[CSGO] Hooking AcceptInput

Please post any questions about developing your plugin here. Please use the search function before posting!
User avatar
VinciT
Senior Member
Posts: 114
Joined: Thu Dec 18, 2014 2:41 am

[CSGO] Hooking AcceptInput

Postby VinciT » Sat Oct 20, 2018 3:40 am

I'm trying to hook CBaseEntity::AcceptInput and I keep getting 'ESP not present' (followed by a crash) whenever the hook is called.
This is the offset I've added (thanks to SM):

Syntax: Select all

# bool CBaseEntity::AcceptInput( const char *szInputName, CBaseEntity *pActivator, CBaseEntity *pCaller, variant_t Value, int outputID )
[[accept_input]]
offset_linux = 41
offset_windows = 40
arguments = POINTER, POINTER, POINTER, POINTER, INT
return_type = BOOL
Am I messing up the arguments or is there something else at play here?
User avatar
L'In20Cible
Project Leader
Posts: 1186
Joined: Sat Jul 14, 2012 9:29 pm
Location: Québec

Re: [CSGO] Hooking AcceptInput

Postby L'In20Cible » Sat Oct 20, 2018 5:48 am

You need to specify the convention. It is defaulted to CDECL and you are hooking a THISCALL method. Also, your prototype is not right. Should be:

Syntax: Select all

# bool CBaseEntity::AcceptInput( const char *szInputName, CBaseEntity *pActivator, CBaseEntity *pCaller, variant_t Value, int outputID )
[[accept_input]]
offset_linux = 41
offset_windows = 40
arguments = POINTER, STRING, POINTER, POINTER, POINTER, INT
return_type = BOOL
convention = THISCALL


However, instead of hooking that method it would be easier to get the specific input function you want to hook from the datamaps and hook it directly. That way you don't have to use signatures.
User avatar
Ayuto
Project Leader
Posts: 2029
Joined: Sat Jul 07, 2012 8:17 am
Location: Germany

Re: [CSGO] Hooking AcceptInput

Postby Ayuto » Sat Oct 20, 2018 6:04 am

You don't need to specify the convention. It's already thiscall in that data file.
User avatar
L'In20Cible
Project Leader
Posts: 1186
Joined: Sat Jul 14, 2012 9:29 pm
Location: Québec

Re: [CSGO] Hooking AcceptInput

Postby L'In20Cible » Sat Oct 20, 2018 7:12 am

Ayuto wrote:You don't need to specify the convention. It's already thiscall in that data file.

What file? :confused:
User avatar
Ayuto
Project Leader
Posts: 2029
Joined: Sat Jul 07, 2012 8:17 am
Location: Germany

Re: [CSGO] Hooking AcceptInput

Postby Ayuto » Sat Oct 20, 2018 9:05 am

I guess it's the file to reconstruct the CBaseEntity class. When the file is parsed, SP already assumes THISCALL plus the this pointer is added automatically to the arguments.
User avatar
VinciT
Senior Member
Posts: 114
Joined: Thu Dec 18, 2014 2:41 am

Re: [CSGO] Hooking AcceptInput

Postby VinciT » Sat Oct 20, 2018 3:44 pm

Thanks for the quick replies! Sadly, it's still crashing. I'm trying to get the player that used a func_button to trigger something else (in this case a func_door).
I tried using the OnEntityOutput listener for this, but it doesn't trigger for some entities. So I thought I should hook the input instead. This is my test code:

Syntax: Select all

# ../door_test/door_test.py

# Source.Python
from entities.hooks import EntityPreHook, EntityCondition


is_door = EntityCondition.equals_entity_classname('func_door')


@EntityPreHook(is_door, 'accept_input')
def pre_accept_input(stack_data):
print(stack_data)

Without setting the convention in the .ini file, I get the following error:

Code: Select all

[SP] Caught an Exception:
Traceback (most recent call last):
  File "..\addons\source-python\plugins\door_test\door_test.py", line 12, in pre_accept_input
    print(stack_data)

UnicodeDecodeError: 'utf-8' codec can't decode byte 0xd9 in position 2: invalid continuation byte


ESP not present.
If I set the convention, I get two errors:

Code: Select all

[SP] Caught an Exception:
Traceback (most recent call last):
  File "..\addons\source-python\packages\source-python\memory\helpers.py", line 144, in as_conventio
n
    return Convention.names[value]
KeyError: 'thiscall'

During handling of the above exception, another exception occurred:
Traceback (most recent call last):
  File "..\addons\source-python\packages\source-python\plugins\command.py", line 162, in load_plugin

