mac80211: add generic cipher scheme support

This adds generic cipher scheme support to mac80211, such schemes
are fully under control by the driver. On hw registration drivers
may specify additional HW ciphers with a scheme how these ciphers
have to be handled by mac80211 TX/RR. A cipher scheme specifies a
cipher suite value, a size of the security header to be added to
or stripped from frames and how the PN is to be verified on RX.
Signed-off-by: Max Stepanov <Max.Stepanov@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/mac80211.h

@@ -1228,6 +1228,36 @@ struct ieee80211_key_conf {
 	u8 key[0];
 };
 
+/**
+ * struct ieee80211_cipher_scheme - cipher scheme
+ *
+ * This structure contains a cipher scheme information defining
+ * the secure packet crypto handling.
+ *
+ * @cipher: a cipher suite selector
+ * @iftype: a cipher iftype bit mask indicating an allowed cipher usage
+ * @hdr_len: a length of a security header used the cipher
+ * @pn_len: a length of a packet number in the security header
+ * @pn_off: an offset of pn from the beginning of the security header
+ * @key_idx_off: an offset of key index byte in the security header
+ * @key_idx_mask: a bit mask of key_idx bits
+ * @key_idx_shift: a bit shift needed to get key_idx
+ *     key_idx value calculation:
+ *      (sec_header_base[key_idx_off] & key_idx_mask) >> key_idx_shift
+ * @mic_len: a mic length in bytes
+ */
+struct ieee80211_cipher_scheme {
+	u32 cipher;
+	u16 iftype;
+	u8 hdr_len;
+	u8 pn_len;
+	u8 pn_off;
+	u8 key_idx_off;
+	u8 key_idx_mask;
+	u8 key_idx_shift;
+	u8 mic_len;
+};
+
 /**
  * enum set_key_cmd - key command
  *
@@ -1636,6 +1666,10 @@ enum ieee80211_hw_flags {
  * @uapsd_max_sp_len: maximum number of total buffered frames the WMM AP may
  *	deliver to a WMM STA during any Service Period triggered by the WMM STA.
  *	Use IEEE80211_WMM_IE_STA_QOSINFO_SP_* for correct values.
+ *
+ * @n_cipher_schemes: a size of an array of cipher schemes definitions.
+ * @cipher_schemes: a pointer to an array of cipher scheme definitions
+ *	supported by HW.
  */
 struct ieee80211_hw {
 	struct ieee80211_conf conf;
@@ -1663,6 +1697,8 @@ struct ieee80211_hw {
 	netdev_features_t netdev_features;
 	u8 uapsd_queues;
 	u8 uapsd_max_sp_len;
+	u8 n_cipher_schemes;
+	const struct ieee80211_cipher_scheme *cipher_schemes;
 };
 
 /**

net/mac80211/cfg.c

@@ -133,7 +133,9 @@ static int ieee80211_add_key(struct wiphy *wiphy, struct net_device *dev,
 			     struct key_params *params)
 {
 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+	struct ieee80211_local *local = sdata->local;
 	struct sta_info *sta = NULL;
+	const struct ieee80211_cipher_scheme *cs = NULL;
 	struct ieee80211_key *key;
 	int err;
 
@@ -145,22 +147,28 @@ static int ieee80211_add_key(struct wiphy *wiphy, struct net_device *dev,
 	case WLAN_CIPHER_SUITE_WEP40:
 	case WLAN_CIPHER_SUITE_TKIP:
 	case WLAN_CIPHER_SUITE_WEP104:
-		if (IS_ERR(sdata->local->wep_tx_tfm))
+		if (IS_ERR(local->wep_tx_tfm))
 			return -EINVAL;
 		break;
+	case WLAN_CIPHER_SUITE_CCMP:
+	case WLAN_CIPHER_SUITE_AES_CMAC:
+	case WLAN_CIPHER_SUITE_GCMP:
+		break;
 	default:
+		cs = ieee80211_cs_get(local, params->cipher, sdata->vif.type);
 		break;
 	}
 
 	key = ieee80211_key_alloc(params->cipher, key_idx, params->key_len,
-				  params->key, params->seq_len, params->seq);
+				  params->key, params->seq_len, params->seq,
+				  cs);
 	if (IS_ERR(key))
 		return PTR_ERR(key);
 
 	if (pairwise)
 		key->conf.flags |= IEEE80211_KEY_FLAG_PAIRWISE;
 
-	mutex_lock(&sdata->local->sta_mtx);
+	mutex_lock(&local->sta_mtx);
 
 	if (mac_addr) {
 		if (ieee80211_vif_is_mesh(&sdata->vif))
@@ -216,10 +224,13 @@ static int ieee80211_add_key(struct wiphy *wiphy, struct net_device *dev,
 		break;
 	}
 
+	if (sta)
+		sta->cipher_scheme = cs;
+
 	err = ieee80211_key_link(key, sdata, sta);
 
  out_unlock:
-	mutex_unlock(&sdata->local->sta_mtx);
+	mutex_unlock(&local->sta_mtx);
 
 	return err;
 }
@@ -244,7 +255,7 @@ static int ieee80211_del_key(struct wiphy *wiphy, struct net_device *dev,
 			goto out_unlock;
 
 		if (pairwise)
-			key = key_mtx_dereference(local, sta->ptk);
+			key = key_mtx_dereference(local, sta->ptk[key_idx]);
 		else
 			key = key_mtx_dereference(local, sta->gtk[key_idx]);
 	} else
@@ -291,7 +302,7 @@ static int ieee80211_get_key(struct wiphy *wiphy, struct net_device *dev,
 			goto out;
 
 		if (pairwise)
-			key = rcu_dereference(sta->ptk);
+			key = rcu_dereference(sta->ptk[key_idx]);
 		else if (key_idx < NUM_DEFAULT_KEYS)
 			key = rcu_dereference(sta->gtk[key_idx]);
 	} else
@@ -968,11 +979,19 @@ static int ieee80211_start_ap(struct wiphy *wiphy, struct net_device *dev,
 	 */
 	sdata->control_port_protocol = params->crypto.control_port_ethertype;
 	sdata->control_port_no_encrypt = params->crypto.control_port_no_encrypt;
+	sdata->encrypt_headroom = ieee80211_cs_headroom(sdata->local,
+							&params->crypto,
+							sdata->vif.type);
+
 	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) {
 		vlan->control_port_protocol =
 			params->crypto.control_port_ethertype;
 		vlan->control_port_no_encrypt =
 			params->crypto.control_port_no_encrypt;
+		vlan->encrypt_headroom =
+			ieee80211_cs_headroom(sdata->local,
+					      &params->crypto,
+					      vlan->vif.type);
 	}
 
 	sdata->vif.bss_conf.beacon_int = params->beacon_interval;

net/mac80211/ieee80211_i.h

@@ -728,6 +728,7 @@ struct ieee80211_sub_if_data {
 	u16 sequence_number;
 	__be16 control_port_protocol;
 	bool control_port_no_encrypt;
+	int encrypt_headroom;
 
 	struct ieee80211_tx_queue_params tx_conf[IEEE80211_NUM_ACS];
 
@@ -1749,6 +1750,15 @@ void ieee80211_dfs_radar_detected_work(struct work_struct *work);
 int ieee80211_send_action_csa(struct ieee80211_sub_if_data *sdata,
 			      struct cfg80211_csa_settings *csa_settings);
 
+bool ieee80211_cs_valid(const struct ieee80211_cipher_scheme *cs);
+bool ieee80211_cs_list_valid(const struct ieee80211_cipher_scheme *cs, int n);
+const struct ieee80211_cipher_scheme *
+ieee80211_cs_get(struct ieee80211_local *local, u32 cipher,
+		 enum nl80211_iftype iftype);
+int ieee80211_cs_headroom(struct ieee80211_local *local,
+			  struct cfg80211_crypto_settings *crypto,
+			  enum nl80211_iftype iftype);
+
 #ifdef CONFIG_MAC80211_NOINLINE
 #define debug_noinline noinline
 #else

net/mac80211/iface.c

@@ -401,6 +401,8 @@ int ieee80211_add_virtual_monitor(struct ieee80211_local *local)
 	snprintf(sdata->name, IFNAMSIZ, "%s-monitor",
 		 wiphy_name(local->hw.wiphy));
 
+	sdata->encrypt_headroom = IEEE80211_ENCRYPT_HEADROOM;
+
 	ieee80211_set_default_queues(sdata);
 
 	ret = drv_add_interface(local, sdata);
@@ -1273,6 +1275,7 @@ static void ieee80211_setup_sdata(struct ieee80211_sub_if_data *sdata,
 
 	sdata->control_port_protocol = cpu_to_be16(ETH_P_PAE);
 	sdata->control_port_no_encrypt = false;
+	sdata->encrypt_headroom = IEEE80211_ENCRYPT_HEADROOM;
 
 	sdata->noack_map = 0;
 
@@ -1689,6 +1692,8 @@ int ieee80211_if_add(struct ieee80211_local *local, const char *name,
 	sdata->ap_power_level = IEEE80211_UNSET_POWER_LEVEL;
 	sdata->user_power_level = local->user_power_level;
 
+	sdata->encrypt_headroom = IEEE80211_ENCRYPT_HEADROOM;
+
 	/* setup type-dependent data */
 	ieee80211_setup_sdata(sdata, type);
 

net/mac80211/key.c

@@ -267,22 +267,22 @@ static void ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
 	if (new)
 		list_add_tail(&new->list, &sdata->key_list);
 
-	if (sta && pairwise) {
-		rcu_assign_pointer(sta->ptk, new);
-	} else if (sta) {
-		if (old)
-			idx = old->conf.keyidx;
-		else
-			idx = new->conf.keyidx;
-		rcu_assign_pointer(sta->gtk[idx], new);
-	} else {
-		WARN_ON(new && old && new->conf.keyidx != old->conf.keyidx);
+	WARN_ON(new && old && new->conf.keyidx != old->conf.keyidx);
 
