#!/bin/bash
#
# Copyright (C) 2021 Masatake YAMATO <yamato@redhat.com>
#
# This file is part of util-linux.
#
# This file is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This file is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#

TS_TOPDIR="${0%/*}/../.."
TS_DESC="ownership and hierarchy"

. "$TS_TOPDIR"/functions.sh
ts_init "$*"

# ts_skip_nonroot
grep -q '#define HAVE_LINUX_NSFS_H' ${top_builddir}/config.h || ts_skip "no ioctl_ns support"

[ -r /proc/self/ns/user ] || ts_skip "no USER namespace kernel support"
[ -r /proc/self/ns/pid ] || ts_skip "no PID namespace kernel support"

ts_check_test_command "$TS_CMD_LSNS"
ts_check_test_command "$TS_CMD_UNSHARE"
ts_check_prog "stat"
ts_check_prog "mkfifo"
ts_check_prog "touch"
ts_check_prog "uniq"

"$TS_CMD_LSNS" > /dev/null 2>&1
if [ $? -eq 2 ]; then
	ts_skip "ioctl not supported"
fi

$TS_CMD_UNSHARE --user --pid --mount-proc --fork true &> /dev/null || ts_skip "no namespace support"

ts_cd "$TS_OUTDIR"

# The parent process receives namespaces ids via FIFO_DATA from bash
# run by unshare. The parent can wait till the bash process provides
# data.
FIFO_DATA=$TS_OUTDIR/FIFO_DATA-HIERARCHY

# The bash process run by unshare waits with this fifo till the parent
# process exits.  As a result, namespaecs referred by the bash
# process can be alive till the parent process exits.
FIFO_WAIT=$TS_OUTDIR/FIFO_WAIT-HIERARCHY

function cleanup {
    rm -f $FIFO_DATA
    rm -f $FIFO_WAIT
}

function init {
    cleanup
    mkfifo $FIFO_DATA
    mkfifo $FIFO_WAIT
}

init
(
    exec 4> $FIFO_WAIT
    my_userns=$(stat -c %i -L /proc/self/ns/user)
    my_pidns=$(stat -c %i -L /proc/self/ns/pid)
    read child_userns < $FIFO_DATA
    read child_pidns  < $FIFO_DATA

    expected="$child_userns $my_userns $my_userns"
    actual=$("$TS_CMD_LSNS" -t user -n -o NS,PNS,ONS "$child_userns" | uniq)
    test "$expected" = "$actual"
    RESULT=$?
    if [ $RESULT -ne 0 ]; then
	echo
	echo userns expected: "$expected"
	echo userns actual:   "$actual"
	cleanup
	exit $RESULT
    fi

    expected="$child_pidns $my_pidns $child_userns"
    actual=$("$TS_CMD_LSNS" -t pid -n -o NS,PNS,ONS "$child_pidns" | uniq)
    test "$expected" = "$actual"
    RESULT=$?
    if [ $RESULT -ne 0 ]; then
	echo
	echo pidns expected: "$expected"
	echo pidns actual:   "$actual"
	cleanup
    fi
    exit $RESULT
) &
mainpid=$!
(
    exec 4< $FIFO_WAIT
    $TS_CMD_UNSHARE --user --pid --mount-proc --fork bash -s > $FIFO_DATA <<'EOF'
    stat -c %i -L /proc/self/ns/user
    stat -c %i -L /proc/self/ns/pid
    # Wait till FIFO_WAIT is clsoed.
    read -u 4
EOF
) &
subpid=$!

wait $subpid
wait $mainpid

RESULT=$?
echo $RESULT >> $TS_OUTPUT

cleanup
ts_finalize