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In order to communicate via TCP/IP to your FreeRunner, a basic understanding of the networking expectations is required. Each end of the USB connection forms a LAN (local area network) segment, with the FreeRunner's USB networking device at one end (default 192.168.0.202) and your laptop or desktop at the other end (192.168.0.200 in this guide).
Normally, your desktop machine will know how to reach the Internet, having had its gateway (the IP address of the machine or device which knows how to send packets to machines beyond your subnet) configured via DHCP or statically (probably via a router). For the FreeRunner to reach the Internet, your desktop will have to be configured to route and masquerade (NAT) packets from it.
Normally, none of this is an issue, but problems can arise when the subnet between the FreeRunner and your desktop overlap with the desktop to the router (which forms a second LAN), since your desktop might not know how to route traffic properly.
In other words: if your existing router and desktop have addresses 192.168.0.(something) changing them to eg 192.168.1.(something) might save you a lot of troubleshooting later. The guides to set up USB networking for your FreeRunner assume that your router/desktop IP range differs from the USB network IP range.
A discussion of this is here http://lists.openmoko.org/pipermail/support/2008-August/001283.html
Try this first (as root on your desktop, with FreeRunner attached via USB cable and booted properly, not at the Boot Menu). If it works, then you can add permanent configuration or use more sophisticated setups below.
iptables -A POSTROUTING -t nat -j MASQUERADE -s 192.168.0.0/24 sysctl -w net.ipv4.ip_forward=1 ifconfig usb0 192.168.0.200
If your Internet connection is also in the range 192.168.0.x then instead you might want to use:
ifconfig usb0 192.168.0.200 netmask 255.255.255.248
Then (ideally, not as root):
ssh root@192.168.0.202
The default password is blank.
Your Linux desktop/laptop needs to have suitable support, in particular, you will need to have enabled full masquerading in the kernel and USB networking options enabled. For default kernels in many Linux distributions, this will already be the case. If not, you will need to enable:
Both USB networking options are available in the
Device Drivers -> USB support -> USB Network Adapters
or
Device Drivers -> Network Device Support -> USB Network Adapters -> Multipurpose USB Networking Framework.
For more info see the usbnet driver homepage.
Masquerading options (tested on Linux 2.6.26.3) are found in:
Networking ---> Networking options --->
To see the other options, enable
Then, from
Networking ---> Networking options ---> [*] Network packet filtering framework (Netfilter) ---> Core Netfilter Configuration --->
You need at least following options enabled as modules:
Rest of the needed options are found from
Networking ---> Networking options ---> [*] Network packet filtering framework (Netfilter) ---> IP: Netfilter Configuration --->
You need to enable (again, as modules is fine):
On some systems, you may have firewall rules which prevent this working - such as added by the iptables service on Fedora. You may care to stop these, and/or review any rules or policies you think might cause issues.
The most relevant table is the nat table, which controls translation of addresses:
iptables -L -t nat -v -n
Unless you have a special setup, you'll want to see only the MASQUERADE rule that you apply below, and ACCEPT as the default policy. Also look at the filter table:
iptables -L -t filter -v -n
If this contains anything in the FORWARD chain, then this may prevent passing packets. It can be flushed with:
iptables -t filter -F FORWARD
In addition to routing issues, to be practical, DNS will need to work. In some cases, you might already be running a DNS server on your desktop such as dnsmasq or bind9, which is the default assumption the FreeRunner makes. In other cases, you'll need to configure DNS to that of your router, or a DNS server further out on the internet such as that provided by your ISP.
DNS is configured in /etc/resolv.conf on your FreeRunner.
You should add the IP address of the DNS servers as provided by your ISP. Check your router's or PC's network status for the nameserver IP addresses.
echo nameserver xxx.xxx.xxx.xxx > /etc/resolv.conf
You can also add the public DNS server called openDNS:
echo nameserver 208.67.222.222 > /etc/resolv.conf echo nameserver 208.67.220.220 >> /etc/resolv.conf
These settings will be lost on reboot. You can set the DNS for the next connect, by adding the following to the end of the usb0 setting in /etc/network/interfaces, right above the bluetooth networking section:
up echo nameserver 208.67.222.222 > /etc/resolv.conf up echo nameserver 208.67.220.220 >> /etc/resolv.conf
If you move about, making assumptions about the network may not be convenient, and it is possible to proxy DNS requests via your host laptop (which you are also taking with you), without running or installing a DNS server. There are a number of ways to do this:
The script is designed to use dnrd as the DNS proxy. The script and a copy of dnrd are available. The script also performs the initial setup of the connection as per the USB_Networking#Manual_method above.
