> First, any good tethering app should be immune to a simple TTL check. If t... | Hacker News

Hacker Newsnew | past | comments | ask | show | jobs | submit

zem on May 9, 2011 | parent | context | favorite | on: How AT&T Recognizes Unauthorized Tethering from Ja...

> First, any good tethering app should be immune to a simple TTL check.

If the phone sets its TTL to 255, what can you do?

kevko on May 9, 2011 [–]

The goal is not to forward packets blindly like a NAT. You emulate the NAT's behavior by running a TCP state machine in user space and converting packets to regular Android SDK calls. This is what all of the non-root tethering apps likely do, because raw socket access is not allowed.

zem on May 10, 2011 | [–]

ooh, i see. nice.

Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact