Subject: FSP Frequently Asked Questions (Read This Before Posting!)
From: [email-masked] (Pete Bevin)
Date: Tue, 28 Sep 1993 02:08:04 GMT
Newsgroups: alt.comp.fsp,alt.answers,news.answers

Archive-name: fsp-faq
Last-modified: 21st August 1993

Frequently Asked Questions about FSP
------------------------------------

*** Please read this before posting to alt.comp.fsp. ***

##########################################################################
### IMPORTANT NOTICE: EVERYONE PLEASE READ THIS!
###
### Joseph Traub is no longer the FSP maintainer, and the site he
### maintained at seismo.soar.cs.cmu.edu no longer runs an FSP daemon.
### Please do NOT mail anyone at CMU about the FSP server -- the admins
### there have complained about the volume of unwanted mail.
###
### If you have questions about FSP, please mail one of the new
### maintainers -- see below for details.
##########################################################################

This is the answers to some of the frequently asked questions about FSP.
It is posted weekly to alt.comp.fsp, alt.answers and news.answers.

This article answers the following questions.

Section 1: Introduction and Help
        Q1.1 What's alt.comp.fsp?  What's FSP?
        Q1.2 Where can I get FSP?
        Q1.3 Help!  I don't understand how to use FSP!
        Q1.4 What are those funny "R" and "I" characters?
        Q1.5 Why should I, as a site admin, run an FSP daemon?

Section 2: FSP software and resources
        Q2.1 Where can I get an FTP-like interface for FSP?
        Q2.2 Where can I get a graphical interface for FSP?
        Q2.3 Where can I get hold of a list of sites?
        Q2.4 Where can I get hold of hundreds of pictures of naked women
             in compromising positions?

Section 3: Technical Issues
        Q3.1 What are the main differences between FSP and FTP?  How
             does FSP work?
        Q3.2 How secure/anonymous is FSP?
        Q3.3 Why not add passwords to FSP?
        Q3.4 So what *does* FSP stand for?

Section 4: Who's who in FSP?
        Q4.1 Who wrote FSP?
        Q4.2 Who helped put this FAQ together?

This FAQ is written and maintained by Pete Bevin ([email-masked])
with help from Phil Richards ([email-masked]).

If you have any comments, suggestion, or additions, send me (Pete) some mail.

Section 1: Introduction and Help

Q1.1: What's alt.comp.fsp?  What's fsp?

        Alt.comp.fsp is a Usenet newsgroup for discussing the FSP file
        transmission protocol.  It was created on Tuesday 4th May 1993
        by Wen-King Su ([email-masked]) after there was no
        objection on alt.config.  Before the newsgroup, there was a
        mailing list (fsp-discussion) for talking about FSP software
        internals.  This newsgroup is for discussion of both writing and
        using the software.

        FSP is a protocol, a bit like FTP (but see below), for moving
        files around.  It's designed for anonymous archives, and has
        protection against server and network overloading.  It doesn't
        use connections, so it can survive things falling over.

        Quote: `FSP is what anonymous FTP *should* be'.

Q1.2: Where can I get FSP from?

        The `official' place for FSP distributions is ftp.germany.eu.net
        (192.76.144.75), in the directory /pub/network/inet/fsp.  It is
        available both by FTP and FSP: the FSP server is on port 2001.
        Another official site is taxus.uib.no (129.177.30.10), which
        only runs an FSP server -- it's on port 9000.  The directory
        on taxus is /fspdist.

        (Note: If you're using Unix, and you don't want to set up a
        server, you will probably want to get one of the FTP-like clients
        instead -- fspclient, fspcli, or fspsh -- from the same place).

        The latest versions are:

                Unix, VMS:      fsp.271.tar.gz
                OS/2:           fsp2-03b.zip
                MS-DOS:         pcfsp104.zip

        The Unix version is the `original', and was originally written by
        Wen-King Su: Joseph Traub took over for a while, and Phil Richards
        and Pete Bevin maintain it now.  The same distribution contains
        patches by Sven Pechler to make it run on VMS.  Larkin Lowrey
        wrote the OS/2 version, and Lindsey Smith wrote the MS-DOS
        version.  Email addresses are at the end.

