#!/bin/bash

  # SPDX-License-Identifier: GPL-2.0

  #
  # Script for max single flow performance
  #  - If correctly tuned[1], single CPU 10G wirespeed small pkts is possible[2]
  #
  # Using pktgen "burst" option (use -b $N)
  #  - To boost max performance
  #  - Avail since: kernel v3.18
  #   * commit 38b2cf2982dc73 ("net: pktgen: packet bursting via skb->xmit_more")
  #  - This avoids writing the HW tailptr on every driver xmit
  #  - The performance boost is impressive, see commit and blog [2]
  #
  # Notice: On purpose generates a single (UDP) flow towards target,
  #   reason behind this is to only overload/activate a single CPU on
  #   target host.  And no randomness for pktgen also makes it faster.
  #
  # Tuning see:
  #  [1] http://netoptimizer.blogspot.dk/2014/06/pktgen-for-network-overload-testing.html
  #  [2] http://netoptimizer.blogspot.dk/2014/10/unlocked-10gbps-tx-wirespeed-smallest.html
  #
  basedir=`dirname $0`
  source ${basedir}/functions.sh
  root_check_run_with_sudo "$@"
  
  # Parameter parsing via include
  source ${basedir}/parameters.sh
  # Set some default params, if they didn't get set

  if [ -z "$DEST_IP" ]; then
      [ -z "$IP6" ] && DEST_IP="198.18.0.42" || DEST_IP="FD00::1"
  fi

  [ -z "$DST_MAC" ]   && DST_MAC="90:e2:ba:ff:ff:ff"
  [ -z "$BURST" ]     && BURST=32

  [ -z "$CLONE_SKB" ] && CLONE_SKB="0" # No need for clones when bursting

  [ -z "$COUNT" ]     && COUNT="0" # Zero means indefinitely

  if [ -n "$DEST_IP" ]; then
      validate_addr${IP6} $DEST_IP
      read -r DST_MIN DST_MAX <<< $(parse_addr${IP6} $DEST_IP)
  fi

  if [ -n "$DST_PORT" ]; then

      read -r UDP_DST_MIN UDP_DST_MAX <<< $(parse_ports $DST_PORT)
      validate_ports $UDP_DST_MIN $UDP_DST_MAX

  fi

  
  # Base Config
  DELAY="0"  # Zero means max speed

  
  # General cleanup everything since last run
  pg_ctrl "reset"
  
  # Threads are specified with parameter -t value in $THREADS

  for ((thread = $F_THREAD; thread <= $L_THREAD; thread++)); do

      dev=${DEV}@${thread}
  
      # Add remove all other devices and add_device $dev to thread
      pg_thread $thread "rem_device_all"
      pg_thread $thread "add_device" $dev
  
      # Base config
      pg_set $dev "flag QUEUE_MAP_CPU"
      pg_set $dev "count $COUNT"
      pg_set $dev "clone_skb $CLONE_SKB"
      pg_set $dev "pkt_size $PKT_SIZE"
      pg_set $dev "delay $DELAY"
      pg_set $dev "flag NO_TIMESTAMP"
  
      # Destination
      pg_set $dev "dst_mac $DST_MAC"

      pg_set $dev "dst${IP6}_min $DST_MIN"
      pg_set $dev "dst${IP6}_max $DST_MAX"

      if [ -n "$DST_PORT" ]; then
  	# Single destination port or random port range
  	pg_set $dev "flag UDPDST_RND"

  	pg_set $dev "udp_dst_min $UDP_DST_MIN"
  	pg_set $dev "udp_dst_max $UDP_DST_MAX"

      fi

      # Setup burst, for easy testing -b 0 disable bursting
      # (internally in pktgen default and minimum burst=1)
      if [[ ${BURST} -ne 0 ]]; then
  	pg_set $dev "burst $BURST"
      else
  	info "$dev: Not using burst"
      fi
  done
  
  # Run if user hits control-c
  function control_c() {
      # Print results

      for ((thread = $F_THREAD; thread <= $L_THREAD; thread++)); do

  	dev=${DEV}@${thread}
  	echo "Device: $dev"
  	cat /proc/net/pktgen/$dev | grep -A2 "Result:"
      done
  }
  # trap keyboard interrupt (Ctrl-C)
  trap control_c SIGINT
  
  echo "Running... ctrl^C to stop" >&2
  pg_ctrl "start"