Bungeeguard Support (#382)

* Fixed Bungeeguard Support

- Fixed incomplete bungeeguard support
- Added bungeeguard options to config.yml

* Updated compatibility docs

- Added bungeeguard as a forwarding option

.web/docs/guide/compatibility.md

@@ -13,14 +13,14 @@ We highly recommend using [Paper](https://papermc.io/) for running a server in m
 Gate is tested with older and most recent versions of it.
 
 You can use `modern` forwarding (like Velocity does) if you run Paper
-1.13.2 or higher. If you use Paper 1.12.2 or lower, you must use `legacy` BungeeCord-style forwarding.
+1.13.2 or higher. If you use Paper 1.12.2 or lower, you can use `legacy` BungeeCord-style forwarding or the more secure `bungeeguard` [Bungeeguard](https://www.spigotmc.org/resources/bungeeguard.79601/) forwarding.
 
 ## Spigot
 
 Spigot is not well-tested with Gate.
 However, it is based on vanilla and as it is the base for Paper, it is relatively well-supported.
 
-Spigot does not support Gate/Velocity modern forwarding, but does support legacy BungeeCord forwarding.
+Spigot does not support Gate/Velocity modern forwarding, but does support legacy BungeeCord forwarding and the more secure Bungeeguard forwarding when using the [Bungeeguard](https://www.spigotmc.org/resources/bungeeguard.79601/) plugin.
 
 ## Forks of Spigot/Paper
 

config.yml

@@ -82,10 +82,12 @@ config:
   # This allows you to customize how player information such as IPs and UUIDs are forwarded to your server.
   # See the documentation for more information.
   forwarding:
-    # Options: legacy, none, velocity
+    # Options: legacy, none, bungeeguard, velocity
     mode: legacy
     # The secret used if the mode is velocity.
     #velocitySecret: secret_here
+    # The secret used if the mode is bungeeguard.
+    #bungeeGuardSecret: secret_here
   # Proxy protocol (HA-Proxy) determines whether Gate should support proxy protocol for players.
   # Do not enable this if you don't know what it is.
   proxyProtocol: false

pkg/edition/java/proxy/server.go

@@ -6,6 +6,7 @@ import (
 	"errors"
 	"fmt"
 	"go.minekube.com/gate/pkg/edition/java/forge/modernforge"
+	"go.minekube.com/gate/pkg/edition/java/profile"
 	"net"
 	"strings"
 	"sync"
@@ -495,7 +496,24 @@ func (s *serverConnection) createLegacyForwardingAddress() string {
 }
 
 func (s *serverConnection) createBungeeGuardForwardingAddress(secret string) string {
-	// TODO see https://github.com/PaperMC/Velocity/blob/e60e2063a87c8904b5ad89680aa51698b1ef8a0c/proxy/src/main/java/com/velocitypowered/proxy/connection/backend/VelocityServerConnection.java#L154
+	// Bungeeguard IP forwading is the same as the legacy Bungeecord IP forwarding but with an additional
+	// property in the profile properties that contains the bungeeguard-token.
+	playerIP := netutil.Host(s.player.RemoteAddr())
+	b := new(strings.Builder)
+	b.WriteString(s.server.ServerInfo().Addr().String())
+	const sep = "\000"
+	b.WriteString(sep)
+	b.WriteString(playerIP)
+	b.WriteString(sep)
+	b.WriteString(s.player.profile.ID.Undashed())
+	b.WriteString(sep)
+	props, err := json.Marshal(
+		append(s.player.profile.Properties, profile.Property{Name: "bungeeguard-token", Value: secret}))
+	if err != nil { // should never happen
+		panic(err)
+	}
+	b.WriteString(string(props)) // first convert props to string
+	return b.String()
 }
 
 // Returns the active backend server connection or false if inactive.

pkg/edition/java/proxy/session_client_auth.go

@@ -72,10 +72,6 @@ func (a *authSessionHandler) Activated() {
 	// Some connection types may need to alter the game profile.
 	gameProfile := *a.inbound.delegate.Type().AddGameProfileTokensIfRequired(
 		a.profile, a.config().Forwarding.Mode)
-
-	if a.config().Forwarding.Mode == config.BungeeGuardForwardingMode {
-		gameProfile.Properties = append(gameProfile.Properties, profile.Property{Name: "bungeeguard-token", Value: a.config().Forwarding.BungeeGuardSecret})
-	}
 	profileRequest := NewGameProfileRequestEvent(a.inbound, gameProfile, a.onlineMode)
 	a.eventMgr.Fire(profileRequest)
 	conn := a.inbound.delegate.MinecraftConn