        (A note about .gz and .z files: they are compressed using GNU
        gzip.  Ask your local guru, or read the FAQ for comp.compression.)

        There is no Mac version, and no VM version.  If you want to get
        famous, here's your chance to get on the FSP bandwagon :-)

Q1.3: Help!  I don't understand how to use FSP!

        If you're already familiar with FTP, you might want to use one
        of the FTP-like clients instead, or even a graphical interface.
        See the answers to questions 2.1 and 2.2 below for details of
        how to get them.

        The following tutorial is adapted from an article in
        alt.comp.fsp by David DeSimone <[email-masked]>.

        The original FSP seems to have been designed for use with csh
        aliases, so if you use csh, try these aliases in your .cshrc:

        # FSP aliases:
        alias fcat   '(set noglob; exec fcatcmd \!*)'
        alias fcd    'setenv FSP_DIR `(set noglob; exec fcdcmd \!*)`'
        alias fget   '(set noglob; exec fgetcmd \!*)'
        alias fgrab  '(set noglob; exec fgrabcmd \!*)'
        alias fls    '(set noglob; exec flscmd -F \!*)'
        alias fll    '(set noglob; exec flscmd -l \!*)'
        alias fpro   '(set noglob; exec fprocmd \!*)'
        alias fpwd   'echo "$FSP_HOST ($FSP_PORT): $FSP_DIR"'
        alias frm    '(set noglob; exec frmcmd \!*)'
        alias frmdir '(set noglob; exec frmdircmd \!*)'
        alias fhost  'set fsp_host=(\!*); source ~/bin/fhost; unset fsp_host'

        The last alias, "fhost", is my own invention, and the ~/bin/fhost
        file looks like this:

        #!/bin/csh
        #
        # Since this script sets environment variables, it really needs
        # to be source'd rather than executed.  Thus the following alias
        # should be used:
        #
        # alias fhost 'set fsp_host=(\!*); source ~/.bin/fhost; unset fsp_host'
        #
 
        if ( $#fsp_host > 0 ) then

            setenv FSP_HOST $fsp_host[1]

            if ( $#fsp_host > 1 ) then
                setenv FSP_PORT $fsp_host[2]
            else
                setenv FSP_PORT 21
            endif

            if ( $#fsp_host > 2 ) then
                setenv FSP_DIR $fsp_host[3]
            else
                setenv FSP_DIR /
            endif

        endif

        if ( $?FSP_HOST ) then
            echo "$FSP_HOST ($FSP_PORT): $FSP_DIR"
        endif

        This alias lets you "connect" to a host quickly and easily.  For
        instance, to start out I give the following command:

        % fhost wuarchive.wustl.edu
        wuarchive.wustl.edu (21): /
         
        The "fhost" command tells me where I'm connected, on what port,
        and in what directory.

        Since all "fhost" does is set up some environemnt variables, we
        aren't REALLY connected.  To find out if the site is responding,
        just do a quick "fls":

        % fls
        README          etc/            mirrors2/       pub/
        README.NFS      graphics/       mirrors3/       systems/
        bin/            info/           mirrors4/       techreports/
        decus/          languages/      multimedia/     usenet/
        doc/            lost+found/     packages/       vendorware/
        edu/            mirrors/        private/

        Looks like we're up and running!  Navigating with FSP is now
        just like using the local filesystem, except the commands have
        "f" in front of them.  For instance:

        % fcd /systems/amiga/incoming
        directory mode: (owner: some other machine)(delete: NO)(create: NO)
        % fls
        AT3D-Demo.bad           devel/                  utils/
        AT3D-Demo.readme        fish/                   wb30/
        AT3D.lha                games/                  z_newfiles_Jul01
        Amiga.help              gfx/                    z_newfiles_Jul02
        DAKDUNGN.LZH            hardware/               z_newfiles_Jul03
        DAKDUNGN.README         imagine/                z_newfiles_Jul04
        DP_Desc_June.run        ls-lR.incoming          z_newfiles_Jun25
        README.UPLOADER         ls-lR.incoming.Z        z_newfiles_Jun26
        TREE                    misc/                   z_newfiles_Jun27
        archive/                mods/                   z_newfiles_Jun28
        audio/                  news/                   z_newfiles_Jun29
        cam_list.zoo            patch/                  z_newfiles_Jun30
        comm/                   programming/
        demos/                  text/
         
        Other nice commands like "fcat filename" let me see what's out
        there, or for larger files, "fcat filename | less" is very
        effective.

        Once I see a nice file that I want copied to my local system, I
        just give the "fget filename" command and away it goes.  Usually
        I type "fget filename &" which throws the transfer request into
        the background.  Then I can immediately go off and "fcd" to some
        other directory and look for more files to grab, "fcat"-ing the
        README files and such.

Q1.4 What are those funny "R" and "I" characters?

        When FSP doesn't get any response from the server, it keeps on
        sending requests.  The first time it retries, it prints an "R",
        (meaning "Retry"), and the second, third, and subsequent times,
        it prints an "I".  You might also see an "E", which means "error":
        FSP got a packet, but it was corrupted for some reason.

        Fspclient does it slightly differently: it starts by printing
        "r" and "R" characters, and then uses "-\|/" characters to draw
        a spinning bar.  As Phil Richards (the author) says, `I quite
        often see spinning bars, but usually only after the fifth pint'.

Q1.5 Why should I, as a site admin, run an FSP daemon?

        Because it's one more way people can access your site, and it
        won't cost you much extra load on the machine.  The FSP daemon
        never forks, so it won't increase your load average by more than
        one.  FSP doesn't add much to the network load either, and you
        can limit the amount of data the daemon will send out (eg, to
        2.5k/sec).

        FSP allows comprehensive logging, running off inetd, README
        files per directory, banning on per-host or per-network basis,
        reverse naming and read-only sites.  The only thing anonymous
        FTP gives that FSP doesn't is having the user type in an email
        address, and of course, this can easily be faked.  FSP logs give
        the user's hostname, which is harder to fake.

-----------------------------------------------------------------------------

Section 2: FSP software and resources

Q2.1 Where can I get an FTP-like interface for FSP?

        The interface I use is Phil Richards' ([email-masked])
        fspclient.  The latest version (still pre-alpha, but more
        reliable than your average beta release) is fspclient.0.0-h.
        You can get it by FTP from ftp.robots.ox.ac.uk as
        /pub/ox.src/fspclient.0.0-h+.tar.Z .

        Another interface to use is Nicolai Langfeldt's 'fspcli'.  It
        has a ftp like interface and more.  It is in the release
        directory on ftp.germany, and it has also been posted on
        alt.sources.  Another nice thing about it is that it's a
        small(ish) perl script rather than a large compiled executable,
        and it's not alpha OR beta.  Presently the latest version is 1.2

        Ove Ruben R Olsen ([email-masked]) has written a client quite
        similar to Nicolai's, but even smaller.  It is available in
        the fspsh directory on taxus.uib.no/9000 (see below).

        Note that if you want to use either of the last two clients,
        you'll have to have the Perl language installed.  You can get
        the latest version by FTP from prep.ai.mit.edu in
        /pub/gnu/perl*, or by FSP from wuarchive (see below) in
        /mirrors/gnu/perl*.

Q2.2 Where can I get a graphical interface for FSP?

        Andy Doherty <[email-masked]> has written an xview client
        for the X Window System.  It is available from ftp.germany as
        `fsptool-1.3.1.tar.gz'.  Like fspcli and fspshell, it acts as
        an interface to the standard FSP shell commands, rather than
        rewriting them itself.

        Note that to use this package, you will need the xview libraries:
        if you're using a Sun workstation, you're OK: otherwise, you
        may have to get and compile them yourself.

        If you're an OS/2 user, you can use the OS/2 client by Albert
        Crosby <[email-masked]>.  It wraps around the OS/2
        FSP software (see above), and also requires RexxMenu and RxU.
        It can read a list of files in the standard FSP host listing
        format, and uses RexxMenu's point-and-click interface.

Q2.3 Where can I get hold of a list of sites?

        Dan Charrois <[email-masked]> maintains a list of FSP
        servers, and you can get more information about it by sending a
        message to "[email-masked]" with the subject "fsp list" and
        the word "help" on a line by itself in the body of the message.
        You can get the latest list by saying "list" instead of "help".
        The help message will tell you how to add new site information.

        You are also encouraged to post site information to alt.comp.fsp,
        and if you post in the format below, most people will be able
        to slurp your list straight into their front-end programs.
        There's an unofficial standard for the format, which you can
        find on taxus in the file "fsplist.std".

        In the meantime, here's a list to get you going.

        128.52.46.11      21   alpha   / # GNU Alpha releases
        158.125.220.8     21   genie   / # small UK site
        192.76.144.75     2001 germany / # big German archive
        fsp.luth.se       6969 luth    / # Top of Europe
        131.215.131.148   21   mosaic  / # BSD386/Usenet
        134.109.132.2     21   pyrrhus / # OS2, linux, simtel, etc.
        146.169.2.1       21   src     / # big UK site
        129.177.30.10     9000 taxus   / # fspadm, fsp-shell tools
        131.155.140.128   21   terra   / # big Netherlands site
        18.172.1.2        21   tsx     / # linux
        fsp.warwick.ac.uk 21   warwick / # Computer Underground Digest
        128.252.135.4     21   wu      / # everything you ever wanted

Q2.4 Where can I get hold of hundreds of pictures of naked women in
     compromising positions?

        Don't ask me, I only edit the FAQ :-)

        Seriously, FSP has a reputation of being for "crooks and
        perverts".  If you know any good sites carrying illegal
        material, then do them a favour and keep them to yourself.
        Posting them won't make you any friends.

        If someone posts a list of sites, and you didn't want them to,
        please don't publicly flame them.  It doesn't endear you to
        anyone.  If you must put them right, send email.  Thank you.

---------------------------------------------------------------------------

Section 3: Technical Issues

Q3.1 What are the main differences between FSP and FTP?  How does FSP work?

        From the user's point of view, the differences are not that
        great, except that some of the more annoying features of FTP
        are gone.  Here are the main differences.

                a. The protocol can stand things going down: if the
                server or the network falls over in the middle of a
                transfer, you can just wait until it comes back up.
                You don't have to reconnect, and even better, if the
                server went down 90% through grabbing a file, you can
                continue from where you left off.

                b. The protocol doesn't need a username or password.
                You just throw packets at the server.  You don't have
                to identify yourself (though you're not completely
                anonymous -- see below).

                c. It's harder to kill off a site with an FSP server
                than with an FTP server.  The FSP daemon is designed to
                be as lightweight as possible:  it doesn't fork off any
                sub-processes, and it takes steps to limit the amount
                of traffic it handles.

                d. The user interface is completely different.  The
                interface that comes with the package consists of
                eleven commands that you can call from the shell.  In
                effect, your shell is providing all the nice functions
                like command line editing.  This makes the interface
                much more versatile than FTP's.  (See below for how to
                get an FTP-like interface, though).

                e. FSP is a bit slower than FTP.  This is a feature,
                not a bug.  The point is to keep the communication
                lightweight, and not to flood the net.

        From the programmer's point of view, fsp is a complete rewrite.

                a. Instead of TCP sockets, it uses datagrams to
                communicate, so that the connection doesn't break on a
                flaky line.

                b. FTP works by opening a port, and then asking the
                server to send a file to it.  FSP uses the same port
                all the time for communication, and asks for segments
                of a file.  So you can start off a transfer half way
                through a file, if you really want to.

                c. The server tries to make sure you don't ask for
                packets too quickly.  Each packet it sends out has a
                random identification number, which the client must
                return on the next request.  (If the client loses the
                number, it must wait a few seconds before the server
                accepts another packet from it).  Therefore, the client
                has to wait for an answer to each request before it
                sends out the next one.

