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Diffstat (limited to 'project2/proj2_s4498062/dns/resource.py')
| -rw-r--r-- | project2/proj2_s4498062/dns/resource.py | 241 |
1 files changed, 0 insertions, 241 deletions
diff --git a/project2/proj2_s4498062/dns/resource.py b/project2/proj2_s4498062/dns/resource.py deleted file mode 100644 index d54cdba..0000000 --- a/project2/proj2_s4498062/dns/resource.py +++ /dev/null @@ -1,241 +0,0 @@ -""" A DNS resource record - -This class contains classes for DNS resource records and record data. This -module is fully implemented. You will have this module in the implementation -of your resolver and server. -""" - -import socket -import struct -import time - -from dns.types import Type - - -class ResourceRecord(object): - """ DNS resource record """ - def __init__(self, name, type_, class_, ttl, rdata, timestamp=time.time()): - """ Create a new resource record - - Args: - name (str): domain name - type_ (Type): the type - class_ (Class): the class - rdata (RecordData): the record data - """ - self.name = name - self.type_ = type_ - self.class_ = class_ - self.ttl = ttl - self.rdata = rdata - self.timestamp = timestamp - - def to_bytes(self, offset, composer): - """ Convert ResourceRecord to bytes """ - record = composer.to_bytes(offset, [self.name]) - record += struct.pack("!HHI", self.type_, self.class_, self.ttl) - offset += len(record) + 2 - rdata = self.rdata.to_bytes(offset, composer) - record += struct.pack("!H", len(rdata)) + rdata - return record - - @classmethod - def from_bytes(cls, packet, offset, parser): - """ Convert ResourceRecord from bytes """ - names, offset = parser.from_bytes(packet, offset, 1) - name = names[0] - type_, class_, ttl, rdlen = struct.unpack_from("!HHIH", packet, offset) - offset += 10 - rdata = RecordData.from_bytes(type_, packet, offset, rdlen, parser) - offset += rdlen - return cls(name, type_, class_, ttl, rdata), offset - - -class RecordData(object): - """ Record Data """ - - def __init__(self, data): - """ Initialize the record data - - Args: - data (str): data - """ - self.data = data - - @staticmethod - def create(type_, data): - """ Create a RecordData object from bytes - - Args: - type_ (Type): type - packet (bytes): packet - offset (int): offset in message - rdlength (int): length of rdata - parser (int): domain name parser - """ - classdict = { - Type.A: ARecordData, - Type.CNAME: CNAMERecordData, - Type.NS: NSRecordData, - Type.AAAA: AAAARecordData - } - if type_ in classdict: - return classdict[type_](data) - else: - return GenericRecordData(data) - - @staticmethod - def from_bytes(type_, packet, offset, rdlength, parser): - """ Create a RecordData object from bytes - - Args: - type_ (Type): type - packet (bytes): packet - offset (int): offset in message - rdlength (int): length of rdata - parser (int): domain name parser - """ - classdict = { - Type.A: ARecordData, - Type.CNAME: CNAMERecordData, - Type.NS: NSRecordData, - Type.AAAA: AAAARecordData - } - if type_ in classdict: - return classdict[type_].from_bytes( - packet, offset, rdlength, parser) - else: - return GenericRecordData.from_bytes( - packet, offset, rdlength, parser) - - -class ARecordData(RecordData): - """Data of an A record""" - - def to_bytes(self, offset, composer): - """ Convert to bytes - - Args: - offset (int): offset in message - composer (Composer): domain name composer - """ - return socket.inet_aton(self.data) - - @classmethod - def from_bytes(cls, packet, offset, rdlength, parser): - """ Create a RecordData object from bytes - - Args: - packet (bytes): packet - offset (int): offset in message - rdlength (int): length of rdata - parser (int): domain name parser - """ - data = socket.inet_ntoa(packet[offset:offset+4]) - return cls(data) - - -class CNAMERecordData(RecordData): - """Data of a CNAME record""" - - def to_bytes(self, offset, composer): - """ Convert to bytes - - Args: - offset (int): offset in message - composer (Composer): domain name composer - """ - return composer.to_bytes(offset, [self.data]) - - @classmethod - def from_bytes(cls, packet, offset, rdlength, parser): - """ Create a RecordData object from bytes - - Args: - packet (bytes): packet - offset (int): offset in message - rdlength (int): length of rdata - parser (int): domain name parser - """ - names, offset = parser.from_bytes(packet, offset, 1) - data = names[0] - return cls(data) - - -class NSRecordData(RecordData): - """Data of an NS record""" - - def to_bytes(self, offset, composer): - """ Convert to bytes - - Args: - offset (int): offset in message - composer (Composer): domain name composer - """ - return composer.to_bytes(offset, [self.data]) - - @classmethod - def from_bytes(cls, packet, offset, rdlength, parser): - """ Create a RecordData object from bytes - - Args: - packet (bytes): packet - offset (int): offset in message - rdlength (int): length of rdata - parser (int): domain name parser - """ - names, offset = parser.from_bytes(packet, offset, 1) - data = names[0] - return cls(data) - - -class AAAARecordData(RecordData): - """Data of an AAAA record""" - - def to_bytes(self, offset, composer): - """ Convert to bytes - - Args: - offset (int): offset in message - composer (Composer): domain name composer - """ - return socket.inet_pton(socket.AF_INET6, self.data) - - @classmethod - def from_bytes(cls, packet, offset, rdlength, parser): - """ Create a RecordData object from bytes - - Args: - packet (bytes): packet - offset (int): offset in message - rdlength (int): length of rdata - parser (int): domain name parser - """ - data = socket.inet_ntop(socket.AF_INET6, packet[offset:offset+16]) - return cls(data) - - -class GenericRecordData(RecordData): - """Data of a generic record""" - - def to_bytes(self, offset, composer): - """ Convert to bytes - - Args: - offset (int): offset in message - composer (Composer): domain name composer - """ - return self.data - - @classmethod - def from_bytes(cls, packet, offset, rdlength, parser): - """ Create a RecordData object from bytes - - Args: - packet (bytes): packet - offset (int): offset in message - rdlength (int): length of rdata - parser (int): domain name parser - """ - data = packet[offset:offset+rdlength] - return cls(data) |