from __future__ import unicode_literals try: import mmap except ImportError: mmap = None import struct from awdb.compat import compat_ip_address, string_type from awdb.const import MODE_AUTO, MODE_MMAP, MODE_FILE, MODE_MEMORY, MODE_FD from awdb.decoder import Decoder from awdb.errors import InvalidDatabaseError from awdb.file import FileBuffer class Reader(object): _DATA_SECTION_SEPARATOR_SIZE = 16 _METADATA_START_MARKER = b"\xAB\xCD\xEFipplus360.com" _ipv4_start = None def __init__(self, database, mode=MODE_AUTO): if (mode == MODE_AUTO and mmap) or mode == MODE_MMAP: with open(database, 'rb') as db_file: self._buffer = mmap.mmap(db_file.fileno(), 0, access=mmap.ACCESS_READ) self._buffer_size = self._buffer.size() filename = database elif mode in (MODE_AUTO, MODE_FILE): self._buffer = FileBuffer(database) self._buffer_size = self._buffer.size() filename = database elif mode == MODE_MEMORY: with open(database, 'rb') as db_file: self._buffer = db_file.read() self._buffer_size = len(self._buffer) filename = database elif mode == MODE_FD: self._buffer = database.read() self._buffer_size = len(self._buffer) filename = database.name else: raise ValueError( 'Unsupported open mode ({0}). Only MODE_AUTO, MODE_FILE, ' 'MODE_MEMORY and MODE_FD are supported by the pure Python ' 'Reader'.format(mode)) metadata_start = self._buffer.rfind( self._METADATA_START_MARKER, max(0, self._buffer_size - 128 * 1024)) if metadata_start == -1: self.close() raise InvalidDatabaseError('Error opening database file ({0}). ' 'Is this a valid AW DB file?' ''.format(filename)) metadata_start += len(self._METADATA_START_MARKER) metadata_decoder = Decoder(self._buffer, metadata_start) (metadata, _) = metadata_decoder.decode(metadata_start) self._metadata = Metadata(**metadata) self._decoder = Decoder( self._buffer, self._metadata.search_tree_size + self._DATA_SECTION_SEPARATOR_SIZE) self.closed = False def metadata(self): return self._metadata def get(self, ip_address): (record, _) = self.get_with_prefix_len(ip_address) return record def get_with_prefix_len(self, ip_address): if isinstance(ip_address, string_type): address = compat_ip_address(ip_address) else: address = ip_address try: packed_address = bytearray(address.packed) except AttributeError: raise TypeError('argument 1 must be a string or ipaddress object') if address.version == 6 and self._metadata.ip_version == 4: raise ValueError( 'Error looking up {0}. You attempted to look up ' 'an IPv6 address in an IPv4-only database.'.format(ip_address)) (pointer, prefix_len) = self._find_address_in_tree(packed_address) if pointer: return self._resolve_data_pointer(pointer), prefix_len return None, prefix_len def _find_address_in_tree(self, packed): bit_count = len(packed) * 8 node = self._start_node(bit_count) node_count = self._metadata.node_count i = 0 while i < bit_count and node < node_count: bit = 1 & (packed[i >> 3] >> 7 - (i % 8)) node = self._read_node(node, bit) i = i + 1 if node == node_count: return 0, i if node > node_count: return node, i raise InvalidDatabaseError('Invalid node in search tree') def _start_node(self, length): if self._metadata.ip_version != 6 or length == 128: return 0 if self._ipv4_start: return self._ipv4_start node = 0 for _ in range(96): if node >= self._metadata.node_count: break node = self._read_node(node, 0) self._ipv4_start = node return node def _read_node(self, node_number, index): base_offset = node_number * self._metadata.node_byte_size record_size = self._metadata.record_size if record_size == 24: offset = base_offset + index * 3 node_bytes = b'\x00' + self._buffer[offset:offset + 3] elif record_size == 28: offset = base_offset + 3 * index node_bytes = bytearray(self._buffer[offset:offset + 4]) if index: node_bytes[0] = 0x0F & node_bytes[0] else: middle = (0xF0 & node_bytes.pop()) >> 4 node_bytes.insert(0, middle) elif record_size == 32: offset = base_offset + index * 4 node_bytes = self._buffer[offset:offset + 4] else: raise InvalidDatabaseError( 'Unknown record size: {0}'.format(record_size)) return struct.unpack(b'!I', node_bytes)[0] def _resolve_data_pointer(self, pointer): resolved = pointer - self._metadata.node_count + \ self._metadata.search_tree_size if resolved >= self._buffer_size: raise InvalidDatabaseError( "The AW DB file's search tree is corrupt") (data, _) = self._decoder.decode(resolved) return data def close(self): if type(self._buffer) not in (str, bytes): self._buffer.close() self.closed = True def __exit__(self, *args): self.close() def __enter__(self): if self.closed: raise ValueError('Attempt to reopen a closed AW DB') return self class Metadata(object): def __init__(self, **kwargs): self.node_count = kwargs['node_count'] self.record_size = kwargs['record_size'] self.ip_version = kwargs['ip_version'] self.database_type = kwargs['database_type'] self.languages = kwargs['languages'] self.binary_format_major_version = kwargs[ 'binary_format_major_version'] self.binary_format_minor_version = kwargs[ 'binary_format_minor_version'] self.build_epoch = kwargs['build_epoch'] self.description = kwargs['description'] @property def node_byte_size(self): return self.record_size // 4 @property def search_tree_size(self): return self.node_count * self.node_byte_size def __repr__(self): args = ', '.join('%s=%r' % x for x in self.__dict__.items()) return '{module}.{class_name}({data})'.format( module=self.__module__, class_name=self.__class__.__name__, data=args)