BareRTC/pkg/websocket.go

544 lines
14 KiB
Go

package barertc
import (
"context"
"encoding/json"
"errors"
"fmt"
"net/http"
"sort"
"strings"
"sync"
"time"
"git.kirsle.net/apps/barertc/pkg/config"
"git.kirsle.net/apps/barertc/pkg/jwt"
"git.kirsle.net/apps/barertc/pkg/log"
"git.kirsle.net/apps/barertc/pkg/messages"
"git.kirsle.net/apps/barertc/pkg/util"
"nhooyr.io/websocket"
)
// Subscriber represents a connected WebSocket session.
type Subscriber struct {
// User properties
ID int // ID assigned by server
Username string
ChatStatus string
VideoStatus int
DND bool // Do Not Disturb status (DMs are closed)
JWTClaims *jwt.Claims
authenticated bool // has passed the login step
loginAt time.Time
conn *websocket.Conn
ctx context.Context
cancel context.CancelFunc
messages chan []byte
closeSlow func()
muteMu sync.RWMutex
booted map[string]struct{} // usernames booted off your camera
blocked map[string]struct{} // usernames you have blocked
muted map[string]struct{} // usernames you muted
// Record which message IDs belong to this user.
midMu sync.Mutex
messageIDs map[int64]struct{}
}
// ReadLoop spawns a goroutine that reads from the websocket connection.
func (sub *Subscriber) ReadLoop(s *Server) {
go func() {
for {
msgType, data, err := sub.conn.Read(sub.ctx)
if err != nil {
log.Error("ReadLoop error(%d=%s): %+v", sub.ID, sub.Username, err)
s.DeleteSubscriber(sub)
// Notify if this user was auth'd and not hidden
if sub.authenticated && sub.ChatStatus != "hidden" {
s.Broadcast(messages.Message{
Action: messages.ActionPresence,
Username: sub.Username,
Message: "has exited the room!",
})
s.SendWhoList()
}
return
}
if msgType != websocket.MessageText {
log.Error("Unexpected MessageType")
continue
}
// Read the user's posted message.
var msg messages.Message
if err := json.Unmarshal(data, &msg); err != nil {
log.Error("Read(%d=%s) Message error: %s", sub.ID, sub.Username, err)
continue
}
if msg.Action != messages.ActionFile {
log.Debug("Read(%d=%s): %s", sub.ID, sub.Username, data)
}
// What action are they performing?
switch msg.Action {
case messages.ActionLogin:
s.OnLogin(sub, msg)
case messages.ActionMessage:
s.OnMessage(sub, msg)
case messages.ActionFile:
s.OnFile(sub, msg)
case messages.ActionMe:
s.OnMe(sub, msg)
case messages.ActionOpen:
s.OnOpen(sub, msg)
case messages.ActionBoot:
s.OnBoot(sub, msg)
case messages.ActionMute, messages.ActionUnmute:
s.OnMute(sub, msg, msg.Action == messages.ActionMute)
case messages.ActionBlock:
s.OnBlock(sub, msg)
case messages.ActionBlocklist:
s.OnBlocklist(sub, msg)
case messages.ActionCandidate:
s.OnCandidate(sub, msg)
case messages.ActionSDP:
s.OnSDP(sub, msg)
case messages.ActionWatch:
s.OnWatch(sub, msg)
case messages.ActionUnwatch:
s.OnUnwatch(sub, msg)
case messages.ActionTakeback:
s.OnTakeback(sub, msg)
case messages.ActionReact:
s.OnReact(sub, msg)
case messages.ActionReport:
s.OnReport(sub, msg)
default:
sub.ChatServer("Unsupported message type.")
