2010-01-23 20:45:39

by Maxim Levitsky

[permalink] [raw]
Subject: mac80211: Breakage in software encryption (iwl3945)

I updated the kernel and lost connection to my WPA2
AP. Strangely the WPA handshake completes, but DHCP not.

I also unfortunately found that all that time I was using software
encryption (this is iwl3945 loaded with swcrypto=1).
Hardware encryption doesn't work ether and didn't work in the slightly
older kernel (but it did work once, I sure)

Now, the commit a6bae9e7ab19876a157c91019852395539e4f20e breaks software
encryption, with behaviour like described above.

Best regards,
Maxim Levitsky



2010-01-25 15:12:18

by Maxim Levitsky

[permalink] [raw]
Subject: Re: mac80211: Breakage in software encryption (iwl3945)

On Mon, 2010-01-25 at 00:27 +0100, Jochen Friedrich wrote:
> Hi Maxim,
>
> >> On Sat, 2010-01-23 at 22:10 +0200, Maxim Levitsky wrote:
> >>> I updated the kernel and lost connection to my WPA2
> >>> AP. Strangely the WPA handshake completes, but DHCP not.
> >> What did you upgrade to?
> > latest -git of wireless-testing
>
> I have the same problem since compat-wireless-2010-01-20 with
> iwl3945. compat-wireless-2010-01-15 works OK. However, as i don't
> use any module parameters, i guess i'm using hw encryption.
Nether did I use any parameters. However software encryption is the
default today, this is why nobody notice it is broken.

I use WPA2 thus CCMP.


Best regards,
Maxim Levitsky


2010-01-25 00:05:50

by Jochen Friedrich

[permalink] [raw]
Subject: Re: mac80211: Breakage in software encryption (iwl3945)

Jochen Friedrich wrote:
> Hi Maxim,
>
>>> On Sat, 2010-01-23 at 22:10 +0200, Maxim Levitsky wrote:
>>>> I updated the kernel and lost connection to my WPA2
>>>> AP. Strangely the WPA handshake completes, but DHCP not.
>>> What did you upgrade to?
>> latest -git of wireless-testing
>
> I have the same problem since compat-wireless-2010-01-20 with
> iwl3945. compat-wireless-2010-01-15 works OK. However, as i don't
> use any module parameters, i guess i'm using hw encryption.

I bisected this to commit 813d76694043d00b59475baa1fbfaf54a2eb7fad.
Reverting this patch makes compat-wireless-2010-01-20 and later run OK.

Thanks,
Jochen

2010-01-24 18:24:31

by Maxim Levitsky

[permalink] [raw]
Subject: Re: mac80211: Breakage in software encryption (iwl3945)

On Sun, 2010-01-24 at 11:56 +0100, Johannes Berg wrote:
> Maxim,
>
> Your mail is confusing me.
>
> On Sat, 2010-01-23 at 22:10 +0200, Maxim Levitsky wrote:
> > I updated the kernel and lost connection to my WPA2
> > AP. Strangely the WPA handshake completes, but DHCP not.
>
> What did you upgrade to?
latest -git of wireless-testing

>
> > I also unfortunately found that all that time I was using software
> > encryption (this is iwl3945 loaded with swcrypto=1).
> > Hardware encryption doesn't work ether and didn't work in the slightly
> > older kernel (but it did work once, I sure)
>
> That must be a different problem, surely?
Sure, and I open a bugreport about it too.

>
> > Now, the commit a6bae9e7ab19876a157c91019852395539e4f20e breaks software
> > encryption, with behaviour like described above.
>
> And how did you arrive at that conclusion? Have you reverted the patch
> and it works again? I really don't see how this particular patch could
> break it since afaict it's entirely correct, there are exactly two tests
> for IEEE80211_TX_INTFL_DONT_ENCRYPT in mac80211, both of which execute
> before the code I removed.

I didn't want to add the standard meme: 'Commit X just before Y works,
commit Y doesn't. I reverted Y and now everything works fine.'

I bisected it, manually this time. Sorry for confusion.

I will continue that discussion in the thread about this patch.
(Also sorry for not including commit description....)


Best regards,
Maxim Levitsky


2010-01-25 09:32:10

by Johannes Berg

[permalink] [raw]
Subject: Re: mac80211: Breakage in software encryption (iwl3945)

On Mon, 2010-01-25 at 01:05 +0100, Jochen Friedrich wrote:

> > I have the same problem since compat-wireless-2010-01-20 with
> > iwl3945. compat-wireless-2010-01-15 works OK. However, as i don't
> > use any module parameters, i guess i'm using hw encryption.
>
> I bisected this to commit 813d76694043d00b59475baa1fbfaf54a2eb7fad.
> Reverting this patch makes compat-wireless-2010-01-20 and later run OK.

Thanks. I'll look into that today.

johannes


Attachments:
signature.asc (801.00 B)
This is a digitally signed message part

2010-01-24 10:40:38

by Sedat Dilek

[permalink] [raw]
Subject: Re: mac80211: Breakage in software encryption (iwl3945)

Hi,

it is very helpful to give commit-id *and* commit-msg so that others
can follow more easily.
Which GIT repository (branch) is that?

Kind Regards,
- Sedat -

On Sat, Jan 23, 2010 at 9:10 PM, Maxim Levitsky <[email protected]> wrote:
> I updated the kernel and lost connection to my WPA2
> AP. Strangely the WPA handshake completes, but DHCP not.
>
> I also unfortunately found that all that time I was using software
> encryption (this is iwl3945 loaded with swcrypto=1).
> Hardware encryption doesn't work ether and didn't work in the slightly
> older kernel (but it did work once, I sure)
>
> Now, the commit a6bae9e7ab19876a157c91019852395539e4f20e breaks software
> encryption, with behaviour like described above.
>
> Best regards,
> Maxim Levitsky
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
> the body of a message to [email protected]
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>

2010-01-24 10:56:57

by Johannes Berg

[permalink] [raw]
Subject: Re: mac80211: Breakage in software encryption (iwl3945)

Maxim,

Your mail is confusing me.

On Sat, 2010-01-23 at 22:10 +0200, Maxim Levitsky wrote:
> I updated the kernel and lost connection to my WPA2
> AP. Strangely the WPA handshake completes, but DHCP not.

What did you upgrade to?

> I also unfortunately found that all that time I was using software
> encryption (this is iwl3945 loaded with swcrypto=1).
> Hardware encryption doesn't work ether and didn't work in the slightly
> older kernel (but it did work once, I sure)

That must be a different problem, surely?

> Now, the commit a6bae9e7ab19876a157c91019852395539e4f20e breaks software
> encryption, with behaviour like described above.

And how did you arrive at that conclusion? Have you reverted the patch
and it works again? I really don't see how this particular patch could
break it since afaict it's entirely correct, there are exactly two tests
for IEEE80211_TX_INTFL_DONT_ENCRYPT in mac80211, both of which execute
before the code I removed.

johannes


Attachments:
signature.asc (801.00 B)
This is a digitally signed message part

2010-01-24 10:32:47

by Marcus Better

[permalink] [raw]
Subject: Re: mac80211: Breakage in software encryption (iwl3945)

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Maxim Levitsky wrote:
> I updated the kernel and lost connection to my WPA2
> AP. Strangely the WPA handshake completes, but DHCP not.

I have observed this a few times with 2.6.32.4. I could work around it by
unloading and re-loading iwl3945.

> Now, the commit a6bae9e7ab19876a157c91019852395539e4f20e breaks software
> encryption, with behaviour like described above.

I don't think 2.6.32.4 includes that commit though.

Cheers,

Marcus
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2010-01-24 23:27:55

by Jochen Friedrich

[permalink] [raw]
Subject: Re: mac80211: Breakage in software encryption (iwl3945)

Hi Maxim,

>> On Sat, 2010-01-23 at 22:10 +0200, Maxim Levitsky wrote:
>>> I updated the kernel and lost connection to my WPA2
>>> AP. Strangely the WPA handshake completes, but DHCP not.
>> What did you upgrade to?
> latest -git of wireless-testing

I have the same problem since compat-wireless-2010-01-20 with
iwl3945. compat-wireless-2010-01-15 works OK. However, as i don't
use any module parameters, i guess i'm using hw encryption.

Thanks,
Jochen