dendrite/setup/mscs/msc2946/msc2946.go

570 lines
18 KiB
Go

// Copyright 2021 The Matrix.org Foundation C.I.C.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Package msc2946 'Spaces Summary' implements https://github.com/matrix-org/matrix-doc/pull/2946
package msc2946
import (
"context"
"encoding/json"
"fmt"
"net/http"
"strings"
"sync"
"time"
"github.com/gorilla/mux"
chttputil "github.com/matrix-org/dendrite/clientapi/httputil"
"github.com/matrix-org/dendrite/clientapi/jsonerror"
fs "github.com/matrix-org/dendrite/federationsender/api"
"github.com/matrix-org/dendrite/internal/hooks"
"github.com/matrix-org/dendrite/internal/httputil"
roomserver "github.com/matrix-org/dendrite/roomserver/api"
"github.com/matrix-org/dendrite/setup"
userapi "github.com/matrix-org/dendrite/userapi/api"
"github.com/matrix-org/gomatrixserverlib"
"github.com/matrix-org/util"
"github.com/tidwall/gjson"
)
const (
ConstCreateEventContentKey = "type"
ConstSpaceChildEventType = "m.space.child"
ConstSpaceParentEventType = "m.space.parent"
)
// Defaults sets the request defaults
func Defaults(r *gomatrixserverlib.MSC2946SpacesRequest) {
r.Limit = 2000
r.MaxRoomsPerSpace = -1
}
// Enable this MSC
func Enable(
base *setup.BaseDendrite, rsAPI roomserver.RoomserverInternalAPI, userAPI userapi.UserInternalAPI,
fsAPI fs.FederationSenderInternalAPI, keyRing gomatrixserverlib.JSONVerifier,
) error {
db, err := NewDatabase(&base.Cfg.MSCs.Database)
if err != nil {
return fmt.Errorf("Cannot enable MSC2946: %w", err)
}
hooks.Enable()
hooks.Attach(hooks.KindNewEventPersisted, func(headeredEvent interface{}) {
he := headeredEvent.(*gomatrixserverlib.HeaderedEvent)
hookErr := db.StoreReference(context.Background(), he)
if hookErr != nil {
util.GetLogger(context.Background()).WithError(hookErr).WithField("event_id", he.EventID()).Error(
"failed to StoreReference",
)
}
})
base.PublicClientAPIMux.Handle("/unstable/org.matrix.msc2946/rooms/{roomID}/spaces",
httputil.MakeAuthAPI("spaces", userAPI, spacesHandler(db, rsAPI, fsAPI, base.Cfg.Global.ServerName)),
).Methods(http.MethodPost, http.MethodOptions)
base.PublicFederationAPIMux.Handle("/unstable/org.matrix.msc2946/spaces/{roomID}", httputil.MakeExternalAPI(
"msc2946_fed_spaces", func(req *http.Request) util.JSONResponse {
fedReq, errResp := gomatrixserverlib.VerifyHTTPRequest(
req, time.Now(), base.Cfg.Global.ServerName, keyRing,
)
if fedReq == nil {
return errResp
}
// Extract the room ID from the request. Sanity check request data.