Another easy setup is using a UDP forwarder like the one from http://www.tapor.com/udpf/ - use it with the command"
udpf-elf -p=53-f=`cat /etc/resolv.conf|awk '$1 == "nameserver"{print $2; exit(0);}'`:53
It is possible to forward DNS requests with iptables using the DNAT target:
iptables -t nat -A PREROUTING -p tcp -s 192.168.0.202 -d 192.168.0.200 --dport domain -j DNAT --to-destination 192.168.0.1 iptables -t nat -A PREROUTING -p udp -s 192.168.0.202 -d 192.168.0.200 --dport domain -j DNAT --to-destination 192.168.0.1
Where 192.168.0.1 is the IP of your router.
Test if it works:
ping www.google.com
If so, then this is sufficient for most internet access. But manual changes to resolv.conf are usually lost later if for example one uses DHCP, especially for WiFi, and so may not be convenient to configure manually.
You should be able to connect to your Neo! Make sure you can ping your Neo to be sure.
ping 192.168.0.202
Then log into your Neo using ssh:
ssh root@192.168.0.202
The default password is blank (press enter).
You can also scp files back and forth. You can telnet, SSH, SMB or do whatever you want if you install software that enables you to set up TCP/IP network over your USB connection.
Now, make sure you can ping back to your desktop
ping 192.168.0.200
(Note that some systems like Vista, don't respond to ICMP ping by default)
Try pinging the outside world (a Google IP address)
ping 74.125.19.147
This demonstrates that masquerading is working - your desktop is sending/receiving packets to the wider internet.
Lastly, verify that DNS is correctly configured between the Neo & Network:
ping www.google.com
Based on Hotplugging usbnet by Marcin 'Hrw' Juszkiewicz. These instructions should keep you from having to run the Simple Manual Linux Configuration every time you plug in and want to connect to an Openmoko device. One run and then you're done!
If the Simple Manual Linux Configuration does not work for your OS or Distro (MacOS X, MS Windows, etc) there may be instructions here that work for you.
See Windows USB Ethernet emulation for Neo1973.
You need to load the cdce kernel module (if it is not already linked into your kernel). As root do:
# kldload cdce
The Neo should then show up as cdce0 interface and you can handle the cdce0 interface just like the usb0 device under Linux. For more information see the cdce manpage. An easy way to assign the IP address to the cdce0 interface is using the devd(8) daemon. Create the following two files,
/usr/local/etc/devd/cdce.conf as:
notify 1 { match "system" "IFNET"; match "subsystem" "cdce0"; match "type" "ATTACH"; action "/usr/local/etc/devd/cdce.sh $subsystem $type"; };
and /usr/local/etc/devd/cdce.sh as:
#!/bin/sh case $2 in 'ATTACH') ifconfig cdce0 192.168.0.200 netmask 255.255.255.0 exit 0 ; ;; esac exit 0
Then restart the devd(8) daemon with:
# /etc/rc.d/devd restart
If you now plugin the FreeRunner into the USB port the cdce0 interface gets created and the IP addr will be assigned.
Edit /etc/network/interfaces and add:
auto usb0 iface usb0 inet static address 192.168.0.200 netmask 255.255.255.0 network 192.168.0.0 up iptables -A POSTROUTING -t nat -j MASQUERADE -s 192.168.0.0/24 & up echo 1 > /proc/sys/net/ipv4/ip_forward & up iptables -P FORWARD ACCEPT & down iptables -D POSTROUTING -t nat -j MASQUERADE -s 192.168.0.0/24 &
This is more sophisticated than the manual setup. The 'auto usb' stanza ties into the Linux hotplug system so that when the device appears and vanishes, as happens when the FreeRunner is connected via USB, this is run.
In addition, the desktop-side netmask is limited to a much smaller range, so that overlapping subnets are less of a problem - Linux will use more specific routes first when deciding where to send packets.
