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"""Utils module.""" |
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from functools import cache |
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from .settings import COOKIE_PREFIX |
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7
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8
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def int_dpid(dpid): |
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"""Convert a str dpid to an int.""" |
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dpid = int(dpid.replace(":", ""), 16) |
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return dpid |
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1 |
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def get_cookie(dpid): |
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"""Return the cookie integer given a dpid.""" |
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return (0x0000FFFFFFFFFFFF & int(int_dpid(dpid))) | (COOKIE_PREFIX << 56) |
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@cache |
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def try_to_gen_intf_mac(address: str, dpid: str, port_number: int) -> str: |
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"""Try to generate interface address if needed in a best effort way. |
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This is a sanity check to ensure that the source interface will |
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have a valid MAC, just so packets don't get potentially discarded. |
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""" |
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if all(( |
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not _is_default_mac(address), |
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not _has_mac_multicast_bit_set(address) |
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)): |
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return address |
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dpid_split = dpid.split(":") |
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if len(dpid_split) != 8: |
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return address |
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address = _gen_mac_address(dpid_split, port_number) |
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address = _make_unicast_local_mac(address) |
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return address |
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40
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def _has_mac_multicast_bit_set(address: str) -> bool: |
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"""Check whether it has the multicast bit set or not.""" |
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try: |
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return int(address[1], 16) & 1 |
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except (TypeError, ValueError, IndexError): |
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return False |
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48
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49
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def _is_default_mac(address: str) -> bool: |
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"""Check whether is default mac or not.""" |
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return address == "00:00:00:00:00:00" |
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54
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def _gen_mac_address(dpid_split: list[str], port_number: int) -> str: |
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"""Generate a MAC address deriving from dpid lsb 40 bits. |
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A dpid is 8 bytes long: 16 bits + 48 bits. |
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""" |
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port_number = port_number % (1 << 8) |
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return ":".join(dpid_split[-5:] + [f"{port_number:02x}"]) |
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61
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def _make_unicast_local_mac(address: str) -> str: |
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""" |
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Make an unicast locally administered address. |
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66
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The first two bits (b0, b1) of the most significant MAC address byte is for |
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its uniqueness and wether its locally administered or not. This functions |
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ensures it's a unicast (b0 -> 0) and locally administered (b1 -> 1). |
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""" |
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return address[:1] + "e" + address[2:] |
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kytos-ng /
of_lldp