    plugin = self.manager.load(plugin_name)
  File "..\addons\source-python\packages\source-python\plugins\manager.py", line 194, in load
    plugin._load()
  File "..\addons\source-python\packages\source-python\plugins\instance.py", line 74, in _load
    self.module = import_module(self.import_name)
  File "..\addons\source-python\plugins\door_test\door_test.py", line 10, in <module>
    @EntityPreHook(is_door, 'accept_input')
  File "..\addons\source-python\packages\source-python\entities\hooks.py", line 129, in __call__
    if self.initialize(entity):
  File "..\addons\source-python\packages\source-python\entities\hooks.py", line 162, in initialize
    self.hooked_function = getattr(entity, self.function)
  File "..\addons\source-python\packages\source-python\entities\_base.py", line 107, in __getattr__
    for server_class in self.server_classes:
  File "..\addons\source-python\packages\source-python\entities\_base.py", line 244, in server_class
es
    yield from server_classes.get_entity_server_classes(self)
  File "..\addons\source-python\packages\source-python\entities\classes.py", line 198, in get_entity
_server_classes
    datamap=entity_datamaps.get(class_name, {}),
  File "..\addons\source-python\packages\source-python\entities\classes.py", line 232, in _get_serve
r_class
    instance = self.create_type_from_file(class_name, manager_contents)
  File "..\addons\source-python\packages\source-python\memory\manager.py", line 342, in create_type_
from_file
    type_name, GameConfigObj(f), bases)
  File "..\addons\source-python\packages\source-python\memory\manager.py", line 413, in create_type_
from_dict
    for name, data in vfuncs:
  File "..\addons\source-python\packages\source-python\memory\helpers.py", line 397, in parse_data
    value if value is default else converter(manager, value))
  File "..\addons\source-python\packages\source-python\memory\helpers.py", line 146, in as_conventio
n
    return manager.custom_conventions[value]

KeyError: 'thiscall'

Code: Select all

[SP] Caught an Exception:
Traceback (most recent call last):
  File "..\addons\source-python\packages\source-python\entities\hooks.py", line 227, in on_entity_cr
eated
    _waiting_entity_hooks.initialize(base_entity.index)
  File "..\addons\source-python\packages\source-python\entities\hooks.py", line 212, in initialize
    if hook.initialize(entity):
  File "..\addons\source-python\packages\source-python\entities\hooks.py", line 162, in initialize
    self.hooked_function = getattr(entity, self.function)
  File "..\addons\source-python\packages\source-python\entities\_base.py", line 116, in __getattr__
    raise AttributeError('Attribute "{0}" not found'.format(attr))

AttributeError: Attribute "accept_input" not found
User avatar
VinciT
Senior Member
Posts: 114
Joined: Thu Dec 18, 2014 2:41 am

Re: [CSGO] Hooking AcceptInput

Postby VinciT » Sat Oct 20, 2018 4:35 pm

I tried using the offset with only one argument, to see if it would work, and it does! No more crashing.

Syntax: Select all

(<_memory.Pointer object at 0x0EDB4DA0>, 'Use')

Syntax: Select all

[[accept_input]]
offset_linux = 41
offset_windows = 40
arguments = STRING
return_type = BOOL
But there's a problem - the buttons aren't sending any outputs. I added return True at the end of the hook, but they're still broken.
Then I tried adding another argument (POINTER) and it started crashing again.
User avatar
Ayuto
Project Leader
Posts: 2029
Joined: Sat Jul 07, 2012 8:17 am
Location: Germany

Re: [CSGO] Hooking AcceptInput

Postby Ayuto » Sat Oct 20, 2018 5:16 pm

Could you please post the output of "sp info". Also, to which ini-file have you added the data (I'm assuming some CBaseEntity.ini in Source.Python's data files).

You get the KeyError if you specify the convetion, because it's case-sensitive (use upper case). Also, you don't necessarily need the quotes.
User avatar
VinciT
Senior Member
Posts: 114
Joined: Thu Dec 18, 2014 2:41 am

Re: [CSGO] Hooking AcceptInput

Postby VinciT » Sat Oct 20, 2018 5:30 pm

Code: Select all

--------------------------------------------------------
Checksum      : 405a773ffd84ab3fe11824740fa5cb2b
Date          : 2018-10-20 17:27:09.301686
OS            : Windows-8.1-6.3.9600
Game          : csgo
SP version    : 663
Github commit : d13b5c9e380d021166ac6ab5ce487fafeea686e7
Server plugins:
   00: Source.Python, (C) 2012-2018, Source.Python Team.
SP plugins:
   00: door_test
--------------------------------------------------------
Yep, your assumption is correct. I added it directly to SP's CBaseEntity.ini (..csgo\addons\source-python\data\source-python\entities\csgo\CBaseEntity.ini)
I changed the convention to THISCALL, but it's still crashing whenever I add the second argument to the data.
User avatar
Ayuto
Project Leader
Posts: 2029
Joined: Sat Jul 07, 2012 8:17 am
Location: Germany

Re: [CSGO] Hooking AcceptInput

Postby Ayuto » Sat Oct 20, 2018 7:32 pm

On Windows the variant_t argument, which has the size of 20 bytes, gets copied to the stack instead of a single pointer that gets pushed to the stack. Thus, we need to add a few fake arguments, so we don't mess up the stack:

Code: Select all

# bool CBaseEntity::AcceptInput( const char *szInputName, CBaseEntity *pActivator, CBaseEntity *pCaller, variant_t Value, int outputID )
    [[accept_input]]
        offset_linux = 41
        offset_windows = 40
        arguments_linux = STRING, POINTER, POINTER, POINTER, INT
        arguments_windows = STRING, POINTER, POINTER, POINTER, POINTER, POINTER, POINTER, POINTER, INT
        return_type = BOOL
I haven't tested it, but you should be able to access the arguments like this on Windows:

Code: Select all

# args[0] = this
# args[1] = input_name
# args[2] = activator
# args[3] = caller
# args[8] = value
# args[9] = output_id
User avatar
VinciT
Senior Member
Posts: 114
Joined: Thu Dec 18, 2014 2:41 am

Re: [CSGO] Hooking AcceptInput

Postby VinciT » Sat Oct 20, 2018 8:54 pm

Ayuto, you're amazing! It works! Thank you so much.

Return to “Plugin Development Support”

Who is online

Users browsing this forum: Sam and 6 guests