QUIC: IPv6 constant looks suspicious in native helper

[wfurt]

I noticed this while reviewing #53461.

namespace System.Net.Quic.Implementations.MsQuic.Internal
{
    internal static class MsQuicAddressHelpers
    {
        internal const ushort IPv4 = 2;
        internal const ushort IPv6 = 23;

..
       internal static SOCKADDR_INET IPEndPointToINet(IPEndPoint endpoint)
       {
                       socketAddress.Ipv6._family = IPv6;

AF_INET6 is 10 on Linux and 30 on macOS. It feels like this should come from PAL.
It also seems like our tests use CreateQuicListener() that use IPEndPoint(IPAddress.Loopback, 0) so we may have test gaps for IPv6.

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Issue Details

---

I noticed this while reviewing #53461.

namespace System.Net.Quic.Implementations.MsQuic.Internal
{
    internal static class MsQuicAddressHelpers
    {
        internal const ushort IPv4 = 2;
        internal const ushort IPv6 = 23;

..
       internal static SOCKADDR_INET IPEndPointToINet(IPEndPoint endpoint)
       {
                       socketAddress.Ipv6._family = IPv6;

AF_INET6 is 10 on Linux and 30 on macOS. It feels like this should come from PAL.
It also seems like our tests use CreateQuicListener() that use IPEndPoint(IPAddress.Loopback, 0) so we may have test gaps for IPv6.

Author:	wfurt
Assignees:	-
Labels:	area-System.Net.Quic
Milestone:	-

[treysis]

Loopback/localhost shouldn't be used. It is very unclear what the system will resolve it to. Either you specify the address family, or you use literal addresses for localhost.

[ThadHouse]

In MsQuic, we ensure all IPv6 family values seen through the API are 23, to match windows, and our does have users use QUIC_ADDRESS_FAMILY_INET6 which is always that value even on posix platforms.