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NAME

       tinyleaf - Very simple IHAVE-only NNTP server

SYNOPSIS

       tinyleaf spool [processor]

DESCRIPTION

       tinyleaf is intended to be the simplest possible transit news server
       that still does something useful.  It must be run under inetd(8) or
       some equivalent, and only implements three commands (HELP, IHAVE, and
       QUIT).  When it receives an article, it saves it into the directory
       spool and, if processor is given, passes information about the article
       to processor via a pipe.  The file name of the article will be the MD5
       hash of its message-ID, and if a file by that name already exists,
       tinyleaf will refuse the article, reporting it as a duplicate.

       If processor is given, it should specify the path to a program.  That
       program is started when tinyleaf starts, and its current working
       directory will be spool.  For each article received by tinyleaf, a
       single line will be sent to standard input of processor.  That line
       will consist of the file name of the received article (relative to
       spool), a single space, and the message-ID of the received article.
       Note that the message-ID will be taken from the argument to the IHAVE
       command and may not match the Message-ID: header in the article.  When
       tinyleaf shuts down, standard input to processor will be closed.

       tinyleaf does no syntax verification of received articles whatsoever;
       it just stores them and optionally passes them off to processor.  It
       also never deletes articles; normally, processor should do that when
       it’s finished doing whatever it needs to with the article.

       tinyleaf expects NNTP commands on standard input and replies on
       standard output.  Status information and any error messages are sent to
       standard error.  It does no authentication; any authentication must be
       done by inetd(8) or by a wrapper program.  (One simple authentication
       mechanism is to invoke tinyleaf via tcpd(8) from TCP wrappers and use
       /etc/hosts.allow and /etc/hosts.deny to restrict who can talk to the
       server.)

       tinyleaf has a (currently hard-coded) maximum message size of 1 MB and
       a (similarly hard-coded) timeout of ten minutes for each command or
       chunk of article data.

EXAMPLE

       Suppose that you want to archive news articles on a particular host
       (like the FTP server for a newsgroup archive) where you don’t want the
       overhead of running a full-blown news server.  Write a program that
       reads one line at a time from standard input and treats everything
       before the first space as the filename of a news article to archive.
       Each time the program reads a line, it should archive that file and
       then delete it, and it should exit when it gets end of file on standard
       input.

       Then, add a line like:

           nntp stream tcp nowait archive /usr/sbin/tcpd \
             <pathbin>/tinyleaf <pathspool>/tinyleaf <pathbin>/archive

       (all on one line -- the backslash and split in this line is just for
       readability) where "archive" is the user that owns the archive,
       /usr/sbin/tcpd is the path to tcpd(8), pathbin/tinyleaf is the path to
       this program, pathspool/tinyleaf is some scratch directory that the
       user "archive" has write access to, and pathbin/archive is the path to
       your archive script.

       You can now restrict access to tinyleaf to just your local news server
       with "/etc/hosts.allow" and "/etc/hosts.deny" and set up an ordinary
       feed from the server to the archive host, just like you would to any
       other news server, of only the newsgroup that you want to archive.

       Note that the archiving script should probably perform basic syntax and
       validity checks on the input, since tinyleaf doesn’t.

       This is the application that motivated the original development of this
       program.

BUGS

       The timeout and maximum message size should really be configurable.
       tinyleaf should also probably not just respond 500 to every command
       other than HELP, IHAVE, and QUIT; there are more useful (and more
       expected) error codes that could be returned.

       An option to scan the spool directory for any left-over files and pass
       them to the processor when starting up would be useful.

HISTORY

       Written by Russ Allbery <rra@stanford.edu> for InterNetNews.

       $Id: tinyleaf.pod 8794 2009-11-15 09:28:19Z iulius $

SEE ALSO

       hosts_access(5), inetd(8), tcpd(8).