- adns
- Advanced, easy to use, asynchronous-capable DNS client library.
+ GNU adns
+
+ Advanced, easy to use, asynchronous-capable DNS client library and
+ utilities.
+
+ adns is a resolver library for C (and C++) programs, and a collection
+ of useful DNS resolver utilities.
+
+C library
- adns is a resolver library for C (and C++) programs. In contrast with
- the existing interfaces, gethostbyname et al and libresolv, it has the
- following features:
+ In contrast with the standard interfaces, gethostbyname et al and
+ libresolv, it has the following features:
* It is reasonably easy to use for simple programs which just want
to translate names to addresses, look up MX records, etc.
* It can be used in an asynchronous, non-blocking, manner. Many
correspondence, CNAME pointing to CNAME) is performed
automatically.
* Time-to-live, CNAME and other similar information is returned in
- an easy-to-use form, without affecting ease-of-use.
+ an easy-to-use form, without getting in the way.
* There is no global state in the library; resolver state is an
opaque data structure which the client creates explicitly. A
program can have several instances of the resolver.
* Understands conventional resolv.conf, but this can overridden by
environment variables.
* Flexibility. For example, the application can tell adns to: ignore
- environment variables (for setuid programs), disable sanity checks
- eg to return arbitrary data, override or ignore resolv.conf in
- favour of supplied configuration, change its caching behaviour,
- use a different flow of control model, etc.
+ environment variables (for setuid programs), disable hostname
+ syntax sanity checks to return arbitrary data, override or ignore
+ resolv.conf in favour of supplied configuration, etc.
* Believed to be correct ! For example, will correctly back off to
TCP in case of long replies or queries, or to other nameservers if
several are available. It has sensible handling of bad responses
etc.
+
+DNS utility programs
+ adns also comes with a number of utility programs for use from the
+ command line and in scripts:
+ * adnslogres is a much faster version of Apache's logresolv program.
+ * adnsresfilter is a filter which copies its input to its output,
+ replacing IP addresses by the corresponding names, without unduly
+ delaying the output. For example, you can usefully pipe the output
+ of netstat -n, tcpdump -ln, and the like, into it.
+ * adnshost is a general-purpose DNS lookup utility which can be used
+ easily in from the command line and from shell scripts to do
+ simple lookups. In a more advanced mode it can be used as a
+ general-purpose DNS helper program for scripting languages which
+ can invoke and communicate with subprocesses. See the [1]adnshost
+ usage message for a summary of its capabilities.
+
Forthcoming:
-
+
I hope that future versions may also have the following features:
- * The library can be used by threads in a multithreaded program in a
- natural way. It will multiplex many threads' queries through a
- single query socket.
- * Limited caching behaviour.
+ * The library should be useable by threads in a multithreaded
+ program in a natural way. It should multiplex many threads'
+ queries through a single query socket.
* IPv6 support.
+ * Some kind of awareness of DNSSEC.
+ * Possibly some very limited caching behaviour.
+ * There was, at one point, a draft native Perl interface from Tony
+ Finch.
+
+Documentation
+
+ I'm afraid there is no manual yet. However, competent C programmers
+ should be able to use the library based on the [2]commented adns.h
+ header file, and the usage messages for the programs should be
+ sufficient.
+
+Feedback
+
+ I'd be pleased if you would let me know if you're using my library in
+ your project, and what you think of it.
+
+ If you are subscribed to adns-discuss please send feedback, including
+ bug reports, there; otherwise send mail to
+ adns-bugreports@chiark.greenend.org.uk. If you'd prefer that your
+ message wasn't forwarded to the adns-bugreports list, send it to
+ adns-maint@chiark.greenend.org.uk.
+
+Mailinglists
+
+ I have set up mailinglists adns-announce and adns-discuss. The
+ announcements list is moderated and will contain only announcements of
+ important bugs, new versions, etc. The bug reports address mentioned
+ above is also a mailing list; feel free to subscribe to it.
+
+ There are [3]archives and subscription web pages, or you can subscribe
+ by sending mail containing the word `subscribe' to
+ adns-announce-REQUEST@chiark.greenend.org.uk or
+ adns-discuss-REQUEST@chiark.greenend.org.uk.
+
+Download
+
+ Available for download from [4]chiark.greenend.org.uk are:
+ * The [5]current release as a gzipped tarfile.
+ * [6]adns.h API header file with comments, and [7]usage message for
+ adnshost (currently there is no manual, sorry).
