From 632c9bad43231579ba8b5b381d56be7c7b3e0339 Mon Sep 17 00:00:00 2001 From: Matthew Vance Date: Sat, 4 Apr 2020 17:29:49 -0500 Subject: [PATCH] :hammer: Improve Unbound config --- unbound/unbound.sh | 392 +++++++++++++++++++++++++++++++++++++-------- 1 file changed, 323 insertions(+), 69 deletions(-) diff --git a/unbound/unbound.sh b/unbound/unbound.sh index 63bf6b9..b6c4e3c 100644 --- a/unbound/unbound.sh +++ b/unbound/unbound.sh @@ -1,20 +1,33 @@ -#! /bin/sh +#!/bin/bash reserved=12582912 -availableMemory=$((1024 * $( (fgrep MemAvailable /proc/meminfo || fgrep MemTotal /proc/meminfo) | sed 's/[^0-9]//g' ) )) +availableMemory=$((1024 * $( (grep MemAvailable /proc/meminfo || grep MemTotal /proc/meminfo) | sed 's/[^0-9]//g' ) )) if [ $availableMemory -le $(($reserved * 2)) ]; then echo "Not enough memory" >&2 exit 1 fi availableMemory=$(($availableMemory - $reserved)) -msg_cache_size=$(($availableMemory / 3)) rr_cache_size=$(($availableMemory / 3)) +# Use roughly twice as much rrset cache memory as msg cache memory +msg_cache_size=$(($rr_cache_size / 2)) nproc=$(nproc) -if [ $nproc -gt 1 ]; then - threads=$(($nproc - 1)) +export nproc +if [ "$nproc" -gt 1 ]; then + threads=$((nproc - 1)) + # Calculate base 2 log of the number of processors + nproc_log=$(perl -e 'printf "%5.5f\n", log($ENV{nproc})/log(2);') + + # Round the logarithm to an integer + rounded_nproc_log="$(printf '%.*f\n' 0 "$nproc_log")" + + # Set *-slabs to a power of 2 close to the num-threads value. + # This reduces lock contention. + slabs=$(( 2 ** rounded_nproc_log )) else threads=1 + slabs=4 fi + # Lookup IP of Stubby container as work around because forward-host did not # resolve stubby correctly and does not support @port syntax. # This uses ping rather than 'dig +short stubby' to avoid needing dnsutils @@ -23,72 +36,313 @@ stubby_ip=$(ping -4 -c 1 stubby | head -n 1 | cut -d ' ' -f 3 | cut -d '(' -f 2 stubby_port=@8053 stubby=$stubby_ip$stubby_port -# Use this default unbound.conf unless a user mounts a custom one: if [ ! -f /opt/unbound/etc/unbound/unbound.conf ]; then -sed \ - -e "s/@MSG_CACHE_SIZE@/${msg_cache_size}/" \ - -e "s/@RR_CACHE_SIZE@/${rr_cache_size}/" \ - -e "s/@THREADS@/${threads}/" \ - -e "s/@STUBBY@/${stubby}/" \ - > /opt/unbound/etc/unbound/unbound.conf << EOT + sed \ + -e "s/@MSG_CACHE_SIZE@/${msg_cache_size}/" \ + -e "s/@RR_CACHE_SIZE@/${rr_cache_size}/" \ + -e "s/@THREADS@/${threads}/" \ + -e "s/@SLABS@/${slabs}/" \ + -e "s/@STUBBY@/${stubby}/" \ + > /opt/unbound/etc/unbound/unbound.conf << EOT server: - verbosity: 1 - num-threads: @THREADS@ - interface: 0.0.0.0@53 - so-reuseport: yes - edns-buffer-size: 1472 - delay-close: 10000 - cache-min-ttl: 60 - cache-max-ttl: 86400 - do-daemonize: no - deny-any: yes - username: "_unbound" - log-queries: no - hide-version: yes - hide-identity: yes - identity: "DNS" - harden-algo-downgrade: yes - harden-short-bufsize: yes - harden-large-queries: yes - harden-glue: yes - harden-dnssec-stripped: yes - harden-below-nxdomain: yes - harden-referral-path: no - do-not-query-localhost: no - prefetch: yes - prefetch-key: yes - qname-minimisation: yes - aggressive-nsec: yes - ratelimit: 1000 - rrset-roundrobin: yes - minimal-responses: yes - chroot: "/opt/unbound/etc/unbound" - directory: "/opt/unbound/etc/unbound" - auto-trust-anchor-file: "var/root.key" - num-queries-per-thread: 4096 - outgoing-range: 8192 - msg-cache-size: @MSG_CACHE_SIZE@ - rrset-cache-size: @RR_CACHE_SIZE@ - neg-cache-size: 4M - serve-expired: yes - use-caps-for-id: yes - unwanted-reply-threshold: 10000 - val-clean-additional: yes - private-address: 10.0.0.0/8 - private-address: 172.16.0.0/12 - private-address: 192.168.0.0/16 - private-address: 169.254.0.0/16 - private-address: fd00::/8 - private-address: fe80::/10 - private-address: ::ffff:0:0/96 - access-control: 127.0.0.1/32 allow - access-control: 192.168.0.0/16 allow - access-control: 172.16.0.0/12 allow - access-control: 10.0.0.0/8 allow - include: /opt/unbound/etc/unbound/a-records.conf - forward-zone: - name: "." - forward-addr: @STUBBY@ + ########################################################################### + # BASIC