Script for handling the Cake scheduler on EdgeOS

slash-config-cake.sh

# Save as /etc/config/cake

# The interface to be limited
IF=eth0
# Kbps values
DNSPEED=100000
UPSPEED=7500
# Percentages
DNLIMIT=60 # ERLite3 can only manage 60Mbps
UPLIMIT=95
# Custom options
UPOPTS=''
DNOPTS='besteffort'

slash-etc-init.d-cake.sh

#!/bin/bash
# Save as /etc/init.d/cake

### BEGIN INIT INFO
# Provides:       cake
# Required-Start: $network
# Required-Stop:  $network
# Default-Start:  2 3 4 5
# Default-Stop:   1
# Short-Description: Enable CAKE scheduler
### END INIT INFO

PATH=/sbin:/bin:/usr/sbin:/usr/bin

. /lib/lsb/init-functions

TC=/sbin/tc
IP=/sbin/ip

if [ -r /config/cake ]; then
  . /config/cake
  if [ -z "$DNSPEED" -o -z "$UPSPEED" \
    -o -z "$DNLIMIT" -o -z "$UPLIMIT" \
    -o -z "$IF" ]; then
    echo "Error: /config/cake is not complete!"
    exit 5
  fi; if [ ! -x $TC -o ! -x $IP ]; then
    echo "Error: both $TC and $IP must be present and executable!"
    # exit 5
  fi
else
  echo "Error: /config/cake must exist!"
  exit 5
fi

if [ "$#" -gt 1 -a "$2" != "stop" ]; then
  UPOPTS="${@:2}"
  DNOPTS="$UPOPTS"
  echo "Applying custom options '$UPOPTS'."
fi

load() {
  modprobe sch_cake
  modprobe act_mirred
  set_limits
  return $?
}

unload() {
  # Adapted from pgage's Cake start/stop script (UBNT Forums)
  # http://community.ubnt.com/ubnt/attachments/ubnt/EdgeMAX/132960/1/cake_sh.zip
  tc filter del dev $IF parent ffff: protocol all      \
    prio 10 u32 match u32 0 0 flowid 1:1 action mirred \
    egress redirect dev ifb4${IF}
  tc qdisc del dev ifb4${IF} root
  ifconfig ifb4${IF} down
  tc qdisc del dev $IF ingress
  tc qdisc del dev $IF handle ffff: ingress
  ip link delete dev ifb4${IF}
  tc qdisc del dev $IF root
  modprobe -r act_mirred
  modprobe -r sch_cake
  return $?
}

set_limits() {
  DNLIMIT=$(($DNSPEED/100*$DNLIMIT))
  UPLIMIT=$(($UPSPEED/100*$UPLIMIT))
  echo -e "\nDownload limit: ${DNLIMIT}kbps\nUpload limit:   ${UPLIMIT}kbps"
  #
  # Cake is always about regulation of outbound, unless...
  tc qdisc add dev $IF root cake bandwidth ${UPLIMIT}kbit $UPOPTS
  #
  # ... an IFB interface is present which regulates inbound (IFB
  # = Intermediate Block Interface. Documentation can be found
  # at https://www.bufferbloat.net/projects/codel/wiki/Cake/)
  ip link add name ifb4${IF} type ifb
  tc qdisc add dev ifb4${IF} handle ffff: ingress
  tc qdisc add dev ifb4${IF} root cake bandwidth ${DNLIMIT}kbit $DNOPTS
  ifconfig ifb4${IF} up
  # Why is the filter not applied to the IFB interface too, though?
  tc filter add dev $IF parent ffff: protocol all      \
    prio 10 u32 match u32 0 0 flowid 1:1 action mirred \
    egress redirect dev ifb4${IF}
  return 0 # FIXME: Be more honest here!
}

usage() {
  # Usage notes also taken and adapted from pgage's script
  # FIXME: Rework the script so pgage's commandline arguments work properly again!
  echo "Usage: $0 <start|stop|reload|status> [cake args]"
  echo
  echo Note: This script must be run as root or with sudo
  echo
  echo Turn Cake on:
  echo "    $0 start [cake args]"
  echo
  echo Turn Cake off:
  echo "    $0 stop"
  echo
  echo Change Cake options:
  echo "    $0 reload [cake args]"
  echo
  echo Show status:
  echo "    $0 status"
  echo
  echo "[cake args] are optional and provide any additional arguments to Cake"
  echo "    See https://www.bufferbloat.net/projects/codel/wiki/Cake/"
  echo
  echo Examples:
  echo
  echo 'ADSL modem using PPPoE with LLC-Snap connected via Ethernet:'
  echo $0 reload pppoe-llcsnap via-ethernet # 360kbit 5mbit
  echo
  echo 'Symmetric WiFi uplink, enable host fairness (triple isolation) with NAT support:'
  echo $0 start triple-isolate nat # 30mbit 30mbit
  echo
  echo 'UHF to Curiosity rover on Mars:'
  echo $0 start interplanetary # 32kbit 32kbit
}

case $1 in
  start)
    log_daemon_msg "Enabling Cake scheduler" "cake"
    load
    log_end_msg $?
    ;;
  stop)
    log_daemon_msg "Disabling Cake scheduler" "cake"
    unload
    log_end_msg $?
    ;;
  reload)
    log_daemon_msg "Setting new limits for Cake scheduler" "cake"
    set_limits
    log_end_msg $?
    ;;
  status)
    while true; do
      echo -e  "\033c"
      $TC -s qdisc
      echo -en "\n(Hit <Ctrl-C> to exit)"
      sleep 2
    done
    ;;
  *)
    usage
    echo
    exit 2
    ;;
esac