static Bool clipLineInRectangle(int xmin, int ymin, int xmax, int ymax, int *x1, int *y1, int *x2, int *y2)
{
#define TOP (1<<0)
#define BOT (1<<1)
#define LEF (1<<2)
#define RIG (1<<3)
#define CHECK_OUT(X,Y) (((Y) > ymax ? TOP : ((Y) < ymin ? BOT : 0))\
| ((X) > xmax ? RIG : ((X) < xmin ? LEF : 0)))
int ocode1, ocode2, ocode;
int accept = 0;
int x, y;
ocode1 = CHECK_OUT(*x1, *y1);
ocode2 = CHECK_OUT(*x2, *y2);
for (;;) {
if (!ocode1 && !ocode2) { /* completely inside */
accept = 1;
break;
} else if (ocode1 & ocode2) {
break;
}
if (ocode1)
ocode = ocode1;
else
ocode = ocode2;
if (ocode & TOP) {
x = *x1 + (*x2 - *x1) * (ymax - *y1) / (*y2 - *y1);
y = ymax;
} else if (ocode & BOT) {
x = *x1 + (*x2 - *x1) * (ymin - *y1) / (*y2 - *y1);
y = ymin;
} else if (ocode & RIG) {
y = *y1 + (*y2 - *y1) * (xmax - *x1) / (*x2 - *x1);
x = xmax;
} else { /* //if (ocode & LEF) { */
y = *y1 + (*y2 - *y1) * (xmax - *x1) / (*x2 - *x1);
x = xmin;
}
if (ocode == ocode1) {
*x1 = x;
*y1 = y;
ocode1 = CHECK_OUT(x, y);
} else {
*x2 = x;
*y2 = y;
ocode2 = CHECK_OUT(x, y);
}
}
return accept;
}
//
// IOCTL_PREPARE_TO_UNLOAD
//
NTSTATUS LklPrepareToUnload(PDEVICE_OBJECT device,PIRP irp)
{
NTSTATUS status = STATUS_SUCCESS;
BOOLEAN acq_resource = FALSE;
CHECK_OUT(device != lklfsd.device, STATUS_INVALID_DEVICE_REQUEST);
ExAcquireResourceExclusiveLite(&lklfsd.global_resource, TRUE);
acq_resource = TRUE;
CHECK_OUT_MSG(FLAG_ON(lklfsd.flags, VFS_UNLOAD_PENDING), STATUS_ACCESS_DENIED,
"Aldready ready to unload");
CHECK_OUT_MSG(!IsListEmpty(&lklfsd.vcb_list), STATUS_ACCESS_DENIED,
"Mounted volumes exists");
DbgPrint("Unloading LklVfs");
IoUnregisterFileSystem(lklfsd.device);
//unload_linux_kernel();
IoDeleteDevice(lklfsd.device);
lklfsd.driver->DriverUnload = DriverUnload;
SET_FLAG(lklfsd.flags, VFS_UNLOAD_PENDING);
try_exit:
if (acq_resource)
RELEASE(&lklfsd.global_resource);
return status;
}
NTSTATUS LklMount(IN PDEVICE_OBJECT dev,IN PVPB vpb)
{
NTSTATUS status = STATUS_SUCCESS;
PDEVICE_OBJECT volume_device=NULL;
PLKLVCB vcb = NULL;
LARGE_INTEGER AllocationSize;
ULONG ioctlSize;
int sectors;
PSTR dev_name;
STATFS my_stat;
ULONG rc;
CHECK_OUT(dev == lklfsd.device, STATUS_INVALID_DEVICE_REQUEST);
CHECK_OUT(FLAG_ON(lklfsd.flags, VFS_UNLOAD_PENDING),STATUS_UNRECOGNIZED_VOLUME);
DbgPrint("Mount volume");
status = IoCreateDevice(lklfsd.driver, sizeof(LKLVCB), NULL,
FILE_DEVICE_DISK_FILE_SYSTEM, 0, FALSE, &volume_device);
CHECK_OUT(!NT_SUCCESS(status), status);
if (dev->AlignmentRequirement > volume_device->AlignmentRequirement)
volume_device->AlignmentRequirement = dev->AlignmentRequirement;
CLEAR_FLAG(volume_device->Flags, DO_DEVICE_INITIALIZING);
volume_device->StackSize = (CCHAR)(dev->StackSize+1);
CreateVcb(volume_device,dev,vpb,&AllocationSize);
