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