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 disable_dnssec rest
 201                 while IFS="," read -r enabled zone servers remark disable_dnssec rest; 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} ${zone}"
 210                                         ;;
 211                                 *)
 212                                         if [ "${disable_dnssec}" = "on" ]; then
 213                                                 insecure_zones="${insecure_zones} ${zone}"
 214                                         fi
 215                                         ;;
 216                         esac
 217
 218                         # Reverse-lookup zones must be stubs
 219                         case "${zone}" in
 220                                 *.in-addr.arpa)
 221                                         echo "stub-zone:"
 222                                         echo "  name: ${zone}"
 223                                         for server in ${servers//|/ }; do
 224                                                 if [[ ${server} =~ ^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
 225                                                         echo "  stub-addr: ${server}"
 226                                                 else
 227                                                         echo "  stub-host: ${server}"
 228                                                 fi
 229                                         done
 230                                         echo
 231                                         echo "server:"
 232                                         echo "  local-zone: \"${zone}\" transparent"
 233                                         echo
 234                                         ;;
 235                                 *)
 236                                         echo "forward-zone:"
 237                                         echo "  name: ${zone}"
 238                                         for server in ${servers//|/ }; do
 239                                                 if [[ ${server} =~ ^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
 240                                                         echo "  forward-addr: ${server}"
 241                                                 else
 242                                                         echo "  forward-host: ${server}"
 243                                                 fi
 244                                         done
 245                                         echo
 246                                         ;;
 247                         esac
 248                 done < /var/ipfire/dnsforward/config
 249
 250                 if [ -n "${insecure_zones}" ]; then
 251                         echo "server:"
 252
 253                         for zone in ${insecure_zones}; do
 254                                 echo "  domain-insecure: ${zone}"
 255                         done
 256                 fi
 257         ) > /etc/unbound/forward.conf
 258 }
 259
 260 write_tuning_conf() {
 261         # https://www.unbound.net/documentation/howto_optimise.html
 262
 263         # Determine number of online processors
 264         local processors=$(getconf _NPROCESSORS_ONLN)
 265
 266         # Determine number of slabs
 267         local slabs=1
 268         while [ ${slabs} -lt ${processors} ]; do
 269                 slabs=$(( ${slabs} * 2 ))
 270         done
 271
 272         # Determine amount of system memory
 273         local mem=$(get_memory_amount)
 274
 275         # In the worst case scenario, unbound can use double the
 276         # amount of memory allocated to a cache due to malloc overhead
 277
 278         # Even larger systems with more than 8GB of RAM
 279         if [ ${mem} -ge 8192 ]; then
 280                 mem=1024
 281
 282         # Extra large systems with more than 4GB of RAM
 283         elif [ ${mem} -ge 4096 ]; then
 284                 mem=512
 285
 286         # Large systems with more than 2GB of RAM
 287         elif [ ${mem} -ge 2048 ]; then
 288                 mem=256
 289
 290         # Medium systems with more than 1GB of RAM
 291         elif [ ${mem} -ge 1024 ]; then
 292                 mem=128
 293
 294         # Small systems with less than 256MB of RAM
 295         elif [ ${mem} -le 256 ]; then
 296                 mem=16
 297
 298         # Everything else
 299         else
 300                 mem=64
 301         fi
 302
 303         (
 304                 config_header
 305
 306                 # We run one thread per processor
 307                 echo "num-threads: ${processors}"
 308                 echo "so-reuseport: yes"
 309
 310                 # Adjust number of slabs
 311                 echo "infra-cache-slabs: ${slabs}"
 312                 echo "key-cache-slabs: ${slabs}"
 313                 echo "msg-cache-slabs: ${slabs}"
 314                 echo "rrset-cache-slabs: ${slabs}"
 315
 316                 # Slice up the cache
 317                 echo "rrset-cache-size: $(( ${mem} / 2 ))m"
 318                 echo "msg-cache-size: $(( ${mem} / 4 ))m"
 319                 echo "key-cache-size: $(( ${mem} / 4 ))m"
 320
 321                 # Increase parallel queries
 322                 echo "outgoing-range: 8192"
 323                 echo "num-queries-per-thread: 4096"
 324
 325                 # Use larger send/receive buffers
 326                 echo "so-sndbuf: 4m"
 327                 echo "so-rcvbuf: 4m"
 328         ) > /etc/unbound/tuning.conf
 329 }
 330
 331 get_memory_amount() {
 332         local key val unit
 333
 334         while read -r key val unit; do
 335                 case "${key}" in
 336                         MemTotal:*)
 337                                 # Convert to MB
 338                                 echo "$(( ${val} / 1024 ))"
 339                                 break
 340                                 ;;
 341                 esac
 342         done < /proc/meminfo
 343 }
 344
 345 test_name_server() {
 346         local ns=${1}
 347         local args
 348
 349         # Return codes:
 350         # 0     DNSSEC validating
 351         # 1     Error: unreachable, etc.
