| # Authors: Karl MacMillan <kmacmillan@mentalrootkit.com> |
| # |
| # Copyright (C) 2006 Red Hat |
| # see file 'COPYING' for use and warranty information |
| # |
| # This program is free software; you can redistribute it and/or |
| # modify it under the terms of the GNU General Public License as |
| # published by the Free Software Foundation; version 2 only |
| # |
| # This program 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 General Public License for more details. |
| # |
| # You should have received a copy of the GNU General Public License |
| # along with this program; if not, write to the Free Software |
| # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| # |
| |
| """ |
| Classes for representing and manipulating interfaces. |
| """ |
| |
| import copy |
| import itertools |
| |
| from . import access |
| from . import refpolicy |
| from . import objectmodel |
| from . import matching |
| from .sepolgeni18n import _ |
| |
| |
| class Param: |
| """ |
| Object representing a paramater for an interface. |
| """ |
| def __init__(self): |
| self.__name = "" |
| self.type = refpolicy.SRC_TYPE |
| self.obj_classes = refpolicy.IdSet() |
| self.required = True |
| |
| def set_name(self, name): |
| if not access.is_idparam(name): |
| raise ValueError("Name [%s] is not a param" % name) |
| self.__name = name |
| |
| def get_name(self): |
| return self.__name |
| |
| name = property(get_name, set_name) |
| |
| num = property(fget=lambda self: int(self.name[1:])) |
| |
| def __repr__(self): |
| return "<sepolgen.policygen.Param instance [%s, %s, %s]>" % \ |
| (self.name, refpolicy.field_to_str[self.type], " ".join(self.obj_classes)) |
| |
| |
| # Helper for extract perms |
| def __param_insert(name, type, av, params): |
| ret = 0 |
| if name in params: |
| p = params[name] |
| # The entries are identical - we're done |
| if type == p.type: |
| return |
| # Hanldle implicitly typed objects (like process) |
| if (type == refpolicy.SRC_TYPE or type == refpolicy.TGT_TYPE) and \ |
| (p.type == refpolicy.TGT_TYPE or p.type == refpolicy.SRC_TYPE): |
| #print name, refpolicy.field_to_str[p.type] |
| # If the object is not implicitly typed, tell the |
| # caller there is a likely conflict. |
| ret = 1 |
| if av: |
| avobjs = [av.obj_class] |
| else: |
| avobjs = [] |
| for obj in itertools.chain(p.obj_classes, avobjs): |
| if obj in objectmodel.implicitly_typed_objects: |
| ret = 0 |
| break |
| # "Promote" to a SRC_TYPE as this is the likely usage. |
| # We do this even if the above test fails on purpose |
| # as there is really no sane way to resolve the conflict |
| # here. The caller can take other actions if needed. |
| p.type = refpolicy.SRC_TYPE |
| else: |
| # There is some conflict - no way to resolve it really |
| # so we just leave the first entry and tell the caller |
| # there was a conflict. |
| ret = 1 |
| else: |
| p = Param() |
| p.name = name |
| p.type = type |
| params[p.name] = p |
| |
| if av: |
| p.obj_classes.add(av.obj_class) |
| return ret |
| |
| |
| |
| def av_extract_params(av, params): |
| """Extract the paramaters from an access vector. |
| |
| Extract the paramaters (in the form $N) from an access |
| vector, storing them as Param objects in a dictionary. |
| Some attempt is made at resolving conflicts with other |
| entries in the dict, but if an unresolvable conflict is |
| found it is reported to the caller. |
| |
| The goal here is to figure out how interface paramaters are |
| actually used in the interface - e.g., that $1 is a domain used as |
| a SRC_TYPE. In general an interface will look like this: |