vcb = (PLKLVCB) volume_device->DeviceExtension;
if(!FLAG_ON(vcb->flags, VFS_VCB_FLAGS_VCB_INITIALIZED))
TRY_RETURN(STATUS_INSUFFICIENT_RESOURCES);
// yup, here we read the disk geometry
ioctlSize = sizeof(DISK_GEOMETRY);
status = BlockDeviceIoControl(dev, IOCTL_DISK_GET_DRIVE_GEOMETRY, NULL, 0,
&vcb->disk_geometry, &ioctlSize);
CHECK_OUT(!NT_SUCCESS(status), status);
ioctlSize = sizeof(PARTITION_INFORMATION);
status = BlockDeviceIoControl(dev, IOCTL_DISK_GET_PARTITION_INFO, NULL, 0,
&vcb->partition_information, &ioctlSize);
CHECK_OUT(!NT_SUCCESS(status), status);
int bytes_per_sector = 0;
switch (vcb->disk_geometry.BytesPerSector)
{
case 256:
bytes_per_sector = 8;
break;
case 512:
bytes_per_sector = 9;
break;
case 1024:
bytes_per_sector = 10;
break;
case 2048:
bytes_per_sector = 11;
break;
case 4096:
bytes_per_sector = 12;
break;
case 8192:
bytes_per_sector = 13;
break;
}
sectors = vcb->partition_information.PartitionLength.QuadPart >> bytes_per_sector;
// try a linux mount if this fails, then we fail to mount
// the volume
ExAcquireResourceExclusiveLite(&(lklfsd.global_resource), TRUE);
lklfsd.no_mounts++;
status = sys_mount_wrapper(vcb->target_device, sectors, &vcb->linux_device);
DbgPrint("Mounting device '%s' retstatus=%d", dev_name, status);
ExFreePool(dev_name);
RELEASE(&(lklfsd.global_resource));
CHECK_OUT(!NT_SUCCESS(status), status);
//get info about the successfully mounted volume
rc = sys_statfs_wrapper(vcb->linux_device.mnt, &my_stat);
vpb->DeviceObject = volume_device;
// complete vpb fields
#define UNKNOWN_LABEL "Local Disk"
CharToWchar(vpb->VolumeLabel, UNKNOWN_LABEL , sizeof(UNKNOWN_LABEL));
vpb->VolumeLabel[sizeof(UNKNOWN_LABEL)] = 0;
vpb->VolumeLabelLength = sizeof(UNKNOWN_LABEL)*2;
vpb->SerialNumber = my_stat.f_type;
try_exit:
if(!NT_SUCCESS(status))
{
ExAcquireResourceExclusiveLite(&(lklfsd.global_resource), TRUE);
lklfsd.no_mounts--;
RELEASE(&(lklfsd.global_resource));
if(volume_device) {
FreeVcb((PLKLVCB) volume_device->DeviceExtension);
IoDeleteDevice(volume_device);
}
}
return status;
}
//
// FSCTL_LOCK_VOLUME
//
NTSTATUS DDKAPI VfsLockVolume(PIRP irp, PIO_STACK_LOCATION stack_location)
{
NTSTATUS status = STATUS_UNSUCCESSFUL;
PDEVICE_OBJECT device = NULL;
PLKLVCB vcb;
BOOLEAN notified = FALSE;
BOOLEAN resource_acquired = FALSE;
PFILE_OBJECT file_obj = NULL;
// request to fs device not permited
device = stack_location->DeviceObject;
CHECK_OUT(device == lklfsd.device, STATUS_INVALID_DEVICE_REQUEST);
// get vcb
vcb = (PLKLVCB)device->DeviceExtension;
ASSERT(vcb);
// file object - should be the file object for a volume open,
// even so we accept it for any open file
file_obj = stack_location->FileObject;
ASSERT(file_obj);
// notify volume locked
