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 configuration files from. Each file must end in ``.conf``.
45 .. function:: reloadAllCertificates()
47 .. versionadded:: 1.4.0
49 Reload all DNSCrypt and TLS certificates, along with their associated keys.
51 .. function:: setSyslogFacility(facility)
53 .. versionadded:: 1.4.0
55 Set the syslog logging facility to ``facility``.
57 :param int facility: The new facility as a numeric value. Defaults to LOG_DAEMON.
62 .. function:: addLocal(address[, options])
64 .. versionadded:: 1.2.0
66 .. versionchanged:: 1.3.0
67 Added ``cpus`` to the options.
69 .. versionchanged:: 1.4.0
70 Removed ``doTCP`` from the options. A listen socket on TCP is always created.
72 Add to the list of listen addresses.
74 :param str address: The IP Address with an optional port to listen on.
75 The default port is 53.
76 :param table options: A table with key: value pairs with listen options.
80 * ``doTCP=true``: bool - Also bind on TCP on ``address``. Removed in 1.4.0.
81 * ``reusePort=false``: bool - Set the ``SO_REUSEPORT`` socket option.
82 * ``tcpFastOpenQueueSize=0``: int - Set the TCP Fast Open queue size, enabling TCP Fast Open when available and the value is larger than 0.
83 * ``interface=""``: str - Set the network interface to use.
84 * ``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.
88 addLocal('0.0.0.0:5300', { reusePort=true })
90 This will bind to both UDP and TCP on port 5300 with SO_REUSEPORT enabled.
92 .. function:: addLocal(address[[[,do_tcp], so_reuseport], tcp_fast_open_qsize])
96 Add to the list of addresses listened on.
98 :param str address: The IP Address with an optional port to listen on.
99 The default port is 53.
100 :param bool do_tcp: Also bind a TCP port on ``address``, defaults to true.
101 :param bool so_reuseport: Use ``SO_REUSEPORT`` if it is available, defaults to false
102 :param int tcp_fast_open_qsize: The size of the TCP Fast Open queue. Set to a number
103 higher than 0 to enable TCP Fast Open when available.
106 .. function:: addDOHLocal(address, [certFile(s) [, keyFile(s) [, urls [, options]]]])
108 .. versionadded:: 1.4.0
110 Listen on the specified address and TCP port for incoming DNS over HTTPS connections, presenting the specified X.509 certificate.
111 If no certificate (or key) files are specified, listen for incoming DNS over HTTP connections instead.
113 :param str address: The IP Address with an optional port to listen on.
114 The default port is 443.
115 :param str certFile(s): The path to a X.509 certificate file in PEM format, or a list of paths to such files.
116 :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.
117 :param str-or-list urls: A base URL, or a list of base URLs, to accept queries on. Any query with a path under one of these will be treated as a DoH query. The default is /.
118 :param table options: A table with key: value pairs with listen options.
122 * ``reusePort=false``: bool - Set the ``SO_REUSEPORT`` socket option.
123 * ``tcpFastOpenQueueSize=0``: int - Set the TCP Fast Open queue size, enabling TCP Fast Open when available and the value is larger than 0.
124 * ``interface=""``: str - Set the network interface to use.
125 * ``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.
126 * ``idleTimeout=30``: int - Set the idle timeout, in seconds.
127 * ``ciphers``: str - The TLS ciphers to use, in OpenSSL format. Ciphers for TLS 1.3 must be specified via ``ciphersTLS13``.
128 * ``ciphersTLS13``: str - The TLS ciphers to use for TLS 1.3, in OpenSSL format.
129 * ``serverTokens``: str - The content of the Server: HTTP header returned by dnsdist. The default is "h2o/dnsdist".
130 * ``customResponseHeaders={}``: table - Set custom HTTP header(s) returned by dnsdist.
131 * ``ocspResponses``: list - List of files containing OCSP responses, in the same order than the certificates and keys, that will be used to provide OCSP stapling responses.
132 * ``minTLSVersion``: str - Minimum version of the TLS protocol to support. Possible values are 'tls1.0', 'tls1.1', 'tls1.2' and 'tls1.3'. Default is to require at least TLS 1.0.
133 * ``numberOfTicketsKeys``: int - The maximum number of tickets keys to keep in memory at the same time. 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.
134 * ``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. dnsdist supports several tickets keys to be able to decrypt existing sessions after the rotation.
135 * ``ticketsKeysRotationDelay``: int - Set the delay before the TLS tickets key is rotated, in seconds. Default is 43200 (12h).
136 * ``sessionTickets``: bool - Whether session resumption via session tickets is enabled. Default is true, meaning tickets are enabled.
137 * ``numberOfStoredSessions``: int - The maximum number of sessions kept in memory at the same time. Default is 20480. Setting this value to 0 disables stored session entirely.
138 * ``preferServerCiphers``: bool - Whether to prefer the order of ciphers set by the server instead of the one set by the client. Default is false, meaning that the order of the client is used.
139 * ``keyLogFile``: str - Write the TLS keys in the specified file so that an external program can decrypt TLS exchanges, in the format described in https://developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS/Key_Log_Format.
141 .. function:: addTLSLocal(address, certFile(s), keyFile(s) [, options])
143 .. versionadded:: 1.3.0
144 .. versionchanged:: 1.3.1
145 ``certFile(s)`` and ``keyFile(s)`` parameters accept a list of files.
146 ``sessionTickets`` option added.
147 .. versionchanged:: 1.3.3
148 ``numberOfStoredSessions`` option added.
149 .. versionchanged:: 1.4.0
150 ``ciphersTLS13``, ``minTLSVersion``, ``ocspResponses``, ``preferServerCiphers``, ``keyLogFile`` options added.
152 Listen on the specified address and TCP port for incoming DNS over TLS connections, presenting the specified X.509 certificate.
154 :param str address: The IP Address with an optional port to listen on.
155 The default port is 853.
156 :param str certFile(s): The path to a X.509 certificate file in PEM format, or a list of paths to such files.
157 :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.
