N900 USB networking

This page describes how to enable Networking on the N900 via USB, to share your PC's internet to N900 via USB. The first part describes how to configure the N900. The second part describes how to configure various PC platforms to share internet. This article is based on the Maemo 4.x USB networking article. It is also possible to use the N900 as a USB router, to share N900 internet to PC.

You might want to use the N900 as a USB network device to log into your N900 remotely, or to transfer data from your N900 to another computer, in a situation where wifi or Bluetooth are not an option. If you wish to connect your N900 to a Linux machine over TCP/IP, the PC connectivity section in the Maemo SDK documentation also contains useful information.

Contents

[edit] N900 USB network configuration

If you are going to use windows as your host, the configuration needed on your N900 are a little different, so skip directly to the "Starting USB network mode with Windows" Part.

There is a default USB network interface configuration on Nokia N900. In the file /etc/network/interfaces, you should see a section which looks like this:

auto usb0
iface usb0 inet static
       address 192.168.2.15
       netmask 255.255.255.0
       gateway 192.168.2.14

You can also add the following lines to set the default route correctly

      up route del default
      up route add default gw  192.168.2.14

Also you can add the following lines to set the nameserver (dnsmasq will automatically change /etc/resolve.conf)

      dns-nameservers 8.8.8.8 8.8.4.4

and

      up run-standalone.sh dbus-send --type=method_call --system --dest=com.nokia.icd /com/nokia/icd com.nokia.icd.connect string:DUMMY uint32:0
      down run-standalone.sh dbus-send --system --dest=com.nokia.icd /com/nokia/icd_ui com.nokia.icd_ui.disconnect boolean:true

to properly set/reset the connection manager on connection/disconnection, especially if you have set up a DUMMY network as decribed later.


With this default configuration, the N900 USB interface will have the IP address 192.168.2.15, and the remote end will have the IP address 192.168.2.14. By default, the USB network interface on the N900 is configured. You need to install the package usb-network-modules.

[edit] Starting USB network mode

First, set up the host (the computer at the other end of the USB connection, not the N900) to have an IP address of the gateway --in our case here, it's 192.168.2.14. For a typical Linux computer, one might use the command "ifconfig usb0 192.168.2.14" (add "sudo" to the beginning of that command if necessary). There may be other ways to do it for various versions of operating systems.

Plug one end of the USB cable on the host and the other end into the N900. The N900 will bring up the mode-selection dialog. Select 'PC Suite mode'.


USB Mode-Selection dialog


Open a root shell in X Terminal on the N900 and activate the interface by executing the following:

sudo gainroot
ifup usb0

If all went well, no errors will be displayed. The command 'ifconfig usb0' will give the following output:

Nokia-N900-42-11:~# ifconfig usb0
usb0      Link encap:Ethernet  HWaddr F2:50:8F:04:1D:8B  
          inet addr:192.168.2.15  Bcast:192.168.2.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:1021 errors:0 dropped:0 overruns:0 frame:0
          TX packets:2003 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:86091 (84.0 KiB)  TX bytes:2556598 (2.4 MiB)

You should also be able to ping 192.168.2.15

Nokia-N900-42-11:~# ping 192.168.2.15
PING 192.168.2.15 (192.168.2.15): 56 data bytes
64 bytes from 192.168.2.15: seq=0 ttl=64 time=0.367 ms
64 bytes from 192.168.2.15: seq=1 ttl=64 time=0.214 ms
^C
--- 192.168.2.15 ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max = 0.214/0.290/0.367 ms

To automatically setup usb0 when entering PC suite mode edit the file /etc/default/usbnetwork and set the variable USBNETWORK_ENABLE.

# Automatically enable USB network when PC Suite mode is active (default disabled)
USBNETWORK_ENABLE=1

In fact if you want to use the `Mail to exchange' feature to synchronize mail, calendar or contacts with an exchange server (such as Google mail) the 'PC suite mode' might block the exchange. So do not use it when connected in that mode, instead choose the 'charging only' mode instead. This mode can be achieved by choosing neither of the offers in the above menu. Simply tap above the menu to close it. This 'charging only' mode still gives you the usb0 interface provided that you initialized it once through the 'PC suite mode'.

If you can not ping the outside world (for example: local network works but Google does not), check your routing tables.

/home/user # route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
192.168.2.0     *               255.255.255.0   U     0      0        0 usb0
default         192.168.2.14    0.0.0.0         UG    0      0        0 usb0
default         *               0.0.0.0         U     0      0        0 gprs0

If you have a situation like above where the cell network's packets are at a lower default priority, you might have to run the following to fix it:

/home/user # route del default
/home/user # route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
192.168.2.0     *               255.255.255.0   U     0      0        0 usb0
default         *               0.0.0.0         U     0      0        0 gprs0
/home/user # ping google.com
PING google.com (74.125.45.103): 56 data bytes
64 bytes from 74.125.45.103: seq=0 ttl=51 time=257.081 ms
64 bytes from 74.125.45.103: seq=1 ttl=51 time=236.481 ms
64 bytes from 74.125.45.103: seq=2 ttl=51 time=256.226 ms
^C
--- google.com ping statistics ---
3 packets transmitted, 3 packets received, 0% packet loss
round-trip min/avg/max = 236.481/249.929/257.081 ms

If after having fixed the routing table you still are not able to ping the outside world try to add a nameserver to /etc/resolv.conf

nameserver 127.0.0.1
# added Google DNS
nameserver 8.8.8.8
nameserver 8.8.4.4

[edit] Stopping USB network mode

This is optional. It is not necessary to stop the interface after unplugging the USB cable.

However, to stop the USB interface, unplug the USB cable and execute the following in 'X Terminal'

sudo gainroot
ifdown usb0

[edit] Starting USB network mode with Windows

To use the USB network mode alongside with a Windows host, you must use MADDE. MADDE will not work with just changing the configuration in the /etc/network/interfaces file. Different modification are needed:

  1. Install MADDE package (actually MADDE for Windows is not required, but just files maemo_usbnet.inf and maemo_usbnet.cat for installation network device Linux USB Ethernet/RNDIS Gadget).
  2. Add the following lines to /usr/sbin/pcsuite-enable.sh (Do not forget to change the ip address so it matches the one configured on your host's usb port.) (pcsuite-enable.sh is called by the ke-recv which handles memory card mounting, USB mass storage logic, and some other things, based on HAL.)
    run-standalone.sh dbus-send --type=method_call --system --dest=com.nokia.icd /com/nokia/icd com.nokia.icd.connect string:DUMMY uint32:0
    route del default
    route add default gw 192.168.2.14
    

    so it looks like this :

    if [ $RC != 0 ]; then
        logger "$0: failed to install g_nokia"
        run-standalone.sh dbus-send --type=method_call --system --dest=com.nokia.icd /com/nokia/icd com.nokia.icd.connect string:DUMMY uint32:0
        route del default
        route add default gw 192.168.2.14
        exit 1
    else
        sleep 2
    fi
  3. Add the following lines to /usr/sbin/pcsuite-disable.sh (Don't forget to change the ip...)
     ifdown usb0
     run-standalone.sh dbus-send --system --dest=com.nokia.icd /com/nokia/icd_ui com.nokia.icd_ui.disconnect boolean:true
     route del default netmask 0.0.0.0 gw 192.168.2.14
    

    So it looks like this:

     logger "$0: do nothing to pass USB certs"
     ifdown usb0
     run-standalone.sh dbus-send --system --dest=com.nokia.icd /com/nokia/icd_ui com.nokia.icd_ui.disconnect boolean:true
     route del default netmask 0.0.0.0 gw 192.168.2.14
     exit 0
    
  4. This will cause the dummy network to connect when USB networking is used, right after you press the "PC Suite" button in the popup that comes after connecting the USB cable. This will only work if you got MADDE installed and configured for "Windows network". Also, a route will be added to your host machine, with Windows it is very easy to share connections. You should now have network connectivity to your PC + Internet.
  5. Once you disconnect the USB cable, the dummy network will disconnect and the route will be deleted.
  6. Add a DNS server of your choice to /etc/resolv.conf, for example:
    nameserver 8.8.8.8
    nameserver 8.8.4.4
    

Windows 7 (and probably Vista) have firewall setups based network location. This means you might run into problems trying to connect to services on your Windows boxen, because by default N900 USB Network adapter isn't known to Windows as a proper type of NDIS device. This causes Windows to put connections made over USB into "unidentified connections" category and apply Public Location firewall rules to it. Now of course you could poke all the holes into your Public firewall profile and make it look like Swiss cheese, but fortunately some VirtualBox people ran into the same thing with their loopback adapter and solved it for us:

  1. open Registry Editor
  2. browse to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002BE10318} (all network adapters are stored here)
  3. find your N900 USB adapter sub-key, it says the adapter name somewhere in key
  4. add DWORD key *NdisDeviceType with a value 1

Now your USB connection is considered part of Private firewall profile. Stay safe and go buy Swiss cheese in supermarket instead.

