dendrite/roomserver/internal/perform/perform_join.go
2024-01-03 17:39:08 -07:00

815 lines
29 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 perform
import (
"context"
"crypto/ed25519"
"database/sql"
"errors"
"fmt"
"strings"
"time"
"github.com/getsentry/sentry-go"
"github.com/matrix-org/gomatrixserverlib"
"github.com/matrix-org/gomatrixserverlib/fclient"
"github.com/matrix-org/gomatrixserverlib/spec"
"github.com/matrix-org/util"
"github.com/sirupsen/logrus"
"github.com/tidwall/gjson"
fsAPI "github.com/matrix-org/dendrite/federationapi/api"
"github.com/matrix-org/dendrite/internal/eventutil"
"github.com/matrix-org/dendrite/roomserver/api"
rsAPI "github.com/matrix-org/dendrite/roomserver/api"
"github.com/matrix-org/dendrite/roomserver/internal/helpers"
"github.com/matrix-org/dendrite/roomserver/internal/input"
"github.com/matrix-org/dendrite/roomserver/internal/query"
"github.com/matrix-org/dendrite/roomserver/storage"
"github.com/matrix-org/dendrite/roomserver/types"
"github.com/matrix-org/dendrite/setup/config"
)
type Joiner struct {
Cfg *config.RoomServer
FSAPI fsAPI.RoomserverFederationAPI
RSAPI rsAPI.RoomserverInternalAPI
DB storage.Database
Inputer *input.Inputer
Queryer *query.Queryer
}
// PerformJoin handles joining matrix rooms, including over federation by talking to the federationapi.
func (r *Joiner) PerformJoin(
ctx context.Context,
req *rsAPI.PerformJoinRequest,
) (roomID string, joinedVia spec.ServerName, err error) {
logger := logrus.WithContext(ctx).WithFields(logrus.Fields{
"room_id": req.RoomIDOrAlias,
"user_id": req.UserID,
"servers": req.ServerNames,
})
logger.Info("User requested to room join")
roomID, joinedVia, err = r.performJoin(context.Background(), req)
if err != nil {
logger.WithError(err).Error("Failed to join room")
sentry.CaptureException(err)
return "", "", err
}
logger.Info("User joined room successfully")
return roomID, joinedVia, nil
}
func (r *Joiner) performJoin(
ctx context.Context,
req *rsAPI.PerformJoinRequest,
) (string, spec.ServerName, error) {
_, domain, err := gomatrixserverlib.SplitID('@', req.UserID)
if err != nil {
return "", "", rsAPI.ErrInvalidID{Err: fmt.Errorf("supplied user ID %q in incorrect format", req.UserID)}
}
if !r.Cfg.Matrix.IsLocalServerName(domain) {
return "", "", rsAPI.ErrInvalidID{Err: fmt.Errorf("user %q does not belong to this homeserver", req.UserID)}
}
if strings.HasPrefix(req.RoomIDOrAlias, "!") {
return r.performJoinRoomByID(ctx, req)
}
if strings.HasPrefix(req.RoomIDOrAlias, "#") {
return r.performJoinRoomByAlias(ctx, req)
}
return "", "", rsAPI.ErrInvalidID{Err: fmt.Errorf("room ID or alias %q is invalid", req.RoomIDOrAlias)}
}
func (r *Joiner) performJoinRoomByAlias(
ctx context.Context,
req *rsAPI.PerformJoinRequest,
) (string, spec.ServerName, error) {
// Get the domain part of the room alias.
_, domain, err := gomatrixserverlib.SplitID('#', req.RoomIDOrAlias)
if err != nil {
return "", "", fmt.Errorf("alias %q is not in the correct format", req.RoomIDOrAlias)
}
req.ServerNames = append(req.ServerNames, domain)
// Check if this alias matches our own server configuration. If it
// doesn't then we'll need to try a federated join.
var roomID string
if !r.Cfg.Matrix.IsLocalServerName(domain) {
// The alias isn't owned by us, so we will need to try joining using
// a remote server.
dirReq := fsAPI.PerformDirectoryLookupRequest{
RoomAlias: req.RoomIDOrAlias, // the room alias to lookup
ServerName: domain, // the server to ask
}
dirRes := fsAPI.PerformDirectoryLookupResponse{}
err = r.FSAPI.PerformDirectoryLookup(ctx, &dirReq, &dirRes)
if err != nil {
logrus.WithError(err).Errorf("error looking up alias %q", req.RoomIDOrAlias)
return "", "", fmt.Errorf("looking up alias %q over federation failed: %w", req.RoomIDOrAlias, err)
}
roomID = dirRes.RoomID
req.ServerNames = append(req.ServerNames, dirRes.ServerNames...)
} else {
var getRoomReq = rsAPI.GetRoomIDForAliasRequest{
Alias: req.RoomIDOrAlias,
IncludeAppservices: true,
}
var getRoomRes = rsAPI.GetRoomIDForAliasResponse{}
// Otherwise, look up if we know this room alias locally.
err = r.RSAPI.GetRoomIDForAlias(ctx, &getRoomReq, &getRoomRes)
if err != nil {
return "", "", fmt.Errorf("lookup room alias %q failed: %w", req.RoomIDOrAlias, err)
}
roomID = getRoomRes.RoomID
}
// If the room ID is empty then we failed to look up the alias.
if roomID == "" {
return "", "", fmt.Errorf("alias %q not found", req.RoomIDOrAlias)
}
// If we do, then pluck out the room ID and continue the join.
req.RoomIDOrAlias = roomID
return r.performJoinRoomByID(ctx, req)
}
// TODO: Break this function up a bit & move to GMSL
// nolint:gocyclo
func (r *Joiner) performJoinRoomByID(
ctx context.Context,
req *rsAPI.PerformJoinRequest,
) (string, spec.ServerName, error) {
// The original client request ?server_name=... may include this HS so filter that out so we
// don't attempt to make_join with ourselves
for i := 0; i < len(req.ServerNames); i++ {
if r.Cfg.Matrix.IsLocalServerName(req.ServerNames[i]) {
// delete this entry
req.ServerNames = append(req.ServerNames[:i], req.ServerNames[i+1:]...)
i--
}
}
// Get the domain part of the room ID.
roomID, err := spec.NewRoomID(req.RoomIDOrAlias)
if err != nil {
return "", "", rsAPI.ErrInvalidID{Err: fmt.Errorf("room ID %q is invalid: %w", req.RoomIDOrAlias, err)}
}
// If the server name in the room ID isn't ours then it's a
// possible candidate for finding the room via federation. Add
// it to the list of servers to try.
if !r.Cfg.Matrix.IsLocalServerName(roomID.Domain()) {
req.ServerNames = append(req.ServerNames, roomID.Domain())
}
// Force a federated join if we aren't in the room and we've been
// given some server names to try joining by.
inRoomReq := &rsAPI.QueryServerJoinedToRoomRequest{
RoomID: req.RoomIDOrAlias,
}
inRoomRes := &rsAPI.QueryServerJoinedToRoomResponse{}
if err = r.Queryer.QueryServerJoinedToRoom(ctx, inRoomReq, inRoomRes); err != nil {
return "", "", fmt.Errorf("r.Queryer.QueryServerJoinedToRoom: %w", err)
}
serverInRoom := inRoomRes.IsInRoom
forceFederatedJoin := len(req.ServerNames) > 0 && !serverInRoom
userID, err := spec.NewUserID(req.UserID, true)
if err != nil {
return "", "", rsAPI.ErrInvalidID{Err: fmt.Errorf("user ID %q is invalid: %w", req.UserID, err)}
}
// Look up the room NID for the supplied room ID.
var senderID spec.SenderID
checkInvitePending := false
info, err := r.DB.RoomInfo(ctx, req.RoomIDOrAlias)
if err == nil && info != nil {
switch info.RoomVersion {
case gomatrixserverlib.RoomVersionPseudoIDs:
senderIDPtr, queryErr := r.Queryer.QuerySenderIDForUser(ctx, *roomID, *userID)
if queryErr == nil {
checkInvitePending = true
}
if senderIDPtr == nil {
// create user room key if needed
key, keyErr := r.RSAPI.GetOrCreateUserRoomPrivateKey(ctx, *userID, *roomID)
if keyErr != nil {
util.GetLogger(ctx).WithError(keyErr).Error("GetOrCreateUserRoomPrivateKey failed")
return "", "", fmt.Errorf("GetOrCreateUserRoomPrivateKey failed: %w", keyErr)
}
senderID = spec.SenderIDFromPseudoIDKey(key)
} else {
senderID = *senderIDPtr
}
default:
checkInvitePending = true
senderID = spec.SenderID(userID.String())
}
}
userDomain := userID.Domain()
// Force a federated join if we're dealing with a pending invite
// and we aren't in the room.
if checkInvitePending {
isInvitePending, inviteSender, _, inviteEvent, inviteErr := helpers.IsInvitePending(ctx, r.DB, req.RoomIDOrAlias, senderID)
if inviteErr == nil && !serverInRoom && isInvitePending {
inviter, queryErr := r.RSAPI.QueryUserIDForSender(ctx, *roomID, inviteSender)
if queryErr != nil {
return "", "", fmt.Errorf("r.RSAPI.QueryUserIDForSender: %w", queryErr)
}
// If we were invited by someone from another server then we can
// assume they are in the room so we can join via them.
if inviter != nil && !r.Cfg.Matrix.IsLocalServerName(inviter.Domain()) {
req.ServerNames = append(req.ServerNames, inviter.Domain())
forceFederatedJoin = true
memberEvent := gjson.Parse(string(inviteEvent.JSON()))
// only set unsigned if we've got a content.membership, which we _should_
if memberEvent.Get("content.membership").Exists() {
req.Unsigned = map[string]interface{}{
"prev_sender": memberEvent.Get("sender").Str,
"prev_content": map[string]interface{}{
"is_direct": memberEvent.Get("content.is_direct").Bool(),
"membership": memberEvent.Get("content.membership").Str,
},
}
}
}
}
}
// If a guest is trying to join a room, check that the room has a m.room.guest_access event
if req.IsGuest {
var guestAccessEvent *types.HeaderedEvent
guestAccess := "forbidden"
guestAccessEvent, err = r.DB.GetStateEvent(ctx, req.RoomIDOrAlias, spec.MRoomGuestAccess, "")
if (err != nil && !errors.Is(err, sql.ErrNoRows)) || guestAccessEvent == nil {
logrus.WithError(err).Warn("unable to get m.room.guest_access event, defaulting to 'forbidden'")
}
if guestAccessEvent != nil {
guestAccess = gjson.GetBytes(guestAccessEvent.Content(), "guest_access").String()
}
// Servers MUST only allow guest users to join rooms if the m.room.guest_access state event
// is present on the room and has the guest_access value can_join.
if guestAccess != "can_join" {
return "", "", rsAPI.ErrNotAllowed{Err: fmt.Errorf("guest access is forbidden")}
}
}
// If we should do a forced federated join then do that.
var joinedVia spec.ServerName
if forceFederatedJoin {
joinedVia, err = r.performFederatedJoinRoomByID(ctx, req)
return req.RoomIDOrAlias, joinedVia, err
}
// Try to construct an actual join event from the template.
// If this succeeds then it is a sign that the room already exists
// locally on the homeserver.
// TODO: Check what happens if the room exists on the server
// but everyone has since left. I suspect it does the wrong thing.
var buildRes rsAPI.QueryLatestEventsAndStateResponse
identity := r.Cfg.Matrix.SigningIdentity
// at this point we know we have an existing room
if inRoomRes.RoomVersion == gomatrixserverlib.RoomVersionPseudoIDs {
var pseudoIDKey ed25519.PrivateKey
pseudoIDKey, err = r.RSAPI.GetOrCreateUserRoomPrivateKey(ctx, *userID, *roomID)
if err != nil {
util.GetLogger(ctx).WithError(err).Error("GetOrCreateUserRoomPrivateKey failed")
return "", "", err
}
mapping := &gomatrixserverlib.MXIDMapping{
UserRoomKey: spec.SenderIDFromPseudoIDKey(pseudoIDKey),
UserID: userID.String(),
}
// Sign the mapping with the server identity
if err = mapping.Sign(identity.ServerName, identity.KeyID, identity.PrivateKey); err != nil {
return "", "", err
}
req.Content["mxid_mapping"] = mapping
// sign the event with the pseudo ID key
identity = fclient.SigningIdentity{
ServerName: spec.ServerName(spec.SenderIDFromPseudoIDKey(pseudoIDKey)),
KeyID: "ed25519:1",
PrivateKey: pseudoIDKey,
}
}
senderIDString := string(senderID)
// Prepare the template for the join event.
proto := gomatrixserverlib.ProtoEvent{
Type: spec.MRoomMember,
SenderID: senderIDString,
StateKey: &senderIDString,
RoomID: req.RoomIDOrAlias,
Redacts: "",
}
if err = proto.SetUnsigned(struct{}{}); err != nil {
return "", "", fmt.Errorf("eb.SetUnsigned: %w", err)
}
// It is possible for the request to include some "content" for the
// event. We'll always overwrite the "membership" key, but the rest,
// like "display_name" or "avatar_url", will be kept if supplied.
if req.Content == nil {
req.Content = map[string]interface{}{}
}
req.Content["membership"] = spec.Join
if authorisedVia, aerr := r.populateAuthorisedViaUserForRestrictedJoin(ctx, req, senderID); aerr != nil {
return "", "", aerr
} else if authorisedVia != "" {
req.Content["join_authorised_via_users_server"] = authorisedVia
}
if err = proto.SetContent(req.Content); err != nil {
return "", "", fmt.Errorf("eb.SetContent: %w", err)
}
event, err := eventutil.QueryAndBuildEvent(ctx, &proto, &identity, time.Now(), r.RSAPI, &buildRes)
switch err.(type) {
case nil:
// The room join is local. Send the new join event into the
// roomserver. First of all check that the user isn't already
// a member of the room. This is best-effort (as in we won't
// fail if we can't find the existing membership) because there
// is really no harm in just sending another membership event.
membershipRes := &api.QueryMembershipForUserResponse{}
_ = r.Queryer.QueryMembershipForSenderID(ctx, *roomID, senderID, membershipRes)
// If we haven't already joined the room then send an event
// into the room changing our membership status.
if !membershipRes.RoomExists || !membershipRes.IsInRoom {
inputReq := rsAPI.InputRoomEventsRequest{
InputRoomEvents: []rsAPI.InputRoomEvent{
{
Kind: rsAPI.KindNew,
Event: event,
SendAsServer: string(userDomain),
},
},
}
inputRes := rsAPI.InputRoomEventsResponse{}
r.Inputer.InputRoomEvents(ctx, &inputReq, &inputRes)
if err = inputRes.Err(); err != nil {
return "", "", rsAPI.ErrNotAllowed{Err: err}
}
}
case eventutil.ErrRoomNoExists:
// The room doesn't exist locally. If the room ID looks like it should
// be ours then this probably means that we've nuked our database at
// some point.
if r.Cfg.Matrix.IsLocalServerName(roomID.Domain()) {
// If there are no more server names to try then give up here.
// Otherwise we'll try a federated join as normal, since it's quite
// possible that the room still exists on other servers.
if len(req.ServerNames) == 0 {
return "", "", eventutil.ErrRoomNoExists{}
}
}
// Perform a federated room join.
joinedVia, err = r.performFederatedJoinRoomByID(ctx, req)
return req.RoomIDOrAlias, joinedVia, err
default:
// Something else went wrong.
return "", "", fmt.Errorf("error joining local room: %q", err)
}
// By this point, if req.RoomIDOrAlias contained an alias, then
// it will have been overwritten with a room ID by performJoinRoomByAlias.
// We should now include this in the response so that the CS API can
// return the right room ID.
return req.RoomIDOrAlias, userDomain, nil
}
func (r *Joiner) PerformSendJoinCryptoIDs(
ctx context.Context,
req *rsAPI.PerformJoinRequestCryptoIDs,
) error {
logger := logrus.WithContext(ctx).WithFields(logrus.Fields{
"room_id": req.RoomID,
"user_id": req.UserID,
"servers": req.ServerNames,
})
logger.Info("performing send join")
res := fsAPI.PerformJoinResponse{}
r.FSAPI.PerformSendJoin(ctx, &fsAPI.PerformSendJoinRequestCryptoIDs{
RoomID: req.RoomID,
UserID: req.UserID,
ServerNames: req.ServerNames,
Unsigned: req.Unsigned,
Event: req.JoinEvent,
}, &res)
if res.LastError != nil {
return res.LastError
}
return nil
}
func (r *Joiner) PerformSendInviteCryptoIDs(
ctx context.Context,
req *rsAPI.PerformInviteRequestCryptoIDs,
) error {
logger := logrus.WithContext(ctx).WithFields(logrus.Fields{
"room_id": req.RoomID,
"user_id": req.UserID,
})
logger.Info("performing send invite")
err := r.FSAPI.SendInviteCryptoIDs(ctx, req.InviteEvent, req.UserID, req.InviteEvent.Version())
if err != nil {
return err
}
return nil
}
// PerformJoin handles joining matrix rooms, including over federation by talking to the federationapi.
func (r *Joiner) PerformJoinCryptoIDs(
ctx context.Context,
req *rsAPI.PerformJoinRequest,
) (joinEvent gomatrixserverlib.PDU, roomID string, version gomatrixserverlib.RoomVersion, serverName spec.ServerName, err error) {
logger := logrus.WithContext(ctx).WithFields(logrus.Fields{
"room_id": req.RoomIDOrAlias,
"user_id": req.UserID,
"servers": req.ServerNames,
})
logger.Info("User requested to room join")
join, roomID, version, serverName, err := r.makeJoinEvent(context.Background(), req)
if err != nil {
logger.WithError(err).Error("Failed to make join room event")
sentry.CaptureException(err)
return nil, "", "", "", err
}
return join, roomID, version, serverName, nil
}
func (r *Joiner) makeJoinEvent(
ctx context.Context,
req *rsAPI.PerformJoinRequest,
) (gomatrixserverlib.PDU, string, gomatrixserverlib.RoomVersion, spec.ServerName, error) {
_, domain, err := gomatrixserverlib.SplitID('@', req.UserID)
if err != nil {
return nil, "", "", "", rsAPI.ErrInvalidID{Err: fmt.Errorf("supplied user ID %q in incorrect format", req.UserID)}
}
if !r.Cfg.Matrix.IsLocalServerName(domain) {
return nil, "", "", "", rsAPI.ErrInvalidID{Err: fmt.Errorf("user %q does not belong to this homeserver", req.UserID)}
}
if strings.HasPrefix(req.RoomIDOrAlias, "!") {
return r.performJoinRoomByIDCryptoIDs(ctx, req)
}
if strings.HasPrefix(req.RoomIDOrAlias, "#") {
return r.performJoinRoomByAliasCryptoIDs(ctx, req)
}
return nil, "", "", "", rsAPI.ErrInvalidID{Err: fmt.Errorf("room ID or alias %q is invalid", req.RoomIDOrAlias)}
}
func (r *Joiner) performJoinRoomByAliasCryptoIDs(
ctx context.Context,
req *rsAPI.PerformJoinRequest,
) (gomatrixserverlib.PDU, string, gomatrixserverlib.RoomVersion, spec.ServerName, error) {
// Get the domain part of the room alias.
_, domain, err := gomatrixserverlib.SplitID('#', req.RoomIDOrAlias)
if err != nil {
return nil, "", "", "", fmt.Errorf("alias %q is not in the correct format", req.RoomIDOrAlias)
}
req.ServerNames = append(req.ServerNames, domain)
// Check if this alias matches our own server configuration. If it
// doesn't then we'll need to try a federated join.
var roomID string
if !r.Cfg.Matrix.IsLocalServerName(domain) {
// The alias isn't owned by us, so we will need to try joining using
// a remote server.
dirReq := fsAPI.PerformDirectoryLookupRequest{
RoomAlias: req.RoomIDOrAlias, // the room alias to lookup
ServerName: domain, // the server to ask
}
dirRes := fsAPI.PerformDirectoryLookupResponse{}
err = r.FSAPI.PerformDirectoryLookup(ctx, &dirReq, &dirRes)
if err != nil {
logrus.WithError(err).Errorf("error looking up alias %q", req.RoomIDOrAlias)
return nil, "", "", "", fmt.Errorf("looking up alias %q over federation failed: %w", req.RoomIDOrAlias, err)
}
roomID = dirRes.RoomID
req.ServerNames = append(req.ServerNames, dirRes.ServerNames...)
} else {
var getRoomReq = rsAPI.GetRoomIDForAliasRequest{
Alias: req.RoomIDOrAlias,
IncludeAppservices: true,
}
var getRoomRes = rsAPI.GetRoomIDForAliasResponse{}
// Otherwise, look up if we know this room alias locally.
err = r.RSAPI.GetRoomIDForAlias(ctx, &getRoomReq, &getRoomRes)
if err != nil {
return nil, "", "", "", fmt.Errorf("lookup room alias %q failed: %w", req.RoomIDOrAlias, err)
}
roomID = getRoomRes.RoomID
}
// If the room ID is empty then we failed to look up the alias.
if roomID == "" {
return nil, "", "", "", fmt.Errorf("alias %q not found", req.RoomIDOrAlias)
}
// If we do, then pluck out the room ID and continue the join.
req.RoomIDOrAlias = roomID
return r.performJoinRoomByIDCryptoIDs(ctx, req)
}
// TODO: Break this function up a bit & move to GMSL
// nolint:gocyclo
func (r *Joiner) performJoinRoomByIDCryptoIDs(
ctx context.Context,
req *rsAPI.PerformJoinRequest,
) (gomatrixserverlib.PDU, string, gomatrixserverlib.RoomVersion, spec.ServerName, error) {
// The original client request ?server_name=... may include this HS so filter that out so we
// don't attempt to make_join with ourselves
for i := 0; i < len(req.ServerNames); i++ {
if r.Cfg.Matrix.IsLocalServerName(req.ServerNames[i]) {
// delete this entry
req.ServerNames = append(req.ServerNames[:i], req.ServerNames[i+1:]...)
i--
}
}
// Get the domain part of the room ID.
roomID, err := spec.NewRoomID(req.RoomIDOrAlias)
if err != nil {
return nil, "", "", "", rsAPI.ErrInvalidID{Err: fmt.Errorf("room ID %q is invalid: %w", req.RoomIDOrAlias, err)}
}
// If the server name in the room ID isn't ours then it's a
// possible candidate for finding the room via federation. Add
// it to the list of servers to try.
if !r.Cfg.Matrix.IsLocalServerName(roomID.Domain()) {
req.ServerNames = append(req.ServerNames, roomID.Domain())
}
// Force a federated join if we aren't in the room and we've been
// given some server names to try joining by.
inRoomReq := &rsAPI.QueryServerJoinedToRoomRequest{
RoomID: req.RoomIDOrAlias,
}
inRoomRes := &rsAPI.QueryServerJoinedToRoomResponse{}
if err = r.Queryer.QueryServerJoinedToRoom(ctx, inRoomReq, inRoomRes); err != nil {
return nil, "", "", "", fmt.Errorf("r.Queryer.QueryServerJoinedToRoom: %w", err)
}
serverInRoom := inRoomRes.IsInRoom
forceFederatedJoin := len(req.ServerNames) > 0 && !serverInRoom
userID, err := spec.NewUserID(req.UserID, true)
if err != nil {
return nil, "", "", "", rsAPI.ErrInvalidID{Err: fmt.Errorf("user ID %q is invalid: %w", req.UserID, err)}
}
//TODO: CryptoIDs - what is provided & calculated senderIDs don't match?
// Look up the room NID for the supplied room ID.
var senderID spec.SenderID
checkInvitePending := false
info, err := r.DB.RoomInfo(ctx, req.RoomIDOrAlias)
if err == nil && info != nil {
switch info.RoomVersion {
case gomatrixserverlib.RoomVersionCryptoIDs:
senderIDPtr, queryErr := r.Queryer.QuerySenderIDForUser(ctx, *roomID, *userID)
if queryErr == nil {
checkInvitePending = true
}
if senderIDPtr == nil {
senderID = req.SenderID
} else {
senderID = *senderIDPtr
}
default:
checkInvitePending = true
senderID = spec.SenderID(userID.String())
}
}
// Force a federated join if we're dealing with a pending invite
// and we aren't in the room.
if checkInvitePending {
isInvitePending, inviteSender, _, inviteEvent, inviteErr := helpers.IsInvitePending(ctx, r.DB, req.RoomIDOrAlias, senderID)
if inviteErr == nil && !serverInRoom && isInvitePending {
inviter, queryErr := r.RSAPI.QueryUserIDForSender(ctx, *roomID, inviteSender)
if queryErr != nil {
return nil, "", "", "", fmt.Errorf("r.RSAPI.QueryUserIDForSender: %w", queryErr)
}
// If we were invited by someone from another server then we can
// assume they are in the room so we can join via them.
if inviter != nil && !r.Cfg.Matrix.IsLocalServerName(inviter.Domain()) {
req.ServerNames = append(req.ServerNames, inviter.Domain())
forceFederatedJoin = true
memberEvent := gjson.Parse(string(inviteEvent.JSON()))
// only set unsigned if we've got a content.membership, which we _should_
if memberEvent.Get("content.membership").Exists() {
req.Unsigned = map[string]interface{}{
"prev_sender": memberEvent.Get("sender").Str,
"prev_content": map[string]interface{}{
"is_direct": memberEvent.Get("content.is_direct").Bool(),
"membership": memberEvent.Get("content.membership").Str,
},
}
}
}
}
}
// If a guest is trying to join a room, check that the room has a m.room.guest_access event
if req.IsGuest {
var guestAccessEvent *types.HeaderedEvent
guestAccess := "forbidden"
guestAccessEvent, err = r.DB.GetStateEvent(ctx, req.RoomIDOrAlias, spec.MRoomGuestAccess, "")
if (err != nil && !errors.Is(err, sql.ErrNoRows)) || guestAccessEvent == nil {
logrus.WithError(err).Warn("unable to get m.room.guest_access event, defaulting to 'forbidden'")
}
if guestAccessEvent != nil {
guestAccess = gjson.GetBytes(guestAccessEvent.Content(), "guest_access").String()
}
// Servers MUST only allow guest users to join rooms if the m.room.guest_access state event
// is present on the room and has the guest_access value can_join.
if guestAccess != "can_join" {
return nil, "", "", "", rsAPI.ErrNotAllowed{Err: fmt.Errorf("guest access is forbidden")}
}
}
// If we should do a forced federated join then do that.
if forceFederatedJoin {
joinEvent, version, serverName, federatedJoinErr := r.performFederatedMakeJoinByIDCryptoIDs(ctx, req)
return joinEvent, req.RoomIDOrAlias, version, serverName, federatedJoinErr
}
// Try to construct an actual join event from the template.
// If this succeeds then it is a sign that the room already exists
// locally on the homeserver.
// TODO: Check what happens if the room exists on the server
// but everyone has since left. I suspect it does the wrong thing.
var buildRes rsAPI.QueryLatestEventsAndStateResponse
identity := r.Cfg.Matrix.SigningIdentity
// at this point we know we have an existing room
if inRoomRes.RoomVersion == gomatrixserverlib.RoomVersionCryptoIDs {
mapping := &gomatrixserverlib.MXIDMapping{
UserRoomKey: senderID,
UserID: userID.String(),
}
// Sign the mapping with the server identity
if err = mapping.Sign(identity.ServerName, identity.KeyID, identity.PrivateKey); err != nil {
return nil, "", "", "", err
}
req.Content["mxid_mapping"] = mapping
// sign the event with the pseudo ID key
identity = fclient.SigningIdentity{
ServerName: spec.ServerName(senderID),
KeyID: "ed25519:1",
PrivateKey: nil,
}
}
senderIDString := string(senderID)
// Prepare the template for the join event.
proto := gomatrixserverlib.ProtoEvent{
Type: spec.MRoomMember,
SenderID: senderIDString,
StateKey: &senderIDString,
RoomID: req.RoomIDOrAlias,
Redacts: "",
}
if err = proto.SetUnsigned(struct{}{}); err != nil {
return nil, "", "", "", fmt.Errorf("eb.SetUnsigned: %w", err)
}
// It is possible for the request to include some "content" for the
// event. We'll always overwrite the "membership" key, but the rest,
// like "display_name" or "avatar_url", will be kept if supplied.
if req.Content == nil {
req.Content = map[string]interface{}{}
}
req.Content["membership"] = spec.Join
if authorisedVia, aerr := r.populateAuthorisedViaUserForRestrictedJoin(ctx, req, senderID); aerr != nil {
return nil, "", "", "", aerr
} else if authorisedVia != "" {
req.Content["join_authorised_via_users_server"] = authorisedVia
}
if err = proto.SetContent(req.Content); err != nil {
return nil, "", "", "", fmt.Errorf("eb.SetContent: %w", err)
}
joinEvent, err := eventutil.QueryAndBuildEvent(ctx, &proto, &identity, time.Now(), r.RSAPI, &buildRes)
switch err.(type) {
case nil:
// Do nothing
case eventutil.ErrRoomNoExists:
// The room doesn't exist locally. If the room ID looks like it should
// be ours then this probably means that we've nuked our database at
// some point.
if r.Cfg.Matrix.IsLocalServerName(roomID.Domain()) {
// If there are no more server names to try then give up here.
// Otherwise we'll try a federated join as normal, since it's quite
// possible that the room still exists on other servers.
if len(req.ServerNames) == 0 {
return nil, "", "", "", eventutil.ErrRoomNoExists{}
}
}
// Perform a federated room join.
joinEvent, version, serverName, federatedJoinErr := r.performFederatedMakeJoinByIDCryptoIDs(ctx, req)
return joinEvent, req.RoomIDOrAlias, version, serverName, federatedJoinErr
default:
// Something else went wrong.
return nil, "", "", "", fmt.Errorf("error joining local room: %q", err)
}
// By this point, if req.RoomIDOrAlias contained an alias, then
// it will have been overwritten with a room ID by performJoinRoomByAlias.
// We should now include this in the response so that the CS API can
// return the right room ID.
return joinEvent, req.RoomIDOrAlias, inRoomRes.RoomVersion, userID.Domain(), nil
}
func (r *Joiner) performFederatedMakeJoinByIDCryptoIDs(
ctx context.Context,
req *rsAPI.PerformJoinRequest,
) (gomatrixserverlib.PDU, gomatrixserverlib.RoomVersion, spec.ServerName, error) {
// Try joining by all of the supplied server names.
fedReq := fsAPI.PerformJoinRequest{
RoomID: req.RoomIDOrAlias, // the room ID to try and join
UserID: req.UserID, // the user ID joining the room
ServerNames: req.ServerNames, // the server to try joining with
Content: req.Content, // the membership event content
Unsigned: req.Unsigned, // the unsigned event content, if any
}
joinEvent, version, serverName, err := r.FSAPI.PerformMakeJoin(ctx, &fedReq)
if err != nil {
return nil, "", "", err
}
return joinEvent, version, serverName, nil
}
func (r *Joiner) performFederatedJoinRoomByID(
ctx context.Context,
req *rsAPI.PerformJoinRequest,
) (spec.ServerName, error) {
// Try joining by all of the supplied server names.
fedReq := fsAPI.PerformJoinRequest{
RoomID: req.RoomIDOrAlias, // the room ID to try and join
UserID: req.UserID, // the user ID joining the room
ServerNames: req.ServerNames, // the server to try joining with
Content: req.Content, // the membership event content
Unsigned: req.Unsigned, // the unsigned event content, if any
}
fedRes := fsAPI.PerformJoinResponse{}
r.FSAPI.PerformJoin(ctx, &fedReq, &fedRes)
if fedRes.LastError != nil {
return "", fedRes.LastError
}
return fedRes.JoinedVia, nil
}
func (r *Joiner) populateAuthorisedViaUserForRestrictedJoin(
ctx context.Context,
joinReq *rsAPI.PerformJoinRequest,
senderID spec.SenderID,
) (string, error) {
roomID, err := spec.NewRoomID(joinReq.RoomIDOrAlias)
if err != nil {
return "", err
}
return r.Queryer.QueryRestrictedJoinAllowed(ctx, *roomID, senderID)
}