From a1263cd48ce10cfb6e639633dc00809efef5cfce Mon Sep 17 00:00:00 2001
From: "Marcelo C." <marcelo@duplicati.com>
Date: Fri, 10 Jan 2025 12:05:40 -0300
Subject: [PATCH] Path normalization

Path separators are converted to \ which is Windows & Linux compatible, overwriting the Path.Combine separator (which would be host dependant)
---
 .../Backend/CIFS/SMBShareConnection.cs        | 28 +++++++++++++------
 1 file changed, 20 insertions(+), 8 deletions(-)

diff --git a/Duplicati/Library/Backend/CIFS/SMBShareConnection.cs b/Duplicati/Library/Backend/CIFS/SMBShareConnection.cs
index ce44882a4..f47b08233 100644
--- a/Duplicati/Library/Backend/CIFS/SMBShareConnection.cs
+++ b/Duplicati/Library/Backend/CIFS/SMBShareConnection.cs
@@ -102,7 +102,7 @@ public class SMBShareConnection : IDisposable, IAsyncDisposable
             NTStatus status;
             object fileHandle;
             FileStatus fileStatus;
-            status = _smbFileStore.CreateFile(out fileHandle, out fileStatus, Path.Combine(_connectionParameters.Path, fileName),
+            status = _smbFileStore.CreateFile(out fileHandle, out fileStatus, NormalizeSlashes(Path.Combine(_connectionParameters.Path, fileName)),
                 AccessMask.GENERIC_WRITE | AccessMask.DELETE | AccessMask.SYNCHRONIZE,
                 FileAttributes.Normal,
                 ShareAccess.None,
@@ -145,15 +145,15 @@ public class SMBShareConnection : IDisposable, IAsyncDisposable
         try
         {
             // Normalize path separators to forward slashes and trim any trailing separators
-            string normalizedPath = path.Replace('\\', '/').TrimEnd('/');
+            string linuxNormalizedPath = path.Replace('/', '\\').TrimEnd('\\');
             string currentPath = "";
 
-            foreach (string part in normalizedPath.Split('/', StringSplitOptions.RemoveEmptyEntries))
+            foreach (string part in linuxNormalizedPath.Split('\\', StringSplitOptions.RemoveEmptyEntries))
             {
                 if (string.IsNullOrWhiteSpace(part) || part == ".")
                     continue;
 
-                currentPath = currentPath.Length == 0 ? part : $"{currentPath}/{part}";
+                currentPath = currentPath.Length == 0 ? part : $"{currentPath}\\{part}";
                 object? fileHandle = null;
                 try
                 {
@@ -208,7 +208,7 @@ public class SMBShareConnection : IDisposable, IAsyncDisposable
                 var status = _smbFileStore.CreateFile(
                     out directoryHandle,
                     out fileStatus,
-                    _connectionParameters.Path,
+                    NormalizeSlashes(_connectionParameters.Path),
                     AccessMask.GENERIC_READ,
                     FileAttributes.Directory,
                     ShareAccess.Read | ShareAccess.Write,
@@ -220,7 +220,7 @@ public class SMBShareConnection : IDisposable, IAsyncDisposable
                     if (status == NTStatus.STATUS_OBJECT_PATH_NOT_FOUND || status == NTStatus.STATUS_OBJECT_NAME_NOT_FOUND)
                         throw new FolderMissingException();
                     else
-                        throw new UserInformationException($"{LC.L("Failed to open directory")} {_connectionParameters.Path} with status {status.ToString()}","DirectoryOpenError");
+                        throw new UserInformationException($"{LC.L("Failed to open directory")} { NormalizeSlashes(_connectionParameters.Path)} with status {status.ToString()}","DirectoryOpenError");
 
                 List<QueryDirectoryFileInformation> fileList;
                 status = _smbFileStore.QueryDirectory(
@@ -279,7 +279,7 @@ public class SMBShareConnection : IDisposable, IAsyncDisposable
             object? fileHandle;
             FileStatus fileStatus;
             NTStatus status = _smbFileStore.CreateFile(out fileHandle, out fileStatus,
-                Path.Combine(_connectionParameters.Path, filename), // This is where the file name is concatenated with the path
+                NormalizeSlashes(Path.Combine(_connectionParameters.Path, filename)),
                 AccessMask.GENERIC_READ | AccessMask.SYNCHRONIZE, FileAttributes.Normal, ShareAccess.Read,
                 CreateDisposition.FILE_OPEN,
                 CreateOptions.FILE_NON_DIRECTORY_FILE | CreateOptions.FILE_SYNCHRONOUS_IO_ALERT, null);
@@ -341,7 +341,7 @@ public class SMBShareConnection : IDisposable, IAsyncDisposable
             object fileHandle;
             FileStatus fileStatus;
             NTStatus status = _smbFileStore.CreateFile(out fileHandle, out fileStatus,
-                Path.Combine(_connectionParameters.Path, filename), // This is where the file name is concatenated with the path
+                NormalizeSlashes(Path.Combine(_connectionParameters.Path, filename)),
                 AccessMask.GENERIC_WRITE | AccessMask.SYNCHRONIZE,
                 FileAttributes.Normal, ShareAccess.None,
                 CreateDisposition.FILE_SUPERSEDE,
@@ -383,6 +383,18 @@ public class SMBShareConnection : IDisposable, IAsyncDisposable
             _semaphore.Release();
         }
     }
+    
+    /// <summary>
+    /// Normalizes paths to use backslashes (for Windows shares compatibility) and removes trailing slashes.
+    ///
+    /// Samba deals with \ and / in paths, but Windows shares require backslashes.
+    /// </summary>
+    /// <param name="path">Path to be normalized</param>
+    /// <returns></returns>
+    private string NormalizeSlashes(string path)
+    {
+        return path.Replace('/', '\\').TrimEnd('\\');
+    }
 
     /// <summary>
     /// Synchronously dispose the resources.