macro parser

README.md

@@ -29,9 +29,9 @@ key-mapper-service
 ## Macros
 
 It is possible to write timed macros into the center column:
-- `r(3, k("a").w(10))` aaa
-- `r(2, k("a").k("-")).k("b")` a-a-b
-- `w(1000).m("SHIFT_L", r(2, k("a"))).w(10, 20).k("b")` AAb
+- `r(3, k(a).w(10))` aaa
+- `r(2, k(a).k(-)).k(b)` a-a-b
+- `w(1000).m(SHIFT_L, r(2, k(a))).w(10, 20).k(b)` AAb
 
 Documentation:
 - `r` repeats

bin/key-mapper-gtk

@@ -24,7 +24,6 @@
 
 import sys
 import atexit
-import getpass
 from argparse import ArgumentParser
 
 import gi
@@ -38,6 +37,13 @@ from keymapper.daemon import Daemon
 from keymapper.dev.permissions import can_read_devices
 
 
+try:
+    from rich.traceback import install
+    install(show_locals=True)
+except ImportError:
+    pass
+
+
 if __name__ == '__main__':
     parser = ArgumentParser()
     parser.add_argument(

bin/key-mapper-service

@@ -38,6 +38,13 @@ from keymapper.daemon import Daemon
 from keymapper.dev.permissions import can_read_devices
 
 
+try:
+    from rich.traceback import install
+    install(show_locals=True)
+except ImportError:
+    pass
+
+
 if __name__ == '__main__':
     parser = ArgumentParser()
     parser.add_argument(

keymapper/dev/injector.py

@@ -22,6 +22,7 @@
 """Keeps injecting keycodes in the background based on the mapping."""
 
 
+import os
 import re
 import asyncio
 import time
@@ -225,8 +226,6 @@ class KeycodeInjector:
             where to read keycodes from
         keymapper_device : evdev.UInput
             where to write keycodes to
-        mapping : Mapping
-            to figure out which keycodes to write
         """
         logger.debug(
             'Started injecting into %s, fd %s',
@@ -250,6 +249,17 @@ class KeycodeInjector:
             if character is None:
                 # unknown keycode, forward it
                 target_keycode = input_keycode
+            elif '(' in character:
+                # must be a macro. Only allow it if the injector is not
+                # running as root.
+                if os.geteuid() == 0:
+                    logger.error(
+                        'Cannot allow running macros as root to avoid '
+                        'injecting arbitrary code'
+                    )
+                    continue
+
+                Macro()
             else:
                 target_keycode = system_mapping.get_keycode(character)
                 if target_keycode is None:
@@ -274,6 +284,14 @@ class KeycodeInjector:
             )
             keymapper_device.syn()
 
+        # this should only ever happen in tests to avoid blocking them
+        # forever, as soon as all events are consumed. In normal operation
+        # there is no end to the events.
+        logger.error(
+            'The injector for "%s" stopped early',
+            keymapper_device.device.path
+        )
+
     @ensure_numlock
     def stop_injecting(self):
         """Stop injecting keycodes."""

keymapper/dev/macros.py

@@ -39,27 +39,18 @@ w(1000).m('SHIFT_L', r(2, k('a'))).w(10).k('b'): <1s> 'A' 'A' <10ms> 'b'
 
 
 import time
+import re
 import random
 
+try:
+    from rich.traceback import install
+    install(show_locals=True)
+except ImportError:
+    pass
 
-# TODO parse securely
-
-
-def m(*args):
-    return Macro().m(*args)
-
-
-def r(*args):
-    return Macro().r(*args)
-
-
-def k(*args):
-    return Macro().k(*args)
-
-
-def w(*args):
-    return Macro().w(*args)
+from keymapper.logger import logger
 
+logger.setLevel(5)
 
 class Macro:
     """Supports chaining and preparing actions."""
@@ -76,7 +67,7 @@ class Macro:
         """Stop the macro."""
         # TODO
 
-    def m(self, modifier, macro):
+    def modify(self, modifier, macro):
         """Do stuff while a modifier is activated.
 
         Parameters
@@ -89,7 +80,7 @@ class Macro:
         # TODO release modifier
         return self
 
-    def r(self, repeats, macro):
+    def repeat(self, repeats, macro):
         """Repeat actions.
 
         Parameters
@@ -101,30 +92,160 @@ class Macro:
             self.tasks.append(macro.run)
         return self
 
-    def k(self, character):
+    def keycode(self, character):
         """Write the character."""
         # TODO write character
         self.tasks.append(lambda: print(character))
         return self
 
-    def w(self, min, max=None):
+    def wait(self, min, max=None):
         """Wait a random time in milliseconds"""
         # TODO random
         self.tasks.append(lambda: time.sleep(min / 1000))
         return self
 
