> [!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
- Create BitMask256 struct with scalar operations (benchmarks showed AVX2 vectorization provides no benefit for this size)
- Refactor Map.cs to use BitMask256 for full Z range support (-128 to 127)
- Remove SectorSpawnCache struct, use BitMask256 directly in manager
- Update tests to use BitMask256 directly
- Remove unused test assertions for old 64-bit behavior
> [!IMPORTANT]
> **Developer Note**
> THIS IS A BREAKING CHANGE TO THE NEW API GUMP.
> Please give us feedback in [discord ](https://muo.gg/discord) if you have issues, need help, or have ideas for a better API change!
### Summary
* Adds support for size/style to dynamic/static builder.
* Drastically simplifies the dynamic/static builder api for AddHtml.
* Cleans up some legacy gump files.
New Jail System for MUO
----------------------------
Commands:
[jail [player] [reason] - Jail with time escalation per offense (5 to 120 minutes, GM only)
[unjail [player] - Manual release from jail regardless of time (GM only)
[jailinfo [player] - Check jail status and history (GM only)
[jailrecord - Checks their own jail record stats (player access)
Jail/Unjail can be found in the client view of a player in Admin Gump

Jail record gump, invoked with [jailrecord (30 second cooldown)

### Summary
Refactors ScheduledEvent and EventScheduler API to use TimeOnly so recurrence offset is explicit.
API:
```cs
public ScheduledEvent(
DateTime startAfter,
DateTime endOn,
TimeOnly time,
IRecurrencePattern recurrence,
TimeZoneInfo timeZone = null
)
```
Example:
```cs
// Schedule a daily event at 8:00 AM UTC
EventScheduler.DailyAt(
new DateTime(2024, 6, 1, 8, 0, 0, DateTimeKind.Utc),
() => Console.WriteLine("Daily event triggered!")
);
// Schedule a custom recurring event at 3:30 PM UTC every Monday
var recurrence = new WeeklyRecurrencePattern(1, DaysOfWeek.Monday);
EventScheduler.Shared.ScheduleEvent(
DateTime.UtcNow,
new TimeOnly(15, 30),
() => Console.WriteLine("Weekly Monday event!"),
recurrence
);
```
### Summary
* Adds an event scheduler.
* Adds conveniences for hourly, daily, weekly, biweekly, monthly, ordinal monthly, and yearly recurrences
Example:
```cs
var tz = TimeZoneInfo.FindSystemTimeZoneById("America/New_York");
// Specify the time of the day, and the day of the week you want it to occur. Make sure it is translated into Utc.
// The next occurrence will be _after_ the specified date/time.
var scheduledEvent = EventScheduler.WeeklyAt(new DateTime(2025, 04, 26, 17, 00, 00), StartEvent, tz);
void StartEvent()
{
World.Broadcast(0x30, false, "The event has started!");
}
Console.WriteLine("Event starts on {0}", scheduledEvent.NextOccurrence);
```
In this example, on _Saturday, May 3rd, 2025 @ 5pm ET_, the message "The event has started!" will be broadcasted.
### Summary
* Bumps to .NET 9 with updated dependencies
* Comparing a value type against null is no longer allowed
* CI/CD now uses the version specified in global.json
* Serialization generator updated to .NET 9 with bug fixes, fixes to turkish language, and parallelization
- Fixes double return issue with object property list that is causing corruption.
- Adds DEBUG_ARRAYPOOL define constant which will crash on double return or invalid return scenarios.
> [!IMPORTANT]
> **Developer Notes**
> STArrayPool rented arrays **MUST NOT** be returned **ONLY ONCE** otherwise there will be corruption from double-use.
> Use `DEBUG_ARRAYPOOL` to test potential broken STArrayPool use cases.
> [!NOTE]
> **Why can't I enable the debug all the time?**
> Other than the fact that it will crash due to bad code, the actual tracking system is highly detrimental/problematic for performance and memory consumption by creating objects that have a stack trace.
### Summary
- Fixed a bug caused by a bad assumption. If `m_List[index]` is sparse and null values are casted, the server does not crash.
- Fixed a bug where `PooledRefList.ToList` extension method returned the wrong list size.
### Summary
- Removes copying private setters
- Fixes duping containers
- Adds public `Dupe.DoDupe` functions for external scripts to hook into the existing logic.
### Summary
- Fixes an issue that causes CUO to crash due to bad string caching in static gumps
- Fixes wrong/bad 16bit html gump hues.
- Moves `C16232` (16-bit to 32-bit) and `C32216` (32-bit to 16-bit) to Utility class for broader use.
TODO:
- Some gumps have different 32bit (for string content) vs 16bit (for localized content) strings. Does this matter?
### Summary
- Fixes `[AdvancedSearch` being accessible by players 😱
- Adds `[GenCommands` to generate the same commands html page on https://muo.gg/commands.
