1 # SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
2
3 from collections import namedtuple
4 from enum import Enum
5 import functools
6 import os
7 import random
8 import socket
9 import struct
10 from struct import Struct
11 import sys
12 import yaml
13 import ipaddress
14 import uuid
15
16 from .nlspec import SpecFamily
17
18 #
19 # Generic Netlink code which should really be in some library, but I can't quickly find one.
20 #
21
22
23 class Netlink:
24 # Netlink socket
25 SOL_NETLINK = 270
26
27 NETLINK_ADD_MEMBERSHIP = 1
28 NETLINK_CAP_ACK = 10
29 NETLINK_EXT_ACK = 11
30 NETLINK_GET_STRICT_CHK = 12
31
32 # Netlink message
33 NLMSG_ERROR = 2
34 NLMSG_DONE = 3
35
36 NLM_F_REQUEST = 1
37 NLM_F_ACK = 4
38 NLM_F_ROOT = 0x100
39 NLM_F_MATCH = 0x200
40
41 NLM_F_REPLACE = 0x100
42 NLM_F_EXCL = 0x200
43 NLM_F_CREATE = 0x400
44 NLM_F_APPEND = 0x800
45
46 NLM_F_CAPPED = 0x100
47 NLM_F_ACK_TLVS = 0x200
48
49 NLM_F_DUMP = NLM_F_ROOT | NLM_F_MATCH
50
51 NLA_F_NESTED = 0x8000
52 NLA_F_NET_BYTEORDER = 0x4000
53
54 NLA_TYPE_MASK = NLA_F_NESTED | NLA_F_NET_BYTEORDER
55
56 # Genetlink defines
57 NETLINK_GENERIC = 16
58
59 GENL_ID_CTRL = 0x10
60
61 # nlctrl
62 CTRL_CMD_GETFAMILY = 3
63
64 CTRL_ATTR_FAMILY_ID = 1
65 CTRL_ATTR_FAMILY_NAME = 2
66 CTRL_ATTR_MAXATTR = 5
67 CTRL_ATTR_MCAST_GROUPS = 7
68
69 CTRL_ATTR_MCAST_GRP_NAME = 1
70 CTRL_ATTR_MCAST_GRP_ID = 2
71
72 # Extack types
73 NLMSGERR_ATTR_MSG = 1
74 NLMSGERR_ATTR_OFFS = 2
75 NLMSGERR_ATTR_COOKIE = 3
76 NLMSGERR_ATTR_POLICY = 4
77 NLMSGERR_ATTR_MISS_TYPE = 5
78 NLMSGERR_ATTR_MISS_NEST = 6
79
80 # Policy types
81 NL_POLICY_TYPE_ATTR_TYPE = 1
82 NL_POLICY_TYPE_ATTR_MIN_VALUE_S = 2
83 NL_POLICY_TYPE_ATTR_MAX_VALUE_S = 3
84 NL_POLICY_TYPE_ATTR_MIN_VALUE_U = 4
85 NL_POLICY_TYPE_ATTR_MAX_VALUE_U = 5
86 NL_POLICY_TYPE_ATTR_MIN_LENGTH = 6
87 NL_POLICY_TYPE_ATTR_MAX_LENGTH = 7
88 NL_POLICY_TYPE_ATTR_POLICY_IDX = 8
89 NL_POLICY_TYPE_ATTR_POLICY_MAXTYPE = 9
90 NL_POLICY_TYPE_ATTR_BITFIELD32_MASK = 10
91 NL_POLICY_TYPE_ATTR_PAD = 11
92 NL_POLICY_TYPE_ATTR_MASK = 12
93
94 AttrType = Enum('AttrType', ['flag', 'u8', 'u16', 'u32', 'u64',
95 's8', 's16', 's32', 's64',
96 'binary', 'string', 'nul-string',
97 'nested', 'nested-array',
98 'bitfield32', 'sint', 'uint'])
99
100 class NlError(Exception):
101 def __init__(self, nl_msg):
102 self.nl_msg = nl_msg
103 self.error = -nl_msg.error
104
105 def __str__(self):
106 return f"Netlink error: {os.strerror(self.error)}\n{self.nl_msg}"
107
108
109 class ConfigError(Exception):
110 pass
111
112
113 class NlAttr:
114 ScalarFormat = namedtuple('ScalarFormat', ['native', 'big', 'little'])
115 type_formats = {
116 'u8' : ScalarFormat(Struct('B'), Struct("B"), Struct("B")),
117 's8' : ScalarFormat(Struct('b'), Struct("b"), Struct("b")),
118 'u16': ScalarFormat(Struct('H'), Struct(">H"), Struct("<H")),
119 's16': ScalarFormat(Struct('h'), Struct(">h"), Struct("<h")),
120 'u32': ScalarFormat(Struct('I'), Struct(">I"), Struct("<I")),
121 's32': ScalarFormat(Struct('i'), Struct(">i"), Struct("<i")),
122 'u64': ScalarFormat(Struct('Q'), Struct(">Q"), Struct("<Q")),
123 's64': ScalarFormat(Struct('q'), Struct(">q"), Struct("<q"))
124 }
125
126 def __init__(self, raw, offset):
127 self._len, self._type = struct.unpack("HH", raw[offset : offset + 4])
128 self.type = self._type & ~Netlink.NLA_TYPE_MASK
129 self.is_nest = self._type & Netlink.NLA_F_NESTED
130 self.payload_len = self._len
131 self.full_len = (self.payload_len + 3) & ~3
132 self.raw = raw[offset + 4 : offset + self.payload_len]
133
134 @classmethod
135 def get_format(cls, attr_type, byte_order=None):
136 format = cls.type_formats[attr_type]
137 if byte_order:
138 return format.big if byte_order == "big-endian" \
139 else format.little
140 return format.native
141
142 def as_scalar(self, attr_type, byte_order=None):
143 format = self.get_format(attr_type, byte_order)
144 return format.unpack(self.raw)[0]
145
146 def as_auto_scalar(self, attr_type, byte_order=None):
147 if len(self.raw) != 4 and len(self.raw) != 8:
148 raise Exception(f"Auto-scalar len payload be 4 or 8 bytes, got {len(self.raw)}")
149 real_type = attr_type[0] + str(len(self.raw) * 8)
150 format = self.get_format(real_type, byte_order)
151 return format.unpack(self.raw)[0]
152
153 def as_strz(self):
154 return self.raw.decode('ascii')[:-1]
155
156 def as_bin(self):
157 return self.raw
158
159 def as_c_array(self, type):
160 format = self.get_format(type)
161 return [ x[0] for x in format.iter_unpack(self.raw) ]
162
163 def __repr__(self):
164 return f"[type:{self.type} len:{self._len}] {self.raw}"
165
166
167 class NlAttrs:
168 def __init__(self, msg, offset=0):
169 self.attrs = []
170
171 while offset < len(msg):
172 attr = NlAttr(msg, offset)
173 offset += attr.full_len
174 self.attrs.append(attr)
175
176 def __iter__(self):
177 yield from self.attrs
178
179 def __repr__(self):
180 msg = ''
181 for a in self.attrs:
182 if msg:
183 msg += '\n'
184 msg += repr(a)
185 return msg
186
187
188 class NlMsg:
189 def __init__(self, msg, offset, attr_space=None):
190 self.hdr = msg[offset : offset + 16]
191
192 self.nl_len, self.nl_type, self.nl_flags, self.nl_seq, self.nl_portid = \
193 struct.unpack("IHHII", self.hdr)
194
195 self.raw = msg[offset + 16 : offset + self.nl_len]
196
197 self.error = 0
198 self.done = 0
199
200 extack_off = None
201 if self.nl_type == Netlink.NLMSG_ERROR:
202 self.error = struct.unpack("i", self.raw[0:4])[0]
203 self.done = 1
204 extack_off = 20
205 elif self.nl_type == Netlink.NLMSG_DONE:
206 self.error = struct.unpack("i", self.raw[0:4])[0]
207 self.done = 1
208 extack_off = 4
209
210 self.extack = None
211 if self.nl_flags & Netlink.NLM_F_ACK_TLVS and extack_off:
212 self.extack = dict()
213 extack_attrs = NlAttrs(self.raw[extack_off:])
214 for extack in extack_attrs:
215 if extack.type == Netlink.NLMSGERR_ATTR_MSG:
216 self.extack['msg'] = extack.as_strz()
217 elif extack.type == Netlink.NLMSGERR_ATTR_MISS_TYPE:
218 self.extack['miss-type'] = extack.as_scalar('u32')
219 elif extack.type == Netlink.NLMSGERR_ATTR_MISS_NEST:
220 self.extack['miss-nest'] = extack.as_scalar('u32')
221 elif extack.type == Netlink.NLMSGERR_ATTR_OFFS:
222 self.extack['bad-attr-offs'] = extack.as_scalar('u32')
223 elif extack.type == Netlink.NLMSGERR_ATTR_POLICY:
224 self.extack['policy'] = self._decode_policy(extack.raw)
225 else:
226 if 'unknown' not in self.extack:
227 self.extack['unknown'] = []
228 self.extack['unknown'].append(extack)
229
230 if attr_space:
231 # We don't have the ability to parse nests yet, so only do global
232 if 'miss-type' in self.extack and 'miss-nest' not in self.extack:
233 miss_type = self.extack['miss-type']
234 if miss_type in attr_space.attrs_by_val:
235 spec = attr_space.attrs_by_val[miss_type]
236 self.extack['miss-type'] = spec['name']
237 if 'doc' in spec:
238 self.extack['miss-type-doc'] = spec['doc']
239
240 def _decode_policy(self, raw):
241 policy = {}
242 for attr in NlAttrs(raw):
243 if attr.type == Netlink.NL_POLICY_TYPE_ATTR_TYPE:
244 type = attr.as_scalar('u32')
245 policy['type'] = Netlink.AttrType(type).name
246 elif attr.type == Netlink.NL_POLICY_TYPE_ATTR_MIN_VALUE_S:
247 policy['min-value'] = attr.as_scalar('s64')
248 elif attr.type == Netlink.NL_POLICY_TYPE_ATTR_MAX_VALUE_S:
249 policy['max-value'] = attr.as_scalar('s64')
250 elif attr.type == Netlink.NL_POLICY_TYPE_ATTR_MIN_VALUE_U:
251 policy['min-value'] = attr.as_scalar('u64')
