Re-implement access control using an updated model.

The new model is based on permssions, privileges and roles.
Most importantly it corrects the reverse membership that caused problems
in the previous implementation. You add permission to privileges and
privileges to roles, not the other way around (even though it works that
way behind the scenes).

A permission object is a combination of a simple group and an aci.
The linkage between the aci and the permission is the description of
the permission. This shows as the name/description of the aci.

ldap:///self and groups granting groups (v1-style) are not supported by
this model (it will be provided separately).

This makes the aci plugin internal only.

ticket 445

ipalib/plugins/role.py

@@ -0,0 +1,212 @@
+# Authors:
+#   Rob Crittenden <rcritten@redhat.com>
+#   Pavel Zuna <pzuna@redhat.com>
+#
+# Copyright (C) 2009  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
+"""
+Roles
+
+A role is used for fine-grained delegation. A permission grants the ability
+to perform given low-level tasks (add a user, modify a group, etc.). A
+privilege combines one or more permissions into a higher-level abstraction
+such as useradmin. A useradmin would be able to add, delete and modify users.
+
+Privileges are assigned to Roles.
+
+Users, groups, hosts and hostgroups may be members of a Role.
+
+Roles can not contain other roles.
+
+EXAMPLES:
+
+ Add a new role:
+   ipa role-add --desc="Junior-level admin" junioradmin
+
+ Add some privileges to this role:
+   ipa role-add-privilege --privileges=addusers junioradmin
+   ipa role-add-privilege --privileges=change_password junioradmin
+   ipa role-add-privilege --privileges=add_user_to_default_group juioradmin
+
+ Add a group of users to this role:
+   ipa group-add --desc="User admins" useradmins
+   ipa role-add-member --groups=useradmins junioradmin
+
+ Display information about a role:
+   ipa role-show junioradmin
+
+ The result of this is that any users in the group 'useradmins' can
+ add users, reset passwords or add a user to the default IPA user group.
+"""
+
+from ipalib.plugins.baseldap import *
+from ipalib import api, Str, _, ngettext
+from ipalib import Command
+from ipalib.plugins import privilege
+
+
+class role(LDAPObject):
+    """
+    Role object.
+    """
+    container_dn = api.env.container_rolegroup
+    object_name = 'role'
+    object_name_plural = 'roles'
+    object_class = ['groupofnames', 'nestedgroup']
+    default_attributes = ['cn', 'description', 'member', 'memberof',
+        'memberindirect'
+    ]
+    attribute_members = {
+        'member': ['user', 'group', 'host', 'hostgroup'],
+        'memberof': ['privilege'],
+#        'memberindirect': ['user', 'group', 'host', 'hostgroup'],
+    }
+    reverse_members = {
+        'member': ['privilege'],
+    }
+    rdnattr='cn'
+
+    label = _('Role Groups')
+
+    takes_params = (
+        Str('cn',
+            cli_name='name',
+            label=_('Role name'),
+            primary_key=True,
+            normalizer=lambda value: value.lower(),
+        ),
+        Str('description',
+            cli_name='desc',
+            label=_('Description'),
+            doc=_('A description of this role-group'),
+        ),
+    )
+
+api.register(role)
+
+
+class role_add(LDAPCreate):
+    """
+    Add a new role.
+    """
+
+    msg_summary = _('Added role "%(value)s"')
+
+api.register(role_add)
+
+
+class role_del(LDAPDelete):
+    """
+    Delete a role.
+    """
+
+    msg_summary = _('Deleted role "%(value)s"')
+
+api.register(role_del)
+
+
+class role_mod(LDAPUpdate):
+    """
+    Modify a role.
+    """
+
+    msg_summary = _('Modified role "%(value)s"')
+
+api.register(role_mod)
+
+
+class role_find(LDAPSearch):
+    """
+    Search for roles.
+    """
+
+    msg_summary = ngettext(
+        '%(count)d role matched', '%(count)d roles matched'
+    )
+
+api.register(role_find)
+
+
+class role_show(LDAPRetrieve):
+    """
+    Display information about a role.
+    """
+
+api.register(role_show)
+
+
+class role_add_member(LDAPAddMember):
+    """
+    Add members to a role.
+    """
+
+api.register(role_add_member)
+
+
+class role_remove_member(LDAPRemoveMember):
+    """
+    Remove members from a role.
+    """
+
+api.register(role_remove_member)
+
+
+class role_add_privilege(LDAPAddReverseMember):
+    """
+    Add privileges to a role.
+    """
+    show_command = 'role_show'
+    member_command = 'privilege_add_member'
+    reverse_attr = 'privilege'
+    member_attr = 'role'
+
+    has_output = (
+        output.Entry('result'),
+        output.Output('failed',
+            type=dict,
+            doc=_('Members that could not be added'),
+        ),
+        output.Output('completed',
+            type=int,
+            doc=_('Number of privileges added'),
+        ),
+    )
+
+api.register(role_add_privilege)
+
+
+class role_remove_privilege(LDAPRemoveReverseMember):
+    """
+    Remove privileges from a role.
+    """
+    show_command = 'role_show'
+    member_command = 'privilege_remove_member'
+    reverse_attr = 'privilege'
+    member_attr = 'role'
+
+    has_output = (
+        output.Entry('result'),
+        output.Output('failed',
+            type=dict,
+            doc=_('Members that could not be added'),
+        ),
+        output.Output('completed',
+            type=int,
+            doc=_('Number of privileges removed'),
+        ),
+    )
+
+api.register(role_remove_privilege)