find-cbaseentity-setowner

name	find-CBaseEntity_SetOwner
description	Find and identify the CBaseEntity_SetOwner virtual function in CS2 binary using IDA Pro MCP. Use this skill when reverse engineering CS2 server.dll or libserver.so to locate the SetOwner function. CBaseEntity_SetOwner is a virtual function on CBaseEntity, resolved via vtable offset in CCSPlayer_WeaponServices_EquipWeapon. Trigger: CBaseEntity_SetOwner, SetOwner
disable-model-invocation	true

Find CBaseEntity_SetOwner

Locate the CBaseEntity_SetOwner virtual function in CS2 server binary using IDA Pro MCP tools.

Overview

CBaseEntity_SetOwner is a virtual function on CBaseEntity. It is identified by decompiling CCSPlayer_WeaponServices_EquipWeapon and resolving the vtable call at offset 416 (Windows) / 408 (Linux) from the weapon entity's vtable pointer.

Prerequisites

• CCSPlayer_WeaponServices_EquipWeapon must already be identified (YAML must exist)
• CBaseEntity vtable must already be identified (vtable YAML must exist)

If either is missing, run the corresponding skill first:

• /find-CCSPlayer_WeaponServices_PickupItem-AND-CCSPlayer_WeaponServices_EquipWeapon
• /write-vtable-as-yaml with class_name=CBaseEntity

Method

1. Get CCSPlayer_WeaponServices_EquipWeapon Function Info

ALWAYS Use SKILL /get-func-from-yaml with func_name=CCSPlayer_WeaponServices_EquipWeapon.

If the skill returns an error, stop and report to user. Otherwise, extract func_va for subsequent steps.

2. Get CBaseEntity VTable Info

ALWAYS Use SKILL /get-vtable-from-yaml with class_name=CBaseEntity.

If the skill returns an error, stop and report to user. Otherwise, extract vtable_va, vtable_numvfunc and vtable_entries for subsequent steps.

3. Decompile CCSPlayer_WeaponServices_EquipWeapon and Locate SetOwner Call

Decompile the function at func_va from step 1 and look for the following code pattern:

Windows binary:

  sub_XXXXXXXX((__int64)(a2 + 182));
  v7 = *(void (__fastcall **)(_QWORD *, _QWORD))(*a2 + 416LL); // <-- CBaseEntity_SetOwner
  if ( !*(_QWORD *)(a1 + 56) )
    nullsub_XXX(a1);
  v7(a2, *(_QWORD *)(a1 + 56));
  sub_YYYYYYYY(a1, a2);
  v8 = *(void (__fastcall **)(_QWORD *, _QWORD))(*a2 + 816LL);

Linux binary:

  sub_XXXXXXXX(a2 + 274);
  v9 = *(void (__fastcall **)(_QWORD *, double, double, double))(*a2 + 408LL); // <-- CBaseEntity_SetOwner
  if ( !*(_QWORD *)(a1 + 56) )
    nullsub_XXXX();
  v9(a2, ...);
  sub_YYYYYYYY(a1, a2);
  v10 = *(void (__fastcall **)(_QWORD *, _QWORD))(*a2 + 808LL);

Key identification:

• Windows: vtable offset 416 (0x1A0), vtable index = 416 / 8 = 52
• Linux: vtable offset 408 (0x198), vtable index = 408 / 8 = 51

4. Resolve VTable Entry

Using the vtable entries from step 2, look up the entry at the platform-specific index:

• Windows: vtable_entries[52]
• Linux: vtable_entries[51]

The address at that index is CBaseEntity_SetOwner.

5. Rename CBaseEntity_SetOwner

Verify the function name at the resolved address. If not already renamed:

mcp__ida-pro-mcp__rename(batch={"func": {"addr": "<resolved_addr>", "name": "CBaseEntity_SetOwner"}})

6. Generate and Validate Unique Signature

ALWAYS Use SKILL /generate-signature-for-function to generate a robust and unique signature for CBaseEntity_SetOwner.

7. Write IDA Analysis Output as YAML

ALWAYS Use SKILL /write-vfunc-as-yaml to write the analysis results.

Required parameters:

• func_name: CBaseEntity_SetOwner
• func_addr: The resolved function address from step 4
• func_sig: The validated signature from step 6

VTable parameters:

• vtable_name: CBaseEntity
• vfunc_offset: 0x1A0 (Windows) / 0x198 (Linux) — may change with game updates
• vfunc_index: 52 (Windows) / 51 (Linux) — may change with game updates

Function Characteristics

• VTable Class: CBaseEntity
• Parameters: (CBaseEntity* this, CBaseEntity* owner)
• Purpose: Sets the owner entity for a given entity (e.g., assigning weapon ownership to a player pawn during equip)
• Called from: CCSPlayer_WeaponServices_EquipWeapon — called with the player's pawn as the owner argument

VTable Information

• VTable Name: CBaseEntity
• VTable Mangled Name:
  • Windows: ??_7CBaseEntity@@6B@
  • Linux: _ZTV11CBaseEntity
• VTable Offset: 0x1A0 (Windows) / 0x198 (Linux) — may change with game updates
• VTable Index: 52 (Windows) / 51 (Linux) — may change with game updates

Output YAML Format

The output YAML filename depends on the platform:

• server.dll → CBaseEntity_SetOwner.windows.yaml
• libserver.so / libserver.so → CBaseEntity_SetOwner.linux.yaml

Troubleshooting

If CCSPlayer_WeaponServices_EquipWeapon YAML not found:

• Run /find-CCSPlayer_WeaponServices_PickupItem-AND-CCSPlayer_WeaponServices_EquipWeapon first

If CBaseEntity vtable YAML not found:

• Run /write-vtable-as-yaml with class_name=CBaseEntity first

If the vtable offset differs from expected:

• The vtable layout may have changed in a game update
• Look for the first vtable call after sub_XXXXXXXX(a2 + 182) / sub_XXXXXXXX(a2 + 274) in the decompiled output
• The call passes *(_QWORD *)(a1 + 56) (the player pawn) as the second argument — this is the distinguishing pattern