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dendrite/roomserver/internal/perform/perform_invite.go
2023-05-09 22:46:49 +00:00

285 lines
11 KiB
Go

// 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 perform
import (
"context"
"fmt"
federationAPI "github.com/matrix-org/dendrite/federationapi/api"
"github.com/matrix-org/dendrite/roomserver/api"
"github.com/matrix-org/dendrite/roomserver/internal/helpers"
"github.com/matrix-org/dendrite/roomserver/internal/input"
"github.com/matrix-org/dendrite/roomserver/state"
"github.com/matrix-org/dendrite/roomserver/storage"
"github.com/matrix-org/dendrite/roomserver/storage/shared"
"github.com/matrix-org/dendrite/roomserver/types"
"github.com/matrix-org/dendrite/setup/config"
"github.com/matrix-org/gomatrixserverlib"
"github.com/matrix-org/gomatrixserverlib/fclient"
"github.com/matrix-org/gomatrixserverlib/spec"
"github.com/matrix-org/util"
log "github.com/sirupsen/logrus"
)
type Inviter struct {
DB storage.Database
Cfg *config.RoomServer
FSAPI federationAPI.RoomserverFederationAPI
Inputer *input.Inputer
}
// nolint:gocyclo
func (r *Inviter) PerformInvite(
ctx context.Context,
req *api.PerformInviteRequest,
) ([]api.OutputEvent, error) {
var outputUpdates []api.OutputEvent
event := req.Event
if event.StateKey() == nil {
return nil, fmt.Errorf("invite must be a state event")
}
_, senderDomain, err := gomatrixserverlib.SplitID('@', event.Sender())
if err != nil {
return nil, fmt.Errorf("sender %q is invalid", event.Sender())
}
roomID := event.RoomID()
targetUserID := *event.StateKey()
info, err := r.DB.RoomInfo(ctx, roomID)
if err != nil {
return nil, fmt.Errorf("failed to load RoomInfo: %w", err)
}
_, domain, err := gomatrixserverlib.SplitID('@', targetUserID)
if err != nil {
return nil, api.ErrInvalidID{Err: fmt.Errorf("the user ID %s is invalid", targetUserID)}
}
isTargetLocal := r.Cfg.Matrix.IsLocalServerName(domain)
isOriginLocal := r.Cfg.Matrix.IsLocalServerName(senderDomain)
if !isOriginLocal && !isTargetLocal {
return nil, api.ErrInvalidID{Err: fmt.Errorf("the invite must be either from or to a local user")}
}
logger := util.GetLogger(ctx).WithFields(map[string]interface{}{
"inviter": event.Sender(),
"invitee": *event.StateKey(),
"room_id": roomID,
"event_id": event.EventID(),
})
logger.WithFields(log.Fields{
"room_version": req.RoomVersion,
"room_info_exists": info != nil,
"target_local": isTargetLocal,
"origin_local": isOriginLocal,
}).Debug("processing invite event")
inviteState := req.InviteRoomState
if len(inviteState) == 0 && info != nil {
var is []fclient.InviteV2StrippedState
if is, err = buildInviteStrippedState(ctx, r.DB, info, req); err == nil {
inviteState = is
}
}
if len(inviteState) == 0 {
if err = event.SetUnsignedField("invite_room_state", struct{}{}); err != nil {
return nil, fmt.Errorf("event.SetUnsignedField: %w", err)
}
} else {
if err = event.SetUnsignedField("invite_room_state", inviteState); err != nil {
return nil, fmt.Errorf("event.SetUnsignedField: %w", err)
}
}
updateMembershipTableManually := func() ([]api.OutputEvent, error) {
var updater *shared.MembershipUpdater
if updater, err = r.DB.MembershipUpdater(ctx, roomID, targetUserID, isTargetLocal, req.RoomVersion); err != nil {
return nil, fmt.Errorf("r.DB.MembershipUpdater: %w", err)
}
outputUpdates, err = helpers.UpdateToInviteMembership(updater, &types.Event{
EventNID: 0,
PDU: event.PDU,
}, outputUpdates, req.Event.Version())
if err != nil {
return nil, fmt.Errorf("updateToInviteMembership: %w", err)
}
if err = updater.Commit(); err != nil {
return nil, fmt.Errorf("updater.Commit: %w", err)
}
logger.Debugf("updated membership to invite and sending invite OutputEvent")
return outputUpdates, nil
}
if (info == nil || info.IsStub()) && !isOriginLocal && isTargetLocal {
// The invite came in over federation for a room that we don't know about
// yet. We need to handle this a bit differently to most invites because
// we don't know the room state, therefore the roomserver can't process
// an input event. Instead we will update the membership table with the
// new invite and generate an output event.
return updateMembershipTableManually()
}
var isAlreadyJoined bool
if info != nil {
_, isAlreadyJoined, _, err = r.DB.GetMembership(ctx, info.RoomNID, *event.StateKey())
if err != nil {
return nil, fmt.Errorf("r.DB.GetMembership: %w", err)
}
}
if isAlreadyJoined {
// If the user is joined to the room then that takes precedence over this
// invite event. It makes little sense to move a user that is already
// joined to the room into the invite state.
// This could plausibly happen if an invite request raced with a join
// request for a user. For example if a user was invited to a public
// room and they joined the room at the same time as the invite was sent.
// The other way this could plausibly happen is if an invite raced with
// a kick. For example if a user was kicked from a room in error and in
// response someone else in the room re-invited them then it is possible
// for the invite request to race with the leave event so that the
// target receives invite before it learns that it has been kicked.
