IP Over Bluetooth and Connection Manager Integration

How do I get Internet access from my Internet Tablet at work with no WiFi access point available? The only solution I have is to use IP over Bluetooth (i.e. L2CAP), and connect through my laptop. After a lot of google-ing I eventually found a solution that works on OS2008 (aka maemo 4 , aka chinook). Well, that sorts out the "getting connected" part of the problem.

For Integration in the connection manager the solution described in the maemo community wiki seemed to fit the bill but the binary provided for the dbus listening daemon won't run on OS2008. Bummer. Digging around I found an enhanced version that can launch scripts based on user defined filters: dbus-scripts written by Graham Cobb.

Now on to the interesting stuff...

1. For the PC or phone side configuration, refer to the BluetoothNetworking page at maemo.org.
   
   
2. On the N810, you need root access as described in the previous post.
   
   
3. Install the dbus-scrips package from the maemo xtras-devel repository. (thanks Graham for uploading!)
   
   
4. Run X term and login as root:
   
   sudo su -


5. Create a dummy access point:
   
   gconftool-2 -s -t string /system/osso/connectivity/IAP/BluetoothIP/type DUMMY


6. create the filter for the dbus-scripts daemon. Put the following in a file named for example bluetooth-ip.filter then copy the file on your Tablet in /etc/dbus-scripts.d/
   
   /usr/local/share/dbus-scripts/bluetooth-ip * * com.nokia.icd status_changed BluetoothIP DUMMY
   
   This will launch the script /usr/local/share/dbus-scripts/bluetooth-ip as soon as the BluetoothIP connection is brought up or down from the connection manager.
   
   
7. And here's the actual bluetooth-ip script that does all the dbus magic:
   
   

   #!/bin/sh
   
   #BT MAC of PC/phone
   BTADDR='00:19:CC:EB:42:3E' # replace with your own!
   #bluetooth name of PC/phone, not important, just for infoprints
   BTNAME="PC-Bluetooth"
   #desired IP address of your tablet
   IP=192.168.0.2
   #default gateway - IP address of PC/phone
   GW=192.168.0.1
   #DNS server
   NS=123.45.67.89
   
   # remote PAN role, one of NAP, GN
   PAN_ROLE=NAP
   
   infoprint(){
     DBUS_SESSION_BUS_ADDRESS='unix:path=/tmp/session_bus_socket' dbus-send --session --print-reply --dest=org.freedesktop.Notifications /org/freedesktop/Notifications org.freedesktop.Notifications.SystemNoteInfoprint "string:$*" &
   }
   
   dbus_method(){
     local dest=$1
     shift
     DBUS_REPLY=$(dbus-send 2>&1 --system --type=method_call --print-reply --dest="$dest" $* )
   }
   
   dbus_result(){
     echo $DBUS_REPLY | cut -d ' ' -f 7 | tr -d \"
   }
   
   find_connection(){
     #find or create connection
   
     echo "Searching for $BTADDR ..."
     [ -t 1 ] || infoprint "Searching for $BTADDR"
   
     if dbus_method org.bluez /org/bluez org.bluez.Manager.ActivateService string:network ; then
         NET_BUS=$(dbus_result)
         # echo destination $NET_BUS
         if dbus_method "${NET_BUS}" /org/bluez/network org.bluez.network.Manager.FindConnection string:"${BTADDR}" ; then
             CONN=$(dbus_result)
         else
             if dbus_method "${NET_BUS}" /org/bluez/network org.bluez.network.Manager.CreateConnection string:"${BTADDR}" string:"$PAN_ROLE" ; then
                 CONN=$(dbus_result)
             fi
         fi
     fi
   
     if [ "$CONN" = "" ] ; then
         echo $DBUS_REPLY
         echo "Setting up connection to $BTADDR failed"
         [ -t 1 ] || infoprint "Connection to $BTADDR failed"
         exit
     fi
   }
   
   bnep_start(){
     find_connection
     if dbus_method "${NET_BUS}" ${CONN} org.bluez.network.Connection.Connect ; then
         BNEPDEV=$(dbus_result)
         echo connected to $BNEPDEV
         ifconfig $BNEPDEV $IP up
         if route -n | grep -q '^0.0.0.0' ; then
             echo "default gateway already set, skipping GW and DNS setting"
         else
             route add default gw $GW
             echo "nameserver $NS" >/tmp/resolv.conf.lo
         fi
         [ -t 1 ] || infoprint "Connected to $BTNAME"
     fi
   }
   
   bnep_stop(){
     find_connection
     if [ "$CONN" != "" ] ; then
         echo connection $CONN
         if dbus_method "${NET_BUS}" ${CONN} org.bluez.network.Connection.Disconnect ; then
             echo "OK, bringing down"
             echo -n '' >/tmp/resolv.conf.lo
             [ -t 1 ] || infoprint "$BTNAME disconnected"
         fi
     fi
   }
   
   [ "$3" =  "com.nokia.icd" ] || exit 0
   [ "$7" = "CONNECTED" ] && bnep_start
   [ "$7" = "IDLE" ] && bnep_stop
   
   

   Place this script in /usr/local/share/dbus-scripts (you may have to create the folder) and make it executable:
   
   chmod +x /usr/local/share/dbus-scripts/bluetooth-ip
   
   This is heavily based on this forum thread at InternetTabletTalk.com. You'll find additional info on the various parameters of the script in that thread. And thanks to fanoush for his hard work on this!
   
   
8. Now all you have to do is restart the dbus-scripts daemon:
   
   /etc/init.d/dbus-scripts restart
   
   
9. Make sure that your N810 and PC or phone have been paired: Settings -> Control Panel -> Bluetooth -> Devices -> New.
   
   
10. Go to the connection manager and select your new BluetoothIP connection..... and cross your fingers!

Troubleshooting tips:

• From Xterm you can run the dbus-scripts daemon in debug mode. Stop it first (as root):
  
  /etc/init.d/dbus-scripts stop
  
  Now start it manually in debug mode:
  
  dbus-scripts --system --debug
  
  Try to connect again and go back to the Xterm window to see if there's any error message (scroll up!)
  
  
• If you get a notification that the connection is established but you can't access any web site, check that the DNS in the bluetooth-ip script is set to the same as on your computer (try ipconfig from the command line). You can also try to ping your computer or phone. If you get a reply, then the problem is very likely on the computer or phone.
  
  
• Make sure that the IP addresses in the bluetooth-ip script match with your computer's or phone. Also make sure you select IP addresses in the same subnet.
  
  
• If you're trying this while you have a WiFi access point nearby and your Tablet is set to automatically connect to it, disable automatic connections, otherwise the connection manager will automatically pick up the access point instead of starting the dummy connection.
  

Granted, it's not really for the faint of heart. But in the end it's quite rewarding. What would one do to avoid typing a few commands in a terminal? ;)