[edit] Fixing the MAC address

By default, the N900 sets a random MAC address for the USB interface every time you reboot. This makes some operating systems (Mac OS X) detect a new device whenever you connect the N900 and ask you to configure the network interface. The solutions is to set a fixed MAC address

sudo gainroot
echo options g_nokia host_addr=00:11:22:33:44:55 > /etc/modprobe.d/g_nokia 

After the next reboot your N900 will always be detected as the same device.

[edit] Host USB Network Configuration

The PC Host configuration is detailed in the Maemo 4.x USB Networking article. Please refer to it for details.


[edit] Host configuration on Debian Lenny

Create the file in /etc/udev/rules.d/99-nokia-n900.rules and put in the following lines:

SUBSYSTEM=="net", ACTION=="add", ATTRS{idVendor}=="0421", ATTRS{idProduct}=="01c8", ATTRS{manufacturer}=="Nokia", ATTRS{product}=="N900 (PC-Suite Mode)", NAME="n900"
#SUBSYSTEM=="net", ACTION=="add", ATTRS{idVendor}=="0421", ATTRS{idProduct}=="01c8", ATTRS{manufacturer}=="Nokia", ATTRS{product}=="N900 (PC-Suite Mode)", NAME="n900p"

The second rule is commented out as it is not needed for usb networking. A different approach uses a DEVPATH key:

SUBSYSTEM=="net", ACTION=="add", DEVPATH=="/devices/pci0000:00/0000:00:1a.7/usb1/1-2/1-2:1.8/net/usb0", ATTRS{idVendor}=="0421", ATTRS{idProduct}=="01c8", ATTRS{manufacturer}=="Nokia", ATTRS{product}=="N900 (PC-Suite Mode)", NAME="n900"
SUBSYSTEM=="net", ACTION=="add", DEVPATH=="/devices/pci0000:00/0000:00:1a.7/usb1/1-2/1-2:1.0/net/usbpn0", ATTRS{idVendor}=="0421", ATTRS{idProduct}=="01c8", ATTRS{manufacturer}=="Nokia", ATTRS{product}=="N900 (PC-Suite Mode)", NAME="n900p"

Your DEVPATH may be different though, depending on which USB port is used on the host computer etc, so to make this work reliably you have to use always the same usb port.

You can use

udevadm monitor --kernel

while plugging in the N900 to see what is the correct path.

Newer kernels/udev versions seem to be confused to seeing both usb0 and usbpn0 devices. Luckily DEVPATH accepts wildcards, so you may want to try something like:

SUBSYSTEM=="net", ACTION=="add", DEVPATH=="*/net/usb[0-9]", ATTRS{idVendor}=="0421", ATTRS{idProduct}=="01c8", ATTRS{manufacturer} =="Nokia", ATTRS{product}=="N900 (PC-Suite Mode)", NAME="n900"

After adding the udev rules, you have to reload them with:

udevadm control --reload-rules

Then edit /etc/network/interfaces and add:

allow-hotplug n900
auto n900
iface n900 inet static
	address 192.168.2.14
	netmask 255.255.255.0
	up iptables -A POSTROUTING -t nat -s 192.168.2.15/32 -j MASQUERADE
	up echo 1 > /proc/sys/net/ipv4/ip_forward
        down iptables -D POSTROUTING -t nat -s 192.168.2.15/32 -j MASQUERADE
	down echo 0 > /proc/sys/net/ipv4/ip_forward

Now put your USB cable in the PC and in the N900 and on the host. To check that everything is set up properly you can run:

ifconfig n900

[edit] Automatic configuration with Ubuntu 9.10/10.04/11.10

Note: this instructions should be fixed/improved:

Create the file in /etc/udev/rules.d/99-nokia-n900.rules and put in the following lines:

SUBSYSTEM=="net", ACTION=="add", ENV{ID_USB_DRIVER}=="cdc_ether", ENV{ID_MODEL}="N900__PC-Suite_Mode", ENV{ID_VENDOR}=="Nokia", NAME="n900"
SUBSYSTEM=="net", ACTION=="add", ENV{ID_USB_DRIVER}=="cdc_phonet", ENV{ID_MODEL}="N900__PC-Suite_Mode", ENV{ID_VENDOR}=="Nokia", NAME="n900pn"

Then edit /etc/network/interfaces and add:

auto n900
iface n900 inet static
	address 192.168.2.14
	netmask 255.255.255.0
	up iptables -A POSTROUTING -t nat -s 192.168.2.15/32 -j MASQUERADE
	up echo 1 > /proc/sys/net/ipv4/ip_forward
        down iptables -D POSTROUTING -t nat -s 192.168.2.15/32 -j MASQUERADE
	down echo 0 > /proc/sys/net/ipv4/ip_forward

