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${i})"
  64         done | xargs echo
  65 }
  66
  67 config_header() {
  68         echo "# This file is automatically generated and any changes"
  69         echo "# will be overwritten. DO NOT EDIT!"
  70         echo
  71 }
  72
  73 update_forwarders() {
  74         if [ "${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                         echo "forward-zone:"
 214                         echo "  name: ${zone}"
 215                         echo "  forward-addr: ${server}"
 216                         echo
 217                 done < /var/ipfire/dnsforward/config
 218
 219                 if [ -n "${insecure_zones}" ]; then
 220                         echo "server:"
 221
 222                         for zone in ${insecure_zones}; do
 223                                 echo "  domain-insecure: ${zone}"
 224                         done
 225                 fi
 226         ) > /etc/unbound/forward.conf
 227 }
 228
 229 write_tuning_conf() {
 230         # https://www.unbound.net/documentation/howto_optimise.html
 231
 232         # Determine number of online processors
 233         local processors=$(getconf _NPROCESSORS_ONLN)
 234
 235         # Determine number of slabs
 236         local slabs=1
 237         while [ ${slabs} -lt ${processors} ]; do
 238                 slabs=$(( ${slabs} * 2 ))
 239         done
 240
 241         # Determine amount of system memory
 242         local mem=$(get_memory_amount)
 243
 244         # In the worst case scenario, unbound can use double the
 245         # amount of memory allocated to a cache due to malloc overhead
 246
 247         # Large systems with more than 2GB of RAM
 248         if [ ${mem} -ge 2048 ]; then
 249                 mem=128
 250
 251         # Small systems with less than 256MB of RAM
 252         elif [ ${mem} -le 256 ]; then
 253                 mem=8
 254
 255         # Everything else
 256         else
 257                 mem=32
 258         fi
 259
 260         (
 261                 config_header
 262
 263                 # We run one thread per processor
 264                 echo "num-threads: ${processors}"
 265
 266                 # Adjust number of slabs
 267                 echo "infra-cache-slabs: ${slabs}"
 268                 echo "key-cache-slabs: ${slabs}"
 269                 echo "msg-cache-slabs: ${slabs}"
 270                 echo "rrset-cache-slabs: ${slabs}"
 271
 272                 # Slice up the cache
 273                 echo "rrset-cache-size: $(( ${mem} / 2 ))m"
 274                 echo "msg-cache-size: $(( ${mem} / 4 ))m"
 275                 echo "key-cache-size: $(( ${mem} / 4 ))m"
 276
 277                 # Increase parallel queries
 278                 echo "outgoing-range: 8192"
 279                 echo "num-queries-per-thread: 4096"
 280         ) > /etc/unbound/tuning.conf
 281 }
 282
 283 get_memory_amount() {
 284         local key val unit
 285
 286         while read -r key val unit; do
 287                 case "${key}" in
 288                         MemTotal:*)
 289                                 # Convert to MB
 290                                 echo "$(( ${val} / 1024 ))"
 291                                 break
 292                                 ;;
 293                 esac
 294         done < /proc/meminfo
 295 }
 296
 297 test_name_server() {
 298         local ns=${1}
 299         local args
 300
 301         # Return codes:
 302         # 0     DNSSEC validating
 303         # 1     Error: unreachable, etc.
 304         # 2     DNSSEC aware
 305         # 3     NOT DNSSEC-aware
 306
 307         # Exit when the server is not reachable
 308         ns_is_online ${ns} || return 1
 309
 310         # Determine the maximum edns buffer size that works
 311         local edns_buffer_size=$(ns_determine_edns_buffer_size ${ns})
 312         if [ -n "${edns_buffer_size}" ]; then
 313                 args="${args} +bufsize=${edns_buffer_size}"
 314         fi
 315
 316         local errors
 317         for rr in DNSKEY DS RRSIG; do
 318                 if ! ns_forwards_${rr} ${ns} ${args}; then
 319                         errors="${errors} ${rr}"
 320                 fi
 321         done
 322
 323         if [ -n "${errors}" ]; then
 324                 echo >&2 "Unable to retrieve the following resource records from ${ns}: ${errors:1}"
 325                 return 3
 326         fi
 327
 328         if ns_is_validating ${ns} ${args}; then
 329                 # Return 0 if validating
 330                 return 0
 331         else
 332                 # Is DNSSEC-aware
 333                 return 2
 334         fi
 335 }
 336
 337 # Sends an A query to the nameserver w/o DNSSEC
 338 ns_is_online() {
 339         local ns=${1}
 340         shift
 341
 342         dig @${ns} +nodnssec A ${TEST_DOMAIN} $@ >/dev/null
 343 }
 344
 345 # Resolving ${TEST_DOMAIN_FAIL} will fail if the nameserver is validating
 346 ns_is_validating() {
 347         local ns=${1}
 348         shift
 349
 350         dig @${ns} A ${TEST_DOMAIN_FAIL} $@ | grep -q SERVFAIL
 351 }
 352
 353 # Checks if we can retrieve the DNSKEY for this domain.
