wifi: mac80211: Fix AAD/Nonce computation for management frames with MLO

Per IEEE Std 802.11be-2024, 12.5.2.3.3, if the MPDU is an
individually addressed Data frame between an AP MLD and a
non-AP MLD associated with the AP MLD, then A1/A2/A3
will be MLD MAC addresses. Otherwise, Al/A2/A3 will be
over-the-air link MAC addresses.

Currently, during AAD and Nonce computation for software based
encryption/decryption cases, mac80211 directly uses the addresses it
receives in the skb frame header. However, after the first
authentication, management frame addresses for non-AP MLD stations
are translated to MLD addresses from over the air link addresses in
software. This means that the skb header could contain translated MLD
addresses, which when used as is, can lead to incorrect AAD/Nonce
computation.

In the following manner, ensure that the right set of addresses are used:

In the receive path, stash the pre-translated link addresses in
ieee80211_rx_data and use them for the AAD/Nonce computations
when required.

In the transmit path, offload the encryption for a CCMP/GCMP key
to the hwsim driver that can then ensure that encryption and hence
the AAD/Nonce computations are performed on the frame containing the
right set of addresses, i.e, MLD addresses if unicast data frame and
link addresses otherwise.

To do so, register the set key handler in hwsim driver so mac80211 is
aware that it is the driver that would take care of encrypting the
frame. Offload encryption for a CCMP/GCMP key, while keeping the
encryption for WEP/TKIP and MMIE generation for a AES_CMAC or a
AES_GMAC key still at the SW crypto in mac layer

Co-developed-by: Rohan Dutta <quic_drohan@quicinc.com>
Signed-off-by: Rohan Dutta <quic_drohan@quicinc.com>
Signed-off-by: Sai Pratyusha Magam <sai.magam@oss.qualcomm.com>
Link: https://patch.msgid.link/20260226042959.3766157-1-sai.magam@oss.qualcomm.com
[only store and apply link_addrs for unicast non-data
 rather storing always and applying for !unicast_data]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/drivers/net/wireless/virtual/mac80211_hwsim.c b/drivers/net/wireless/virtual/mac80211_hwsim.c
index d2a43eec4641ee830e924791ed01ffe4bf7afd60..d8bb348099659da1a09d50a2ffa48996d7ef5dd6 100644 (file)
--- a/drivers/net/wireless/virtual/mac80211_hwsim.c
+++ b/drivers/net/wireless/virtual/mac80211_hwsim.c
@@ -1992,6 +1992,25 @@ mac80211_hwsim_select_tx_link(struct mac80211_hwsim_data *data,
        return NULL;
 }
 
+static int mac80211_hwsim_set_key(struct ieee80211_hw *hw, enum set_key_cmd cmd,
+                                 struct ieee80211_vif *vif,
+                                 struct ieee80211_sta *sta,
+                                 struct ieee80211_key_conf *key)
+{
+       switch (key->cipher) {
+       case WLAN_CIPHER_SUITE_CCMP:
+       case WLAN_CIPHER_SUITE_CCMP_256:
+       case WLAN_CIPHER_SUITE_GCMP:
+       case WLAN_CIPHER_SUITE_GCMP_256:
+               break;
+       default:
+               return 1;
+       }
+
+       key->flags |= IEEE80211_KEY_FLAG_RESERVE_TAILROOM;
+       return 0;
+}
+
 static void mac80211_hwsim_tx(struct ieee80211_hw *hw,
                              struct ieee80211_tx_control *control,
                              struct sk_buff *skb)
@@ -2002,7 +2021,7 @@ static void mac80211_hwsim_tx(struct ieee80211_hw *hw,
        struct ieee80211_chanctx_conf *chanctx_conf;
        struct ieee80211_channel *channel;
        struct ieee80211_vif *vif = txi->control.vif;
-       bool ack;
+       bool ack, unicast_data;
        enum nl80211_chan_width confbw = NL80211_CHAN_WIDTH_20_NOHT;
        u32 _portid, i;
 
@@ -2012,6 +2031,16 @@ static void mac80211_hwsim_tx(struct ieee80211_hw *hw,
                return;
        }
 
+       unicast_data = is_unicast_ether_addr(hdr->addr1) &&
+                      ieee80211_is_data(hdr->frame_control);
+
+       if (unicast_data && ieee80211_encrypt_tx_skb(skb) < 0) {
+               ieee80211_free_txskb(hw, skb);
+               return;
+       }
+       /* re-assign hdr since skb data may have shifted after encryption */
+       hdr = (void *)skb->data;
+
        if (vif && vif->type == NL80211_IFTYPE_NAN && !data->tmp_chan) {
                /* For NAN Device simulation purposes, assume that NAN is always
                 * on channel 6 or channel 149, unless a ROC is in progress (for
@@ -2097,6 +2126,13 @@ static void mac80211_hwsim_tx(struct ieee80211_hw *hw,
                }
        }
 
