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).

Author: seritools

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

@@ -16,6 +16,9 @@ use core::ffi::NonZero_c_ulong;
 mod windows_sys;
 pub use windows_sys::*;
 
+#[path = "c/wspiapi.rs"] // c.rs is included from two places so we need to specify this
+mod wspiapi;
+
 pub type DWORD = c_ulong;
 pub type NonZeroDWORD = NonZero_c_ulong;
 pub type LARGE_INTEGER = c_longlong;
@@ -609,6 +612,51 @@ compat_fn_with_fallback! {
     }
 }
 
+compat_fn_with_fallback! {
+    pub static WS2_32: &CStr = ansi_str!("ws2_32");
+    const LOAD: bool = true;
+
+    // >= NT4/2000 with IPv6 Tech Preview
+    pub fn getaddrinfo(
+        node: *const c_char,
+        service: *const c_char,
+        hints: *const ADDRINFOA,
+        res: *mut *mut ADDRINFOA
+    ) -> c_int {
+        wship6::getaddrinfo(node, service, hints, res)
+    }
+
+    // >= NT4/2000 with IPv6 Tech Preview
+    pub fn freeaddrinfo(res: *mut ADDRINFOA) -> () {
+        wship6::freeaddrinfo(res)
+    }
+}
+
+mod wship6 {
+    use super::wspiapi::{wspiapi_freeaddrinfo, wspiapi_getaddrinfo};
+    use super::{c_char, c_int, ADDRINFOA};
+
+    compat_fn_with_fallback! {
+        pub static WSHIP6: &CStr = ansi_str!("wship6");
+        const LOAD: bool = false;
+
+        // >= 2000 with IPv6 Tech Preview
+        pub fn getaddrinfo(
+            node: *const c_char,
+            service: *const c_char,
+            hints: *const ADDRINFOA,
+            res: *mut *mut ADDRINFOA
+        ) -> c_int {
+            wspiapi_getaddrinfo(node, service, hints, res)
+        }
+
+        // >= 2000 with IPv6 Tech Preview
+        pub fn freeaddrinfo(res: *mut ADDRINFOA) -> () {
+            wspiapi_freeaddrinfo(res)
+        }
+    }
+}
+
 #[link(name = "kernel32")]
 extern "system" {
     pub fn LoadLibraryA(lpFileName: LPCSTR) -> HMODULE;

library/std/src/sys/windows/c/windows_sys.lst

@@ -1965,8 +1965,6 @@ Windows.Win32.Networking.WinSock.closesocket
 Windows.Win32.Networking.WinSock.connect
 Windows.Win32.Networking.WinSock.FD_SET
 Windows.Win32.Networking.WinSock.FIONBIO
-Windows.Win32.Networking.WinSock.freeaddrinfo
-Windows.Win32.Networking.WinSock.getaddrinfo
 Windows.Win32.Networking.WinSock.getpeername
 Windows.Win32.Networking.WinSock.getsockname
 Windows.Win32.Networking.WinSock.getsockopt

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

@@ -605,19 +605,6 @@ extern "system" {
     pub fn connect(s: SOCKET, name: *const SOCKADDR, namelen: i32) -> i32;
 }
 #[link(name = "ws2_32")]
-extern "system" {
-    pub fn freeaddrinfo(paddrinfo: *const ADDRINFOA) -> ();
-}
-#[link(name = "ws2_32")]
-extern "system" {
-    pub fn getaddrinfo(
-        pnodename: PCSTR,
-        pservicename: PCSTR,
-        phints: *const ADDRINFOA,
-        ppresult: *mut *mut ADDRINFOA,
-    ) -> i32;
-}
-#[link(name = "ws2_32")]
 extern "system" {
     pub fn getpeername(s: SOCKET, name: *mut SOCKADDR, namelen: *mut i32) -> i32;
 }