@@ -1,10 +1,12 @@
# 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
from .nlspec import SpecFamily
@@ -76,10 +78,17 @@ class NlError(Exception):
class NlAttr:
- type_formats = { 'u8' : ('B', 1), 's8' : ('b', 1),
- 'u16': ('H', 2), 's16': ('h', 2),
- 'u32': ('I', 4), 's32': ('i', 4),
- 'u64': ('Q', 8), 's64': ('q', 8) }
+ 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])
@@ -88,25 +97,17 @@ class NlAttr:
self.full_len = (self.payload_len + 3) & ~3
self.raw = raw[offset + 4:offset + self.payload_len]
- def format_byte_order(byte_order):
+ @classmethod
+ def get_format(cls, attr_type, byte_order=None):
+ format = cls.type_formats[attr_type]
if byte_order:
- return ">" if byte_order == "big-endian" else "<"
- return ""
+ return format.big if byte_order == "big-endian" \
+ else format.little
+ return format.native
- def as_u8(self):
- return struct.unpack("B", self.raw)[0]
-
- def as_u16(self, byte_order=None):
- endian = NlAttr.format_byte_order(byte_order)
- return struct.unpack(f"{endian}H", self.raw)[0]
-
- def as_u32(self, byte_order=None):
- endian = NlAttr.format_byte_order(byte_order)
- return struct.unpack(f"{endian}I", self.raw)[0]
-
- def as_u64(self, byte_order=None):
- endian = NlAttr.format_byte_order(byte_order)
- return struct.unpack(f"{endian}Q", self.raw)[0]
+ 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]
@@ -115,17 +116,17 @@ class NlAttr:
return self.raw
def as_c_array(self, type):
- format, _ = self.type_formats[type]
- return list({ x[0] for x in struct.iter_unpack(format, self.raw) })
+ format = self.get_format(type)
+ return list({ 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
- format, size = self.type_formats[m.type]
- decoded = struct.unpack_from(format, self.raw, offset)
- offset += size
+ format = self.get_format(m.type)
+ decoded = format.unpack_from(self.raw, offset)
+ offset += format.size
value[m.name] = decoded[0]
return value
@@ -184,11 +185,11 @@ class NlMsg:
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_u32()
+ self.extack['miss-type'] = extack.as_scalar('u32')
elif extack.type == Netlink.NLMSGERR_ATTR_MISS_NEST:
- self.extack['miss-nest'] = extack.as_u32()
+ self.extack['miss-nest'] = extack.as_scalar('u32')
elif extack.type == Netlink.NLMSGERR_ATTR_OFFS:
- self.extack['bad-attr-offs'] = extack.as_u32()
+ self.extack['bad-attr-offs'] = extack.as_scalar('u32')
else:
if 'unknown' not in self.extack:
self.extack['unknown'] = []
@@ -272,11 +273,11 @@ def _genl_load_families():
fam = dict()
for attr in gm.raw_attrs:
if attr.type == Netlink.CTRL_ATTR_FAMILY_ID:
- fam['id'] = attr.as_u16()
+ 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_u32()
+ fam['maxattr'] = attr.as_scalar('u32')
elif attr.type == Netlink.CTRL_ATTR_MCAST_GROUPS:
fam['mcast'] = dict()
for entry in NlAttrs(attr.raw):
@@ -286,7 +287,7 @@ def _genl_load_families():
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_u32()
+ 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:
@@ -304,9 +305,9 @@ class GenlMsg:
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
+ format = NlAttr.get_format(m.type)
+ decoded = format.unpack_from(nl_msg.raw, offset)
+ offset += format.size
self.fixed_header_attrs[m.name] = decoded[0]
self.raw = nl_msg.raw[offset:]
@@ -381,23 +382,16 @@ class YnlFamily(SpecFamily):
attr_payload += self._add_attr(attr['nested-attributes'], subname, subvalue)
elif attr["type"] == 'flag':
attr_payload = b''
- elif attr["type"] == 'u8':
- attr_payload = struct.pack("B", int(value))
- elif attr["type"] == 'u16':
- endian = NlAttr.format_byte_order(attr.byte_order)
- attr_payload = struct.pack(f"{endian}H", int(value))
- elif attr["type"] == 'u32':
- endian = NlAttr.format_byte_order(attr.byte_order)
- attr_payload = struct.pack(f"{endian}I", int(value))
- elif attr["type"] == 'u64':
- endian = NlAttr.format_byte_order(attr.byte_order)
- attr_payload = struct.pack(f"{endian}Q", int(value))
elif attr["type"] == 'string':
attr_payload = str(value).encode('ascii') + b'\x00'
elif attr["type"] == 'binary':
attr_payload = value
else:
- raise Exception(f'Unknown type at {space} {name} {value} {attr["type"]}')
+ try:
+ format = NlAttr.get_format(attr['type'], attr.byte_order)
+ attr_payload = format.pack(int(value))
+ except:
+ 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
@@ -434,22 +428,17 @@ class YnlFamily(SpecFamily):
if attr_spec["type"] == 'nest':
subdict = self._decode(NlAttrs(attr.raw), attr_spec['nested-attributes'])
decoded = subdict
- elif attr_spec['type'] == 'u8':
- decoded = attr.as_u8()
- elif attr_spec['type'] == 'u16':
- decoded = attr.as_u16(attr_spec.byte_order)
- elif attr_spec['type'] == 'u32':
- decoded = attr.as_u32(attr_spec.byte_order)
- elif attr_spec['type'] == 'u64':
- decoded = attr.as_u64(attr_spec.byte_order)
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
- else:
- raise Exception(f'Unknown {attr.type} {attr_spec["name"]} {attr_spec["type"]}')
+ elif attr_spec["type"]:
+ try:
+ decoded = attr.as_scalar(attr_spec['type'], attr_spec.byte_order)
+ except:
+ raise Exception(f'Unknown {attr_spec["type"]} with name {attr_spec["name"]}')
if not attr_spec.is_multi:
rsp[attr_spec['name']] = decoded
@@ -555,8 +544,8 @@ class YnlFamily(SpecFamily):
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)
+ format = NlAttr.get_format(m.type)
+ 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)
Use a dict of predefined Struct() objects to decode scalar types in native, big or little endian format. This removes the repetitive code for the scalar variants and ensures all the signed variants are supported. Signed-off-by: Donald Hunter <donald.hunter@gmail.com> --- tools/net/ynl/lib/ynl.py | 107 ++++++++++++++++++--------------------- 1 file changed, 48 insertions(+), 59 deletions(-)