Fix: reject invalid server IPs (CIDR) in Conditional Forwarding table

[amonkarsidhant]

Fixes #3829

What does this PR aim to accomplish?

Reject invalid server IPs (CIDR notation like 192.168.1.0/24) in the Conditional Forwarding table. Previously, the Server IP field accepted these invalid values due to two bugs.

How does this PR accomplish the above?

1. Fix footer row save button not being disabled (settings-dns.lp): Added class=actions to the footer row's <th> containing the save button. The validation handler uses javascript\n.siblings(.actions).find(.saveRevServers).prop(disabled, true);\n but the footer row's <th> lacked the actions class, so the button was never disabled.

2. Add server-side IP validation (scripts/js/settings-dns.js): Added IP format validation in addRevServer() and saveRecord() using existing utils.validateIPv4WithPort() and utils.validateIPv6WithPort() functions, which already reject CIDR notation.

Link documentation PRs if any are needed to support this PR

N/A

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By submitting this pull request, I confirm the following:

1. ✅ Based against the development branch
2. ✅ Commits are DCO-signed-off
3. ✅ Commits are GPG-signed
4. ✅ No documentation changes needed

[rdwebdesign]

The original issue was actually a bad validation function, that allowed /24 in the IP.
The function was already fixed in development branch.

but the footer row's <th> lacked the actions class, so the button was never disabled.

This is not the case.

The table cell has the .actions class:

The class is set using datatables className: option:

web/scripts/js/settings-dns.js

Line 177 in b2a4078

{ data: null, width: "82px", className: "actions" },

The values type on the table footer were validated, but using a broken function.

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Add server-side IP validation (scripts/js/settings-dns.js): Added IP format validation in addRevServer() and saveRecord() using existing utils.validateIPv4WithPort() and utils.validateIPv6WithPort() functions, which already reject CIDR notation.

The validation function was broken. Adding the validation here (using that broken function) wouldn't change anything.

This would take effect now that the validation function has been fixed, but the values ​​will already be validated, so this is not necessary.

[github-actions]

This pull request has conflicts, please resolve those before we can evaluate the pull request.

[DL6ER]

The conflicts here are context only: settings-dns.lp was reindented during the AdminLTE 4 migration (#3809), nothing collides with your change. A rebase onto current development should be all it takes.

Worth noting that the class="actions" part fixes something on its own: without it, $(this).siblings(".actions") in settings-dns.js finds nothing in the add-row, so its save button is never disabled when a cell is invalid.