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From:   Sunil Dutt <usdutt@codeaurora.org>
To:     johannes@sipsolutions.net
Cc:     linux-wireless@vger.kernel.org, Sunil Dutt <usdutt@codeaurora.org>
Subject: [PATCH] nl80211: Document the expectation for NL80211_ATTR_IE in NL80211_CMD_CONNECT
Date:   Fri, 13 Sep 2019 18:11:44 +0530
Message-Id: <1568378504-15179-1-git-send-email-usdutt@codeaurora.org>
Sender: linux-wireless-owner@vger.kernel.org
Precedence: bulk

This commit documents the expectation for NL80211_ATTR_IE when included
in NL80211_CMD_CONNECT, as following.

Driver shall not modify the IEs specified through NL80211_ATTR_IE if
NL80211_ATTR_MAC is included. However, if NL80211_ATTR_MAC_HINT is
included, these IEs through NL80211_ATTR_IE are specified by the user
space based on the best possible BSS selected. Thus, if the driver ends
up selecting a different BSS, it can modify these IEs accordingly (e.g.
userspace asks the driver to perform PMKSA caching with BSS1 and the
driver ends up selecting BSS2 with different PMKSA cache entry. RSNIE
has to get updated with the apt PMKID).

Signed-off-by: Sunil Dutt <usdutt@codeaurora.org>
---
 include/uapi/linux/nl80211.h | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index beee59c..325aaf1 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -571,6 +571,14 @@
  *	set of BSSID,frequency parameters is used (i.e., either the enforcing
  *	%NL80211_ATTR_MAC,%NL80211_ATTR_WIPHY_FREQ or the less strict
  *	%NL80211_ATTR_MAC_HINT and %NL80211_ATTR_WIPHY_FREQ_HINT).
+ *	Driver shall not modify the IEs specified through %NL80211_ATTR_IE if
+ *	%NL80211_ATTR_MAC is included. However, if %NL80211_ATTR_MAC_HINT is
+ *	included, these IEs through %NL80211_ATTR_IE are specified by the user
+ *	space based on the best possible BSS selected. Thus, if the driver ends
+ *	up selecting a different BSS, it can modify these IEs accordingly (e.g.
+ *	userspace asks the driver to perform PMKSA caching with BSS1 and the
+ *	driver ends up selecting BSS2 with different PMKSA cache entry. RSNIE
+ *	has to get updated with the apt PMKID).
  *	%NL80211_ATTR_PREV_BSSID can be used to request a reassociation within
  *	the ESS in case the device is already associated and an association with
  *	a different BSS is desired.
-- 
1.9.1