SETTINGS + ########################################################################### + # Time to live maximum for RRsets and messages in the cache. If the maximum + # kicks in, responses to clients still get decrementing TTLs based on the + # original (larger) values. When the internal TTL expires, the cache item + # has expired. Can be set lower to force the resolver to query for data + # often, and not trust (very large) TTL values. + cache-max-ttl: 86400 + + # Time to live minimum for RRsets and messages in the cache. If the minimum + # kicks in, the data is cached for longer than the domain owner intended, + # and thus less queries are made to look up the data. Zero makes sure the + # data in the cache is as the domain owner intended, higher values, + # especially more than an hour or so, can lead to trouble as the data in + # the cache does not match up with the actual data any more. + cache-min-ttl: 300 + + # Set the working directory for the program. + directory: "/opt/unbound/etc/unbound" + + # RFC 6891. Number of bytes size to advertise as the EDNS reassembly buffer + # size. This is the value put into datagrams over UDP towards peers. + # 4096 is RFC recommended. 1472 has a reasonable chance to fit within a + # single Ethernet frame, thus lessing the chance of fragmentation + # reassembly problems (usually seen as timeouts). Setting to 512 bypasses + # even the most stringent path MTU problems, but is not recommended since + # the amount of TCP fallback generated is excessive. + edns-buffer-size: 1472 + + # Listen to for queries from clients and answer from this network interface + # and port. + interface: 0.0.0.0@53 + + # Rotates RRSet order in response (the pseudo-random number is taken from + # the query ID, for speed and thread safety). + rrset-roundrobin: yes + + # Drop user privileges after binding the port. + username: "_unbound" + + ########################################################################### + # LOGGING + ########################################################################### + + # Do not print log lines to inform about local zone actions + log-local-actions: no + + # Do not print one line per query to the log + log-queries: no + + # Do not print one line per reply to the log + log-replies: no + + # Do not print log lines that say why queries return SERVFAIL to clients + log-servfail: no + + # Further limit logging + logfile: /dev/null + + # Only log errors + verbosity: 0 + + ########################################################################### + # PRIVACY SETTINGS + ########################################################################### + + # RFC 8198. Use the DNSSEC NSEC chain to synthesize NXDO-MAIN and other + # denials, using information from previous NXDO-MAINs answers. In other + # words, use cached NSEC records to generate negative answers within a + # range and positive answers from wildcards. This increases performance, + # decreases latency and resource utilization on both authoritative and + # recursive servers, and increases privacy. Also, it may help increase + # resilience to certain DoS attacks in some circumstances. + aggressive-nsec: yes + + # Extra delay for timeouted UDP ports before they are closed, in msec. + # This prevents very delayed answer packets from the upstream (recursive) + # servers from bouncing against closed ports and setting off all sort of + # close-port counters, with eg. 1500 msec. When timeouts happen you need + # extra sockets, it checks the ID and remote IP of packets, and unwanted + # packets are added to the unwanted packet counter. + delay-close: 10000 + + # Prevent the unbound server from forking into the background as a daemon + do-daemonize: no + + # Add localhost to the do-not-query-address list. + do-not-query-localhost: no + + # Number of bytes size of the aggressive negative cache. + neg-cache-size: 4M + + # Send minimum amount of information to upstream servers to enhance + # privacy (best privacy). + qname-minimisation: yes + + ########################################################################### + # SECURITY