For Ubuntu 11.10, put these lines to /etc/udev/rules.d/99-nokia-n900.rules

SUBSYSTEM=="net", ACTION=="add", ATTRS{idVendor}=="0421", ATTRS{idProduct}=="01c8", ATTRS{manufacturer}=="Nokia", ATTRS{product}=="N900 (PC-Suite Mode)", NAME="usb0", RUN+="/sbin/ifconfig usb0 192.168.2.14 up", RUN+="/sbin/iptables -A POSTROUTING -t nat -s 192.168.2.15/32 -j MASQUERADE"

and don't modify /etc/network/interfaces in the way above, because you will make the boot slow with the message "waiting for network configuration". But for forwarding you should add to /etc/sysctl.conf

net.ipv4.ip_forward=1

The Network Manager on Ubuntu 11.10 won't auto detect this usb0 interface, you will have to check it via ping or via Network Tools.

For Ubuntu 11.04, just plug the USB cable in, with already-configured N900,the Network Manager will auto handle usb0 interface.

For Ubuntu 9.10 (NOT 10.04) you have to fix /etc/init/network-interface.conf, change the line:

stop on net-device-removed INTERFACE=$INTERFACE

with:

stop on net-device-remove INTERFACE=$INTERFACE

(Note the difference: net-device-removed)

For all versions: You have to reload udev rules with:

udevadm control --reload-rules

You have to restart NetworkManager so it re-reads the interfaces file (otherwise it'll clobber your network device):

sudo /etc/init.d/network-manager restart

or

sudo service network-manager restart

Now put your USB cable in the PC and in the N900.

If you are unable to autoconnect through the networking applet, you may need to manually bring up the interface:

ifup n900

If all went fine:

  • you should see with ifconfig -a two new network interfaces, n900 and n900pn, the first one configured with the proper ip address 192.168.2.15, and should be able to ping the N900.
  • the N900 should be able to use the PC internet connection immediately.

[edit] Host configuration on Archlinux via netcfg

You will need to add the following lines into /etc/network.d/N900:

CONNECTION='ethernet'
DESCRIPTION='Nokia n900 maemo USB passthrough network'
INTERFACE='usb0'
IP='static'
ADDR='192.168.2.14'
# GATEWAY='192.168.2.14'
# DNS=('192.168.2.14')
# PRE_UP='  << script loading of main module(s)! >>'
POST_UP='
         echo 1 > /proc/sys/net/ipv4/ip_forward &&
         iptables -A POSTROUTING -t nat -s 192.168.2.0/24 -j MASQUERADE &&
         iptables -I INPUT -s 192.168.2.15 -j ACCEPT &&
         iptables -P FORWARD ACCEPT'
POST_DOWN='
         echo 0 > /proc/sys/net/ipv4/ip_forward &&
         iptables -F &&
         iptables -t nat -F &&
         echo ":: Unloading cdc_ether" &&
         modprobe -r cdc_ether &&
         echo ":: Unloading cdc_phonet" &&
         modprobe -r cdc_phonet &&
         echo ":: Unloading usbnet" &&
         modprobe -r usbnet &&
         echo ":: Unloading phonet" &&
         modprobe -r phonet &&
         echo ":: Unloading cdc_acm" &&
         modprobe -r cdc_acm'

You need to also add these to udev if you are also using udev. Normally they go into /etc/udev.d/rules/:

SUBSYSTEM=="net", ACTION=="add", ENV{ID_USB_DRIVER}=="cdc_ether", ENV{ID_MODEL}="N900__PC-Suite_Mode", ENV{ID_VENDOR}=="Nokia", NAME="usb0"
SUBSYSTEM=="net", ACTION=="add", ENV{ID_USB_DRIVER}=="cdc_phonet", ENV{ID_MODEL}="N900__PC-Suite_Mode", ENV{ID_VENDOR}=="Nokia", NAME="usb1"

Of course your entire configuration does not exactly have to be like this, it is only a rough guide.

If you don't use netcfg, you can have the udev rule directly configure the interface with e.g. /etc/udev/rules.d/99-nokia-n900.rules:

SUBSYSTEM=="net", ACTION=="add", ATTRS{idVendor}=="0421", ATTRS{idProduct}=="01c8", ATTRS{manufacturer}=="Nokia", ATTRS{product}=="N900 (PC-Suite Mode)", NAME="n900", RUN+="/sbin/ifconfig n900 192.168.2.14"

This may even work with multiple USB devices connected, because it's matching on the vendor and product IDs rather than the interface name.

