dendrite/clientapi/routing/state.go
Neil Alexander c60270eea3
Enforce history visibility etc for /rooms/{roomID}/state (#1340)
* Enforce history visibility etc for /rooms/{roomID}/state

* Deduplicate OnIncomingStateRequest and OnIncomingStateTypeRequest

* Revert "Deduplicate OnIncomingStateRequest and OnIncomingStateTypeRequest"

This reverts commit 335035d66e.
2020-08-25 18:43:56 +01:00

322 lines
12 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 routing
import (
"context"
"encoding/json"
"fmt"
"net/http"
"github.com/matrix-org/dendrite/clientapi/jsonerror"
"github.com/matrix-org/dendrite/roomserver/api"
userapi "github.com/matrix-org/dendrite/userapi/api"
"github.com/matrix-org/gomatrixserverlib"
"github.com/matrix-org/util"
log "github.com/sirupsen/logrus"
)
type stateEventInStateResp struct {
gomatrixserverlib.ClientEvent
PrevContent json.RawMessage `json:"prev_content,omitempty"`
ReplacesState string `json:"replaces_state,omitempty"`
}
// OnIncomingStateRequest is called when a client makes a /rooms/{roomID}/state
// request. It will fetch all the state events from the specified room and will
// append the necessary keys to them if applicable before returning them.
// Returns an error if something went wrong in the process.
// TODO: Check if the user is in the room. If not, check if the room's history
// is publicly visible. Current behaviour is returning an empty array if the
// user cannot see the room's history.
func OnIncomingStateRequest(ctx context.Context, device *userapi.Device, rsAPI api.RoomserverInternalAPI, roomID string) util.JSONResponse {
var worldReadable bool
var wantLatestState bool
// First of all, get the latest state of the room. We need to do this
// so that we can look at the history visibility of the room. If the
// room is world-readable then we will always return the latest state.
stateRes := api.QueryLatestEventsAndStateResponse{}
if err := rsAPI.QueryLatestEventsAndState(ctx, &api.QueryLatestEventsAndStateRequest{
RoomID: roomID,
StateToFetch: []gomatrixserverlib.StateKeyTuple{},
}, &stateRes); err != nil {
util.GetLogger(ctx).WithError(err).Error("queryAPI.QueryLatestEventsAndState failed")
return jsonerror.InternalServerError()
}
// Look at the room state and see if we have a history visibility event
// that marks the room as world-readable. If we don't then we assume that
// the room is not world-readable.
for _, ev := range stateRes.StateEvents {
if ev.Type() == gomatrixserverlib.MRoomHistoryVisibility {
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 jsonerror.InternalServerError()
}
if visibility, ok := content["history_visibility"]; ok {
worldReadable = visibility == "world_readable"
break
}
}
}
// If the room isn't world-readable then we will instead try to find out
// the state of the room based on the user's membership. If the user is
// in the room then we'll want the latest state. If the user has never
// been in the room and the room isn't world-readable, then we won't
// return any state. If the user was in the room previously but is no
// longer then we will return the state at the time that the user left.
// membershipRes will only be populated if the room is not world-readable.
var membershipRes api.QueryMembershipForUserResponse
if !worldReadable {
// The room isn't world-readable so try to work out based on the
// user's membership if we want the latest state or not.
err := rsAPI.QueryMembershipForUser(ctx, &api.QueryMembershipForUserRequest{
RoomID: roomID,
UserID: device.UserID,
}, &membershipRes)
if err != nil {
util.GetLogger(ctx).WithError(err).Error("Failed to QueryMembershipForUser")
return jsonerror.InternalServerError()
}
// If the user has never been in the room then stop at this point.
// We won't tell the user about a room they have never joined.
if !membershipRes.HasBeenInRoom {
return util.JSONResponse{
Code: http.StatusForbidden,
JSON: jsonerror.Forbidden(fmt.Sprintf("Unknown room %q or user %q has never joined this room", roomID, device.UserID)),
}
}
// Otherwise, if the user has been in the room, whether or not we
// give them the latest state will depend on if they are *still* in
// the room.
wantLatestState = membershipRes.IsInRoom
} else {
// The room is world-readable so the user join state is irrelevant,
// just get the latest room state instead.
wantLatestState = true
}
util.GetLogger(ctx).WithFields(log.Fields{
"roomID": roomID,
"state_at_event": !wantLatestState,
}).Info("Fetching all state")
stateEvents := []gomatrixserverlib.ClientEvent{}
if wantLatestState {
// If we are happy to use the latest state, either because the user is
// still in the room, or because the room is world-readable, then just
// use the result of the previous QueryLatestEventsAndState response
// to find the state event, if provided.
for _, ev := range stateRes.StateEvents {
stateEvents = append(
stateEvents,
gomatrixserverlib.HeaderedToClientEvent(ev, gomatrixserverlib.FormatAll),
)
}
} else {
// Otherwise, take the event ID of their leave event and work out what
// the state of the room was before that event.
var stateAfterRes api.QueryStateAfterEventsResponse
err := rsAPI.QueryStateAfterEvents(ctx, &api.QueryStateAfterEventsRequest{
RoomID: roomID,
PrevEventIDs: []string{membershipRes.EventID},
StateToFetch: []gomatrixserverlib.StateKeyTuple{},
}, &stateAfterRes)
if err != nil {
util.GetLogger(ctx).WithError(err).Error("Failed to QueryMembershipForUser")
return jsonerror.InternalServerError()
}
for _, ev := range stateRes.StateEvents {
stateEvents = append(
stateEvents,
gomatrixserverlib.HeaderedToClientEvent(ev, gomatrixserverlib.FormatAll),
)
}
}
// Return the results to the requestor.
