Previously, the action frames to group address was not encrypted. But
[1] "Table 8-38 Category values" indicates "Mesh" and "Multihop" category
action frames should be encrypted (Group addressed privacy == yes). And the
encyption key should be MGTK ([1] 10.13 Group addressed robust management frame
procedures). So this patch modifies the code to make it suitable for spec.
[1] IEEE Std 802.11-2012
Signed-off-by: Masashi Honma <masashi.honma@xxxxxxxxx>
---
include/linux/ieee80211.h | 32 ++++++++++++++++++++++++++++++++
net/mac80211/rx.c | 7 ++++++-
net/mac80211/tx.c | 6 +++++-
3 files changed, 43 insertions(+), 2 deletions(-)
diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index b118744..7c0771a 100644
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -19,6 +19,7 @@
#include <linux/types.h>
#include <linux/if_ether.h>
+#include <linux/etherdevice.h>
#include <asm/byteorder.h>
#include <asm/unaligned.h>
@@ -2487,6 +2488,37 @@ static inline bool ieee80211_is_public_action(struct ieee80211_hdr *hdr,
}
/**
+ * _ieee80211_is_group_privacy_action - check if frame is a group addressed
+ * privacy action frame
+ * @hdr: the frame
+ */
+static inline bool _ieee80211_is_group_privacy_action(struct ieee80211_hdr *hdr)
+{
+ struct ieee80211_mgmt *mgmt;
+
+ if (!ieee80211_is_action(hdr->frame_control) ||
+ !is_multicast_ether_addr(hdr->addr1))
+ return false;
+
+ mgmt = (struct ieee80211_mgmt *)hdr;
+
+ return mgmt->u.action.category == WLAN_CATEGORY_MESH_ACTION ||
+ mgmt->u.action.category == WLAN_CATEGORY_MULTIHOP_ACTION;
+}
+
+/**
+ * ieee80211_is_group_privacy_action - check if frame is a group addressed
+ * privacy action frame
+ * @skb: the skb containing the frame, length will be checked
+ */
+static inline bool ieee80211_is_group_privacy_action(struct sk_buff *skb)
+{
+ if (skb->len < IEEE80211_MIN_ACTION_SIZE)
+ return false;
+ return _ieee80211_is_group_privacy_action((void *)skb->data);
+}
+
+/**
* ieee80211_tu_to_usec - convert time units (TU) to microseconds
* @tu: the TUs
*/
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 5e65e83..2300c0f 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1624,8 +1624,13 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
if (mmie_keyidx < NUM_DEFAULT_KEYS ||
mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
return RX_DROP_MONITOR; /* unexpected BIP keyidx */
- if (rx->sta)
+ if (rx->sta) {
+ if (ieee80211_is_group_privacy_action(skb) &&
+ test_sta_flag(rx->sta, WLAN_STA_MFP))
+ return RX_DROP_MONITOR;
+
rx->key = rcu_dereference(rx->sta->gtk[mmie_keyidx]);
+ }
if (!rx->key)
rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
} else if (!ieee80211_has_protected(fc)) {
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 2030443..e194df6 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -590,6 +590,9 @@ ieee80211_tx_h_select_key(struct ieee80211_tx_data *tx)
else if (tx->sta &&
(key = rcu_dereference(tx->sta->ptk[tx->sta->ptk_idx])))
tx->key = key;
+ else if (ieee80211_is_group_privacy_action(tx->skb) &&
+ (key = rcu_dereference(tx->sdata->default_multicast_key)))
+ tx->key = key;
else if (ieee80211_is_mgmt(hdr->frame_control) &&
is_multicast_ether_addr(hdr->addr1) &&
ieee80211_is_robust_mgmt_frame(tx->skb) &&
@@ -622,7 +625,8 @@ ieee80211_tx_h_select_key(struct ieee80211_tx_data *tx)
case WLAN_CIPHER_SUITE_GCMP_256:
if (!ieee80211_is_data_present(hdr->frame_control) &&
!ieee80211_use_mfp(hdr->frame_control, tx->sta,
- tx->skb))
+ tx->skb) &&
+ !ieee80211_is_group_privacy_action(tx->skb))
tx->key = NULL;
else
skip_hw = (tx->key->conf.flags &
--
2.5.0
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