81 lines
3.0 KiB
Python
81 lines
3.0 KiB
Python
from firegex.nfproxy.internals.data import DataStreamCtx
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from firegex.nfproxy.internals.exceptions import NotReadyToRun, StreamFullDrop, StreamFullReject
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from firegex.nfproxy.internals.models import FullStreamAction
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class InternalTCPStream:
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def __init__(self,
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data: bytes,
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is_ipv6: bool,
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):
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self.data = bytes(data)
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self.__is_ipv6 = bool(is_ipv6)
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self.__total_stream_size = len(data)
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@property
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def is_ipv6(self) -> bool:
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return self.__is_ipv6
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@property
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def total_stream_size(self) -> int:
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return self.__total_stream_size
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def _push_new_data(self, data: bytes):
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self.data += data
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self.__total_stream_size += len(data)
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@classmethod
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def _fetch_packet(cls, internal_data:DataStreamCtx, is_input:bool=False):
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if internal_data.current_pkt is None or internal_data.current_pkt.is_tcp is False:
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raise NotReadyToRun()
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if internal_data.current_pkt.is_input != is_input:
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raise NotReadyToRun()
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datahandler: TCPInputStream = internal_data.data_handler_context.get(cls, None)
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if datahandler is None:
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datahandler = cls(internal_data.current_pkt.data, internal_data.current_pkt.is_ipv6)
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internal_data.data_handler_context[cls] = datahandler
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else:
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if datahandler.total_stream_size+len(internal_data.current_pkt.data) > internal_data.stream_max_size:
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match internal_data.full_stream_action:
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case FullStreamAction.FLUSH:
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datahandler = cls(internal_data.current_pkt.data, internal_data.current_pkt.is_ipv6)
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internal_data.data_handler_context[cls] = datahandler
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case FullStreamAction.REJECT:
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raise StreamFullReject()
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case FullStreamAction.DROP:
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raise StreamFullDrop()
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case FullStreamAction.ACCEPT:
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raise NotReadyToRun()
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else:
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datahandler._push_new_data(internal_data.current_pkt.data)
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return datahandler
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class TCPInputStream(InternalTCPStream):
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"""
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This datamodel will assemble the TCP input stream from the client sent data.
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The function that use this data model will be handled when:
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- The packet is TCP
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- At least 1 packet has been sent
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- A new client packet has been received
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"""
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@classmethod
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def _fetch_packet(cls, internal_data:DataStreamCtx):
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return super()._fetch_packet(internal_data, is_input=True)
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TCPClientStream = TCPInputStream
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class TCPOutputStream:
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"""
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This datamodel will assemble the TCP output stream from the server sent data.
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The function that use this data model will be handled when:
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- The packet is TCP
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- At least 1 packet has been sent
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- A new server packet has been sent
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"""
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@classmethod
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def _fetch_packet(cls, internal_data:DataStreamCtx):
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return super()._fetch_packet(internal_data, is_input=False)
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TCPServerStream = TCPOutputStream
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