From 3bc79b275ef2ac0a2bb6805183e62baa29b6a1a2 Mon Sep 17 00:00:00 2001
From: Ken Brown <kbrown@cornell.edu>
Date: Sat, 21 Dec 2019 17:53:52 -0500
Subject: [PATCH] Cygwin: FIFO: use FILE_PIPE_REJECT_REMOTE_CLIENTS flag

Add that flag to the pipe type argument when creating the Windows
named pipe.  And add a definition of that flag to ntdll.h (copied from
/usr/include/w32api/ddk/ntifs.h).
---
 winsup/cygwin/fhandler_fifo.cc | 3 ++-
 winsup/cygwin/ntdll.h          | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/winsup/cygwin/fhandler_fifo.cc b/winsup/cygwin/fhandler_fifo.cc
index 92797ce60..fd8223000 100644
--- a/winsup/cygwin/fhandler_fifo.cc
+++ b/winsup/cygwin/fhandler_fifo.cc
@@ -184,7 +184,8 @@ fhandler_fifo::create_pipe_instance (bool first)
   timeout.QuadPart = -500000;
   status = NtCreateNamedPipeFile (&ph, access, &attr, &io, sharing,
 				  first ? FILE_CREATE : FILE_OPEN, 0,
-				  FILE_PIPE_MESSAGE_TYPE,
+				  FILE_PIPE_MESSAGE_TYPE
+				    | FILE_PIPE_REJECT_REMOTE_CLIENTS,
 				  FILE_PIPE_MESSAGE_MODE,
 				  nonblocking, max_instances,
 				  DEFAULT_PIPEBUFSIZE, DEFAULT_PIPEBUFSIZE,
diff --git a/winsup/cygwin/ntdll.h b/winsup/cygwin/ntdll.h
index e19cc8ab5..1c07d0255 100644
--- a/winsup/cygwin/ntdll.h
+++ b/winsup/cygwin/ntdll.h
@@ -557,7 +557,8 @@ enum
 enum
 {
   FILE_PIPE_BYTE_STREAM_TYPE = 0,
-  FILE_PIPE_MESSAGE_TYPE = 1
+  FILE_PIPE_MESSAGE_TYPE = 1,
+  FILE_PIPE_REJECT_REMOTE_CLIENTS = 2
 };
 
 typedef struct _FILE_PIPE_PEEK_BUFFER {