlmsg_seq = ++ys->seq;
+
+	return nlh;
+}
+
+struct nlmsghdr *
+ynl_gemsg_start(struct ynl_sock *ys, __u32 id, __u16 flags,
+		__u8 cmd, __u8 version)
+{
+	struct genlmsghdr gehdr;
+	struct nlmsghdr *nlh;
+	void *data;
+
+	nlh = ynl_msg_start(ys, id, flags);
+
+	memset(&gehdr, 0, sizeof(gehdr));
+	gehdr.cmd = cmd;
+	gehdr.version = version;
+
+	data = mnl_nlmsg_put_extra_header(nlh, sizeof(gehdr));
+	memcpy(data, &gehdr, sizeof(gehdr));
+
+	return nlh;
+}
+
+void ynl_msg_start_req(struct ynl_sock *ys, __u32 id)
+{
+	ynl_msg_start(ys, id, NLM_F_REQUEST | NLM_F_ACK);
+}
+
+void ynl_msg_start_dump(struct ynl_sock *ys, __u32 id)
+{
+	ynl_msg_start(ys, id, NLM_F_REQUEST | NLM_F_ACK | NLM_F_DUMP);
+}
+
+struct nlmsghdr *
+ynl_gemsg_start_req(struct ynl_sock *ys, __u32 id, __u8 cmd, __u8 version)
+{
+	return ynl_gemsg_start(ys, id, NLM_F_REQUEST | NLM_F_ACK, cmd, version);
+}
+
+struct nlmsghdr *
+ynl_gemsg_start_dump(struct ynl_sock *ys, __u32 id, __u8 cmd, __u8 version)
+{
+	return ynl_gemsg_start(ys, id, NLM_F_REQUEST | NLM_F_ACK | NLM_F_DUMP,
+			       cmd, version);
+}
+
+int ynl_recv_ack(struct ynl_sock *ys, int ret)
+{
+	if (!ret) {
+		yerr(ys, YNL_ERROR_EXPECT_ACK,
+		     "Expecting an ACK but nothing received");
+		return -1;
+	}
+
+	ret = mnl_socket_recvfrom(ys->sock, ys->rx_buf, MNL_SOCKET_BUFFER_SIZE);
+	if (ret < 0) {
+		perr(ys, "Socket receive failed");
+		return ret;
+	}
+	return mnl_cb_run(ys->rx_buf, ret, ys->seq, ys->portid,
+			  ynl_cb_null, ys);
+}
+
+int ynl_cb_null(const struct nlmsghdr *nlh, void *data)
+{
+	struct ynl_parse_arg *yarg = data;
+
+	yerr(yarg->ys, YNL_ERROR_UNEXPECT_MSG,
+	     "Received a message when none were expected");
+
+	return MNL_CB_ERROR;
+}
+
+/* Init/fini and genetlink boiler plate */
+static int
+ynl_get_family_info_mcast(struct ynl_sock *ys, const struct nlattr *mcasts)
+{
+	const struct nlattr *entry, *attr;
+	unsigned int i;
+
+	mnl_attr_for_each_nested(attr, mcasts)
+		ys->n_mcast_groups++;
+
+	if (!ys->n_mcast_groups)
+		return 0;
+
+	ys->mcast_groups = calloc(ys->n_mcast_groups,
+				  sizeof(*ys->mcast_groups));
+	if (!ys->mcast_groups)
+		return MNL_CB_ERROR;
+
+	i = 0;
+	mnl_attr_for_each_nested(entry, mcasts) {
+		mnl_attr_for_each_nested(attr, entry) {
+			if (mnl_attr_get_type(attr) == CTRL_ATTR_MCAST_GRP_ID)
+				ys->mcast_groups[i].id = mnl_attr_get_u32(attr);
+			if (mnl_attr_get_type(attr) == CTRL_ATTR_MCAST_GRP_NAME) {
+				strncpy(ys->mcast_groups[i].name,
+					mnl_attr_get_str(attr),
+					GENL_NAMSIZ - 1);
