find-CNetworkMessages_GetIsForServer

Name: find-CNetworkMessages_GetIsForServer
Author: HLND2T

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How to install find-CNetworkMessages_GetIsForServer?

hlnd2t/cs2_vibesignatures/find-cnetworkmessages_getisforserver

$npx -y skills add HLND2T/CS2_VibeSignatures --skill find-CNetworkMessages_GetIsForServer

Installs into the current project.

Summary

Find and identify the CNetworkMessages_GetIsForServer virtual function in CS2 binary using IDA Pro MCP. Use this skill when reverse engineering CS2 networksystem.dll or libnetworksystem.so to locate the GetIsForServer vfunc by reusing the known CNetworkMessages_SetIsForServer slo

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SKILL.md

1	# Find CNetworkMessages_GetIsForServer
2
3	Locate `CNetworkMessages_GetIsForServer` vfunc in CS2 `networksystem.dll` or `libnetworksystem.so` using IDA Pro MCP tools.
4
5	## Method
6
7	### 1. Load CNetworkMessages_SetIsForServer from YAML
8
9	ALWAYS Use SKILL `/get-func-from-yaml` with `func_name=CNetworkMessages_SetIsForServer`.
10
11	If the skill returns an error, STOP and report to user.
12
13	Otherwise, extract:
14	- `func_va` of `CNetworkMessages_SetIsForServer`
15	- `vfunc_index`
16	- `vfunc_offset`
17
18	### 2. Load CNetworkMessages VTable from YAML
19
20	ALWAYS Use SKILL `/get-vtable-from-yaml` with `class_name=CNetworkMessages`.
21
22	If the skill returns an error, STOP and report to user.
23
24	Otherwise, extract:
25	- `vtable_numvfunc`
26	- `vtable_entries`
27
28	### 3. Resolve the Adjacent Getter Slot
29
30	Compute the candidate slot for `CNetworkMessages_GetIsForServer`:
31
32	- `target_vfunc_index = CNetworkMessages_SetIsForServer.vfunc_index + 1`
33	- `target_vfunc_offset = CNetworkMessages_SetIsForServer.vfunc_offset + 8`
34
35	Validate that `target_vfunc_index < vtable_numvfunc`, then read:
36
37	- `candidate_func_addr = CNetworkMessages_vtable[target_vfunc_index]`
38
39	This adjacent-slot rule is required because `GetIsForServer` immediately follows `SetIsForServer` in the `CNetworkMessages` vtable for `networksystem.dll` / `libnetworksystem.so`.
40
41	### 4. Decompile the Setter and Getter Candidate
42
43	Decompile both functions:
44
45	```text
46	mcp__ida-pro-mcp__decompile addr="<CNetworkMessages_SetIsForServer_func_va>"
47	mcp__ida-pro-mcp__decompile addr="<candidate_func_addr>"
48	```
49
50	First, confirm `CNetworkMessages_SetIsForServer` is the simple byte setter pattern:
51
52	```c
53	void __fastcall CNetworkMessages_SetIsForServer(__int64 a1, char a2)
54	{
55	(_BYTE )(a1 + 1374) = a2;
56	}
57	```
58
59	Windows assembly example:
60
61	```asm
62	mov [rcx+55Eh], dl
63	retn
64	```
65
66	Then confirm the adjacent vtable entry is the matching byte getter using the same member offset:
67
68	```c
69	__int64 __fastcall sub_1800CB790(__int64 a1)
70	{
71	return (unsigned __int8 )(a1 + 1374);
72	}
73	```
74
75	Windows assembly example:
76
77	```asm
78	movzx eax, byte ptr [rcx+55Eh]
79	retn
80	```
81
82	The exact member offset may change across game updates. The identification rule is:
83
84	1. `SetIsForServer` writes one byte to `this + <member_offset>`
85	2. `candidate_func_addr` is the next vtable entry (`index + 1`)
86	3. The candidate reads and returns one unsigned byte from the same `this + <member_offset>`
87
88	If all three conditions hold, the candidate is `CNetworkMessages_GetIsForServer`.
89
90	### 5. Generate Function Signature
91
92	ALWAYS Use SKILL `/generate-signature-for-function` with `addr=<candidate_func_addr>` to generate a robust and unique `func_sig` for `CNetworkMessages_GetIsForServer`.
93
94	Use the returned validated `func_sig` in the next step.
95
96	### 6. Write IDA Analysis Output as YAML
97
98	ALWAYS Use SKILL `/write-vfunc-as-yaml` to write the analysis results.
99
100	Required parameters:
101	- `func_name`: `CNetworkMessages_GetIsForServer`
102	- `func_addr`: `<candidate_func_addr>`
103	- `func_sig`: The validated signature from step 5
104	- `vfunc_sig`: `None`
105
106	VTable parameters:
107	- `vtable_name`: `CNetworkMessages`
108	- `vfunc_offset`: `<target_vfunc_offset>` in hex
109	- `vfunc_index`: `<target_vfunc_index>`
110
111	## Function Characteristics
112
113	- Purpose: Returns whether the `CNetworkMessages` instance is configured for server-side behavior
114	- Binary: `networksystem.dll` / `libnetworksystem.so`
115	- Parameters: `(this)` only
116	- Return value: An unsigned byte / boolean flag loaded from the same member written by `CNetworkMessages_SetIsForServer`
117
118	## Discovery Strategy
119
120	1. Reuse the existing `CNetworkMessages_SetIsForServer` YAML to obtain the authoritative slot index
121	2. Reuse the existing `CNetworkMessages_vtable` YAML to resolve the adjacent vtable entry
122	3. Confirm the semantic pair:
123	- setter writes `this + <member_offset>`
124	- adjacent getter returns `this + <member_offset>`
125	4. Generate a stable `func_sig` from the resolved getter body
126
127	This is robust because:
128	- The vtable adjacency (`SetIsForServer` followed by `GetIsForServer`) is stable and explicit
129	- The setter/getter pair must touch the same byte member
130	- The final YAML stores both the resolved function signature and the precise vtable metadata
131
132	## Output YAML Format
133
134	The output YAML filename depends on the platform:
135	- `networksystem.dll` -> `CNetworkMessages_GetIsForServer.windows.yaml`
136	- `libnetworksystem.so` -> `CNetworkMessages_GetIsForServer.linux.yaml`

