dendrite/roomserver/internal/perform/perform_peek.go
Matthew Hodgson 39507bacc3
Peeking via MSC2753 (#1370)
Initial implementation of MSC2753, as tested by https://github.com/matrix-org/sytest/pull/944.
Doesn't yet handle unpeeks, peeked EDUs, or history viz changing during a peek - these will follow.
https://github.com/matrix-org/dendrite/pull/1370 has full details.
2020-09-10 14:39:18 +01:00

207 lines
6.3 KiB
Go

// Copyright 2020 New Vector Ltd
//
// 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"
"encoding/json"
"fmt"
"strings"
fsAPI "github.com/matrix-org/dendrite/federationsender/api"
"github.com/matrix-org/dendrite/internal/config"
"github.com/matrix-org/dendrite/roomserver/api"
"github.com/matrix-org/dendrite/roomserver/internal/input"
"github.com/matrix-org/dendrite/roomserver/storage"
"github.com/matrix-org/gomatrixserverlib"
"github.com/matrix-org/util"
"github.com/sirupsen/logrus"
)
type Peeker struct {
ServerName gomatrixserverlib.ServerName
Cfg *config.RoomServer
FSAPI fsAPI.FederationSenderInternalAPI
DB storage.Database
Inputer *input.Inputer
}
// PerformPeek handles peeking into matrix rooms, including over federation by talking to the federationsender.
func (r *Peeker) PerformPeek(
ctx context.Context,
req *api.PerformPeekRequest,
res *api.PerformPeekResponse,
) {
roomID, err := r.performPeek(ctx, req)
if err != nil {
perr, ok := err.(*api.PerformError)
if ok {
res.Error = perr
} else {
res.Error = &api.PerformError{
Msg: err.Error(),
}
}
}
res.RoomID = roomID
}
func (r *Peeker) performPeek(
ctx context.Context,
req *api.PerformPeekRequest,
) (string, error) {
// FIXME: there's way too much duplication with performJoin
_, domain, err := gomatrixserverlib.SplitID('@', req.UserID)
if err != nil {
return "", &api.PerformError{
Code: api.PerformErrorBadRequest,
Msg: fmt.Sprintf("Supplied user ID %q in incorrect format", req.UserID),
}
}
if domain != r.Cfg.Matrix.ServerName {
return "", &api.PerformError{
Code: api.PerformErrorBadRequest,
Msg: fmt.Sprintf("User %q does not belong to this homeserver", req.UserID),
}
}
if strings.HasPrefix(req.RoomIDOrAlias, "!") {
return r.performPeekRoomByID(ctx, req)
}
if strings.HasPrefix(req.RoomIDOrAlias, "#") {
return r.performPeekRoomByAlias(ctx, req)
}
return "", &api.PerformError{
Code: api.PerformErrorBadRequest,
Msg: fmt.Sprintf("Room ID or alias %q is invalid", req.RoomIDOrAlias),
}
}
func (r *Peeker) performPeekRoomByAlias(
ctx context.Context,
req *api.PerformPeekRequest,
) (string, error) {
// Get the domain part of the room alias.
_, domain, err := gomatrixserverlib.SplitID('#', req.RoomIDOrAlias)
if err != nil {
return "", fmt.Errorf("Alias %q is not in the correct format", req.RoomIDOrAlias)
}
req.ServerNames = append(req.ServerNames, domain)
// Check if this alias matches our own server configuration. If it
// doesn't then we'll need to try a federated peek.
var roomID string
if domain != r.Cfg.Matrix.ServerName {
// The alias isn't owned by us, so we will need to try peeking using
// a remote server.
dirReq := fsAPI.PerformDirectoryLookupRequest{
RoomAlias: req.RoomIDOrAlias, // the room alias to lookup
ServerName: domain, // the server to ask
}
dirRes := fsAPI.PerformDirectoryLookupResponse{}
err = r.FSAPI.PerformDirectoryLookup(ctx, &dirReq, &dirRes)
if err != nil {
logrus.WithError(err).Errorf("error looking up alias %q", req.RoomIDOrAlias)
return "", fmt.Errorf("Looking up alias %q over federation failed: %w", req.RoomIDOrAlias, err)
}
roomID = dirRes.RoomID
req.ServerNames = append(req.ServerNames, dirRes.ServerNames...)
} else {
// Otherwise, look up if we know this room alias locally.
roomID, err = r.DB.GetRoomIDForAlias(ctx, req.RoomIDOrAlias)
if err != nil {
return "", fmt.Errorf("Lookup room alias %q failed: %w", req.RoomIDOrAlias, err)
}
}
// If the room ID is empty then we failed to look up the alias.
if roomID == "" {
return "", fmt.Errorf("Alias %q not found", req.RoomIDOrAlias)
}
// If we do, then pluck out the room ID and continue the peek.
req.RoomIDOrAlias = roomID
return r.performPeekRoomByID(ctx, req)
}
func (r *Peeker) performPeekRoomByID(
ctx context.Context,
req *api.PerformPeekRequest,
) (roomID string, err error) {
roomID = req.RoomIDOrAlias
// Get the domain part of the room ID.
_, domain, err := gomatrixserverlib.SplitID('!', roomID)
if err != nil {
return "", &api.PerformError{
Code: api.PerformErrorBadRequest,
Msg: fmt.Sprintf("Room ID %q is invalid: %s", roomID, err),
}
}
// If the server name in the room ID isn't ours then it's a
// possible candidate for finding the room via federation. Add
// it to the list of servers to try.
if domain != r.Cfg.Matrix.ServerName {
req.ServerNames = append(req.ServerNames, domain)
}
// If this room isn't world_readable, we reject.
// XXX: would be nicer to call this with NIDs
// XXX: we should probably factor out history_visibility checks into a common utility method somewhere
// which handles the default value etc.
var worldReadable = false
ev, _ := r.DB.GetStateEvent(ctx, roomID, "m.room.history_visibility", "")
if ev != nil {
content := map[string]string{}
if err = json.Unmarshal(ev.Content(), &content); err != nil {
util.GetLogger(ctx).WithError(err).Error("json.Unmarshal for history visibility failed")
return
}
if visibility, ok := content["history_visibility"]; ok {
worldReadable = visibility == "world_readable"
}
}
if !worldReadable {
return "", &api.PerformError{
Code: api.PerformErrorNotAllowed,
Msg: "Room is not world-readable",
}
}
// TODO: handle federated peeks
err = r.Inputer.WriteOutputEvents(roomID, []api.OutputEvent{
{
Type: api.OutputTypeNewPeek,
NewPeek: &api.OutputNewPeek{
RoomID: roomID,
UserID: req.UserID,
DeviceID: req.DeviceID,
},
},
})
if err != nil {
return
}
// By this point, if req.RoomIDOrAlias contained an alias, then
// it will have been overwritten with a room ID by performPeekRoomByAlias.
// We should now include this in the response so that the CS API can
// return the right room ID.
return roomID, nil
}