+				ys->mcast_groups[i].name[GENL_NAMSIZ - 1] = 0;
+			}
+		}
+	}
+
+	return 0;
+}
+
+static int ynl_get_family_info_cb(const struct nlmsghdr *nlh, void *data)
+{
+	struct ynl_parse_arg *yarg = data;
+	struct ynl_sock *ys = yarg->ys;
+	const struct nlattr *attr;
+	bool found_id = true;
+
+	mnl_attr_for_each(attr, nlh, sizeof(struct genlmsghdr)) {
+		if (mnl_attr_get_type(attr) == CTRL_ATTR_MCAST_GROUPS)
+			if (ynl_get_family_info_mcast(ys, attr))
+				return MNL_CB_ERROR;
+
+		if (mnl_attr_get_type(attr) != CTRL_ATTR_FAMILY_ID)
+			continue;
+
+		if (mnl_attr_get_payload_len(attr) != sizeof(__u16)) {
+			yerr(ys, YNL_ERROR_ATTR_INVALID, "Invalid family ID");
+			return MNL_CB_ERROR;
+		}
+
+		ys->family_id = mnl_attr_get_u16(attr);
+		found_id = true;
+	}
+
+	if (!found_id) {
+		yerr(ys, YNL_ERROR_ATTR_MISSING, "Family ID missing");
+		return MNL_CB_ERROR;
+	}
+	return MNL_CB_OK;
+}
+
+static int ynl_sock_read_family(struct ynl_sock *ys, const char *family_name)
+{
+	struct ynl_parse_arg yarg = { .ys = ys, };
+	struct nlmsghdr *nlh;
+	int err;
+
+	nlh = ynl_gemsg_start_req(ys, GENL_ID_CTRL, CTRL_CMD_GETFAMILY, 1);
+	mnl_attr_put_strz(nlh, CTRL_ATTR_FAMILY_NAME, family_name);
+
+	err = mnl_socket_sendto(ys->sock, nlh, nlh->nlmsg_len);
+	if (err < 0) {
+		perr(ys, "failed to request socket family info");
+		return err;
+	}
+
+	err = mnl_socket_recvfrom(ys->sock, ys->rx_buf, MNL_SOCKET_BUFFER_SIZE);
+	if (err <= 0) {
+		perr(ys, "failed to receive the socket family info");
+		return err;
+	}
+	err = mnl_cb_run2(ys->rx_buf, err, ys->seq, ys->portid,
+			  ynl_get_family_info_cb, &yarg,
+			  ynl_cb_array, ARRAY_SIZE(ynl_cb_array));
+	if (err < 0) {
+		free(ys->mcast_groups);
+		perr(ys, "failed to receive the socket family info - no such family?");
+		return err;
+	}
+
+	return ynl_recv_ack(ys, err);
+}
+
+struct ynl_sock *
+ynl_sock_create(const struct ynl_family *yf, struct ynl_error *yse)
+{
+	struct ynl_sock *ys;
+	int one = 1;
+
+	ys = malloc(sizeof(*ys) + 2 * MNL_SOCKET_BUFFER_SIZE);
+	if (!ys)
+		return NULL;
+	memset(ys, 0, sizeof(*ys));
+
+	ys->family = yf;
+	ys->tx_buf = &ys->raw_buf[0];
+	ys->rx_buf = &ys->raw_buf[MNL_SOCKET_BUFFER_SIZE];
+	ys->ntf_last_next = &ys->ntf_first;
+
+	ys->sock = mnl_socket_open(NETLINK_GENERIC);
+	if (!ys->sock) {
+		__perr(yse, "failed to create a netlink socket");
+		goto err_free_sock;
+	}
+
+	if (mnl_socket_setsockopt(ys->sock, NETLINK_CAP_ACK,
+				  &one, sizeof(one))) {
+		__perr(yse, "failed to enable netlink ACK");
+		goto err_close_sock;
+	}
+	if (mnl_socket_setsockopt(ys->sock, NETLINK_EXT_ACK,
+				  &one, sizeof(one))) {
+		__perr(yse, "failed to enable netlink ext ACK");
+		goto err_close_sock;
+	}
+
+	ys->seq = random();
+	ys->portid = mnl_socket_get_portid(ys->sock);
+
+	if (ynl_sock_read_family(ys, yf->name)) {
+		if (yse)
+			memcpy(yse, &ys->err, sizeof(*yse));
+		goto err_close_sock;
+	}
+
+	return ys;
+
+err_close_sock:
+	mnl_socket_close(ys->sock);
+err_free_sock:
+	free(ys);
+	return NULL;
+}
+
+void ynl_sock_destroy(struct ynl_sock *ys)
+{
+	struct ynl_ntf_base_type *ntf;
+
+	mnl_socket_close(ys->sock);
+	while ((ntf = ynl_ntf_dequeue(ys)))
+		ynl_ntf_free(ntf);
+	free(ys->mcast_groups);
+	free(ys);
+}
+
+/* YNL multicast handling */
+
+void ynl_ntf_free(struct ynl_ntf_base_type *ntf)
+{
+	ntf->free(ntf);
+}
+
+int ynl_subscribe(struct ynl_sock *ys, const char *grp_name)
+{
+	unsigned int i;
+	int err;
+
+	for (i = 0; i < ys->n_mcast_groups; i++)
+		if (!strcmp(ys->mcast_groups[i].name, grp_name))
+			break;
+	if (i == ys->n_mcast_groups) {
+		yerr(ys, ENOENT, "Multicast group '%s' not found", grp_name);
+		return -1;
+	}
+
+	err = mnl_socket_setsockopt(ys->sock, NETLINK_ADD_MEMBERSHIP,
+				    &ys->mcast_groups[i].id,
+				    sizeof(ys->mcast_groups[i].id));
+	if (err < 0) {
+		perr(ys, "Subscribing to multicast group failed");
+		return -1;
+	}
+
+	return 0;
+}
+
+int ynl_socket_get_fd(struct ynl_sock *ys)
+{
+	return mnl_socket_get_fd(ys->sock);
+}
+
+struct ynl_ntf_base_type *ynl_ntf_dequeue(struct ynl_sock *ys)
+{
+	struct ynl_ntf_base_type *ntf;
+
+	if (!ynl_has_ntf(ys))
+		return NULL;
+
+	ntf = ys->ntf_first;
+	ys->ntf_first = ntf->next;
+	if (ys->ntf_last_next == &ntf->next)
+		ys->ntf_last_next = &ys->ntf_first;
+
+	return ntf;
+}
+
+static int ynl_ntf_parse(struct ynl_sock *ys, const struct nlmsghdr *nlh)
+{
+	struct ynl_parse_arg yarg = { .ys = ys, };
+	const struct ynl_ntf_info *info;
+	struct ynl_ntf_base_type *rsp;
+	struct genlmsghdr *gehdr;
+	int ret;
+
+	gehdr = mnl_nlmsg_get_payload(nlh);
+	if (gehdr->cmd >= ys->family->ntf_info_size)
+		return MNL_CB_ERROR;
+	info = &ys->family->ntf_info[gehdr->cmd];
+	if (!info->cb)
+		return MNL_CB_ERROR;
+
+	rsp = calloc(1, info->alloc_sz);
+	rsp->free = info->free;
+	yarg.data = rsp->data;
+	yarg.rsp_policy = info->policy;
+
+	ret = info->cb(nlh, &yarg);
+	if (ret <= MNL_CB_STOP)
+		goto err_free;
+
+	rsp->family = nlh->nlmsg_type;
+	rsp->cmd = gehdr->cmd;
+
+	*ys->ntf_last_next = rsp;
+	ys->ntf_last_next = &rsp->next;
+
+	return MNL_CB_OK;