 354 # dig will print the SOA if nothing was found
 355 ns_forwards_DNSKEY() {
 356         local ns=${1}
 357         shift
 358
 359         dig @${ns} DNSKEY ${TEST_DOMAIN} $@ | grep -qv SOA
 360 }
 361
 362 ns_forwards_DS() {
 363         local ns=${1}
 364         shift
 365
 366         dig @${ns} DS ${TEST_DOMAIN} $@ | grep -qv SOA
 367 }
 368
 369 ns_forwards_RRSIG() {
 370         local ns=${1}
 371         shift
 372
 373         dig @${ns} +dnssec A ${TEST_DOMAIN} $@ | grep -q RRSIG
 374 }
 375
 376 ns_supports_tcp() {
 377         local ns=${1}
 378         shift
 379
 380         dig @${ns} +tcp A ${TEST_DOMAIN} $@ >/dev/null || return 1
 381 }
 382
 383 ns_determine_edns_buffer_size() {
 384         local ns=${1}
 385         shift
 386
 387         local b
 388         for b in 4096 2048 1500 1480 1464 1400 1280 512; do
 389                 if dig @${ns} +dnssec +bufsize=${b} A ${TEST_DOMAIN} $@ >/dev/null; then
 390                         echo "${b}"
 391                         return 0
 392                 fi
 393         done
 394
 395         return 1
 396 }
 397
 398 get_root_nameservers() {
 399         while read -r hostname ttl record address; do
 400                 # Searching for A records
 401                 [ "${record}" = "A" ] || continue
 402
 403                 echo "${address}"
 404         done < /etc/unbound/root.hints
 405 }
 406
 407 can_resolve_root() {
 408         local ns
 409         for ns in $(get_root_nameservers); do
 410                 if dig @${ns} +dnssec SOA . $@ >/dev/null; then
 411                         return 0
 412                 fi
 413         done
 414
 415         # none of the servers was reachable
 416         return 1
 417 }
 418
 419 enable_dnssec() {
 420         local status=$(unbound-control get_option val-permissive-mode)
 421
 422         # Don't do anything if DNSSEC is already activated
 423         [ "${status}" = "no" ] && return 0
 424
 425         # Activate DNSSEC and flush cache with any stale and unvalidated data
 426         unbound-control -q set_option val-permissive-mode: no
 427         unbound-control -q flush_zone .
 428 }
 429
 430 disable_dnssec() {
 431         unbound-control -q set_option val-permissive-mode: yes
 432 }
 433
 434 case "$1" in
 435         start)
 436                 # Print a nicer messagen when unbound is already running
 437                 if pidofproc -s unbound; then
 438                         statusproc /usr/sbin/unbound
 439                         exit 0
 440                 fi
 441
 442                 eval $(/usr/local/bin/readhash /var/ipfire/ethernet/settings)
 443
 444                 # Create control keys at first run
 445                 if [ ! -r "/etc/unbound/unbound_control.key" ]; then
 446                         unbound-control-setup -d /etc/unbound &>/dev/null
 447                 fi
 448
 449                 # Update configuration files
 450                 write_tuning_conf
 451                 write_forward_conf
 452
 453                 boot_mesg "Starting Unbound DNS Proxy..."
 454                 loadproc /usr/sbin/unbound || exit $?
 455
 456                 # Make own hostname resolveable
 457                 own_hostname
 458
 459                 # Update any known forwarding name servers
 460                 update_forwarders
 461
 462                 # Update hosts
 463                 update_hosts
 464                 ;;
 465
 466         stop)
 467                 boot_mesg "Stopping Unbound DNS Proxy..."
 468                 killproc /usr/sbin/unbound
 469                 ;;
 470
 471         restart)
 472                 $0 stop
 473                 sleep 1
 474                 $0 start
 475                 ;;
 476
 477         status)
 478                 statusproc /usr/sbin/unbound
 479                 ;;
 480
 481         update-forwarders)
 482                 # Do not try updating forwarders when unbound is not running
 483                 if ! pgrep unbound &>/dev/null; then
 484                         exit 0
 485                 fi
 486
 487                 update_forwarders
 488                 ;;
 489
 490         test-name-server)
 491                 ns=${2}
 492
 493                 test_name_server ${ns}
 494                 ret=${?}
 495
 496                 case "${ret}" in
 497                         0)
 498                                 echo "${ns} is validating"
 499                                 ;;
 500                         2)
 501                                 echo "${ns} is DNSSEC-aware"
 502                                 ;;
 503                         3)
 504                                 echo "${ns} is NOT DNSSEC-aware"
 505                                 ;;
 506                         *)
 507                                 echo "Test failed for an unknown reason"
 508                                 exit ${ret}
 509                                 ;;
 510                 esac
 511
 512                 if ns_supports_tcp ${ns}; then
 513                         echo "${ns} supports TCP fallback"
 514                 else
 515                         echo "${ns} does not support TCP fallback"
 516                 fi
 517
 518                 edns_buffer_size=$(ns_determine_edns_buffer_size ${ns})
 519                 if [ -n "${edns_buffer_size}" ]; then
 520                         echo "EDNS buffer size for ${ns}: ${edns_buffer_size}"
 521                 fi
 522
 523                 exit ${ret}
 524                 ;;
 525
 526         *)
 527                 echo "Usage: $0 {start|stop|restart|status|update-forwarders|test-name-server}"
 528                 exit 1
 529                 ;;
 530 esac
 531
 532 # End $rc_base/init.d/unbound