#!/bin/sh
#
# PROVIDE: ossec_hids
# REQUIRE: DAEMON
# BEFORE:  LOGIN
# KEYWORD: shutdown

# ossec_hids_enable (bool):             Set it to YES to enable %%PORTNAME%%.
#                                       Default: NO
# ossec_hids_clear_log (bool):          Set it to YES to clear ossec.log before %%PORTNAME%% startup.
#                                       Default: NO
# ossec_hids_clear_ar_log (bool):       Set it to YES to clear active-responses.log before %%PORTNAME%% startup.
#                                       Default: NO
# ossec_hids_fetch_connect_time (int):  Time in seconds to wait for the download of the shared configuration to start.
#                                       Used only by agent installation.
#                                       Default: 20
# ossec_hids_fetch_read_time (int):     Time in seconds to wait for subsequent download chunks of the shared configuration.
#                                       Used only by agent installation.
#                                       Default: 5

. /etc/rc.subr

name="ossec_hids"
rcvar=ossec_hids_enable

load_rc_config $name

: ${ossec_hids_enable="NO"}
: ${ossec_hids_clear_log="NO"}
: ${ossec_hids_clear_ar_log="NO"}
: ${ossec_hids_fetch_connect_time=20}
: ${ossec_hids_fetch_read_time=5}

ossec_type="%%OSSEC_TYPE%%"
ossec_home="%%OSSEC_HOME%%"

ossec_conf="${ossec_home}/etc/ossec.conf"
ossec_conf_dir="${ossec_home}/etc/ossec.conf.d"
ossec_conf_bin="${ossec_home}/bin/config/ossec-conf"

agent_conf="${ossec_home}/etc/shared/agent.conf"
agent_conf_dir="${ossec_home}/etc/agent.conf.d"
agent_conf_bin="${ossec_home}/bin/config/agent-conf"

ossec_client_keys="${ossec_home}/etc/client.keys"
ossec_ar_tmp="${ossec_home}/active-response"
ossec_log="${ossec_home}/logs/ossec.log"
ossec_ar_log="${ossec_home}/logs/active-responses.log"
ossec_merged="${ossec_home}/etc/shared/merged.mg"

ossec_local_time="/etc/localtime"

extra_commands="reload ossec_conf"
case ${ossec_type} in
    server)
        extra_commands="${extra_commands} agent_conf reset_counter"
        ;;
    agent)
        extra_commands="${extra_commands} fetch_config reset_counter"
        ;;
esac
if [ -x "${ossec_conf_bin}" ]; then
    extra_commands="${extra_commands} merge_config"
fi

start_cmd="ossec_hids_command start"
stop_cmd="ossec_hids_command stop"
restart_cmd="ossec_hids_command restart"
status_cmd="ossec_hids_command status"
reload_cmd="ossec_hids_command reload"
reset_counter_cmd="ossec_hids_command start"
fetch_config_cmd="ossec_hids_command restart"
merge_config_cmd="ossec_hids_create_config force"
ossec_conf_cmd="ossec_hids_ossec_conf"
agent_conf_cmd="ossec_hids_agent_conf"

start_precmd="ossec_hids_prepare"
restart_precmd="ossec_hids_prepare"
reload_precmd="ossec_hids_prepare"
reset_counter_precmd="ossec_hids_prepare"
fetch_config_precmd="ossec_hids_prepare"

ossec_hids_create_file() {
    local path=$1
    local owner=$2
    local mode=$3

    if [ ! -e "${path}" ]; then
        touch "${path}" && chown ${owner} "${path}" && chmod ${mode} "${path}"
    fi
}

ossec_hids_check() {
    case ${ossec_type} in
        server)
            if [ ! -s "${ossec_client_keys}" ]; then
                echo "WARNING: There are no client keys created - remote connections will be disabled."
                echo
            fi
            ;;
        agent)
            if [ ! -s "${ossec_client_keys}" ]; then
                echo "WARNING: There are is no client key imported - connection to server not possible."
                echo
            fi
            ;;
    esac

    return 0
}

ossec_hids_config_is_outdated() {
    dst_file="$1"
    src_dir="$2"

    if [ ! -e "${dst_file}" ]; then
        return 0
    fi

    for src_file in $(find "${src_dir}" -maxdepth 1 -type f -name "*.conf"); do
        if [ "${src_file}" -nt "${dst_file}" ]; then
            return 0
        fi
    done

    return 1
}

ossec_hids_create_config() {
    case ${ossec_type} in
        server)
            if [ -x "${agent_conf_bin}" ]; then
                # Merge agent.conf.d files into agent.conf
                if [ "$1" == "force" ] || ossec_hids_config_is_outdated "${agent_conf}" "${agent_conf_dir}"; then
                    ossec_hids_create_file "${agent_conf}" %%USER%%:%%OSSEC_GROUP%% 0640
                    "${agent_conf_bin}" > "${agent_conf}"
                fi
            fi
            ;;
    esac