 
-# TODO make these into tests
-
-print()
-r(3, k('a').w(200)).run()
-
-print()
-r(2, k('a').k('-')).k('b').run()
-
-print()
-w(400).m('SHIFT_L', r(2, k('a'))).w(10).k('b').run()
-
-print()
-# prints nothing yet
-k('a').r(3, k('b'))
+def parse(macro):
+    """parse and generate a Macro that can be run as often as you want.
+
+    Parameters
+    ----------
+    macro : string
+        "r(3, k(a).w(10))"
+        "r(2, k(a).k(-)).k(b)"
+        "w(1000).m(SHIFT_L, r(2, k(a))).w(10, 20).k(b)"
+    """
+    try:
+        return parse_recurse(macro)
+    except Exception as e:
+        logger.error(e)
+    # parsing unsuccessful
+    return None
+
+
+def extract_params(inner):
+    """Extract parameters from the inner contents of a call.
+
+    Parameters
+    ----------
+    inner : string
+        for example 'r, r(2, k(a))' should result in ['r', 'r(2, k(a)']
+    """
+    inner = inner.strip()
+    brackets = 0
+    params = []
+    start = 0
+    for position, char in enumerate(inner):
+        if char == '(':
+            brackets += 1
+        if char == ')':
+            brackets -= 1
+        if (char == ',') and brackets == 0:
+            # , potentially starts another parameter, but only if
+            # the current brackets are all closed.
+            params.append(inner[start:position].strip())
+            # skip the comma
+            start = position + 1
+
+    if brackets == 0 and start != len(inner):
+        # one last parameter
+        params.append(inner[start:].strip())
+
+    return params
+
+
+def parse_recurse(macro, macro_instance=None, depth=0):
+    """Handle a subset of the macro, e.g. one parameter or function call.
+
+    Parameters
+    ----------
+    macro : string
+        Just like parse
+    macro_instance : Macro or None
+        A macro instance to add tasks to
+    depth : int
+        For logging and debugging purposes
+    """
+    # to anyone who knows better about compilers and thinks this is horrible:
+    # please make a pull request. Because it probably is.
+    # not using eval for security reasons ofc. And this syntax doesn't need
+    # string quotes for its params.
+    if macro_instance is None:
+        macro_instance = Macro()
+
+    macro = macro.strip()
+    logger.spam('%sinput %s', '  ' * depth, macro)
+    space = '  ' * depth
+
+    # is it another macro?
+    call_match = re.match(r'^(\w+)\(.+?', macro)
+    call = call_match[1] if call_match else None
+    if call is not None:
+        # available functions in the macro
+        functions = {
+            'm': macro_instance.modify,
+            'r': macro_instance.repeat,
+            'k': macro_instance.keycode,
+            'w': macro_instance.wait
+        }
+
+        if functions.get(call) is None:
+            logger.error(f'Unknown function %s', call)
+
+        # get all the stuff inbetween
+        brackets = 0
+        position = 0
+        for char in macro:
+            position += 1
+
+            if char == '(':
+                brackets += 1
+                continue
+
+            if char == ')':
+                brackets -= 1
+                if brackets < 0:
+                    logger.error(f'There is one ")" too much at %s', position)
+                    return
+                if brackets == 0:
+                    # the closing bracket of the call
+                    break
+
+        if brackets != 0:
+            logger.error(f'There are %s closing brackets missing', brackets)
+
+        inner = macro[2:position - 1]
+
+        # split "3, k(a).w(10)" into parameters
+        string_params = extract_params(inner)
+        logger.spam('%scalls %s with %s', space, call, string_params)
+        # evaluate the params
+        params = [
+            parse_recurse(param.strip(), None, depth + 1)
+            for param in string_params
+        ]
+
+        logger.spam('%scalling %s with %s', space, call, params)
+        functions[call](*params)
+
+        # is after this another call? Chain it to the macro_instance
+        if len(macro) > position and macro[position] == '.':
+            chain = macro[position + 1:]
+            logger.spam('%sfollowed by %s', space, chain)
+            parse_recurse(chain, macro_instance, depth)
+
+        return macro_instance
+    else:
+        # probably a parameter for an outer function
+        try:
+            macro = int(macro)
+        except ValueError:
+            pass
+        return macro
+
+
+parse("k(1).k(2).k(3)").run()
+parse("r(1, k(2))").run()
+parse("r(3, k(a).w(10))").run()
+parse("r(2, k(a).k(-)).k(b)").run()
+parse("w(1000).m(SHIFT_L, r(2, k(a))).w(10, 20).k(b)").run()

tests/testcases/macros.py

@@ -0,0 +1,44 @@
+#!/usr/bin/python3
+# -*- coding: utf-8 -*-
+# key-mapper - GUI for device specific keyboard mappings
+# Copyright (C) 2020 sezanzeb <proxima@hip70890b.de>
+#
+# This file is part of key-mapper.
+#
+# key-mapper is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# key-mapper is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with key-mapper.  If not, see <https://www.gnu.org/licenses/>.
+
+
+import unittest
+
+from keymapper.dev.macros import Macro, k, m, r, w
+
+
+class TestMacros(unittest.TestCase):
+    def test_1(self):
+        r(3, k('a').w(200)).run()
+
+    def test_2(self):
+        r(2, k('a').k('-')).k('b').run()
+
+    def test_3(self):
+        w(400).m('SHIFT_L', r(2, k('a'))).w(10).k('b').run()
+
+    def test_4(self):
+        # prints nothing without .run
+        k('a').r(3, k('b'))
+
+
+
+if __name__ == "__main__":
+    unittest.main()