+
+err_free:
+	info->free(rsp);
+	return MNL_CB_ERROR;
+}
+
+static int ynl_ntf_trampoline(const struct nlmsghdr *nlh, void *data)
+{
+	return ynl_ntf_parse((struct ynl_sock *)data, nlh);
+}
+
+int ynl_ntf_check(struct ynl_sock *ys)
+{
+	ssize_t len;
+	int err;
+
+	do {
+		/* libmnl doesn't let us pass flags to the recv to make
+		 * it non-blocking so we need to poll() or peek() :|
+		 */
+		struct pollfd pfd = { };
+
+		pfd.fd = mnl_socket_get_fd(ys->sock);
+		pfd.events = POLLIN;
+		err = poll(&pfd, 1, 1);
+		if (err < 1)
+			return err;
+
+		len = mnl_socket_recvfrom(ys->sock, ys->rx_buf,
+					  MNL_SOCKET_BUFFER_SIZE);
+		if (len < 0)
+			return len;
+
+		err = mnl_cb_run2(ys->rx_buf, len, ys->seq, ys->portid,
+				  ynl_ntf_trampoline, ys,
+				  ynl_cb_array, NLMSG_MIN_TYPE);
+		if (err < 0)
+			return err;
+	} while (err > 0);
+
+	return 0;
+}
+
+/* YNL specific helpers used by the auto-generated code */
+
+struct ynl_dump_list_type *YNL_LIST_END = (void *)(0xb4d123);
+
+void ynl_error_unknown_notification(struct ynl_sock *ys, __u8 cmd)
+{
+	yerr(ys, YNL_ERROR_UNKNOWN_NTF,
+	     "Unknown notification message type '%d'", cmd);
+}
+
+int ynl_error_parse(struct ynl_parse_arg *yarg, const char *msg)
+{
+	yerr(yarg->ys, YNL_ERROR_INV_RESP, "Error parsing response: %s", msg);
+	return MNL_CB_ERROR;
+}
+
+static int
+ynl_check_alien(struct ynl_sock *ys, const struct nlmsghdr *nlh, __u32 rsp_cmd)
+{
+	struct genlmsghdr *gehdr;
+
+	if (mnl_nlmsg_get_payload_len(nlh) < sizeof(*gehdr)) {
+		yerr(ys, YNL_ERROR_INV_RESP,
+		     "Kernel responded with truncated message");
+		return -1;
+	}
+
+	gehdr = mnl_nlmsg_get_payload(nlh);
+	if (gehdr->cmd != rsp_cmd)
+		return ynl_ntf_parse(ys, nlh);
+
+	return 0;
+}
+
+static int ynl_req_trampoline(const struct nlmsghdr *nlh, void *data)
+{
+	struct ynl_req_state *yrs = data;
+	int ret;
+
+	ret = ynl_check_alien(yrs->yarg.ys, nlh, yrs->rsp_cmd);
+	if (ret)
+		return ret < 0 ? MNL_CB_ERROR : MNL_CB_OK;
+
+	return yrs->cb(nlh, &yrs->yarg);
+}
+
+int ynl_exec(struct ynl_sock *ys, struct nlmsghdr *req_nlh,
+	     struct ynl_req_state *yrs)
+{
+	ssize_t len;
+	int err;
+
+	err = mnl_socket_sendto(ys->sock, req_nlh, req_nlh->nlmsg_len);
+	if (err < 0)
+		return err;
+
+	do {
+		len = mnl_socket_recvfrom(ys->sock, ys->rx_buf,
+					  MNL_SOCKET_BUFFER_SIZE);
+		if (len < 0)
+			return len;
+
+		err = mnl_cb_run2(ys->rx_buf, len, ys->seq, ys->portid,
+				  ynl_req_trampoline, yrs,
+				  ynl_cb_array, NLMSG_MIN_TYPE);
+		if (err < 0)
+			return err;
