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