ipa-adtrust-install: allow to reset te NetBIOS domain name

Fixes https://fedorahosted.org/freeipa/ticket/3192

install/tools/ipa-adtrust-install

@@ -71,7 +71,7 @@ def parse_options():
     return safe_options, options
 
 def netbios_name_error(name):
-    print "Illegal NetBIOS name [%s].\n" % name
+    print "\nIllegal NetBIOS name [%s].\n" % name
     print "Up to 15 characters and only uppercase ASCII letter and digits are allowed."
 
 def read_netbios_name(netbios_default):
@@ -101,6 +101,90 @@ def read_admin_password(admin_name):
     admin_password = read_password(admin_name, confirm=False, validate=None)
     return admin_password
 
+def set_and_check_netbios_name(netbios_name, unattended):
+    """
+    Depending if trust in already configured or not a given NetBIOS domain
+    name must be handled differently.
+
+    If trust is not configured the given NetBIOS is used or the NetBIOS is
+    generated if none was given on the command line.
+
+    If trust is  already configured the given NetBIOS name is used to reset
+    the stored NetBIOS name it it differs from the current one.
+    """
+
+    flat_name_attr = 'ipantflatname'
+    cur_netbios_name = None
+    gen_netbios_name = None
+    reset_netbios_name = False
+    dom_dn = None
+
+    try:
+        (dom_dn, entry) = api.Backend.ldap2.get_entry(DN(('cn', api.env.domain),
+                                    api.env.container_cifsdomains,
+                                    ipautil.realm_to_suffix(api.env.realm)),
+                                    [flat_name_attr])
+    except errors.NotFound:
+        # trust not configured
+        pass
+    else:
+        cur_netbios_name = entry.get(flat_name_attr)[0]
+
+    if cur_netbios_name and not netbios_name:
+        # keep the current NetBIOS name
+        netbios_name = cur_netbios_name
+        reset_netbios_name = False
+    elif cur_netbios_name and cur_netbios_name != netbios_name:
+        # change the NetBIOS name
+        print "Current NetBIOS domain name is %s, new name is %s.\n" % \
+              (cur_netbios_name, netbios_name)
+        print "Please note that changing the NetBIOS name might " \
+              "break existing trust relationships."
+        if unattended:
+            reset_netbios_name = True
+            print "NetBIOS domain name will be changed to %s.\n" % \
+                  netbios_name
+        else:
+            print "Say 'yes' if the NetBIOS shall be changed and " \
+                  "'no' if the old one shall be kept."
+            reset_netbios_name = ipautil.user_input(
+                            'Do you want to reset the NetBIOS domain name?',
+                            default = False, allow_empty = False)
+        if not reset_netbios_name:
+            netbios_name = cur_netbios_name
+    elif cur_netbios_name and cur_netbios_name == netbios_name:
+        # keep the current NetBIOS name
+        reset_netbios_name = False
+    elif not cur_netbios_name:
+        if not netbios_name:
+            gen_netbios_name = adtrustinstance.make_netbios_name(api.env.domain)
+
+        if dom_dn:
+            # Fix existing trust configuration
+            print "Trust is configured but no NetBIOS domain name found, " \
+                  "setting it now."
+            reset_netbios_name = True
+        else:
+            # initial trust configuration
+            reset_netbios_name = False
+    else:
+        # all possible cases should be covered above
+        raise Exception('Unexpected state while checking NetBIOS domain name')
+
+    if not adtrustinstance.check_netbios_name(netbios_name):
+        if unattended:
+            netbios_name_error(netbios_name)
+            sys.exit("Aborting installation.")
+        else:
+            if netbios_name:
+                netbios_name_error(netbios_name)
+                netbios_name = None
+
+    if not unattended and not netbios_name:
+        netbios_name = read_netbios_name(gen_netbios_name)
+
+    return (netbios_name, reset_netbios_name)
+
 def ensure_admin_kinit(admin_name, admin_password):
     try:
         ipautil.run(['kinit', admin_name], stdin=admin_password+'\n')
@@ -197,22 +281,6 @@ def main():
         print "Please wait until the prompt is returned."
         print ""
 
-    netbios_name = options.netbios_name
-    if not netbios_name:
-        netbios_name = adtrustinstance.make_netbios_name(api.env.domain)
-
-    if not adtrustinstance.check_netbios_name(netbios_name):
-        if options.unattended:
-            netbios_name_error(netbios_name)
-            sys.exit("Aborting installation.")
-        else:
-            netbios_name = None
-            if options.netbios_name:
-                netbios_name_error(options.netbios_name)
-
-    if not options.unattended and ( not netbios_name or not options.netbios_name):
-        netbios_name = read_netbios_name(netbios_name)
-
     admin_password = options.admin_password
     if not (options.unattended or admin_password):
         admin_password = read_admin_password(options.admin_name)
@@ -248,11 +316,16 @@ def main():
     except Exception, e:
         sys.exit("Unrecognized error during check of admin rights: %s" % (str(e)))
 
+    (netbios_name, reset_netbios_name) = \
+                                set_and_check_netbios_name(options.netbios_name,
+                                options.unattended)
+
     smb = adtrustinstance.ADTRUSTInstance(fstore)
     smb.realm = api.env.realm
     smb.autobind = service.ENABLED
     smb.setup(api.env.host, ip_address, api.env.realm, api.env.domain,
-              netbios_name, options.rid_base, options.secondary_rid_base,
+              netbios_name, reset_netbios_name,
+              options.rid_base, options.secondary_rid_base,
               options.no_msdcs, options.add_sids)
     smb.find_local_id_range()
     smb.create_instance()

install/tools/man/ipa-adtrust-install.1

@@ -42,7 +42,11 @@ Enable debug logging when more verbose output is needed
 The IP address of the IPA server. If not provided then this is determined based on the hostname of the server.
 .TP
 \fB\-\-netbios\-name\fR=\fINETBIOS_NAME\fR
-The NetBIOS name for the IPA domain. If not provided then this is determined based on the leading component of the DNS domain name.
+The NetBIOS name for the IPA domain. If not provided then this is determined
+based on the leading component of the DNS domain name. Running
+ipa\-adtrust\-install for a second time with a different NetBIOS name will
+change the name. Please note that changing the NetBIOS name might break
+existing trust relationships to other domains.
 .TP
 \fB\-\-no\-msdcs\fR
 Do not create DNS service records for Windows in managed DNS server. Since those

ipaserver/install/adtrustinstance.py

@@ -115,6 +115,7 @@ class ADTRUSTInstance(service.Service):
         self.realm = None
         self.domain_name = None
         self.netbios_name = None
+        self.reset_netbios_name = None
         self.no_msdcs = None
         self.add_sids = None
         self.smbd_user = None
@@ -295,11 +296,27 @@ class ADTRUSTInstance(service.Service):
                                  "define it and run again.")
             raise e
 
+    def __reset_netbios_name(self):
+        """
+        Set the NetBIOS domain name to a new value.
+        """
+        self.print_msg("Reset NetBIOS domain name")
+
+        try:
+            self.admin_conn.modify_s(self.smb_dom_dn,
+                                     [(ldap.MOD_REPLACE, self.ATTR_FLAT_NAME,
+                                       self.netbios_name)])
+        except ldap.LDAPError:
+            self.print_msg("Failed to reset the NetBIOS domain name")
+
     def __create_samba_domain_object(self):
 
         try:
             self.admin_conn.getEntry(self.smb_dom_dn, ldap.SCOPE_BASE)
-            root_logger.info("Samba domain object already exists")
+            if self.reset_netbios_name:
+                self.__reset_netbios_name()
+            else :
+                self.print_msg("Samba domain object already exists")
             return
         except errors.NotFound:
             pass
@@ -653,13 +670,14 @@ class ADTRUSTInstance(service.Service):
                              FQDN = self.fqdn)
 
     def setup(self, fqdn, ip_address, realm_name, domain_name, netbios_name,
-              rid_base, secondary_rid_base, no_msdcs=False, add_sids=False,
-              smbd_user="samba"):
+              reset_netbios_name, rid_base, secondary_rid_base,
+              no_msdcs=False, add_sids=False, smbd_user="samba"):
         self.fqdn = fqdn
         self.ip_address = ip_address
         self.realm = realm_name
         self.domain_name = domain_name
         self.netbios_name = netbios_name
+        self.reset_netbios_name = reset_netbios_name
         self.rid_base = rid_base
         self.secondary_rid_base = secondary_rid_base
         self.no_msdcs = no_msdcs