Improve hostname and domain name validation

DNS plugin did not check DNS zone and DNS record validity and
user was thus able to create domains like "foo bar" or other
invalid DNS labels which would really confuse both user and
bind-dyndb-ldap plugin.

This patch at first consolidates hostname/domain name validators
so that they use common functions and we don't have regular
expressions and other checks defined in several places. These
new cleaned validators are then used for zone/record name
validation.

https://fedorahosted.org/freeipa/ticket/2384

ipalib/plugins/dns.py

@@ -28,7 +28,8 @@ from ipalib import Command
 from ipalib.parameters import Flag, Bool, Int, Decimal, Str, StrEnum, Any
 from ipalib.plugins.baseldap import *
 from ipalib import _, ngettext
-from ipalib.util import validate_zonemgr, normalize_zonemgr, validate_hostname
+from ipalib.util import (validate_zonemgr, normalize_zonemgr,
+        validate_hostname, validate_dns_label, validate_domain_name)
 from ipapython import dnsclient
 from ipapython.ipautil import valid_ip, CheckedIPAddress
 from ldap import explode_dn
@@ -299,7 +300,7 @@ def _normalize_bind_aci(bind_acis):
     acis += u';'
     return acis
 
-def _domain_name_validator(ugettext, value):
+def _bind_hostname_validator(ugettext, value):
     try:
         # Allow domain name which is not fully qualified. These are supported
         # in bind and then translated as <non-fqdn-name>.<domain>.
@@ -310,6 +311,22 @@ def _domain_name_validator(ugettext, value):
 
     return None
 
+def _dns_record_name_validator(ugettext, value):
+    if value == _dns_zone_record:
+        return
+
+    try:
+        map(lambda label:validate_dns_label(label, allow_underscore=True), \
+            value.split(u'.'))
+    except ValueError, e:
+        return unicode(e)
+
+def _domain_name_validator(ugettext, value):
+    try:
+        validate_domain_name(value)
+    except ValueError, e:
+        return unicode(e)
+
 def _hostname_validator(ugettext, value):
     try:
         validate_hostname(value)
@@ -777,7 +794,7 @@ class AFSDBRecord(DNSRecord):
             maxvalue=65535,
         ),
         Str('hostname',
-            _domain_name_validator,
+            _bind_hostname_validator,
             label=_('Hostname'),
         ),
     )
@@ -816,7 +833,7 @@ class CNAMERecord(DNSRecord):
     rfc = 1035
     parts = (
         Str('hostname',
-            _domain_name_validator,
+            _bind_hostname_validator,
             label=_('Hostname'),
             doc=_('A hostname which this alias hostname points to'),
         ),
@@ -837,7 +854,7 @@ class DNAMERecord(DNSRecord):
     rfc = 2672
     parts = (
         Str('target',
-            _domain_name_validator,
+            _bind_hostname_validator,
             label=_('Target'),
         ),
     )
@@ -916,7 +933,7 @@ class KXRecord(DNSRecord):
             maxvalue=65535,
         ),
         Str('exchanger',
-            _domain_name_validator,
+            _bind_hostname_validator,
             label=_('Exchanger'),
             doc=_('A host willing to act as a key exchanger'),
         ),
@@ -1057,7 +1074,7 @@ class MXRecord(DNSRecord):
             maxvalue=65535,
         ),
         Str('exchanger',
-            _domain_name_validator,
+            _bind_hostname_validator,
             label=_('Exchanger'),
             doc=_('A host willing to act as a mail exchanger'),
         ),
@@ -1069,7 +1086,7 @@ class NSRecord(DNSRecord):
 
     parts = (
         Str('hostname',
-            _domain_name_validator,
+            _bind_hostname_validator,
             label=_('Hostname'),
         ),
     )
@@ -1083,7 +1100,7 @@ class NSECRecord(DNSRecord):
 
     parts = (
         Str('next',
-            _domain_name_validator,
+            _bind_hostname_validator,
             label=_('Next Domain Name'),
         ),
         StrEnum('types+',
@@ -1181,7 +1198,7 @@ def _srv_target_validator(ugettext, value):
     if value == u'.':
         # service not available
         return
-    return _domain_name_validator(ugettext, value)
+    return _bind_hostname_validator(ugettext, value)
 
 class SRVRecord(DNSRecord):
     rrtype = 'SRV'
@@ -1426,6 +1443,7 @@ class dnszone(LDAPObject):
 
     takes_params = (
         Str('idnsname',
+            _domain_name_validator,
             cli_name='name',
             label=_('Zone name'),
             doc=_('Zone name (FQDN)'),
@@ -1742,6 +1760,7 @@ class dnsrecord(LDAPObject):
 
     takes_params = (
         Str('idnsname',
+            _dns_record_name_validator,
             cli_name='name',
             label=_('Record name'),
             doc=_('Record name'),