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:`Netmask`: represents a netmask
22 * :class:`NetmaskGroup`: represents a group of netmasks
23 * :class:`QPSLimiter`: implements a QPS-based filter
24 * :class:`SuffixMatchNode`: represents a group of domain suffixes for rapid testing of membership
25 * :class:`DNSHeader`: represents the header of a DNS packet, see :ref:`DNSHeader`
26 * :class:`ClientState`: sometimes also called Bind or Frontend, represents the addresses and ports dnsdist is listening on
28 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:
32 getServer(0).order=12 -- set order of server 0 to 12
33 getServer(0):addPool("abuse") -- add this server to the abuse pool
35 The ``.`` means ``order`` is a data member, while the ``:`` means ``addPool`` is a member function.
40 .. function:: includeDirectory(path)
42 Include configuration files from ``path``.
44 :param str path: The directory to load configuration files from. Each file must end in ``.conf``.
46 .. function:: reloadAllCertificates()
48 .. versionadded:: 1.4.0
50 Reload all DNSCrypt and TLS certificates, along with their associated keys.
52 .. function:: setSyslogFacility(facility)
54 .. versionadded:: 1.4.0
56 Set the syslog logging facility to ``facility``.
58 :param int facility: The new facility as a numeric value. Defaults to LOG_DAEMON.
63 .. function:: addLocal(address[, options])
65 .. versionadded:: 1.2.0
67 .. versionchanged:: 1.3.0
68 Added ``cpus`` to the options.
70 .. versionchanged:: 1.4.0
71 Removed ``doTCP`` from the options. A listen socket on TCP is always created.
73 Add to the list of listen addresses.
75 :param str address: The IP Address with an optional port to listen on.
76 The default port is 53.
77 :param table options: A table with key: value pairs with listen options.
81 * ``doTCP=true``: bool - Also bind on TCP on ``address``. Removed in 1.4.0.
82 * ``reusePort=false``: bool - Set the ``SO_REUSEPORT`` socket option.
83 * ``tcpFastOpenQueueSize=0``: int - Set the TCP Fast Open queue size, enabling TCP Fast Open when available and the value is larger than 0.
84 * ``interface=""``: str - Set the network interface to use.
85 * ``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.
89 addLocal('0.0.0.0:5300', { reusePort=true })
91 This will bind to both UDP and TCP on port 5300 with SO_REUSEPORT enabled.
93 .. function:: addLocal(address[[[,do_tcp], so_reuseport], tcp_fast_open_qsize])
97 Add to the list of addresses listened on.
99 :param str address: The IP Address with an optional port to listen on.
100 The default port is 53.
101 :param bool do_tcp: Also bind a TCP port on ``address``, defaults to true.
102 :param bool so_reuseport: Use ``SO_REUSEPORT`` if it is available, defaults to false
103 :param int tcp_fast_open_qsize: The size of the TCP Fast Open queue. Set to a number
104 higher than 0 to enable TCP Fast Open when available.
107 .. function:: addDOHLocal(address, [certFile(s) [, keyFile(s) [, urls [, options]]]])
109 .. versionadded:: 1.4.0
111 .. versionchanged:: 1.5.0
112 ``sendCacheControlHeaders``, ``sessionTimeout`` options added.
113 ``url`` now defaults to ``/dns-query`` instead of ``/``
115 Listen on the specified address and TCP port for incoming DNS over HTTPS connections, presenting the specified X.509 certificate.
116 If no certificate (or key) files are specified, listen for incoming DNS over HTTP connections instead.
118 :param str address: The IP Address with an optional port to listen on.
119 The default port is 443.
120 :param str certFile(s): The path to a X.509 certificate file in PEM format, or a list of paths to such files.
121 :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.
122 :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 /dns-query.
123 :param table options: A table with key: value pairs with listen options.
127 * ``reusePort=false``: bool - Set the ``SO_REUSEPORT`` socket option.
128 * ``tcpFastOpenQueueSize=0``: int - Set the TCP Fast Open queue size, enabling TCP Fast Open when available and the value is larger than 0.
129 * ``interface=""``: str - Set the network interface to use.
130 * ``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.
131 * ``idleTimeout=30``: int - Set the idle timeout, in seconds.
132 * ``ciphers``: str - The TLS ciphers to use, in OpenSSL format. Ciphers for TLS 1.3 must be specified via ``ciphersTLS13``.
133 * ``ciphersTLS13``: str - The TLS ciphers to use for TLS 1.3, in OpenSSL format.
134 * ``serverTokens``: str - The content of the Server: HTTP header returned by dnsdist. The default is "h2o/dnsdist".
135 * ``customResponseHeaders={}``: table - Set custom HTTP header(s) returned by dnsdist.
136 * ``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.
137 * ``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.
138 * ``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.
139 * ``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.
140 * ``ticketsKeysRotationDelay``: int - Set the delay before the TLS tickets key is rotated, in seconds. Default is 43200 (12h).
141 * ``sessionTimeout``: int - Set the TLS session lifetime in seconds, this is used both for TLS ticket lifetime and for sessions kept in memory.
142 * ``sessionTickets``: bool - Whether session resumption via session tickets is enabled. Default is true, meaning tickets are enabled.
143 * ``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.
144 * ``preferServerCiphers``: bool - Whether to prefer the order of ciphers set by the server instead of the one set by the client. Default is true, meaning that the order of the server is used.
145 * ``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. Note that this feature requires OpenSSL >= 1.1.1.
146 * ``sendCacheControlHeaders``: bool - Whether to parse the response to find the lowest TTL and set a HTTP Cache-Control header accordingly. Default is true.
148 .. function:: addTLSLocal(address, certFile(s), keyFile(s) [, options])
150 .. versionadded:: 1.3.0
151 .. versionchanged:: 1.3.1
152 ``certFile(s)`` and ``keyFile(s)`` parameters accept a list of files.
153 ``sessionTickets`` option added.
154 .. versionchanged:: 1.3.3
155 ``numberOfStoredSessions`` option added.
