This repository has been archived on 2024-04-08. You can view files and clone it, but cannot push or open issues or pull requests.
deb-mbse/html/flow.html
2003-11-09 14:46:31 +00:00

173 lines
8.6 KiB
HTML

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"
<HTML>
<!-- $Id$ -->
<HEAD>
<META http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<META http-equiv="Content-Style-Type" content="text/css">
<META NAME="Language" content='en'>
<META name="author" lang="en" content="Michiel Broek">
<META name="copyright" lang="en" content="Copyright Michiel Broek">
<META name="description" lang="en" content="MBSE BBS Manual">
<META name="keywords" lang="en" content="MBSE BBS, MBSE, BBS, manual, fido, fidonet, gateway, tosser, mail, tic, mailer">
<TITLE>Running a BBS under Unix.</TITLE>
<LINK rel=stylesheet HREF="manual.css">
</HEAD>
<BODY>
<BLOCKQUOTE>
<div align='right'><h5>Last update 21-Jan-2002</h5></div>
<div align='center'><H1>Running a BBS under Unix.</H1></div>
<h3>Introduction</H3>
<P>
Everyone who has been running a (single line) BBS under DOS until now will
need to understand that running a BBS under Unix (or any other multitasking
os) is completly different of what you are used to. Under DOS things were
quite simple, from AUTOEXEC.BAT you started a new .BAT file that would run
forever and started all needed programs after each other.
The programs that where started
depended on the errorlevel of the previous program. Only one program could
run at the same time.
<P>
People who had previous run a BBS on another multitasking os, or were running
a BBS on a small lan with a fileserver and workstations for each line, are
already more used to the idea of running more programs at the same time,
and to "signal" what to do next with semafore files.
<P>
The Unix aproach is more or less the same, but there are more differences.
The main difference is that there is no mailer connected with the modem waiting
for a call, instead there is a getty process watching your modem(s). Another
big difference is that you don't see what's happening, there is no screen
with the mailer or bbs picture on it. All programs run in the background. If
you don't like that, stop now and go back to your old DOS bbs. It's just the
way everything is done.
<P>
Programs that must start at specific times (events in DOS), are started from
cron, this is the event scheduler for Unix. With this
program maintenance can be started, polls created etc. For starting programs
when they are needed there is a taskmanager loaded at system bootup. This
taskmanager "watches" the semafore directory of the bbs and will start what
is needed. It will also watch the mailer outbound to see if there are nodes
to call.
<P>&nbsp;<P>
<H3>Waiting for a call .....</H3>
<P>
Under Unix this is done with the mgetty program, this is the
process that is connected with each modem (or ISDN adapter) and waits for a
call. The mgetty program (written by Gert Doering, gert@greenie.muc.de) will
detect the call, and find out what or who did make the call. It can detect
incoming humans who want a login prompt, PPP calls from users who want to
make a PPP connection (browsing your BBS whith netscape for example), A fax
machine trying to deliver a fax and finally a mailer trying to establish
an EMSI, FSC-0006 or FSC-0001 session. The mgetty program is responsible for
starting the right client programs. How to do this is explained in the
installation manuals, but be sure to compile it with Fido and PPP support.
<P>&nbsp;<P>
<H3>A Human is calling.</H3>
<P>
This could be a bbs user. For each user to login to your bbs there is a
unix account. They automatic create such an account the first time they login
with the <b>bbs</b> account. During the creation of their account the shell that is
installed for there account is the mbsebbs binary, so that's the only thing
that they get if they call in. When they logout the bbs, or drop carrier etc,
the session is ended and mgetty takes over the line again.
Note that they never can get a Unix shell unless you install a <b>door</b>
in the bbs that calls a shell for them.
<P>
Because for dialin with mgetty the mblogin program is used and not the normal
login program, only bbs users can login. All other users including <b>root</b> are
denied access.
You might consider installing SSH on your system for remote maintenance.
<p>
It is also possible to install the mblogin program as the login program for
telnet users if you are directly connected to the internet.
