gethostbyaddr outputs binary string

[RobertEcker]

Description

PHP 8.1.0
The following code:

<?php
var_dump(gethostbyaddr('89.222.225.0'));
var_dump(gethostbyaddr('192.88.99.1'));

Resulted in this output:

But I expected this output instead:

string(12) "89.222.225.0" (which is still shown when I use PHP 8.0.3)
string(12) "192.88.99.1"

PHP Version

PHP 8.1.0

Operating System

Windows 10 (x64)

[Gemorroj]

I can confirm issue on Win10 x64

PS C:\Users\wapin> php -v
PHP 8.0.13 (cli) (built: Nov 16 2021 21:58:37) ( ZTS Visual C++ 2019 x64 )
Copyright (c) The PHP Group
Zend Engine v4.0.13, Copyright (c) Zend Technologies
    with Zend OPcache v8.0.13, Copyright (c), by Zend Technologies
    with Xdebug v3.1.2, Copyright (c) 2002-2021, by Derick Rethans
PS C:\Users\wapin> php -a
Interactive shell

php > var_dump(gethostbyaddr('89.222.225.0'));
php shell code:1:
string(12) "89.222.225.0"
php > var_dump(gethostbyaddr('192.88.99.1'));
php shell code:1:
string(11) "192.88.99.1"

PS S:\php81> ./php -v
PHP 8.1.0 (cli) (built: Nov 23 2021 21:48:28) (ZTS Visual C++ 2019 x64)
Copyright (c) The PHP Group
Zend Engine v4.1.0, Copyright (c) Zend Technologies
PS S:\php81> ./php -a
Interactive shell

php > var_dump(gethostbyaddr('89.222.225.0'));
string(0) ""
php > var_dump(gethostbyaddr('192.88.99.1'));
string(0) ""

[RobertEcker]

it also depends somehow from the previous (working) result

<?php
var_dump(gethostbyaddr('80.1.2.3'));
var_dump(gethostbyaddr('89.222.225.0'));
var_dump(gethostbyaddr('192.88.99.1'));
^Z
string(49) "cpc99474-lich12-2-0-cust514.3-2.cable.virginm.net"
string(16) "cpc99474-lich12-"
string(16) "cpc99474-lich12-"

[damianwadley]

First thing I see is in the new usage of getnameinfo: the code checks <0 for error but MSDN and getnameinfo(3) lists it as merely returning non-zero.

[pierrejoye]

@remicollet what was the reason to use getnameinfo in php_gethostbyaddr instead of gethostbyaddr (which is exactly what this function does)? I can't find discussion or bug # about that change.

I do like this little quote from various OSes doc, incl. windows one:

Note The ability to perform reverse DNS lookups using the getnameinfo function is convenient, but such lookups are considered inherently unreliable, and should be used only as a hint.