Tether Launches HTML5-Based iPhone Tethering Solution

http://www.macrumors.com/2012/03/09/tether-launches-html5-based-iphone-tethering-solution/

by angkec • 14 years ago

105 63 14 years ago

robbiet480• 14 years ago

How! That's what I really want to know. Streaming sockets?

guan• 14 years ago

Would everything have to go through their servers? I can’t imagine that HTML5 apps on iOS have permission to open enough sockets to avoid that.

Wilya3• 14 years ago

In the video, the guy shows that, by tethering, he can access Hulu even though he's not in the US. So, yeah, it seems they proxy everything through their servers.

justinweiss• 14 years ago

Yeah, it looks like they use WebSockets, and the iPhone webpage just pipes data from the Mac/PC app to their servers.

garindra2• 14 years ago

If everything has to go through their servers and then downloaded by the Mac/PC, then it basically defeats the whole purpose of tethering.

The real trick is that they found a way to pipe data from the iPhone to the Mac without going through the internet, all using a good ol' browser web page.

yoda_sl• 14 years ago

Interesting concept... Thinking about it, they are making Safari act as the proxy/gateway. I did not dig into it but are they using web socket for achieving that? I can see their desktop app, sending the request/proxying to Safari which will in turns act the gateway to the net. Neat.

angkec• 14 years ago

Ok so I went ahead and bought the service. Here's what I found out: You'll have to keep the tether client application running on your Mac or PC. So not gonna work for wifi-only iPads. Then you will need to keep the html5 webpage open in order to receive data. They instruct you to set iPhone's screen lock to "never" so it doesn't automatically shuts the web page down in 1 minute or so. So I imagine you can't take phone calls when tethering as the webpage will go offline.

Pricing wise, the first year costs $15 and will be $30 from second year on. They set my paypal up for recurring payment.

Performance wise it's pretty fast on my iPhone 4. Setting up took about 2~3 min, very easy to do. The html5 app needs to connect to both the tether website and the client computer. Took me a few tries to connect to both but once they are connected the speed is pretty comparable to tetherme in jailbroken iPhones.

moonchrome2• 14 years ago

>So not gonna work for wifi-only iPads

Excuse my ignorance of Apple products but how can tethering work on a device without a internet connection ? You want to go trough a iPad proxy to get to a WiFi connection ? Why not just connect to WiFi with the PC ?

Wilya3• 14 years ago

You could want to use the iPad as the client. Ie use an iPhone to give internet connection to the iPad. (I guess that what the GP meant)

lucaspiller• 14 years ago

Interesting that iOS shuts down the connection when the browser is closed or the phone locked. Is is the same with SocketIO? On Android the connection remains open as long as the browser has the tab open.

tonster• 14 years ago

This is so cool! Like to see that even though they were rejected from the app store they still went ahead and found a way to make their idea a reality.

shankinson9• 14 years ago

Hey guys. I'm the developer behind this tech.

Glad to see it's got you thinking :). It took a lot of brainstorming and testing/debugging to get this up and running.

Hope you enjoy it!

garindra2• 14 years ago

It did get me and I'm sure a lot of other people thinking. Would you mind answering this Quora question that I set up so I can sleep tonight?

http://www.quora.com/How-does-the-Tether-HTML5-app-work

shankinson9• 14 years ago

I can't really go into much more detail than the first responder did without getting into trouble :)

Let's just say it's magic.

wcchandler2• 14 years ago

Any plans for Linux clients?

If anything, simply releasing a "Here's what the client is doing so recreate it however possible..." might suffice.

(edited; previously sounded impolite)

Wilya3• 14 years ago

The way they do it is elegant, and could be used in many other places than just the iPhone. All you need is a browser that supports websockets.

I'm not really aware of that stuff, but I'm a bit curious. Do websockets really work over mobile networks (which are, at least in my experience, transparent proxied, and where anything outside of HTTP-on-port-80/HTTPS-on-port-443 is blacklisted into oblivion) ?

shankinson9• 14 years ago

Yes they do. We've tested them on iPhones, BlackBerry browser, and the Aurora browser on Android.

kenrikm2• 14 years ago

I was able to get the original before it was pulled from the App Store. it worked well, glad to see they found a work around. I expect some type of backlash from AT&T/Verizon/Sprint However, I hope they make enough to afford the lawyers.

mikeash• 14 years ago

Non-web stuff works fine on the mobile networks I've tried it on. I occasionally ssh from my phone directly to my home computer or server, and I've never had a problem with it. Skype works fine over cell data, as do various instant messaging clients.

