[DNSAPI] Add the Resolver Service RPC client code and implement DnsFlushResolverCache()

Patch by Peter Hater and Christoph von Wittich.
Slightly modified by me.

CORE-12159

dll/win32/dnsapi/CMakeLists.txt

@@ -1,9 +1,12 @@
 
 include_directories(
     include
+    ${REACTOS_SOURCE_DIR}/sdk/include/reactos/idl
     ${REACTOS_SOURCE_DIR}/sdk/lib/3rdparty/adns/src
     ${REACTOS_SOURCE_DIR}/sdk/lib/3rdparty/adns/adns_win32)
 
+add_rpc_files(client ${REACTOS_SOURCE_DIR}/sdk/include/reactos/idl/dnsrslvr.idl)
+
 add_definitions(-DADNS_JGAA_WIN32 -D_CRT_NO_POSIX_ERROR_CODES)
 spec2def(dnsapi.dll dnsapi.spec ADD_IMPORTLIB)
 
@@ -14,8 +17,10 @@ list(APPEND SOURCE
     dnsapi/names.c
     dnsapi/query.c
     dnsapi/record.c
+    dnsapi/rpc.c
     dnsapi/stubs.c
-    dnsapi/precomp.h)
+    dnsapi/precomp.h
+    ${CMAKE_CURRENT_BINARY_DIR}/dnsrslvr_c.c)
 
 add_library(dnsapi MODULE
     ${SOURCE}
@@ -23,7 +28,7 @@ add_library(dnsapi MODULE
     ${CMAKE_CURRENT_BINARY_DIR}/dnsapi.def)
 
 set_module_type(dnsapi win32dll)
-target_link_libraries(dnsapi adns)
-add_importlibs(dnsapi advapi32 user32 ws2_32 iphlpapi msvcrt kernel32 ntdll)
+target_link_libraries(dnsapi adns ${PSEH_LIB})
+add_importlibs(dnsapi advapi32 rpcrt4 user32 ws2_32 iphlpapi msvcrt kernel32 ntdll)
 add_pch(dnsapi dnsapi/precomp.h SOURCE)
 add_cd_file(TARGET dnsapi DESTINATION reactos/system32 FOR all)

dll/win32/dnsapi/dnsapi/precomp.h

@@ -25,6 +25,8 @@
 #define NTOS_MODE_USER
 #include <ndk/rtlfuncs.h>
 
+#include <dnsrslvr_c.h>
+
 /* Internal DNSAPI Headers */
 #include <internal/windns.h>
 

dll/win32/dnsapi/dnsapi/query.c

@@ -1072,3 +1072,26 @@ DnsIntFreeRecordList(PDNS_RECORD ToDelete)
         ToDelete = next;
     }
 }
+
+BOOL
+WINAPI
+DnsFlushResolverCache(VOID)
+{
+    DNS_STATUS Status = ERROR_SUCCESS;
+
+    DPRINT("DnsFlushResolverCache()\n");
+
+    RpcTryExcept
+    {
+        Status = R_ResolverFlushCache(NULL);
+        DPRINT("R_ResolverFlushCache() returned %lu\n", Status);
+    }
+    RpcExcept(EXCEPTION_EXECUTE_HANDLER)
+    {
+        Status = RpcExceptionCode();
+        DPRINT("Exception returned %lu\n", Status);
+    }
+    RpcEndExcept;
+
+    return (Status == ERROR_SUCCESS);
+}

dll/win32/dnsapi/dnsapi/rpc.c

@@ -0,0 +1,75 @@
+#define WIN32_NO_STATUS
+#define _INC_WINDOWS
+#define COM_NO_WINDOWS_H
+#include <stdarg.h>
+#include <windef.h>
+#include <winbase.h>
+#include <dnsrslvr_c.h>
+
+#define NDEBUG
+#include <debug.h>
+
+handle_t __RPC_USER
+DNSRSLVR_HANDLE_bind(DNSRSLVR_HANDLE pszMachineName)
+{
+    handle_t hBinding = NULL;
+    LPWSTR pszStringBinding;
+    RPC_STATUS Status;
+
+    DPRINT1("DNSRSLVR_HANDLE_bind(%S)\n", pszMachineName);
+
+    Status = RpcStringBindingComposeW(NULL,
+                                      L"ncalrpc",
+                                      pszMachineName,
+                                      L"DNSResolver",
+                                      NULL,
+                                      &pszStringBinding);
+    if (Status != RPC_S_OK)
+    {
+        DPRINT1("RpcStringBindingCompose returned 0x%x\n", Status);
+        return NULL;
+    }
+
+    /* Set the binding handle that will be used to bind to the server. */
+    Status = RpcBindingFromStringBindingW(pszStringBinding,
+                                          &hBinding);
+    if (Status != RPC_S_OK)
+    {
+        DPRINT1("RpcBindingFromStringBinding returned 0x%x\n", Status);
+    }
+
+    Status = RpcStringFreeW(&pszStringBinding);
+    if (Status != RPC_S_OK)
+    {
+        DPRINT1("RpcStringFree returned 0x%x\n", Status);
+    }
+
+    return hBinding;
+}
+
+void __RPC_USER
+DNSRSLVR_HANDLE_unbind(DNSRSLVR_HANDLE pszMachineName,
+                       handle_t hBinding)
+{
+    RPC_STATUS Status;
+
+    DPRINT("DNSRSLVR_HANDLE_unbind(%S)\n", pszMachineName);
+
+    Status = RpcBindingFree(&hBinding);
+    if (Status != RPC_S_OK)
+    {
+        DPRINT1("RpcBindingFree returned 0x%x\n", Status);
+    }
+}
+
+void __RPC_FAR * __RPC_USER
+midl_user_allocate(SIZE_T len)
+{
+    return HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, len);
+}
+
+void __RPC_USER
+midl_user_free(void __RPC_FAR * ptr)
+{
+    HeapFree(GetProcessHeap(), 0, ptr);
+}

dll/win32/dnsapi/dnsapi/stubs.c

@@ -216,13 +216,6 @@ DnsFindAuthoritativeZone()
     return ERROR_OUTOFMEMORY;
 }
 
-BOOL WINAPI
-DnsFlushResolverCache(VOID)
-{
-    UNIMPLEMENTED;
-    return TRUE;
-}
-
 BOOL WINAPI
 DnsFlushResolverCacheEntry_A(PCSTR entry)
 {