## 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
}
```
## Summary
- Adds `public virtual bool Murderer => Kills >= 5` property to `Mobile`, replacing ~30 scattered `Kills >= 5` / `Kills < 5` magic-number checks across the codebase
- `BaseCreature` overrides `Murderer` to also return `true` when `AlwaysMurderer` is set
- Updates `Corpse` serialization to v15, storing `_murderer` as a `bool` field (migrated from `int Kills >= 5` in earlier versions)
Summary
- Adds CLAUDE.md at repo root with 14 terse code audit rules (always loaded, low token cost)
- Adds pointer files for other AI tools: AGENTS.md (Codex), GEMINI.md, .github/COPILOT-INSTRUCTIONS.md (Copilot), .cursorrules (Cursor) — all redirect to CLAUDE.md as single source of truth
- Gitignores /.claude so personal AI config isn't distributed
- Moves Claude skills to dev-docs/claude-skills/ (opt-in, not auto-loaded)
- Adds 14 dev-docs covering codebase conventions
Code Audit Rules (in CLAUDE.md)
1. LINQ tiered rules (Tier 1 free, Tier 2 warm, Tier 3 forbidden)
2. No Console.WriteLine — use LogFactory.GetLogger()
3. No concurrency primitives in game code
4. No World.Mobiles/World.Items iteration
5. Clean up refs in OnDelete()/OnAfterDelete()
6. Cancel timers in OnDelete()/OnAfterDelete()
7. STArrayPool<T>.Shared not ArrayPool<T>.Shared
8. PooledRefList<T> not new List<T>() on hot paths
9. Serialization: partial class, [Constructible], no serialized TimerExecutionToken
10. No Task.Run/new Thread() in game code
11. Never assume era — ask which expansion
12. _camelCase fields, PascalCase properties/methods
13. No empty gumps — use DisplayTo() pattern
14. PropertyList string literals must be {} holes, cliloc-as-argument uses :#
### Summary
Updates all calls to container.EnumerateItems() to properly dispose of the underlying PooledRefQueue so that we are properly recycling pooled arrays.
### Summary
- Bump IORingGroup 1.0.0 → 1.0.1 — fixes a disconnect handling bug in the native ring layer
- Fix ghost NetStates — Dispose() set _running = false before checking it, so the "force immediate disconnect" path
was dead code. Capture wasRunning before clearing it, add [Obsolete] guard, and route internal callers through
DisposeInternal()
- Fix unauthenticated socket cleanup — graceful disconnect on unauthed connections could get stuck with pending sends;
now force-immediate after Disconnect() if DisconnectPending is already set
- Replace ConcurrentQueue<NetState> _disposed with Queue<NetState> — server is single-threaded; moved the field into
the Network partial class where it's consumed
- Move ConnectingSocketIdleLimit into the Network partial class alongside DisconnectUnattachedSockets
- Reset activity timer on receive, not just send — receiving data directly proves liveness instead of relying on the
ping→pong→send round-trip to reset the timer
- Move CheckAllAlive from Timer into Slice — the timer fired before I/O completions were processed, so after server
stalls (world saves), buffered client pings hadn't reset timestamps yet, causing false disconnects. Now runs at the
end of Slice() after all recv completions are handled
- Lower inactivity timeout 90s → 30s, check interval 90s → 5s — clients ping every ~1s, so 30s of silence is ~30
missed pings; worst-case detection drops from ~180s to ~35s
- Simplify CheckAlive — early-return when socket is null or alive; force-kill stuck DisconnectPending sockets
immediately instead of calling Disconnect() again
- Remove unused imports from GameEncryption.cs
### Summary
- Fix AccountGold gold duplication exploit: When AccountGold.Enabled was true, double-clicking a BankCheck deposited
the full value to the account but then continued creating physical gold piles for the same amount, duplicating the
value
- Fix Deposit/DepositUpTo partial deposit exploit: Both methods created new max-size gold piles and checks without
first filling existing partial stacks, wasting container slots and causing premature "bank full" failures that could
be leveraged to manipulate gold distribution
- Fix BagOfSending bank stacking: Gold and BankCheck items sent via BagOfSending now use Banker.Deposit for efficient
stacking instead of naive TryDropItem, which could fail on a full bank even when existing piles had room
- Improve gold/check deposit efficiency: Banker.Deposit and Banker.DepositUpTo now top off existing gold piles (up to
60k) and bank checks (up to 1M) before creating new items, maximizing use of available container slots
### Summary
Changes component verification so the order is now housing.bin, then txt files in client, then txt files in Data/Components folder on the server.
> [!IMPORTANT]
> **Breaking Changes**
> - DecodePacket and EncodePacket delegates replaced with IClientEncryption interface
> - NetState.Connection (Socket) replaced with internal RingSocket management
> - NetState.RecvPipe and NetState.SendPipe removed (buffers managed internally)
## Summary
Upgrades the networking stack from PollGroup-based I/O to io_uring, significantly improving I/O performance on Linux.
This also adds native client encryption support for encrypted UO clients.
