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dendrite/roomserver/internal/alias.go
Kegsay 18231f25b4
Implement rejected events (#1426)
* WIP Event rejection

* Still send back errors for rejected events

Instead, discard them at the federationapi /send layer rather than
re-implementing checks at the clientapi/PerformJoin layer.

* Implement rejected events

Critically, rejected events CAN cause state resolution to happen
as it can merge forks in the DAG. This is fine, _provided_ we
do not add the rejected event when performing state resolution,
which is what this PR does. It also fixes the error handling
when NotAllowed happens, as we were checking too early and needlessly
handling NotAllowed in more than one place.

* Update test to match reality

* Modify InputRoomEvents to no longer return an error

Errors do not serialise across HTTP boundaries in polylith mode,
so instead set fields on the InputRoomEventsResponse. Add `Err()`
function to make the API shape basically the same.

* Remove redundant returns; linting

* Update blacklist
2020-09-16 13:00:52 +01:00

276 lines
8.1 KiB
Go

// Copyright 2017 Vector Creations 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 internal
import (
"context"
"encoding/json"
"errors"
"fmt"
"time"
"github.com/matrix-org/dendrite/roomserver/api"
"github.com/matrix-org/gomatrixserverlib"
)
// RoomserverInternalAPIDatabase has the storage APIs needed to implement the alias API.
type RoomserverInternalAPIDatabase interface {
// Save a given room alias with the room ID it refers to.
// Returns an error if there was a problem talking to the database.
SetRoomAlias(ctx context.Context, alias string, roomID string, creatorUserID string) error
// Look up the room ID a given alias refers to.
// Returns an error if there was a problem talking to the database.
GetRoomIDForAlias(ctx context.Context, alias string) (string, error)
// Look up all aliases referring to a given room ID.
// Returns an error if there was a problem talking to the database.
GetAliasesForRoomID(ctx context.Context, roomID string) ([]string, error)
// Get the user ID of the creator of an alias.
// Returns an error if there was a problem talking to the database.
GetCreatorIDForAlias(ctx context.Context, alias string) (string, error)
// Remove a given room alias.
// Returns an error if there was a problem talking to the database.
RemoveRoomAlias(ctx context.Context, alias string) error
// Look up the room version for a given room.
GetRoomVersionForRoom(
ctx context.Context, roomID string,
) (gomatrixserverlib.RoomVersion, error)
}
// SetRoomAlias implements alias.RoomserverInternalAPI
func (r *RoomserverInternalAPI) SetRoomAlias(
ctx context.Context,
request *api.SetRoomAliasRequest,
response *api.SetRoomAliasResponse,
) error {
// Check if the alias isn't already referring to a room
roomID, err := r.DB.GetRoomIDForAlias(ctx, request.Alias)
if err != nil {
return err
}
if len(roomID) > 0 {
// If the alias already exists, stop the process
response.AliasExists = true
return nil
}
response.AliasExists = false
// Save the new alias
if err := r.DB.SetRoomAlias(ctx, request.Alias, request.RoomID, request.UserID); err != nil {
return err
}
// Send a m.room.aliases event with the updated list of aliases for this room
// At this point we've already committed the alias to the database so we
// shouldn't cancel this request.
// TODO: Ensure that we send unsent events when if server restarts.
return r.sendUpdatedAliasesEvent(context.TODO(), request.UserID, request.RoomID)
}
// GetRoomIDForAlias implements alias.RoomserverInternalAPI
func (r *RoomserverInternalAPI) GetRoomIDForAlias(
ctx context.Context,
request *api.GetRoomIDForAliasRequest,
response *api.GetRoomIDForAliasResponse,
) error {
// Look up the room ID in the database
roomID, err := r.DB.GetRoomIDForAlias(ctx, request.Alias)
if err != nil {
return err
}
/*
TODO: Why is this here? It creates an unnecessary dependency
from the roomserver to the appservice component, which should be
altogether optional.
if roomID == "" {
// No room found locally, try our application services by making a call to
// the appservice component
aliasReq := appserviceAPI.RoomAliasExistsRequest{Alias: request.Alias}
var aliasResp appserviceAPI.RoomAliasExistsResponse
