From 0bb882c4bb9acefe26a5713520e5c4ce42cafd79 Mon Sep 17 00:00:00 2001
From: Michael Tremer <michael.tremer@ipfire.org>
Date: Mon, 4 Oct 2021 18:52:20 +0100
Subject: [PATCH] QoS: Drop support for hardcoded ACK rules

This feature has to go in order to take advantage of CONNMARK which will
drastically decrease CPU load when passing packets.

We no longer will see every packet in the QOS-INC chain in order to
change classification of that packet. It is also party counter-intuitive
to have parts of one connection in one class and the corresponding ACK
packets in another.

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
Signed-off-by: Arne Fitzenreiter <arne_f@ipfire.org>
---
 config/qos/makeqosscripts.pl | 27 ---------------------------
 html/cgi-bin/qos.cgi         | 22 ++--------------------
 2 files changed, 2 insertions(+), 47 deletions(-)

diff --git a/config/qos/makeqosscripts.pl b/config/qos/makeqosscripts.pl
index 5bdd5b811a..230dc3265b 100644
--- a/config/qos/makeqosscripts.pl
+++ b/config/qos/makeqosscripts.pl
@@ -72,7 +72,6 @@ $qossettings{'DEF_OUT_SPD'} = '';
 $qossettings{'DEF_INC_SPD'} = '';
 $qossettings{'DEFCLASS_INC'} = '';
 $qossettings{'DEFCLASS_OUT'} = '';
-$qossettings{'ACK'} = '';
 $qossettings{'RED_DEV'} = `cat /var/ipfire/red/iface`;
 $qossettings{'IMQ_DEV'} = 'imq0';
 $qossettings{'TOS'} = '';
@@ -80,7 +79,6 @@ $qossettings{'VALID'} = 'yes';
 
 &General::readhash("${General::swroot}/qos/settings", \%qossettings);
 
-my $ACK_MARK = ($qossettings{'ACK'} << $QOS_OUT_SHIFT) . "/$QOS_OUT_MASK";
 my $DEF_OUT_MARK = ($qossettings{'DEFCLASS_OUT'} << $QOS_OUT_SHIFT) . "/$QOS_OUT_MASK";
 my $DEF_INC_MARK = ($qossettings{'DEFCLASS_INC'} << $QOS_INC_SHIFT) . "/$QOS_INC_MASK";
 
@@ -224,31 +222,6 @@ print <<END
 	### Don't change mark on traffic for the ipsec tunnel
 	iptables -t mangle -A QOS-OUT -m mark --mark 50 -j RETURN
 
