first commit

backend/internal/api/websocket.go

@@ -0,0 +1,35 @@
+package api
+
+import (
+	"net"
+	"net/http"
+	"net/url"
+	"strings"
+
+	"github.com/gorilla/websocket"
+)
+
+var upgrader = websocket.Upgrader{
+	ReadBufferSize:  1024,
+	WriteBufferSize: 1024,
+	CheckOrigin: func(r *http.Request) bool {
+		origin := r.Header.Get("Origin")
+		if origin == "" {
+			return true
+		}
+		originURL, err := url.Parse(origin)
+		if err != nil {
+			return false
+		}
+		originHost := strings.ToLower(stripPort(originURL.Host))
+		requestHost := strings.ToLower(stripPort(r.Host))
+		return originHost != "" && originHost == requestHost
+	},
+}
+
+func stripPort(host string) string {
+	if parsedHost, _, err := net.SplitHostPort(host); err == nil {
+		return parsedHost
+	}
+	return strings.Trim(host, "[]")
+}