dendrite/syncapi/internal/keychange.go

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// Copyright 2020 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 internal
import (
"context"
"strings"
keytypes "github.com/matrix-org/dendrite/userapi/types"
"github.com/matrix-org/gomatrixserverlib"
"github.com/matrix-org/gomatrixserverlib/spec"
"github.com/matrix-org/util"
"github.com/sirupsen/logrus"
"github.com/tidwall/gjson"
roomserverAPI "github.com/matrix-org/dendrite/roomserver/api"
"github.com/matrix-org/dendrite/syncapi/storage"
"github.com/matrix-org/dendrite/syncapi/synctypes"
"github.com/matrix-org/dendrite/syncapi/types"
"github.com/matrix-org/dendrite/userapi/api"
)
// DeviceOTKCounts adds one-time key counts to the /sync response
func DeviceOTKCounts(ctx context.Context, keyAPI api.SyncKeyAPI, userID, deviceID string, res *types.Response) error {
var queryRes api.QueryOneTimeKeysResponse
_ = keyAPI.QueryOneTimeKeys(ctx, &api.QueryOneTimeKeysRequest{
UserID: userID,
DeviceID: deviceID,
}, &queryRes)
if queryRes.Error != nil {
return queryRes.Error
}
res.DeviceListsOTKCount = queryRes.Count.KeyCount
return nil
}
// DeviceListCatchup fills in the given response for the given user ID to bring it up-to-date with device lists. hasNew=true if the response
// was filled in, else false if there are no new device list changes because there is nothing to catch up on. The response MUST
// be already filled in with join/leave information.
func DeviceListCatchup(
ctx context.Context, db storage.SharedUsers, userAPI api.SyncKeyAPI, rsAPI roomserverAPI.SyncRoomserverAPI,
userID string, res *types.Response, from, to types.StreamPosition,
) (newPos types.StreamPosition, hasNew bool, err error) {
// Track users who we didn't track before but now do by virtue of sharing a room with them, or not.
newlyJoinedRooms := joinedRooms(res, userID)
newlyLeftRooms := leftRooms(res)
if len(newlyJoinedRooms) > 0 || len(newlyLeftRooms) > 0 {
changed, left, err := TrackChangedUsers(ctx, rsAPI, userID, newlyJoinedRooms, newlyLeftRooms)
if err != nil {
return to, false, err
}
res.DeviceLists.Changed = changed
res.DeviceLists.Left = left
hasNew = len(changed) > 0 || len(left) > 0
}
// now also track users who we already share rooms with but who have updated their devices between the two tokens
offset := keytypes.OffsetOldest
toOffset := keytypes.OffsetNewest
if to > 0 && to > from {
toOffset = int64(to)
}
if from > 0 {
offset = int64(from)
}
var queryRes api.QueryKeyChangesResponse
_ = userAPI.QueryKeyChanges(ctx, &api.QueryKeyChangesRequest{
Offset: offset,
ToOffset: toOffset,
}, &queryRes)
if queryRes.Error != nil {
// don't fail the catchup because we may have got useful information by tracking membership
util.GetLogger(ctx).WithError(queryRes.Error).Error("QueryKeyChanges failed")
return to, hasNew, nil
}
// Work out which user IDs we care about — that includes those in the original request,
// the response from QueryKeyChanges (which includes ALL users who have changed keys)
// as well as every user who has a join or leave event in the current sync response. We
// will request information about which rooms these users are joined to, so that we can
// see if we still share any rooms with them.
joinUserIDs, leaveUserIDs := membershipEvents(res)
queryRes.UserIDs = append(queryRes.UserIDs, joinUserIDs...)
queryRes.UserIDs = append(queryRes.UserIDs, leaveUserIDs...)
queryRes.UserIDs = util.UniqueStrings(queryRes.UserIDs)
sharedUsersMap := filterSharedUsers(ctx, db, userID, queryRes.UserIDs)
userSet := make(map[string]bool)
for _, userID := range res.DeviceLists.Changed {
userSet[userID] = true
}
for userID, count := range sharedUsersMap {
if !userSet[userID] && count > 0 {
res.DeviceLists.Changed = append(res.DeviceLists.Changed, userID)
hasNew = true
userSet[userID] = true
}
}
// Finally, add in users who have joined or left.