+	} while (err > 0);
+
+	return 0;
+}
+
+static int ynl_dump_trampoline(const struct nlmsghdr *nlh, void *data)
+{
+	struct ynl_dump_state *ds = data;
+	struct ynl_dump_list_type *obj;
+	struct ynl_parse_arg yarg = {};
+	int ret;
+
+	ret = ynl_check_alien(ds->ys, nlh, ds->rsp_cmd);
+	if (ret)
+		return ret < 0 ? MNL_CB_ERROR : MNL_CB_OK;
+
+	obj = calloc(1, ds->alloc_sz);
+	if (!obj)
+		return MNL_CB_ERROR;
+
+	if (!ds->first)
+		ds->first = obj;
+	if (ds->last)
+		ds->last->next = obj;
+	ds->last = obj;
+
+	yarg.ys = ds->ys;
+	yarg.rsp_policy = ds->rsp_policy;
+	yarg.data = &obj->data;
+
+	return ds->cb(nlh, &yarg);
+}
+
+static void *ynl_dump_end(struct ynl_dump_state *ds)
+{
+	if (!ds->first)
+		return YNL_LIST_END;
+
+	ds->last->next = YNL_LIST_END;
+	return ds->first;
+}
+
+int ynl_exec_dump(struct ynl_sock *ys, struct nlmsghdr *req_nlh,
+		  struct ynl_dump_state *yds)
+{
+	ssize_t len;
+	int err;
+
+	err = mnl_socket_sendto(ys->sock, req_nlh, req_nlh->nlmsg_len);
+	if (err < 0)
+		return err;
+
+	do {
+		len = mnl_socket_recvfrom(ys->sock, ys->rx_buf,
+					  MNL_SOCKET_BUFFER_SIZE);
+		if (len < 0)
+			goto err_close_list;
+
+		err = mnl_cb_run2(ys->rx_buf, len, ys->seq, ys->portid,
+				  ynl_dump_trampoline, yds,
+				  ynl_cb_array, NLMSG_MIN_TYPE);
+		if (err < 0)
+			goto err_close_list;
+	} while (err > 0);
+
+	yds->first = ynl_dump_end(yds);
+	return 0;
+
+err_close_list:
+	yds->first = ynl_dump_end(yds);
+	return -1;
+}
diff --git a/tools/net/ynl/lib/ynl.h b/tools/net/ynl/lib/ynl.h
new file mode 100644
index 0000000000..9eafa3552c
--- /dev/null
+++ b/tools/net/ynl/lib/ynl.h
@@ -0,0 +1,237 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+#ifndef __YNL_C_H
+#define __YNL_C_H 1
+
+#include <stddef.h>
+#include <libmnl/libmnl.h>
+#include <linux/genetlink.h>
+#include <linux/types.h>
+
+struct mnl_socket;
+struct nlmsghdr;
+
+/*
+ * User facing code
+ */
+
+struct ynl_ntf_base_type;
+struct ynl_ntf_info;
+struct ynl_sock;
+
+enum ynl_error_code {
+	YNL_ERROR_NONE = 0,
+	__YNL_ERRNO_END = 4096,
+	YNL_ERROR_INTERNAL,
+	YNL_ERROR_EXPECT_ACK,
+	YNL_ERROR_EXPECT_MSG,
+	YNL_ERROR_UNEXPECT_MSG,
+	YNL_ERROR_ATTR_MISSING,
+	YNL_ERROR_ATTR_INVALID,
+	YNL_ERROR_UNKNOWN_NTF,
+	YNL_ERROR_INV_RESP,
+};
+
+/**
+ * struct ynl_error - error encountered by YNL
+ * @code:	errno (low values) or YNL error code (enum ynl_error_code)
+ * @attr_offs:	offset of bad attribute (for very advanced users)
+ * @msg:	error message
+ *
+ * Error information for when YNL operations fail.
