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Started by Terry Dawson
Wed, 06 Nov 1996 00:00
Linux AX25 HOWTO (part 1/2)
Author: Terry Dawson
Date: Wed, 06 Nov 1996 00:00
Date: Wed, 06 Nov 1996 00:00
1428 lines
54163 bytes
54163 bytes
Archive-name: linux/howto/ax25/part1
Last-modified: 23 Jun 96
-----BEGIN PGP SIGNED MESSAGE-----
*** The `Linux AX25 HOWTO' is posted automatically by the
*** Linux HOWTO coordinator, Greg Hankins <gregh@sunsite.unc.edu>. Please
*** direct any comments or questions about this HOWTO to the author,
*** Terry Dawson <terry@perf.no.itg.telecom.com.au>.
- --- BEGIN Linux AX25 HOWTO part 1/2 ---
Linux AX25-HOWTO, Amateur Radio.
Terry Dawson, VK2KTJ, terry@perf.no.itg.telecom.com.au
v1.1, 14 June 1996
The Linux Operating System is perhaps the only operating system in the
world that can boast native and standard support for the AX.25 packet
radio protocol utilised by Amateur Radio Operators worldwide. This
document aims to describe how to install and configure this support.
1. Introduction.
This document was originally an appendix to the HAM-HOWTO, but grew
too large to be reasonably managed in that fashion. This document
describes how to install and configure the native AX.25 and NetRom
support for Linux. A few typical configurations are described that
could be used as models to work from.
1.1. Changes from the previous version
Additions:
Baycom support - ye gads!
Corrections/Updates:
Included SLIP support in kernel config - oops.
2.0.0 kernel and ax25-tools update.
Updated net-tools to 1.32-alpha version.
Removed Jonathons `special' net-tools.
A bit of shuffling about to make more sense.
Updated the example configurations.
A minor copyright ooops.
1.2. Other related documentation.
There is a lot of related documentation. There are many documents that
relate to Linux networking in more general ways and I strongly
recommend you also read these as they will assist you in your efforts
and provide you with stronger insight into other possible
configurations.
They are:
The HAM-HOWTO <http://sunsite.unc.edu/mdw/HOWTO/HAM-HOWTO.html>
the Net-2-HOWTO <http://sunsite.unc.edu/mdw/HOWTO/NET-2-HOWTO.html>
the Ethernet-HOWTO <http://sunsite.unc.edu/mdw/HOWTO/Ethernet-
HOWTO.html>
the IPX-HOWTO <http://sunsite.unc.edu/mdw/HOWTO/IPX-HOWTO.html>
and
the Firewall-HOWTO <http://sunsite.unc.edu/mdw/HOWTO/Firewall-
HOWTO.html>
2. Where to obtain new versions of this document.
The best place to obtain the latest version of this document is from a
Linux Documentation Project archive. The Linux Documentation Project
runs a Web Server and this document appears there as The AX25-HOWTO
<http://sunsite.unc.edu/mdw/HOWTO/AX25-HOWTO.html>. You can always
contact me, but I pass new versions of the document directly to the
LDP HOWTO coordinator, so if it isn't there then chances are I haven't
finished it.
3. Linux and the AX.25 and NetRom Packet Radio Protocols.
The AX.25 protocol offers both connected and connectionless modes of
operation, and is used either by itself for point-point links, or to
carry other protocols such as TCP/IP and NetRom.
It is similar to X.25 level 2 in structure, with some extensions to
make it more useful in the amateur radio environment.
The NetRom protocol is an attempt at a full network protocol and uses
AX.25 at its lowest layer as a datalink protocol. It provides a
network layer that is an adapted form of AX.25.
Alan Cox developed some early kernel based AX.25 software support for
Linux. Jonathon Naylor <g4klx@g4klx.demon.co.uk> has taken up ongoing
development of the code, has added NetRom support and is now the
developer of the AX.25 related kernel code and utilities. DAMA support
was developed by Joerg, DL1BKE. Finally Baycom support was added by
Thomas Sailer, <sailer@ife.ee.ethz.ch>.
The Linux code supports KISS based TNC's (Terminal Node Controllers),
the Ottawa PI card, the Gracilis PacketTwin card and other Z8530 SCC
based cards with the generic SCC driver and both the Parallel and
Serial port Baycom modems.
The User programs contain a simple PMS (Personal Message System), a
beacon facility, a line mode connect program, `listen' an example of
how to capture all AX.25 frames at raw interface level and programs to
configure the NetRom protocol. Included also are an AX.25 server style
program to handle and despatch incoming AX.25 connections and a NetRom
daemon which does most of the hard work for NetRom support.
4. The AX.25/NetRom software components.
The AX.25 software is comprised of three components, the kernel
source, the network configuration tools and the utility programs.
The version 1.3.xx Linux kernels include the AX.25, NetRom, Z8530 SCC,
PI card and PacketTwin drivers by default. I recommend you obtain and
use the version 1.3.xx kernel source.
These are three reasons I'm recommending you use the alpha version
software even though most everyone else will recommend you don't use
it:
� it makes the process of building and configuring the software a
whole lot simpler. There are no patches to apply it is a simple
matter of configuring and compiling a kernel with the appropriate
options enabled.
� it is the most recent software and is most likely to provide the
most satisfactory results.
� like all new software, it needs testing and bug reports. The more
people that take the software and attempt to use it in their own
configurations the more likely it will be that bugs are uncovered
and the easier it will be to get the software debugged. Join the
team, contribute bug reports and help everybody.
Be warned though, this software is alpha and may have problem that you
wouldn't otherwise encounter. Please take all the usual precautions
and be sure to keep a working kernel as backup when testing new
kernels. It is wise to test a new kernel by booting from it from
floppy before actually installing it with lilo, though I haven't
bothered for about 90 kernels revisions so I'm fairly confident you
can pretty safely run with alpha kernels.
4.1. Finding the kernel, tools and utility packages.
4.1.1. The kernel source:
The kernel source can be found in its usual place at:
ftp.funet.fi
/pub/Linux/PEOPLE/Linus/v2.0/
4.1.2. The network tools:
The latest alpha release of the standard Linux network tools support
AX.25 and NetRom and can be found at:
ftp.inka.de
/pub/comp/Linux/networking/net-tools/net-tools-1.32-alpha.tar.gz
or:
ftp.linux.org.uk
/pub/linux/Networking/PROGRAMS/NetTools/net-tools-1.32-alpha.tar.gz
The latest ipfwadm package can be found at:
ftp.xos.nl
/pub/linux/ipfwadm/
4.1.3. The AX25 utilities:
The AX.25 utility programs can be found at:
sunsite.unc.edu
/pub/Linux/apps/ham/ax25-utils-2.0.0.tar.gz
or:
ftp.ucsd.edu
/hamradio/packet/tcpip/incoming/ax25-utils-2.0.0.tar.gz
5. Installing the AX.25/NetRom software.
To successfully install AX.25 support on your linux system you must
configure and install an appropriate kernel and then install the AX.25
utilities.
5.1. Compiling the kernel.
If you are already familiar with the process of compiling the Linux
Kernel then you can skip this section, just be sure to select the
appropriate options when compiling the kernel. If you are not, then
read on.
The normal place for the kernel source to be unpacked to is the
/usr/src directory into a subdirectory called linux. To do this you
should be logged in as root and execute a series of commands similar
to the following:
# mv linux linux.old
# cd /usr/src
# gzip -dc linux-2.0.0.tar.gz | tar xvofp -
# cd linux
After you have unpacked the kernel source into place you need to run
the configuration script and choose the options that suit your
hardware configuration and the options that you wish built into your
kernel. You do this by using the command:
# make config
You might also try:
# make menuconfig
if you prefer a full screen menu based method. I'm going to describe
the original method, but you use whichever you are most comfortable
with.
In either case you will be offered a range of options at which you
must answer `Y' or `N'. (Note you may also answer `M' if you are using
modules. For the sake of simplicity I will assume you are not, please
make appropriate modifications if you are).
