= Replicant USB Networking =

This page explains how to connect your Replciant phone to the Internet via an USB connection to a computer connected to the Internet.

• A phone running Replicant
• A computer with USB connectivity and network access running GNU/Linux

Two scripts are necessary: one to run on the host computer and one to run on the device.

=== Replicant USB Networking - PC ===

Here's the script to run on the computer. Copy the following text to a file named "run_pc.sh" (or any other name, you just need to keep the same name along the process):

{{{
#!/bin/sh

1. Replicant USB Networking
2. ========================
4. Copyright (C) 2010 Paul Kocialkowski, GPLv3+
6. This program is free software: you can redistribute it and/or modify
7. it under the terms of the GNU General Public License as published by
8. the Free Software Foundation, either version 3 of the License, or
9. (at your option) any later version.
11. You should have received a copy of the GNU General Public License
12. along with this program. If not, see <http://www.gnu.org/licenses/&gt;.

IPTABLES_CLEAN_RULES=true

USB_IFACE="usb0"
INTERNET_IFACE="eth0"

USB_IFACE_IP="192.168.4.200"

1. Clean iptables rules

iptables_rules_clean () {
if [ $IPTABLES_CLEAN_RULES = false ]
then
return
fi

iptables --flush
    iptables --table nat --flush
    iptables --delete-chain
    iptables --table nat --delete-chain
}

1. Inject iptables forwarding rules

iptables_forward_rules_apply () {
iptables --table nat --append POSTROUTING --out-interface $INTERNET_IFACE -j MASQUERADE
iptables --append FORWARD --in-interface $USB_IFACE -j ACCEPT
echo 1 > /proc/sys/net/ipv4/ip_forward
}

1. Configure network link

usb_networking_configure () {
ifconfig $USB_IFACE up
ifconfig $USB_IFACE $USB_IFACE_IP
}

usb_networking_disable () {
ifconfig $USB_IFACE down
echo 0 > /proc/sys/net/ipv4/ip_forward
}

case $1 in
"start")
echo "Starting Replicant USB Networking"
iptables_rules_clean
usb_networking_configure
iptables_forward_rules_apply
;;
"stop")
echo "Stopping Replicant USB Networking"
usb_networking_disable
iptables_rules_clean
;;
*)#!/bin/sh

1. Replicant USB Networking
2. ========================
4. Copyright (C) 2010 Paul Kocialkowski, GPLv3+
6. This program is free software: you can redistribute it and/or modify
7. it under the terms of the GNU General Public License as published by
8. the Free Software Foundation, either version 3 of the License, or
9. (at your option) any later version.
11. You should have received a copy of the GNU General Public License
12. along with this program. If not, see <http://www.gnu.org/licenses/&gt;.

IPTABLES_CLEAN_RULES=true

USB_IFACE="usb0"
INTERNET_IFACE="eth0"

USB_IFACE_IP="192.168.4.200"

1. Clean iptables rules

iptables_rules_clean () {
if [ $IPTABLES_CLEAN_RULES = false ]
then
return
fi

iptables --flush
    iptables --table nat --flush
    iptables --delete-chain
    iptables --table nat --delete-chain
}

1. Inject iptables forwarding rules

iptables_forward_rules_apply () {
iptables --table nat --append POSTROUTING --out-interface $INTERNET_IFACE -j MASQUERADE
iptables --append FORWARD --in-interface $USB_IFACE -j ACCEPT
echo 1 > /proc/sys/net/ipv4/ip_forward
}

1. Configure network link

usb_networking_configure () {
ifconfig $USB_IFACE up
ifconfig $USB_IFACE $USB_IFACE_IP
}

usb_networking_disable () {
ifconfig $USB_IFACE down
echo 0 > /proc/sys/net/ipv4/ip_forward
}

case $1 in
"start")
echo "Starting Replicant USB Networking"
iptables_rules_clean
usb_networking_configure
iptables_forward_rules_apply
;;
"stop")
echo "Stopping Replicant USB Networking"
usb_networking_disable
iptables_rules_clean
;;
*)
echo "Usage: sh $0 {start|stop}"
;;
esac
echo "Usage: sh $0 {start|stop}"
;;
esac
}}}

Then, set this file executable: {{{ chmod a+x run_pc.sh }}}

=== Replicant USB Networking - Device ===

Here's the script to run on the device. Copy the following text to a file named "run_dev.sh" (or any other name, you just need to keep the same name along the process):

{{{
#!/system/bin/sh

1. Replicant USB Networking
2. ========================
4. Copyright (C) 2010 Paul Kocialkowski, GPLv3+
6. This program is free software: you can redistribute it and/or modify
7. it under the terms of the GNU General Public License as published by
8. the Free Software Foundation, either version 3 of the License, or
9. (at your option) any later version.
11. You should have received a copy of the GNU General Public License
12. along with this program. If not, see <http://www.gnu.org/licenses/&gt;.

1. Enable USB Networking

USB_IFACE="usb0"

USB_IFACE_IP="192.168.4.202"
GATEWAY_IP="192.168.4.200"
DNS1_IP="8.8.8.8"

usb_networking_enable () {
echo 1 > /sys/class/usb_composite/rndis/enable
ifconfig usb0 up
}

usb_networking_configure () {
ifconfig $USB_IFACE $USB_IFACE_IP
route add default gw $GATEWAY_IP dev $USB_IFACE
setprop net.dns1 $DNS1_IP

1. setprop net.dns1 $( cat /system/etc/resolv.conf | sed -e "s|.*#.*||" -e "s|^.*nameserver \(.*\)$|\1|g" | grep -v "^$" | head -n 1 )
   }

usb_networking_disable () {
echo 0 > /sys/class/usb_composite/rndis/enable
ifconfig usb0 down
}

case $1 in
"start")
echo "Starting Replicant USB Networking"
usb_networking_enable
usb_networking_configure
;;
"stop")
echo "Stopping Replicant USB Networking"
usb_networking_disable
;;
*)
echo "Usage: sh $0 {start|stop}"
;;
esac
}}}

Now you need to copy it to your phone. Start adb server as root: {{{ # adb start-server }} and copy the file (as regular user): {{{ adb push run_dev.sh /sdcard/ }}} (you can change /sdcard/ to any other writable disk place, just remind where you put it).