3 Configuration Reference
4 =======================
6 This page lists all configuration options for dnsdist.
10 When an IPv6 IP:PORT combination is needed, the bracketed syntax from :rfc:`RFC 3986 <3986#section-3.2.2>` should be used.
11 e.g. "[2001:DB8:14::C0FF:FEE]:5300".
16 Within dnsdist several core object types exist:
18 * :class:`Server`: generated with :func:`newServer`, represents a downstream server
19 * :class:`ComboAddress`: represents an IP address and port
20 * :class:`DNSName`: represents a domain name
21 * :class:`NetmaskGroup`: represents a group of netmasks
22 * :class:`QPSLimiter`: implements a QPS-based filter
23 * :class:`SuffixMatchNode`: represents a group of domain suffixes for rapid testing of membership
24 * :class:`DNSHeader`: represents the header of a DNS packet, see :ref:`DNSHeader`
25 * :class:`ClientState`: sometimes also called Bind or Frontend, represents the addresses and ports dnsdist is listening on
27 The existence of most of these objects can mostly be ignored, unless you plan to write your own hooks and policies, but it helps to understand an expressions like:
31 getServer(0).order=12 -- set order of server 0 to 12
32 getServer(0):addPool("abuse") -- add this server to the abuse pool
34 The ``.`` means ``order`` is a data member, while the ``:`` means ``addPool`` is a member function.
39 .. function:: includeDirectory(path)
41 Include configuration files from ``path``.
43 :param str path: The directory to load the configuration from
48 .. function:: addLocal(address[, options])
50 .. versionadded:: 1.2.0
52 .. versionchanged:: 1.3.0
53 Added ``cpus`` to the options.
55 Add to the list of listen addresses.
57 :param str address: The IP Address with an optional port to listen on.
58 The default port is 53.
59 :param table options: A table with key: value pairs with listen options.
63 * ``doTCP=true``: bool - Also bind on TCP on ``address``.
64 * ``reusePort=false``: bool - Set the ``SO_REUSEPORT`` socket option.
65 * ``tcpFastOpenSize=0``: int - Set the TCP Fast Open queue size, enabling TCP Fast Open when available and the value is larger than 0.
66 * ``interface=""``: str - Set the network interface to use.
67 * ``cpus={}``: table - Set the CPU affinity for this listener thread, asking the scheduler to run it on a single CPU id, or a set of CPU ids. This parameter is only available if the OS provides the pthread_setaffinity_np() function.
71 addLocal('0.0.0.0:5300', { doTCP=true, reusePort=true })
73 This will bind to both UDP and TCP on port 5300 with SO_REUSEPORT enabled.
75 .. function:: addLocal(address[[[,do_tcp], so_reuseport], tcp_fast_open_qsize])
79 Add to the list of addresses listened on.
81 :param str address: The IP Address with an optional port to listen on.
82 The default port is 53.
83 :param bool do_tcp: Also bind a TCP port on ``address``, defaults to true.
84 :param bool so_reuseport: Use ``SO_REUSEPORT`` if it is available, defaults to false
85 :param int tcp_fast_open_qsize: The size of the TCP Fast Open queue. Set to a number
86 higher than 0 to enable TCP Fast Open when available.
89 .. function:: addTLSLocal(address, certFile(s), keyFile(s) [, options])
91 .. versionadded:: 1.3.0
92 .. versionchanged:: 1.3.1
93 ``certFile(s)`` and ``keyFile(s)`` parameters accept a list of files.
94 ``sessionTickets`` option added.
95 .. versionchanged:: 1.3.3
96 ``numberOfStoredSessions`` option added.
98 Listen on the specified address and TCP port for incoming DNS over TLS connections, presenting the specified X.509 certificate.
100 :param str address: The IP Address with an optional port to listen on.
101 The default port is 853.
102 :param str certFile(s): The path to a X.509 certificate file in PEM format, or a list of paths to such files.
103 :param str keyFile(s): The path to the private key file corresponding to the certificate, or a list of paths to such files, whose order should match the certFile(s) ones.
104 :param table options: A table with key: value pairs with listen options.
108 * ``reusePort=false``: bool - Set the ``SO_REUSEPORT`` socket option.
109 * ``tcpFastOpenSize=0``: int - Set the TCP Fast Open queue size, enabling TCP Fast Open when available and the value is larger than 0.
110 * ``interface=""``: str - Set the network interface to use.
111 * ``cpus={}``: table - Set the CPU affinity for this listener thread, asking the scheduler to run it on a single CPU id, or a set of CPU ids. This parameter is only available if the OS provides the pthread_setaffinity_np() function.
112 * ``provider``: str - The TLS library to use between GnuTLS and OpenSSL, if they were available and enabled at compilation time.
113 * ``ciphers``: str - The TLS ciphers to use. The exact format depends on the provider used.
114 * ``numberOfTicketsKeys``: int - The maximum number of tickets keys to keep in memory at the same time, if the provider supports it (GnuTLS doesn't, OpenSSL does). Only one key is marked as active and used to encrypt new tickets while the remaining ones can still be used to decrypt existing tickets after a rotation. Default to 5.
115 * ``ticketKeyFile``: str - The path to a file from where TLS tickets keys should be loaded, to support RFC 5077. These keys should be rotated often and never written to persistent storage to preserve forward secrecy. The default is to generate a random key. The OpenSSL provider supports several tickets keys to be able to decrypt existing sessions after the rotation, while the GnuTLS provider only supports one key.
116 * ``ticketsKeysRotationDelay``: int - Set the delay before the TLS tickets key is rotated, in seconds. Default is 43200 (12h).