 352         # 2     DNSSEC aware
 353         # 3     NOT DNSSEC-aware
 354
 355         # Exit when the server is not reachable
 356         ns_is_online ${ns} || return 1
 357
 358         # Determine the maximum edns buffer size that works
 359         local edns_buffer_size=$(ns_determine_edns_buffer_size ${ns})
 360         if [ -n "${edns_buffer_size}" ]; then
 361                 args="${args} +bufsize=${edns_buffer_size}"
 362         fi
 363
 364         local errors
 365         for rr in DNSKEY DS RRSIG; do
 366                 if ! ns_forwards_${rr} ${ns} ${args}; then
 367                         errors="${errors} ${rr}"
 368                 fi
 369         done
 370
 371         if [ -n "${errors}" ]; then
 372                 echo >&2 "Unable to retrieve the following resource records from ${ns}: ${errors:1}"
 373                 return 3
 374         fi
 375
 376         if ns_is_validating ${ns} ${args}; then
 377                 # Return 0 if validating
 378                 return 0
 379         else
 380                 # Is DNSSEC-aware
 381                 return 2
 382         fi
 383 }
 384
 385 # Sends an A query to the nameserver w/o DNSSEC
 386 ns_is_online() {
 387         local ns=${1}
 388         shift
 389
 390         dig @${ns} +nodnssec A ${TEST_DOMAIN} $@ >/dev/null
 391 }
 392
 393 # Resolving ${TEST_DOMAIN_FAIL} will fail if the nameserver is validating
 394 ns_is_validating() {
 395         local ns=${1}
 396         shift
 397
 398         if ! dig @${ns} A ${TEST_DOMAIN_FAIL} $@ | grep -q SERVFAIL; then
 399                 return 1
 400         else
 401                 # Determine if NS replies with "ad" data flag if DNSSEC enabled
 402                 dig @${ns} +dnssec SOA ${TEST_DOMAIN} $@ | awk -F: '/\;\;\ flags\:/ { s=1; if (/\ ad/) s=0; exit s }'
 403         fi
 404 }
 405
 406 # Checks if we can retrieve the DNSKEY for this domain.
 407 # dig will print the SOA if nothing was found
 408 ns_forwards_DNSKEY() {
 409         local ns=${1}
 410         shift
 411
 412         dig @${ns} DNSKEY ${TEST_DOMAIN} $@ | grep -qv SOA
 413 }
 414
 415 ns_forwards_DS() {
 416         local ns=${1}
 417         shift
 418
 419         dig @${ns} DS ${TEST_DOMAIN} $@ | grep -qv SOA
 420 }
 421
 422 ns_forwards_RRSIG() {
 423         local ns=${1}
 424         shift
 425
 426         dig @${ns} +dnssec A ${TEST_DOMAIN} $@ | grep -q RRSIG
 427 }
 428
 429 ns_supports_tcp() {
 430         local ns=${1}
 431         shift
 432
 433         dig @${ns} +tcp A ${TEST_DOMAIN} $@ >/dev/null || return 1
 434 }
 435
 436 ns_determine_edns_buffer_size() {
 437         local ns=${1}
 438         shift
 439
 440         local b
 441         for b in 4096 2048 1500 1480 1464 1400 1280 512; do
 442                 if dig @${ns} +dnssec +bufsize=${b} A ${TEST_DOMAIN} $@ >/dev/null; then
 443                         echo "${b}"
 444                         return 0
 445                 fi
 446         done
 447
 448         return 1
 449 }
 450
 451 get_root_nameservers() {
 452         while read -r hostname ttl record address; do
 453                 # Searching for A records
 454                 [ "${record}" = "A" ] || continue
 455
 456                 echo "${address}"
 457         done < /etc/unbound/root.hints
 458 }
 459
 460 can_resolve_root() {
 461         local ns
 462         for ns in $(get_root_nameservers); do
 463                 if dig @${ns} +dnssec SOA . $@ >/dev/null; then
 464                         return 0
 465                 fi
 466         done
 467
 468         # none of the servers was reachable
 469         return 1
 470 }
 471
 472 enable_dnssec() {
 473         local status=$(unbound-control get_option val-permissive-mode)
 474
 475         # Log DNSSEC status
 476         echo "on" > /var/ipfire/red/dnssec-status
 477
 478         # Don't do anything if DNSSEC is already activated
 479         [ "${status}" = "no" ] && return 0
 480
 481         # Activate DNSSEC and flush cache with any stale and unvalidated data
 482         unbound-control -q set_option val-permissive-mode: no
 483         unbound-control -q flush_zone .