The options most relevant to an AX.25 configuration are:
Networking support (CONFIG_NET) [Y/n/?] Y
Loopback device support (CONFIG_BLK_DEV_LOOP) [N/y/m/?] Y
Network firewalls (CONFIG_FIREWALL) [N/y/?]
TCP/IP networking (CONFIG_INET) [Y/n/?] Y
IP: forwarding/gatewaying (CONFIG_IP_FORWARD) [N/y/?]
IP: firewalling (CONFIG_IP_FIREWALL) [N/y/?] (NEW)
IP: tunneling (CONFIG_NET_IPIP) [N/y/m/?] (NEW)
Amateur Radio AX.25 Level 2 (CONFIG_AX25) [N/y/?] Y
AX.25 over Ethernet (CONFIG_BPQETHER) [N/y/?] (NEW)
Amateur Radio NET/ROM (CONFIG_NETROM) [N/y/?] (NEW)
Kernel/User network link driver(ALPHA) (CONFIG_NETLINK) [N/y/?]
Network device support (CONFIG_NETDEVICES) [Y/n/?] Y
SLIP (serial line) support (CONFIG_SLIP) [N/y/m/?] Y
Radio network interfaces (CONFIG_NET_RADIO) [N/y/?]
BAYCOM ser12 and par96 kiss emulation driver for AX.25 (CONFIG_BAYCOM) [N/y/m/?]
Z8530 SCC kiss emulation driver for AX.25 (CONFIG_SCC) [N/y/m/?]
Other ISA cards (CONFIG_NET_ISA) [N/y/?]
Ottawa PI and PI/2 support (CONFIG_PI) [N/y/?] (NEW)
Gracilis PackeTwin support (CONFIG_PT) [N/y/?] (NEW)
Standard/generic serial support (CONFIG_SERIAL) [Y/n/?]
The options I have flagged with a `Y' are those that you must must
answer `Y' to. The rest are dependent on what hardware you have and
what options you want to include. Some of these options are described
in more detail later on, so if you don't know what you want yet, then
read ahead and come back to this step later.
After you have completed the kernel configuration you should be able
to cleanly compile your new kernel:
# make dep
# make clean
# make zImage
Make sure you move your arch/i386/boot/zImage file wherever you want
it and then run lilo to ensure that you actually boot from it.
5.2. The network configuration tools.
After you have compiled the kernel you should compile the new network
configuration tools. These tools allow you to modify the configuration
of network devices and to add routes to the routing table.
The new alpha release of the standard net-tools package includes
support for AX.25 and NetRom support. I've tested this and it seems to
work well for me.
5.2.1. Building the standard net-tools release.
Don't forget to read the Release file and follow any instructions
there. The steps I used to compile the tools were:
# cd /usr/src
# tar xvfz net-tools-1.32-alpha.tar.gz
# cd net-tools-1.32-alpha
# make config
At this stage you will be presented with a series of configuration
questions, similar to the kernel configuration questions. Be sure to
include support for all of the protocols and network devices types
that you intend to use. If you do not know how to answer a particular
question then answer `Y'.
The tools compiled cleanly against a 2.0.0 kernel without error.
When the compilation is complete, you should need only use the:
# make install
command to install the programs in their proper place.
If you wish to use the IP firewall facilities then you will need the
latest firewall administration tool ipfwadm. This tool replaces the
older ipfw tool which will not work with new kernels.
I compiled the ipfwadm utility with the following commands:
# cd /usr/src
# tar xvfz ipfwadm-2.0beta2.tar.gz
# cd ipfwadm-2.0beta2
# make install
# cp ipfwadm.8 /usr/man/man8
# cp ipfw.4 /usr/man/man4
5.3. The AX.25 user programs.
After you have successfully compiled and booted your new kernel, you
need to compile the user programs. To compile and install the user
programs you should use a series of commands similar to the following:
# cd /usr/local
# gzip -dc ax25-utils-2.0.0.tar.gz | tar xvvof -
# cd ax25-utils-2.0
# make install
The files will be installed under the /usr/local directory by default
in subdirectories: bin, sbin, etc and man.
If you get messages something like:
gcc -Wall -Wstrict-prototypes -O2 -I../lib -c call.c
call.c: In function `statline':
call.c:268: warning: implicit declaration of function `attron'
call.c:268: `A_REVERSE' undeclared (first use this function)
call.c:268: (Each undeclared identifier is reported only once
call.c:268: for each function it appears in.)
then you should read the README.ncurses file in the top level
directory. You can do as Jonathon suggests, or you can try replacing:
#include <curses.h>
with:
#include <ncurses/curses.h>
in the:
call/call.c
call/menu.c
files.
6. Configuring a RAW AX.25 connected mode interface.
The first stage to configuration of an AX.25 interface is to configure
it to work as a `vanilla' AX.25 interface with no TCP/IP. The
following configuration will get you to the point of being able to
make AX.25 calls from your Linux machine to other AX.25 nodes.
The AX.25 software has been designed to work with a TNC in kiss mode
or with other cards such as the Ottawa PI2 card, PacketTwin and other
SCC cards via special drivers that emulate a kiss tnc.
For real KISS TNC's there are two steps to complete in order to create
an AX.25 port ready to use to make outgoing calls. For other types of
hardware you need only complete the first step.
6.1. Creating the /usr/local/etc/axports file.
The AX.25 ports have a configuration file that is read by many
programs that want to find information about an AX.25 port. This file
is called the:
/usr/local/etc/axports
file. The format of the file is as follows:
portname callsign baudrate paclen window description
where:
portname
is a text name that you will refer to the port by.
callsign
is the AX.25 callsign you want to assign to the port.
baudrate
is the speed at which you wish the port to communicate with your
TNC.
paclen
is the maximum packet length you want to configure the port to
use for AX.25 connected mode connections.
window
is the AX.25 window (K) parameter. This is the same as the
MAXFRAME setting of many tnc's.
description
is a textual description of the port.
In my case, mine looks like:
radio VK2KTJ-0 4800 256 2 144.800 MHz
6.2. Creating the AX.25 device
If you are using an SCC card like the PI2 or PacketTwin then you do
not need to create the network device, as the kernel driver will
automatically do this for you. If you are using a KISS TNC then you
will need to create the AX.25 interface as it will not already exist.
Creating an AX.25 port is very similar to creating a slip device.
You will need to have the TNC preconfigured and connected to your
serial port. You can use a communications program like minicom or
seyon to configure the TNC into kiss mode if you wish.
You use the axattach program in much the same way as you would use the
slattach program (refer to the NET-2-HOWTO for more information on
slattach and the other network software for Linux). For example:
# /usr/local/sbin/axattach /dev/ttyS0 radio
would configure your /dev/ttyS1 serial device to be a kiss interface
configured as per the details for the line beginning with the portname
"radio" in the /usr/local/etc/axports file.
All this step has done is to actually activate the device in the
kernel, you need to run other programs before you an actually make use
of the port.
6.2.1. Setting the callsign for SCC cards.
If you are using a PI or PacketTwin card then you should use the
axparms -setcall command to change the callsign of the appropriate
port to that which you intend to use. Refer to the PI/PacketTwin
section for the names of the network devices to use.
6.2.2. Testing the interface.
You now should be able to make outgoing AX.25 connections. To test
AX.25 connected mode you could use the call program as demonstrated:
/usr/local/bin/call radio VK2DAY via VK2SUT
Note: you must tell call which AX.25 port you wish to make the call
on, as the same AX.25 node might be reachable on any of the ports you
have configured.
The call program is a linemode terminal program for making AX.25
calls. It recognises lines that start with `~' as command lines. The
`~.' command will close the connection.
Please refer to the man pages in /usr/local/man and the README file in
ax25-utils-2.0.0 distribution for more information.
7. Configuring an AX.25 interface for tcp/ip.
It is very simple to configure an AX.25 port to carry tcp/ip. Jonathon
has modified the axattach command so that you can include the IP
address that you want the interface to be configured with on the
command line. For example, to modify the example presented earlier, I
could use the command:
# /usr/local/sbin/axattach -i 44.136.8.5 -m 512 /dev/ttyS0 radio
# /sbin/route add -net 44.136.8.0 sl0
# /sbin/route add default sl0
to create the AX.25 interface with an IP address of 44.136.8.6 and an
MTU of 512 bytes. You should still use the ifconfig to configure the
other parameters if necessary.
