Date: Fri, 1 Aug 2014 16:37:46 +0100 From: Tom Jones <jones@sdf.org> To: Adrian Chadd <adrian@freebsd.org> Cc: freebsd-net@freebsd.org Subject: Re: [PATCH] Implementation of draft-ietf-tcpm-newcwv-06 Message-ID: <20140801153744.GA76021@gmail.com> In-Reply-To: <20140801141920.GC75551@gmail.com> References: <20140630170453.GA21404@gmail.com> <CAJ-VmonjB5C%2BDfJkDUeyJrqzHa1ptaQPZYtcyqN1PpKeii51Fg@mail.gmail.com> <20140630205359.GA2221@gmail.com> <20140801141920.GC75551@gmail.com>
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On Fri, Aug 01, 2014 at 03:19:20PM +0100, Tom Jones wrote:
>
> I have updated the patch to move the new variable introduced with newcwv into a
> struct within the tcpcb.
Forgot some files in the diff.
--
Tom | I don't see how we are going to build the dystopian megapoli
@adventureloop | we were promised in 80s and early 90s cyberpunk fiction if
adventurist.me | you guys keep complaining.
:wq
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Index: sys/conf/files
===================================================================
--- sys/conf/files (revision 269231)
+++ sys/conf/files (working copy)
@@ -3383,6 +3383,7 @@ netinet/tcp_reass.c optional inet | inet6
netinet/tcp_sack.c optional inet | inet6
netinet/tcp_subr.c optional inet | inet6
netinet/tcp_syncache.c optional inet | inet6
+netinet/tcp_newcwv.c optional inet | inet6
netinet/tcp_timer.c optional inet | inet6
netinet/tcp_timewait.c optional inet | inet6
netinet/tcp_usrreq.c optional inet | inet6
Index: sys/netinet/tcp_input.c
===================================================================
--- sys/netinet/tcp_input.c (revision 269231)
+++ sys/netinet/tcp_input.c (working copy)
@@ -105,6 +105,7 @@ __FBSDID("$FreeBSD$");
#include <netinet6/tcp6_var.h>
#include <netinet/tcpip.h>
#include <netinet/tcp_syncache.h>
+#include <netinet/tcp_newcwv.h>
#ifdef TCPDEBUG
#include <netinet/tcp_debug.h>
#endif /* TCPDEBUG */
@@ -174,6 +175,11 @@ SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, abc_l_var
&VNET_NAME(tcp_abc_l_var), 2,
"Cap the max cwnd increment during slow-start to this number of segments");
+VNET_DEFINE(int, tcp_do_newcwv) = 0;
+SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, newcwv, CTLFLAG_RW,
+ &VNET_NAME(tcp_do_newcwv), 0,
+ "Enable draft-ietf-tcpm-newcwv-06 (New Congestion Window Validation)");
+
static SYSCTL_NODE(_net_inet_tcp, OID_AUTO, ecn, CTLFLAG_RW, 0, "TCP ECN");
VNET_DEFINE(int, tcp_do_ecn) = 0;
@@ -285,9 +291,12 @@ cc_ack_received(struct tcpcb *tp, struct tcphdr *t
INP_WLOCK_ASSERT(tp->t_inpcb);
tp->ccv->bytes_this_ack = BYTES_THIS_ACK(tp, th);
- if (tp->snd_cwnd <= tp->snd_wnd)
+ /* draft-ietf-tcpm-newcwv relaxes conditions for growing cwnd */
+ if (tp->snd_cwnd <= tp->snd_wnd ||
+ (V_tcp_do_newcwv && tp->newcwv.pipeack >= (tp->snd_cwnd >> 1)) ) {
tp->ccv->flags |= CCF_CWND_LIMITED;
- else
+ tp->newcwv.cwnd_valid_ts = ticks;
+ } else
tp->ccv->flags &= ~CCF_CWND_LIMITED;
if (type == CC_ACK) {
@@ -309,6 +318,12 @@ cc_ack_received(struct tcpcb *tp, struct tcphdr *t
tp->ccv->curack = th->th_ack;
CC_ALGO(tp)->ack_received(tp->ccv, type);
}
+
+ /*
+ * update draft-ietf-newcwv-06 pipeack
+ */