-		if (old)
-			idx = old->conf.keyidx;
-		else
-			idx = new->conf.keyidx;
+	if (old)
+		idx = old->conf.keyidx;
+	else
+		idx = new->conf.keyidx;
 
+	if (sta) {
+		if (pairwise) {
+			rcu_assign_pointer(sta->ptk[idx], new);
+			sta->ptk_idx = idx;
+		} else {
+			rcu_assign_pointer(sta->gtk[idx], new);
+			sta->gtk_idx = idx;
+		}
+	} else {
 		defunikey = old &&
 			old == key_mtx_dereference(sdata->local,
 						sdata->default_unicast_key);
@@ -316,9 +316,11 @@ static void ieee80211_key_replace(struct ieee80211_sub_if_data *sdata,
 		list_del(&old->list);
 }
 
-struct ieee80211_key *ieee80211_key_alloc(u32 cipher, int idx, size_t key_len,
-					  const u8 *key_data,
-					  size_t seq_len, const u8 *seq)
+struct ieee80211_key *
+ieee80211_key_alloc(u32 cipher, int idx, size_t key_len,
+		    const u8 *key_data,
+		    size_t seq_len, const u8 *seq,
+		    const struct ieee80211_cipher_scheme *cs)
 {
 	struct ieee80211_key *key;
 	int i, j, err;
@@ -397,6 +399,18 @@ struct ieee80211_key *ieee80211_key_alloc(u32 cipher, int idx, size_t key_len,
 			return ERR_PTR(err);
 		}
 		break;
+	default:
+		if (cs) {
+			size_t len = (seq_len > MAX_PN_LEN) ?
+						MAX_PN_LEN : seq_len;
+
+			key->conf.iv_len = cs->hdr_len;
+			key->conf.icv_len = cs->mic_len;
+			for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++)
+				for (j = 0; j < len; j++)
+					key->u.gen.rx_pn[i][j] =
+							seq[len - j - 1];
+		}
 	}
 	memcpy(key->conf.key, key_data, key_len);
 	INIT_LIST_HEAD(&key->list);
@@ -479,7 +493,7 @@ int ieee80211_key_link(struct ieee80211_key *key,
 	mutex_lock(&sdata->local->key_mtx);
 
 	if (sta && pairwise)
-		old_key = key_mtx_dereference(sdata->local, sta->ptk);
+		old_key = key_mtx_dereference(sdata->local, sta->ptk[idx]);
 	else if (sta)
 		old_key = key_mtx_dereference(sdata->local, sta->gtk[idx]);
 	else
@@ -629,8 +643,10 @@ void ieee80211_free_sta_keys(struct ieee80211_local *local,
 		list_add(&key->list, &keys);
 	}
 
-	key = key_mtx_dereference(local, sta->ptk);
-	if (key) {
+	for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
+		key = key_mtx_dereference(local, sta->ptk[i]);
+		if (!key)
+			continue;
 		ieee80211_key_replace(key->sdata, key->sta,
 				key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
 				key, NULL);
@@ -881,7 +897,7 @@ ieee80211_gtk_rekey_add(struct ieee80211_vif *vif,
 
 	key = ieee80211_key_alloc(keyconf->cipher, keyconf->keyidx,
 				  keyconf->keylen, keyconf->key,
-				  0, NULL);
+				  0, NULL, NULL);
 	if (IS_ERR(key))
 		return ERR_CAST(key);
 

net/mac80211/key.h

@@ -18,6 +18,7 @@
 
 #define NUM_DEFAULT_KEYS 4
 #define NUM_DEFAULT_MGMT_KEYS 2
+#define MAX_PN_LEN 16
 
 struct ieee80211_local;
 struct ieee80211_sub_if_data;
@@ -93,6 +94,10 @@ struct ieee80211_key {
 			u32 replays; /* dot11RSNAStatsCMACReplays */
 			u32 icverrors; /* dot11RSNAStatsCMACICVErrors */
 		} aes_cmac;
+		struct {
+			/* generic cipher scheme */
+			u8 rx_pn[IEEE80211_NUM_TIDS + 1][MAX_PN_LEN];
+		} gen;
 	} u;
 
 	/* number of times this key has been used */
@@ -113,9 +118,11 @@ struct ieee80211_key {
 	struct ieee80211_key_conf conf;
 };
 
-struct ieee80211_key *ieee80211_key_alloc(u32 cipher, int idx, size_t key_len,
-					  const u8 *key_data,
-					  size_t seq_len, const u8 *seq);
+struct ieee80211_key *
+ieee80211_key_alloc(u32 cipher, int idx, size_t key_len,
+		    const u8 *key_data,
+		    size_t seq_len, const u8 *seq,
+		    const struct ieee80211_cipher_scheme *cs);
 /*
  * Insert a key into data structures (sdata, sta if necessary)
  * to make it used, free old key. On failure, also free the new key.

net/mac80211/main.c

@@ -651,15 +651,14 @@ struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
 }
 EXPORT_SYMBOL(ieee80211_alloc_hw);
 