You do not need to do it this way, you can of course just use the
ifconfig program to configure the ip address and netmask details for
the port and add a route via the port, just as you would for any other
tcp/ip interface.
# /sbin/ifconfig sl0 44.136.8.5
# /sbin/ifconfig sl0 netmask 255.255.255.0
# /sbin/ifconfig sl0 broadcast 44.136.8.255
# /sbin/ifconfig sl0 arp mtu 256 up
# /sbin/route add -net 44.136.8.0 sl0
# /sbin/route add default sl0
The commands listed above are typical of the sort of configuration
many of you would be familiar with if you have used NOS or any of its
derivatives or any other tcp/ip software. Note that the default route
might not be required in your configuration if you have some other
network device configured.
To test it out, try a ping or a telnet to a local host.
# ping -i 5 44.136.8.58
Note the use of the `-i 5' arguments to ping to tell it to send pings
every 5 seconds instead of its default of 1 second.
8. Configuring an AX.25 interface for NetRom.
To configure NetRom on an AX.25 interface you must configure two
files.
8.1. Configuring /usr/local/etc/nrports
The first is the /usr/local/etc/nrports file. This file describes the
NetRom port in much the same way as the /usr/local/etc/axports file
describes the AX.25 ports.
This file is formatted as follows:
name callsign alias paclen description
Where:
name
is the text name that you wish to refer to the port by.
callsign
is the callsign that the NetRom traffic from this port will use.
alias
is the NetRom alias this port will have assigned to it.
paclen
is the maximum size of NetRom frames transmitted by this port.
description
is a free text description of the port.
An example would look something like the following:
netrom VK2KTJ-1 LINUX 235 Linux Switch Port
Note that the ports are referred to by name by programs such as call.
8.2. Configuring /usr/local/etc/nrbroadcast
The second file is the /usr/local/etc/nrbroadcast file.
This file is formatted as follows:
axport min_obs def_qual worst_qual verbose
Where:
axport
is the port name obtained from the /usr/local/etc/axports file.
If you do not have an entry in /usr/local/etc/nrbroadcasts for a
port then this means that no NetRom routing will occur and any
received NetRom broadcasts will be ignored for that port.
min_obs
is the minimum obselesence value for the port.
def_qual
is the default quality for the port.
worst_qual
is the worst quality value for the port, any routes under this
quality will be ignored.
verbose
is a flag determining whether full NetRom routing broadcasts
will occur from this port or only a routing broadcast
advertising the node itself.
An example would look something like the following:
radio 1 200 10 1
8.3. Creating the NetRom device
When you have the two configuration files completed you must create
the NetRom device in much the same way as you did for the AX.25
devices. This time you use the nrattach command:
# nrattach netrom
This command would start the NetRom device (nr0) named netrom
configured with the details specified in the /usr/local/etc/nrports
file.
8.4. Starting the NetRom daemon
The NetRom daemon manages the NetRom routing tables and generates the
NetRom routing broadcasts. You start NetRom with the command:
# /usr/local/sbin/netromd
You should soon see the /proc/net/nr_neigh file filling up with
information about your NetRom neighbours.
Remember to put the /usr/local/sbin/netromd command in your rc files
so that it is started automatically each time you reboot.
9. Configuring IP on a NetRom interface.
Configuring a NetRom interface for tcp/ip is almost identical to
configuring an AX.25 interface for tcp/ip.
Again you can either specify the ip address and mtu on the nrattach
command line, or use the ifconfig and route commands, but you need to
manually add arp entries for hosts you wish to route to because there
is no mechanism available for your machine to learn what NetRom
address it should use to reach a particular IP host.
So, to create an nr0 device with an IP address of 44.136.8.5 and an
mtu of 512 and configured with the details from the
/usr/local/etc/nrports file for a NetRom port named netrom you would
use:
# /usr/local/sbin/nrattach -i 44.136.8.5 -m 512 netrom
# route add 44.136.8.5 nr0
or you could use something like the following commands manually:
# ifconfig nr0 44.136.8.5 hw netrom VK2KTJ-1
# route add 44.136.8.5 nr0
Then for each IP host you wish to reach via NetRom you need to set
route and arp entries. To reach a destination host with an IP address
of 44.136.80.4 at NetRom address BBS:VK3BBS via a NetRom neighbour
with callsign VK2SUT-0 you would use commands as follows:
# route add 44.136.80.4 nr0
# arp -t netrom -s 44.136.80.4 vk2sut-0
# nrparms -nodes vk3bbs + BBS 120 6 sl0 vk2sut-0
The `120' and `6' arguments to the nrparms command are the NetRom
quality and obsolescence count values for the route.
10. Configuring an Ethernet device for AX.25 ala BPQ
Linux support BPQ Ethernet compatibility. This enables you to run the
AX.25 protocol over your Ethernet LAN and to interwork your linux
machine with other BPQ machines on the LAN.
Configuration is quite straightforward. You firstly must have
configured a standard Ethernet device. This means you will have
compiled your kernel to support your Ethernet card, and executed
configuration commands similar to the following:
# ifconfig eth0 44.136.8.5 netmask 255.255.255.248 up
# ifconfig eth0 broadcast 44.136.8.103
# route add -net 44.136.8.96 netmask 255.255.255.248 eth0
To configure the BPQ support you need to associate an AX.25 callsign
with your Ethernet hardware address. You should use the following:
# axparms -dev eth0 vk2ktj-9
This says that AX.25 callsign vk2ktj-9 is associated with the eth0
device.
BPQ Ethernet normally uses a multicast address. The Linux
implementation does not, and instead it uses the normal Ethernet
broadcast address. The NET.CFG file for the BPQ ODI driver should
therefore look similar to this:
LINK SUPPORT
MAX STACKS 1
MAX BOARDS 1
LINK DRIVER E2000 ; or other MLID to suit your card
INT 10 ;
PORT 300 ; to suit your card
FRAME ETHERNET_II
PROTOCOL BPQ 8FF ETHERNET_II ; required for BPQ - can change PID
BPQPARMS ; optional - only needed if you want
; to override the default target addr
ETH_ADDR FF:FF:FF:FF:FF:FF ; Target address
11. Ottawa PI/PI2 card driver and Gracilis PacketTwin driver.
The Ottawa PI and the Gracilis PacketTwin are Z8530 SCC based card for
IBM PC type machines that are in common usage by Amateur Radio
operators worldwide. The PI card supports a high speed half duplex
(single DMA channel) port, and a low speed (<9k6bps interrupt driven)
half duplex port. The PI2 is a new version of the card that supports
an on board radio modem and improved hardware design. The PacketTwin
card supports two high speed port and is capable of accepting on board
modems.
The PI card driver was written by David Perry, <dp@hydra.carleton.edu>
The PacketTwin card driver was written by Craig Small VK2XLZ,
<csmall@triode.apana.org.au>. Both drivers are a standard feature of
the 1.3.xx kernel.
Please refer to the AX.25 section above for details on how to
configure the kernel to include the PI card or the PacketTwin card
drivers.
Once you have the appropriate driver configured into your kernel then
you should reboot and when you do, you should see mention of the PI or
PacketTwin card driver in the messages that appear on the screen while
the kernel is booting. The drivers test each of the I/O port addresses
that the card might be configured for and reports any that it finds.
You should then look at the /proc/net/dev file and you should see
reference to devices called pi0a and pi0b or pt0a and pt0b for the PI
and PacketTwin cards respectively.
If the devices don't appear then recheck that you have configured and
compiled your kernel correctly and that you are in fact actually
running your new kernel. If you still don't then this suggests that
your PI or PacketTwin card was not detected by the kernel while it
booted and may indicate that you have some sort of hardware
conflicting with your PI/PT card that prevented it being detected.