params, err := httputil.URLDecodeMapValues(mux.Vars(req))
if err != nil {
return util.ErrorResponse(err)
}
roomID := params["roomID"]
return federatedSpacesHandler(req.Context(), fedReq, roomID, db, rsAPI, fsAPI, base.Cfg.Global.ServerName)
},
)).Methods(http.MethodPost, http.MethodOptions)
return nil
}
func federatedSpacesHandler(
ctx context.Context, fedReq *gomatrixserverlib.FederationRequest, roomID string, db Database,
rsAPI roomserver.RoomserverInternalAPI, fsAPI fs.FederationSenderInternalAPI,
thisServer gomatrixserverlib.ServerName,
) util.JSONResponse {
inMemoryBatchCache := make(map[string]set)
var r gomatrixserverlib.MSC2946SpacesRequest
Defaults(&r)
if err := json.Unmarshal(fedReq.Content(), &r); err != nil {
return util.JSONResponse{
Code: http.StatusBadRequest,
JSON: jsonerror.BadJSON("The request body could not be decoded into valid JSON. " + err.Error()),
}
}
w := walker{
req: &r,
rootRoomID: roomID,
serverName: fedReq.Origin(),
thisServer: thisServer,
ctx: ctx,
db: db,
rsAPI: rsAPI,
fsAPI: fsAPI,
inMemoryBatchCache: inMemoryBatchCache,
}
res := w.walk()
return util.JSONResponse{
Code: 200,
JSON: res,
}
}
func spacesHandler(
db Database, rsAPI roomserver.RoomserverInternalAPI, fsAPI fs.FederationSenderInternalAPI,
thisServer gomatrixserverlib.ServerName,
) func(*http.Request, *userapi.Device) util.JSONResponse {
return func(req *http.Request, device *userapi.Device) util.JSONResponse {
inMemoryBatchCache := make(map[string]set)
// Extract the room ID from the request. Sanity check request data.
params, err := httputil.URLDecodeMapValues(mux.Vars(req))
if err != nil {
return util.ErrorResponse(err)
}
roomID := params["roomID"]
var r gomatrixserverlib.MSC2946SpacesRequest
Defaults(&r)
if resErr := chttputil.UnmarshalJSONRequest(req, &r); resErr != nil {
return *resErr
}
w := walker{
req: &r,
rootRoomID: roomID,
caller: device,
thisServer: thisServer,
ctx: req.Context(),
db: db,
rsAPI: rsAPI,
fsAPI: fsAPI,
inMemoryBatchCache: inMemoryBatchCache,
}
res := w.walk()
return util.JSONResponse{
Code: 200,
JSON: res,
}
}
}
type walker struct {
req *gomatrixserverlib.MSC2946SpacesRequest
rootRoomID string
caller *userapi.Device
serverName gomatrixserverlib.ServerName
thisServer gomatrixserverlib.ServerName
db Database
rsAPI roomserver.RoomserverInternalAPI
fsAPI fs.FederationSenderInternalAPI
ctx context.Context
// user ID|device ID|batch_num => event/room IDs sent to client
inMemoryBatchCache map[string]set
mu sync.Mutex
}
func (w *walker) roomIsExcluded(roomID string) bool {
for _, exclRoom := range w.req.ExcludeRooms {
if exclRoom == roomID {
return true
}
}
return false
}
func (w *walker) callerID() string {
if w.caller != nil {
return w.caller.UserID + "|" + w.caller.ID
}
return string(w.serverName)
}
func (w *walker) alreadySent(id string) bool {
w.mu.Lock()
defer w.mu.Unlock()
m, ok := w.inMemoryBatchCache[w.callerID()]
if !ok {
return false
}
return m[id]
}
func (w *walker) markSent(id string) {
w.mu.Lock()
defer w.mu.Unlock()
m := w.inMemoryBatchCache[w.callerID()]
if m == nil {
m = make(set)
}
m[id] = true
w.inMemoryBatchCache[w.callerID()] = m
}
func (w *walker) walk() *gomatrixserverlib.MSC2946SpacesResponse {
var res gomatrixserverlib.MSC2946SpacesResponse
// Begin walking the graph starting with the room ID in the request in a queue of unvisited rooms
unvisited := []string{w.rootRoomID}
processed := make(set)
for len(unvisited) > 0 {
roomID := unvisited[0]
unvisited = unvisited[1:]
// If this room has already been processed, skip. NB: do not remember this between calls
if processed[roomID] || roomID == "" {
continue
}
// Mark this room as processed.
