Submit fixed script.
Not completely right - seems gubuntu/ubuntu both get unhappy after running
with the 'bridge' option and the PC's routes get hosed (right after the
script is run all is fine, but some agent then removes the routes on the
bridged iface and sets up routes on the native iface (eth0) and things on
the PC lose net access. Note that you can manually reset the routes and make
it happy again).
The fix I applied to the script was related to turning on rndis on the device
and setting device side dns servers correctly so my 'fix' is not responsible
for the eventual unhappniess on the PC. Also, the rev-tether continues
to work fine even when the PC is unhappy, so this may be useful.
Perhaps somebody can figure out who is changing the pc routes and why.
bug:4208971
Change-Id: I6ef6a88c71779b2083dad26a4be35ff74c26aae4
diff --git a/scripts/reverse_tether.sh b/scripts/reverse_tether.sh
new file mode 100755
index 0000000..82f7c59
--- /dev/null
+++ b/scripts/reverse_tether.sh
@@ -0,0 +1,261 @@
+#!/bin/bash
+# Copyright 2010 Google Inc.
+# All right reserved.
+# Author: Szymon Jakubczak <szym@google.com>
+#
+# Configure the host and the Android phone for "reverse tethering".
+# (Route all network traffic via the host.)
+
+# default values
+: ${BRIDGE:=usbeth}
+: ${LAN_DEV:=eth0} # LAN uplink on the host
+: ${HOST_DEV:=usb0} # name of the RNDIS interface on the host
+: ${PHONE_DEV:=rndis0} # name of the RNDIS interface on the phone
+
+: ${PHONE_IP:=192.168.77.2} # for NAT and tests
+: ${HOST_IP:=192.168.77.1}
+: ${NETMASK:=255.255.255.0}
+
+# location of the hwaddr utility
+: ${HWADDR:=/home/build/nonconf/google3/experimental/users/szym/moblat/hwaddr/hwaddr-armeabi}
+: ${PHONE_HW:=""} # hardware (Ethernet) address for the interface (bridge only)
+
+# for NAT configuration
+: ${DNS1:=8.8.8.8}
+: ${DNS2:=8.8.4.4}
+
+# export ADB=/path/to/sdk/adb for custom adb
+ADB="${ADB:-adb} ${SERIAL:+-s $SERIAL}"
+
+set -e
+trap error ERR
+
+error() {
+ echo >&2 "Error occured: $?"
+}
+
+usage() {
+ echo "Usage: $0 <command>"
+ echo " rndis -- start RNDIS and test ping the phone"
+ echo " nat -- use host as NAT"
+ echo " nat+secure -- nat + extra security"
+ echo " bridge -- use host as bridge"
+ echo " stop -- switch back to 3G"
+ echo " stop-all -- clean up everything"
+ echo
+ echo "Advanced Commands"
+ echo " Host:"
+ echo " nat_start "
+ echo " nat_secure "
+ echo " nat_stop "
+ echo " bridge_start "
+ echo " bridge_add "
+ echo " bridge_stop "
+ echo " Phone:"
+ echo " rndis_start "
+ echo " rndis_stop "
+ echo " rndis_test "
+ echo " route_nat "
+ echo " route_bridge "
+ echo " route_reset "
+ echo
+ echo "Options and Environment Variables:"
+ echo " -h|--help"
+ echo " -b bridge_name BRIDGE=$BRIDGE"
+ echo " -s serial_number SERIAL=$SERIAL"
+ echo " -u host_usb_device HOST_DEV=$HOST_DEV"
+ echo " -l host_lan_device LAN_DEV=$LAN_DEV"
+ echo " -d dns1 dns2 DNS1=$DNS1"
+ echo " DNS2=$DNS2"
+ echo " -p phone_ip PHONE_IP=$PHONE_IP"
+ echo " -a host_ip HOST_IP=$HOST_IP"
+ echo " -m netmask NETMASK=$NETMASK"
+ echo " -e hardware_addr PHONE_HW=$PHONE_HW"
+ echo
+ echo " HWADDR=$HWADDR"
+ echo " ADB=$ADB"
+}
+
+##################################
+### PHONE configuration routines
+##################################
+rndis_start() {
+ echo "Starting RNDIS..."
+ $ADB wait-for-device
+ $ADB shell "svc usb setFunction rndis"
+ $ADB wait-for-device
+ $ADB shell "ifconfig $PHONE_DEV down"
+ if [[ -n "$PHONE_HW" ]]; then
+ $ADB push $HWADDR /data/local/hwaddr # TODO(szym) handle failures?
+ $ADB shell "/data/local/hwaddr $PHONE_DEV $PHONE_HW"
+ $ADB shell "/data/local/hwaddr $PHONE_DEV"
+ fi
+}
+
+rndis_stop() {
+ $ADB shell "svc usb setFunction" #empty to clear
+}
+
+rndis_test() {
+ # configure some IPs, so that we can ping
+ $ADB shell "ifconfig $PHONE_DEV $PHONE_IP netmask $NETMASK up"
+ sudo ifconfig $HOST_DEV $HOST_IP netmask $NETMASK up
+ echo "Pinging the phone..."