If all of the above went as planned then you will need to configure
your PI/PT card with an AX.25 address and for IP. The configuration of
the PI/PT cards is virtually identical to that of any other IP
interface. Something like the following should work ok for you:
# /usr/local/sbin/axparms -setcall pi0a VK2KTJ-2
# /sbin/ifconfig pi0a 44.136.8.5
# /sbin/ifconfig pi0a netmask 255.255.255.0
# /sbin/ifconfig pi0a broadcast 44.136.8.255
# /sbin/ifconfig pi0a arp mtu 256 up
# /sbin/route add -net 44.136.8.0 pi0a
# /sbin/route add default pi0a
Note that pi0a refers to the `a' port on the first PI card found, and
that pi0b would therefore refer to the `b' port on the first PI card
found. pt0a would therefore be the first port on the first PacketTwin
card detected.
Note also the use of the axparms -setcall command to set the AX.25
callsign of the port.
As usual, when this has been done you can test the interface with the
ping or telnet command to ensure it is working.
12. Z8530 SCC Kiss Emulation
Joerg Reuter, DL1BKE has developed generic support for Z8530 SCC based
cards. His driver is configurable to support a range of different
types of cards and present an interface that looks like a KISS TNC so
you can treat it as though it were a KISS TNC.
12.1. Obtaining and building the configuration tool package.
The kernel driver is included in the standard kernel distribution, but
there are a suite of configuration tools that you will need to obtain
as well.
To compile the kernel support you must be sure to answer `Y' to:
`Z8530 SCC kiss emulation driver for AX.25' when asked during a kernel
`make config'.
You can obtain the configuration tools package from:
ftp.ucsd.edu
/hamradio/packet/tcpip/incoming/z8530drv-2.0.dl1bke.real.tar.gz
The following command were what I used to compile and install the
package for kernel version 1.3.93:
# cd /usr/src
# gzip -dc z8530drv-2.0.dl1bke.real.tar.gz | tar xvpofz -
# cd z8530drv
# rm gencfg sccinit sccstat
# make dep
# make utils
# make install
Note: I've not followed the instructions included because the version
of driver in the 2.0.0 kernel is actually newer than that included in
the package and the normal installation process would have overwritten
the new kernel source with the older version.
After the above is complete you should have three new programs
installed in your /sbin directory: gencfg, sccinit and sccstat. It is
these programs that you will use to configure the driver for your
card.
You will also have a group of new special device files created in your
/dev called scc0 .. scc7. These will be used later and will be the
`KISS' devices you will end up using.
12.2. Configuring the driver for your card.
The z8530 SCC driver has been designed to be as flexible as possible
so as to support as many different types of cards as possible. With
this flexibility has come some cost in configuration.
There is more comprehensive documentation in the package and you
should read this if you have any problems. You should particularly
look at doc/scc_eng.doc or doc/scc_ger.doc for more detailed
information. I've paraphrased the important details, but as a result
there is a lot of lower level detail that I have not included.
The main configuration file is read by the sccinit program and is
called /etc/z8530drv.rc. This file is broken into two main stages:
Configuration of the hardware parameters and channel configuration.
After you have configured this file you need only add:
# sccinit
into the rc file that configures your network and the driver will be
initialised according to the contents of the configuration file. You
must do this before you attempt to use the driver.
12.2.1. Configuration of the hardware parameters.
The first section is broken into stanzas, each stanza representing an
8530 chip. Each stanza is a list of keywords with arguments. You may
specify up to four SCC chips in this file by default. The #define
MAXSCC 4 in scc.c can be increased if you require support for more.
The allowable keywords and arguments are:
chip
the chip keyword is used to separate stanzas. It will take
anything as an argument. The arguments are not used.
data_a
this keyword is used to specify the address of the data port for
the z8530 channel `A'. The argument is a hexadecimal number e.g.
0x300
ctrl_a
this keyword is used to specify the address of the control port
for the z8530 channel `A'. The arguments is a hexadecimal number
e.g. 0x304
data_b
this keyword is used to specify the address of the data port for
the z8530 channel `B'. The argument is a hexadecimal number e.g.
0x301
ctrl_b
this keyword is used to specify the address of the control port
for the z8530 channel `B'. The arguments is a hexadecimal number
e.g. 0x305
irq
this keyword is used to specify the IRQ used by the 8530 SCC
described in this stanza. The argument is an integer e.g. 5
pclock
this keyword is used to specify the frequency of the clock at
the PCLK pin of the 8530. The argument is an integer frequency
in Hz which defaults to 4915200 if the keyword is not supplied.
board
the type of board supporting this 8530 SCC. The argument is a
character string. The allowed values are:
PA0HZP
the PA0HZP SCC Card
EAGLE
the Eagle card
PC100
the DRSI PC100 SCC card
PRIMUS
the PRIMUS-PC (DG9BL) card
BAYCOM
BayCom (U)SCC card
escc
this keyword is optional and is used to enable support for the
Extended SCC chips (ESCC) such as the 8580, 85180, or the 85280.
The argument is a character string with allowed values of `yes'
or `no'. The default is `no'.
vector
this keyword is optional and specifies the address of the vector
latch (also known as "intack port") for PA0HZP cards. There can
be only one vector latch for all chips. The default is 0.
special
this keyword is optional and specifies the address of the
special function register on several cards. The default is 0.
option
this keyword is optional and defaults to 0.
Some example configurations for the more popular cards are as follows:
BayCom USCC
chip 1
data_a 0x300
ctrl_a 0x304
data_b 0x301
ctrl_b 0x305
irq 5
board BAYCOM
#
# SCC chip 2
#
chip 2
data_a 0x302
ctrl_a 0x306
data_b 0x303
ctrl_b 0x307
board BAYCOM
PA0HZP SCC card
chip 1
data_a 0x153
data_b 0x151
ctrl_a 0x152
ctrl_b 0x150
irq 9
pclock 4915200
board PA0HZP
vector 0x168
escc no
#
#
#
chip 2
data_a 0x157
data_b 0x155
ctrl_a 0x156
ctrl_b 0x154
irq 9
pclock 4915200
board PA0HZP
vector 0x168
escc no
DRSI SCC card
chip 1
data_a 0x303
data_b 0x301
ctrl_a 0x302
ctrl_b 0x300
irq 7
pclock 4915200
board DRSI
escc no
If you already have a working configuration for your card under NOS,
then you can use the gencfg command to convert the PE1CHL NOS driver
commands into a form suitable for use in the z8530 driver
configuration file.
To use gencfg you simply invoke it with the same parameters as you
used for the PE1CHL driver in NET/NOS. For example:
# gencfg 2 0x150 4 2 0 1 0x168 9 4915200
will generate a skeleton configuration for the OptoSCC card.
12.2.2. Channel Configuration
The Channel Configuration section is where you specify all of the
other parameters associated with the port you are configuring. Again
this section is broken into stanzas. One stanza represents one logical
port, and therefore there would be two of these for each one of the
hardware parameters stanzas as each 8530 SCC supports two ports.
These keywords and arguments are also written to the /etc/z8530drv.rc
file and must appear after the hardware parameters section.
Sequence is very important in this section, but if you stick with the
suggested sequence it should work ok. The keywords and arguments are:
device
this keyword must be the first line of a port definition and
specifies the name of the special device file that the rest of
the configuration applies to. e.g. /dev/scc0
speed
this keyword specifies the speed in bits per second of the
interface. The argument is an integer: e.g. 1200
clock
this keyword specifies where the clock for the data will be
sourced. Allowable values are:
dpll
normal halfduplex operation
external
MODEM supplies its own Rx/Tx clock
divider
use fullduplex divider if installed.
mode
this keyword specifies the data coding to be used. Allowable
arguments are: nrzi or nrz
rxbuffers
this keyword specifies the number of receive buffers to allocate
memory for. The argument is an integer, e.g. 8.
txbuffers
this keyword specifies the number of transmit buffers to
allocate memory for. The argument is an integer, e.g. 8.
bufsize
this keyword specifies the size of the receive and transmit
buffers. The arguments is in bytes and represents the total
length of the frame, so it must also take into account the AX.25
headers and not just the length of the data field. This keyword
is optional and default to 384
txdelay
the KISS transmit delay value, the argument is an integer in mS.
persist
the KISS persist value, the argument is an integer.
slot
the KISS slot time value, the argument is an integer in mS.
tail
the KISS transmit tail value, the argument is an integer in mS.
fulldup
the KISS full duplex flag, the argument is an integer. 1==Full
Duplex, 0==Half Duplex.
wait
the KISS wait value, the argument is an integer in mS.
min
the KISS min value, the argument is an integer in S.
maxkey
the KISS maximum keyup time, the argument is an integer in S.
idle
the KISS idle timer value, the argument is an integer in S.
maxdef
the KISS maxdef value, the argument is an integer.
group
the KISS group value, the argument is an integer.
txoff
the KISS txoff value, the argument is an integer in mS.
softdcd
the KISS softdcd value, the argument is an integer.
slip
the KISS slip flag, the argument is an integer.
