FileSystemApiHookFunction

FileSystemApiHookFunction(
 pIFSFunc FSDFnAddr,
 int FunctionNum,
 int Drive,
 int ResourceFlags,
 int CodePage,
 pioreq pir
 )

The hook function is called on every api call that the IFS manager needs to call the FSDs on. The hook function is called with the following parameters:

FSDFnAddr

Supplies the address of the FSD function that is to be called for this api.

FunctionNum

Supplies the function that is being performed. This is usually one of the list of functions described in section 8.5. Exceptions are noted as appropriate. They are as follows:

Function Type Values:
Value	Meaning
IFSFN_READ	Read a file.
IFSFN_WRITE	Write a file.
IFSFN_FINDNEXT	FindNext operation on a handle.
IFSFN_FCNNEXT	FindFirstChangeNotifyNext function.
IFSFN_SEEK	Seek on a file.
IFSFN_CLOSE	Close a file handle.
IFSFN_FINDCLOSE	Close a find context handle.
IFSFN_FCNCLOSE	Close a find change notify context handle.
IFSFN_COMMIT	Commit a file.
IFSFN_FILELOCKS	Lock a region of a file.
IFSFN_FILETIMES	Get/set time of a file.
IFSFN_PIPEREQUEST	Handle-based pipe request. See section 8.6.1
IFSFN_HANDLEINFO	Handle information on pipes. See section 8.6.3.
IFSFN_ENUMHANDLE	Enumerate information about handle.
IFSFN_CONNECT	Connect/mount a resource (net, local or character FSD).
IFSFN_DELETE	Delete a file.
IFSFN_DIR	Directory-based operations.
IFSFN_FILEATTRIB	Get/set attributes of a file.
IFSFN_FLUSH	Flush a resource.
IFSFN_GETDISKINFO	Get disk free space.
IFSFN_OPEN	Open/create a file.
IFSFN_RENAME	Rename a file.
IFSFN_SEARCH	DOS-style search operation.
IFSFN_QUERY	Query information about resource.
IFSFN_DISCONNECT	Disconnect/unmount a resource (net, local or character FSD).
IFSFN_UNCPIPEREQ	UNC-path based pipe request. See section 8.6.2.
IFSFN_IOCTL16DRIVE	Ioctl operation.
IFSFN_GETDISKPARMS	Get disk parameters.
IFSFN_FINDOPEN	LFN-style FindFirst operation.
IFSFN_DASDIO	Direct disk access operations.

Drive

Supplies the 1-based drive the operation is being performed on (-1 if UNC).

ResourceFlags

Supplies the kind of resource the operation is being performed on.

Resource Flags:
Value	Meaning
IFSFH_RES_UNC	UNC resource.
IFSFH_RES_NETWORK	Network drive.
IFSFH_RES_LOCAL	Local drive.
IFSFH_RES_CFSD	Character device.

CodePage

Supplies the codepage that the user string was passed in on.

CodePage Values:
Value	Meaning
BCS_WANSI	Windows ANSI codepage.
BCS_OEM	Currently configured OEM codepage.

pir

Supplies pointer to IOREQ structure. This structure is filled in based on the function being performed as described in section 8.5.

The function return value again depends on the function being processed. The hooker needs to preserve the same return behaviour that is expected of the FSD for each of the different apis if it hooks any of the calls.