}
}
}()
}
// IsAdmin safely checks if the subscriber is an admin.
func (sub *Subscriber) IsAdmin() bool {
return sub.JWTClaims != nil && sub.JWTClaims.IsAdmin
}
// IsVIP safely checks if the subscriber has VIP status.
func (sub *Subscriber) IsVIP() bool {
return sub.JWTClaims != nil && sub.JWTClaims.VIP
}
// SendJSON sends a JSON message to the websocket client.
func (sub *Subscriber) SendJSON(v interface{}) error {
data, err := json.Marshal(v)
if err != nil {
return err
}
log.Debug("SendJSON(%d=%s): %s", sub.ID, sub.Username, data)
// Add the message to the recipient's queue. If the queue is too full,
// disconnect the client as they can't keep up.
select {
case sub.messages <- data:
default:
go sub.closeSlow()
}
return nil
}
// SendMe sends the current user state to the client.
func (sub *Subscriber) SendMe() {
sub.SendJSON(messages.Message{
Action: messages.ActionMe,
Username: sub.Username,
VideoStatus: sub.VideoStatus,
})
}
// ChatServer is a convenience function to deliver a ChatServer error to the client.
func (sub *Subscriber) ChatServer(message string, v ...interface{}) {
sub.SendJSON(messages.Message{
Action: messages.ActionError,
Username: "ChatServer",
Message: fmt.Sprintf(message, v...),
})
}
// WebSocket handles the /ws websocket connection endpoint.
func (s *Server) WebSocket() http.HandlerFunc {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
ip := util.IPAddress(r)
log.Info("WebSocket connection from %s - %s", ip, r.Header.Get("User-Agent"))
log.Debug("Headers: %+v", r.Header)
c, err := websocket.Accept(w, r, &websocket.AcceptOptions{
CompressionMode: websocket.CompressionDisabled,
})
if err != nil {
w.WriteHeader(http.StatusInternalServerError)
fmt.Fprintf(w, "Could not accept websocket connection: %s", err)
return
}
defer c.Close(websocket.StatusInternalError, "the sky is falling")
log.Debug("WebSocket: %s has connected", ip)
c.SetReadLimit(config.Current.WebSocketReadLimit)
// CloseRead starts a goroutine that will read from the connection
// until it is closed.
// ctx := c.CloseRead(r.Context())
ctx, cancel := context.WithCancel(r.Context())
sub := &Subscriber{
conn: c,
ctx: ctx,
cancel: cancel,
messages: make(chan []byte, s.subscriberMessageBuffer),
closeSlow: func() {
c.Close(websocket.StatusPolicyViolation, "connection too slow to keep up with messages")
},
booted: make(map[string]struct{}),
muted: make(map[string]struct{}),
blocked: make(map[string]struct{}),
messageIDs: make(map[int64]struct{}),
ChatStatus: "online",
}
s.AddSubscriber(sub)
defer s.DeleteSubscriber(sub)
go sub.ReadLoop(s)
pinger := time.NewTicker(PingInterval)
for {
select {
case msg := <-sub.messages:
err = writeTimeout(ctx, time.Second*time.Duration(config.Current.WebSocketSendTimeout), c, msg)
if err != nil {
return
}
case <-pinger.C:
// Send a ping, and a refreshed JWT token if the user sent one.
var token string
if sub.JWTClaims != nil {
if jwt, err := sub.JWTClaims.ReSign(); err != nil {
log.Error("ReSign JWT token for %s: %s", sub.Username, err)
} else {
token = jwt
}
}
sub.SendJSON(messages.Message{
Action: messages.ActionPing,
JWTToken: token,
})
case <-ctx.Done():
pinger.Stop()
return
}
}
})
}
// Auto incrementing Subscriber ID, assigned in AddSubscriber.
var SubscriberID int
// AddSubscriber adds a WebSocket subscriber to the server.
func (s *Server) AddSubscriber(sub *Subscriber) {
// Assign a unique ID.