+ * Users should interact with the err member of struct ynl_sock directly.
+ * The main exception to that rule is ynl_sock_create().
+ */
+struct ynl_error {
+	enum ynl_error_code code;
+	unsigned int attr_offs;
+	char msg[512];
+};
+
+/**
+ * struct ynl_family - YNL family info
+ * Family description generated by codegen. Pass to ynl_sock_create().
+ */
+struct ynl_family {
+/* private: */
+	const char *name;
+	const struct ynl_ntf_info *ntf_info;
+	unsigned int ntf_info_size;
+};
+
+/**
+ * struct ynl_sock - YNL wrapped netlink socket
+ * @err: YNL error descriptor, cleared on every request.
+ */
+struct ynl_sock {
+	struct ynl_error err;
+
+/* private: */
+	const struct ynl_family *family;
+	struct mnl_socket *sock;
+	__u32 seq;
+	__u32 portid;
+	__u16 family_id;
+
+	unsigned int n_mcast_groups;
+	struct {
+		unsigned int id;
+		char name[GENL_NAMSIZ];
+	} *mcast_groups;
+
+	struct ynl_ntf_base_type *ntf_first;
+	struct ynl_ntf_base_type **ntf_last_next;
+
+	struct nlmsghdr *nlh;
+	struct ynl_policy_nest *req_policy;
+	unsigned char *tx_buf;
+	unsigned char *rx_buf;
+	unsigned char raw_buf[];
+};
+
+struct ynl_sock *
+ynl_sock_create(const struct ynl_family *yf, struct ynl_error *e);
+void ynl_sock_destroy(struct ynl_sock *ys);
+
+#define ynl_dump_foreach(dump, iter)					\
+	for (typeof(dump->obj) *iter = &dump->obj;			\
+	     !ynl_dump_obj_is_last(iter);				\
+	     iter = ynl_dump_obj_next(iter))
+
+int ynl_subscribe(struct ynl_sock *ys, const char *grp_name);
+int ynl_socket_get_fd(struct ynl_sock *ys);
+int ynl_ntf_check(struct ynl_sock *ys);
+
+/**
+ * ynl_has_ntf() - check if socket has *parsed* notifications
+ * @ys: active YNL socket
+ *
+ * Note that this does not take into account notifications sitting
+ * in netlink socket, just the notifications which have already been
+ * read and parsed (e.g. during a ynl_ntf_check() call).
+ */
+static inline bool ynl_has_ntf(struct ynl_sock *ys)
+{
+	return ys->ntf_last_next != &ys->ntf_first;
+}
+struct ynl_ntf_base_type *ynl_ntf_dequeue(struct ynl_sock *ys);
+
+void ynl_ntf_free(struct ynl_ntf_base_type *ntf);
+
+/*
+ * YNL internals / low level stuff
+ */
+
+/* Generic mnl helper code */
+
+enum ynl_policy_type {
+	YNL_PT_REJECT = 1,
+	YNL_PT_IGNORE,
+	YNL_PT_NEST,
+	YNL_PT_FLAG,
+	YNL_PT_BINARY,
+	YNL_PT_U8,
+	YNL_PT_U16,
+	YNL_PT_U32,
+	YNL_PT_U64,
+	YNL_PT_NUL_STR,
+};
+
+struct ynl_policy_attr {
+	enum ynl_policy_type type;
+	unsigned int len;
+	const char *name;
+	struct ynl_policy_nest *nest;
+};
+
+struct ynl_policy_nest {
+	unsigned int max_attr;
+	struct ynl_policy_attr *table;
+};
+
+struct ynl_parse_arg {
+	struct ynl_sock *ys;
+	struct ynl_policy_nest *rsp_policy;
+	void *data;
+};
+
+struct ynl_dump_list_type {
+	struct ynl_dump_list_type *next;
+	unsigned char data[] __attribute__ ((aligned (8)));
+};
+extern struct ynl_dump_list_type *YNL_LIST_END;
+
+static inline bool ynl_dump_obj_is_last(void *obj)
+{
+	unsigned long uptr = (unsigned long)obj;
+
+	uptr -= offsetof(struct ynl_dump_list_type, data);
+	return uptr == (unsigned long)YNL_LIST_END;
+}
+
+static inline void *ynl_dump_obj_next(void *obj)
+{
+	unsigned long uptr = (unsigned long)obj;
+	struct ynl_dump_list_type *list;
+
