packet loose mock use tc

packet-loose.sh

#!/bin/env bash

# --------------------------------------------
#
# 网络丢包模拟工具
#
# --------------------------------------------

block(){
  interface=$1
  dest=$2
  [ -z $interface -o -z $dest ] && usage 
  percentage=${3:-80}
  tc qdisc del dev $interface root
  tc qdisc add dev $interface root handle 1: prio bands 4
  tc qdisc add dev $interface parent 1:4 handle 20: netem delay 10ms 1ms loss ${percentage}%
  tc filter add dev $interface parent 1:0 protocol ip pref 55 handle ::55 u32 match ip dst $dest flowid 1:4
}

clear(){
  interface=$1
  [ -z $interface ] && usage
  tc qdisc del dev $interface root
}

usage() {
cat <<EOF 

Network disaster mocking tool : packet send loose at some ratio 


$0 block|clear <OPTIONS>

   block <interface> <destination-ip-address> [percentage]

   clear <interface>

examples :

   $0 block eth0 192.168.100.2 80 # loose 80% of send packet to 192.168.100.2 via eth0

   $0 clear eth0 # cleanup the previouse block rule
EOF
}

# ------------------------------------
case $1 in
   block)
     shift
     block $@
     ;;
   clear)
     clear $2 
    ;;
   *) 
    usage
    ;;
esac
# ------------------------------------