processed[roomID] = true
// Collect rooms/events to send back (either locally or fetched via federation)
var discoveredRooms []gomatrixserverlib.MSC2946Room
var discoveredEvents []gomatrixserverlib.MSC2946StrippedEvent
// If we know about this room and the caller is authorised (joined/world_readable) then pull
// events locally
if w.roomExists(roomID) && w.authorised(roomID) {
// Get all `m.space.child` and `m.space.parent` state events for the room. *In addition*, get
// all `m.space.child` and `m.space.parent` state events which *point to* (via `state_key` or `content.room_id`)
// this room. This requires servers to store reverse lookups.
events, err := w.references(roomID)
if err != nil {
util.GetLogger(w.ctx).WithError(err).WithField("room_id", roomID).Error("failed to extract references for room")
continue
}
discoveredEvents = events
pubRoom := w.publicRoomsChunk(roomID)
roomType := ""
create := w.stateEvent(roomID, gomatrixserverlib.MRoomCreate, "")
if create != nil {
// escape the `.`s so gjson doesn't think it's nested
roomType = gjson.GetBytes(create.Content(), strings.ReplaceAll(ConstCreateEventContentKey, ".", `\.`)).Str
}
// Add the total number of events to `PublicRoomsChunk` under `num_refs`. Add `PublicRoomsChunk` to `rooms`.
discoveredRooms = append(discoveredRooms, gomatrixserverlib.MSC2946Room{
PublicRoom: *pubRoom,
NumRefs: len(discoveredEvents),
RoomType: roomType,
})
} else {
// attempt to query this room over federation, as either we've never heard of it before
// or we've left it and hence are not authorised (but info may be exposed regardless)
fedRes, err := w.federatedRoomInfo(roomID)
if err != nil {
util.GetLogger(w.ctx).WithError(err).WithField("room_id", roomID).Errorf("failed to query federated spaces")
continue
}
if fedRes != nil {
discoveredRooms = fedRes.Rooms
discoveredEvents = fedRes.Events
}
}
// If this room has not ever been in `rooms` (across multiple requests), send it now
for _, room := range discoveredRooms {
if !w.alreadySent(room.RoomID) && !w.roomIsExcluded(room.RoomID) {
res.Rooms = append(res.Rooms, room)
w.markSent(room.RoomID)
}
}
uniqueRooms := make(set)
// If this is the root room from the original request, insert all these events into `events` if
// they haven't been added before (across multiple requests).
if w.rootRoomID == roomID {
for _, ev := range discoveredEvents {
if !w.alreadySent(eventKey(&ev)) {
res.Events = append(res.Events, ev)
uniqueRooms[ev.RoomID] = true
uniqueRooms[spaceTargetStripped(&ev)] = true
w.markSent(eventKey(&ev))
}
}
} else {
// Else add them to `events` honouring the `limit` and `max_rooms_per_space` values. If either
// are exceeded, stop adding events. If the event has already been added, do not add it again.
numAdded := 0
for _, ev := range discoveredEvents {
if w.req.Limit > 0 && len(res.Events) >= w.req.Limit {
break
}
if w.req.MaxRoomsPerSpace > 0 && numAdded >= w.req.MaxRoomsPerSpace {
break
}
if w.alreadySent(eventKey(&ev)) {
continue
}
// Skip the room if it's part of exclude_rooms but ONLY IF the source matches, as we still
// want to catch arrows which point to excluded rooms.
if w.roomIsExcluded(ev.RoomID) {
continue
}
res.Events = append(res.Events, ev)
uniqueRooms[ev.RoomID] = true
uniqueRooms[spaceTargetStripped(&ev)] = true
w.markSent(eventKey(&ev))
// we don't distinguish between child state events and parent state events for the purposes of
// max_rooms_per_space, maybe we should?
numAdded++
}
}
// For each referenced room ID in the events being returned to the caller (both parent and child)
// add the room ID to the queue of unvisited rooms. Loop from the beginning.
