Really free Atheros driver for Linux [LWN.net]

Really free Atheros driver for Linux

Posted Nov 16, 2006 0:04 UTC (Thu) by drag (subscriber, #31333)
In reply to: Really free Atheros driver for Linux by N0NB
Parent article: SFLC: OpenBSD Atheros driver is clean

Whatever. I am now willing to beleive that the excuse for FCC compliance is around 70% bullshit.

OpenBSD folks reverse engineering the Linux binary drivers have said that the drivers do a hell of a lot more then just regulating what frequencies you can use. If it was true that they were forced to do it for FCC regulations then the binary-only modules wouldn't be doing those things.

In his efforts to understand how the ipw3945 driver controls the firmware, Damien found that the binary daemon was simple to bypass, offering no real control. "I was able to make the daemon think it was in another regulatory domain," he explained, "just by adding a few lines of code into the GPL'd part of the driver." The binary-only daemon is described as necessary due to FCC regulations, causing Damien to retort, "I think Intel (and Atheros) use FCC rules as a pretext to hide intellectual property in the binary-only portions of their drivers." He went on to explain that the Intel regulatory daemon, as well as the Atheros HAL, implement a number of complex algorithms, including automatic calibration of the radio power based on temperature variations, and dynamic tuning of the radio sensitivity based on received signal strength. "These algorithms go far beyond the simple enforcement of regulatory compliance," he added, "and can really make the difference by extending the operating range of the adapter, improving throughput in various environmental conditions, and reducing power consumption. That is why vendors want to keep these algorithms secret.

In Other words it's BS. I wouldn't mind it so much having a regulatory deamon or binary if only to work around government worthlessness, but I don't think that it's realy all that is going on.

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Really free Atheros driver for Linux

Posted Nov 16, 2006 4:17 UTC (Thu) by proski (subscriber, #104) [Link]

What's going to stop a bad guy from lying to the driver what country he is in? How can the driver or even a userspace deamon know it's not running in Japan if the root says so? And then the bad guy runs an AP in the 4.9 GHz band to jam first responders.

Technical restrictions are no substitute to law, morale and common sense. They can protect honest people from honest mistakes, but closing the source goes far beyond common sense. It's a typical case of security through obscurity with an additional effect of hobbling free software.

Really free Atheros driver for Linux

Posted Nov 16, 2006 15:51 UTC (Thu) by pizza (subscriber, #46) [Link]

> Whatever. I am now willing to beleive that the excuse for FCC compliance is around 70% bullshit.

I've been saying this all along, and it's only been reinforced with my dealings with wireless chipset companies [1]. They're far more worried about their "Intellectual Property" being exposed (or rather, worried that someone else will claim they mis-appropriated IP, and get sued..)

The MadWiFi HAL does far, far more than restrict RF-level operation; if that's all it did it would be downright tiny. And as others have said, you can always lie about the country information and generally wreak havoc with your 15mW transmitter.

[1] My day job is writing 802.11 drivers.