MFC r266941, r266955

Needed for anticipated dummynet AQM MFC next week.

r266941 | hiren | 2014-06-01 00:28:24 -0700 (Sun, 01 Jun 2014) | 9 lines

ECN marking implenetation for dummynet.
Changes include both DCTCP and RFC 3168 ECN marking methodology.

DCTCP draft: http://tools.ietf.org/html/draft-bensley-tcpm-dctcp-00

Submitted by:	Midori Kato (aoimidori27@gmail.com)
Worked with:	Lars Eggert (lars@netapp.com)
Reviewed by:	luigi, hiren

r266955 | hiren | 2014-06-01 13:19:17 -0700 (Sun, 01 Jun 2014) | 5 lines

DNOLD_IS_ECN introduced by r266941 is not required.
DNOLD_* flags are for compat with old binaries.

Suggested by: luigi

Discussed with:	hiren
Relnotes:	yes

3 files changed, 26 insertions, 10 deletions

diff --git a/sbin/ipfw/dummynet.c b/sbin/ipfw/dummynet.c
index 28dc2c7..cb62853 100644
--- a/sbin/ipfw/dummynet.c
+++ b/sbin/ipfw/dummynet.c
@@ -56,6 +56,7 @@ static struct _s_x dummynet_params[] = {
 	{ "sched_mask",		TOK_SCHED_MASK },
 	{ "flow_mask",		TOK_FLOW_MASK },
 	{ "droptail",		TOK_DROPTAIL },
+	{ "ecn",		TOK_ECN },
 	{ "red",		TOK_RED },
 	{ "gred",		TOK_GRED },
 	{ "bw",			TOK_BW },
@@ -239,7 +240,7 @@ print_flowset_parms(struct dn_fs *fs, char *prefix)
 	else
 		plr[0] = '\0';
 
-	if (fs->flags & DN_IS_RED)	/* RED parameters */
+	if (fs->flags & DN_IS_RED) {	/* RED parameters */
 		sprintf(red,
 		    "\n\t %cRED w_q %f min_th %d max_th %d max_p %f",
 		    (fs->flags & DN_IS_GENTLE_RED) ? 'G' : ' ',
@@ -247,7 +248,9 @@ print_flowset_parms(struct dn_fs *fs, char *prefix)
 		    fs->min_th,
 		    fs->max_th,
 		    1.0 * fs->max_p / (double)(1 << SCALE_RED));
-	else
+		if (fs->flags & DN_IS_ECN)
+			strncat(red, " (ecn)", 6);
+	} else
 		sprintf(red, "droptail");
 
 	if (prefix[0]) {
@@ -1046,13 +1049,17 @@ end_mask:
 			}
 			if ((end = strsep(&av[0], "/"))) {
 			    double max_p = strtod(end, NULL);
-			    if (max_p > 1 || max_p <= 0)
-				errx(EX_DATAERR, "0 < max_p <= 1");
+			    if (max_p > 1 || max_p < 0)
+				errx(EX_DATAERR, "0 <= max_p <= 1");
 			    fs->max_p = (int)(max_p * (1 << SCALE_RED));
 			}
 			ac--; av++;
 			break;
 
+		case TOK_ECN:
+			fs->flags |= DN_IS_ECN;
+			break;
+
 		case TOK_DROPTAIL:
 			NEED(fs, "droptail is only for flowsets");
 			fs->flags &= ~(DN_IS_RED|DN_IS_GENTLE_RED);
@@ -1175,13 +1182,20 @@ end_mask:
 			errx(EX_DATAERR, "2 <= queue size <= %ld", limit);
 	    }
 
+	    if ((fs->flags & DN_IS_ECN) && !(fs->flags & DN_IS_RED))
+		errx(EX_USAGE, "enable red/gred for ECN");
+
 	    if (fs->flags & DN_IS_RED) {
 		size_t len;
 		int lookup_depth, avg_pkt_size;
 
-		if (fs->min_th >= fs->max_th)
+		if (!(fs->flags & DN_IS_ECN) && (fs->min_th >= fs->max_th))
 		    errx(EX_DATAERR, "min_th %d must be < than max_th %d",
 			fs->min_th, fs->max_th);
+		else if ((fs->flags & DN_IS_ECN) && (fs->min_th > fs->max_th))
+		    errx(EX_DATAERR, "min_th %d must be =< than max_th %d",
+			fs->min_th, fs->max_th);
+
 		if (fs->max_th == 0)
 		    errx(EX_DATAERR, "max_th must be > 0");
 
diff --git a/sbin/ipfw/ipfw.8 b/sbin/ipfw/ipfw.8
index 65fa334..13b8cc7 100644
--- a/sbin/ipfw/ipfw.8
+++ b/sbin/ipfw/ipfw.8
@@ -1,7 +1,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd October 25, 2012
+.Dd May 31, 2014
 .Dt IPFW 8
 .Os
 .Sh NAME
@@ -2442,22 +2442,23 @@ and
 control the maximum lengths that can be specified.
 .Pp
 .It Cm red | gred Ar w_q Ns / Ns Ar min_th Ns / Ns Ar max_th Ns / Ns Ar max_p
+[ecn]
 Make use of the RED (Random Early Detection) queue management algorithm.
 .Ar w_q
 and
 .Ar max_p
 are floating
-point numbers between 0 and 1 (0 not included), while
+point numbers between 0 and 1 (inclusive), while
 .Ar min_th
 and
 .Ar max_th
 are integer numbers specifying thresholds for queue management
 (thresholds are computed in bytes if the queue has been defined
 in bytes, in slots otherwise).
-The
+The two parameters can also be of the same value if needed. The
 .Nm dummynet
-also supports the gentle RED variant (gred).
-Three
+also supports the gentle RED variant (gred) and ECN (Explicit Congestion
+Notification) as optional. Three
 .Xr sysctl 8
 variables can be used to control the RED behaviour:
 .Bl -tag -width indent
diff --git a/sbin/ipfw/ipfw2.h b/sbin/ipfw/ipfw2.h
index 6e895b8..2301c40 100644
--- a/sbin/ipfw/ipfw2.h
+++ b/sbin/ipfw/ipfw2.h
@@ -165,6 +165,7 @@ enum tokens {
 	TOK_BURST,
 	TOK_RED,
 	TOK_GRED,
+	TOK_ECN,
 	TOK_DROPTAIL,
 	TOK_PROTO,
 	/* dummynet tokens */