def from_bytes(cls, packet):
"""Create Message from bytes.
Args:
packet (bytes): byte representation of the message.
"""
header, offset = Header.from_bytes(packet), 12
questions = []
for _ in range(header.qd_count):
question, offset = Question.from_bytes(packet, offset)
questions.append(question)
answers = []
for _ in range(header.an_count):
answer, offset = ResourceRecord.from_bytes(packet, offset)
answers.append(answer)
authorities = []
for _ in range(header.ns_count):
authority, offset = ResourceRecord.from_bytes(packet, offset)
authorities.append(authority)
additionals = []
for _ in range(header.ar_count):
additional, offset = ResourceRecord.from_bytes(packet, offset)
additionals.append(additional)
return cls(header, questions, answers, authorities, additionals)
def test_resource_from_bytes(self, MockName, MockRData):
MockName.from_bytes.return_value = (Name("example.com"), 13)
MockRData.create_from_bytes.return_value = ARecordData("1.1.1.1")
packet = (b"\x07example\x03com\x00\x00\x01\x00\x02\x00\x00\x00\x03\x00"
b"\x04\x01\x01\x01\x01")
record1, offset = ResourceRecord.from_bytes(packet, 0)
record2 = ResourceRecord(Name("example.com"), Type.A, Class.CS, 3,
ARecordData("1.1.1.1"))
self.assertEqual(record1, record2)
MockName.from_bytes.assert_called_with(packet, 0)
MockRData.create_from_bytes.assert_called_with(Type.A, packet, 23, 4)
def from_bytes(cls, packet):
""" Create Message from bytes
Args:
packet (bytes): byte representation of the message
"""
parser = Parser()
# Parse header
header, offset = Header.from_bytes(packet), 12
# Parse questions
questions = []
for _ in range(header.qd_count):
question, offset = Question.from_bytes(packet, offset, parser)
questions.append(question)
# Parse answers
answers = []
for _ in range(header.an_count):
answer, offset = ResourceRecord.from_bytes(packet, offset, parser)
answers.append(answer)
# Parse authorities
authorities = []
for _ in range(header.ns_count):
authority, offset = ResourceRecord.from_bytes(packet, offset, parser)
authorities.append(authority)
# Parse additionals
additionals = []
for _ in range(header.ar_count):
additional, offset = ResourceRecord.from_bytes(packet, offset, parser)
additionals.append(additional)
return cls(header, questions, answers, authorities, additionals)