From 042d25816150f3c1ea9d7e2c656325cf8e1d2b4e Mon Sep 17 00:00:00 2001
From: InfRandomness <infrandomness@gmail.com>
Date: Sun, 27 Feb 2022 23:08:47 +0000
Subject: [PATCH] Modify message catch-all arms

---
 CHANGELOG.md                           |  1 +
 server/src/sys/msg/character_screen.rs |  8 +++++++-
 server/src/sys/msg/general.rs          |  8 +++++++-
 server/src/sys/msg/in_game.rs          |  8 +++++++-
 server/src/sys/msg/terrain.rs          | 18 ++++++++++++++++--
 5 files changed, 38 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index a010a5b978..01bd5e395b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 
 - Improved site placement
+- [Server] Kick clients who send messages on the wrong stream
 
 ### Removed
 
diff --git a/server/src/sys/msg/character_screen.rs b/server/src/sys/msg/character_screen.rs
index 77f6ff35c4..296abb3da0 100644
--- a/server/src/sys/msg/character_screen.rs
+++ b/server/src/sys/msg/character_screen.rs
@@ -175,7 +175,13 @@ impl Sys {
                     );
                 }
             },
-            _ => tracing::error!("not a client_character_screen msg"),
+            _ => {
+                debug!("Kicking possibly misbehaving client due to invalid character request");
+                server_emitter.emit(ServerEvent::ClientDisconnect(
+                    entity,
+                    common::comp::DisconnectReason::NetworkError,
+                ));
+            },
         }
         Ok(())
     }
diff --git a/server/src/sys/msg/general.rs b/server/src/sys/msg/general.rs
index 9c56cc20ec..0527da7dcf 100644
--- a/server/src/sys/msg/general.rs
+++ b/server/src/sys/msg/general.rs
@@ -57,7 +57,13 @@ impl Sys {
                     common::comp::DisconnectReason::ClientRequested,
                 ));
             },
-            _ => tracing::error!("not a client_general msg"),
+            _ => {
+                debug!("Kicking possible misbehaving client due to invalid message request");
+                server_emitter.emit(ServerEvent::ClientDisconnect(
+                    entity,
+                    common::comp::DisconnectReason::NetworkError,
+                ));
+            },
         }
         Ok(())
     }
diff --git a/server/src/sys/msg/in_game.rs b/server/src/sys/msg/in_game.rs
index 5ee80a324a..0b1972eb1b 100644
--- a/server/src/sys/msg/in_game.rs
+++ b/server/src/sys/msg/in_game.rs
@@ -297,7 +297,13 @@ impl Sys {
             | ClientGeneral::TerrainChunkRequest { .. }
             | ClientGeneral::ChatMsg(_)
             | ClientGeneral::Command(..)
-            | ClientGeneral::Terminate => tracing::error!("not a client_in_game msg"),
+            | ClientGeneral::Terminate => {
+                debug!("Kicking possibly misbehaving client due to invalid client in game request");
+                server_emitter.emit(ServerEvent::ClientDisconnect(
+                    entity,
+                    common::comp::DisconnectReason::NetworkError,
+                ));
+            },
         }
         Ok(())
     }
diff --git a/server/src/sys/msg/terrain.rs b/server/src/sys/msg/terrain.rs
index 13d495cddf..e6b39c1808 100644
--- a/server/src/sys/msg/terrain.rs
+++ b/server/src/sys/msg/terrain.rs
@@ -1,6 +1,7 @@
 use crate::{client::Client, metrics::NetworkRequestMetrics, presence::Presence, ChunkRequest};
 use common::{
     comp::Pos,
+    event::{EventBus, ServerEvent},
     spiral::Spiral2d,
     terrain::{TerrainChunkSize, TerrainGrid},
     vol::RectVolSize,
@@ -8,7 +9,7 @@ use common::{
 use common_ecs::{Job, Origin, ParMode, Phase, System};
 use common_net::msg::{ClientGeneral, SerializedTerrainChunk, ServerGeneral};
 use rayon::iter::ParallelIterator;
-use specs::{Entities, Join, ParJoin, ReadExpect, ReadStorage, Write};
+use specs::{Entities, Join, ParJoin, Read, ReadExpect, ReadStorage, Write};
 use tracing::{debug, trace};
 
 /// This system will handle new messages from clients
@@ -17,6 +18,7 @@ pub struct Sys;
 impl<'a> System<'a> for Sys {
     type SystemData = (
         Entities<'a>,
+        Read<'a, EventBus<ServerEvent>>,
         ReadExpect<'a, TerrainGrid>,
         ReadExpect<'a, NetworkRequestMetrics>,
         Write<'a, Vec<ChunkRequest>>,
@@ -33,6 +35,7 @@ impl<'a> System<'a> for Sys {
         job: &mut Job<Self>,
         (
             entities,
+            server_event_bus,
             terrain,
             network_metrics,
             mut chunk_requests,
@@ -47,6 +50,8 @@ impl<'a> System<'a> for Sys {
             .map(|(entity, client, maybe_presence)| {
                 let mut chunk_requests = Vec::new();
                 let _ = super::try_recv_all(client, 5, |client, msg| {
+                    // TODO: Refactor things (https://gitlab.com/veloren/veloren/-/merge_requests/3245#note_856538056)
+                    let mut server_emitter = server_event_bus.emitter();
                     let presence = match maybe_presence {
                         Some(g) => g,
                         None => {
@@ -96,7 +101,16 @@ impl<'a> System<'a> for Sys {
                                 network_metrics.chunks_request_dropped.inc();
                             }
                         },
-                        _ => tracing::error!("not a client_terrain msg"),
+                        _ => {
+                            debug!(
+                                "Kicking possibly misbehaving client due to invalud terrain \
+                                 request"
+                            );
+                            server_emitter.emit(ServerEvent::ClientDisconnect(
+                                entity,
+                                common::comp::DisconnectReason::NetworkError,
+                            ));
+                        },
                     }
                     Ok(())
                 });