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tinydns-data(8) - phpMan
tinydns-data(8) System Manager's Manual tinydns-data(8)
NAME
tinydns-data - data tool for tinydns
DESCRIPTION
This is a reference page. For tutorial information, see the instructions for
running a DNS server (http://cr.yp.to/djbdns/run-server.html).
tinydns-data reads local DNS information from a file named data in the current directory.
It creates data.cdb in a binary format designed for fast access by tinydns(8). It may
also create some other files with names beginning with data.
tinydns-data updates data.cdb atomically, so you can use it safely while tinydns(8) is
running. If anything goes wrong with the creation of data.cdb, tinydns-data stops and
leaves the old data.cdb in place.
Data format
The DNS information in data is a series of lines. There are several types of lines, as
shown below.
Each line starts with a special character and continues with a series of colon-separated
fields. In some cases the fields may be omitted; however, all colons must be included
except at the end of the line. Spaces and tabs at the end of a line are ignored. Blank
lines are ignored.
Each line contains a ttl (``time to live'') specifying the number of seconds that the
line's DNS records may be cached. Beware that cache times below 300 seconds will be
treated as 300 by some clients, and NS cache times below 2 seconds can cause lookup fail‐
ures. You may omit ttl; tinydns-data will use default cache times, carefully selected to
work well in normal situations.
You may include a timestamp on each line. If ttl is nonzero (or omitted), the timestamp
is a starting time for the information in the line; the line will be ignored before that
time. If ttl is zero, the timestamp is an ending time (``time to die'') for the informa‐
tion in the line; tinydns(8) dynamically adjusts ttl so that the line's DNS records are
not cached for more than a few seconds past the ending time. A timestamp is an external
TAI64 timestamp, printed as 16 lowercase hexadecimal characters. For example, the lines
+www.heaven.af.mil:1.2.3.4:0:4000000038af1379 +www.heaven.af.mil:1.2.3.7::4000000038af1379
specify that www.heaven.af.mil will have address 1.2.3.4 until time 4000000038af1379
(2000-02-19 22:04:31 UTC) and will then switch to IP address 1.2.3.7.
For versions 1.04 and above: You may include a client location on each line. The line is
ignored for clients outside that location. Client locations are specified by % lines:
%lo:ipprefix
means that IP addresses starting with ipprefix are in location lo. lo is a sequence of
one or two ASCII letters. A client is in only one location; longer prefixes override
shorter prefixes. For example,
%in:192.168
%ex
+jupiter.heaven.af.mil:192.168.1.2:::in
+jupiter.heaven.af.mil:1.2.3.4:::ex
specifies that jupiter.heaven.af.mil has address 192.168.1.2 for clients in the 192.168.*
network and address 1.2.3.4 for everyone else.
Common data lines
.fqdn:ip:x:ttl:timestamp:lo
Name server for our domain fqdn.
tinydns-data creates
an NS (``name server'') record showing x.ns.fqdn as a name server for fqdn;
an A (``address'') record showing ip as the IP address of x.ns.fqdn; and
an SOA (``start of authority'') record for fqdn listing x.ns.fqdn as the primary
name server and hostmaster@fqdn as the contact address.
You may have several name servers for one domain, with a different x for each server.
tinydns(8) will return only one SOA record per domain.
If x contains a dot then tinydns-data will use x as the server name rather than x.ns.fqdn.
This feature is provided only for compatibility reasons; names not ending with fqdn will
force clients to contact parent servers much more often than they otherwise would, and
will reduce the overall reliability of DNS. You should omit ip if x has IP addresses
assigned elsewhere in data; in this case, tinydns-data will omit the A record.
Examples:
.panic.mil:1.8.7.55:a
creates an NS record showing a.ns.panic.mil as a name server for panic.mil, an A record
showing 1.8.7.55 as the IP address of a.ns.panic.mil, and an SOA record for panic.mil.
.panic.mil:1.8.7.56:dns2.panic.mil
creates an NS record showing dns2.panic.mil as a name server for panic.mil, an A record
showing 1.8.7.56 as the IP address of dns2.panic.mil, and an SOA record for panic.mil.
.panic.mil::a.ns.heaven.af.mil
creates an NS record showing a.ns.heaven.af.mil as a name server for panic.mil, and an SOA
record for panic.mil.
&fqdn:ip:x:ttl:timestamp:lo
Name server for domain fqdn.
tinydns-data creates
an NS record showing x.ns.fqdn as a name server for fqdn and
an A record showing ip as the IP address of x.ns.fqdn.
If x contains a dot then it is treated specially; see above.
You may have several name servers for one domain, with a different x for each server.
Normally & is used for domains delegated by this server to child servers, while . is used
for domains delegated to this server.
Examples:
&serious.panic.mil:1.8.248.6:a
creates an NS record showing a.ns.serious.panic.mil as a name server for seri‐
ous.panic.mil, and an A record showing 1.8.248.6 as the IP address of a.ns.seri‐
ous.panic.mil.
&serious.panic.mil:1.8.248.7:ns7.panic.mil
creates an NS record showing ns7.panic.mil as a name server for serious.panic.mil, and an
A record showing 1.8.248.7 as the IP address of ns7.panic.mil.
=fqdn:ip:ttl:timestamp:lo
Host fqdn with IP address ip.
tinydns-data creates
an A record showing ip as the IP address of fqdn and
a PTR (``pointer'') record showing fqdn as the name of d.c.b.a.in-addr.arpa if ip
is a.b.c.d.
Remember to specify name servers for some suffix of fqdn; otherwise tinydns(8) will not
respond to queries about fqdn. The same comment applies to other records described below.
Similarly, remember to specify name servers for some suffix of d.c.b.a.in-addr.arpa, if
that domain has been delegated to you.
Example:
=button.panic.mil:1.8.7.108
creates an A record showing 1.8.7.108 as the IP address of button.panic.mil, and a PTR
record showing button.panic.mil as the name of 108.7.8.1.in-addr.arpa.
+fqdn:ip:ttl:timestamp:lo
Alias fqdn with IP address ip. This is just like =fqdn:ip:ttl except that tinydns-data
does not create the PTR record.
For versions 1.04 and above: tinydns(8) returns addresses (from + or = or @ or . or &
lines) in a random order in the answer section. If there are more than 8 records, it
returns a random set of 8.
Example:
+button.panic.mil:1.8.7.109
creates an A record showing 1.8.7.109 as another IP address for button.panic.mil.
@fqdn:ip:x:dist:ttl:timestamp:lo
Mail exchanger for fqdn.
tinydns-data creates
an MX (``mail exchanger'') record showing x.mx.fqdn as a mail exchanger for fqdn at
distance dist and
an A record showing ip as the IP address of x.mx.fqdn.
You may omit dist; the default distance is 0.
If x contains a dot then it is treated specially; see above.
You may create several MX records for fqdn, with a different x for each server. Make sure
to arrange for the SMTP server on each IP address to accept mail for fqdn.
Example:
@panic.mil:1.8.7.88:mail.panic.mil
creates an MX record showing mail.panic.mil as a mail exchanger for panic.mil at distance
0, and an A record showing 1.8.7.88 as the IP address of mail.panic.mil.
#comment
Comment line. The line is ignored.
Uncommon data lines
-fqdn:s:ttl:timestamp:lo
For versions 1.04 and above: This type of line is used by programs that automatically edit
+ lines in data to temporarily exclude addresses of overloaded or dead machines. The line
is ignored.
'fqdn:s:ttl:timestamp:lo
TXT (``text'') record for fqdn. tinydns-data creates a TXT record for fqdn containing the
string s. You may use octal nnn codes to include arbitrary bytes inside s; for example,
072 is a colon.
^fqdn:p:ttl:timestamp:lo
PTR record for fqdn. tinydns-data creates a PTR record for fqdn pointing to the domain
name p.
Cfqdn:p:ttl:timestamp:lo
CNAME (``canonical name'') record for fqdn. tinydns-data creates a CNAME record for fqdn
pointing to the domain name p.
Don't use Cfqdn if there are any other records for fqdn Don't use Cfqdn for common
aliases; use +fqdn instead. Remember the wise words of Inigo Montoya: ``You keep using
CNAME records. I do not think they mean what you think they mean.''
Zfqdn:mname:rname:ser:ref:ret:exp:min:ttl:timestamp:lo
SOA record for fqdn showing mname as the primary name server, rname (with the first .
converted to @) as the contact address, ser as the serial number, ref as the refresh time,
ret as the retry time, exp as the expire time, and min as the minimum time. ser, ref,
ret, exp, and min may be omitted; they default to, respectively, the modification time of
the data file, 16384 seconds, 2048 seconds, 1048576 seconds, and 2560 seconds.
:fqdn:n:rdata:ttl:timestamp:lo
Generic record for fqdn. tinydns-data creates a record of type n for fqdn showing rdata.
n must be an integer between 1 and 65535; it must not be 2 (NS), 5 (CNAME), 6 (SOA), 12
(PTR), 15 (MX), or 252 (AXFR). The proper format of rdata depends on n. You may use
octal nnn codes to include arbitrary bytes inside rdata.
Wildcards
tinydns supports wildcards of the form *.fqdn. Information for *.fqdn is provided for
every name ending with .fqdn, except names that have their own records and names that are
covered by more specific wildcards.
For example, the lines
+pink.floyd.u.heaven.af.mil:1.2.3.4
+*.u.heaven.af.mil:1.2.3.200
have the same effect as
+pink.floyd.u.heaven.af.mil:1.2.3.4
+joe.u.heaven.af.mil:1.2.3.200
+bill.u.heaven.af.mil:1.2.3.200
+floyd.u.heaven.af.mil:1.2.3.200
+ishtar.u.heaven.af.mil:1.2.3.200
+joe.bob.u.heaven.af.mil:1.2.3.200
+sally.floyd.u.heaven.af.mil:1.2.3.200
+post.pink.floyd.u.heaven.af.mil:1.2.3.200
and so on.
As another example, the lines
+pink.floyd.u.heaven.af.mil:1.2.3.4
@*.u.heaven.af.mil::mail.heaven.af.mil
have the same effect as
+pink.floyd.u.heaven.af.mil:1.2.3.4
@joe.u.heaven.af.mil::mail.heaven.af.mil
@bill.u.heaven.af.mil::mail.heaven.af.mil
@floyd.u.heaven.af.mil::mail.heaven.af.mil
@ishtar.u.heaven.af.mil::mail.heaven.af.mil
@joe.bob.u.heaven.af.mil::mail.heaven.af.mil
@sally.floyd.u.heaven.af.mil::mail.heaven.af.mil
@post.pink.floyd.u.heaven.af.mil::mail.heaven.af.mil
and so on. Notice that the wildcard does not apply to pink.floyd.u.heaven.af.mil, because
that name has its own records.
A typical data file:
=lion.heaven.af.mil:1.2.3.4
@heaven.af.mil:1.2.3.4
@3.2.1.in-addr.arpa:1.2.3.4
=tiger.heaven.af.mil:1.2.3.5
.heaven.af.mil:1.2.3.5:a
.3.2.1.in-addr.arpa:1.2.3.5:a
=bear.heaven.af.mil:1.2.3.6
.heaven.af.mil:1.2.3.6:b
.3.2.1.in-addr.arpa:1.2.3.6:b
=cheetah.heaven.af.mil:1.2.3.248
=panther.heaven.af.mil:1.2.3.249
Here is the same information in BIND zone-file format with the two zones merged:
heaven.af.mil. 2560 IN SOA a.ns.heaven.af.mil. hostmaster.heaven.af.mil. ...
heaven.af.mil. 259200 IN NS a.ns.heaven.af.mil.
heaven.af.mil. 259200 IN NS b.ns.heaven.af.mil.
heaven.af.mil. 86400 IN MX mx.heaven.af.mil.
3.2.1.in-addr.arpa. 2560 IN SOA a.ns.3.2.1.in-addr.arpa. hostmaster.3.2.1.in-addr.arpa.
...
3.2.1.in-addr.arpa. 259200 IN NS a.ns.3.2.1.in-addr.arpa.
3.2.1.in-addr.arpa. 259200 IN NS b.ns.3.2.1.in-addr.arpa.
3.2.1.in-addr.arpa. 86400 IN MX mx.3.2.1.in-addr.arpa.
4.3.2.1.in-addr.arpa. 86400 IN PTR lion.heaven.af.mil.
lion.heaven.af.mil. 86400 IN A 1.2.3.4
mx.heaven.af.mil. 86400 IN A 1.2.3.4
mx.3.2.1.in-addr.arpa. 86400 IN A 1.2.3.4
5.3.2.1.in-addr.arpa. 86400 IN PTR tiger.heaven.af.mil.
tiger.heaven.af.mil. 86400 IN A 1.2.3.5
a.ns.heaven.af.mil. 259200 IN A 1.2.3.5
a.ns.3.2.1.in-addr.arpa. 259200 IN A 1.2.3.5
6.3.2.1.in-addr.arpa. 86400 IN PTR bear.heaven.af.mil.
bear.heaven.af.mil. 86400 IN A 1.2.3.6
b.ns.heaven.af.mil. 259200 IN A 1.2.3.6
b.ns.3.2.1.in-addr.arpa. 259200 IN A 1.2.3.6
248.3.2.1.in-addr.arpa. 86400 IN PTR cheetah.heaven.af.mil.
cheetah.heaven.af.mil. 86400 IN A 1.2.3.248
249.3.2.1.in-addr.arpa. 86400 IN PTR panther.heaven.af.mil.
panther.heaven.af.mil. 86400 IN A 1.2.3.249
Design notes
The data format is very easy for programs to edit, and reasonably easy for humans to edit,
unlike the traditional zone-file format.
tinydns-data could support a name wherever an IP address is required; it would look up the
name in DNS and use the resulting address. This would reliably track changes in offsite
IP addresses if the database were rebuilt periodically.
SEE ALSO
tinydns(8)
http://cr.yp.to/djbdns.html
tinydns-data(8)
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