#!/bin/bash
# SPDX-License-Identifier: GPL-2.0+
#
# Author: Justin Iurman <justin.iurman@uliege.be>
#
# This script evaluates the IOAM insertion for IPv6 by checking the IOAM data
# consistency directly inside packets on the receiver side. Tests are divided
# into three categories: OUTPUT (evaluates the IOAM processing by the sender),
# INPUT (evaluates the IOAM processing by a receiver) and GLOBAL (evaluates
# wider use cases that do not fall into the other two categories). Both OUTPUT
# and INPUT tests only use a two-node topology (alpha and beta), while GLOBAL
# tests use the entire three-node topology (alpha, beta, gamma). Each test is
# documented inside its own handler in the code below.
#
# An IOAM domain is configured from Alpha to Gamma but not on the reverse path.
# When either Beta or Gamma is the destination (depending on the test category),
# Alpha adds an IOAM option (Pre-allocated Trace) inside a Hop-by-hop.
#
#
#            +-------------------+            +-------------------+
#            |                   |            |                   |
#            |    Alpha netns    |            |    Gamma netns    |
#            |                   |            |                   |
#            |  +-------------+  |            |  +-------------+  |
#            |  |    veth0    |  |            |  |    veth0    |  |
#            |  |  db01::2/64 |  |            |  |  db02::2/64 |  |
#            |  +-------------+  |            |  +-------------+  |
#            |         .         |            |         .         |
#            +-------------------+            +-------------------+
#                      .                                .
#                      .                                .
#                      .                                .
#            +----------------------------------------------------+
#            |         .                                .         |
#            |  +-------------+                  +-------------+  |
#            |  |    veth0    |                  |    veth1    |  |
#            |  |  db01::1/64 | ................ |  db02::1/64 |  |
#            |  +-------------+                  +-------------+  |
#            |                                                    |
#            |                      Beta netns                    |
#            |                                                    |
#            +----------------------------------------------------+
#
#
#
#        =============================================================
#        |                Alpha - IOAM configuration                 |
#        +===========================================================+
#        | Node ID             | 1                                   |
#        +-----------------------------------------------------------+
#        | Node Wide ID        | 11111111                            |
#        +-----------------------------------------------------------+
#        | Ingress ID          | 0xffff (default value)              |
#        +-----------------------------------------------------------+
#        | Ingress Wide ID     | 0xffffffff (default value)          |
#        +-----------------------------------------------------------+
#        | Egress ID           | 101                                 |
#        +-----------------------------------------------------------+
#        | Egress Wide ID      | 101101                              |
#        +-----------------------------------------------------------+
#        | Namespace Data      | 0xdeadbee0                          |
#        +-----------------------------------------------------------+
#        | Namespace Wide Data | 0xcafec0caf00dc0de                  |
#        +-----------------------------------------------------------+
#        | Schema ID           | 777                                 |
#        +-----------------------------------------------------------+
#        | Schema Data         | something that will be 4n-aligned   |
#        +-----------------------------------------------------------+
#
#
#        =============================================================
#        |                 Beta - IOAM configuration                 |
#        +===========================================================+
#        | Node ID             | 2                                   |
#        +-----------------------------------------------------------+
#        | Node Wide ID        | 22222222                            |
#        +-----------------------------------------------------------+
#        | Ingress ID          | 201                                 |
#        +-----------------------------------------------------------+
#        | Ingress Wide ID     | 201201                              |
#        +-----------------------------------------------------------+
#        | Egress ID           | 202                                 |
#        +-----------------------------------------------------------+
#        | Egress Wide ID      | 202202                              |
#        +-----------------------------------------------------------+
#        | Namespace Data      | 0xdeadbee1                          |
#        +-----------------------------------------------------------+
#        | Namespace Wide Data | 0xcafec0caf11dc0de                  |
#        +-----------------------------------------------------------+
#        | Schema ID           | 666                                 |
#        +-----------------------------------------------------------+
#        | Schema Data         | Hello there -Obi                    |
#        +-----------------------------------------------------------+
#
#
#        =============================================================
#        |                Gamma - IOAM configuration                 |
#        +===========================================================+
#        | Node ID             | 3                                   |
#        +-----------------------------------------------------------+
#        | Node Wide ID        | 33333333                            |
#        +-----------------------------------------------------------+
#        | Ingress ID          | 301                                 |
#        +-----------------------------------------------------------+
#        | Ingress Wide ID     | 301301                              |
#        +-----------------------------------------------------------+
#        | Egress ID           | 0xffff (default value)              |
#        +-----------------------------------------------------------+
#        | Egress Wide ID      | 0xffffffff (default value)          |
#        +-----------------------------------------------------------+
#        | Namespace Data      | 0xdeadbee2                          |
#        +-----------------------------------------------------------+
#        | Namespace Wide Data | 0xcafec0caf22dc0de                  |
#        +-----------------------------------------------------------+
#        | Schema ID           | 0xffffff (= None)                   |
#        +-----------------------------------------------------------+
#        | Schema Data         |                                     |
#        +-----------------------------------------------------------+

