jft-shaper

#!/bin/sh

### Usage: jft-shaper -h
### Usage: jft-shaper -i INTERVAL # interval in seconds
### Usage: jft-shaper -t <adsl|institution|datacenter> # shapes this machine to traces of the type
### Usage: jft-shaper -b MAXBW # max bandwith of the target machine in kilobits per second

usage()
{
  perl -ne '/^### Usage:/ && do { s/^### ?//; print }' < $0
  exit 1
}

help()
{
  perl -ne '/^###/ && do { s/^### ?//; print }' < $0
  exit 0
}

# Parse arguments
eval set -- $(getopt -n $0 -o hs:t:i:b: -- ${1+"$@"})
[ $? = 0 ] || usage

for arg; do
  case $arg in
    -i) INTVAL="$2"; shift; shift ;;
    -b) MAXBW="$2"; shift; shift ;;
    -t) TYPE="$2"; shift; shift ;;
    -h) help ;;
    --) shift; break ;;
    -*) usage ;;
  esac
done

[ $# = 0 ] || usage

[ X"$TYPE" = X ] && usage
[ -f /data/cfg/traces/$TYPE ] || 
  { echo "Traces for $TYPE not found in /data/state"; exit 1; }
[ X"$INTVAL" = X ] && usage
[ X"$MAXBW" = X ] && usage

# set to default rate upon exit
trap "exit 0" SIGTERM SIGINT
trap "sudo /sbin/tc qdisc del dev seth0 root tbf" EXIT

set -e
while true; do
  # loop reads traces and sets the rate at every INTVAL interval seconds
  cat /data/cfg/traces/$TYPE | while read p; do
    r=$(echo "scale=0; (1.0 - $p) * $MAXBW / 1.0" | bc)
    echo rate is $r and perc available is 1.0 - $p and MAXBW is $MAXBW
    (sudo /sbin/tc qdisc add dev seth0 root tbf rate ${r}kbit latency 50ms burst 1540)
    sleep $INTVAL
    (sudo /sbin/tc qdisc del dev seth0 root tbf)
  done 
done

exit 0