-int ieee80211_register_hw(struct ieee80211_hw *hw)
+static int ieee80211_init_cipher_suites(struct ieee80211_local *local)
 {
-	struct ieee80211_local *local = hw_to_local(hw);
-	int result, i;
-	enum ieee80211_band band;
-	int channels, max_bitrates;
-	bool supp_ht, supp_vht;
-	netdev_features_t feature_whitelist;
-	struct cfg80211_chan_def dflt_chandef = {};
+	bool have_wep = !(IS_ERR(local->wep_tx_tfm) ||
+			  IS_ERR(local->wep_rx_tfm));
+	bool have_mfp = local->hw.flags & IEEE80211_HW_MFP_CAPABLE;
+	const struct ieee80211_cipher_scheme *cs = local->hw.cipher_schemes;
+	int n_suites = 0, r = 0, w = 0;
+	u32 *suites;
 	static const u32 cipher_suites[] = {
 		/* keep WEP first, it may be removed below */
 		WLAN_CIPHER_SUITE_WEP40,
@@ -671,6 +670,93 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
 		WLAN_CIPHER_SUITE_AES_CMAC
 	};
 
+	/* Driver specifies the ciphers, we have nothing to do... */
+	if (local->hw.wiphy->cipher_suites && have_wep)
+		return 0;
+
+	/* Set up cipher suites if driver relies on mac80211 cipher defs */
+	if (!local->hw.wiphy->cipher_suites && !cs) {
+		local->hw.wiphy->cipher_suites = cipher_suites;
+		local->hw.wiphy->n_cipher_suites = ARRAY_SIZE(cipher_suites);
+
+		if (!have_mfp)
+			local->hw.wiphy->n_cipher_suites--;
+
+		if (!have_wep) {
+			local->hw.wiphy->cipher_suites += 2;
+			local->hw.wiphy->n_cipher_suites -= 2;
+		}
+
+		return 0;
+	}
+
+	if (!local->hw.wiphy->cipher_suites) {
+		/*
+		 * Driver specifies cipher schemes only
+		 * We start counting ciphers defined by schemes, TKIP and CCMP
+		 */
+		n_suites = local->hw.n_cipher_schemes + 2;
+
+		/* check if we have WEP40 and WEP104 */
+		if (have_wep)
+			n_suites += 2;
+
+		/* check if we have AES_CMAC */
+		if (have_mfp)
+			n_suites++;
+
+		suites = kmalloc(sizeof(u32) * n_suites, GFP_KERNEL);
+		if (!suites)
+			return -ENOMEM;
+
+		suites[w++] = WLAN_CIPHER_SUITE_CCMP;
+		suites[w++] = WLAN_CIPHER_SUITE_TKIP;
+
+		if (have_wep) {
+			suites[w++] = WLAN_CIPHER_SUITE_WEP40;
+			suites[w++] = WLAN_CIPHER_SUITE_WEP104;
+		}
+
+		if (have_mfp)
+			suites[w++] = WLAN_CIPHER_SUITE_AES_CMAC;
+
+		for (r = 0; r < local->hw.n_cipher_schemes; r++)
+			suites[w++] = cs[r].cipher;
+	} else {
+		/* Driver provides cipher suites, but we need to exclude WEP */
+		suites = kmemdup(local->hw.wiphy->cipher_suites,
+				 sizeof(u32) * local->hw.wiphy->n_cipher_suites,
+				 GFP_KERNEL);
+		if (!suites)
+			return -ENOMEM;
+
+		for (r = 0; r < local->hw.wiphy->n_cipher_suites; r++) {
+			u32 suite = local->hw.wiphy->cipher_suites[r];
+
+			if (suite == WLAN_CIPHER_SUITE_WEP40 ||
+			    suite == WLAN_CIPHER_SUITE_WEP104)
+				continue;
+			suites[w++] = suite;
+		}
+	}
+
+	local->hw.wiphy->cipher_suites = suites;
+	local->hw.wiphy->n_cipher_suites = w;
+	local->wiphy_ciphers_allocated = true;
+
+	return 0;
+}
+
+int ieee80211_register_hw(struct ieee80211_hw *hw)
+{
+	struct ieee80211_local *local = hw_to_local(hw);
+	int result, i;
+	enum ieee80211_band band;
+	int channels, max_bitrates;
+	bool supp_ht, supp_vht;
+	netdev_features_t feature_whitelist;
+	struct cfg80211_chan_def dflt_chandef = {};
+
 	if (hw->flags & IEEE80211_HW_QUEUE_CONTROL &&
 	    (local->hw.offchannel_tx_hw_queue == IEEE80211_INVAL_HW_QUEUE ||
 	     local->hw.offchannel_tx_hw_queue >= local->hw.queues))
@@ -851,43 +937,12 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
 	if (local->hw.wiphy->max_scan_ie_len)
 		local->hw.wiphy->max_scan_ie_len -= local->scan_ies_len;
 
-	/* Set up cipher suites unless driver already did */
-	if (!local->hw.wiphy->cipher_suites) {
-		local->hw.wiphy->cipher_suites = cipher_suites;
-		local->hw.wiphy->n_cipher_suites = ARRAY_SIZE(cipher_suites);
-		if (!(local->hw.flags & IEEE80211_HW_MFP_CAPABLE))
-			local->hw.wiphy->n_cipher_suites--;
-	}
-	if (IS_ERR(local->wep_tx_tfm) || IS_ERR(local->wep_rx_tfm)) {
-		if (local->hw.wiphy->cipher_suites == cipher_suites) {
-			local->hw.wiphy->cipher_suites += 2;
-			local->hw.wiphy->n_cipher_suites -= 2;
-		} else {
-			u32 *suites;
-			int r, w = 0;
-
-			/* Filter out WEP */
-
-			suites = kmemdup(
-				local->hw.wiphy->cipher_suites,
-				sizeof(u32) * local->hw.wiphy->n_cipher_suites,
-				GFP_KERNEL);
-			if (!suites) {
-				result = -ENOMEM;
-				goto fail_wiphy_register;
-			}
-			for (r = 0; r < local->hw.wiphy->n_cipher_suites; r++) {
-				u32 suite = local->hw.wiphy->cipher_suites[r];
-				if (suite == WLAN_CIPHER_SUITE_WEP40 ||
-				    suite == WLAN_CIPHER_SUITE_WEP104)
-					continue;
-				suites[w++] = suite;
-			}
-			local->hw.wiphy->cipher_suites = suites;
-			local->hw.wiphy->n_cipher_suites = w;
-			local->wiphy_ciphers_allocated = true;
-		}
-	}
+	WARN_ON(!ieee80211_cs_list_valid(local->hw.cipher_schemes,
+					 local->hw.n_cipher_schemes));
+
+	result = ieee80211_init_cipher_suites(local);
+	if (result < 0)
+		goto fail_wiphy_register;
 
 	if (!local->ops->remain_on_channel)
 		local->hw.wiphy->max_remain_on_channel_duration = 5000;

net/mac80211/mesh_hwmp.c

@@ -254,13 +254,13 @@ int mesh_path_error_tx(struct ieee80211_sub_if_data *sdata,
 		return -EAGAIN;
 
 	skb = dev_alloc_skb(local->tx_headroom +
-			    IEEE80211_ENCRYPT_HEADROOM +
+			    sdata->encrypt_headroom +
 			    IEEE80211_ENCRYPT_TAILROOM +
 			    hdr_len +
 			    2 + 15 /* PERR IE */);
 	if (!skb)
 		return -1;
-	skb_reserve(skb, local->tx_headroom + IEEE80211_ENCRYPT_HEADROOM);
+	skb_reserve(skb, local->tx_headroom + sdata->encrypt_headroom);
 	mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
 	memset(mgmt, 0, hdr_len);
 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |

net/mac80211/mlme.c

@@ -1747,6 +1747,8 @@ static void ieee80211_set_disassoc(struct ieee80211_sub_if_data *sdata,
 
 	ifmgd->flags = 0;
 	ieee80211_vif_release_channel(sdata);
+
+	sdata->encrypt_headroom = IEEE80211_ENCRYPT_HEADROOM;
 }
 
 void ieee80211_sta_rx_notify(struct ieee80211_sub_if_data *sdata,
@@ -4191,6 +4193,8 @@ int ieee80211_mgd_assoc(struct ieee80211_sub_if_data *sdata,
 
 	sdata->control_port_protocol = req->crypto.control_port_ethertype;
 	sdata->control_port_no_encrypt = req->crypto.control_port_no_encrypt;
+	sdata->encrypt_headroom = ieee80211_cs_headroom(local, &req->crypto,
+							sdata->vif.type);
 
 	/* kick off associate process */
 

net/mac80211/rx.c

@@ -638,6 +638,27 @@ static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
 	return le16_to_cpu(mmie->key_id);
 }
 
+static int iwl80211_get_cs_keyid(const struct ieee80211_cipher_scheme *cs,
+				 struct sk_buff *skb)
+{
+	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
+	__le16 fc;
+	int hdrlen;
+	u8 keyid;
+
+	fc = hdr->frame_control;
+	hdrlen = ieee80211_hdrlen(fc);
+
+	if (skb->len < hdrlen + cs->hdr_len)
+		return -EINVAL;
+
+	skb_copy_bits(skb, hdrlen + cs->key_idx_off, &keyid, 1);
+	keyid &= cs->key_idx_mask;
+	keyid >>= cs->key_idx_shift;
+
+	return keyid;
+}
+
 static ieee80211_rx_result ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
 {
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
@@ -1360,6 +1381,7 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
 	struct ieee80211_key *sta_ptk = NULL;
 	int mmie_keyidx = -1;
 	__le16 fc;
+	const struct ieee80211_cipher_scheme *cs = NULL;
 
 	/*
 	 * Key selection 101
@@ -1397,11 +1419,19 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
 
