pf: reply-to not set for IPv6 GW

[kulikov-a]

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Describe the bug
Hello everybody.
I noticed that for rules with a permitted reply-to directive, this directive is not set for the corresponding rule in rule.debug with the inet6 protocol.
Is that what you intended? If so, please explain why?
This can be easily fixed in the Gateways.php getInterfaceGateway function:
before (set only ipv4 gw name):
// The interface might have a gateway configured
if (isset($this->configHandle->interfaces->$interface)) {
$intf_gateway = $this->configHandle->interfaces->$interface->gateway;
} else {
$intf_gateway = null;
}
after (set gw name according to ip ver):
// The interface might have a gateway configured
if (isset($this->configHandle->interfaces->$interface)) {
if ($ipproto == "inet") {
$intf_gateway = $this->configHandle->interfaces->$interface->gateway;
} else {
$intf_gateway = $this->configHandle->interfaces->$interface->gatewayv6;
}
} else {
$intf_gateway = null;
}

Thanks!

Environment
Software version used and hardware type if relevant.
e.g.:

OPNsense 20.7.4

[AdSchellevis]

@kulikov-a looks like a bug to me, 80d7eb0 should fix it.