iwlwifi: mvm: don't overwrite the key indices in D3 entry

When entering D3, we need to use hardcoded key indices because the
firmware requires that.  To do so, we are overwriting the HW key index
in the keyconf structure, which makes it impossible to reuse the
indices that were used before entering D3.  Additionally, we overwrite
all the non-PTK keys with index 1, because the firmware only allows
one non-PTK key to be set.  This is bad, because when we resume, we
may try to set more than one key with index 1, which will obviously
fail.

To fix this, allow the callers to set a pre-defined index to use in
iwl_mvm_set_sta_key() instead of relying on the hw_key_idx value from
the keyconf struct (which requires overwriting it).  In normal cases,
the caller can pass STA_KEY_IDX_INVALID, which will cause a new key
offset to be chosen.  During HW_RESTART, we pass the offset that is in
use.  And during D3 entry, we pass the hardcoded indices we need to
use.

Additionally, don't clear the fw_key_table in D3 entry, so that the
flags are still set with the pre-D3 values when exiting D3.

fixes=I3165c22362483f0152d9ec1d2a987fb5529727c1

Fixes: b546dcd6b742 ("iwlwifi: mvm: don't reset key index on HW restart")
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/mvm/sta.c b/drivers/net/wireless/iwlwifi/mvm/sta.c
index 300a249..4e26008 100644
--- a/drivers/net/wireless/iwlwifi/mvm/sta.c
+++ b/drivers/net/wireless/iwlwifi/mvm/sta.c
@@ -1227,7 +1227,8 @@
 static int iwl_mvm_send_sta_key(struct iwl_mvm *mvm,
 				struct iwl_mvm_sta *mvm_sta,
 				struct ieee80211_key_conf *keyconf, bool mcast,
-				u32 tkip_iv32, u16 *tkip_p1k, u32 cmd_flags)
+				u32 tkip_iv32, u16 *tkip_p1k, u32 cmd_flags,
+				u8 key_offset)
 {
 	struct iwl_mvm_add_sta_key_cmd cmd = {};
 	__le16 key_flags;
@@ -1269,7 +1270,7 @@
 	if (mcast)
 		key_flags |= cpu_to_le16(STA_KEY_MULTICAST);
 
-	cmd.key_offset = keyconf->hw_key_idx;
+	cmd.key_offset = key_offset;
 	cmd.key_flags = key_flags;
 	cmd.sta_id = sta_id;
 
@@ -1360,6 +1361,7 @@
 				 struct ieee80211_vif *vif,
 				 struct ieee80211_sta *sta,
 				 struct ieee80211_key_conf *keyconf,
+				 u8 key_offset,
 				 bool mcast)
 {
 	struct iwl_mvm_sta *mvm_sta = iwl_mvm_sta_from_mac80211(sta);
@@ -1375,17 +1377,17 @@
 		ieee80211_get_key_rx_seq(keyconf, 0, &seq);
 		ieee80211_get_tkip_rx_p1k(keyconf, addr, seq.tkip.iv32, p1k);
 		ret = iwl_mvm_send_sta_key(mvm, mvm_sta, keyconf, mcast,
-					   seq.tkip.iv32, p1k, 0);
+					   seq.tkip.iv32, p1k, 0, key_offset);
 		break;
 	case WLAN_CIPHER_SUITE_CCMP:
 	case WLAN_CIPHER_SUITE_WEP40:
 	case WLAN_CIPHER_SUITE_WEP104:
 		ret = iwl_mvm_send_sta_key(mvm, mvm_sta, keyconf, mcast,
-					   0, NULL, 0);
+					   0, NULL, 0, key_offset);
 		break;
 	default:
 		ret = iwl_mvm_send_sta_key(mvm, mvm_sta, keyconf, mcast,
-					   0, NULL, 0);
+					   0, NULL, 0, key_offset);
 	}
 
 	return ret;
@@ -1433,7 +1435,7 @@
 			struct ieee80211_vif *vif,
 			struct ieee80211_sta *sta,
 			struct ieee80211_key_conf *keyconf,
-			bool have_key_offset)
+			u8 key_offset)
 {
 	bool mcast = !(keyconf->flags & IEEE80211_KEY_FLAG_PAIRWISE);
 	u8 sta_id;
@@ -1470,18 +1472,25 @@
 	if (WARN_ON_ONCE(iwl_mvm_sta_from_mac80211(sta)->vif != vif))
 		return -EINVAL;
 
-	if (!have_key_offset) {
-		/*
-		 * The D3 firmware hardcodes the PTK offset to 0, so we have to
-		 * configure it there. As a result, this workaround exists to
-		 * let the caller set the key offset (hw_key_idx), see d3.c.
-		 */
-		keyconf->hw_key_idx = iwl_mvm_set_fw_key_idx(mvm);
-		if (keyconf->hw_key_idx == STA_KEY_IDX_INVALID)
+	/* If the key_offset is not pre-assigned, we need to find a
+	 * new offset to use.  In normal cases, the offset is not
+	 * pre-assigned, but during HW_RESTART we want to reuse the
+	 * same indices, so we pass them when this function is called.
+	 *
+	 * In D3 entry, we need to hardcoded the indices (because the
+	 * firmware hardcodes the PTK offset to 0).  In this case, we
+	 * need to make sure we don't overwrite the hw_key_idx in the
+	 * keyconf structure, because otherwise we cannot configure
+	 * the original ones back when resuming.
+	 */
+	if (key_offset == STA_KEY_IDX_INVALID) {
+		key_offset  = iwl_mvm_set_fw_key_idx(mvm);
+		if (key_offset == STA_KEY_IDX_INVALID)
 			return -ENOSPC;
+		keyconf->hw_key_idx = key_offset;
 	}
 
-	ret = __iwl_mvm_set_sta_key(mvm, vif, sta, keyconf, mcast);
+	ret = __iwl_mvm_set_sta_key(mvm, vif, sta, keyconf, key_offset, mcast);
 	if (ret) {
 		__clear_bit(keyconf->hw_key_idx, mvm->fw_key_table);
 		goto end;
@@ -1495,7 +1504,8 @@
 	 */
 	if (keyconf->cipher == WLAN_CIPHER_SUITE_WEP40 ||
 	    keyconf->cipher == WLAN_CIPHER_SUITE_WEP104) {
-		ret = __iwl_mvm_set_sta_key(mvm, vif, sta, keyconf, !mcast);
+		ret = __iwl_mvm_set_sta_key(mvm, vif, sta, keyconf,
+					    key_offset, !mcast);
 		if (ret) {
 			__clear_bit(keyconf->hw_key_idx, mvm->fw_key_table);
 			__iwl_mvm_remove_sta_key(mvm, sta_id, keyconf, mcast);
@@ -1602,7 +1612,7 @@
 
 	mvm_sta = iwl_mvm_sta_from_mac80211(sta);
 	iwl_mvm_send_sta_key(mvm, mvm_sta, keyconf, mcast,
-			     iv32, phase1key, CMD_ASYNC);
+			     iv32, phase1key, CMD_ASYNC, keyconf->hw_key_idx);
 	rcu_read_unlock();
 }