Copyright (c) 1993-1997 by Eugene G. Crosser

This is a README file for ifgate - Internet/FidoNet gateway

You may do virtually what you wish with this software, as long as
the explicit reference to its original author is retained:

Eugene G. Crosser <crosser@average.org>, 2:5020/230@FidoNet

THIS SOFTWARE IS PROVIDED AS IS AND COME WITH NO WARRANTY OF ANY KIND,
EITHER EXPRESSED OR IMPLIED. IN NO EVENT WILL THE COPYRIGHT HOLDER BE
LIABLE FOR ANY DAMAGES RESULTING FROM THE USE OF THIS SOFTWARE.

This is a "production" version, it is more or less thoroughly tested.
But that does not mean that it is error-free.  If you think that you
found a bug, contact the author at crosser@average.org

All programs show version information and a short help message when run 
with "-h" key.

This piece of software was tested with the following MTAs: Smail3,
sendmail and Zmailer, and following netnews packages: cnews and INN.

Ifmail program converts RFC-822 compliant mail and RFC-1036 compliant 
news to FTN packets. It must run setuid owner of fidonet related stuff. 
The current packet naming is BinkleyTerm, with file/directory names in 
lowcase. Naming conventions are implemented in a separate source file, 
pktname.c, to make modifications easier.

The opposite way program is called iftoss. It expects a non-arcmail
packet on stdin and passes converted mail messages and/or generated
newsbatch to sendmail and/or rnews.  ATTENTION: if you specify non-zero
debugging level for iftoss, resultant messages/newsbatches will go to
the directory "/tmp/ifmail" instead of being fed to sendmail/rnews.
Sure, you must have /tmp directory writable for ifgate programs (not
only for debugging).

There are also two frontends: ifpack and ifunpack. Ifpack scans the 
outbound directory and packs *.?ut packets into arcmail file attaches, 
and ifunpack scans the inbound directory, unpacks and removes arcmail 
files, and feeds packets to iftoss (and then removes them, or renames 
if tossing was unsuccessful). If you have a stat[v]fs() system call on 
your system, ifunpack checks available space before unpacking/tossing.

ifstat program shows the status of the outbound directory.

For ifmail, default is mail mode operation. In mail mode, you must specify 
recipient(s) address(es) in the command line, in the form: 
"Eugene.Crosser@p14.f6.n5020.z2.fidonet.org". When the news mode is in 
effect, i.e. "-n" key is specified or the program is called by alias 
"ifnews", a news article (or batch) is expected on stdin. "-r" key is used 
to specify the destination of the packet, in the form 
"[pNN.]fNN.nNN[.zNN[.domain]]". In news mode, if -r key is omitted, the 
first recipient address is used as routing address, and if it is absent 
too, $NEWSSITE environment variable is used as a routing address.

Ifmail and iftoss programs try to preserve as much information as
possible in "X-FTN-..." headers and "^ARFC-..." kludges, and restore
messages more or less accurately to their original form when double-
gatewaying.  The function that makes desicion wheter to convert an RFC
header to an ^aRFC- kludge or put it into the body of the message is in
the file "message.c".

A dbm-based alias database is supported, so if a message passes from a
newsgroup to echo, the author's free form name and domain address are 
stored, and when a netmail reply comes from fidonet to that free form name, 
it is passed as a mail message to the remembered domain address.
ATTENTION: this mechanism won't work for you if you specify fidonet-style
address as the "visible name" in your MTA.  Do not do it!  Even if you
don't have an official Internet domain, use something.uucp as your
primary machine name, NOT fN.nM.zL.fidonet.org.

Several addresses may be specified in the config file, netmail from fidonet 
addressed to any of those addresses is assumed local and resolved through 
the aforementioned database, otherwise the mail will be routed through the 
normal MTA (and presumably packed to some other fidonet node). If there
is a "To:" line at the beginning of the fido message, destination
address is taken from it (ONLY THE FIRST ONE!).

On the other hand, if you make a system mail alias file accessible to the 
iftoss program, it makes attempt to "backward resolve" the "from" 
addresses, that is, if the originating address of the FidoNet message
matches the right side of some mail alias, the "Reply-To:" header of the
generated mail/news message will contain "alias@your.domain.name" address.

Message IDs are converted as follows: "^AMSGID: <address> <hexnum>" is 
converted to "<decimalnum>@<address>". If there was no MSGID in the
fidonet message, messageid of the form <creation-time>@<from-address> is 
generated, so that when a single message is gatewayed in several distinct
places, it will have the same messageid anyway (for some (little) risk of 
having two different messages with the same messageid). RFC822 Message-IDs 
are converted back when they can be, otherwise the messageid 
"<local>@<domain>" is converted to "^AMSGID <domain> crc32(<local>)". 
When an RFC message is split, unique MSGIDs are generated for all parts 
after the first one. In any case, the original "Message-ID:" header is
preserved in the "^ARFC-Message-ID:" kludge and used if the message comes 
back to usenet on some (other) gateway.

On the way from news to echo, if the node to which the packet is being
created is present in the "X-FTN-SEEN-BY:" header(s), the message is not
included into the packet. SEEN-BY lines in the messages included into
the packet consist of (1) your node primary address, (2) copy of
"X-FTN-SEEN-BY:" header(s), (3) ftn addresses that could be parsed from
the CNews/INN file "$NEWSCTL/log" in the line with the corresponding
Message-ID. For the latter to work, you should have a Cnews compatible
log file available for reading and have an "ndbm" package.

ATTENTION: your feed name in the cnews "sys" file should be fNNN.nMMM or
pNNN.fMMM.nLLL, without zone and domain, see example.  In some cases,
though, you will need to specify zone and/or domain of the feed, e.g. if
you are exporting echomail to several networks.  In such case, specify
the "cutdown" fNNN.nMMM notation after slash, to prevent exporting back.
This trick may also be useful if your hub presents non-primary AKA in
the echomail that it gives to you.

Ifmail does some attempt to process file attaches, but only locally.
No pass to Internet and back, but if a fileattach netmail message is
routed from one fidonet node to another, it probably will take the
attached file with it.

There is also a feature to define "forbidden" groups. If a usenet
message is crossposted to some of the gated groups _and_ to some of the
forbidden groups it will not be passed to any fidonet echoes.  Messages
containing the "Control:" header are not passed to FidoNet too.

Acknowledgements:

Some ideas taken from Fidogate/RFmail package, written by Teemu Torma
and hacked by Martin Junius.  Some modules taken from INN package.
Thanks to Michael Bravo <mbravo@tctube.spb.su> (who was the first) and
many others for testing.
