2020-08-17 07:37:15

by Chung-Hsien Hsu

[permalink] [raw]
Subject: [PATCH v2 1/4] nl80211: support 4-way handshake offloading for WPA/WPA2-PSK in AP mode

Let drivers advertise support for AP-mode WPA/WPA2-PSK 4-way handshake
offloading with a new NL80211_EXT_FEATURE_4WAY_HANDSHAKE_AP_PSK flag.

Extend use of NL80211_ATTR_PMK attribute indicating it might be passed
as part of NL80211_CMD_START_AP command, and contain the PSK (which is
the PMK, hence the name).

The driver is assumed to handle the 4-way handshake by itself in this
case, instead of relying on user space.

Signed-off-by: Chung-Hsien Hsu <[email protected]>
Signed-off-by: Chi-Hsien Lin <[email protected]>
---
include/uapi/linux/nl80211.h | 41 ++++++++++++++++++++++++------------
net/wireless/nl80211.c | 4 +++-
2 files changed, 31 insertions(+), 14 deletions(-)

diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index 4e6339ab1fce..0d267ac3858c 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -183,18 +183,27 @@
*
* By setting @NL80211_EXT_FEATURE_4WAY_HANDSHAKE_STA_PSK flag drivers
* can indicate they support offloading EAPOL handshakes for WPA/WPA2
- * preshared key authentication. In %NL80211_CMD_CONNECT the preshared
- * key should be specified using %NL80211_ATTR_PMK. Drivers supporting
- * this offload may reject the %NL80211_CMD_CONNECT when no preshared
- * key material is provided, for example when that driver does not
- * support setting the temporal keys through %CMD_NEW_KEY.
+ * preshared key authentication in station mode. In %NL80211_CMD_CONNECT
+ * the preshared key should be specified using %NL80211_ATTR_PMK. Drivers
+ * supporting this offload may reject the %NL80211_CMD_CONNECT when no
+ * preshared key material is provided, for example when that driver does
+ * not support setting the temporal keys through %NL80211_CMD_NEW_KEY.
*
* Similarly @NL80211_EXT_FEATURE_4WAY_HANDSHAKE_STA_1X flag can be
* set by drivers indicating offload support of the PTK/GTK EAPOL
- * handshakes during 802.1X authentication. In order to use the offload
- * the %NL80211_CMD_CONNECT should have %NL80211_ATTR_WANT_1X_4WAY_HS
- * attribute flag. Drivers supporting this offload may reject the
- * %NL80211_CMD_CONNECT when the attribute flag is not present.
+ * handshakes during 802.1X authentication in station mode. In order to
+ * use the offload the %NL80211_CMD_CONNECT should have
+ * %NL80211_ATTR_WANT_1X_4WAY_HS attribute flag. Drivers supporting this
+ * offload may reject the %NL80211_CMD_CONNECT when the attribute flag is
+ * not present.
+ *
+ * By setting @NL80211_EXT_FEATURE_4WAY_HANDSHAKE_AP_PSK flag drivers
+ * can indicate they support offloading EAPOL handshakes for WPA/WPA2
+ * preshared key authentication in AP mode. In %NL80211_CMD_START_AP
+ * the preshared key should be specified using %NL80211_ATTR_PMK. Drivers
+ * supporting this offload may reject the %NL80211_CMD_START_AP when no
+ * preshared key material is provided, for example when that driver does
+ * not support setting the temporal keys through %NL80211_CMD_NEW_KEY.
*
* For 802.1X the PMK or PMK-R0 are set by providing %NL80211_ATTR_PMK
* using %NL80211_CMD_SET_PMK. For offloaded FT support also
@@ -2362,10 +2371,11 @@ enum nl80211_commands {
*
* @NL80211_ATTR_PMK: attribute for passing PMK key material. Used with
* %NL80211_CMD_SET_PMKSA for the PMKSA identified by %NL80211_ATTR_PMKID.
- * For %NL80211_CMD_CONNECT it is used to provide PSK for offloading 4-way
- * handshake for WPA/WPA2-PSK networks. For 802.1X authentication it is
- * used with %NL80211_CMD_SET_PMK. For offloaded FT support this attribute
- * specifies the PMK-R0 if NL80211_ATTR_PMKR0_NAME is included as well.
+ * For %NL80211_CMD_CONNECT and %NL80211_CMD_START_AP it is used to provide
+ * PSK for offloading 4-way handshake for WPA/WPA2-PSK networks. For 802.1X
+ * authentication it is used with %NL80211_CMD_SET_PMK. For offloaded FT
+ * support this attribute specifies the PMK-R0 if NL80211_ATTR_PMKR0_NAME
+ * is included as well.
*
* @NL80211_ATTR_SCHED_SCAN_MULTI: flag attribute which user-space shall use to
* indicate that it supports multiple active scheduled scan requests.
@@ -5773,6 +5783,10 @@ enum nl80211_feature_flags {
* @NL80211_EXT_FEATURE_CONTROL_PORT_OVER_NL80211_TX_STATUS: The driver
* can report tx status for control port over nl80211 tx operations.
*
+ * @NL80211_EXT_FEATURE_4WAY_HANDSHAKE_AP_PSK: Device wants to do 4-way
+ * handshake with PSK in AP mode (PSK is passed as part of the start AP
+ * command).
+ *
* @NUM_NL80211_EXT_FEATURES: number of extended features.
* @MAX_NL80211_EXT_FEATURES: highest extended feature index.
*/
@@ -5828,6 +5842,7 @@ enum nl80211_ext_feature_index {
NL80211_EXT_FEATURE_BEACON_PROTECTION_CLIENT,
NL80211_EXT_FEATURE_SCAN_FREQ_KHZ,
NL80211_EXT_FEATURE_CONTROL_PORT_OVER_NL80211_TX_STATUS,
+ NL80211_EXT_FEATURE_4WAY_HANDSHAKE_AP_PSK,

/* add new features before the definition below */
NUM_NL80211_EXT_FEATURES,
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 0e07fb8585fb..8e7c6a022205 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -9438,7 +9438,9 @@ static int nl80211_crypto_settings(struct cfg80211_registered_device *rdev,
if (nla_len(info->attrs[NL80211_ATTR_PMK]) != WLAN_PMK_LEN)
return -EINVAL;
if (!wiphy_ext_feature_isset(&rdev->wiphy,
- NL80211_EXT_FEATURE_4WAY_HANDSHAKE_STA_PSK))
+ NL80211_EXT_FEATURE_4WAY_HANDSHAKE_STA_PSK) &&
+ !wiphy_ext_feature_isset(&rdev->wiphy,
+ NL80211_EXT_FEATURE_4WAY_HANDSHAKE_AP_PSK))
return -EINVAL;
settings->psk = nla_data(info->attrs[NL80211_ATTR_PMK]);
}
--
2.25.0