156 .. versionchanged:: 1.4.0
157 ``ciphersTLS13``, ``minTLSVersion``, ``ocspResponses``, ``preferServerCiphers``, ``keyLogFile`` options added.
158 .. versionchanged:: 1.5.0
159 ``sessionTimeout`` option added.
161 Listen on the specified address and TCP port for incoming DNS over TLS connections, presenting the specified X.509 certificate.
163 :param str address: The IP Address with an optional port to listen on.
164 The default port is 853.
165 :param str certFile(s): The path to a X.509 certificate file in PEM format, or a list of paths to such files.
166 :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.
167 :param table options: A table with key: value pairs with listen options.
171 * ``reusePort=false``: bool - Set the ``SO_REUSEPORT`` socket option.
172 * ``tcpFastOpenQueueSize=0``: int - Set the TCP Fast Open queue size, enabling TCP Fast Open when available and the value is larger than 0.
173 * ``interface=""``: str - Set the network interface to use.
174 * ``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.
175 * ``provider``: str - The TLS library to use between GnuTLS and OpenSSL, if they were available and enabled at compilation time. Default is to use OpenSSL when available.
176 * ``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``.
177 * ``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.
178 * ``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.
179 * ``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.
180 * ``ticketsKeysRotationDelay``: int - Set the delay before the TLS tickets key is rotated, in seconds. Default is 43200 (12h).
181 * ``sessionTimeout``: int - Set the TLS session lifetime in seconds, this is used both for TLS ticket lifetime and for sessions kept in memory.
182 * ``sessionTickets``: bool - Whether session resumption via session tickets is enabled. Default is true, meaning tickets are enabled.
183 * ``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.
184 * ``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.
185 * ``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.
186 * ``preferServerCiphers``: bool - Whether to prefer the order of ciphers set by the server instead of the one set by the client. Default is true, meaning that the order of the server is used.
187 * ``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. Note that this feature requires OpenSSL >= 1.1.1.
189 .. function:: setLocal(address[, options])
191 .. versionadded:: 1.2.0
193 Remove the list of listen addresses and add a new one.
195 :param str address: The IP Address with an optional port to listen on.
196 The default port is 53.
197 :param table options: A table with key: value pairs with listen options.
199 The options that can be set are the same as :func:`addLocal`.
201 .. function:: setLocal(address[[[,do_tcp], so_reuseport], tcp_fast_open_qsize])
203 .. deprecated:: 1.2.0
205 Remove the list of listen addresses and add a new one.
207 :param str address: The IP Address with an optional port to listen on.
208 The default port is 53.
209 :param bool do_tcp: Also bind a TCP port on ``address``, defaults to true.
210 :param bool so_reuseport: Use ``SO_REUSEPORT`` if it is available, defaults to false
211 :param int tcp_fast_open_qsize: The size of the TCP Fast Open queue. Set to a number
212 higher than 0 to enable TCP Fast Open when available.
215 Control Socket, Console and Webserver
216 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
218 .. function:: addConsoleACL(netmask)
220 .. versionadded:: 1.3.0
222 Add a netmask to the existing console ACL, allowing remote clients to connect to the console. Please make sure that encryption
223 has been enabled with :func:`setKey` before doing so. The default is to only allow 127.0.0.1/8 and ::1/128.
225 :param str netmask: A CIDR netmask, e.g. ``"192.0.2.0/24"``. Without a subnetmask, only the specific address is allowed.
227 .. function:: controlSocket(address)
229 Bind to ``addr`` and listen for a connection for the console. Since 1.3.0 only connections from local users are allowed
230 by default, :func:`addConsoleACL` and :func:`setConsoleACL` can be used to enable remote connections. Please make sure
231 that encryption has been enabled with :func:`setKey` before doing so. Enabling encryption is also strongly advised for
232 local connections, since not enabling it allows any local user to connect to the console.
234 :param str address: An IP address with optional port. By default, the port is 5199.
236 .. function:: inClientStartup()
238 Returns true while the console client is parsing the configuration.
240 .. function:: inConfigCheck()
242 .. versionadded:: 1.5.0
244 Returns true while the configuration is being checked, ie when run with ``--check-config``.
246 .. function:: makeKey()
248 Generate and print an encryption key.
250 .. function:: setConsoleConnectionsLogging(enabled)
252 .. versionadded:: 1.2.0
254 Whether to log the opening and closing of console connections.
256 :param bool enabled: Default to true.
258 .. function:: setKey(key)
260 Use ``key`` as shared secret between the client and the server
262 :param str key: An encoded key, as generated by :func:`makeKey`
264 .. function:: setConsoleACL(netmasks)
266 .. versionadded:: 1.3.0
268 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
269 has been enabled with :func:`setKey` before doing so.
271 :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.
273 .. function:: showConsoleACL()
275 Print a list of all netmasks allowed to connect to the console.
277 .. function:: testCrypto()
279 Test the crypto code, will report errors when something is not ok.
281 .. function:: setConsoleOutputMaxMsgSize(size)
283 .. versionadded:: 1.3.3
285 Set the maximum size in bytes of a single console message, default set to 10 MB.
287 :param int size: The new maximum size.
289 Webserver configuration
290 ~~~~~~~~~~~~~~~~~~~~~~~
292 .. function:: webserver(listen_address, password[, apikey[, custom_headers]])
294 Launch the :doc:`../guides/webserver` with statistics and the API.
296 :param str listen_address: The IP address and Port to listen on
297 :param str password: The password required to access the webserver
298 :param str apikey: The key required to access the API
299 :param {[str]=str,...} custom_headers: Allows setting custom headers and removing the defaults
301 .. function:: setAPIWritable(allow [,dir])
303 Allow modifications via the API.
304 Optionally saving these changes to disk.
305 Modifications done via the API will not be written to the configuration by default and will not persist after a reload
307 :param bool allow: Set to true to allow modification through the API
308 :param str dir: A valid directory where the configuration files will be written by the API.
310 .. function:: setWebserverConfig(options)
312 .. versionadded:: 1.3.3
314 Setup webserver configuration. See :func:`webserver`.
316 :param table options: A table with key: value pairs with webserver options.
