Fix SMB create and directory mask defaults (#14655)

This is a regression that slipped into large refactor effort to
remove clustering vestiges in Electric Eel. The values for
default create mask and directory mask became more restrictive than
in previous TrueNAS versions. This commit resets them to old defaults
for the directory mask (775) but a slightly more restrictive default for
files (664) since execute is generally not desired for newly created
files. Tests validating new defaults is also added.

Generally, these values are not used when SMB shares are created with
our recommended default configuration (using NFSv4 ACLs with a
restricted aclmode) and so impact on userbase during BETA / RC
cycles was minimal.

src/middlewared/middlewared/plugins/smb_/util_smbconf.py

@@ -110,8 +110,8 @@ def generate_smb_conf_dict(
         'netbios aliases': ' '.join(smb_service_config['netbiosalias']),
         'guest account': smb_service_config['guest'] if smb_service_config['guest'] else 'nobody',
         'obey pam restrictions': any(home_share),
-        'create mask': smb_service_config['filemask'] or '0744',
-        'directory mask': smb_service_config['dirmask'] or '0755',
+        'create mask': smb_service_config['filemask'] or '0664',
+        'directory mask': smb_service_config['dirmask'] or '0775',
         'ntlm auth': smb_service_config['ntlmv1_auth'],
         'server multichannel support': smb_service_config['multichannel'],
         'unix charset': smb_service_config['unixcharset'],

src/middlewared/middlewared/pytest/unit/plugins/test_smb.py

@@ -232,6 +232,8 @@ def test__base_smb():
     assert conf['idmap config * : backend'] == 'tdb'
     assert conf['idmap config * : range'] == '90000001 - 100000000'
     assert conf['server smb encrypt'] == 'default'
+    assert conf['directory mask'] == '0775'
+    assert conf['create mask'] == '0664'
 
 
 def test__syslog():