win_dns_client - Handle null chars in raw registry dns servers value

[jborean93]

SUMMARY

If Set-DnsClientServerAddress was used to set both IPv4 and IPv6 DNS servers at the same time, the raw registry value will contain null chars. This causes problems on subsequent runs because the code will try to parse '{ip}\0\0\0\0' into a IPAddress object which fails with

{
    "changed": false,
    "msg": "Unhandled exception while executing module: Cannot convert value \"8.8.8.8\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\" to type \"System.Net.IPAddress\". Error: \"An invalid IP address was specified.\""
}

The code here trims the raw value for any null chars so the cast later one works. To replicate this you can run the following to get the host in the same state.

$adapter = Get-NetAdapter -Name 'INSERT ADAPTER NAME HERE'

$dnsServers = @(
    [System.Net.IPAddress]'8.8.4.4'
    [System.Net.IPAddress]'8.8.8.8'
    [System.Net.IPAddress]'2001:4860:4860::8888'
    [System.Net.IPAddress]'2001:4860:4860::8844'
)
Set-DnsClientServerAddress -InterfaceIndex $adapter.InterfaceIndex -ServerAddresses $dnsServers

ISSUE TYPE

• Bugfix Pull Request

COMPONENT NAME

win_dns_client