package connectionheader import ( "net/http" "net/textproto" "strings" "golang.org/x/net/http/httpguts" ) const ( connectionHeader = "Connection" upgradeHeader = "Upgrade" ) // Remover removes hop-by-hop headers listed in the "Connection" header. // See RFC 7230, section 6.1. func Remover(next http.Handler) http.HandlerFunc { return func(rw http.ResponseWriter, req *http.Request) { var reqUpType string if httpguts.HeaderValuesContainsToken(req.Header[connectionHeader], upgradeHeader) { reqUpType = req.Header.Get(upgradeHeader) } removeConnectionHeaders(req.Header) if reqUpType != "" { req.Header.Set(connectionHeader, upgradeHeader) req.Header.Set(upgradeHeader, reqUpType) } else { req.Header.Del(connectionHeader) } next.ServeHTTP(rw, req) } } func removeConnectionHeaders(h http.Header) { for _, f := range h[connectionHeader] { for _, sf := range strings.Split(f, ",") { if sf = textproto.TrimString(sf); sf != "" { h.Del(sf) } } } }