svn commit: r367007 - in head/sys/netinet: . cc

[Richard Scheffenegger]

Author: rscheff
Date: Sat Oct 24 16:09:18 2020
New Revision: 367007
URL: https://svnweb.freebsd.org/changeset/base/367007

Log:
  tcp: move cwnd and ssthresh updates into cc modules
  
  This will pave the way of setting ssthresh differently in TCP CUBIC, according
  to RFC8312 section 4.7.
  
  No functional change, only code movement.
  
  Submitted by:	chengc_netapp.com
  Reviewed by:	rrs, tuexen, rscheff
  MFC after:	2 weeks
  Sponsored by:	NetApp, Inc.
  Differential Revision:	https://reviews.freebsd.org/D26807

Modified:
  head/sys/netinet/cc/cc_cubic.c
  head/sys/netinet/cc/cc_dctcp.c
  head/sys/netinet/cc/cc_htcp.c
  head/sys/netinet/cc/cc_newreno.c
  head/sys/netinet/tcp_input.c

Modified: head/sys/netinet/cc/cc_cubic.c
==============================================================================
--- head/sys/netinet/cc/cc_cubic.c	Sat Oct 24 16:05:37 2020	(r367006)
+++ head/sys/netinet/cc/cc_cubic.c	Sat Oct 24 16:09:18 2020	(r367007)
@@ -264,8 +264,10 @@ static void
 cubic_cong_signal(struct cc_var *ccv, uint32_t type)
 {
 	struct cubic *cubic_data;
+	u_int mss;
 
 	cubic_data = ccv->cc_data;
+	mss = tcp_maxseg(ccv->ccvc.tcp);
 
 	switch (type) {
 	case CC_NDUPACK:
@@ -292,6 +294,10 @@ cubic_cong_signal(struct cc_var *ccv, uint32_t type)
 		break;
 
 	case CC_RTO:
+		CCV(ccv, snd_ssthresh) = max(min(CCV(ccv, snd_wnd),
+						 CCV(ccv, snd_cwnd)) / 2 / mss,
+					     2) * mss;
+		CCV(ccv, snd_cwnd) = mss;
 		/*
 		 * Grab the current time and record it so we know when the
 		 * most recent congestion event was. Only record it when the

Modified: head/sys/netinet/cc/cc_dctcp.c
==============================================================================
--- head/sys/netinet/cc/cc_dctcp.c	Sat Oct 24 16:05:37 2020	(r367006)
+++ head/sys/netinet/cc/cc_dctcp.c	Sat Oct 24 16:09:18 2020	(r367007)
@@ -235,7 +235,7 @@ dctcp_cong_signal(struct cc_var *ccv, uint32_t type)
 	if (CCV(ccv, t_flags2) & TF2_ECN_PERMIT) {
 		dctcp_data = ccv->cc_data;
 		cwin = CCV(ccv, snd_cwnd);
-		mss = CCV(ccv, t_maxseg);
+		mss = tcp_maxseg(ccv->ccvc.tcp);
 
 		switch (type) {
 		case CC_NDUPACK:
@@ -282,6 +282,10 @@ dctcp_cong_signal(struct cc_var *ccv, uint32_t type)
 			dctcp_data->ece_curr = 1;
 			break;
 		case CC_RTO:
+			CCV(ccv, snd_ssthresh) = max(min(CCV(ccv, snd_wnd),
+							 CCV(ccv, snd_cwnd)) / 2 / mss,
+						     2) * mss;
+			CCV(ccv, snd_cwnd) = mss;
 			dctcp_update_alpha(ccv);
 			dctcp_data->save_sndnxt += CCV(ccv, t_maxseg);
 			dctcp_data->num_cong_events++;