-	### MARK ACKs
-	iptables -t mangle -A QOS-OUT -p tcp --tcp-flags SYN,RST SYN -j MARK --set-xmark $ACK_MARK
-	iptables -t mangle -A QOS-OUT -p tcp --tcp-flags SYN,RST SYN -j RETURN
-
-	iptables -t mangle -A QOS-OUT -p icmp -m length --length 40:100 -j MARK --set-xmark $ACK_MARK
-	iptables -t mangle -A QOS-OUT -p icmp -m length --length 40:100 -j RETURN
-
-	iptables -t mangle -A QOS-OUT -p tcp --syn -m length --length 40:68 -j MARK --set-xmark $ACK_MARK
-	iptables -t mangle -A QOS-OUT -p tcp --syn -m length --length 40:68 -j RETURN
-
-	iptables -t mangle -A QOS-OUT -p tcp --tcp-flags ALL SYN,ACK -m length --length 40:68 -j MARK --set-xmark $ACK_MARK
-	iptables -t mangle -A QOS-OUT -p tcp --tcp-flags ALL SYN,ACK -m length --length 40:68 -j RETURN
-
-	iptables -t mangle -A QOS-OUT -p tcp --tcp-flags ALL ACK -m length --length 40:100 -j MARK --set-xmark $ACK_MARK
-	iptables -t mangle -A QOS-OUT -p tcp --tcp-flags ALL ACK -m length --length 40:100 -j RETURN
-
-	iptables -t mangle -A QOS-OUT -p tcp --tcp-flags ALL RST -j MARK --set-xmark $ACK_MARK
-	iptables -t mangle -A QOS-OUT -p tcp --tcp-flags ALL RST -j RETURN
-
-	iptables -t mangle -A QOS-OUT -p tcp --tcp-flags ALL ACK,RST -j MARK --set-xmark $ACK_MARK
-	iptables -t mangle -A QOS-OUT -p tcp --tcp-flags ALL ACK,RST -j RETURN
-
-	iptables -t mangle -A QOS-OUT -p tcp --tcp-flags ALL ACK,FIN -j MARK --set-xmark $ACK_MARK
-	iptables -t mangle -A QOS-OUT -p tcp --tcp-flags ALL ACK,FIN -j RETURN
-
 	### SET TOS
 END
 ;
diff --git a/html/cgi-bin/qos.cgi b/html/cgi-bin/qos.cgi
index ab427879e9..c2ff4a08d2 100644
--- a/html/cgi-bin/qos.cgi
+++ b/html/cgi-bin/qos.cgi
@@ -68,7 +68,6 @@ $qossettings{'DEF_OUT_SPD'} = '';
 $qossettings{'DEF_INC_SPD'} = '';
 $qossettings{'DEFCLASS_INC'} = '';
 $qossettings{'DEFCLASS_OUT'} = '';
-$qossettings{'ACK'} = '';
 $qossettings{'RED_DEV'} = 'ppp0';
 $qossettings{'IMQ_DEV'} = 'imq0';
 $qossettings{'VALID'} = 'yes';
@@ -518,7 +517,6 @@ END
 		}
 		$qossettings{'DEFCLASS_INC'} = "210";
 		$qossettings{'DEFCLASS_OUT'} = "110";
-		$qossettings{'ACK'} ="101";
 		$qossettings{'ENABLED'} = 'on';
 		&General::writehash("${General::swroot}/qos/settings", \%qossettings);
 		&General::system("/usr/local/bin/qosctrl", "generate");
@@ -660,7 +658,7 @@ END
 END
 ;
 	}
-	if (($qossettings{'DEFCLASS_OUT'} ne '') && ($qossettings{'DEFCLASS_INC'} ne '')&& ($qossettings{'ACK'} ne '')) {
+	if (($qossettings{'DEFCLASS_OUT'} ne '') && ($qossettings{'DEFCLASS_INC'} ne '')) {
 		print <<END
 		<form method='post' action='$ENV{'SCRIPT_NAME'}'>
 		<table width='66%'>
@@ -668,7 +666,6 @@ END
 		<tr><td width='50%' align='right'>$Lang::tr{'downlink std class'}: 	<td width='30%' align='left'>$qossettings{'DEFCLASS_INC'}
 		    <td width='20%' rowspan='3' align='center' valign='middle'><input type='submit' name='ACTIONDEF' value='$Lang::tr{'modify'}' />
 		<tr><td width='50%' align='right'>$Lang::tr{'uplink std class'}: 	<td width='30%' align='left'>$qossettings{'DEFCLASS_OUT'}
-		<tr><td width='50%' align='right'>ACKs:				<td width='30%' align='left'>$qossettings{'ACK'}
 	 	<tr><td colspan='3' width='100%'><hr />
 		<tr><td colspan='3' width='100%' align='center'>
 		</table>
@@ -692,7 +689,7 @@ if ( ($qossettings{'OUT_SPD'} eq '') || ($qossettings{'INC_SPD'} eq '') ) {
 	exit
 }
 
-if ( ($qossettings{'DEFCLASS_INC'} eq '') || ($qossettings{'DEFCLASS_OUT'} eq '') || ($qossettings{'ACK'} eq '') ) {
+if ( ($qossettings{'DEFCLASS_INC'} eq '') || ($qossettings{'DEFCLASS_OUT'} eq '') ) {
 	&changedefclasses();
 	&Header::closebigbox();
 	&Header::closepage();
@@ -742,21 +739,6 @@ END
 			else { print "<option selected value='$c'>$c</option>\n"; }
 		}
 		print <<END
-		</select><td width='33%' align='center'>&nbsp;
-		</table>
-		<hr />
-		<table width='66%'>
-		<tr><td width='100%' colspan='3'>$Lang::tr{'enter ack class'}
-		<tr><td width='33%' align='right'>ACKs:<td width='33%' align='left'><select name='ACK'>
-END
-;
-		for ( $c = 100 ; $c <= 120 ; $c++ )
-		{
-			if ( $qossettings{'ACK'} ne $c )
-			{ print "<option value='$c'>$c</option>\n"; }
-			else {	print "<option selected value='$c'>$c</option>\n"; }
-		}
-		print <<END
 		</select><td width='33%' align='center'><input type='submit' name='ACTION' value="$Lang::tr{'save'}" />
 		</table>
 		</form>
-- 
2.39.5