 	/* start without a key */
 	rx->key = NULL;
+	fc = hdr->frame_control;
 
-	if (rx->sta)
-		sta_ptk = rcu_dereference(rx->sta->ptk);
+	if (rx->sta) {
+		int keyid = rx->sta->ptk_idx;
 
-	fc = hdr->frame_control;
+		if (ieee80211_has_protected(fc) && rx->sta->cipher_scheme) {
+			cs = rx->sta->cipher_scheme;
+			keyid = iwl80211_get_cs_keyid(cs, rx->skb);
+			if (unlikely(keyid < 0))
+				return RX_DROP_UNUSABLE;
+		}
+		sta_ptk = rcu_dereference(rx->sta->ptk[keyid]);
+	}
 
 	if (!ieee80211_has_protected(fc))
 		mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
@@ -1463,6 +1493,7 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
 		return RX_CONTINUE;
 	} else {
 		u8 keyid;
+
 		/*
 		 * The device doesn't give us the IV so we won't be
 		 * able to look up the key. That's ok though, we
@@ -1478,15 +1509,21 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
 
 		hdrlen = ieee80211_hdrlen(fc);
 
-		if (rx->skb->len < 8 + hdrlen)
-			return RX_DROP_UNUSABLE; /* TODO: count this? */
+		if (cs) {
+			keyidx = iwl80211_get_cs_keyid(cs, rx->skb);
 
-		/*
-		 * no need to call ieee80211_wep_get_keyidx,
-		 * it verifies a bunch of things we've done already
-		 */
-		skb_copy_bits(rx->skb, hdrlen + 3, &keyid, 1);
-		keyidx = keyid >> 6;
+			if (unlikely(keyidx < 0))
+				return RX_DROP_UNUSABLE;
+		} else {
+			if (rx->skb->len < 8 + hdrlen)
+				return RX_DROP_UNUSABLE; /* TODO: count this? */
+			/*
+			 * no need to call ieee80211_wep_get_keyidx,
+			 * it verifies a bunch of things we've done already
+			 */
+			skb_copy_bits(rx->skb, hdrlen + 3, &keyid, 1);
+			keyidx = keyid >> 6;
+		}
 
 		/* check per-station GTK first, if multicast packet */
 		if (is_multicast_ether_addr(hdr->addr1) && rx->sta)
@@ -1534,11 +1571,7 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
 		result = ieee80211_crypto_aes_cmac_decrypt(rx);
 		break;
 	default:
-		/*
-		 * We can reach here only with HW-only algorithms
-		 * but why didn't it decrypt the frame?!
-		 */
-		return RX_DROP_UNUSABLE;
+		result = ieee80211_crypto_hw_decrypt(rx);
 	}
 
 	/* the hdr variable is invalid after the decrypt handlers */

net/mac80211/sta_info.h

@@ -231,8 +231,10 @@ struct sta_ampdu_mlme {
  * @hnext: hash table linked list pointer
  * @local: pointer to the global information
  * @sdata: virtual interface this station belongs to
- * @ptk: peer key negotiated with this station, if any
+ * @ptk: peer keys negotiated with this station, if any
+ * @ptk_idx: last installed peer key index
  * @gtk: group keys negotiated with this station, if any
+ * @gtk_idx: last installed group key index
  * @rate_ctrl: rate control algorithm reference
  * @rate_ctrl_priv: rate control private per-STA pointer
  * @last_tx_rate: rate used for last transmit, to report to userspace as
@@ -303,6 +305,7 @@ struct sta_ampdu_mlme {
  * @chain_signal_avg: signal average (per chain)
  * @known_smps_mode: the smps_mode the client thinks we are in. Relevant for
  *	AP only.
+ * @cipher_scheme: optional cipher scheme for this station
  */
 struct sta_info {
 	/* General information, mostly static */
@@ -312,7 +315,9 @@ struct sta_info {
 	struct ieee80211_local *local;
 	struct ieee80211_sub_if_data *sdata;
 	struct ieee80211_key __rcu *gtk[NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS];
-	struct ieee80211_key __rcu *ptk;
+	struct ieee80211_key __rcu *ptk[NUM_DEFAULT_KEYS];
+	u8 gtk_idx;
+	u8 ptk_idx;
 	struct rate_control_ref *rate_ctrl;
 	void *rate_ctrl_priv;
 	spinlock_t lock;
@@ -414,6 +419,7 @@ struct sta_info {
 	unsigned int beacon_loss_count;
 
 	enum ieee80211_smps_mode known_smps_mode;
+	const struct ieee80211_cipher_scheme *cipher_scheme;
 
