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bdraco merged 1 commit into from
Jun 14, 2021
Merged

Make DNSRecords hashable #611

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179 changes: 179 additions & 0 deletions tests/test_dns.py
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Original file line number Diff line number Diff line change
Expand Up @@ -851,3 +851,182 @@ def test_qu_packet_parser():
parsed = DNSIncoming(qu_packet)
assert parsed.questions[0].unicast is True
assert ",QU," in str(parsed.questions[0])


def test_dns_record_hashablity_does_not_consider_ttl():
"""Test DNSRecord are hashable."""

# Verify the TTL is not considered in the hash
record1 = r.DNSAddress('irrelevant', const._TYPE_A, const._CLASS_IN, const._DNS_OTHER_TTL, b'same')
record2 = r.DNSAddress('irrelevant', const._TYPE_A, const._CLASS_IN, const._DNS_HOST_TTL, b'same')

record_set = set([record1, record2])
assert len(record_set) == 1

record_set.add(record1)
assert len(record_set) == 1

record3_dupe = r.DNSAddress('irrelevant', const._TYPE_A, const._CLASS_IN, const._DNS_HOST_TTL, b'same')

record_set.add(record3_dupe)
assert len(record_set) == 1


def test_dns_address_record_hashablity():
"""Test DNSAddress are hashable."""
address1 = r.DNSAddress('irrelevant', const._TYPE_A, const._CLASS_IN, 1, b'a')
address2 = r.DNSAddress('irrelevant', const._TYPE_A, const._CLASS_IN, 1, b'b')
address3 = r.DNSAddress('irrelevant', const._TYPE_A, const._CLASS_IN, 1, b'c')
address4 = r.DNSAddress('irrelevant', const._TYPE_AAAA, const._CLASS_IN, 1, b'c')

record_set = set([address1, address2, address3, address4])
assert len(record_set) == 4

record_set.add(address1)
assert len(record_set) == 4

address3_dupe = r.DNSAddress('irrelevant', const._TYPE_A, const._CLASS_IN, 1, b'c')

record_set.add(address3_dupe)
assert len(record_set) == 4

# Verify we can remove records
additional_set = set([address1, address2])
record_set -= additional_set
assert record_set == set([address3, address4])


def test_dns_hinfo_record_hashablity():
"""Test DNSHinfo are hashable."""
hinfo1 = r.DNSHinfo('irrelevant', const._TYPE_HINFO, 0, 0, 'cpu1', 'os')
hinfo2 = r.DNSHinfo('irrelevant', const._TYPE_HINFO, 0, 0, 'cpu2', 'os')

record_set = set([hinfo1, hinfo2])
assert len(record_set) == 2

record_set.add(hinfo1)
assert len(record_set) == 2

hinfo2_dupe = r.DNSHinfo('irrelevant', const._TYPE_HINFO, 0, 0, 'cpu2', 'os')

record_set.add(hinfo2_dupe)
assert len(record_set) == 2


def test_dns_pointer_record_hashablity():
"""Test DNSPointer are hashable."""
ptr1 = r.DNSPointer('irrelevant', const._TYPE_PTR, const._CLASS_IN, const._DNS_OTHER_TTL, '123')
ptr2 = r.DNSPointer('irrelevant', const._TYPE_PTR, const._CLASS_IN, const._DNS_OTHER_TTL, '456')

record_set = set([ptr1, ptr2])
assert len(record_set) == 2

record_set.add(ptr1)
assert len(record_set) == 2

ptr2_dupe = r.DNSPointer('irrelevant', const._TYPE_PTR, const._CLASS_IN, const._DNS_OTHER_TTL, '456')

record_set.add(ptr2_dupe)
assert len(record_set) == 2


def test_dns_text_record_hashablity():
"""Test DNSText are hashable."""
text1 = r.DNSText('irrelevant', 0, 0, 0, b'12345678901')
text2 = r.DNSText('irrelevant', 1, 0, 0, b'12345678901')
text3 = r.DNSText('irrelevant', 0, 1, 0, b'12345678901')
text4 = r.DNSText('irrelevant', 0, 0, 1, b'12345678901')
text5 = r.DNSText('irrelevant', 0, 0, 0, b'ABCDEFGHIJK')

record_set = set([text1, text2, text3, text4, text5])
assert len(record_set) == 5

record_set.add(text1)
assert len(record_set) == 5

text1_dupe = r.DNSText('irrelevant', 0, 0, 0, b'12345678901')