+ if(V_tcp_do_newcwv && !IN_FASTRECOVERY(tp->t_flags))
+ tcp_newcwv_update_pipeack(tp);
}
static void inline
@@ -378,6 +393,12 @@ cc_conn_init(struct tcpcb *tp)
tp->snd_cwnd = 4 * tp->t_maxseg;
}
+ /*
+ * Initialise NewCWV state
+ */
+ tp->newcwv.init_cwnd = tp->snd_cwnd;
+ tcp_newcwv_reset(tp);
+
if (CC_ALGO(tp)->conn_init != NULL)
CC_ALGO(tp)->conn_init(tp->ccv);
}
@@ -426,6 +447,11 @@ cc_cong_signal(struct tcpcb *tp, struct tcphdr *th
tp->t_badrxtwin = 0;
break;
}
+
+ if (V_tcp_do_newcwv &&
+ (type == CC_NDUPACK || type == CC_ECN) &&
+ tp->newcwv.pipeack <= (tp->snd_cwnd >> 1) )
+ tcp_newcwv_enter_recovery(tp);
if (CC_ALGO(tp)->cong_signal != NULL) {
if (th != NULL)
@@ -447,6 +473,13 @@ cc_post_recovery(struct tcpcb *tp, struct tcphdr *
}
/* XXXLAS: EXIT_RECOVERY ? */
tp->t_bytes_acked = 0;
+
+ if(V_tcp_do_newcwv) {
+ if(tp->newcwv.loss_flight_size)
+ tcp_newcwv_end_recovery(tp);
+ tcp_newcwv_reset(tp);
+ }
+ tp->newcwv.loss_flight_size = 0;
}
#ifdef TCP_SIGNATURE
Index: sys/netinet/tcp_newcwv.c
===================================================================
--- sys/netinet/tcp_newcwv.c (revision 0)
+++ sys/netinet/tcp_newcwv.c (working copy)
@@ -0,0 +1,175 @@
+/*
+ * Copyright (c) 2014 Tom Jones <jones@sdf.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ */
+
+#include <sys/cdefs.h>
+
+#include <sys/param.h>
+#include <sys/kernel.h>
+#include <sys/libkern.h>
+#include <sys/socket.h>
+#include <sys/socketvar.h>
+
+#include <netinet/tcp.h>
+#include <netinet/tcp_var.h>
+#include <netinet/tcp_newcwv.h>
+
+/*
+ * An implementation of NewCWV (draft-ietf-tcpm-newcwv-06) for FreeBSD.
+ * Based on the Linux implementation by Raffaello Secchi and the an initial
+ * implementation of draft-ietf-tcpm-newcwv-00 by Aris Angelogiannopoulos.
+ */
+
+#define nextbin(x) (((x)+1) & 0x03)
+#define prevbin(x) (((x)-1) & 0x03)
+
+#define NCWV_UNDEF 0xFFFFFFFF
+#define NCWV_FIVEMINS (300*hz)
+
+void add_element(struct tcpcb *,u_int32_t);
+u_int32_t remove_expired_elements(struct tcpcb *);
+
+void
+tcp_newcwv_update_pipeack(struct tcpcb *tp)
+{
+ u_int32_t tmp_pipeack;
+ tp->newcwv.psp = MAX(3 * tp->t_srtt,hz);
+
+ if (tp->snd_una >= tp->newcwv.prev_snd_nxt) {
+ /* get the pipeack sample */
+ tmp_pipeack = tp->snd_una - tp->newcwv.prev_snd_una;
+
+ tp->newcwv.prev_snd_una = tp->snd_una;
+ tp->newcwv.prev_snd_nxt = tp->snd_nxt;
+
+ /* create a new element at the end of current pmp */
+ if(ticks > tp->newcwv.time_stamp[tp->newcwv.head] +
+ (tp->newcwv.psp >> 2))
+ add_element(tp,tmp_pipeack);
+ else
+ tp->newcwv.psample[tp->newcwv.head] = tmp_pipeack;
+ }
+
+ tp->newcwv.pipeack = remove_expired_elements(tp);
+
+ /* check if cwnd is validated */
+ if (tp->newcwv.pipeack == NCWV_UNDEF ||
+ ((tp->newcwv.pipeack << 1) >= (tp->snd_cwnd * tp->t_maxseg))) {
+ tp->newcwv.cwnd_valid_ts = ticks;
+ }
+}
+
+void
+add_element(struct tcpcb *tp,u_int32_t value)
+{
+ tp->newcwv.head = nextbin(tp->newcwv.head);
+ tp->newcwv.psample[tp->newcwv.head] = value;
+ tp->newcwv.time_stamp[tp->newcwv.head] = ticks;
+}
+
+u_int32_t
+remove_expired_elements(struct tcpcb *tp)
+{
+ uint8_t head = tp->newcwv.head;
+ u_int32_t tmp = tp->newcwv.psample[head];
+
+ while(tp->newcwv.psample[head] != NCWV_UNDEF) {