12.3. Using the driver.
To use the driver you simply treat the /dev/scc* devices just as you
would a serial tty device with a KISS TNC connected to it. For
example, to configure Linux Kernel networking to use your SCC card you
could use something like:
# axattach -s 4800 /dev/scc0 VK2KTJ
You can also use NOS to attach to it in precisely the same way. From
JNOS for example you would use something like:
attach asy scc0 0 ax25 scc0 256 256 4800
12.4. The sccstat and sccparam tools.
To assist in the diagnosis of problems you can use the sccstat program
to display the current configuration of an SCC device. To use it try:
# sccstat /dev/scc0
you will displayed a very large amount of information relating to the
configuration and health of the /dev/scc0 SCC port.
The sccparam command allows you to change or modify a configuration
after you have booted. Its syntax is very similar to the NOS param
command, so to set the txtail setting of a device to 100mS you would
use:
# sccparam /dev/scc0 txtail 0x8
13. Configuring an interface for a Baycom modem.
Thomas Sailer, <sailer@ife.ee.ethz.ch>, despite the popularly held
belief that it would not work very well, has developed Linux support
for Baycom modems. His driver supports the Ser12 serial port, Par96
and the enhanced Par97 parallel port modems.
When the driver is running it follows the standard of looking like a
KISS interface, so you treat it in much the same way as you would the
PI card, PacketTwin or SCC driver ports.
13.1. Compiling the kernel
The driver is only available as a module, so you must have compiled
module support into your kernel, and also selected the appopriate
options to support the Baycom driver during the make config stage when
compiling your kernel.
The relevant options that you must answer `Y' for are:
Radio network interfaces (CONFIG_NET_RADIO) [N/y/?]
BAYCOM ser12 and par96 kiss emulation driver for AX.25 (CONFIG_BAYCOM) [N/y/m/?]
13.2. Creating the /dev device files.
The Baycom driver uses special device files in the /dev directory.
You need to create these manually. The following commands should work
ok for you:
# mknod /dev/bc0 c 60 0
# mknod /dev/bc1 c 60 1
# mknod /dev/bc2 c 60 2
# mknod /dev/bc3 c 60 3
You will use these later.
13.3. Loading the module.
When the kernel compilation is complete and you have installed the
module baycom.o wherever you normally keep your modules
(conventionally they are stored in /lib/modules/2.0.0/), you must
start the module. The module takes configuration paramters from the
insmod command line, so you must start it manually from an rc file or
if you use the kerneld program you must configure it with the relevant
paramters so that it supplies them when it loads the module.
If you use kerneld you will need to add the following line to your
/etc/conf.modules file:
alias char-major-60 baycom
There are four main items to specify when loading the module, they
are:
modem
the baycom modem type you are configuring it for.
1. Ser12 type modem.
2. Par96 or Par97 type modem.
iobase
the i/o address of the serial or parallel port you will use.
0x3f8
COM1:
0x2f8
COM2:
0x378
LPT1:
0x278
LPT2:
irq
the Interrupt Request (IRQ) line your port will use.
4 COM1:
3 COM2:
7 LPT1:
5 LPT2:
options
some baycom specific options.
0 use hardware generated DCD signal.
1 use software DCD signal.
13.4. A small trap to be aware of.
Because the Baycom driver uses the serial and parallel ports of your
machines, and because it is a low level driver for these, it competes
with the existing serial and parallel drivers in the kernel. There are
some ways of working around this problem. The first way is to make
sure that you load the Baycom module first so that it takes the
hardware it needs before the serial or parallel device driver modules
load and search for their own. With the serial driver you have the
luxury of being able to disable it for a single port using the
setserial command, this will be demonstrated in the examples. If you
are using the parallel port modems then beware of the lp.o Line
Printer and plip.o Parallel Line IP modules.
13.5. Some example configurations.
These examples are for the two most common configurations.
Disable the serial driver for COM1: then configure the Baycom driver
for a Ser12 serial port modem on COM1: with the software DCD option
enabled:
# setserial /dev/ttyS0 uart none
# insmod baycom modem=1 iobase=0x3f8 irq=4 options=1
Par96 parallel port type modem on LPT1: using hardware DCD detection:
# insmod baycom modem=2 iobase=0x378 irq=7 options=0
The first device created is /dev/bc0, the second is /dev/bc1 etc.
13.6. Configuring multiple devices.
Using the insmod program and its command line arguments you can only
configure one Baycom modem. There is a setbaycom utility which I have
not yet located that will allow you to configure others. If you happen
to find it please let me know where it is kept so that I can include
details for it here.
13.7. Actually using the devices.
This device driver when loaded looks like a serial tty driver with a
KISS TNC attached. This means that configuration of the AX.25 software
for this driver is identical to the configuration for a KISS TNC
presented earlier. You need to use the axattach program and add the
port to your /usr/local/etc/axports file. The only difference is that
you would use the device /dev/bc0 instead of /dev/ttyS0.
14. Configuring ax25d to accept incoming AX.25/Netrom connections.
Linux is a powerful operating system and offers a great deal of
flexibility in how it is configured. With this flexibility comes a
cost in configuring it to do what you want. When configuring your
Linux machine to accept incoming AX.25 or NetRom connections there are
a number of questions you need to ask yourself. The most important of
which is: "What do I want users to see when they connect?". As
detailed in the HAM-HOWTO there are BBS systems that are being
developed that you might want users to see when they connect,
alternatively you might want to give users a login prompt so that they
can make use of a shell account, or you might even have written your
own program, such as a customised database or a game, that you want
people to connect to. Whatever you choose, you must tell the AX.25
software about this so that it knows what software to run when it
accepts an incoming AX.25 connection.
14.1. Creating the /usr/local/etc/ax25d.conf file.
This file is the configuration file for the ax25d AX.25 daemon which
handles incoming AX.25 and NetRom connections.
The file is a little cryptic looking at first, but you'll soon
discover it is very simple in practice, with a small trap for you to
be wary of.
The format of the ax25d.conf file is as follows:
# This is a comment and is ignored by the ax25d program.
[<interface_call>]
<peer1> window T1 T2 T3 N2 <mode> <uid> <cmd> <cmd-name> <arguments>
<peer2> window T1 T2 T3 N2 <mode> <uid> <cmd> <cmd-name> <arguments>
defaults window T1 T2 T3 N2 <mode> <uid> <cmd> <cmd-name> <arguments>
<peer3> window T1 T2 T3 N2 <mode> <uid> <cmd> <cmd-name> <arguments>
default window T1 T2 T3 N2 <mode> <uid> <cmd> <cmd-name> <arguments>
Where:
# at the start of a line marks a comment and is completely ignored
by the ax25d program.
<interface_call>
is the AX.25 callsign of the AX.25 or NetRom interface that this
particular paragraph is for.
<peer>
is the callsign of the peer node that this particular
configuration applies to. If you don't specify an SSID here then
any SSID will match.
window
is the AX.25 Window parameter (K) or MAXFRAME parameter for this
configuration.
T1 is the Frame retransmission (T1) timer in half second units.
T2 is the amount of time the AX.25 software will wait for another
incoming frame before preparing a response in 1 second units.
T3 is the amount of time of inactivity before the AX.25 software
will disconnect the session in 1 second units.
N2 is the number of consecutive retransmissions that will occur
before the connection is closed.