for roomID := range uniqueRooms {
unvisited = append(unvisited, roomID)
}
}
return &res
}
func (w *walker) stateEvent(roomID, evType, stateKey string) *gomatrixserverlib.HeaderedEvent {
var queryRes roomserver.QueryCurrentStateResponse
tuple := gomatrixserverlib.StateKeyTuple{
EventType: evType,
StateKey: stateKey,
}
err := w.rsAPI.QueryCurrentState(w.ctx, &roomserver.QueryCurrentStateRequest{
RoomID: roomID,
StateTuples: []gomatrixserverlib.StateKeyTuple{tuple},
}, &queryRes)
if err != nil {
return nil
}
return queryRes.StateEvents[tuple]
}
func (w *walker) publicRoomsChunk(roomID string) *gomatrixserverlib.PublicRoom {
pubRooms, err := roomserver.PopulatePublicRooms(w.ctx, []string{roomID}, w.rsAPI)
if err != nil {
util.GetLogger(w.ctx).WithError(err).Error("failed to PopulatePublicRooms")
return nil
}
if len(pubRooms) == 0 {
return nil
}
return &pubRooms[0]
}
// federatedRoomInfo returns more of the spaces graph from another server. Returns nil if this was
// unsuccessful.
func (w *walker) federatedRoomInfo(roomID string) (*gomatrixserverlib.MSC2946SpacesResponse, error) {
// only do federated requests for client requests
if w.caller == nil {
return nil, nil
}
// extract events which point to this room ID and extract their vias
events, err := w.db.References(w.ctx, roomID)
if err != nil {
return nil, fmt.Errorf("failed to get References events: %w", err)
}
vias := make(set)
for _, ev := range events {
if ev.StateKeyEquals(roomID) {
// event points at this room, extract vias
content := struct {
Vias []string `json:"via"`
}{}
if err = json.Unmarshal(ev.Content(), &content); err != nil {
continue // silently ignore corrupted state events
}
for _, v := range content.Vias {
vias[v] = true
}
}
}
util.GetLogger(w.ctx).Infof("Querying federatedRoomInfo via %+v", vias)
ctx := context.Background()
// query more of the spaces graph using these servers
for serverName := range vias {
if serverName == string(w.thisServer) {
continue
}
res, err := w.fsAPI.MSC2946Spaces(ctx, gomatrixserverlib.ServerName(serverName), roomID, gomatrixserverlib.MSC2946SpacesRequest{
Limit: w.req.Limit,
MaxRoomsPerSpace: w.req.MaxRoomsPerSpace,
})
if err != nil {
util.GetLogger(w.ctx).WithError(err).Warnf("failed to call MSC2946Spaces on server %s", serverName)
continue
}
return &res, nil
}
return nil, nil
}
func (w *walker) roomExists(roomID string) bool {
var queryRes roomserver.QueryServerJoinedToRoomResponse
err := w.rsAPI.QueryServerJoinedToRoom(w.ctx, &roomserver.QueryServerJoinedToRoomRequest{
RoomID: roomID,
ServerName: w.thisServer,
}, &queryRes)
if err != nil {
util.GetLogger(w.ctx).WithError(err).Error("failed to QueryServerJoinedToRoom")
return false
}
// if the room exists but we aren't in the room then we might have stale data so we want to fetch
// it fresh via federation
return queryRes.RoomExists && queryRes.IsInRoom
}
// authorised returns true iff the user is joined this room or the room is world_readable
func (w *walker) authorised(roomID string) bool {
if w.caller != nil {
return w.authorisedUser(roomID)
}
return w.authorisedServer(roomID)
}
// authorisedServer returns true iff the server is joined this room or the room is world_readable
func (w *walker) authorisedServer(roomID string) bool {
// Check history visibility first
hisVisTuple := gomatrixserverlib.StateKeyTuple{
EventType: gomatrixserverlib.MRoomHistoryVisibility,
