net/adblock/files/adblock.sh

   1 #!/bin/sh
   2 # dns based ad/abuse domain blocking
   3 # written by Dirk Brenken (dev@brenken.org)
   4
   5 # This is free software, licensed under the GNU General Public License v3.
   6 # You should have received a copy of the GNU General Public License
   7 # along with this program. If not, see <http://www.gnu.org/licenses/>.
   8
   9 # set initial defaults
  10 #
  11 LC_ALL=C
  12 PATH="/usr/sbin:/usr/bin:/sbin:/bin"
  13 adb_ver="3.0.1"
  14 adb_sysver="$(ubus -S call system board | jsonfilter -e '@.release.description')"
  15 adb_enabled=0
  16 adb_debug=0
  17 adb_manmode=0
  18 adb_forcesrt=0
  19 adb_forcedns=0
  20 adb_triggerdelay=0
  21 adb_backup=0
  22 adb_backupdir="/mnt"
  23 adb_fetch="/usr/bin/wget"
  24 adb_fetchparm="--quiet --no-cache --no-cookies --max-redirect=0 --timeout=10 --no-check-certificate -O"
  25 adb_dns="dnsmasq"
  26 adb_dnsprefix="adb_list"
  27 adb_dnsfile="${adb_dnsprefix}.overall"
  28 adb_rtfile="/tmp/adb_runtime.json"
  29 adb_action="${1:-"start"}"
  30 adb_cnt=0
  31 adb_rc=0
  32
  33 # f_envload: load adblock environment
  34 #
  35 f_envload()
  36 {
  37     local dns_up cnt=0
  38
  39     # source in system libraries
  40     #
  41     if [ -r "/lib/functions.sh" ] && [ -r "/usr/share/libubox/jshn.sh" ]
  42     then
  43         . "/lib/functions.sh"
  44         . "/usr/share/libubox/jshn.sh"
  45     else
  46         f_log "error" "system libraries not found"
  47     fi
  48
  49     # parse global section by callback
  50     #
  51     config_cb()
  52     {
  53         local type="${1}"
  54         if [ "${type}" = "adblock" ]
  55         then
  56             option_cb()
  57             {
  58                 local option="${1}"
  59                 local value="${2}"
  60                 eval "${option}=\"${value}\""
  61             }
  62         else
  63             reset_cb
  64         fi
  65     }
  66
  67     # parse 'source' sections
  68     #
  69     parse_config()
  70     {
  71         local value opt section="${1}" options="enabled adb_src adb_src_rset adb_src_cat"
  72         eval "adb_sources=\"${adb_sources} ${section}\""
  73         for opt in ${options}
  74         do
  75             config_get value "${section}" "${opt}"
  76             if [ -n "${value}" ]
  77             then
  78                 eval "${opt}_${section}=\"${value}\""
  79             fi
  80         done
  81     }
  82
  83     # load adblock config
  84     #
  85     config_load adblock
  86     config_foreach parse_config source
  87
  88     # set/check dns backend environment
  89     #
  90     case "${adb_dns}" in
  91         dnsmasq)
  92             adb_dnsuser="${adb_dns}"
  93             adb_dnsdir="${adb_dnsdir:-"/tmp/dnsmasq.d"}"
  94             adb_dnsformat="awk '{print \"local=/\"\$0\"/\"}'"
  95             ;;
  96         unbound)
  97             adb_dnsuser="${adb_dns}"
  98             adb_dnsdir="${adb_dnsdir:-"/var/lib/unbound"}"
  99             adb_dnsformat="awk '{print \"local-zone: \042\"\$0\"\042 static\"}'"
 100             ;;
 101         named)
 102             adb_dnsuser="bind"
 103             adb_dnsdir="${adb_dnsdir:-"/var/lib/bind"}"
 104             adb_dnsformat="awk '{print \"\"\$0\" IN CNAME .\n*.\"\$0\" IN CNAME .\"}'"
 105             ;;
 106         kresd)
 107             adb_dnsuser="root"
 108             adb_dnsdir="${adb_dnsdir:-"/etc/kresd"}"
 109             adb_dnsformat="awk '{print \"\"\$0\" CNAME .\n*.\"\$0\" CNAME .\"}'"
 110             adb_dnsheader="\$TTL 2h"$'\n'"@ IN SOA localhost. root.localhost. (2 6h 1h 1w 2h)"$'\n'"  IN NS  localhost."
