ALS: Automotive Grade Linux [LWN.net]

ALS: Automotive Grade Linux

Posted Sep 26, 2012 20:01 UTC (Wed) by aleXXX (subscriber, #2742)
Parent article: ALS: Automotive Grade Linux

"Of course, CAN bus may be on its way out; the protocol offers no security and certainly lacks the flexibility of standard TCP/IP."
...but it comes with timing guarantees, which you probably want to have when things like the braking system etc. use it for communication.

Alex

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ALS: Automotive Grade Linux

Posted Sep 27, 2012 4:24 UTC (Thu) by smurf (subscriber, #17840) [Link] (3 responses)

This is why cars typically have two CAN busses. One for the safety critical low level stuff, and one for the bells and whistles.
The bells and whistles should be replace-able with TCP/IP very easily.
The low-level stuff, not so much, obviously.

ALS: Automotive Grade Linux

Posted Sep 27, 2012 16:39 UTC (Thu) by alison (subscriber, #63752) [Link]

Check out autosec.org and read the (refereed academic) papers there about how the alleged firewalling between CAN subnets is largely unimplemented. In my own vehicle using the scantool.net STN1110 OBDLink MX, I can listen to ECUs on several subnets. CAN (actually controller area network) has very little security, and GENIVI has a Networking Expert Group and a Security Team that are laboring to create new standards to address the situation.

As someone who has participated in GENIVI, I am excited about the new AGL and look forward to learning more. I am delighted that the previously quiet Toyota is stepping up to provide leadership alongside Samsung and Intel with Tizen. Linux is winning big in automotive, which will be an increasingly vital arena as autonomous vehicles become inevitable. California has made self-driving cars legal within the week, so we shouldn't squabble, but roll up our sleeves and get to the work.

The article is yet more great coverage of Linux IVI by Nate Willis and Michael Kerrisk. Thank you LWN!

ALS: Automotive Grade Linux

Posted Sep 27, 2012 18:43 UTC (Thu) by dmk (guest, #50141) [Link] (1 responses)

Well, at least in cars of one big manufacturer there are more than 2 CAN Busses...

ALS: Automotive Grade Linux

Posted Oct 6, 2012 6:26 UTC (Sat) by alison (subscriber, #63752) [Link]

My car has MS-CAN, HS-CAN and OBDII. I can read all three from the OBDII port:

http://she-devel.com/Mazda3_Controller_Area_Network_Exper...

My vehicle dates to 2005, so newer cars likely do have better security, although the kind of inter-bus communication I report is observed in many newer models as well.

ALS: Automotive Grade Linux

Posted Sep 27, 2012 14:57 UTC (Thu) by giggls (subscriber, #48434) [Link] (1 responses)

Given a suitable Layer2 IPv6 will be able to provide Realtime capabilities better than those of CAN. Which is capable of realtime communication only if all stations behave well.

Sven

ALS: Automotive Grade Linux

Posted Sep 27, 2012 19:59 UTC (Thu) by Cyberax (✭ supporter ✭, #52523) [Link]

AFAIR, CAN actually has a feature called 'dominant bits' which can _physically_ override the current transmission for really time-critical data.