Re: Cake compiled for the EdgeRouter devices

I completely rewrote the little script from earlier and it's now a proper init script. Place the below code into `/etc/init.d/cake`. Please note that it is not complete as unloading the modules does not work yet. If I figure it out, I'll update this post. Hoping this can be helpful to people, any feedback appreciated!

#!/bin/bash

### 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 /etc/default/cake ]; then
  . /etc/default/cake
  if [ -z "$DNSPEED" -o -z "$UPSPEED" \
    -o -z "$DNLIMIT" -o -z "$UPLIMIT" \
    -o -z "$IF" ]; then
    echo "Error: /etc/default/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: /etc/default/cake must exist!"
  exit 5
fi

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

unload() {
  # FIXME: Figure out how to get the modules unloaded again.
  # https://github.com/dtaht/sch_cake/issues/35
  ifconfig ifb4eth0 down
  ip link del dev ifb4eth0
  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"
  tc qdisc add dev $IF root cake bandwidth ${UPLIMIT}kbit
  ip link add name ifb4${IF} type ifb
  tc qdisc del dev $IF ingress
  tc qdisc del dev $IF handle ffff: ingress
  tc qdisc del dev ifb4${IF} root
  tc qdisc add dev ifb4${IF} root cake bandwidth ${DNLIMIT}kbit besteffort
  ifconfig ifb4${IF} up
  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.
}

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)
    $TC -s qdisc
    ;;
  *)
    echo "Usage: $0 {start|stop|reload|status}"
    exit 2
    ;;
esac

The init script requires `/etc/default/cake` to be present. Mine looks like this:

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

 @denist: If you're happy with the results, you can make the script run during boot by saying e.g. `ln -s /etc/init.d/cake /etc/rc2.d/S10cake`.