# Traffic shaper sub-class

# **** 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::ShaperClass;
use strict;
use warnings;

require Vyatta::Config;
use Vyatta::Qos::Match;
use Vyatta::Qos::Util qw/getDsfield getRate/;

my %fields = (
    id        => undef,
    dsmark    => undef,
    _priority => undef,
    _rate     => undef,
    _ceiling  => undef,
    _burst    => undef,
    _match    => undef,
    _limit    => undef,
    _qdisc    => undef,
);

sub new {
    my ( $that, $config, $id ) = @_;
    my $class = ref($that) || $that;
    my $self = {%fields};

    $self->{id} = $id;

    bless $self, $class;
    $self->_define($config);

    return $self;
}

sub _define {
    my ( $self, $config ) = @_;
    my $level   = $config->setLevel();
    my @matches = ();

    $self->{_rate} = $config->returnValue("bandwidth");
    defined $self->{_rate} or die "$level bandwidth not defined\n";

    $self->{_priority} = $config->returnValue("priority");
    $self->{_ceiling}  = $config->returnValue("ceiling");
    $self->{_burst}    = $config->returnValue("burst");
    $self->{_limit}    = $config->returnValue("queue-limit");
    $self->{_qdisc}    = $config->returnValue("queue-type");

    $self->{dsmark} = getDsfield( $config->returnValue("set-dscp") );

    foreach my $match ( $config->listNodes("match") ) {
        $config->setLevel("$level match $match");
        push @matches, new Vyatta::Qos::Match($config);
    }
    $self->{_match} = \@matches;
}

sub matchRules {
    my ($self) = @_;
    my $matches = $self->{_match};
    return @$matches;
}

sub _getPercentRate {
    my ( $rate, $speed ) = @_;

    if ( !defined $rate ) {
        return;    # leave rate undef
    }

    # Rate might be a percentage of speed
    if ( $rate =~ /%$/ ) {
        my $percent = substr( $rate, 0, length($rate) - 1 );
        if ( $percent < 0 || $percent > 100 ) {
            die "Invalid percentage bandwidth: $percent\n";
        }

        $rate = ( $percent * $speed ) / 100.;
    }
    else {
        $rate = getRate($rate);
    }

    return $rate;
}

sub rateCheck {
    my ( $self, $limit, $level ) = @_;

    my $rate = _getPercentRate( $self->{_rate}, $limit );
    if ( $rate > $limit ) {
        print STDERR "Configuration error in: $level\n";
        printf STDERR
          "The bandwidth reserved for this class (%dKbps) must be less than\n",
          $rate / 1000;
        printf STDERR "the bandwidth for the overall policy (%dKbps)\n",
          $limit / 1000;
        exit 1;
    }

    my $ceil = _getPercentRate( $self->{_ceiling}, $limit );
    if ( defined $ceil && $ceil < $rate ) {
        print STDERR "Configuration error in: $level\n";
        printf STDERR
"The bandwidth ceiling for this class (%dKbps) must be greater or equal to\n",
          $ceil / 1000;
        printf STDERR "the reserved bandwidth for the class (%dKbps)\n",
          $rate / 1000;
        exit 1;
    }
}

sub prioQdisc {
    my ( $self, $out, $dev, $rate ) = @_;
    my $prio_id = 0x4000 + $self->{id};
    my $limit   = $self->{_limit};

    printf {$out} "handle %x: prio\n", $prio_id;

    if ($limit) {
        foreach my $i (qw/1 2 3/) {
            printf {$out} "qdisc add dev %s parent %x:%d pfifo limit %d\n",
              $dev, $prio_id, $i, $limit;
        }
    }
}

sub sfqQdisc {
    my ( $self, $out, $dev, $rate ) = @_;

    print ${out} "sfq";
    print ${out} " limit $self->{_limit}" if ( $self->{_limit} );
    print ${out} "\n";
}

sub fifoQdisc {
    my ( $self, $out, $dev, $rate ) = @_;

    print ${out} "pfifo";
    print ${out} " limit $self->{_limit}" if ( $self->{_limit} );
    print ${out} "\n";
}

# Red is has way to many configuration options
# make some assumptions to make this sane (based on LARTC)
#   average size := 1000 bytes
#   limit        := queue-limit * average
#   max          := limit / 8
#   min          := max / 3
#   burst        := (2 * min + max) / (3 * average)
sub redQdisc {
    my ( $self, $out, $dev, $rate ) = @_;
    my $limit = $self->{_limit};
    my $avg   = 1000;
    my $qlimit;

    if ( defined $limit ) {
        $qlimit = $limit * $avg;    # red limit in bytes
    }
    else {

        # rate is in bits/sec so queue-limit = 8 * 500ms * rate
        $qlimit = $rate / 2;
    }
    my $qmax = $qlimit / 8;
    my $qmin = $qmax / 3;

    printf ${out} "red limit %d min %d max %d avpkt %d",
      $qlimit, $qmin, $qmax, $avg;
    printf ${out} " burst %d probability 0.02 bandwidth %d ecn\n",
      ( 2 * $qmin + $qmax ) / ( 3 * $avg ), $rate / 1000;
}

my %qdiscOptions = (
    'priority'      => \&prioQdisc,
    'fair-queue'    => \&sfqQdisc,
    'random-detect' => \&redQdisc,
    'drop-tail'     => \&fifoQdisc,
);

sub htbClass {
    my ( $self, $out, $dev, $parent, $speed ) = @_;
    my $rate = _getPercentRate( $self->{_rate},    $speed );
    my $ceil = _getPercentRate( $self->{_ceiling}, $speed );

    printf ${out} "class add dev %s parent %x:1 classid %x:%x htb rate %s",
      $dev, $parent, $parent, $self->{id}, $rate;

    print ${out} " ceil $ceil"              if ($ceil);
    print ${out} " burst $self->{_burst}"   if ( defined $self->{_burst} );
    print ${out} " prio $self->{_priority}" if ( defined $self->{_priority} );
    print {$out} "\n";

    # create leaf qdisc
    my $q = $qdiscOptions{ $self->{_qdisc} };
    if ( defined $q ) {
        printf {$out} "qdisc add dev %s parent %x:%x ",
          $dev, $parent, $self->{id};
        $q->( $self, $out, $dev, $rate );
    }
    else {
        die "Unknown queue type $self->{_qdisc}\n";
    }
}

sub dsmarkClass {
    my ( $self, $out, $parent, $dev ) = @_;

    printf ${out} "class change dev %s classid %x:%x dsmark",
      $dev, $parent, $self->{id};

    if ( $self->{dsmark} ) {
        print ${out} " mask 0 value $self->{dsmark}\n";
    }
    else {
        print ${out} " mask 0xff value 0\n";
    }
}

1;