<mode>
provides a mechanism for determining certain types of general
permissions. The modes are enabled or disabled by setting or
resetting bits in an 8 bit map. You set that map by setting
<mode> to the sum of the following values:
1 Setup utmp, and run on a ptty (planned).
2 UNUSED.
4 UNUSED.
8 UNUSED.
16 UNUSED.
32 UNUSED.
64 Disallow digipeated uplinks, only allow direct connections.
128
Lockout, Barred, immediate disconnect.
<uid>
is the userid that the program to be run to support the
connection should be run as.
<cmd>
is the full pathname of the command to be run, with no arguments
specified.
<cmd-name>
is the text that should appear in a ps as the command name
running (normally the same as <cmd> except without the directory
path information.
<arguments>
are the command line argument to be passed to the <:cmd> when it
is run. You pass useful information into these arguments by use
of the following tokens:
%U AX.25 callsign of the connected party without the SSID, in
uppercase.
%u AX.25 callsign of the connected party without the SSID, in
lowercase.
%S AX.25 callsign of the connected party with the SSID, in
uppercase.
%s AX.25 callsign of the connected party with the SSID, in
lowercase.
You need one section in the above format for each AX.25 or NetRom
interface you want to accept incoming AX.25 or NetRom connections on.
There are two special lines in the paragraph, one starts with the
string `defaults' and other starts with the string `default' (yes
there is a difference). These lines serve special functions.
The `default' lines purpose should be obvious, this line acts as a
catch-all, so that any incoming connection on the <interface_call>
interface that doesn't have a specific rule will match the `default'
rule. If you don't have a `default' rule, then any connections not
matching any specific rule will be disconnected immediately without
notice.
The `defaults' line is a little more subtle, and here is the trap I
mentioned earlier. In any of the fields for any definition for a peer
you can use the `*' character to say `use the default value'. The
`default' line is what sets those default values. The kernel software
itself has some defaults which will be used if you don't specify any.
The trap is that the these defaults apply only to those rules below
the `default' line not to those above. You may have more than one
`default' rule per interface definition, and in this way you may
create groups of default configurations.
14.2. A simple example ax25d.conf file.
Ok, an illustrative example:
# ax25d.conf for VK2KTJ - 21/11/95
# This configuration uses the AX.25 port defined earlier.
[VK2KTJ-1]
NOCALL * * * * * 0 guest /usr/games/fortune
defaults 1 10 * * * 0 root /usr/local/sbin/axspawn axspawn %u +
VK2XLZ-1 * * * * * * * * *
VK2DAY-1 * * * * * * * * *
default 1 10 5 100 5 0 root /usr/local/bin/pms pms -a -o vk2ktj
#
This example says that anybody connecting to the interface on my
machine with the callsign VK2KTJ-1 will have the following rules
applied:
Anyone whose callsign is set to `NOCALL' should use the kernel default
parameters and have the fortune program run as guest for them.
The defaults line changes two parameters from the kernel defaults
(Window and T1) and will run the /usr/local/sbin/axspawn program for
them. Any copies of /usr/local/sbin/axspawn run this way will appear
as axspawn in a ps listing for convenience. The next two lines
definitions for two stations who will receive those permissions.
The last line in the paragraph is the `catch all' definition that
everybody else will get (including VK2XLZ and VK2DAY using any other
SSID other than -1). This definition sets all of the parameters
implicitly and will cause the pms program to be run with a command
line argument indicating that it is being run for an AX.25 connection
(assuming VK2KTJ-1 to be an AX.25 interface) and that the owner
callsign is VK2KTJ. (See the `Configuring the PMS' section below for
more details).
If you wanted to define rules for another interface, a NetRom
interface for example, then you would add another paragraph coded in
the same way with rules and callsign appropriate to it.
This example is a contrived one but I think it illustrates clearly the
important features of the syntax of the configuration file. Jonathon
includes a much longer and more detailed example in the ax25-utils
package that you should look at if you need more information.
14.3. Starting ax25d
When you have the two configuration files completed you start ax25d
with the command:
# /usr/local/sbin/ax25d
Article Unavailable
Linux AX25 HOWTO (part 2/2)
Author: Terry Dawson
Date: Wed, 06 Nov 1996 00:00
Date: Wed, 06 Nov 1996 00:00
571 lines
24901 bytes
24901 bytes
Archive-name: linux/howto/ax25/part2
Last-modified: 23 Jun 96
-----BEGIN PGP SIGNED MESSAGE-----
*** The `Linux AX25 HOWTO' is posted automatically by the
*** Linux HOWTO coordinator, Greg Hankins <gregh@sunsite.unc.edu>. Please
*** direct any comments or questions about this HOWTO to the author,
*** Terry Dawson <terry@perf.no.itg.telecom.com.au>.
- --- BEGIN Linux AX25 HOWTO part 2/2 ---
shell
this is the login shell of any new users.
associate
this flag indicates whether outgoing AX.25 connections made by
this user after they login will use their own callsign, or your
stations callsign.
14.5. Configuring the pms
The pms program is an implementation of a simple personal message
system. It was originally written by Alan Cox. Dave Brown, N2RJT,
<dcb@vectorbd.com> has taken on further development of it. At present
it is still very simple, supporting only the ability to send mail to
the owner of the system and to obtain some limited system information
but Dave is working to expand its capability to make it more useful.
Configuring the pms program is still a little clumsy at the moment
because it is new but bare with it while Dave works on it. The only
difficult part is modifying the source code to support your local mail
delivery agent and whether you use the ttylinkd program or the talk-
ax25 program.
After that is done there are a couple of simple files that you should
create that give users some information about the system and then you
need to add appropriate entries into the ax25d.conf file so that
connected users are presented with the PMS.
14.5.1. Customising pms.c
If you take a look at the pms.c file in the ax25-utils package you
will see that there a few items that you can configure. Perhaps the
most important to configure is the one that allows you to specify what
local mail delivery agent you use. In most installations the deliver
program may well work, but in the minimal installation on my gateway
machine I needed to modify the line that previously said:
#define MAIL_DELIVERY_AGENT "deliver %s"
to:
#define MAIL_DELIVERY_AGENT "/bin/mail.local %s"
There is no easy way of knowing what local delivery agent your machine
is configured to use, so perhaps you could simply look for either of
these files in the obvious places and choose whichever seems to be
there.
I also have the ttylinkd program installed, so I needed to modify the
section relating to it. I keep my copy of the ttylinkd program in my
/usr/sbin directory, so I modified the line that previously said:
/* #define MY_TALK "/usr/local/sbin/ttylinkd" */
to:
#define MY_TALK "/usr/sbin/ttylinkd"
If you use the talk-ax25 program then you would remove the /* and */
from around that line instead.
There is one last definition that might be useful to you, and that is
if you have a default email gateway. This line is the line containing
the string MY_GATEWAY. If you have an email gateway that you use, then
you should remove the comments from this line and change the address
to that of your gateway.
14.5.2. Create the /usr/local/pms/motd file.
The /usr/local/pms/motd file contains the `message of the day' that
users will be presented with after they connect and receive the usual
BBS id header. The file is a simple text file, any text you include in
this file will be sent to users.
14.5.3. Create the /usr/local/pms/info file.
The /usr/local/pms/info file is also a simple text file in which you
would put more detailed information about your station or
configuration. This file is presented to users in response to their
issuing of the Info command from the PMS> prompt.
14.5.4. Associate AX.25 callsigns with system users.
When a connected user sends mail to an AX.25 callsign, the pms expects
that callsign to be mapped, or associated with a real system user on
your machine.
You make this association with the axparms command. An example looks
like:
# axparms -assoc vk2ktj terry
This command associates that AX.25 callsign vk2ktj with the user terry
on the machine, so any mail for vk2ktj on the pms will be sent to
terry.
Remember to put these associations into your rc file so that they are
available each time your reboot.