Another possible configuration that adds DNS forward and removes the iptables changes after unplugging:
in /etc/network/interfaces add
# freerunner auto usb0 iface usb0 inet static address 192.168.0.200 netmask 255.255.255.192 post-up /etc/network/freerunner start pre-down /etc/network/freerunner stop
create file /etc/network/freerunner
#!/bin/sh # # configures the freerunner for internet # # DEVICE=usb0 IPADDR=192.168.0.200 REMOTE_IPADDR=192.168.0.202 NETMASK=255.255.255.0 # get first ip for dns DNSIP=$(cat /etc/resolv.conf | grep nameserver | awk '{ print $2 }' | head -n 1 ) case "$1" in start) iptables -A POSTROUTING -t nat -j MASQUERADE -s $REMOTE_IPADDR iptables -A PREROUTING -t nat -p tcp -s $REMOTE_IPADDR -d $IPADDR --dport domain -j DNAT --to-destination $DNSIP iptables -A PREROUTING -t nat -p udp -s $REMOTE_IPADDR -d $IPADDR --dport domain -j DNAT --to-destination $DNSIP if [ "$(cat /proc/sys/net/ipv4/ip_forward)" = "0" ]; then echo "temoprarely allow ip_forward for openmoko" > /var/run/openmoko.ip_forward echo 1 > /proc/sys/net/ipv4/ip_forward fi ;; stop) iptables -D POSTROUTING -t nat -j MASQUERADE -s $REMOTE_IPADDR iptables -D PREROUTING -t nat -p tcp -s $REMOTE_IPADDR -d $IPADDR --dport domain -j DNAT --to-destination $DNSIP iptables -D PREROUTING -t nat -p udp -s $REMOTE_IPADDR -d $IPADDR --dport domain -j DNAT --to-destination $DNSIP if [ -f /var/run/openmoko.ip_forward ]; then rm /var/run/openmoko.ip_forward echo 0 > /proc/sys/net/ipv4/ip_forward fi ;; esac
Make /etc/network/freerunner executable with
chmod +x /etc/network/freerunner
Ubuntu Feisty, Gutsy and Hardy reportedly have a bug where ifdown is not run when the interface is unplugged, meaning this only works once after the system is booted. This is mentioned at https://bugs.launchpad.net/ubuntu/+source/ifupdown/+bug/130437
One can patch /etc/udev/rules.d/85-ifupdown.rules, editing the two lines at the end of the file:
SUBSYSTEM=="net", DRIVERS=="?*", GOTO="net_start" GOTO="net_end" LABEL="net_start" # Bring devices up and down only if they're marked auto. # Use start-stop-daemon so we don't wait on dhcp ACTION=="add", RUN+="/sbin/start-stop-daemon --start --background --pidfile /var/run/network/bogus --startas /sbin/ifup -- --allow auto $env{INTERFACE}" LABEL="net_end" ACTION=="remove", RUN+="/sbin/start-stop-daemon --start --background --pidfile /var/run/network/bogus --startas /sbin/ifdown -- --allow auto $env{INTERFACE}"
The bug is that the LABEL="net_end" is at the wrong position
This appears to be fixed in Ubuntu 8.04 Mattt 11:38, 30 July 2008 (UTC)
This first file configures the network system for the usb0 interface. Any time you plug in the FreeRunner the interface will be configured.
/etc/sysconfig/network-scripts/ifcfg-usb0:
DEVICE=usb0 BOOTPROTO=static IPADDR=192.168.0.200 NETMASK=255.255.255.0 NETWORK=192.168.0.0 BROADCAST=192.168.0.255 ONBOOT=yes METRIC=10 MII_NOT_SUPPORTED=no USERCTL=yes
This next file configures the static routes that we need to communicate to the subnet. Since it has "usb0" in the name, the system will automatically apply these static routes any time that the usb0 interface is configured. (i.e. when you connect the FreeRunner)
/etc/sysconfig/network-scripts/usb0-routes:
ADDRESS0=192.168.0.200 NETMASK0=255.255.255.0
Now we need to restart the network system to pick up the changes.
service network restart
/etc/sysconfig/network/ifcfg-usb0:
# USB configuration for PDAs (openmoko) IPADDR=192.168.0.200 NETMASK=255.255.255.0 STARTMODE=onboot
For more information on getting USB networking up using YaST, see USB Networking with openSUSE.
