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/**
* Standalone signaling server for the Nextcloud Spreed app.
* Copyright (C) 2017 struktur AG
*
* @author Joachim Bauch <bauch@struktur.de>
*
* @license GNU AGPL version 3 or any later version
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package signaling
import (
"context"
"encoding/json"
"log"
"net/url"
"strings"
"sync"
"sync/atomic"
"time"
"unsafe"
"github.com/nats-io/nats.go"
)
var (
// Sessions expire 30 seconds after the connection closed.
sessionExpireDuration = 30 * time.Second
// Warn if a session has 32 or more pending messages.
warnPendingMessagesCount = 32
PathToOcsSignalingBackend = "ocs/v2.php/apps/spreed/api/v1/signaling/backend"
)
type ClientSession struct {
roomJoinTime int64
running int32
hub *Hub
privateId string
publicId string
data *SessionIdData
clientType string
features []string
userId string
userData *json.RawMessage
supportsPermissions bool
permissions map[Permission]bool
backend *Backend
backendUrl string
parsedBackendUrl *url.URL
natsReceiver chan *nats.Msg
stopRun chan bool
runStopped chan bool
expires time.Time
mu sync.Mutex
client *Client
room unsafe.Pointer
roomSessionId string
userSubscription NatsSubscription
sessionSubscription NatsSubscription
roomSubscription NatsSubscription
publishers map[string]McuPublisher
subscribers map[string]McuSubscriber
pendingClientMessages []*ServerMessage
hasPendingChat bool
hasPendingParticipantsUpdate bool
virtualSessions map[*VirtualSession]bool
}
func NewClientSession(hub *Hub, privateId string, publicId string, data *SessionIdData, backend *Backend, hello *HelloClientMessage, auth *BackendClientAuthResponse) (*ClientSession, error) {
s := &ClientSession{
hub: hub,
privateId: privateId,
publicId: publicId,
data: data,
clientType: hello.Auth.Type,
features: hello.Features,
userId: auth.UserId,
userData: auth.User,
backend: backend,
natsReceiver: make(chan *nats.Msg, 64),
stopRun: make(chan bool, 1),
runStopped: make(chan bool, 1),
}
if s.clientType == HelloClientTypeInternal {
s.backendUrl = hello.Auth.internalParams.Backend
s.parsedBackendUrl = hello.Auth.internalParams.parsedBackend
} else {
s.backendUrl = hello.Auth.Url
s.parsedBackendUrl = hello.Auth.parsedUrl
}
if !strings.Contains(s.backendUrl, "/ocs/v2.php/") {
backendUrl := s.backendUrl
if !strings.HasSuffix(backendUrl, "/") {
backendUrl += "/"
}
backendUrl += PathToOcsSignalingBackend
if u, err := url.Parse(backendUrl); err != nil {
return nil, err
} else {
if strings.Contains(u.Host, ":") && hasStandardPort(u) {
u.Host = u.Hostname()
}
s.backendUrl = backendUrl
s.parsedBackendUrl = u
}
}
if err := s.SubscribeNats(hub.nats); err != nil {
return nil, err
}
atomic.StoreInt32(&s.running, 1)
go s.run()
return s, nil
}
func (s *ClientSession) PrivateId() string {
return s.privateId
}
func (s *ClientSession) PublicId() string {
return s.publicId
}
func (s *ClientSession) RoomSessionId() string {
return s.roomSessionId
}
func (s *ClientSession) Data() *SessionIdData {
return s.data
}
func (s *ClientSession) ClientType() string {
return s.clientType
}
func (s *ClientSession) GetFeatures() []string {
return s.features
}
func (s *ClientSession) HasFeature(feature string) bool {
for _, f := range s.features {
if f == feature {
return true
}
}
return false
}
func (s *ClientSession) HasPermission(permission Permission) bool {
s.mu.Lock()
defer s.mu.Unlock()
return s.hasPermissionLocked(permission)
}
func (s *ClientSession) hasPermissionLocked(permission Permission) bool {
if !s.supportsPermissions {
// Old-style session that doesn't receive permissions from Nextcloud.