// TODO: This is sub-optimal because we will add users to `changed` even if we already shared a room with them.
for _, userID := range joinUserIDs {
if !userSet[userID] && sharedUsersMap[userID] > 0 {
res.DeviceLists.Changed = append(res.DeviceLists.Changed, userID)
hasNew = true
userSet[userID] = true
}
}
for _, userID := range leaveUserIDs {
if sharedUsersMap[userID] == 0 {
// we no longer share a room with this user when they left, so add to left list.
res.DeviceLists.Left = append(res.DeviceLists.Left, userID)
}
}
util.GetLogger(ctx).WithFields(logrus.Fields{
"user_id": userID,
"from": offset,
"to": toOffset,
"response_offset": queryRes.Offset,
}).Tracef("QueryKeyChanges request result: %+v", res.DeviceLists)
return types.StreamPosition(queryRes.Offset), hasNew, nil
}
// TrackChangedUsers calculates the values of device_lists.changed|left in the /sync response.
func TrackChangedUsers(
ctx context.Context, rsAPI roomserverAPI.SyncRoomserverAPI, userID string, newlyJoinedRooms, newlyLeftRooms []string,
) (changed, left []string, err error) {
// process leaves first, then joins afterwards so if we join/leave/join/leave we err on the side of including users.
// Leave algorithm:
// - Get set of users and number of times they appear in rooms prior to leave. - QuerySharedUsersRequest with 'IncludeRoomID'.
// - Get users in newly left room. - QueryCurrentState
// - Loop set of users and decrement by 1 for each user in newly left room.
// - If count=0 then they share no more rooms so inform BOTH parties of this via 'left'=[...] in /sync.
var queryRes roomserverAPI.QuerySharedUsersResponse
var stateRes roomserverAPI.QueryBulkStateContentResponse
if len(newlyLeftRooms) > 0 {
err = rsAPI.QuerySharedUsers(ctx, &roomserverAPI.QuerySharedUsersRequest{
UserID: userID,
IncludeRoomIDs: newlyLeftRooms,
}, &queryRes)
if err != nil {
return nil, nil, err
}
err = rsAPI.QueryBulkStateContent(ctx, &roomserverAPI.QueryBulkStateContentRequest{
RoomIDs: newlyLeftRooms,
StateTuples: []gomatrixserverlib.StateKeyTuple{
{
EventType: spec.MRoomMember,
StateKey: "*",
},
},
AllowWildcards: true,
}, &stateRes)
if err != nil {
return nil, nil, err
}
for _, state := range stateRes.Rooms {
for tuple, membership := range state {
if membership != spec.Join {
continue
}
queryRes.UserIDsToCount[tuple.StateKey]--
}
}
for userID, count := range queryRes.UserIDsToCount {
if count <= 0 {
left = append(left, userID) // left is returned
}
}
}
// Join algorithm:
// - Get the set of all joined users prior to joining room - QuerySharedUsersRequest with 'ExcludeRoomID'.
// - Get users in newly joined room - QueryCurrentState
// - Loop set of users in newly joined room, do they appear in the set of users prior to joining?
// - If yes: then they already shared a room in common, do nothing.
// - If no: then they are a brand new user so inform BOTH parties of this via 'changed=[...]'
err = rsAPI.QuerySharedUsers(ctx, &roomserverAPI.QuerySharedUsersRequest{
UserID: userID,
ExcludeRoomIDs: newlyJoinedRooms,
}, &queryRes)
if err != nil {
return nil, left, err
}
err = rsAPI.QueryBulkStateContent(ctx, &roomserverAPI.QueryBulkStateContentRequest{
RoomIDs: newlyJoinedRooms,
StateTuples: []gomatrixserverlib.StateKeyTuple{
{
EventType: spec.MRoomMember,
StateKey: "*",
},
},
AllowWildcards: true,
}, &stateRes)
if err != nil {
return nil, left, err
}
for _, state := range stateRes.Rooms {
for tuple, membership := range state {
if membership != spec.Join {
continue
}
// new user who we weren't previously sharing rooms with
if _, ok := queryRes.UserIDsToCount[tuple.StateKey]; !ok {
changed = append(changed, tuple.StateKey) // changed is returned
}
}
}
return changed, left, nil
}
// filterSharedUsers takes a list of remote users whose keys have changed and filters
// it down to include only users who the requesting user shares a room with.
