Hi,
I've got this chip within my OQO 01+, generally the driver seems very
stable (thankyou for your work!), however when trying to use WPA with the
chip the association conversation fails.
Of course, I can provide the logs from both the device and hostapd on the
other end, but suspect that the answer will fall into one of the
categories:-
(a) Be patient! Test it once I've said the driver supports it.
(b) Go off and try and implement x, y and z, see what happens.
(c) Not a chance with this chip, sorry. The firmware can't send x, so the
association won't ever work.
WPA would be very useful for me, so would be glad to help in any way. If
the answer is (c), ah well, still nice to know though.
Cheers,
Jamie Lentin <[email protected]> writes:
> Hi,
Hello,
> I've got this chip within my OQO 01+, generally the driver seems very
> stable (thankyou for your work!),
Which driver? There is at76c50x-usb (using mac80211) and at76_usb in
staging (which is going away sometime in the future). Because
at76c50x-usb is the path forward, I will omit at76_usb here.
> however when trying to use WPA with the chip the association
> conversation fails.
Yes, at76c50x-usb doesn't support WPA right now.
> Of course, I can provide the logs from both the device and hostapd on
> the other end, but suspect that the answer will fall into one of the
> categories:-
>
> (a) Be patient! Test it once I've said the driver supports it.
>
> (b) Go off and try and implement x, y and z, see what happens.
>
> (c) Not a chance with this chip, sorry. The firmware can't send x, so
> the association won't ever work.
>
> WPA would be very useful for me, so would be glad to help in any way.
> If the answer is (c), ah well, still nice to know though.
The answer is (b). At least some chipsets seem to support WPA. I'm busy
with other projects right now and I don't have time to implement WPA
support, but I can give you hints. I see two ways forward:
1) use mac80211 to encrypt the frames
Currently encryption happens in hardware, but also mac80211 can do it.
And mac80211 sw encryption supports TKIP and AES, so with luck you will
get WPA working with that method. Remove .set_key from at76_ops and see
what happens.
2) enable firmware support for WPA
Milan Plzik had some patches for at76_usb which added WPA firmware
support. The patches are here:
http://git.kernel.org/?p=linux/kernel/git/linville/wireless-legacy.git;a=shortlog;h=at76
You can port them for at76c50x-usb and get WPA working. First check that
the WPA firmware supports your device, though.
If you need any help, send email to me and this list. We'll help you as
we can.
--
Kalle Valo
>> I've got this chip within my OQO 01+, generally the driver seems very
>> stable (thankyou for your work!),
>
> Which driver? There is at76c50x-usb (using mac80211) and at76_usb in
> staging (which is going away sometime in the future). Because
> at76c50x-usb is the path forward, I will omit at76_usb here.
Yes at76c50x-usb, sorry. I'd tried at76_usb also, but not the
WPA-enabled version you suggest below.
> The answer is (b). At least some chipsets seem to support WPA. I'm busy
> with other projects right now and I don't have time to implement WPA
> support, but I can give you hints. I see two ways forward:
Thanks---this has certainly got me further than I would have done on my
own. I've been playing with it when I've had the time and this is as far
as I've got so far.
> 1) use mac80211 to encrypt the frames
>
> Currently encryption happens in hardware, but also mac80211 can do it.
> And mac80211 sw encryption supports TKIP and AES, so with luck you will
> get WPA working with that method. Remove .set_key from at76_ops and see
> what happens.
Comparing other drivers' no_hwcrypt options, I think removing set_key is
unnecessary (mac80211 will fallback when it gets -EOPNOTSUPP from
set_key), but I have removed it anyway to see what happens.
The 4-way handshake works, however hostapd doesn't receive a response to
the group handshake. hostapd says "EAPOL-Key timeout" once it gets to
this point. wpa_supplicant on the device:-
State: 4WAY_HANDSHAKE -> 4WAY_HANDSHAKE
WPA: RX message 3 of 4-Way Handshake from 00:0f:b5:97:37:54 (ver=2)
WPA: IE KeyData - hexdump(len=28): dd 1a 00 50 f2 01 01 00 00 50 f2 02 02
00 00 50 f2 04 00 50 f2 02 01 00 00 50 f2 02
WPA: Sending EAPOL-Key 4/4
WPA: Installing PTK to the driver.
WPA: RSC - hexdump(len=6): 00 00 00 00 00 00
wpa_driver_nl80211_set_key: alg=3 addr=0x80c5f04 key_idx=0 set_tx=1
seq_len=6 key_len=16
addr=00:0f:b5:97:37:54
State: 4WAY_HANDSHAKE -> GROUP_HANDSHAKE
RTM_NEWLINK: operstate=0 ifi_flags=0x1003 ([UP])
RTM_NEWLINK, IFLA_IFNAME: Interface 'wlan0' added
Wireless event: cmd=0x8b15 len=20
Wireless event: new AP: 00:00:00:00:00:00
Setting scan request: 0 sec 100000 usec
Added BSSID 00:0f:b5:97:37:54 into blacklist
CTRL-EVENT-DISCONNECTED - Disconnect event - remove keys
wpa_driver_nl80211_set_key: alg=0 addr=0x80b89b0 key_idx=0 set_tx=0
seq_len=0 key_len=0
nl80211: set_key failed; err=-2
wpa_driver_nl80211_set_key: alg=0 addr=0x80b89b0 key_idx=1 set_tx=0
seq_len=0 key_len=0
nl80211: set_key failed; err=-2
wpa_driver_nl80211_set_key: alg=0 addr=0x80b89b0 key_idx=2 set_tx=0
seq_len=0 key_len=0
nl80211: set_key failed; err=-2
wpa_driver_nl80211_set_key: alg=0 addr=0x80b89b0 key_idx=3 set_tx=0
seq_len=0 key_len=0
nl80211: set_key failed; err=-2
wpa_driver_nl80211_set_key: alg=0 addr=0x80c4640 key_idx=0 set_tx=0
seq_len=0 key_len=0
addr=00:0f:b5:97:37:54
nl80211: set_key failed; err=-2
State: GROUP_HANDSHAKE -> DISCONNECTED
Comparing output to a working card, wpa_supplicant doesn't seem to be
receiving the group handshake frames from hostapd. Comparing DBG_RX_DATA
to what wireshark finds (from a third computer), none of the group key
handshake frames get as far as DBG_RX_DATA, although when using TKIP
there is a 802.11 ACK frame going back (CCMP is ignored entirely). Is the
firmware trying to decrypt and ditching them, since it doesn't have the
relevant keys? Any ideas on what I can poke to stop this?
> 2) enable firmware support for WPA
>
> Milan Plzik had some patches for at76_usb which added WPA firmware
> support. The patches are here:
>
> http://git.kernel.org/?p=linux/kernel/git/linville/wireless-legacy.git;a=shortlog;h=at76
>
> You can port them for at76c50x-usb and get WPA working. First check that
> the WPA firmware supports your device, though.
This looks do-able, unfortunately the firmware version I have is older
than the version insisted by FIRMWARE_IS_WPA:-
usb 3-1: using firmware atmel_at76c505a-rfmd2958.bin (version 1.102.0-113)
The "standard" set of firmwares[1] doesn't seem to include any firmwares
newer than this. Does anyone know where the 1.103 firmwares come from?
The original Atmel driver seems to compile images into the source code,
I'll try splicing this in and see what version I end up with, but if
anyone knows better please let me know---considering the age of the
include in CVS I'm not that hopeful it'll work.
Many thanks,
[1] http://www.thekelleys.org.uk/atmel