dendrite/roomserver/internal/query/query_room_hierarchy.go
Sam Wedgwood 9582827493
de-MSC-ifying space summaries (MSC2946) (#3134)
- This PR moves and refactors the
[code](https://github.com/matrix-org/dendrite/blob/main/setup/mscs/msc2946/msc2946.go)
for
[MSC2946](https://github.com/matrix-org/matrix-spec-proposals/pull/2946)
('Space Summaries') to integrate it into the rest of the codebase.
- Means space summaries are no longer hidden behind an MSC flag
- Solves #3096

Signed-off-by: Sam Wedgwood <sam@wedgwood.dev>
2023-07-20 15:06:05 +01:00

530 lines
19 KiB
Go

// Copyright 2023 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 query
import (
"context"
"encoding/json"
"fmt"
"sort"
fs "github.com/matrix-org/dendrite/federationapi/api"
roomserver "github.com/matrix-org/dendrite/roomserver/api"
"github.com/matrix-org/dendrite/roomserver/types"
userapi "github.com/matrix-org/dendrite/userapi/api"
"github.com/matrix-org/gomatrixserverlib"
"github.com/matrix-org/gomatrixserverlib/fclient"
"github.com/matrix-org/gomatrixserverlib/spec"
"github.com/matrix-org/util"
"github.com/tidwall/gjson"
)
// Traverse the room hierarchy using the provided walker up to the provided limit,
// returning a new walker which can be used to fetch the next page.
//
// If limit is -1, this is treated as no limit, and the entire hierarchy will be traversed.
//
// If returned walker is nil, then there are no more rooms left to traverse. This method does not modify the provided walker, so it
// can be cached.
func (querier *Queryer) QueryNextRoomHierarchyPage(ctx context.Context, walker roomserver.RoomHierarchyWalker, limit int) ([]fclient.RoomHierarchyRoom, *roomserver.RoomHierarchyWalker, error) {
if authorised, _ := authorised(ctx, querier, walker.Caller, walker.RootRoomID, nil); !authorised {
return nil, nil, roomserver.ErrRoomUnknownOrNotAllowed{Err: fmt.Errorf("room is unknown/forbidden")}
}
discoveredRooms := []fclient.RoomHierarchyRoom{}
// Copy unvisited and processed to avoid modifying original walker (which is typically in cache)
unvisited := make([]roomserver.RoomHierarchyWalkerQueuedRoom, len(walker.Unvisited))
copy(unvisited, walker.Unvisited)
processed := walker.Processed.Copy()
// Depth first -> stack data structure
for len(unvisited) > 0 {
if len(discoveredRooms) >= limit && limit != -1 {
break
}
// pop the stack
queuedRoom := 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.Contains(queuedRoom.RoomID) || (walker.MaxDepth > 0 && queuedRoom.Depth > walker.MaxDepth) {
continue
}
// Mark this room as processed.
processed.Add(queuedRoom.RoomID)
// if this room is not a space room, skip.
