WinSock2 fallbacks

Add fallback implementations for `getaddrinfo` and `freeaddrinfo`

    These fall back to wship6.dll (NT4/2000) if available, or are impl'd via a translation
    of the header-only wspiapi.h implementations (IPv4 only, all Windows versions with
    WS2 support).

Stub `SetHandleInformation`/`Socket::set_no_inherit`

    SetHandleInformation is exported by kernel32 on Win9X/ME, but is just
    stubbed, returning `ERROR_CALL_NOT_IMPLEMENTED`. Sockets are
    non-inheritable on these systems anyways, so we "fail successfully".
    https://www.betaarchive.com/wiki/index.php/Microsoft_KB_Archive/150523#MORE_INFORMATION

    SetHandleInformation is also unavailable on WinNT before 3.51. This is
    fine, however, because MS did not supply WinSock 2 for Windows NT before
    4.0, so this function is not called.

Author: seritools

library/std/src/os/windows/io/socket.rs

@@ -92,14 +92,27 @@ impl OwnedSocket {
     #[allow(fuzzy_provenance_casts)]
     #[cfg(not(target_vendor = "uwp"))]
     pub(crate) fn set_no_inherit(&self) -> io::Result<()> {
-        cvt(unsafe {
+        let res = cvt(unsafe {
             sys::c::SetHandleInformation(
                 self.as_raw_socket() as sys::c::HANDLE,
                 sys::c::HANDLE_FLAG_INHERIT,
                 0,
             )
         })
-        .map(drop)
+        .map(drop);
+
+        match res {
+            // SetHandleInformation is exported by kernel32 on Win9X/ME, but is just stubbed,
+            // returning `ERROR_CALL_NOT_IMPLEMENTED`. Sockets are non-inheritable on these
+            // systems anyways, so we "fail successfully" here.
+            // https://www.betaarchive.com/wiki/index.php/Microsoft_KB_Archive/150523#MORE_INFORMATION
+
+            // SetHandleInformation is also unavailable on WinNT before 3.51. This is fine,
+            // however, because MS did not supply WinSock 2 for Windows NT before 4.0, so this
+            // function is not called.
+            Err(e) if e.raw_os_error() == Some(sys::c::ERROR_CALL_NOT_IMPLEMENTED as i32) => Ok(()),
+            res => res,
+        }
     }
 
     #[cfg(target_vendor = "uwp")]

library/std/src/sys/windows/c.rs

@@ -13,6 +13,7 @@ use crate::ptr;
 use core::ffi::NonZero_c_ulong;
 
 mod windows_sys;
+mod wspiapi;
 pub use windows_sys::*;
 
 pub type DWORD = c_ulong;
@@ -265,7 +266,7 @@ pub unsafe fn getaddrinfo(
     hints: *const ADDRINFOA,
     res: *mut *mut ADDRINFOA,
 ) -> c_int {
-    windows_sys::getaddrinfo(node.cast::<u8>(), service.cast::<u8>(), hints, res)
+    ws2_32::getaddrinfo(node.cast::<u8>(), service.cast::<u8>(), hints, res)
 }
 
 cfg_if::cfg_if! {
@@ -398,6 +399,13 @@ compat_fn_with_fallback! {
         SetLastError(ERROR_CALL_NOT_IMPLEMENTED);
         FALSE
     }
+
+    // >= NT 3.51+
+    // https://docs.microsoft.com/en-us/windows/win32/api/handleapi/nf-handleapi-sethandleinformation
+    pub fn SetHandleInformation(hobject: HANDLE, dwmask: u32, dwflags: HANDLE_FLAGS) -> BOOL {
+        SetLastError(ERROR_CALL_NOT_IMPLEMENTED);
+        FALSE
+    }
 }
 
 compat_fn_lazy! {
@@ -646,3 +654,48 @@ pub struct WSADATA {
     pub iMaxUdpDg: u16,
     pub lpVendorInfo: PSTR,
 }
+
+mod ws2_32 {
+    use super::*;
+    compat_fn_with_fallback! {
+        pub static WS2_32: &CStr = c"ws2_32" => { load: true, unicows: false };
+
+        // >= NT4/2000 with IPv6 Tech Preview
+        pub fn getaddrinfo(
+            pnodename: PCSTR,
+            pservicename: PCSTR,
+            phints: *const ADDRINFOA,
+            ppresult: *mut *mut ADDRINFOA,
+        ) -> i32 {
+            wship6::getaddrinfo(pnodename, pservicename, phints, ppresult)
+        }
+        // >= NT4/2000 with IPv6 Tech Preview
+        pub fn freeaddrinfo(paddrinfo: *const ADDRINFOA) -> () {
+            wship6::freeaddrinfo(paddrinfo)
+        }
+    }
+}
+pub use ws2_32::freeaddrinfo;
+
+mod wship6 {
+    use super::wspiapi::{wspiapi_freeaddrinfo, wspiapi_getaddrinfo};
+    use super::{ADDRINFOA, PCSTR};
+
+    compat_fn_with_fallback! {
+        pub static WSHIP6: &CStr = c"wship6" => { load: true, unicows: false };
+
+        // >= 2000 with IPv6 Tech Preview
+        pub fn getaddrinfo(
+            pnodename: PCSTR,
+            pservicename: PCSTR,
+            phints: *const ADDRINFOA,
+            ppresult: *mut *mut ADDRINFOA,
+        ) -> i32 {
+            wspiapi_getaddrinfo(pnodename, pservicename, phints, ppresult)
+        }
+        // >= 2000 with IPv6 Tech Preview
+        pub fn freeaddrinfo(paddrinfo: *const ADDRINFOA)-> () {
+            wspiapi_freeaddrinfo(paddrinfo)
+        }
+    }
+}