From 3920ce68b13e847d07d30e43f6564570ef0504e1 Mon Sep 17 00:00:00 2001
From: Christoph Egger <christoph@christoph-egger.org>
Date: Mon, 16 Nov 2015 14:06:31 +0100
Subject: [PATCH] Add check for same SOA on all NSes

---
 dnssec-check | 61 ++++++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 55 insertions(+), 6 deletions(-)

diff --git a/dnssec-check b/dnssec-check
index ad3d08c..e88fc5d 100755
--- a/dnssec-check
+++ b/dnssec-check
@@ -2,7 +2,9 @@
 
 from __future__ import print_function
 import ldns
-from unbound import ub_ctx, idn2dname, RR_TYPE_SOA, RR_TYPE_DNSKEY, RR_TYPE_RRSIG, ub_strerror
+from unbound import ub_ctx, idn2dname, ub_strerror
+from unbound import RR_TYPE_SOA, RR_TYPE_DNSKEY, RR_TYPE_RRSIG, RR_TYPE_NS
+from unbound import RR_TYPE_A, RR_TYPE_AAAA
 from optparse import OptionParser
 import sys
 from datetime import datetime, timedelta
@@ -42,7 +44,46 @@ def check_dnssec_expire(resolver, name, warn, crit):
                 print("WARN (expires in %s) %s" % (delta, name))
                 return 1
     return 0
+
+def check_zone_synced(resolver, name):
+    s, result = resolver.resolve(name, RR_TYPE_NS)
+    if 0 != s:
+        ub_strerror(s)
+        return 3
+
+    nameservers = result.data.as_domain_list()
+    nsips = []
+    for nameserver in nameservers:
+        for rrtype in [RR_TYPE_AAAA, RR_TYPE_A]:
+            s, result = resolver.resolve(nameserver, rrtype=rrtype)
+            if 0 != s:
+                ub_strerror(s)
+                return 3
+            nsips = nsips + result.data.as_address_list()
     
+    results = dict()
+    for ip in nsips:
+        newres = ub_ctx()
+        newres.set_fwd(ip)
+        s, result = newres.resolve(name, rrtype=RR_TYPE_SOA)
+        if 0 != s:
+            ub_strerror(s)
+            return 3
+
+        s, result = ldns.ldns_wire2pkt(result.packet)
+        soas = list(result.rr_list_by_type(RR_TYPE_SOA,
+                                           ldns.LDNS_SECTION_ANSWER).rrs())
+
+        if len(soas) != 1:
+            return 3
+        serial = str(soas[0]).split()[6]
+        results[serial] = results.get(serial, []) + [ip]
+
+    if len(results) == 1:
+        return 0
+    else:
+        print("CRIT (different SOAs): %s", results)
+        return 2
 
 def main():
     parser = OptionParser()
@@ -73,15 +114,23 @@ def main():
     final = 0
     for name in opts.names:
         name = idn2dname(name.decode(encoding))
-        result = check_dnssec_expire(resolver, name,
+        result1 = check_zone_synced(resolver, name)
+        if result1 == 2:
+            final = 2
+        elif result1 == 1 and final != 2:
+            final = 1
+        elif result1 == 3 and final not in [1, 2]:
+            final = 3
+
+        result2 = check_dnssec_expire(resolver, name,
                                      timedelta(opts.warn), timedelta(opts.crit))
-        if result == 0 and opts.verbose:
+        if result1 + result2 == 0 and opts.verbose:
             print("OK %s" % name)
-        if result == 2:
+        if result2 == 2:
             final = 2
-        elif result == 1 and final != 2:
+        elif result2 == 1 and final != 2:
             final = 1
-        elif result == 3 and final not in [1, 2]:
+        elif result2 == 3 and final not in [1, 2]:
             final = 3
 
     sys.exit(final)
-- 
2.39.2