252 elif attr.type == Netlink.NL_POLICY_TYPE_ATTR_MAX_VALUE_U:
253 policy['max-value'] = attr.as_scalar('u64')
254 elif attr.type == Netlink.NL_POLICY_TYPE_ATTR_MIN_LENGTH:
255 policy['min-length'] = attr.as_scalar('u32')
256 elif attr.type == Netlink.NL_POLICY_TYPE_ATTR_MAX_LENGTH:
257 policy['max-length'] = attr.as_scalar('u32')
258 elif attr.type == Netlink.NL_POLICY_TYPE_ATTR_BITFIELD32_MASK:
259 policy['bitfield32-mask'] = attr.as_scalar('u32')
260 elif attr.type == Netlink.NL_POLICY_TYPE_ATTR_MASK:
261 policy['mask'] = attr.as_scalar('u64')
262 return policy
263
264 def cmd(self):
265 return self.nl_type
266
267 def __repr__(self):
268 msg = f"nl_len = {self.nl_len} ({len(self.raw)}) nl_flags = 0x{self.nl_flags:x} nl_type = {self.nl_type}"
269 if self.error:
270 msg += '\n\terror: ' + str(self.error)
271 if self.extack:
272 msg += '\n\textack: ' + repr(self.extack)
273 return msg
274
275
276 class NlMsgs:
277 def __init__(self, data, attr_space=None):
278 self.msgs = []
279
280 offset = 0
281 while offset < len(data):
282 msg = NlMsg(data, offset, attr_space=attr_space)
283 offset += msg.nl_len
284 self.msgs.append(msg)
285
286 def __iter__(self):
287 yield from self.msgs
288
289
290 genl_family_name_to_id = None
291
292
293 def _genl_msg(nl_type, nl_flags, genl_cmd, genl_version, seq=None):
294 # we prepend length in _genl_msg_finalize()
295 if seq is None:
296 seq = random.randint(1, 1024)
297 nlmsg = struct.pack("HHII", nl_type, nl_flags, seq, 0)
298 genlmsg = struct.pack("BBH", genl_cmd, genl_version, 0)
299 return nlmsg + genlmsg
300
301
302 def _genl_msg_finalize(msg):
303 return struct.pack("I", len(msg) + 4) + msg
304
305
306 def _genl_load_families():
307 with socket.socket(socket.AF_NETLINK, socket.SOCK_RAW, Netlink.NETLINK_GENERIC) as sock:
308 sock.setsockopt(Netlink.SOL_NETLINK, Netlink.NETLINK_CAP_ACK, 1)
309
310 msg = _genl_msg(Netlink.GENL_ID_CTRL,
311 Netlink.NLM_F_REQUEST | Netlink.NLM_F_ACK | Netlink.NLM_F_DUMP,
312 Netlink.CTRL_CMD_GETFAMILY, 1)
313 msg = _genl_msg_finalize(msg)
314
315 sock.send(msg, 0)
316
317 global genl_family_name_to_id
318 genl_family_name_to_id = dict()
319
320 while True:
321 reply = sock.recv(128 * 1024)
322 nms = NlMsgs(reply)
323 for nl_msg in nms:
324 if nl_msg.error:
325 print("Netlink error:", nl_msg.error)
326 return
327 if nl_msg.done:
328 return
329
330 gm = GenlMsg(nl_msg)
331 fam = dict()
332 for attr in NlAttrs(gm.raw):
333 if attr.type == Netlink.CTRL_ATTR_FAMILY_ID:
334 fam['id'] = attr.as_scalar('u16')
335 elif attr.type == Netlink.CTRL_ATTR_FAMILY_NAME:
336 fam['name'] = attr.as_strz()
337 elif attr.type == Netlink.CTRL_ATTR_MAXATTR:
338 fam['maxattr'] = attr.as_scalar('u32')
339 elif attr.type == Netlink.CTRL_ATTR_MCAST_GROUPS:
340 fam['mcast'] = dict()
341 for entry in NlAttrs(attr.raw):
342 mcast_name = None
343 mcast_id = None
344 for entry_attr in NlAttrs(entry.raw):
345 if entry_attr.type == Netlink.CTRL_ATTR_MCAST_GRP_NAME:
346 mcast_name = entry_attr.as_strz()
347 elif entry_attr.type == Netlink.CTRL_ATTR_MCAST_GRP_ID:
348 mcast_id = entry_attr.as_scalar('u32')
349 if mcast_name and mcast_id is not None:
350 fam['mcast'][mcast_name] = mcast_id
351 if 'name' in fam and 'id' in fam:
352 genl_family_name_to_id[fam['name']] = fam
353
354
355 class GenlMsg:
356 def __init__(self, nl_msg):
357 self.nl = nl_msg
358 self.genl_cmd, self.genl_version, _ = struct.unpack_from("BBH", nl_msg.raw, 0)
359 self.raw = nl_msg.raw[4:]
360
361 def cmd(self):
362 return self.genl_cmd
363
364 def __repr__(self):
365 msg = repr(self.nl)
366 msg += f"\tgenl_cmd = {self.genl_cmd} genl_ver = {self.genl_version}\n"
367 for a in self.raw_attrs:
368 msg += '\t\t' + repr(a) + '\n'