117 * ``sessionTickets``: bool - Whether session resumption via session tickets is enabled. Default is true, meaning tickets are enabled.
118 * ``numberOfStoredSessions``: int - The maximum number of sessions kept in memory at the same time. At this time this is only supported by the OpenSSL provider, as stored sessions are not supported with the GnuTLS one. Default is 20480. Setting this value to 0 disables stored session entirely.
120 .. function:: setLocal(address[, options])
122 .. versionadded:: 1.2.0
124 Remove the list of listen addresses and add a new one.
126 :param str address: The IP Address with an optional port to listen on.
127 The default port is 53.
128 :param table options: A table with key: value pairs with listen options.
130 The options that can be set are the same as :func:`addLocal`.
132 .. function:: setLocal(address[[[,do_tcp], so_reuseport], tcp_fast_open_qsize])
134 .. deprecated:: 1.2.0
136 Remove the list of listen addresses and add a new one.
138 :param str address: The IP Address with an optional port to listen on.
139 The default port is 53.
140 :param bool do_tcp: Also bind a TCP port on ``address``, defaults to true.
141 :param bool so_reuseport: Use ``SO_REUSEPORT`` if it is available, defaults to false
142 :param int tcp_fast_open_qsize: The size of the TCP Fast Open queue. Set to a number
143 higher than 0 to enable TCP Fast Open when available.
146 Control Socket, Console and Webserver
147 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
149 .. function:: addConsoleACL(netmask)
151 .. versionadded:: 1.3.0
153 Add a netmask to the existing console ACL, allowing remote clients to connect to the console. Please make sure that encryption
154 has been enabled with :func:`setKey` before doing so. The default is to only allow 127.0.0.1/8 and ::1/128.
156 :param str netmask: A CIDR netmask, e.g. ``"192.0.2.0/24"``. Without a subnetmask, only the specific address is allowed.
158 .. function:: controlSocket(address)
160 Bind to ``addr`` and listen for a connection for the console. Since 1.3.0 only connections from local users are allowed
161 by default, :func:`addConsoleACL` and :func:`setConsoleACL` can be used to enable remote connections. Please make sure
162 that encryption has been enabled with :func:`setKey` before doing so. Enabling encryption is also strongly advised for
163 local connections, since not enabling it allows any local user to connect to the console.
165 :param str address: An IP address with optional port. By default, the port is 5199.
167 .. function:: inClientStartup()
169 Returns true while the console client is parsing the configuration.
171 .. function:: makeKey()
173 Generate and print an encryption key.
175 .. function:: setConsoleConnectionsLogging(enabled)
177 .. versionadded:: 1.2.0
179 Whether to log the opening and closing of console connections.
181 :param bool enabled: Default to true.
183 .. function:: setKey(key)
185 Use ``key`` as shared secret between the client and the server
187 :param str key: An encoded key, as generated by :func:`makeKey`
189 .. function:: setConsoleACL(netmasks)
191 .. versionadded:: 1.3.0
193 Remove the existing console ACL and add the netmasks from the table, allowing remote clients to connect to the console. Please make sure that encryption
194 has been enabled with :func:`setKey` before doing so.
196 :param {str} netmasks: A table of CIDR netmask, e.g. ``{"192.0.2.0/24", "2001:DB8:14::/56"}``. Without a subnetmask, only the specific address is allowed.
198 .. function:: showConsoleACL()
200 Print a list of all netmasks allowed to connect to the console.
202 .. function:: testCrypto()
204 Test the crypto code, will report errors when something is not ok.
206 .. function:: setConsoleOutputMaxMsgSize(size)
208 .. versionadded:: 1.3.3
210 Set the maximum size in bytes of a single console message, default set to 10 MB.
212 :param int size: The new maximum size.
214 Webserver configuration
215 ~~~~~~~~~~~~~~~~~~~~~~~
217 .. function:: webserver(listen_address, password[, apikey[, custom_headers]])
219 Launch the :doc:`../guides/webserver` with statistics and the API.
221 :param str listen_address: The IP address and Port to listen on
222 :param str password: The password required to access the webserver
223 :param str apikey: The key required to access the API
224 :param {[str]=str,...} custom_headers: Allows setting custom headers and removing the defaults
226 .. function:: setAPIWritable(allow [,dir])
228 Allow modifications via the API.
229 Optionally saving these changes to disk.
230 Modifications done via the API will not be written to the configuration by default and will not persist after a reload
232 :param bool allow: Set to true to allow modification through the API
233 :param str dir: A valid directory where the configuration files will be written by the API.
235 .. function:: setWebserverConfig(options)
237 .. versionadded:: 1.3.3
239 Setup webserver configuration. See :func:`webserver`.
241 :param table options: A table with key: value pairs with webserver options.
245 * ``password=newPassword``: string - Changes the API password
246 * ``apikey=newKey``: string - Changes the API Key (set to an empty string do disable it)
247 * ``custom_headers={[str]=str,...}``: map of string - Allows setting custom headers and removing the defaults.
252 .. function:: addACL(netmask)
254 Add a netmask to the existing ACL controlling which clients can send UDP and TCP queries. See :ref:`ACL` for more information.
256 :param str netmask: A CIDR netmask, e.g. ``"192.0.2.0/24"``. Without a subnetmask, only the specific address is allowed.
258 .. function:: setACL(netmasks)
260 Remove the existing ACL and add the netmasks from the table of those allowed to send UDP and TCP queries. See :ref:`ACL` for more information.
