diff options
Diffstat (limited to 'tools/net/ynl/lib/ynl.py')
| -rw-r--r-- | tools/net/ynl/lib/ynl.py | 311 |
1 files changed, 216 insertions, 95 deletions
diff --git a/tools/net/ynl/lib/ynl.py b/tools/net/ynl/lib/ynl.py index 571c2e2189..25810e18b0 100644 --- a/tools/net/ynl/lib/ynl.py +++ b/tools/net/ynl/lib/ynl.py @@ -7,6 +7,7 @@ import random import socket import struct from struct import Struct +import sys import yaml import ipaddress import uuid @@ -84,6 +85,10 @@ class NlError(Exception): return f"Netlink error: {os.strerror(-self.nl_msg.error)}\n{self.nl_msg}" +class ConfigError(Exception): + pass + + class NlAttr: ScalarFormat = namedtuple('ScalarFormat', ['native', 'big', 'little']) type_formats = { @@ -113,20 +118,6 @@ class NlAttr: 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] @@ -148,23 +139,6 @@ class NlAttr: 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}" @@ -245,11 +219,11 @@ class NlMsg: 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" + msg = f"nl_len = {self.nl_len} ({len(self.raw)}) nl_flags = 0x{self.nl_flags:x} nl_type = {self.nl_type}" if self.error: - msg += '\terror: ' + str(self.error) + msg += '\n\terror: ' + str(self.error) if self.extack: - msg += '\textack: ' + repr(self.extack) + msg += '\n\textack: ' + repr(self.extack) return msg @@ -371,7 +345,7 @@ class NetlinkProtocol: fixed_header_size = 0 if ynl: op = ynl.rsp_by_value[msg.cmd()] - fixed_header_size = ynl._fixed_header_size(op.fixed_header) + fixed_header_size = ynl._struct_size(op.fixed_header) msg.raw_attrs = NlAttrs(msg.raw, fixed_header_size) return msg @@ -380,6 +354,9 @@ class NetlinkProtocol: raise Exception(f'Multicast group "{mcast_name}" not present in the spec') return mcast_groups[mcast_name].value + def msghdr_size(self): + return 16 + class GenlProtocol(NetlinkProtocol): def __init__(self, family_name): @@ -405,6 +382,28 @@ class GenlProtocol(NetlinkProtocol): raise Exception(f'Multicast group "{mcast_name}" not present in the family') return self.genl_family['mcast'][mcast_name] + def msghdr_size(self): + return super().msghdr_size() + 4 + + +class SpaceAttrs: + SpecValuesPair = namedtuple('SpecValuesPair', ['spec', 'values']) + + def __init__(self, attr_space, attrs, outer = None): + outer_scopes = outer.scopes if outer else [] + inner_scope = self.SpecValuesPair(attr_space, attrs) + self.scopes = [inner_scope] + outer_scopes + + def lookup(self, name): + for scope in self.scopes: + if name in scope.spec: + if name in scope.values: + return scope.values[name] + spec_name = scope.spec.yaml['name'] + raise Exception( + f"No value for '{name}' in attribute space '{spec_name}'") + raise Exception(f"Attribute '{name}' not defined in any attribute-set") + # # YNL implementation details. @@ -412,7 +411,8 @@ class GenlProtocol(NetlinkProtocol): class YnlFamily(SpecFamily): - def __init__(self, def_path, schema=None, process_unknown=False): + def __init__(self, def_path, schema=None, process_unknown=False, + recv_size=0): super().__init__(def_path, schema) self.include_raw = False @@ -427,6 +427,17 @@ class YnlFamily(SpecFamily): except KeyError: raise Exception(f"Family '{self.yaml['name']}' not supported by the kernel") + self._recv_dbg = False + # Note that netlink will use conservative (min) message size for + # the first dump recv() on the socket, our setting will only matter + # from the second recv() on. + self._recv_size = recv_size if recv_size else 131072 + # Netlink will always allocate at least PAGE_SIZE - sizeof(skb_shinfo) + # for a message, so smaller receive sizes will lead to truncation. + # Note that the min size for other families may be larger than 4k! + if self._recv_size < 4000: + raise ConfigError() + 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) @@ -450,18 +461,61 @@ class YnlFamily(SpecFamily): self.sock.setsockopt(Netlink.SOL_NETLINK, Netlink.NETLINK_ADD_MEMBERSHIP, mcast_id) - def _add_attr(self, space, name, value): + def set_recv_dbg(self, enabled): + self._recv_dbg = enabled + + def _recv_dbg_print(self, reply, nl_msgs): + if not self._recv_dbg: + return + print("Recv: read", len(reply), "bytes,", + len(nl_msgs.msgs), "messages", file=sys.stderr) + for nl_msg in nl_msgs: + print(" ", nl_msg, file=sys.stderr) + + def _encode_enum(self, attr_spec, value): + enum = self.consts[attr_spec['enum']] + if enum.type == 'flags' or attr_spec.get('enum-as-flags', False): + scalar = 0 + if isinstance(value, str): + value = [value] + for single_value in value: + scalar += enum.entries[single_value].user_value(as_flags = True) + return scalar + else: + return enum.entries[value].user_value() + + def _get_scalar(self, attr_spec, value): + try: + return int(value) + except (ValueError, TypeError) as e: + if 'enum' not in attr_spec: + raise e + return self._encode_enum(attr_spec, value) + + def _add_attr(self, space, name, value, search_attrs): try: attr = self.attr_sets[space][name] except KeyError: raise Exception(f"Space '{space}' has no attribute '{name}'") nl_type = attr.value + + if attr.is_multi and isinstance(value, list): + attr_payload = b'' + for subvalue in value: + attr_payload += self._add_attr(space, name, subvalue, search_attrs) + return attr_payload + if attr["type"] == 'nest': nl_type |= Netlink.NLA_F_NESTED attr_payload = b'' + sub_attrs = SpaceAttrs(self.attr_sets[space], value, search_attrs) for subname, subvalue in value.items(): - attr_payload += self._add_attr(attr['nested-attributes'], subname, subvalue) + attr_payload += self._add_attr(attr['nested-attributes'], + subname, subvalue, sub_attrs) elif attr["type"] == 'flag': + if not value: + # If value is absent or false then skip attribute creation. + return b'' attr_payload = b'' elif attr["type"] == 'string': attr_payload = str(value).encode('ascii') + b'\x00' @@ -470,18 +524,36 @@ class YnlFamily(SpecFamily): attr_payload = value elif isinstance(value, str): attr_payload = bytes.fromhex(value) + elif isinstance(value, dict) and attr.struct_name: + attr_payload = self._encode_struct(attr.struct_name, value) else: raise Exception(f'Unknown type for binary attribute, value: {value}') - elif attr.is_auto_scalar: - scalar = int(value) - real_type = attr["type"][0] + ('32' if scalar.bit_length() <= 32 else '64') - format = NlAttr.get_format(real_type, attr.byte_order) - attr_payload = format.pack(int(value)) - elif attr['type'] in NlAttr.type_formats: - format = NlAttr.get_format(attr['type'], attr.byte_order) - attr_payload = format.pack(int(value)) + elif attr['type'] in NlAttr.type_formats or attr.is_auto_scalar: + scalar = self._get_scalar(attr, value) + if attr.is_auto_scalar: + attr_type = attr["type"][0] + ('32' if scalar.bit_length() <= 32 else '64') + else: + attr_type = attr["type"] + format = NlAttr.get_format(attr_type, attr.byte_order) + attr_payload = format.pack(scalar) elif attr['type'] in "bitfield32": - attr_payload = struct.pack("II", int(value["value"]), int(value["selector"])) + scalar_value = self._get_scalar(attr, value["value"]) + scalar_selector = self._get_scalar(attr, value["selector"]) + attr_payload = struct.pack("II", scalar_value, scalar_selector) + elif attr['type'] == 'sub-message': + msg_format = self._resolve_selector(attr, search_attrs) + attr_payload = b'' + if msg_format.fixed_header: + attr_payload += self._encode_struct(msg_format.fixed_header, value) + if msg_format.attr_set: + if msg_format.attr_set in self.attr_sets: + nl_type |= Netlink.NLA_F_NESTED + sub_attrs = SpaceAttrs(msg_format.attr_set, value, search_attrs) + for subname, subvalue in value.items(): + attr_payload += self._add_attr(msg_format.attr_set, + subname, subvalue, sub_attrs) + else: + raise Exception(f"Unknown attribute-set '{msg_format.attr_set}'") else: raise Exception(f'Unknown type at {space} {name} {value} {attr["type"]}') @@ -504,17 +576,13 @@ class YnlFamily(SpecFamily): 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) + decoded = self._decode_struct(attr.raw, attr_spec.struct_name) elif attr_spec.sub_type: decoded = attr.as_c_array(attr_spec.sub_type) else: decoded = attr.as_bin() if attr_spec.display_hint: - decoded = NlAttr.formatted_string(decoded, attr_spec.display_hint) + decoded = self._formatted_string(decoded, attr_spec.display_hint) return decoded def _decode_array_nest(self, attr, attr_spec): @@ -528,6 +596,16 @@ class YnlFamily(SpecFamily): decoded.append({ item.type: subattrs }) return decoded + def _decode_nest_type_value(self, attr, attr_spec): + decoded = {} + value = attr + for name in attr_spec['type-value']: + value = NlAttr(value.raw, 0) + decoded[name] = value.type + subattrs = self._decode(NlAttrs(value.raw), attr_spec['nested-attributes']) + decoded.update(subattrs) + return decoded + def _decode_unknown(self, attr): if attr.is_nest: return self._decode(NlAttrs(attr.raw), None) @@ -549,29 +627,27 @@ class YnlFamily(SpecFamily): else: rsp[name] = [decoded] - def _resolve_selector(self, attr_spec, vals): + def _resolve_selector(self, attr_spec, search_attrs): sub_msg = attr_spec.sub_message if sub_msg not in self.sub_msgs: raise Exception(f"No sub-message spec named {sub_msg} for {attr_spec.name}") sub_msg_spec = self.sub_msgs[sub_msg] selector = attr_spec.selector - if selector not in vals: - raise Exception(f"There is no value for {selector} to resolve '{attr_spec.name}'") - value = vals[selector] + value = search_attrs.lookup(selector) if value not in sub_msg_spec.formats: raise Exception(f"No message format for '{value}' in sub-message spec '{sub_msg}'") spec = sub_msg_spec.formats[value] return spec - def _decode_sub_msg(self, attr, attr_spec, rsp): - msg_format = self._resolve_selector(attr_spec, rsp) + def _decode_sub_msg(self, attr, attr_spec, search_attrs): + msg_format = self._resolve_selector(attr_spec, search_attrs) decoded = {} offset = 0 if msg_format.fixed_header: - decoded.update(self._decode_fixed_header(attr, msg_format.fixed_header)); - offset = self._fixed_header_size(msg_format.fixed_header) + decoded.update(self._decode_struct(attr.raw, msg_format.fixed_header)); + offset = self._struct_size(msg_format.fixed_header) if msg_format.attr_set: if msg_format.attr_set in self.attr_sets: subdict = self._decode(NlAttrs(attr.raw, offset), msg_format.attr_set) @@ -580,10 +656,12 @@ class YnlFamily(SpecFamily): raise Exception(f"Unknown attribute-set '{attr_space}' when decoding '{attr_spec.name}'") return decoded - def _decode(self, attrs, space): + def _decode(self, attrs, space, outer_attrs = None): + rsp = dict() if space: attr_space = self.attr_sets[space] - rsp = dict() + search_attrs = SpaceAttrs(attr_space, rsp, outer_attrs) + for attr in attrs: try: attr_spec = attr_space.attrs_by_val[attr.type] @@ -595,7 +673,7 @@ class YnlFamily(SpecFamily): continue if attr_spec["type"] == 'nest': - subdict = self._decode(NlAttrs(attr.raw), attr_spec['nested-attributes']) + subdict = self._decode(NlAttrs(attr.raw), attr_spec['nested-attributes'], search_attrs) decoded = subdict elif attr_spec["type"] == 'string': decoded = attr.as_strz() @@ -618,7 +696,9 @@ class YnlFamily(SpecFamily): selector = self._decode_enum(selector, attr_spec) decoded = {"value": value, "selector": selector} elif attr_spec["type"] == 'sub-message': - decoded = self._decode_sub_msg(attr, attr_spec, rsp) + decoded = self._decode_sub_msg(attr, attr_spec, search_attrs) + elif attr_spec["type"] == 'nest-type-value': + decoded = self._decode_nest_type_value(attr, attr_spec) else: if not self.process_unknown: raise Exception(f'Unknown {attr_spec["type"]} with name {attr_spec["name"]}') @@ -659,20 +739,23 @@ class YnlFamily(SpecFamily): return msg = self.nlproto.decode(self, NlMsg(request, 0, op.attr_set)) - offset = 20 + self._fixed_header_size(op.fixed_header) + offset = self.nlproto.msghdr_size() + self._struct_size(op.fixed_header) path = self._decode_extack_path(msg.raw_attrs, op.attr_set, offset, extack['bad-attr-offs']) if path: del extack['bad-attr-offs'] extack['bad-attr'] = path - def _fixed_header_size(self, name): + def _struct_size(self, name): if name: - fixed_header_members = self.consts[name].members + members = self.consts[name].members size = 0 - for m in fixed_header_members: + for m in members: if m.type in ['pad', 'binary']: - size += m.len + if m.struct: + size += self._struct_size(m.struct) + else: + size += m.len else: format = NlAttr.get_format(m.type, m.byte_order) size += format.size @@ -680,26 +763,71 @@ class YnlFamily(SpecFamily): else: return 0 - def _decode_fixed_header(self, msg, name): - fixed_header_members = self.consts[name].members - fixed_header_attrs = dict() + def _decode_struct(self, data, name): + members = self.consts[name].members + attrs = dict() offset = 0 - for m in fixed_header_members: + for m in members: value = None if m.type == 'pad': offset += m.len elif m.type == 'binary': - value = msg.raw[offset : offset + m.len] - offset += m.len + if m.struct: + len = self._struct_size(m.struct) + value = self._decode_struct(data[offset : offset + len], + m.struct) + offset += len + else: + value = data[offset : offset + m.len] + offset += m.len else: format = NlAttr.get_format(m.type, m.byte_order) - [ value ] = format.unpack_from(msg.raw, offset) + [ value ] = format.unpack_from(data, offset) offset += format.size if value is not None: if m.enum: value = self._decode_enum(value, m) - fixed_header_attrs[m.name] = value - return fixed_header_attrs + elif m.display_hint: + value = self._formatted_string(value, m.display_hint) + attrs[m.name] = value + return attrs + + def _encode_struct(self, name, vals): + members = self.consts[name].members + attr_payload = b'' + for m in members: + value = vals.pop(m.name) if m.name in vals else None + if m.type == 'pad': + attr_payload += bytearray(m.len) + elif m.type == 'binary': + if m.struct: + if value is None: + value = dict() + attr_payload += self._encode_struct(m.struct, value) + else: + if value is None: + attr_payload += bytearray(m.len) + else: + attr_payload += bytes.fromhex(value) + else: + if value is None: + value = 0 + format = NlAttr.get_format(m.type, m.byte_order) + attr_payload += format.pack(value) + return attr_payload + + def _formatted_string(self, raw, display_hint): + if display_hint == 'mac': + formatted = ':'.join('%02x' % b for b in raw) + elif display_hint == 'hex': + formatted = bytes.hex(raw, ' ') + elif display_hint in [ 'ipv4', 'ipv6' ]: + formatted = format(ipaddress.ip_address(raw)) + elif display_hint == 'uuid': + formatted = str(uuid.UUID(bytes=raw)) + else: + formatted = raw + return formatted def handle_ntf(self, decoded): msg = dict() @@ -708,7 +836,7 @@ class YnlFamily(SpecFamily): 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)) + attrs.update(self._decode_struct(decoded.raw, op.fixed_header)) msg['name'] = op['name'] msg['msg'] = attrs @@ -717,11 +845,12 @@ class YnlFamily(SpecFamily): def check_ntf(self): while True: try: - reply = self.sock.recv(128 * 1024, socket.MSG_DONTWAIT) + reply = self.sock.recv(self._recv_size, socket.MSG_DONTWAIT) except BlockingIOError: return nms = NlMsgs(reply) + self._recv_dbg_print(reply, nms) for nl_msg in nms: if nl_msg.error: print("Netlink error in ntf!?", os.strerror(-nl_msg.error)) @@ -760,20 +889,11 @@ class YnlFamily(SpecFamily): 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 - if m.type == 'pad': - msg += bytearray(m.len) - elif m.type == 'binary': - msg += bytes.fromhex(value) - else: - format = NlAttr.get_format(m.type, m.byte_order) - msg += format.pack(value) + msg += self._encode_struct(op.fixed_header, vals) + search_attrs = SpaceAttrs(op.attr_set, vals) for name, value in vals.items(): - msg += self._add_attr(op.attr_set.name, name, value) + msg += self._add_attr(op.attr_set.name, name, value, search_attrs) msg = _genl_msg_finalize(msg) self.sock.send(msg, 0) @@ -781,8 +901,9 @@ class YnlFamily(SpecFamily): done = False rsp = [] while not done: - reply = self.sock.recv(128 * 1024) + reply = self.sock.recv(self._recv_size) nms = NlMsgs(reply, attr_space=op.attr_set) + self._recv_dbg_print(reply, nms) for nl_msg in nms: if nl_msg.extack: self._decode_extack(msg, op, nl_msg.extack) @@ -809,7 +930,7 @@ class YnlFamily(SpecFamily): 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_msg.update(self._decode_struct(decoded.raw, op.fixed_header)) rsp.append(rsp_msg) if not rsp: |