| |
| interface(`foo', ` |
| allow $1 foo : file read; |
| ') |
| |
| This is simple to figure out - $1 is a SRC_TYPE. A few interfaces |
| are more complex, for example: |
| |
| interface(`foo_trans',` |
| domain_auto_trans($1,fingerd_exec_t,fingerd_t) |
| |
| allow $1 fingerd_t:fd use; |
| allow fingerd_t $1:fd use; |
| allow fingerd_t $1:fifo_file rw_file_perms; |
| allow fingerd_t $1:process sigchld; |
| ') |
| |
| Here the usage seems ambigious, but it is not. $1 is still domain |
| and therefore should be returned as a SRC_TYPE. |
| |
| Returns: |
| 0 - success |
| 1 - conflict found |
| """ |
| ret = 0 |
| found_src = False |
| if access.is_idparam(av.src_type): |
| if __param_insert(av.src_type, refpolicy.SRC_TYPE, av, params) == 1: |
| ret = 1 |
| |
| if access.is_idparam(av.tgt_type): |
| if __param_insert(av.tgt_type, refpolicy.TGT_TYPE, av, params) == 1: |
| ret = 1 |
| |
| if access.is_idparam(av.obj_class): |
| if __param_insert(av.obj_class, refpolicy.OBJ_CLASS, av, params) == 1: |
| ret = 1 |
| |
| for perm in av.perms: |
| if access.is_idparam(perm): |
| if __param_insert(perm, PERM) == 1: |
| ret = 1 |
| |
| return ret |
| |
| def role_extract_params(role, params): |
| if access.is_idparam(role.role): |
| return __param_insert(role.role, refpolicy.ROLE, None, params) |
| |
| def type_rule_extract_params(rule, params): |
| def extract_from_set(set, type): |
| ret = 0 |
| for x in set: |
| if access.is_idparam(x): |
| if __param_insert(x, type, None, params): |
| ret = 1 |
| return ret |
| |
| ret = 0 |
| if extract_from_set(rule.src_types, refpolicy.SRC_TYPE): |
| ret = 1 |
| |
| if extract_from_set(rule.tgt_types, refpolicy.TGT_TYPE): |
| ret = 1 |
| |
| if extract_from_set(rule.obj_classes, refpolicy.OBJ_CLASS): |
| ret = 1 |
| |
| if access.is_idparam(rule.dest_type): |
| if __param_insert(rule.dest_type, refpolicy.DEST_TYPE, None, params): |
| ret = 1 |
| |
| return ret |
| |
| def ifcall_extract_params(ifcall, params): |
| ret = 0 |
| for arg in ifcall.args: |
| if access.is_idparam(arg): |
| # Assume interface arguments are source types. Fairly safe |
| # assumption for most interfaces |
| if __param_insert(arg, refpolicy.SRC_TYPE, None, params): |
| ret = 1 |
| |
| return ret |
| |
| class AttributeVector: |
| def __init__(self): |
| self.name = "" |
| self.access = access.AccessVectorSet() |
| |
| def add_av(self, av): |
| self.access.add_av(av) |
| |
| class AttributeSet: |
| def __init__(self): |
| self.attributes = { } |
| |
| def add_attr(self, attr): |
| self.attributes[attr.name] = attr |
| |
| def from_file(self, fd): |
| def parse_attr(line): |
| fields = line[1:-1].split() |
| if len(fields) != 2 or fields[0] != "Attribute": |
| raise SyntaxError("Syntax error Attribute statement %s" % line) |
| a = AttributeVector() |
| a.name = fields[1] |
| |
| return a |
| |
| a = None |
| for line in fd: |
| line = line[:-1] |
| if line[0] == "[": |
| if a: |
| self.add_attr(a) |
| a = parse_attr(line) |
| elif a: |
| l = line.split(",") |
| av = access.AccessVector(l) |
| a.add_av(av) |
| if a: |
| self.add_attr(a) |
| |
| class InterfaceVector: |
| def __init__(self, interface=None, attributes={}): |
| # Enabled is a loose concept currently - we are essentially |
| # not enabling interfaces that we can't handle currently. |
| # See InterfaceVector.add_ifv for more information. |
| self.enabled = True |
| self.name = "" |
| # The access that is enabled by this interface - eventually |
| # this will include indirect access from typeattribute |
| # statements. |