 111             ;;
 112         dnscrypt-proxy)
 113             adb_dnsuser="nobody"
 114             adb_dnsdir="${adb_dnsdir:-"/tmp"}"
 115             adb_dnsformat="awk '{print \$0}'"
 116             ;;
 117     esac
 118
 119     if [ -d "${adb_dnsdir}" ] && [ ! -f "${adb_dnsdir}/${adb_dnsfile}" ]
 120     then
 121         > "${adb_dnsdir}/${adb_dnsfile}"
 122     fi
 123
 124     case "${adb_action}" in
 125         start|restart|reload)
 126             > "${adb_rtfile}"
 127             if [ "${adb_action}" = "start" ] && [ "${adb_trigger}" = "timed" ]
 128             then
 129                 sleep ${adb_triggerdelay}
 130             fi
 131         ;;
 132     esac
 133
 134     while [ ${cnt} -le 30 ]
 135     do
 136         dns_up="$(ubus -S call service list "{\"name\":\"${adb_dns}\"}" 2>/dev/null | jsonfilter -l1 -e "@[\"${adb_dns}\"].instances.*.running" 2>/dev/null)"
 137         if [ "${dns_up}" = "true" ]
 138         then
 139             break
 140         fi
 141         sleep 1
 142         cnt=$((cnt+1))
 143     done
 144
 145     if [ -z "${adb_dns}" ] || [ -z "${adb_dnsformat}" ] || [ ! -x "$(command -v ${adb_dns})" ] || [ ! -d "${adb_dnsdir}" ]
 146     then
 147         f_log "error" "'${adb_dns}' not running, DNS backend not found"
 148     fi
 149
 150     # force dns to local resolver
 151     #
 152     if [ ${adb_forcedns} -eq 1 ] && [ -z "$(uci -q get firewall.adblock_dns)" ]
 153     then
 154         uci -q set firewall.adblock_dns="redirect"
 155         uci -q set firewall.adblock_dns.name="Adblock DNS"
 156         uci -q set firewall.adblock_dns.src="lan"
 157         uci -q set firewall.adblock_dns.proto="tcp udp"
 158         uci -q set firewall.adblock_dns.src_dport="53"
 159         uci -q set firewall.adblock_dns.dest_port="53"
 160         uci -q set firewall.adblock_dns.target="DNAT"
 161     elif [ ${adb_forcedns} -eq 0 ] && [ -n "$(uci -q get firewall.adblock_dns)" ]
 162     then
 163         uci -q delete firewall.adblock_dns
 164     fi
 165     if [ -n "$(uci -q changes firewall)" ]
 166     then
 167         uci -q commit firewall
 168         if [ $(/etc/init.d/firewall enabled; printf "%u" ${?}) -eq 0 ]
 169         then
 170             /etc/init.d/firewall reload >/dev/null 2>&1
 171         fi
 172     fi
 173 }
 174
 175 # f_envcheck: check/set environment prerequisites
 176 #
 177 f_envcheck()
 178 {
 179     local ssl_lib
 180
 181     # check 'enabled' option
 182     #
 183     if [ ${adb_enabled} -ne 1 ]
 184     then
 185         if [ -s "${adb_dnsdir}/${adb_dnsfile}" ]
 186         then
 187             f_rmdns
 188             f_dnsrestart
 189         fi
 190         f_jsnupdate
 191         f_log "info " "adblock is currently disabled, please set adb_enabled to '1' to use this service"
 192         exit 0
 193     fi
 194
 195     # check fetch utility
 196     #
 197     ssl_lib="-"
 198     if [ -x "${adb_fetch}" ]
 199     then
 200         if [ "$(readlink -fn "${adb_fetch}")" = "/usr/bin/wget-nossl" ]
 201         then
 202             adb_fetchparm="--quiet --no-cache --no-cookies --max-redirect=0 --timeout=10 -O"
 203         elif [ "$(readlink -fn "${adb_fetch}")" = "/bin/busybox" ] ||
 204             ([ "$(readlink -fn "/bin/wget")" = "/bin/busybox" ] && [ "$(readlink -fn "${adb_fetch}")" != "/usr/bin/wget" ])
 205         then
 206             adb_fetch="/bin/busybox"
 207             adb_fetchparm="-q -O"
 208         else
 209             ssl_lib="built-in"
 210         fi
 211     fi
 212     if [ ! -x "${adb_fetch}" ] && [ "$(readlink -fn "/bin/wget")" = "/bin/uclient-fetch" ]
 213     then
 214         adb_fetch="/bin/uclient-fetch"
 215         if [ -f "/lib/libustream-ssl.so" ]
 216         then
 217             adb_fetchparm="-q --timeout=10 --no-check-certificate -O"
 218             ssl_lib="libustream-ssl"
 219         else
 220             adb_fetchparm="-q --timeout=10 -O"
 221         fi
 222     fi
 223     if [ ! -x "${adb_fetch}" ] || [ -z "${adb_fetch}" ] || [ -z "${adb_fetchparm}" ]
 224     then
 225         f_log "error" "no download utility found, please install 'uclient-fetch' with 'libustream-mbedtls' or the full 'wget' package"
 226     fi
 227     adb_fetchinfo="${adb_fetch##*/} (${ssl_lib})"
 228
 229     # create adblock temp file/directory
 230     #
 231     adb_tmpload="$(mktemp -tu)"
 232     adb_tmpfile="$(mktemp -tu)"
 233     adb_tmpdir="$(mktemp -p /tmp -d)"
 234
 235     # prepare whitelist entries
 236     #
 237     if [ -s "${adb_whitelist}" ] && [ -n "${adb_whitelist_rset}" ]
 238     then
 239         awk "${adb_whitelist_rset}" "${adb_whitelist}" > "${adb_tmpdir}/tmp.whitelist"
 240     fi
 241 }
 242
 243 # f_rmtemp: remove temporary files & directories
 244 #
 245 f_rmtemp()
 246 {
 247     if [ -d "${adb_tmpdir}" ]
 248     then
 249         rm -f "${adb_tmpload}"
 250         rm -f "${adb_tmpfile}"
 251         rm -rf "${adb_tmpdir}"
 252     fi
 253 }
 254
 255 # f_rmdns: remove dns related files & directories
 256 #
 257 f_rmdns()
 258 {
 259     if [ -n "${adb_dns}" ]
 260     then
 261         > "${adb_dnsdir}/${adb_dnsfile}"
 262         > "${adb_rtfile}"
 263         rm -f "${adb_dnsdir}/.${adb_dnsfile}"
 264         rm -f "${adb_backupdir}/${adb_dnsprefix}"*.gz
 265     fi
 266 }
 267
 268 # f_dnsrestart: restart the dns backend
 269 #
 270 f_dnsrestart()
 271 {
 272     local dns_up cnt=0
 273
 274     "/etc/init.d/${adb_dns}" restart >/dev/null 2>&1
 275     while [ ${cnt} -le 10 ]
 276     do
 277         dns_up="$(ubus -S call service list "{\"name\":\"${adb_dns}\"}" | jsonfilter -l1 -e "@[\"${adb_dns}\"].instances.*.running")"
 278         if [ "${dns_up}" = "true" ]
 279         then
 280             return 0
 281         fi
 282         cnt=$((cnt+1))
 283         sleep 1
 284     done
 285     return 1
 286 }
 287
 288 # f_list: backup/restore/remove block lists
 289 #
 290 f_list()
 291 {
 292     local mode="${1}" in_rc="${adb_rc}" cnt=0
 293
 294     case "${mode}" in
 295         backup)
 296             cnt="$(wc -l < "${adb_tmpfile}")"
 297             if [ ${adb_backup} -eq 1 ] && [ -d "${adb_backupdir}" ]
 298             then
 299                 gzip -cf "${adb_tmpfile}" > "${adb_backupdir}/${adb_dnsprefix}.${src_name}.gz"
 300                 adb_rc=${?}
 301             fi
 302             ;;
 303         restore)
 304             if [ ${adb_backup} -eq 1 ] && [ -d "${adb_backupdir}" ] &&
 305                 [ -f "${adb_backupdir}/${adb_dnsprefix}.${src_name}.gz" ]
 306             then