262 :param {str} netmasks: A table of CIDR netmask, e.g. ``{"192.0.2.0/24", "2001:DB8:14::/56"}``. Without a subnetmask, only the specific address is allowed.
264 .. function:: showACL()
266 Print a list of all netmasks allowed to send queries over UDP and TCP. See :ref:`ACL` for more information.
271 .. function:: setECSSourcePrefixV4(prefix)
273 When ``useClientSubnet`` in :func:`newServer` is set and dnsdist adds an EDNS Client Subnet Client option to the query, truncate the requestors IPv4 address to ``prefix`` bits
275 :param int prefix: The prefix length
277 .. function:: setECSSourcePrefixV6(prefix)
279 When ``useClientSubnet`` in :func:`newServer` is set and dnsdist adds an EDNS Client Subnet Client option to the query, truncate the requestor's IPv6 address to bits
281 :param int prefix: The prefix length
286 .. function:: setRingBuffersLockRetries(num)
287 .. versionadded:: 1.3.0
289 Set the number of shards to attempt to lock without blocking before giving up and simply blocking while waiting for the next shard to be available
291 :param int num: The maximum number of attempts. Defaults to 5 if there are more than one shard, 0 otherwise.
293 .. function:: setRingBuffersSize(num [, numberOfShards])
294 .. versionchanged:: 1.3.0
295 ``numberOfShards`` optional parameter added.
297 Set the capacity of the ringbuffers used for live traffic inspection to ``num``, and the number of shards to ``numberOfShards`` if specified.
299 :param int num: The maximum amount of queries to keep in the ringbuffer. Defaults to 10000
300 :param int numberOfShards: the number of shards to use to limit lock contention. Defaults to 1
305 .. function:: newServer(server_string)
306 newServer(server_table)
308 .. versionchanged:: 1.3.0
309 - Added ``checkClass`` to server_table.
310 - Added ``sockets`` to server_table
311 - Added ``checkFunction`` to server_table
313 .. versionchanged:: 1.3.4
314 - Added ``checkTimeout`` to server_table
315 - Added ``rise`` to server_table.
317 Add a new backend server. Call this function with either a string::
320 "IP:PORT" -- IP and PORT of the backend server
326 address="IP:PORT", -- IP and PORT of the backend server (mandatory)
327 id=STRING, -- Use a pre-defined UUID instead of a random one
328 qps=NUM, -- Limit the number of queries per second to NUM, when using the `firstAvailable` policy
329 order=NUM, -- The order of this server, used by the `leastOustanding` and `firstAvailable` policies
330 weight=NUM, -- The weight of this server, used by the `wrandom`, `whashed` and `chashed` policies, default: 1
331 -- Supported values are a minimum of 1, and a maximum of 2147483647.
332 pool=STRING|{STRING}, -- The pools this server belongs to (unset or empty string means default pool) as a string or table of strings
333 retries=NUM, -- The number of TCP connection attempts to the backend, for a given query
334 tcpConnectTimeout=NUM, -- The timeout (in seconds) of a TCP connection attempt
335 tcpSendTimeout=NUM, -- The timeout (in seconds) of a TCP write attempt
336 tcpRecvTimeout=NUM, -- The timeout (in seconds) of a TCP read attempt
337 tcpFastOpen=BOOL, -- Whether to enable TCP Fast Open
338 ipBindAddrNoPort=BOOL, -- Whether to enable IP_BIND_ADDRESS_NO_PORT if available, default: true
339 name=STRING, -- The name associated to this backend, for display purpose
340 checkClass=NUM, -- Use NUM as QCLASS in the health-check query, default: DNSClass.IN
341 checkName=STRING, -- Use STRING as QNAME in the health-check query, default: "a.root-servers.net."
342 checkType=STRING, -- Use STRING as QTYPE in the health-check query, default: "A"
343 checkFunction=FUNCTION,-- Use this function to dynamically set the QNAME, QTYPE and QCLASS to use in the health-check query (see :ref:`Healthcheck`)
344 checkTimeout=NUM, -- The timeout (in milliseconds) of a health-check query, default: 1000 (1s)
345 setCD=BOOL, -- Set the CD (Checking Disabled) flag in the health-check query, default: false
346 maxCheckFailures=NUM, -- Allow NUM check failures before declaring the backend down, default: 1
347 mustResolve=BOOL, -- Set to true when the health check MUST return a NOERROR RCODE and an answer
348 useClientSubnet=BOOL, -- Add the client's IP address in the EDNS Client Subnet option when forwarding the query to this backend
349 source=STRING, -- The source address or interface to use for queries to this backend, by default this is left to the kernel's address selection
350 -- The following formats are supported:
351 -- "address", e.g. "192.0.2.2"
352 -- "interface name", e.g. "eth0"
353 -- "address@interface", e.g. "192.0.2.2@eth0"
354 addXPF=NUM, -- Add the client's IP address and port to the query, along with the original destination address and port,
355 -- using the experimental XPF record from `draft-bellis-dnsop-xpf <https://datatracker.ietf.org/doc/draft-bellis-dnsop-xpf/>`_ and the specified option code. Default is disabled (0)
356 sockets=NUM, -- Number of sockets (and thus source ports) used toward the backend server, defaults to a single one
357 disableZeroScope=BOOL, -- Disable the EDNS Client Subnet 'zero scope' feature, which does a cache lookup for an answer valid for all subnets (ECS scope of 0) before adding ECS information to the query and doing the regular lookup
358 rise=NUM -- Require NUM consecutive successful checks before declaring the backend up, default: 1
361 :param str server_string: A simple IP:PORT string.
