tools: ynl: Add fixed-header support to ynl

Add support for netlink families that add an optional fixed header structure
after the genetlink header and before any attributes. The fixed-header can be
specified on a per op basis, or once for all operations, which serves as a
default value that can be overridden.

Signed-off-by: Donald Hunter <donald.hunter@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Donald Hunter 2023-03-27 09:31:35 +01:00 committed by Jakub Kicinski
parent 2607191395
commit f036d936ca
3 changed files with 44 additions and 12 deletions

View file

@ -261,6 +261,14 @@ properties:
async-enum:
description: Name for the enum type with notifications/events.
type: string
# Start genetlink-legacy
fixed-header: &fixed-header
description: |
Name of the structure defining the optional fixed-length protocol
header. This header is placed in a message after the netlink and
genetlink headers and before any attributes.
type: string
# End genetlink-legacy
list:
description: List of commands
type: array
@ -293,6 +301,9 @@ properties:
type: array
items:
enum: [ strict, dump ]
# Start genetlink-legacy
fixed-header: *fixed-header
# End genetlink-legacy
do: &subop-type
description: Main command handler.
type: object

View file

@ -263,16 +263,17 @@ class SpecOperation(SpecElement):
Information about a single Netlink operation.
Attributes:
value numerical ID when serialized, None if req/rsp values differ
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
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
yaml raw spec as loaded from the spec file
"""
def __init__(self, family, yaml, req_value, rsp_value):
super().__init__(family, yaml)
@ -284,6 +285,7 @@ class SpecOperation(SpecElement):
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
@ -324,6 +326,7 @@ class SpecFamily(SpecElement):
msgs_by_value dict of all messages (indexed by name)
ops dict of all valid requests / responses
consts dict of all constants/enums
fixed_header string, optional name of family default fixed header struct
"""
def __init__(self, spec_path, schema_path=None):
with open(spec_path, "r") as stream:
@ -397,6 +400,7 @@ class SpecFamily(SpecElement):
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:
@ -408,6 +412,7 @@ class SpecFamily(SpecElement):
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:

View file

@ -278,14 +278,22 @@ def _genl_load_families():
class GenlMsg:
def __init__(self, nl_msg):
def __init__(self, nl_msg, fixed_header_members=[]):
self.nl = nl_msg
self.hdr = nl_msg.raw[0:4]
self.raw = nl_msg.raw[4:]
offset = 4
self.genl_cmd, self.genl_version, _ = struct.unpack("BBH", self.hdr)
self.fixed_header_attrs = dict()
for m in fixed_header_members:
format, size = NlAttr.type_formats[m.type]
decoded = struct.unpack_from(format, nl_msg.raw, offset)
offset += size
self.fixed_header_attrs[m.name] = decoded[0]
self.raw = nl_msg.raw[offset:]
self.raw_attrs = NlAttrs(self.raw)
def __repr__(self):
@ -509,6 +517,13 @@ class YnlFamily(SpecFamily):
req_seq = random.randint(1024, 65535)
msg = _genl_msg(self.family.family_id, 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)
format, _ = NlAttr.type_formats[m.type]
msg += struct.pack(format, value)
for name, value in vals.items():
msg += self._add_attr(op.attr_set.name, name, value)
msg = _genl_msg_finalize(msg)
@ -535,7 +550,7 @@ class YnlFamily(SpecFamily):
done = True
break
gm = GenlMsg(nl_msg)
gm = GenlMsg(nl_msg, fixed_header_members)
# Check if this is a reply to our request
if nl_msg.nl_seq != req_seq or gm.genl_cmd != op.rsp_value:
if gm.genl_cmd in self.async_msg_ids:
@ -545,7 +560,8 @@ class YnlFamily(SpecFamily):
print('Unexpected message: ' + repr(gm))
continue
rsp.append(self._decode(gm.raw_attrs, op.attr_set.name))
rsp.append(self._decode(gm.raw_attrs, op.attr_set.name)
| gm.fixed_header_attrs)
if not rsp:
return None