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