 307                 gunzip -cf "${adb_backupdir}/${adb_dnsprefix}.${src_name}.gz" > "${adb_tmpfile}"
 308                 adb_rc=${?}
 309             fi
 310             ;;
 311         remove)
 312             if [ -d "${adb_backupdir}" ]
 313             then
 314                 rm -f "${adb_backupdir}/${adb_dnsprefix}.${src_name}.gz"
 315             fi
 316             adb_rc=${?}
 317             ;;
 318         merge)
 319             if [ -s "${adb_tmpfile}" ]
 320             then
 321                 cat "${adb_tmpfile}" >> "${adb_tmpdir}/${adb_dnsfile}"
 322                 adb_rc=${?}
 323             fi
 324             ;;
 325         format)
 326             if [ -s "${adb_tmpdir}/tmp.whitelist" ]
 327             then
 328                 grep -vf "${adb_tmpdir}/tmp.whitelist" "${adb_tmpdir}/${adb_dnsfile}" | eval "${adb_dnsformat}" > "${adb_dnsdir}/${adb_dnsfile}"
 329             else
 330                 eval "${adb_dnsformat}" "${adb_tmpdir}/${adb_dnsfile}" > "${adb_dnsdir}/${adb_dnsfile}"
 331             fi
 332             if [ -n "${adb_dnsheader}" ]
 333             then
 334                 printf '%s\n' "${adb_dnsheader}" | cat - "${adb_dnsdir}/${adb_dnsfile}" > "${adb_tmpdir}/${adb_dnsfile}"
 335                 cat "${adb_tmpdir}/${adb_dnsfile}" > "${adb_dnsdir}/${adb_dnsfile}"
 336             fi
 337             adb_rc=${?}
 338             ;;
 339     esac
 340     f_log "debug" "name: ${src_name}, mode: ${mode}, count: ${cnt}, in_rc: ${in_rc}, out_rc: ${adb_rc}"
 341 }
 342
 343 # f_tldcompression: top level domain compression
 344 #
 345 f_tldcompression()
 346 {
 347     local source="${1}" temp="${adb_tmpload}"
 348
 349     awk -F "." '{for(f=NF;f > 1;f--) printf "%s.", $f;print $1}' "${source}" 2>/dev/null | sort -u > "${temp}"
 350     awk '{if(NR==1){tld=$NF};while(getline){if($NF !~ tld"\\."){print tld;tld=$NF}}print tld}' "${temp}" 2>/dev/null > "${source}"
 351     awk -F "." '{for(f=NF;f > 1;f--) printf "%s.", $f;print $1}' "${source}" 2>/dev/null > "${temp}"
 352     sort -u "${temp}" > "${source}"
 353 }
 354
 355 # f_switch: suspend/resume adblock processing
 356 #
 357 f_switch()
 358 {
 359     local source target status mode="${1}"
 360
 361     if [ -s "${adb_dnsdir}/${adb_dnsfile}" ] && [ "${mode}" = "suspend" ]
 362     then
 363         source="${adb_dnsdir}/${adb_dnsfile}"
 364         target="${adb_dnsdir}/.${adb_dnsfile}"
 365         status="suspended"
 366     elif [ -s "${adb_dnsdir}/.${adb_dnsfile}" ] && [ "${mode}" = "resume" ]
 367     then
 368         source="${adb_dnsdir}/.${adb_dnsfile}"
 369         target="${adb_dnsdir}/${adb_dnsfile}"
 370         status="resumed"
 371     fi
 372     if [ -n "${status}" ]
 373     then
 374         cat "${source}" > "${target}"
 375         > "${source}"
 376         f_dnsrestart
 377         f_jsnupdate
 378         f_log "info " "adblock processing ${status}"
 379     fi
 380 }
 381
 382 # f_query: query block list for certain (sub-)domains
 383 #
 384 f_query()
 385 {
 386     local search result cnt
 387     local domain="${1}"
 388     local tld="${domain#*.}"
 389
 390     if [ ! -s "${adb_dnsdir}/${adb_dnsfile}" ]
 391     then
 392          printf "%s\n" "::: no active block list found, please start / resume adblock first"