362 :param table server_table: A table with at least a 'name' key
364 .. function:: getServer(index) -> Server
366 Get a :class:`Server`
368 :param int index: The number of the server (as seen in :func:`showServers`).
369 :returns: The :class:`Server` object or nil
371 .. function:: getServers()
373 Returns a table with all defined servers.
375 .. function:: rmServer(index)
378 Remove a backend server.
380 :param int index: The number of the server (as seen in :func:`showServers`).
381 :param Server server: A :class:`Server` object as returned by e.g. :func:`getServer`.
385 A server object returned by :func:`getServer` can be manipulated with these functions.
389 This object represents a backend server. It has several methods.
391 .. method:: Server:addPool(pool)
393 Add this server to a pool.
395 :param str pool: The pool to add the server to
397 .. method:: Server:getName() -> string
399 Get the name of this server.
401 :returns: The name of the server, or an empty string if it does not have one
403 .. method:: Server:getNameWithAddr() -> string
405 Get the name plus IP address and port of the server
407 :returns: A string containing the server name if any plus the server address and port
409 .. method:: Server:getOutstanding() -> int
411 Get the number of outstanding queries for this server.
413 :returns: The number of outstanding queries
415 .. method:: Server:isUp() -> bool
417 Returns the up status of the server
419 :returns: true when the server is up, false otherwise
421 .. method:: Server:rmPool(pool)
423 Removes the server from the named pool
425 :param str pool: The pool to remove the server from
427 .. method:: Server:setAuto([status])
429 .. versionchanged:: 1.3.0
430 ``status`` optional parameter added.
432 Set the server in the default auto state.
433 This will enable health check queries that will set the server ``up`` and ``down`` appropriately.
435 :param bool status: Set the initial status of the server to ``up`` (true) or ``down`` (false) instead of using the last known status
437 .. method:: Server:setQPS(limit)
439 Limit the queries per second for this server.
441 :param int limit: The maximum number of queries per second
443 .. method:: Server:setDown()
445 Set the server in an ``DOWN`` state.
446 The server will not receive queries and the health checks are disabled
448 .. method:: Server:setUp()
450 Set the server in an ``UP`` state.
451 This server will still receive queries and health checks are disabled
453 Apart from the functions, a :class:`Server` object has these attributes:
455 .. attribute:: Server.name
457 The name of the server
459 .. attribute:: Server.upStatus
461 Whether or not this server is up or down
463 .. attribute:: Server.order
465 The order of the server
467 .. attribute:: Server.weight
469 The weight of the server
474 :class:`Server`\ s can be part of any number of pools.
475 Pools are automatically created when a server is added to a pool (with :func:`newServer`), or can be manually created with :func:`addPool`.
477 .. function:: addPool(name) -> ServerPool
479 Returns a :class:`ServerPool`.
481 :param string name: The name of the pool to create
483 .. function:: getPool(name) -> ServerPool
485 Returns a :class:`ServerPool` or nil.
487 :param string name: The name of the pool
489 .. function:: getPoolServers(name) -> [ Server ]
491 Returns a list of :class:`Server`\ s or nil.
493 :param string name: The name of the pool
495 .. function:: showPools()
497 Display the name, associated cache, server policy and associated servers for every pool.
499 .. class:: ServerPool
501 This represents the pool where zero or more servers are part of.
503 .. method:: ServerPool:getCache() -> PacketCache
505 Returns the :class:`PacketCache` for this pool or nil.
507 .. method:: ServerPool:getECS()
509 .. versionadded:: 1.3.0
511 Whether dnsdist will add EDNS Client Subnet information to the query before looking up into the cache,
512 when all servers from this pool are down. For more information see :meth:`ServerPool:setECS`.
514 .. method:: ServerPool:setCache(cache)
516 Adds ``cache`` as the pool's cache.
518 :param PacketCache cache: The new cache to add to the pool
520 .. method:: ServerPool:unsetCache()
522 Removes the cache from this pool.
524 .. method:: ServerPool:setECS()
526 .. versionadded:: 1.3.0
528 Set to true if dnsdist should add EDNS Client Subnet information to the query before looking up into the cache,
529 when all servers from this pool are down. If at least one server is up, the preference of the
530 selected server is used, this parameter is only useful if all the backends in this pool are down
531 and have EDNS Client Subnet enabled, since the queries in the cache will have been inserted with
532 ECS information. Default is false.
537 A Pool can have a packet cache to answer queries directly in stead of going to the backend.
538 See :doc:`../guides/cache` for a how to.
540 .. function:: newPacketCache(maxEntries[, maxTTL=86400[, minTTL=0[, temporaryFailureTTL=60[, staleTTL=60[, dontAge=false[, numberOfShards=1[, deferrableInsertLock=true[, maxNegativeTTL=3600[, parseECS=false [,options]]]]]]]]) -> PacketCache
542 .. versionchanged:: 1.3.0
543 ``numberOfShards`` and ``deferrableInsertLock`` parameters added.
545 .. versionchanged:: 1.3.1
546 ``maxNegativeTTL`` and ``parseECS`` parameters added.
548 .. versionchanged:: 1.3.4
549 ``options`` parameter added.
551 Creates a new :class:`PacketCache` with the settings specified.
552 Starting with 1.3.4, all parameters can be specified in the ``options`` table, overriding the value from the existing parameters if any.
