Cellular Network Infrastructure

#!/bin/sh

#

# usage:

#

#  virtual-link.sh <netem-cmd> <namespace-name> <subnet-prefix>

#

# e.g.

#

#  virtual-link.sh "delay 200ms 50ms 50%" abis 10.9.8.

#

# (omit any number of trailing arguments for default values)

netem_cmd="${1:-delay 200ms 50ms 50%}"

ns="${2:-abis}"

link_in="${ns}-in"

link_out="${ns}-out"

subnet_prefix="${3:-10.9.8.}"

addr_out="${subnet_prefix}1"

addr_in="${subnet_prefix}2"

addr_mask_out="${addr_out}/24"

addr_mask_in="${addr_in}/24"

set -e -x

test $USER = root

ip netns add $ns

ip link add $link_in type veth peer name $link_out

ip link set $link_in netns $ns

ip link set $link_out up

ip addr add $addr_mask_out dev $link_out

ip a

ip netns exec abis  ip link set $link_in up

ip netns exec abis  ip link set lo up

ip netns exec abis  ip addr add $addr_mask_in dev $link_in

ip netns exec abis  ip a

tc qdisc add dev $link_out root handle 1:0 netem $netem_cmd

ip netns exec abis  tc qdisc add dev $link_in root handle 1:0 netem $netem_cmd

ping -c 3 $addr_in

ip netns exec abis  ping -c 3 $addr_out

set +x

echo To clean up:  netns delete $ns