StateKey: "",
}
var queryRoomRes roomserver.QueryCurrentStateResponse
err := w.rsAPI.QueryCurrentState(w.ctx, &roomserver.QueryCurrentStateRequest{
RoomID: roomID,
StateTuples: []gomatrixserverlib.StateKeyTuple{
hisVisTuple,
},
}, &queryRoomRes)
if err != nil {
util.GetLogger(w.ctx).WithError(err).Error("failed to QueryCurrentState")
return false
}
hisVisEv := queryRoomRes.StateEvents[hisVisTuple]
if hisVisEv != nil {
hisVis, _ := hisVisEv.HistoryVisibility()
if hisVis == "world_readable" {
return true
}
}
// check if server is joined to the room
var queryRes fs.QueryJoinedHostServerNamesInRoomResponse
err = w.fsAPI.QueryJoinedHostServerNamesInRoom(w.ctx, &fs.QueryJoinedHostServerNamesInRoomRequest{
RoomID: roomID,
}, &queryRes)
if err != nil {
util.GetLogger(w.ctx).WithError(err).Error("failed to QueryJoinedHostServerNamesInRoom")
return false
}
for _, srv := range queryRes.ServerNames {
if srv == w.serverName {
return true
}
}
return false
}
// authorisedUser returns true iff the user is joined this room or the room is world_readable
func (w *walker) authorisedUser(roomID string) bool {
hisVisTuple := gomatrixserverlib.StateKeyTuple{
EventType: gomatrixserverlib.MRoomHistoryVisibility,
StateKey: "",
}
roomMemberTuple := gomatrixserverlib.StateKeyTuple{
EventType: gomatrixserverlib.MRoomMember,
StateKey: w.caller.UserID,
}
var queryRes roomserver.QueryCurrentStateResponse
err := w.rsAPI.QueryCurrentState(w.ctx, &roomserver.QueryCurrentStateRequest{
RoomID: roomID,
StateTuples: []gomatrixserverlib.StateKeyTuple{
hisVisTuple, roomMemberTuple,
},
}, &queryRes)
if err != nil {
util.GetLogger(w.ctx).WithError(err).Error("failed to QueryCurrentState")
return false
}
memberEv := queryRes.StateEvents[roomMemberTuple]
hisVisEv := queryRes.StateEvents[hisVisTuple]
if memberEv != nil {
membership, _ := memberEv.Membership()
if membership == gomatrixserverlib.Join {
return true
}
}
if hisVisEv != nil {
hisVis, _ := hisVisEv.HistoryVisibility()
if hisVis == "world_readable" {
return true
}
}
return false
}
// references returns all references pointing to or from this room.
func (w *walker) references(roomID string) ([]gomatrixserverlib.MSC2946StrippedEvent, error) {
events, err := w.db.References(w.ctx, roomID)
if err != nil {
return nil, err
}
el := make([]gomatrixserverlib.MSC2946StrippedEvent, 0, len(events))
for _, ev := range events {
// only return events that have a `via` key as per MSC1772
// else we'll incorrectly walk redacted events (as the link
// is in the state_key)
if gjson.GetBytes(ev.Content(), "via").Exists() {
strip := stripped(ev.Event)
if strip == nil {
continue
}
el = append(el, *strip)
}
}
return el, nil
}
type set map[string]bool
func stripped(ev *gomatrixserverlib.Event) *gomatrixserverlib.MSC2946StrippedEvent {
if ev.StateKey() == nil {
return nil
}
return &gomatrixserverlib.MSC2946StrippedEvent{
Type: ev.Type(),
StateKey: *ev.StateKey(),
Content: ev.Content(),
Sender: ev.Sender(),
RoomID: ev.RoomID(),
}
}
func eventKey(event *gomatrixserverlib.MSC2946StrippedEvent) string {
return event.RoomID + "|" + event.Type + "|" + event.StateKey
}
func spaceTargetStripped(event *gomatrixserverlib.MSC2946StrippedEvent) string {
if event.StateKey == "" {
return "" // no-op
}
switch event.Type {
case ConstSpaceParentEventType:
return event.StateKey
case ConstSpaceChildEventType:
return event.StateKey
}
return ""
}