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dendrite/setup/mscs/msc2946/msc2946.go
2022-03-24 10:03:22 +00:00

722 lines
23 KiB
Go

// Copyright 2021 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 msc2946 'Spaces Summary' implements https://github.com/matrix-org/matrix-doc/pull/2946
package msc2946
import (
"context"
"encoding/json"
"net/http"
"net/url"
"sort"
"strconv"
"strings"
"sync"
"time"
"github.com/google/uuid"
"github.com/gorilla/mux"
"github.com/matrix-org/dendrite/clientapi/jsonerror"
fs "github.com/matrix-org/dendrite/federationapi/api"
"github.com/matrix-org/dendrite/internal/caching"
"github.com/matrix-org/dendrite/internal/httputil"
roomserver "github.com/matrix-org/dendrite/roomserver/api"
"github.com/matrix-org/dendrite/setup/base"
userapi "github.com/matrix-org/dendrite/userapi/api"
"github.com/matrix-org/gomatrixserverlib"
"github.com/matrix-org/util"
"github.com/tidwall/gjson"
)
const (
ConstCreateEventContentKey = "type"
ConstCreateEventContentValueSpace = "m.space"
ConstSpaceChildEventType = "m.space.child"
ConstSpaceParentEventType = "m.space.parent"
)
type MSC2946ClientResponse struct {
Rooms []gomatrixserverlib.MSC2946Room `json:"rooms"`
NextBatch string `json:"next_batch,omitempty"`
}
// Enable this MSC
func Enable(
base *base.BaseDendrite, rsAPI roomserver.RoomserverInternalAPI, userAPI userapi.UserInternalAPI,
fsAPI fs.FederationInternalAPI, keyRing gomatrixserverlib.JSONVerifier, cache caching.SpaceSummaryRoomsCache,
) error {
clientAPI := httputil.MakeAuthAPI("spaces", userAPI, spacesHandler(rsAPI, fsAPI, cache, base.Cfg.Global.ServerName))
base.PublicClientAPIMux.Handle("/v1/rooms/{roomID}/hierarchy", clientAPI).Methods(http.MethodGet, http.MethodOptions)
base.PublicClientAPIMux.Handle("/unstable/org.matrix.msc2946/rooms/{roomID}/hierarchy", clientAPI).Methods(http.MethodGet, http.MethodOptions)
fedAPI := httputil.MakeExternalAPI(
"msc2946_fed_spaces", func(req *http.Request) util.JSONResponse {
fedReq, errResp := gomatrixserverlib.VerifyHTTPRequest(
req, time.Now(), base.Cfg.Global.ServerName, keyRing,
)
if fedReq == nil {
return errResp
}
// Extract the room ID from the request. Sanity check request data.
params, err := httputil.URLDecodeMapValues(mux.Vars(req))
if err != nil {
return util.ErrorResponse(err)
}
roomID := params["roomID"]
return federatedSpacesHandler(req.Context(), fedReq, roomID, cache, rsAPI, fsAPI, base.Cfg.Global.ServerName)
},
)
base.PublicFederationAPIMux.Handle("/unstable/org.matrix.msc2946/hierarchy/{roomID}", fedAPI).Methods(http.MethodGet)
base.PublicFederationAPIMux.Handle("/v1/hierarchy/{roomID}", fedAPI).Methods(http.MethodGet)
return nil
}
func federatedSpacesHandler(
ctx context.Context, fedReq *gomatrixserverlib.FederationRequest, roomID string,
cache caching.SpaceSummaryRoomsCache,
rsAPI roomserver.RoomserverInternalAPI, fsAPI fs.FederationInternalAPI,
thisServer gomatrixserverlib.ServerName,
) util.JSONResponse {
u, err := url.Parse(fedReq.RequestURI())
if err != nil {
return util.JSONResponse{
Code: 400,
JSON: jsonerror.InvalidParam("bad request uri"),
}
}
w := walker{
rootRoomID: roomID,
serverName: fedReq.Origin(),
thisServer: thisServer,
ctx: ctx,
cache: cache,
suggestedOnly: u.Query().Get("suggested_only") == "true",
limit: 1000,
// The main difference is that it does not recurse into spaces and does not support pagination.