func filterSharedUsers(
ctx context.Context, db storage.SharedUsers, userID string, usersWithChangedKeys []string,
) map[string]int {
sharedUsersMap := make(map[string]int, len(usersWithChangedKeys))
for _, changedUserID := range usersWithChangedKeys {
sharedUsersMap[changedUserID] = 0
if changedUserID == userID {
// We forcibly put ourselves in this list because we should be notified about our own device updates
// and if we are in 0 rooms then we don't technically share any room with ourselves so we wouldn't
// be notified about key changes.
sharedUsersMap[userID] = 1
}
}
sharedUsers, err := db.SharedUsers(ctx, userID, usersWithChangedKeys)
if err != nil {
util.GetLogger(ctx).WithError(err).Errorf("db.SharedUsers failed: %s", err)
// default to all users so we do needless queries rather than miss some important device update
return sharedUsersMap
}
for _, userID := range sharedUsers {
sharedUsersMap[userID]++
}
return sharedUsersMap
}
func joinedRooms(res *types.Response, userID string) []string {
var roomIDs []string
for roomID, join := range res.Rooms.Join {
// we would expect to see our join event somewhere if we newly joined the room.
// Normal events get put in the join section so it's not enough to know the room ID is present in 'join'.
newlyJoined := membershipEventPresent(join.State.Events, userID)
if newlyJoined {
roomIDs = append(roomIDs, roomID)
continue
}
newlyJoined = membershipEventPresent(join.Timeline.Events, userID)
if newlyJoined {
roomIDs = append(roomIDs, roomID)
}
}
return roomIDs
}
func leftRooms(res *types.Response) []string {
roomIDs := make([]string, len(res.Rooms.Leave))
i := 0
for roomID := range res.Rooms.Leave {
roomIDs[i] = roomID
i++
}
return roomIDs
}
func membershipEventPresent(events []synctypes.ClientEvent, userID string) bool {
for _, ev := range events {
// it's enough to know that we have our member event here, don't need to check membership content
// as it's implied by being in the respective section of the sync response.
if ev.Type == spec.MRoomMember && ev.StateKey != nil && *ev.StateKey == userID {
// ignore e.g. join -> join changes
if gjson.GetBytes(ev.Unsigned, "prev_content.membership").Str == gjson.GetBytes(ev.Content, "membership").Str {
continue
}
return true
}
}
return false
}
// returns the user IDs of anyone joining or leaving a room in this response. These users will be added to
// the 'changed' property because of https://matrix.org/docs/spec/client_server/r0.6.1#id84
// "For optimal performance, Alice should be added to changed in Bob's sync only when she adds a new device,
// or when Alice and Bob now share a room but didn't share any room previously. However, for the sake of simpler
// logic, a server may add Alice to changed when Alice and Bob share a new room, even if they previously already shared a room."
func membershipEvents(res *types.Response) (joinUserIDs, leaveUserIDs []string) {
for _, room := range res.Rooms.Join {
for _, ev := range room.Timeline.Events {
if ev.Type == spec.MRoomMember && ev.StateKey != nil {
if strings.Contains(string(ev.Content), `"join"`) {
joinUserIDs = append(joinUserIDs, *ev.StateKey)
} else if strings.Contains(string(ev.Content), `"invite"`) {
joinUserIDs = append(joinUserIDs, *ev.StateKey)
} else if strings.Contains(string(ev.Content), `"leave"`) {
leaveUserIDs = append(leaveUserIDs, *ev.StateKey)
} else if strings.Contains(string(ev.Content), `"ban"`) {
leaveUserIDs = append(leaveUserIDs, *ev.StateKey)
}
}
}
}
return
}