Even if that weren't true, websockets was designed to look a whole lot like HTTP precisely so that it could work with existing proxies and firewalls.

saurik2• 14 years ago

My experience is the exact opposite: all networks I've used in the US (Sprint, Verizon, AT&T, and T-Mobile; in essence, all of the major ones) and the few I've used in the UK (while roaming) have all had sufficiently few outgoing ports blocked that I've never run into one (and I use my iPhone as if it were a computer ;P). That said, WebSockets is just an upgrade extension to HTTP, so it is going to go over 80/443 anyway.

jcitme• 14 years ago

Same experience here. I use SSH over a wide variety of ports, and never had it blocked by 3G before...

sev• 14 years ago

Very cool! Too bad the iphone can't lock, and that the wifi-only iPad can't benefit from this.

On a side note, UI related, when I am on this page: http://tether.com/iphone/ and click "Order Now" at the top right, the modal window opens behind the YouTube video.

shankinson9• 14 years ago

Thanks, I'll get our web dev guy to look into that.

mikebabineau• 14 years ago

Looks like a great service, unfortunate that they're subject to the HTML5/browser limitations (can't lock, etc).

Is there another way to distribute their native version besides through the app store?

My company use TestFlight (https://testflightapp.com/) for iOS game development. Is there anything similar, but better suited to end-user distribution?

smathieu• 14 years ago

For a company that will be handling all of my web browsing, I would have expected them to not store my password in clear text.

Doesn't inspire confidence :(

Great product idea though!

kenrikm2• 14 years ago

Disclaimer (I have not tried the new one) How do you know they store it in clear text? Have you seen inside their database? I mean they could be accepting the password in clear text but maybe they run it though a MD5/Sh1/Salt process before it actually gets to the database.

shankinson9• 14 years ago

I'm assuming you mean the ad-hoc password. I will change this in the next release.

I can assure you that the data is encrypted from the phone to the server and never stored anywhere.

rogerchucker• 14 years ago

Can we expect any way to tether a Wifi-only iPad or iPod touch to this service in future?

cft2• 14 years ago

Too bad Android does not have any visible plans to implement WebSocket (which is now RFC 6455). Perhaps the development of HTML5 apps on Android has lower priority for Google than for Apple, to force the development effort into native, which they can curate and control. This hypothesis is also corroborated by comparing HTML5 performance in Android and in iOS (Android is usually 300-500% slower).

notatoad4• 14 years ago

chrome for android supports websockets.

cft2• 14 years ago

Only on 4.0: it represents less than 1.5% of all Androids now. iOS had Websockets since 4.1, for over 1.5 years. Unless Chrome gets back-ported to Android 2.2 and 2.3 it will take a very long time.

dave1010uk• 14 years ago

Opera Mobile supports Web Sockets and runs on almost any Android device.

http://caniuse.com/#feat=websockets

RandallBrown• 14 years ago

I don't understand how this works. It seems like when you're connected to the ad-hoc wifi network, all web requests would go through there. How do they get around this?

rhplus• 14 years ago

I'm assuming they're making use of the fact that the iPhone is multihomed when wifi and cellular connections are both enabled. This means that any outboard traffic from iOS could take two routes, but the ad-hoc wifi network is only advertising routes to IP addresses in a (predetermined) private address space. So when the websockets app talks to a private IP address it choses the wifi route and when it talks to a public IP address it choses the cellular route.

http://en.wikipedia.org/wiki/Multihoming

st3fan2• 14 years ago

This is based on speculation and guesswork ... but this is what I think they were doing with their original iTether application:

On the client (the Mac) they have a IOKit ethernet driver that shows up in Network Settings. This becomes your default route (after some fake DHCP magic) and then captures packets and relays them to their application that runs in userland.

Their userland application contains a lightweight TCP/IP stack that interprets those packets. (For example http://www.sics.se/~adam/lwip/)

The lightweight TCP/IP stack contains unimplemented callbacks for opening/closing sending/receiving data. In this case those callbacks are implemented as a higher level network protocol.

That 'wrapped' TCP/IP protocol is then relayed to the iPhone via the usbmux protocol. This allows you to map a TCP/IP service on the device to a local port on the Mac. (I happen to have written a nice usbmux proxy three years ago)

So now the wrapped TCP/IP is arriving at the iPhone, in the form of higher level 'network stack commands'. The iPhone app now simply has to interpret these commands and translate them into real socket open/close read/write commands.