source lib.sh

################################################################################
#                                                                              #
# WARNING: Be careful if you modify the block below - it MUST be kept          #
#          synchronized with configurations inside ioam6_parser.c and always   #
#          reflect the same.                                                   #
#                                                                              #
################################################################################

ALPHA=(
	1					# ID
	11111111				# Wide ID
	0xffff					# Ingress ID
	0xffffffff				# Ingress Wide ID
	101					# Egress ID
	101101					# Egress Wide ID
	0xdeadbee0				# Namespace Data
	0xcafec0caf00dc0de			# Namespace Wide Data
	777					# Schema ID (0xffffff = None)
	"something that will be 4n-aligned"	# Schema Data
)

BETA=(
	2
	22222222
	201
	201201
	202
	202202
	0xdeadbee1
	0xcafec0caf11dc0de
	666
	"Hello there -Obi"
)

GAMMA=(
	3
	33333333
	301
	301301
	0xffff
	0xffffffff
	0xdeadbee2
	0xcafec0caf22dc0de
	0xffffff
	""
)

TESTS_OUTPUT="
	out_undef_ns
	out_no_room
	out_bits
	out_full_supp_trace
"

TESTS_INPUT="
	in_undef_ns
	in_no_room
	in_oflag
	in_bits
	in_full_supp_trace
"

TESTS_GLOBAL="
	fwd_full_supp_trace
"


################################################################################
#                                                                              #
#                                   LIBRARY                                    #
#                                                                              #
################################################################################

check_kernel_compatibility()
{
  setup_ns ioam_tmp_node
  ip link add name veth0 netns $ioam_tmp_node type veth \
         peer name veth1 netns $ioam_tmp_node

  ip -netns $ioam_tmp_node link set veth0 up
  ip -netns $ioam_tmp_node link set veth1 up

  ip -netns $ioam_tmp_node ioam namespace add 0
  ns_ad=$?

  ip -netns $ioam_tmp_node ioam namespace show | grep -q "namespace 0"
  ns_sh=$?

  if [[ $ns_ad != 0 || $ns_sh != 0 ]]
  then
    echo "SKIP: kernel version probably too old, missing ioam support"
    ip link del veth0 2>/dev/null || true
    cleanup_ns $ioam_tmp_node || true
    exit $ksft_skip
  fi

  ip -netns $ioam_tmp_node route add db02::/64 encap ioam6 mode inline \
         trace prealloc type 0x800000 ns 0 size 4 dev veth0
  tr_ad=$?

  ip -netns $ioam_tmp_node -6 route | grep -q "encap ioam6"
  tr_sh=$?

  if [[ $tr_ad != 0 || $tr_sh != 0 ]]
  then
    echo "SKIP: cannot attach an ioam trace to a route, did you compile" \
         "without CONFIG_IPV6_IOAM6_LWTUNNEL?"
    ip link del veth0 2>/dev/null || true
    cleanup_ns $ioam_tmp_node || true
    exit $ksft_skip
  fi

  ip link del veth0 2>/dev/null || true
  cleanup_ns $ioam_tmp_node || true

  lsmod | grep -q "ip6_tunnel"
  ip6tnl_loaded=$?

  if [ $ip6tnl_loaded = 0 ]
  then
    encap_tests=0
  else
    modprobe ip6_tunnel &>/dev/null
    lsmod | grep -q "ip6_tunnel"
    encap_tests=$?

    if [ $encap_tests != 0 ]
    then
      ip a | grep -q "ip6tnl0"
      encap_tests=$?

      if [ $encap_tests != 0 ]
      then
        echo "Note: ip6_tunnel not found neither as a module nor inside the" \
             "kernel, tests that require it (encap mode) will be omitted"
      fi
    fi
  fi
}

cleanup()
{
  ip link del ioam-veth-alpha 2>/dev/null || true
  ip link del ioam-veth-gamma 2>/dev/null || true

  cleanup_ns $ioam_node_alpha $ioam_node_beta $ioam_node_gamma || true

  if [ $ip6tnl_loaded != 0 ]
  then
    modprobe -r ip6_tunnel 2>/dev/null || true
  fi
}

setup()
{
  setup_ns ioam_node_alpha ioam_node_beta ioam_node_gamma

  ip link add name ioam-veth-alpha netns $ioam_node_alpha type veth \
         peer name ioam-veth-betaL netns $ioam_node_beta
  ip link add name ioam-veth-betaR netns $ioam_node_beta type veth \
         peer name ioam-veth-gamma netns $ioam_node_gamma

  ip -netns $ioam_node_alpha link set ioam-veth-alpha name veth0
  ip -netns $ioam_node_beta link set ioam-veth-betaL name veth0
  ip -netns $ioam_node_beta link set ioam-veth-betaR name veth1
  ip -netns $ioam_node_gamma link set ioam-veth-gamma name veth0

  ip -netns $ioam_node_alpha addr add db01::2/64 dev veth0
  ip -netns $ioam_node_alpha link set veth0 up
  ip -netns $ioam_node_alpha link set lo up
  ip -netns $ioam_node_alpha route add db02::/64 via db01::1 dev veth0
  ip -netns $ioam_node_alpha route del db01::/64
  ip -netns $ioam_node_alpha route add db01::/64 dev veth0

  ip -netns $ioam_node_beta addr add db01::1/64 dev veth0
  ip -netns $ioam_node_beta addr add db02::1/64 dev veth1
  ip -netns $ioam_node_beta link set veth0 up
  ip -netns $ioam_node_beta link set veth1 up
  ip -netns $ioam_node_beta link set lo up

  ip -netns $ioam_node_gamma addr add db02::2/64 dev veth0
  ip -netns $ioam_node_gamma link set veth0 up
  ip -netns $ioam_node_gamma link set lo up
  ip -netns $ioam_node_gamma route add db01::/64 via db02::1 dev veth0

  # - IOAM config -
  ip netns exec $ioam_node_alpha sysctl -wq net.ipv6.ioam6_id=${ALPHA[0]}
  ip netns exec $ioam_node_alpha sysctl -wq net.ipv6.ioam6_id_wide=${ALPHA[1]}
  ip netns exec $ioam_node_alpha sysctl -wq net.ipv6.conf.veth0.ioam6_id=${ALPHA[4]}
  ip netns exec $ioam_node_alpha sysctl -wq net.ipv6.conf.veth0.ioam6_id_wide=${ALPHA[5]}
  ip -netns $ioam_node_alpha ioam namespace add 123 data ${ALPHA[6]} wide ${ALPHA[7]}
  ip -netns $ioam_node_alpha ioam schema add ${ALPHA[8]} "${ALPHA[9]}"
  ip -netns $ioam_node_alpha ioam namespace set 123 schema ${ALPHA[8]}

  ip netns exec $ioam_node_beta sysctl -wq net.ipv6.conf.all.forwarding=1
  ip netns exec $ioam_node_beta sysctl -wq net.ipv6.ioam6_id=${BETA[0]}
  ip netns exec $ioam_node_beta sysctl -wq net.ipv6.ioam6_id_wide=${BETA[1]}
  ip netns exec $ioam_node_beta sysctl -wq net.ipv6.conf.veth0.ioam6_enabled=1
  ip netns exec $ioam_node_beta sysctl -wq net.ipv6.conf.veth0.ioam6_id=${BETA[2]}
  ip netns exec $ioam_node_beta sysctl -wq net.ipv6.conf.veth0.ioam6_id_wide=${BETA[3]}
  ip netns exec $ioam_node_beta sysctl -wq net.ipv6.conf.veth1.ioam6_id=${BETA[4]}
  ip netns exec $ioam_node_beta sysctl -wq net.ipv6.conf.veth1.ioam6_id_wide=${BETA[5]}
  ip -netns $ioam_node_beta ioam namespace add 123 data ${BETA[6]} wide ${BETA[7]}
  ip -netns $ioam_node_beta ioam schema add ${BETA[8]} "${BETA[9]}"
  ip -netns $ioam_node_beta ioam namespace set 123 schema ${BETA[8]}

  ip netns exec $ioam_node_gamma sysctl -wq net.ipv6.ioam6_id=${GAMMA[0]}
  ip netns exec $ioam_node_gamma sysctl -wq net.ipv6.ioam6_id_wide=${GAMMA[1]}
  ip netns exec $ioam_node_gamma sysctl -wq net.ipv6.conf.veth0.ioam6_enabled=1
  ip netns exec $ioam_node_gamma sysctl -wq net.ipv6.conf.veth0.ioam6_id=${GAMMA[2]}
  ip netns exec $ioam_node_gamma sysctl -wq net.ipv6.conf.veth0.ioam6_id_wide=${GAMMA[3]}
  ip -netns $ioam_node_gamma ioam namespace add 123 data ${GAMMA[6]} wide ${GAMMA[7]}

  sleep 1

  ip netns exec $ioam_node_alpha ping6 -c 5 -W 1 db02::2 &>/dev/null
  if [ $? != 0 ]
  then
    echo "Setup FAILED"
    cleanup &>/dev/null
    exit 0
  fi
}

log_test_passed()
{
  local desc=$1
  printf "TEST: %-60s  [ OK ]\n" "${desc}"
}

log_test_failed()
{
  local desc=$1
  printf "TEST: %-60s  [FAIL]\n" "${desc}"
}

log_results()
{
  echo "- Tests passed: ${npassed}"
  echo "- Tests failed: ${nfailed}"
}

run_test()
{
  local name=$1
  local desc=$2
  local node_src=$3
  local node_dst=$4
  local ip6_dst=$5
  local trace_type=$6
  local ioam_ns=$7
  local type=$8

  ip netns exec $node_dst ./ioam6_parser $name $trace_type $ioam_ns $type &
  local spid=$!
  sleep 0.1

  ip netns exec $node_src ping6 -t 64 -c 1 -W 1 $ip6_dst &>/dev/null
  if [ $? != 0 ]
  then
    nfailed=$((nfailed+1))
    log_test_failed "${desc}"
    kill -2 $spid &>/dev/null
  else
    wait $spid
    if [ $? = 0 ]
    then
      npassed=$((npassed+1))
      log_test_passed "${desc}"
    else
      nfailed=$((nfailed+1))
      log_test_failed "${desc}"
    fi
  fi
}

run()
{
  echo
  printf "%0.s-" {1..74}
  echo
  echo "OUTPUT tests"
  printf "%0.s-" {1..74}
  echo

  # set OUTPUT settings
  ip netns exec $ioam_node_beta sysctl -wq net.ipv6.conf.veth0.ioam6_enabled=0

  for t in $TESTS_OUTPUT
  do
    $t "inline"
    [ $encap_tests = 0 ] && $t "encap"
  done

  # clean OUTPUT settings
  ip netns exec $ioam_node_beta sysctl -wq net.ipv6.conf.veth0.ioam6_enabled=1
  ip -netns $ioam_node_alpha route change db01::/64 dev veth0


  echo
  printf "%0.s-" {1..74}
  echo
  echo "INPUT tests"
  printf "%0.s-" {1..74}
  echo

  # set INPUT settings
  ip -netns $ioam_node_alpha ioam namespace del 123

  for t in $TESTS_INPUT
  do
    $t "inline"
    [ $encap_tests = 0 ] && $t "encap"
  done

  # clean INPUT settings
  ip -netns $ioam_node_alpha ioam namespace add 123 \
         data ${ALPHA[6]} wide ${ALPHA[7]}
  ip -netns $ioam_node_alpha ioam namespace set 123 schema ${ALPHA[8]}
  ip -netns $ioam_node_alpha route change db01::/64 dev veth0

  echo
  printf "%0.s-" {1..74}
  echo
  echo "GLOBAL tests"
  printf "%0.s-" {1..74}
  echo

  for t in $TESTS_GLOBAL
  do
    $t "inline"
    [ $encap_tests = 0 ] && $t "encap"
  done

  echo
  log_results
}

bit2type=(
  0x800000 0x400000 0x200000 0x100000 0x080000 0x040000 0x020000 0x010000
  0x008000 0x004000 0x002000 0x001000 0x000800 0x000400 0x000200 0x000100
  0x000080 0x000040 0x000020 0x000010 0x000008 0x000004 0x000002
)
bit2size=( 4 4 4 4 4 4 4 4 8 8 8 4 4 4 4 4 4 4 4 4 4 4 4 )


################################################################################
#                                                                              #
#                              OUTPUT tests                                    #
#                                                                              #
#   Two nodes (sender/receiver), IOAM disabled on ingress for the receiver.    #
################################################################################

out_undef_ns()
{
  ##############################################################################
  # Make sure that the encap node won't fill the trace if the chosen IOAM      #
  # namespace is not configured locally.                                       #
  ##############################################################################
  local desc="Unknown IOAM namespace"

  [ "$1" = "encap" ] && mode="$1 tundst db01::1" || mode="$1"
  [ "$1" = "encap" ] && ip -netns $ioam_node_beta link set ip6tnl0 up

  ip -netns $ioam_node_alpha route change db01::/64 encap ioam6 mode $mode \
         trace prealloc type 0x800000 ns 0 size 4 dev veth0

  run_test ${FUNCNAME[0]} "${desc} ($1 mode)" $ioam_node_alpha $ioam_node_beta \
         db01::1 0x800000 0 $1

  [ "$1" = "encap" ] && ip -netns $ioam_node_beta link set ip6tnl0 down
}

out_no_room()
{
  ##############################################################################
  # Make sure that the encap node won't fill the trace and will set the        #
  # Overflow flag since there is no room enough for its data.                  #
  ##############################################################################
  local desc="Missing trace room"

  [ "$1" = "encap" ] && mode="$1 tundst db01::1" || mode="$1"
  [ "$1" = "encap" ] && ip -netns $ioam_node_beta link set ip6tnl0 up

  ip -netns $ioam_node_alpha route change db01::/64 encap ioam6 mode $mode \
         trace prealloc type 0xc00000 ns 123 size 4 dev veth0

  run_test ${FUNCNAME[0]} "${desc} ($1 mode)" $ioam_node_alpha $ioam_node_beta \
         db01::1 0xc00000 123 $1

  [ "$1" = "encap" ] && ip -netns $ioam_node_beta link set ip6tnl0 down
}

out_bits()
{
  ##############################################################################
  # Make sure that, for each trace type bit, the encap node will either:       #
  #  (i)  fill the trace with its data when it is a supported bit              #
  #  (ii) not fill the trace with its data when it is an unsupported bit       #
  ##############################################################################
  local desc="Trace type with bit <n> only"

  local tmp=${bit2size[22]}
  bit2size[22]=$(( $tmp + ${#ALPHA[9]} + ((4 - (${#ALPHA[9]} % 4)) % 4) ))

  [ "$1" = "encap" ] && mode="$1 tundst db01::1" || mode="$1"
  [ "$1" = "encap" ] && ip -netns $ioam_node_beta link set ip6tnl0 up

  for i in {0..22}
  do
    ip -netns $ioam_node_alpha route change db01::/64 encap ioam6 mode $mode \
           trace prealloc type ${bit2type[$i]} ns 123 size ${bit2size[$i]} \
           dev veth0 &>/dev/null

    local cmd_res=$?
    local descr="${desc/<n>/$i}"

    if [[ $i -ge 12 && $i -le 21 ]]
    then
      if [ $cmd_res != 0 ]
      then
        npassed=$((npassed+1))
        log_test_passed "$descr ($1 mode)"
      else
        nfailed=$((nfailed+1))
        log_test_failed "$descr ($1 mode)"
      fi
    else
	run_test "out_bit$i" "$descr ($1 mode)" $ioam_node_alpha \
           $ioam_node_beta db01::1 ${bit2type[$i]} 123 $1
    fi
  done

  [ "$1" = "encap" ] && ip -netns $ioam_node_beta link set ip6tnl0 down

  bit2size[22]=$tmp
}

out_full_supp_trace()
{
  ##############################################################################
  # Make sure that the encap node will correctly fill a full trace. Be careful,#
  # "full trace" here does NOT mean all bits (only supported ones).            #
  ##############################################################################
  local desc="Full supported trace"

  [ "$1" = "encap" ] && mode="$1 tundst db01::1" || mode="$1"
  [ "$1" = "encap" ] && ip -netns $ioam_node_beta link set ip6tnl0 up

  ip -netns $ioam_node_alpha route change db01::/64 encap ioam6 mode $mode \
         trace prealloc type 0xfff002 ns 123 size 100 dev veth0

  run_test ${FUNCNAME[0]} "${desc} ($1 mode)" $ioam_node_alpha $ioam_node_beta \
         db01::1 0xfff002 123 $1

  [ "$1" = "encap" ] && ip -netns $ioam_node_beta link set ip6tnl0 down
}


################################################################################
#                                                                              #
#                               INPUT tests                                    #
#                                                                              #
#     Two nodes (sender/receiver), the sender MUST NOT fill the trace upon     #
#     insertion -> the IOAM namespace configured on the sender is removed      #
#     and is used in the inserted trace to force the sender not to fill it.    #
################################################################################

in_undef_ns()
{
  ##############################################################################
  # Make sure that the receiving node won't fill the trace if the related IOAM #
  # namespace is not configured locally.                                       #
  ##############################################################################
  local desc="Unknown IOAM namespace"

  [ "$1" = "encap" ] && mode="$1 tundst db01::1" || mode="$1"
  [ "$1" = "encap" ] && ip -netns $ioam_node_beta link set ip6tnl0 up

  ip -netns $ioam_node_alpha route change db01::/64 encap ioam6 mode $mode \
         trace prealloc type 0x800000 ns 0 size 4 dev veth0

  run_test ${FUNCNAME[0]} "${desc} ($1 mode)" $ioam_node_alpha $ioam_node_beta \
         db01::1 0x800000 0 $1

  [ "$1" = "encap" ] && ip -netns $ioam_node_beta link set ip6tnl0 down
}

in_no_room()
{
  ##############################################################################
  # Make sure that the receiving node won't fill the trace and will set the    #
  # Overflow flag if there is no room enough for its data.                     #
  ##############################################################################
  local desc="Missing trace room"

  [ "$1" = "encap" ] && mode="$1 tundst db01::1" || mode="$1"
  [ "$1" = "encap" ] && ip -netns $ioam_node_beta link set ip6tnl0 up

  ip -netns $ioam_node_alpha route change db01::/64 encap ioam6 mode $mode \
         trace prealloc type 0xc00000 ns 123 size 4 dev veth0

  run_test ${FUNCNAME[0]} "${desc} ($1 mode)" $ioam_node_alpha $ioam_node_beta \
         db01::1 0xc00000 123 $1

  [ "$1" = "encap" ] && ip -netns $ioam_node_beta link set ip6tnl0 down
}

in_bits()
{
  ##############################################################################
  # Make sure that, for each trace type bit, the receiving node will either:   #
  #  (i)  fill the trace with its data when it is a supported bit              #
  #  (ii) not fill the trace with its data when it is an unsupported bit       #
  ##############################################################################
  local desc="Trace type with bit <n> only"

  local tmp=${bit2size[22]}
  bit2size[22]=$(( $tmp + ${#BETA[9]} + ((4 - (${#BETA[9]} % 4)) % 4) ))

  [ "$1" = "encap" ] && mode="$1 tundst db01::1" || mode="$1"
  [ "$1" = "encap" ] && ip -netns $ioam_node_beta link set ip6tnl0 up

  for i in {0..11} {22..22}
  do
    ip -netns $ioam_node_alpha route change db01::/64 encap ioam6 mode $mode \
           trace prealloc type ${bit2type[$i]} ns 123 size ${bit2size[$i]} \
           dev veth0

    run_test "in_bit$i" "${desc/<n>/$i} ($1 mode)" $ioam_node_alpha \
           $ioam_node_beta db01::1 ${bit2type[$i]} 123 $1
  done

