From 17eaa956bde35daad99b36b820daf8e8227add74 Mon Sep 17 00:00:00 2001
From: ssrlive <30760636+ssrlive@users.noreply.github.com>
Date: Fri, 20 Apr 2018 22:59:37 +0800
Subject: [PATCH] win: add Windows XP support to uv_if_indextoname()

This commit attempts to dynamically load
ConvertInterfaceIndexToLuid() and ConvertInterfaceLuidToNameW()
from iphlpapi.dll before using them. If they are not available,
UV_ENOSYS is returned.

PR-URL: https://github.com/libuv/libuv/pull/1810
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
---
 src/win/getaddrinfo.c | 10 ++++++++--
 src/win/winapi.c      | 11 +++++++++++
 src/win/winapi.h      | 15 +++++++++++++++
 3 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/src/win/getaddrinfo.c b/src/win/getaddrinfo.c
index 282d919c..5adc7663 100644
--- a/src/win/getaddrinfo.c
+++ b/src/win/getaddrinfo.c
@@ -392,15 +392,21 @@ int uv_if_indextoname(unsigned int ifindex, char* buffer, size_t* size) {
   DWORD bufsize;
   int r;
 
+  uv__once_init();
+
   if (buffer == NULL || size == NULL || *size == 0)
     return UV_EINVAL;
 
-  r = ConvertInterfaceIndexToLuid(ifindex, &luid);
+  if (pConvertInterfaceIndexToLuid == NULL)
+    return UV_ENOSYS;
+  r = pConvertInterfaceIndexToLuid(ifindex, &luid);
 
   if (r != 0)
     return uv_translate_sys_error(r);
 
-  r = ConvertInterfaceLuidToNameW(&luid, wname, ARRAY_SIZE(wname));
+  if (pConvertInterfaceLuidToNameW == NULL)
+    return UV_ENOSYS;
+  r = pConvertInterfaceLuidToNameW(&luid, wname, ARRAY_SIZE(wname));
 
   if (r != 0)
     return uv_translate_sys_error(r);
diff --git a/src/win/winapi.c b/src/win/winapi.c
index 4ccdf0a5..c3307861 100644
--- a/src/win/winapi.c
+++ b/src/win/winapi.c
@@ -55,12 +55,16 @@ sPowerRegisterSuspendResumeNotification pPowerRegisterSuspendResumeNotification;
 /* User32.dll function pointer */
 sSetWinEventHook pSetWinEventHook;
 
+/* iphlpapi.dll function pointer */
+sConvertInterfaceIndexToLuid pConvertInterfaceIndexToLuid = NULL;
+sConvertInterfaceLuidToNameW pConvertInterfaceLuidToNameW = NULL;
 
 void uv_winapi_init(void) {
   HMODULE ntdll_module;
   HMODULE kernel32_module;
   HMODULE powrprof_module;
   HMODULE user32_module;
+  HMODULE iphlpapi_module;
 
   ntdll_module = GetModuleHandleA("ntdll.dll");
   if (ntdll_module == NULL) {
@@ -166,4 +170,11 @@ void uv_winapi_init(void) {
       GetProcAddress(user32_module, "SetWinEventHook");
   }
 
+  iphlpapi_module = LoadLibraryA("iphlpapi.dll");
+  if (iphlpapi_module != NULL) {
+    pConvertInterfaceIndexToLuid = (sConvertInterfaceIndexToLuid)
+      GetProcAddress(iphlpapi_module, "ConvertInterfaceIndexToLuid");
+    pConvertInterfaceLuidToNameW = (sConvertInterfaceLuidToNameW)
+      GetProcAddress(iphlpapi_module, "ConvertInterfaceLuidToNameW");
+  }
 }
diff --git a/src/win/winapi.h b/src/win/winapi.h
index cc54b79b..38570c2f 100644
--- a/src/win/winapi.h
+++ b/src/win/winapi.h
@@ -4775,4 +4775,19 @@ extern sPowerRegisterSuspendResumeNotification pPowerRegisterSuspendResumeNotifi
 /* User32.dll function pointer */
 extern sSetWinEventHook pSetWinEventHook;
 
+/* iphlpapi.dll function pointer */
+union _NET_LUID_LH;
+typedef DWORD (WINAPI *sConvertInterfaceIndexToLuid)(
+    ULONG InterfaceIndex,
+    union _NET_LUID_LH *InterfaceLuid);
+
+typedef DWORD (WINAPI *sConvertInterfaceLuidToNameW)(
+    const union _NET_LUID_LH *InterfaceLuid,
+    PWSTR InterfaceName,
+    size_t Length);
+
+extern sConvertInterfaceIndexToLuid pConvertInterfaceIndexToLuid;
+extern sConvertInterfaceLuidToNameW pConvertInterfaceLuidToNameW;
+
+
 #endif /* UV_WIN_WINAPI_H_ */