// This is somewhat equivalent to a Client-Server request with a max_depth=1.
maxDepth: 1,
rsAPI: rsAPI,
fsAPI: fsAPI,
// inline cache as we don't have pagination in federation mode
paginationCache: make(map[string]paginationInfo),
}
return w.walk()
}
func spacesHandler(
rsAPI roomserver.RoomserverInternalAPI,
fsAPI fs.FederationInternalAPI,
cache caching.SpaceSummaryRoomsCache,
thisServer gomatrixserverlib.ServerName,
) func(*http.Request, *userapi.Device) util.JSONResponse {
// declared outside the returned handler so it persists between calls
// TODO: clear based on... time?
paginationCache := make(map[string]paginationInfo)
return func(req *http.Request, device *userapi.Device) util.JSONResponse {
// Extract the room ID from the request. Sanity check request data.
params, err := httputil.URLDecodeMapValues(mux.Vars(req))
if err != nil {
return util.ErrorResponse(err)
}
roomID := params["roomID"]
w := walker{
suggestedOnly: req.URL.Query().Get("suggested_only") == "true",
limit: parseInt(req.URL.Query().Get("limit"), 1000),
maxDepth: parseInt(req.URL.Query().Get("max_depth"), -1),
paginationToken: req.URL.Query().Get("from"),
rootRoomID: roomID,
caller: device,
thisServer: thisServer,
ctx: req.Context(),
cache: cache,
rsAPI: rsAPI,
fsAPI: fsAPI,
paginationCache: paginationCache,
}
return w.walk()
}
}
type paginationInfo struct {
processed set
unvisited []roomVisit
}
type walker struct {
rootRoomID string
caller *userapi.Device
serverName gomatrixserverlib.ServerName
thisServer gomatrixserverlib.ServerName
rsAPI roomserver.RoomserverInternalAPI
fsAPI fs.FederationInternalAPI
ctx context.Context
cache caching.SpaceSummaryRoomsCache
suggestedOnly bool
limit int
maxDepth int
paginationToken string
paginationCache map[string]paginationInfo
mu sync.Mutex
}
func (w *walker) newPaginationCache() (string, paginationInfo) {
p := paginationInfo{
processed: make(set),
unvisited: nil,
}
tok := uuid.NewString()
return tok, p
}
func (w *walker) loadPaginationCache(paginationToken string) *paginationInfo {
w.mu.Lock()
defer w.mu.Unlock()
p := w.paginationCache[paginationToken]
return &p
}
func (w *walker) storePaginationCache(paginationToken string, cache paginationInfo) {
w.mu.Lock()
defer w.mu.Unlock()
w.paginationCache[paginationToken] = cache
}
type roomVisit struct {
roomID string
parentRoomID string
depth int
vias []string // vias to query this room by
}
func (w *walker) walk() util.JSONResponse {
if authorised, _ := w.authorised(w.rootRoomID, ""); !authorised {
if w.caller != nil {
// CS API format
return util.JSONResponse{
Code: 403,
JSON: jsonerror.Forbidden("room is unknown/forbidden"),
}
} else {
// SS API format
return util.JSONResponse{
Code: 404,
JSON: jsonerror.NotFound("room is unknown/forbidden"),
}
}
}
var discoveredRooms []gomatrixserverlib.MSC2946Room
var cache *paginationInfo
if w.paginationToken != "" {
cache = w.loadPaginationCache(w.paginationToken)
if cache == nil {
return util.JSONResponse{
Code: 400,
JSON: jsonerror.InvalidArgumentValue("invalid from"),
}
}
} else {
tok, c := w.newPaginationCache()
cache = &c
w.paginationToken = tok
// Begin walking the graph starting with the room ID in the request in a queue of unvisited rooms
c.unvisited = append(c.unvisited, roomVisit{
roomID: w.rootRoomID,
parentRoomID: "",
depth: 0,
})
}
processed := cache.processed
unvisited := cache.unvisited
// Depth first -> stack data structure
for len(unvisited) > 0 {
if len(discoveredRooms) >= w.limit {
break
}
// pop the stack
rv := unvisited[len(unvisited)-1]
unvisited = unvisited[:len(unvisited)-1]
// If this room has already been processed, skip.
