Files
OpenCore-Legacy-Patcher/opencore_legacy_patcher/volume/properties.py
2024-08-01 11:16:00 -06:00

110 lines
3.3 KiB
Python

"""
properties.py: Query volume properties for a given path using macOS's getattrlist.
"""
import ctypes
class attrreference_t(ctypes.Structure):
_fields_ = [
("attr_dataoffset", ctypes.c_int32),
("attr_length", ctypes.c_uint32)
]
class attrlist_t(ctypes.Structure):
_fields_ = [
("bitmapcount", ctypes.c_ushort),
("reserved", ctypes.c_uint16),
("commonattr", ctypes.c_uint),
("volattr", ctypes.c_uint),
("dirattr", ctypes.c_uint),
("fileattr", ctypes.c_uint),
("forkattr", ctypes.c_uint)
]
class volattrbuf(ctypes.Structure):
_fields_ = [
("length", ctypes.c_uint32),
("mountPoint", attrreference_t),
("volCapabilities", ctypes.c_uint64),
("mountPointSpace", ctypes.c_char * 1024),
]
class PathAttributes:
def __init__(self, path: str) -> None:
self._path = path
if not isinstance(self._path, str):
try:
self._path = str(self._path)
except:
raise ValueError(f"Invalid path: {path}")
_libc = ctypes.CDLL("/usr/lib/libc.dylib")
# Reference:
# https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man2/getattrlist.2.html
try:
self._getattrlist = _libc.getattrlist
except AttributeError:
return
self._getattrlist.argtypes = [
ctypes.c_char_p, # Path
ctypes.POINTER(attrlist_t), # Attribute list
ctypes.c_void_p, # Attribute buffer
ctypes.c_ulong, # Attribute buffer size
ctypes.c_ulong # Options
]
self._getattrlist.restype = ctypes.c_int
# Reference:
# https://github.com/apple-oss-distributions/xnu/blob/xnu-10063.121.3/bsd/sys/attr.h
ATTR_BIT_MAP_COUNT = 0x00000005
ATTR_VOL_MOUNTPOINT = 0x00001000
ATTR_VOL_CAPABILITIES = 0x00020000
attrList = attrlist_t()
attrList.bitmapcount = ATTR_BIT_MAP_COUNT
attrList.volattr = ATTR_VOL_MOUNTPOINT | ATTR_VOL_CAPABILITIES
volAttrBuf = volattrbuf()
if self._getattrlist(self._path.encode(), ctypes.byref(attrList), ctypes.byref(volAttrBuf), ctypes.sizeof(volAttrBuf), 0) != 0:
return
self._volAttrBuf = volAttrBuf
def supports_clonefile(self) -> bool:
"""
Verify if path provided supports Apple's clonefile function.
Equivalent to checking for Copy on Write support.
"""
VOL_CAP_INT_CLONE = 0x00010000
if not hasattr(self, "_volAttrBuf"):
return False
if self._volAttrBuf.volCapabilities & VOL_CAP_INT_CLONE:
return True
return False
def mount_point(self) -> str:
"""
Return mount point of path.
"""
if not hasattr(self, "_volAttrBuf"):
return ""
mount_point_ptr = ctypes.cast(
ctypes.addressof(self._volAttrBuf.mountPoint) + self._volAttrBuf.mountPoint.attr_dataoffset,
ctypes.POINTER(ctypes.c_char * self._volAttrBuf.mountPoint.attr_length)
)
return mount_point_ptr.contents.value.decode()