At this point packets are flowing through a fake Ethernet device driver to a secondary TCP/IP stack, over a USB cable to an iOS app which will do actual socket calls and talk to the real network.

Soooo, my guess is that for this new app they use basically the same setup except that the iOS app is gone and replaced with a simple web page with web sockets that point to both that fake TCP/IP stack on the mac and to a hosted proxy service on their end. Relaying data back and forth.

Crazy hack. Amazing it works :-)

saurik2• 14 years ago

Maybe it is just my warped perspective, but when I looked at the technology this all came to mind immediately, but I just as immediately dismissed it because of the "hosted proxy service": the fee was seemingly "too low".

So, I feel like you've left out the key non-obvious part: it turns out that even if you do the brain-dead un-optimized "let's use Amazon EC2" for your proxies, $30/yr at $0.05c/GB (down: up is free) buys 50GB/mo.

Given that the user is then going to be filing this data over their 3G connections, 50GB/mo is (based on reports of users tethering that complain about rate limiting and caps) at the very high-end of usage.

So, with that aside, the rest of this actually boils down to: "the webpage just makes two outgoing websocket connections; one to a proxy, and the other to an app on the PC, itself providing a custom network driver".

shankinson9• 14 years ago

Not really but good guess. We didn't make TetherMe. Maybe you mean iTether?

kevko• 14 years ago

That's basically the way to make such apps.

However, for this particular service, I think that you could get away with much less by leveraging existing work: modify an OpenVPN client so that it has an additional listen socket; then, use a websockets-based relay to link the OpenVPN client's listen socket and your OpenVPN servers.

A nice thing about this setup is that the webpage with the websockets relay can be dynamically generated and point to any server of your choice for quick load-balancing; it would also make it difficult for carriers to block any single server. The biggest problem would be scaling, since OpenVPN might load a server with just hundreds of active clients (http://forums.openvpn.net/topic9148.html), in which case a custom solution might be better...

Regardless of how they did it, very clever workaround!

thought_alarm2• 14 years ago

Wow. Cool hack.

But if you're friends with an iOS developer, you can ask him or her to build an ad-hoc copy of iProxy for your iPhone and it won't cost you anything.

(Or get 100 of your closest iPhone-using friends to pitch in on an iOS developer account)

https://github.com/tcurdt/iProxy/wiki

st3fan2• 14 years ago

Or jailbreak your phone and re-enable tethering.

thought_alarm2• 14 years ago

Nah.

fuzzythinker• 14 years ago

Why must I sign up in order to find out how much it cost?

shankinson9• 14 years ago

That's a good question. We'll change that.

stephen_g• 14 years ago

Do US carriers really still restrict tethering? That's really a shame, because the iPhone's built in tethering support is very good, and extremely elegant compared to apps and methods like this one...

masklinn• 14 years ago

I found the exact same thing, especially since they (finally) implemented the Access Point "tethering", it drains more battery but is incredibly convenient and simple to setup.

Once upon a time, I used the very first iPhone proxy application (NetShare), it was significantly more fiddly than native support. And of course you couldn't use the phone while it proxied, that's not an issue with native support.

anonhacker• 14 years ago

I feel like this is not so hard to do with NodeJS and Web sockets.

Small NodeJS app that serves the client connection webpage and acts as a proxy. Set the proxy locally, When you get requests instead of fetching them ask the socket for the data and headers.

On the client just do an XMLHttpRequest for whatever and shove it back down the web socket to the proxy server. Done, Right? I'll do a little experiment when i have time...

cyanbane• 14 years ago

This sounds awesome, but please don't send my password back over email.

abalone• 14 years ago

More fundamental than the "do they use websockets" question is "what is the multihoming behavior of iOS?"

Sockets alone are not enough -- you need cooperation from the OS to route connections over both wifi and cell data links in the desired fashion.

In this case we can infer it's two connections made by a script running on a web page: one with the "tethered" machine (over wifi) and one with Tether's proxy server (over cell data). The proxy server works in concert with a client on the tethered machine, and the script just relays data between those two connections.

The interesting thing is that iOS permits a single web page to connect over both network links simultaneously. I'm no expert but that seems like something Apple could, and would, kill with an update.

Really clever hack, though.

Tether Launches HTML5-Based iPhone Tethering Solution

Related Stories