if err = r.AppserviceAPI.RoomAliasExists(ctx, &aliasReq, &aliasResp); err != nil {
return err
}
if aliasResp.AliasExists {
roomID, err = r.DB.GetRoomIDForAlias(ctx, request.Alias)
if err != nil {
return err
}
}
}
*/
response.RoomID = roomID
return nil
}
// GetAliasesForRoomID implements alias.RoomserverInternalAPI
func (r *RoomserverInternalAPI) GetAliasesForRoomID(
ctx context.Context,
request *api.GetAliasesForRoomIDRequest,
response *api.GetAliasesForRoomIDResponse,
) error {
// Look up the aliases in the database for the given RoomID
aliases, err := r.DB.GetAliasesForRoomID(ctx, request.RoomID)
if err != nil {
return err
}
response.Aliases = aliases
return nil
}
// GetCreatorIDForAlias implements alias.RoomserverInternalAPI
func (r *RoomserverInternalAPI) GetCreatorIDForAlias(
ctx context.Context,
request *api.GetCreatorIDForAliasRequest,
response *api.GetCreatorIDForAliasResponse,
) error {
// Look up the aliases in the database for the given RoomID
creatorID, err := r.DB.GetCreatorIDForAlias(ctx, request.Alias)
if err != nil {
return err
}
response.UserID = creatorID
return nil
}
// RemoveRoomAlias implements alias.RoomserverInternalAPI
func (r *RoomserverInternalAPI) RemoveRoomAlias(
ctx context.Context,
request *api.RemoveRoomAliasRequest,
response *api.RemoveRoomAliasResponse,
) error {
// Look up the room ID in the database
roomID, err := r.DB.GetRoomIDForAlias(ctx, request.Alias)
if err != nil {
return err
}
// Remove the dalias from the database
if err := r.DB.RemoveRoomAlias(ctx, request.Alias); err != nil {
return err
}
// Send an updated m.room.aliases event
// At this point we've already committed the alias to the database so we
// shouldn't cancel this request.
// TODO: Ensure that we send unsent events when if server restarts.
return r.sendUpdatedAliasesEvent(context.TODO(), request.UserID, roomID)
}
type roomAliasesContent struct {
Aliases []string `json:"aliases"`
}
// Build the updated m.room.aliases event to send to the room after addition or
// removal of an alias
func (r *RoomserverInternalAPI) sendUpdatedAliasesEvent(
ctx context.Context, userID string, roomID string,
) error {
serverName := string(r.Cfg.Matrix.ServerName)
builder := gomatrixserverlib.EventBuilder{
Sender: userID,
RoomID: roomID,
Type: "m.room.aliases",
StateKey: &serverName,
}
// Retrieve the updated list of aliases, marhal it and set it as the
// event's content
aliases, err := r.DB.GetAliasesForRoomID(ctx, roomID)
if err != nil {
return err
}
content := roomAliasesContent{Aliases: aliases}
rawContent, err := json.Marshal(content)
if err != nil {
return err
}
err = builder.SetContent(json.RawMessage(rawContent))
if err != nil {
return err
}
// Get needed state events and depth
eventsNeeded, err := gomatrixserverlib.StateNeededForEventBuilder(&builder)
if err != nil {
return err
}
if len(eventsNeeded.Tuples()) == 0 {
return errors.New("expecting state tuples for event builder, got none")
}
req := api.QueryLatestEventsAndStateRequest{
RoomID: roomID,
StateToFetch: eventsNeeded.Tuples(),
}
var res api.QueryLatestEventsAndStateResponse
if err = r.QueryLatestEventsAndState(ctx, &req, &res); err != nil {
return err
}
builder.Depth = res.Depth
builder.PrevEvents = res.LatestEvents
// Add auth events
authEvents := gomatrixserverlib.NewAuthEvents(nil)
for i := range res.StateEvents {
err = authEvents.AddEvent(&res.StateEvents[i].Event)
if err != nil {
return err
}
}
refs, err := eventsNeeded.AuthEventReferences(&authEvents)
if err != nil {
return err
}
builder.AuthEvents = refs
roomInfo, err := r.DB.RoomInfo(ctx, roomID)
if err != nil {
return err
}
if roomInfo == nil {
return fmt.Errorf("room %s does not exist", roomID)
}
// Build the event
now := time.Now()
event, err := builder.Build(
now, r.Cfg.Matrix.ServerName, r.Cfg.Matrix.KeyID,
r.Cfg.Matrix.PrivateKey, roomInfo.RoomVersion,
)
if err != nil {
return err
}
// Create the request
ire := api.InputRoomEvent{
Kind: api.KindNew,
Event: event.Headered(roomInfo.RoomVersion),
AuthEventIDs: event.AuthEventIDs(),
SendAsServer: serverName,
}
inputReq := api.InputRoomEventsRequest{
InputRoomEvents: []api.InputRoomEvent{ire},
}
var inputRes api.InputRoomEventsResponse
// Send the request
r.InputRoomEvents(ctx, &inputReq, &inputRes)
return inputRes.Err()
}