 393     elif [ -z "${domain}" ] || [ "${domain}" = "${tld}" ]
 394     then
 395         printf "%s\n" "::: invalid domain input, please submit a single domain, e.g. 'doubleclick.net'"
 396     else
 397         cd "${adb_dnsdir}"
 398         while [ "${domain}" != "${tld}" ]
 399         do
 400             search="${domain//./\.}"
 401             if [ "${adb_dns}" = "dnsmasq" ] || [ "${adb_dns}" = "unbound" ]
 402             then
 403                 result="$(awk -F '/|\"' "/[\/\"\.]${search}/{i++;{printf(\"  + %s\n\",\$2)};if(i>9){exit}}" "${adb_dnsfile}")"
 404             else
 405                 result="$(awk "/(^[^\*][a-z]*[\.]+${search}|^${search})/{i++;{printf(\"  + %s\n\",\$1)};if(i>9){exit}}" "${adb_dnsfile}")"
 406             fi
 407             printf "%s\n" "::: max. ten results for domain '${domain}'"
 408             printf "%s\n" "${result:-"  - no match"}"
 409             domain="${tld}"
 410             tld="${domain#*.}"
 411         done
 412     fi
 413 }
 414
 415 # f_jsnupdate: update runtime information
 416 #
 417 f_jsnupdate()
 418 {
 419     local status rundate="$(/bin/date "+%d.%m.%Y %H:%M:%S")"
 420
 421     if [ ${adb_rc} -gt 0 ]
 422     then
 423         status="error"
 424     elif [ ${adb_enabled} -ne 1 ]
 425     then
 426         status="disabled"
 427     elif [ -s "${adb_dnsdir}/.${adb_dnsfile}" ]
 428     then
 429         status="paused"
 430     else
 431         status="enabled"
 432         if [ -s "${adb_dnsdir}/${adb_dnsfile}" ]
 433         then
 434             if [ "${adb_dns}" = "named" ] || [ "${adb_dns}" = "kresd" ]
 435             then
 436                 adb_cnt="$(( ( $(wc -l < "${adb_dnsdir}/${adb_dnsfile}") - $(printf "%s" "${adb_dnsheader}" | grep -c "^") ) / 2 ))"
 437             else
 438                 adb_cnt="$(( $(wc -l < "${adb_dnsdir}/${adb_dnsfile}") - $(printf "%s" "${adb_dnsheader}" | grep -c "^") ))"
 439             fi
 440         fi
 441     fi
 442
 443     if [ -z "${adb_fetchinfo}" ] && [ -s "${adb_rtfile}" ]
 444     then
 445         json_load "$(cat "${adb_rtfile}" 2>/dev/null)"
 446         json_select data
 447         json_get_var adb_fetchinfo "fetch_utility"
 448     fi
 449
 450     json_init
 451     json_add_object "data"
 452     json_add_string "adblock_status" "${status}"
 453     json_add_string "adblock_version" "${adb_ver}"
 454     json_add_string "blocked_domains" "${adb_cnt}"
 455     json_add_string "fetch_utility" "${adb_fetchinfo}"
 456     json_add_string "dns_backend" "${adb_dns} (${adb_dnsdir})"
 457     json_add_string "last_rundate" "${rundate}"
 458     json_add_string "system_release" "${adb_sysver}"
 459     json_close_object
 460     json_dump > "${adb_rtfile}"
 461 }
 462
 463 # f_status: output runtime information
 464 #
 465 f_status()
 466 {
 467     local key keylist value
 468
 469     if [ -s "${adb_rtfile}" ]
 470     then
 471         printf "%s\n" "::: adblock runtime information"
 472         json_load "$(cat "${adb_rtfile}" 2>/dev/null)"
 473         json_select data
 474         json_get_keys keylist
 475         for key in ${keylist}
 476         do
 477             json_get_var value "${key}"
 478             printf "  + %-15s : %s\n" "${key}" "${value}"
 479         done
 480     fi
 481 }
 482
