checkdnsrr/dns_check_record works in CLI but not in mod_php on macOS

[VanessaPhippsCfa]

Description

The following code:

<?php
$result = checkdnsrr('google.com', 'A');
var_dump($result);

Resulted in this output:

bool(false)

But I expected this output instead:

bool(true)

3v4l link: https://3v4l.org/mchKq

3v4l also seems unable to get "true" out of this. However, this works fine on my machine:

/opt/homebrew/bin/php -r '$result = checkdnsrr("google.com", "A"); var_dump($result);'

My Rocky 6 production server (yes we're upgrading) also gets true for this code, even in mod_php.

I initially spotted this behavior in 7.4, but verified it's present on 8.4 as well.

PHP Version

PHP 8.4.7 (cli) (built: May  6 2025 12:31:58) (NTS)
Copyright (c) The PHP Group
Built by Homebrew
Zend Engine v4.4.7, Copyright (c) Zend Technologies
    with Zend OPcache v8.4.7, Copyright (c), by Zend Technologies

Here's the top of the mod_php phpinfo() output:

PHP Version 8.4.7

System	Darwin Vanessas-MacBook-Pro.local 24.4.0 Darwin Kernel Version 24.4.0: Fri Apr 11 18:33:47 PDT 2025; root:xnu-11417.101.15~117/RELEASE_ARM64_T6030 arm64
Build Date	May 6 2025 12:31:58
Build System	Darwin Sequoia-arm64.local 24.4.0 Darwin Kernel Version 24.4.0: Fri Apr 11 18:33:24 PDT 2025; root:xnu-11417.101.15~117/RELEASE_ARM64_VMAPPLE arm64
Build Provider	Homebrew

Operating System

macOS Sequoia 15.4.1 on ARM (Apple M3 Pro)

[Suv-P]

Adding further details to help narrow down issue

Works as expected on

ProductName: macOS
ProductVersion: 15.5
BuildVersion: 24F74

PHP 8.4.2 (cli) (built: Dec 17 2024 15:31:31) (NTS)
Copyright (c) The PHP Group
Zend Engine v4.4.2, Copyright (c) Zend Technologies
with Zend OPcache v8.4.2, Copyright (c), by Zend Technologies

bool(true)

Work on CLI using php -r as well as script run using php cli

[staabm]

I can confirm it works as expected on my setup, too.

➜  ~ /opt/homebrew/bin/php -r '$result = checkdnsrr("google.com", "A"); var_dump($result);'
bool(true)
➜  ~ php -v
PHP 8.4.7 (cli) (built: May  6 2025 12:31:58) (NTS)
Copyright (c) The PHP Group
Built by Homebrew
Zend Engine v4.4.7, Copyright (c) Zend Technologies

Apple M4 Pro
ProductName: macOS
ProductVersion: 15.5

---

did you make sure checkdnsrr is not forbidden via php.ini disable_functions directive ?

[VanessaPhippsCfa]

Thanks for the tests @Suv-P and @staabm . Can you test on mod_php as well? My CLI works, same as yours. It's only with mod_php that I see the problem.

Script (both CLI and mod_php)

At /opt/homebrew/var/www/checkdnsrrtest.php.

<?php
$result = checkdnsrr('google.com', 'A');
var_dump($result);

CLI

% /opt/homebrew/bin/php /opt/homebrew/var/www/checkdnsrrtest.php
bool(true)

mod_php

Browser location: http://localhost:8080/checkdnsrrtest.php

Result:

bool(false)

Re: disable_functions

That part of my /opt/homebrew/etc/php/8.4/php.ini is empty, and it is not set elsewhere in the file.

; This directive allows you to disable certain functions.
; It receives a comma-delimited list of function names.
; http://php.net/disable-functions
disable_functions =

More installation details

I'm on macOS 15.5 now. Still having this problem.

I'm using the Homebrew Apache on port 8080.

% /opt/homebrew/bin/httpd -v
Server version: Apache/2.4.63 (Unix)
Server built:   Jan 20 2025 19:35:41

I'm loading mod_php like this, in /opt/homebrew/etc/httpd/httpd.conf.

LoadModule php_module /opt/homebrew/Cellar/php/8.4.7/lib/httpd/modules/libphp.so