Move setting SELinux booleans to platform code

Create a platform task for setting SELinux booleans.

Use an exception for the case when the booleans could not be set
(since this is an error if not handled).
Since ipaplatform should not depend on ipalib, create a new
errors module in ipapython for SetseboolError.

Handle uninstallation with the same task, which means
the booleans are now restored with a single call to
setsebool.

Preparation for: https://fedorahosted.org/freeipa/ticket/4157

Fixes: https://fedorahosted.org/freeipa/ticket/2934
Fixes: https://fedorahosted.org/freeipa/ticket/2519
Reviewed-By: Thierry Bordaz <tbordaz@redhat.com>

ipaplatform/base/tasks.py

@@ -132,4 +132,23 @@ class BaseTaskNamespace(object):
 
         return
 
+    def set_selinux_booleans(self, required_settings, backup_func=None):
+        """Set the specified SELinux booleans
+
+        :param required_settings: A dictionary mapping the boolean names
+                                  to desired_values.
+                                  The desired value can be 'on' or 'off'.
+
+        :param backup_func: A function called for each boolean with two
+                            arguments: the name and the previous value
+
+        If SELinux is disabled, return False; on success returns True.
+
+        If setting the booleans fails,
+        an ipapython.errors.SetseboolError is raised.
+        """
+
+        return
+
+
 task_namespace = BaseTaskNamespace()

ipaplatform/fedora/tasks.py

@@ -24,7 +24,6 @@ This module contains default Fedora-specific implementations of system tasks.
 '''
 
 import os
-import shutil
 import stat
 import socket
 import sys
@@ -35,8 +34,9 @@ from subprocess import CalledProcessError
 from nss.error import NSPRError
 from pyasn1.error import PyAsn1Error
 
-from ipapython.ipa_log_manager import root_logger
+from ipapython.ipa_log_manager import root_logger, log_mgr
 from ipapython import ipautil
+import ipapython.errors
 
 from ipalib import x509 # FIXME: do not import from ipalib
 
@@ -45,6 +45,9 @@ from ipaplatform.fedora.authconfig import FedoraAuthConfig
 from ipaplatform.base.tasks import BaseTaskNamespace
 
 
+log = log_mgr.get_logger(__name__)
+
+
 class FedoraTaskNamespace(BaseTaskNamespace):
 
     def restore_context(self, filepath, restorecon=paths.SBIN_RESTORECON):
@@ -326,4 +329,50 @@ class FedoraTaskNamespace(BaseTaskNamespace):
             except OSError:
                 pass
 
+    def set_selinux_booleans(self, required_settings, backup_func=None):
+        def get_setsebool_args(changes):
+            args = [paths.SETSEBOOL, "-P"]
+            args.extend(["%s=%s" % update for update in changes.iteritems()])
+
+            return args
+
+        if (os.path.exists(paths.SELINUXENABLED)):
+            try:
+                ipautil.run([paths.SELINUXENABLED])
+            except ipautil.CalledProcessError:
+                # selinuxenabled returns 1 if not enabled
+                return False
+        else:
+            return False
+
+        updated_vars = {}
+        failed_vars = {}
+        for setting, state in required_settings.iteritems():
+            try:
+                (stdout, stderr, rc) = ipautil.run([paths.GETSEBOOL, setting])
+                original_state = stdout.split()[2]
+                if backup_func is not None:
+                    backup_func(setting, original_state)
+
+                if original_state != state:
+                    updated_vars[setting] = state
+            except ipautil.CalledProcessError, e:
+                log.error("Cannot get SELinux boolean '%s': %s", setting, e)
+                failed_vars[setting] = state
+
+        if updated_vars:
+            args = get_setsebool_args(updated_vars)
+            try:
+                ipautil.run(args)
+            except ipautil.CalledProcessError:
+                failed_vars.update(updated_vars)
+
+        if failed_vars:
+            raise ipapython.errors.SetseboolError(
+                failed=failed_vars,
+                command=' '.join(get_setsebool_args(failed_vars)))
+
+        return True
+
+
 tasks = FedoraTaskNamespace()