FsRtlNotifyVolumeEvent(file_obj, FSRTL_VOLUME_LOCK);
notified = TRUE;
// acquire vcb lock
ExAcquireResourceSharedLite(&vcb->vcb_resource, TRUE);
resource_acquired = TRUE;
// check lock flag
if (FLAG_ON(vcb->flags, VFS_VCB_FLAGS_VOLUME_LOCKED)) {
VfsReportError("Volume already locked");
TRY_RETURN(STATUS_ACCESS_DENIED);
}
// abort if open files still exist
if (vcb->open_count) {
VfsReportError("Open files still exist");
TRY_RETURN(STATUS_ACCESS_DENIED);
}
// release lock
RELEASE(&vcb->vcb_resource);
resource_acquired = FALSE;
// purge volume
VfsPurgeVolume(vcb, TRUE);
ExAcquireResourceExclusiveLite(&vcb->vcb_resource, TRUE);
resource_acquired = TRUE;
// if there are still open referneces we can't lock the volume
if (vcb->reference_count > 1) {
VfsReportError("Could not purge cached files");
TRY_RETURN(STATUS_ACCESS_DENIED);
}
// set flag in both vcb and vpb structures
SET_FLAG(vcb->flags, VFS_VCB_FLAGS_VOLUME_LOCKED);
SetVpbFlag(vcb->vpb, VFS_VCB_FLAGS_VOLUME_LOCKED);
DbgPrint("*** Volume LOCKED ***\n");
status = STATUS_SUCCESS;
try_exit:
if (resource_acquired)
RELEASE(&vcb->vcb_resource);
if (!NT_SUCCESS(status) && notified)
FsRtlNotifyVolumeEvent(file_obj, FSRTL_VOLUME_LOCK_FAILED);
return status;
}
//
// IRP_MJ_DEVICE_CONTROL - is synchronous
//
NTSTATUS DDKAPI VfsDeviceControl(PDEVICE_OBJECT device, PIRP irp)
{
NTSTATUS status=STATUS_SUCCESS;
BOOLEAN top_level;
ULONG ioctl = 0;
PIO_STACK_LOCATION stack_location = NULL;
PIO_STACK_LOCATION next_stack_location = NULL;
BOOLEAN complete_request = FALSE;
PLKLVCB vcb = NULL;
PLKLFCB fcb = NULL;
PFILE_OBJECT file = NULL;
PDEVICE_OBJECT targetDevice = NULL;
ASSERT(device);
ASSERT(irp);
top_level = LklIsIrpTopLevel(irp);
FsRtlEnterFileSystem();
stack_location = IoGetCurrentIrpStackLocation(irp);
ASSERT(stack_location);
ioctl = stack_location->Parameters.DeviceIoControl.IoControlCode;
if (ioctl == IOCTL_PREPARE_TO_UNLOAD) {
complete_request = TRUE;
DbgPrint("Prepare to unload");
status = LklPrepareToUnload(device,irp);
TRY_RETURN(status);
}
file = stack_location->FileObject;
ASSERT(file);
fcb = (PLKLFCB) file->FsContext;
CHECK_OUT(fcb == NULL, STATUS_INVALID_PARAMETER);
if (fcb->id.type == VCB) {
vcb = (PLKLVCB) fcb;
} else {
vcb = fcb->vcb;
}
CHECK_OUT(vcb == NULL, STATUS_INVALID_PARAMETER);
targetDevice = vcb->target_device;
// Pass on the IOCTL to the driver below
complete_request = FALSE;
next_stack_location = IoGetNextIrpStackLocation(irp);
*next_stack_location = *stack_location;
IoSetCompletionRoutine(irp, LklIoctlCompletion, NULL, TRUE, TRUE, TRUE);
status = IoCallDriver(targetDevice, irp);
try_exit:
if(complete_request)
LklCompleteRequest(irp, status);
if (top_level)
IoSetTopLevelIrp(NULL);
FsRtlExitFileSystem();
return status;
}