+ /* remove the element if expired */
+ if (tp->newcwv.time_stamp[head] < ticks - tp->newcwv.psp) {
+ tp->newcwv.psample[head] = NCWV_UNDEF;
+ return tmp;
+ }
+
+ /* search for the max pipeack */
+ if(tp->newcwv.psample[head] > tmp)
+ tmp = tp->newcwv.psample[head];
+
+ head = prevbin(head);
+ if(head == tp->newcwv.head)
+ return tmp;
+ }
+
+ return tmp;
+}
+
+/* Initialise NewCWV state */
+void
+tcp_newcwv_reset(struct tcpcb *tp)
+{
+ tp->newcwv.prev_snd_una = tp->snd_una;
+ tp->newcwv.prev_snd_nxt = tp->snd_nxt;
+ tp->newcwv.cwnd_valid_ts = ticks;
+ tp->newcwv.loss_flight_size = 0;
+
+ tp->newcwv.head = 0;
+ tp->newcwv.psample[0] = NCWV_UNDEF;
+ tp->newcwv.pipeack = NCWV_UNDEF;
+}
+
+/* NewCWV actions at loss detection */
+void
+tcp_newcwv_enter_recovery(struct tcpcb *tp)
+{
+ u_int32_t pipe;
+
+ if(tp->newcwv.pipeack == NCWV_UNDEF)
+ return;
+
+ tp->newcwv.prior_retrans = tp->t_sndrexmitpack;
+
+ /* Calculate the flight size */
+ u_int32_t awnd = (tp->snd_nxt - tp->snd_fack) + tp->sackhint.sack_bytes_rexmit;
+ tp->newcwv.loss_flight_size = awnd;
+
+ pipe = MAX(tp->newcwv.pipeack,tp->newcwv.loss_flight_size);
+ tp->snd_cwnd = MAX(pipe >> 1,1);
+}
+
+/* NewCWV actions at the end of recovery */
+void
+tcp_newcwv_end_recovery(struct tcpcb *tp)
+{
+ u_int32_t retrans,pipe;
+
+ retrans = (tp->t_sndrexmitpack - tp->newcwv.prior_retrans) * tp->t_maxseg;
+ pipe = MAX(tp->newcwv.pipeack,tp->newcwv.loss_flight_size) - retrans;
+
+ /* Ensure that snd_ssthresh is non 0 */
+ tp->snd_ssthresh = MAX(pipe >> 1,1);
+ tp->snd_cwnd = tp->snd_ssthresh;
+}
+
+void
+tcp_newcwv_datalim_closedown(struct tcpcb *tp)
+{
+ while ((ticks - tp->newcwv.cwnd_valid_ts) > NCWV_FIVEMINS &&
+ tp->snd_cwnd > tp->newcwv.init_cwnd) {
+
+ tp->newcwv.cwnd_valid_ts += NCWV_FIVEMINS;
+ tp->snd_ssthresh = MAX( (3 * tp->snd_cwnd ) >> 2,tp->snd_ssthresh);
+ tp->snd_cwnd = MAX(tp->snd_cwnd >> 1, tp->newcwv.init_cwnd);
+ }
+}
Property changes on: sys/netinet/tcp_newcwv.c
___________________________________________________________________
Added: svn:keywords
## -0,0 +1 ##
+FreeBSD=%H
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+native
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Index: sys/netinet/tcp_newcwv.c.orig
===================================================================
Index: sys/netinet/tcp_newcwv.h
===================================================================
--- sys/netinet/tcp_newcwv.h (revision 0)
+++ sys/netinet/tcp_newcwv.h (working copy)
@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2014 Tom Jones <jones@sdf.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ */
+
+#ifndef _NETINET_TCP_NEWCWV_H_
+#define _NETINET_TCP_NEWCWV_H_
+
+#include <netinet/tcp_var.h>
+
+void tcp_newcwv_update_pipeack(struct tcpcb *);
+void tcp_newcwv_reset(struct tcpcb *);
+void tcp_newcwv_enter_recovery(struct tcpcb *);
+void tcp_newcwv_end_recovery(struct tcpcb *);
+void tcp_newcwv_datalim_closedown(struct tcpcb *);
+
+#endif /* _NETINET_TCP_NEWCWV_H_ */
Property changes on: sys/netinet/tcp_newcwv.h
___________________________________________________________________
Added: svn:eol-style
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+native
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## -0,0 +1 ##
+FreeBSD=%H
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Index: sys/netinet/tcp_newcwv.h.orig
===================================================================
Index: sys/netinet/tcp_output.c
===================================================================
--- sys/netinet/tcp_output.c (revision 269231)
+++ sys/netinet/tcp_output.c (working copy)
@@ -74,6 +74,7 @@ __FBSDID("$FreeBSD$");
#include <netinet/tcp_timer.h>
#include <netinet/tcp_var.h>
#include <netinet/tcpip.h>
+#include <netinet/tcp_newcwv.h>
#ifdef TCPDEBUG
#include <netinet/tcp_debug.h>
#endif
@@ -691,6 +692,10 @@ send:
#endif
hdrlen = sizeof (struct tcpiphdr);
+ /* Trigger the newcwv timer */
+ if(V_tcp_do_newcwv)
+ tcp_newcwv_datalim_closedown(tp);
+
/*
* Compute options for segment.
* We only have to care about SYN and established connection
Index: sys/netinet/tcp_subr.c
===================================================================
--- sys/netinet/tcp_subr.c (revision 269231)
+++ sys/netinet/tcp_subr.c (working copy)
@@ -800,6 +800,7 @@ tcp_newtcpcb(struct inpcb *inp)
tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP);
if (V_tcp_do_sack)
tp->t_flags |= TF_SACK_PERMIT;
+
TAILQ_INIT(&tp->snd_holes);
tp->t_inpcb = inp; /* XXX */
/*
Index: sys/netinet/tcp_var.h
===================================================================
--- sys/netinet/tcp_var.h (revision 269231)
+++ sys/netinet/tcp_var.h (working copy)
@@ -172,6 +172,22 @@ struct tcpcb {
int t_sndzerowin; /* zero-window updates sent */
u_int t_badrxtwin; /* window for retransmit recovery */
u_char snd_limited; /* segments limited transmitted */
+/* NewCWV releated state */
+ struct {
+ u_int32_t pipeack;
+ u_int32_t psp; /* pipeack sampling period */
+
+ u_int32_t head;
+ u_int32_t psample[4]; /* pipe ack samples */
+ u_int32_t time_stamp[4]; /* time stamp samples */
+ u_int32_t prev_snd_una; /* previous snd_una in this sampe */
+ u_int32_t prev_snd_nxt; /* previous snd_nxt in this sampe */
+
+ u_int32_t loss_flight_size; /* flightsize at loss detection */
+ u_int32_t prior_retrans; /* Retransmission before going into FR */
+ u_int32_t cwnd_valid_ts; /*last time cwnd was found valid */
+ u_int32_t init_cwnd; /* The inital cwnd */
+ } newcwv;
/* SACK related state */
int snd_numholes; /* number of holes seen by sender */
TAILQ_HEAD(sackhole_head, sackhole) snd_holes;
@@ -605,6 +621,7 @@ VNET_DECLARE(int, tcp_recvspace);
VNET_DECLARE(int, path_mtu_discovery);
VNET_DECLARE(int, tcp_do_rfc3465);
VNET_DECLARE(int, tcp_abc_l_var);
+VNET_DECLARE(int, tcp_do_newcwv);
#define V_tcb VNET(tcb)
#define V_tcbinfo VNET(tcbinfo)
#define V_tcp_mssdflt VNET(tcp_mssdflt)
@@ -617,6 +634,7 @@ VNET_DECLARE(int, tcp_abc_l_var);
#define V_path_mtu_discovery VNET(path_mtu_discovery)
#define V_tcp_do_rfc3465 VNET(tcp_do_rfc3465)
#define V_tcp_abc_l_var VNET(tcp_abc_l_var)
+#define V_tcp_do_newcwv VNET(tcp_do_newcwv)
VNET_DECLARE(int, tcp_do_sack); /* SACK enabled/disabled */
VNET_DECLARE(int, tcp_sc_rst_sock_fail); /* RST on sock alloc failure */
--sdtB3X0nJg68CQEu--
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