return true
}
if val, found := s.permissions[permission]; found {
return val
}
return false
}
func permissionsEqual(a, b map[Permission]bool) bool {
if a == nil && b == nil {
return true
} else if a != nil && b == nil {
return false
} else if a == nil && b != nil {
return false
}
if len(a) != len(b) {
return false
}
for k, v1 := range a {
if v2, found := b[k]; !found || v1 != v2 {
return false
}
}
return true
}
func (s *ClientSession) SetPermissions(permissions []Permission) {
var p map[Permission]bool
for _, permission := range permissions {
if p == nil {
p = make(map[Permission]bool)
}
p[permission] = true
}
s.mu.Lock()
defer s.mu.Unlock()
if s.supportsPermissions && permissionsEqual(s.permissions, p) {
return
}
s.permissions = p
s.supportsPermissions = true
log.Printf("Permissions of session %s changed: %s", s.PublicId(), permissions)
}
func (s *ClientSession) Backend() *Backend {
return s.backend
}
func (s *ClientSession) BackendUrl() string {
return s.backendUrl
}
func (s *ClientSession) ParsedBackendUrl() *url.URL {
return s.parsedBackendUrl
}
func (s *ClientSession) AuthUserId() string {
return s.userId
}
func (s *ClientSession) UserId() string {
userId := s.userId
if userId == "" {
if room := s.GetRoom(); room != nil {
if data := room.GetRoomSessionData(s); data != nil {
userId = data.UserId
}
}
}
return userId
}
func (s *ClientSession) UserData() *json.RawMessage {
return s.userData
}
func (s *ClientSession) run() {
loop:
for {
select {
case msg := <-s.natsReceiver:
s.processClientMessage(msg)
case <-s.stopRun:
break loop
}
}
s.runStopped <- true
}
func (s *ClientSession) StartExpire() {
// The hub mutex must be held when calling this method.
s.expires = time.Now().Add(sessionExpireDuration)
s.hub.expiredSessions[s] = true
}
func (s *ClientSession) StopExpire() {
// The hub mutex must be held when calling this method.
delete(s.hub.expiredSessions, s)
}
func (s *ClientSession) IsExpired(now time.Time) bool {
return now.After(s.expires)
}
func (s *ClientSession) SetRoom(room *Room) {
atomic.StorePointer(&s.room, unsafe.Pointer(room))
if room != nil {
atomic.StoreInt64(&s.roomJoinTime, time.Now().UnixNano())
} else {
atomic.StoreInt64(&s.roomJoinTime, 0)
}
}
func (s *ClientSession) GetRoom() *Room {
return (*Room)(atomic.LoadPointer(&s.room))
}
func (s *ClientSession) getRoomJoinTime() time.Time {
return time.Unix(0, atomic.LoadInt64(&s.roomJoinTime))
}
func (s *ClientSession) releaseMcuObjects() {
if len(s.publishers) > 0 {
go func(publishers map[string]McuPublisher) {
ctx := context.TODO()
for _, publisher := range publishers {
publisher.Close(ctx)
}
}(s.publishers)
s.publishers = nil
}
if len(s.subscribers) > 0 {
go func(subscribers map[string]McuSubscriber) {
ctx := context.TODO()
for _, subscriber := range subscribers {
subscriber.Close(ctx)
}
}(s.subscribers)
s.subscribers = nil
}
}
func (s *ClientSession) Close() {
s.closeAndWait(true)
}
func (s *ClientSession) closeAndWait(wait bool) {
s.hub.removeSession(s)
s.mu.Lock()
defer s.mu.Unlock()
if s.userSubscription != nil {
if err := s.userSubscription.Unsubscribe(); err != nil {
log.Printf("Error closing user subscription in session %s: %s", s.PublicId(), err)
}
s.userSubscription = nil
}
if s.sessionSubscription != nil {
if err := s.sessionSubscription.Unsubscribe(); err != nil {
log.Printf("Error closing session subscription in session %s: %s", s.PublicId(), err)
}
s.sessionSubscription = nil
}
go func(virtualSessions map[*VirtualSession]bool) {
for session := range virtualSessions {
session.Close()
}
}(s.virtualSessions)
s.virtualSessions = nil
s.releaseMcuObjects()
s.clearClientLocked(nil)
s.backend.RemoveSession(s)
if atomic.CompareAndSwapInt32(&s.running, 1, 0) {
s.stopRun <- true
// Only wait if called from outside the Session goroutine.