<P>&nbsp;<P>
<H3>A PPP call is detected.</H3>
<P>
Installing a PPP server on your system is beyound the scope of this project.
However if you did install it, users can login your bbs with their favourite
browser and use your bbs. Note that the necessary tools to automatic create
newsgroups don't exist at this time. With the proper setup you can automatic
create and maintain html pages for the file areas.
<P>&nbsp;<P>
<H3>A mailer call is detected.</h3>
<P>
If a mailer is detected by mgetty, the <b>mbcico</b> program is started and will
take over from mgetty. It will establish a mail session with the caller and
the mail and or files will be exchanged just like any DOS mailer would do.
After the call, mbcico will hangup and mgetty will take control of your modem
again. If there is any mail received, mbcico will place the semafore <b>mailin</b>
so that another process can take care of the received mail.
<P>&nbsp;<P>
<h3>There is mail in the inbound</h3>
<P>
As I said before, if the <b>mailin</b> semafore is present, the task manager will
then start the <b>mbfido</b> program that will toss the mail, process any files
received and if necessary it will create other semafore's for example to link
the message bases, start the nodelist compiler etc. Note that this can be done
while there may be a new mailsession going on, a bbs user is online, it doesn't
matter. Processing mail and files can be done real multitasking without any
damage to other processes.
<P>&nbsp;<P>
<H3>It's time to poll a node</h3>
<P>
At the time that you whish to poll a node, let cron create "poll" requests.
When a poll is created, the semafore <b>scanout</b> is also created.
The taskmanager will then start mbcico at regular intervals so that mail will
get out. If there is no more mail to send, the <b>scanout</b> semafore is removed.
If a timeslot ends, you can just remove the "poll" requests that didn't succeed.
<P>&nbsp;<P>
<H3>It's Zone Mail Hour, so now what</h3>
<P>
Relax, if you have netmail ready for nodes the
mailer script will try to send these mails to those nodes. If it was crash
mail, and the destination was a non CM node, the mailer will try to send those
mails too. Note that other crashmails are send anytime. Also note that packed
mail and files are not send during ZMH. If a node calls you during ZMH he will
get everything that's waiting, including packed mail and files. The task manager
(more on that later) calculates the Zone Mail Hour from UTC time, you don't
have to change anything for summer- and wintertime. The taskmanager knows about
all zone mail hours of all Fidonet zones (1..6). For othernets, zone mail hour
is taken from the setup as default value. The taskmanager will also handle the
mail for nodes with the Txx flag (FSC-0062) on the right times.
<P>&nbsp;<P>
<H3>Daily maintenane</h3>
<P>
This is started by cron jobs. There is no need to take
your bbs lines down during maintenance, you can do it any time of the day.
I have made several scripts for this, daily, weekly and monthly.
<P>&nbsp;<P>
<h3>How about system load</h3>
<P>
Because GNU/Linux is a 32 bit os, not bothered with a graphical user interface
(unless you install it), it has all the time in the world to serve your
bbs programs. Background programs are build to release time to the Unix os,
they don't need to run fast because it's background processing. The bbs and
the mailer, have a low server load although there is no timerelease build
in. Only the bbs has some short moments when it needs a lot of your system,
for example when a user logs in and scans for new mail. The bbs I run is a
486-DX4 100 MHz, 20 MB ram, with 2 analogue lines, this seems to work fine.
When this system's MOBO died, I used a 386DX33 for several months with
20 MB ram, and the only thing users ever noticed was that scanning for new
mail was slower. I think this is the slowest harware that will work.
However, you must always use 16550A uarts for the COM ports. For best
performance use SCSI disks. I noticed that old 5"FH SCSI disks perform better
for bbs usage then modern EIDE disks. This is probably caused by the fact that
the kernel needs more time for the cheap IDE bus.
If you want to use X11 on your bbs, you need more ram and a faster CPU or a
separate machine via a lan and export the display to that machine.
<P>
<A HREF="index.htm"><IMG SRC="images/b_arrow.png" ALT="Back" Border="0">Go Back</A>
</BLOCKQUOTE>
</BODY>
</HTML>