554 :param int maxEntries: The maximum number of entries in this cache
555 :param int maxTTL: Cap the TTL for records to his number
556 :param int minTTL: Don't cache entries with a TTL lower than this
557 :param int temporaryFailureTTL: On a SERVFAIL or REFUSED from the backend, cache for this amount of seconds
558 :param int staleTTL: When the backend servers are not reachable, and global configuration ``setStaleCacheEntriesTTL`` is set appropriately, TTL that will be used when a stale cache entry is returned
559 :param bool dontAge: Don't reduce TTLs when serving from the cache. Use this when :program:`dnsdist` fronts a cluster of authoritative servers
560 :param int numberOfShards: Number of shards to divide the cache into, to reduce lock contention
561 :param bool deferrableInsertLock: Whether the cache should give up insertion if the lock is held by another thread, or simply wait to get the lock
562 :param int maxNegativeTTL: Cache a NXDomain or NoData answer from the backend for at most this amount of seconds, even if the TTL of the SOA record is higher
563 :param bool parseECS: Whether any EDNS Client Subnet option present in the query should be extracted and stored to be able to detect hash collisions involving queries with the same qname, qtype and qclass but a different incoming ECS value. Enabling this option adds a parsing cost and only makes sense if at least one backend might send different responses based on the ECS value, so it's disabled by default
564 :param table options: A table with key: value pairs with the options listed below:
568 * ``deferrableInsertLock=true``: bool - Whether the cache should give up insertion if the lock is held by another thread, or simply wait to get the lock.
569 * ``dontAge=false``: bool - Don't reduce TTLs when serving from the cache. Use this when :program:`dnsdist` fronts a cluster of authoritative servers.
570 * ``keepStaleData=false``: bool - Whether to suspend the removal of expired entries from the cache when there is no backend available in at least one of the pools using this cache.
571 * ``maxEntries``: int - The maximum number of entries in this cache.
572 * ``maxNegativeTTL=3600``: int - Cache a NXDomain or NoData answer from the backend for at most this amount of seconds, even if the TTL of the SOA record is higher.
573 * ``maxTTL=86400``: int - Cap the TTL for records to his number.
574 * ``minTTL=0``: int - Don't cache entries with a TTL lower than this.
575 * ``numberOfShards=1``: int - Number of shards to divide the cache into, to reduce lock contention.
576 * ``parseECS=false``: bool - Whether any EDNS Client Subnet option present in the query should be extracted and stored to be able to detect hash collisions involving queries with the same qname, qtype and qclass but a different incoming ECS value. Enabling this option adds a parsing cost and only makes sense if at least one backend might send different responses based on the ECS value, so it's disabled by default.
577 * ``staleTTL=60``: int - When the backend servers are not reachable, and global configuration ``setStaleCacheEntriesTTL`` is set appropriately, TTL that will be used when a stale cache entry is returned.
578 * ``temporaryFailureTTL=60``: int - On a SERVFAIL or REFUSED from the backend, cache for this amount of seconds..
580 .. class:: PacketCache
582 Represents a cache that can be part of :class:`ServerPool`.
584 .. method:: PacketCache:dump(fname)
586 .. versionadded:: 1.3.1
588 Dump a summary of the cache entries to a file.
590 :param str fname: The path to a file where the cache summary should be dumped. Note that if the target file already exists, it will not be overwritten.
592 .. method:: PacketCache:expunge(n)
594 Remove entries from the cache, leaving at most ``n`` entries
596 :param int n: Number of entries to keep
598 .. method:: PacketCache:expungeByName(name [, qtype=dnsdist.ANY[, suffixMatch=false]])
600 .. versionchanged:: 1.2.0
601 ``suffixMatch`` parameter added.
603 Remove entries matching ``name`` and type from the cache.
605 :param DNSName name: The name to expunge
606 :param int qtype: The type to expunge
607 :param bool suffixMatch: When set to true, remove al entries under ``name``
609 .. method:: PacketCache:getStats()
611 .. versionadded:: 1.3.4
613 Return the cache stats (number of entries, hits, misses, deferred lookups, deferred inserts, lookup collisions, insert collisons and TTL too shorts) as a Lua table.
615 .. method:: PacketCache:isFull() -> bool
617 Return true if the cache has reached the maximum number of entries.
619 .. method:: PacketCache:printStats()
621 Print the cache stats (number of entries, hits, misses, deferred lookups, deferred inserts, lookup collisions, insert collisons and TTL too shorts).
623 .. method:: PacketCache:purgeExpired(n)
625 Remove expired entries from the cache until there is at most ``n`` entries remaining in the cache.
627 :param int n: Number of entries to keep
629 .. method:: PacketCache:toString() -> string
631 Return the number of entries in the Packet Cache, and the maximum number of entries
636 Also called frontend or bind, the Client State object returned by :func:`getBind` and listed with :func:`showBinds` represents an address and port dnsdist is listening on.
638 .. function:: getBind(index) -> ClientState
640 Return a :class:`ClientState` object.
642 :param int index: The object index
644 ClientState functions
645 ~~~~~~~~~~~~~~~~~~~~~
647 .. class:: ClientState
649 This object represents an address and port dnsdist is listening on. When ``reuseport`` is in use, several ClientState objects can be present for the same address and port.
651 .. method:: ClientState:attachFilter(filter)
653 Attach a BPF filter to this frontend.
655 :param BPFFilter filter: The filter to attach to this frontend
657 .. method:: ClientState:detachFilter()
659 Remove the BPF filter associated to this frontend, if any.
661 .. method:: ClientState:toString() -> string
663 Return the address and port this frontend is listening on.
665 :returns: The address and port this frontend is listening on
667 .. attribute:: ClientState.muted
669 If set to true, queries received on this frontend will be normally processed and sent to a backend if needed, but no response will be ever be sent to the client over UDP. TCP queries are processed normally and responses sent to the client.
