[Xastir] AX25

[Lance Cotton]

Bill Vodall WA7NWP wrote:
>> > Xastir does need SUID, but not because of the serial port. Xastir 
>> needs SU
>> > privileges in order to open the eoc ax.25 port.
> 
> That's a bit strange.  Is the ax25 Listen command SUID?   I know it
> (Listen) works once the associated serial port is set RW for the
> regular user.   Maybe Listen is doing some magic with the serial port
> that a regular user program wouldn't try.

That's an unusual statement to me -- the listen (and other ax25 
commands) don't even know about serial ports. When you run the 
kissattach command, it "creates" a network interface (usually ax0) and 
if the /etc/ax25/axports file is set up correctly, also associates the 
newly created network interface to the port defined in /etc/ax25/axports 
with the matching callsign-ssid.

The ax0 interface is comparable to the eth0 network interface. eth0 has 
an associated MAC address, ax0 has an associated callsign-ssid.

There are other ways to create AX.25 network interfaces than using a 
serial-line modem, such as the baycom-style modems, USB modems, and the 
soundcard modem.

In any case, it sounds like the ax25 `listen` command is already SUID. 
This means it begins running in superuser mode until the program decides 
it's done all it needs to do in that mode and then drops back to 
standard user privileges.

-Lance KJ5O