 	/* keep last! */
 	struct ieee80211_sta sta;

net/mac80211/tx.c

@@ -557,7 +557,8 @@ ieee80211_tx_h_select_key(struct ieee80211_tx_data *tx)
 
 	if (unlikely(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT))
 		tx->key = NULL;
-	else if (tx->sta && (key = rcu_dereference(tx->sta->ptk)))
+	else if (tx->sta &&
+		 (key = rcu_dereference(tx->sta->ptk[tx->sta->ptk_idx])))
 		tx->key = key;
 	else if (ieee80211_is_mgmt(hdr->frame_control) &&
 		 is_multicast_ether_addr(hdr->addr1) &&
@@ -840,15 +841,16 @@ static int ieee80211_fragment(struct ieee80211_tx_data *tx,
 		rem -= fraglen;
 		tmp = dev_alloc_skb(local->tx_headroom +
 				    frag_threshold +
-				    IEEE80211_ENCRYPT_HEADROOM +
+				    tx->sdata->encrypt_headroom +
 				    IEEE80211_ENCRYPT_TAILROOM);
 		if (!tmp)
 			return -ENOMEM;
 
 		__skb_queue_tail(&tx->skbs, tmp);
 
-		skb_reserve(tmp, local->tx_headroom +
-				 IEEE80211_ENCRYPT_HEADROOM);
+		skb_reserve(tmp,
+			    local->tx_headroom + tx->sdata->encrypt_headroom);
+
 		/* copy control information */
 		memcpy(tmp->cb, skb->cb, sizeof(tmp->cb));
 
@@ -1485,7 +1487,7 @@ void ieee80211_xmit(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb,
 
 	headroom = local->tx_headroom;
 	if (may_encrypt)
-		headroom += IEEE80211_ENCRYPT_HEADROOM;
+		headroom += sdata->encrypt_headroom;
 	headroom -= skb_headroom(skb);
 	headroom = max_t(int, 0, headroom);
 
@@ -2108,7 +2110,7 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
 	 */
 
 	if (head_need > 0 || skb_cloned(skb)) {
-		head_need += IEEE80211_ENCRYPT_HEADROOM;
+		head_need += sdata->encrypt_headroom;
 		head_need += local->tx_headroom;
 		head_need = max_t(int, 0, head_need);
 		if (ieee80211_skb_resize(sdata, skb, head_need, true)) {

net/mac80211/util.c

@@ -2475,3 +2475,71 @@ int ieee80211_send_action_csa(struct ieee80211_sub_if_data *sdata,
 	ieee80211_tx_skb(sdata, skb);
 	return 0;
 }
+
+bool ieee80211_cs_valid(const struct ieee80211_cipher_scheme *cs)
+{
+	return !(cs == NULL || cs->cipher == 0 ||
+		 cs->hdr_len < cs->pn_len + cs->pn_off ||
+		 cs->hdr_len <= cs->key_idx_off ||
+		 cs->key_idx_shift > 7 ||
+		 cs->key_idx_mask == 0);
+}
+
+bool ieee80211_cs_list_valid(const struct ieee80211_cipher_scheme *cs, int n)
+{
+	int i;
+
+	/* Ensure we have enough iftype bitmap space for all iftype values */
+	WARN_ON((NUM_NL80211_IFTYPES / 8 + 1) > sizeof(cs[0].iftype));
+
+	for (i = 0; i < n; i++)
+		if (!ieee80211_cs_valid(&cs[i]))
+			return false;
+
+	return true;
+}
+
+const struct ieee80211_cipher_scheme *
+ieee80211_cs_get(struct ieee80211_local *local, u32 cipher,
+		 enum nl80211_iftype iftype)
+{
+	const struct ieee80211_cipher_scheme *l = local->hw.cipher_schemes;
+	int n = local->hw.n_cipher_schemes;
+	int i;
+	const struct ieee80211_cipher_scheme *cs = NULL;
+
+	for (i = 0; i < n; i++) {
+		if (l[i].cipher == cipher) {
+			cs = &l[i];
+			break;
+		}
+	}
+
+	if (!cs || !(cs->iftype & BIT(iftype)))
+		return NULL;
+
+	return cs;
+}
+
+int ieee80211_cs_headroom(struct ieee80211_local *local,
+			  struct cfg80211_crypto_settings *crypto,
+			  enum nl80211_iftype iftype)
+{
+	const struct ieee80211_cipher_scheme *cs;
+	int headroom = IEEE80211_ENCRYPT_HEADROOM;
+	int i;
+
+	for (i = 0; i < crypto->n_ciphers_pairwise; i++) {
+		cs = ieee80211_cs_get(local, crypto->ciphers_pairwise[i],
+				      iftype);
+
+		if (cs && headroom < cs->hdr_len)
+			headroom = cs->hdr_len;
+	}
+
+	cs = ieee80211_cs_get(local, crypto->cipher_group, iftype);
+	if (cs && headroom < cs->hdr_len)
+		headroom = cs->hdr_len;
+
+	return headroom;
+}

net/mac80211/wpa.c

@@ -545,6 +545,106 @@ ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx)
 	return RX_CONTINUE;
 }
 
