Properly detect missing SMART support

Reported by Patrick Kuijvenhoven on https://github.com/ercpe/smart-check/issues/5.

Previously, we did not check the value of `SMART support is` in the information section of the smartctl output and relied entirely on the other sections.
Now we check that value too and report a failed check if the device (or maybe a raid controller) announces that the device has no SMART capability.

smartcheck/__main__.py

@@ -86,31 +86,35 @@ def main():
         check = SMARTCheck(stream, args.disks_file)
 
         if check.data_parsed:
-            attribute_errors = check.check_attributes(ignore_attributes=args.ignore_attributes)
-
-            if args.exclude_notices:
-                for k in [x for x, y in attribute_errors.items() if y.level == AttributeWarning.Notice]:
-                    del attribute_errors[k]
-
-            if attribute_errors:
-                msg = ', '.join([ae.long_message if args.verbose else ae.short_message for ae in attribute_errors.values()])
-
-                # set the exit code of NOTICEs to WARNINGs if (-n / --notices-are-warnings) is set
-                if args.notices_are_warnings and \
-                        any((ae.level == AttributeWarning.Notice for ae in attribute_errors.values())):
-                    exit_code = 1
-
-                if any((ae.level == AttributeWarning.Warning for ae in attribute_errors.values())):
-                    exit_code = 1
-                if any((ae.level == AttributeWarning.Critical for ae in attribute_errors.values())):
+            if check.has_smart_support():
+                attribute_errors = check.check_attributes(ignore_attributes=args.ignore_attributes)
+    
+                if args.exclude_notices:
+                    for k in [x for x, y in attribute_errors.items() if y.level == AttributeWarning.Notice]:
+                        del attribute_errors[k]
+    
+                if attribute_errors:
+                    msg = ', '.join([ae.long_message if args.verbose else ae.short_message for ae in attribute_errors.values()])
+    
+                    # set the exit code of NOTICEs to WARNINGs if (-n / --notices-are-warnings) is set
+                    if args.notices_are_warnings and \
+                            any((ae.level == AttributeWarning.Notice for ae in attribute_errors.values())):
+                        exit_code = 1
+    
+                    if any((ae.level == AttributeWarning.Warning for ae in attribute_errors.values())):
+                        exit_code = 1
+                    if any((ae.level == AttributeWarning.Critical for ae in attribute_errors.values())):
+                        exit_code = 2
+    
+                if not check.check_tests(latest_only=args.accept_recovered_self_test):
+                    msg = (msg.strip() + '; S.M.A.R.T. self test reported an error').lstrip(';').strip()
                     exit_code = 2
-
-            if not check.check_tests(latest_only=args.accept_recovered_self_test):
-                msg = (msg.strip() + '; S.M.A.R.T. self test reported an error').lstrip(';').strip()
-                exit_code = 2
-
-            if check.ata_error_count:
-                msg = (msg.strip() + '; %s ATA errors found' % check.ata_error_count).lstrip(';').strip()
+    
+                if check.ata_error_count:
+                    msg = (msg.strip() + '; %s ATA errors found' % check.ata_error_count).lstrip(';').strip()
+                    exit_code = 2
+            else:
+                msg = 'Device is missing S.M.A.R.T. support'
                 exit_code = 2
 
             if not exit_code and not msg:

smartcheck/check.py

@@ -17,12 +17,13 @@ TESTS_SECTION_START = 'SMART Self-test log structure revision number'
 ATA_ERROR_COUNT = re.compile('^ATA Error Count: (\d+).*', re.MULTILINE | re.IGNORECASE)
 
 INFORMATION_RE = [
-    ("model_family", re.compile('Model Family: (.*)', re.UNICODE)),
-    ("device_model", re.compile("(?:Device Model|Product): (.*)", re.UNICODE)),
-    ("serial", re.compile("Serial Number: (.*)", re.UNICODE | re.IGNORECASE)),
-    ("firmware_version", re.compile("Firmware version: (.*)", re.UNICODE)),
-    ("ata_version", re.compile("ATA Version is: (.*)", re.UNICODE)),
-    ("sata_version", re.compile("SATA Version is: (.*)", re.UNICODE)),
+    ('model_family', re.compile(r'Model Family: (.*)', re.UNICODE)),
+    ('device_model', re.compile(r'(?:Device Model|Product): (.*)', re.UNICODE)),
+    ('serial', re.compile(r'Serial Number: (.*)', re.UNICODE | re.IGNORECASE)),
+    ('firmware_version', re.compile(r'Firmware version: (.*)', re.UNICODE)),
+    ('ata_version', re.compile(r'ATA Version is: (.*)', re.UNICODE)),
+    ('sata_version', re.compile(r'SATA Version is: (.*)', re.UNICODE)),
+    ('smart_support', re.compile(r'SMART support is:\s+(.*)', re.UNICODE))
 ]
 