369 return msg
370
371
372 class NetlinkProtocol:
373 def __init__(self, family_name, proto_num):
374 self.family_name = family_name
375 self.proto_num = proto_num
376
377 def _message(self, nl_type, nl_flags, seq=None):
378 if seq is None:
379 seq = random.randint(1, 1024)
380 nlmsg = struct.pack("HHII", nl_type, nl_flags, seq, 0)
381 return nlmsg
382
383 def message(self, flags, command, version, seq=None):
384 return self._message(command, flags, seq)
385
386 def _decode(self, nl_msg):
387 return nl_msg
388
389 def decode(self, ynl, nl_msg, op):
390 msg = self._decode(nl_msg)
391 if op is None:
392 op = ynl.rsp_by_value[msg.cmd()]
393 fixed_header_size = ynl._struct_size(op.fixed_header)
394 msg.raw_attrs = NlAttrs(msg.raw, fixed_header_size)
395 return msg
396
397 def get_mcast_id(self, mcast_name, mcast_groups):
398 if mcast_name not in mcast_groups:
399 raise Exception(f'Multicast group "{mcast_name}" not present in the spec')
400 return mcast_groups[mcast_name].value
401
402 def msghdr_size(self):
403 return 16
404
405
406 class GenlProtocol(NetlinkProtocol):
407 def __init__(self, family_name):
408 super().__init__(family_name, Netlink.NETLINK_GENERIC)
409
410 global genl_family_name_to_id
411 if genl_family_name_to_id is None:
412 _genl_load_families()
413
414 self.genl_family = genl_family_name_to_id[family_name]
415 self.family_id = genl_family_name_to_id[family_name]['id']
416
417 def message(self, flags, command, version, seq=None):
418 nlmsg = self._message(self.family_id, flags, seq)
419 genlmsg = struct.pack("BBH", command, version, 0)
420 return nlmsg + genlmsg
421
422 def _decode(self, nl_msg):
423 return GenlMsg(nl_msg)
424
425 def get_mcast_id(self, mcast_name, mcast_groups):
426 if mcast_name not in self.genl_family['mcast']:
427 raise Exception(f'Multicast group "{mcast_name}" not present in the family')
428 return self.genl_family['mcast'][mcast_name]
429
430 def msghdr_size(self):
431 return super().msghdr_size() + 4
432
433
434 class SpaceAttrs:
435 SpecValuesPair = namedtuple('SpecValuesPair', ['spec', 'values'])
436
437 def __init__(self, attr_space, attrs, outer = None):
438 outer_scopes = outer.scopes if outer else []
439 inner_scope = self.SpecValuesPair(attr_space, attrs)
440 self.scopes = [inner_scope] + outer_scopes
441
442 def lookup(self, name):
443 for scope in self.scopes:
444 if name in scope.spec:
445 if name in scope.values:
446 return scope.values[name]
447 spec_name = scope.spec.yaml['name']
448 raise Exception(
449 f"No value for '{name}' in attribute space '{spec_name}'")
450 raise Exception(f"Attribute '{name}' not defined in any attribute-set")
451
452
453 #
454 # YNL implementation details.
455 #
456
457
458 class YnlFamily(SpecFamily):
459 def __init__(self, def_path, schema=None, process_unknown=False,
460 recv_size=0):
461 super().__init__(def_path, schema)
462
463 self.include_raw = False
464 self.process_unknown = process_unknown
465
466 try:
467 if self.proto == "netlink-raw":
468 self.nlproto = NetlinkProtocol(self.yaml['name'],
469 self.yaml['protonum'])
470 else:
471 self.nlproto = GenlProtocol(self.yaml['name'])
472 except KeyError:
473 raise Exception(f"Family '{self.yaml['name']}' not supported by the kernel")
474
475 self._recv_dbg = False
476 # Note that netlink will use conservative (min) message size for
477 # the first dump recv() on the socket, our setting will only matter
478 # from the second recv() on.
479 self._recv_size = recv_size if recv_size else 131072
480 # Netlink will always allocate at least PAGE_SIZE - sizeof(skb_shinfo)
481 # for a message, so smaller receive sizes will lead to truncation.
482 # Note that the min size for other families may be larger than 4k!