| self.access = access.AccessVectorSet() |
| # Paramaters are stored in a dictionary (key: param name |
| # value: Param object). |
| self.params = { } |
| if interface: |
| self.from_interface(interface, attributes) |
| self.expanded = False |
| |
| def from_interface(self, interface, attributes={}): |
| self.name = interface.name |
| |
| # Add allow rules |
| for avrule in interface.avrules(): |
| if avrule.rule_type != refpolicy.AVRule.ALLOW: |
| continue |
| # Handle some policy bugs |
| if "dontaudit" in interface.name: |
| #print "allow rule in interface: %s" % interface |
| continue |
| avs = access.avrule_to_access_vectors(avrule) |
| for av in avs: |
| self.add_av(av) |
| |
| # Add typeattribute access |
| if attributes: |
| for typeattribute in interface.typeattributes(): |
| for attr in typeattribute.attributes: |
| if attr not in attributes.attributes: |
| # print "missing attribute " + attr |
| continue |
| attr_vec = attributes.attributes[attr] |
| for a in attr_vec.access: |
| av = copy.copy(a) |
| if av.src_type == attr_vec.name: |
| av.src_type = typeattribute.type |
| if av.tgt_type == attr_vec.name: |
| av.tgt_type = typeattribute.type |
| self.add_av(av) |
| |
| |
| # Extract paramaters from roles |
| for role in interface.roles(): |
| if role_extract_params(role, self.params): |
| pass |
| #print "found conflicting role param %s for interface %s" % \ |
| # (role.name, interface.name) |
| # Extract paramaters from type rules |
| for rule in interface.typerules(): |
| if type_rule_extract_params(rule, self.params): |
| pass |
| #print "found conflicting params in rule %s in interface %s" % \ |
| # (str(rule), interface.name) |
| |
| for ifcall in interface.interface_calls(): |
| if ifcall_extract_params(ifcall, self.params): |
| pass |
| #print "found conflicting params in ifcall %s in interface %s" % \ |
| # (str(ifcall), interface.name) |
| |
| |
| def add_av(self, av): |
| if av_extract_params(av, self.params) == 1: |
| pass |
| #print "found conflicting perms [%s]" % str(av) |
| self.access.add_av(av) |
| |
| def to_string(self): |
| s = [] |
| s.append("[InterfaceVector %s]" % self.name) |
| for av in self.access: |
| s.append(str(av)) |
| return "\n".join(s) |
| |
| def __str__(self): |
| return self.__repr__() |
| |
| def __repr__(self): |
| return "<InterfaceVector %s:%s>" % (self.name, self.enabled) |
| |
| |
| class InterfaceSet: |
| def __init__(self, output=None): |
| self.interfaces = { } |
| self.tgt_type_map = { } |
| self.tgt_type_all = [] |
| self.output = output |
| |
| def o(self, str): |
| if self.output: |
| self.output.write(str + "\n") |
| |
| def to_file(self, fd): |
| for iv in sorted(self.interfaces.values(), key=lambda x: x.name): |
| fd.write("[InterfaceVector %s " % iv.name) |
| for param in sorted(iv.params.values(), key=lambda x: x.name): |
| fd.write("%s:%s " % (param.name, refpolicy.field_to_str[param.type])) |
| fd.write("]\n") |
| avl = sorted(iv.access.to_list()) |
| for av in avl: |
| fd.write(",".join(av)) |
| fd.write("\n") |
| |
| def from_file(self, fd): |
| def parse_ifv(line): |
| fields = line[1:-1].split() |
| if len(fields) < 2 or fields[0] != "InterfaceVector": |
| raise SyntaxError("Syntax error InterfaceVector statement %s" % line) |
| ifv = InterfaceVector() |
| ifv.name = fields[1] |
| if len(fields) == 2: |
| return |
| for field in fields[2:]: |
| p = field.split(":") |
| if len(p) != 2: |
| raise SyntaxError("Invalid param in InterfaceVector statement %s" % line) |
| param = Param() |
| param.name = p[0] |
| param.type = refpolicy.str_to_field[p[1]] |
