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 field 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 <eagle@eyrie.org> for InterNetNews.

SEE ALSO

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