The Diald README File ---------------------------------------------------------------------------- This is release 0.16 of diald. Diald is a daemon that provides on demand IP links via SLIP or PPP. The purpose of diald is to make it transparently appear that you have a permanent connection to a remote site. Diald sets up a "proxy" device which stands in for the physical connection to a remote site. It then monitors the proxy, waiting for packets to arrive. When interesting packets arrive it will attempt to establish the physical link to the remote site using either SLIP or PPP, and if it succeeds it will forward traffic from the proxy to the physical link. As well, diald will monitor traffic once the physical link is up, and when it has determined that the link is idle, the remote connection is terminated. The criteria for bringing the link up and taking it down are configurable at run time, and are based upon the type of traffic passing over the link. Getting Diald The file is called diald-0.16.tar.gz. I've uploaded it to sunsite.unc.edu:/pub/Linux/Incoming. It should move to sunsite.unc.edu:/pub/Linux/system/Network/serial after a suitable interval. It can also be obtained from the diald home page at "http://www.dna.lth.se/~erics/diald.html". Note that the diald home page has moved from its old location at the University of Toronto. Mailing List David S. Miller provides a mailing for the discussion of diald on his Majordomo server at vger.rutgers.edu. Send mail containing the line "subscribe linux-diald" in the BODY of the message to Majordomo@vger.rutgers.edu to join the list. Send mail with the word "help" in the body to get help on the correct use of the Majordomo list server. Announcements of new releases are made on the mailing list, and its a good place to ask questions of users who already have diald up and running. I would prefer the mailing list to be my primary channel of communication with users. This gives you the added benefit of asking your questions of everyone on the list, many of whom may have the same question, or some of who may have already solved your problem. This minimizes the time I have to spend answering questions about diald, and gives me more time to spend improving the program. Let me repeat that. Please, if at all possible, use the mailing list to ask questions! I read the list every day, sometimes more than once, and your question will not be answered any more quickly if it is sent directly to me, in fact, if I don't see the answer to your question right away, then it may just get filed until I have time to deal with it. Someone on the mailing list will probably be able to suggest a solution to your problem well before that. The mailing list is being archived by Jeremy Hall . Copies of the archive can be obtained at ftp://rex.isdn.net/pub/diald. Currently the archives are updated once a month. FAQ There is a copy of the FAQ distributed with the diald release in the subdirectory "doc". This is the version that was current when the diald release was packaged. This may not be the most up to date version of the FAQ. The most up to date version can always be obtained from the diald home page. (See "Getting Diald" for the address of the home page.) Before Installation You must have SLIP devices in your kernel in order to use diald, EVEN IF YOU PLAN TO USE ONLY PPP CONNECTIONS! Let me repeat that, diald needs SLIP to work under all circumstances. It uses a SLIP link on a pseudo terminal to create the proxy device that stands in for the real connection. Naturally, if you plan on using diald to establish PPP connections, you must also have PPP devices in your kernel. You must also have a program like "chat" to do dialing. Configuring Diald Various pathnames that diald needs to know can be configured in "config.h". Edit this file appropriately. The eventual installation location for the diald binaries, the man pages and the diald definitions files can be configured in the Makefile. Basic Installation (First Time Users) First run "make depend" then "make" and then "make install" as root. This makes the diald daemon and installs it. After installation you need to write a /etc/diald.conf file to be able to use diald. Read the manual page to find out what this file can contain. The diald-examples manual page gives several example diald.conf files. Installation If You Are Already Using an Earlier Version Unlike previous releases of diald, the basic installation procedure no longer installs an /etc/diald.conf file. Therefore, you can follow the same installation procedure as for first time users (above). The set of standard filters rules is now located in "/usr/lib/diald/standard.filter". This used to be installed as /etc/diald.conf. If you want, you can now include this file into your /etc/diald.conf file with the new "include" directive. If you wish to change the rules in this file you should just copy them into another file and edit them as desired. You can either place rules directly in /etc/diald.conf, or put then in another file that is included by /etc/diald.conf. In any case, the syntax of the filter rules has not changed between diald 0.14 and diald 0.15, so you should be able to continue using your old /etc/diald.conf file. If you want to use a particuarly old /etc/diald.conf file you may need to update some of the contents as the names and meanings of various commands have evolved a little over time. In particular a major change in syntax took place between version 0.3 and 0.4 and a change in semantics took place between version 0.7 and 0.8 and again between 0.10 and 0.11. See the CHANGES file for more information. If you are planning to use diald with a kernel numbered 1.3.75 or greater, then you MUST compile diald using the include files for that kernel. Using Diald There are several manual pages that cover the use of diald. The "diald" manual page is the basic reference manual for diald. It will point you at other relevant manual pages. Of particular interest will be the "diald-examples" manual page, which will help you get diald configured. You might also want to look at the contents of the "contrib" directory in this distribution. Bugs, Limitations and Warnings There are some known problems and limitations. Lines in options files can contain at most 1024 characters. Longer lines are silently truncated. If there are no filter rules specified then no packets will be matched and the daemon won't do anything. It should probably match all packets by default in this case. Diald attempts to automatically adjust the MTU of the proxy to match the MTU of the actual connection negotiated by ppp, but this is not guaranteed to work, since changing the MTU on an active interface is not supported by the kernel. It is possible that an auto adjusted MTU will cause some long packets to get dropped on the floor. If you are having problems you should match these values manually. Diald will report the negotiated MTU in the system logs and warn you that you should adjust the settings. The monitor command represents a security risk as anyone who has access to a diald control fifo can ask diald to write to any named pipe in the system. Be careful with the permissions on your fifo's. Please send bug reports, patches or suggestions for improvements to me, preferably via the mailing list. Eric Schenk Eric.Schenk@dna.lth.se Lund, Sweden, January 28th, 1997.