The user can now set timeout in seconds.

The user can now specify  reference nameserver.

1 files changed, 30 insertions, 15 deletions

diff --git a/dnscheck_nsd.py b/dnscheck_nsd.py
index b00600b..bd875e0 100644
--- a/dnscheck_nsd.py
+++ b/dnscheck_nsd.py
@@ -8,7 +8,7 @@ from socket import gethostbyname, gethostbyaddr, gaierror
 import dns.resolver
 
 logger = logging.getLogger('dnscheck_nsd')
-logger.setLevel(logging.DEBUG)
+logger.setLevel(logging.INFO)
 ch = logging.StreamHandler()
 ch.setLevel(logging.DEBUG)
 formatter = logging.Formatter('%(name)s - %(levelname)s - %(message)s')
@@ -16,19 +16,23 @@ ch.setFormatter(formatter)
 logger.addHandler(ch)
 
 VERBOSE = False
-REFERENCE_NS = 'sunic.sunet.se'
 
-def get_resolver(nameserver=None):
+def get_resolver(nameserver=None, lifetime=30):
+    logger.debug('Resolver instance with nameserver %s.' % nameserver)
     if not nameserver:
-        return dns.resolver.Resolver()
+        resolver = dns.resolver.Resolver()
     else:
         resolver = dns.resolver.Resolver()
         try:
-            resolver.nameservers=[nameserver]
+            resolver.nameservers=[gethostbyname(nameserver)]
         except gaierror:
-            logger.error('Could not find nameserver: %s' % nameserver)
-            sys.exit(1)
-        return resolver
+            try:
+                resolver.nameservers=[nameserver] # Maybe it is an IPv6 address?
+            except gaierror:
+                logger.error('Could not find nameserver: %s' % nameserver)
+                sys.exit(1)
+    resolver.lifetime = lifetime
+    return resolver
 
 def compare_soa(zone, resolvers):
     answers = []
@@ -41,10 +45,13 @@ def compare_soa(zone, resolvers):
                 else:
                     logger.info('NS %s: %s' % (gethostbyaddr(resolver.nameservers[0])[0], answer))
         except dns.exception.Timeout:
-            logger.error('%s timed out.' % gethostbyaddr(resolver.nameservers[0])[0])
+            logger.error('%s timed out. SOA request for %s failed.' % (gethostbyaddr(resolver.nameservers[0])[0], zone))
+            return 'timeout'
+        except dns.resolver.NoAnswer:
+            logger.error('%s returned no answer for %s.' % (gethostbyaddr(resolver.nameservers[0])[0], zone))
             return 'timeout'
         except dns.resolver.NXDOMAIN:
-            logger.error('NS %s responded NXDOMAIN for %s.' % (gethostbyaddr(resolver.nameservers[0])[0], zone))
+            logger.error('NS %s responded domain not found (NXDOMAIN) for %s.' % (gethostbyaddr(resolver.nameservers[0])[0], zone))
             return 'no match'
         if answer:
             answers.append(answer)
@@ -61,9 +68,11 @@ def print_soa(zone, resolvers):
             else:
                 print 'NS %s: %s' % (gethostbyaddr(resolver.nameservers[0])[0], answer)
         except dns.exception.Timeout:
-            print '%s timed out. Print SOA for %s failed.' % (gethostbyaddr(resolver.nameservers[0])[0], zone)
+            print '%s timed out. SOA request for %s failed.' % (gethostbyaddr(resolver.nameservers[0])[0], zone)
+        except dns.resolver.NoAnswer:
+            logger.error('%s returned no answer for %s.' % (gethostbyaddr(resolver.nameservers[0])[0], zone))
         except dns.resolver.NXDOMAIN:
-            logger.error('NS %s responded NXDOMAIN for %s.' % (gethostbyaddr(resolver.nameservers[0])[0], zone))
+            logger.error('NS %s responded domain not found (NXDOMAIN) for %s.' % (gethostbyaddr(resolver.nameservers[0])[0], zone))
 
 def parse_file(f):
     result = []
@@ -93,7 +102,10 @@ def parse_file(f):
 def main():
     # User friendly usage output
     parser = argparse.ArgumentParser()
+    parser.add_argument('--nameserver', '-ns', type=str, default='', help="IP address or hostname, default localhost")
+    parser.add_argument('--timeout', '-t', type=float, default=5, help="timeout in seconds, default 5")
     parser.add_argument('--verbose', '-v', action='store_true', default=False)
+    parser.add_argument('--debug', action='store_true', default=False)
     parser.add_argument(
         'file',
         nargs='?',
@@ -105,15 +117,18 @@ def main():
     if args.verbose:
         global VERBOSE
         VERBOSE = True
-    ref_resolver = get_resolver(nameserver=gethostbyname(REFERENCE_NS))
+    if args.debug:
+        logger.setLevel(logging.DEBUG)
+    ref_resolver = get_resolver(nameserver=args.nameserver, lifetime=args.timeout)
     for item in parse_file(args.file):
-        resolver = get_resolver(nameserver=item['ns_address'])
+        resolver = get_resolver(nameserver=item['ns_address'], lifetime=args.timeout)
         result = compare_soa(item['domain'], [ref_resolver, resolver])
         if result == 'timeout':
-            print 'Check for zone %s timed out.' % item['domain']
+            print 'Check for zone %s failed.\n' % item['domain']
         if result == 'no match':
             print 'SOA did not match:'
             print_soa(item['domain'], [ref_resolver, resolver])
+            print ''
         if result == 'match' and VERBOSE:
             print 'Check complete for zone %s.\n' % item['domain']