483 if self._recv_size < 4000:
484 raise ConfigError()
485
486 self.sock = socket.socket(socket.AF_NETLINK, socket.SOCK_RAW, self.nlproto.proto_num)
487 self.sock.setsockopt(Netlink.SOL_NETLINK, Netlink.NETLINK_CAP_ACK, 1)
488 self.sock.setsockopt(Netlink.SOL_NETLINK, Netlink.NETLINK_EXT_ACK, 1)
489 self.sock.setsockopt(Netlink.SOL_NETLINK, Netlink.NETLINK_GET_STRICT_CHK, 1)
490
491 self.async_msg_ids = set()
492 self.async_msg_queue = []
493
494 for msg in self.msgs.values():
495 if msg.is_async:
496 self.async_msg_ids.add(msg.rsp_value)
497
498 for op_name, op in self.ops.items():
499 bound_f = functools.partial(self._op, op_name)
500 setattr(self, op.ident_name, bound_f)
501
502
503 def ntf_subscribe(self, mcast_name):
504 mcast_id = self.nlproto.get_mcast_id(mcast_name, self.mcast_groups)
505 self.sock.bind((0, 0))
506 self.sock.setsockopt(Netlink.SOL_NETLINK, Netlink.NETLINK_ADD_MEMBERSHIP,
507 mcast_id)
508
509 def set_recv_dbg(self, enabled):
510 self._recv_dbg = enabled
511
512 def _recv_dbg_print(self, reply, nl_msgs):
513 if not self._recv_dbg:
514 return
515 print("Recv: read", len(reply), "bytes,",
516 len(nl_msgs.msgs), "messages", file=sys.stderr)
517 for nl_msg in nl_msgs:
518 print(" ", nl_msg, file=sys.stderr)
519
520 def _encode_enum(self, attr_spec, value):
521 enum = self.consts[attr_spec['enum']]
522 if enum.type == 'flags' or attr_spec.get('enum-as-flags', False):
523 scalar = 0
524 if isinstance(value, str):
525 value = [value]
526 for single_value in value:
527 scalar += enum.entries[single_value].user_value(as_flags = True)
528 return scalar
529 else:
530 return enum.entries[value].user_value()
531
532 def _get_scalar(self, attr_spec, value):
533 try:
534 return int(value)
535 except (ValueError, TypeError) as e:
536 if 'enum' not in attr_spec:
537 raise e
538 return self._encode_enum(attr_spec, value)
539
540 def _add_attr(self, space, name, value, search_attrs):
541 try:
542 attr = self.attr_sets[space][name]
543 except KeyError:
544 raise Exception(f"Space '{space}' has no attribute '{name}'")
545 nl_type = attr.value
546
547 if attr.is_multi and isinstance(value, list):
548 attr_payload = b''
549 for subvalue in value:
550 attr_payload += self._add_attr(space, name, subvalue, search_attrs)
551 return attr_payload
552
553 if attr["type"] == 'nest':
554 nl_type |= Netlink.NLA_F_NESTED
555 attr_payload = b''
556 sub_attrs = SpaceAttrs(self.attr_sets[space], value, search_attrs)
557 for subname, subvalue in value.items():
558 attr_payload += self._add_attr(attr['nested-attributes'],
559 subname, subvalue, sub_attrs)
560 elif attr["type"] == 'flag':
561 if not value:
562 # If value is absent or false then skip attribute creation.
563 return b''
564 attr_payload = b''
565 elif attr["type"] == 'string':
566 attr_payload = str(value).encode('ascii') + b'\x00'
567 elif attr["type"] == 'binary':
568 if isinstance(value, bytes):
569 attr_payload = value
570 elif isinstance(value, str):
571 attr_payload = bytes.fromhex(value)
572 elif isinstance(value, dict) and attr.struct_name:
573 attr_payload = self._encode_struct(attr.struct_name, value)
574 else:
575 raise Exception(f'Unknown type for binary attribute, value: {value}')
576 elif attr['type'] in NlAttr.type_formats or attr.is_auto_scalar:
577 scalar = self._get_scalar(attr, value)
578 if attr.is_auto_scalar:
579 attr_type = attr["type"][0] + ('32' if scalar.bit_length() <= 32 else '64')
580 else:
581 attr_type = attr["type"]
582 format = NlAttr.get_format(attr_type, attr.byte_order)
583 attr_payload = format.pack(scalar)
584 elif attr['type'] in "bitfield32":
585 scalar_value = self._get_scalar(attr, value["value"])
586 scalar_selector = self._get_scalar(attr, value["selector"])
587 attr_payload = struct.pack("II", scalar_value, scalar_selector)
588 elif attr['type'] == 'sub-message':
589 msg_format = self._resolve_selector(attr, search_attrs)
590 attr_payload = b''
591 if msg_format.fixed_header:
592 attr_payload += self._encode_struct(msg_format.fixed_header, value)
593 if msg_format.attr_set:
594 if msg_format.attr_set in self.attr_sets:
595 nl_type |= Netlink.NLA_F_NESTED
596 sub_attrs = SpaceAttrs(msg_format.attr_set, value, search_attrs)
597 for subname, subvalue in value.items():
598 attr_payload += self._add_attr(msg_format.attr_set,
599 subname, subvalue, sub_attrs)
600 else:
601 raise Exception(f"Unknown attribute-set '{msg_format.attr_set}'")
602 else:
603 raise Exception(f'Unknown type at {space} {name} {value} {attr["type"]}')
604
605 pad = b'\x00' * ((4 - len(attr_payload) % 4) % 4)
606 return struct.pack('HH', len(attr_payload) + 4, nl_type) + attr_payload + pad
607
608 def _decode_enum(self, raw, attr_spec):
609 enum = self.consts[attr_spec['enum']]
610 if enum.type == 'flags' or attr_spec.get('enum-as-flags', False):
611 i = 0
612 value = set()
613 while raw:
614 if raw & 1:
615 value.add(enum.entries_by_val[i].name)
616 raw >>= 1
617 i += 1
618 else:
619 value = enum.entries_by_val[raw].name