+       if (!unicast_data && ieee80211_encrypt_tx_skb(skb) < 0) {
+               ieee80211_free_txskb(hw, skb);
+               return;
+       }
+       /* re-assign hdr since skb data may have shifted after encryption */
+       hdr = (void *)skb->data;
+
        if (WARN(!channel, "TX w/o channel - queue = %d\n", txi->hw_queue)) {
                ieee80211_free_txskb(hw, skb);
                return;
@@ -4245,6 +4281,7 @@ static int mac80211_hwsim_set_radar_background(struct ieee80211_hw *hw,
        .stop_nan = mac80211_hwsim_stop_nan,                    \
        .nan_change_conf = mac80211_hwsim_change_nan_config,    \
        .set_radar_background = mac80211_hwsim_set_radar_background, \
+       .set_key = mac80211_hwsim_set_key,                      \
        HWSIM_DEBUGFS_OPS
 
 #define HWSIM_NON_MLO_OPS                                      \
@@ -5684,6 +5721,7 @@ static int mac80211_hwsim_new_radio(struct genl_info *info,
                            WIPHY_FLAG_AP_UAPSD |
                            WIPHY_FLAG_SUPPORTS_5_10_MHZ |
                            WIPHY_FLAG_HAS_CHANNEL_SWITCH;
+       hw->wiphy->flags |= WIPHY_FLAG_IBSS_RSN;
        hw->wiphy->features |= NL80211_FEATURE_ACTIVE_MONITOR |
                               NL80211_FEATURE_AP_MODE_CHAN_WIDTH_CHANGE |
                               NL80211_FEATURE_STATIC_SMPS |
@@ -5702,6 +5740,12 @@ static int mac80211_hwsim_new_radio(struct genl_info *info,
                              NL80211_EXT_FEATURE_SCAN_MIN_PREQ_CONTENT);
        wiphy_ext_feature_set(hw->wiphy,
                              NL80211_EXT_FEATURE_BSS_COLOR);
+       wiphy_ext_feature_set(hw->wiphy,
+                             NL80211_EXT_FEATURE_SPP_AMSDU_SUPPORT);
+       wiphy_ext_feature_set(hw->wiphy,
+                             NL80211_EXT_FEATURE_CAN_REPLACE_PTK0);
+       wiphy_ext_feature_set(hw->wiphy,
+                             NL80211_EXT_FEATURE_EXT_KEY_ID);
 
        hw->wiphy->interface_modes = param->iftypes;
 

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 89027e94ba5ceeea8be4d3bb440c18038e5f6ded..9f8251fb9832d9c5480c25c532443902ce16ab44 100644 (file)
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -7966,4 +7966,11 @@ int ieee80211_emulate_switch_vif_chanctx(struct ieee80211_hw *hw,
  * Return: %true iff the vif is a NAN interface and NAN is started
  */
 bool ieee80211_vif_nan_started(struct ieee80211_vif *vif);
+
+/**
+ * ieee80211_encrypt_tx_skb - Encrypt the transmit skb
+ * @skb: the skb
+ * Return: 0 if success and non-zero on error
+ */
+int ieee80211_encrypt_tx_skb(struct sk_buff *skb);
 #endif /* MAC80211_H */

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index e60b814dd89e03a5b6dd7537375b49246e5b78a5..a4babf7624e5de4a56843571aac0e7b571a8d4a3 100644 (file)
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -256,6 +256,8 @@ struct ieee80211_rx_data {
                        u8 pn[IEEE80211_CCMP_PN_LEN];
                } ccm_gcm;
        };
+
+       u8 link_addrs[3 * ETH_ALEN];
 };
 
 struct ieee80211_csa_settings {

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 11d6c56c9d7eeb6571dd90eaaf157584b5f5d511..6c4b549444c6e98da21f88c42e07d97df1a11e83 100644 (file)
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -5127,6 +5127,11 @@ static bool ieee80211_prepare_and_rx_handle(struct ieee80211_rx_data *rx,
                hdr = (struct ieee80211_hdr *)rx->skb->data;
        }
 
+       /* Store a copy of the pre-translated link addresses for SW crypto */
+       if (unlikely(is_unicast_ether_addr(hdr->addr1) &&
+                    !ieee80211_is_data(hdr->frame_control)))
+               memcpy(rx->link_addrs, &hdr->addrs, 3 * ETH_ALEN);
+
        if (unlikely(rx->sta && rx->sta->sta.mlo) &&
            is_unicast_ether_addr(hdr->addr1) &&
            !ieee80211_is_probe_resp(hdr->frame_control) &&

