Tethering via WiFi - Troubleshooting

[divinehawk]

FYI,

I've been able to successfully use iptables to configure ip masquerading (NAT). With it, I am tethered over WiFi without using tetherbot (which still works as a backup). Hopefully someone else can package this to be more useful.
Update: See posts #13 and #15 on how to use Ad-hoc mode.

• Root required
• Existing wifi network required (and configured)

1> Disable WiFi through the UI. Then turn on Wifi manually using the following commands as root. Normally the phone data interface and WiFi can't be turned on at the same time. (Can this be done through the android gui somehow?)

insmod /system/lib/modules/wlan.ko wlan_loader -f /system/etc/wifi/Fw1251r1c.bin -e /proc/calibration -i /system/etc/wifi/tiwlan.ini cd /data/local/tmp wpa_supplicant -f -Dtiwlan0 -itiwlan0 -c/data/misc/wifi/wpa_supplicant.conf & sleep 5 ifconfig tiwlan0 192.168.2.30 netmask 255.255.255.0 ifconfig tiwlan0 up

Note that I had to use a static ip since dhcp will typically add in a gateway.

2> Enable and configure ip forwarding

iptables -I FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT iptables -I FORWARD -s 192.168.2.0/24 -j ACCEPT iptables -P FORWARD DROP iptables -t nat -I POSTROUTING -s 192.168.2.0/24 -j MASQUERADE echo 1 > /proc/sys/net/ipv4/ip_forward

3> On your computers, set your default gateway to your phone's WiFi IP address (192.168.2.30 - in my case). Also set your DNS to a real DNS server.

Attached is the iptables binary, compiled with the android sdk.

[hondamx525]

just curious as to why you would want the "tethering" this way. isnt it most likely that any wifi your phone can connect to your computer most probably can too? just curious?

[neoobs]

Originally Posted by hondamx525 just curious as to why you would want the "tethering" this way. isnt it most likely that any wifi your phone can connect to your computer most probably can too? just curious?

This is just progress on tethering. The proxy method is a horrible way of tethering. iptables is the correct way if done correctly. His developments while useless to most are still good because it is progressive. And he can get hotspots now LOL

[divinehawk]

Originally Posted by hondamx525 just curious as to why you would want the "tethering" this way. isnt it most likely that any wifi your phone can connect to your computer most probably can too? just curious?

The above configuration uses your existing wifi settings (I haven't tried ad-hoc mode).

USB networking would be better, or even bluetooth. But I'm not sure this is possible.

[aad4321]

wmwifi router is such an amasing program for windows mobile. Not only does it create an access point with encryption, it also has a dhcp server set up, so multiple computers can share the 3G access. If something like this comes to the android, it will be BADASS!

[scootley]

divinehawk, do you really need an access point? have you tried this using an ad-hoc network? (I am not sure if the G1's WiFi supports ad-hoc networks)

[divinehawk]

Originally Posted by scootley divinehawk, do you really need an access point? have you tried this using an ad-hoc network? (I am not sure if the G1's WiFi supports ad-hoc networks)

Doesn't look like the gui will let you do ad-hoc. Maybe if a modified wpa_supplicant.conf. I'll report back if I have success.

Ideal mode would be for the phone to *act* as an access point. But that usually requires driver support.

[alansj]

Originally Posted by divinehawk USB networking would be better, or even bluetooth. But I'm not sure this is possible.

# adb --help
[...]
adb forward <local> <remote> - forward socket connections
                                 forward specs are one of: 
                                   tcp:<port>
[...]

...but I guess everybody already knew that. I suppose that doing it via iptables under this approach, you are still limited to specific ports.

[neoobs]

Originally Posted by alansj # adb --help [...] adb forward <local> <remote> - forward socket connections forward specs are one of: tcp:<port> [...]

that only works if you want to make a proxy... I think he is trying to make it a true internet sharing app similar to that of the wing and other WM devices

[alansj]

How about something similar to PdaNet?

http://www.theiphoneblog.com/2008/10...r-with-pdanet/

It's interesting that it works by having you set up an ad-hoc wireless network from your computer and then connecting to that from the iPhone. Maybe that's essentially what scootley was suggesting above.

PdaNet .deb here:
http://apt.modmyi.com/2debs/pdanet1.40.deb