// If this room exceeds the specified depth, skip.
if processed.isSet(rv.roomID) || rv.roomID == "" || (w.maxDepth > 0 && rv.depth > w.maxDepth) {
continue
}
// Mark this room as processed.
processed.set(rv.roomID)
// if this room is not a space room, skip.
var roomType string
create := w.stateEvent(rv.roomID, gomatrixserverlib.MRoomCreate, "")
if create != nil {
// escape the `.`s so gjson doesn't think it's nested
roomType = gjson.GetBytes(create.Content(), strings.ReplaceAll(ConstCreateEventContentKey, ".", `\.`)).Str
}
// Collect rooms/events to send back (either locally or fetched via federation)
var discoveredChildEvents []gomatrixserverlib.MSC2946StrippedEvent
// If we know about this room and the caller is authorised (joined/world_readable) then pull
// events locally
roomExists := w.roomExists(rv.roomID)
if !roomExists {
// attempt to query this room over federation, as either we've never heard of it before
// or we've left it and hence are not authorised (but info may be exposed regardless)
fedRes := w.federatedRoomInfo(rv.roomID, rv.vias)
if fedRes != nil {
discoveredChildEvents = fedRes.Room.ChildrenState
discoveredRooms = append(discoveredRooms, fedRes.Room)
if len(fedRes.Children) > 0 {
discoveredRooms = append(discoveredRooms, fedRes.Children...)
}
// mark this room as a space room as the federated server responded.
// we need to do this so we add the children of this room to the unvisited stack
// as these children may be rooms we do know about.
roomType = ConstCreateEventContentValueSpace
}
} else if authorised, isJoinedOrInvited := w.authorised(rv.roomID, rv.parentRoomID); authorised {
// Get all `m.space.child` state events for this room
events, err := w.childReferences(rv.roomID)
if err != nil {
util.GetLogger(w.ctx).WithError(err).WithField("room_id", rv.roomID).Error("failed to extract references for room")
continue
}
discoveredChildEvents = events
pubRoom := w.publicRoomsChunk(rv.roomID)
discoveredRooms = append(discoveredRooms, gomatrixserverlib.MSC2946Room{
PublicRoom: *pubRoom,
RoomType: roomType,
ChildrenState: events,
})
// don't walk children if the user is not joined/invited to the space
if !isJoinedOrInvited {
continue
}
} else {
// room exists but user is not authorised
continue
}
// don't walk the children
// if the parent is not a space room
if roomType != ConstCreateEventContentValueSpace {
continue
}
// For each referenced room ID in the child events being returned to the caller
// add the room ID to the queue of unvisited rooms. Loop from the beginning.
// We need to invert the order here because the child events are lo->hi on the timestamp,
// so we need to ensure we pop in the same lo->hi order, which won't be the case if we
// insert the highest timestamp last in a stack.
for i := len(discoveredChildEvents) - 1; i >= 0; i-- {
spaceContent := struct {
Via []string `json:"via"`
}{}
ev := discoveredChildEvents[i]
_ = json.Unmarshal(ev.Content, &spaceContent)
unvisited = append(unvisited, roomVisit{
roomID: ev.StateKey,
parentRoomID: rv.roomID,
depth: rv.depth + 1,
vias: spaceContent.Via,
})
}
}
if len(unvisited) > 0 {
// we still have more rooms so we need to send back a pagination token,
// we probably hit a room limit
cache.processed = processed
cache.unvisited = unvisited
w.storePaginationCache(w.paginationToken, *cache)
} else {
// clear the pagination token so we don't send it back to the client
// Note we do NOT nuke the cache just in case this response is lost
// and the client retries it.