| ifv.params[param.name] = param |
| return ifv |
| |
| ifv = None |
| for line in fd: |
| line = line[:-1] |
| if line[0] == "[": |
| if ifv: |
| self.add_ifv(ifv) |
| ifv = parse_ifv(line) |
| elif ifv: |
| l = line.split(",") |
| av = access.AccessVector(l) |
| ifv.add_av(av) |
| if ifv: |
| self.add_ifv(ifv) |
| |
| self.index() |
| |
| def add_ifv(self, ifv): |
| self.interfaces[ifv.name] = ifv |
| |
| def index(self): |
| for ifv in self.interfaces.values(): |
| tgt_types = set() |
| for av in ifv.access: |
| if access.is_idparam(av.tgt_type): |
| self.tgt_type_all.append(ifv) |
| tgt_types = set() |
| break |
| tgt_types.add(av.tgt_type) |
| |
| for type in tgt_types: |
| l = self.tgt_type_map.setdefault(type, []) |
| l.append(ifv) |
| |
| def add(self, interface, attributes={}): |
| ifv = InterfaceVector(interface, attributes) |
| self.add_ifv(ifv) |
| |
| def add_headers(self, headers, output=None, attributes={}): |
| for i in itertools.chain(headers.interfaces(), headers.templates()): |
| self.add(i, attributes) |
| |
| self.expand_ifcalls(headers) |
| self.index() |
| |
| def map_param(self, id, ifcall): |
| if access.is_idparam(id): |
| num = int(id[1:]) |
| if num > len(ifcall.args): |
| # Tell caller to drop this because it must have |
| # been generated from an optional param. |
| return None |
| else: |
| arg = ifcall.args[num - 1] |
| if isinstance(arg, list): |
| return arg |
| else: |
| return [arg] |
| else: |
| return [id] |
| |
| def map_add_av(self, ifv, av, ifcall): |
| src_types = self.map_param(av.src_type, ifcall) |
| if src_types is None: |
| return |
| |
| tgt_types = self.map_param(av.tgt_type, ifcall) |
| if tgt_types is None: |
| return |
| |
| obj_classes = self.map_param(av.obj_class, ifcall) |
| if obj_classes is None: |
| return |
| |
| new_perms = refpolicy.IdSet() |
| for perm in av.perms: |
| p = self.map_param(perm, ifcall) |
| if p is None: |
| continue |
| else: |
| new_perms.update(p) |
| if len(new_perms) == 0: |
| return |
| |
| for src_type in src_types: |
| for tgt_type in tgt_types: |
| for obj_class in obj_classes: |
| ifv.access.add(src_type, tgt_type, obj_class, new_perms) |
| |
| def do_expand_ifcalls(self, interface, if_by_name): |
| # Descend an interface call tree adding the access |
| # from each interface. This is a depth first walk |
| # of the tree. |
| |
| stack = [(interface, None)] |
| ifv = self.interfaces[interface.name] |
| ifv.expanded = True |
| |
| while len(stack) > 0: |
| cur, cur_ifcall = stack.pop(-1) |
| |
| cur_ifv = self.interfaces[cur.name] |
| if cur != interface: |
| |
| for av in cur_ifv.access: |
| self.map_add_av(ifv, av, cur_ifcall) |
| |
| # If we have already fully expanded this interface |
| # there is no reason to descend further. |
| if cur_ifv.expanded: |
| continue |
| |
| for ifcall in cur.interface_calls(): |
| if ifcall.ifname == interface.name: |
| self.o(_("Found circular interface class")) |
| return |
| try: |
| newif = if_by_name[ifcall.ifname] |
| except KeyError: |
| self.o(_("Missing interface definition for %s" % ifcall.ifname)) |
| continue |
| |
| stack.append((newif, ifcall)) |
| |
| |
| def expand_ifcalls(self, headers): |
| # Create a map of interface names to interfaces - |
| # this mirrors the interface vector map we already |
| # have. |
| if_by_name = { } |
| |
| for i in itertools.chain(headers.interfaces(), headers.templates()): |
| if_by_name[i.name] = i |
| |
| |
| for interface in itertools.chain(headers.interfaces(), headers.templates()): |
| self.do_expand_ifcalls(interface, if_by_name) |
| |
