Refactor room version support, add default room version config

src/client_server/capabilities.rs

@@ -1,9 +1,8 @@
-use crate::{Result, Ruma};
+use crate::{database::DatabaseGuard, Result, Ruma};
 use ruma::{
     api::client::discovery::get_capabilities::{
         self, Capabilities, RoomVersionStability, RoomVersionsCapability,
     },
-    RoomVersionId,
 };
 use std::collections::BTreeMap;
 
@@ -11,15 +10,26 @@ use std::collections::BTreeMap;
 ///
 /// Get information on the supported feature set and other relevent capabilities of this server.
 pub async fn get_capabilities_route(
+    db: DatabaseGuard,
     _body: Ruma<get_capabilities::v3::IncomingRequest>,
 ) -> Result<get_capabilities::v3::Response> {
     let mut available = BTreeMap::new();
-    available.insert(RoomVersionId::V5, RoomVersionStability::Stable);
-    available.insert(RoomVersionId::V6, RoomVersionStability::Stable);
+    if db.globals.allow_unstable_room_versions() {
+        for room_version in &db.globals.unstable_room_versions {
+            available.insert(room_version.clone(), RoomVersionStability::Stable);
+        }
+    } else {
+        for room_version in &db.globals.unstable_room_versions {
+            available.insert(room_version.clone(), RoomVersionStability::Unstable);
+        }
+    }
+    for room_version in &db.globals.stable_room_versions {
+        available.insert(room_version.clone(), RoomVersionStability::Stable);
+    }
 
     let mut capabilities = Capabilities::new();
     capabilities.room_versions = RoomVersionsCapability {
-        default: RoomVersionId::V6,
+        default: db.globals.default_room_version(),
         available,
     };
 

src/client_server/membership.rs

@@ -492,7 +492,7 @@ async fn join_room_by_id_helper(
                     federation::membership::prepare_join_event::v1::Request {
                         room_id,
                         user_id: sender_user,
-                        ver: &[RoomVersionId::V5, RoomVersionId::V6],
+                        ver: &db.globals.supported_room_versions(),
                     },
                 )
                 .await;
@@ -507,11 +507,7 @@ async fn join_room_by_id_helper(
         let (make_join_response, remote_server) = make_join_response_and_server?;
 
         let room_version = match make_join_response.room_version {
-            Some(room_version)
-                if room_version == RoomVersionId::V5 || room_version == RoomVersionId::V6 =>
-            {
-                room_version
-            }
+            Some(room_version) if db.rooms.is_supported_version(&db, &room_version) => room_version,
             _ => return Err(Error::BadServerResponse("Room version is not supported")),
         };
 
@@ -828,9 +824,12 @@ pub(crate) async fn invite_helper<'a>(
                 })
                 .transpose()?;
 
-            // If there was no create event yet, assume we are creating a version 6 room right now
+            // If there was no create event yet, assume we are creating a room with the default
+            // version right now
             let room_version_id = create_event_content
-                .map_or(RoomVersionId::V6, |create_event| create_event.room_version);
+                .map_or(db.globals.default_room_version(), |create_event| {
+                    create_event.room_version
+                });
             let room_version =
                 RoomVersion::new(&room_version_id).expect("room version is supported");
 

src/client_server/room.rs

@@ -23,7 +23,7 @@ use ruma::{
     },
     int,
     serde::{CanonicalJsonObject, JsonObject},
-    RoomAliasId, RoomId, RoomVersionId,
+    RoomAliasId, RoomId,
 };
 use serde_json::{json, value::to_raw_value};
 use std::{cmp::max, collections::BTreeMap, sync::Arc};
@@ -100,7 +100,7 @@ pub async fn create_room_route(
 
     let room_version = match body.room_version.clone() {
         Some(room_version) => {
-            if room_version == RoomVersionId::V5 || room_version == RoomVersionId::V6 {
+            if db.rooms.is_supported_version(&db, &room_version) {
                 room_version
             } else {
                 return Err(Error::BadRequest(
@@ -109,7 +109,7 @@ pub async fn create_room_route(
                 ));
             }
         }
-        None => RoomVersionId::V6,
+        None => db.globals.default_room_version(),
     };
 
     let content = match &body.creation_content {
@@ -484,7 +484,7 @@ pub async fn upgrade_room_route(
 ) -> Result<upgrade_room::v3::Response> {
     let sender_user = body.sender_user.as_ref().expect("user is authenticated");
 