158 :param table options: A table with key: value pairs with listen options.
162 * ``reusePort=false``: bool - Set the ``SO_REUSEPORT`` socket option.
163 * ``tcpFastOpenQueueSize=0``: int - Set the TCP Fast Open queue size, enabling TCP Fast Open when available and the value is larger than 0.
164 * ``interface=""``: str - Set the network interface to use.
165 * ``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.
166 * ``provider``: str - The TLS library to use between GnuTLS and OpenSSL, if they were available and enabled at compilation time.
167 * ``ciphers``: str - The TLS ciphers to use. The exact format depends on the provider used. When the OpenSSL provder is used, ciphers for TLS 1.3 must be specified via ``ciphersTLS13``.
168 * ``ciphersTLS13``: str - The ciphers to use for TLS 1.3, when the OpenSSL provider is used. When the GnuTLS provider is used, ``ciphers`` applies regardless of the TLS protocol and this setting is not used.
169 * ``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.
170 * ``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.
171 * ``ticketsKeysRotationDelay``: int - Set the delay before the TLS tickets key is rotated, in seconds. Default is 43200 (12h).
172 * ``sessionTickets``: bool - Whether session resumption via session tickets is enabled. Default is true, meaning tickets are enabled.
173 * ``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.
174 * ``ocspResponses``: list - List of files containing OCSP responses, in the same order than the certificates and keys, that will be used to provide OCSP stapling responses.
175 * ``minTLSVersion``: str - Minimum version of the TLS protocol to support. Possible values are 'tls1.0', 'tls1.1', 'tls1.2' and 'tls1.3'. Default is to require at least TLS 1.0. Note that this value is ignored when the GnuTLS provider is in use, and the ``ciphers`` option should be set accordingly instead. For example, 'NORMAL:!VERS-TLS1.0:!VERS-TLS1.1' will disable TLS 1.0 and 1.1.
176 * ``preferServerCiphers``: bool - Whether to prefer the order of ciphers set by the server instead of the one set by the client. Default is false, meaning that the order of the client is used.
177 * ``keyLogFile``: str - Write the TLS keys in the specified file so that an external program can decrypt TLS exchanges, in the format described in https://developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS/Key_Log_Format.
179 .. function:: setLocal(address[, options])
181 .. versionadded:: 1.2.0
183 Remove the list of listen addresses and add a new one.
185 :param str address: The IP Address with an optional port to listen on.
186 The default port is 53.
187 :param table options: A table with key: value pairs with listen options.
189 The options that can be set are the same as :func:`addLocal`.
191 .. function:: setLocal(address[[[,do_tcp], so_reuseport], tcp_fast_open_qsize])
193 .. deprecated:: 1.2.0
195 Remove the list of listen addresses and add a new one.
197 :param str address: The IP Address with an optional port to listen on.
198 The default port is 53.
199 :param bool do_tcp: Also bind a TCP port on ``address``, defaults to true.
200 :param bool so_reuseport: Use ``SO_REUSEPORT`` if it is available, defaults to false
201 :param int tcp_fast_open_qsize: The size of the TCP Fast Open queue. Set to a number
202 higher than 0 to enable TCP Fast Open when available.
205 Control Socket, Console and Webserver
206 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
208 .. function:: addConsoleACL(netmask)
210 .. versionadded:: 1.3.0
212 Add a netmask to the existing console ACL, allowing remote clients to connect to the console. Please make sure that encryption
213 has been enabled with :func:`setKey` before doing so. The default is to only allow 127.0.0.1/8 and ::1/128.
215 :param str netmask: A CIDR netmask, e.g. ``"192.0.2.0/24"``. Without a subnetmask, only the specific address is allowed.
217 .. function:: controlSocket(address)
219 Bind to ``addr`` and listen for a connection for the console. Since 1.3.0 only connections from local users are allowed
220 by default, :func:`addConsoleACL` and :func:`setConsoleACL` can be used to enable remote connections. Please make sure
221 that encryption has been enabled with :func:`setKey` before doing so. Enabling encryption is also strongly advised for
222 local connections, since not enabling it allows any local user to connect to the console.
224 :param str address: An IP address with optional port. By default, the port is 5199.
226 .. function:: inClientStartup()
228 Returns true while the console client is parsing the configuration.
230 .. function:: makeKey()
232 Generate and print an encryption key.
234 .. function:: setConsoleConnectionsLogging(enabled)
236 .. versionadded:: 1.2.0
238 Whether to log the opening and closing of console connections.
240 :param bool enabled: Default to true.
242 .. function:: setKey(key)
244 Use ``key`` as shared secret between the client and the server
246 :param str key: An encoded key, as generated by :func:`makeKey`
248 .. function:: setConsoleACL(netmasks)
250 .. versionadded:: 1.3.0
252 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
253 has been enabled with :func:`setKey` before doing so.
255 :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.
257 .. function:: showConsoleACL()
259 Print a list of all netmasks allowed to connect to the console.
261 .. function:: testCrypto()
263 Test the crypto code, will report errors when something is not ok.
265 .. function:: setConsoleOutputMaxMsgSize(size)
267 .. versionadded:: 1.3.3
269 Set the maximum size in bytes of a single console message, default set to 10 MB.
271 :param int size: The new maximum size.
273 Webserver configuration
274 ~~~~~~~~~~~~~~~~~~~~~~~
276 .. function:: webserver(listen_address, password[, apikey[, custom_headers]])
278 Launch the :doc:`../guides/webserver` with statistics and the API.
280 :param str listen_address: The IP address and Port to listen on
281 :param str password: The password required to access the webserver
282 :param str apikey: The key required to access the API
283 :param {[str]=str,...} custom_headers: Allows setting custom headers and removing the defaults
285 .. function:: setAPIWritable(allow [,dir])
287 Allow modifications via the API.
288 Optionally saving these changes to disk.
289 Modifications done via the API will not be written to the configuration by default and will not persist after a reload
291 :param bool allow: Set to true to allow modification through the API
292 :param str dir: A valid directory where the configuration files will be written by the API.
