iwlwifi: mvm: add support for GCMP encryption

Newer hardware supports GCMP and GCMP 256-bit ciphers.
Add support for adding/setting GCMP key for TX mode.

In the TX command handling GCMP-256 is handled in a different
way as the key size should be up to 128-bits:
Set the key value to the key index in the key table,
and specify that this key should be taken form the key table
instead of from the TX command.

While at it - convert security control flags to an enum.

Signed-off-by: Ayala Beker <ayala.beker@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

1 files changed, 30 insertions, 9 deletions

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/tx.c b/drivers/net/wireless/intel/iwlwifi/mvm/tx.c
index 1f23ceeb2350..2373142b0f43 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/tx.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/tx.c
@@ -388,6 +388,23 @@ void iwl_mvm_set_tx_cmd_rate(struct iwl_mvm *mvm, struct iwl_tx_cmd *tx_cmd,
 	tx_cmd->rate_n_flags = cpu_to_le32((u32)rate_plcp | rate_flags);
 }
 
+static inline void iwl_mvm_set_tx_cmd_pn(struct ieee80211_tx_info *info,
+					 u8 *crypto_hdr)
+{
+	struct ieee80211_key_conf *keyconf = info->control.hw_key;
+	u64 pn;
+
+	pn = atomic64_inc_return(&keyconf->tx_pn);
+	crypto_hdr[0] = pn;
+	crypto_hdr[2] = 0;
+	crypto_hdr[3] = 0x20 | (keyconf->keyidx << 6);
+	crypto_hdr[1] = pn >> 8;
+	crypto_hdr[4] = pn >> 16;
+	crypto_hdr[5] = pn >> 24;
+	crypto_hdr[6] = pn >> 32;
+	crypto_hdr[7] = pn >> 40;
+}
+
 /*
  * Sets the fields in the Tx cmd that are crypto related
  */
@@ -405,15 +422,7 @@ static void iwl_mvm_set_tx_cmd_crypto(struct iwl_mvm *mvm,
 	case WLAN_CIPHER_SUITE_CCMP:
 	case WLAN_CIPHER_SUITE_CCMP_256:
 		iwl_mvm_set_tx_cmd_ccmp(info, tx_cmd);
-		pn = atomic64_inc_return(&keyconf->tx_pn);
-		crypto_hdr[0] = pn;
-		crypto_hdr[2] = 0;
-		crypto_hdr[3] = 0x20 | (keyconf->keyidx << 6);
-		crypto_hdr[1] = pn >> 8;
-		crypto_hdr[4] = pn >> 16;
-		crypto_hdr[5] = pn >> 24;
-		crypto_hdr[6] = pn >> 32;
-		crypto_hdr[7] = pn >> 40;
+		iwl_mvm_set_tx_cmd_pn(info, crypto_hdr);
 		break;
 
 	case WLAN_CIPHER_SUITE_TKIP:
@@ -433,6 +442,18 @@ static void iwl_mvm_set_tx_cmd_crypto(struct iwl_mvm *mvm,
 
 		memcpy(&tx_cmd->key[3], keyconf->key, keyconf->keylen);
 		break;
+	case WLAN_CIPHER_SUITE_GCMP:
+	case WLAN_CIPHER_SUITE_GCMP_256:
+		/* TODO: Taking the key from the table might introduce a race
+		 * when PTK rekeying is done, having an old packets with a PN
+		 * based on the old key but the message encrypted with a new
+		 * one.
+		 * Need to handle this.
+		 */
+		tx_cmd->sec_ctl |= TX_CMD_SEC_GCMP | TC_CMD_SEC_KEY_FROM_TABLE;
+		tx_cmd->key[0] = keyconf->hw_key_idx;
+		iwl_mvm_set_tx_cmd_pn(info, crypto_hdr);
+		break;
 	default:
 		tx_cmd->sec_ctl |= TX_CMD_SEC_EXT;
 	}