-    if !matches!(body.new_version, RoomVersionId::V5 | RoomVersionId::V6) {
+    if !db.rooms.is_supported_version(&db, &body.new_version) {
         return Err(Error::BadRequest(
             ErrorKind::UnsupportedRoomVersion,
             "This server does not support that room version.",

src/config.rs

@@ -4,7 +4,7 @@ use std::{
     net::{IpAddr, Ipv4Addr},
 };
 
-use ruma::ServerName;
+use ruma::{RoomVersionId, ServerName};
 use serde::{de::IgnoredAny, Deserialize};
 use tracing::warn;
 
@@ -46,6 +46,10 @@ pub struct Config {
     pub allow_federation: bool,
     #[serde(default = "true_fn")]
     pub allow_room_creation: bool,
+    #[serde(default = "true_fn")]
+    pub allow_unstable_room_versions: bool,
+    #[serde(default = "default_default_room_version")]
+    pub default_room_version: RoomVersionId,
     #[serde(default = "false_fn")]
     pub allow_jaeger: bool,
     #[serde(default = "false_fn")]
@@ -246,3 +250,8 @@ fn default_log() -> String {
 fn default_turn_ttl() -> u64 {
     60 * 60 * 24
 }
+
+// I know, it's a great name
+fn default_default_room_version() -> RoomVersionId {
+    RoomVersionId::V6
+}

src/database/globals.rs

@@ -4,7 +4,8 @@ use ruma::{
         client::sync::sync_events,
         federation::discovery::{ServerSigningKeys, VerifyKey},
     },
-    DeviceId, EventId, MilliSecondsSinceUnixEpoch, RoomId, ServerName, ServerSigningKeyId, UserId,
+    DeviceId, EventId, MilliSecondsSinceUnixEpoch, RoomId, RoomVersionId, ServerName,
+    ServerSigningKeyId, UserId,
 };
 use std::{
     collections::{BTreeMap, HashMap},
@@ -41,6 +42,8 @@ pub struct Globals {
     jwt_decoding_key: Option<jsonwebtoken::DecodingKey<'static>>,
     federation_client: reqwest::Client,
     default_client: reqwest::Client,
+    pub stable_room_versions: Vec<RoomVersionId>,
+    pub unstable_room_versions: Vec<RoomVersionId>,
     pub(super) server_signingkeys: Arc<dyn Tree>,
     pub bad_event_ratelimiter: Arc<RwLock<HashMap<Box<EventId>, RateLimitState>>>,
     pub bad_signature_ratelimiter: Arc<RwLock<HashMap<Vec<String>, RateLimitState>>>,
@@ -145,6 +148,11 @@ impl Globals {
             })
             .build()?;
 
+        // Supported and stable room versions
+        let stable_room_versions = vec![RoomVersionId::V6];
+        // Experimental, partially supported room versions
+        let unstable_room_versions = vec![RoomVersionId::V5];
+
         let s = Self {
             globals,
             config,
@@ -162,6 +170,8 @@ impl Globals {
             default_client,
             server_signingkeys,
             jwt_decoding_key,
+            stable_room_versions,
+            unstable_room_versions,
             bad_event_ratelimiter: Arc::new(RwLock::new(HashMap::new())),
             bad_signature_ratelimiter: Arc::new(RwLock::new(HashMap::new())),
             servername_ratelimiter: Arc::new(RwLock::new(HashMap::new())),
@@ -232,6 +242,22 @@ impl Globals {
         self.config.allow_room_creation
     }
 
