RAHHH

backend/lib/python3.12/site-packages/twisted/pair/ethernet.py

@@ -0,0 +1,59 @@
+# -*- test-case-name: twisted.pair.test.test_ethernet -*-
+# Copyright (c) Twisted Matrix Laboratories.
+# See LICENSE for details.
+
+#
+
+
+"""Support for working directly with ethernet frames"""
+
+import struct
+
+from zope.interface import Interface, implementer
+
+from twisted.internet import protocol
+from twisted.pair import raw
+
+
+class IEthernetProtocol(Interface):
+    """An interface for protocols that handle Ethernet frames"""
+
+    def addProto(num, proto):
+        """Add an IRawPacketProtocol protocol"""
+
+    def datagramReceived(data, partial):
+        """An Ethernet frame has been received"""
+
+
+class EthernetHeader:
+    def __init__(self, data):
+        (self.dest, self.source, self.proto) = struct.unpack(
+            "!6s6sH", data[: 6 + 6 + 2]
+        )
+
+
+@implementer(IEthernetProtocol)
+class EthernetProtocol(protocol.AbstractDatagramProtocol):
+    def __init__(self):
+        self.etherProtos = {}
+
+    def addProto(self, num, proto):
+        proto = raw.IRawPacketProtocol(proto)
+        if num < 0:
+            raise TypeError("Added protocol must be positive or zero")
+        if num >= 2**16:
+            raise TypeError("Added protocol must fit in 16 bits")
+        if num not in self.etherProtos:
+            self.etherProtos[num] = []
+        self.etherProtos[num].append(proto)
+
+    def datagramReceived(self, data, partial=0):
+        header = EthernetHeader(data[:14])
+        for proto in self.etherProtos.get(header.proto, ()):
+            proto.datagramReceived(
+                data=data[14:],
+                partial=partial,
+                dest=header.dest,
+                source=header.source,
+                protocol=header.proto,
+            )