if wait {
s.mu.Unlock()
// Wait for Session goroutine to stop
<-s.runStopped
s.mu.Lock()
}
}
}
func GetSubjectForUserId(userId string, backend *Backend) string {
if backend == nil || backend.IsCompat() {
return GetEncodedSubject("user", userId)
} else {
return GetEncodedSubject("user", userId+"|"+backend.Id())
}
}
func (s *ClientSession) SubscribeNats(n NatsClient) error {
s.mu.Lock()
defer s.mu.Unlock()
var err error
if s.userId != "" {
if s.userSubscription, err = n.Subscribe(GetSubjectForUserId(s.userId, s.backend), s.natsReceiver); err != nil {
return err
}
}
if s.sessionSubscription, err = n.Subscribe("session."+s.publicId, s.natsReceiver); err != nil {
return err
}
return nil
}
func (s *ClientSession) SubscribeRoomNats(n NatsClient, roomid string, roomSessionId string) error {
s.mu.Lock()
defer s.mu.Unlock()
var err error
if s.roomSubscription, err = n.Subscribe(GetSubjectForRoomId(roomid, s.Backend()), s.natsReceiver); err != nil {
return err
}
if roomSessionId != "" {
if err = s.hub.roomSessions.SetRoomSession(s, roomSessionId); err != nil {
s.doUnsubscribeRoomNats(true)
return err
}
}
log.Printf("Session %s joined room %s with room session id %s", s.PublicId(), roomid, roomSessionId)
s.roomSessionId = roomSessionId
return nil
}
func (s *ClientSession) LeaveCall() {
s.mu.Lock()
defer s.mu.Unlock()
room := s.GetRoom()
if room == nil {
return
}
log.Printf("Session %s left call %s", s.PublicId(), room.Id())
s.releaseMcuObjects()
}
func (s *ClientSession) LeaveRoom(notify bool) *Room {
s.mu.Lock()
defer s.mu.Unlock()
room := s.GetRoom()
if room == nil {
return nil
}
s.doUnsubscribeRoomNats(notify)
s.SetRoom(nil)
s.releaseMcuObjects()
room.RemoveSession(s)
return room
}
func (s *ClientSession) UnsubscribeRoomNats() {
s.mu.Lock()
defer s.mu.Unlock()
s.doUnsubscribeRoomNats(true)
}
func (s *ClientSession) doUnsubscribeRoomNats(notify bool) {
if s.roomSubscription != nil {
if err := s.roomSubscription.Unsubscribe(); err != nil {
log.Printf("Error closing room subscription in session %s: %s", s.PublicId(), err)
}
s.roomSubscription = nil
}
s.hub.roomSessions.DeleteRoomSession(s)
room := s.GetRoom()
if notify && room != nil && s.roomSessionId != "" {
// Notify
go func(sid string) {
ctx := context.Background()
request := NewBackendClientRoomRequest(room.Id(), s.userId, sid)
request.Room.Action = "leave"
var response map[string]interface{}
if err := s.hub.backend.PerformJSONRequest(ctx, s.ParsedBackendUrl(), request, &response); err != nil {
log.Printf("Could not notify about room session %s left room %s: %s", sid, room.Id(), err)
} else {
log.Printf("Removed room session %s: %+v", sid, response)
}
}(s.roomSessionId)
}
s.roomSessionId = ""
}
func (s *ClientSession) ClearClient(client *Client) {
s.mu.Lock()
defer s.mu.Unlock()
s.clearClientLocked(client)
}
func (s *ClientSession) clearClientLocked(client *Client) {
