From 62a6bbab6652f67835a0b3d8aa2be676a5af5379 Mon Sep 17 00:00:00 2001
From: Bill Zissimopoulos <billziss@navimatics.com>
Date: Wed, 3 Aug 2022 17:29:45 +0100
Subject: [PATCH] dll: FspSxsSuffix

---
 src/dll/fsctl.c   |  8 ++++----
 src/dll/library.h |  1 +
 src/dll/sxs.c     | 17 ++++++++++++-----
 3 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/src/dll/fsctl.c b/src/dll/fsctl.c
index 61263c1b..a825d23b 100644
--- a/src/dll/fsctl.c
+++ b/src/dll/fsctl.c
@@ -308,7 +308,7 @@ static BOOL WINAPI FspFsctlServiceVersionInitialize(
     QUERY_SERVICE_CONFIGW *ServiceConfig = 0;
     DWORD Size;
 
-    wsprintfW(DriverName, L"" FSP_FSCTL_DRIVER_NAME "%s", FspSxsIdent());
+    wsprintfW(DriverName, L"" FSP_FSCTL_DRIVER_NAME "%s", FspSxsSuffix());
 
     ScmHandle = OpenSCManagerW(0, 0, 0);
     if (0 == ScmHandle)
@@ -383,7 +383,7 @@ static NTSTATUS FspFsctlStartService(VOID)
     DWORD LastError;
     NTSTATUS Result;
 
-    wsprintfW(DriverName, L"" FSP_FSCTL_DRIVER_NAME "%s", FspSxsIdent());
+    wsprintfW(DriverName, L"" FSP_FSCTL_DRIVER_NAME "%s", FspSxsSuffix());
 
     AcquireSRWLockExclusive(&Lock);
 
@@ -588,7 +588,7 @@ NTSTATUS FspFsctlRegister(VOID)
     SERVICE_DESCRIPTION ServiceDescription;
     NTSTATUS Result;
 
-    wsprintfW(DriverName, L"" FSP_FSCTL_DRIVER_NAME "%s", FspSxsIdent());
+    wsprintfW(DriverName, L"" FSP_FSCTL_DRIVER_NAME "%s", FspSxsSuffix());
 
     if (0 == GetModuleFileNameW(DllInstance, DriverPath, MAX_PATH))
         return FspNtStatusFromWin32(GetLastError());
@@ -677,7 +677,7 @@ NTSTATUS FspFsctlUnregister(VOID)
     DWORD LastError;
     NTSTATUS Result;
 
-    wsprintfW(DriverName, L"" FSP_FSCTL_DRIVER_NAME "%s", FspSxsIdent());
+    wsprintfW(DriverName, L"" FSP_FSCTL_DRIVER_NAME "%s", FspSxsSuffix());
 
     ScmHandle = OpenSCManagerW(0, 0, SC_MANAGER_CREATE_SERVICE);
         /*
diff --git a/src/dll/library.h b/src/dll/library.h
index b14039a9..539120c2 100644
--- a/src/dll/library.h
+++ b/src/dll/library.h
@@ -71,6 +71,7 @@ NTSTATUS FspEventLogRegister(VOID);
 NTSTATUS FspEventLogUnregister(VOID);
 
 PWSTR FspSxsIdent(VOID);
+PWSTR FspSxsSuffix(VOID);
 
 PSID FspWksidNew(WELL_KNOWN_SID_TYPE WellKnownSidType, PNTSTATUS PResult);
 PSID FspWksidGet(WELL_KNOWN_SID_TYPE WellKnownSidType);
diff --git a/src/dll/sxs.c b/src/dll/sxs.c
index c98e1c02..58332826 100644
--- a/src/dll/sxs.c
+++ b/src/dll/sxs.c
@@ -22,7 +22,7 @@
 #include <dll/library.h>
 
 static INIT_ONCE FspSxsIdentInitOnce = INIT_ONCE_STATIC_INIT;
-static WCHAR FspSxsIdentBuf[32 + 1] = L"";
+static WCHAR FspSxsIdentBuf[32 + 2] = L"";
 
 static BOOL WINAPI FspSxsIdentInitialize(
     PINIT_ONCE InitOnce, PVOID Parameter, PVOID *Context)
@@ -31,8 +31,8 @@ static BOOL WINAPI FspSxsIdentInitialize(
     WCHAR Path[MAX_PATH];
     DWORD Size;
     HANDLE Handle = INVALID_HANDLE_VALUE;
-    CHAR Buffer[ARRAYSIZE(FspSxsIdentBuf) - 1];
-    WCHAR WBuffer[ARRAYSIZE(FspSxsIdentBuf) - 1];
+    CHAR Buffer[ARRAYSIZE(FspSxsIdentBuf) - 2];
+    WCHAR WBuffer[ARRAYSIZE(FspSxsIdentBuf) - 2];
 
     if (0 == GetModuleFileNameW(DllInstance, Path, MAX_PATH))
         goto exit;
@@ -93,8 +93,9 @@ static BOOL WINAPI FspSxsIdentInitialize(
     if (0 == Size)
         goto exit;
 
-    memcpy(FspSxsIdentBuf, WBuffer, Size * sizeof(WCHAR));
-    FspSxsIdentBuf[Size] = L'\0';
+    FspSxsIdentBuf[0] = L'-';
+    memcpy(FspSxsIdentBuf + 1, WBuffer, Size * sizeof(WCHAR));
+    FspSxsIdentBuf[1 + Size] = L'\0';
 
 exit:
     if (INVALID_HANDLE_VALUE != Handle)
@@ -104,6 +105,12 @@ exit:
 }
 
 PWSTR FspSxsIdent(VOID)
+{
+    InitOnceExecuteOnce(&FspSxsIdentInitOnce, FspSxsIdentInitialize, 0, 0);
+    return FspSxsIdentBuf + 1;
+}
+
+PWSTR FspSxsSuffix(VOID)
 {
     InitOnceExecuteOnce(&FspSxsIdentInitOnce, FspSxsIdentInitialize, 0, 0);
     return FspSxsIdentBuf;