src/initscripts/system/unbound

   1 #!/bin/sh
   2 # Begin $rc_base/init.d/unbound
   3
   4 # Description : Unbound DNS resolver boot script for IPfire
   5 # Author      : Marcel Lorenz <marcel.lorenz@ipfire.org>
   6
   7 . /etc/sysconfig/rc
   8 . ${rc_functions}
   9
  10 TEST_DOMAIN="ipfire.org"
  11
  12 # This domain will never validate
  13 TEST_DOMAIN_FAIL="dnssec-failed.org"
  14
  15 INSECURE_ZONES=
  16 USE_FORWARDERS=1
  17
  18 # Cache any local zones for 60 seconds
  19 LOCAL_TTL=60
  20
  21 # EDNS buffer size
  22 EDNS_DEFAULT_BUFFER_SIZE=4096
  23
  24 # Load optional configuration
  25 [ -e "/etc/sysconfig/unbound" ] && . /etc/sysconfig/unbound
  26
  27 function cidr() {
  28     local cidr nbits IFS;
  29     IFS=. read -r i1 i2 i3 i4 <<< ${1}
  30     IFS=. read -r m1 m2 m3 m4 <<< ${2}
  31     cidr=$(printf "%d.%d.%d.%d\n" "$((i1 & m1))" "$((i2 & m2))" "$((i3 & m3))" "$((i4 & m4))")
  32     nbits=0
  33     IFS=.
  34     for dec in $2 ; do
  35         case $dec in
  36             255) let nbits+=8;;
  37             254) let nbits+=7;;
  38             252) let nbits+=6;;
  39             248) let nbits+=5;;
  40             240) let nbits+=4;;
  41             224) let nbits+=3;;
  42             192) let nbits+=2;;
  43             128) let nbits+=1;;
  44             0);;
  45             *) echo "Error: $dec is not recognised"; exit 1
  46         esac
  47     done
  48     echo "${cidr}/${nbits}"
  49 }
  50
  51 ip_address_revptr() {
  52         local addr=${1}
  53
  54         local a1 a2 a3 a4
  55         IFS=. read -r a1 a2 a3 a4 <<< ${addr}
  56
  57         echo "${a4}.${a3}.${a2}.${a1}.in-addr.arpa"
  58 }
  59
  60 read_name_servers() {
  61         local i
  62         for i in 1 2; do
  63                 echo "$(</var/ipfire/red/dns${i})"
  64         done 2>/dev/null | xargs echo
  65 }
  66
  67 config_header() {
  68         echo "# This file is automatically generated and any changes"
  69         echo "# will be overwritten. DO NOT EDIT!"
  70         echo
  71 }
  72
  73 update_forwarders() {
  74         if [ "${USE_FORWARDERS}" = "1" -a -e "/var/ipfire/red/active" ]; then
  75                 local forwarders
  76                 local broken_forwarders
  77
  78                 local ns
  79                 for ns in $(read_name_servers); do
  80                         test_name_server ${ns} &>/dev/null
  81                         case "$?" in
  82                                 # Only use DNSSEC-validating or DNSSEC-aware name servers
  83                                 0|2)
  84                                         forwarders="${forwarders} ${ns}"
  85                                         ;;
  86                                 *)
  87                                         broken_forwarders="${broken_forwarders} ${ns}"
  88                                         ;;
  89                         esac
  90                 done
  91
  92                 # Determine EDNS buffer size
  93                 local new_edns_buffer_size=${EDNS_DEFAULT_BUFFER_SIZE}
  94
  95                 for ns in ${forwarders}; do
  96                         local edns_buffer_size=$(ns_determine_edns_buffer_size ${ns})
  97                         if [ -n "${edns_buffer_size}" ]; then
  98                                 if [ ${edns_buffer_size} -lt ${new_edns_buffer_size} ]; then
  99                                         new_edns_buffer_size=${edns_buffer_size}
 100                                 fi
 101                         fi
 102                 done
 103
 104                 if [ ${new_edns_buffer_size} -lt ${EDNS_DEFAULT_BUFFER_SIZE} ]; then
 105                         boot_mesg "EDNS buffer size reduced to ${new_edns_buffer_size}" ${WARNING}
 106                         echo_warning
 107
 108                         unbound-control -q set_option edns-buffer-size: ${new_edns_buffer_size}
 109                 fi
 110
 111                 # Show warning for any broken upstream name servers