var roomType string
create := stateEvent(ctx, querier, queuedRoom.RoomID, spec.MRoomCreate, "")
if create != nil {
var createContent gomatrixserverlib.CreateContent
err := json.Unmarshal(create.Content(), &createContent)
if err != nil {
util.GetLogger(ctx).WithError(err).WithField("create_content", create.Content()).Warn("failed to unmarshal m.room.create event")
}
roomType = createContent.RoomType
}
// Collect rooms/events to send back (either locally or fetched via federation)
var discoveredChildEvents []fclient.RoomHierarchyStrippedEvent
// If we know about this room and the caller is authorised (joined/world_readable) then pull
// events locally
roomExists := roomExists(ctx, querier, queuedRoom.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 := federatedRoomInfo(ctx, querier, walker.Caller, walker.SuggestedOnly, queuedRoom.RoomID, queuedRoom.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 = spec.MSpace
}
} else if authorised, isJoinedOrInvited := authorised(ctx, querier, walker.Caller, queuedRoom.RoomID, queuedRoom.ParentRoomID); authorised {
// Get all `m.space.child` state events for this room
events, err := childReferences(ctx, querier, walker.SuggestedOnly, queuedRoom.RoomID)
if err != nil {
util.GetLogger(ctx).WithError(err).WithField("room_id", queuedRoom.RoomID).Error("failed to extract references for room")
continue
}
discoveredChildEvents = events
pubRoom := publicRoomsChunk(ctx, querier, queuedRoom.RoomID)
discoveredRooms = append(discoveredRooms, fclient.RoomHierarchyRoom{
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 != spec.MSpace {
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)
childRoomID, err := spec.NewRoomID(ev.StateKey)
if err != nil {
util.GetLogger(ctx).WithError(err).WithField("invalid_room_id", ev.StateKey).WithField("parent_room_id", queuedRoom.RoomID).Warn("Invalid room ID in m.space.child state event")
} else {
unvisited = append(unvisited, roomserver.RoomHierarchyWalkerQueuedRoom{
RoomID: *childRoomID,
ParentRoomID: &queuedRoom.RoomID,
Depth: queuedRoom.Depth + 1,
Vias: spaceContent.Via,
})
}
}
}
if len(unvisited) == 0 {
// If no more rooms to walk, then don't return a walker for future pages
return discoveredRooms, nil, nil
} else {
// If there are more rooms to walk, then return a new walker to resume walking from (for querying more pages)
newWalker := roomserver.RoomHierarchyWalker{
RootRoomID: walker.RootRoomID,
Caller: walker.Caller,
SuggestedOnly: walker.SuggestedOnly,
MaxDepth: walker.MaxDepth,
Unvisited: unvisited,
Processed: processed,
}
return discoveredRooms, &newWalker, nil
}
}
// authorised returns true iff the user is joined this room or the room is world_readable
func authorised(ctx context.Context, querier *Queryer, caller types.DeviceOrServerName, roomID spec.RoomID, parentRoomID *spec.RoomID) (authed, isJoinedOrInvited bool) {
if clientCaller := caller.Device(); clientCaller != nil {
return authorisedUser(ctx, querier, clientCaller, roomID, parentRoomID)
} else {
return authorisedServer(ctx, querier, roomID, *caller.ServerName()), false
}
}
// authorisedServer returns true iff the server is joined this room or the room is world_readable, public, or knockable
func authorisedServer(ctx context.Context, querier *Queryer, roomID spec.RoomID, callerServerName spec.ServerName) bool {
// Check history visibility / join rules first
hisVisTuple := gomatrixserverlib.StateKeyTuple{
EventType: spec.MRoomHistoryVisibility,
StateKey: "",
}
joinRuleTuple := gomatrixserverlib.StateKeyTuple{
EventType: spec.MRoomJoinRules,
StateKey: "",
}
var queryRoomRes roomserver.QueryCurrentStateResponse
err := querier.QueryCurrentState(ctx, &roomserver.QueryCurrentStateRequest{
RoomID: roomID.String(),
StateTuples: []gomatrixserverlib.StateKeyTuple{
hisVisTuple, joinRuleTuple,
},
}, &queryRoomRes)
if err != nil {
util.GetLogger(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 := []spec.RoomID{roomID}
joinRuleEv := queryRoomRes.StateEvents[joinRuleTuple]
if joinRuleEv != nil {
rule, ruleErr := joinRuleEv.JoinRule()
if ruleErr != nil {
util.GetLogger(ctx).WithError(ruleErr).WithField("parent_room_id", roomID).Warn("failed to get join rule")
return false
}
if rule == spec.Public || rule == spec.Knock {
return true
}
if rule == spec.Restricted {
allowJoinedToRoomIDs = append(allowJoinedToRoomIDs, restrictedJoinRuleAllowedRooms(ctx, joinRuleEv)...)
}
}
// check if server is joined to any allowed room
for _, allowedRoomID := range allowJoinedToRoomIDs {
var queryRes fs.QueryJoinedHostServerNamesInRoomResponse
err = querier.FSAPI.QueryJoinedHostServerNamesInRoom(ctx, &fs.QueryJoinedHostServerNamesInRoomRequest{
RoomID: allowedRoomID.String(),
}, &queryRes)
if err != nil {
util.GetLogger(ctx).WithError(err).Error("failed to QueryJoinedHostServerNamesInRoom")
continue
}
for _, srv := range queryRes.ServerNames {
if srv == callerServerName {
return true
}
}
}
return false
}
// authorisedUser returns true iff the user is invited/joined this room or the room is world_readable
// or if the room has a public or knock join rule.
// Failing that, if the room has a restricted join rule and belongs to the space parent listed, it will return true.
func authorisedUser(ctx context.Context, querier *Queryer, clientCaller *userapi.Device, roomID spec.RoomID, parentRoomID *spec.RoomID) (authed bool, isJoinedOrInvited bool) {
hisVisTuple := gomatrixserverlib.StateKeyTuple{
EventType: spec.MRoomHistoryVisibility,
StateKey: "",
}
joinRuleTuple := gomatrixserverlib.StateKeyTuple{
EventType: spec.MRoomJoinRules,
StateKey: "",
}
roomMemberTuple := gomatrixserverlib.StateKeyTuple{
EventType: spec.MRoomMember,
StateKey: clientCaller.UserID,
}
var queryRes roomserver.QueryCurrentStateResponse
err := querier.QueryCurrentState(ctx, &roomserver.QueryCurrentStateRequest{
RoomID: roomID.String(),
StateTuples: []gomatrixserverlib.StateKeyTuple{
hisVisTuple, joinRuleTuple, roomMemberTuple,
},
}, &queryRes)
if err != nil {
util.GetLogger(ctx).WithError(err).Error("failed to QueryCurrentState")
return false, false
}
memberEv := queryRes.StateEvents[roomMemberTuple]
if memberEv != nil {
membership, _ := memberEv.Membership()
if membership == spec.Join || membership == spec.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 != nil && joinRuleEv != nil {
var allowed bool
rule, ruleErr := joinRuleEv.JoinRule()
if ruleErr != nil {
util.GetLogger(ctx).WithError(ruleErr).WithField("parent_room_id", parentRoomID).Warn("failed to get join rule")
} else if rule == spec.Public || rule == spec.Knock {
allowed = true
} else if rule == spec.Restricted {
allowedRoomIDs := restrictedJoinRuleAllowedRooms(ctx, joinRuleEv)
// check parent is in the allowed set
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 = querier.QueryCurrentState(ctx, &roomserver.QueryCurrentStateRequest{
RoomID: parentRoomID.String(),
StateTuples: []gomatrixserverlib.StateKeyTuple{
roomMemberTuple,
},
}, &queryRes2)
if err != nil {
util.GetLogger(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 == spec.Join {
return true, false
}
}
}
}
}
return false, false
}
// helper function to fetch a state event
func stateEvent(ctx context.Context, querier *Queryer, roomID spec.RoomID, evType, stateKey string) *types.HeaderedEvent {
var queryRes roomserver.QueryCurrentStateResponse
tuple := gomatrixserverlib.StateKeyTuple{
EventType: evType,
StateKey: stateKey,
}
err := querier.QueryCurrentState(ctx, &roomserver.QueryCurrentStateRequest{
RoomID: roomID.String(),
StateTuples: []gomatrixserverlib.StateKeyTuple{tuple},
}, &queryRes)
if err != nil {
return nil
}
return queryRes.StateEvents[tuple]
}
// returns true if the current server is participating in the provided room
func roomExists(ctx context.Context, querier *Queryer, roomID spec.RoomID) bool {
var queryRes roomserver.QueryServerJoinedToRoomResponse
err := querier.QueryServerJoinedToRoom(ctx, &roomserver.QueryServerJoinedToRoomRequest{
RoomID: roomID.String(),
ServerName: querier.Cfg.Global.ServerName,
}, &queryRes)
if err != nil {
util.GetLogger(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
}
// federatedRoomInfo returns more of the spaces graph from another server. Returns nil if this was
// unsuccessful.
func federatedRoomInfo(ctx context.Context, querier *Queryer, caller types.DeviceOrServerName, suggestedOnly bool, roomID spec.RoomID, vias []string) *fclient.RoomHierarchyResponse {
// only do federated requests for client requests
if caller.Device() == nil {
return nil
}
resp, ok := querier.Cache.GetRoomHierarchy(roomID.String())
if ok {
util.GetLogger(ctx).Debugf("Returning cached response for %s", roomID)
return &resp
}
util.GetLogger(ctx).Debugf("Querying %s via %+v", roomID, vias)
innerCtx := context.Background()
// query more of the spaces graph using these servers
for _, serverName := range vias {
if serverName == string(querier.Cfg.Global.ServerName) {
continue
}
res, err := querier.FSAPI.RoomHierarchies(innerCtx, querier.Cfg.Global.ServerName, spec.ServerName(serverName), roomID.String(), suggestedOnly)
if err != nil {
util.GetLogger(ctx).WithError(err).Warnf("failed to call RoomHierarchies 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 = []fclient.RoomHierarchyStrippedEvent{}
}
for i := 0; i < len(res.Children); i++ {
child := res.Children[i]
if child.ChildrenState == nil {
child.ChildrenState = []fclient.RoomHierarchyStrippedEvent{}
}
res.Children[i] = child
}
querier.Cache.StoreRoomHierarchy(roomID.String(), res)
return &res
}
return nil
}
// references returns all child references pointing to or from this room.
func childReferences(ctx context.Context, querier *Queryer, suggestedOnly bool, roomID spec.RoomID) ([]fclient.RoomHierarchyStrippedEvent, error) {
createTuple := gomatrixserverlib.StateKeyTuple{
EventType: spec.MRoomCreate,
StateKey: "",
}
var res roomserver.QueryCurrentStateResponse
err := querier.QueryCurrentState(context.Background(), &roomserver.QueryCurrentStateRequest{
RoomID: roomID.String(),
AllowWildcards: true,
StateTuples: []gomatrixserverlib.StateKeyTuple{
createTuple, {
EventType: spec.MSpaceChild,
StateKey: "*",
},
},
}, &res)
if err != nil {
return nil, err
}
// don't return any child refs if the room is not a space room
if create := res.StateEvents[createTuple]; create != nil {
var createContent gomatrixserverlib.CreateContent
err := json.Unmarshal(create.Content(), &createContent)
if err != nil {
util.GetLogger(ctx).WithError(err).WithField("create_content", create.Content()).Warn("failed to unmarshal m.room.create event")
}
roomType := createContent.RoomType
if roomType != spec.MSpace {
return []fclient.RoomHierarchyStrippedEvent{}, nil
}
}
delete(res.StateEvents, createTuple)
el := make([]fclient.RoomHierarchyStrippedEvent, 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.PDU)
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 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
}
// fetch public room information for provided room
func publicRoomsChunk(ctx context.Context, querier *Queryer, roomID spec.RoomID) *fclient.PublicRoom {
pubRooms, err := roomserver.PopulatePublicRooms(ctx, []string{roomID.String()}, querier)
if err != nil {
util.GetLogger(ctx).WithError(err).Error("failed to PopulatePublicRooms")
return nil
}
if len(pubRooms) == 0 {
return nil
}
return &pubRooms[0]
}
func stripped(ev gomatrixserverlib.PDU) *fclient.RoomHierarchyStrippedEvent {
if ev.StateKey() == nil {
return nil
}
return &fclient.RoomHierarchyStrippedEvent{
Type: ev.Type(),
StateKey: *ev.StateKey(),
Content: ev.Content(),
Sender: string(ev.SenderID()),
OriginServerTS: ev.OriginServerTS(),
}
}
// given join_rule event, return list of rooms where membership of that room allows joining.
func restrictedJoinRuleAllowedRooms(ctx context.Context, joinRuleEv *types.HeaderedEvent) (allows []spec.RoomID) {
rule, _ := joinRuleEv.JoinRule()
if rule != spec.Restricted {
return nil
}
var jrContent gomatrixserverlib.JoinRuleContent
if err := json.Unmarshal(joinRuleEv.Content(), &jrContent); err != nil {
util.GetLogger(ctx).Warnf("failed to check join_rule on room %s: %s", joinRuleEv.RoomID(), err)
return nil
}
for _, allow := range jrContent.Allow {
if allow.Type == spec.MRoomMembership {
allowedRoomID, err := spec.NewRoomID(allow.RoomID)
if err != nil {
util.GetLogger(ctx).Warnf("invalid room ID '%s' found in join_rule on room %s: %s", allow.RoomID, joinRuleEv.RoomID(), err)
} else {
allows = append(allows, *allowedRoomID)
}
}
}
return
}