linux-wireless.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Alexander Wetzel <alexander@wetzel-home.de>
To: Johannes Berg <johannes@sipsolutions.net>, luciano.coelho@intel.com
Cc: linux-wireless@vger.kernel.org, linuxwifi@intel.com
Subject: Re: [PATCH] iwlwifi: Extended Key ID support for mvm and dvm
Date: Mon, 19 Aug 2019 21:57:06 +0200	[thread overview]
Message-ID: <da471544-3370-8ba1-2265-d02ab09cdcee@wetzel-home.de> (raw)
In-Reply-To: <204c346ab9fc71865e4cb5f5c29ec33ca05050e2.camel@sipsolutions.net>

>> +
>> +	/* The new Tx API does not allow to pass the key or keyid of a MPDU to
>> +	 * the hw, preventing us to control which key(id) to use per MPDU.
>> +	 * Till that's fixed we can't use Extended Key ID for the newer cards.
> 
> Technically we still don't need per MPDU, we just need to switch which
> one to use for TX after installing it for RX already.

The Extended Key ID API we finally merged in mac80211 is not notifying 
the driver when to switch the key over to the other id.
The current API provides the key/keyid per MPDU and let's mac80211 have 
the full control what's the correct key for each frame.

That's especially critical for drivers setting 
IEEE80211_KEY_FLAG_GENERATE_IV and/or supporting A-MPDU's. Allowing the 
driver to override the mac80211 decision is only safe when the 
driver/card generates the PNs itself and also handles the A-MPDU key 
borders correctly.

While less desirable we still could get that working: The mvm driver 
would have to detect the key borders and then tell the firmware to 
switch over to the other key. But we would have to make sure to not 
re-enable A-MPDU aggregation till the card really has switched.

Alexander


  reply	other threads:[~2019-08-19 20:03 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-19 18:05 [PATCH] iwlwifi: Extended Key ID support for mvm and dvm Alexander Wetzel
2019-08-19 18:51 ` Johannes Berg
2019-08-19 19:57   ` Alexander Wetzel [this message]
2019-08-19 20:03     ` Johannes Berg
2019-08-19 20:09       ` Johannes Berg
2019-08-19 20:50         ` Alexander Wetzel
2019-08-19 20:42       ` Alexander Wetzel
2019-09-06 20:41 ` Alexander Wetzel

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=da471544-3370-8ba1-2265-d02ab09cdcee@wetzel-home.de \
    --to=alexander@wetzel-home.de \
    --cc=johannes@sipsolutions.net \
    --cc=linux-wireless@vger.kernel.org \
    --cc=linuxwifi@intel.com \
    --cc=luciano.coelho@intel.com \
    /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;
as well as URLs for NNTP newsgroup(s).