record_set.add(text1_dupe)
assert len(record_set) == 5


def test_dns_text_record_hashablity():
"""Test DNSText are hashable."""
text1 = r.DNSText('irrelevant', 0, 0, const._DNS_OTHER_TTL, b'12345678901')
text2 = r.DNSText('irrelevant', 1, 0, const._DNS_OTHER_TTL, b'12345678901')
text3 = r.DNSText('irrelevant', 0, 1, const._DNS_OTHER_TTL, b'12345678901')
text4 = r.DNSText('irrelevant', 0, 0, const._DNS_OTHER_TTL, b'ABCDEFGHIJK')

record_set = set([text1, text2, text3, text4])

assert len(record_set) == 4

record_set.add(text1)
assert len(record_set) == 4

text1_dupe = r.DNSText('irrelevant', 0, 0, const._DNS_OTHER_TTL, b'12345678901')

record_set.add(text1_dupe)
assert len(record_set) == 4


def test_dns_text_record_hashablity():
"""Test DNSText are hashable."""
text1 = r.DNSText('irrelevant', 0, 0, const._DNS_OTHER_TTL, b'12345678901')
text2 = r.DNSText('irrelevant', 1, 0, const._DNS_OTHER_TTL, b'12345678901')
text3 = r.DNSText('irrelevant', 0, 1, const._DNS_OTHER_TTL, b'12345678901')
text4 = r.DNSText('irrelevant', 0, 0, const._DNS_OTHER_TTL, b'ABCDEFGHIJK')

record_set = set([text1, text2, text3, text4])

assert len(record_set) == 4

record_set.add(text1)
assert len(record_set) == 4

text1_dupe = r.DNSText('irrelevant', 0, 0, const._DNS_OTHER_TTL, b'12345678901')

record_set.add(text1_dupe)
assert len(record_set) == 4


def test_dns_text_record_hashablity():
"""Test DNSText are hashable."""
text1 = r.DNSText('irrelevant', 0, 0, const._DNS_OTHER_TTL, b'12345678901')
text2 = r.DNSText('irrelevant', 1, 0, const._DNS_OTHER_TTL, b'12345678901')
text3 = r.DNSText('irrelevant', 0, 1, const._DNS_OTHER_TTL, b'12345678901')
text4 = r.DNSText('irrelevant', 0, 0, const._DNS_OTHER_TTL, b'ABCDEFGHIJK')

record_set = set([text1, text2, text3, text4])

assert len(record_set) == 4

record_set.add(text1)
assert len(record_set) == 4

text1_dupe = r.DNSText('irrelevant', 0, 0, const._DNS_OTHER_TTL, b'12345678901')

record_set.add(text1_dupe)
assert len(record_set) == 4


def test_dns_service_record_hashablity():
"""Test DNSService are hashable."""
srv1 = r.DNSService('irrelevant', const._TYPE_SRV, const._CLASS_IN, const._DNS_HOST_TTL, 0, 0, 80, 'a')
srv2 = r.DNSService('irrelevant', const._TYPE_SRV, const._CLASS_IN, const._DNS_HOST_TTL, 0, 1, 80, 'a')
srv3 = r.DNSService('irrelevant', const._TYPE_SRV, const._CLASS_IN, const._DNS_HOST_TTL, 0, 0, 81, 'a')
srv4 = r.DNSService('irrelevant', const._TYPE_SRV, const._CLASS_IN, const._DNS_HOST_TTL, 0, 0, 80, 'ab')

record_set = set([srv1, srv2, srv3, srv4])

assert len(record_set) == 4

record_set.add(srv1)
assert len(record_set) == 4

srv1_dupe = r.DNSService(
'irrelevant', const._TYPE_SRV, const._CLASS_IN, const._DNS_HOST_TTL, 0, 0, 80, 'a'
)

record_set.add(srv1_dupe)
assert len(record_set) == 4
39 changes: 30 additions & 9 deletions zeroconf/_dns.py
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Original file line number Diff line number Diff line change
Expand Up @@ -70,6 +70,10 @@ def __init__(self, name: str, type_: int, class_: int) -> None:
self.class_ = class_ & _CLASS_MASK
self.unique = (class_ & _CLASS_UNIQUE) != 0

def _entry_tuple(self) -> Tuple[str, int, int]:
"""Entry Tuple for DNSEntry."""
return (self.key, self.type, self.class_)

def __eq__(self, other: Any) -> bool:
"""Equality test on key (lowercase name), type, and class"""
return (
Expand Down Expand Up @@ -105,9 +109,6 @@ class DNSQuestion(DNSEntry):

