# common.py - functions that are used by different modules # # Copyright (C) 2010, 2011, 2012 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 logging import sys import ldap import ldap.dn from attmap import Attributes import cache import cfg import constants def isvalidname(name): """Checks to see if the specified name seems to be a valid user or group name. This test is based on the definition from POSIX (IEEE Std 1003.1, 2004, 3.426 User Name, 3.189 Group Name and 3.276 Portable Filename Character Set): http://www.opengroup.org/onlinepubs/009695399/basedefs/xbd_chap03.html#tag_03_426 http://www.opengroup.org/onlinepubs/009695399/basedefs/xbd_chap03.html#tag_03_189 http://www.opengroup.org/onlinepubs/009695399/basedefs/xbd_chap03.html#tag_03_276 The standard defines user names valid if they contain characters from the set [A-Za-z0-9._-] where the hyphen should not be used as first character. As an extension this test allows some more characters.""" return bool(cfg.validnames.search(name)) def validate_name(name): """Checks to see if the specified name seems to be a valid user or group name. See isvalidname().""" if not cfg.validnames.search(name): raise ValueError('%r: denied by validnames option' % name) class Search(object): """ Class that performs a search. Subclasses are expected to define the actual searches and should implement the following members: case_sensitive - check that these attributes are present in the response if they were in the request case_insensitive - check that these attributes are present in the response if they were in the request limit_attributes - override response attributes with request attributes (ensure that only one copy of the value is returned) required - attributes that are required canonical_first - search the DN for these attributes and ensure that they are listed first in the attribute values mk_filter() (optional) - function that returns the LDAP search filter The module that contains the Request class can also contain the following definitions: attmap - an attribute mapping definition (using he Attributes class) filter - an LDAP search filter bases - search bases to be used, falls back to cfg.bases scope - search scope, falls back to cfg.scope """ canonical_first = [] required = [] case_sensitive = [] case_insensitive = [] limit_attributes = [] # FIXME: figure out which of these arguments are actually needed def __init__(self, conn, base=None, scope=None, filter=None, attributes=None, parameters=None): # load information from module that defines the class self.conn = conn module = sys.modules[self.__module__] self.attmap = getattr(module, 'attmap', None) self.filter = filter or getattr(module, 'filter', None) self.parameters = parameters or {} if base: self.bases = [base] else: self.bases = getattr(module, 'bases', cfg.bases) self.scope = scope or getattr(module, 'scope', cfg.scope) self.attributes = attributes or self.attmap.attributes() def __iter__(self): return self.items() def items(self): """Return the results from the search.""" filter = self.mk_filter() for base in self.bases: logging.debug('SEARCHING %s %s', base, filter) try: for entry in self.conn.search_s(base, self.scope, filter, self.attributes): if entry[0]: entry = self.handle_entry(entry[0], entry[1]) if entry: yield entry except ldap.NO_SUCH_OBJECT: # FIXME: log message pass def escape(self, value): """Escape the provided value so it may be used in a search filter.""" return ldap.filter.escape_filter_chars(str(value)) def mk_filter(self): """Return the active search filter (based on the read parameters).""" if self.parameters: return '(&%s%s)' % ( self.filter, ''.join(self.attmap.mk_filter(attribute, value) for attribute, value in self.parameters.items())) return self.filter def handle_entry(self, dn, attributes): """Handle an entry with the specified attributes, filtering it with the request parameters where needed.""" # translate the attributes using the attribute mapping if self.attmap: attributes = self.attmap.translate(attributes) # make sure value from DN is first value for attr in self.canonical_first: primary_value = self.attmap.get_rdn_value(dn, attr) if primary_value: values = attributes[attr] if primary_value in values: values.remove(primary_value) attributes[attr] = [primary_value] + values # check that these attributes have at least one value for attr in self.required: if not attributes.get(attr, None): logging.warning('%s: %s: missing', dn, self.attmap[attr]) return # check that requested attribute is present (case sensitive) for attr in self.case_sensitive: value = self.parameters.get(attr, None) if value and str(value) not in attributes[attr]: logging.debug('%s: %s: does not contain %r value', dn, self.attmap[attr], value) return # not found, skip entry # check that requested attribute is present (case insensitive) for attr in self.case_insensitive: value = self.parameters.get(attr, None) if value and str(value).lower() not in (x.lower() for x in attributes[attr]): logging.debug('%s: %s: does not contain %r value', dn, self.attmap[attr], value) return # not found, skip entry # limit attribute values to requested value for attr in self.limit_attributes: if attr in self.parameters: attributes[attr] = [self.parameters[attr]] # return the entry return dn, attributes class Request(object): """ Request handler class. Subclasses are expected to handle actual requests and should implement the following members: action - the NSLCD_ACTION_* action that should trigger this handler read_parameters() - a function that reads the request parameters of the request stream write() - function that writes a single LDAP entry to the result stream """ def __init__(self, fp, conn, calleruid): self.fp = fp self.conn = conn self.calleruid = calleruid module = sys.modules[self.__module__] self.search = getattr(module, 'Search', None) if not hasattr(module, 'cache_obj'): cache_cls = getattr(module, 'Cache', None) module.cache_obj = cache_cls() if cache_cls else None self.cache = module.cache_obj def read_parameters(self, fp): """This method should read the parameters from ths stream and store them in self.""" pass def handle_request(self, parameters): """This method handles the request based on the parameters read with read_parameters().""" try: with cache.con: for dn, attributes in self.search(conn=self.conn, parameters=parameters): for values in self.convert(dn, attributes, parameters): self.fp.write_int32(constants.NSLCD_RESULT_BEGIN) self.write(*values) if self.cache: self.cache.store(*values) except ldap.SERVER_DOWN: if self.cache: logging.debug('read from cache') # we assume server went down before writing any entries for values in self.cache.retrieve(parameters): self.fp.write_int32(constants.NSLCD_RESULT_BEGIN) self.write(*values) else: raise # write the final result code self.fp.write_int32(constants.NSLCD_RESULT_END) def __call__(self): parameters = self.read_parameters(self.fp) or {} logging.debug('%s(%r)', self.__class__.__name__, parameters) self.fp.write_int32(constants.NSLCD_VERSION) self.fp.write_int32(self.action) self.handle_request(parameters) def get_handlers(module): """Return a dictionary mapping actions to Request classes.""" import inspect res = {} if isinstance(module, basestring): module = __import__(module, globals()) for name, cls in inspect.getmembers(module, inspect.isclass): if issubclass(cls, Request) and hasattr(cls, 'action'): res[cls.action] = cls return res