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 28dcdd7f0e05b6c42260261ea7c1bcf24907de9c..dd691ff549c3a0aea03c7b90e5d56a7725547074 100644 (file)
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -5315,6 +5315,38 @@ static int ieee80211_beacon_protect(struct sk_buff *skb,
        return 0;
 }
 
+int ieee80211_encrypt_tx_skb(struct sk_buff *skb)
+{
+       struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
+       struct ieee80211_sub_if_data *sdata;
+       struct sk_buff *check_skb;
+       struct ieee80211_tx_data tx;
+       ieee80211_tx_result res;
+
+       if (!info->control.hw_key)
+               return 0;
+
+       memset(&tx, 0, sizeof(tx));
+       tx.key = container_of(info->control.hw_key, struct ieee80211_key, conf);
+       /* NULL it out now so we do full SW crypto */
+       info->control.hw_key = NULL;
+       __skb_queue_head_init(&tx.skbs);
+       __skb_queue_tail(&tx.skbs, skb);
+
+       sdata = IEEE80211_DEV_TO_SUB_IF(skb->dev);
+       tx.sdata = sdata;
+       tx.local = sdata->local;
+       res = ieee80211_tx_h_encrypt(&tx);
+       check_skb = __skb_dequeue(&tx.skbs);
+       /* we may crash after this, but it'd be a bug in crypto */
+       WARN_ON(check_skb != skb);
+       if (WARN_ON_ONCE(res != TX_CONTINUE))
+               return -EINVAL;
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(ieee80211_encrypt_tx_skb);
+
 static void
 ieee80211_beacon_get_finish(struct ieee80211_hw *hw,
                            struct ieee80211_vif *vif,

diff --git a/net/mac80211/wpa.c b/net/mac80211/wpa.c
index fdf98c21d32c0bef54f66c6704b8c973ab14b52b..64a57475ce506416d47067baa775640d30721358 100644 (file)
--- a/net/mac80211/wpa.c
+++ b/net/mac80211/wpa.c
@@ -315,7 +315,8 @@ ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx)
  * Calculate AAD for CCMP/GCMP, returning qos_tid since we
  * need that in CCMP also for b_0.
  */
-static u8 ccmp_gcmp_aad(struct sk_buff *skb, u8 *aad, bool spp_amsdu)
+static u8 ccmp_gcmp_aad(struct sk_buff *skb, u8 *aad, bool spp_amsdu,
+                       bool aad_nonce_computed)
 {
        struct ieee80211_hdr *hdr = (void *)skb->data;
        __le16 mask_fc;
@@ -358,7 +359,8 @@ static u8 ccmp_gcmp_aad(struct sk_buff *skb, u8 *aad, bool spp_amsdu)
         * FC | A1 | A2 | A3 | SC | [A4] | [QC] */
        put_unaligned_be16(len_a, &aad[0]);
        put_unaligned(mask_fc, (__le16 *)&aad[2]);
-       memcpy(&aad[4], &hdr->addrs, 3 * ETH_ALEN);
+       if (!aad_nonce_computed)
+               memcpy(&aad[4], &hdr->addrs, 3 * ETH_ALEN);
 
        /* Mask Seq#, leave Frag# */
        aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
@@ -377,10 +379,10 @@ static u8 ccmp_gcmp_aad(struct sk_buff *skb, u8 *aad, bool spp_amsdu)
 }
 
 static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad,
-                               bool spp_amsdu)
+                               bool spp_amsdu, bool aad_nonce_computed)
 {
        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
-       u8 qos_tid = ccmp_gcmp_aad(skb, aad, spp_amsdu);
+       u8 qos_tid = ccmp_gcmp_aad(skb, aad, spp_amsdu, aad_nonce_computed);
 
        /* In CCM, the initial vectors (IV) used for CTR mode encryption and CBC
         * mode authentication are not allowed to collide, yet both are derived
@@ -395,7 +397,8 @@ static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad,
         * Nonce Flags: Priority (b0..b3) | Management (b4) | Reserved (b5..b7)
         */
        b_0[1] = qos_tid | (ieee80211_is_mgmt(hdr->frame_control) << 4);
-       memcpy(&b_0[2], hdr->addr2, ETH_ALEN);
+       if (!aad_nonce_computed)
+               memcpy(&b_0[2], hdr->addr2, ETH_ALEN);
        memcpy(&b_0[8], pn, IEEE80211_CCMP_PN_LEN);
 }
 
