Enhance bench_run.sh script

#   CAPTURE_FILTER  capture filter                         (default: "sctp or udp port 2152")

#   DRY_RUN=1    print the commands instead of running them

#

# Usage: scripts/bench_run.sh [--sync] [--build] [--deploy-ut] [--no-ut] [--name NAME]

# Usage: scripts/bench_run.sh [--sync] [--build] [--deploy-ut] [--no-ut] [--no-ut-restart] [--name NAME]

#   --name NAME   base name of the capture (default: the first active test case of the [EXECUTE] section)

#   --no-ut       do not touch the upper tester (no restart, no journal)

#   --no-ut-restart  do not restart the upper tester, but still copy back its journal (e.g. it was just restarted,

#                 or it runs in a terminal for debugging: then there is no journal to copy)

#

# Requirements, to avoid password prompts (the script still works with them, interactively):

#   - ssh keys: ssh-copy-id $PI_USER@$PI_HOST (and ATS_HOST when run from the development machine);

#   - on the Pi: sudo without password for the restart of the upper tester (upper_tester/deploy/sudoers-upper-tester),

#     and the Pi user in the systemd-journal group to read its journal (sudo usermod -aG systemd-journal $PI_USER);

#   - on the ATS host: sudo for tcpdump (asked for when the capture starts and stops).

#   - on the ATS host: tcpdump able to capture without sudo (setcap, Annex A.8 of TODO.md), or sudo without password

#     for tcpdump; otherwise the test runs without capture.

set -u

BUILD=0

DEPLOY_UT=0

USE_UT=1

RESTART_UT=1

NAME=""

usage() {

        --build)     BUILD=1; shift ;;

        --deploy-ut) DEPLOY_UT=1; shift ;;

        --no-ut)     USE_UT=0; shift ;;

        --no-ut-restart) RESTART_UT=0; shift ;;

        --name)      NAME="$2"; shift 2 ;;

        -h|--help)   usage; exit 0 ;;

        *)           echo "Unknown option: $1" >&2; usage >&2; exit 2 ;;

    step "Deploying the upper tester to $PI:$UT_DIR"

    run rsync -a --delete --exclude __pycache__ --exclude docs "$TOP/upper_tester/" "$PI:$UT_DIR/" || exit 1

fi

if [[ $USE_UT == 1 ]]; then

if [[ $USE_UT == 1 && $RESTART_UT == 0 ]]; then

    step "Upper tester ($UT_SERVICE) on $PI: not restarted (--no-ut-restart)"

elif [[ $USE_UT == 1 ]]; then

    step "Restarting the upper tester ($UT_SERVICE) on $PI"

    # -t: sudo can ask for its password, unless upper_tester/deploy/sudoers-upper-tester is installed

    run ssh -t "$PI" "sudo systemctl restart $UT_SERVICE && sleep 2 && systemctl is-active $UT_SERVICE" || exit 1

START=$(date -u '+%Y-%m-%d %H:%M:%S')

step "Starting the capture on $ATS_HOST ($CAPTURE_IF: $CAPTURE_FILTER)"

# sudo -v first, interactively, so that the background tcpdump does not wait for a password

ats -t "sudo -v && (sudo nohup tcpdump -i $CAPTURE_IF -w $CAPTURE_TMP '$CAPTURE_FILTER' >/dev/null 2>&1 & echo \$! > $PID_TMP)" || exit 1

[[ "$DRY_RUN" == "1" ]] || sleep 2

# tcpdump runs without sudo when it has the capture capabilities (see Annex A.8 of TODO.md), otherwise with sudo if

# that needs no password. Without either, the test still runs, without capture: a password cannot be typed for a

# background process

CAPTURE=1

ats "rm -f $CAPTURE_TMP $PID_TMP;

     if timeout 2 tcpdump -i $CAPTURE_IF -c 1 -w /dev/null >/dev/null 2>&1 || [ \$? -eq 124 ]; then SUDO=;

     elif sudo -n true 2>/dev/null; then SUDO=sudo;

     else echo 'No capture: tcpdump needs root and sudo asks for a password (see Annex A.8 of TODO.md)'; exit 3; fi;

     \$SUDO nohup tcpdump -i $CAPTURE_IF -w $CAPTURE_TMP '$CAPTURE_FILTER' >/dev/null 2>&1 & echo \$! > $PID_TMP;

     echo \"\$SUDO\" > $PID_TMP.sudo; sleep 2;

     kill -0 \$(cat $PID_TMP) 2>/dev/null || \$SUDO kill -0 \$(cat $PID_TMP) 2>/dev/null || { echo 'tcpdump did not start'; exit 3; }" || CAPTURE=0

step "Running $ATS on $ATS_HOST"

ats -t "cd $ATS_DIR/scripts && ATS=$ATS ./run_all.bash"

if [[ $CAPTURE == 1 ]]; then

    step "Stopping the capture"

ats -t "sudo kill -INT \$(cat $PID_TMP); sleep 1; sudo chmod a+r $CAPTURE_TMP"

    ats "SUDO=\$(cat $PID_TMP.sudo); \$SUDO kill -INT \$(cat $PID_TMP); sleep 1; \$SUDO chmod a+r $CAPTURE_TMP"

fi

mkdir -p "$TOP/logs/$ATS" "$TOP/captures"

if [[ $ATS_LOCAL == 1 ]]; then

    step "Keeping the capture (the logs are already in logs/$ATS)"

    run cp "$CAPTURE_TMP" "$TOP/captures/$NAME.pcap"

    [[ $CAPTURE == 1 ]] && run cp "$CAPTURE_TMP" "$TOP/captures/$NAME.pcap"

else

    step "Copying back the logs and the capture"

    run scp -q "$ATS_HOST:$ATS_DIR/logs/$ATS/*.log" "$TOP/logs/$ATS/"

    run scp -q "$ATS_HOST:$CAPTURE_TMP" "$TOP/captures/$NAME.pcap"

    [[ $CAPTURE == 1 ]] && run scp -q "$ATS_HOST:$CAPTURE_TMP" "$TOP/captures/$NAME.pcap"

fi

if [[ $USE_UT == 1 ]]; then

    step "Copying back the upper tester journal since $START (UTC)"