 112                 if [ -n "${broken_forwarders}" ]; then
 113                         boot_mesg "Ignoring broken upstream name server(s): ${broken_forwarders:1}" ${WARNING}
 114                         echo_warning
 115                 fi
 116
 117                 if [ -n "${forwarders}" ]; then
 118                         boot_mesg "Configuring upstream name server(s): ${forwarders:1}" ${INFO}
 119                         echo_ok
 120
 121                         # Make sure DNSSEC is activated
 122                         enable_dnssec
 123
 124                         echo "${forwarders}" > /var/ipfire/red/dns
 125                         unbound-control -q forward ${forwarders}
 126                         return 0
 127
 128                 # In case we have found no working forwarders
 129                 else
 130                         # Test if the recursor mode is available
 131                         if can_resolve_root +bufsize=${new_edns_buffer_size}; then
 132                                 # Make sure DNSSEC is activated
 133                                 enable_dnssec
 134
 135                                 boot_mesg "Falling back to recursor mode" ${WARNING}
 136                                 echo_warning
 137
 138                         # If not, we set DNSSEC in permissive mode and allow using all recursors
 139                         elif [ -n "${broken_forwarders}" ]; then
 140                                 disable_dnssec
 141
 142                                 boot_mesg "DNSSEC has been set to permissive mode" ${FAILURE}
 143                                 echo_failure
 144
 145                                 echo "${broken_forwarders}" > /var/ipfire/red/dns
 146                                 unbound-control -q forward ${broken_forwarders}
 147                                 return 0
 148                         fi
 149                 fi
 150         fi
 151
 152         # If forwarders cannot be used we run in recursor mode
 153         echo "local recursor" > /var/ipfire/red/dns
 154         unbound-control -q forward off
 155 }
 156
 157 own_hostname() {
 158         local hostname=$(hostname -f)
 159         # 1.1.1.1 is reserved for unused green, skip this
 160         if [ -n "${GREEN_ADDRESS}" -a "${GREEN_ADDRESS}" != "1.1.1.1" ]; then
 161                 unbound-control -q local_data "${hostname} ${LOCAL_TTL} IN A ${GREEN_ADDRESS}"
 162         fi
 163
 164         local address
 165         for address in ${GREEN_ADDRESS} ${BLUE_ADDRESS} ${ORANGE_ADDRESS}; do
 166                 [ -n "${address}" ] || continue
 167                 [ "${address}" = "1.1.1.1" ] && continue
 168
 169                 address=$(ip_address_revptr ${address})
 170                 unbound-control -q local_data "${address} ${LOCAL_TTL} IN PTR ${hostname}"
 171         done
 172 }
 173
 174 update_hosts() {
 175         local enabled address hostname domainname
 176
 177         while IFS="," read -r enabled address hostname domainname; do
 178                 [ "${enabled}" = "on" ] || continue
 179
 180                 # Build FQDN
 181                 local fqdn="${hostname}.${domainname}"
 182
 183                 unbound-control -q local_data "${fqdn} ${LOCAL_TTL} IN A ${address}"
 184
 185                 # Skip reverse resolution if the address equals the GREEN address
 186                 [ "${address}" = "${GREEN_ADDRESS}" ] && continue
 187
 188                 # Add RDNS
 189                 address=$(ip_address_revptr ${address})
 190                 unbound-control -q local_data "${address} ${LOCAL_TTL} IN PTR ${fqdn}"
 191         done < /var/ipfire/main/hosts
 192 }
 193
 194 write_forward_conf() {
 195         (
 196                 config_header
 197
 198                 local insecure_zones="${INSECURE_ZONES}"
 199
 200                 local enabled zone server servers remark
 201                 while IFS="," read -r enabled zone servers remark; do
 202                         # Line must be enabled.
 203                         [ "${enabled}" = "on" ] || continue
 204
 205                         # Zones that end with .local are commonly used for internal
 206                         # zones and therefore not signed
 207                         case "${zone}" in
 208                                 *.local)
 209                                         insecure_zones="${insecure_zones} ${zone}"
 210                                         ;;
 211                         esac
 212
 213                         # Reverse-lookup zones must be stubs
 214                         case "${zone}" in
 215                                 *.in-addr.arpa)
 216                                         echo "stub-zone:"
 217                                         echo "  name: ${zone}"
 218                                         for server in ${servers//|/ }; do
 219                                                 echo "  stub-addr: ${server}"
 220                                         done
 221                                         echo
 222                                         echo "server:"
 223                                         echo "  local-zone: \"${zone}\" transparent"
 224                                         echo
 225                                         ;;
 226                                 *)
 227                                         echo "forward-zone:"
 228                                         echo "  name: ${zone}"
 229                                         for server in ${servers//|/ }; do
 230                                                 echo "  forward-addr: ${server}"
 231                                         done
 232                                         echo
 233                                         ;;
 234                         esac
 235                 done < /var/ipfire/dnsforward/config
 236
 237                 if [ -n "${insecure_zones}" ]; then
 238                         echo "server:"
 239
 240                         for zone in ${insecure_zones}; do
 241                                 echo "  domain-insecure: ${zone}"
 242                         done
 243                 fi
 244         ) > /etc/unbound/forward.conf
 245 }
 246
 247 write_tuning_conf() {
 248         # https://www.unbound.net/documentation/howto_optimise.html
 249
 250         # Determine number of online processors
 251         local processors=$(getconf _NPROCESSORS_ONLN)
 252
 253         # Determine number of slabs
 254         local slabs=1
 255         while [ ${slabs} -lt ${processors} ]; do
 256                 slabs=$(( ${slabs} * 2 ))
 257         done
 258
 259         # Determine amount of system memory
 260         local mem=$(get_memory_amount)
 261
 262         # In the worst case scenario, unbound can use double the
 263         # amount of memory allocated to a cache due to malloc overhead
 264
 265         # Even larger systems with more than 8GB of RAM
 266         if [ ${mem} -ge 8192 ]; then
 267                 mem=1024
 268
 269         # Extra large systems with more than 4GB of RAM
 270         elif [ ${mem} -ge 4096 ]; then
 271                 mem=512
 272
 273         # Large systems with more than 2GB of RAM
 274         elif [ ${mem} -ge 2048 ]; then
 275                 mem=256
 276
 277         # Medium systems with more than 1GB of RAM
 278         elif [ ${mem} -ge 1024 ]; then
 279                 mem=128
 280
 281         # Small systems with less than 256MB of RAM
 282         elif [ ${mem} -le 256 ]; then
 283                 mem=16
 284
 285         # Everything else
 286         else
 287                 mem=64
 288         fi
 289
 290         (
 291                 config_header
 292
 293                 # We run one thread per processor
 294                 echo "num-threads: ${processors}"
 295                 echo "so-reuseport: yes"
 296
 297                 # Adjust number of slabs
 298                 echo "infra-cache-slabs: ${slabs}"
 299                 echo "key-cache-slabs: ${slabs}"
 300                 echo "msg-cache-slabs: ${slabs}"
 301                 echo "rrset-cache-slabs: ${slabs}"
 302
 303                 # Slice up the cache
 304                 echo "rrset-cache-size: $(( ${mem} / 2 ))m"
 305                 echo "msg-cache-size: $(( ${mem} / 4 ))m"
 306                 echo "key-cache-size: $(( ${mem} / 4 ))m"
 307
 308                 # Increase parallel queries
 309                 echo "outgoing-range: 8192"
 310                 echo "num-queries-per-thread: 4096"
 311
 312                 # Use larger send/receive buffers
 313                 echo "so-sndbuf: 4m"
 314                 echo "so-rcvbuf: 4m"
 315         ) > /etc/unbound/tuning.conf
 316 }
 317
 318 get_memory_amount() {
 319         local key val unit
 320
 321         while read -r key val unit; do
 322                 case "${key}" in
 323                         MemTotal:*)
 324                                 # Convert to MB
 325                                 echo "$(( ${val} / 1024 ))"
 326                                 break
 327                                 ;;
 328                 esac
 329         done < /proc/meminfo
 330 }
 331
 332 test_name_server() {
 333         local ns=${1}
 334         local args
 335
 336         # Return codes:
 337         # 0     DNSSEC validating
 338         # 1     Error: unreachable, etc.
 339         # 2     DNSSEC aware
 340         # 3     NOT DNSSEC-aware
 341
 342         # Exit when the server is not reachable
 343         ns_is_online ${ns} || return 1
 344
 345         # Determine the maximum edns buffer size that works
 346         local edns_buffer_size=$(ns_determine_edns_buffer_size ${ns})
 347         if [ -n "${edns_buffer_size}" ]; then
 348                 args="${args} +bufsize=${edns_buffer_size}"
 349         fi
 350
 351         local errors
 352         for rr in DNSKEY DS RRSIG; do
 353                 if ! ns_forwards_${rr} ${ns} ${args}; then
 354                         errors="${errors} ${rr}"
 355                 fi
 356         done
 357
 358         if [ -n "${errors}" ]; then
 359                 echo >&2 "Unable to retrieve the following resource records from ${ns}: ${errors:1}"
 360                 return 3
 361         fi
 362
 363         if ns_is_validating ${ns} ${args}; then
 364                 # Return 0 if validating
 365                 return 0
 366         else
 367                 # Is DNSSEC-aware
 368                 return 2
 369         fi
 370 }
 371
 372 # Sends an A query to the nameserver w/o DNSSEC
 373 ns_is_online() {
 374         local ns=${1}
 375         shift
 376
 377         dig @${ns} +nodnssec A ${TEST_DOMAIN} $@ >/dev/null
 378 }
 379
 380 # Resolving ${TEST_DOMAIN_FAIL} will fail if the nameserver is validating
 381 ns_is_validating() {
 382         local ns=${1}
 383         shift
 384
 385         if ! dig @${ns} A ${TEST_DOMAIN_FAIL} $@ | grep -q SERVFAIL; then
 386                 return 1
 387         else
 388                 # Determine if NS replies with "ad" data flag if DNSSEC enabled
 389                 dig @${ns} +dnssec SOA ${TEST_DOMAIN} $@ | awk -F: '/\;\;\ flags\:/ { s=1; if (/\ ad/) s=0; exit s }'
 390         fi
 391 }
 392
 393 # Checks if we can retrieve the DNSKEY for this domain.
 394 # dig will print the SOA if nothing was found
 395 ns_forwards_DNSKEY() {
 396         local ns=${1}
 397         shift
 398
 399         dig @${ns} DNSKEY ${TEST_DOMAIN} $@ | grep -qv SOA
 400 }
 401
 402 ns_forwards_DS() {
 403         local ns=${1}
 404         shift
 405
 406         dig @${ns} DS ${TEST_DOMAIN} $@ | grep -qv SOA
 407 }
 408
 409 ns_forwards_RRSIG() {
 410         local ns=${1}
 411         shift
 412
 413         dig @${ns} +dnssec A ${TEST_DOMAIN} $@ | grep -q RRSIG
 414 }
 415
 416 ns_supports_tcp() {
 417         local ns=${1}
 418         shift
 419
 420         dig @${ns} +tcp A ${TEST_DOMAIN} $@ >/dev/null || return 1
 421 }
 422
 423 ns_determine_edns_buffer_size() {
 424         local ns=${1}
 425         shift
 426
 427         local b
 428         for b in 4096 2048 1500 1480 1464 1400 1280 512; do
 429                 if dig @${ns} +dnssec +bufsize=${b} A ${TEST_DOMAIN} $@ >/dev/null; then
 430                         echo "${b}"
 431                         return 0
 432                 fi
 433         done
 434
 435         return 1
 436 }
 437
 438 get_root_nameservers() {
 439         while read -r hostname ttl record address; do
 440                 # Searching for A records
 441                 [ "${record}" = "A" ] || continue
 442
 443                 echo "${address}"
 444         done < /etc/unbound/root.hints
 445 }
 446
 447 can_resolve_root() {
 448         local ns
 449         for ns in $(get_root_nameservers); do
 450                 if dig @${ns} +dnssec SOA . $@ >/dev/null; then
 451                         return 0
 452                 fi
 453         done
 454
 455         # none of the servers was reachable
 456         return 1
 457 }
 458
 459 enable_dnssec() {
 460         local status=$(unbound-control get_option val-permissive-mode)
 461
 462         # Log DNSSEC status
 463         echo "on" > /var/ipfire/red/dnssec-status
 464
 465         # Don't do anything if DNSSEC is already activated
 466         [ "${status}" = "no" ] && return 0
 467
 468         # Activate DNSSEC and flush cache with any stale and unvalidated data
 469         unbound-control -q set_option val-permissive-mode: no
 470         unbound-control -q flush_zone .