 484 }
 485
 486 disable_dnssec() {
 487         # Log DNSSEC status
 488         echo "off" > /var/ipfire/red/dnssec-status
 489
 490         unbound-control -q set_option val-permissive-mode: yes
 491 }
 492
 493 fix_time_if_dns_fail() {
 494         # If DNS still not work try to init ntp with
 495         # hardcoded ntp.ipfire.org (81.3.27.46)
 496         if [ -e /var/ipfire/red/active ]; then
 497                 host 0.ipfire.pool.ntp.org > /dev/null 2>&1
 498                 if [ "${?}" != "0" ]; then
 499                         boot_mesg "DNS still not functioning... Trying to sync time with ntp.ipfire.org (81.3.27.46)..."
 500                         loadproc /usr/local/bin/settime 81.3.27.46
 501                 fi
 502         fi
 503 }
 504
 505 case "$1" in
 506         start)
 507                 # Print a nicer messagen when unbound is already running
 508                 if pidofproc -s unbound; then
 509                         statusproc /usr/sbin/unbound
 510                         exit 0
 511                 fi
 512
 513                 eval $(/usr/local/bin/readhash /var/ipfire/ethernet/settings)
 514
 515                 # Update configuration files
 516                 write_tuning_conf
 517                 write_forward_conf
 518
 519                 boot_mesg "Starting Unbound DNS Proxy..."
 520                 loadproc /usr/sbin/unbound || exit $?
 521
 522                 # Make own hostname resolveable
 523                 own_hostname
 524
 525                 # Update any known forwarding name servers
 526                 update_forwarders
 527
 528                 # Update hosts
 529                 update_hosts
 530
 531                 fix_time_if_dns_fail
 532                 ;;
 533
 534         stop)
 535                 boot_mesg "Stopping Unbound DNS Proxy..."
 536                 killproc /usr/sbin/unbound
 537                 ;;
 538
 539         restart)
 540                 $0 stop
 541                 sleep 1
 542                 $0 start
 543                 ;;
 544
 545         status)
 546                 statusproc /usr/sbin/unbound
 547                 ;;
 548
 549         update-forwarders)
 550                 # Do not try updating forwarders when unbound is not running
 551                 if ! pgrep unbound &>/dev/null; then
 552                         exit 0
 553                 fi
 554
 555                 update_forwarders
 556
 557                 unbound-control flush_negative > /dev/null
 558                 unbound-control flush_bogus > /dev/null
 559
 560                 fix_time_if_dns_fail
 561                 ;;
 562
 563         test-name-server)
 564                 ns=${2}
 565
 566                 test_name_server ${ns}
 567                 ret=${?}
 568
 569                 case "${ret}" in
 570                         0)
 571                                 echo "${ns} is validating"
 572                                 ;;
 573                         2)
 574                                 echo "${ns} is DNSSEC-aware"
 575                                 ;;
 576                         3)
 577                                 echo "${ns} is NOT DNSSEC-aware"
 578                                 ;;
 579                         *)
 580                                 echo "Test failed for an unknown reason"
 581                                 exit ${ret}
 582                                 ;;
 583                 esac
 584
 585                 if ns_supports_tcp ${ns}; then
 586                         echo "${ns} supports TCP fallback"
 587                 else
 588                         echo "${ns} does not support TCP fallback"
 589                 fi
 590
 591                 edns_buffer_size=$(ns_determine_edns_buffer_size ${ns})
 592                 if [ -n "${edns_buffer_size}" ]; then
 593                         echo "EDNS buffer size for ${ns}: ${edns_buffer_size}"
 594                 fi
 595
 596                 exit ${ret}
 597                 ;;
 598
 599         *)
 600                 echo "Usage: $0 {start|stop|restart|status|update-forwarders|test-name-server}"
 601                 exit 1
 602                 ;;
 603 esac
 604
 605 # End $rc_base/init.d/unbound