2025-12-25 upload

venv/Lib/site-packages/pydivert/packet/ip.py

@@ -0,0 +1,216 @@
+# -*- coding: utf-8 -*-
+# Copyright (C) 2016  Fabio Falcinelli, Maximilian Hils
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+import socket
+import struct
+
+from pydivert.packet.header import Header
+from pydivert.util import PY2, PY34, flag_property, indexbyte as i, raw_property
+
+
+class IPHeader(Header):
+    _src_addr = slice(0, 0)
+    _dst_addr = slice(0, 0)
+    _af = None
+
+    @property
+    def src_addr(self):
+        """
+        The packet source address.
+        """
+        try:
+            return socket.inet_ntop(self._af, self.raw[self._src_addr].tobytes())
+        except (ValueError, socket.error):
+            pass
+
+    @src_addr.setter
+    def src_addr(self, val):
+        self.raw[self._src_addr] = socket.inet_pton(self._af, val)
+
+    @property
+    def dst_addr(self):
+        """
+        The packet destination address.
+        """
+        try:
+            return socket.inet_ntop(self._af, self.raw[self._dst_addr].tobytes())
+        except (ValueError, socket.error):
+            pass
+
+    @dst_addr.setter
+    def dst_addr(self, val):
+        self.raw[self._dst_addr] = socket.inet_pton(self._af, val)
+
+    @property
+    def packet_len(self):
+        """
+        The total packet length, including *all* headers, as reported by the IP header.
+        """
+        raise NotImplementedError()  # pragma: no cover
+
+    @packet_len.setter
+    def packet_len(self, val):
+        raise NotImplementedError()  # pragma: no cover
+
+
+class IPv4Header(IPHeader):
+    _src_addr = slice(12, 16)
+    _dst_addr = slice(16, 20)
+    _af = socket.AF_INET
+
+    @property
+    def header_len(self):
+        """
+        The IP header length in bytes.
+        """
+        return self.hdr_len * 4
+
+    @property
+    def hdr_len(self):
+        """
+        The header length in words of 32bit.
+        """
+        return i(self.raw[0]) & 0x0F
+
+    @hdr_len.setter
+    def hdr_len(self, val):
+        if val < 5:
+            raise ValueError("IP header length must be greater or equal than 5.")
+        struct.pack_into('!B', self.raw, 0, 0x40 | val)
+
+    packet_len = raw_property('!H', 2, docs=IPHeader.packet_len.__doc__)
+    tos = raw_property('!B', 1, docs='The Type Of Service field (six-bit DiffServ field and a two-bit ECN field).')
+    ident = raw_property('!H', 4, docs='The Identification field.')
+
+    reserved = flag_property('reserved', 6, 0b10000000)
+    evil = flag_property('evil', 6, 0b10000000, docs='Just an april\'s fool joke for the RESERVED flag.')
+    df = flag_property('df', 6, 0b01000000)
+    mf = flag_property('mf', 6, 0b00100000)
+
+    ttl = raw_property('!B', 8, docs='The Time To Live field.')
+    protocol = raw_property('!B', 9, docs='The Protocol field.')
+    cksum = raw_property('!H', 10, docs='The IP header Checksum field.')
+
+    @property
+    def flags(self):
+        """
+        The flags field: RESERVED (the evil bit), DF (don't fragment), MF (more fragments).
+        """
+        return i(self.raw[6]) >> 5
+
+    @flags.setter
+    def flags(self, val):
+        struct.pack_into('!B', self.raw, 6, (val << 5) | (self.frag_offset & 0xFF00))
+
+    @property
+    def frag_offset(self):
+        """
+        The Fragment Offset field in blocks of 8 bytes.
+        """
+        return struct.unpack_from("!H", self.raw, 6)[0] & 0x1FFF
+
+    @frag_offset.setter
+    def frag_offset(self, val):
+        self.raw[6:8] = struct.pack("!H", (self.flags << 13) | (val & 0x1FFF))
+
+    @property
+    def dscp(self):
+        """
+        The Differentiated Services Code Point field (originally defined as Type of Service) also known as DiffServ.
+        """
+        return (i(self.raw[1]) >> 2) & 0x3F
+
+    @dscp.setter
+    def dscp(self, val):
+        struct.pack_into('!B', self.raw, 1, (val << 2) | self.ecn)
+
+    diff_serv = dscp
+
+    @property
+    def ecn(self):
+        """
+        The Explicit Congestion Notification field.
+        """
+        return i(self.raw[1]) & 0x03
+
+    @ecn.setter
+    def ecn(self, val):
+        struct.pack_into('!B', self.raw, 1, (self.dscp << 2) | (val & 0x03))
+
+
+class IPv6Header(IPHeader):
+    _src_addr = slice(8, 24)
+    _dst_addr = slice(24, 40)
+    _af = socket.AF_INET6
+    header_len = 40
+
+    payload_len = raw_property('!H', 4, docs='The Payload Length field.')
+    next_hdr = raw_property('!B', 6, docs='The Next Header field. Replaces the Protocol field in IPv4.')
+    hop_limit = raw_property('!B', 7, docs='The Hop Limit field. Replaces the TTL field in IPv4.')
+
+    @property
+    def packet_len(self):
+        return self.payload_len + self.header_len
+
+    @packet_len.setter
+    def packet_len(self, val):
+        self.payload_len = val - self.header_len
+
+    @property
+    def traffic_class(self):
+        """
+        The Traffic Class field (six-bit DiffServ field and a two-bit ECN field).
+        """
+        return (struct.unpack_from('!H', self.raw, 0)[0] >> 4) & 0x00FF
+
+    @traffic_class.setter
+    def traffic_class(self, val):
+        struct.pack_into('!H', self.raw, 0, 0x6000 | (val << 4) | (self.flow_label & 0x000F0000))
+
+    @property
+    def flow_label(self):
+        """
+        The Flow Label field.
+        """
+        return struct.unpack_from('!I', self.raw, 0)[0] & 0x000FFFFF
+
+    @flow_label.setter
+    def flow_label(self, val):
+        struct.pack_into('!I', self.raw, 0, 0x60000000 | (self.traffic_class << 20) | (val & 0x000FFFFF))
+
+    @property
+    def diff_serv(self):
+        """
+        The DiffServ field.
+        """
+        return (self.traffic_class & 0xFC) >> 2
+
+    @diff_serv.setter
+    def diff_serv(self, val):
+        self.traffic_class = self.ecn | (val << 2)
+
+    @property
+    def ecn(self):
+        """
+        The Explicit Congestion Notification field.
+        """
+        return self.traffic_class & 0x03
+
+    @ecn.setter
+    def ecn(self, val):
+        self.traffic_class = (self.diff_serv << 2) | val
+
+    if not PY2 and not PY34:
+        packet_len.__doc__ = IPHeader.packet_len.__doc__