@@ -488,7 +491,8 @@ static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb,
 
        pos += IEEE80211_CCMP_HDR_LEN;
        ccmp_special_blocks(skb, pn, b_0, aad,
-                           key->conf.flags & IEEE80211_KEY_FLAG_SPP_AMSDU);
+                           key->conf.flags & IEEE80211_KEY_FLAG_SPP_AMSDU,
+                           false);
        return ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, b_0, aad, pos, len,
                                         skb_put(skb, mic_len));
 }
@@ -566,9 +570,22 @@ ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx,
                if (!(status->flag & RX_FLAG_DECRYPTED)) {
                        u8 aad[2 * AES_BLOCK_SIZE];
                        u8 b_0[AES_BLOCK_SIZE];
+                       bool aad_nonce_computed = false;
+
+                       if (is_unicast_ether_addr(hdr->addr1) &&
+                           !ieee80211_is_data(hdr->frame_control)) {
+                               /* AAD computation */
+                               memcpy(&aad[4], rx->link_addrs, 3 * ETH_ALEN);
+                               /* Nonce computation */
+                               ether_addr_copy(&b_0[2],
+                                               &rx->link_addrs[ETH_ALEN]);
+                               aad_nonce_computed = true;
+                       }
+
                        /* hardware didn't decrypt/verify MIC */
                        ccmp_special_blocks(skb, pn, b_0, aad,
-                                           key->conf.flags & IEEE80211_KEY_FLAG_SPP_AMSDU);
+                                           key->conf.flags & IEEE80211_KEY_FLAG_SPP_AMSDU,
+                                           aad_nonce_computed);
 
                        if (ieee80211_aes_ccm_decrypt(
                                    key->u.ccmp.tfm, b_0, aad,
@@ -593,14 +610,15 @@ ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx,
 }
 
 static void gcmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *j_0, u8 *aad,
-                               bool spp_amsdu)
+                               bool spp_amsdu, bool aad_nonce_computed)
 {
        struct ieee80211_hdr *hdr = (void *)skb->data;
 
-       memcpy(j_0, hdr->addr2, ETH_ALEN);
+       if (!aad_nonce_computed)
+               memcpy(j_0, hdr->addr2, ETH_ALEN);
        memcpy(&j_0[ETH_ALEN], pn, IEEE80211_GCMP_PN_LEN);
 
-       ccmp_gcmp_aad(skb, aad, spp_amsdu);
+       ccmp_gcmp_aad(skb, aad, spp_amsdu, aad_nonce_computed);
 }
 
 static inline void gcmp_pn2hdr(u8 *hdr, const u8 *pn, int key_id)
@@ -690,7 +708,8 @@ static int gcmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
 
        pos += IEEE80211_GCMP_HDR_LEN;
        gcmp_special_blocks(skb, pn, j_0, aad,
-                           key->conf.flags & IEEE80211_KEY_FLAG_SPP_AMSDU);
+                           key->conf.flags & IEEE80211_KEY_FLAG_SPP_AMSDU,
+                           false);
        return ieee80211_aes_gcm_encrypt(key->u.gcmp.tfm, j_0, aad, pos, len,
                                         skb_put(skb, IEEE80211_GCMP_MIC_LEN));
 }
@@ -763,9 +782,21 @@ ieee80211_crypto_gcmp_decrypt(struct ieee80211_rx_data *rx)
                if (!(status->flag & RX_FLAG_DECRYPTED)) {
                        u8 aad[2 * AES_BLOCK_SIZE];
                        u8 j_0[AES_BLOCK_SIZE];
+                       bool aad_nonce_computed = false;
+
+                       if (is_unicast_ether_addr(hdr->addr1) &&
+                           !ieee80211_is_data(hdr->frame_control)) {
+                               /* AAD computation */
+                               memcpy(&aad[4], rx->link_addrs, 3 * ETH_ALEN);
+                               /* Nonce computation */
+                               ether_addr_copy(&j_0[0],
+                                               &rx->link_addrs[ETH_ALEN]);
+                               aad_nonce_computed = true;
+                       }
                        /* hardware didn't decrypt/verify MIC */
                        gcmp_special_blocks(skb, pn, j_0, aad,
-                                           key->conf.flags & IEEE80211_KEY_FLAG_SPP_AMSDU);
+                                           key->conf.flags & IEEE80211_KEY_FLAG_SPP_AMSDU,
+                                           aad_nonce_computed);
 
                        if (ieee80211_aes_gcm_decrypt(
                                    key->u.gcmp.tfm, j_0, aad,