hidraw: add initial hidraw ioctl(s)

Signed-off-by: Filipe Laíns <lains@archlinux.org>

1 files changed, 118 insertions, 0 deletions

diff --git a/ioctl/hidraw.py b/ioctl/hidraw.py
new file mode 100644
index 0000000..13b476c
--- /dev/null
+++ b/ioctl/hidraw.py
@@ -0,0 +1,118 @@
+# SPDX-License-Identifier: MIT
+
+import array
+import ctypes
+import fcntl
+import os
+
+from typing import BinaryIO, List, Tuple
+
+import ioctl
+
+
+class HidrawReportDescriptor(ctypes.Structure):
+    HID_MAX_DESCRIPTOR_SIZE = 4096
+    _fields_ = [
+        ('size', ctypes.c_uint),
+        ('value', ctypes.c_ubyte * HID_MAX_DESCRIPTOR_SIZE),
+    ]
+
+
+class HidrawDevinfo(ctypes.Structure):
+    _fields_ = [
+        ('bustype', ctypes.c_uint),
+        ('vendor', ctypes.c_ushort),
+        ('product', ctypes.c_ushort),
+    ]
+
+
+class Hidraw(object):
+    '''
+    Represents a hidraw node
+
+    See linux/hidraw.h
+    '''
+    HIDIOCGRDESCSIZE = 0x01
+    HIDIOCGRDESC = 0x02
+    HIDIOCGRAWINFO = 0x03
+    HIDIOCGRAWNAME = 0x04
+    HIDIOCGRAWPHYS = 0x05
+    HIDIOCSFEATURE = 0x06
+    HIDIOCGFEATURE = 0x07
+
+    HID_NAME_SIZE = 1024
+
+    def __init__(self, path: str) -> None:
+        self._path = path
+        self._fd = open(path, 'rb+')
+        fcntl.fcntl(self._fd, fcntl.F_SETFL, os.O_NONBLOCK)
+
+    def __str__(self) -> str:
+        return f'Hidraw({self.path})'
+
+    @property
+    def path(self) -> str:
+        '''
+        Node path
+        '''
+        return self._path
+
+    @property
+    def fd(self) -> BinaryIO:
+        '''
+        Node file descriptor
+        '''
+        return self._fd
+
+    @property
+    def report_descriptor_size(self) -> int:
+        '''
+        Size of the report descriptor of the hidraw node
+        '''
+        return ctypes.c_uint.from_buffer(
+            ioctl.IOCTL.IOR(
+                'H', self.HIDIOCGRDESCSIZE, ctypes.sizeof(ctypes.c_uint)
+            ).perform(self._fd)
+        ).value
+
+    @property
+    def report_descriptor(self) -> List[int]:
+        '''
+        Report descriptor of the hidraw node
+        '''
+        # fcntl.ioctl does not support such big buffer sizes when using the default buffer so we need to provide our own buffer
+        buf = array.array(
+            'B', self.report_descriptor_size.to_bytes(4, 'little') +
+            HidrawReportDescriptor.HID_MAX_DESCRIPTOR_SIZE * b'\x00'
+        )
+
+        ioctl.IOCTL.IOR(
+            'H', self.HIDIOCGRDESC, ctypes.sizeof(HidrawReportDescriptor)
+        ).perform(self._fd, buf=buf)
+
+        ret = HidrawReportDescriptor.from_buffer(buf)
+        return list(ret.value)[:ret.size]
+
+    @property
+    def info(self) -> Tuple[int, int, int]:
+        '''
+        Device info of the hidraw node
+        '''
+        dev_info = HidrawDevinfo.from_buffer(
+            ioctl.IOCTL.IOR(
+                'H', self.HIDIOCGRAWINFO, ctypes.sizeof(HidrawDevinfo)
+            ).perform(self._fd)
+        )
+
+        return dev_info.bustype, dev_info.vendor, dev_info.product
+
+    @property
+    def name(self) -> str:
+        '''
+        HID name of the hidraw node
+        '''
+        return ioctl.IOCTL.IOR(
+            'H', self.HIDIOCGRAWNAME, self.HID_NAME_SIZE
+        ).perform(self._fd).decode('utf-8').strip('\x00')
+
+    # TODO: HIDIOCGRAWPHYS, HIDIOCSFEATURE, HIDIOCGFEATURE, HIDIOCGRAWUNIQ