Validate given record type (Fix #98)

dnseval.py

@@ -155,6 +155,11 @@ def main():
             print("Invalid option: %s" % o)
             usage()
 
+    # validate RR type
+    if not util.dns.valid_rdatatype(rdatatype):
+        print('Error: Invalid record type "%s" ' % rdatatype)
+        sys.exit(1)
+
     color = Colors(color_mode)
 
     try:
@@ -174,7 +179,7 @@ def main():
             f = dns.resolver.get_default_resolver().nameservers
 
         if len(f) == 0:
-            print("No nameserver specified")
+            print("Error: No nameserver specified")
 
         f = [name.strip() for name in f]  # remove annoying blanks
         f = [x for x in f if not x.startswith('#') and len(x)]  # remove comments and empty entries

dnsping.py

@@ -39,6 +39,7 @@
 import dns.resolver
 import requests
 
+import util.dns
 from util.dns import PROTO_UDP, PROTO_TCP, PROTO_TLS, PROTO_HTTPS, proto_to_text, unsupported_feature, random_string
 from util.shared import __version__
 
@@ -209,6 +210,11 @@ def main():
     response_time = []
     i = 0
 
+    # validate RR type
+    if not util.dns.valid_rdatatype(rdatatype):
+        print('Error: Invalid record type "%s" ' % rdatatype)
+        sys.exit(1)
+
     print("%s DNS: %s:%d, hostname: %s, proto: %s, type: %s, flags: [%s]" %
           (__progname__, dnsserver, dst_port, qname, proto_to_text(proto), rdatatype,
            dns.flags.to_text(request_flags)), flush=True)

dnstraceroute.py

@@ -203,6 +203,11 @@ def main():
 
     color = Colors(color_mode)
 
+    # validate RR type
+    if not util.dns.valid_rdatatype(rdatatype):
+        print('Error: Invalid record type "%s" ' % rdatatype)
+        sys.exit(1)
+
     # Use system DNS server if parameter is not specified
     # remember not all systems have /etc/resolv.conf (i.e. Android)
     if dnsserver is None:

util/dns.py

@@ -197,6 +197,15 @@ def unsupported_feature():
     sys.exit(127)
 
 
+def valid_rdatatype(rtype):
+    # validate RR type
+    try:
+        _ = dns.rdatatype.from_text(rtype)
+    except dns.rdatatype.UnknownRdatatype:
+        return False
+    return True
+
+
 def flags_to_text(flags):
     # Standard DNS flags