 483 # f_log: write to syslog, exit on error
 484 #
 485 f_log()
 486 {
 487     local class="${1}" log_msg="${2}"
 488
 489     if [ -n "${log_msg}" ] && ([ "${class}" != "debug" ] || [ ${adb_debug} -eq 1 ])
 490     then
 491         logger -t "adblock-[${adb_ver}] ${class}" "${log_msg}"
 492         if [ "${class}" = "error" ]
 493         then
 494             logger -t "adblock-[${adb_ver}] ${class}" "Please check 'https://github.com/openwrt/packages/blob/master/net/adblock/files/README.md' (${adb_sysver})"
 495             f_rmtemp
 496             if [ -s "${adb_dnsdir}/${adb_dnsfile}" ]
 497             then
 498                 f_rmdns
 499                 f_dnsrestart
 500             fi
 501             adb_rc=1
 502             f_jsnupdate
 503             exit 1
 504         fi
 505     fi
 506 }
 507
 508 # main function for block list processing
 509 #
 510 f_main()
 511 {
 512     local src_name src_rset shalla_archive enabled url hash_old hash_new
 513     local mem_total="$(awk '/^MemTotal/ {print int($2/1000)}' "/proc/meminfo")"
 514
 515     f_log "info " "start adblock processing ..."
 516     f_log "debug" "action: ${adb_action}, manual_mode:${adb_manmode}, backup: ${adb_backup}, dns: ${adb_dns}, fetch: ${adb_fetchinfo}, mem_total: ${mem_total}, force_srt/_dns: ${adb_forcesrt}/${adb_forcedns}"
 517     > "${adb_rtfile}"
 518     for src_name in ${adb_sources}
 519     do
 520         eval "enabled=\"\${enabled_${src_name}}\""
 521         eval "url=\"\${adb_src_${src_name}}\""
 522         eval "src_rset=\"\${adb_src_rset_${src_name}}\""
 523         > "${adb_tmpload}"
 524         > "${adb_tmpfile}"
 525         adb_rc=4
 526
 527         # basic pre-checks
 528         #
 529         f_log "debug" "name: ${src_name}, enabled: ${enabled}, url: ${url}, rset: ${src_rset}"
 530         if [ "${enabled}" != "1" ] || [ -z "${url}" ] || [ -z "${src_rset}" ]
 531         then
 532             f_list remove
 533             continue
 534         fi
 535
 536         # manual / backup mode
 537         #
 538         if [ ${adb_manmode} -eq 1 ] && [ "${adb_action}" = "start" ] && [ "${src_name}" != "blacklist" ]
 539         then
 540             f_list restore
 541             if [ ${adb_rc} -eq 0 ] && [ -s "${adb_tmpfile}" ]
 542             then
 543                 f_list merge
 544                 continue
 545             fi
 546         fi
 547
 548         # download block list
 549         #
 550         if [ "${src_name}" = "blacklist" ] && [ -s "${url}" ]
 551         then
 552             cat "${url}" > "${adb_tmpload}"
 553             adb_rc=${?}
 554         elif [ "${src_name}" = "shalla" ]
 555         then
 556             shalla_archive="${adb_tmpdir}/shallalist.tar.gz"
 557             "${adb_fetch}" ${adb_fetchparm} "${shalla_archive}" "${url}" 2>/dev/null
 558             adb_rc=${?}
 559             if [ ${adb_rc} -eq 0 ]
 560             then
 561                 for category in ${adb_src_cat_shalla}
 562                 do
 563                     tar -xOzf "${shalla_archive}" "BL/${category}/domains" >> "${adb_tmpload}"
 564                     adb_rc=${?}
 565                     if [ ${adb_rc} -ne 0 ]
 566                     then
 567                         break
 568                     fi
 569                 done
