mdw@git.distorted.org.uk Git - adns/blob - README

   1                                     GNU adns
   2
   3    Advanced, easy to use, asynchronous-capable DNS client library and
   4    utilities.
   5
   6    adns is a resolver library for C (and C++) programs, and a collection
   7    of useful DNS resolver utilities.
   8
   9 C library
  10
  11    In contrast with the standard interfaces, gethostbyname et al and
  12    libresolv, it has the following features:
  13      * It is reasonably easy to use for simple programs which just want to
  14        translate names to addresses, look up MX records, etc.
  15      * It can be used in an asynchronous, non-blocking, manner. Many
  16        queries can be handled simultaneously.
  17      * Responses are decoded automatically into a natural representation
  18        for a C program - there is no need to deal with DNS packet and
  19        RRDATA formats.
  20      * Sanity checking (eg, name syntax checking, reverse/forward
  21        correspondence, CNAME pointing to CNAME) is performed automatically
  22        by default.
  23      * Time-to-live, CNAME and other similar information is returned in an
  24        easy-to-use form, without getting in the way.
  25      * There is no global state in the library; resolver state is an
  26        opaque data structure which the client creates explicitly. A
  27        program can have several instances of the resolver.
  28      * Errors are reported to the application in a way that distinguishes
  29        the various causes of failure properly.
  30      * adns understands conventional resolv.conf, but this can overridden
  31        by environment variables.
  32      * Flexibility. For example, the application can tell adns to: ignore
  33        environment variables (for setuid programs), disable hostname
  34        syntax sanity checks to return arbitrary data, override or ignore
  35        resolv.conf in favour of supplied configuration, etc.
  36      * Believed to be correct ! For example, will correctly back off to
  37        TCP in case of long replies or queries, or to other nameservers if
  38        several are available. It has sensible handling of bad responses
  39        etc.
  40
  41 DNS utility programs
  42
  43    adns also comes with a number of utility programs for use from the
  44    command line and in scripts:
  45      * adnslogres is a much faster version of Apache's logresolv program.
  46      * adnsresfilter is a filter which copies its input to its output,
  47        replacing IP addresses by the corresponding names, without unduly
  48        delaying the output. For example, you can usefully pipe the output
  49        of netstat -n, tcpdump -ln, and the like, into it.
  50      * adnshost is a general-purpose DNS lookup utility which can be used
  51        easily in from the command line and from shell scripts to do simple
  52        lookups. In a more advanced mode it can be used as a
  53        general-purpose DNS helper program for scripting languages which
  54        can invoke and communicate with subprocesses. See the [1]adnshost
  55        usage message for a summary of its capabilities.
  56
  57 Documentation
  58
  59    I'm afraid there is no manual yet. However, competent C programmers
  60    should be able to use the library based on the [2]commented adns.h
  61    header file, and the usage messages for the programs should be
  62    sufficient.
  63
  64 Feedback
  65
  66    I'd be pleased if you would let me know if you're using my library in
  67    your project, and what you think of it.
  68
  69    Bug reports should be reported to the [3]GNU Debbugs. Send an email to
  70    submit@debbugs.gnu.org and at the top of your email, in a paragraph of
  71    its own, write the single line
  72 Package: adns
  73
  74    Your bug report will be published via to the adns-discuss list.
  75
  76    Feedback and discussion takes place on the adns-discuss list. You can
  77    mail me privately at ijackson@chiark.greenend.org.uk.
  78
  79 Mailinglists
  80
  81    I have set up mailinglists adns-announce and adns-discuss. The
  82    announcements list is moderated and will contain only announcements of
  83    important bugs, new versions, etc.
  84
  85    There are [4]archives and subscription web pages, or you can subscribe
  86    by sending mail containing the word `subscribe' to
  87    adns-announce-REQUEST@chiark.greenend.org.uk or
  88    adns-discuss-REQUEST@chiark.greenend.org.uk.
  89
  90 Documentation
  91
  92      * [5]adns.h API header file with documentation comments
  93      * [6]usage message for adnshost
  94
  95 Download and source code
  96
  97      * The [7]current release as a gzipped tarfile.
  98      * [8]Previous versions and other files (including OpenPGP
  99        signatures).
 100      * [9]master git (version control) repository browser.
 101
 102    adns is also available from the [10]GNU Project FTP servers and their
 103    [11]mirrors.
 104
 105 Installation note
 106
 107    adns requires a real nameserver like BIND running on the same system or
 108    a nearby one, which must be willing to provide `recursive service'.
 109    I.e., adns is a `stub resolver'.
 110
 111    adns requires that your real nameserver is on the same machine, or
 112    connected via a secure network, so that an attacker cannot fake the
 113    replies to adns's queries.
 114
 115 References and related projects
 116
 117      * [12]Python bindings by Andy Dustman.
 118      * [13]liboop event loop library has a built-in binding for adns.
 119      * [14]port to MS Visual Studio 6 C++ by Jarle Aase.
 120
 121 Copyright and licensing
 122
 123    adns is Copyright 1997-2000,2003,2006,2014-2016 Ian Jackson, Copyright
 124    2014 Mark Wooding, Copyright 1999-2000,2003,2006 Tony Finch, and
 125    Copyright (C) 1991 Massachusetts Institute of Technology.
 126
 127    adns is free software; you can redistribute it and/or modify it under
 128    the terms of the GNU General Public License as published by the Free
 129    Software Foundation; either version 3 of the License, or (at your
 130    option) any later version.
 131
 132    This program and documentation is distributed in the hope that it will
 133    be useful, but without any warranty; without even the implied warranty
 134    of merchantability or fitness for a particular purpose. See the [15]GNU
 135    General Public License for more details.
 136
 137    You should have received a copy of the GNU General Public License along
 138    with adns, or one should be available above; if not, write to the
 139    [16]Free Software Foundation or email ijackson@chiark.greenend.org.uk.
 140      __________________________________________________________________
 141
 142    Ian Jackson / ijackson@chiark.greenend.org.uk.
 143
 144    [17]GNU home page; [18]chiark home page; [19]site or mirror home page
 145
 146    This web page is Copyright (C)1996-2005,2014-2016 Ian Jackson. See the
 147    [20]Copyright/acknowledgements.
 148
 149 References
 150
 151    1. http://www.chiark.greenend.org.uk/~ian/adns/docs/adnshost.txt
 152    2. http://www.chiark.greenend.org.uk/~ian/adns/docs/adns.h.txt
 153    3. http://debbugs.gnu.org/
 154    4. http://www.chiark.greenend.org.uk/mailman/listinfo
 155    5. http://www.chiark.greenend.org.uk/~ian/adns/docs/adns.h.txt
 156    6. http://www.chiark.greenend.org.uk/~ian/adns/docs/adnshost.txt
 157    7. http://www.chiark.greenend.org.uk/~ian/adns/adns.tar.gz
 158    8. http://www.chiark.greenend.org.uk/~ian/adns/ftp/
 159    9. http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git/adns.git/
 160   10. http://www.gnu.org/
 161   11. http://www.gnu.org/order/ftp.html
 162   12. http://code.google.com/p/adns-python
 163   13. http://www.lysator.liu.se/liboop/
 164   14. http://adns.jgaa.com/
 165   15. http://www.chiark.greenend.org.uk/~ian/adns/docs/COPYING.txt
 166   16. http://www.fsf.org/
 167   17. http://www.gnu.org/
 168   18. http://www.chiark.greenend.org.uk/
 169   19. file:///
 170   20. http://www.chiark.greenend.org.uk/~ian/sw-www-copy.html