13. Configuring the node software

13.1. Creating the /etc/ax25/node.conf file

The node.conf file is where the main configuration of the node takes place. It is a simple text file and its format is as follows:

# /etc/ax25/node.conf # configuration file for the node(8) program. # # Lines beginning with '#' are comments and are ignored. # Hostname # Specifies the hostname of the node machine hostname radio.gw.vk2ktj.ampr.org # Local Network # allows you to specify what is consider 'local' for the # purposes of permission checking using nodes.perms. localnet 44.136.8.96/29 # Hide Ports # If specified allows you to make ports invisible to users. The # listed ports will not be listed by the (P)orts command. hiddenports rose netrom # Node Identification. # this will appear in the node prompt NodeId LINUX:VK2KTJ-9 # NET/ROM port # This is the name of the NET/ROM port that will be used for # outgoing NET/ROM connections from the node. NrPort netrom # Node Idle Timeout # Specifies the idle time for connections to this node in seconds. idletimout 1800 # Connection Idle Timeout # Specifies the idle timer for connections made via this node in # seconds. conntimeout 1800 # Reconnect # Specifies whether users should be reconnected to the node # when their remote connections disconnect, or whether they # should be disconnected complete. reconnect on # Command Aliases # Provide a way of making complex node commands simple. alias CONV "telnet vk1xwt.ampr.org 3600" alias BBS "connect radio vk2xsb" # External Command Aliases # Provide a means of executing external commands under the node. # extcmd <cmdname> <flag> <userid> <command> # Flag == 1 is the only implemented function. # <command> is formatted as per ax25d.conf extcmd PMS 1 root /usr/sbin/pms pms -u %U -o VK2KTJ # Logging # Set logging to the system log. 3 is the noisiest, 0 is disabled. loglevel 3 # The escape character # 20 = (Control-T) EscapeChar 20

13.2. Creating the /etc/ax25/node.perms file

The node allows you to assign permissions to users. These permissions allow you to determine which users should be allowed to make use of options such as the (T)elnet, and (C)onnect commands, for example, and which shouldn't. The node.perms file is where this information is stored and contains five key fields. For all fields an asterisk `*' character matches anything. This is useful for building default rules.

A sample nodes.perms might look like:

# /etc/ax25/node.perms # # The node operator is VK2KTJ, has a password of 'secret' and # is allowed all permissions by all connection methods vk2ktj * * secret 255 # The following users are banned from connecting NOCALL * * * 0 PK232 * * * 0 PMS * * * 0 # INET users are banned from connecting. * inet * * 0 # AX.25, NET/ROM, Local, Host and AMPR users may (C)onnect and (T)elnet # to local and ampr hosts but not to other IP addresses. * ax25 * * 159 * netrom * * 159 * local * * 159 * host * * 159 * ampr * * 159

13.3. Configuring node to run from ax25d

The node program would normally be run by the ax25d program. To do this you need to add appropriate rules to the /etc/ax25/ax25d.conf file. In my configuration I wanted users to have a choice of either connecting to the node or connecting to other services. ax25d allows you to do this by cleverly creating creating port aliases. For example, given the ax25d configuration presented above, I want to configure node so that all users who connect to VK2KTJ-1 are given the node. To do this I add the following to my /etc/ax25/ax25d.conf file:

[vk2ktj-1 via radio] default * * * * * 0 root /usr/sbin/node node

This says that the Linux kernel code will answer any connection requests for the callsign `VK2KTJ-1' heard on the AX.25 port named `radio', and will cause the node program to be run.

13.4. Configuring node to run from inetd

If you want users to be able to telnet a port on your machine and obtain access to the node you can go this fairly easily. The first thing to decide is what port users should connect to. In this example I've arbitrarily chosen port 4000, though Tomi gives details on how you could replace the normal telnet daemon with the node in his documentation.

You need to modify two files.

To /etc/services you should add:

node 3694/tcp #OH2BNS's node software

and to /etc/inetd.conf you should add:

node stream tcp nowait root /usr/sbin/node node

When this is done, and you have restarted the inetd program any user who telnet connects to port 3694 of your machine will be prompted to login and if configured, their password and then they will be connected to the node.