"""A DNS question entry"""

def __init__(self, name: str, type_: int, class_: int) -> None:
DNSEntry.__init__(self, name, type_, class_)

def answered_by(self, rec: 'DNSRecord') -> bool:
"""Returns true if the question is answered by the record"""
return (
Expand Down Expand Up @@ -141,7 +142,7 @@ class DNSRecord(DNSEntry):

# TODO: Switch to just int ttl
def __init__(self, name: str, type_: int, class_: int, ttl: Union[float, int]) -> None:
DNSEntry.__init__(self, name, type_, class_)
super().__init__(name, type_, class_)
self.ttl = ttl
self.created = current_time_millis()
self._expiration_time = self.get_expiration_time(_EXPIRE_FULL_TIME_PERCENT)
Expand Down Expand Up @@ -205,7 +206,7 @@ class DNSAddress(DNSRecord):
"""A DNS address record"""

def __init__(self, name: str, type_: int, class_: int, ttl: int, address: bytes) -> None:
DNSRecord.__init__(self, name, type_, class_, ttl)
super().__init__(name, type_, class_, ttl)
self.address = address

def write(self, out: 'DNSOutgoing') -> None:
Expand All @@ -218,6 +219,10 @@ def __eq__(self, other: Any) -> bool:
isinstance(other, DNSAddress) and DNSEntry.__eq__(self, other) and self.address == other.address
)

def __hash__(self) -> int:
"""Hash to compare like DNSAddresses."""
return hash((*self._entry_tuple(), self.address))

def __repr__(self) -> str:
"""String representation"""
try:
Expand All @@ -235,7 +240,7 @@ class DNSHinfo(DNSRecord):
"""A DNS host information record"""

def __init__(self, name: str, type_: int, class_: int, ttl: int, cpu: str, os: str) -> None:
DNSRecord.__init__(self, name, type_, class_, ttl)
super().__init__(name, type_, class_, ttl)
self.cpu = cpu
self.os = os

Expand All @@ -253,6 +258,10 @@ def __eq__(self, other: Any) -> bool:
and self.os == other.os
)

def __hash__(self) -> int:
"""Hash to compare like DNSHinfo."""
return hash((*self._entry_tuple(), self.cpu, self.os))

def __repr__(self) -> str:
"""String representation"""
return self.to_string(self.cpu + " " + self.os)
Expand All @@ -263,7 +272,7 @@ class DNSPointer(DNSRecord):
"""A DNS pointer record"""

def __init__(self, name: str, type_: int, class_: int, ttl: int, alias: str) -> None:
DNSRecord.__init__(self, name, type_, class_, ttl)
super().__init__(name, type_, class_, ttl)
self.alias = alias

def write(self, out: 'DNSOutgoing') -> None:
Expand All @@ -274,6 +283,10 @@ def __eq__(self, other: Any) -> bool:
"""Tests equality on alias"""
return isinstance(other, DNSPointer) and self.alias == other.alias and DNSEntry.__eq__(self, other)

def __hash__(self) -> int:
"""Hash to compare like DNSPointer."""
return hash((*self._entry_tuple(), self.alias))

def __repr__(self) -> str:
"""String representation"""
return self.to_string(self.alias)
Expand All @@ -285,13 +298,17 @@ class DNSText(DNSRecord):

def __init__(self, name: str, type_: int, class_: int, ttl: int, text: bytes) -> None:
assert isinstance(text, (bytes, type(None)))
DNSRecord.__init__(self, name, type_, class_, ttl)
super().__init__(name, type_, class_, ttl)
self.text = text

def write(self, out: 'DNSOutgoing') -> None:
"""Used in constructing an outgoing packet"""
out.write_string(self.text)

def __hash__(self) -> int:
"""Hash to compare like DNSText."""
return hash((*self._entry_tuple(), self.text))

def __eq__(self, other: Any) -> bool:
"""Tests equality on text"""
return isinstance(other, DNSText) and self.text == other.text and DNSEntry.__eq__(self, other)
Expand All @@ -318,7 +335,7 @@ def __init__(
port: int,
server: str,
) -> None:
DNSRecord.__init__(self, name, type_, class_, ttl)
super().__init__(name, type_, class_, ttl)
self.priority = priority
self.weight = weight
self.port = port
Expand All @@ -342,6 +359,10 @@ def __eq__(self, other: Any) -> bool:
and DNSEntry.__eq__(self, other)
)

def __hash__(self) -> int:
"""Hash to compare like DNSService."""
return hash((*self._entry_tuple(), self.priority, self.weight, self.port, self.server))

def __repr__(self) -> str:
"""String representation"""
return self.to_string("%s:%s" % (self.server, self.port))
Expand Down