🎨 Use filter_var to check IPv4 and IPv6 addresses

[rudnerbjoern]

Base information

Question	Answer
Related to a SourceForge thread / Another PR / Combodo ticket?	No
Type of change?	Enhancement

Symptom (bug) / Objective (enhancement)

• Use filter_var($variable, FILTER_VALIDATE_IP, FILTER_FLAG_IPV6) and filter_var($variable, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4) when checking for IP addresses.
• Remove redundant checks for empty strings.

Proposed solution (bug and enhancement)

Make validation of IP addresses more robust due to the use of PHP functions

Checklist before requesting a review

• I have performed a self-review of my code, and that it's compliant with Combodo's guidelines
• I have tested all changes I made on an iTop instance
• I have added a unit test, otherwise I have explained why I couldn't
• I have made sure the PR is clear and detailled enough so anyone can understand the real purpose without digging in the code

Checklist of things to do before PR is ready to merge

none

[Hipska]

Good idea to change this to better to maintain methods, just some minor remarks.

[rudnerbjoern]

I've updated the code to the suggestions of @Hipska

[Hipska]

You could also rewrite the following:

				$sIP = $oVM['managementip'] ?? '';
				if (filter_var($sIP, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4)) {

To something like:

				$sIP = filter_var($oVM['managementip'] ?? '', FILTER_VALIDATE_IP, FILTER_FLAG_IPV4)
				if ($sIP !== false) {

Or just if ($sIP) {, but I think Combodo would prefer the one above.

[rudnerbjoern]

Yes, we discussed that. But to me it "hurts" to see a bool written into a variable pretending to be a string. (I know now that this is valid PHP, but it just feels not right for me to do this)

[Hipska]

Please reopen conversation to let Combodo decide on it.

[rudnerbjoern]

sorry