14.5.5. Add the PMS to the /usr/local/etc/ax25d.conf file.
Adding the pms to your ax25d.conf file is very simple. There is one
small thing you need to think about though. Dave has added command
line arguments to the PMS to allow it to handle a number of different
text end-of-line conventions. AX.25 and NetRom by convention expect
the end-of-line to be carriage return, linefeed while the standard
unix end-of-line is just newline. So, for example, if you wanted to
add an entry that meant that the default action for a connection
received on an AX.25 port is to start the PMS then you would add a
line that looked something like:
default 1 10 5 100 5 0 root /usr/local/bin/pms pms -a -o vk2ktj
This simply runs the pms program, telling it that it is an AX.25
connection it is connected to and that the PMS owner is vk2ktj. Check
the man page for what you should specify for other connection methods.
14.5.6. Test the PMS.
To test the PMS, you can try the following command from the command
line:
# /usr/local/bin/pms -u vk2ktj -o vk2ktj
Substitute your own callsign for mine and this will run the pms,
telling it that it is to use the unix end-of-line convention, and that
user logging in is vk2ktj. You can do all the things connected users
can.
Additionally you might try getting some other node to connect to you
to confirm that your ax25d.conf configuration works.
15. HOWTO link NOS and the Linux kernel networking software
Many people like to run some version of NOS under Linux because it has
all of the features and facilities they are used to. Most of those
people would also like to have the NOS running on their machine
capable of talking to the Linux kernel so that they can offer some of
the linux capabilities to radio users.
15.1. Linking NOS and Linux using a pipe device
Brandon S. Allbery, KF8NH, contributed the following information to
explain how to interconnect the NOS running on a Linux machine with
the kernel code using the Linux pipe device.
Since both Linux and NOS support the slip protocol it is possible to
link the two together by creating a slip link. You could do this by
using two serial ports with a loopback cable between them, but this
would be slow and costly. Linux provides a feature that many other
Unix-like operating systems provide called `pipes'. These are special
pseudo devices that look like a standard tty device to software but in
fact loopback to another pipe device. To use these pipes the first
program must open the master end of the pipe, and the open then the
second program can open the slave end of the pipe. When both ends are
open the programs can communicate with each other simply by writing
characters to the pipes in the way they would if they were terminal
devices.
To use this feature to connect the Linux Kernel and a copy of NOS, or
some other program you first must choose a pipe device to use. You can
find one by looking in your /dev directory. The master end of the
pipes are named: ptyp[1-f] and the slave end of the pipes are known
as: ttyp[1-f]. Remember they come in pairs, so if you select
/dev/ptypf as your master end then you must use /dev/ttypf as the
slave end.
Once you have chosen a pipe device pair to use you should allocate the
master end to you linux kernel and the slave end to the NOS program,
as the Linux kernel starts first and the master end of the pipe must
be opened first. You must also remember that your Linux kernel must
have a different IP address to your NOS, so you will need to allocate
a unique address for it if you haven't already.
You configure the pipe just as if it were a serial device, so to
create the slip link from your linux kernel you can use commands
similar to the following:
# /sbin/slattach -s 38400 -p slip /dev/ptypf &
# /sbin/ifconfig sl0 broadcast 44.255.255.255 pointopoint 44.70.248.67 /
mtu 1536 44.70.4.88
# /sbin/route add 44.70.248.67 sl0
# /sbin/route add -net 44.0.0.0 gw 44.70.248.67
In this example the Linux kernel has been given IP address 44.70.4.88
and the NOS program is using IP address 44.70.248.67. The route
command in the last line simply tells your linux kernel to route all
datagrams for the amprnet via the slip link created by the slattach
command. Normally you would put these commands into your
/etc/rc.d/rc.inet2 file after all your other network configuration is
complete so that the slip link is created automatically when you
reboot. Note: there is no advantage in using cslip instead of slip as
it actually reduces performance because the link is only a virtual one
and occurs fast enough that having to compress the headers first takes
longer than transmitting the uncompressed datagram.
To configure the NOS end of the link you could try the following:
# you can call the interface anything you want; I use "linux" for convenience.
attach asy ttypf - slip linux 1024 1024 38400
route addprivate 44.70.4.88 linux
These commands will create a slip port named `linux' via the slave end
of the pipe device pair to your linux kernel, and a route to it to
make it work. When you have started NOS you should be able to ping and
telnet to your NOS from your Linux machine and vice versa. If not,
double check that you have made no mistakes especially that you have
the addresses configured properly and have the pipe devices around the
right way.
16. Some sample configurations.
Following are examples of the most common types of configurations.
These are guides only as there are as many ways of configuring your
network as there are networks to configure, but they may give you a
start.
16.1. Small Ethernet LAN with Linux as a router to Radio LAN
Many of you may have small local area networks at home and want to
connect the machines on that network to your local radio LAN. This is
the type of configuration I use at home. I arranged to have a suitable
block of addresses allocated to me that I could capture in a single
route for convenience and I use these on my Ethernet LAN. Your local
IP coordinator will assist you in doing this if you want to try it as
well. The addresses for the Ethernet LAN form a subset of the radio
LAN addresses. The following configuration is the actual one for my
linux router on my network at home:
. . . . . .
--- .
| Network /---------\ . Network
| 44.136.8.96/29| | . 44.136.8/24 \ | /
| | Linux | . \|/
| | | . |
| eth0 | Router | . /-----\ /----------\ |
|---------------| |-----| TNC |----| Radio |---/
| 44.136.8.97 | and | . \-----/ \----------/
| | | sl0
| | Server | 44.136.8.5
| | | .
| | | .
| \_________/ .
--- . . . . . .
#!/bin/sh
# /etc/rc.net
# This configuration provides one KISS based AX.25 port and one
# Ethernet device.
echo "/etc/rc.net"
echo " Configuring:"
echo -n " loopback:"
/sbin/ifconfig lo 127.0.0.1
/sbin/route add 127.0.0.1
echo " done."
echo -n " ethernet:"
/sbin/ifconfig eth0 44.136.8.97 netmask 255.255.255.248 \
broadcast 44.136.8.103 up
/sbin/route add 44.136.8.97 eth0
/sbin/route add -net 44.136.8.96 netmask 255.255.255.248 eth0
echo " done."
echo -n " AX.25: "
axattach -i 44.136.8.5 -m 512 /dev/ttyS1 4800
ifconfig sl0 netmask 255.255.255.0 broadcast 44.136.8.255
route add -host 44.136.8.5 sl0
route add -net 44.136.8.0 window 1024 sl0
echo -n " Netrom: "
nrattach -i 44.136.8.5 netrom
echo " Routing:"
/sbin/route add default gw 44.136.8.68 window 1024 sl0
echo " default route."
echo done.
# end
/usr/local/etc/axports
# name callsign speed paclen window description
4800 VK2KTJ-0 4800 256 2 144.800 MHz
/usr/local/etc/nrports
# name callsign alias paclen description
netrom VK2KTJ-1 LINUX 235 Linux Switch Port
/usr/local/etc/nrbroadcast
# ax25_name min_obs def_qual worst_qual verbose
4800 1 120 10 1
� You must have IP_FORWARDING enabled in your kernel.
� The AX.25 configuration files are pretty much those used as
examples in the earlier sections, refer to those where necessary.
� I've chosen to use an IP address for my radio port that is not
within my home network block. I needn't have done so, I could have
easily used 44.136.8.97 for that port too.
� 44.136.8.68 is my local IPIP encapsulated gateway and hence is
where I point my default route.
� Each of the machines on my Ethernet network have a route:
route add -net 44.0.0.0 gw 44.136.8.97 window 512 mss 512 eth0
The use of the mss and window parameters means that I can get optimum
performance from both local Ethernet and radio based connections.
� I also run my sendmail, http, ftp and other daemons on the router
machine so that it needs to be the only machine to provide others
with facilities.
� The router machine is a lowly 386DX20 with a 20Mb harddrive and a
very minimal linux configuration.
16.2. IPIP encapsulated gateway configuration.
Linux is now very commonly used for tcp/ip encapsulated gateways
around the world. The new tunnel driver supports multiple encapsulated
routes and makes the older ipip daemon obsolete.
A typical configuration would look similar to the following.
. . . . . .
