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From:   Veerendranath Jakkam <quic_vjakkam@quicinc.com>
To:     <johannes@sipsolutions.net>
CC:     <linux-wireless@vger.kernel.org>
Subject: [PATCH 1/2] nl80211: Allow transmitting auth frames with random TA
Date:   Fri, 8 Jul 2022 22:22:11 +0530
Message-ID: <20220708165212.2069149-1-quic_vjakkam@quicinc.com>
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Allow authentication frames with a random local address as transmit
address if the driver supports.

This is required for below cases:
- Enabling use of randomized transmit address for PASN authentication
  frames improve privacy of WLAN clients.
- To allow user space to use link address indicated by driver as
  transmit address for authentication frames triggered by
  NL80211_CMD_EXTERNAL_AUTH for MLO connection.

Signed-off-by: Veerendranath Jakkam <quic_vjakkam@quicinc.com>
---
 include/uapi/linux/nl80211.h |  4 ++++
 net/wireless/mlme.c          | 11 +++++++++++
 2 files changed, 15 insertions(+)

diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index 279f9715919e..9e665f7b3e23 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -6225,6 +6225,9 @@ enum nl80211_feature_flags {
  * @NL80211_EXT_FEATURE_RADAR_BACKGROUND: Device supports background radar/CAC
  *	detection.
  *
+ * @NL80211_EXT_FEATURE_AUTH_TX_RANDOM_TA: Device supports randomized TA
+ *	for authentication frames in @NL80211_CMD_FRAME.
+ *
  * @NUM_NL80211_EXT_FEATURES: number of extended features.
  * @MAX_NL80211_EXT_FEATURES: highest extended feature index.
  */
@@ -6292,6 +6295,7 @@ enum nl80211_ext_feature_index {
 	NL80211_EXT_FEATURE_BSS_COLOR,
 	NL80211_EXT_FEATURE_FILS_CRYPTO_OFFLOAD,
 	NL80211_EXT_FEATURE_RADAR_BACKGROUND,
+	NL80211_EXT_FEATURE_AUTH_TX_RANDOM_TA,
 
 	/* add new features before the definition below */
 	NUM_NL80211_EXT_FEATURES,
diff --git a/net/wireless/mlme.c b/net/wireless/mlme.c
index 2bb4da97b66a..176513a75ddf 100644
--- a/net/wireless/mlme.c
+++ b/net/wireless/mlme.c
@@ -736,6 +736,16 @@ int cfg80211_mlme_mgmt_tx(struct cfg80211_registered_device *rdev,
 	}
 
 	if (!ether_addr_equal(mgmt->sa, wdev_address(wdev))) {
+		/* Allow random TA to be used with authentication frames if the
+		 * driver has indicated support for this. Otherwise, only allow
+		 * the local address to be used.
+		 */
+		if (ieee80211_is_auth(mgmt->frame_control) &&
+		    wiphy_ext_feature_isset(
+			   &rdev->wiphy,
+			   NL80211_EXT_FEATURE_AUTH_TX_RANDOM_TA))
+			goto out_tx;
+
 		/* Allow random TA to be used with Public Action frames if the
 		 * driver has indicated support for this. Otherwise, only allow
 		 * the local address to be used.
@@ -755,6 +765,7 @@ int cfg80211_mlme_mgmt_tx(struct cfg80211_registered_device *rdev,
 			return -EINVAL;
 	}
 
+out_tx:
 	/* Transmit the Action frame as requested by user space */
 	return rdev_mgmt_tx(rdev, wdev, params, cookie);
 }
-- 
2.25.1