## Major Changes
io_uring Networking Architecture
- Replaced PollGroup with IORingGroup for async socket I/O operations
- Removed Pipe.cs (mirrored ring buffer) and TcpServer.cs in favor of RingSocketManager
- Added NetState.Network.cs - centralized network infrastructure handling accept, recv, send, and disconnect
completions
- Added SocketHelper.cs - platform-specific socket utilities for raw socket handle operations (getpeername,
getsockname)
- Buffer management now handled by RingSocketManager with configurable slab allocation
### Client Encryption Support
- Added full encryption stack in Network/Encryption/:
- EncryptionConfig.cs - configurable encryption modes (None, Unencrypted, Encrypted, Both)
- EncryptionManager.cs - encryption detection and initialization for login/game packets
- LoginEncryption.cs - handles login packet encryption with version-derived keys
- GameEncryption.cs - handles game server encryption using Twofish
- TwofishEngine.cs - optimized Twofish block cipher implementation
- LoginKeys.cs - encryption key table for client versions
- IClientEncryption.cs - interface for client encryption implementations
### NetState Improvements
- Replaced Socket Connection with RingSocket _socket for managed socket lifecycle
- Changed from GCHandle polling to event-based completion processing
- Disconnect handling now properly waits for pending sends to flush
- Simplified connecting socket management using lazy queue removal
### Configuration
- New settings: network.encryptionMode and network.encryptionDebug
- Encryption mode flags: Unencrypted, Encrypted, or Both
### Dependencies
- Replaced PollGroup NuGet package with IORingGroup
- Linux requires liburing-dev / liburing-devel package
### Test plan
- Verify server starts and accepts connections on Linux with io_uring
- Verify server starts and accepts connections on Windows (fallback to IOCP)
- Test unencrypted client connections (ClassicUO with encryption disabled)
- Test encrypted client connections if available
- Verify graceful disconnect flushes pending data
- Confirm CI builds pass on all target platforms
## Summary
- Adds proper Latin1 encoding support, replacing CP1252 usage throughout the codebase
- Adds specialized, optimized string decoding methods with safe string filtering for each encoding type
- Filters invalid Unicode characters (C0/C1 control codes, non-characters) by removal rather than replacement since
the UO client renders nothing for these characters
- Fixes UTF-16 null terminator position handling to correctly advance by 2 bytes
## Changes
TextEncoding.cs
- Added SearchValues-based invalid byte/char detection for efficient filtering
- Added encoding-specific GetString methods: GetStringAscii, GetStringLatin1, GetStringUtf8, GetStringBigUni,
GetStringLittleUni
- Each method supports a safeString parameter for filtering invalid characters
- Little-endian UTF-16 uses direct memory cast for zero-copy decoding on LE systems
- Invalid characters are removed (not replaced with U+FFFD) since the client renders nothing for them
SpanReader.cs
- Added ReadLatin1() and ReadLatin1Safe() methods
- Rewrote encoding-specific read methods to use optimized TextEncoding.GetString* methods
- Fixed UTF-16 null terminator handling: position now correctly advances by byteLength (2) instead of 1
SpanWriter.cs
- Added WriteLatin1 and WriteLatin1Null methods
## Packet Updates
- Updated all packet code to use Latin1 encoding instead of CP1252
- Affected: account packets, equipment packets, menu packets, message packets, mobile packets, player packets, secure
trade packets, vendor packets, gump packets, book packets, mahjong packets
## Filtering Behavior
Invalid characters filtered in safe mode:
```
┌───────────────┬────────────────────────┐
│ Range │ Description │
├───────────────┼────────────────────────┤
│ 0x00-0x1F │ C0 control codes │
├───────────────┼────────────────────────┤
│ 0x7F │ DEL │
├───────────────┼────────────────────────┤
│ 0x80-0x9F │ C1 control codes │
├───────────────┼────────────────────────┤
│ 0xFFFE-0xFFFF │ Unicode non-characters │
└───────────────┴────────────────────────┘
```
Note: Surrogate pairs (0xD800-0xDFFF) are not filtered because proper validation requires context checking for paired
vs unpaired surrogates. The UO client renders nothing for these anyway.
## Test Plan
- All 631 Server.Tests pass
- Verified client rendering behavior using TestUnicodeGump command (pages 1-5)
- Confirmed U+FFFD, unpaired surrogates, and non-characters all render as blank in client
- Verified Latin1 characters (0xA0-0xFF) display correctly
- Verified C1 control codes (0x80-0x9F) are filtered and don't display
### Summary
* Fixes migration a socket from one poll group to another
* Fixes epoll/wepoll incompatibility
* Updates minimum support to Windows 10+ (Server 2019+)
* Enhances performance by supporting synchronous IOCP completions when available (up to 30% increase in performance).
Fix [add command failing with ambiguous type names + refactor for performance
### Problem
[add blight would fail with "No type with that name was found" because multiple types contain "blight" (e.g., Server.Items.Blight, Server.Ethics.Evil.Blight, Server.Items.BlightGrippedLongbow, Server.Items.QuiverOfBlight). The old code only succeeded when exactly one type matched the search regardless of constructability and inheriting Mobi les/Items.
### Solution
Exact match takes priority: If a type's name exactly equals the search string (case-insensitive), use it directly. Otherwise, show the AddGump with all partial matches.
- [add blight → Creates Blight (exact name match)
- [add bligh → Shows gump with Blight, BlightGrippedLongbow, etc.
### Refactoring
- CommandEventArgs context: Added GetContext<T>/SetContext<T> to pass resolved type through the command chain without method signature changes
- Removed TrySetupTarget duplication: Validation now happens only in ValidateArgs, eliminating redundant code paths
- Split type matching:
- ExactMatch(string) → Returns Type for exact name match (used by [add)
- MatchEmptyCtor(string) → Returns ConstructorInfo[] for gump display (empty-callable constructors only)
### Memory & Performance Improvements
| Optimization | Benefit |
|-------------------------------|----------------------------------------------------------------------------------------------|
| _mobileItemTypes cache | Filters Mobile/Item types once per assembly, reused on all subsequent searches |
| ReadOnlySpan<string> for args | Avoids string[] heap allocations when slicing arguments |
| ValueStringBuilder | Stack-allocated string building, avoids StringBuilder heap allocation |
| Single type resolution | Type resolved once in ValidateArgs, passed via context to Execute (was resolved 2-3x before) |
