find-cbaseplayerpawn-commitsuicide

name	find-CBasePlayerPawn_CommitSuicide
description	Find and identify the CBasePlayerPawn_CommitSuicide function in CS2 binary using IDA Pro MCP. Use this skill when reverse engineering CS2 server.dll or server.so to locate the CommitSuicide function by searching for the "bot_kill" command string, tracing to its handler, and identifying the CommitSuicide vfunc call in the kill loop.
disable-model-invocation	true

Find CBasePlayerPawn_CommitSuicide

Locate CBasePlayerPawn_CommitSuicide in CS2 server.dll or server.so using IDA Pro MCP tools.

Method

1. Search for the bot_kill command string:

   mcp__ida-pro-mcp__find_regex pattern="bot_kill.*all"
   

   This should find a string like: "bot_kill <all> <t|ct> <type> <difficulty> <name> - Kills a specific bot, or all bots, matching the given criteria."

2. Find cross-references to the string:

   mcp__ida-pro-mcp__xrefs_to addrs="<string_addr>"
   

   This leads to a ConCommand registration function. Decompile it to find the command handler (callback) address — the first argument stored before the description string in the registration call.

3. Decompile the bot_kill command handler and locate the kill loop:

   mcp__ida-pro-mcp__decompile addr="<handler_addr>"
   

   Look for a loop pattern like this:

   do
   {
     v24 = *(_QWORD *)v23;
     if ( (*(unsigned __int8 (__fastcall **)(_QWORD))(**(_QWORD **)(*(_QWORD *)v23 + 24LL) + <IsAlive_offset>))(*(_QWORD *)(*(_QWORD *)v23 + 24LL)) )
     {
       (*(void (__fastcall **)(_QWORD, _QWORD, _QWORD))(**(_QWORD **)(v24 + 24) + <CommitSuicide_offset>))(
         *(_QWORD *)(v24 + 24),
         0LL,
         0LL);
       if ( !v5 )
         break;
     }
     ++v21;
     v23 += 8;
   }
   while ( v21 < v20 );
   

   The loop iterates over matched bots. For each bot:

   • *(v24 + 24) dereferences the PlayerPawn pointer
   • The first vfunc call (with <IsAlive_offset>) checks if the pawn is alive
   • The second vfunc call (with <CommitSuicide_offset>) calls pPlayerPawn->CommitSuicide(false, false)
   • If not in "all" mode (!v5), it breaks after the first kill

   Extract <CommitSuicide_offset> from the decompiled code (e.g., 3200LL = 0xC80).

4. Get CBasePlayerPawn vtable information:

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

   Extract vtable_va, vtable_numvfunc and vtable_entries from the result.

5. Map the vfunc offset to a vtable index and resolve the function address:

   vfunc_index = <CommitSuicide_offset> / 8
   

   Look up vtable_entries[vfunc_index] to get the function address.

6. Verify function characteristics to confirm CBasePlayerPawn::CommitSuicide:

   Decompile the resolved function address. The function should match:

   Windows:

   char __fastcall CBasePlayerPawn_CommitSuicide(float *a1, unsigned __int8 a2, char a3)
   {
      __int64 v4; // rbp
      char result; // al
      _BYTE v7[112]; // [rsp+40h] [rbp-138h] BYREF
      __int64 v8; // [rsp+B0h] [rbp-C8h]
      int v9; // [rsp+180h] [rbp+8h] BYREF
      char v10; // [rsp+198h] [rbp+20h] BYREF
   
      v4 = a2;
      result = (*(__int64 (__fastcall **)(float *))(*(_QWORD *)a1 + 1336LL))(a1); // IsAlive check
      if ( result )
      {
         sub_XXX(&v9, *(_DWORD *)(*((_QWORD *)a1 + 2) + 56LL));
         result = sub_XXX(a1 + 824, (float *)&v9);
         if ( !result || a3 )
         {
            sub_XXX(&v9, *(_DWORD *)(*((_QWORD *)a1 + 2) + 56LL));
            a1[824] = *(float *)sub_XXX(&v10, &v9);
            sub_XXX((unsigned int)v7, (_DWORD)a1, (_DWORD)a1, 0, 1065353216, (_DWORD)v4 << 6, 0);
            v8 |= (32 * (v4 ^ 1) + 32) | 0x116;
            sub_XXX(a1, (__int64)v7, 0LL); // CBaseEntity::TakeDamageOld
            return sub_XXX((__int64)v7);
         }
      }
       result;
   }
   

7. Rename the function:

   mcp__ida-pro-mcp__rename batch={"func": [{"addr": "<function_addr>", "name": "CBasePlayerPawn_CommitSuicide"}]}
   

8. Generate and validate unique signature:

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

9. Write IDA analysis output as YAML beside the binary:

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

   Required parameters:

   • func_name: CBasePlayerPawn_CommitSuicide
   • func_addr: The function address from step 5
   • func_sig: The validated signature from step 8

   VTable parameters:

   • vtable_name: CBasePlayerPawn
   • vfunc_index: The vtable index from step 5
   • vfunc_offset: vfunc_offset = vfunc_index * 8

Function Characteristics

• Parameters: (this, bool bExplodeDeath, bool bForce) where this is CBasePlayerPawn pointer
• Purpose: Handles player suicide by constructing a CTakeDamageInfo and calling TakeDamageOld
• Key Operations:
  • Checks if pawn is alive via vtable call (IsAlive)
  • Checks cooldown timer to prevent rapid suicide calls
  • Constructs a 112-byte CTakeDamageInfo on the stack
  • Sets damage flags: (32 * (bExplodeDeath ^ 1) + 32) | 0x116
  • Calls CBaseEntity::TakeDamageOld(this, info, 0)
  • Destructs the CTakeDamageInfo

VTable Information

• VTable Name: CBasePlayerPawn::\vftable'`
• VTable Mangled Name: ??_7CBasePlayerPawn@@6B@ (Windows) / _ZTV16CBasePlayerPawn (Linux)
• VTable Index: Changes with game updates. Resolve via <CommitSuicide_offset> / 8.
• VTable Offset: Changes with game updates. Extract from the bot_kill handler loop.

• Note that for server.so, the first 16 bytes of "vftable" are for RTTI. The real vftable = _ZTV16CBasePlayerPawn + 0x10.

String-Based Discovery

The primary discovery method uses the bot_kill console command:

1. Search string: "bot_kill <all>" or "bot_kill.*all"
2. Xref chain: String → ConCommand registration → command handler callback
3. Kill loop: The handler iterates matched bots, calling pPlayerPawn->CommitSuicide(false, false) via vtable

This is more robust than scanning vtable entries because:

• The bot_kill string is unique and stable across updates
• The kill loop structure is distinctive and unlikely to change
• The vfunc offset is extracted directly from the call site

Output YAML Format

The output YAML filename depends on the platform:

• server.dll → CBasePlayerPawn_CommitSuicide.windows.yaml
• server.so → CBasePlayerPawn_CommitSuicide.linux.yaml