return util.JSONResponse{
Code: http.StatusOK,
JSON: stateEvents,
}
}
// OnIncomingStateTypeRequest is called when a client makes a
// /rooms/{roomID}/state/{type}/{statekey} request. It will look in current
// state to see if there is an event with that type and state key, if there
// is then (by default) we return the content, otherwise a 404.
// If eventFormat=true, sends the whole event else just the content.
// nolint:gocyclo
func OnIncomingStateTypeRequest(
ctx context.Context, device *userapi.Device, rsAPI api.RoomserverInternalAPI,
roomID, evType, stateKey string, eventFormat bool,
) util.JSONResponse {
var worldReadable bool
var wantLatestState bool
// Always fetch visibility so that we can work out whether to show
// the latest events or the last event from when the user was joined.
// Then include the requested event type and state key, assuming it
// isn't for the same.
stateToFetch := []gomatrixserverlib.StateKeyTuple{
{
EventType: evType,
StateKey: stateKey,
},
}
if evType != gomatrixserverlib.MRoomHistoryVisibility && stateKey != "" {
stateToFetch = append(stateToFetch, gomatrixserverlib.StateKeyTuple{
EventType: gomatrixserverlib.MRoomHistoryVisibility,
StateKey: "",
})
}
// First of all, get the latest state of the room. We need to do this
// so that we can look at the history visibility of the room. If the
// room is world-readable then we will always return the latest state.
stateRes := api.QueryLatestEventsAndStateResponse{}
if err := rsAPI.QueryLatestEventsAndState(ctx, &api.QueryLatestEventsAndStateRequest{
RoomID: roomID,
StateToFetch: stateToFetch,
}, &stateRes); err != nil {
util.GetLogger(ctx).WithError(err).Error("queryAPI.QueryLatestEventsAndState failed")
return jsonerror.InternalServerError()
}
// Look at the room state and see if we have a history visibility event
// that marks the room as world-readable. If we don't then we assume that
// the room is not world-readable.
for _, ev := range stateRes.StateEvents {
if ev.Type() == gomatrixserverlib.MRoomHistoryVisibility {
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 jsonerror.InternalServerError()
}
if visibility, ok := content["history_visibility"]; ok {
worldReadable = visibility == "world_readable"
break
}
}
}
// If the room isn't world-readable then we will instead try to find out
// the state of the room based on the user's membership. If the user is
// in the room then we'll want the latest state. If the user has never
// been in the room and the room isn't world-readable, then we won't
// return any state. If the user was in the room previously but is no
// longer then we will return the state at the time that the user left.
// membershipRes will only be populated if the room is not world-readable.
var membershipRes api.QueryMembershipForUserResponse
if !worldReadable {
// The room isn't world-readable so try to work out based on the
// user's membership if we want the latest state or not.
err := rsAPI.QueryMembershipForUser(ctx, &api.QueryMembershipForUserRequest{
RoomID: roomID,
UserID: device.UserID,
}, &membershipRes)
if err != nil {
util.GetLogger(ctx).WithError(err).Error("Failed to QueryMembershipForUser")
return jsonerror.InternalServerError()
}
// If the user has never been in the room then stop at this point.
// We won't tell the user about a room they have never joined.
if !membershipRes.HasBeenInRoom {
return util.JSONResponse{
Code: http.StatusForbidden,
JSON: jsonerror.Forbidden(fmt.Sprintf("Unknown room %q or user %q has never joined this room", roomID, device.UserID)),
}
}
// Otherwise, if the user has been in the room, whether or not we
// give them the latest state will depend on if they are *still* in
// the room.
wantLatestState = membershipRes.IsInRoom
} else {
// The room is world-readable so the user join state is irrelevant,
// just get the latest room state instead.
wantLatestState = true
}
util.GetLogger(ctx).WithFields(log.Fields{
"roomID": roomID,
"evType": evType,
"stateKey": stateKey,
"state_at_event": !wantLatestState,
}).Info("Fetching state")
var event *gomatrixserverlib.HeaderedEvent
if wantLatestState {
// If we are happy to use the latest state, either because the user is
// still in the room, or because the room is world-readable, then just
// use the result of the previous QueryLatestEventsAndState response
// to find the state event, if provided.
for _, ev := range stateRes.StateEvents {
if ev.Type() == evType && ev.StateKeyEquals(stateKey) {
event = &ev
break
}
}
} else {
// Otherwise, take the event ID of their leave event and work out what
// the state of the room was before that event.
var stateAfterRes api.QueryStateAfterEventsResponse
err := rsAPI.QueryStateAfterEvents(ctx, &api.QueryStateAfterEventsRequest{
RoomID: roomID,
PrevEventIDs: []string{membershipRes.EventID},
StateToFetch: []gomatrixserverlib.StateKeyTuple{
{
EventType: evType,
StateKey: stateKey,
},
},
}, &stateAfterRes)
if err != nil {
util.GetLogger(ctx).WithError(err).Error("Failed to QueryMembershipForUser")
return jsonerror.InternalServerError()
}
if len(stateAfterRes.StateEvents) > 0 {
event = &stateAfterRes.StateEvents[0]
}
}
// If there was no event found that matches all of the above criteria then
// return an error.
if event == nil {
return util.JSONResponse{
Code: http.StatusNotFound,
JSON: jsonerror.NotFound(fmt.Sprintf("Cannot find state event for %q", evType)),
}
}
stateEvent := stateEventInStateResp{
ClientEvent: gomatrixserverlib.HeaderedToClientEvent(*event, gomatrixserverlib.FormatAll),
}
var res interface{}
if eventFormat {
res = stateEvent
} else {
res = stateEvent.Content
}
return util.JSONResponse{
Code: http.StatusOK,
JSON: res,
}
}