dendrite/clientapi/routing/directory_public.go

374 lines
12 KiB
Go

// Copyright 2020 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 routing
import (
"context"
"math/rand"
"net/http"
"sort"
"strconv"
"strings"
"sync"
"time"
"github.com/matrix-org/dendrite/clientapi/api"
"github.com/matrix-org/dendrite/clientapi/httputil"
"github.com/matrix-org/dendrite/clientapi/jsonerror"
currentstateAPI "github.com/matrix-org/dendrite/currentstateserver/api"
roomserverAPI "github.com/matrix-org/dendrite/roomserver/api"
"github.com/matrix-org/gomatrixserverlib"
"github.com/matrix-org/util"
)
type PublicRoomReq struct {
Since string `json:"since,omitempty"`
Limit int16 `json:"limit,omitempty"`
Filter filter `json:"filter,omitempty"`
}
type filter struct {
SearchTerms string `json:"generic_search_term,omitempty"`
}
// GetPostPublicRooms implements GET and POST /publicRooms
func GetPostPublicRooms(
req *http.Request, rsAPI roomserverAPI.RoomserverInternalAPI, stateAPI currentstateAPI.CurrentStateInternalAPI,
) util.JSONResponse {
var request PublicRoomReq
if fillErr := fillPublicRoomsReq(req, &request); fillErr != nil {
return *fillErr
}
response, err := publicRooms(req.Context(), request, rsAPI, stateAPI)
if err != nil {
return jsonerror.InternalServerError()
}
return util.JSONResponse{
Code: http.StatusOK,
JSON: response,
}
}
// GetPostPublicRoomsWithExternal is the same as GetPostPublicRooms but also mixes in public rooms from the provider supplied.
func GetPostPublicRoomsWithExternal(
req *http.Request, rsAPI roomserverAPI.RoomserverInternalAPI, stateAPI currentstateAPI.CurrentStateInternalAPI,
fedClient *gomatrixserverlib.FederationClient, extRoomsProvider api.ExternalPublicRoomsProvider,
) util.JSONResponse {
var request PublicRoomReq
if fillErr := fillPublicRoomsReq(req, &request); fillErr != nil {
return *fillErr
}
response, err := publicRooms(req.Context(), request, rsAPI, stateAPI)
if err != nil {
return jsonerror.InternalServerError()
}
if request.Since != "" {
// TODO: handle pagination tokens sensibly rather than ignoring them.
// ignore paginated requests since we don't handle them yet over federation.
// Only the initial request will contain federated rooms.
return util.JSONResponse{
Code: http.StatusOK,
JSON: response,
}
}
// If we have already hit the limit on the number of rooms, bail.
var limit int
if request.Limit > 0 {
limit = int(request.Limit) - len(response.Chunk)
if limit <= 0 {
return util.JSONResponse{
Code: http.StatusOK,
JSON: response,
}
}
}
// downcasting `limit` is safe as we know it isn't bigger than request.Limit which is int16
fedRooms := bulkFetchPublicRoomsFromServers(req.Context(), fedClient, extRoomsProvider.Homeservers(), int16(limit))
response.Chunk = append(response.Chunk, fedRooms...)
// de-duplicate rooms with the same room ID. We can join the room via any of these aliases as we know these servers
// are alive and well, so we arbitrarily pick one (purposefully shuffling them to spread the load a bit)
var publicRooms []gomatrixserverlib.PublicRoom
haveRoomIDs := make(map[string]bool)
rand.Shuffle(len(response.Chunk), func(i, j int) {
response.Chunk[i], response.Chunk[j] = response.Chunk[j], response.Chunk[i]
})
for _, r := range response.Chunk {
if haveRoomIDs[r.RoomID] {
continue
}
haveRoomIDs[r.RoomID] = true
publicRooms = append(publicRooms, r)
}
// sort by member count
sort.SliceStable(publicRooms, func(i, j int) bool {
return publicRooms[i].JoinedMembersCount > publicRooms[j].JoinedMembersCount
})
response.Chunk = publicRooms
return util.JSONResponse{
Code: http.StatusOK,
JSON: response,
}
}
// bulkFetchPublicRoomsFromServers fetches public rooms from the list of homeservers.
// Returns a list of public rooms up to the limit specified.
func bulkFetchPublicRoomsFromServers(
ctx context.Context, fedClient *gomatrixserverlib.FederationClient, homeservers []string, limit int16,
) (publicRooms []gomatrixserverlib.PublicRoom) {
// follow pipeline semantics, see https://blog.golang.org/pipelines for more info.
// goroutines send rooms to this channel
roomCh := make(chan gomatrixserverlib.PublicRoom, int(limit))
// signalling channel to tell goroutines to stop sending rooms and quit
done := make(chan bool)
// signalling to say when we can close the room channel
var wg sync.WaitGroup
wg.Add(len(homeservers))
// concurrently query for public rooms
for _, hs := range homeservers {
go func(homeserverDomain string) {
defer wg.Done()
util.GetLogger(ctx).WithField("hs", homeserverDomain).Info("Querying HS for public rooms")
fres, err := fedClient.GetPublicRooms(ctx, gomatrixserverlib.ServerName(homeserverDomain), int(limit), "", false, "")
if err != nil {
util.GetLogger(ctx).WithError(err).WithField("hs", homeserverDomain).Warn(
"bulkFetchPublicRoomsFromServers: failed to query hs",
)
return
}
for _, room := range fres.Chunk {
// atomically send a room or stop
select {
case roomCh <- room:
case <-done:
util.GetLogger(ctx).WithError(err).WithField("hs", homeserverDomain).Info("Interrupted whilst sending rooms")
return
}
}
}(hs)
}
// Close the room channel when the goroutines have quit so we don't leak, but don't let it stop the in-flight request.
// This also allows the request to fail fast if all HSes experience errors as it will cause the room channel to be
// closed.
go func() {
wg.Wait()
util.GetLogger(ctx).Info("Cleaning up resources")
close(roomCh)
}()
// fan-in results with timeout. We stop when we reach the limit.
FanIn:
for len(publicRooms) < int(limit) || limit == 0 {
// add a room or timeout
select {
case room, ok := <-roomCh:
if !ok {
util.GetLogger(ctx).Info("All homeservers have been queried, returning results.")
break FanIn
}
publicRooms = append(publicRooms, room)
case <-time.After(15 * time.Second): // we've waited long enough, let's tell the client what we got.
util.GetLogger(ctx).Info("Waited 15s for federated public rooms, returning early")
break FanIn
case <-ctx.Done(): // the client hung up on us, let's stop.
util.GetLogger(ctx).Info("Client hung up, returning early")
break FanIn
}
}
// tell goroutines to stop
close(done)
return publicRooms
}
func publicRooms(ctx context.Context, request PublicRoomReq, rsAPI roomserverAPI.RoomserverInternalAPI,
stateAPI currentstateAPI.CurrentStateInternalAPI) (*gomatrixserverlib.RespPublicRooms, error) {
var response gomatrixserverlib.RespPublicRooms
var limit int16
var offset int64
limit = request.Limit
if limit == 0 {
limit = 50
}
offset, err := strconv.ParseInt(request.Since, 10, 64)
// ParseInt returns 0 and an error when trying to parse an empty string
// In that case, we want to assign 0 so we ignore the error
if err != nil && len(request.Since) > 0 {
util.GetLogger(ctx).WithError(err).Error("strconv.ParseInt failed")
return nil, err
}
var queryRes roomserverAPI.QueryPublishedRoomsResponse
err = rsAPI.QueryPublishedRooms(ctx, &roomserverAPI.QueryPublishedRoomsRequest{}, &queryRes)
if err != nil {
util.GetLogger(ctx).WithError(err).Error("QueryPublishedRooms failed")
return nil, err
}
response.TotalRoomCountEstimate = len(queryRes.RoomIDs)
roomIDs, prev, next := sliceInto(queryRes.RoomIDs, offset, limit)
if prev >= 0 {
response.PrevBatch = "T" + strconv.Itoa(prev)
}
if next >= 0 {
response.NextBatch = "T" + strconv.Itoa(next)
}
response.Chunk, err = fillInRooms(ctx, roomIDs, stateAPI)
return &response, err
}
// fillPublicRoomsReq fills the Limit, Since and Filter attributes of a GET or POST request
// on /publicRooms by parsing the incoming HTTP request
// Filter is only filled for POST requests
func fillPublicRoomsReq(httpReq *http.Request, request *PublicRoomReq) *util.JSONResponse {
if httpReq.Method != "GET" && httpReq.Method != "POST" {
return &util.JSONResponse{
Code: http.StatusMethodNotAllowed,
JSON: jsonerror.NotFound("Bad method"),
}
}
if httpReq.Method == "GET" {
limit, err := strconv.Atoi(httpReq.FormValue("limit"))
// Atoi returns 0 and an error when trying to parse an empty string
// In that case, we want to assign 0 so we ignore the error
if err != nil && len(httpReq.FormValue("limit")) > 0 {
util.GetLogger(httpReq.Context()).WithError(err).Error("strconv.Atoi failed")
return &util.JSONResponse{
Code: 400,
JSON: jsonerror.BadJSON("limit param is not a number"),
}
}
request.Limit = int16(limit)
request.Since = httpReq.FormValue("since")
} else {
resErr := httputil.UnmarshalJSONRequest(httpReq, request)
if resErr != nil {
return resErr
}
}
// strip the 'T' which is only required because when sytest does pagination tests it stops
// iterating when !prev_batch which then fails if prev_batch==0, so add arbitrary text to
// make it truthy not falsey.
request.Since = strings.TrimPrefix(request.Since, "T")
return nil
}
// due to lots of switches
// nolint:gocyclo
func fillInRooms(ctx context.Context, roomIDs []string, stateAPI currentstateAPI.CurrentStateInternalAPI) ([]gomatrixserverlib.PublicRoom, error) {
avatarTuple := gomatrixserverlib.StateKeyTuple{EventType: "m.room.avatar", StateKey: ""}
nameTuple := gomatrixserverlib.StateKeyTuple{EventType: "m.room.name", StateKey: ""}
canonicalTuple := gomatrixserverlib.StateKeyTuple{EventType: gomatrixserverlib.MRoomCanonicalAlias, StateKey: ""}
topicTuple := gomatrixserverlib.StateKeyTuple{EventType: "m.room.topic", StateKey: ""}
guestTuple := gomatrixserverlib.StateKeyTuple{EventType: "m.room.guest_access", StateKey: ""}
visibilityTuple := gomatrixserverlib.StateKeyTuple{EventType: gomatrixserverlib.MRoomHistoryVisibility, StateKey: ""}
joinRuleTuple := gomatrixserverlib.StateKeyTuple{EventType: gomatrixserverlib.MRoomJoinRules, StateKey: ""}
var stateRes currentstateAPI.QueryBulkStateContentResponse
err := stateAPI.QueryBulkStateContent(ctx, &currentstateAPI.QueryBulkStateContentRequest{
RoomIDs: roomIDs,
AllowWildcards: true,
StateTuples: []gomatrixserverlib.StateKeyTuple{
nameTuple, canonicalTuple, topicTuple, guestTuple, visibilityTuple, joinRuleTuple, avatarTuple,
{EventType: gomatrixserverlib.MRoomMember, StateKey: "*"},
},
}, &stateRes)
if err != nil {
util.GetLogger(ctx).WithError(err).Error("QueryBulkStateContent failed")
return nil, err
}
chunk := make([]gomatrixserverlib.PublicRoom, len(roomIDs))
i := 0
for roomID, data := range stateRes.Rooms {
pub := gomatrixserverlib.PublicRoom{
RoomID: roomID,
}
joinCount := 0
var joinRule, guestAccess string
for tuple, contentVal := range data {
if tuple.EventType == gomatrixserverlib.MRoomMember && contentVal == "join" {
joinCount++
continue
}
switch tuple {
case avatarTuple:
pub.AvatarURL = contentVal
case nameTuple:
pub.Name = contentVal
case topicTuple:
pub.Topic = contentVal
case canonicalTuple:
pub.CanonicalAlias = contentVal
case visibilityTuple:
pub.WorldReadable = contentVal == "world_readable"
// need both of these to determine whether guests can join
case joinRuleTuple:
joinRule = contentVal
case guestTuple:
guestAccess = contentVal
}
}
if joinRule == gomatrixserverlib.Public && guestAccess == "can_join" {
pub.GuestCanJoin = true
}
pub.JoinedMembersCount = joinCount
chunk[i] = pub
i++
}
return chunk, nil
}
// sliceInto returns a subslice of `slice` which honours the since/limit values given.
//
// 0 1 2 3 4 5 6 index
// [A, B, C, D, E, F, G] slice
//
// limit=3 => A,B,C (prev='', next='3')
// limit=3&since=3 => D,E,F (prev='0', next='6')
// limit=3&since=6 => G (prev='3', next='')
//
// A value of '-1' for prev/next indicates no position.
func sliceInto(slice []string, since int64, limit int16) (subset []string, prev, next int) {
prev = -1
next = -1
if since > 0 {
prev = int(since) - int(limit)
}
nextIndex := int(since) + int(limit)
if len(slice) > nextIndex { // there are more rooms ahead of us
next = nextIndex
}
// apply sanity caps
if since < 0 {
since = 0
}
if nextIndex > len(slice) {
nextIndex = len(slice)
}
subset = slice[since:nextIndex]
return
}