Q3.2 How secure/anonymous is FSP?

        By default, the FSP daemon keeps logs of transactions, along
        with their site names.  An FSP administrator could use this to
        find out who you are, with a reasonable degree of certainty.

        In short, FSP gives you no more privacy than anonymous FTP.
        Anyone who tells you different has a less devious mind than most
        FSP admins I know.

        Why not make FSP more anonymous?  Well, it's impossible to make
        a protocol with complete anonymity, since at some point, the
        remote site will have to send a file back to you, and it needs
        at least an address to send it to.

        If you really need privacy, you can encrypt any files you make
        available, and only give out the decryption password to a select
        few.  But of course, you have to trust them to keep the password
        safe.

Q3.3 Why not add passwords to FSP?

        (Thanks to Joseph Traub for the material for this section)

        1. They don't add much security.  If you use one password for
           the whole site, then you might just as well set up the site
           and only tell a few people its port number.  That's no more
           or less secure than using a password.  Besides, it's easier
           just to set up the server only to respond to certain hosts.

        2. Any other password system is likely to be a big lose on
           efficiency, since you'll have to check every single packet.

        3. The main use of server passwords appears to be so that people
           can move pirated software around, and the authors don't want
           to add code to support that.

        To quote Joseph Traub, the ex-FSP maintainer: 

                If you really want to do passworded file transfer, grab
                a copy of the ftpd source code (which is also on my
                server) and modify it to a) use a higher port number
                (Yes virginia, you CAN specify port numbers to most ftp
                clients) and b) to read a file other than /etc/password
                to look up user information.

                This capability does NOT belong in FSP because it gets
                away from the concept of lightweight simple file
                transfers.

        And to quote Phil Richards, one of the current FSP maintainers:

                I agree.

        Just for added emphasis, the other FSP maintainer adds:

                Me too :-)

Q3.4 So what *does* FSP stand for?

        As of 12th August 1993, FSP stands for `File Service Protocol'.
        Thanks to [email-masked] (Michael Grubb) for the words, and
        Wen-King for the initials.

        Other suggestions were:

                File Slurping Protocol
                Flaky Stream Protocol
                FTP's Sexier Partner

---------------------------------------------------------------------------

Section 4: Who's Who?

Q4.1: Who writes and maintains FSP software?

        Wen-King Su ([email-masked]) wrote the original Unix
        version (versions 1.0 to 2.6.4).

        Joseph Traub (was [email-masked]) was maintainer from Dec
        1992 to July 1993 (versions 2.6.5 to 2.7.1).

        The current maintainers are Phil Richards ([email-masked])
        and Pete Bevin ([email-masked]).  Phil is also the maintainer
        of fspclient, an FTP-like interface for FSP.

        Sven Pechler ([email-masked]) wrote and maintains a VMS
        version.  OS/2 is handled by Larkin Lowrey ([email-masked]),
        and Lindsey Smith, of the MS-DOS rewrite is [email-masked].

Q4.2 Who helped put this FAQ together?

        The following people have contributed to the FAQ.  Thanks very
        much to all of them.

                Pete Bevin <[email-masked]>
                Tony Brannigan <[email-masked]>
                Maurizio Codogno <[email-masked]>
                David DeSimone <[email-masked]>
                Ian Dickinson <[email-masked]>
                Andy Doherty <[email-masked]>
                Jan Nicolai Langfeldt <[email-masked]>
                Ove Ruben R Olsen <[email-masked]>
                Lutz Prechelt <[email-masked]>
                Phil Richards <[email-masked]>
                Lindsey Smith <[email-masked]>
                Wen-King Su <[email-masked]>
                Joseph Traub <[email-masked]>