# tio.py - I/O functions # # Copyright (C) 2010, 2011 Arthur de Jong # # This library is free software; you can redistribute it and/or # modify it under the terms of the GNU Lesser General Public # License as published by the Free Software Foundation; either # version 2.1 of the License, or (at your option) any later version. # # This library is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU # Lesser General Public License for more details. # # You should have received a copy of the GNU Lesser General Public # License along with this library; if not, write to the Free Software # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA # 02110-1301 USA import struct import os import socket import errno # definition for reading and writing INT32 values _int32 = struct.Struct('i') # FIXME: use something from config.py to determine the correct size _uid_t = struct.Struct('i') # FIXME: use something from config.py to determine the correct size _gid_t = struct.Struct('i') # FIXME: use something from config.py to determine the correct size _struct_timeval = struct.Struct('ll') class TIOStreamError(Exception): pass class TIOStream(object): """File-like object that allows reading and writing nslcd-protocol entities.""" def __init__(self, conn): conn.setblocking(1) conn.setsockopt(socket.SOL_SOCKET, socket.SO_RCVTIMEO, _struct_timeval.pack(0, 500000)) conn.setsockopt(socket.SOL_SOCKET, socket.SO_SNDTIMEO, _struct_timeval.pack(60, 0)) self.fp = os.fdopen(conn.fileno(), 'w+b', 1024*1024) def read(self, size): return self.fp.read(size) def read_int32(self): return _int32.unpack(self.read(_int32.size))[0] def read_uid_t(self): return _uid_t.unpack(self.read(_uid_t.size))[0] def read_gid_t(self): return _gid_t.unpack(self.read(_gid_t.size))[0] def read_string(self, maxsize=None): len = self.read_int32() if maxsize and len >= maxsize: raise TIOStreamError() return self.read(len) def read_address(self): """Read an address (usually IPv4 or IPv6) from the stream and return the address as a string representation.""" af = self.read_int32() return socket.inet_ntop(af, self.read_string(maxsize=64)) def write(self, value): self.fp.write(value) def write_int32(self, value): self.write(_int32.pack(value)) def write_uid_t(self, value): self.write(_uid_t.pack(value)) def write_gid_t(self, value): self.write(_gid_t.pack(value)) def write_string(self, value): self.write_int32(len(value)) self.write(value) def write_stringlist(self, value): lst = tuple(value) self.write_int32(len(lst)) for string in lst: self.write_string(string) @staticmethod def _to_address(value): # try IPv4 first try: return socket.AF_INET, socket.inet_pton(socket.AF_INET, value) except socket.error: pass # try the next one # fall back to IPv6 return socket.AF_INET6, socket.inet_pton(socket.AF_INET6, value) def write_address(self, value): """Write an address (usually IPv4 or IPv6) in a string representation to the stream.""" # first try to make it into an IPv6 address af, address = TIOStream._to_address(value) self.write_int32(af) self.write_string(address) def close(self): try: self.fp.close() except IOError: pass def __del__(self): self.close()