4f7b30dad2
Signed-off-by: HIYAMA Manabu <hiyama.manabu@po.ntts.co.jp> Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
112 lines
3.0 KiB
Python
112 lines
3.0 KiB
Python
# Copyright (C) 2012 Nippon Telegraph and Telephone Corporation.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
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# implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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import struct
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import socket
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from . import packet_base
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from . import packet_utils
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ICMP_ECHO_REPLY = 0
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ICMP_DEST_UNREACH = 3
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ICMP_SRC_QUENCH = 4
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ICMP_REDIRECT = 5
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ICMP_ECHO_REQUEST = 8
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class icmp(packet_base.PacketBase):
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_PACK_STR = '!BBH'
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_MIN_LEN = struct.calcsize(_PACK_STR)
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_ICMP_TYPES = {}
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@staticmethod
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def register_icmp_type(*args):
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def _register_icmp_type(cls):
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for type_ in args:
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icmp._ICMP_TYPES[type_] = cls
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return cls
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return _register_icmp_type
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def __init__(self, type_, code, csum, data=None):
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super(icmp, self).__init__()
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self.type = type_
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self.code = code
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self.csum = csum
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self.data = data
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@classmethod
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def parser(cls, buf):
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(type_, code, csum) = struct.unpack_from(cls._PACK_STR, buf)
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msg = cls(type_, code, csum)
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offset = cls._MIN_LEN
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if len(buf) > offset:
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cls_ = cls._ICMP_TYPES.get(type_, None)
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if cls_:
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msg.data = cls_.parser(buf, offset)
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else:
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msg.data = buf[offset:]
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return msg, None
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def serialize(self, payload, prev):
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hdr = bytearray(struct.pack(icmp._PACK_STR, self.type,
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self.code, self.csum))
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if self.data is not None:
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if self.type in icmp._ICMP_TYPES:
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hdr += self.data.serialize()
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else:
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hdr += self.data
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if self.csum == 0:
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if len(hdr) % 2:
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hdr += '\0'
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self.csum = socket.htons(packet_utils.checksum(hdr))
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struct.pack_into('!H', hdr, 2, self.csum)
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return hdr
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@icmp.register_icmp_type(ICMP_ECHO_REPLY, ICMP_ECHO_REQUEST)
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class echo(object):
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_PACK_STR = '!HH'
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_MIN_LEN = struct.calcsize(_PACK_STR)
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def __init__(self, id_, seq, data=None):
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self.id = id_
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self.seq = seq
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self.data = data
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@classmethod
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def parser(cls, buf, offset):
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(id_, seq) = struct.unpack_from(cls._PACK_STR, buf, offset)
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msg = cls(id_, seq)
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offset += cls._MIN_LEN
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if len(buf) > offset:
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msg.data = buf[offset:]
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return msg
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def serialize(self):
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hdr = bytearray(struct.pack(echo._PACK_STR, self.id,
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self.seq))
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if self.data is not None:
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hdr += self.data
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return hdr
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