620 return value
621
622 def _decode_binary(self, attr, attr_spec):
623 if attr_spec.struct_name:
624 decoded = self._decode_struct(attr.raw, attr_spec.struct_name)
625 elif attr_spec.sub_type:
626 decoded = attr.as_c_array(attr_spec.sub_type)
627 else:
628 decoded = attr.as_bin()
629 if attr_spec.display_hint:
630 decoded = self._formatted_string(decoded, attr_spec.display_hint)
631 return decoded
632
633 def _decode_array_attr(self, attr, attr_spec):
634 decoded = []
635 offset = 0
636 while offset < len(attr.raw):
637 item = NlAttr(attr.raw, offset)
638 offset += item.full_len
639
640 if attr_spec["sub-type"] == 'nest':
641 subattrs = self._decode(NlAttrs(item.raw), attr_spec['nested-attributes'])
642 decoded.append({ item.type: subattrs })
643 elif attr_spec["sub-type"] == 'binary':
644 subattrs = item.as_bin()
645 if attr_spec.display_hint:
646 subattrs = self._formatted_string(subattrs, attr_spec.display_hint)
647 decoded.append(subattrs)
648 elif attr_spec["sub-type"] in NlAttr.type_formats:
649 subattrs = item.as_scalar(attr_spec['sub-type'], attr_spec.byte_order)
650 if attr_spec.display_hint:
651 subattrs = self._formatted_string(subattrs, attr_spec.display_hint)
652 decoded.append(subattrs)
653 else:
654 raise Exception(f'Unknown {attr_spec["sub-type"]} with name {attr_spec["name"]}')
655 return decoded
656
657 def _decode_nest_type_value(self, attr, attr_spec):
658 decoded = {}
659 value = attr
660 for name in attr_spec['type-value']:
661 value = NlAttr(value.raw, 0)
662 decoded[name] = value.type
663 subattrs = self._decode(NlAttrs(value.raw), attr_spec['nested-attributes'])
664 decoded.update(subattrs)
665 return decoded
666
667 def _decode_unknown(self, attr):
668 if attr.is_nest:
669 return self._decode(NlAttrs(attr.raw), None)
670 else:
671 return attr.as_bin()
672
673 def _rsp_add(self, rsp, name, is_multi, decoded):
674 if is_multi == None:
675 if name in rsp and type(rsp[name]) is not list:
676 rsp[name] = [rsp[name]]
677 is_multi = True
678 else:
679 is_multi = False
680
681 if not is_multi:
682 rsp[name] = decoded
683 elif name in rsp:
684 rsp[name].append(decoded)
685 else:
686 rsp[name] = [decoded]
687
688 def _resolve_selector(self, attr_spec, search_attrs):
689 sub_msg = attr_spec.sub_message
690 if sub_msg not in self.sub_msgs:
691 raise Exception(f"No sub-message spec named {sub_msg} for {attr_spec.name}")
692 sub_msg_spec = self.sub_msgs[sub_msg]
693
694 selector = attr_spec.selector
695 value = search_attrs.lookup(selector)
696 if value not in sub_msg_spec.formats:
697 raise Exception(f"No message format for '{value}' in sub-message spec '{sub_msg}'")
698
699 spec = sub_msg_spec.formats[value]
700 return spec
701
702 def _decode_sub_msg(self, attr, attr_spec, search_attrs):
703 msg_format = self._resolve_selector(attr_spec, search_attrs)
704 decoded = {}
705 offset = 0
706 if msg_format.fixed_header:
707 decoded.update(self._decode_struct(attr.raw, msg_format.fixed_header));
708 offset = self._struct_size(msg_format.fixed_header)
709 if msg_format.attr_set:
710 if msg_format.attr_set in self.attr_sets:
711 subdict = self._decode(NlAttrs(attr.raw, offset), msg_format.attr_set)
712 decoded.update(subdict)
713 else:
714 raise Exception(f"Unknown attribute-set '{attr_space}' when decoding '{attr_spec.name}'")
715 return decoded
716
717 def _decode(self, attrs, space, outer_attrs = None):
718 rsp = dict()
719 if space:
720 attr_space = self.attr_sets[space]
721 search_attrs = SpaceAttrs(attr_space, rsp, outer_attrs)
722
723 for attr in attrs:
724 try:
725 attr_spec = attr_space.attrs_by_val[attr.type]
726 except (KeyError, UnboundLocalError):
727 if not self.process_unknown:
728 raise Exception(f"Space '{space}' has no attribute with value '{attr.type}'")
729 attr_name = f"UnknownAttr({attr.type})"
730 self._rsp_add(rsp, attr_name, None, self._decode_unknown(attr))
731 continue
732
733 if attr_spec["type"] == 'nest':
734 subdict = self._decode(NlAttrs(attr.raw), attr_spec['nested-attributes'], search_attrs)
735 decoded = subdict
736 elif attr_spec["type"] == 'string':
737 decoded = attr.as_strz()
738 elif attr_spec["type"] == 'binary':
739 decoded = self._decode_binary(attr, attr_spec)
740 elif attr_spec["type"] == 'flag':
741 decoded = True
742 elif attr_spec.is_auto_scalar:
743 decoded = attr.as_auto_scalar(attr_spec['type'], attr_spec.byte_order)
744 elif attr_spec["type"] in NlAttr.type_formats:
745 decoded = attr.as_scalar(attr_spec['type'], attr_spec.byte_order)
746 if 'enum' in attr_spec:
747 decoded = self._decode_enum(decoded, attr_spec)
748 elif attr_spec.display_hint:
749 decoded = self._formatted_string(decoded, attr_spec.display_hint)
750 elif attr_spec["type"] == 'indexed-array':
751 decoded = self._decode_array_attr(attr, attr_spec)
752 elif attr_spec["type"] == 'bitfield32':
753 value, selector = struct.unpack("II", attr.raw)
754 if 'enum' in attr_spec:
755 value = self._decode_enum(value, attr_spec)
