From: James Cameron <quozl@laptop.org>
To: linux-wireless@vger.kernel.org
Subject: libertas: probe responses with zero length SSID cause scan result loss
Date: Tue, 11 Feb 2014 17:33:29 +1100 [thread overview]
Message-ID: <20140211063329.GO5487@us.netrek.org> (raw)
G'day,
I'd appreciate a sanity check, as I'm not sure what I am doing.
We saw for years that scan results for an OLPC XO-1 laptop would be
unreliable in large groups. APs would not be easily found. We
presumed other causes until recently.
Using monitor mode on another computer, and "iwlist eth0 scan" on the
XO-1, I found probe responses from an AP, and ACKs from the host to
the AP, but the output omitted the AP.
Further, the AP would be missing if there was a probe response from
another XO-1 running mesh, and an ACK from the host to that XO-1.
Enabling debugging, lbs_ret_scan was reporting "scan response: invalid
IE fmt" because the probe response had a zero length SSID IE.
Is a zero length SSID IE valid? (We can't change the wireless firmware
at this stage.)
Background data and dmesg fragments:
http://dev.laptop.org/ticket/12757
Patch being tested (lacks signoff and any review):
http://dev.laptop.org/git/olpc-kernel/commit/?h=x86-3.3&id=e98f01abce522fb70a3852b23b62205244ef69b8
--
James Cameron
http://quozl.linux.org.au/
next reply other threads:[~2014-02-11 6:33 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-11 6:33 James Cameron [this message]
2014-02-13 17:01 ` libertas: probe responses with zero length SSID cause scan result loss Dan Williams
2014-02-13 20:27 ` James Cameron
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20140211063329.GO5487@us.netrek.org \
--to=quozl@laptop.org \
--cc=linux-wireless@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox