#!/bin/sh
set -eu

cc_bin=${CC_BIN:-/usr/bin/cc}
uid1=${BUILD_UID1:-35001}
gid1=${BUILD_GID1:-35001}
uid2=${BUILD_UID2:-35002}
gid2=${BUILD_GID2:-35002}
hold_seconds=${HOLD_SECONDS:-2}
cleanup_workdir=0
mount_points=
jail_ids=

if [ -n "${WORKDIR:-}" ]; then
  workdir=$WORKDIR
  mkdir -p "$workdir"
else
  workdir=$(mktemp -d /tmp/fruix-privdrop-prototype.XXXXXX)
  cleanup_workdir=1
fi

if [ "${KEEP_WORKDIR:-0}" -eq 1 ]; then
  cleanup_workdir=0
fi

record_mount() {
  mount_points="$1
$mount_points"
}

record_jail() {
  jail_ids="$1
$jail_ids"
}

cleanup() {
  set +e

  old_ifs=$IFS
  IFS='
'
  for jail_id in $jail_ids; do
    [ -n "$jail_id" ] || continue
    sudo jail -r "$jail_id" >/dev/null 2>&1 || true
  done
  for mount_point in $mount_points; do
    [ -n "$mount_point" ] || continue
    sudo umount "$mount_point" >/dev/null 2>&1 || true
  done
  IFS=$old_ifs

  if [ "$cleanup_workdir" -eq 1 ]; then
    sudo rm -rf "$workdir"
  fi
}
trap cleanup EXIT INT TERM

helper_src=tests/daemon/freebsd-build-user-helper.c
helper_bin=$workdir/tools/freebsd-build-user-helper
protected_dir=$workdir/protected
outside_sentinel=$workdir/outside-sentinel
metadata_file=$workdir/freebsd-privdrop-metadata.txt
helper_compile_log=$workdir/helper-compile.log
helper_compile_err=$workdir/helper-compile.err
job1_out=$workdir/job1.out
job1_err=$workdir/job1.err
job2_out=$workdir/job2.out
job2_err=$workdir/job2.err
job1_stat=$workdir/job1.stat
job2_stat=$workdir/job2.stat

mkdir -p "$workdir/tools" "$protected_dir" "$workdir/job1-host" "$workdir/job2-host"
printf 'host-only-outside-sentinel\n' > "$outside_sentinel"
printf 'protected-root-owned\n' > "$protected_dir/root-note.txt"
chmod 0755 "$protected_dir"
chmod 0644 "$protected_dir/root-note.txt"

"$cc_bin" -Wall -Wextra -std=c11 "$helper_src" -o "$helper_bin" >"$helper_compile_log" 2>"$helper_compile_err"

prepare_job_tree() {
  job_name=$1
  job_uid=$2
  job_gid=$3
  peer_uid=$4
  peer_gid=$5

  job_host=$workdir/$job_name-host
  root=$job_host/root
  work_mount=$job_host/work
  peer_mount=$job_host/peer
  mkdir -p "$root/tools" "$root/protected" "$root/work" "$root/peer" "$root/tmp" "$work_mount" "$peer_mount"
  chmod 1777 "$root/tmp"

  printf '%s-allowed\n' "$job_name" > "$work_mount/allowed.txt"
  printf '%s-secret\n' "$job_name" > "$work_mount/secret.txt"
  chmod 0600 "$work_mount/allowed.txt" "$work_mount/secret.txt"
  chmod 0700 "$work_mount"
  sudo chown -R "$job_uid:$job_gid" "$work_mount"

  printf 'peer-for-%s\n' "$job_name" > "$peer_mount/secret.txt"
  chmod 0600 "$peer_mount/secret.txt"
  chmod 0700 "$peer_mount"
  sudo chown -R "$peer_uid:$peer_gid" "$peer_mount"

  for host_path in /lib /libexec; do
    sudo mkdir -p "$root$host_path"
    sudo mount_nullfs -o ro "$host_path" "$root$host_path"
    record_mount "$root$host_path"
  done