if s.client == nil {
return
} else if client != nil && s.client != client {
log.Printf("Trying to clear other client in session %s", s.PublicId())
return
}
prevClient := s.client
s.client = nil
prevClient.SetSession(nil)
}
func (s *ClientSession) GetClient() *Client {
s.mu.Lock()
defer s.mu.Unlock()
return s.getClientUnlocked()
}
func (s *ClientSession) getClientUnlocked() *Client {
return s.client
}
func (s *ClientSession) SetClient(client *Client) *Client {
if client == nil {
panic("Use ClearClient to set the client to nil")
}
s.mu.Lock()
defer s.mu.Unlock()
if client == s.client {
// No change
return nil
}
client.SetSession(s)
prev := s.client
if prev != nil {
s.clearClientLocked(prev)
}
s.client = client
return prev
}
func (s *ClientSession) sendCandidate(client McuClient, sender string, streamType string, candidate interface{}) {
candidate_message := &AnswerOfferMessage{
To: s.PublicId(),
From: sender,
Type: "candidate",
RoomType: streamType,
Payload: map[string]interface{}{
"candidate": candidate,
},
}
candidate_data, err := json.Marshal(candidate_message)
if err != nil {
log.Println("Could not serialize candidate", candidate_message, err)
return
}
response_message := &ServerMessage{
Type: "message",
Message: &MessageServerMessage{
Sender: &MessageServerMessageSender{
Type: "session",
SessionId: sender,
},
Data: (*json.RawMessage)(&candidate_data),
},
}
s.sendMessageUnlocked(response_message)
}
func (s *ClientSession) sendMessageUnlocked(message *ServerMessage) bool {
if c := s.getClientUnlocked(); c != nil {
if c.SendMessage(message) {
return true
}
}
s.storePendingMessage(message)
return true
}
func (s *ClientSession) SendError(e *Error) bool {
message := &ServerMessage{
Type: "error",
Error: e,
}
return s.SendMessage(message)
}
func (s *ClientSession) SendMessage(message *ServerMessage) bool {
s.mu.Lock()
defer s.mu.Unlock()
return s.sendMessageUnlocked(message)
}
func (s *ClientSession) SendMessages(messages []*ServerMessage) bool {
s.mu.Lock()
defer s.mu.Unlock()
for _, message := range messages {
s.sendMessageUnlocked(message)
}
return true
}
func (s *ClientSession) OnIceCandidate(client McuClient, candidate interface{}) {
s.mu.Lock()
defer s.mu.Unlock()
for _, sub := range s.subscribers {
if sub.Id() == client.Id() {
s.sendCandidate(client, sub.Publisher(), client.StreamType(), candidate)
return
}
}
for _, pub := range s.publishers {
if pub.Id() == client.Id() {
s.sendCandidate(client, s.PublicId(), client.StreamType(), candidate)
return
}
}
log.Printf("Session %s received candidate %+v for unknown client %s", s.PublicId(), candidate, client.Id())
}
func (s *ClientSession) OnIceCompleted(client McuClient) {
// TODO(jojo): This causes a JavaScript error when creating a candidate from "null".
// Figure out a better way to signal this.
// An empty candidate signals the end of candidates.
