Execute shell commands

evdevremapkeys.py

@@ -27,6 +27,8 @@
 import functools
 from pathlib import Path
 import signal
+import os
+import pwd
 
 
 import daemon
@@ -37,14 +39,27 @@
 
 
 @asyncio.coroutine
-def handle_events(input, output, remappings):
+def handle_events(input, output, remappings, user, commands, passunmapped):
     while True:
         events = yield from input.async_read()  # noqa
         for event in events:
-            if event.type == ecodes.EV_KEY and \
+            mapped = False
+
+            if remappings is not None and \
+               event.type == ecodes.EV_KEY and \
                event.code in remappings:
+                mapped = True
                 remap_event(output, event, remappings)
-            else:
+
+            if commands is not None and \
+               event.type == ecodes.EV_KEY and \
+               event.code in commands:
+                mapped = True
+                if event.value == evdev.events.KeyEvent.key_down or\
+                   event.value == evdev.events.KeyEvent.key_hold:
+                 execute_command(event, user, commands)
+
+            if passunmapped and not mapped:
                 output.write_event(event)
                 output.syn()
 
@@ -56,6 +71,20 @@ def remap_event(output, event, remappings):
     output.syn()
 
 
+def execute_command(event, user, commands):
+    for command in commands[event.code]:
+        newpid = os.fork()
+        if newpid == 0:
+            if user is not None:
+                gid = pwd.getpwnam(user).pw_gid
+                uid = pwd.getpwnam(user).pw_uid
+                #group id needs to be set before the user id,
+                #otherwise the permissions are dropped too soon
+                os.setgid(gid)
+                os.setuid(uid)
+            os.execl('/bin/sh', '/bin/sh', '-c', command)
+
+
 def load_config(config_override):
     conf_path = None
     if config_override is None:
@@ -73,15 +102,27 @@ def load_config(config_override):
     with open(conf_path.as_posix(), 'r') as fd:
         config = yaml.safe_load(fd)
         for device in config['devices']:
-            device['remappings'] = resolve_ecodes(device['remappings'])
+            if 'remappings' in device:
+                device['remappings'] = resolve_ecodes_remappings(device['remappings'])
+            if 'commands' in device:
+                device['commands'] = resolve_ecodes_commands(device['commands'])
 
     return config
 
 
-def resolve_ecodes(by_name):
+def resolve_ecodes_remappings(by_name):
     by_id = {}
-    for key, values in by_name.items():
-        by_id[ecodes.ecodes[key]] = [ecodes.ecodes[value] for value in values]
+    if by_name is not None:
+        for key, values in by_name.items():
+            by_id[ecodes.ecodes[key]] = [ecodes.ecodes[value] for value in values]
+    return by_id
+
+
+def resolve_ecodes_commands(by_name):
+    by_id = {}
+    if by_name is not None:
+        for key, values in by_name.items():
+            by_id[ecodes.ecodes[key]] = values;
     return by_id
 
 
@@ -115,14 +156,18 @@ def register_device(device):
     # EV_SYN is automatically added to uinput devices
     del caps[ecodes.EV_SYN]
 
-    remappings = device['remappings']
+    remappings = device.get('remappings', None);
+    user = device.get('command_user', None);
+    commands = device.get('commands', None);
+    passunmapped = device.get('pass_unmapped', True);
+
     extended = set(caps[ecodes.EV_KEY])
     [extended.update(keys) for keys in remappings.values()]
     caps[ecodes.EV_KEY] = list(extended)
 
     output = UInput(caps, name=device['output_name'])
 
-    asyncio.ensure_future(handle_events(input, output, remappings))
+    asyncio.ensure_future(handle_events(input, output, remappings, user, commands, passunmapped))
 
 
 @asyncio.coroutine
@@ -144,6 +189,9 @@ def run_loop(args):
                             functools.partial(asyncio.ensure_future,
                                               shutdown(loop)))
 
+    #prevent defunct processes
+    signal.signal(signal.SIGCHLD, signal.SIG_IGN)
+
     try:
         loop.run_forever()
     except KeyboardInterrupt: