Source code for dns.opcode

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"""DNS Opcodes."""

import dns.enum
import dns.exception


class Opcode(dns.enum.IntEnum):
    #: Query
    QUERY = 0
    #: Inverse Query (historical)
    IQUERY = 1
    #: Server Status (unspecified and unimplemented anywhere)
    STATUS = 2
    #: Notify
    NOTIFY = 4
    #: Dynamic Update
    UPDATE = 5

    @classmethod
    def _maximum(cls):
        return 15

    @classmethod
    def _unknown_exception_class(cls):
        return UnknownOpcode


[docs]class UnknownOpcode(dns.exception.DNSException): """An DNS opcode is unknown."""
[docs]def from_text(text: str) -> Opcode: """Convert text into an opcode. *text*, a ``str``, the textual opcode Raises ``dns.opcode.UnknownOpcode`` if the opcode is unknown. Returns an ``int``. """ return Opcode.from_text(text)
[docs]def from_flags(flags: int) -> Opcode: """Extract an opcode from DNS message flags. *flags*, an ``int``, the DNS flags. Returns an ``int``. """ return Opcode((flags & 0x7800) >> 11)
[docs]def to_flags(value: Opcode) -> int: """Convert an opcode to a value suitable for ORing into DNS message flags. *value*, an ``int``, the DNS opcode value. Returns an ``int``. """ return (value << 11) & 0x7800
[docs]def to_text(value: Opcode) -> str: """Convert an opcode to text. *value*, an ``int`` the opcode value, Raises ``dns.opcode.UnknownOpcode`` if the opcode is unknown. Returns a ``str``. """ return Opcode.to_text(value)
[docs]def is_update(flags: int) -> bool: """Is the opcode in flags UPDATE? *flags*, an ``int``, the DNS message flags. Returns a ``bool``. """ return from_flags(flags) == Opcode.UPDATE
### BEGIN generated Opcode constants QUERY = Opcode.QUERY IQUERY = Opcode.IQUERY STATUS = Opcode.STATUS NOTIFY = Opcode.NOTIFY UPDATE = Opcode.UPDATE ### END generated Opcode constants