// s.OnIceCandidate(client, nil)
}
func (s *ClientSession) PublisherClosed(publisher McuPublisher) {
s.mu.Lock()
defer s.mu.Unlock()
for id, p := range s.publishers {
if p == publisher {
delete(s.publishers, id)
break
}
}
}
func (s *ClientSession) SubscriberClosed(subscriber McuSubscriber) {
s.mu.Lock()
defer s.mu.Unlock()
for id, sub := range s.subscribers {
if sub == subscriber {
delete(s.subscribers, id)
break
}
}
}
func (s *ClientSession) GetOrCreatePublisher(ctx context.Context, mcu Mcu, streamType string) (McuPublisher, error) {
s.mu.Lock()
defer s.mu.Unlock()
publisher, found := s.publishers[streamType]
if !found {
client := s.getClientUnlocked()
s.mu.Unlock()
var bitrate int
if backend := s.Backend(); backend != nil {
if streamType == streamTypeScreen {
bitrate = backend.maxScreenBitrate
} else {
bitrate = backend.maxStreamBitrate
}
}
var err error
publisher, err = mcu.NewPublisher(ctx, s, s.PublicId(), streamType, bitrate, client)
s.mu.Lock()
if err != nil {
return nil, err
}
if s.publishers == nil {
s.publishers = make(map[string]McuPublisher)
}
if prev, found := s.publishers[streamType]; found {
// Another thread created the publisher while we were waiting.
go func(pub McuPublisher) {
closeCtx := context.TODO()
pub.Close(closeCtx)
}(publisher)
publisher = prev
} else {
s.publishers[streamType] = publisher
}
log.Printf("Publishing %s as %s for session %s", streamType, publisher.Id(), s.PublicId())
}
return publisher, nil
}
func (s *ClientSession) GetPublisher(streamType string) McuPublisher {
s.mu.Lock()
defer s.mu.Unlock()
return s.publishers[streamType]
}
func (s *ClientSession) GetOrCreateSubscriber(ctx context.Context, mcu Mcu, id string, streamType string) (McuSubscriber, error) {
s.mu.Lock()
defer s.mu.Unlock()
// TODO(jojo): Add method to remove subscribers.
subscriber, found := s.subscribers[id+"|"+streamType]
if !found {
s.mu.Unlock()
var err error
subscriber, err = mcu.NewSubscriber(ctx, s, id, streamType)
s.mu.Lock()
if err != nil {
return nil, err
}
if s.subscribers == nil {
s.subscribers = make(map[string]McuSubscriber)
}
if prev, found := s.subscribers[id+"|"+streamType]; found {
// Another thread created the subscriber while we were waiting.
go func(sub McuSubscriber) {
closeCtx := context.TODO()
sub.Close(closeCtx)
}(subscriber)
subscriber = prev
} else {
s.subscribers[id+"|"+streamType] = subscriber
}
log.Printf("Subscribing %s from %s as %s in session %s", streamType, id, subscriber.Id(), s.PublicId())
}
return subscriber, nil
}
func (s *ClientSession) GetSubscriber(id string, streamType string) McuSubscriber {
s.mu.Lock()
defer s.mu.Unlock()
return s.subscribers[id+"|"+streamType]
}
func (s *ClientSession) processClientMessage(msg *nats.Msg) {
var message NatsMessage
if err := s.hub.nats.Decode(msg, &message); err != nil {
log.Printf("Could not decode NATS message %+v for session %s: %s", *msg, s.PublicId(), err)
return
}
switch message.Type {
case "permissions":
s.SetPermissions(message.Permissions)
go func() {
s.mu.Lock()
defer s.mu.Unlock()
if !s.hasPermissionLocked(PERMISSION_MAY_PUBLISH_MEDIA) {
if publisher, found := s.publishers[streamTypeVideo]; found {
delete(s.publishers, streamTypeVideo)
log.Printf("Session %s is no longer allowed to publish media, closing publisher %s", s.PublicId(), publisher.Id())
go func() {
publisher.Close(context.Background())
}()
}
}
if !s.hasPermissionLocked(PERMISSION_MAY_PUBLISH_SCREEN) {
if publisher, found := s.publishers[streamTypeScreen]; found {
delete(s.publishers, streamTypeScreen)
log.Printf("Session %s is no longer allowed to publish screen, closing publisher %s", s.PublicId(), publisher.Id())
go func() {
publisher.Close(context.Background())
}()
}
}
}()
return
case "message":
if message.Message.Type == "bye" && message.Message.Bye.Reason == "room_session_reconnected" {
s.mu.Lock()
roomSessionId := s.RoomSessionId()
s.mu.Unlock()
log.Printf("Closing session %s because same room session %s connected", s.PublicId(), roomSessionId)
s.LeaveRoom(false)
defer s.closeAndWait(false)
}
}
serverMessage := s.processNatsMessage(&message)
if serverMessage == nil {
return
}
s.SendMessage(serverMessage)
}
func (s *ClientSession) storePendingMessage(message *ServerMessage) {
if message.IsChatRefresh() {
if s.hasPendingChat {
// Only send a single "chat-refresh" message on resume.
