Differential D5173 Diff 13194 sys/netinet/tcp_input.c

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sys/netinet/tcp_input.c

Show First 20 Lines • Show All 157 Lines • ▼ Show 20 Lines	SYSCTL_INT(_net_inet_tcp, OID_AUTO, rfc6675_pipe, CTLFLAG_VNET \| CTLFLAG_RW,
"Use calculated pipe/in-flight bytes per RFC 6675");		"Use calculated pipe/in-flight bytes per RFC 6675");

VNET_DEFINE(int, tcp_do_rfc3042) = 1;		VNET_DEFINE(int, tcp_do_rfc3042) = 1;
#define V_tcp_do_rfc3042 VNET(tcp_do_rfc3042)		#define V_tcp_do_rfc3042 VNET(tcp_do_rfc3042)
SYSCTL_INT(_net_inet_tcp, OID_AUTO, rfc3042, CTLFLAG_VNET \| CTLFLAG_RW,		SYSCTL_INT(_net_inet_tcp, OID_AUTO, rfc3042, CTLFLAG_VNET \| CTLFLAG_RW,
&VNET_NAME(tcp_do_rfc3042), 0,		&VNET_NAME(tcp_do_rfc3042), 0,
"Enable RFC 3042 (Limited Transmit)");		"Enable RFC 3042 (Limited Transmit)");

VNET_DEFINE(int, tcp_do_rfc3390) = 1;		VNET_DEFINE(int, tcp_do_rfc3390);
SYSCTL_INT(_net_inet_tcp, OID_AUTO, rfc3390, CTLFLAG_VNET \| CTLFLAG_RW,		static int tcp_sysctl_rfc3390_handler(SYSCTL_HANDLER_ARGS);
&VNET_NAME(tcp_do_rfc3390), 0,		SYSCTL_PROC(_net_inet_tcp, OID_AUTO, rfc3390,
		CTLFLAG_VNET \| CTLTYPE_INT \| CTLFLAG_RW,
		&VNET_NAME(tcp_do_rfc3390), 0, &tcp_sysctl_rfc3390_handler, "I",
"Enable RFC 3390 (Increasing TCP's Initial Congestion Window)");		"Enable RFC 3390 (Increasing TCP's Initial Congestion Window)");

		VNET_DEFINE(int, tcp_do_rfc6928);
		static int tcp_sysctl_rfc6928_handler(SYSCTL_HANDLER_ARGS);
		SYSCTL_PROC(_net_inet_tcp, OID_AUTO, rfc6928,
		CTLFLAG_VNET \| CTLTYPE_INT \| CTLFLAG_RW,
		&VNET_NAME(tcp_do_rfc6928), 0, &tcp_sysctl_rfc6928_handler, "I",
		"Enable RFC 6928 (Increasing TCP's Initial Congestion Window)");

VNET_DEFINE(int, tcp_initcwnd_segments) = 10;		VNET_DEFINE(int, tcp_initcwnd_segments) = 10;
SYSCTL_INT(_net_inet_tcp, OID_AUTO, initcwnd_segments,		SYSCTL_INT(_net_inet_tcp, OID_AUTO, initcwnd_segments,
CTLFLAG_VNET \| CTLFLAG_RW, &VNET_NAME(tcp_initcwnd_segments), 0,		CTLFLAG_VNET \| CTLFLAG_RW, &VNET_NAME(tcp_initcwnd_segments), 0,
"Slow-start flight size (initial congestion window) in number of segments");		"Slow-start flight size (initial congestion window) in number of segments");

		VNET_DEFINE(int, tcp_initcwnd_bytes) = 14600;
		SYSCTL_INT(_net_inet_tcp, OID_AUTO, initcwnd_bytes,
		CTLFLAG_VNET \| CTLFLAG_RW, &VNET_NAME(tcp_initcwnd_bytes), 0,
		"Slow-start flight size (initial congestion window) in number of bytes");

VNET_DEFINE(int, tcp_do_rfc3465) = 1;		VNET_DEFINE(int, tcp_do_rfc3465) = 1;
SYSCTL_INT(_net_inet_tcp, OID_AUTO, rfc3465, CTLFLAG_VNET \| CTLFLAG_RW,		SYSCTL_INT(_net_inet_tcp, OID_AUTO, rfc3465, CTLFLAG_VNET \| CTLFLAG_RW,
&VNET_NAME(tcp_do_rfc3465), 0,		&VNET_NAME(tcp_do_rfc3465), 0,
"Enable RFC 3465 (Appropriate Byte Counting)");		"Enable RFC 3465 (Appropriate Byte Counting)");

VNET_DEFINE(int, tcp_abc_l_var) = 2;		VNET_DEFINE(int, tcp_abc_l_var) = 2;
SYSCTL_INT(_net_inet_tcp, OID_AUTO, abc_l_var, CTLFLAG_VNET \| CTLFLAG_RW,		SYSCTL_INT(_net_inet_tcp, OID_AUTO, abc_l_var, CTLFLAG_VNET \| CTLFLAG_RW,
&VNET_NAME(tcp_abc_l_var), 2,		&VNET_NAME(tcp_abc_l_var), 2,
▲ Show 20 Lines • Show All 160 Lines • ▼ Show 20 Lines	if (metrics.rmx_ssthresh) {
* buffer limit on the path. Use this to set		* buffer limit on the path. Use this to set
* the slow start threshhold, but set the		* the slow start threshhold, but set the
* threshold to no less than 2*mss.		* threshold to no less than 2*mss.
*/		*/
tp->snd_ssthresh = max(2 * maxseg, metrics.rmx_ssthresh);		tp->snd_ssthresh = max(2 * maxseg, metrics.rmx_ssthresh);
TCPSTAT_INC(tcps_usedssthresh);		TCPSTAT_INC(tcps_usedssthresh);
}		}

