/dev/ttyUSB0 and PPP

Fri Feb 24 04:56:24 UTC 2006

On Thu, 2006-02-23 at 10:11 -0800, Rick Stevens wrote:
> On Wed, 2006-02-22 at 20:50 -0800, Harold Hallikainen wrote:
> > > On Tue, 2006-02-21 at 19:49 -0800, Harold Hallikainen wrote:
> > >> > On Sun, 2006-02-19 at 18:15 -0800, Harold Hallikainen wrote:
> > >> >> > I'm trying to set up a ppp connection through my cellphone. I'm
> > >> using
> > >> >> a
> > >> >> USB to EIA232 adapter on FC4_64. I can talk to the cellphone (send AT
> > >> >> commands, dial, etc.) from GtkTerm using /dev/ttyUSB0 when logged in
> > >> as
> > >> >> root. As another user, I get permission denied.
> > >> >> >
> > >> >> > Desktop/SystemSettings/Network lets me define a modem device on
> > >> ports
> > >> >> such
> > >> >> > as  dev/ttyS0, etc., dev/modem, dev/tty|1, dev/input/ttyACM0,
> > >> >> dev/ttyM0,
> > >> >> etc. But, no /dev/ttyUSB0.
> > >> >> >
> > >> >> > So... what do I do to set up a ppp connection on my cellphone modem
> > >> on
> > >> >> /dev/ttyUSB0?
> > >> >> >
> > >> >>
> > >> >>
> > >> >> Still working on this... A google search came up with the suggestion
> > >> >> that
> > >> >> I add
> > >> >>
> > >> >> ln -s /dev/ttyUSB0 /dev/modem
> > >> >>
> > >> >> to my /etc/rc.local . I've done that and am still having trouble
> > >> getting
> > >> >> ppp to dial out. I'm using the network configure menu
> > >> >> desktop/SystemSettings/network. At one point, I could see it dial
> > >> just
> > >> >> the
> > >> >> 1 dialing prefix, but not the rest of the number. Currently, it
> > >> doesn't
> > >> >> try to dial at all. Instead, I get "cannot connect to network device"
> > >> >> when
> > >> >> I try to activate it.
> > >> >>
> > >> >> As root, I can talk to the cellphone using gtkterm. As a non-root
> > >> user,
> > >> >> I
> > >> >> get permission denied. Here's a little more info:
> > >> >>
> > >> >>
> > >> >> [root at hhlaptop ~]# ls -l /dev/modem
> > >> >> lrwxrwxrwx  1 root root 12 Feb 19 18:00 /dev/modem -> /dev/ttyUSB0
> > >> >> [root at hhlaptop ~]# ls -l /dev/ttyUSB0
> > >> >> crw-rw----  1 root uucp 188, 0 Feb 19 18:04 /dev/ttyUSB0
> > >> >> [root at hhlaptop ~]#
> > >> >>
> > >> >>
> > >> >> So... any ideas?
> > >> >
> > >> > Well, the first thing is to change the permissions on /dev/ttyUSB0.
> > >> > You need to edit the /etc/udev/rules.d/50-udev.rules and change the
> > >> >
> > >> >     KERNEL=="ttyUSB*", GROUP="uucp", MODE="0660", OPTIONS="last_rule"
> > >> >
> > >> > line to read "MODE=0666" to permit world read/write operations, then
> > >> > unplug the dongle and plug it back in.
> > >> >
> > >>
> > >>
> > >> THANKS Rick! After this change, gtkTerm can talk to the cellphone on the
> > >> USB as a non-root user. I then tried the internet connection wizard. It
> > >> exits with error 8. Here's what shows up in /var/log/messages:
> > >>
> > >> Feb 21 19:36:59 hhlaptop ifup-ppp: pppd started for home on /dev/modem
> > >> at
> > >> 19200
> > >> Feb 21 19:36:59 hhlaptop kernel: CSLIP: code copyright 1989 Regents of
> > >> the
> > >> University of California
> > >> Feb 21 19:36:59 hhlaptop kernel: PPP generic driver version 2.4.2
> > >> Feb 21 19:36:59 hhlaptop pppd[3187]: pppd 2.4.2 started by root, uid 0
> > >> Feb 21 19:37:00 hhlaptop wvdial[3203]: WvDial: Internet dialer version
> > >> 1.54.0
> > >> Feb 21 19:37:00 hhlaptop wvdial[3203]: Initializing modem.
> > >> Feb 21 19:37:00 hhlaptop wvdial[3203]: Sending: ATZ
> > >> Feb 21 19:37:05 hhlaptop wvdial[3203]: Sending: ATQ0
> > >> Feb 21 19:37:05 hhlaptop wvdial[3203]: ATQ0
> > >> Feb 21 19:37:05 hhlaptop wvdial[3203]: OK
> > >> Feb 21 19:37:05 hhlaptop wvdial[3203]: Re-Sending: ATZ
> > >> Feb 21 19:37:05 hhlaptop wvdial[3203]: ATZ
> > >> Feb 21 19:37:05 hhlaptop wvdial[3203]: OK
> > >> Feb 21 19:37:11 hhlaptop wvdial[3203]: stdin not read/write and $MODEM
> > >> not
> > >> set
> > >> Feb 21 19:37:11 hhlaptop pppd[3187]: Connect script failed
> > >> Feb 21 19:37:12 hhlaptop pppd[3187]: Exit.
> > >>
> > >>
> > >> So, it looks like pppd is being passed device/modem, but wvdial is not
> > >> able to communicate with it. I'm guessing the OK entries are the
> > >> responses
> > >> from the cellphone, so it looks like we're talking to it. So, what's the
> > >> line at 19:37:11 mean?
> > >
> > > Have you edited /etc/wvdial.conf?  You have to set the MODEM variable in
> > > the "Dialer Defaults" section of that file.  Something like:
> > >
> > > 	[Dialer Defaults]
> > > 	Modem = /dev/ttyS0
> > > 	Baud = 57600
> > > 	Init = ATZ
> > > 	Init2 = AT S11=50
> > > 	Phone = 555-4242
> > > 	Username = apenwarr
> > > 	Password = my-password
> > >
> > > Full details are in the wvdial(1) and wvdial.conf(5) man pages.
> > 
> > 
> > OK... Further note! The config file created by the gui looked reasonable.
> > I changed the modem from /dev/modem to /dev/ttyUSB0 and tried again. I'm
> > still getting "error 8" and similar log entries:
> > 
> > Feb 22 20:44:09 hhlaptop ifup-ppp: pppd started for home on /dev/modem at
> > 19200
> > Feb 22 20:44:09 hhlaptop kernel: CSLIP: code copyright 1989 Regents of the
> > University of California
> > Feb 22 20:44:09 hhlaptop kernel: PPP generic driver version 2.4.2
> > Feb 22 20:44:09 hhlaptop pppd[3215]: pppd 2.4.2 started by root, uid 0
> > Feb 22 20:44:10 hhlaptop wvdial[3231]: WvDial: Internet dialer version 1.54.0
> > Feb 22 20:44:10 hhlaptop wvdial[3231]: Initializing modem.
> > Feb 22 20:44:10 hhlaptop wvdial[3231]: Sending: ATZ
> > Feb 22 20:44:15 hhlaptop wvdial[3231]: Sending: ATQ0
> > Feb 22 20:44:15 hhlaptop wvdial[3231]: ATQ0
> > Feb 22 20:44:15 hhlaptop wvdial[3231]: OK
> > Feb 22 20:44:15 hhlaptop wvdial[3231]: Re-Sending: ATZ
> > Feb 22 20:44:15 hhlaptop wvdial[3231]: ATZ
> > Feb 22 20:44:15 hhlaptop wvdial[3231]: OK
> > Feb 22 20:44:21 hhlaptop wvdial[3231]: stdin not read/write and $MODEM not
> > set
> > Feb 22 20:44:21 hhlaptop pppd[3215]: Connect script failed
> > Feb 22 20:44:22 hhlaptop pppd[3215]: Exit.
> > 
> > 
> > I think the key here is "stdin not read/write and $modem not set." The OK
> > lines seem to be my modem (cellphone) responding to the AT commands. I did
> > a Google search on the phrase quoted above, and it appears to be a common
> > problem. My search has not yet revealed a solution. I'll continue the
> > search, but would certainly appreciate any ideas!
> 
> Try changing the "Modem = /dev/ttyUSB0" to "MODEM = /dev/ttyUSB0" and
> see.  Shell variables are case sensitive.  Since the error message is
> bitching about "$MODEM", my guess is that it's looking for "MODEM = "
> and not "Modem = ".
> 
> And if that fixes it, send a Bugzilla report about it.  That's nasty!

