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GDNSD.ZONEFILE(5)		     gdnsd		     GDNSD.ZONEFILE(5)

       gdnsd.zonefile -	gdnsd zonefile syntax


	 $TTL 86400

	 @     SOA ns1 hostmaster (
	       1      ;	serial
	       7200   ;	refresh
	       30M    ;	retry
	       3D     ;	expire
	       900    ;	ncache

	 @     NS
	 @     NS      ns2
	 @     NS

	 ns1   A ; a comment      A

	 @     7200    MX      10 mail-a
	 @     7200    MX      100 mail-b

	 $ttl 86400
	 ; a comment
	 mail-a	       A
	 mail-b	       A

	 subz	       NS      ns1.subz
	 subz	       NS      ns2.subz
	 ns1.subz      A
	 ns2.subz      A

	 www   600/10  DYNA    some_plugin!resource_name
	 alias	       CNAME   www

	 _http._tcp    1800    SRV     5 500 80	www

	 foo	       TXT     "blah blah" "blah"
	 _spf	       TXT     "v=spf1 ..."

       This is the primary zonefile syntax for gdnsd(8).  The syntax is
       designed	to be as close as possible to the standard zonefile syntax
       from RFC	1035 (which is the "standard" format one typically sees	with
       traditional BIND	servers).  This	document will just cover a few
       important highlights and/or deviations from the norm.

       The standard $TTL and $ORIGIN directives	are supported with their
       normal syntax and semantics.

       $TTL changes the	default	TTL of any records coming after	it, and	can
       occur multiple times.  Note that	in the absence of a zonefile-level
       $TTL setting, the default TTL comes from	the global config option
       "zones_default_ttl", which in turn defaults to 86400 (1 day).

       $ORIGIN changes what is appended	to unqualified hostnames (those
       lacking a final ".") seen in the	zone file from that point forward, as
       well as any "@" entries (which is an alias for the current origin).
       $ORIGIN itself may also be an unqualified name, in which	case the
       previous	origin is appended to it.  Any fully-qualified $ORIGIN must be
       within the zone described by this zonefile.  The	default	origin is the
       zone name itself.

       $ADDR_LIMIT_V4 is a non-standard, gdnsd-specific	directive.  It
       requires	a single unsigned integer argument.  The argument limits the
       total number of "A" records to include in the server's responses	for
       any given "A" rrset (whether static or dynamic).	 The default limit is
       zero, which is interpreted as no	limit.	Setting	the limit via this
       directive affects all rrsets until the value is changed again by
       another directive.  gdnsd always	rotates	the RRs	of an address RR-set
       in a round-robin	fashion, and this rotation occurs before the limit is
       applied,	allowing a small pseudo-random subset of a larger list to be
       delivered via this mechanism.

       $ADDR_LIMIT_V6 same as above, but for IPv6 "AAAA" rrsets.

       The RFC-standard	$INCLUDE directive is not supported because it would
       greatly complicate the detection	of zone	update transactions with our
       current filesystem-based	change detection scheme.  Most legitimate uses
       of $INCLUDE to reduce redundancy	should be replaced with	a zonefile-
       generating script instead, perhaps using	a template system.

       BIND's $GENERATE	extension is not supported at this time, but there's
       no fundamental reason it	couldn't be added at a later date.

       gdnsd(8)	supports the following standard	RR types with their standard
       RDATA formats: SOA, A, AAAA, NS,	PTR, CNAME, MX,	SRV, TXT, and NAPTR.
       All RRs must be in class	"IN", which is the implicit default.

       It also supports	the generic format for unknown RR types	documented in
       RFC 3597, which has syntax like:

	 foo TYPE31337 \# 10 0123456789	ABCDEF0123

       ... which indicates an RR of numeric type 31337 containing 10 bytes of
       RDATA, specified	as the final part of the RR as a pair of 5-byte	hex
       strings.	 See RFC 3597 itself for full details.	Note however that
       gdnsd does not allow using the RFC 3597 format for types	gdnsd
       explicitly supports (all	of which predate 3597 anyways),	and that even
       in the RFC 3597 case we still only allow	class "IN" RRs.