w.paginationToken = ""
}
if w.caller != nil {
// return CS API format
return util.JSONResponse{
Code: 200,
JSON: MSC2946ClientResponse{
Rooms: discoveredRooms,
NextBatch: w.paginationToken,
},
}
}
// return SS API format
// the first discovered room will be the room asked for, and subsequent ones the depth=1 children
if len(discoveredRooms) == 0 {
return util.JSONResponse{
Code: 404,
JSON: jsonerror.NotFound("room is unknown/forbidden"),
}
}
return util.JSONResponse{
Code: 200,
JSON: gomatrixserverlib.MSC2946SpacesResponse{
Room: discoveredRooms[0],
Children: discoveredRooms[1:],
},
}
}
func (w *walker) stateEvent(roomID, evType, stateKey string) *gomatrixserverlib.HeaderedEvent {
var queryRes roomserver.QueryCurrentStateResponse
tuple := gomatrixserverlib.StateKeyTuple{
EventType: evType,
StateKey: stateKey,
}
err := w.rsAPI.QueryCurrentState(w.ctx, &roomserver.QueryCurrentStateRequest{
RoomID: roomID,
StateTuples: []gomatrixserverlib.StateKeyTuple{tuple},
}, &queryRes)
if err != nil {
return nil
}
return queryRes.StateEvents[tuple]
}
func (w *walker) publicRoomsChunk(roomID string) *gomatrixserverlib.PublicRoom {
pubRooms, err := roomserver.PopulatePublicRooms(w.ctx, []string{roomID}, w.rsAPI)
if err != nil {
util.GetLogger(w.ctx).WithError(err).Error("failed to PopulatePublicRooms")
return nil
}
if len(pubRooms) == 0 {
return nil
}
return &pubRooms[0]
}
// federatedRoomInfo returns more of the spaces graph from another server. Returns nil if this was
// unsuccessful.
func (w *walker) federatedRoomInfo(roomID string, vias []string) *gomatrixserverlib.MSC2946SpacesResponse {
// only do federated requests for client requests
if w.caller == nil {
return nil
}
resp, ok := w.cache.GetSpaceSummary(roomID)
if ok {
util.GetLogger(w.ctx).Debugf("Returning cached response for %s", roomID)
return &resp
}
util.GetLogger(w.ctx).Debugf("Querying %s via %+v", roomID, vias)
ctx := context.Background()
// query more of the spaces graph using these servers
for _, serverName := range vias {
if serverName == string(w.thisServer) {
continue
}
res, err := w.fsAPI.MSC2946Spaces(ctx, gomatrixserverlib.ServerName(serverName), roomID, w.suggestedOnly)
if err != nil {
util.GetLogger(w.ctx).WithError(err).Warnf("failed to call MSC2946Spaces on server %s", serverName)
continue
}
// ensure nil slices are empty as we send this to the client sometimes
if res.Room.ChildrenState == nil {
res.Room.ChildrenState = []gomatrixserverlib.MSC2946StrippedEvent{}
}
for i := 0; i < len(res.Children); i++ {
child := res.Children[i]
if child.ChildrenState == nil {
child.ChildrenState = []gomatrixserverlib.MSC2946StrippedEvent{}
}
res.Children[i] = child
}
w.cache.StoreSpaceSummary(roomID, res)
return &res
}
return nil
}
func (w *walker) roomExists(roomID string) bool {
var queryRes roomserver.QueryServerJoinedToRoomResponse
err := w.rsAPI.QueryServerJoinedToRoom(w.ctx, &roomserver.QueryServerJoinedToRoomRequest{
RoomID: roomID,
ServerName: w.thisServer,
}, &queryRes)
if err != nil {
util.GetLogger(w.ctx).WithError(err).Error("failed to QueryServerJoinedToRoom")
return false
}
// if the room exists but we aren't in the room then we might have stale data so we want to fetch
// it fresh via federation
return queryRes.RoomExists && queryRes.IsInRoom
}
// authorised returns true iff the user is joined this room or the room is world_readable
func (w *walker) authorised(roomID, parentRoomID string) (authed, isJoinedOrInvited bool) {
if w.caller != nil {
return w.authorisedUser(roomID, parentRoomID)
}
return w.authorisedServer(roomID), false
}
// authorisedServer returns true iff the server is joined this room or the room is world_readable
func (w *walker) authorisedServer(roomID string) bool {
// Check history visibility / join rules first
hisVisTuple := gomatrixserverlib.StateKeyTuple{
EventType: gomatrixserverlib.MRoomHistoryVisibility,
StateKey: "",
}
joinRuleTuple := gomatrixserverlib.StateKeyTuple{
EventType: gomatrixserverlib.MRoomJoinRules,
StateKey: "",
}
var queryRoomRes roomserver.QueryCurrentStateResponse
err := w.rsAPI.QueryCurrentState(w.ctx, &roomserver.QueryCurrentStateRequest{
RoomID: roomID,
StateTuples: []gomatrixserverlib.StateKeyTuple{
hisVisTuple, joinRuleTuple,
},
}, &queryRoomRes)
if err != nil {
util.GetLogger(w.ctx).WithError(err).Error("failed to QueryCurrentState")
return false
}
hisVisEv := queryRoomRes.StateEvents[hisVisTuple]
if hisVisEv != nil {
hisVis, _ := hisVisEv.HistoryVisibility()
if hisVis == "world_readable" {
return true
}
}
// check if this room is a restricted room and if so, we need to check if the server is joined to an allowed room ID
// in addition to the actual room ID (but always do the actual one first as it's quicker in the common case)
allowJoinedToRoomIDs := []string{roomID}
joinRuleEv := queryRoomRes.StateEvents[joinRuleTuple]
if joinRuleEv != nil {
allowJoinedToRoomIDs = append(allowJoinedToRoomIDs, w.restrictedJoinRuleAllowedRooms(joinRuleEv, "m.room_membership")...)