320 * ``password=newPassword``: string - Changes the API password
321 * ``apiKey=newKey``: string - Changes the API Key (set to an empty string do disable it)
322 * ``custom_headers={[str]=str,...}``: map of string - Allows setting custom headers and removing the defaults.
327 .. function:: addACL(netmask)
329 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.
331 :param str netmask: A CIDR netmask, e.g. ``"192.0.2.0/24"``. Without a subnetmask, only the specific address is allowed.
333 .. function:: rmACL(netmask)
335 Remove a network from the existing ACL controlling which clients can send UDP, TCP, DNS over TLS and DNS over HTTPS queries. See :ref:`ACL` for more information.
336 This function only removes previously added entries, it does not remove subnets of entries.
338 :param str netmask: A CIDR netmask, e.g. ``"192.0.2.0/24"``. Without a subnetmask, only the specific address is allowed.
342 addACL("192.0.2.0/24") -- for example add subnet to the ACL
343 rmACL("192.0.2.10") -- does NOT work, the ACL is unchanged
344 rmACL("192.0.2.0/24") -- does work, the exact match is removed from the ACL
346 .. function:: setACL(netmasks)
348 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.
350 :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.
352 .. function:: showACL()
354 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.
359 .. function:: setECSOverride(bool)
361 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
363 :param bool: Whether to override an existing EDNS Client Subnet option present in the query. Defaults to false
365 .. function:: setECSSourcePrefixV4(prefix)
367 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
369 :param int prefix: The prefix length
371 .. function:: setECSSourcePrefixV6(prefix)
373 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
375 :param int prefix: The prefix length
380 .. function:: setRingBuffersLockRetries(num)
382 .. versionadded:: 1.3.0
384 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
386 :param int num: The maximum number of attempts. Defaults to 5 if there is more than one shard, 0 otherwise.
388 .. function:: setRingBuffersSize(num [, numberOfShards])
390 .. versionchanged:: 1.3.0
391 ``numberOfShards`` optional parameter added.
393 Set the capacity of the ringbuffers used for live traffic inspection to ``num``, and the number of shards to ``numberOfShards`` if specified.
395 :param int num: The maximum amount of queries to keep in the ringbuffer. Defaults to 10000
396 :param int numberOfShards: the number of shards to use to limit lock contention. Defaults to 1
401 .. function:: newServer(server_string)
402 newServer(server_table)
404 .. versionchanged:: 1.3.0
405 Added ``checkClass``, ``sockets`` and ``checkFunction`` to server_table.
407 .. versionchanged:: 1.4.0
408 Added ``checkInterval``, ``checkTimeout`` and ``rise`` to server_table.
410 Add a new backend server. Call this function with either a string::
413 "IP:PORT" -- IP and PORT of the backend server
419 address="IP:PORT", -- IP and PORT of the backend server (mandatory)
420 id=STRING, -- Use a pre-defined UUID instead of a random one
421 qps=NUM, -- Limit the number of queries per second to NUM, when using the `firstAvailable` policy
422 order=NUM, -- The order of this server, used by the `leastOutstanding` and `firstAvailable` policies
423 weight=NUM, -- The weight of this server, used by the `wrandom`, `whashed` and `chashed` policies, default: 1
424 -- Supported values are a minimum of 1, and a maximum of 2147483647.
425 pool=STRING|{STRING}, -- The pools this server belongs to (unset or empty string means default pool) as a string or table of strings
426 retries=NUM, -- The number of TCP connection attempts to the backend, for a given query
427 tcpConnectTimeout=NUM, -- The timeout (in seconds) of a TCP connection attempt
428 tcpSendTimeout=NUM, -- The timeout (in seconds) of a TCP write attempt
429 tcpRecvTimeout=NUM, -- The timeout (in seconds) of a TCP read attempt
430 tcpFastOpen=BOOL, -- Whether to enable TCP Fast Open
431 ipBindAddrNoPort=BOOL, -- Whether to enable IP_BIND_ADDRESS_NO_PORT if available, default: true
432 name=STRING, -- The name associated to this backend, for display purpose
433 checkClass=NUM, -- Use NUM as QCLASS in the health-check query, default: DNSClass.IN
434 checkName=STRING, -- Use STRING as QNAME in the health-check query, default: "a.root-servers.net."
435 checkType=STRING, -- Use STRING as QTYPE in the health-check query, default: "A"
436 checkFunction=FUNCTION,-- Use this function to dynamically set the QNAME, QTYPE and QCLASS to use in the health-check query (see :ref:`Healthcheck`)
437 checkTimeout=NUM, -- The timeout (in milliseconds) of a health-check query, default: 1000 (1s)
438 setCD=BOOL, -- Set the CD (Checking Disabled) flag in the health-check query, default: false
439 maxCheckFailures=NUM, -- Allow NUM check failures before declaring the backend down, default: 1
440 checkInterval=NUM -- The time in seconds between health checks
441 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
442 useClientSubnet=BOOL, -- Add the client's IP address in the EDNS Client Subnet option when forwarding the query to this backend
443 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
444 -- The following formats are supported:
445 -- "address", e.g. "192.0.2.2"
446 -- "interface name", e.g. "eth0"
447 -- "address@interface", e.g. "192.0.2.2@eth0"
448 addXPF=NUM, -- Add the client's IP address and port to the query, along with the original destination address and port,
449 -- 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)
450 sockets=NUM, -- Number of sockets (and thus source ports) used toward the backend server, defaults to a single one
451 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. This requires the ``parseECS`` option of the corresponding cache to be set to true
452 rise=NUM -- Require NUM consecutive successful checks before declaring the backend up, default: 1
455 :param str server_string: A simple IP:PORT string.
456 :param table server_table: A table with at least a 'name' key
458 .. function:: getServer(index) -> Server
460 .. versionchanged:: 1.5.0
461 ``index`` might be an UUID.
463 Get a :class:`Server`
465 :param int or str index: The number of the server (as seen in :func:`showServers`) or its UUID as a string.
466 :returns: The :class:`Server` object or nil
468 .. function:: getServers()
470 Returns a table with all defined servers.
472 .. function:: rmServer(index)
476 .. versionchanged:: 1.5.0
477 ``uuid`` selection added.
479 Remove a backend server.
481 :param int or str index: The number of the server (as seen in :func:`showServers`), its UUID as a string, or a server object.
482 :param Server server: A :class:`Server` object as returned by e.g. :func:`getServer`.
486 A server object returned by :func:`getServer` can be manipulated with these functions.
490 This object represents a backend server. It has several methods.
492 .. method:: Server:addPool(pool)
494 Add this server to a pool.
496 :param str pool: The pool to add the server to
498 .. method:: Server:getName() -> string
500 Get the name of this server.
502 :returns: The name of the server, or an empty string if it does not have one
504 .. method:: Server:getNameWithAddr() -> string
506 Get the name plus IP address and port of the server
508 :returns: A string containing the server name if any plus the server address and port
510 .. method:: Server:getOutstanding() -> int
512 Get the number of outstanding queries for this server.
514 :returns: The number of outstanding queries
516 .. method:: Server:isUp() -> bool
518 Returns the up status of the server
520 :returns: true when the server is up, false otherwise
522 .. method:: Server:rmPool(pool)
524 Removes the server from the named pool
526 :param str pool: The pool to remove the server from
528 .. method:: Server:setAuto([status])
530 .. versionchanged:: 1.3.0
531 ``status`` optional parameter added.
533 Set the server in the default auto state.
534 This will enable health check queries that will set the server ``up`` and ``down`` appropriately.
536 :param bool status: Set the initial status of the server to ``up`` (true) or ``down`` (false) instead of using the last known status
538 .. method:: Server:setQPS(limit)
540 Limit the queries per second for this server.
542 :param int limit: The maximum number of queries per second
544 .. method:: Server:setDown()
546 Set the server in an ``DOWN`` state.
547 The server will not receive queries and the health checks are disabled
549 .. method:: Server:setUp()
551 Set the server in an ``UP`` state.
552 This server will still receive queries and health checks are disabled
554 Apart from the functions, a :class:`Server` object has these attributes:
556 .. attribute:: Server.name
558 The name of the server
560 .. attribute:: Server.upStatus
562 Whether or not this server is up or down
564 .. attribute:: Server.order
566 The order of the server
568 .. attribute:: Server.weight
570 The weight of the server
575 :class:`Server`\ s can be part of any number of pools.
576 Pools are automatically created when a server is added to a pool (with :func:`newServer`), or can be manually created with :func:`addPool`.
578 .. function:: addPool(name) -> ServerPool
580 Returns a :class:`ServerPool`.
582 :param string name: The name of the pool to create
584 .. function:: getPool(name) -> ServerPool
586 Returns a :class:`ServerPool` or nil.
588 :param string name: The name of the pool
590 .. function:: getPoolServers(name) -> [ Server ]
592 Returns a list of :class:`Server`\ s or nil.
594 :param string name: The name of the pool
596 .. function:: showPools()
598 Display the name, associated cache, server policy and associated servers for every pool.
600 .. class:: ServerPool
602 This represents the pool where zero or more servers are part of.
604 .. method:: ServerPool:getCache() -> PacketCache
606 Returns the :class:`PacketCache` for this pool or nil.
608 .. method:: ServerPool:getECS()
610 .. versionadded:: 1.3.0
612 Whether dnsdist will add EDNS Client Subnet information to the query before looking up into the cache,
613 when all servers from this pool are down. For more information see :meth:`ServerPool:setECS`.
615 .. method:: ServerPool:setCache(cache)
617 Adds ``cache`` as the pool's cache.
619 :param PacketCache cache: The new cache to add to the pool
621 .. method:: ServerPool:unsetCache()
623 Removes the cache from this pool.
625 .. method:: ServerPool:setECS()
627 .. versionadded:: 1.3.0
629 Set to true if dnsdist should add EDNS Client Subnet information to the query before looking up into the cache,
630 when all servers from this pool are down. If at least one server is up, the preference of the
631 selected server is used, this parameter is only useful if all the backends in this pool are down
632 and have EDNS Client Subnet enabled, since the queries in the cache will have been inserted with
633 ECS information. Default is false.
638 A Pool can have a packet cache to answer queries directly instead of going to the backend.
639 See :doc:`../guides/cache` for a how to.
641 .. function:: newPacketCache(maxEntries[, maxTTL=86400[, minTTL=0[, temporaryFailureTTL=60[, staleTTL=60[, dontAge=false[, numberOfShards=1[, deferrableInsertLock=true[, maxNegativeTTL=3600[, parseECS=false]]]]]]]) -> PacketCache
643 .. versionchanged:: 1.3.0
644 ``numberOfShards`` and ``deferrableInsertLock`` parameters added.
646 .. versionchanged:: 1.3.1
647 ``maxNegativeTTL`` and ``parseECS`` parameters added.
649 .. deprecated:: 1.4.0
651 Creates a new :class:`PacketCache` with the settings specified.
653 :param int maxEntries: The maximum number of entries in this cache
654 :param int maxTTL: Cap the TTL for records to his number
655 :param int minTTL: Don't cache entries with a TTL lower than this
656 :param int temporaryFailureTTL: On a SERVFAIL or REFUSED from the backend, cache for this amount of seconds
657 :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
658 :param bool dontAge: Don't reduce TTLs when serving from the cache. Use this when :program:`dnsdist` fronts a cluster of authoritative servers
659 :param int numberOfShards: Number of shards to divide the cache into, to reduce lock contention
660 :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
661 :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
662 :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
664 .. function:: newPacketCache(maxEntries, [options]) -> PacketCache
666 .. versionadded:: 1.4.0
668 Creates a new :class:`PacketCache` with the settings specified.
670 :param int maxEntries: The maximum number of entries in this cache
674 * ``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.
675 * ``dontAge=false``: bool - Don't reduce TTLs when serving from the cache. Use this when :program:`dnsdist` fronts a cluster of authoritative servers.