+static ieee80211_tx_result
+ieee80211_crypto_cs_encrypt(struct ieee80211_tx_data *tx,
+			    struct sk_buff *skb)
+{
+	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
+	struct ieee80211_key *key = tx->key;
+	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
+	const struct ieee80211_cipher_scheme *cs = key->sta->cipher_scheme;
+	int hdrlen;
+	u8 *pos;
+
+	if (info->control.hw_key &&
+	    !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) {
+		/* hwaccel has no need for preallocated head room */
+		return TX_CONTINUE;
+	}
+
+	if (unlikely(skb_headroom(skb) < cs->hdr_len &&
+		     pskb_expand_head(skb, cs->hdr_len, 0, GFP_ATOMIC)))
+		return TX_DROP;
+
+	hdrlen = ieee80211_hdrlen(hdr->frame_control);
+
+	pos = skb_push(skb, cs->hdr_len);
+	memmove(pos, pos + cs->hdr_len, hdrlen);
+	skb_set_network_header(skb, skb_network_offset(skb) + cs->hdr_len);
+
+	return TX_CONTINUE;
+}
+
+static inline int ieee80211_crypto_cs_pn_compare(u8 *pn1, u8 *pn2, int len)
+{
+	int i;
+
+	/* pn is little endian */
+	for (i = len - 1; i >= 0; i--) {
+		if (pn1[i] < pn2[i])
+			return -1;
+		else if (pn1[i] > pn2[i])
+			return 1;
+	}
+
+	return 0;
+}
+
+static ieee80211_rx_result
+ieee80211_crypto_cs_decrypt(struct ieee80211_rx_data *rx)
+{
+	struct ieee80211_key *key = rx->key;
+	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
+	const struct ieee80211_cipher_scheme *cs = NULL;
+	int hdrlen = ieee80211_hdrlen(hdr->frame_control);
+	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
+	int data_len;
+	u8 *rx_pn;
+	u8 *skb_pn;
+	u8 qos_tid;
+
+	if (!rx->sta || !rx->sta->cipher_scheme ||
+	    !(status->flag & RX_FLAG_DECRYPTED))
+		return RX_DROP_UNUSABLE;
+
+	if (!ieee80211_is_data(hdr->frame_control))
+		return RX_CONTINUE;
+
+	cs = rx->sta->cipher_scheme;
+
+	data_len = rx->skb->len - hdrlen - cs->hdr_len;
+
+	if (data_len < 0)
+		return RX_DROP_UNUSABLE;
+
+	if (ieee80211_is_data_qos(hdr->frame_control))
+		qos_tid = *ieee80211_get_qos_ctl(hdr) &
+				IEEE80211_QOS_CTL_TID_MASK;
+	else
+		qos_tid = 0;
+
+	if (skb_linearize(rx->skb))
+		return RX_DROP_UNUSABLE;
+
+	hdr = (struct ieee80211_hdr *)rx->skb->data;
+
+	rx_pn = key->u.gen.rx_pn[qos_tid];
+	skb_pn = rx->skb->data + hdrlen + cs->pn_off;
+
+	if (ieee80211_crypto_cs_pn_compare(skb_pn, rx_pn, cs->pn_len) <= 0)
+		return RX_DROP_UNUSABLE;
+
+	memcpy(rx_pn, skb_pn, cs->pn_len);
+
+	/* remove security header and MIC */
+	if (pskb_trim(rx->skb, rx->skb->len - cs->mic_len))
+		return RX_DROP_UNUSABLE;
+
+	memmove(rx->skb->data + cs->hdr_len, rx->skb->data, hdrlen);
+	skb_pull(rx->skb, cs->hdr_len);
+
+	return RX_CONTINUE;
+}
 
 static void bip_aad(struct sk_buff *skb, u8 *aad)
 {
@@ -685,6 +785,7 @@ ieee80211_crypto_hw_encrypt(struct ieee80211_tx_data *tx)
 {
 	struct sk_buff *skb;
 	struct ieee80211_tx_info *info = NULL;
+	ieee80211_tx_result res;
 
 	skb_queue_walk(&tx->skbs, skb) {
 		info  = IEEE80211_SKB_CB(skb);
@@ -692,9 +793,24 @@ ieee80211_crypto_hw_encrypt(struct ieee80211_tx_data *tx)
 		/* handle hw-only algorithm */
 		if (!info->control.hw_key)
 			return TX_DROP;
+
+		if (tx->key->sta->cipher_scheme) {
+			res = ieee80211_crypto_cs_encrypt(tx, skb);
+			if (res != TX_CONTINUE)
+				return res;
+		}
 	}
 
 	ieee80211_tx_set_protected(tx);
 
 	return TX_CONTINUE;
 }
+
+ieee80211_rx_result
+ieee80211_crypto_hw_decrypt(struct ieee80211_rx_data *rx)
+{
+	if (rx->sta->cipher_scheme)
+		return ieee80211_crypto_cs_decrypt(rx);
+
+	return RX_DROP_UNUSABLE;
+}

net/mac80211/wpa.h

@@ -34,5 +34,7 @@ ieee80211_rx_result
 ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx);
 ieee80211_tx_result
 ieee80211_crypto_hw_encrypt(struct ieee80211_tx_data *tx);
+ieee80211_rx_result
+ieee80211_crypto_hw_decrypt(struct ieee80211_rx_data *rx);
 
 #endif /* WPA_H */