    if [ -x "${ossec_conf_bin}" ]; then
        # Merge ossec.conf.d files into ossec.conf
        if [ "$1" == "force" ] || ossec_hids_config_is_outdated "${ossec_conf}" "${ossec_conf_dir}"; then
            ossec_hids_create_file "${ossec_conf}" %%USER%%:%%OSSEC_GROUP%% 0640
            "${ossec_conf_bin}" > "${ossec_conf}"
        fi
    fi

    return 0
}

ossec_hids_create_env() {
    # Copy required files from outside of home directory
    if [ ! -e "${ossec_local_time}" ]; then
        echo "ERROR: Missing \"${ossec_local_time}\". Run command \"tzsetup\"."
        echo
        return 1
    fi
    install -o %%USER%% -g %%OSSEC_GROUP%% -m 0440 "${ossec_local_time}" "${ossec_home}${ossec_local_time}"

    return 0
}

ossec_hids_clean() {
    if [ "${ossec_type}" == "server" ]; then
        rm -f "${ossec_merged}"
    fi

    if checkyesno ossec_hids_clear_log && [ -e "${ossec_log}" ]; then
        echo -n > "${ossec_log}"
    fi

    if checkyesno ossec_hids_clear_ar_log && [ -e "${ossec_ar_log}" ]; then
        echo -n > "${ossec_ar_log}"
    fi

    return 0
}

ossec_hids_reset_counter() {
    case ${ossec_type} in
        local)
            echo "ERROR: Counters are only available for agent and server installations."
            echo
            return 1
            ;;
        *)
            ossec_hids_command status > /dev/null && ossec_hids_command stop && sleep 2 && echo
            agent_ids=`${ossec_home}/bin/manage_agents -l | sed -En -e 's|.*ID:[[:space:]]*([[:digit:]]+).*|\1|p'`
            agent_counter=0
            for agent_id in ${agent_ids}; do
                rm -f "${ossec_home}/queue/rids/${agent_id}" && agent_counter=$((agent_counter + 1))
            done
            echo "Removed ${agent_counter} counter(s)."
            echo
            ;;
    esac

    return 0
}

ossec_hids_fetch_config() {
    case ${ossec_type} in
        agent)
            ossec_hids_command status > /dev/null && ossec_hids_command stop && sleep 2 && echo
            rm -f "${ossec_merged}"
            ossec_hids_command start || return 1
            echo
            echo "Waiting ${ossec_hids_fetch_connect_time} seconds for the shared configuration download to start."
            sleep ${ossec_hids_fetch_connect_time}
            if [ ! -s "${ossec_merged}" ]; then
                echo "ERROR: Failed to download shared configuration from the OSSEC server."
                echo
                ossec_log_tail=$(tail "${ossec_log}")
                echo "Portion of the \"${ossec_log}\":"
                echo "${ossec_log_tail}"
                echo
                if echo "${ossec_log_tail}" | grep -q "ERROR: Unable to send message to"; then
                    echo "Check if your configuration contains the correct server address in \"server-ip\" option."
                    echo
                fi
                if echo "${ossec_log_tail}" | grep -q "ERROR: Incorrectly formatted message from"; then
                    echo "If you are certain the imported agent key is correct then execute command:"
                    echo "$(realpath $0) reset_counter"
                    echo "and fetch config again:"
                    echo "$(realpath $0) fetch_config"
                    echo
                fi
                return 1
            else
                # The download has started
                while true; do
                    current_time=$(date +%s)
                    modification_time=$(stat -f %m "${ossec_merged}")
                    if [ $((current_time - modification_time)) -gt ${ossec_hids_fetch_read_time} ]; then
                        echo "Download finished."
                        echo
                        break;
                    else
                        echo "Download in progress..."
                        sleep 10
                    fi
                done
            fi
            ;;
        *)
            echo "ERROR: Shared configuration is only available for agent installations."
            echo
            return 1
            ;;
    esac

    return 0
}

ossec_hids_prepare() {
    case ${rc_arg} in
        start|restart)
            ossec_hids_create_env && \
            ossec_hids_create_config && \
            ossec_hids_clean && \
            ossec_hids_check || return 1
            ;;
        reset_counter)
            ossec_hids_create_env && \
            ossec_hids_create_config && \
            ossec_hids_clean && \
            ossec_hids_reset_counter && \
            ossec_hids_check || return 1
            ;;
        fetch_config)
            ossec_hids_create_env && \
            ossec_hids_create_config && \
            ossec_hids_clean && \
            ossec_hids_fetch_config && \
            ossec_hids_check || return 1
            ;;
        reload)
            ossec_hids_create_env && \
            ossec_hids_create_config || return 1
            ;;
    esac

    return 0
}

ossec_hids_ossec_conf() {
    if [ -x "${ossec_conf_bin}" ]; then
        "${ossec_conf_bin}"
    elif [ -f "${ossec_conf}" ]; then
        cat "${ossec_conf}"
    fi
}

ossec_hids_agent_conf() {
    if [ -x "${agent_conf_bin}" ]; then
        "${agent_conf_bin}"
    elif [ -f "${agent_conf}" ]; then
        cat "${agent_conf}"
    fi
}

ossec_hids_command() {
    "${ossec_home}/bin/ossec-control" "$1"
}

run_rc_command "$1"