dendrite/roomserver/internal/perform_leave.go

208 lines
6.4 KiB
Go

package internal
import (
"context"
"fmt"
"strings"
"time"
fsAPI "github.com/matrix-org/dendrite/federationsender/api"
"github.com/matrix-org/dendrite/internal/eventutil"
"github.com/matrix-org/dendrite/roomserver/api"
"github.com/matrix-org/gomatrixserverlib"
)
// WriteOutputEvents implements OutputRoomEventWriter
func (r *RoomserverInternalAPI) PerformLeave(
ctx context.Context,
req *api.PerformLeaveRequest,
res *api.PerformLeaveResponse,
) error {
_, domain, err := gomatrixserverlib.SplitID('@', req.UserID)
if err != nil {
return fmt.Errorf("Supplied user ID %q in incorrect format", req.UserID)
}
if domain != r.Cfg.Matrix.ServerName {
return fmt.Errorf("User %q does not belong to this homeserver", req.UserID)
}
if strings.HasPrefix(req.RoomID, "!") {
return r.performLeaveRoomByID(ctx, req, res)
}
return fmt.Errorf("Room ID %q is invalid", req.RoomID)
}
func (r *RoomserverInternalAPI) performLeaveRoomByID(
ctx context.Context,
req *api.PerformLeaveRequest,
res *api.PerformLeaveResponse, // nolint:unparam
) error {
// If there's an invite outstanding for the room then respond to
// that.
isInvitePending, senderUser, err := r.isInvitePending(ctx, req.RoomID, req.UserID)
if err == nil && isInvitePending {
return r.performRejectInvite(ctx, req, res, senderUser)
}
// There's no invite pending, so first of all we want to find out
// if the room exists and if the user is actually in it.
latestReq := api.QueryLatestEventsAndStateRequest{
RoomID: req.RoomID,
StateToFetch: []gomatrixserverlib.StateKeyTuple{
{
EventType: gomatrixserverlib.MRoomMember,
StateKey: req.UserID,
},
},
}
latestRes := api.QueryLatestEventsAndStateResponse{}
if err = r.QueryLatestEventsAndState(ctx, &latestReq, &latestRes); err != nil {
return err
}
if !latestRes.RoomExists {
return fmt.Errorf("Room %q does not exist", req.RoomID)
}
// Now let's see if the user is in the room.
if len(latestRes.StateEvents) == 0 {
return fmt.Errorf("User %q is not a member of room %q", req.UserID, req.RoomID)
}
membership, err := latestRes.StateEvents[0].Membership()
if err != nil {
return fmt.Errorf("Error getting membership: %w", err)
}
if membership != gomatrixserverlib.Join {
// TODO: should be able to handle "invite" in this case too, if
// it's a case of kicking or banning or such
return fmt.Errorf("User %q is not joined to the room (membership is %q)", req.UserID, membership)
}
// Prepare the template for the leave event.
userID := req.UserID
eb := gomatrixserverlib.EventBuilder{
Type: gomatrixserverlib.MRoomMember,
Sender: userID,
StateKey: &userID,
RoomID: req.RoomID,
Redacts: "",
}
if err = eb.SetContent(map[string]interface{}{"membership": "leave"}); err != nil {
return fmt.Errorf("eb.SetContent: %w", err)
}
if err = eb.SetUnsigned(struct{}{}); err != nil {
return fmt.Errorf("eb.SetUnsigned: %w", err)
}
// We know that the user is in the room at this point so let's build
// a leave event.
// TODO: Check what happens if the room exists on the server
// but everyone has since left. I suspect it does the wrong thing.
buildRes := api.QueryLatestEventsAndStateResponse{}
event, err := eventutil.BuildEvent(
ctx, // the request context
&eb, // the template leave event
r.Cfg, // the server configuration
time.Now(), // the event timestamp to use
r, // the roomserver API to use
&buildRes, // the query response
)
if err != nil {
return fmt.Errorf("eventutil.BuildEvent: %w", err)
}
// Give our leave event to the roomserver input stream. The
// roomserver will process the membership change and notify
// downstream automatically.
inputReq := api.InputRoomEventsRequest{
InputRoomEvents: []api.InputRoomEvent{
{
Kind: api.KindNew,
Event: event.Headered(buildRes.RoomVersion),
AuthEventIDs: event.AuthEventIDs(),
SendAsServer: string(r.Cfg.Matrix.ServerName),
},
},
}
inputRes := api.InputRoomEventsResponse{}
if err = r.InputRoomEvents(ctx, &inputReq, &inputRes); err != nil {
return fmt.Errorf("r.InputRoomEvents: %w", err)
}
return nil
}
func (r *RoomserverInternalAPI) performRejectInvite(
ctx context.Context,
req *api.PerformLeaveRequest,
res *api.PerformLeaveResponse, // nolint:unparam
senderUser string,
) error {
_, domain, err := gomatrixserverlib.SplitID('@', senderUser)
if err != nil {
return fmt.Errorf("User ID %q invalid: %w", senderUser, err)
}
// Ask the federation sender to perform a federated leave for us.
leaveReq := fsAPI.PerformLeaveRequest{
RoomID: req.RoomID,
UserID: req.UserID,
ServerNames: []gomatrixserverlib.ServerName{domain},
}
leaveRes := fsAPI.PerformLeaveResponse{}
if err := r.fsAPI.PerformLeave(ctx, &leaveReq, &leaveRes); err != nil {
return err
}
// TODO: Withdraw the invite, so that the sync API etc are
// notified that we rejected it.
return nil
}
func (r *RoomserverInternalAPI) isInvitePending(
ctx context.Context,
roomID, userID string,
) (bool, string, error) {
// Look up the room NID for the supplied room ID.
roomNID, err := r.DB.RoomNID(ctx, roomID)
if err != nil {
return false, "", fmt.Errorf("r.DB.RoomNID: %w", err)
}
// Look up the state key NID for the supplied user ID.
targetUserNIDs, err := r.DB.EventStateKeyNIDs(ctx, []string{userID})
if err != nil {
return false, "", fmt.Errorf("r.DB.EventStateKeyNIDs: %w", err)
}
targetUserNID, targetUserFound := targetUserNIDs[userID]
if !targetUserFound {
return false, "", fmt.Errorf("missing NID for user %q (%+v)", userID, targetUserNIDs)
}
// Let's see if we have an event active for the user in the room. If
// we do then it will contain a server name that we can direct the
// send_leave to.
senderUserNIDs, err := r.DB.GetInvitesForUser(ctx, roomNID, targetUserNID)
if err != nil {
return false, "", fmt.Errorf("r.DB.GetInvitesForUser: %w", err)
}
if len(senderUserNIDs) == 0 {
return false, "", nil
}
// Look up the user ID from the NID.
senderUsers, err := r.DB.EventStateKeys(ctx, senderUserNIDs)
if err != nil {
return false, "", fmt.Errorf("r.DB.EventStateKeys: %w", err)
}
if len(senderUsers) == 0 {
return false, "", fmt.Errorf("no senderUsers")
}
senderUser, senderUserFound := senderUsers[senderUserNIDs[0]]
if !senderUserFound {
return false, "", fmt.Errorf("missing user for NID %d (%+v)", senderUserNIDs[0], senderUsers)
}
return true, senderUser, nil
}