}
// check if server is joined to any allowed room
for _, allowedRoomID := range allowJoinedToRoomIDs {
var queryRes fs.QueryJoinedHostServerNamesInRoomResponse
err = w.fsAPI.QueryJoinedHostServerNamesInRoom(w.ctx, &fs.QueryJoinedHostServerNamesInRoomRequest{
RoomID: allowedRoomID,
}, &queryRes)
if err != nil {
util.GetLogger(w.ctx).WithError(err).Error("failed to QueryJoinedHostServerNamesInRoom")
continue
}
for _, srv := range queryRes.ServerNames {
if srv == w.serverName {
return true
}
}
}
return false
}
// authorisedUser returns true iff the user is invited/joined this room or the room is world_readable.
// Failing that, if the room has a restricted join rule and belongs to the space parent listed, it will return true.
func (w *walker) authorisedUser(roomID, parentRoomID string) (authed bool, isJoinedOrInvited bool) {
hisVisTuple := gomatrixserverlib.StateKeyTuple{
EventType: gomatrixserverlib.MRoomHistoryVisibility,
StateKey: "",
}
joinRuleTuple := gomatrixserverlib.StateKeyTuple{
EventType: gomatrixserverlib.MRoomJoinRules,
StateKey: "",
}
roomMemberTuple := gomatrixserverlib.StateKeyTuple{
EventType: gomatrixserverlib.MRoomMember,
StateKey: w.caller.UserID,
}
var queryRes roomserver.QueryCurrentStateResponse
err := w.rsAPI.QueryCurrentState(w.ctx, &roomserver.QueryCurrentStateRequest{
RoomID: roomID,
StateTuples: []gomatrixserverlib.StateKeyTuple{
hisVisTuple, joinRuleTuple, roomMemberTuple,
},
}, &queryRes)
if err != nil {
util.GetLogger(w.ctx).WithError(err).Error("failed to QueryCurrentState")
return false, false
}
memberEv := queryRes.StateEvents[roomMemberTuple]
if memberEv != nil {
membership, _ := memberEv.Membership()
if membership == gomatrixserverlib.Join || membership == gomatrixserverlib.Invite {
return true, true
}
}
hisVisEv := queryRes.StateEvents[hisVisTuple]
if hisVisEv != nil {
hisVis, _ := hisVisEv.HistoryVisibility()
if hisVis == "world_readable" {
return true, false
}
}
joinRuleEv := queryRes.StateEvents[joinRuleTuple]
if parentRoomID != "" && joinRuleEv != nil {
allowedRoomIDs := w.restrictedJoinRuleAllowedRooms(joinRuleEv, "m.room_membership")
// check parent is in the allowed set
var allowed bool
for _, a := range allowedRoomIDs {
if parentRoomID == a {
allowed = true
break
}
}
if allowed {
// ensure caller is joined to the parent room
var queryRes2 roomserver.QueryCurrentStateResponse
err = w.rsAPI.QueryCurrentState(w.ctx, &roomserver.QueryCurrentStateRequest{
RoomID: parentRoomID,
StateTuples: []gomatrixserverlib.StateKeyTuple{
roomMemberTuple,
},
}, &queryRes2)
if err != nil {
util.GetLogger(w.ctx).WithError(err).WithField("parent_room_id", parentRoomID).Warn("failed to check user is joined to parent room")
} else {
memberEv = queryRes2.StateEvents[roomMemberTuple]
if memberEv != nil {
membership, _ := memberEv.Membership()
if membership == gomatrixserverlib.Join {
return true, false
}
}
}
}
}
return false, false
}