671 Status, Statistics and More
672 ---------------------------
674 .. function:: dumpStats()
676 Print all statistics dnsdist gathers
678 .. function:: getTLSContext(idx)
680 .. versionadded:: 1.3.0
682 Return the TLSContext object for the context of index ``idx``.
684 .. function:: getTLSFrontend(idx)
686 .. versionadded:: 1.3.1
688 Return the TLSFrontend object for the TLS bind of index ``idx``.
690 .. function:: grepq(selector[, num])
691 grepq(selectors[, num])
693 Prints the last ``num`` queries matching ``selector`` or ``selectors``.
697 * a netmask (e.g. '192.0.2.0/24')
698 * a DNS name (e.g. 'dnsdist.org')
699 * a response time (e.g. '100ms')
701 :param str selector: Select queries based on this property.
702 :param {str} selectors: A lua table of selectors. Only queries matching all selectors are shown
703 :param int num: Show a maximum of ``num`` recent queries, default is 10.
705 .. function:: setVerboseHealthChecks(verbose)
707 Set whether health check errors should be logged. This is turned off by default.
709 :param bool verbose: Set to true if you want to enable health check errors logging
711 .. function:: showBinds()
713 Print a list of all the current addresses and ports dnsdist is listening on, also called ``frontends``
715 .. function:: showResponseLatency()
717 Show a plot of the response time latency distribution
719 .. function:: showServers([options])
721 .. versionchanged:: 1.3.4
722 ``options`` optional parameter added
724 This function shows all backend servers currently configured and some statistics.
725 These statics have the following fields:
727 * ``#`` - The number of the server, can be used as the argument for :func:`getServer`
728 * ``UUID`` - The UUID of the backend. Can be set with the ``id`` option of :func:`newServer`
729 * ``Address`` - The IP address and port of the server
730 * ``State`` - The current state of the server
731 * ``Qps`` - Current number of queries per second
732 * ``Qlim`` - Configured maximum number of queries per second
733 * ``Ord`` - The order number of the server
734 * ``Wt`` - The weight of the server
735 * ``Queries`` - Total amount of queries sent to this server
736 * ``Drops`` - Number of queries that were dropped by this server
737 * ``Drate`` - Number of queries dropped per second by this server
738 * ``Lat`` - The latency of this server in milliseconds
739 * ``Pools`` - The pools this server belongs to
741 :param table options: A table with key: value pairs with display options.
745 * ``showUUIDs=false``: bool - Whether to display the UUIDs, defaults to false.
747 .. function:: showTCPStats()
749 Show some statistics regarding TCP
751 .. function:: showTLSContexts()
753 .. versionadded:: 1.3.0
755 Print the list of all availables DNS over TLS contexts.
757 .. function:: showVersion()
759 Print the version of dnsdist
761 .. function:: topBandwidth([num])
763 Print the top ``num`` clients that consume the most bandwidth.
765 :param int num: Number to show, defaults to 10.
767 .. function:: topClients([num])
769 Print the top ``num`` clients sending the most queries over length of ringbuffer
771 :param int num: Number to show, defaults to 10.
773 .. function:: topQueries([num[, labels]])
775 Print the ``num`` most popular QNAMEs from queries.
776 Optionally grouped by the rightmost ``labels`` DNS labels.
778 :param int num: Number to show, defaults to 10
779 :param int label: Number of labels to cut down to
781 .. function:: topResponses([num[, rcode[, labels]]])
783 Print the ``num`` most seen responses with an RCODE of ``rcode``.
784 Optionally grouped by the rightmost ``labels`` DNS labels.
786 :param int num: Number to show, defaults to 10
787 :param int rcode: :ref:`Response code <DNSRCode>`, defaults to 0 (No Error)
788 :param int label: Number of labels to cut down to
790 .. function:: topSlow([num[, limit[, labels]]])
792 Print the ``num`` slowest queries that are slower than ``limit`` milliseconds.
793 Optionally grouped by the rightmost ``labels`` DNS labels.
795 :param int num: Number to show, defaults to 10
796 :param int limit: Show queries slower than this amount of milliseconds, defaults to 2000
797 :param int label: Number of labels to cut down to
804 .. function:: addDynBlocks(addresses, message[, seconds=10[, action]])
806 .. versionchanged:: 1.2.0
807 ``action`` parameter added.
809 Block a set of addresses with ``message`` for (optionally) a number of seconds.
810 The default number of seconds to block for is 10.
812 :param addresses: set of Addresses as returned by an exceed function
813 :param string message: The message to show next to the blocks
814 :param int seconds: The number of seconds this block to expire
815 :param int action: The action to take when the dynamic block matches, see :ref:`here <DNSAction>`. (default to DNSAction.None, meaning the one set with :func:`setDynBlocksAction` is used)
817 Please see the documentation for :func:`setDynBlocksAction` to confirm which actions are supported by the action paramater.
819 .. function:: clearDynBlocks()
821 Remove all current dynamic blocks.
823 .. function:: showDynBlocks()
825 List all dynamic blocks in effect.
827 .. function:: setDynBlocksAction(action)
829 .. versionchanged:: 1.3.3
830 ``DNSAction.NXDomain`` action added.
832 Set which action is performed when a query is blocked.
833 Only DNSAction.Drop (the default), DNSAction.NoOp, DNSAction.NXDomain, DNSAction.Refused, DNSAction.Truncate and DNSAction.NoRecurse are supported.
