Function ReadTXtimestampBuf

timestamp/timestamp_linux.go:338–377

ReadTXtimestampBuf returns HW TX timestamp, needs to be provided 2 buffers which all can be re-used after ReadTXtimestampBuf finishes.

(connFd int, oob, toob []byte)

				return time.Time{}, ErrNoTimestamp
			}
		}
		if h.Level == unix.SOL_IPV6 && int(h.Type) == unix.IPV6_RECVERR ||
			h.Level == unix.SOL_IP && int(h.Type) == unix.IP_RECVERR {
			cseq, err = scmDataToSeqID(b[i+socketControlMessageHeaderOffset : i+mlen])
			if err != nil {
				return time.Time{}, ErrNoTimestamp
			}
		}
	}
	if tstamp.IsZero() {
		return time.Time{}, ErrNoTimestamp
	}
	if cseq == seqID {
		return tstamp, nil
	}
	return time.Time{}, ErrNoTimestamp
}

// ReadTXtimestampBuf returns HW TX timestamp, needs to be provided 2 buffers which all can be re-used after ReadTXtimestampBuf finishes.
func ReadTXtimestampBuf(connFd int, oob, toob []byte) (time.Time, int, error) {
	// Accessing hw timestamp
	var boob int

	txfound := false
	// Sometimes we end up with more than 1 TX TS in the buffer.
	// We need to empty it and completely otherwise we end up with a shifted queue read:
	// Sync is out -> read TS from the previous Sync
	// Because we always perform at least 2 tries we start with 0 so on success we are at 1.
	timeStart := time.Now()
	attempts := 0
	for ; attempts < AttemptsTXTS; attempts++ {
		if !txfound {
			// Wait for the poll event, ignore the error
			_ = waitForHWTS(connFd)
		}

		tboob, err := recvoob(connFd, toob)
		if err != nil {
			// We've already seen the valid TX TS and now we have an empty queue.
			// All good
			if txfound {
				break
			}