SubscriberID++
sub.ID = SubscriberID
log.Debug("AddSubscriber: ID #%d", sub.ID)
s.subscribersMu.Lock()
s.subscribers[sub] = struct{}{}
s.subscribersMu.Unlock()
}
// GetSubscriber by username.
func (s *Server) GetSubscriber(username string) (*Subscriber, error) {
for _, sub := range s.IterSubscribers() {
if sub.Username == username {
return sub, nil
}
}
return nil, errors.New("not found")
}
// DeleteSubscriber removes a subscriber from the server.
func (s *Server) DeleteSubscriber(sub *Subscriber) {
log.Error("DeleteSubscriber: %s", sub.Username)
// Cancel its context to clean up the for-loop goroutine.
if sub.cancel != nil {
sub.cancel()
}
s.subscribersMu.Lock()
delete(s.subscribers, sub)
s.subscribersMu.Unlock()
}
// IterSubscribers loops over the subscriber list with a read lock.
func (s *Server) IterSubscribers() []*Subscriber {
var result = []*Subscriber{}
// Lock for reads.
s.subscribersMu.RLock()
for sub := range s.subscribers {
result = append(result, sub)
}
s.subscribersMu.RUnlock()
return result
}
// UniqueUsername ensures a username will be unique or renames it. If the name is already unique, the error result is nil.
func (s *Server) UniqueUsername(username string) (string, error) {
var (
subs = s.IterSubscribers()
usernames = map[string]interface{}{}
origUsername = username
counter = 2
)
for _, sub := range subs {
usernames[sub.Username] = nil
}
// Check until unique.
for {
if _, ok := usernames[username]; ok {
username = fmt.Sprintf("%s %d", origUsername, counter)
counter++
} else {
break
}
}
if username != origUsername {
return username, errors.New("username was not unique and a unique name has been returned")
}
return username, nil
}
// Broadcast a message to the chat room.
func (s *Server) Broadcast(msg messages.Message) {
if len(msg.Message) < 1024 {
log.Debug("Broadcast: %+v", msg)
}
// Get the sender of this message.
sender, err := s.GetSubscriber(msg.Username)
if err != nil {
log.Error("Broadcast: sender name %s not found as a current subscriber!", msg.Username)
sender = nil
}
// Get the list of users who are online NOW, so we don't hold the mutex lock too long.
// Example: sending a fat GIF to a large audience could hang up the server for a long
// time until every copy of the GIF has been sent.
var subs = s.IterSubscribers()
for _, sub := range subs {
if !sub.authenticated {
continue
}
// Don't deliver it if the receiver has muted us.
if sub.Mutes(msg.Username) {
log.Debug("Do not broadcast message to %s: they have muted or booted %s", sub.Username, msg.Username)
continue
}
// Don't deliver it if there is any blocking between sender and receiver.
if sender != nil && sender.Blocks(sub) {
log.Debug("Do not broadcast message to %s: blocking between them and %s", msg.Username, sub.Username)
continue
}
// VIP channels: only deliver to subscribed VIP users.
if ch, ok := config.Current.GetChannel(msg.Channel); ok && ch.VIP && !sub.IsVIP() && !sub.IsAdmin() {
log.Debug("Do not broadcast message to %s: VIP channel and they are not VIP", sub.Username)
continue
}
sub.SendJSON(msg)
}
}
// SendTo sends a message to a given username.
func (s *Server) SendTo(username string, msg messages.Message) error {
log.Debug("SendTo(%s): %+v", username, msg)
username = strings.TrimPrefix(username, "@")
var found bool
var subs = s.IterSubscribers()
for _, sub := range subs {
if sub.Username == username {
found = true
sub.SendJSON(messages.Message{
Action: msg.Action,
Channel: msg.Channel,
Username: msg.Username,
Message: msg.Message,
MessageID: msg.MessageID,
})
}
}
if !found {
return fmt.Errorf("%s is not online", username)
}
return nil
}
// SendWhoList broadcasts the connected members to everybody in the room.
func (s *Server) SendWhoList() {
var (
subscribers = s.IterSubscribers()
usernames = []string{} // distinct and sorted usernames
userSub = map[string]*Subscriber{}
)
for _, sub := range subscribers {
if !sub.authenticated {
continue
}
usernames = append(usernames, sub.Username)
userSub[sub.Username] = sub
}
sort.Strings(usernames)
// Build the WhoList for each subscriber.
