winfsp/inc/winfsp/fsctl.h

/**
 * @file winfsp/fsctl.h
 *
 * @copyright 2015 Bill Zissimopoulos
 */

#ifndef WINFSP_FSCTL_H_INCLUDED
#define WINFSP_FSCTL_H_INCLUDED

#include <devioctl.h>

// {6F9D25FA-6DEE-4A9D-80F5-E98E14F35E54}
extern const __declspec(selectany) GUID FspFsctlDeviceClassGuid =
    { 0x6f9d25fa, 0x6dee, 0x4a9d, { 0x80, 0xf5, 0xe9, 0x8e, 0x14, 0xf3, 0x5e, 0x54 } };
// {B48171C3-DD50-4852-83A3-344C50D93B17}
extern const __declspec(selectany) GUID FspFsvrtDeviceClassGuid =
    { 0xb48171c3, 0xdd50, 0x4852, { 0x83, 0xa3, 0x34, 0x4c, 0x50, 0xd9, 0x3b, 0x17 } };

#define FSP_FSCTL_DISK_DEVICE_NAME      "WinFsp.Disk"
#define FSP_FSCTL_NET_DEVICE_NAME       "WinFsp.Net"

/* alignment macros */
#define FSP_FSCTL_ALIGN_UP(x, s)        (((x) + ((s) - 1L)) & ~((s) - 1L))
#define FSP_FSCTL_DEFAULT_ALIGNMENT     8
#define FSP_FSCTL_DEFAULT_ALIGN_UP(x)   FSP_FSCTL_ALIGN_UP(x, FSP_FSCTL_DEFAULT_ALIGNMENT)
#define FSP_FSCTL_DECLSPEC_ALIGN        __declspec(align(FSP_FSCTL_DEFAULT_ALIGNMENT))

/* fsctl device codes */
#define FSP_FSCTL_CREATE                \
    CTL_CODE(FILE_DEVICE_FILE_SYSTEM, 0x800 + 'C', METHOD_BUFFERED, FILE_ANY_ACCESS)

/* fsvrt device codes */
#define FSP_FSCTL_DELETE                \
    CTL_CODE(FILE_DEVICE_FILE_SYSTEM, 0x800 + 'D', METHOD_BUFFERED, FILE_ANY_ACCESS)
#define FSP_FSCTL_TRANSACT              \
    CTL_CODE(FILE_DEVICE_FILE_SYSTEM, 0x800 + 'T', METHOD_BUFFERED, FILE_ANY_ACCESS)

#define FSP_FSCTL_CREATE_BUFFER_SIZE    128
#define FSP_FSCTL_TRANSACT_BUFFER_SIZE  (16 * 1024)

#define FSP_FSCTL_VOLUME_PARAMS_SIZE    FSP_FSCTL_DEFAULT_ALIGN_UP(sizeof(FSP_FSCTL_VOLUME_PARAMS))
#define FSP_FSCTL_TRANSACT_REQ_SIZEMAX  (4 * 1024)
#define FSP_FSCTL_TRANSACT_RSP_SIZEMAX  (4 * 1024)