+ ping -q -c 1 -W 1 $PHONE_IP
+ echo "Success!"
+}
+
+update_dns() {
+ $ADB shell 'setprop net.dnschange $((`getprop net.dnschange`+1))'
+}
+
+default_routes() {
+ $ADB shell 'cat /proc/net/route' | awk '{ if ($2==00000000) print $1 }'
+}
+
+route_none() {
+ $ADB shell "svc data disable"
+ $ADB shell "svc wifi disable"
+ # kill all default route interfaces (just in case something remains)
+ for dev in `default_routes`; do
+ $ADB shell "ifconfig $dev down"
+ done
+}
+route_nat() {
+ echo "Setting up phone routes and DNS..."
+ route_none
+ $ADB shell "ifconfig $PHONE_DEV $PHONE_IP netmask $NETMASK up"
+ $ADB shell "route add default gw $HOST_IP dev $PHONE_DEV"
+ $ADB shell "setprop net.dns1 $DNS1"
+ $ADB shell "setprop net.dns2 $DNS2"
+ update_dns
+}
+route_bridge() {
+ echo "Running DHCP on the phone..."
+ route_none
+ $ADB shell "ifconfig $PHONE_DEV up"
+ $ADB shell "netcfg $PHONE_DEV dhcp"
+ $ADB shell "ifconfig $PHONE_DEV" # for diagnostics
+
+ DNS1=`$ADB shell getprop net.${PHONE_DEV}.dns1`
+ $ADB shell "setprop net.dns1 $DNS1"
+ DNS2=`$ADB shell getprop net.${PHONE_DEV}.dns2`
+ $ADB shell "setprop net.dns2 $DNS2"
+ update_dns
+}
+route_reset() {
+ route_none
+ $ADB shell "svc data enable"
+}
+
+#################################
+### HOST configuration routines
+#################################
+nat_start() {
+ echo "Configuring NAT..."
+ sudo sysctl -w net.ipv4.ip_forward=1
+ sudo iptables -F
+ sudo iptables -t nat -F
+ sudo iptables -t nat -A POSTROUTING -o $LAN_DEV -j MASQUERADE
+ sudo iptables -P FORWARD ACCEPT
+ sudo ifconfig $HOST_DEV $HOST_IP netmask $NETMASK up
+}
+nat_secure() {
+ echo "Making your NAT secure..."
+ sudo iptables -A FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT
+ sudo iptables -A FORWARD -m state --state NEW -i $HOST_DEV -j ACCEPT
+ sudo iptables -P FORWARD DROP
+ sudo ifconfig usb0 $HOST_IP netmask $NETMASK up
+}
+nat_stop() {
+ sudo sysctl -w net.ipv4.ip_forward=0
+ sudo iptables -F
+ sudo iptables -t nat -F
+}
+
+bridge_start() {
+ echo "Configuring bridge..."
+ sudo brctl addbr $BRIDGE || return 0 # all good
+ sudo brctl setfd $BRIDGE 0
+ sudo ifconfig $LAN_DEV 0.0.0.0
+ sudo brctl addif $BRIDGE $LAN_DEV
+ sudo dhclient $BRIDGE || {
+ echo "DHCP failed. Recovering..."
+ bridge_stop
+ false
+ }
+}
+bridge_add() {
+ echo "Adding usb0 to the bridge"
+ sudo brctl delif $BRIDGE $HOST_DEV 2>/dev/null || true # ignore
+ sudo ifconfig $HOST_DEV 0.0.0.0
+ sudo brctl addif $BRIDGE $HOST_DEV
+}
+bridge_stop() {
+ sudo ifconfig $BRIDGE down || true # ignore errors
+ sudo brctl delbr $BRIDGE || true
+ sudo dhclient $LAN_DEV
+}
+
+### command-line interpreter
+if [ $# == "0" ]; then
+ usage
+fi
+
+while (( $# )); do
+case $1 in
+--help|-h)
+ usage
+ exit
+ ;;
+
+-b) shift; BRIDGE=$1 ;;
+-s) shift; SERIAL=$1 ;;
+-u) shift; HOST_DEV=$1 ;;
+-l) shift; LAN_DEV=$1 ;;
+-d) shift; DNS1=$1; shift; DNS2=$1 ;;
+-p) shift; PHONE_IP=$1 ;;
+-a) shift; HOST_IP=$1 ;;
+-m) shift; NETMASK=$1 ;;
+-e) shift; PHONE_HW=$1 ;;
+
+rndis)
+ rndis_start
+ rndis_test
+ ;;
+
+bridge)
+ ifconfig $HOST_DEV >/dev/null || $0 rndis
+ bridge_start
+ bridge_add
+ route_bridge
+ ;;
+
+nat)
+ ifconfig $HOST_DEV >/dev/null || $0 rndis
+ nat_start
+ route_nat
+ ;;
+
+nat+secure)
+ $0 nat
+ nat_secure
+ ;;
+
+stop)
+ route_reset
+ ;;
+
+stop-all)
+ bridge_stop
+ nat_stop
+ route_reset
+ rndis_stop
+ ;;
+
+*) # execute 'advanced command' by function name
+ $1
+ ;;
+esac
+shift
+done
