04d438239d
## Summary
Server-side movement throttle that prevents speed hacking while accurately identifying cheaters with detection of lagging connections.
**Key features:**
- Credit buffer (200ms) absorbs timing jitter from legitimate players
- Movement queue handles larger bursts, draining at proper game-tick intervals
- RTT measurement distinguishes network lag from speed hacks
- Queue depth detection catches ACK-throttled speed hacks (going straight)
## How It Works
**Throttle** (prevention): Movements arriving too early either consume credit or get queued. The queue drains at
correct intervals, so speed hackers can't move faster regardless of what they send.
**Detection** (identification): Combines multiple signals to identify cheaters:
| Signal | What it catches |
|--------|-----------------|
| Queue depth ≥4 sustained | ACK-throttled speed hacks (client limits unacked moves to 5) |
| Movement rate >1.05x | Direction-change speed hacks where timing is visible |
| Stable RTT + high queue | Eliminates false positives from laggy players |
**RTT-Aware Logic:**
- Probes only sent to players actively moving (event-driven, not global loop)
- Stable low-latency + problems = suspicious
- Unstable/high-latency + problems = probably just lag, throttle handles it
## Configuration
```json
{
"movementThrottle.maxCredit": 200,
"movementThrottle.softQueueLimit": 6,
"movementThrottle.hardQueueLimit": 10,
"movementThrottle.debugLogging": false
}
```
39 lines
1 KiB
C#
39 lines
1 KiB
C#
using System.Collections.Generic;
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namespace Server.Network;
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public sealed class VendorSellList : Packet
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{
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public VendorSellList(Mobile shopkeeper, List<SellItemState> sis) : base(0x9E)
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{
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EnsureCapacity(256);
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Stream.Write(shopkeeper.Serial);
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Stream.Write((ushort)sis.Count);
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foreach (var state in sis)
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{
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Stream.Write(state.Item.Serial);
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Stream.Write((ushort)state.Item.ItemID);
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Stream.Write((ushort)state.Item.Hue);
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Stream.Write((ushort)state.Item.Amount);
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Stream.Write((ushort)state.Price);
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var name = string.IsNullOrWhiteSpace(state.Item.Name) ? state.Name ?? "" : state.Item.Name.Trim();
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Stream.Write((ushort)name.Length);
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Stream.WriteAsciiFixed(name, (ushort)name.Length);
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}
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}
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}
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public sealed class EndVendorSell : Packet
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{
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public EndVendorSell(Mobile vendor) : base(0x3B, 8)
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{
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Stream.Write((ushort)8); // length
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Stream.Write(vendor.Serial);
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Stream.Write((byte)0);
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}
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}
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