/etc/sysconfig/network-scripts/ifcfg-usb0:
# USB configuration for PDAs (openmoko) # from http://www.handhelds.org/moin/moin.cgi/UsbNet DEVICE=usb0 BOOTPROTO=none IPADDR=192.168.0.200 NETMASK=255.255.255.0 ONBOOT=yes
This setup is probably over-complex:
/etc/sysconfig/network-scripts/ifcfg-usb0:
DEVICE=usb0 IPADDR=192.168.0.200 NETMASK=255.255.255.0
/etc/sysconfig/network-scripts/ifup-usb:
#!/bin/bash . /etc/init.d/functions cd /etc/sysconfig/network-scripts . ./network-functions [ -f ../network ] && . ../network CONFIG=${1} need_config ${CONFIG} source_config NETBITS=`ipcalc -p ${IPADDR} ${NETMASK} | awk -F'=' '{print $2;}'` /sbin/ip addr flush dev ${DEVICE} 2>/dev/null /sbin/ip link set dev ${DEVICE} up /sbin/ip addr add dev ${DEVICE} ${IPADDR}/${NETBITS} /sbin/iptables -I POSTROUTING -t nat -j MASQUERADE -s ${IPADDR}/${NETBITS} /sbin/sysctl net.ipv4.ip_forward=1 /sbin/iptables -I FORWARD -s ${IPADDR}/${NETBITS} -j ACCEPT /sbin/iptables -I FORWARD -d ${IPADDR}/${NETBITS} -j ACCEPT
Set /etc/sysconfig/network-scripts/ifdown-usb:
#!/bin/bash . /etc/init.d/functions cd /etc/sysconfig/network-scripts . ./network-functions [ -f ../network ] && . ../network CONFIG=${1} need_config ${CONFIG} source_config NETBITS=`ipcalc -p ${IPADDR} ${NETMASK} | awk -F'=' '{print $2;}'` /sbin/iptables -D FORWARD -d ${IPADDR}/${NETBITS} -j ACCEPT /sbin/iptables -D FORWARD -s ${IPADDR}/${NETBITS} -j ACCEPT /sbin/sysctl net.ipv4.ip_forward=0 /sbin/iptables -D POSTROUTING -t nat -j MASQUERADE -s ${IPADDR}/${NETBITS} /sbin/ip link set dev ${DEVICE} down /sbin/ip addr flush dev ${DEVICE} 2>/dev/null
If you are using NetworkManager, restart it and enable the usb device from its menu, otherwise it will disable your connection shortly after you enable it.
/sbin/service NetworkManager restart
Edit /etc/sysconfig/network-scripts/net.hotplug:
After this command:
case $INTERFACE in # interfaces that are registered after being "up" (?)
add
usb0) ifconfig usb0 192.168.0.200 netmask 255.255.255.0 route add 192.168.0.202 usb0 iptables -I INPUT 1 -s 192.168.0.202 -j ACCEPT iptables -I OUTPUT 1 -s 192.168.0.200 -j ACCEPT iptables -A POSTROUTING -t nat -j MASQUERADE -s 192.168.0.0/24 echo 1 > /proc/sys/net/ipv4/ip_forward exit 0 ;;
Open /etc/conf.d/net and add:
# Neo config_usb0=( "192.168.0.200 netmask 255.255.255.0" ) routes_usb0=( "192.168.0.202/32 via 192.168.0.200" )
Create a new init script:
cd /etc/init.d ln -s net.lo net.usb0
Put iptables into use:
iptables -I INPUT 1 -s 192.168.0.202 -j ACCEPT iptables -I OUTPUT 1 -s 192.168.0.200 -j ACCEPT iptables -A POSTROUTING -t nat -j MASQUERADE -s 192.168.0.0/24
Store them:
/etc/init.d/iptables save
If you want the routing by default:
rc-update add iptables default
You must also inform the kernel, to start forwarding.
echo 1 > /proc/sys/net/ipv4/ip_forward
One way to automate all this is to create /etc/conf.d/net.usb0 as follows. It sets IP forwarding and the iptables rules all in one go. It removes the iptables rules and disables ip forwarding when the FreeRunner is unplugged.
preup() { echo 1 > /proc/sys/net/ipv4/ip_forward iptables -I INPUT 1 -s 192.168.0.202 -j ACCEPT iptables -I OUTPUT 1 -s 192.168.0.200 -j ACCEPT iptables -A POSTROUTING -t nat -j MASQUERADE -s 192.168.0.0/24 return 0 } postdown() { echo 0 > /proc/sys/net/ipv4/ip_forward iptables -D INPUT -s 192.168.0.202 -j ACCEPT iptables -D OUTPUT -s 192.168.0.200 -j ACCEPT iptables -D POSTROUTING -t nat -j MASQUERADE -s 192.168.0.0/24 return 0 }
Following is based on Enrico Zini's solution.
Create a new udev rules file /etc/udev/rules.d/91-openmoko.rules:
SUBSYSTEM=="net", ACTION=="add", ATTRS{idVendor}=="1457", ATTRS{idProduct}=="5122", RUN+="/etc/openmoko/openmoko-usb $env{INTERFACE} start" SUBSYSTEM=="net", ACTION=="remove", ENV{INTERFACE}=="usb[0-9]", RUN+="/etc/openmoko/openmoko-usb $env{INTERFACE} stop"
Then create the script /etc/openmoko/openmoko-usb:
#!/bin/sh INTERFACE=$1 ACTION=$2 # udev fails silently when the script fails, e.g. due to commands not # being found PATH=/usr/sbin:/sbin:/usr/bin:/bin case $ACTION in 'start') # Put all your setup here ;; 'stop') # Put all your tear down here ;; *) echo "Usage: $0 {start|stop}" exit 1 ;; esac
The INTERFACE will be usb0 in most cases.