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find-CNetworkMessages_GetIsForServer

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How to install find-CNetworkMessages_GetIsForServer?

hlnd2t/cs2_vibesignatures/find-cnetworkmessages_getisforserver

$npx -y skills add HLND2T/CS2_VibeSignatures --skill find-CNetworkMessages_GetIsForServer

Installs into the current project.

Summary

Files · 1

View on GitHub

SKILL.md

1	# Find CNetworkMessages_GetIsForServer
2
3	Locate `CNetworkMessages_GetIsForServer` vfunc in CS2 `networksystem.dll` or `libnetworksystem.so` using IDA Pro MCP tools.
4
5	## Method
6
7	### 1. Load CNetworkMessages_SetIsForServer from YAML
8
9	ALWAYS Use SKILL `/get-func-from-yaml` with `func_name=CNetworkMessages_SetIsForServer`.
10
11	If the skill returns an error, STOP and report to user.
12
13	Otherwise, extract:
14	- `func_va` of `CNetworkMessages_SetIsForServer`
15	- `vfunc_index`
16	- `vfunc_offset`
17
18	### 2. Load CNetworkMessages VTable from YAML
19
20	ALWAYS Use SKILL `/get-vtable-from-yaml` with `class_name=CNetworkMessages`.
21
22	If the skill returns an error, STOP and report to user.
23
24	Otherwise, extract:
25	- `vtable_numvfunc`
26	- `vtable_entries`
27
28	### 3. Resolve the Adjacent Getter Slot
29
30	Compute the candidate slot for `CNetworkMessages_GetIsForServer`:
31
32	- `target_vfunc_index = CNetworkMessages_SetIsForServer.vfunc_index + 1`
33	- `target_vfunc_offset = CNetworkMessages_SetIsForServer.vfunc_offset + 8`
34
35	Validate that `target_vfunc_index < vtable_numvfunc`, then read:
36
37	- `candidate_func_addr = CNetworkMessages_vtable[target_vfunc_index]`
38
39	This adjacent-slot rule is required because `GetIsForServer` immediately follows `SetIsForServer` in the `CNetworkMessages` vtable for `networksystem.dll` / `libnetworksystem.so`.
40
41	### 4. Decompile the Setter and Getter Candidate
42
43	Decompile both functions:
44
45	```text
46	mcp__ida-pro-mcp__decompile addr="<CNetworkMessages_SetIsForServer_func_va>"
47	mcp__ida-pro-mcp__decompile addr="<candidate_func_addr>"
48	```
49
50	First, confirm `CNetworkMessages_SetIsForServer` is the simple byte setter pattern:
51
52	```c
53	void __fastcall CNetworkMessages_SetIsForServer(__int64 a1, char a2)
54	{
55	(_BYTE )(a1 + 1374) = a2;
56	}
57	```
58
59	Windows assembly example:
60
61	```asm
62	mov [rcx+55Eh], dl
63	retn
64	```
65
66	Then confirm the adjacent vtable entry is the matching byte getter using the same member offset:
67
68	```c
69	__int64 __fastcall sub_1800CB790(__int64 a1)
70	{
71	return (unsigned __int8 )(a1 + 1374);
72	}
73	```
74
75	Windows assembly example:
76
77	```asm
78	movzx eax, byte ptr [rcx+55Eh]
79	retn
80	```
81
82	The exact member offset may change across game updates. The identification rule is:
83
84	1. `SetIsForServer` writes one byte to `this + <member_offset>`
85	2. `candidate_func_addr` is the next vtable entry (`index + 1`)
86	3. The candidate reads and returns one unsigned byte from the same `this + <member_offset>`
87
88	If all three conditions hold, the candidate is `CNetworkMessages_GetIsForServer`.
89
90	### 5. Generate Function Signature
91
92	ALWAYS Use SKILL `/generate-signature-for-function` with `addr=<candidate_func_addr>` to generate a robust and unique `func_sig` for `CNetworkMessages_GetIsForServer`.
93
94	Use the returned validated `func_sig` in the next step.
95
96	### 6. Write IDA Analysis Output as YAML
97
98	ALWAYS Use SKILL `/write-vfunc-as-yaml` to write the analysis results.
99
100	Required parameters:
101	- `func_name`: `CNetworkMessages_GetIsForServer`
102	- `func_addr`: `<candidate_func_addr>`
103	- `func_sig`: The validated signature from step 5
104	- `vfunc_sig`: `None`
105
106	VTable parameters:
107	- `vtable_name`: `CNetworkMessages`
108	- `vfunc_offset`: `<target_vfunc_offset>` in hex
109	- `vfunc_index`: `<target_vfunc_index>`
110
111	## Function Characteristics
112
113	- Purpose: Returns whether the `CNetworkMessages` instance is configured for server-side behavior
114	- Binary: `networksystem.dll` / `libnetworksystem.so`
115	- Parameters: `(this)` only
116	- Return value: An unsigned byte / boolean flag loaded from the same member written by `CNetworkMessages_SetIsForServer`
117
118	## Discovery Strategy
119
120	1. Reuse the existing `CNetworkMessages_SetIsForServer` YAML to obtain the authoritative slot index
121	2. Reuse the existing `CNetworkMessages_vtable` YAML to resolve the adjacent vtable entry
122	3. Confirm the semantic pair:
123	- setter writes `this + <member_offset>`
124	- adjacent getter returns `this + <member_offset>`
125	4. Generate a stable `func_sig` from the resolved getter body
126
127	This is robust because:
128	- The vtable adjacency (`SetIsForServer` followed by `GetIsForServer`) is stable and explicit
129	- The setter/getter pair must touch the same byte member
130	- The final YAML stores both the resolved function signature and the precise vtable metadata
131
132	## Output YAML Format
133
134	The output YAML filename depends on the platform:
135	- `networksystem.dll` -> `CNetworkMessages_GetIsForServer.windows.yaml`
136	- `libnetworksystem.so` -> `CNetworkMessages_GetIsForServer.linux.yaml`

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