       Additionally, gdnsd supports two	special-case, non-standard virtual
       resource	record types DYNA and DYNC:

       "DYNA" is for dynamically-determined address records (both A and	AAAA)
       via plugin code.	 The right-hand-side of	a "DYNA" RR is a plugin	name
       and a resource name separated by	an exclamation mark.  The named	plugin
       will be fed the resource	name and the DNS client's IP address and/or
       edns-client-subnet information, and it is up to the plugin code which
       addresses of which types	to return in the response.

       The dynamic plugin lookup for "DYNA" will be used anywhere that regular
       "A" and/or "AAAA" records would be used.	 This includes not only	direct
       responses to "A"	and "AAAA" queries, but	also things like Additional-
       section RRs and "ANY"-query output.  "DYNA" cannot co-exist with	actual
       static A	or AAAA	records	at the same name, but can co-exist with	any
       other RR-type.


	 ; asks	plugin 'geoip' to provide address data from
	 ;  its	resource named 'pubwww'	for address queries.
	 foo DYNA geoip!pubwww
	 foo MX	10 mail

       "DYNC" has the same syntax as "DYNA" above, but different data rules.
       Plugins results returned	via "DYNC" can be either addresses or a
       "CNAME" record.	"DYNC" cannot co-exist with any	other resource record
       at the same name, much like normal "CNAME" RRs.	This also implies that
       "DYNC" cannot be	used at	the zone root, as the zone root	requires "NS"
       and "SOA" RRs.  While "DYNC" responses are included in "ANY" queries
       for the given name, they	are not	used in	Additional-section processing,
       even when the plugin responds with address records rather than "CNAME".


	 ; asks	plugin 'geoip' to provide address data or a CNAME
	 ;  (at	the plugin's discretion) for its resource named
	 ;  'www'.  No other RRs of any	type for name 'foo' are
	 ;  legal alongside this record.
	 foo DYNC geoip!www

       "DYNA" and "DYNC" TTL fields have a syntax extension and	slightly
       different meanings than the TTL field of	a traditional, fixed RR.  The
       format for DYNA/DYNC TTLs is "MAX[/MIN]", with "MIN" defaulting to half
       of "MAX"	if not specified explicitly.

       Based on	the configuration and state of the underlying monitored
       services, (see "service_types" in gdnsd.config(8)), gdnsd knows the
       minimum time to the next	possible state-change which could affect a
       given "DYNA" or "DYNC" result.  For example, given the configuration
       and state, it may be known that in order	for a currently	"DOWN" address
       to transition to	the "UP" state (and thus change	the answer to a	given
       query) would require 7 more successful monitoring checks	in a row at
       8-second	intervals, and therefore cannot	happen in less than 56
       seconds.	 In this case 56 seconds would be the internally-calculated

       In cases	where multiple monitored resources factor into a plugin's
       decision	and/or response	(e.g. multifo),	the calculated TTL will
       generally be the	minimum	of all involved	internal monitoring TTLs.
       This calculated TTL is then clamped to the "MAX"	and "MIN" limits from
       the zonefile.


	   ; Explicit range of 30 - 300:
	   www 300/30 DYNC weighted!foo
	   ; Implicit range of 150 - 300:
	   www 300 DYNA	metafo!myservice
	   ; Avoid all TTL-mangling and	use a fixed value of 10	minutes:
	   www 600/600 DYNA geoip!foo-dist

   TXT data auto-splitting
       gdnsd's "TXT" RRs support the auto-splitting of long string constants.
       Rather than manually breaking the data into 255-byte chunks as required
       by the protocol,	you can	specify	a single long chunk and	have the
       server break it at 255 byte boundaries automatically.  (this behavior
       can be disabled via gdnsd.config(5) as well, which will turn oversized
       chunks into zonefile parsing errors).

       gdnsd(8), gdnsd.config(5)

       The gdnsd manual.

       Copyright (c) 2012 Brandon L Black <>

       This file is part of gdnsd.

       gdnsd is	free software: you can redistribute it and/or modify it	under
       the terms of the	GNU General Public License as published	by the Free
       Software	Foundation, either version 3 of	the License, or	(at your
       option) any later version.

       gdnsd is	distributed in the hope	that it	will be	useful,	but WITHOUT
       ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
       FITNESS FOR A PARTICULAR	PURPOSE.  See the GNU General Public License
       for more	details.

       You should have received	a copy of the GNU General Public License along
       with gdnsd.  If not, see	<>.

gdnsd 2.2.4			  2017-05-18		     GDNSD.ZONEFILE(5)


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