Differential D9668 Diff 27281 head/sys/netinet/tcp_stacks/fastpath.c

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head/sys/netinet/tcp_stacks/fastpath.c

Show First 20 Lines • Show All 393 Lines • ▼ Show 20 Lines	#endif
tp->rcv_up = tp->rcv_nxt;		tp->rcv_up = tp->rcv_nxt;
TCPSTAT_ADD(tcps_rcvbyte, tlen);		TCPSTAT_ADD(tcps_rcvbyte, tlen);
#ifdef TCPDEBUG		#ifdef TCPDEBUG
if (so->so_options & SO_DEBUG)		if (so->so_options & SO_DEBUG)
tcp_trace(TA_INPUT, ostate, tp,		tcp_trace(TA_INPUT, ostate, tp,
(void *)tcp_saveipgen, &tcp_savetcp, 0);		(void *)tcp_saveipgen, &tcp_savetcp, 0);
#endif		#endif
TCP_PROBE3(debug__input, tp, th, m);		TCP_PROBE3(debug__input, tp, th, m);
/*
* Automatic sizing of receive socket buffer. Often the send
* buffer size is not optimally adjusted to the actual network
* conditions at hand (delay bandwidth product). Setting the
* buffer size too small limits throughput on links with high
* bandwidth and high delay (eg. trans-continental/oceanic links).
*
* On the receive side the socket buffer memory is only rarely
* used to any significant extent. This allows us to be much
* more aggressive in scaling the receive socket buffer. For
* the case that the buffer space is actually used to a large
* extent and we run out of kernel memory we can simply drop
* the new segments; TCP on the sender will just retransmit it
* later. Setting the buffer size too big may only consume too
* much kernel memory if the application doesn't read() from
* the socket or packet loss or reordering makes use of the
* reassembly queue.
*
* The criteria to step up the receive buffer one notch are:
* 1. Application has not set receive buffer size with
* SO_RCVBUF. Setting SO_RCVBUF clears SB_AUTOSIZE.
* 2. the number of bytes received during the time it takes
* one timestamp to be reflected back to us (the RTT);
* 3. received bytes per RTT is within seven eighth of the
* current socket buffer size;
* 4. receive buffer size has not hit maximal automatic size;
*
* This algorithm does one step per RTT at most and only if
* we receive a bulk stream w/o packet losses or reorderings.
* Shrinking the buffer during idle times is not necessary as
* it doesn't consume any memory when idle.
*
* TODO: Only step up if the application is actually serving
* the buffer to better manage the socket buffer resources.
*/
if (V_tcp_do_autorcvbuf &&
(to->to_flags & TOF_TS) &&
to->to_tsecr &&
(so->so_rcv.sb_flags & SB_AUTOSIZE)) {
if (TSTMP_GT(to->to_tsecr, tp->rfbuf_ts) &&
to->to_tsecr - tp->rfbuf_ts < hz) {
if (tp->rfbuf_cnt >
(so->so_rcv.sb_hiwat / 8 * 7) &&
so->so_rcv.sb_hiwat <
V_tcp_autorcvbuf_max) {
newsize =
min(so->so_rcv.sb_hiwat +
V_tcp_autorcvbuf_inc,
V_tcp_autorcvbuf_max);
}
/* Start over with next RTT. */
tp->rfbuf_ts = 0;
tp->rfbuf_cnt = 0;
} else
tp->rfbuf_cnt += tlen; /* add up */
}

		newsize = tcp_autorcvbuf(m, th, so, tp, tlen);

/* Add data to socket buffer. */		/* Add data to socket buffer. */
SOCKBUF_LOCK(&so->so_rcv);		SOCKBUF_LOCK(&so->so_rcv);
if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {		if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
m_freem(m);		m_freem(m);
} else {		} else {
/*		/*
* Set new socket buffer size.		* Set new socket buffer size.
* Give up when limit is reached.		* Give up when limit is reached.
▲ Show 20 Lines • Show All 59 Lines • ▼ Show 20 Lines	#endif
* Receive window is amount of space in rcv queue,		* Receive window is amount of space in rcv queue,
* but not less than advertised window.		* but not less than advertised window.
*/		*/
inc = &tp->t_inpcb->inp_inc;		inc = &tp->t_inpcb->inp_inc;
win = sbspace(&so->so_rcv);		win = sbspace(&so->so_rcv);
if (win < 0)		if (win < 0)
win = 0;		win = 0;
tp->rcv_wnd = imax(win, (int)(tp->rcv_adv - tp->rcv_nxt));		tp->rcv_wnd = imax(win, (int)(tp->rcv_adv - tp->rcv_nxt));

/* Reset receive buffer auto scaling when not in bulk receive mode. */
tp->rfbuf_ts = 0;
tp->rfbuf_cnt = 0;

switch (tp->t_state) {		switch (tp->t_state) {

/*		/*
* If the state is SYN_RECEIVED:		* If the state is SYN_RECEIVED:
* if seg contains an ACK, but not for our SYN/ACK, send a RST.		* if seg contains an ACK, but not for our SYN/ACK, send a RST.
*/		*/
case TCPS_SYN_RECEIVED:		case TCPS_SYN_RECEIVED:
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