Custom DDNS UI Error / Bug [+solution]

[chp]

Hi,

I'm running 378.54_2 on an RT-AC56U.

I've created a custom DDNS script (/jffs/scripts/ddns-start) which is saved and works perfectly when manually called from the CLI. I want it to be called automatically when the WAN IP changes, so having read the instructions I went to the admin pages WAN->DDNS and selected:

Enable the DDNS client: Yes
Server: Custom
Host Name: "my hostname"
Forced refresh interval: 21

However, when I click "Apply", I get the pop-up error message "Account name cannot be blank" and cannot proceed. I have set "Enable JFFS custom scripts and configs" to yes.

This looks like a UI bug (validating a non-existent field?). I see that someone else has reported a similar problem: http://www.snbforums.com/threads/custom-ddns-script-afraid-org-issues.25212/


SOLUTION:

I've had a look at the problem and as suspected the fault lies in the form validation in Advanced_ASUSDDNS_Content.asp

Line 174 of the returned content (line 157 of the source file) reads:

if(document.form.ddns_server_x.selectedIndex != 9){ // Not CUSTOM

This clause is supposed to only carry out the account name validation if a service other than CUSTOM has been selected. It seems that the number of items in the "server" select have been changed without the validation code being updated - the CUSTOM entry now has index 11, not 9. Changing this check to test for 11 instead of 9 solves the problem and the custom DDNS script is run perfectly.

Perhaps this minor fix could be incorporated into the next release?

edit: Updated with source file line number

 

[RMerlin]

Changing the index would break again the next time Asus adds a new DDNS provider (as I've seen them doing again in a recent beta). I changed it to look for the name instead of the index value.