Modified: head/sys/netinet/cc/cc_htcp.c
==============================================================================
--- head/sys/netinet/cc/cc_htcp.c	Sat Oct 24 16:05:37 2020	(r367006)
+++ head/sys/netinet/cc/cc_htcp.c	Sat Oct 24 16:09:18 2020	(r367007)
@@ -271,8 +271,10 @@ static void
 htcp_cong_signal(struct cc_var *ccv, uint32_t type)
 {
 	struct htcp *htcp_data;
+	u_int mss;
 
 	htcp_data = ccv->cc_data;
+	mss = tcp_maxseg(ccv->ccvc.tcp);
 
 	switch (type) {
 	case CC_NDUPACK:
@@ -311,6 +313,10 @@ htcp_cong_signal(struct cc_var *ccv, uint32_t type)
 		break;
 
 	case CC_RTO:
+		CCV(ccv, snd_ssthresh) = max(min(CCV(ccv, snd_wnd),
+						 CCV(ccv, snd_cwnd)) / 2 / mss,
+					     2) * mss;
+		CCV(ccv, snd_cwnd) = mss;
 		/*
 		 * Grab the current time and record it so we know when the
 		 * most recent congestion event was. Only record it when the

Modified: head/sys/netinet/cc/cc_newreno.c
==============================================================================
--- head/sys/netinet/cc/cc_newreno.c	Sat Oct 24 16:05:37 2020	(r367006)
+++ head/sys/netinet/cc/cc_newreno.c	Sat Oct 24 16:09:18 2020	(r367007)
@@ -237,7 +237,7 @@ newreno_cong_signal(struct cc_var *ccv, uint32_t type)
 	u_int mss;
 
 	cwin = CCV(ccv, snd_cwnd);
-	mss = CCV(ccv, t_maxseg);
+	mss = tcp_maxseg(ccv->ccvc.tcp);
 	nreno = ccv->cc_data;
 	beta = (nreno == NULL) ? V_newreno_beta : nreno->beta;
 	beta_ecn = (nreno == NULL) ? V_newreno_beta_ecn : nreno->beta_ecn;
@@ -274,6 +274,12 @@ newreno_cong_signal(struct cc_var *ccv, uint32_t type)
 			CCV(ccv, snd_cwnd) = cwin;
 			ENTER_CONGRECOVERY(CCV(ccv, t_flags));
 		}
+		break;
+	case CC_RTO:
+		CCV(ccv, snd_ssthresh) = max(min(CCV(ccv, snd_wnd),
+						 CCV(ccv, snd_cwnd)) / 2 / mss,
+					     2) * mss;
+		CCV(ccv, snd_cwnd) = mss;
 		break;
 	}
 }

Modified: head/sys/netinet/tcp_input.c
==============================================================================
--- head/sys/netinet/tcp_input.c	Sat Oct 24 16:05:37 2020	(r367006)
+++ head/sys/netinet/tcp_input.c	Sat Oct 24 16:09:18 2020	(r367007)
@@ -429,8 +429,6 @@ cc_conn_init(struct tcpcb *tp)
 void inline
 cc_cong_signal(struct tcpcb *tp, struct tcphdr *th, uint32_t type)
 {
-	u_int maxseg;
-
 	INP_WLOCK_ASSERT(tp->t_inpcb);
 
 #ifdef STATS
@@ -460,13 +458,9 @@ cc_cong_signal(struct tcpcb *tp, struct tcphdr *th, ui
 		}
 		break;
 	case CC_RTO:
-		maxseg = tcp_maxseg(tp);
 		tp->t_dupacks = 0;
 		tp->t_bytes_acked = 0;
 		EXIT_RECOVERY(tp->t_flags);
-		tp->snd_ssthresh = max(2, min(tp->snd_wnd, tp->snd_cwnd) / 2 /
-		    maxseg) * maxseg;
-		tp->snd_cwnd = maxseg;
 		if (tp->t_flags2 & TF2_ECN_PERMIT)
 			tp->t_flags2 |= TF2_ECN_SND_CWR;
 		break;