// There are a few ways this could be plausibly handled in the roomserver.
// 1) Store the invite, but mark it as retired. That will result in the
// permanent rejection of that invite event. So even if the target
// user leaves the room and the invite is retransmitted it will be
// ignored. However a new invite with a new event ID would still be
// accepted.
// 2) Silently discard the invite event. This means that if the event
// was retransmitted at a later date after the target user had left
// the room we would accept the invite. However since we hadn't told
// the sending server that the invite had been discarded it would
// have no reason to attempt to retry.
// 3) Signal the sending server that the user is already joined to the
// room.
// For now we will implement option 2. Since in the abesence of a retry
// mechanism it will be equivalent to option 1, and we don't have a
// signalling mechanism to implement option 3.
logger.Debugf("user already joined")
return nil, api.ErrNotAllowed{Err: fmt.Errorf("user is already joined to room")}
}
// If the invite originated remotely then we can't send an
// InputRoomEvent for the invite as it will never pass auth checks
// due to lacking room state, but we still need to tell the client
// about the invite so we can accept it, hence we return an output
// event to send to the Sync API.
if !isOriginLocal {
return updateMembershipTableManually()
}
// The invite originated locally. Therefore we have a responsibility to
// try and see if the user is allowed to make this invite. We can't do
// this for invites coming in over federation - we have to take those on
// trust.
_, err = helpers.CheckAuthEvents(ctx, r.DB, info, event, event.AuthEventIDs())
if err != nil {
logger.WithError(err).WithField("event_id", event.EventID()).WithField("auth_event_ids", event.AuthEventIDs()).Error(
"processInviteEvent.checkAuthEvents failed for event",
)
return nil, api.ErrNotAllowed{Err: err}
}
// If the invite originated from us and the target isn't local then we
// should try and send the invite over federation first. It might be
// that the remote user doesn't exist, in which case we can give up
// processing here.
if req.SendAsServer != api.DoNotSendToOtherServers && !isTargetLocal {
fsReq := &federationAPI.PerformInviteRequest{
RoomVersion: req.RoomVersion,
Event: event,
InviteRoomState: inviteState,
}
fsRes := &federationAPI.PerformInviteResponse{}
if err = r.FSAPI.PerformInvite(ctx, fsReq, fsRes); err != nil {
logger.WithError(err).WithField("event_id", event.EventID()).Error("r.FSAPI.PerformInvite failed")
return nil, api.ErrNotAllowed{Err: err}
}
event = fsRes.Event
logger.Debugf("Federated PerformInvite success with event ID %s", event.EventID())
}
// Send the invite event to the roomserver input stream. This will
// notify existing users in the room about the invite, update the
// membership table and ensure that the event is ready and available
// to use as an auth event when accepting the invite.
// It will NOT notify the invitee of this invite.
inputReq := &api.InputRoomEventsRequest{
InputRoomEvents: []api.InputRoomEvent{
{
Kind: api.KindNew,
Event: event,
Origin: senderDomain,
SendAsServer: req.SendAsServer,
},
},
}
inputRes := &api.InputRoomEventsResponse{}
r.Inputer.InputRoomEvents(context.Background(), inputReq, inputRes)
if err = inputRes.Err(); err != nil {
logger.WithError(err).WithField("event_id", event.EventID()).Error("r.InputRoomEvents failed")
return nil, api.ErrNotAllowed{Err: err}
}
// Don't notify the sync api of this event in the same way as a federated invite so the invitee
// gets the invite, as the roomserver will do this when it processes the m.room.member invite.
return outputUpdates, nil
}
func buildInviteStrippedState(
ctx context.Context,
db storage.Database,
info *types.RoomInfo,
input *api.PerformInviteRequest,
) ([]fclient.InviteV2StrippedState, error) {
stateWanted := []gomatrixserverlib.StateKeyTuple{}
// "If they are set on the room, at least the state for m.room.avatar, m.room.canonical_alias, m.room.join_rules, and m.room.name SHOULD be included."
// https://matrix.org/docs/spec/client_server/r0.6.0#m-room-member
for _, t := range []string{
spec.MRoomName, spec.MRoomCanonicalAlias,
spec.MRoomJoinRules, spec.MRoomAvatar,
spec.MRoomEncryption, spec.MRoomCreate,
} {
stateWanted = append(stateWanted, gomatrixserverlib.StateKeyTuple{
EventType: t,
StateKey: "",
})
}
roomState := state.NewStateResolution(db, info)
stateEntries, err := roomState.LoadStateAtSnapshotForStringTuples(
ctx, info.StateSnapshotNID(), stateWanted,
)
if err != nil {
return nil, err
}
stateNIDs := []types.EventNID{}
for _, stateNID := range stateEntries {
stateNIDs = append(stateNIDs, stateNID.EventNID)
}
if info == nil {
return nil, types.ErrorInvalidRoomInfo
}
stateEvents, err := db.Events(ctx, info.RoomVersion, stateNIDs)
if err != nil {
return nil, err
}
inviteState := []fclient.InviteV2StrippedState{
fclient.NewInviteV2StrippedState(input.Event.PDU),
}
stateEvents = append(stateEvents, types.Event{PDU: input.Event.PDU})
for _, event := range stateEvents {
inviteState = append(inviteState, fclient.NewInviteV2StrippedState(event.PDU))
}
return inviteState, nil
}