294 .. function:: setWebserverConfig(options)
296 .. versionadded:: 1.3.3
298 Setup webserver configuration. See :func:`webserver`.
300 :param table options: A table with key: value pairs with webserver options.
304 * ``password=newPassword``: string - Changes the API password
305 * ``apikey=newKey``: string - Changes the API Key (set to an empty string do disable it)
306 * ``custom_headers={[str]=str,...}``: map of string - Allows setting custom headers and removing the defaults.
311 .. function:: addACL(netmask)
313 Add a netmask to the existing ACL controlling which clients can send UDP, TCP, DNS over TLS and DNS over HTTPS queries. See :ref:`ACL` for more information.
315 :param str netmask: A CIDR netmask, e.g. ``"192.0.2.0/24"``. Without a subnetmask, only the specific address is allowed.
317 .. function:: setACL(netmasks)
319 Remove the existing ACL and add the netmasks from the table of those allowed to send UDP, TCP, DNS over TLS and DNS over HTTPS queries. See :ref:`ACL` for more information.
321 :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.
323 .. function:: showACL()
325 Print a list of all netmasks allowed to send queries over UDP, TCP, DNS over TLS and DNS over HTTPS. See :ref:`ACL` for more information.
330 .. function:: setECSOverride(bool)
332 When ``useClientSubnet`` in :func:`newServer` is set and dnsdist adds an EDNS Client Subnet Client option to the query, override an existing option already present in the query, if any
334 :param bool: Whether to override an existing EDNS Client Subnet option present in the query. Defaults to false
336 .. function:: setECSSourcePrefixV4(prefix)
338 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
340 :param int prefix: The prefix length
342 .. function:: setECSSourcePrefixV6(prefix)
344 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
346 :param int prefix: The prefix length
351 .. function:: setRingBuffersLockRetries(num)
353 .. versionadded:: 1.3.0
355 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
357 :param int num: The maximum number of attempts. Defaults to 5 if there is more than one shard, 0 otherwise.
359 .. function:: setRingBuffersSize(num [, numberOfShards])
361 .. versionchanged:: 1.3.0
362 ``numberOfShards`` optional parameter added.
364 Set the capacity of the ringbuffers used for live traffic inspection to ``num``, and the number of shards to ``numberOfShards`` if specified.
366 :param int num: The maximum amount of queries to keep in the ringbuffer. Defaults to 10000
367 :param int numberOfShards: the number of shards to use to limit lock contention. Defaults to 1
372 .. function:: newServer(server_string)
373 newServer(server_table)
375 .. versionchanged:: 1.3.0
376 Added ``checkClass``, ``sockets`` and ``checkFunction`` to server_table.
378 .. versionchanged:: 1.4.0
379 Added ``checkInterval``, ``checkTimeout`` and ``rise`` to server_table.
381 Add a new backend server. Call this function with either a string::
384 "IP:PORT" -- IP and PORT of the backend server
390 address="IP:PORT", -- IP and PORT of the backend server (mandatory)
391 id=STRING, -- Use a pre-defined UUID instead of a random one
392 qps=NUM, -- Limit the number of queries per second to NUM, when using the `firstAvailable` policy
393 order=NUM, -- The order of this server, used by the `leastOutstanding` and `firstAvailable` policies
394 weight=NUM, -- The weight of this server, used by the `wrandom`, `whashed` and `chashed` policies, default: 1
395 -- Supported values are a minimum of 1, and a maximum of 2147483647.
396 pool=STRING|{STRING}, -- The pools this server belongs to (unset or empty string means default pool) as a string or table of strings
397 retries=NUM, -- The number of TCP connection attempts to the backend, for a given query
398 tcpConnectTimeout=NUM, -- The timeout (in seconds) of a TCP connection attempt
399 tcpSendTimeout=NUM, -- The timeout (in seconds) of a TCP write attempt
400 tcpRecvTimeout=NUM, -- The timeout (in seconds) of a TCP read attempt
401 tcpFastOpen=BOOL, -- Whether to enable TCP Fast Open
402 ipBindAddrNoPort=BOOL, -- Whether to enable IP_BIND_ADDRESS_NO_PORT if available, default: true
403 name=STRING, -- The name associated to this backend, for display purpose
404 checkClass=NUM, -- Use NUM as QCLASS in the health-check query, default: DNSClass.IN
405 checkName=STRING, -- Use STRING as QNAME in the health-check query, default: "a.root-servers.net."
406 checkType=STRING, -- Use STRING as QTYPE in the health-check query, default: "A"
407 checkFunction=FUNCTION,-- Use this function to dynamically set the QNAME, QTYPE and QCLASS to use in the health-check query (see :ref:`Healthcheck`)
408 checkTimeout=NUM, -- The timeout (in milliseconds) of a health-check query, default: 1000 (1s)
409 setCD=BOOL, -- Set the CD (Checking Disabled) flag in the health-check query, default: false
410 maxCheckFailures=NUM, -- Allow NUM check failures before declaring the backend down, default: 1
411 checkInterval=NUM -- The time in seconds between health checks
412 mustResolve=BOOL, -- Set to true when the health check MUST return a RCODE different from NXDomain, ServFail and Refused. Default is false, meaning that every RCODE except ServFail is considered valid
413 useClientSubnet=BOOL, -- Add the client's IP address in the EDNS Client Subnet option when forwarding the query to this backend
414 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
415 -- The following formats are supported:
416 -- "address", e.g. "192.0.2.2"
417 -- "interface name", e.g. "eth0"
418 -- "address@interface", e.g. "192.0.2.2@eth0"
419 addXPF=NUM, -- Add the client's IP address and port to the query, along with the original destination address and port,
420 -- 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)
421 sockets=NUM, -- Number of sockets (and thus source ports) used toward the backend server, defaults to a single one
422 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
423 rise=NUM -- Require NUM consecutive successful checks before declaring the backend up, default: 1
426 :param str server_string: A simple IP:PORT string.