Well, that didn't fix it! Here's a the config file:

[Modem0]
MODEM = /dev/ttyUSB0
Baud = 19200
SetVolume = 0
Dial Command = ATDT
Init1 = ATZ
Init3 = ATM0
Modem = /dev/modem
FlowControl = CRTSCTS

[Dialer home]
Area Code = 805
Username = ******
Password = **********
Phone = *** ****
Dial Prefix = 1
Stupid Mode = 1
Init1 = ATZ
Init2 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
Inherits = Modem0
[Dialer home0]
Init1 = ATZ
Init2 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
Inherits = Modem0

And here's what comes out the log:

Feb 23 20:00:48 hhlaptop pppd[4049]: Starting link
Feb 23 20:00:49 hhlaptop wvdial[4610]: WvDial: Internet dialer version
1.54.0
Feb 23 20:00:49 hhlaptop wvdial[4610]: Initializing modem.
Feb 23 20:00:49 hhlaptop wvdial[4610]: Sending: ATZ
Feb 23 20:00:54 hhlaptop wvdial[4610]: Sending: ATQ0
Feb 23 20:00:54 hhlaptop wvdial[4610]: ATQ0
Feb 23 20:00:54 hhlaptop wvdial[4610]: OK
Feb 23 20:00:54 hhlaptop wvdial[4610]: Re-Sending: ATZ
Feb 23 20:00:54 hhlaptop wvdial[4610]: ATZ
Feb 23 20:00:54 hhlaptop wvdial[4610]: OK
Feb 23 20:01:00 hhlaptop wvdial[4610]: stdin not read/write and $MODEM
not set
Feb 23 20:01:00 hhlaptop pppd[4049]: Connect script failed

So... I guess it's time for me to spend the weekend on Google! I'll also
check the linux networking newsgroup. THANKS Rick!

Harold