+	uptr -= offsetof(struct ynl_dump_list_type, data);
+	list = (void *)uptr;
+	uptr = (unsigned long)list->next;
+	uptr += offsetof(struct ynl_dump_list_type, data);
+
+	return (void *)uptr;
+}
+
+struct ynl_ntf_base_type {
+	__u16 family;
+	__u8 cmd;
+	struct ynl_ntf_base_type *next;
+	void (*free)(struct ynl_ntf_base_type *ntf);
+	unsigned char data[] __attribute__ ((aligned (8)));
+};
+
+extern mnl_cb_t ynl_cb_array[NLMSG_MIN_TYPE];
+
+struct nlmsghdr *
+ynl_gemsg_start_req(struct ynl_sock *ys, __u32 id, __u8 cmd, __u8 version);
+struct nlmsghdr *
+ynl_gemsg_start_dump(struct ynl_sock *ys, __u32 id, __u8 cmd, __u8 version);
+
+int ynl_attr_validate(struct ynl_parse_arg *yarg, const struct nlattr *attr);
+
+int ynl_recv_ack(struct ynl_sock *ys, int ret);
+int ynl_cb_null(const struct nlmsghdr *nlh, void *data);
+
+/* YNL specific helpers used by the auto-generated code */
+
+struct ynl_req_state {
+	struct ynl_parse_arg yarg;
+	mnl_cb_t cb;
+	__u32 rsp_cmd;
+};
+
+struct ynl_dump_state {
+	struct ynl_sock *ys;
+	struct ynl_policy_nest *rsp_policy;
+	void *first;
+	struct ynl_dump_list_type *last;
+	size_t alloc_sz;
+	mnl_cb_t cb;
+	__u32 rsp_cmd;
+};
+
+struct ynl_ntf_info {
+	struct ynl_policy_nest *policy;
+	mnl_cb_t cb;
+	size_t alloc_sz;
+	void (*free)(struct ynl_ntf_base_type *ntf);
+};
+
+int ynl_exec(struct ynl_sock *ys, struct nlmsghdr *req_nlh,
+	     struct ynl_req_state *yrs);
+int ynl_exec_dump(struct ynl_sock *ys, struct nlmsghdr *req_nlh,
+		  struct ynl_dump_state *yds);
+
+void ynl_error_unknown_notification(struct ynl_sock *ys, __u8 cmd);
+int ynl_error_parse(struct ynl_parse_arg *yarg, const char *msg);
+
+#endif
diff --git a/tools/net/ynl/lib/ynl.py b/tools/net/ynl/lib/ynl.py
new file mode 100644
index 0000000000..13c4b019a8
--- /dev/null
+++ b/tools/net/ynl/lib/ynl.py
@@ -0,0 +1,729 @@
+# 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.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
+
+    @classmethod
+    def formatted_string(cls, 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 as_scalar(self, attr_type, byte_order=None):
+        format = self.get_format(attr_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 as_struct(self, members):
+        value = dict()
+        offset = 0
+        for m in members:
+            # TODO: handle non-scalar members
+            if m.type == 'binary':
+                decoded = self.raw[offset:offset+m['len']]
+                offset += m['len']
+            elif m.type in NlAttr.type_formats:
+                format = self.get_format(m.type, m.byte_order)
+                [ decoded ] = format.unpack_from(self.raw, offset)
+                offset += format.size
+            if m.display_hint:
+                decoded = self.formatted_string(decoded, m.display_hint)
+            value[m.name] = decoded
+        return value
+
+    def __repr__(self):
+        return f"[type:{self.type} len:{self._len}] {self.raw}"
+
+
+class NlAttrs:
+    def __init__(self, msg):
+        self.attrs = []
+
+        offset = 0
+        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._fixed_header_size(op)
+        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]
+
+
+#
+# YNL implementation details.