[edit] Windows

Windows USB networking does not work out of the box, but the old 770 workaround still works. So follow these steps:

  1. install the Mad Developer application on N900 and start it and press "Usb Networking" -> "Windows Network" -> "Close".
  2. Press button "Edit" and enter following IP Address: 192.168.2.15, Netmask: 255.255.255.0, Peer IP: 192.168.2.14. and then press "Configure" (this address will be used for the SCP client as well).
  3. For Windows OS download install-madde-0.6.72.exe. Open file with 7-Zip and extract somewhere (best to the desktop) files "maemo_usbnet.inf" and "maemo_usbnet.cat"
  4. Connect your N900 via USB and choose PC Suite mode.
  5. PC will obtain drivers for new network device, just point it to the downloaded files. This will install network device "Linux USB Ethernet/RNDIS Gadget"
  6. Set for "Linux USB Ethernet/RNDIS Gadget" IP address 192.168.2.14.
  7. For Vista / Windows7 open "Network and Sharing center" and select "Manage network connections" (left menu) --> right click on network device which have internet access and choose "Properties" --> select tab "Sharing" --> check box "Allow other devices to connect..." --> under "Home networking connection" select the network connection (Local Area Connection n#) which is dedicated to "Linux USB Ethernet/RNDIS Gadget".
  8. When you have finished USB Networking, to retrieve default state of N900 press in Mad Developer: "Usb Networking" -> "Unix Network" -> "Close".

[edit] Mac OS X

OS X will detect a new network interface and ask you to configure it. Choose DHCP with manual address and set the IP address to 192.168.2.14

To use the Internet connection of your Mac via USB networking make sure to enable System Preferences -> Sharing -> Internet sharing for the N900 interface Howto

[edit] One-time Quick & Dirty Connection

If you just need a one-time connection quickly, with no need to edit configuration files or set things up for automatic detection/connection, then as an alternative to the above, the following has worked for this user (kwtm). Make sure "usb-network-modules" and "rootsh" are installed (via Applications Manager or equivalent).

  1. connect the N900 to the Other Computer via USB cable, and select "PC Suite mode" when asked.
  2. open a terminal on the N900 and type:
    sudo gainroot
    ifconfig usb0 192.168.2.15
    ifconfig usb0 up
    
  3. on your Other Computer, open a terminal and type the following for Ubuntu; modify appropriately for other computers:
    sudo ifconfig usb0 192.168.2.14
    sudo ifconfig usb0 up
    ssh -l user -v 192.168.2.15
    

That is all. You should now be connected via terminal to your N900. Whatever you type on your Other Computer, it will be as if you are typing on the N900 itself in a terminal. Non-Ubuntu Linux computers might not use the "sudo" command, so you will have to gain root another way. One possibility that will probably work is to use the "su" command first, allowing you to omit "sudo" on the above commands:

su   # (And then enter the root password when asked)
ifconfig usb0 192.168.2.14
ifconfig usb0 up
exit # (This stops the root mode)
ssh -l user -v 192.168.2.15

[I have no idea what to do for Windows computers. Perhaps someone can post the equivalent commands?]

[edit] Using USB networking for Maemo applications

By default, standard network applications works well with USB networking, while Maemo-specific applications do not.

Install libicd-network-dummy from Fremantle Nokia-binaries repository or better libicd-network-null from extras-devel, and when USB networking is up pickup "Dummy network" from the connection manager. One way to do it:

apt-get install libicd-network-dummy
 or
apt-get install libicd-network-null

If the dummy network does not show up in the network manager you could run the following commands in xterm:

gconftool-2 -s -t string /system/osso/connectivity/IAP/DUMMY/type DUMMY
gconftool-2 -s -t string /system/osso/connectivity/IAP/DUMMY/name "Dummy network"

and maybe

gconftool-2 -s -t string /system/osso/connectivity/IAP/DUMMY/autoconnect false

If connect automatically is used with "Any Connection", the phone will also use Dummy Network, which is not good. To prevent this, you need to run the following command :

gconftool -s /system/osso/connectivity/network_type/auto_connect -t list --list-type string "[WLAN_INFRA,GPRS]"

Keep in mind the above command will get overwritten if you change the value via UI. (If you choose any / wifi / gprs, and you will want to go back to "wifi or gprs" you will have to do the CLI thing again.

Then restart icd2:

killall icd2

or reboot the device.