427 :param table server_table: A table with at least a 'name' key
429 .. function:: getServer(index) -> Server
431 Get a :class:`Server`
433 :param int index: The number of the server (as seen in :func:`showServers`).
434 :returns: The :class:`Server` object or nil
436 .. function:: getServers()
438 Returns a table with all defined servers.
440 .. function:: rmServer(index)
443 Remove a backend server.
445 :param int index: The number of the server (as seen in :func:`showServers`).
446 :param Server server: A :class:`Server` object as returned by e.g. :func:`getServer`.
450 A server object returned by :func:`getServer` can be manipulated with these functions.
454 This object represents a backend server. It has several methods.
456 .. method:: Server:addPool(pool)
458 Add this server to a pool.
460 :param str pool: The pool to add the server to
462 .. method:: Server:getName() -> string
464 Get the name of this server.
466 :returns: The name of the server, or an empty string if it does not have one
468 .. method:: Server:getNameWithAddr() -> string
470 Get the name plus IP address and port of the server
472 :returns: A string containing the server name if any plus the server address and port
474 .. method:: Server:getOutstanding() -> int
476 Get the number of outstanding queries for this server.
478 :returns: The number of outstanding queries
480 .. method:: Server:isUp() -> bool
482 Returns the up status of the server
484 :returns: true when the server is up, false otherwise
486 .. method:: Server:rmPool(pool)
488 Removes the server from the named pool
490 :param str pool: The pool to remove the server from
492 .. method:: Server:setAuto([status])
494 .. versionchanged:: 1.3.0
495 ``status`` optional parameter added.
497 Set the server in the default auto state.
498 This will enable health check queries that will set the server ``up`` and ``down`` appropriately.
500 :param bool status: Set the initial status of the server to ``up`` (true) or ``down`` (false) instead of using the last known status
502 .. method:: Server:setQPS(limit)
504 Limit the queries per second for this server.
506 :param int limit: The maximum number of queries per second
508 .. method:: Server:setDown()
510 Set the server in an ``DOWN`` state.
511 The server will not receive queries and the health checks are disabled
513 .. method:: Server:setUp()
515 Set the server in an ``UP`` state.
516 This server will still receive queries and health checks are disabled
518 Apart from the functions, a :class:`Server` object has these attributes:
520 .. attribute:: Server.name
522 The name of the server
524 .. attribute:: Server.upStatus
526 Whether or not this server is up or down
528 .. attribute:: Server.order
530 The order of the server
532 .. attribute:: Server.weight
534 The weight of the server
539 :class:`Server`\ s can be part of any number of pools.
540 Pools are automatically created when a server is added to a pool (with :func:`newServer`), or can be manually created with :func:`addPool`.
542 .. function:: addPool(name) -> ServerPool
544 Returns a :class:`ServerPool`.
546 :param string name: The name of the pool to create
548 .. function:: getPool(name) -> ServerPool
550 Returns a :class:`ServerPool` or nil.
552 :param string name: The name of the pool
554 .. function:: getPoolServers(name) -> [ Server ]
556 Returns a list of :class:`Server`\ s or nil.
558 :param string name: The name of the pool
560 .. function:: showPools()
562 Display the name, associated cache, server policy and associated servers for every pool.
564 .. class:: ServerPool
566 This represents the pool where zero or more servers are part of.
568 .. method:: ServerPool:getCache() -> PacketCache
570 Returns the :class:`PacketCache` for this pool or nil.
572 .. method:: ServerPool:getECS()
574 .. versionadded:: 1.3.0
576 Whether dnsdist will add EDNS Client Subnet information to the query before looking up into the cache,
577 when all servers from this pool are down. For more information see :meth:`ServerPool:setECS`.
579 .. method:: ServerPool:setCache(cache)
581 Adds ``cache`` as the pool's cache.
583 :param PacketCache cache: The new cache to add to the pool
585 .. method:: ServerPool:unsetCache()
587 Removes the cache from this pool.
589 .. method:: ServerPool:setECS()
591 .. versionadded:: 1.3.0
593 Set to true if dnsdist should add EDNS Client Subnet information to the query before looking up into the cache,
594 when all servers from this pool are down. If at least one server is up, the preference of the
595 selected server is used, this parameter is only useful if all the backends in this pool are down
596 and have EDNS Client Subnet enabled, since the queries in the cache will have been inserted with
597 ECS information. Default is false.
602 A Pool can have a packet cache to answer queries directly instead of going to the backend.
603 See :doc:`../guides/cache` for a how to.
605 .. function:: newPacketCache(maxEntries[, maxTTL=86400[, minTTL=0[, temporaryFailureTTL=60[, staleTTL=60[, dontAge=false[, numberOfShards=1[, deferrableInsertLock=true[, maxNegativeTTL=3600[, parseECS=false]]]]]]]) -> PacketCache
607 .. versionchanged:: 1.3.0
608 ``numberOfShards`` and ``deferrableInsertLock`` parameters added.
610 .. versionchanged:: 1.3.1
611 ``maxNegativeTTL`` and ``parseECS`` parameters added.
613 .. deprecated:: 1.4.0
615 Creates a new :class:`PacketCache` with the settings specified.
617 :param int maxEntries: The maximum number of entries in this cache
618 :param int maxTTL: Cap the TTL for records to his number
619 :param int minTTL: Don't cache entries with a TTL lower than this
620 :param int temporaryFailureTTL: On a SERVFAIL or REFUSED from the backend, cache for this amount of seconds
621 :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
622 :param bool dontAge: Don't reduce TTLs when serving from the cache. Use this when :program:`dnsdist` fronts a cluster of authoritative servers
623 :param int numberOfShards: Number of shards to divide the cache into, to reduce lock contention
624 :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
625 :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
626 :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
628 .. function:: newPacketCache(maxEntries, [options]) -> PacketCache
630 .. versionadded:: 1.4.0
632 Creates a new :class:`PacketCache` with the settings specified.
634 :param int maxEntries: The maximum number of entries in this cache
638 * ``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.
639 * ``dontAge=false``: bool - Don't reduce TTLs when serving from the cache. Use this when :program:`dnsdist` fronts a cluster of authoritative servers.
