kete: parse incoming uhid data

tools/kete.py

@@ -14,6 +14,7 @@
 from gi.repository import GObject, Gio, GLib
 import sys
 import argparse
+import binascii
 import cmd
 import errno
 import os
@@ -21,6 +22,7 @@ import json
 import logging
 import re
 import readline
+import struct
 import threading
 import time
 import svgwrite
@@ -80,6 +82,12 @@ completer_delims = completer_delims.replace(':', '')
 readline.set_completer_delims(completer_delims)
 
 
+def b2hex(bs):
+    '''Convert bytes() to a two-letter hex string in the form "1a 2b c3"'''
+    hx = binascii.hexlify(bs).decode('ascii')
+    return ' '.join([''.join(s) for s in zip(hx[::2], hx[1::2])])
+
+
 class DBusError(Exception):
     def __init__(self, message):
         self.message = message
@@ -613,8 +621,31 @@ class LiveChanger(Worker):
         if self.device is None:
             return
 
-        logger.debug(f'{self.device}: starting live mode')
-        self.device.start_live(-1)
+        read_fd, write_fd = os.pipe()
+
+        logger.info(f'{self.device}: starting live mode, please press button on device')
+        self._cb = GLib.io_add_watch(read_fd, GLib.IO_IN, self._on_uhid_data)
+        self.device.start_live(write_fd)
+
+    def _on_uhid_data(self, source, cb_condition):
+        buf = os.read(source, 4380)
+
+        header = '< L'
+        uhid_type = struct.unpack_from(header, buf)[0]
+
+        if uhid_type == 11:  # UHID_CREATE2
+            fmt = '< L 128s 64s 64s H H L L L L 4096s'
+            uhid_type, name, phys, uniq, rdesc_size, bus, vid, pid, version, country, rdesc = struct.unpack_from(fmt, buf)
+            name = name.rstrip(b'\x00')
+            rdesc = rdesc[:rdesc_size]
+            logger.info(f'Live mode started for device {name} with rdesc {b2hex(rdesc)}')
+        elif uhid_type == 12:  # UHID_INPUT2
+            fmt = '< L H 4096s'
+            uhid_type, data_len, data = struct.unpack_from(fmt, buf)
+            data = data[:data_len]
+            logger.info(f'Live data: {b2hex(data)}')
+
+        return True
 
     def stop(self):
         logger.debug(f'{self.device}: stopping live mode')
@@ -625,6 +656,7 @@ class LiveChanger(Worker):
                     e.code != Gio.IOErrorEnum.EXISTS or
                     Gio.dbus_error_get_remote_error(e) != 'org.freedesktop.DBus.Error.ServiceUnknown'):
                 raise e
+        GLib.source_remove(self._cb)
 
 
 class TuhiKeteShellLogHandler(logging.StreamHandler):