From e180bdc7c2bdda577b87381cc134d3edd3a8837b Mon Sep 17 00:00:00 2001 From: Neil Alexander Date: Mon, 25 Nov 2019 11:22:31 +0000 Subject: [PATCH] Update AWDL posts, include OWLink URLs --- _posts/2019-08-19-awdl.md | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) diff --git a/_posts/2019-08-19-awdl.md b/_posts/2019-08-19-awdl.md index 327c169..4969a56 100644 --- a/_posts/2019-08-19-awdl.md +++ b/_posts/2019-08-19-awdl.md @@ -9,10 +9,13 @@ author: Neil Alexander I was mostly prompted to write this post in response to a [Hacker News thread](https://news.ycombinator.com/item?id=20735462) recently, which announced -the release of an open-source implementation of the Apple Wireless Direct Link -(AWDL) protocol. AWDL is the secret sauce behind AirDrop, peer-to-peer AirPlay -and some other Apple wireless technologies. Even though everything covered in -this post was done some time ago, I have never spent the time to document it. +the release of an [open-source AirDrop implementation called +OpenDrop](https://github.com/seemoo-lab/opendrop) from the same team who +produced an [open-source implementation of Apple Wireless Direct Link (AWDL) +protocol called OWL](https://github.com/seemoo-lab/owl). AWDL is the secret +sauce behind AirDrop, peer-to-peer AirPlay and some other Apple wireless +technologies. Even though everything covered in this post was done some time +ago, I have never spent the time to document it. With a few exceptions, most wireless networks in the world operate in "infrastructure mode" which is where a wireless access point serves one or more @@ -48,6 +51,13 @@ These "hops" between wireless channels happen so quickly that there's very little disruption to what the user is doing with their Wi-Fi connection already (except for some minor wireless performance degradation - to be covered later). +A number of papers have been published by the OWLink team on the inner workings +of the AWDL protocol, which can be [found +here](https://owlink.org/publications/). In particular, [this +paper](https://arxiv.org/pdf/1808.03156.pdf) from Mobicom 2018 contains a +significant amount of detail about the AWDL protocol itself, channel hopping +techniques and security considerations, amongst other things. + ### Mesh opportunities Yggdrasil is designed to create a mesh network automatically out of @@ -69,7 +79,8 @@ configuration options, and it should scale well too in principle. Yggdrasil can already discover potential peers on the same network segment by using multicast service discovery, which sounds a lot like what AWDL does on the -social channel. You can configure which interfaces Yggdrasil beacons on with the `MulticastInterfaces` configuration directive. +social channel. You can configure which interfaces Yggdrasil beacons on with the +`MulticastInterfaces` configuration directive. I wanted to know if we could blend the two so that Yggdrasil could automatically discover other nearby devices and initiate peering connections with them using