find-ccsbotmanager-addbot-botnavignore

name

find-CCSBotManager_AddBot_BotNavIgnore

description

Find and patch the g_pNavMesh null-check inside CCSBotManager_AddBot in CS2 binary using IDA Pro MCP. This patch removes the navigation mesh requirement so bots can be added even without a nav mesh loaded. Use this skill when reverse engineering CS2 server.dll or server.so to locate and patch the nav mesh check in AddBot. Trigger: bot nav ignore, AddBot nav mesh patch, bot without nav, CCSBotManager nav ignore

CCSBotManager_AddBot_BotNavIgnore Patch Workflow

Overview

Locate the g_pNavMesh null-check at the beginning of CCSBotManager_AddBot and generate a patch that converts the conditional jz (jump-if-zero) into an unconditional jmp past the early-return, so bots can be added even when no navigation mesh is loaded.

The target code pattern in pseudocode:

if ( !g_pNavMesh || !*(_BYTE *)(g_pNavMesh + 264) )   // <-- patch target: skip this check
    return 0;

In assembly, the first branch of this check is:

mov     rax, cs:g_pNavMesh
...
test    rax, rax
jz      loc_XXXXXXXX         ; <-- patch this: jz -> jmp to loc after the nav check

The jz is a near conditional jump (0F 84 rel32 — 6 bytes). Patching it to jmp rel32 (E9 <new_rel32> 90 — 5 bytes + 1 NOP) makes it always jump past both the null-pointer check and the g_pNavMesh + 264 byte check, landing at the code that continues bot creation.

The jump target should be the loc_ label that is reached after both nav mesh checks pass (the code right after the second jz that also targets the same early-return).

Prerequisites

• CCSBotManager_AddBot must already be identified. Use SKILL /get-func-from-yaml with func_name=CCSBotManager_AddBot to load its address. If YAML does not exist, run SKILL /find-CCSBotManager_AddBot-AND-g_pCSBotManager-AND-g_pNavMesh first.

Location Steps

1. Get CCSBotManager_AddBot Function Address

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

If the skill returns an error, stop and report to user.

2. Decompile and Locate the Nav Mesh Check

Decompile the function:

mcp__ida-pro-mcp__decompile(addr="<func_va>")

In the decompiled output, search for the nav mesh check pattern at the very beginning of the function body. The key indicators are:

• if ( !g_pNavMesh || !*(_BYTE *)(g_pNavMesh + 264) ) or equivalent
• Immediately followed by return 0;

Note the address annotation on the if-statement line.

3. Disassemble the Function Prologue

Disassemble the first ~30 instructions of the function to find the exact test rax, rax + jz pair:

mcp__ida-pro-mcp__disasm(addr="<func_va>", max_instructions=30)

Look for this assembly pattern:

mov     rax, cs:g_pNavMesh
...
test    rax, rax
jz      loc_XXXXXXXX         ; early return if g_pNavMesh == NULL
cmp     byte ptr [rax+108h], 0
jz      loc_XXXXXXXX         ; early return if nav mesh not loaded

Record:

• patch_va: Address of the first jz instruction (the test rax, rax / jz pair)
• jump_target: The address of the code right AFTER the second jz — this is where execution continues when both checks pass. This is the label we want to jump to unconditionally.

4. Determine Patch Bytes

Read the original bytes of the jz instruction:

mcp__ida-pro-mcp__get_bytes(regions={"addr": "<patch_va>", "size": 6})

The jz is a near conditional jump: 0F 84 rel32 (6 bytes).

Compute the new unconditional jump to the target (the code after both nav checks):

• new_rel32 = jump_target - (patch_va + 5)
• patch_bytes = E9 <new_rel32_le> 90

Where <new_rel32_le> is the 4-byte little-endian encoding of new_rel32.

5. Generate Patch Signature

ALWAYS Use SKILL /generate-signature-for-patch to generate and validate the signature.

Required context for the skill:

• func_name: CCSBotManager_AddBot
• func_va: From step 1
• patch_va: Address of the jz instruction from step 3
• original_instruction: e.g., jz loc_1802A1485
• patched_instruction: e.g., jmp loc_1802A104F + nop
• description: Remove g_pNavMesh null-check in CCSBotManager_AddBot - patch conditional jz to unconditional jmp to skip nav mesh validation

6. Write YAML Output

ALWAYS Use SKILL /write-patch-as-yaml to persist the results.

Required parameters:

• patch_name: CCSBotManager_AddBot_BotNavIgnore
• patch_sig: The validated signature from step 5
• patch_bytes: The computed patch bytes from step 4
• patch_sig_disp: From step 5 result (omit if 0)

Output YAML Files

• CCSBotManager_AddBot_BotNavIgnore.windows.yaml
• CCSBotManager_AddBot_BotNavIgnore.linux.yaml