return
}
s.hasPendingChat = true
}
if !s.hasPendingParticipantsUpdate && message.IsParticipantsUpdate() {
s.hasPendingParticipantsUpdate = true
}
s.pendingClientMessages = append(s.pendingClientMessages, message)
if len(s.pendingClientMessages) >= warnPendingMessagesCount {
log.Printf("Session %s has %d pending messages", s.PublicId(), len(s.pendingClientMessages))
}
}
func (s *ClientSession) processNatsMessage(msg *NatsMessage) *ServerMessage {
switch msg.Type {
case "message":
if msg.Message == nil {
log.Printf("Received NATS message without payload: %+v", msg)
return nil
}
switch msg.Message.Type {
case "message":
if msg.Message.Message != nil &&
msg.Message.Message.Sender != nil &&
msg.Message.Message.Sender.SessionId == s.PublicId() {
// Don't send message back to sender (can happen if sent to user or room)
return nil
}
case "control":
if msg.Message.Control != nil &&
msg.Message.Control.Sender != nil &&
msg.Message.Control.Sender.SessionId == s.PublicId() {
// Don't send message back to sender (can happen if sent to user or room)
return nil
}
case "event":
if msg.Message.Event.Target == "participants" &&
msg.Message.Event.Type == "update" {
m := msg.Message.Event.Update
users := make(map[string]bool)
for _, entry := range m.Users {
users[entry["sessionId"].(string)] = true
}
for _, entry := range m.Changed {
if users[entry["sessionId"].(string)] {
continue
}
m.Users = append(m.Users, entry)
}
// TODO(jojo): Only send all users if current session id has
// changed its "inCall" flag to true.
m.Changed = nil
} else if msg.Message.Event.Target == "room" {
// Can happen mostly during tests where an older room NATS message
// could be received by a subscriber that joined after it was sent.
if msg.SendTime.Before(s.getRoomJoinTime()) {
log.Printf("Message %+v was sent before room was joined, ignoring", msg.Message)
return nil
}
}
}
return msg.Message
default:
log.Printf("Received NATS message with unsupported type %s: %+v", msg.Type, msg)
return nil
}
}
func (s *ClientSession) NotifySessionResumed(client *Client) {
s.mu.Lock()
if len(s.pendingClientMessages) == 0 {
s.mu.Unlock()
if room := s.GetRoom(); room != nil {
room.NotifySessionResumed(s)
}
return
}
messages := s.pendingClientMessages
hasPendingParticipantsUpdate := s.hasPendingParticipantsUpdate
s.pendingClientMessages = nil
s.hasPendingChat = false
s.hasPendingParticipantsUpdate = false
s.mu.Unlock()
log.Printf("Send %d pending messages to session %s", len(messages), s.PublicId())
// Send through session to handle connection interruptions.
s.SendMessages(messages)
if !hasPendingParticipantsUpdate {
// Only need to send initial participants list update if none was part of the pending messages.
if room := s.GetRoom(); room != nil {
room.NotifySessionResumed(s)
}
}
}
func (s *ClientSession) AddVirtualSession(session *VirtualSession) {
s.mu.Lock()
if s.virtualSessions == nil {
s.virtualSessions = make(map[*VirtualSession]bool)
}
s.virtualSessions[session] = true
s.mu.Unlock()
}
func (s *ClientSession) RemoveVirtualSession(session *VirtualSession) {
s.mu.Lock()
delete(s.virtualSessions, session)
s.mu.Unlock()
}