package promscrape import ( "context" "fmt" "net" "strconv" "strings" "sync" "sync/atomic" "time" "github.com/VictoriaMetrics/VictoriaMetrics/lib/netutil" "github.com/VictoriaMetrics/metrics" ) func statStdDial(ctx context.Context, _, addr string) (net.Conn, error) { d := getStdDialer() network := netutil.GetTCPNetwork() conn, err := d.DialContext(ctx, network, addr) dialsTotal.Inc() if err != nil { dialErrors.Inc() if !netutil.TCP6Enabled() && !isTCPv4Addr(addr) { err = fmt.Errorf("%w; try -enableTCP6 command-line flag if you scrape ipv6 addresses", err) } return nil, err } conns.Inc() sc := &statConn{ Conn: conn, } return sc, nil } func getStdDialer() *net.Dialer { stdDialerOnce.Do(func() { stdDialer = &net.Dialer{ Timeout: 30 * time.Second, KeepAlive: 30 * time.Second, DualStack: netutil.TCP6Enabled(), } }) return stdDialer } var ( stdDialer *net.Dialer stdDialerOnce sync.Once ) var ( dialsTotal = metrics.NewCounter(`vm_promscrape_dials_total`) dialErrors = metrics.NewCounter(`vm_promscrape_dial_errors_total`) conns = metrics.NewCounter(`vm_promscrape_conns`) ) type statConn struct { closed atomic.Int32 net.Conn } func (sc *statConn) Read(p []byte) (int, error) { n, err := sc.Conn.Read(p) connReadsTotal.Inc() if err != nil { connReadErrors.Inc() } connBytesRead.Add(n) return n, err } func (sc *statConn) Write(p []byte) (int, error) { n, err := sc.Conn.Write(p) connWritesTotal.Inc() if err != nil { connWriteErrors.Inc() } connBytesWritten.Add(n) return n, err } func (sc *statConn) Close() error { err := sc.Conn.Close() if sc.closed.Add(1) == 1 { conns.Dec() } return err } var ( connReadsTotal = metrics.NewCounter(`vm_promscrape_conn_reads_total`) connWritesTotal = metrics.NewCounter(`vm_promscrape_conn_writes_total`) connReadErrors = metrics.NewCounter(`vm_promscrape_conn_read_errors_total`) connWriteErrors = metrics.NewCounter(`vm_promscrape_conn_write_errors_total`) connBytesRead = metrics.NewCounter(`vm_promscrape_conn_bytes_read_total`) connBytesWritten = metrics.NewCounter(`vm_promscrape_conn_bytes_written_total`) ) func isTCPv4Addr(addr string) bool { s := addr for i := 0; i < 3; i++ { n := strings.IndexByte(s, '.') if n < 0 { return false } if !isUint8NumString(s[:n]) { return false } s = s[n+1:] } n := strings.IndexByte(s, ':') if n < 0 { return false } if !isUint8NumString(s[:n]) { return false } s = s[n+1:] // Verify TCP port n, err := strconv.Atoi(s) if err != nil { return false } return n >= 0 && n < (1<<16) } func isUint8NumString(s string) bool { n, err := strconv.Atoi(s) if err != nil { return false } return n >= 0 && n < (1<<8) }