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: $(( ${mem} / 4 ))m"
 276         ) > /etc/unbound/tuning.conf
 277 }
 278
 279 get_memory_amount() {
 280         local key val unit
 281
 282         while read -r key val unit; do
 283                 case "${key}" in
 284                         MemTotal:*)
 285                                 # Convert to MB
 286                                 echo "$(( ${val} / 1024 ))"
 287                                 break
 288                                 ;;
 289                 esac
 290         done < /proc/meminfo
 291 }
 292
 293 test_name_server() {
 294         local ns=${1}
 295         local args
 296
 297         # Return codes:
 298         # 0     DNSSEC validating
 299         # 1     Error: unreachable, etc.
 300         # 2     DNSSEC aware
 301         # 3     NOT DNSSEC-aware
 302
 303         # Exit when the server is not reachable
 304         ns_is_online ${ns} || return 1
 305
 306         # Determine the maximum edns buffer size that works
 307         local edns_buffer_size=$(ns_determine_edns_buffer_size ${ns})
 308         if [ -n "${edns_buffer_size}" ]; then
 309                 args="${args} +bufsize=${edns_buffer_size}"
 310         fi
 311
 312         local errors
 313         for rr in DNSKEY DS RRSIG; do
 314                 if ! ns_forwards_${rr} ${ns} ${args}; then
 315                         errors="${errors} ${rr}"
 316                 fi
 317         done
 318
 319         if [ -n "${errors}" ]; then
 320                 echo >&2 "Unable to retrieve the following resource records from ${ns}: ${errors:1}"
 321                 return 3
 322         fi
 323
 324         if ns_is_validating ${ns} ${args}; then
 325                 # Return 0 if validating
 326                 return 0
 327         else
 328                 # Is DNSSEC-aware
 329                 return 2
 330         fi
 331 }
 332
 333 # Sends an A query to the nameserver w/o DNSSEC
 334 ns_is_online() {
 335         local ns=${1}
 336         shift
 337
 338         dig @${ns} +nodnssec A ${TEST_DOMAIN} $@ >/dev/null
 339 }
 340
 341 # Resolving ${TEST_DOMAIN_FAIL} will fail if the nameserver is validating
 342 ns_is_validating() {
 343         local ns=${1}
 344         shift
 345
 346         dig @${ns} A ${TEST_DOMAIN_FAIL} $@ | grep -q SERVFAIL
 347 }
 348
 349 # Checks if we can retrieve the DNSKEY for this domain.
 350 # dig will print the SOA if nothing was found
 351 ns_forwards_DNSKEY() {
 352         local ns=${1}
 353         shift
 354
 355         dig @${ns} DNSKEY ${TEST_DOMAIN} $@ | grep -qv SOA
 356 }
 357
 358 ns_forwards_DS() {
 359         local ns=${1}
 360         shift
 361
 362         dig @${ns} DS ${TEST_DOMAIN} $@ | grep -qv SOA
 363 }
 364
 365 ns_forwards_RRSIG() {
 366         local ns=${1}
 367         shift
 368
 369         dig @${ns} +dnssec A ${TEST_DOMAIN} $@ | grep -q RRSIG
 370 }
 371
 372 ns_supports_tcp() {
 373         local ns=${1}
 374         shift
 375
 376         dig @${ns} +tcp A ${TEST_DOMAIN} $@ >/dev/null || return 1
 377 }
 378
 379 ns_determine_edns_buffer_size() {
 380         local ns=${1}
 381         shift
 382
 383         local b
 384         for b in 4096 2048 1500 1480 1464 1400 1280 512; do
 385                 if dig @${ns} +dnssec +bufsize=${b} A ${TEST_DOMAIN} $@ >/dev/null; then
 386                         echo "${b}"
 387                         return 0
 388                 fi
 389         done
 390
 391         return 1
 392 }
 393
 394 get_root_nameservers() {
 395         while read -r hostname ttl record address; do
 396                 # Searching for A records
 397                 [ "${record}" = "A" ] || continue
 398
 399                 echo "${address}"
 400         done < /etc/unbound/root.hints
 401 }
 402
 403 can_resolve_root() {
 404         local ns
 405         for ns in $(get_root_nameservers); do
 406                 if dig @${ns} +dnssec SOA . $@ >/dev/null; then
 407                         return 0
 408                 fi
 409         done
 410
 411         # none of the servers was reachable
 412         return 1
 413 }
 414
 415 enable_dnssec() {
 416         local status=$(unbound-control get_option val-permissive-mode)
 417
 418         # Don't do anything if DNSSEC is already activated
 419         [ "${status}" = "no" ] && return 0
 420
 421         # Activate DNSSEC and flush cache with any stale and unvalidated data
 422         unbound-control -q set_option val-permissive-mode: no
 423         unbound-control -q flush_zone .
