s4 smbd standard tests: limit forked processes

Tests to confirm the standard process model honours the smbd.conf
variable "max smbd processes", when forking a new process on accept.

Signed-off-by: Gary Lockyer <gary@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>

1 files changed, 78 insertions, 0 deletions

diff --git a/python/samba/tests/process_limits.py b/python/samba/tests/process_limits.py
new file mode 100644
index 00000000000..b62906e294f
--- /dev/null
+++ b/python/samba/tests/process_limits.py
@@ -0,0 +1,78 @@
+# Tests for limiting processes forked on accept by the standard process model
+#
+# Copyright (C) Andrew Bartlett <abartlet@samba.org> 2018
+#
+# 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; either version 3 of the License, or
+# (at your option) any later version.
+#
+# 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, see <http://www.gnu.org/licenses/>.
+#
+
+from __future__ import print_function
+"""Tests limits on processes forked by fork on accept in the standard process
+   model.
+   NOTE: This test runs in an environment with an artificially low setting for
+         smbd max processes
+"""
+
+
+import os
+from samba.tests import TestCase
+from samba.samdb import SamDB
+from ldb import LdbError, ERR_OPERATIONS_ERROR
+
+
+class StandardModelProcessLimitTests(TestCase):
+
+    def setUp(self):
+        super(StandardModelProcessLimitTests, self).setUp()
+
+    def tearDown(self):
+        super(StandardModelProcessLimitTests, self).tearDown()
+
+    def simple_bind(self):
+        creds = self.insta_creds(template=self.get_credentials())
+        creds.set_bind_dn("%s\\%s" % (creds.get_domain(),
+                                      creds.get_username()))
+
+        return SamDB(url="ldaps://%s" % os.environ["SERVER"],
+                     lp=self.get_loadparm(),
+                     credentials=creds)
+
+    def test_process_limits(self):
+        creds = self.insta_creds(template=self.get_credentials())
+        creds.set_bind_dn("%s\\%s" % (creds.get_domain(),
+                                      creds.get_username()))
+
+        connections = []
+        try:
+            # Open a series of LDAP connections, the maximum number of
+            # active connections should be 20, so the 21st should fail.
+            # But as it is possible that there may be other processes holding
+            # connections, need to allow for earlier connection failures.
+            for _ in range(21):
+                connections.append(self.simple_bind())
+            self.fail(
+                "Processes not limited, able to make more than 20 connections")
+        except LdbError as e:
+            (errno, estr) = e.args
+            if errno != ERR_OPERATIONS_ERROR:
+                raise
+            if not (estr.endswith("NT_STATUS_CONNECTION_DISCONNECTED") or
+                    estr.endswith("NT_STATUS_CONNECTION_RESET")):
+                raise
+            pass
+        #
+        # Clean up the connections we've just opened, by deleting the
+        # connection in python. This should invoke the talloc destructor to
+        # release any resources and close the actual connection to the server.
+        for c in connections:
+            del c