640 * ``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.
641 * ``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.
642 * ``maxTTL=86400``: int - Cap the TTL for records to his number.
643 * ``minTTL=0``: int - Don't cache entries with a TTL lower than this.
644 * ``numberOfShards=1``: int - Number of shards to divide the cache into, to reduce lock contention.
645 * ``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.
646 * ``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.
647 * ``temporaryFailureTTL=60``: int - On a SERVFAIL or REFUSED from the backend, cache for this amount of seconds..
649 .. class:: PacketCache
651 Represents a cache that can be part of :class:`ServerPool`.
653 .. method:: PacketCache:dump(fname)
655 .. versionadded:: 1.3.1
657 Dump a summary of the cache entries to a file.
659 :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.
661 .. method:: PacketCache:expunge(n)
663 Remove entries from the cache, leaving at most ``n`` entries
665 :param int n: Number of entries to keep
667 .. method:: PacketCache:expungeByName(name [, qtype=DNSQType.ANY[, suffixMatch=false]])
669 .. versionchanged:: 1.2.0
670 ``suffixMatch`` parameter added.
672 Remove entries matching ``name`` and type from the cache.
674 :param DNSName name: The name to expunge
675 :param int qtype: The type to expunge, can be a pre-defined :ref:`DNSQType`
676 :param bool suffixMatch: When set to true, remove al entries under ``name``
678 .. method:: PacketCache:getStats()
680 .. versionadded:: 1.4.0
682 Return the cache stats (number of entries, hits, misses, deferred lookups, deferred inserts, lookup collisions, insert collisions and TTL too shorts) as a Lua table.
684 .. method:: PacketCache:isFull() -> bool
686 Return true if the cache has reached the maximum number of entries.
688 .. method:: PacketCache:printStats()
690 Print the cache stats (number of entries, hits, misses, deferred lookups, deferred inserts, lookup collisions, insert collisions and TTL too shorts).
692 .. method:: PacketCache:purgeExpired(n)
694 Remove expired entries from the cache until there is at most ``n`` entries remaining in the cache.
696 :param int n: Number of entries to keep
698 .. method:: PacketCache:toString() -> string
700 Return the number of entries in the Packet Cache, and the maximum number of entries
705 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.
707 .. function:: getBind(index) -> ClientState
709 Return a :class:`ClientState` object.
711 :param int index: The object index
713 ClientState functions
714 ~~~~~~~~~~~~~~~~~~~~~
716 .. class:: ClientState
718 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.
720 .. method:: ClientState:attachFilter(filter)
722 Attach a BPF filter to this frontend.
724 :param BPFFilter filter: The filter to attach to this frontend
726 .. method:: ClientState:detachFilter()
728 Remove the BPF filter associated to this frontend, if any.
730 .. method:: ClientState:toString() -> string
732 Return the address and port this frontend is listening on.
734 :returns: The address and port this frontend is listening on
736 .. attribute:: ClientState.muted
738 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.
740 Status, Statistics and More
741 ---------------------------
743 .. function:: dumpStats()
745 Print all statistics dnsdist gathers
747 .. function:: getDOHFrontend(idx)
749 .. versionadded:: 1.4.0
751 Return the DOHFrontend object for the DNS over HTTPS bind of index ``idx``.
753 .. function:: getTLSContext(idx)
755 .. versionadded:: 1.3.0
757 Return the TLSContext object for the context of index ``idx``.
759 .. function:: getTLSFrontend(idx)
761 .. versionadded:: 1.3.1
763 Return the TLSFrontend object for the TLS bind of index ``idx``.
765 .. function:: grepq(selector[, num])
766 grepq(selectors[, num])
768 Prints the last ``num`` queries matching ``selector`` or ``selectors``.
772 * a netmask (e.g. '192.0.2.0/24')
773 * a DNS name (e.g. 'dnsdist.org')
774 * a response time (e.g. '100ms')
776 :param str selector: Select queries based on this property.
777 :param {str} selectors: A lua table of selectors. Only queries matching all selectors are shown
778 :param int num: Show a maximum of ``num`` recent queries, default is 10.
780 .. function:: setVerboseHealthChecks(verbose)
782 Set whether health check errors should be logged. This is turned off by default.
784 :param bool verbose: Set to true if you want to enable health check errors logging
786 .. function:: showBinds()
788 Print a list of all the current addresses and ports dnsdist is listening on, also called ``frontends``
790 .. function:: showDOHFrontends()
792 .. versionadded:: 1.4.0
794 Print the list of all availables DNS over HTTPS frontends.
796 .. function:: showDOHResponseCodes()
798 .. versionadded:: 1.4.0
800 Print the HTTP response codes statistics for all availables DNS over HTTPS frontends.
802 .. function:: showResponseLatency()
804 Show a plot of the response time latency distribution
806 .. function:: showServers([options])
808 .. versionchanged:: 1.4.0
809 ``options`` optional parameter added
811 This function shows all backend servers currently configured and some statistics.
812 These statics have the following fields:
814 * ``#`` - The number of the server, can be used as the argument for :func:`getServer`
815 * ``UUID`` - The UUID of the backend. Can be set with the ``id`` option of :func:`newServer`
816 * ``Address`` - The IP address and port of the server
817 * ``State`` - The current state of the server
818 * ``Qps`` - Current number of queries per second
819 * ``Qlim`` - Configured maximum number of queries per second
820 * ``Ord`` - The order number of the server
821 * ``Wt`` - The weight of the server
822 * ``Queries`` - Total amount of queries sent to this server
823 * ``Drops`` - Number of queries that were dropped by this server
824 * ``Drate`` - Number of queries dropped per second by this server
825 * ``Lat`` - The latency of this server in milliseconds
826 * ``Pools`` - The pools this server belongs to
828 :param table options: A table with key: value pairs with display options.
832 * ``showUUIDs=false``: bool - Whether to display the UUIDs, defaults to false.
834 .. function:: showTCPStats()
836 Show some statistics regarding TCP
838 .. function:: showTLSContexts()
840 .. versionadded:: 1.3.0
842 Print the list of all availables DNS over TLS contexts.
844 .. function:: showTLSErrorCounters()
846 .. versionadded:: 1.4.0
848 Display metrics about TLS handshake failures.
850 .. function:: showVersion()
852 Print the version of dnsdist
854 .. function:: topBandwidth([num])
856 Print the top ``num`` clients that consume the most bandwidth.
858 :param int num: Number to show, defaults to 10.
860 .. function:: topClients([num])
862 Print the top ``num`` clients sending the most queries over length of ringbuffer
864 :param int num: Number to show, defaults to 10.
866 .. function:: topQueries([num[, labels]])
868 Print the ``num`` most popular QNAMEs from queries.
869 Optionally grouped by the rightmost ``labels`` DNS labels.
871 :param int num: Number to show, defaults to 10
872 :param int label: Number of labels to cut down to
874 .. function:: topResponses([num[, rcode[, labels]]])
876 Print the ``num`` most seen responses with an RCODE of ``rcode``.
877 Optionally grouped by the rightmost ``labels`` DNS labels.
879 :param int num: Number to show, defaults to 10
880 :param int rcode: :ref:`Response code <DNSRCode>`, defaults to 0 (No Error)
881 :param int label: Number of labels to cut down to
883 .. function:: topSlow([num[, limit[, labels]]])
885 Print the ``num`` slowest queries that are slower than ``limit`` milliseconds.
886 Optionally grouped by the rightmost ``labels`` DNS labels.
888 :param int num: Number to show, defaults to 10
889 :param int limit: Show queries slower than this amount of milliseconds, defaults to 2000
890 :param int label: Number of labels to cut down to
897 .. function:: addDynBlocks(addresses, message[, seconds=10[, action]])
899 .. versionchanged:: 1.2.0
900 ``action`` parameter added.
902 Block a set of addresses with ``message`` for (optionally) a number of seconds.
903 The default number of seconds to block for is 10.
905 :param addresses: set of Addresses as returned by an exceed function
906 :param string message: The message to show next to the blocks
907 :param int seconds: The number of seconds this block to expire
908 :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)
910 Please see the documentation for :func:`setDynBlocksAction` to confirm which actions are supported by the action paramater.
912 .. function:: clearDynBlocks()
914 Remove all current dynamic blocks.
916 .. function:: showDynBlocks()
918 List all dynamic blocks in effect.
920 .. function:: setDynBlocksAction(action)
922 .. versionchanged:: 1.3.3
923 ``DNSAction.NXDomain`` action added.
925 Set which action is performed when a query is blocked.
926 Only DNSAction.Drop (the default), DNSAction.NoOp, DNSAction.NXDomain, DNSAction.Refused, DNSAction.Truncate and DNSAction.NoRecurse are supported.
930 Getting addresses that exceeded parameters
931 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
933 .. function:: exceedServFails(rate, seconds)
935 Get set of addresses that exceed ``rate`` servfails/s over ``seconds`` seconds
937 :param int rate: Number of Servfails per second to exceed
938 :param int seconds: Number of seconds the rate has been exceeded
940 .. function:: exceedNXDOMAINs(rate, seconds)
942 get set of addresses that exceed ``rate`` NXDOMAIN/s over ``seconds`` seconds
944 :param int rate: Number of NXDOMAIN per second to exceed
945 :param int seconds: Number of seconds the rate has been exceeded
947 .. function:: exceedRespByterate(rate, seconds)
949 get set of addresses that exceeded ``rate`` bytes/s answers over ``seconds`` seconds
951 :param int rate: Number of bytes per second to exceed
952 :param int seconds: Number of seconds the rate has been exceeded
954 .. function:: exceedQRate(rate, seconds)
956 Get set of address that exceed ``rate`` queries/s over ``seconds`` seconds
958 :param int rate: Number of queries per second to exceed
959 :param int seconds: Number of seconds the rate has been exceeded
961 .. function:: exceedQTypeRate(type, rate, seconds)
963 Get set of address that exceed ``rate`` queries/s for queries of QType ``type`` over ``seconds`` seconds
965 :param int type: QType
966 :param int rate: Number of QType queries per second to exceed
967 :param int seconds: Number of seconds the rate has been exceeded
972 Instead of using several `exceed*()` lines, dnsdist 1.3.0 introduced a new `DynBlockRulesGroup` object
973 which can be used to group dynamic block rules.
975 See :doc:`../guides/dynblocks` for more information about the case where using a `DynBlockRulesGroup` might be
976 faster than the existing rules.
978 .. function:: dynBlockRulesGroup() -> DynBlockRulesGroup
980 .. versionadded:: 1.3.0
982 Creates a new :class:`DynBlockRulesGroup` object.
984 .. class:: DynBlockRulesGroup
986 Represents a group of dynamic block rules.
988 .. method:: DynBlockRulesGroup:setQueryRate(rate, seconds, reason, blockingTime [, action [, warningRate]])
990 .. versionchanged:: 1.3.3
991 ``warningRate`` parameter added.
993 Adds a query rate-limiting rule, equivalent to:
995 addDynBlocks(exceedQRate(rate, seconds), reason, blockingTime, action)
998 :param int rate: Number of queries per second to exceed
999 :param int seconds: Number of seconds the rate has been exceeded
1000 :param string reason: The message to show next to the blocks
1001 :param int blockingTime: The number of seconds this block to expire
1002 :param int action: The action to take when the dynamic block matches, see :ref:`here <DNSAction>`. (default to the one set with :func:`setDynBlocksAction`)
1003 :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
1005 .. method:: DynBlockRulesGroup:setRCodeRate(rcode, rate, seconds, reason, blockingTime [, action [, warningRate]])
1007 .. versionchanged:: 1.3.3
1008 ``warningRate`` parameter added.
