Function tcp_log_state_change

freebsd/netinet/tcp_log_buf.c:1745–1779

* Change the logging state for a TCPCB. Returns 0 on success or an * error code on failure. */

 * error code on failure.
 */
int
tcp_log_state_change(struct tcpcb *tp, int state)
{
	struct tcp_log_mem *log_entry;

	INP_WLOCK_ASSERT(tp->t_inpcb);
	switch(state) {
	case TCP_LOG_STATE_CLEAR:
		while ((log_entry = STAILQ_FIRST(&tp->t_logs)) != NULL)
			tcp_log_remove_log_head(tp, log_entry);
		/* Fall through */

	case TCP_LOG_STATE_OFF:
		tp->t_logstate = TCP_LOG_STATE_OFF;
		break;

	case TCP_LOG_STATE_TAIL:
	case TCP_LOG_STATE_HEAD:
	case TCP_LOG_STATE_CONTINUAL:
	case TCP_LOG_STATE_HEAD_AUTO:
	case TCP_LOG_STATE_TAIL_AUTO:
		tp->t_logstate = state;
		break;

	default:
		return (EINVAL);
	}
	if (tcp_disable_all_bb_logs) {
		/* We are prohibited from doing any logs */
		tp->t_logstate = TCP_LOG_STATE_OFF;
	}
	tp->t_flags2 &= ~(TF2_LOG_AUTO);

	return (0);
}

/* If tcp_drain() is called, flush half the log entries. */
void