revert the preserve host header change as it failed on Antares

src/AspNetCore/Inc/protocolconfig.h

@@ -33,6 +33,12 @@ class PROTOCOL_CONFIG
         return m_msTimeout;
     }
 
+    BOOL
+    QueryPreserveHostHeader() const
+    {
+        return m_fPreserveHostHeader;
+    }
+
     BOOL
     QueryReverseRewriteHeaders() const
     {
@@ -84,6 +90,7 @@ class PROTOCOL_CONFIG
  private:
 
     BOOL            m_fKeepAlive;
+    BOOL            m_fPreserveHostHeader;
     BOOL            m_fReverseRewriteHeaders;
     BOOL            m_fIncludePortInXForwardedFor;
 

src/AspNetCore/Src/forwardinghandler.cxx

@@ -635,19 +635,21 @@ FORWARDING_HANDLER::GetHeaders(
     // this is wrong but Kestrel has dependency on it.
     // should change it in the future
     //
-    if (FAILED(hr = PATH::SplitUrl(pRequest->GetRawHttpRequest()->CookedUrl.pFullUrl,
-        &fSecure,
-        &struDestination,
-        &struUrl)) ||
-        FAILED(hr = strTemp.CopyW(struDestination.QueryStr())) ||
-        FAILED(hr = pRequest->SetHeader(HttpHeaderHost,
-                                        strTemp.QueryStr(),
-                                        static_cast<USHORT>(strTemp.QueryCCH()),
-                                        TRUE))) // fReplace
-    {
-        return hr;
+    if (!pProtocol->QueryPreserveHostHeader())
+    {
+        if (FAILED(hr = PATH::SplitUrl(pRequest->GetRawHttpRequest()->CookedUrl.pFullUrl,
+            &fSecure,
+            &struDestination,
+            &struUrl)) ||
+            FAILED(hr = strTemp.CopyW(struDestination.QueryStr())) ||
+            FAILED(hr = pRequest->SetHeader(HttpHeaderHost,
+                strTemp.QueryStr(),
+                static_cast<USHORT>(strTemp.QueryCCH()),
+                TRUE))) // fReplace
+        {
+            return hr;
+        }
     }
-
     //
     // Strip all headers starting with MS-ASPNETCORE.
     // These headers are generated by the asp.net core module and 

src/AspNetCore/Src/protocolconfig.cxx

@@ -11,6 +11,7 @@ PROTOCOL_CONFIG::Initialize()
 
     m_fKeepAlive = TRUE;
     m_msTimeout = 120000;
+    m_fPreserveHostHeader = TRUE;
     m_fReverseRewriteHeaders = FALSE;
 
     if (FAILED(hr = m_strXForwardedForName.CopyW(L"X-Forwarded-For")))