From f8cebd1f923123c3a892f12188a16d810d606fe6 Mon Sep 17 00:00:00 2001
From: Bill Zissimopoulos <billziss@navimatics.com>
Date: Sat, 8 Oct 2016 18:49:28 -0700
Subject: [PATCH] dll: FspDebugLogSetHandle

---
 inc/winfsp/winfsp.h |  7 ++++---
 src/dll/debug.c     | 15 ++++++++++++++-
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/inc/winfsp/winfsp.h b/inc/winfsp/winfsp.h
index 1f94591e..3b74e1df 100644
--- a/inc/winfsp/winfsp.h
+++ b/inc/winfsp/winfsp.h
@@ -1469,9 +1469,10 @@ FSP_API NTSTATUS FspNtStatusFromWin32(DWORD Error);
 FSP_API DWORD FspWin32FromNtStatus(NTSTATUS Status);
 FSP_API VOID FspEventLog(ULONG Type, PWSTR Format, ...);
 FSP_API VOID FspEventLogV(ULONG Type, PWSTR Format, va_list ap);
-FSP_API VOID FspDebugLog(const char *format, ...);
-FSP_API VOID FspDebugLogSD(const char *format, PSECURITY_DESCRIPTOR SecurityDescriptor);
-FSP_API VOID FspDebugLogFT(const char *format, PFILETIME FileTime);
+FSP_API VOID FspDebugLogSetHandle(HANDLE Handle);
+FSP_API VOID FspDebugLog(const char *Format, ...);
+FSP_API VOID FspDebugLogSD(const char *Format, PSECURITY_DESCRIPTOR SecurityDescriptor);
+FSP_API VOID FspDebugLogFT(const char *Format, PFILETIME FileTime);
 FSP_API VOID FspDebugLogRequest(FSP_FSCTL_TRANSACT_REQ *Request);
 FSP_API VOID FspDebugLogResponse(FSP_FSCTL_TRANSACT_RSP *Response);
 FSP_API NTSTATUS FspCallNamedPipeSecurely(PWSTR PipeName,
diff --git a/src/dll/debug.c b/src/dll/debug.c
index 93fa2914..9afba71c 100644
--- a/src/dll/debug.c
+++ b/src/dll/debug.c
@@ -19,6 +19,13 @@
 #include <sddl.h>
 #include <stdarg.h>
 
+static HANDLE FspDebugLogHandle = INVALID_HANDLE_VALUE;
+
+FSP_API VOID FspDebugLogSetHandle(HANDLE Handle)
+{
+    FspDebugLogHandle = Handle;
+}
+
 FSP_API VOID FspDebugLog(const char *format, ...)
 {
     char buf[1024];
@@ -28,7 +35,13 @@ FSP_API VOID FspDebugLog(const char *format, ...)
     wvsprintfA(buf, format, ap);
     va_end(ap);
     buf[sizeof buf - 1] = '\0';
-    OutputDebugStringA(buf);
+    if (INVALID_HANDLE_VALUE != FspDebugLogHandle)
+    {
+        DWORD bytes;
+        WriteFile(FspDebugLogHandle, buf, lstrlenA(buf), &bytes, 0);
+    }
+    else
+        OutputDebugStringA(buf);
 }
 
 FSP_API VOID FspDebugLogSD(const char *format, PSECURITY_DESCRIPTOR SecurityDescriptor)