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>

1 files changed, 100 insertions, 45 deletions

diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 21d5d44444d0..bdb0b6c104b5 100644
--- a/net/mac80211/main.c
+++ b/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;