- Fixes `[helpinfo` so all commands properly show up!
> [!WARNING]
> ### Developer Warning:
> Commands must now be registered in the `Configure` bootup phase.
> If a command is not registered early enough, it may not be available to systems like [helpinfo
> that cache their information.
> [!NOTE]
> ### Developer Note:
> Various commands related to generating content have been changed to _Developer_ and above access level.
### Screenshots
<img width="673" alt="image" src="https://github.com/modernuo/ModernUO/assets/3953314/b105b5c9-5eb4-4ace-93ff-1bfb31e7132f">
<img width="547" alt="image" src="https://github.com/modernuo/ModernUO/assets/3953314/e97487e8-47a5-4aa7-89cc-9fe3deda584d">
## Breaking Changes
* The Firewall and IP Limiter have been rewritten. Please read the notes carefully!
* `TcpServer.Instances` moved back to `NetState.Instances` - sorry - it was stupid to move it to begin with.
> [!Note]
> Sockets that fail the IP Limiter or Firewall will be immediately and forcibly disconnected.
> This means they will be stuck at "Verifying account..." if it was a real client.
### Summary
- Removes firewall wildcard support.
- Removes `AccessRestrictions`.
- Moves Firewall/IPLimiter to the core.
- Moves `TcpServer` to its own thread.
- Removes the `SocketConnect` and `SocketDisconnect` event sinks.
- Moves `Instances` back to `NetState.Instances`.
- Fixes a long standing bug with bad handling of duplicate listener addresses.
#### Firewall
The firewall has been completely rewritten. There is now an "Admin Firewall" which saves to the config file. Secondarily, there is an internal firewall used exclusively by the TcpServer while processing sockets. The Admin firewall mirrors it's additions/deletions to the internal firewall by adding requests to a queue.
> [!IMPORTANT]
> **Wildcard firewall entries, such as `X`, `*`, `?` are not allowed.**
> **Ranges in between IP classes or sextets are not allowed.**
> **Please make sure to use one of the following:**
> * IP Address - `192.168.1.1`
> * CIDR - `192.168.1.0/24`
> * Range - `192.168.1.1-192.168.1.100`
#### IP Limiter
The IP Limiter has been completely rewritten. The available configurations are:
```json
"ipLimiter.enable": "True",
"ipLimiter.maxConnectionsPerIP": 10,
"ipLimiter.clearConnectionAttemptsDuration": "00:00:00:10",
"ipLimiter.clearThrottledDuration": "00:00:02:00",
```
The IP Limiter is set up to prevent spamming connections from the same IP. Every time an IP connects, it is added to a connection list. After 10 attempts, the IP is added to the throttle list. To keep the system fast, the connection list is entirely wiped every 10 seconds, and the throttle list is entirely wiped every 2 minutes.
### Summary
- Works around a sneaky edge case bug in the JIT with stackalloc where sometimes the buffer is not zero'd.
- Fixes SendDisplayBoatHS
- Fixes sending health bars in the `SendEverything()` logic.
- Fixes a bug in sizing for some string helper functions.
### Developer Note
We are enabled `SkipLocalsInit` - do not rely on `stackalloc` to be zero'd. To zero the buffer, use `span.Clear();`
Closes#1606
### Summary
.NET 8 supports Xoroshiro 256** off the shelf and added Shuffle. Switching to that implementation.
### Developer Notes
* Removed many convenience methods that weren't used.
## BREAKING CHANGE
- Deletes `map.GetObjectsInRange` and `map.GetObejctsInBounds`
### Notes
Developers are expected to enumerate mobiles and items separately now using `map.GetMobilesInRange` and `map.GetItemsInRange`. This helps keep the code streamlined so we don't have to maintain multiple copies of ref struct enumerators that do the same thing.
### Fixes
- [X] Fixes bug with planks closing
- [X] Fixes issue with iterating items/mobiles from a null map
## Breaking Changes
Incoming packet registration signature has changed to:
```cs
delegate* void OnReceiveCallback(NetState state, SpanReader reader, int packetLength);
IncomingPackets.Register(int packetID, int length, bool ingame, OnReceiveCallback onReceive);
```
For example, an incoming packet handler signature would now look like this:
```cs
public static void SomeIncomingPacket(NetState state, SpanReader reader, int packetLength)
{
// Parse the data
}
```
## Summary
Updates the network Pipe class to use a mirrored memory technique. This technique involves mapping the same physical memory to two contiguous virtual memory spaces so the byte buffer appears duplicated. This allows writing to a double-sized array to wrap around without the need for the `CircularBuffer` classes.
In practice this allows us to use `Span<byte>` as if the buffer was a regular array.
### Bug Fixes
- [X] Fixes bad fixed length string parsing