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Explaining WLAN Chips' Poor Linux Support
morcheeba writes "Kernel Traffic is reporting (mirror mirror list) that 'Some WLAN Chip Specs Secret To Protect Military Communications.' While this is stretching it a bit -- these radios are generally limited to a narrow frequency range and few modulation types -- software can cause illegal radio operation, especially when the laws vary by country. Is Linux support for 802.11g and Centrino chipsets going to be delayed by manufacturers afraid of FCC harassment? An interesting discussion on the future of Openness in radio chipsets." Interesting comments from Alan Cox in here about just how flexible some of these chips are.
Linux drivers don't come from the Driver Fairy, they usually get written by volunteers. That takes a while: getting the specs, implementing the drivers, testing them, etc. And it usually only happens after the hardware is starting to sell. So, it may well take a year or two for Linux drivers to appear for a piece of hardware. If you want it to happen faster, volunteer yourself.
Of course, a few manufacturers do ship their own Linux drivers. That's nice, but it isn't all that common yet. And many of the drivers that do ship from manufacturers are based on proprietary, commercial driver toolkits and have to be closed source.
Centrino is a special case. Centrino is largely a marketing construct, not a technology, and the marketing group that pushed Centrino inside Intel apparently wants to make Microsoft happy and doesn't like Linux. I doubt this is going to last: Linux is too important for Intel to maintain this position.
2. Some WLAN Chip Specs Secret To Protect Military Communications
28 Apr - 1 May (21 posts) Archive Link: "Broadcom BCM4306/BCM2050 support"
Topics: Networking
People: Martin List-Petersen, David S. Miller, Alan Cox, Carl-Daniel Hailfinger, Richard B. Johnson
Bas Mevissen asked if Linux had any support for Broadcom's BCM4306 or BCM2050 WLAN chips. He saw that the BCM4401 ethernet chip had a Linux driver, and was hopeful that maybe the WLAN chips did as well. Martin List-Petersen replied, "It seems, that the specs haven't been released yet. There are quite a few Wlan cards out there based on the Broadcom chips (nearly all cards, that support 802.11g), so it's quite a shame. (Actually this fits the the TrueMobile 1180, 1300 and 1400, speaking of Dell wireless lan cards)." He added, "The same problem is with the Intel Prowireless 2100 (Centrino) WLan card. No Linux support available yet, which is another choice for the Dell notebooks at the moment." But he also said there was a Petition folks could sign, regarding this very issue. Martin concluded, "I've tried to contact Broadcom directly, but they are just ignoring mails containing the word "Linux", so it seems." David S. Miller also said:
Don't expect specs or opensource drivers for any of these pieces of hardware until these vendors figure out a way to hide the frequency programming interface.
Ie. these cards can be programmed to transmit at any frequency, and various government agencies don't like it when f.e. users can transmit on military frequencies and stuff like that.
The only halfway plausible idea I've seen is to not document the frequency programming registers, and users get a "region" key file that has opaque register values to program into the appropriate registers. The file is per-region (one for US, Germany, etc.)and the wireless kernel driver reads in this file to do the frequency programming.
So don't blame the vendors on this one, several of them would love to publish drivers public for their cards, but simply cannot with upsetting federal regulators.
Alan Cox remarked that folks were already cracking the Windows interface on those cards, and that non-US governments cared about this issue as well. He said, "The fact people are already abusing the technology suggests that they will be forced to go the crypted settings route for next generation hardware anyway." And added, "I talked to one vendor about this stuff and fingers crossed we will see open drivers except for the radio module. In the longer term I suspect vendors will move to signed register sets, so you can load "US 802.11g" but you can't load "police frequency, full power""
At some point Bas suggested that if these vendors were really willing to release their specs, but were only holding back to satisfy government agencies, then maybe they could release some binary drivers in the interim. Martin replied to this, "I totally agree on this. A binary driver could better than nothing at this point. Another thing that wonders me, is why companies like Broadcom, if they are so open to releasing the drivers at some point, where they can make the regulation agencies somewhat happy, are so ignorant then. I've heard of serveral people, that tried to get a statement on the possibilty for Linux drivers from then and the return is nothing. I've actually tried myself. No response at all."
Elsewhere, Carl-Daniel Hailfinger's eyes lit up at the prospect of transmitting on military frequencies. He said he "wants binary only driver for these cards to build opensource driver with ability to set "interesting" frequency range." Martin said, "It's there for Windows." And at some point, Richard B. Johnson said:
Contrary to popular opinion, there is no FCC regulation prohibiting one from receiving some particular frequency. There is, however, a federal law prohibiting the disclosure of a radio message by a third party. This means that the media, or even law enforcement can't listen to a private radio (cell phone) conversation and then disc
with 2.4Ghz ISM wireless network stuff, anyway... on the manufacturing & design side...
:
This is something I hadn't thought of in terms of software. I mean, if you make, say, a wireless router, there are various laws you have to follow to get approval in various places.. things like
The antenna connector has to be non-standard. This is why you'll see like, a TNC conenctor with the threads reversed, or the gender parts half swapped, etc. It's so consmers don't hook it up to amplifiers and things.. or rather, so they understand that they are not supposed to. The same goes for software functions.. there are many functions accessible in the software that would allowt eh device to operate outside of the allowabloe parameters, but we had to keep those hidden & inaccessible. If they were presented to the customer, the customer woudl be able to violate FCC just by using commands we supplied them.
So.. I never considered that with regards to linux drivers.. but it is a good point.
It is funny you mention the Dlink 650+. This is the exact card I had when I decided to go wireless. I couldn't get it to work so I sold it and bought a Lucent Orinoco. But, a few months later I see people using the DLink line (650+ and others) on Linux without a problem. Of course not with the X2 support or the X4 (44mbs) with an upgraded firmware. But then DLink claimed double speed and I did a few experiments when I was using the 650+ in windows and I could not find a speed difference running between 11 and 22. The card and the router were only about 6 feet away when I did the testing. So so much "twice as fast" like they claim. So the 650(+) is supported, just not it's "faster" 2x setting.
...Actually... Linksys doesnt make firewalls. They make shitty NAT appliances. If you want firewalling, then openbsd is an option. If you want it done right, then using ACL on a Cisco 2610 is a better option. And if you're using Cable or DSL and calling that box with linksys or netgear or whatever on it a "router", then you need to have the crap knocked out of you with a cluebat.
Another issue about these NAT appliances made by linksys is... how secure is NAT when dumbasses enable port forwarding? Port forwarding defeats the entire purpose of NAT, IP Masquerade, IP Gatewaying, Transparent Proxying, whatever you wish to call it. NAT gives people an entirely FALSE sense of security, unless properly implemented by the person who configures the NAT appliance.
IF your NAT appliance was set up with your modem, then it was installed by a goon. Cable or DSL goons do not know how to properly config NAT appliances. Almost every cable or DSL installation that I have seen done in this manner has had all ports forwarded to a box, via placing the box in what is known as a "DMZ". Now, given this information, HOW SECURE IS A FIREWALL WHEN IT'S FORWARDING PORTS TO YOUR BOX WITHOUT ASKING QUESTIONS?!
Firewalling is a crummy method of securing internet connections that is usable for home usage, but not normally acceptable for doing anything REAL. If you care about security, then you had better make sure your crappy NAT appliance is configured properly.
Now... on to OpenBSD.
OpenBSD allows ACL, therefore is much nicer for firewalling than a NAT appliance. The problem is that it is dependant on a primarily software solution. Due to the software dependance, it can be exploited. Oops, there goes *BSD, Linux, AIX and anything else you would DARE throw at the problem on the hardware front.
Many of the chipset makers feel that their 'drivers' are also their IP. In the wireless space, the first to market folks get to make the rules. In the case of 802.11a, Atheros was the first to market. There existed a 'binary only' driver that was built on a mandrake linux box. The bad news is the way it was built made it completely useless. I've not heard of anyone having sucuess using it. Rumor has it that Atheros built this driver & they would release 'formal' drivers for their chipsets. This hasn't happened yet. I doubt it will until they have somebody else providing 802.11a chipsets. To them, it's about getting market share & protecting IP.
Recent developments:
Reyk Floeter has started building a GPL driver. It's amusing based on the context of this article, because all this driver can do is SNIFF. That's right, RX Only. Progress has been very slow, and there have been several questions to the list as to how this driver exists, and how it's being built. It would seem that Reyk doesn't have any of the specs & hasn't signed an NDA. I assume he's reverse engineering the windows drivers, but he hasn't stated as much. The development progress has been _VERY_ slow, and this project needs help from OSS devs. Anyone up for a challenge?
Intellegraphics signed the NDA, and has a driver 'for sale'.
While the government has it's paws in everything, I doubt this is the case at this point. This whole article is based on FUD.
That's all. -Eric Johanson, SeattleWireless
People, come on, RTFA, ok?
This is not about 802.11b, it's about 802.11g, the newer standard. The one that can do 54 Mbps? Look arround for drivers for those chipsets (mostly Broadcom or Intel's). You'll find none. Why? Because these things can be programmed to receive *and* transmit on any frequency. Any. That inclues military frequencies. Building a receiver for any frequency is not rocket science. In fact it's boring since it's well known. The problem is that the FCC has to approve this things. The vendor builds it and they have to get approval from the FCC to market it. If the FCC catches word that the vendor is giving the specs to a bunch of hippies, the hardware might not get approved (nothing to do with the FCC per se, it's just politics). The problem is some people out there are _very_ willing to go on a disrupt police communications. And what could be easier that just taking a laptop on a car and just war drive. It gives a whole new meaning to the term, doesn't it?
Some people (RTFA) have proposed solutions, basically signed frequency tables, but since the hardware is out, it's too fscking late. That's going to be in the next gen hardware, but not in the current round. By the look of it, 802.11g on Linux is screwed for the time being.
The 650+ uses the Texas Instruments ACX100 chipset, and they are not willing to release the necessary specs to write drivers for it. Check the ACX100 project on sourceforge to get the details. The only known driver is a binary-only module that will only work for an obscure Mandrake kernel version (PCI version only), and I have only heard of one person who got it to do anything at all.
You might be right about the (lack of) speed difference between the 11Mbps and 22Mbps products, but I haven't tested them. As always, take marketing-speak with a pinch of salt... It can't be entirely bullshit though, or I would have expected to hear a lot more complaints. Does anyone know more about the difference between the two standards that could explain?
All the rest (configuration files, etc.) is just distribution-related fluff.
Maybe they aren't limiting the broadcast characteristics in firmware on the broadcomm G cards because they don't have a final spec yet and they are trying to keep the device/chipset as open as posisble so they can adapt to new changes in the specs if need be. I just wish that I could get it to work on my damn linux box cause right now I am running in mixed mode on my home wireless network.
ZiN
-ZiN-
Actually, the 13cm amateur band is 2300-2310 AND 2390-2450MHz - we lost the 2310-2390 segment to the digital broadcasters (Sirius/XM).
Amateurs are primary users in some portions, and secondary in others, but in all cases are considered a licensed service, whereas Part 15 devices, such as the LAN cards under discussion, are not, and therefore the amateur service outranks them.
It sounds like these LAN cards are poorly designed since they require so many things to be done under software - too many things, in fact. Maybe if they were designed to be more autonomous, they would impose less of an overhead on their host systems, and make for more efficient computing overall. Of course, that's too easy - as many others have mentioned, it's the old battle of WinModems versus real ones. Or, in this case, Windows versus a real operating system.
IMHO, there's a reason for the good NVidia Linux drivers and that is the demand for 3-D capabale graphics workstations running Linux--the kind that movie studios and engineering firms use. I think the geek/Slashdot community's adoration of NVidia is a side effect of their market-driven choice, not the reason for their choice.
The only way that tech specs for wlan cards will be released is if there the financial benefits of their release justify the release.
Chris
It is worse than you think. Some 650's use one chipset, some use another. One chipset works in Linux, one does not. If you buy one for Linux, you are effectively buying a lottery ticket.
Finally! A year of moderation! Ready for 2019?
I just bought one from my local newspaper's classified ads for $35.
Dewey, what part of this looks like authorities should be involved?