756 selector = self._decode_enum(selector, attr_spec)
757 decoded = {"value": value, "selector": selector}
758 elif attr_spec["type"] == 'sub-message':
759 decoded = self._decode_sub_msg(attr, attr_spec, search_attrs)
760 elif attr_spec["type"] == 'nest-type-value':
761 decoded = self._decode_nest_type_value(attr, attr_spec)
762 else:
763 if not self.process_unknown:
764 raise Exception(f'Unknown {attr_spec["type"]} with name {attr_spec["name"]}')
765 decoded = self._decode_unknown(attr)
766
767 self._rsp_add(rsp, attr_spec["name"], attr_spec.is_multi, decoded)
768
769 return rsp
770
771 def _decode_extack_path(self, attrs, attr_set, offset, target):
772 for attr in attrs:
773 try:
774 attr_spec = attr_set.attrs_by_val[attr.type]
775 except KeyError:
776 raise Exception(f"Space '{attr_set.name}' has no attribute with value '{attr.type}'")
777 if offset > target:
778 break
779 if offset == target:
780 return '.' + attr_spec.name
781
782 if offset + attr.full_len <= target:
783 offset += attr.full_len
784 continue
785 if attr_spec['type'] != 'nest':
786 raise Exception(f"Can't dive into {attr.type} ({attr_spec['name']}) for extack")
787 offset += 4
788 subpath = self._decode_extack_path(NlAttrs(attr.raw),
789 self.attr_sets[attr_spec['nested-attributes']],
790 offset, target)
791 if subpath is None:
792 return None
793 return '.' + attr_spec.name + subpath
794
795 return None
796
797 def _decode_extack(self, request, op, extack):
798 if 'bad-attr-offs' not in extack:
799 return
800
801 msg = self.nlproto.decode(self, NlMsg(request, 0, op.attr_set), op)
802 offset = self.nlproto.msghdr_size() + self._struct_size(op.fixed_header)
803 path = self._decode_extack_path(msg.raw_attrs, op.attr_set, offset,
804 extack['bad-attr-offs'])
805 if path:
806 del extack['bad-attr-offs']
807 extack['bad-attr'] = path
808
809 def _struct_size(self, name):
810 if name:
811 members = self.consts[name].members
812 size = 0
813 for m in members:
814 if m.type in ['pad', 'binary']:
815 if m.struct:
816 size += self._struct_size(m.struct)
817 else:
818 size += m.len
819 else:
820 format = NlAttr.get_format(m.type, m.byte_order)
821 size += format.size
822 return size
823 else:
824 return 0
825
826 def _decode_struct(self, data, name):
827 members = self.consts[name].members
828 attrs = dict()
829 offset = 0
830 for m in members:
831 value = None
832 if m.type == 'pad':
833 offset += m.len
834 elif m.type == 'binary':
835 if m.struct:
836 len = self._struct_size(m.struct)
837 value = self._decode_struct(data[offset : offset + len],
838 m.struct)
839 offset += len
840 else:
841 value = data[offset : offset + m.len]
842 offset += m.len
843 else:
844 format = NlAttr.get_format(m.type, m.byte_order)
845 [ value ] = format.unpack_from(data, offset)
846 offset += format.size
847 if value is not None:
848 if m.enum:
849 value = self._decode_enum(value, m)
850 elif m.display_hint:
851 value = self._formatted_string(value, m.display_hint)
852 attrs[m.name] = value
853 return attrs
854
855 def _encode_struct(self, name, vals):
856 members = self.consts[name].members
857 attr_payload = b''
858 for m in members:
859 value = vals.pop(m.name) if m.name in vals else None
860 if m.type == 'pad':
861 attr_payload += bytearray(m.len)
862 elif m.type == 'binary':
863 if m.struct:
864 if value is None:
865 value = dict()
866 attr_payload += self._encode_struct(m.struct, value)
867 else:
868 if value is None:
869 attr_payload += bytearray(m.len)
870 else:
871 attr_payload += bytes.fromhex(value)
872 else:
873 if value is None:
874 value = 0
875 format = NlAttr.get_format(m.type, m.byte_order)
876 attr_payload += format.pack(value)
877 return attr_payload
878
879 def _formatted_string(self, raw, display_hint):
880 if display_hint == 'mac':
881 formatted = ':'.join('%02x' % b for b in raw)
882 elif display_hint == 'hex':
883 if isinstance(raw, int):
884 formatted = hex(raw)
885 else:
886 formatted = bytes.hex(raw, ' ')
887 elif display_hint in [ 'ipv4', 'ipv6' ]:
888 formatted = format(ipaddress.ip_address(raw))
889 elif display_hint == 'uuid':
890 formatted = str(uuid.UUID(bytes=raw))
891 else:
892 formatted = raw
893 return formatted
894
895 def handle_ntf(self, decoded):
896 msg = dict()
897 if self.include_raw:
898 msg['raw'] = decoded
899 op = self.rsp_by_value[decoded.cmd()]
900 attrs = self._decode(decoded.raw_attrs, op.attr_set.name)
901 if op.fixed_header:
902 attrs.update(self._decode_struct(decoded.raw, op.fixed_header))
903
904 msg['name'] = op['name']
905 msg['msg'] = attrs
906 self.async_msg_queue.append(msg)
907
908 def check_ntf(self):
909 while True:
910 try:
911 reply = self.sock.recv(self._recv_size, socket.MSG_DONTWAIT)
912 except BlockingIOError:
913 return
914
915 nms = NlMsgs(reply)
916 self._recv_dbg_print(reply, nms)
917 for nl_msg in nms:
918 if nl_msg.error:
919 print("Netlink error in ntf!?", os.strerror(-nl_msg.error))
920 print(nl_msg)
921 continue
922 if nl_msg.done:
923 print("Netlink done while checking for ntf!?")
