As stated previously, the aim of this document is not to tell you how to configure Linux or the ax25 utilities. However, you do need to add a line in your ax25d.conf to allow connections to DXSpider for your users. For each interface that you wish to allow connections on, use the following format ...
default * * * * * * - sysop /spider/src/client client %u ax25
or, if you wish your users to be able to use SSID's on their callsigns ..
default * * * * * * - sysop /spider/src/client client %s ax25
Allowing telnet connections is quite simple. Firstly you need to add a line in /etc/services to allow connections to a port number, like this ....
spdlogin 8000/tcp # spider anonymous login port
Then add a line in /etc/inetd.conf like this ....
spdlogin stream tcp nowait root /usr/sbin/tcpd /spider/src/client login telnet
This needs to be added above the standard services such as ftp, telnet etc. Once this is done, you need to restart inetd like this ....
killall -HUP inetd
Now login as sysop and cd spider/perl. You can test that spider is accepting telnet logins by issuing the following command ....
client.pl login telnet
You should get a login prompt and on issuing a callsign, you will be given access to the cluster. Note, you will not get a password login. There seems no good reason for a password prompt to be given so it is not asked for.
Assuming all is well, then try a telnet from your linux console ....
telnet localhost 8000
You should now get the login prompt and be able to login as before.
In order to allow cluster node connections, spider needs to know that the connecting callsign is a cluster node. This is the case whether the connect is incoming or outgoing. In spider this is a simple task and can be done in runtime.
Later versions of Spider can distinguish different software and treat them differently. For example, the WCY beacon cannot be handles by AK1A type nodes as AK1A does not know what to do with PC73. There are 4 different types of node at present and although they may not have any major differences at the moment, it allows for compatibility. The 4 types are ...
set/node (AK1A type)
set/spider
set/dxnet
set/clx
For now, we will assume that the cluster we are going to connect to is an AK1A type node.
Start up the cluster as you did before and login as the sysop with client.pl. The cluster node I am wanting to make a connection to is GB7BAA but you would obviously use whatever callsign you required. At the prompt type ...
set/node gb7baa
The case does not matter as long as you have a version of DXSpider later than 1.33. Earlier versions required the callsign to be in upper case.
That is now set, it is as simple as that. To prove it, login on yet another console as sysop and issue the command ...
client.pl gb7baa (using the callsign you set as a node)
You should get an initialisation string from DXSpider like this ...
client.pl gb7baa
PC38^GB7MBC^~
If the callsign you just set up as a cluster node is for an incoming connect, this is all that needs to be done. If the connection is to be outgoing then a connection script needs to be written.
Because DXSpider operates under Linux, connections can be made using just about any protocol; AX25, NETRom, tcp/ip, ROSE etc are all possible examples. Connect scripts live in the /spider/connect directory and are simple ascii files. Writing a script for connections is therefore relatively simple.
The connect scripts consist of lines which start with the following keywords or symbols:-
# All lines starting with a # are ignored, as are completely
blank lines.
timeout timeout followed by a number is the number of seconds to wait for a
command to complete. If there is no timeout specified in the script
then the default is 60 seconds.
abort abort is a regular expression containing one or more strings to look
for to abort a connection. This is a perl regular expression and is
executed ignoring case.
connect connect followed by ax25 or telnet and some type dependent
information. In the case of a telnet connection, there can be up to
two parameters.
The first is the ip address or hostname of the computer you wish to
connect to and the second is the port number you want to use (this
can be left out if it is a normal telnet session).
In the case of an ax25 session then this would normally be a call to
ax25_call or netrom_call as in the example above. It is your
responsibility to get your node and other ax25 parameters to work
before going down this route!
' ' is the delimiting character for a word or phrase of an expect/send
line in a chat type script. The words/phrases normally come in pairs,
either can be empty. Each line reads input from the connection until
it sees the string (or perl regular expression) contained in the
left hand string. If the left hand string is empty then it doesn't
read or wait for anything. The comparison is done ignoring case.
When the left hand string has found what it is looking for (if it is)
then the right hand string is sent to the connection.
This process is repeated for every line of chat script.
client client starts the connection, put the arguments you would want here
if you were starting the client program manually. You only need this
if the script has a different name to the callsign you are trying to
connect to (i.e. you have a script called other which actually
connects to GB7DJK-1 [instead of a script called gb7djk-1]).
