FreeMibTable returns ERROR_INVALID_FUNCTION

[stormshield-kg]

Summary

The windows::Win32::NetworkManagement::IpHelper::FreeMibTable function frees the memory correctly, but always returns an error:

thread 'main' panicked at src\main.rs:12:41:
called `Result::unwrap()` on an `Err` value: Error { code: HRESULT(0x80070001), message: "Incorrect function." }

It seems that the function return void in the C API, but the wrapper in windows-rs returns a Result:
https://learn.microsoft.com/en-us/windows/win32/api/netioapi/nf-netioapi-freemibtable
https://learn.microsoft.com/en-us/windows/win32/api/netioapi/nf-netioapi-getunicastipaddresstable#examples

Crate manifest

[package]
name = "testwindows"
version = "0.1.0"
edition = "2021"

[dependencies]
windows = { version = "0.52.0", features = [
    "Win32_NetworkManagement_IpHelper",
    "Win32_Foundation",
    "Win32_NetworkManagement_Ndis",
    "Win32_Networking_WinSock",
] }

Crate code

use windows::Win32::{
    NetworkManagement::IpHelper::{
        FreeMibTable, GetUnicastIpAddressTable, MIB_UNICASTIPADDRESS_TABLE,
    },
    Networking::WinSock::AF_UNSPEC,
};

fn main() {
    unsafe {
        let mut ip_table_ptr: *mut MIB_UNICASTIPADDRESS_TABLE = std::ptr::null_mut();
        GetUnicastIpAddressTable(AF_UNSPEC, &mut ip_table_ptr as *mut _).unwrap();
        FreeMibTable(ip_table_ptr as _).unwrap();
    }
}

[kennykerr]

FreeMibTable should return void but the Win32 metadata indicates that it returns an error code. I'll transfer this this issue for their consideration.

[stormshield-kg]

Also applicable to windows::Windows::Win32::NetworkManagement::IpHelper::FreeInterfaceDnsSettings, and maybe other functions.