Re: ioctl(PPPIOCGUNIT): Operation not permitted

[Al Hudson <nospam [at] york.ac.uk>]

I don't know if any of this will be of help but..

firstly, I presume you have correctly configured pcmcia modules loaded,
and PPP setup in the kernel, and your serial port pcmcia card (I presume
you're running a serial modem off a pcmcia serial expander, or am I
wrong?) is supported under linux. I'm also assuming pppt is setuid root,
not just being invoked by root.

ioctl() is a device driver write command, so you've got a problem with the
device driver. This is either (as far as I can remember currently ;):
i. a bad device driver,
ii. an incorrectly setup device driver,
iii. the wrong device driver,
iv. the wrong hardware
(there may be some other circumstances that would cause a ioctl() to fail,
they escape me currently)

If you are able to successfully make a connection manually, it might be
worth making sure logging is turned on and having a look at the
/var/log/messages files and see if any handshaking goes on at all - if
absolutely nothing is going on, it's a ppp problem. However, the ioctl()
failiure would suggest it's hardware, or hardware configuration related,
rather than a software thing. But syslog may turn something up.

So I reckon (famous last words) something's jiggering your hardware for
you. Make sure nothing owns ttyS2 - getty might have it's grubby mits on
it, check in /etc/inittab. Also, make sure it has an interrupt available
for it - something may have grabbed it's IRQ. Use setserial to play about
with some stuff, might poke it into life.

So, assuming you've got the correct pcmcia ppp modules installed, and
that you've done a chmod u+s /usr/sbin/pppd, have a play with some of the
stuff I've mentioned and it should at least shed some more light on the
situation.

Cheers,

Alex.

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