func (w *walker) restrictedJoinRuleAllowedRooms(joinRuleEv *gomatrixserverlib.HeaderedEvent, allowType string) (allows []string) {
rule, _ := joinRuleEv.JoinRule()
if rule != "restricted" {
return nil
}
var jrContent gomatrixserverlib.JoinRuleContent
if err := json.Unmarshal(joinRuleEv.Content(), &jrContent); err != nil {
util.GetLogger(w.ctx).Warnf("failed to check join_rule on room %s: %s", joinRuleEv.RoomID(), err)
return nil
}
for _, allow := range jrContent.Allow {
if allow.Type == allowType {
allows = append(allows, allow.RoomID)
}
}
return
}
// references returns all child references pointing to or from this room.
func (w *walker) childReferences(roomID string) ([]gomatrixserverlib.MSC2946StrippedEvent, error) {
createTuple := gomatrixserverlib.StateKeyTuple{
EventType: gomatrixserverlib.MRoomCreate,
StateKey: "",
}
var res roomserver.QueryCurrentStateResponse
err := w.rsAPI.QueryCurrentState(context.Background(), &roomserver.QueryCurrentStateRequest{
RoomID: roomID,
AllowWildcards: true,
StateTuples: []gomatrixserverlib.StateKeyTuple{
createTuple, {
EventType: ConstSpaceChildEventType,
StateKey: "*",
},
},
}, &res)
if err != nil {
return nil, err
}
// don't return any child refs if the room is not a space room
if res.StateEvents[createTuple] != nil {
// escape the `.`s so gjson doesn't think it's nested
roomType := gjson.GetBytes(res.StateEvents[createTuple].Content(), strings.ReplaceAll(ConstCreateEventContentKey, ".", `\.`)).Str
if roomType != ConstCreateEventContentValueSpace {
return []gomatrixserverlib.MSC2946StrippedEvent{}, nil
}
}
delete(res.StateEvents, createTuple)
el := make([]gomatrixserverlib.MSC2946StrippedEvent, 0, len(res.StateEvents))
for _, ev := range res.StateEvents {
content := gjson.ParseBytes(ev.Content())
// only return events that have a `via` key as per MSC1772
// else we'll incorrectly walk redacted events (as the link
// is in the state_key)
if content.Get("via").Exists() {
strip := stripped(ev.Event)
if strip == nil {
continue
}
// if suggested only and this child isn't suggested, skip it.
// if suggested only = false we include everything so don't need to check the content.
if w.suggestedOnly && !content.Get("suggested").Bool() {
continue
}
el = append(el, *strip)
}
}
// sort by origin_server_ts as per MSC2946
sort.Slice(el, func(i, j int) bool {
return el[i].OriginServerTS < el[j].OriginServerTS
})
return el, nil
}
type set map[string]struct{}
func (s set) set(val string) {
s[val] = struct{}{}
}
func (s set) isSet(val string) bool {
_, ok := s[val]
return ok
}
func stripped(ev *gomatrixserverlib.Event) *gomatrixserverlib.MSC2946StrippedEvent {
if ev.StateKey() == nil {
return nil
}
return &gomatrixserverlib.MSC2946StrippedEvent{
Type: ev.Type(),
StateKey: *ev.StateKey(),
Content: ev.Content(),
Sender: ev.Sender(),
RoomID: ev.RoomID(),
OriginServerTS: ev.OriginServerTS(),
}
}
func parseInt(intstr string, defaultVal int) int {
i, err := strconv.ParseInt(intstr, 10, 32)
if err != nil {
return defaultVal
}
return int(i)
}