837 Getting addresses that exceeded parameters
838 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
840 .. function:: exceedServFails(rate, seconds)
842 Get set of addresses that exceed ``rate`` servfails/s over ``seconds`` seconds
844 :param int rate: Number of Servfails per second to exceed
845 :param int seconds: Number of seconds the rate has been exceeded
847 .. function:: exceedNXDOMAINs(rate, seconds)
849 get set of addresses that exceed ``rate`` NXDOMAIN/s over ``seconds`` seconds
851 :param int rate: Number of NXDOMAIN per second to exceed
852 :param int seconds: Number of seconds the rate has been exceeded
854 .. function:: exceedRespByterate(rate, seconds)
856 get set of addresses that exceeded ``rate`` bytes/s answers over ``seconds`` seconds
858 :param int rate: Number of bytes per second to exceed
859 :param int seconds: Number of seconds the rate has been exceeded
861 .. function:: exceedQRate(rate, seconds)
863 Get set of address that exceed ``rate`` queries/s over ``seconds`` seconds
865 :param int rate: Number of queries per second to exceed
866 :param int seconds: Number of seconds the rate has been exceeded
868 .. function:: exceedQTypeRate(type, rate, seconds)
870 Get set of address that exceed ``rate`` queries/s for queries of QType ``type`` over ``seconds`` seconds
872 :param int type: QType
873 :param int rate: Number of QType queries per second to exceed
874 :param int seconds: Number of seconds the rate has been exceeded
879 Instead of using several `exceed*()` lines, dnsdist 1.3.0 introduced a new `DynBlockRulesGroup` object
880 which can be used to group dynamic block rules.
882 See :doc:`../guides/dynblocks` for more information about the case where using a `DynBlockRulesGroup` might be
883 faster than the existing rules.
885 .. function:: dynBlockRulesGroup() -> DynBlockRulesGroup
887 .. versionadded:: 1.3.0
889 Creates a new :class:`DynBlockRulesGroup` object.
891 .. class:: DynBlockRulesGroup
893 Represents a group of dynamic block rules.
895 .. method:: DynBlockRulesGroup:setQueryRate(rate, seconds, reason, blockingTime [, action [, warningRate]])
897 .. versionchanged:: 1.3.3
898 ``warningRate`` parameter added.
900 Adds a query rate-limiting rule, equivalent to:
902 addDynBlocks(exceedQRate(rate, seconds), reason, blockingTime, action)
905 :param int rate: Number of queries per second to exceed
906 :param int seconds: Number of seconds the rate has been exceeded
907 :param string reason: The message to show next to the blocks
908 :param int blockingTime: The number of seconds this block to expire
909 :param int action: The action to take when the dynamic block matches, see :ref:`here <DNSAction>`. (default to the one set with :func:`setDynBlocksAction`)
910 :param int warningRate: If set to a non-zero value, the rate above which a warning message will be issued and a no-op block inserted
912 .. method:: DynBlockRulesGroup:setRCodeRate(rcode, rate, seconds, reason, blockingTime [, action [, warningRate]])
914 .. versionchanged:: 1.3.3
915 ``warningRate`` parameter added.
917 Adds a rate-limiting rule for responses of code ``rcode``, equivalent to:
919 addDynBlocks(exceedServfails(rcode, rate, seconds), reason, blockingTime, action)
922 :param int rcode: The response code
923 :param int rate: Number of responses per second to exceed
924 :param int seconds: Number of seconds the rate has been exceeded
925 :param string reason: The message to show next to the blocks
926 :param int blockingTime: The number of seconds this block to expire
927 :param int action: The action to take when the dynamic block matches, see :ref:`here <DNSAction>`. (default to the one set with :func:`setDynBlocksAction`)
928 :param int warningRate: If set to a non-zero value, the rate above which a warning message will be issued and a no-op block inserted
930 .. method:: DynBlockRulesGroup:setQTypeRate(qtype, rate, seconds, reason, blockingTime [, action [, warningRate]])
932 .. versionchanged:: 1.3.3
933 ``warningRate`` parameter added.
935 Adds a rate-limiting rule for queries of type ``qtype``, equivalent to:
937 addDynBlocks(exceedQTypeRate(type, rate, seconds), reason, blockingTime, action)
940 :param int qtype: The qtype
941 :param int rate: Number of queries per second to exceed
942 :param int seconds: Number of seconds the rate has been exceeded
943 :param string reason: The message to show next to the blocks
944 :param int blockingTime: The number of seconds this block to expire
945 :param int action: The action to take when the dynamic block matches, see :ref:`here <DNSAction>`. (default to the one set with :func:`setDynBlocksAction`)
946 :param int warningRate: If set to a non-zero value, the rate above which a warning message will be issued and a no-op block inserted
948 .. method:: DynBlockRulesGroup:setResponseByteRate(rate, seconds, reason, blockingTime [, action [, warningRate]])
950 .. versionchanged:: 1.3.3
951 ``warningRate`` parameter added.
953 Adds a bandwidth rate-limiting rule for responses, equivalent to:
955 addDynBlocks(exceedRespByterate(rate, seconds), reason, blockingTime, action)
958 :param int rate: Number of bytes per second to exceed
959 :param int seconds: Number of seconds the rate has been exceeded
960 :param string reason: The message to show next to the blocks
961 :param int blockingTime: The number of seconds this block to expire
962 :param int action: The action to take when the dynamic block matches, see :ref:`here <DNSAction>`. (default to the one set with :func:`setDynBlocksAction`)
963 :param int warningRate: If set to a non-zero value, the rate above which a warning message will be issued and a no-op block inserted
965 .. method:: DynBlockRulesGroup:apply()
967 Walk the in-memory query and response ring buffers and apply the configured rate-limiting rules, adding dynamic blocks when the limits have been exceeded.