/*		/* Determine the initial congestion window */
* Set the initial slow-start flight size.		tp->snd_cwnd = tcp_initcwnd(tp, maxseg);
*
* RFC5681 Section 3.1 specifies the default conservative values.
* RFC3390 specifies slightly more aggressive values.
* RFC6928 increases it to ten segments.
* Support for user specified value for initial flight size.
*
* If a SYN or SYN/ACK was lost and retransmitted, we have to
* reduce the initial CWND to one segment as congestion is likely
* requiring us to be cautious.
*/
if (tp->snd_cwnd == 1)
tp->snd_cwnd = maxseg; /* SYN(-ACK) lost */
else if (V_tcp_initcwnd_segments)
tp->snd_cwnd = min(V_tcp_initcwnd_segments * maxseg,
max(2 * maxseg, V_tcp_initcwnd_segments * 1460));
else if (V_tcp_do_rfc3390)
tp->snd_cwnd = min(4 * maxseg, max(2 * maxseg, 4380));
else {
/* Per RFC5681 Section 3.1 */
if (maxseg > 2190)
tp->snd_cwnd = 2 * maxseg;
else if (maxseg > 1095)
tp->snd_cwnd = 3 * maxseg;
else
tp->snd_cwnd = 4 * maxseg;
}

if (CC_ALGO(tp)->conn_init != NULL)		if (CC_ALGO(tp)->conn_init != NULL)
CC_ALGO(tp)->conn_init(tp->ccv);		CC_ALGO(tp)->conn_init(tp->ccv);
}		}

void inline		void inline
cc_cong_signal(struct tcpcb tp, struct tcphdr th, uint32_t type)		cc_cong_signal(struct tcpcb tp, struct tcphdr th, uint32_t type)
{		{
▲ Show 20 Lines • Show All 3,432 Lines • ▼ Show 20 Lines
}		}

int		int
tcp_compute_pipe(struct tcpcb *tp)		tcp_compute_pipe(struct tcpcb *tp)
{		{
return (tp->snd_max - tp->snd_una +		return (tp->snd_max - tp->snd_una +
tp->sackhint.sack_bytes_rexmit -		tp->sackhint.sack_bytes_rexmit -
tp->sackhint.sacked_bytes);		tp->sackhint.sacked_bytes);
		}

		/*
		* Set the initial slow-start flight size.
		*
		* Support for user specified value for initial flight size.
		* RFC6928 increases it to ten segments.
		* RFC3390 specifies slightly more aggressive values.
		* RFC5681 Section 3.1 specifies the default conservative values.
		*
		* If a SYN or SYN/ACK was lost and retransmitted, we have to
		* reduce the initial CWND to one segment as congestion is likely
		* requiring us to be cautious.
		*
		* RFC3390: min (4MSS, max (2MSS, 4380))
		* RFC6928: min (10MSS, max (2MSS, 14600))
		* code: max(2MSS, min(initcwnd_segments MSS, initcwnd_bytes))
		*/
		u_long
		tcp_initcwnd(struct tcpcb *tp, u_int maxseg)
		{
		u_long initcwnd;

		if (tp->snd_cwnd == 1)
		initcwnd = maxseg; /* SYN(-ACK) lost */
		else if (V_tcp_initcwnd_bytes >= 4380)
		initcwnd = max(2 * maxseg,
		min(V_tcp_initcwnd_segments * maxseg,
		V_tcp_initcwnd_bytes));
		else {
		/* Per RFC5681 Section 3.1 */
		if (maxseg > 2190)
		initcwnd = 2 * maxseg;
		else if (maxseg > 1095)
		initcwnd = 3 * maxseg;
		else
		initcwnd = 4 * maxseg;
		}

		return (initcwnd);
		}

		static int
		tcp_sysctl_rfc3390_handler(SYSCTL_HANDLER_ARGS)
		{
		int error, new;

		new = V_tcp_do_rfc3390;
		error = sysctl_handle_int(oidp, &new, 0, req);
		if (error == 0 && req->newptr && new == 1) {
		V_tcp_initcwnd_segments = 4;
		V_tcp_initcwnd_bytes = 4380;
		V_tcp_do_rfc3390 = new;
		}

		return (error);
		}

		static int
		tcp_sysctl_rfc6928_handler(SYSCTL_HANDLER_ARGS)
		{
		int error, new;

		new = V_tcp_do_rfc6928;
		error = sysctl_handle_int(oidp, &new, 0, req);
		if (error == 0 && req->newptr && new == 1) {
		V_tcp_initcwnd_segments = 10;
		V_tcp_initcwnd_bytes = 14600;
		V_tcp_do_rfc6928 = new;
		}

		return (error);
}		}