676 * ``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.
677 * ``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.
678 * ``maxTTL=86400``: int - Cap the TTL for records to his number.
679 * ``minTTL=0``: int - Don't cache entries with a TTL lower than this.
680 * ``numberOfShards=1``: int - Number of shards to divide the cache into, to reduce lock contention.
681 * ``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. Enabling this option is required for the 'zero scope' option to work
682 * ``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.
683 * ``temporaryFailureTTL=60``: int - On a SERVFAIL or REFUSED from the backend, cache for this amount of seconds..
685 .. class:: PacketCache
687 Represents a cache that can be part of :class:`ServerPool`.
689 .. method:: PacketCache:dump(fname)
691 .. versionadded:: 1.3.1
693 Dump a summary of the cache entries to a file.
695 :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.
697 .. method:: PacketCache:expunge(n)
699 Remove entries from the cache, leaving at most ``n`` entries
701 :param int n: Number of entries to keep
703 .. method:: PacketCache:expungeByName(name [, qtype=DNSQType.ANY[, suffixMatch=false]])
705 .. versionchanged:: 1.2.0
706 ``suffixMatch`` parameter added.
708 Remove entries matching ``name`` and type from the cache.
710 :param DNSName name: The name to expunge
711 :param int qtype: The type to expunge, can be a pre-defined :ref:`DNSQType`
712 :param bool suffixMatch: When set to true, remove al entries under ``name``
714 .. method:: PacketCache:getStats()
716 .. versionadded:: 1.4.0
718 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.
720 .. method:: PacketCache:isFull() -> bool
722 Return true if the cache has reached the maximum number of entries.
724 .. method:: PacketCache:printStats()
726 Print the cache stats (number of entries, hits, misses, deferred lookups, deferred inserts, lookup collisions, insert collisions and TTL too shorts).
728 .. method:: PacketCache:purgeExpired(n)
730 Remove expired entries from the cache until there is at most ``n`` entries remaining in the cache.
732 :param int n: Number of entries to keep
734 .. method:: PacketCache:toString() -> string
736 Return the number of entries in the Packet Cache, and the maximum number of entries
741 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.
743 .. function:: getBind(index) -> ClientState
745 Return a :class:`ClientState` object.
747 :param int index: The object index
749 .. function:: getBindCount()
751 .. versionadded:: 1.5.0
753 Return the number of binds (Do53, DNSCrypt, DoH and DoT).
755 ClientState functions
756 ~~~~~~~~~~~~~~~~~~~~~
758 .. class:: ClientState
760 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.
762 .. method:: ClientState:attachFilter(filter)
764 Attach a BPF filter to this frontend.
766 :param BPFFilter filter: The filter to attach to this frontend
768 .. method:: ClientState:detachFilter()
770 Remove the BPF filter associated to this frontend, if any.
772 .. method:: ClientState:toString() -> string
774 Return the address and port this frontend is listening on.
776 :returns: The address and port this frontend is listening on
778 .. attribute:: ClientState.muted
780 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.
782 Status, Statistics and More
783 ---------------------------
785 .. function:: dumpStats()
787 Print all statistics dnsdist gathers
789 .. function:: getDOHFrontend(idx)
791 .. versionadded:: 1.4.0
793 Return the DOHFrontend object for the DNS over HTTPS bind of index ``idx``.
795 .. function:: getDOHFrontendCount()
797 .. versionadded:: 1.5.0
799 Return the number of DOHFrontend binds.
801 .. function:: getTLSContext(idx)
803 .. versionadded:: 1.3.0
805 Return the TLSContext object for the context of index ``idx``.
807 .. function:: getTLSFrontend(idx)
809 .. versionadded:: 1.3.1
811 Return the TLSFrontend object for the TLS bind of index ``idx``.
813 .. function:: getTLSFrontendCount()
815 .. versionadded:: 1.5.0
817 Return the number of TLSFrontend binds.
819 .. function:: grepq(selector[, num])
820 grepq(selectors[, num])
822 Prints the last ``num`` queries matching ``selector`` or ``selectors``.
826 * a netmask (e.g. '192.0.2.0/24')
827 * a DNS name (e.g. 'dnsdist.org')
828 * a response time (e.g. '100ms')
830 :param str selector: Select queries based on this property.
831 :param {str} selectors: A lua table of selectors. Only queries matching all selectors are shown
832 :param int num: Show a maximum of ``num`` recent queries, default is 10.
834 .. function:: setVerboseHealthChecks(verbose)
836 Set whether health check errors should be logged. This is turned off by default.
838 :param bool verbose: Set to true if you want to enable health check errors logging
840 .. function:: showBinds()
842 Print a list of all the current addresses and ports dnsdist is listening on, also called ``frontends``
844 .. function:: showDOHFrontends()
846 .. versionadded:: 1.4.0
848 Print the list of all availables DNS over HTTPS frontends.
850 .. function:: showDOHResponseCodes()
852 .. versionadded:: 1.4.0
854 Print the HTTP response codes statistics for all availables DNS over HTTPS frontends.
856 .. function:: showResponseLatency()
858 Show a plot of the response time latency distribution
860 .. function:: showServers([options])
862 .. versionchanged:: 1.4.0
863 ``options`` optional parameter added
865 This function shows all backend servers currently configured and some statistics.
866 These statics have the following fields:
868 * ``#`` - The number of the server, can be used as the argument for :func:`getServer`
869 * ``UUID`` - The UUID of the backend. Can be set with the ``id`` option of :func:`newServer`
870 * ``Address`` - The IP address and port of the server
871 * ``State`` - The current state of the server
872 * ``Qps`` - Current number of queries per second
873 * ``Qlim`` - Configured maximum number of queries per second
874 * ``Ord`` - The order number of the server
875 * ``Wt`` - The weight of the server
876 * ``Queries`` - Total amount of queries sent to this server
877 * ``Drops`` - Number of queries that were dropped by this server
878 * ``Drate`` - Number of queries dropped per second by this server
879 * ``Lat`` - The latency of this server in milliseconds
880 * ``Pools`` - The pools this server belongs to
882 :param table options: A table with key: value pairs with display options.
