# HG changeset patch # User Julien Cristau # Date 1389367545 -3600 # Node ID 8266c8c375bbeec888bcd4af050f634eedd5e46b # Parent dd88d86d780a56b2c6b4a62878b7086ab5f3d98f [schema] move definition of RQLExpression classes before default permission dicts diff -r dd88d86d780a -r 8266c8c375bb schema.py --- a/schema.py Fri Jan 10 15:02:07 2014 +0100 +++ b/schema.py Fri Jan 10 16:25:45 2014 +0100 @@ -104,6 +104,297 @@ ybo.ETYPE_PROPERTIES += ('eid',) ybo.RTYPE_PROPERTIES += ('eid',) +# Bases for manipulating RQL in schema ######################################### + +def guess_rrqlexpr_mainvars(expression): + defined = set(split_expression(expression)) + mainvars = set() + if 'S' in defined: + mainvars.add('S') + if 'O' in defined: + mainvars.add('O') + if 'U' in defined: + mainvars.add('U') + if not mainvars: + raise Exception('unable to guess selection variables') + return mainvars + +def split_expression(rqlstring): + for expr in rqlstring.split(','): + for noparen1 in expr.split('('): + for noparen2 in noparen1.split(')'): + for word in noparen2.split(): + yield word + +def normalize_expression(rqlstring): + """normalize an rql expression to ease schema synchronization (avoid + suppressing and reinserting an expression if only a space has been + added/removed for instance) + """ + return u', '.join(' '.join(expr.split()) for expr in rqlstring.split(',')) + + +class RQLExpression(object): + """Base class for RQL expression used in schema (constraints and + permissions) + """ + # these are overridden by set_log_methods below + # only defining here to prevent pylint from complaining + info = warning = error = critical = exception = debug = lambda msg,*a,**kw: None + # to be defined in concrete classes + rqlst = None + predefined_variables = None + + def __init__(self, expression, mainvars, eid): + """ + :type mainvars: sequence of RQL variables' names. Can be provided as a + comma separated string. + :param mainvars: names of the variables being selected. + + """ + self.eid = eid # eid of the entity representing this rql expression + assert mainvars, 'bad mainvars %s' % mainvars + if isinstance(mainvars, basestring): + mainvars = set(splitstrip(mainvars)) + elif not isinstance(mainvars, set): + mainvars = set(mainvars) + self.mainvars = mainvars + self.expression = normalize_expression(expression) + try: + self.full_rql = self.rqlst.as_string() + except RQLSyntaxError: + raise RQLSyntaxError(expression) + for mainvar in mainvars: + # if variable is predefined, an extra reference is inserted + # automatically (`VAR eid %(v)s`) + if mainvar in self.predefined_variables: + min_refs = 3 + else: + min_refs = 2 + if len(self.rqlst.defined_vars[mainvar].references()) < min_refs: + _LOGGER.warn('You did not use the %s variable in your RQL ' + 'expression %s', mainvar, self) + # syntax tree used by read security (inserted in queries when necessary) + self.snippet_rqlst = parse(self.minimal_rql, print_errors=False).children[0] + # graph of links between variables, used by rql rewriter + self.vargraph = vargraph(self.rqlst) + # useful for some instrumentation, e.g. localperms permcheck command + self.package = ybo.PACKAGE + + def __str__(self): + return self.full_rql + def __repr__(self): + return '%s(%s)' % (self.__class__.__name__, self.full_rql) + + def __lt__(self, other): + if hasattr(other, 'expression'): + return self.expression < other.expression + return True + + def __eq__(self, other): + if hasattr(other, 'expression'): + return self.expression == other.expression + return False + + def __hash__(self): + return hash(self.expression) + + def __deepcopy__(self, memo): + return self.__class__(self.expression, self.mainvars) + def __getstate__(self): + return (self.expression, self.mainvars) + def __setstate__(self, state): + self.