// TODO: it's the only way to fake videoActive for booted user views.
for _, sub := range subscribers {
if !sub.authenticated {
continue
}
var users = []messages.WhoList{}
for _, un := range usernames {
user := userSub[un]
if user.ChatStatus == "hidden" {
continue
}
// Blocking: hide the presence of both people from the Who List.
if user.Blocks(sub) {
log.Debug("WhoList: hide %s from %s (blocking)", user.Username, sub.Username)
continue
}
who := messages.WhoList{
Username: user.Username,
Status: user.ChatStatus,
Video: user.VideoStatus,
DND: user.DND,
LoginAt: user.loginAt.Unix(),
}
// Hide video flags of other users (never for the current user).
if user.Username != sub.Username {
// If this person had booted us, force their camera to "off"
if user.Boots(sub.Username) || user.Mutes(sub.Username) {
if sub.IsAdmin() {
// They kicked the admin off, but admin can reopen the cam if they want.
// But, unset the user's "auto-open your camera" flag, so if the admin
// reopens it, the admin's cam won't open on the recipient's screen.
who.Video ^= messages.VideoFlagMutualOpen
} else {
// Force their video to "off"
who.Video = 0
}
}
// If this person's VideoFlag is set to VIP Only, force their camera to "off"
// except when the person looking has the VIP status.
if (user.VideoStatus&messages.VideoFlagOnlyVIP == messages.VideoFlagOnlyVIP) && (!sub.IsVIP() && !sub.IsAdmin()) {
who.Video = 0
}
}
if user.JWTClaims != nil {
who.Operator = user.JWTClaims.IsAdmin
who.Avatar = user.JWTClaims.Avatar
who.ProfileURL = user.JWTClaims.ProfileURL
who.Nickname = user.JWTClaims.Nick
who.Emoji = user.JWTClaims.Emoji
who.Gender = user.JWTClaims.Gender
// VIP flags: if we are in MutuallySecret mode, only VIPs can see
// other VIP flags on the Who List.
if config.Current.VIP.MutuallySecret {
if sub.IsVIP() || sub.IsAdmin() {
who.VIP = user.JWTClaims.VIP
}
} else {
who.VIP = user.JWTClaims.VIP
}
}
users = append(users, who)
}
sub.SendJSON(messages.Message{
Action: messages.ActionWhoList,
WhoList: users,
})
}
}
// Boots checks whether the subscriber has blocked username from their camera.
func (s *Subscriber) Boots(username string) bool {
s.muteMu.RLock()
defer s.muteMu.RUnlock()
_, ok := s.booted[username]
return ok
}
// Mutes checks whether the subscriber has muted username.
func (s *Subscriber) Mutes(username string) bool {
s.muteMu.RLock()
defer s.muteMu.RUnlock()
_, ok := s.muted[username]
return ok
}
// Blocks checks whether the subscriber blocks the username, or vice versa (blocking goes both directions).
func (s *Subscriber) Blocks(other *Subscriber) bool {
if s == nil || other == nil {
return false
}
// If either side is an admin, blocking is not allowed.
if s.IsAdmin() || other.IsAdmin() {
return false
}
s.muteMu.RLock()
defer s.muteMu.RUnlock()
// Forward block?
if _, ok := s.blocked[other.Username]; ok {
return true
}
// Reverse block?
other.muteMu.RLock()
defer other.muteMu.RUnlock()
_, ok := other.blocked[s.Username]
return ok
}
func writeTimeout(ctx context.Context, timeout time.Duration, c *websocket.Conn, msg []byte) error {
ctx, cancel := context.WithTimeout(ctx, timeout)
defer cancel()
return c.Write(ctx, websocket.MessageText, msg)
}