  sudo mount_nullfs -o ro "$workdir/tools" "$root/tools"
  record_mount "$root/tools"
  sudo mount_nullfs "$work_mount" "$root/work"
  record_mount "$root/work"
  sudo mount_nullfs -o ro "$peer_mount" "$root/peer"
  record_mount "$root/peer"
  sudo mount_nullfs "$protected_dir" "$root/protected"
  record_mount "$root/protected"

  jail_name=fruix-privdrop-$job_name-$$
  jail_id=$(sudo jail -i -c \
    name="$jail_name" \
    path="$root" \
    host.hostname="$jail_name" \
    persist \
    ip4=disable \
    ip6=disable)
  record_jail "$jail_id"

  printf '%s\n' "$jail_id" > "$job_host/jid"
}

prepare_job_tree job1 "$uid1" "$gid1" "$uid2" "$gid2"
prepare_job_tree job2 "$uid2" "$gid2" "$uid1" "$gid1"

jid1=$(cat "$workdir/job1-host/jid")
jid2=$(cat "$workdir/job2-host/jid")

start_epoch=$(date +%s)
sudo jexec "$jid1" /tools/freebsd-build-user-helper \
  --job-name job1 \
  --uid "$uid1" \
  --gid "$gid1" \
  --allowed-file /work/allowed.txt \
  --own-output /work/result.txt \
  --peer-file /peer/secret.txt \
  --hidden-file /outside-sentinel \
  --protected-file /protected/escape-job1 \
  --hold-seconds "$hold_seconds" >"$job1_out" 2>"$job1_err" &
pid1=$!

sudo jexec "$jid2" /tools/freebsd-build-user-helper \
  --job-name job2 \
  --uid "$uid2" \
  --gid "$gid2" \
  --allowed-file /work/allowed.txt \
  --own-output /work/result.txt \
  --peer-file /peer/secret.txt \
  --hidden-file /outside-sentinel \
  --protected-file /protected/escape-job2 \
  --hold-seconds "$hold_seconds" >"$job2_out" 2>"$job2_err" &
pid2=$!

set +e
wait "$pid1"
rc1=$?
wait "$pid2"
rc2=$?
set -e
end_epoch=$(date +%s)
elapsed=$((end_epoch - start_epoch))

if [ "$rc1" -ne 0 ] || [ "$rc2" -ne 0 ]; then
  echo "freebsd privilege-drop prototype failed" >&2
  cat "$job1_out" >&2 || true
  cat "$job1_err" >&2 || true
  cat "$job2_out" >&2 || true
  cat "$job2_err" >&2 || true
  exit 1
fi

sudo stat -f '%Su %Sg %u %g %Sp' "$workdir/job1-host/work/result.txt" > "$job1_stat"
sudo stat -f '%Su %Sg %u %g %Sp' "$workdir/job2-host/work/result.txt" > "$job2_stat"

cat > "$metadata_file" <<EOF
workdir=$workdir
helper_src=$helper_src
helper_bin=$helper_bin
helper_compile_log=$helper_compile_log
helper_compile_err=$helper_compile_err
jail1_id=$jid1
jail2_id=$jid2
build_uid1=$uid1
build_gid1=$gid1
build_uid2=$uid2
build_gid2=$gid2
hold_seconds=$hold_seconds
elapsed_seconds=$elapsed
job1_rc=$rc1
job2_rc=$rc2
job1_result_stat=$(cat "$job1_stat")
job2_result_stat=$(cat "$job2_stat")
job1_output_begin
$(cat "$job1_out")
job1_output_end
job2_output_begin
$(cat "$job2_out")
job2_output_end
EOF

if [ -n "${METADATA_OUT:-}" ]; then
  mkdir -p "$(dirname "$METADATA_OUT")"
  cp "$metadata_file" "$METADATA_OUT"
fi

printf 'PASS freebsd-privilege-drop-prototype\n'
printf 'Working directory: %s\n' "$workdir"
printf 'Metadata file: %s\n' "$metadata_file"
if [ -n "${METADATA_OUT:-}" ]; then
  printf 'Copied metadata to: %s\n' "$METADATA_OUT"
fi
printf '%s\n' '--- job1 output ---'
cat "$job1_out"
printf '%s\n' '--- job2 output ---'
cat "$job2_out"
printf 'Elapsed seconds: %s\n' "$elapsed"
printf '%s\n' '--- metadata ---'
cat "$metadata_file"