__init__(*state) + + @cachedproperty + def rqlst(self): + select = parse(self.minimal_rql, print_errors=False).children[0] + defined = set(split_expression(self.expression)) + for varname in self.predefined_variables: + if varname in defined: + select.add_eid_restriction(select.get_variable(varname), varname.lower(), 'Substitute') + return select + + # permission rql expression specific stuff ################################# + + @cached + def transform_has_permission(self): + found = None + rqlst = self.rqlst + for var in rqlst.defined_vars.itervalues(): + for varref in var.references(): + rel = varref.relation() + if rel is None: + continue + try: + prefix, action, suffix = rel.r_type.split('_') + except ValueError: + continue + if prefix != 'has' or suffix != 'permission' or \ + not action in ('add', 'delete', 'update', 'read'): + continue + if found is None: + found = [] + rqlst.save_state() + assert rel.children[0].name == 'U' + objvar = rel.children[1].children[0].variable + rqlst.remove_node(rel) + selected = [v.name for v in rqlst.get_selected_variables()] + if objvar.name not in selected: + colindex = len(selected) + rqlst.add_selected(objvar) + else: + colindex = selected.index(objvar.name) + found.append((action, colindex)) + # remove U eid %(u)s if U is not used in any other relation + uvrefs = rqlst.defined_vars['U'].references() + if len(uvrefs) == 1: + rqlst.remove_node(uvrefs[0].relation()) + if found is not None: + rql = rqlst.as_string() + if len(rqlst.selection) == 1 and isinstance(rqlst.where, nodes.Relation): + # only "Any X WHERE X eid %(x)s" remaining, no need to execute the rql + keyarg = rqlst.selection[0].name.lower() + else: + keyarg = None + rqlst.recover() + return rql, found, keyarg + return rqlst.as_string(), None, None + + def _check(self, _cw, **kwargs): + """return True if the rql expression is matching the given relation + between fromeid and toeid + + _cw may be a request or a server side transaction + """ + creating = kwargs.get('creating') + if not creating and self.eid is not None: + key = (self.eid, tuple(sorted(kwargs.iteritems()))) + try: + return _cw.local_perm_cache[key] + except KeyError: + pass + rql, has_perm_defs, keyarg = self.transform_has_permission() + # when creating an entity, expression related to X satisfied + if creating and 'X' in self.rqlst.defined_vars: + return True + if keyarg is None: + kwargs.setdefault('u', _cw.user.eid) + try: + rset = _cw.execute(rql, kwargs, build_descr=True) + except NotImplementedError: + self.critical('cant check rql expression, unsupported rql %s', rql) + if self.eid is not None: + _cw.local_perm_cache[key] = False + return False + except TypeResolverException as ex: + # some expression may not be resolvable with current kwargs + # (type conflict) + self.warning('%s: %s', rql, str(ex)) + if self.eid is not None: + _cw.local_perm_cache[key] = False + return False + except Unauthorized as ex: + self.debug('unauthorized %s: %s', rql, str(ex)) + if self.eid is not None: + _cw.local_perm_cache[key] = False + return False + else: + rset = _cw.eid_rset(kwargs[keyarg]) + # if no special has_*_permission relation in the rql expression, just + # check the result set contains something + if has_perm_defs is None: + if rset: + if self.eid is not None: + _cw.local_perm_cache[key] = True + return True + elif rset: + # check every special has_*_permission relation is satisfied + get_eschema = _cw.vreg.schema.eschema + try: + for eaction, col in has_perm_defs: + for i in xrange(len(rset)): + eschema = get_eschema(rset.description[i][col]) + eschema.check_perm(_cw, eaction, eid=rset[i][col]) + if self.eid is not None: + _cw.local_perm_cache[key] = True + return True + except Unauthorized: + pass + if self.eid is not None: + _cw.local_perm_cache[key] = False + return False + + @property + def minimal_rql(self): + return 'Any %s WHERE %s' % (','.join(sorted(self.mainvars)), + self.expression) + +# rql expressions for use in permission definition ############################# + +class ERQLExpression(RQLExpression): + predefined_variables = 'XU' + + def __init__(self, expression, mainvars=None, eid=None): + RQLExpression.