886 * ``showUUIDs=false``: bool - Whether to display the UUIDs, defaults to false.
888 .. function:: showTCPStats()
890 Show some statistics regarding TCP
892 .. function:: showTLSContexts()
894 .. versionadded:: 1.3.0
896 Print the list of all availables DNS over TLS contexts.
898 .. function:: showTLSErrorCounters()
900 .. versionadded:: 1.4.0
902 Display metrics about TLS handshake failures.
904 .. function:: showVersion()
906 Print the version of dnsdist
908 .. function:: topBandwidth([num])
910 Print the top ``num`` clients that consume the most bandwidth.
912 :param int num: Number to show, defaults to 10.
914 .. function:: topClients([num])
916 Print the top ``num`` clients sending the most queries over length of ringbuffer
918 :param int num: Number to show, defaults to 10.
920 .. function:: topQueries([num[, labels]])
922 Print the ``num`` most popular QNAMEs from queries.
923 Optionally grouped by the rightmost ``labels`` DNS labels.
925 :param int num: Number to show, defaults to 10
926 :param int label: Number of labels to cut down to
928 .. function:: topResponses([num[, rcode[, labels]]])
930 Print the ``num`` most seen responses with an RCODE of ``rcode``.
931 Optionally grouped by the rightmost ``labels`` DNS labels.
933 :param int num: Number to show, defaults to 10
934 :param int rcode: :ref:`Response code <DNSRCode>`, defaults to 0 (No Error)
935 :param int label: Number of labels to cut down to
937 .. function:: topSlow([num[, limit[, labels]]])
939 Print the ``num`` slowest queries that are slower than ``limit`` milliseconds.
940 Optionally grouped by the rightmost ``labels`` DNS labels.
942 :param int num: Number to show, defaults to 10
943 :param int limit: Show queries slower than this amount of milliseconds, defaults to 2000
944 :param int label: Number of labels to cut down to
951 .. function:: addDynBlocks(addresses, message[, seconds=10[, action]])
953 .. versionchanged:: 1.2.0
954 ``action`` parameter added.
956 Block a set of addresses with ``message`` for (optionally) a number of seconds.
957 The default number of seconds to block for is 10.
959 :param addresses: set of Addresses as returned by an exceed function
960 :param string message: The message to show next to the blocks
961 :param int seconds: 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 DNSAction.None, meaning the one set with :func:`setDynBlocksAction` is used)
964 Please see the documentation for :func:`setDynBlocksAction` to confirm which actions are supported by the action paramater.
966 .. function:: clearDynBlocks()
968 Remove all current dynamic blocks.
970 .. function:: showDynBlocks()
972 List all dynamic blocks in effect.
974 .. function:: setDynBlocksAction(action)
976 .. versionchanged:: 1.3.3
977 ``DNSAction.NXDomain`` action added.
979 Set which action is performed when a query is blocked.
980 Only DNSAction.Drop (the default), DNSAction.NoOp, DNSAction.NXDomain, DNSAction.Refused, DNSAction.Truncate and DNSAction.NoRecurse are supported.
984 Getting addresses that exceeded parameters
985 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
987 .. function:: exceedServFails(rate, seconds)
989 Get set of addresses that exceed ``rate`` servfails/s over ``seconds`` seconds
991 :param int rate: Number of Servfails per second to exceed
992 :param int seconds: Number of seconds the rate has been exceeded
994 .. function:: exceedNXDOMAINs(rate, seconds)
996 get set of addresses that exceed ``rate`` NXDOMAIN/s over ``seconds`` seconds
998 :param int rate: Number of NXDOMAIN per second to exceed
999 :param int seconds: Number of seconds the rate has been exceeded
1001 .. function:: exceedRespByterate(rate, seconds)
1003 get set of addresses that exceeded ``rate`` bytes/s answers over ``seconds`` seconds
1005 :param int rate: Number of bytes per second to exceed
1006 :param int seconds: Number of seconds the rate has been exceeded
1008 .. function:: exceedQRate(rate, seconds)
1010 Get set of address that exceed ``rate`` queries/s over ``seconds`` seconds
1012 :param int rate: Number of queries per second to exceed
1013 :param int seconds: Number of seconds the rate has been exceeded
1015 .. function:: exceedQTypeRate(type, rate, seconds)
1017 Get set of address that exceed ``rate`` queries/s for queries of QType ``type`` over ``seconds`` seconds
1019 :param int type: QType
1020 :param int rate: Number of QType queries per second to exceed
1021 :param int seconds: Number of seconds the rate has been exceeded
1026 Instead of using several `exceed*()` lines, dnsdist 1.3.0 introduced a new `DynBlockRulesGroup` object
1027 which can be used to group dynamic block rules.
1029 See :doc:`../guides/dynblocks` for more information about the case where using a `DynBlockRulesGroup` might be
1030 faster than the existing rules.
1032 .. function:: dynBlockRulesGroup() -> DynBlockRulesGroup
1034 .. versionadded:: 1.3.0
1036 Creates a new :class:`DynBlockRulesGroup` object.
1038 .. class:: DynBlockRulesGroup
1040 Represents a group of dynamic block rules.
1042 .. method:: DynBlockRulesGroup:setQueryRate(rate, seconds, reason, blockingTime [, action [, warningRate]])
1044 .. versionchanged:: 1.3.3
1045 ``warningRate`` parameter added.
1047 Adds a query rate-limiting rule, equivalent to:
1049 addDynBlocks(exceedQRate(rate, seconds), reason, blockingTime, action)
1052 :param int rate: Number of queries per second to exceed
1053 :param int seconds: Number of seconds the rate has been exceeded
1054 :param string reason: The message to show next to the blocks
1055 :param int blockingTime: The number of seconds this block to expire
1056 :param int action: The action to take when the dynamic block matches, see :ref:`here <DNSAction>`. (default to the one set with :func:`setDynBlocksAction`)
1057 :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
1059 .. method:: DynBlockRulesGroup:setRCodeRate(rcode, rate, seconds, reason, blockingTime [, action [, warningRate]])
1061 .. versionchanged:: 1.3.3
1062 ``warningRate`` parameter added.
