#!/command/with-contenv bash

# Testing on Docker 20.10.14 with no caps set shows the following caps available to the container:
# Current: cap_chown,cap_dac_override,cap_fowner,cap_fsetid,cap_kill,cap_setgid,cap_setuid,cap_setpcap,cap_net_bind_service,cap_net_raw,cap_sys_chroot,cap_mknod,cap_audit_write,cap_setfcap=ep
# FTL can also use CAP_NET_ADMIN and CAP_SYS_NICE. If we try to set them when they haven't been explicitly enabled, FTL will not start. Test for them first:

/sbin/capsh --has-p=cap_chown 2>/dev/null && CAP_STR+=',CAP_CHOWN'
/sbin/capsh --has-p=cap_net_bind_service 2>/dev/null && CAP_STR+=',CAP_NET_BIND_SERVICE'
/sbin/capsh --has-p=cap_net_raw 2>/dev/null && CAP_STR+=',CAP_NET_RAW'
/sbin/capsh --has-p=cap_net_admin 2>/dev/null && CAP_STR+=',CAP_NET_ADMIN' || DHCP_READY='false'
/sbin/capsh --has-p=cap_sys_nice 2>/dev/null && CAP_STR+=',CAP_SYS_NICE'

if [[ ${CAP_STR} ]]; then
    # We have the (some of) the above caps available to us - apply them to pihole-FTL
    setcap ${CAP_STR:1}+ep "$(which pihole-FTL)" || ret=$?

    if [[ $DHCP_READY == false ]] && [[ $DHCP_ACTIVE == true ]]; then
        # DHCP is requested but NET_ADMIN is not available.
        echo "ERROR: DHCP requested but NET_ADMIN is not available. DHCP will not be started."
        echo "      Please add cap_net_admin to the container's capabilities or disable DHCP."
        DHCP_ACTIVE='false'
        change_setting "DHCP_ACTIVE" "false"
    fi

    if [[ $ret -ne 0 && "${DNSMASQ_USER:-pihole}" != "root" ]]; then
        echo "ERROR: Unable to set capabilities for pihole-FTL. Cannot run as non-root."
        echo "       If you are seeing this error, please set the environment variable 'DNSMASQ_USER' to the value 'root'"
        exit 1
    fi
else
    echo "WARNING: Unable to set capabilities for pihole-FTL."
    echo "         Please ensure that the container has the required capabilities."
    exit 1
fi

s6-echo "Starting pihole-FTL ($FTL_CMD) as ${DNSMASQ_USER}"
# Remove possible leftovers from previous pihole-FTL processes
rm -f /dev/shm/FTL-* 2> /dev/null
rm /run/pihole/FTL.sock 2> /dev/null

# install /dev/null files to ensure they exist (create if non-existing, preserve if existing)
mkdir -pm 0755 /run/pihole /var/log/pihole
[[ ! -f /run/pihole-FTL.pid ]] && install /dev/null /run/pihole-FTL.pid
[[ ! -f /run/pihole-FTL.port ]] && install /dev/null /run/pihole-FTL.port
[[ ! -f /var/log/pihole/FTL.log ]] && install /dev/null /var/log/pihole/FTL.log
[[ ! -f /var/log/pihole/pihole.log ]] && install /dev/null /var/log/pihole/pihole.log
[[ ! -f /etc/pihole/dhcp.leases ]] && install /dev/null /etc/pihole/dhcp.leases

# Ensure that permissions are set so that pihole-FTL can edit all necessary files
chown pihole:pihole /run/pihole-FTL.pid /run/pihole-FTL.port /var/log/pihole/FTL.log /var/log/pihole/pihole.log /etc/pihole/dhcp.leases /run/pihole /etc/pihole
chmod 0644 /run/pihole-FTL.pid /run/pihole-FTL.port /var/log/pihole/FTL.log /var/log/pihole/pihole.log /etc/pihole/dhcp.leases

# Ensure that permissions are set so that pihole-FTL can edit the files. We ignore errors as the file may not (yet) exist
chmod -f 0644 /etc/pihole/macvendor.db
# Chown database files to the user FTL runs as. We ignore errors as the files may not (yet) exist
chown -f pihole:pihole /etc/pihole/pihole-FTL.db /etc/pihole/gravity.db /etc/pihole/macvendor.db
# Chown database file permissions so that the pihole group (web interface) can edit the file. We ignore errors as the files may not (yet) exist
chmod -f 0664 /etc/pihole/pihole-FTL.db

# Backward compatibility for user-scripts that still expect log files in /var/log instead of /var/log/pihole/
# Should be removed with Pi-hole v6.0
if [ ! -f /var/log/pihole.log ]; then
    ln -s /var/log/pihole/pihole.log /var/log/pihole.log
    chown -h pihole:pihole /var/log/pihole.log

fi
if [ ! -f /var/log/pihole-FTL.log ]; then
    ln -s /var/log/pihole/FTL.log /var/log/pihole-FTL.log
    chown -h pihole:pihole /var/log/pihole-FTL.log
fi

# Call capsh with the detected capabilities
capsh --inh=${CAP_STR:1} --addamb=${CAP_STR:1} --user=$DNSMASQ_USER --keep=1 -- -c "/usr/bin/pihole-FTL $FTL_CMD >/dev/null 2>&1"

# Notes on above:
# - DNSMASQ_USER default of pihole is in Dockerfile & can be overwritten by runtime container env
# - /var/log/pihole/pihole*.log has FTL's output that no-daemon would normally print in FG too
#   prevent duplicating it in docker logs by sending to dev null