Add support for priority-queue policy

Bug 3643
Enhancement to expose kernel priority queuing.

1 files changed, 118 insertions, 0 deletions

diff --git a/lib/Vyatta/Qos/Priority.pm b/lib/Vyatta/Qos/Priority.pm
new file mode 100644
index 0000000..b148b1c
--- /dev/null
+++ b/lib/Vyatta/Qos/Priority.pm
@@ -0,0 +1,118 @@
+# Priority Queue
+#
+# **** License ****
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# General Public License for more details.
+#
+# This code was originally developed by Vyatta, Inc.
+# Portions created by Vyatta are Copyright (C) 2008 Vyatta, Inc.
+# All Rights Reserved.
+# **** End License ****
+
+package Vyatta::Qos::Priority;
+use strict;
+use warnings;
+
+require Vyatta::Config;
+require Vyatta::Qos::ShaperClass;
+use POSIX;
+
+# Kernel limits on quantum (bytes)
+use constant {
+   MAXQUANTUM  => 200000,
+   MINQUANTUM  => 1000,
+};
+
+
+# Create a new instance based on config information
+sub new {
+    my ( $that, $config, $name ) = @_;
+    my $level   = $config->setLevel();
+    my @classes = _getClasses($level);
+
+    my $self = {};
+    my $class = ref($that) || $that;
+    bless $self, $class;
+
+    $self->{_level}   = $level;
+    $self->{_classes} = \@classes;
+    return $self;
+}
+
+sub _getClasses {
+    my $level = shift;
+    my @classes;
+    my $config = new Vyatta::Config;
+
+    $config->setLevel($level);
+    $config->exists("default")
+      or die "$level configuration not complete: missing default class\n";
+
+    $config->setLevel("$level default");
+    push @classes, new Vyatta::Qos::ShaperClass($config);
+    $config->setLevel($level);
+
+    foreach my $id ( $config->listNodes("class") ) {
+        $config->setLevel("$level class $id");
+        push @classes, new Vyatta::Qos::ShaperClass( $config, $id );
+    }
+
+    return @classes;
+}
+
+# Note: priority does not have internal classes, only sub-qdisc's
+#
+# Although Linux supports mapping TOS and priority to bands, this
+# is not used here. Instead we apply filters to traffic and statically
+# assign bands.
+sub commands {
+    my ( $self, $dev ) = @_;
+    my $classes = $self->{_classes};
+    my $default = shift @$classes;
+    my $maxid   = 1;
+    my $bands = 2;
+
+    foreach my $class (@$classes) {
+	my $level = "$self->{_level} class $class->{id}";
+	$class->valid_leaf( $level );
+
+        # find largest class id
+	$maxid = $class->{id}
+        if ( defined $class->{id} && $class->{id} > $maxid );
+
+	# find largest priority
+	my $prio = $class->{_priority};
+
+	$bands = $prio + 1
+	    if ( defined $prio && $prio >= $bands);
+    }
+
+    # fill in id of default
+    $default->{id} = ++$maxid;
+    unshift @$classes, $default;
+
+    my $parent = 1;
+    my $root   = "root";
+
+    # Since we use filters to set priority 
+    printf "qdisc add dev %s %s handle %x: prio bands %d\n",
+	$dev, $root, $parent, $bands;
+
+    # prio is not really classful!
+    foreach my $class (@$classes) {
+        $class->gen_leaf( $dev, $parent );
+
+	my $prio = 1;
+        foreach my $match ( $class->matchRules() ) {
+            $match->filter( $dev, $parent, $class->{id}, $prio++ );
+        }
+    }
+}
+
+1;