1064 Adds a rate-limiting rule for responses of code ``rcode``, equivalent to:
1066 addDynBlocks(exceedServfails(rcode, rate, seconds), reason, blockingTime, action)
1069 :param int rcode: The response code
1070 :param int rate: Number of responses per second to exceed
1071 :param int seconds: Number of seconds the rate has been exceeded
1072 :param string reason: The message to show next to the blocks
1073 :param int blockingTime: The number of seconds this block to expire
1074 :param int action: The action to take when the dynamic block matches, see :ref:`here <DNSAction>`. (default to the one set with :func:`setDynBlocksAction`)
1075 :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
1077 .. method:: DynBlockRulesGroup:setRCodeRatio(rcode, ratio, seconds, reason, blockingTime, minimumNumberOfResponses [, action [, warningRate]])
1079 .. versionadded:: 1.5.0
1081 Adds a rate-limiting rule for the ratio of responses of code ``rcode`` over the total number of responses for a given client.
1083 :param int rcode: The response code
1084 :param int ratio: Ratio of responses per second of the given rcode over the total number of responses for this client to exceed
1085 :param int seconds: Number of seconds the ratio has been exceeded
1086 :param string reason: The message to show next to the blocks
1087 :param int blockingTime: The number of seconds this block to expire
1088 :param int minimumNumberOfResponses: How many total responses is required for this rule to apply
1089 :param int action: The action to take when the dynamic block matches, see :ref:`here <DNSAction>`. (default to the one set with :func:`setDynBlocksAction`)
1090 :param int warningRatio: If set to a non-zero value, the ratio above which a warning message will be issued and a no-op block inserted
1092 .. method:: DynBlockRulesGroup:setQTypeRate(qtype, rate, seconds, reason, blockingTime [, action [, warningRate]])
1094 .. versionchanged:: 1.3.3
1095 ``warningRate`` parameter added.
1097 Adds a rate-limiting rule for queries of type ``qtype``, equivalent to:
1099 addDynBlocks(exceedQTypeRate(type, rate, seconds), reason, blockingTime, action)
1102 :param int qtype: The qtype
1103 :param int rate: Number of queries per second to exceed
1104 :param int seconds: Number of seconds the rate has been exceeded
1105 :param string reason: The message to show next to the blocks
1106 :param int blockingTime: The number of seconds this block to expire
1107 :param int action: The action to take when the dynamic block matches, see :ref:`here <DNSAction>`. (default to the one set with :func:`setDynBlocksAction`)
1108 :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
1110 .. method:: DynBlockRulesGroup:setResponseByteRate(rate, seconds, reason, blockingTime [, action [, warningRate]])
1112 .. versionchanged:: 1.3.3
1113 ``warningRate`` parameter added.
1115 Adds a bandwidth rate-limiting rule for responses, equivalent to:
1117 addDynBlocks(exceedRespByterate(rate, seconds), reason, blockingTime, action)
1120 :param int rate: Number of bytes per second to exceed
1121 :param int seconds: Number of seconds the rate has been exceeded
1122 :param string reason: The message to show next to the blocks
1123 :param int blockingTime: The number of seconds this block to expire
1124 :param int action: The action to take when the dynamic block matches, see :ref:`here <DNSAction>`. (default to the one set with :func:`setDynBlocksAction`)
1125 :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
1127 .. method:: DynBlockRulesGroup:apply()
1129 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.
1131 .. method:: DynBlockRulesGroup:setQuiet(quiet)
1133 .. versionadded:: 1.4.0
1135 Set whether newly blocked clients or domains should be logged.
1137 :param bool quiet: True means that insertions will not be logged, false that they will. Default is false.
1139 .. method:: DynBlockRulesGroup:excludeRange(netmasks)
1141 .. versionadded:: 1.3.1
1143 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.
1145 :param int netmasks: A netmask, or list of netmasks, as strings, like for example "192.0.2.1/24"
1147 .. method:: DynBlockRulesGroup:includeRange(netmasks)
1149 .. versionadded:: 1.3.1
1151 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.
1153 :param int netmasks: A netmask, or list of netmasks, as strings, like for example "192.0.2.1/24"
1155 .. method:: DynBlockRulesGroup:toString()
1157 .. versionadded:: 1.3.1
1159 Return a string describing the rules and range exclusions of this DynBlockRulesGroup.
1164 A SuffixMatchNode can be used to quickly check whether a given name belongs to a set or not. This is achieved
1165 using an efficient tree structure based on DNS labels, making lookups cheap.
1166 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,
1167 if 'example.com.' is added to the set, 'www.example.com.' and 'sub.www.example.com.' will match as well.
1168 If you are looking for exact name matching, your might want to consider using a :class:`DNSNameSet` instead.
1170 .. function:: newSuffixMatchNode()
1172 Creates a new :class:`SuffixMatchNode`.
1174 .. class:: SuffixMatchNode
1176 Represent a set of DNS suffixes for quick matching.
1178 .. method:: SuffixMatchNode:add(name)
1180 .. versionchanged:: 1.4.0
1181 This method now accepts strings, lists of DNSNames and lists of strings.
1183 Add a suffix to the current set.
1185 :param DNSName name: The suffix to add to the set.
1186 :param string name: The suffix to add to the set.
1187 :param table name: The suffixes to add to the set. Elements of the table should be of the same type, either DNSName or string.
1189 .. method:: SuffixMatchNode:check(name) -> bool
1191 Return true if the given name is a sub-domain of one of those in the set, and false otherwise.
1193 :param DNSName name: The name to test against the set.
1198 .. function:: maintenance()
1200 If this function exists, it is called every second to so regular tasks.
1201 This can be used for e.g. :doc:`Dynamic Blocks <../guides/dynblocks>`.
1203 .. function:: setAllowEmptyResponse()
1205 .. versionadded:: 1.4.0
1207 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.