/* marshalling */
#pragma warning(push)
#pragma warning(disable:4200)           /* zero-sized array in struct/union */
enum
{
    FspFsctlTransactUnknownKind = 0,
    FspFsctlTransactCreateKind = 'C',
    FspFsctlTransactCreateCleanupCloseKind = 'c',
    FspFsctlTransactCloseKind = 'z',
    FspFsctlTransactReadKind = 'R',
    FspFsctlTransactWriteKind = 'W',
    FspFsctlTransactQueryInformationKind = 'I',
    FspFsctlTransactSetInformationKind = 'i',
    FspFsctlTransactQueryEaKind = 'E',
    FspFsctlTransactSetEaKind = 'e',
    FspFsctlTransactFlushBuffersKind = 'F',
    FspFsctlTransactQueryVolumeInformationKind = 'V',
    FspFsctlTransactSetVolumeInformationKind = 'v',
    FspFsctlTransactDirectoryControlKind = 'D',
    FspFsctlTransactFileSystemControlKind = 'K',
    FspFsctlTransactDeviceControlKind = 'k',
    FspFsctlTransactShutdownKind = 'd',
    FspFsctlTransactLockControlKind = 'L',
    FspFsctlTransactCleanupKind = 'Z',
    FspFsctlTransactQuerySecurityKind = 'S',
    FspFsctlTransactSetSecurityKind = 's',
};
typedef struct
{
    UINT16 Version;
    UINT16 SectorSize;
    UINT32 SerialNumber;
    UINT32 EaSupported:1;               /* supports extended attributes (unimplemented; set to 0) */
    UINT32 FileNameRequired:1;          /* FileName required for all operations (not just Create) */
    UINT32 NoSystemAccessCheck:1;       /* if set the user-mode flie system performs access checks */
} FSP_FSCTL_VOLUME_PARAMS;
typedef struct
{
    UINT16 Offset;
    UINT16 Size;
} FSP_FSCTL_TRANSACT_BUF;
typedef struct
{
    UINT16 Version;
    UINT16 Size;
    UINT32 Kind;
    UINT64 Hint;
    union
    {
        struct
        {
            UINT32 CreateDisposition;   /* FILE_{SUPERSEDE,CREATE,OPEN,OPEN_IF,OVERWRITE,OVERWRITE_IF} */
            UINT32 CreateOptions;       /* FILE_{DIRECTORY_FILE,NON_DIRECTORY_FILE,etc.} */
            UINT32 FileAttributes;      /* FILE_ATTRIBUTE_{NORMAL,DIRECTORY,etc.} */
            FSP_FSCTL_TRANSACT_BUF SecurityDescriptor; /* security descriptor for new files */
            UINT64 AllocationSize;      /* initial allocation size */
            UINT64 AccessToken;         /* (HANDLE); request access token; sent if NoAccessCheck is 0 */
            UINT32 DesiredAccess;       /* FILE_{READ_DATA,WRITE_DATA,etc.} */
            UINT32 ShareAccess;         /* FILE_SHARE_{READ,WRITE,DELETE} */
            UINT16 Ea;                  /* reserved; not currently implemented */
            UINT16 EaSize;              /* reserved; not currently implemented */
            UINT32 UserMode:1;          /* request originated in user mode */
            UINT32 HasTraversePrivilege:1;  /* requestor has TOKEN_HAS_TRAVERSE_PRIVILEGE */
            UINT32 OpenTargetDirectory:1;   /* open target dir and report FILE_{EXISTS,DOES_NOT_EXIST} */
            UINT32 CaseSensitive:1;         /* FileName comparisons should be case-sensitive */
        } Create;
        struct
        {
            UINT64 UserContext;
            UINT64 UserContext2;
            UINT32 Delete:1;            /* if set, the file or directory must be deleted */
        } Cleanup;
        struct
        {
            UINT64 UserContext;
            UINT64 UserContext2;
        } Close;
    } Req;
    FSP_FSCTL_TRANSACT_BUF FileName;
    FSP_FSCTL_DECLSPEC_ALIGN UINT8 Buffer[];
} FSP_FSCTL_TRANSACT_REQ;
typedef struct
{
    UINT16 Version;
    UINT16 Size;
    UINT32 Kind;
    UINT64 Hint;
    struct
    {
        UINT64 Information;
        UINT32 Status;
    } IoStatus;
    union
    {
        union
        {
            /* IoStatus.Status == STATUS_SUCCESS */
            struct
            {
                UINT64 UserContext;     /* open file user context (unique file id) */
                UINT64 UserContext2;    /* kernel file object user context (only low 32 bits valid) */
                UINT32 FileAttributes;  /* FILE_ATTRIBUTE_{NORMAL,DIRECTORY,etc.} */
                FSP_FSCTL_TRANSACT_BUF SecurityDescriptor; /* security descriptor */
            } Opened;
            /* IoStatus.Status == STATUS_REPARSE */
            struct
            {
                FSP_FSCTL_TRANSACT_BUF FileName; /* file name to use for STATUS_REPARSE */
            } Reparse;
        } Create;
    } Rsp;
    FSP_FSCTL_DECLSPEC_ALIGN UINT8 Buffer[];
} FSP_FSCTL_TRANSACT_RSP;
#pragma warning(pop)
static inline FSP_FSCTL_TRANSACT_REQ *FspFsctlTransactProduceRequest(
    FSP_FSCTL_TRANSACT_REQ *Request, SIZE_T RequestSize, PVOID RequestBufEnd)
{
    PVOID NextRequest = (PUINT8)Request + FSP_FSCTL_DEFAULT_ALIGN_UP(RequestSize);
    return NextRequest <= RequestBufEnd ? NextRequest : 0;
}
static inline const FSP_FSCTL_TRANSACT_REQ *FspFsctlTransactConsumeRequest(
    const FSP_FSCTL_TRANSACT_REQ *Request, PVOID RequestBufEnd)
{
    if ((PUINT8)Request + sizeof(Request->Size) > (PUINT8)RequestBufEnd ||
        sizeof(FSP_FSCTL_TRANSACT_REQ) > Request->Size)
        return 0;
    PVOID NextRequest = (PUINT8)Request + FSP_FSCTL_DEFAULT_ALIGN_UP(Request->Size);
    return NextRequest <= RequestBufEnd ? NextRequest : 0;
}
static inline FSP_FSCTL_TRANSACT_RSP *FspFsctlTransactProduceResponse(
    FSP_FSCTL_TRANSACT_RSP *Response, SIZE_T ResponseSize, PVOID ResponseBufEnd)
{
    PVOID NextResponse = (PUINT8)Response + FSP_FSCTL_DEFAULT_ALIGN_UP(ResponseSize);
    return NextResponse <= ResponseBufEnd ? NextResponse : 0;
}
static inline const FSP_FSCTL_TRANSACT_RSP *FspFsctlTransactConsumeResponse(
    const FSP_FSCTL_TRANSACT_RSP *Response, PVOID ResponseBufEnd)
{
    if ((PUINT8)Response + sizeof(Response->Size) > (PUINT8)ResponseBufEnd ||
        sizeof(FSP_FSCTL_TRANSACT_RSP) > Response->Size)
        return 0;
    PVOID NextResponse = (PUINT8)Response + FSP_FSCTL_DEFAULT_ALIGN_UP(Response->Size);
    return NextResponse <= ResponseBufEnd ? NextResponse : 0;
}

#if !defined(WINFSP_SYS_INTERNAL)
FSP_API NTSTATUS FspFsctlCreateVolume(PWSTR DevicePath,
    const FSP_FSCTL_VOLUME_PARAMS *Params, PSECURITY_DESCRIPTOR SecurityDescriptor,
    PWCHAR VolumePathBuf, SIZE_T VolumePathSize);
FSP_API NTSTATUS FspFsctlOpenVolume(PWSTR VolumePath,
    PHANDLE PVolumeHandle);
FSP_API NTSTATUS FspFsctlDeleteVolume(HANDLE VolumeHandle);
FSP_API NTSTATUS FspFsctlTransact(HANDLE VolumeHandle,
    FSP_FSCTL_TRANSACT_RSP *ResponseBuf, SIZE_T ResponseBufSize,
    FSP_FSCTL_TRANSACT_REQ *RequestBuf, SIZE_T *PRequestBufSize);
#endif

#endif