969 .. method:: DynBlockRulesGroup:excludeRange(netmasks)
971 .. versionadded:: 1.3.1
973 Exclude this range, or list of ranges, meaning that no dynamic block will ever be inserted for clients in that range. Default to empty, meaning rules are applied to all ranges. When used in combination with :meth:`DynBlockRulesGroup:includeRange`, the more specific entry wins.
975 :param int netmasks: A netmask, or list of netmasks, as strings, like for example "192.0.2.1/24"
977 .. method:: DynBlockRulesGroup:includeRange(netmasks)
979 .. versionadded:: 1.3.1
981 Include this range, or list of ranges, meaning that rules will be applied to this range. When used in combination with :meth:`DynBlockRulesGroup:excludeRange`, the more specific entry wins.
983 :param int netmasks: A netmask, or list of netmasks, as strings, like for example "192.0.2.1/24"
985 .. method:: DynBlockRulesGroup:toString()
987 .. versionadded:: 1.3.1
989 Return a string describing the rules and range exclusions of this DynBlockRulesGroup.
994 .. function:: maintenance()
996 If this function exists, it is called every second to so regular tasks.
997 This can be used for e.g. :doc:`Dynamic Blocks <../guides/dynblocks>`.
1002 .. class:: TLSContext
1004 .. versionadded:: 1.3.0
1006 This object represents an address and port dnsdist is listening on for DNS over TLS queries.
1008 .. method:: TLSContext:rotateTicketsKey()
1010 Replace the current TLS tickets key by a new random one.
1012 .. method:: TLSContext:loadTicketsKeys(ticketsKeysFile)
1014 Load new tickets keys from the selected file, replacing the existing ones. These keys should be rotated often and never written to persistent storage to preserve forward secrecy. The default is to generate a random key. The OpenSSL provider supports several tickets keys to be able to decrypt existing sessions after the rotation, while the GnuTLS provider only supports one key.
1016 :param str ticketsKeysFile: The path to a file from where TLS tickets keys should be loaded.
1021 .. class:: TLSFrontend
1023 .. versionadded:: 1.3.1
1025 This object represents the configuration of a listening frontend for DNS over TLS queries. To each frontend is associated a TLSContext.
1027 .. method:: TLSContext:loadNewCertificatesAndKeys(certFile(s), keyFile(s))
1029 Create and switch to a new TLS context using the same options than were passed to the corresponding `addTLSLocal()` directive, but loading new certificates and keys from the selected files, replacing the existing ones.
1031 :param str certFile(s): The path to a X.509 certificate file in PEM format, or a list of paths to such files.
1032 :param str keyFile(s): The path to the private key file corresponding to the certificate, or a list of paths to such files, whose order should match the certFile(s) ones.
1034 EDNS on Self-generated answers
1035 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1037 There are several mechanisms in dnsdist that turn an existing query into an answer right away,
1038 without reaching out to the backend, including :func:`SpoofAction`, :func:`RCodeAction`, :func:`TCAction`
1039 and returning a response from ``Lua``. Those responses should, according to :rfc:`6891`, contain an ``OPT``
1040 record if the received request had one, which is the case by default and can be disabled using
1041 :func:`setAddEDNSToSelfGeneratedResponses`.
1043 We must, however, provide a responder's maximum payload size in this record, and we can't easily know the
1044 maximum payload size of the actual backend so we need to provide one. The default value is 1500 and can be
1045 overriden using :func:`setPayloadSizeOnSelfGeneratedAnswers`.
1047 .. function:: setAddEDNSToSelfGeneratedResponses(add)
1049 .. versionadded:: 1.3.3
1051 Whether to add EDNS to self-generated responses, provided that the initial query had EDNS.
1053 :param bool add: Whether to add EDNS, default is true.
1055 .. function:: setPayloadSizeOnSelfGeneratedAnswers(payloadSize)
1057 .. versionadded:: 1.3.3
1059 Set the UDP payload size advertised via EDNS on self-generated responses. In accordance with
1060 :rfc:`RFC 6891 <6891#section-6.2.5>`, values lower than 512 will be treated as equal to 512.
1062 :param int payloadSize: The responder's maximum UDP payload size, in bytes. Default is 1500.
1067 PowerDNS products can poll the security status of their respective versions. This polling, naturally,
1068 happens over DNS. If the result is that a given version has a security problem, the software will
1069 report this at level ‘Error’ during startup, and repeatedly during operations, every
1070 :func:`setSecurityPollInterval` seconds.
1072 By default, security polling happens on the domain ‘secpoll.powerdns.com’, but this can be changed with
1073 the :func:`setSecurityPollSuffix` function. If this setting is made empty, no polling will take place.
1074 Organizations wanting to host their own security zones can do so by changing this setting to a domain name
1075 under their control.
1077 To enable distributors of PowerDNS to signal that they have backported versions, the PACKAGEVERSION
1078 compilation-time macro can be used to set a distributor suffix.
1080 .. function:: setSecurityPollInterval(interval)
1082 .. versionadded:: 1.3.3
1084 Set the interval, in seconds, between two security pollings.
1086 :param int interval: The interval, in seconds, between two pollings. Default is 3600.
1088 .. function:: setSecurityPollSuffix(suffix)
1090 .. versionadded:: 1.3.3
1092 Domain name from which to query security update notifications. Setting this to an empty string disables secpoll.
1094 :param string suffix: The suffix to use, default is 'secpoll.powerdns.com.'.