package http import ( "bytes" "errors" "strings" "v2ray.com/core/common" ) type version byte const ( HTTP1 version = iota HTTP2 ) type SniffHeader struct { version version host string } func (h *SniffHeader) Protocol() string { switch h.version { case HTTP1: return "http1" case HTTP2: return "http2" default: return "unknown" } } func (h *SniffHeader) Domain() string { return h.host } var ( methods = [...]string{"get", "post", "head", "put", "delete", "options", "connect"} errNotHTTPMethod = errors.New("not an HTTP method") ) func beginWithHTTPMethod(b []byte) error { for _, m := range &methods { if len(b) >= len(m) && strings.ToLower(string(b[:len(m)])) == m { return nil } if len(b) < len(m) { return common.ErrNoClue } } return errNotHTTPMethod } func SniffHTTP(b []byte) (*SniffHeader, error) { if err := beginWithHTTPMethod(b); err != nil { return nil, err } sh := &SniffHeader{ version: HTTP1, } headers := bytes.Split(b, []byte{'\n'}) for i := 1; i < len(headers); i++ { header := headers[i] if len(header) == 0 { break } parts := bytes.SplitN(header, []byte{':'}, 2) if len(parts) != 2 { continue } key := strings.ToLower(string(parts[0])) value := strings.ToLower(string(bytes.Trim(parts[1], " "))) if key == "host" { domain := strings.Split(value, ":") sh.host = strings.TrimSpace(domain[0]) } } if len(sh.host) > 0 { return sh, nil } return nil, common.ErrNoClue }