 424 }
 425
 426 disable_dnssec() {
 427         unbound-control -q set_option val-permissive-mode: yes
 428 }
 429
 430 case "$1" in
 431         start)
 432                 # Print a nicer messagen when unbound is already running
 433                 if pidofproc -s unbound; then
 434                         statusproc /usr/sbin/unbound
 435                         exit 0
 436                 fi
 437
 438                 eval $(/usr/local/bin/readhash /var/ipfire/ethernet/settings)
 439
 440                 # Create control keys at first run
 441                 if [ ! -r "/etc/unbound/unbound_control.key" ]; then
 442                         unbound-control-setup -d /etc/unbound &>/dev/null
 443                 fi
 444
 445                 # Update configuration files
 446                 write_tuning_conf
 447                 write_forward_conf
 448
 449                 boot_mesg "Starting Unbound DNS Proxy..."
 450                 loadproc /usr/sbin/unbound || exit $?
 451
 452                 # Make own hostname resolveable
 453                 own_hostname
 454
 455                 # Update any known forwarding name servers
 456                 update_forwarders
 457
 458                 # Update hosts
 459                 update_hosts
 460                 ;;
 461
 462         stop)
 463                 boot_mesg "Stopping Unbound DNS Proxy..."
 464                 killproc /usr/sbin/unbound
 465                 ;;
 466
 467         restart)
 468                 $0 stop
 469                 sleep 1
 470                 $0 start
 471                 ;;
 472
 473         status)
 474                 statusproc /usr/sbin/unbound
 475                 ;;
 476
 477         update-forwarders)
 478                 # Do not try updating forwarders when unbound is not running
 479                 if ! pgrep unbound &>/dev/null; then
 480                         exit 0
 481                 fi
 482
 483                 update_forwarders
 484                 ;;
 485
 486         test-name-server)
 487                 ns=${2}
 488
 489                 test_name_server ${ns}
 490                 ret=${?}
 491
 492                 case "${ret}" in
 493                         0)
 494                                 echo "${ns} is validating"
 495                                 ;;
 496                         2)
 497                                 echo "${ns} is DNSSEC-aware"
 498                                 ;;
 499                         3)
 500                                 echo "${ns} is NOT DNSSEC-aware"
 501                                 ;;
 502                         *)
 503                                 echo "Test failed for an unknown reason"
 504                                 exit ${ret}
 505                                 ;;
 506                 esac
 507
 508                 if ns_supports_tcp ${ns}; then
 509                         echo "${ns} supports TCP fallback"
 510                 else
 511                         echo "${ns} does not support TCP fallback"
 512                 fi
 513
 514                 edns_buffer_size=$(ns_determine_edns_buffer_size ${ns})
 515                 if [ -n "${edns_buffer_size}" ]; then
 516                         echo "EDNS buffer size for ${ns}: ${edns_buffer_size}"
 517                 fi
 518
 519                 exit ${ret}
 520                 ;;
 521
 522         *)
 523                 echo "Usage: $0 {start|stop|restart|status|update-forwarders|test-name-server}"
 524                 exit 1
 525                 ;;
 526 esac
 527
 528 # End $rc_base/init.d/unbound