#!/bin/bash
set -e

# Require root permissions
test "$(id -u)" = "0" || exit 77

# Configuration
LOG_PREFIX=/dev/shm/utcp-benchmark-log
SIZE=10000000

# Network parameters
# Some realistic values:
# - Gbit LAN connection: RATE=1gbit DELAY=0.4ms JITTER=0.04ms LOSS=0%
# - Fast WAN connection: RATE=100mbit DELAY=50ms JITTER=3ms LOSS=0%
# - 5GHz WiFi connection: RATE=90mbit DELAY=5ms JITTER=1ms LOSS=0%
RATE=100mbit
DELAY=10ms
JITTER=1ms
LOSS=0.1%

# Maximum achievable bandwidth is limited to BUFSIZE / (2 * DELAY)
# The Linux kernel has a default maximum send buffer of 4 MiB
#export BUFSIZE=4194304

# Remove old log files
rm -f $LOG_PREFIX-* 2>/dev/null

# Clean up old namespaces
ip link del utcp-left 2>/dev/null || true
ip link del utcp-right 2>/dev/null || true
ip netns delete utcp-left 2>/dev/null || true
ip netns delete utcp-right 2>/dev/null || true

# Set up the left namespace
ip netns add utcp-left
ip link add name utcp-left type veth peer name utcp-right
ip link set utcp-left netns utcp-left

ip netns exec utcp-left ethtool -K utcp-left tso off
ip netns exec utcp-left ip link set dev lo up
ip netns exec utcp-left ip addr add dev utcp-left 192.168.1.1/24
ip netns exec utcp-left ip link set utcp-left up

#ip netns exec utcp-left tc qdisc del dev utcp-left root
ip netns exec utcp-left tc qdisc add dev utcp-left root netem rate $RATE delay $DELAY $JITTER loss random $LOSS

# Set up the right namespace
ip netns add utcp-right
ip link set utcp-right netns utcp-right

ip netns exec utcp-right ethtool -K utcp-right tso off
ip netns exec utcp-right ip link set dev lo up
ip netns exec utcp-right ip addr add dev utcp-right 192.168.1.2/24
ip netns exec utcp-right ip link set utcp-right up

#ip netns exec utcp-right tc qdisc del dev utcp-right root
ip netns exec utcp-right tc qdisc add dev utcp-right root netem rate $RATE delay $DELAY $JITTER loss random $LOSS
# Test using kernel TCP
ip netns exec utcp-right tcpdump -i utcp-right -w $LOG_PREFIX-socat.pcap port 9999 2>/dev/null &
ip netns exec utcp-left socat TCP4-LISTEN:9999 - >/dev/null &
sleep 0.1
head -c $SIZE /dev/zero | ip netns exec utcp-right time socat - TCP4:192.168.1.1:9999 2>$LOG_PREFIX-socat-client.txt >/dev/null
sleep 0.1
kill $(jobs -p) 2>/dev/null

# Test using UTCP
ip netns exec utcp-right tcpdump -i utcp-right -w $LOG_PREFIX-utcp.pcap udp port 9999 2>/dev/null &
ip netns exec utcp-left ../src/utcp-test 9999 2>$LOG_PREFIX-server.txt >/dev/null &
sleep 0.1
head -c $SIZE /dev/zero | ip netns exec utcp-right time ../src/utcp-test 192.168.1.1 9999 2>$LOG_PREFIX-client.txt >/dev/null
sleep 0.1
kill $(jobs -p) 2>/dev/null

# Print timing statistics
echo "Regular TCP:"
tail -2 $LOG_PREFIX-socat-client.txt

echo
echo "UTCP:"
tail -3 $LOG_PREFIX-client.txt