924 continue
925
926 decoded = self.nlproto.decode(self, nl_msg, None)
927 if decoded.cmd() not in self.async_msg_ids:
928 print("Unexpected msg id done while checking for ntf", decoded)
929 continue
930
931 self.handle_ntf(decoded)
932
933 def operation_do_attributes(self, name):
934 """
935 For a given operation name, find and return a supported
936 set of attributes (as a dict).
937 """
938 op = self.find_operation(name)
939 if not op:
940 return None
941
942 return op['do']['request']['attributes'].copy()
943
944 def _encode_message(self, op, vals, flags, req_seq):
945 nl_flags = Netlink.NLM_F_REQUEST | Netlink.NLM_F_ACK
946 for flag in flags or []:
947 nl_flags |= flag
948
949 msg = self.nlproto.message(nl_flags, op.req_value, 1, req_seq)
950 if op.fixed_header:
951 msg += self._encode_struct(op.fixed_header, vals)
952 search_attrs = SpaceAttrs(op.attr_set, vals)
953 for name, value in vals.items():
954 msg += self._add_attr(op.attr_set.name, name, value, search_attrs)
955 msg = _genl_msg_finalize(msg)
956 return msg
957
958 def _ops(self, ops):
959 reqs_by_seq = {}
960 req_seq = random.randint(1024, 65535)
961 payload = b''
962 for (method, vals, flags) in ops:
963 op = self.ops[method]
964 msg = self._encode_message(op, vals, flags, req_seq)
965 reqs_by_seq[req_seq] = (op, msg, flags)
966 payload += msg
967 req_seq += 1
968
969 self.sock.send(payload, 0)
970
971 done = False
972 rsp = []
973 op_rsp = []
974 while not done:
975 reply = self.sock.recv(self._recv_size)
976 nms = NlMsgs(reply, attr_space=op.attr_set)
977 self._recv_dbg_print(reply, nms)
978 for nl_msg in nms:
979 if nl_msg.nl_seq in reqs_by_seq:
980 (op, req_msg, req_flags) = reqs_by_seq[nl_msg.nl_seq]
981 if nl_msg.extack:
982 self._decode_extack(req_msg, op, nl_msg.extack)
983 else:
984 op = None
985 req_flags = []
986
987 if nl_msg.error:
988 raise NlError(nl_msg)
989 if nl_msg.done:
990 if nl_msg.extack:
991 print("Netlink warning:")
992 print(nl_msg)
993
994 if Netlink.NLM_F_DUMP in req_flags:
995 rsp.append(op_rsp)
996 elif not op_rsp:
997 rsp.append(None)
998 elif len(op_rsp) == 1:
999 rsp.append(op_rsp[0])
1000 else:
1001 rsp.append(op_rsp)
1002 op_rsp = []
1003
1004 del reqs_by_seq[nl_msg.nl_seq]
1005 done = len(reqs_by_seq) == 0
1006 break
1007
1008 decoded = self.nlproto.decode(self, nl_msg, op)
1009
1010 # Check if this is a reply to our request
1011 if nl_msg.nl_seq not in reqs_by_seq or decoded.cmd() != op.rsp_value:
1012 if decoded.cmd() in self.async_msg_ids:
1013 self.handle_ntf(decoded)
1014 continue
1015 else:
1016 print('Unexpected message: ' + repr(decoded))
1017 continue
1018
1019 rsp_msg = self._decode(decoded.raw_attrs, op.attr_set.name)
1020 if op.fixed_header:
1021 rsp_msg.update(self._decode_struct(decoded.raw, op.fixed_header))
1022 op_rsp.append(rsp_msg)
1023
1024 return rsp
1025
1026 def _op(self, method, vals, flags=None, dump=False):
1027 req_flags = flags or []
1028 if dump:
1029 req_flags.append(Netlink.NLM_F_DUMP)
1030
1031 ops = [(method, vals, req_flags)]
1032 return self._ops(ops)[0]
1033
1034 def do(self, method, vals, flags=None):
1035 return self._op(method, vals, flags)
1036
1037 def dump(self, method, vals):
1038 return self._op(method, vals, dump=True)
1039
1040 def do_multi(self, ops):
1041 return self._ops(ops)
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