__init__(self, expression, mainvars or 'X', eid) + + def check(self, _cw, eid=None, creating=False, **kwargs): + if 'X' in self.rqlst.defined_vars: + if eid is None: + if creating: + return self._check(_cw, creating=True, **kwargs) + return False + assert creating == False + return self._check(_cw, x=eid, **kwargs) + return self._check(_cw, **kwargs) + + +def vargraph(rqlst): + """ builds an adjacency graph of variables from the rql syntax tree, e.g: + Any O,S WHERE T subworkflow_exit S, T subworkflow WF, O state_of WF + => {'WF': ['O', 'T'], 'S': ['T'], 'T': ['WF', 'S'], 'O': ['WF']} + """ + vargraph = {} + for relation in rqlst.get_nodes(nodes.Relation): + try: + rhsvarname = relation.children[1].children[0].variable.name + lhsvarname = relation.children[0].name + except AttributeError: + pass + else: + vargraph.setdefault(lhsvarname, []).append(rhsvarname) + vargraph.setdefault(rhsvarname, []).append(lhsvarname) + #vargraph[(lhsvarname, rhsvarname)] = relation.r_type + return vargraph + + +class GeneratedConstraint(object): + def __init__(self, rqlst, mainvars): + self.snippet_rqlst = rqlst + self.mainvars = mainvars + self.vargraph = vargraph(rqlst) + + +class RRQLExpression(RQLExpression): + predefined_variables = 'SOU' + + def __init__(self, expression, mainvars=None, eid=None): + if mainvars is None: + mainvars = guess_rrqlexpr_mainvars(expression) + RQLExpression.__init__(self, expression, mainvars, eid) + + def check(self, _cw, fromeid=None, toeid=None): + kwargs = {} + if 'S' in self.rqlst.defined_vars: + if fromeid is None: + return False + kwargs['s'] = fromeid + if 'O' in self.rqlst.defined_vars: + if toeid is None: + return False + kwargs['o'] = toeid + return self._check(_cw, **kwargs) + PUB_SYSTEM_ENTITY_PERMS = { 'read': ('managers', 'users', 'guests',), 'add': ('managers',), @@ -659,297 +950,6 @@ def schema_by_eid(self, eid): return self._eid_index[eid] -# Bases for manipulating RQL in schema ######################################### - -def guess_rrqlexpr_mainvars(expression): - defined = set(split_expression(expression)) - mainvars = set() - if 'S' in defined: - mainvars.add('S') - if 'O' in defined: - mainvars.add('O') - if 'U' in defined: - mainvars.add('U') - if not mainvars: - raise Exception('unable to guess selection variables') - return mainvars - -def split_expression(rqlstring): - for expr in rqlstring.split(','): - for noparen1 in expr.split('('): - for noparen2 in noparen1.split(')'): - for word in noparen2.split(): - yield word - -def normalize_expression(rqlstring): - """normalize an rql expression to ease schema synchronization (avoid - suppressing and reinserting an expression if only a space has been - added/removed for instance) - """ - return u', '.join(' '.join(expr.split()) for expr in rqlstring.split(',')) - - -class RQLExpression(object): - """Base class for RQL expression used in schema (constraints and - permissions) - """ - # these are overridden by set_log_methods below - # only defining here to prevent pylint from complaining - info = warning = error = critical = exception = debug = lambda msg,*a,**kw: None - # to be defined in concrete classes - rqlst = None - predefined_variables = None - - def __init__(self, expression, mainvars, eid): - """ - :type mainvars: sequence of RQL variables' names. Can be provided as a - comma separated string. - :param mainvars: names of the variables being selected. - - """ - self.eid = eid # eid of the entity representing this rql expression - assert mainvars, 'bad mainvars %s' % mainvars - if isinstance(mainvars, basestring): - mainvars = set(splitstrip(mainvars)) - elif not isinstance(mainvars, set): - mainvars = set(mainvars) - self.mainvars = mainvars - self.expression = normalize_expression(expression) - try: - self.full_rql = self.rqlst.as_string() - except RQLSyntaxError: - raise RQLSyntaxError(expression) - for mainvar in mainvars: - # if variable is predefined, an extra reference is inserted - # automatically (`VAR eid %(v)s`) - if mainvar in self.predefined_variables: - min_refs = 3 - else: - min_refs = 2 - if len(self.rqlst.defined_vars[mainvar].references()) < min_refs: - _LOGGER.warn('You did not use the %s variable in your RQL ' - 'expression %s', mainvar, self) - # syntax tree used by read security (inserted in queries when necessary) - self.snippet_rqlst = parse(self.minimal_rql, print_errors=False).children[0] - # graph of links between variables, used by rql rewriter - self.vargraph = vargraph(self.rqlst) - # useful for some instrumentation, e.g. localperms permcheck command - self.package = ybo.PACKAGE - - def __str__(self): - return self.full_rql - def __repr__(self): - return '%s(%s)' % (self.__class__.__name__, self.full_rql) - - def __lt__(self, other): - if hasattr(other, 'expression'): - return self.expression < other.expression - return True - - def __eq__(self, other): - if hasattr(other, 'expression'): - return self.expression == other.expression - return False - - def __hash__(self): - return hash(self.expression) - - def __deepcopy__(self, memo): - return self.__class__(self.expression, self.mainvars) - def __getstate__(self): - return (self.expression, self.mainvars) - def __setstate__(self, state): - self.__init__(*state) - - @cachedproperty - def rqlst(self): - select = parse(self.minimal_rql, print_errors=False).children[0] - defined = set(split_expression(self.expression)) - for varname in self.predefined_variables: - if varname in defined: - select.add_eid_restriction(select.get_variable(varname), varname.lower(), 'Substitute') - return select - - # permission rql expression specific stuff ################################# - - @cached - def transform_has_permission(self): - found = None - rqlst = self.rqlst - for var in rqlst.defined_vars.itervalues(): - for varref in var.references(): - rel = varref.relation() - if rel is None: - continue - try: - prefix, action, suffix = rel.r_type.split('_') - except ValueError: - continue - if prefix != 'has' or suffix != 'permission' or \ - not action in ('add', 'delete', 'update', 'read'): - continue - if found is None: - found = [] - rqlst.save_state() - assert rel.children[0].name == 'U' - objvar = rel.children[1].children[0].variable - rqlst.remove_node(rel) - selected = [v.name for v in rqlst.get_selected_variables()] - if objvar.name not in selected: - colindex = len(selected) - rqlst.add_selected(objvar) - else: - colindex = selected.index(objvar.name) - found.append((action, colindex)) - # remove U eid %(u)s if U is not used in any other relation - uvrefs = rqlst.defined_vars['U'].references() - if len(uvrefs) == 1: - rqlst.remove_node(uvrefs[0].relation()) - if found is not None: - rql = rqlst.as_string() - if len(rqlst.selection) == 1 and isinstance(rqlst.where, nodes.Relation): - # only "Any X WHERE X eid %(x)s" remaining, no need to execute the rql - keyarg = rqlst.selection[0].name.lower() - else: - keyarg = None - rqlst.recover() - return rql, found, keyarg - return rqlst.as_string(), None, None - - def _check(self, _cw, **kwargs): - """return True if the rql expression is matching the given relation - between fromeid and toeid - - _cw may be a request or a server side transaction - """ - creating = kwargs.get('creating') - if not creating and self.eid is not None: - key = (self.eid, tuple(sorted(kwargs.iteritems()))) - try: - return _cw.local_perm_cache[key] - except KeyError: - pass - rql, has_perm_defs, keyarg = self.transform_has_permission() - # when creating an entity, expression related to X satisfied - if creating and 'X' in self.rqlst.defined_vars: - return True - if keyarg is None: - kwargs.setdefault('u', _cw.user.eid) - try: - rset = _cw.execute(rql, kwargs, build_descr=True) - except NotImplementedError: - self.critical('cant check rql expression, unsupported rql %s', rql) - if self.eid is not None: - _cw.local_perm_cache[key] = False - return False - except TypeResolverException as ex: - # some expression may not be resolvable with current kwargs - # (type conflict) - self.warning('%s: %s', rql, str(ex)) - if self.eid is not None: - _cw.local_perm_cache[key] = False - return False - except Unauthorized as ex: - self.debug('unauthorized %s: %s', rql, str(ex)) - if self.eid is not None: - _cw.local_perm_cache[key] = False - return False - else: - rset = _cw.eid_rset(kwargs[keyarg]) - # if no special has_*_permission relation in the rql expression, just - # check the result set contains something - if has_perm_defs is None: - if rset: - if self.eid is not None: - _cw.local_perm_cache[key] = True - return True - elif rset: - # check every special has_*_permission relation is satisfied - get_eschema = _cw.vreg.schema.eschema - try: - for eaction, col in has_perm_defs: - for i in xrange(len(rset)): - eschema = get_eschema(rset.description[i][col]) - eschema.check_perm(_cw, eaction, eid=rset[i][col]) - if self.eid is not None: - _cw.local_perm_cache[key] = True - return True - except Unauthorized: - pass - if self.eid is not None: - _cw.local_perm_cache[key] = False - return False - - @property - def minimal_rql(self): - return 'Any %s WHERE %s' % (','.join(sorted(self.mainvars)), - self.expression) - -# rql expressions for use in permission definition ############################# - -class ERQLExpression(RQLExpression): - predefined_variables = 'XU' - - def __init__(self, expression, mainvars=None, eid=None): - RQLExpression.__init__(self, expression, mainvars or 'X', eid) - - def check(self, _cw, eid=None, creating=False, **kwargs): - if 'X' in self.rqlst.defined_vars: - if eid is None: - if creating: - return self._check(_cw, creating=True, **kwargs) - return False - assert creating == False - return self._check(_cw, x=eid, **kwargs) - return self._check(_cw, **kwargs) - - -def vargraph(rqlst): - """ builds an adjacency graph of variables from the rql syntax tree, e.g: - Any O,S WHERE T subworkflow_exit S, T subworkflow WF, O state_of WF - => {'WF': ['O', 'T'], 'S': ['T'], 'T': ['WF', 'S'], 'O': ['WF']} - """ - vargraph = {} - for relation in rqlst.get_nodes(nodes.Relation): - try: - rhsvarname = relation.children[1].children[0].variable.name - lhsvarname = relation.children[0].name - except AttributeError: - pass - else: - vargraph.setdefault(lhsvarname, []).append(rhsvarname) - vargraph.setdefault(rhsvarname, []).append(lhsvarname) - #vargraph[(lhsvarname, rhsvarname)] = relation.r_type - return vargraph - - -class GeneratedConstraint(object): - def __init__(self, rqlst, mainvars): - self.snippet_rqlst = rqlst - self.mainvars = mainvars - self.vargraph = vargraph(rqlst) - - -class RRQLExpression(RQLExpression): - predefined_variables = 'SOU' - - def __init__(self, expression, mainvars=None, eid=None): - if mainvars is None: - mainvars = guess_rrqlexpr_mainvars(expression) - RQLExpression.__init__(self, expression, mainvars, eid) - - def check(self, _cw, fromeid=None, toeid=None): - kwargs = {} - if 'S' in self.rqlst.defined_vars: - if fromeid is None: - return False - kwargs['s'] = fromeid - if 'O' in self.rqlst.defined_vars: - if toeid is None: - return False - kwargs['o'] = toeid - return self._check(_cw, **kwargs) - # in yams, default 'update' perm for attributes granted to managers and owners. # Within cw, we want to default to users who may edit the entity holding the