1209 .. function:: makeIPCipherKey(password) -> string
1211 .. versionadded:: 1.4.0
1213 Hashes the password to generate a 16-byte key that can be used to pseudonymize IP addresses with IP cipher.
1215 .. function:: generateOCSPResponse(pathToServerCertificate, pathToCACertificate, pathToCAPrivateKey, outputFile, numberOfDaysOfValidity, numberOfMinutesOfValidity)
1217 .. versionadded:: 1.4.0
1219 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.
1220 The resulting file can be directly used with the :func:`addDOHLocal` or the :func:`addTLSLocal` functions.
1222 :param string pathToServerCertificate: Path to a file containing the certificate used by the server.
1223 :param string pathToCACertificate: Path to a file containing the certificate of the certification authority that was used to sign the server certificate.
1224 :param string pathToCAPrivateKey: Path to a file containing the private key corresponding to the certification authority certificate.
1225 :param string outputFile: Path to a file where the resulting OCSP response will be written to.
1226 :param int numberOfDaysOfValidity: Number of days this OCSP response should be valid.
1227 :param int numberOfMinutesOfValidity: Number of minutes this OCSP response should be valid, in addition to the number of days.
1232 .. class:: DOHFrontend
1234 .. versionadded:: 1.4.0
1236 This object represents an address and port dnsdist is listening on for DNS over HTTPS queries.
1238 .. method:: DOHFrontend:loadTicketsKeys(ticketsKeysFile)
1240 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.
1242 :param str ticketsKeysFile: The path to a file from where TLS tickets keys should be loaded.
1244 .. method:: DOHFrontend:reloadCertificates()
1246 Reload the current TLS certificate and key pairs.
1248 .. method:: DOHFrontend:rotateTicketsKey()
1250 Replace the current TLS tickets key by a new random one.
1252 .. method:: DOHFrontend:setResponsesMap(rules)
1254 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.
1256 :param list of DOHResponseMapEntry objects rules: A list of DOHResponseMapEntry objects, obtained with :func:`newDOHResponseMapEntry`.
1259 .. function:: newDOHResponseMapEntry(regex, status, content [, headers]) -> DOHResponseMapEntry
1261 .. versionadded:: 1.4.0
1263 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.
1264 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.
1266 :param str regex: A regular expression to match the path against.
1267 :param int status: The HTTP code to answer with.
1268 :param str content: The content of the HTTP response, or a URL if the status is a redirection (3xx).
1269 :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`.
1274 .. class:: TLSContext
1276 .. versionadded:: 1.3.0
1278 This object represents an address and port dnsdist is listening on for DNS over TLS queries.
1280 .. method:: TLSContext:rotateTicketsKey()
1282 Replace the current TLS tickets key by a new random one.
1284 .. method:: TLSContext:loadTicketsKeys(ticketsKeysFile)
1286 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.
1288 :param str ticketsKeysFile: The path to a file from where TLS tickets keys should be loaded.
1293 .. class:: TLSFrontend
1295 .. versionadded:: 1.3.1
1297 This object represents the configuration of a listening frontend for DNS over TLS queries. To each frontend is associated a TLSContext.
1299 .. method:: TLSContext:loadNewCertificatesAndKeys(certFile(s), keyFile(s))
1301 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.
1303 :param str certFile(s): The path to a X.509 certificate file in PEM format, or a list of paths to such files.
1304 :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.
1306 EDNS on Self-generated answers
1307 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1309 There are several mechanisms in dnsdist that turn an existing query into an answer right away,
1310 without reaching out to the backend, including :func:`SpoofAction`, :func:`RCodeAction`, :func:`TCAction`
1311 and returning a response from ``Lua``. Those responses should, according to :rfc:`6891`, contain an ``OPT``
1312 record if the received request had one, which is the case by default and can be disabled using
1313 :func:`setAddEDNSToSelfGeneratedResponses`.
1315 We must, however, provide a responder's maximum payload size in this record, and we can't easily know the
1316 maximum payload size of the actual backend so we need to provide one. The default value is 1500 and can be
1317 overriden using :func:`setPayloadSizeOnSelfGeneratedAnswers`.
1319 .. function:: setAddEDNSToSelfGeneratedResponses(add)
1321 .. versionadded:: 1.3.3
1323 Whether to add EDNS to self-generated responses, provided that the initial query had EDNS.
1325 :param bool add: Whether to add EDNS, default is true.
1327 .. function:: setPayloadSizeOnSelfGeneratedAnswers(payloadSize)
1329 .. versionadded:: 1.3.3
1331 Set the UDP payload size advertised via EDNS on self-generated responses. In accordance with
1332 :rfc:`RFC 6891 <6891#section-6.2.5>`, values lower than 512 will be treated as equal to 512.
1334 :param int payloadSize: The responder's maximum UDP payload size, in bytes. Default is 1500.
1339 PowerDNS products can poll the security status of their respective versions. This polling, naturally,
1340 happens over DNS. If the result is that a given version has a security problem, the software will
1341 report this at level ‘Error’ during startup, and repeatedly during operations, every
1342 :func:`setSecurityPollInterval` seconds.
1344 By default, security polling happens on the domain ‘secpoll.powerdns.com’, but this can be changed with
1345 the :func:`setSecurityPollSuffix` function. If this setting is made empty, no polling will take place.
1346 Organizations wanting to host their own security zones can do so by changing this setting to a domain name
1347 under their control.
1349 To enable distributors of PowerDNS to signal that they have backported versions, the PACKAGEVERSION
1350 compilation-time macro can be used to set a distributor suffix.
1352 .. function:: setSecurityPollInterval(interval)
1354 .. versionadded:: 1.3.3
1356 Set the interval, in seconds, between two security pollings.
1358 :param int interval: The interval, in seconds, between two pollings. Default is 3600.
1360 .. function:: setSecurityPollSuffix(suffix)
1362 .. versionadded:: 1.3.3
1364 Domain name from which to query security update notifications. Setting this to an empty string disables secpoll.
1366 :param string suffix: The suffix to use, default is 'secpoll.powerdns.com.'.