SETTINGS + ########################################################################### + # Only give access to recursion clients from LAN IPs + access-control: 127.0.0.1/32 allow + access-control: 192.168.0.0/16 allow + access-control: 172.16.0.0/12 allow + access-control: 10.0.0.0/8 allow + # access-control: fc00::/7 allow + # access-control: ::1/128 allow + + # File with trust anchor for one zone, which is tracked with RFC5011 + # probes. + auto-trust-anchor-file: "var/root.key" + + # Enable chroot (i.e, change apparent root directory for the current + # running process and its children) + chroot: "/opt/unbound/etc/unbound" + + # Deny queries of type ANY with an empty response. + deny-any: yes + + # Harden against algorithm downgrade when multiple algorithms are + # advertised in the DS record. + harden-algo-downgrade: yes + + # RFC 8020. returns nxdomain to queries for a name below another name that + # is already known to be nxdomain. + harden-below-nxdomain: yes + + # Require DNSSEC data for trust-anchored zones, if such data is absent, the + # zone becomes bogus. If turned off you run the risk of a downgrade attack + # that disables security for a zone. + harden-dnssec-stripped: yes + + # Only trust glue if it is within the servers authority. + harden-glue: yes + + # Ignore very large queries. + harden-large-queries: yes + + # Perform additional queries for infrastructure data to harden the referral + # path. Validates the replies if trust anchors are configured and the zones + # are signed. This enforces DNSSEC validation on nameserver NS sets and the + # nameserver addresses that are encountered on the referral path to the + # answer. Experimental option. + harden-referral-path: no + + # Ignore very small EDNS buffer sizes from queries. + harden-short-bufsize: yes + + # Refuse id.server and hostname.bind queries + hide-identity: yes + + # Refuse version.server and version.bind queries + hide-version: yes + + # Report this identity rather than the hostname of the server. + identity: "DNS" + + # These private network addresses are not allowed to be returned for public + # internet names. Any occurrence of such addresses are removed from DNS + # answers. Additionally, the DNSSEC validator may mark the answers bogus. + # This protects against DNS Rebinding + private-address: 10.0.0.0/8 + private-address: 172.16.0.0/12 + private-address: 192.168.0.0/16 + private-address: 169.254.0.0/16 + # private-address: fd00::/8 + # private-address: fe80::/10 + # private-address: ::ffff:0:0/96 + + # Enable ratelimiting of queries (per second) sent to nameserver for + # performing recursion. More queries are turned away with an error + # (servfail). This stops recursive floods (e.g., random query names), but + # not spoofed reflection floods. Cached responses are not rate limited by + # this setting. Experimental option. + ratelimit: 1000 + + # Use this certificate bundle for authenticating connections made to + # outside peers (e.g., auth-zone urls, DNS over TLS connections). + tls-cert-bundle: /etc/ssl/certs/ca-certificates.crt + + # Set the total number of unwanted replies to eep track of in every thread. + # When it reaches the threshold, a defensive action of clearing the rrset + # and message caches is taken, hopefully flushing away any poison. + # Unbound suggests a value of 10 million. + unwanted-reply-threshold: 10000 + + # Use 0x20-encoded random bits in the query to foil spoof attempts. This + # perturbs the lowercase and uppercase of query names sent to authority + # servers and checks if the reply still has the correct casing. + # This feature is an experimental implementation of draft dns-0x20. + # Experimental option. + use-caps-for-id: yes + + # Help protect users that rely on this validator for authentication from + # potentially bad data in the additional section. Instruct the validator to + # remove data from the additional section of secure messages that are not + # signed properly. Messages that are insecure, bogus, indeterminate or + # unchecked are not affected. + val-clean-additional: yes + + ########################################################################### + # PERFORMANCE SETTINGS + ########################################################################### + # https://nlnetlabs.nl/documentation/unbound/howto-optimise/ + # https://nlnetlabs.nl/news/2019/Feb/05/unbound-1.9.0-released/ + + # Number of slabs in the infrastructure cache. Slabs reduce lock contention + # by threads. Must be set to a power of 2. + infra-cache-slabs: @SLABS@ + + # Number of incoming TCP buffers to allocate per thread. Default + # is 10. If set to 0, or if do-tcp is "no", no TCP queries from + # clients are accepted. For larger installations increasing this + # value is a good idea. + incoming-num-tcp: 10 + + # Number of slabs in the key cache. Slabs reduce lock contention by + # threads. Must be set to a power of 2. Setting (close) to the number + # of cpus is a reasonable guess. + key-cache-slabs: @SLABS@ + + # Number of bytes size of the message cache. + # Unbound recommendation is to Use roughly twice as much rrset cache memory + # as you use msg cache memory. + msg-cache-size: @MSG_CACHE_SIZE@ + + # Number of slabs in the message cache. Slabs reduce lock contention by + # threads. Must be set to a power of 2. Setting (close) to the number of + # cpus is a reasonable guess. + msg-cache-slabs: @SLABS@ + + # The number of queries that every thread will service simultaneously. If + # more queries arrive that need servicing, and no queries can be jostled + # out (see jostle-timeout), then the queries are dropped. + # This is best set at half the number of the outgoing-range. + # This Unbound instance was compiled with libevent so it can efficiently + # use more than 1024 file descriptors. + num-queries-per-thread: 4096 + + # The number of threads to create to serve clients. + # This is set dynamically at run time to effectively use available CPUs + # resources + num-threads: @THREADS@ + + # Number of ports to open. This number of file descriptors can be opened + # per thread. + # This Unbound instance was compiled with libevent so it can efficiently + # use more than 1024 file descriptors. + outgoing-range: 8192 + + # Number of bytes size of the RRset cache. + # Use roughly twice as much rrset cache memory as msg cache memory + rrset-cache-size: @RR_CACHE_SIZE@ + + # Number of slabs in the RRset cache. Slabs reduce lock contention by + # threads. Must be set to a power of 2. + rrset-cache-slabs: @SLABS@ + + # Do no insert authority/additional sections into response messages when + # those sections are not required. This reduces response size + # significantly, and may avoid TCP fallback for some responses. This may + # cause a slight speedup. + minimal-responses: yes + + # # Fetch the DNSKEYs earlier in the validation process, when a DS record + # is encountered. This lowers the latency of requests at the expense of + # little more CPU usage. + prefetch: yes + + # Fetch the DNSKEYs earlier in the validation process, when a DS record is + # encountered. This lowers the latency of requests at the expense of little + # more CPU usage. + prefetch-key: yes + + # Have unbound attempt to serve old responses from cache with a TTL of 0 in + # the response without waiting for the actual resolution to finish. The + # actual resolution answer ends up in the cache later on. + serve-expired: yes + + # Open dedicated listening sockets for incoming queries for each thread and + # try to set the SO_REUSEPORT socket option on each socket. May distribute + # incoming queries to threads more evenly. + so-reuseport: yes + + ########################################################################### + # LOCAL ZONE + ########################################################################### + + # Include file for local-data and local-data-ptr + include: /opt/unbound/etc/unbound/a-records.conf + + ########################################################################### + # FORWARD ZONE + ########################################################################### + forward-zone: + # Forward to Stubby + name: "." + forward-addr: @STUBBY@ remote-control: control-enable: no