 570             fi
 571             rm -f "${shalla_archive}"
 572             rm -rf "${adb_tmpdir}/BL"
 573         else
 574             "${adb_fetch}" ${adb_fetchparm} "${adb_tmpload}" "${url}" 2>/dev/null
 575             adb_rc=${?}
 576         fi
 577
 578         # check download result and prepare list output (incl. tld compression, list backup & restore)
 579         #
 580         if [ ${adb_rc} -eq 0 ] && [ -s "${adb_tmpload}" ]
 581         then
 582             awk "${src_rset}" "${adb_tmpload}" 2>/dev/null > "${adb_tmpfile}"
 583             if [ -s "${adb_tmpfile}" ]
 584             then
 585                 f_tldcompression "${adb_tmpfile}"
 586                 if [ "${src_name}" != "blacklist" ]
 587                 then
 588                     f_list backup
 589                 fi
 590             else
 591                 f_list restore
 592             fi
 593         else
 594             f_list restore
 595         fi
 596
 597         # list merge
 598         #
 599         if [ ${adb_rc} -eq 0 ] && [ -s "${adb_tmpfile}" ]
 600         then
 601             f_list merge
 602             if [ ${adb_rc} -ne 0 ]
 603             then
 604                 f_list remove
 605             fi
 606         else
 607             f_list remove
 608         fi
 609     done
 610
 611     # hash preparation, whitelist removal and overall sort
 612     #
 613     if [ -f "${adb_dnsdir}/${adb_dnsfile}" ]
 614     then
 615         hash_old="$(sha256sum "${adb_dnsdir}/${adb_dnsfile}" 2>/dev/null | awk '{print $1}')"
 616     fi
 617     if [ -s "${adb_tmpdir}/${adb_dnsfile}" ]
 618     then
 619         if [ ${mem_total} -ge 64 ] || [ ${adb_forcesrt} -eq 1 ]
 620         then
 621             f_tldcompression "${adb_tmpdir}/${adb_dnsfile}"
 622         fi
 623         f_list format
 624     else
 625         > "${adb_dnsdir}/${adb_dnsfile}"
 626     fi
 627     chown "${adb_dnsuser}" "${adb_dnsdir}/${adb_dnsfile}" 2>/dev/null
 628     f_rmtemp
 629
 630     # conditional restart of the dns backend and runtime information export
 631     #
 632     hash_new="$(sha256sum "${adb_dnsdir}/${adb_dnsfile}" 2>/dev/null | awk '{print $1}')"
 633     if [ -z "${hash_old}" ] || [ -z "${hash_new}" ] || [ "${hash_old}" != "${hash_new}" ]
 634     then
 635         f_dnsrestart
 636     fi
 637     if [ ${?} -eq 0 ]
 638     then
 639         f_jsnupdate "${adb_cnt}"
 640         f_log "info " "block list with overall ${adb_cnt} domains loaded successfully (${adb_sysver})"
 641     else
 642         f_log "error" "dns backend restart with active block list failed"
 643     fi
 644 }
 645
 646 # handle different adblock actions
 647 #
 648 f_envload
 649 case "${adb_action}" in
 650     stop)
 651         f_rmtemp
 652         f_rmdns
 653         f_dnsrestart
 654         ;;
 655     restart)
 656         f_rmtemp
 657         f_rmdns
 658         f_envcheck
 659         f_main
 660         ;;
 661     suspend)
 662         f_switch suspend
 663         ;;
 664     resume)
 665         f_switch resume
 666         ;;
 667     query)
 668         f_query "${2}"
 669         ;;
 670     status)
 671         f_status
 672         ;;
 673     *)
 674         f_envcheck
 675         f_main
 676         ;;
 677 esac
 678 exit 0