Tether your Treo smartphone with OpenBSD

I noticed a recent commit to umsm(4), which got me wondering about my Treo 700p. I upgraded to the 700p last year to get the extra throughput offered by Verizon Wireless' EVDO service. The phone has served me well for USB-tethered modem access, albeit using Mac OS X on my MacBook Pro. But a solution that ties me to OS X is really only half a solution. You can imagine my surprise when I discovered how easy it was to connect using my smartphone with OpenBSD!

Because there are still a number of unsupported components with OpenBSD on the MacBook Pro, I run OpenBSD macppc-current on a PowerBook G4. Aside from the Broadcom/Airport Extreme card and firewire, everything works great. The small size and light weight make it an ideal travel system, but having to track down open wireless hotspots for my rum(4) USB adapter has always been a minor annoyance. Until I reviewed umsm(4), I had no idea that OpenBSD supported any EVDO devices. I assumed that even if it was possible, getting my Treo to work with OpenBSD would probably require hours of hacking code and drinking beer (not necessarily in that order).

After booting up the PowerBook, I connected the Treo's sync cable to the laptop and immediately noticed the following in syslog:

uvisor0 at uhub1 port 1
uvisor0: Palm, Inc. Palm Handheld, rev 1.10/1.00, addr 2
ucom0 at uvisor0 portno 0, sync

This was a promising sign. At the very least, I knew I could use OpenBSD to synchronize and backup my Treo using the various Palm utilities in the ports tree. However, since all I had was uvisor(4) access, there was no chance that OpenBSD would see the device as a modem. Fortunately for me, there's a Palm application that allows Treo users to tether their smartphones without paying for a separate tethering package with the carrier. I had purchased it last year to get the phone working with OS X, and it works with both USB and bluetooth connections. As soon as I pressed the "Enable Modem Mode" button in USB Modem, OpenBSD recognized the device properly:

uvisor0: at uhub1 port 1 (addr 2) disconnected
ucom0 detached
uvisor0 detached
umodem0 at uhub1 port 1 configuration 1 interface 0
umodem0: Mobile Stream Treo 700 USB Modem, rev 1.10/1.10, addr 2, iclass 2/2
umodem0: data interface 1, has CM over data, has break
umodem0: status change notification available
ucom0 at umodem0

Now that I had a fully supported hardware modem, I just needed the ppp magic to dial up to Verizon Wireless. Looking back in umsm(4), I saw that a kind developer had already provided a sample configuration for Verizon EVDO service. I created my new /etc/ppp/ppp.conf with the settings, exchanging only my phone number in the set authname directive:

default:
  set device /dev/cuaU0
  set speed 230400
  set dial "ABORT BUSY ABORT NO\\sCARRIER TIMEOUT 5 \
   \"\" AT OK-AT-OK ATE1Q0s7=60 OK \\dATDT\\T TIMEOUT 40 CONNECT"
  set phone "#777"
  set login
  set authname 4517654321@vzw3g.com
  set authkey vzw
  set timeout 120
  set ifaddr 10.0.0.1/0 10.0.0.2/0 255.255.255.0 0.0.0.0
  add default HISADDR
  enable dns

Once the file was saved, I ran ppp(8) to test the connection:

$ sudo ppp -ddial default
Working in ddial mode
Using interface: tun0

Five seconds later, success! I was able to ping external sites and browse the internet. I saw some route warnings in syslog that appear to be related to the set ifaddr directive, but it works fine and at a good speed. Once again, OpenBSD has excelled at providing a simple solution (with excellent documentation) to a modern challenge. I hope that this story helps other users utilize their Treo phones with their OpenBSD systems while they're on the road. If you have any questions about this setup, please post your comments below or email me at jdixon@.