  [ "$1" = "encap" ] && ip -netns $ioam_node_beta link set ip6tnl0 down

  bit2size[22]=$tmp
}

in_oflag()
{
  ##############################################################################
  # Make sure that the receiving node won't fill the trace since the Overflow  #
  # flag is set.                                                               #
  ##############################################################################
  local desc="Overflow flag is set"

  # Exception:
  #   Here, we need the sender to set the Overflow flag. For that, we will add
  #   back the IOAM namespace that was previously configured on the sender.
  ip -netns $ioam_node_alpha ioam namespace add 123

  [ "$1" = "encap" ] && mode="$1 tundst db01::1" || mode="$1"
  [ "$1" = "encap" ] && ip -netns $ioam_node_beta link set ip6tnl0 up

  ip -netns $ioam_node_alpha route change db01::/64 encap ioam6 mode $mode \
         trace prealloc type 0xc00000 ns 123 size 4 dev veth0

  run_test ${FUNCNAME[0]} "${desc} ($1 mode)" $ioam_node_alpha $ioam_node_beta \
         db01::1 0xc00000 123 $1

  [ "$1" = "encap" ] && ip -netns $ioam_node_beta link set ip6tnl0 down

  # And we clean the exception for this test to get things back to normal for
  # other INPUT tests
  ip -netns $ioam_node_alpha ioam namespace del 123
}

in_full_supp_trace()
{
  ##############################################################################
  # Make sure that the receiving node will correctly fill a full trace. Be     #
  # careful, "full trace" here does NOT mean all bits (only supported ones).   #
  ##############################################################################
  local desc="Full supported trace"

  [ "$1" = "encap" ] && mode="$1 tundst db01::1" || mode="$1"
  [ "$1" = "encap" ] && ip -netns $ioam_node_beta link set ip6tnl0 up

  ip -netns $ioam_node_alpha route change db01::/64 encap ioam6 mode $mode \
         trace prealloc type 0xfff002 ns 123 size 80 dev veth0

  run_test ${FUNCNAME[0]} "${desc} ($1 mode)" $ioam_node_alpha $ioam_node_beta \
         db01::1 0xfff002 123 $1

  [ "$1" = "encap" ] && ip -netns $ioam_node_beta link set ip6tnl0 down
}


################################################################################
#                                                                              #
#                              GLOBAL tests                                    #
#                                                                              #
#   Three nodes (sender/router/receiver), IOAM fully enabled on every node.    #
################################################################################

fwd_full_supp_trace()
{
  ##############################################################################
  # Make sure that all three nodes correctly filled the full supported trace   #
  # by checking that the trace data is consistent with the predefined config.  #
  ##############################################################################
  local desc="Forward - Full supported trace"

  [ "$1" = "encap" ] && mode="$1 tundst db02::2" || mode="$1"
  [ "$1" = "encap" ] && ip -netns $ioam_node_gamma link set ip6tnl0 up

  ip -netns $ioam_node_alpha route change db02::/64 encap ioam6 mode $mode \
         trace prealloc type 0xfff002 ns 123 size 244 via db01::1 dev veth0

  run_test ${FUNCNAME[0]} "${desc} ($1 mode)" $ioam_node_alpha $ioam_node_gamma \
         db02::2 0xfff002 123 $1

  [ "$1" = "encap" ] && ip -netns $ioam_node_gamma link set ip6tnl0 down
}


################################################################################
#                                                                              #
#                                     MAIN                                     #
#                                                                              #
################################################################################

npassed=0
nfailed=0

if [ "$(id -u)" -ne 0 ]
then
  echo "SKIP: Need root privileges"
  exit $ksft_skip
fi

if [ ! -x "$(command -v ip)" ]
then
  echo "SKIP: Could not run test without ip tool"
  exit $ksft_skip
fi

ip ioam &>/dev/null
if [ $? = 1 ]
then
  echo "SKIP: iproute2 too old, missing ioam command"
  exit $ksft_skip
fi

check_kernel_compatibility

cleanup &>/dev/null
setup
run
cleanup &>/dev/null