- #READ MAC FILE SYSTEM ON WINDOWS FOR MAC OS X#
- #READ MAC FILE SYSTEM ON WINDOWS FOR MAC OS#
- #READ MAC FILE SYSTEM ON WINDOWS MAC OS X#
- #READ MAC FILE SYSTEM ON WINDOWS DRIVER#
- #READ MAC FILE SYSTEM ON WINDOWS CODE#
In case of lookup vnode operation do not forget about name cache, so lookup is not always called when an application calls open( FileX ), but if you need to see all lookup operations it is possible to disable name caching for a vnode. When an original lookup or create returns a filter calls FltHookVnodeVopAndParent for a returned vnode or does this in a kauth callback which is nearly the same as kauth callback is a postoperation callback called after VNOP_LOOKUP or VNOP_CREATE. When an application opens a file FileX in a directory DirX a vnode for a DirX is provided as a parameter for VnodeAuthorizeCallback so the following calls to file system's lookup or create operations for FileX will be visible for file system filter. The kauth callback is used only to trigger filtering for a file system. The filter registers a kauth callback FltIOKitKAuthVnodeGate::VnodeAuthorizeCallback which in turn calls FltHookVnodeVopAndParent that hooks vnode related operations. If you want to switch back then remove USE_FAKE_FSD preprocessor definition from project settings and replace vnode_Yosemite structure definition. With Sierra(10.12) release the field offsets changed for vnode structure and the project was changed to be compiled with FltFakeFSD.cpp to infer vnode layout.
#READ MAC FILE SYSTEM ON WINDOWS CODE#
An alternative implementation without using the fake FSD can be found in VersionDependent.h and VersionDependent.cpp files, where struct vnodeop_desc_Yosemite was borrowed from Apple's open source code for Yosemite(10.10), it happened that vnode and vnodeop_desc structures haven't change in all latest kernel versions so this code works for Mavericks(10.9) and El Capitan(10.11). All you need to do is to call FltGetVnodeLayout() in a filter initialization code.Īlternatively you can extract declarations from XNU code at.
This is achieved by registering a dummy file system, creating a vnode and inspecting it to find required offsets.
I used this technique in two projects to implement filtering for lookup, create, read and write requests and to implement an isolation file system.įltFakeFSD.h and FltFakeFSD.cpp are optional files that helps to infer the vnode and vnodeop_desc structures layout that are not declared in SDK.
#READ MAC FILE SYSTEM ON WINDOWS DRIVER#
This technique allows to place a filter between VFS and file system driver and supports sophisticated filtering such as isolation file system filter when a filter creates vnodes instead of a file system driver thus gaining a full control over file data. I developed a hooking technique for VFS layer that emulates a stackable file system by replacing vnode operations in array.
#READ MAC FILE SYSTEM ON WINDOWS MAC OS X#
The lack of a stackable file system support by Mac OS X VFS required to find a way to place a filter between VFS invoking vnode operations via VNOP_* functions and a file system driver implementing these vnode operations. To summarize the above, there is no official support from Apple if you need to filter read or/and write requests, filter and modify VFS vnode operation. They are called from system calls and other kernel subsystems, so MAC doesn't provide a consistent interface for VFS filter and if I remember correctly MAC was declared as deprecated for usage by third party developers. Instead of being called by VFS layer MAC registered callbacks are scattered through the kernel code. But MAC has limited functionality and not consistent in relation to file system filtering as it was not designed as a file system filter layer.
The filtering can also be implemented by registering MAC ( Mandatory Access Control ) layer.
#READ MAC FILE SYSTEM ON WINDOWS FOR MAC OS#
In Windows parlance a kauth callback is a postoperation callback for create/open request ( IRP_MJ_CREATE for Windows ), that is all you have for Mac OS X. It doesn't allow filtering read and write operations and provides a limited control over file system operations as a vnode is already created at the moment of kauth callback invoking. The available kernel authorization subsystem ( kauth ) allows only filtering open requests and a limited number of operations on file/directory. Mac OS X doesn't support a full fledged file system filtering like Windows as Apple believes that BSD stackable file system doesn't fit Mac OS X. The project uses the distorm disassembler which is now released under BSD license. This is a non-viral license, only asking that if you use it, you acknowledge the authors, in this case Slava Imameev. The license model is a BSD Open Source License.
#READ MAC FILE SYSTEM ON WINDOWS FOR MAC OS X#
A file system filter for Mac OS X License
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