+#
+
+
+class YnlFamily(SpecFamily):
+    def __init__(self, def_path, schema=None):
+        super().__init__(def_path, schema)
+
+        self.include_raw = False
+
+        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):
+        try:
+            attr = self.attr_sets[space][name]
+        except KeyError:
+            raise Exception(f"Space '{space}' has no attribute '{name}'")
+        nl_type = attr.value
+        if attr["type"] == 'nest':
+            nl_type |= Netlink.NLA_F_NESTED
+            attr_payload = b''
+            for subname, subvalue in value.items():
+                attr_payload += self._add_attr(attr['nested-attributes'], subname, subvalue)
+        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)
+            else:
+                raise Exception(f'Unknown type for binary attribute, value: {value}')
+        elif attr['type'] in NlAttr.type_formats:
+            format = NlAttr.get_format(attr['type'], attr.byte_order)
+            attr_payload = format.pack(int(value))
+        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-as-flags' in attr_spec and attr_spec['enum-as-flags']:
+            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:
+            members = self.consts[attr_spec.struct_name]
+            decoded = attr.as_struct(members)
+            for m in members:
+                if m.enum:
+                    decoded[m.name] = self._decode_enum(decoded[m.name], m)
+        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 = NlAttr.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(self, attrs, 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:
+                raise Exception(f"Space '{space}' has no attribute with value '{attr.type}'")
+            if attr_spec["type"] == 'nest':
+                subdict = self._decode(NlAttrs(attr.raw), attr_spec['nested-attributes'])
+                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["type"] in NlAttr.type_formats:
+                decoded = attr.as_scalar(attr_spec['type'], attr_spec.byte_order)
+            elif attr_spec["type"] == 'array-nest':
+                decoded = self._decode_array_nest(attr, attr_spec)
+            else:
+                raise Exception(f'Unknown {attr_spec["type"]} with name {attr_spec["name"]}')
+
+            if 'enum' in attr_spec:
+                decoded = self._decode_enum(decoded, attr_spec)
+
+            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]
+
+        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._fixed_header_size(op)
+        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 _fixed_header_size(self, op):
+        if op.fixed_header:
+            fixed_header_members = self.consts[op.fixed_header].members
+            size = 0
+            for m in fixed_header_members:
+                format = NlAttr.get_format(m.type, m.byte_order)
+                size += format.size
+            return size
+        else:
+            return 0
+
+    def _decode_fixed_header(self, msg, name):
+        fixed_header_members = self.consts[name].members
+        fixed_header_attrs = dict()
+        offset = 0
+        for m in fixed_header_members:
+            format = NlAttr.get_format(m.type, m.byte_order)
+            [ value ] = format.unpack_from(msg.raw, offset)
+            offset += format.size
+            if m.enum:
+                value = self._decode_enum(value, m)
+            fixed_header_attrs[m.name] = value
+        return fixed_header_attrs
+
+    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_fixed_header(decoded, 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, 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)
+        fixed_header_members = []
+        if op.fixed_header:
+            fixed_header_members = self.consts[op.fixed_header].members
+            for m in fixed_header_members:
+                value = vals.pop(m.name) if m.name in vals else 0
+                format = NlAttr.get_format(m.type, m.byte_order)
+                msg += format.pack(value)
+        for name, value in vals.items():
+            msg += self._add_attr(op.attr_set.name, name, value)
+        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_fixed_header(decoded, 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):
+        return self._op(method, vals, flags)
+
+    def dump(self, method, vals):
+        return self._op(method, vals, [], dump=True)