From 7531b58ae2f97d3dd923e4c66df97bf0ef505ae4 Mon Sep 17 00:00:00 2001
From: Kamron Batman <3953314+kamronbatman@users.noreply.github.com>
Date: Thu, 7 Jan 2021 00:03:12 -0800
Subject: [PATCH] fix(network): Adds protocol extensions (#392)

- [X] Adds protocol extensions for CUO
---
 .../UOContent/Network/ProtocolExtensions.cs   | 179 ++++++++++++++++++
 1 file changed, 179 insertions(+)
 create mode 100644 Projects/UOContent/Network/ProtocolExtensions.cs

diff --git a/Projects/UOContent/Network/ProtocolExtensions.cs b/Projects/UOContent/Network/ProtocolExtensions.cs
new file mode 100644
index 000000000..ccfecb70a
--- /dev/null
+++ b/Projects/UOContent/Network/ProtocolExtensions.cs
@@ -0,0 +1,179 @@
+using System;
+using System.Buffers;
+using System.IO;
+using Server.Engines.PartySystem;
+using Server.Guilds;
+
+namespace Server.Network
+{
+    public static class ProtocolExtensions
+    {
+        private static readonly PacketHandler[] _handlers = new PacketHandler[0x100];
+
+        public static void Configure()
+        {
+            IncomingPackets.Register( 0xF0, 0, false, DecodeBundledPacket);
+            Register(0x00, true, QueryPartyMemberLocations);
+            Register(0x01, true, QueryGuildMemberLocations);
+        }
+
+        public static void Register(int packetID, bool ingame, OnPacketReceive onReceive)
+        {
+            _handlers[packetID] = new PacketHandler(packetID, 0, ingame, onReceive);
+        }
+
+        public static PacketHandler GetHandler(int packetID) =>
+            packetID >= 0 && packetID < _handlers.Length ? _handlers[packetID] : null;
+
+        public static void DecodeBundledPacket(NetState state, CircularBufferReader reader)
+        {
+            int packetID = reader.ReadByte();
+
+            PacketHandler ph = GetHandler(packetID);
+
+            if (ph == null)
+            {
+                return;
+            }
+
+            if (ph.Ingame && state.Mobile == null)
+            {
+                state.WriteConsole("Sent in-game packet (0xBFx{0:X2}) before having been attached to a mobile", packetID);
+                state.Dispose();
+            }
+            else if (ph.Ingame && state.Mobile.Deleted)
+            {
+                state.Dispose();
+            }
+            else
+            {
+                ph.OnReceive(state, reader);
+            }
+        }
+
+        public static void QueryGuildMemberLocations(NetState ns, CircularBufferReader reader)
+        {
+            Mobile from = ns.Mobile;
+
+            ns.SendGuildMemberLocations(from, from.Guild as Guild, reader.ReadBoolean());
+        }
+
+        public static void QueryPartyMemberLocations(NetState ns, CircularBufferReader reader)
+        {
+            Mobile from = ns.Mobile;
+            var party = Party.Get(from);
+
+            if (party != null)
+            {
+                ns.SendPartyMemberLocations(from, party);
+            }
+        }
+
+        public static void SendGuildMemberLocations(this NetState ns, Mobile from, Guild guild, bool sendLocations)
+        {
+            if (ns == null)
+            {
+                return;
+            }
+
+            var count = guild?.Members.Count ?? 0;
+            var maxLength = 9 + (count > 1 ? (count - 1) * (sendLocations ? 10 : 4) : 0);
+            var writer = new SpanWriter(stackalloc byte[maxLength]);
+            writer.Write((byte)0xF0); // Packet ID
+            writer.Seek(2, SeekOrigin.Current);
+            writer.Write((byte)0x02); // Command
+            writer.Write(count > 0 && sendLocations);
+
+            bool sendPacket = false;
+            for (var i = 0; i < count; i++)
+            {
+                var m = guild!.Members[i];
+
+                if (m?.NetState == null || m == from)
+                {
+                    continue;
+                }
+
+                if (sendLocations && Utility.InUpdateRange(from, m) && from.CanSee(m))
+                {
+                    continue;
+                }
+
+                sendPacket = true;
+                writer.Write(m.Serial);
+
+                if (sendLocations)
+                {
+                    writer.Write((short)m.X);
+                    writer.Write((short)m.Y);
+                    writer.Write((byte)(m.Map?.MapID ?? 0));
+
+                    if (m.Alive)
+                    {
+                        writer.Write((byte)(m.Hits * 100 / Math.Max(m.HitsMax, 1)));
+                    }
+                    else
+                    {
+                        writer.Write((byte)0);
+                    }
+                }
+            }
+
+            if (!sendPacket)
+            {
+                return;
+            }
+
+            writer.Write(0);
+            writer.WritePacketLength();
+            ns.Send(writer.Span);
+        }
+
+        public static void SendPartyMemberLocations(this NetState ns, Mobile from, Party party)
+        {
+            if (ns == null)
+            {
+                return;
+            }
+
+            var count = party?.Members.Count ?? 0;
+            var maxLength = 9 + (count > 1 ? (count - 1) * 9 : 0);
+            var writer = new SpanWriter(stackalloc byte[maxLength]);
+            writer.Write((byte)0xF0); // Packet ID
+            writer.Seek(2, SeekOrigin.Current);
+            writer.Write((byte)0x01); // Command
+
+            bool sendPacket = false;
+            for (var i = 0; i < count; i++)
+            {
+                var pmi = party!.Members[i];
+                Mobile mob = pmi?.Mobile;
+
+                if (mob?.NetState == null || mob == from)
+                {
+                    continue;
+                }
+
+                if (Utility.InUpdateRange(from, mob) && from.CanSee(mob))
+                {
+                    continue;
+                }
+
+                sendPacket = true;
+                writer.Write(mob.Serial);
+                writer.Write((short)mob.X);
+                writer.Write((short)mob.Y);
+                writer.Write((byte)(mob.Map?.MapID ?? 0));
+            }
+
+            if (!sendPacket)
+            {
+                return;
+            }
+
+            writer.Write(0);
+            writer.WritePacketLength();
+            ns.Send(writer.Span);
+        }
+    }
+}