1010 Adds a rate-limiting rule for responses of code ``rcode``, equivalent to:
1012 addDynBlocks(exceedServfails(rcode, rate, seconds), reason, blockingTime, action)
1015 :param int rcode: The response code
1016 :param int rate: Number of responses per second to exceed
1017 :param int seconds: Number of seconds the rate has been exceeded
1018 :param string reason: The message to show next to the blocks
1019 :param int blockingTime: The number of seconds this block to expire
1020 :param int action: The action to take when the dynamic block matches, see :ref:`here <DNSAction>`. (default to the one set with :func:`setDynBlocksAction`)
1021 :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
1023 .. method:: DynBlockRulesGroup:setQTypeRate(qtype, rate, seconds, reason, blockingTime [, action [, warningRate]])
1025 .. versionchanged:: 1.3.3
1026 ``warningRate`` parameter added.
1028 Adds a rate-limiting rule for queries of type ``qtype``, equivalent to:
1030 addDynBlocks(exceedQTypeRate(type, rate, seconds), reason, blockingTime, action)
1033 :param int qtype: The qtype
1034 :param int rate: Number of queries per second to exceed
1035 :param int seconds: Number of seconds the rate has been exceeded
1036 :param string reason: The message to show next to the blocks
1037 :param int blockingTime: The number of seconds this block to expire
1038 :param int action: The action to take when the dynamic block matches, see :ref:`here <DNSAction>`. (default to the one set with :func:`setDynBlocksAction`)
1039 :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
1041 .. method:: DynBlockRulesGroup:setResponseByteRate(rate, seconds, reason, blockingTime [, action [, warningRate]])
1043 .. versionchanged:: 1.3.3
1044 ``warningRate`` parameter added.
1046 Adds a bandwidth rate-limiting rule for responses, equivalent to:
1048 addDynBlocks(exceedRespByterate(rate, seconds), reason, blockingTime, action)
1051 :param int rate: Number of bytes per second to exceed
1052 :param int seconds: Number of seconds the rate has been exceeded
1053 :param string reason: The message to show next to the blocks
1054 :param int blockingTime: The number of seconds this block to expire
1055 :param int action: The action to take when the dynamic block matches, see :ref:`here <DNSAction>`. (default to the one set with :func:`setDynBlocksAction`)
1056 :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
1058 .. method:: DynBlockRulesGroup:apply()
1060 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.
1062 .. method:: DynBlockRulesGroup:setQuiet(quiet)
1064 .. versionadded:: 1.4.0
1066 Set whether newly blocked clients or domains should be logged.
1068 :param bool quiet: True means that insertions will not be logged, false that they will. Default is false.
1070 .. method:: DynBlockRulesGroup:excludeRange(netmasks)
1072 .. versionadded:: 1.3.1
1074 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.
1076 :param int netmasks: A netmask, or list of netmasks, as strings, like for example "192.0.2.1/24"
1078 .. method:: DynBlockRulesGroup:includeRange(netmasks)
1080 .. versionadded:: 1.3.1
1082 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.
1084 :param int netmasks: A netmask, or list of netmasks, as strings, like for example "192.0.2.1/24"
1086 .. method:: DynBlockRulesGroup:toString()
1088 .. versionadded:: 1.3.1
1090 Return a string describing the rules and range exclusions of this DynBlockRulesGroup.
1095 A SuffixMatchNode can be used to quickly check whether a given name belongs to a set or not. This is achieved
1096 using an efficient tree structure based on DNS labels, making lookups cheap.
1097 Be careful that Suffix Node matching will match for any sub-domain, regardless of the depth, under the name added to the set. For example,
1098 if 'example.com.' is added to the set, 'www.example.com.' and 'sub.www.example.com.' will match as well.
1099 If you are looking for exact name matching, your might want to consider using a :class:`DNSNameSet` instead.
1101 .. function:: newSuffixMatchNode()
1103 Creates a new :class:`SuffixMatchNode`.
1105 .. class:: SuffixMatchNode
1107 Represent a set of DNS suffixes for quick matching.
1109 .. method:: SuffixMatchNode:add(name)
1111 .. versionchanged:: 1.4.0
1112 This method now accepts strings, lists of DNSNames and lists of strings.
1114 Add a suffix to the current set.
1116 :param DNSName name: The suffix to add to the set.
1117 :param string name: The suffix to add to the set.
1118 :param table name: The suffixes to add to the set. Elements of the table should be of the same type, either DNSName or string.
1120 .. method:: SuffixMatchNode:check(name) -> bool
1122 Return true if the given name is a sub-domain of one of those in the set, and false otherwise.
1124 :param DNSName name: The name to test against the set.
1129 .. function:: maintenance()
1131 If this function exists, it is called every second to so regular tasks.
1132 This can be used for e.g. :doc:`Dynamic Blocks <../guides/dynblocks>`.
1134 .. function:: setAllowEmptyResponse()
1136 .. versionadded:: 1.4.0
1138 Set to true (defaults to false) to allow empty responses (qdcount=0) with a NoError or NXDomain rcode (default) from backends. dnsdist drops these responses by default because it can't match them against the initial query since they don't contain the qname, qtype and qclass, and therefore the risk of collision is much higher than with regular responses.
1140 .. function:: makeIPCipherKey(password) -> string
1142 .. versionadded:: 1.4.0
1144 Hashes the password to generate a 16-byte key that can be used to pseudonymize IP addresses with IP cipher.
1146 .. function:: generateOCSPResponse(pathToServerCertificate, pathToCACertificate, pathToCAPrivateKey, outputFile, numberOfDaysOfValidity, numberOfMinutesOfValidity)
1148 .. versionadded:: 1.4.0
1150 When a local PKI is used to issue the certificate, or for testing purposes, :func:`generateOCSPResponse` can be used to generate an OCSP response file for a certificate, using the certificate and private key of the certification authority that signed that certificate.
1151 The resulting file can be directly used with the :func:`addDOHLocal` or the :func:`addTLSLocal` functions.
1153 :param string pathToServerCertificate: Path to a file containing the certificate used by the server.
1154 :param string pathToCACertificate: Path to a file containing the certificate of the certification authority that was used to sign the server certificate.
