Optionally disable chat rate limiter and add optional chat slur/language filter (#3681)

* feat(chat): basic profanity filter. For #3139

* feat(chat): add setting for disabling chat spam protection. Closes #3523

* feat(chat): wire up the new chat slur filter to admin and chat. Closes #3139

core/chat/chatclient.go

@@ -13,19 +13,21 @@ import (
 	"github.com/gorilla/websocket"
 	"github.com/owncast/owncast/config"
 	"github.com/owncast/owncast/core/chat/events"
+	"github.com/owncast/owncast/core/data"
 	"github.com/owncast/owncast/core/user"
 	"github.com/owncast/owncast/geoip"
 )
 
 // Client represents a single chat client.
 type Client struct {
-	ConnectedAt  time.Time `json:"connectedAt"`
-	timeoutTimer *time.Timer
-	rateLimiter  *rate.Limiter
-	conn         *websocket.Conn
-	User         *user.User `json:"user"`
-	server       *Server
-	Geo          *geoip.GeoDetails `json:"geo"`
+	ConnectedAt   time.Time `json:"connectedAt"`
+	timeoutTimer  *time.Timer
+	rateLimiter   *rate.Limiter
+	messageFilter *ChatMessageFilter
+	conn          *websocket.Conn
+	User          *user.User `json:"user"`
+	server        *Server
+	Geo           *geoip.GeoDetails `json:"geo"`
 	// Buffered channel of outbound messages.
 	send         chan []byte
 	accessToken  string
@@ -90,6 +92,7 @@ func (c *Client) readPump() {
 	// Allow 3 messages every two seconds.
 	limit := rate.Every(2 * time.Second / 3)
 	c.rateLimiter = rate.NewLimiter(limit, 1)
+	c.messageFilter = NewMessageFilter()
 
 	defer func() {
 		c.close()
@@ -129,6 +132,12 @@ func (c *Client) readPump() {
 			continue
 		}
 
+		// Check if this message passes the optional language filter
+		if data.GetChatSlurFilterEnabled() && !c.messageFilter.Allow(string(message)) {
+			c.sendAction("Sorry, that message contained language that is not allowed in this chat.")
+			continue
+		}
+
 		message = bytes.TrimSpace(bytes.ReplaceAll(message, newline, space))
 		c.handleEvent(message)
 	}
@@ -200,7 +209,13 @@ func (c *Client) close() {
 }
 
 func (c *Client) passesRateLimit() bool {
-	return c.User.IsModerator() || (c.rateLimiter.Allow() && !c.inTimeout)
+	// If spam rate limiting is disabled, or the user is a moderator, always
+	// allow the message.
+	if !data.GetChatSpamProtectionEnabled() || c.User.IsModerator() {
+		return true
+	}
+
+	return (c.rateLimiter.Allow() && !c.inTimeout)
 }
 
 func (c *Client) startChatRejectionTimeout() {

core/chat/messageFilter.go

@@ -0,0 +1,18 @@
+package chat
+
+import (
+	goaway "github.com/TwiN/go-away"
+)
+
+// ChatMessageFilter is a allow/deny chat message filter.
+type ChatMessageFilter struct{}
+
+// NewMessageFilter will return an instance of the chat message filter.
+func NewMessageFilter() *ChatMessageFilter {
+	return &ChatMessageFilter{}
+}
+
+// Allow will test if this message should be allowed to be sent.
+func (*ChatMessageFilter) Allow(message string) bool {
+	return !goaway.IsProfane(message)
+}

core/chat/messageFilter_test.go

@@ -0,0 +1,39 @@
+package chat
+
+import (
+	"testing"
+)
+
+func TestFiltering(t *testing.T) {
+	filter := NewMessageFilter()
+
+	filteredTestMessages := []string{
+		"Hello, fucking world!",
+		"Suck my dick",
+		"Eat my ass",
+		"fuck this shit",
+		"@$$h073",
+		"F   u   C  k th1$ $h!t",
+		"u r fag",
+		"fucking sucks",
+	}
+
+	unfilteredTestMessages := []string{
+		"bass fish",
+		"assumptions",
+	}
+
+	for _, m := range filteredTestMessages {
+		result := filter.Allow(m)
+		if result {
+			t.Errorf("%s should be seen as a filtered profane message", m)
+		}
+	}
+
+	for _, m := range unfilteredTestMessages {
+		result := filter.Allow(m)
+		if !result {
+			t.Errorf("%s should not be filtered", m)
+		}
+	}
+}

core/data/config.go

@@ -59,6 +59,8 @@ const (
 	suggestedUsernamesKey           = "suggested_usernames"
 	chatJoinMessagesEnabledKey      = "chat_join_messages_enabled"
 	chatEstablishedUsersOnlyModeKey = "chat_established_users_only_mode"
+	chatSpamProtectionEnabledKey    = "chat_spam_protection_enabled"
+	chatSlurFilterEnabledKey        = "chat_slur_filter_enabled"
 	notificationsEnabledKey         = "notifications_enabled"
 	discordConfigurationKey         = "discord_configuration"
 	browserPushConfigurationKey     = "browser_push_configuration"
@@ -528,6 +530,36 @@ func GetChatEstbalishedUsersOnlyMode() bool {
 	return false
 }
 
+// SetChatSpamProtectionEnabled will enable chat spam protection if set to true.
+func SetChatSpamProtectionEnabled(enabled bool) error {
+	return _datastore.SetBool(chatSpamProtectionEnabledKey, enabled)
+}
+
+// GetChatSpamProtectionEnabled will return if chat spam protection is enabled.
+func GetChatSpamProtectionEnabled() bool {
+	enabled, err := _datastore.GetBool(chatSpamProtectionEnabledKey)
+	if err == nil {
+		return enabled
+	}
+
+	return true
+}
+
+// SetChatSlurFilterEnabled will enable the chat slur filter.
+func SetChatSlurFilterEnabled(enabled bool) error {
+	return _datastore.SetBool(chatSlurFilterEnabledKey, enabled)
+}
+
+// GetChatSlurFilterEnabled will return if the chat slur filter is enabled.
+func GetChatSlurFilterEnabled() bool {
+	enabled, err := _datastore.GetBool(chatSlurFilterEnabledKey)
+	if err == nil {
+		return enabled
+	}
+
+	return false
+}
+
 // GetExternalActions will return the registered external actions.
 func GetExternalActions() []models.ExternalAction {
 	configEntry, err := _datastore.Get(externalActionsKey)