added prefix scan and fixed logout issue

pkg/server/context.go

@@ -25,6 +25,8 @@ const (
 	totpClaim        = "totp"
 	rememberClaim    = "remember"
 	refererClaim     = "referer"
+
+	empty = "(empty)"
 )
 
 func newContext(w http.ResponseWriter, r *http.Request, s *HTTPServer) *Context {
@@ -211,6 +213,14 @@ func (c *Context) Var(name string) (ret string) {
 	return
 }
 
+func (c *Context) Forwarded() (ret string) {
+	ret = c.Request.Header.Get("X-Forwarded-For")
+	if ret == "" {
+		ret = empty
+	}
+	return
+}
+
 // CheckXsrf validates the xsrf token
 func (c *Context) CheckXsrf() (ok bool) {
 	ok = checkXsrf(c.Form("token"), c.Token.RawSig()[:keySize])