There are many possible ways to configure the script but here are two examples, one for a NETRom/AX25 connect and one for tcp/ip.
timeout 60
abort (Busy|Sorry|Fail)
# don't forget to chmod 4775 netrom_call!
connect ax25 /usr/sbin/netrom_call bbs gb7djk g1tlh
'Connect' ''
'Connect' 'c np7'
'Connect' 'c gb7dxm'
# you can leave this out if you call the script 'gb7dxm'
client gb7dxm ax25
timeout 15
connect telnet dirkl.tobit.co.uk
'login' 'gb7djk'
'word' 'gb7djk'
# tell GB7DJK-1 that it is connected to GB7DJK
# you can leave this out if you call this script 'gb7djk'
client gb7djk telnet
Both these examples assume that everything is set up properly at the other end. You will find other examples in the /spider/examples directory.
You start the connection, from within a sysop enabled cluster login, by typing in the word connect followed by a script name like this ....
G0VGS de GB7MBC 13-Dec-1998 2041Z >connect gb7djk-1
connection to GB7DJK-1 started
G0VGS de GB7MBC 13-Dec-1998 2043Z >
This will start a connection using the script called gb7djk-1. You can follow the connection by watching the term or console from where you started cluster.pl. You should see something like this ...
<- D G1TLH connect gb7djk-1
-> D G1TLH connection to GB7DJK-1 started
-> D G1TLH G1TLH de GB7DJK 13-Dec-1998 2046Z >
timeout set to 15
CONNECT sort: telnet command: dirkl.tobit.co.uk
CHAT "login" -> "gb7djk"
received "
Red Hat Linux release 5.1 (Manhattan)
Kernel 2.0.35 on an i586
"
received "login: "
sent "gb7djk"
CHAT "word" -> "gb7djk"
received "gb7djk"
received "Password: "
sent "gb7djk"
Connected to GB7DJK-1, starting normal protocol
<- O GB7DJK-1 telnet
-> B GB7DJK-1 0
GB7DJK-1 channel func state 0 -> init
<- D GB7DJK-1
<- D GB7DJK-1 Last login: Sun Dec 13 17:59:56 from dirk1
<- D GB7DJK-1 PC38^GB7DJK-1^~
<- D GB7DJK-1 PC18^ 1 nodes, 0 local / 1 total users Max users 0 Uptime
0 00:00^5447^~
etc
With later versions of Spider there is a set/login command for users. This tells them when a user or node logs in or out. If you do not add a line to your scripts after the final line (or before the client line which should always be last if needed) then the login/logout information will be sent to users before the login actually completes. This means if a node is unreachable, it will continue sending logins and logouts to users even though it is not actually connecting. To avoid this use the following line ...
'connect' ''
In a script, this might look like ...
timeout 35
abort (Busy|Sorry|Fail)
connect telnet mary 3000
'ogin:' 'gb7mbc'
'>' 'telnet 44.131.93.96 7305'
'connect' ''
Cluster links in particular suffer greatly from the presence of telnet echo. This is caused by the telnet negotiation itself and can create at worst severe loops. At best it creates unnecessary bandwidth and large logfiles! There are things that can be done to limit this problem but will not always work dependent on the route taken to connect.
Telnet echo itself should only be a problem if the connection is being made to the telnet port (23). This port uses special rules that include echo negotiation. If the connection is to a different port, such as 8000, this negotiation does not happen and therefore no echo should be present.
Sometimes it is not possible to make a direct connection to another node and this can cause problems. There is a way of trying to suppress the telnet echo but this will not always work, unfortunately it is difficult to be more specific. Here is an example of what I mean ...
timeout 35
abort (Busy|Sorry|Fail)
connect telnet mary.lancs.ac.uk
'ogin:' 'gb7mbc'
'word:' 'mypasswd'
'\$' 'stty -echo raw'
'\$' 'telnet 44.131.93.96'
'connect' ''
So, the first connection is made by Spider. This is fine as Spider uses the Net_Telnet script from within perl. This actually uses TCP rather than TELNET so no negotiation will be done on the first connection. Once connected to mary.lancs.ac.uk, the command is sent to suppress echo. Now a telnet is made to a cluster node that is accepting connections on port 23. The problem with this link is that the negotiation is made by the remote machine, therefore you have no control over it. The chances are that this link will create echo and there will be no way you can stop it.