 DATA_RE = [
@@ -138,7 +139,7 @@ class SMARTCheck(object):
         if self._database is None:
             if self.db_path:
                 with open(self.db_path) as f:
-                    self._database = yaml.load(f) or {}
+                    self._database = yaml.load(f, Loader=yaml.SafeLoader) or {}
             else:
                 self._database = []
         return self._database
@@ -148,7 +149,7 @@ class SMARTCheck(object):
         if self._generic is None:
             try:
                 with open(GENERIC_ATTRS_FILE) as f:
-                    self._generic = yaml.load(f) or []
+                    self._generic = yaml.load(f, Loader=yaml.SafeLoader) or []
             except:
                 logger.exception("Could not read %s", GENERIC_ATTRS_FILE)
         return self._generic
@@ -246,7 +247,14 @@ class SMARTCheck(object):
         return 0
 
     def check(self, ignore_attributes=None):
-        return len(self.check_attributes(ignore_attributes or [])) == 0 and self.check_tests() and self.ata_error_count == 0
+        # 1. the device should announce smart support in the info section
+        # 2. no attributes should indicate an unhealthy device
+        # 3. no short/long smart tests should have failed
+        # 4. no ATA errors recorded
+        return self.has_smart_support() and \
+               len(self.check_attributes(ignore_attributes or [])) == 0 and \
+               self.check_tests() and \
+               self.ata_error_count == 0
 
     def check_tests(self, latest_only=False):
         ok_test_results = [
@@ -384,3 +392,8 @@ class SMARTCheck(object):
                     raise ValueError("Unknown attribute specification: %s" % db_attrs)
 
         return failed_attributes
+
+    def has_smart_support(self):
+        return self.information and (
+            self.information.get('smart_support') == 'Enabled' or self.information.get('smart_support', '').startswith('Available')
+        )

tests/check.py

@@ -229,3 +229,14 @@ ID# ATTRIBUTE_NAME          FLAG     VALUE WORST THRESH TYPE      UPDATED  WHEN_
         assert f(1) is False
         assert f(2) is False
 
+    def test_smart_not_supported_behind_megaraid(self):
+        # https://github.com/ercpe/smart-check/issues/5
+        #
+        # Either the device does not support S.M.A.R.T. at all or the megaraid controller prevents
+        # smartctl from working correctly. Either way, make sure that we don't report an OK
+        # when the smartctl output reports no SMART capability.
+
+        with open(os.path.join(samples_path, 'AVAGO-MR9340-8i-on-megaraid-no-smart-support.txt')) as f:
+            check = SMARTCheck(f)
+            self.assertTrue(check.check_tests())
+            self.assertFalse(check.check())

tests/samples/AVAGO-MR9340-8i-on-megaraid-no-smart-support.txt

@@ -0,0 +1,23 @@
+smartctl 7.0 2018-12-30 r4883 [x86_64-linux-3.10.0-1127.10.1.el7.x86_64] (local build)
+Copyright (C) 2002-18, Bruce Allen, Christian Franke, www.smartmontools.org
+
+=== START OF INFORMATION SECTION ===
+Vendor:               AVAGO
+Product:              MR9340-8i
+Revision:             4.62
+Compliance:           SPC-3
+User Capacity:        4,000,225,165,312 bytes [4.00 TB]
+Logical block size:   512 bytes
+Logical Unit id:      0x600605b00bf860b026c6a4e8041f90d5
+Serial number:        00d5901f04e8a4c626b060f80bb00506
+Device type:          disk
+Local Time is:        Thu Aug 13 10:10:30 2020 UTC
+SMART support is:     Unavailable - device lacks SMART capability.
+
+=== START OF READ SMART DATA SECTION ===
+Current Drive Temperature:     0 C
+Drive Trip Temperature:        0 C
+
+Error Counter logging not supported
+
+Device does not support Self Test logging