--- .
| Network /---------\ . Network
| 154.27.3/24 | | . 44.136.16/24 \ | /
| | Linux | . \|/
| | | . |
| eth0 | IPIP | . /-----\ /----------\ |
---|---------------| |-----| TNC |----| Radio |---/
| 154.27.3.20 | Gateway | . \-----/ \----------/
| | | sl0
| | | 44.136.16.1
| | | .
| | | .
| \_________/ .
--- . . . . . .
The configuration files of interest are:
# /etc/rc.net
# This file is a simple configuration that provides one KISS AX.25
# radio port, one Ethernet device, and utilises the kernel tunnel driver
# to perform the IPIP encapsulation/decapsulation
#
echo "/etc/rc.net"
echo " Configuring:"
#
echo -n " loopback:"
/sbin/ifconfig lo 127.0.0.1
/sbin/route add 127.0.0.1
echo " done."
#
echo -n " ethernet:"
/sbin/ifconfig eth0 154.27.3.20 netmask 255.255.255.0 \
broadcast 154.27.3.255 up
/sbin/route add 154.27.3.20 eth0
/sbin/route add -net 154.27.3.0 netmask 255.255.255.0 eth0
echo " done."
#
echo -n " AX.25: "
axattach -i 44.136.16.1 -m 512 /dev/ttyS1 4800
/sbin/ifconfig sl0 netmask 255.255.255.0 broadcast 44.136.16.255
/sbin/route add -host 44.136.16.1 sl0
/sbin/route add -net 44.136.16.0 netmask 255.255.255.0 window 1024 sl0
#
echo -n " tunnel:"
/sbin/ifconfig tunl0 44.136.16.1 mtu 512 up
#
echo done.
#
echo -n "Routing ... "
source /etc/ipip.routes
echo done.
#
# end.
and:
# /etc/ipip.routes
# This file is generated using the munge script
#
/sbin/route add 44.134.8.0 netmask 255.255.255.0 tunl0 gw 134.43.26.1
/sbin/route add 44.34.9.0 netmask 255.255.255.0 tunl0 gw 174.84.6.17
/sbin/route add 44.13.28.0 netmask 255.255.255.0 tunl0 gw 212.37.126.3
...
...
...
/usr/local/etc/axports
# name callsign speed paclen window description
4800 VK2KTJ-0 4800 256 2 144.800 MHz
Some points to note here are:
� The new tunnel driver uses the gw field in the routing table in
place of the pointopoint parameter to specify the address of the
remote IPIP gateway. This is why it now supports multiple routes
per interface.
� You can configure two network devices with the same address. In
this example both the sl0 and the tunl0 devices have been
configured with the IP address of the radio port. This is done so
that the remote gateway sees the correct address from your gateway
in encapsulated datagrams sent to it.
� The route commands used to specify the encapsulated routes can be
automatically generated by a modified version of the munge script.
This is included below. The route commands would then be written to
a separate file and read in using the bash source /etc/ipip.routes
command (assuming you called the file with the routing commands
/etc/ipip.routes) as illustrated. The source file must be in the
NOS route command format.
� Note the use of the window argument on the route command. Setting
this parameter to an appropriate value improves the performance of
your radio link.
The new tunnel-munge script:
#!/bin/sh
#
# From: Ron Atkinson <n8fow@hamgate.cc.wayne.edu>
#
# This script is basically the 'munge' script written by Bdale N3EUA
# for the IPIP daemon and is modified by Ron Atkinson N8FOW. It's
# purpose is to convert a KA9Q NOS format gateways route file
# (usually called 'encap.txt') into a Linux routing table format
# for the IP tunnel driver.
#
# Usage: Gateway file on stdin, Linux route format file on stdout.
# eg. tunnel-munge < encap.txt > ampr-routes
#
# NOTE: Before you use this script be sure to check or change the
# following items:
#
# 1) Change the 'Local routes' and 'Misc user routes' sections
# to routes that apply to your own area (remove mine please!)
# 2) On the fgrep line be sure to change the IP address to YOUR
# gateway Internet address. Failure to do so will cause serious
# routing loops.
# 3) The default interface name is 'tunl0'. Make sure this is
# correct for your system.
echo "#"
echo "# IP tunnel route table built by $LOGNAME on `date`"
echo "# by tunnel-munge script v960307."
echo "#"
echo "# Local routes"
echo "route add -net 44.xxx.xxx.xxx netmask 255.mmm.mmm.mmm dev sl0"
echo "#"
echo "# Misc user routes"
echo "#"
echo "# remote routes"
fgrep encap | grep "^route" | grep -v " XXX.XXX.XXX.XXX" | \
awk '{
split($3, s, "/")
split(s[1], n,".")
if (n[1] == "") n[1]="0"
if (n[2] == "") n[2]="0"
if (n[3] == "") n[3]="0"
if (n[4] == "") n[4]="0"
if (s[2] == "1") mask="128.0.0.0"
else if (s[2] == "2") mask="192.0.0.0"
else if (s[2] == "3") mask="224.0.0.0"
else if (s[2] == "4") mask="240.0.0.0"
else if (s[2] == "5") mask="248.0.0.0"
else if (s[2] == "6") mask="252.0.0.0"
else if (s[2] == "7") mask="254.0.0.0"
else if (s[2] == "8") mask="255.0.0.0"
else if (s[2] == "9") mask="255.128.0.0"
else if (s[2] == "10") mask="255.192.0.0"
else if (s[2] == "11") mask="255.224.0.0"
else if (s[2] == "12") mask="255.240.0.0"
else if (s[2] == "13") mask="255.248.0.0"
else if (s[2] == "14") mask="255.252.0.0"
else if (s[2] == "15") mask="255.254.0.0"
else if (s[2] == "16") mask="255.255.0.0"
else if (s[2] == "17") mask="255.255.128.0"
else if (s[2] == "18") mask="255.255.192.0"
else if (s[2] == "19") mask="255.255.224.0"
else if (s[2] == "20") mask="255.255.240.0"
else if (s[2] == "21") mask="255.255.248.0"
else if (s[2] == "22") mask="255.255.252.0"
else if (s[2] == "23") mask="255.255.254.0"
else if (s[2] == "24") mask="255.255.255.0"
else if (s[2] == "25") mask="255.255.255.128"
else if (s[2] == "26") mask="255.255.255.192"
else if (s[2] == "27") mask="255.255.255.224"
else if (s[2] == "28") mask="255.255.255.240"
else if (s[2] == "29") mask="255.255.255.248"
else if (s[2] == "30") mask="255.255.255.252"
else if (s[2] == "31") mask="255.255.255.254"
else mask="255.255.255.255"
if (mask == "255.255.255.255")
printf "route add -host %s.%s.%s.%s gw %s dev tunl0\n"\
,n[1],n[2],n[3],n[4],$5
else
printf "route add -net %s.%s.%s.%s gw %s netmask %s dev tunl0\n"\
,n[1],n[2],n[3],n[4],$5,mask
}'
echo "#"
echo "# default the rest of amprnet via mirrorshades.ucsd.edu"
echo "route add -net 44.0.0.0 gw 128.54.16.18 netmask 255.0.0.0 dev tunl0"
echo "#"
echo "# the end"
17. Discussion relating to Amateur Radio and Linux.
There are various places that discussion relating to Amateur Radio and
Linux take place. They take place in the comp.os.linux.* newsgroups,
they also take place on the HAMS list on vger.rutgers.edu. Other
places where they are held include the tcp-group mailing list at
ucsd.edu (the home of amateur radio tcp/ip discussions), and you might
also try the #linpeople channel on the linuxnet irc network.
To join the Linux linux-hams channel on the mail list server, send
mail to:
Majordomo@vger.rutgers.edu
with the line:
subscribe linux-hams
in the message body. The subject line is ignored.
To join the tcp-group send mail to:
listserver@ucsd.edu
with the line:
subscribe tcp-group
in the body of the text.
Note: Please remember that the tcp-group is primarily for discussion
of the use of advanced protocols, of which tcp/ip is one, in Amateur
Radio. Linux specific questions should not ordinarily go there.
18. Copyright.
The AX25-HOWTO, information on how to install and configure some of
the more important packages providing AX25 support for Linux.
Copyright (c) 1996 Terry Dawson.
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