+    pub fn allow_unstable_room_versions(&self) -> bool {
+        self.config.allow_unstable_room_versions
+    }
+
+    pub fn default_room_version(&self) -> RoomVersionId {
+        if self
+            .supported_room_versions()
+            .contains(&self.config.default_room_version.clone())
+        {
+            self.config.default_room_version.clone()
+        } else {
+            error!("Room version in config isn't supported, falling back to Version 6");
+            RoomVersionId::V6
+        }
+    }
+
     pub fn trusted_servers(&self) -> &[Box<ServerName>] {
         &self.config.trusted_servers
     }
@@ -268,6 +294,19 @@ impl Globals {
         &self.config.emergency_password
     }
 
+    pub fn supported_room_versions(&self) -> Vec<RoomVersionId> {
+        let mut room_versions: Vec<RoomVersionId> = vec![];
+        self.stable_room_versions
+            .iter()
+            .for_each(|room_version| room_versions.push(room_version.clone()));
+        if self.allow_unstable_room_versions() {
+            self.unstable_room_versions
+                .iter()
+                .for_each(|room_version| room_versions.push(room_version.clone()));
+        };
+        room_versions
+    }
+
     /// TODO: the key valid until timestamp is only honored in room version > 4
     /// Remove the outdated keys and insert the new ones.
     ///

src/database/rooms.rs

@@ -133,6 +133,12 @@ pub struct Rooms {
 }
 
 impl Rooms {
+    /// Returns true if a given room version is supported
+    #[tracing::instrument(skip(self, db))]
+    pub fn is_supported_version(&self, db: &Database, room_version: &RoomVersionId) -> bool {
+        db.globals.supported_room_versions().contains(room_version)
+    }
+
     /// Builds a StateMap by iterating over all keys that start
     /// with state_hash, this gives the full state for the given state_hash.
     #[tracing::instrument(skip(self))]
@@ -1839,9 +1845,13 @@ impl Rooms {
             })
             .transpose()?;
 
-        // If there was no create event yet, assume we are creating a version 6 room right now
+
+        // If there was no create event yet, assume we are creating a room with the default
+        // version right now
         let room_version_id = create_event_content
-            .map_or(RoomVersionId::V6, |create_event| create_event.room_version);
+            .map_or(db.globals.default_room_version(), |create_event| {
+                create_event.room_version
+            });
         let room_version = RoomVersion::new(&room_version_id).expect("room version is supported");
 
         let auth_events =
@@ -2672,9 +2682,7 @@ impl Rooms {
         let (make_leave_response, remote_server) = make_leave_response_and_server?;
 
         let room_version_id = match make_leave_response.room_version {
-            Some(version) if version == RoomVersionId::V5 || version == RoomVersionId::V6 => {
-                version
-            }
+            Some(version) if self.is_supported_version(&db, &version) => version,
             _ => return Err(Error::BadServerResponse("Room version is not supported")),
         };
 

src/server_server.rs

@@ -2639,9 +2639,12 @@ pub async fn create_join_event_template_route(
         })
         .transpose()?;
 
-    // If there was no create event yet, assume we are creating a version 6 room right now
-    let room_version_id =
-        create_event_content.map_or(RoomVersionId::V6, |create_event| create_event.room_version);
+    // If there was no create event yet, assume we are creating a room with the default version
+    // right now
+    let room_version_id = create_event_content
+        .map_or(db.globals.default_room_version(), |create_event| {
+            create_event.room_version
+        });
     let room_version = RoomVersion::new(&room_version_id).expect("room version is supported");
 
     if !body.ver.contains(&room_version_id) {
@@ -2943,7 +2946,7 @@ pub async fn create_invite_route(
 
     acl_check(sender_servername, &body.room_id, &db)?;
 
-    if body.room_version != RoomVersionId::V5 && body.room_version != RoomVersionId::V6 {
+    if !db.rooms.is_supported_version(&db, &body.room_version) {
         return Err(Error::BadRequest(
             ErrorKind::IncompatibleRoomVersion {
                 room_version: body.room_version.clone(),