 471 }
 472
 473 disable_dnssec() {
 474         # Log DNSSEC status
 475         echo "off" > /var/ipfire/red/dnssec-status
 476
 477         unbound-control -q set_option val-permissive-mode: yes
 478 }
 479
 480 fix_time_if_dns_fail() {
 481         # If DNS still not work try to init ntp with
 482         # hardcoded ntp.ipfire.org (81.3.27.46)
 483         if [ -e /var/ipfire/red/active ]; then
 484                 host 0.ipfire.pool.ntp.org > /dev/null 2>&1
 485                 if [ "${?}" != "0" ]; then
 486                         boot_mesg "DNS still not functioning... Trying to sync time with ntp.ipfire.org (81.3.27.46)..."
 487                         loadproc /usr/local/bin/settime 81.3.27.46
 488                 fi
 489         fi
 490 }
 491
 492 case "$1" in
 493         start)
 494                 # Print a nicer messagen when unbound is already running
 495                 if pidofproc -s unbound; then
 496                         statusproc /usr/sbin/unbound
 497                         exit 0
 498                 fi
 499
 500                 eval $(/usr/local/bin/readhash /var/ipfire/ethernet/settings)
 501
 502                 # Create control keys at first run
 503                 if [ ! -r "/etc/unbound/unbound_control.key" ]; then
 504                         unbound-control-setup -d /etc/unbound &>/dev/null
 505                 fi
 506
 507                 # Update configuration files
 508                 write_tuning_conf
 509                 write_forward_conf
 510
 511                 boot_mesg "Starting Unbound DNS Proxy..."
 512                 loadproc /usr/sbin/unbound || exit $?
 513
 514                 # Make own hostname resolveable
 515                 own_hostname
 516
 517                 # Update any known forwarding name servers
 518                 update_forwarders
 519
 520                 # Update hosts
 521                 update_hosts
 522
 523                 fix_time_if_dns_fail
 524                 ;;
 525
 526         stop)
 527                 boot_mesg "Stopping Unbound DNS Proxy..."
 528                 killproc /usr/sbin/unbound
 529                 ;;
 530
 531         restart)
 532                 $0 stop
 533                 sleep 1
 534                 $0 start
 535                 ;;
 536
 537         status)
 538                 statusproc /usr/sbin/unbound
 539                 ;;
 540
 541         update-forwarders)
 542                 # Do not try updating forwarders when unbound is not running
 543                 if ! pgrep unbound &>/dev/null; then
 544                         exit 0
 545                 fi
 546
 547                 update_forwarders
 548
 549                 unbound-control flush_negative > /dev/null
 550                 unbound-control flush_bogus > /dev/null
 551
 552                 fix_time_if_dns_fail
 553                 ;;
 554
 555         test-name-server)
 556                 ns=${2}
 557
 558                 test_name_server ${ns}
 559                 ret=${?}
 560
 561                 case "${ret}" in
 562                         0)
 563                                 echo "${ns} is validating"
 564                                 ;;
 565                         2)
 566                                 echo "${ns} is DNSSEC-aware"
 567                                 ;;
 568                         3)
 569                                 echo "${ns} is NOT DNSSEC-aware"
 570                                 ;;
 571                         *)
 572                                 echo "Test failed for an unknown reason"
 573                                 exit ${ret}
 574                                 ;;
 575                 esac
 576
 577                 if ns_supports_tcp ${ns}; then
 578                         echo "${ns} supports TCP fallback"
 579                 else
 580                         echo "${ns} does not support TCP fallback"
 581                 fi
 582
 583                 edns_buffer_size=$(ns_determine_edns_buffer_size ${ns})
 584                 if [ -n "${edns_buffer_size}" ]; then
 585                         echo "EDNS buffer size for ${ns}: ${edns_buffer_size}"
 586                 fi
 587
 588                 exit ${ret}
 589                 ;;
 590
 591         *)
 592                 echo "Usage: $0 {start|stop|restart|status|update-forwarders|test-name-server}"
 593                 exit 1
 594                 ;;
 595 esac
 596
 597 # End $rc_base/init.d/unbound