+ * All versions released so far are also available via [8]anonymous
+ FTP and [9]HTTP.
+
+ You can also access the project CVS repositories:
+ * A mirror of the source code repository is available via rsync from
+ rsync.chiark.greenend.org.uk::ftp/users/ian/cvs-pub/adns (use FTP
+ first to find your way around), or via [10]cvsweb.
+ * This web page is maintained in [11]Savannah, where you can browse
+ the [12]webpage CVS.
+
+ adns is also available from the [13]GNU Project FTP servers and their
+ [14]mirrors.
+
+Technical note
- (Technical note: adns requires a real nameserver like BIND running on
+ adns requires a real nameserver like [15]BIND or [16]Dents running on
the same system or a nearby one, which must be willing to provide
`recursive service'. I.e., adns is a `stub resolver'. All properly
configured UN*X and GNU systems will already have such nameserver(s);
- they are usually listed in /etc/resolv.conf.)
+ they are usually listed in /etc/resolv.conf.
+
+References and related projects
+
+ * [17]Python bindings by Andy Dustman.
+ * [18]Haskell bindings by Peter Simons.
+ * [19]liboop event loop library (by Dan Egnor) has a built-in
+ binding for adns.
+ * [20]port to MS Visual Studio 6 C++ by Jarle Aase.
+
+Copyright and licensing
+
+ adns is Copyright 1997-2000,2003,2006 Ian Jackson, Copyright
+ 1999-2000,2003,2006 Tony Finch, and Copyright (C) 1991 Massachusetts
+ Institute of Technology.
+
+ adns 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 2 of the License, or (at your
+ option) any later version.
+
+ This program and documentation 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
+ [21]GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with adns, or one should be available above; if not, write to
+ the [22]Free Software Foundation, 59 Temple Place - Suite 330, Boston,
+ MA 02111-1307, USA, or email adns-maint@chiark.greenend.org.uk.
+ _________________________________________________________________
+
+ [23]Ian Jackson / [24]adns-maint@chiark.greenend.org.uk; more [25]free
+ software by me.
+
+ [26]GNU home page; [27]chiark home page; [28]site or mirror home page
+
+ This web page is Copyright (C)1996-2005 Ian Jackson. See the
+ [29]Copyright/acknowledgements.
+
+ Use any browser - [30]Campaign for a non-browser-specific WWW
+
+References
+
+ 1. http://www.chiark.greenend.org.uk/~ian/adns/adnshost.txt
+ 2. http://www.chiark.greenend.org.uk/~ian/adns/adns.h.txt
+ 3. http://www.chiark.greenend.org.uk/mailman/listinfo
+ 4. http://www.chiark.greenend.org.uk/~ian/adns/
+ 5. http://www.chiark.greenend.org.uk/~ian/adns/adns.tar.gz
+ 6. http://www.chiark.greenend.org.uk/~ian/adns/adns.h.txt
+ 7. http://www.chiark.greenend.org.uk/~ian/adns/adnshost.txt
+ 8. ftp://ftp.chiark.greenend.org.uk/users/ian/adns/
+ 9. http://www.chiark.greenend.org.uk/~ian/adns/ftp/
+ 10. http://www.chiark.greenend.org.uk/ucgi/~ijackson/cvsweb/adns/
+ 11. http://savannah.gnu.org/
+ 12. http://savannah.gnu.org/cgi-bin/viewcvs/software/adns/?cvsroot=www.gnu.org
+ 13. http://www.gnu.org/
+ 14. http://www.gnu.org/order/ftp.html
+ 15. http://www.isc.org/view.cgi?/products/BIND/index.phtml
+ 16. http://www.dents.org/
+ 17. http://dustman.net/andy/python/adns-python
+ 18. http://cryp.to/hsdns/
+ 19. http://liboop.ofb.net/ref
+ 20. http://adns.jgaa.com/
+ 21. http://www.chiark.greenend.org.uk/~ian/COPYING.txt
+ 22. http://www.fsf.org/
+ 23. http://www.chiark.greenend.org.uk/
+ 24. mailto:adns-maint@chiark.greenend.org.uk
+ 25. http://www.chiark.greenend.org.uk/~ian/software/
+ 26. http://www.gnu.org/
+ 27. http://www.chiark.greenend.org.uk/
+ 28. file://localhost/
+ 29. http://www.chiark.greenend.org.uk/~ian/sw-www-copy.html
+ 30. http://www.anybrowser.org/campaign/
~ianmdlvl / adns.git / blobdiff