bsd/netinet/tcp_output.c

180         &tcp_do_autosendbuf, 1, "Enable send socket buffer auto-tuning");
184         &tcp_autosndbuf_inc, 1, "Increment in send socket bufffer size");
188         &tcp_autosndbuf_max, 1, "Maximum send socket buffer size");
240  * Tcp output routine: figure out what should be sent and send it.
311 	 * to send, then transmit; otherwise, investigate further.
474 	 * to send out new data (when sendalot is 1), bypass this function.
546 	 * If in persist timeout with window of 0, send 1 byte.
548 	 * and timer expired, we will send what we can
554 			 * If we still have some data to send, then
566 			 * to send then the probe will be the FIN
675 	 * Be careful not to send data and/or FIN on SYN segments.
711 	/* Automatic sizing of send socket buffer. Increase the send socket buffer
714 	 *	2. send buffer is filled to 7/8th with data (so we actually
716 	 *	3. our send window (slow start and congestion controlled) is
717 	 *	   larger than sent but unacknowledged data in send buffer.
728 			/* Also increase the send buffer only if the
817 	 *	- This is the last buffer in a write()/send() and we are
819 	 *	- we have more then 1/2 the maximum send window's worth of
825 			goto send;
832 			goto send;
835 			goto send;
845 				goto send;
852 				goto send;
856 				goto send;
868 	 * window, then want to send a window update to peer.
886 			 * We will depend on the delack timer to send a window update
892 				goto send;
906 				goto send;
914 		goto send;
917 		goto send;
919 		goto send;
922 	 * and we have not yet done so, then we need to send.
926 		goto send;
928 	 * In SACK, it is possible for tcp_output to fail to send a segment
950 	 *	is set when we are called to send a persist packet.
955 	 * If send window is too small, there is data to transmit, and no
957 	 * If nothing happens soon, send when timer expires:
969 	 * If there is no reason to send a segment, just return.
970 	 * but if there is some packets left in the packet list, send them now.
999 send:
1043  	   to handle the TCP ECE flag, even if you also later send a
1045  	   - If you ever send a non-ECN-setup SYN/SYN-ACK, you must not set
1055 	 * For a SYN-ACK, send an ECN setup SYN-ACK
1073 				 * that to indicate we should not send data with IP ECT set.
1096 			 * we should send data with IP ECT set.
1261 		 * If there is still more to send, don't close the connection.
1284 	/* Check if there is enough data in the send socket
1570 		 * If no urgent pointer to send, then we pull
1571 		 * the urgent pointer to the left edge of the send window
1572 		 * so that it doesn't drift into the send window on sequence
1701 	 * send to IP level.  There should be a better way
1801 		DTRACE_TCP5(send, struct mbuf *, m, struct inpcb *, tp->t_inpcb,
1807 		DTRACE_TCP5(send, struct mbuf *, m, struct inpcb *, tp->t_inpcb,
1822 		/* For a pure ACK, see if you need to send more of them */
2054 	/* Increment the count of outstanding send operations */
2075 	 * Don't send down a chain of packets when: