bind-to-tinydns 0.4.3                         Daniel Erat <dan-tinydns@erat.org>
================================================================================


What it does / Why it does it
================================================================================
This program attempts to convert a BIND 9 zone file into the tinydns-data
format natively used by the tinydns component of Dan Bernstein's djbdns
package (http://cr.yp.to/djbdns.html).  This can be useful if you need to
periodically convert zones that are stored in BIND format to tinydns format
and you don't have the willingness or the oodles of memory needed to run a
copy of BIND from which you can slave the zones with axfr-get (think >100
MB DNSbl zones, for instance).  For one-time conversions, you should
instead use the AXFR procedure described by Dan
(http://cr.yp.to/djbdns/run-server-bind.html).


Getting / Compiling
================================================================================
The newest version of this program is available from my homepage
(http://erat.org/).  After downloading the source, extract it and run
"make".  Copy bind-to-tinydns wherever you want after this (I would
recommend /usr/local/bin).  Edit the Makefile and source or email me if it
doesn't work.


Usage
================================================================================
bind-to-tinydns is invoked in the following manner:

  bind-to-tinydns <origin> <output file> <temp file>

The BIND zone is read from STDIN.  To convert a BIND zone file named
"input" containing the zone "example.com" to a tinydns-data file named
"output", you would run:

  bind-to-tinydns example.com output output.tmp <input

If the conversion is successful, the program exits with a return value of
0.  Otherwise, it exits with a return value of 1 (after deleting the
temporary file).  It will abort if the temporary file already exists.


Portability
================================================================================
I've only tested this program on Linux.  I hope that it will work on most
UNIX systems.  Please let me know if it doesn't.


Details
================================================================================
The zone file format described in RFC 1035, and by extension, the one used
by BIND, is not parser-friendly.  Without making this program a bigger mess
than it already is, I've tried to make it as close to BIND 9 as possible in
what it accepts and how it interprets data.  I am aware of the following
differences:

- Missing SOA records in zone files do not cause failure.
- Missing NS records in zone files do not cause failure.
- RRs that occur before $TTL directives and before any SOA records do
  not cause failure or warnings (a default TTL of 86400, rather than
  that of the MINIMUM value of the SOA's rdata, is used).
- The parser does not reject or modify RRs with the same owner that
  have different TTLs.
- IN is the only supported record class.  Records in other classes are
  ignored.
- The only supported record types are SOA, NS, MX, A, CNAME, PTR, TXT,
  and SRV.  Records of other types are ignored.
- The $INCLUDE directive is not supported, and causes failure.

If you find additional differences (or worse yet, input that makes the
program crash or go into an infinite loop), or if any of these differences
bug you, please let me know so I can fix the problem.


Version History / Changelog
================================================================================
0.3   20030521	Initial release.
0.4   20030601	Added a string structure and modified functions to use it,
		yielding simpler, safer code and a 33% performance increase
		when processing the TXT-record heavy relays.osirusoft.com
		zone.  Spun off tokenizing and parsing/emitting sections of
		main() into new functions.  Tried to mitigate
		aforementioned safety by adding a bunch of nasty code to
		handle $GENERATE directives (including ${offset,width,base}
		parameters).  The program now accepts lines with
		unterminated double- or backslash-quoted strings, but
		prints a warning.  Fixed a silly bug that would allow
		specific out-of-zone data through.
0.4.1 20030608	Fixed a stupid typo that prevented too-large TTLs in RRs
		from being detected.  Changed str_to_uint() to behave
		closer to the way that my other string-handling functions
		behave.  Added size checks for time values in SOA RDATA.
0.4.2 20040326	Mariano Absatz <baby@baby.com.ar> wrote that he came
		across some zone files generated by Microsoft's DNS software 
		that had invalid (too large) TTL values.  Made his
		recommended changes, so the program spits out a warning and
		uses the default TTL instead of exiting with a fatal error.
		I also made the program a bit more lenient in other places
		(RRs of unknown type are skipped with a warning message
		instead of causing failure, for example).  Thanks Mariano!
0.4.3 20050817  Ick, I can't believe that I wrote this ugly code. :(
                Fixed a bug that Rein <o7rein@uninet.ee> ran into, where an
                origin of "." resulted in all records being declared
                out-of-zone.