@@ -25,7 +25,7 @@

 #include "validate.h"

 LPCTSTR service_instance = TEXT("");

-

+static wchar_t win_sys_path[MAX_PATH];

 /*

  * These are necessary due to certain buggy implementations of (v)snprintf,

@@ -285,3 +285,17 @@ utf8to16(const char *utf8)

     MultiByteToWideChar(CP_UTF8, 0, utf8, -1, utf16, n);

     return utf16;

 }

+

+const wchar_t *

+get_win_sys_path(void)

+{

+    const wchar_t *default_sys_path = L"C:\\Windows\\system32";

+

+    if (!GetSystemDirectoryW(win_sys_path, _countof(win_sys_path)))

+    {

+        wcsncpy(win_sys_path, default_sys_path, _countof(win_sys_path));

+        win_sys_path[_countof(win_sys_path) - 1] = L'\0';

+    }

+

+    return win_sys_path;

+}

@@ -933,11 +933,10 @@ RegisterDNS(LPVOID unused)

 {

     DWORD err;

     DWORD i;

-    WCHAR sys_path[MAX_PATH];

     DWORD timeout = RDNS_TIMEOUT * 1000; /* in milliseconds */

-    /* default path of ipconfig command */

-    WCHAR ipcfg[MAX_PATH] = L"C:\\Windows\\system32\\ipconfig.exe";

+    /* path of ipconfig command */

+    WCHAR ipcfg[MAX_PATH];

     struct

     {

@@ -952,11 +951,8 @@ RegisterDNS(LPVOID unused)

     HANDLE wait_handles[2] = {rdns_semaphore, exit_event};

-    if (GetSystemDirectory(sys_path, MAX_PATH))

-    {

-        swprintf(ipcfg, MAX_PATH, L"%s\\%s", sys_path, L"ipconfig.exe");

-        ipcfg[MAX_PATH-1] = L'\0';

-    }

+    swprintf(ipcfg, _countof(ipcfg), L"%s\\%s", get_win_sys_path(), L"ipconfig.exe");

+    ipcfg[_countof(ipcfg) - 1] = L'\0';

     if (WaitForMultipleObjects(2, wait_handles, FALSE, timeout) == WAIT_OBJECT_0)

     {

@@ -1034,15 +1030,8 @@ netsh_dns_cmd(const wchar_t *action, const wchar_t *proto, const wchar_t *if_nam

     }

     /* Path of netsh */

-    int n = GetSystemDirectory(argv0, MAX_PATH);

-    if (n > 0 && n < MAX_PATH) /* got system directory */

-    {

-        wcsncat(argv0, L"\\netsh.exe", MAX_PATH - n - 1);

-    }

-    else

-    {

-        wcsncpy(argv0, L"C:\\Windows\\system32\\netsh.exe", MAX_PATH);

-    }

+    swprintf(argv0, _countof(argv0), L"%s\\%s", get_win_sys_path(), L"netsh.exe");

+    argv0[_countof(argv0) - 1] = L'\0';

     /* cmd template:

      * netsh interface $proto $action dns $if_name $addr [validate=no]

@@ -97,4 +97,7 @@ DWORD MsgToEventLog(DWORD flags, LPCTSTR lpszMsg, ...);

 /* Convert a utf8 string to utf16. Caller should free the result */

 wchar_t *utf8to16(const char *utf8);

+/* return windows system directory as a pointer to a static string */

+const wchar_t *get_win_sys_path(void);

+

 #endif /* ifndef _SERVICE_H */