1155 :param string pathToCAPrivateKey: Path to a file containing the private key corresponding to the certification authority certificate.
1156 :param string outputFile: Path to a file where the resulting OCSP response will be written to.
1157 :param int numberOfDaysOfValidity: Number of days this OCSP response should be valid.
1158 :param int numberOfMinutesOfValidity: Number of minutes this OCSP response should be valid, in addition to the number of days.
1163 .. class:: DOHFrontend
1165 .. versionadded:: 1.4.0
1167 This object represents an address and port dnsdist is listening on for DNS over HTTPS queries.
1169 .. method:: DOHFrontend:loadTicketsKeys(ticketsKeysFile)
1171 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. dnsdist supports several tickets keys to be able to decrypt existing sessions after the rotation.
1173 :param str ticketsKeysFile: The path to a file from where TLS tickets keys should be loaded.
1175 .. method:: DOHFrontend:reloadCertificates()
1177 Reload the current TLS certificate and key pairs.
1179 .. method:: DOHFrontend:rotateTicketsKey()
1181 Replace the current TLS tickets key by a new random one.
1183 .. method:: DOHFrontend:setResponsesMap(rules)
1185 Set a list of HTTP response rules allowing to intercept HTTP queries very early, before the DNS payload has been processed, and send custom responses including error pages, redirects and static content.
1187 :param list of DOHResponseMapEntry objects rules: A list of DOHResponseMapEntry objects, obtained with :func:`newDOHResponseMapEntry`.
1190 .. function:: newDOHResponseMapEntry(regex, status, content [, headers]) -> DOHResponseMapEntry
1192 .. versionadded:: 1.4.0
1194 Return a DOHResponseMapEntry that can be used with :meth:`DOHFrontend.setResponsesMap`. Every query whose path matches the regular expression supplied in ``regex`` will be immediately answered with a HTTP response.
1195 The status of the HTTP response will be the one supplied by ``status``, and the content set to the one supplied by ``content``, except if the status is a redirection (3xx) in which case the content is expected to be the URL to redirect to.
1197 :param str regex: A regular expression to match the path against.
1198 :param int status: The HTTP code to answer with.
1199 :param str content: The content of the HTTP response, or a URL if the status is a redirection (3xx).
1200 :param table of headers: The custom headers to set for the HTTP response, if any. The default is to use the value of the ``customResponseHeaders`` parameter passed to :func:`addDOHLocal`.
1205 .. class:: TLSContext
1207 .. versionadded:: 1.3.0
1209 This object represents an address and port dnsdist is listening on for DNS over TLS queries.
1211 .. method:: TLSContext:rotateTicketsKey()
1213 Replace the current TLS tickets key by a new random one.
1215 .. method:: TLSContext:loadTicketsKeys(ticketsKeysFile)
1217 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.
1219 :param str ticketsKeysFile: The path to a file from where TLS tickets keys should be loaded.
1224 .. class:: TLSFrontend
1226 .. versionadded:: 1.3.1
1228 This object represents the configuration of a listening frontend for DNS over TLS queries. To each frontend is associated a TLSContext.
1230 .. method:: TLSContext:loadNewCertificatesAndKeys(certFile(s), keyFile(s))
1232 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.
1234 :param str certFile(s): The path to a X.509 certificate file in PEM format, or a list of paths to such files.
1235 :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.
1237 EDNS on Self-generated answers
1238 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1240 There are several mechanisms in dnsdist that turn an existing query into an answer right away,
1241 without reaching out to the backend, including :func:`SpoofAction`, :func:`RCodeAction`, :func:`TCAction`
1242 and returning a response from ``Lua``. Those responses should, according to :rfc:`6891`, contain an ``OPT``
1243 record if the received request had one, which is the case by default and can be disabled using
1244 :func:`setAddEDNSToSelfGeneratedResponses`.
1246 We must, however, provide a responder's maximum payload size in this record, and we can't easily know the
1247 maximum payload size of the actual backend so we need to provide one. The default value is 1500 and can be
1248 overriden using :func:`setPayloadSizeOnSelfGeneratedAnswers`.
1250 .. function:: setAddEDNSToSelfGeneratedResponses(add)
1252 .. versionadded:: 1.3.3
1254 Whether to add EDNS to self-generated responses, provided that the initial query had EDNS.
1256 :param bool add: Whether to add EDNS, default is true.
1258 .. function:: setPayloadSizeOnSelfGeneratedAnswers(payloadSize)
1260 .. versionadded:: 1.3.3
1262 Set the UDP payload size advertised via EDNS on self-generated responses. In accordance with
1263 :rfc:`RFC 6891 <6891#section-6.2.5>`, values lower than 512 will be treated as equal to 512.
1265 :param int payloadSize: The responder's maximum UDP payload size, in bytes. Default is 1500.
1270 PowerDNS products can poll the security status of their respective versions. This polling, naturally,
1271 happens over DNS. If the result is that a given version has a security problem, the software will
1272 report this at level ‘Error’ during startup, and repeatedly during operations, every
1273 :func:`setSecurityPollInterval` seconds.
1275 By default, security polling happens on the domain ‘secpoll.powerdns.com’, but this can be changed with
1276 the :func:`setSecurityPollSuffix` function. If this setting is made empty, no polling will take place.
1277 Organizations wanting to host their own security zones can do so by changing this setting to a domain name
1278 under their control.
1280 To enable distributors of PowerDNS to signal that they have backported versions, the PACKAGEVERSION
1281 compilation-time macro can be used to set a distributor suffix.
1283 .. function:: setSecurityPollInterval(interval)
1285 .. versionadded:: 1.3.3
1287 Set the interval, in seconds, between two security pollings.
1289 :param int interval: The interval, in seconds, between two pollings. Default is 3600.
1291 .. function:: setSecurityPollSuffix(suffix)
1293 .. versionadded:: 1.3.3
1295 Domain name from which to query security update notifications. Setting this to an empty string disables secpoll.
1297 :param string suffix: The suffix to use, default is 'secpoll.powerdns.com.'.