Reportedly, the ssh daemon (dropbear 0.49) on the FreeRunner appears to have a bug when sending the exit status back to the client. From time to time you receive an exit status of 255.
To avoid ssh adding a new line for every ssh host-key to your known_hosts you can add the following to the phone section in ~/.ssh/config (or see the snippet at : USB Networking#Changing_host_keys bellow)
UserKnownHostsFile /dev/null
You might want to use keys to bypass the login prompt too.
To generate ssh keys for use as a login mechanism type:
user@host$ ssh-keygen -t rsa
When prompted for a password either hit enter for no password (not really a good idea) or enter a password for this key. ssh into the phone and create ~/.ssh:
root@phone# mkdir ~/.ssh
Then from your desktop copy the .pub file to the phone.
user@host$ scp ~/.ssh/id_rsa.pub root@phone:~/.ssh/authorized_keys
You should now be able to ssh directly into the phone without a password prompt using a command like 'ssh root@phone' from the account user@host because the public key in the file user@host:~/.ssh/id_rsa.pub is contained in the list of keys which have access in the file root@phone:~/.ssh/authorized_keys (since scp is used, only one key exists, but you can grant access to the phone from more than one account, for example user@host, user@laptop).
To make ssh login as root by default, add the following lines to ~/.ssh/config:
Host phone User root
Replace phone with the hostname or ip of your phone. You should now be able to ssh into the phone without having to type root@ every time.
To disable password logins (after setting up key access) edit /etc/init.d/dropbear and change the following line:
DROPBEAR_EXTRA_ARGS=
to
DROPBEAR_EXTRA_ARGS="-s"
You will need to restart dropbear for this to take effect.
Generate the key:
dropbearkey -t rsa -f id_rsa
The output will look something like this:
Will output 1024 bit rsa secret key to 'id_rsa' Generating key, this may take a while... Public key portion is: ssh-rsa AAAAB3Nza[...] Fingerprint: md5 ca:e8:f0:b7:f6:7b:c2:b6:b9:71:e4:45:86:a9:ff:b8
Copy and paste the one line (in this example, starting with 'ssh-rsa' onto the end of the host's authorized_keys file (often in ~/.ssh/).
From the phone, ssh with -i:
ssh -i id_rsa user@host
If you reflash, your hosts keys will change. Try this ~/.ssh/config snippet:
Host moko HostName 192.168.0.202 StrictHostKeyChecking no UserKnownHostsFile /dev/null User root
This is suggested because ssh on your desktop may complain if the key matching a certain IP changes (stored in .ssh/known_hosts). Now you have set this, you can issue the following command to connect to your moko :
ssh root@moko
To get the GUI on the FreeRunner onto the desktop via USB, you can use ssh as follows:
ssh -l root -X -v 192.168.0.202
Using this, run openmoko-finger-demo for example, and it will open up on the desktop. To get landscape view, just resize the GUI window on the desktop.
If you get an error like this:
dbus.exceptions.DBusException: org.freedesktop.DBus.Error.Spawn.ExecFailed: dbus-launch failed to autolaunch D-Bus session: Autolaunch requested, but X11 support not compiled in.
you need to set the DBUS_SESSION_BUS_ADDRESS environment variable to the value on the FreeRunner before launching the process from your desktop. You can find the value of this variable by using a command such as
ps auxwwwwe | grep -m 1 DBUS_SESSION_BUS_ADDRESS
Note that you must run that command on the FreeRunner. Back on your desktop, run the process you want with the env command like this:
env DBUS_SESSION_BUS_ADDRESS=dbus_address process
To get desktop apps to show up on your FreeRunner, first log in:
ssh -l root 192.168.0.202
Then run:
DISPLAY=:0 xhost +192.168.0.200
After this you can close the ssh session. Back on the desktop computer, run:
DISPLAY=openmoko:0 xclock
Note that the xhost command will allow remote applications on 192.168.0.200 to access the X server. It will allow anyone on the desktop machine to access the X server of the neo, including snooping anything you type on it. To disallow remote applications again, run this in the neo:
DISPLAY=:0 xhost -192.168.0.200
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