iwlwifi: mvm: don't override the rate with the AMSDU len

The TSO code creates A-MSDUs from a single large send. Each
A-MSDU is an skb and skb->len doesn't include the number of
bytes which need to be added for the headers being added
(subframe header, TCP header, IP header, SNAP, padding).

To be able to set the right value in the Tx command, we
put the number of bytes added by those headers in
driver_data in iwl_mvm_tx_tso and use this value in
iwl_mvm_set_tx_cmd.

The problem by setting this value in driver_data is that
it overrides the ieee80211_tx_info. The bug manifested
itself when we send P2P related frames in CCK since the
rate in ieee80211_tx_info is zero-ed. This of course is
a violation of the P2P specification.

To fix this, copy the original ieee80211_tx_info to the
stack and pass it to the functions which need it.
Assign the number of bytes added by the headers to the
driver_data inside the skb itself.

Fixes: a6d5e32f ("iwlwifi: mvm: send large SKBs to the transport")
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

drivers/net/wireless/intel/iwlwifi/mvm/tx.c

@@ -105,6 +105,7 @@ void iwl_mvm_set_tx_cmd(struct iwl_mvm *mvm, struct sk_buff *skb,
 			struct iwl_tx_cmd *tx_cmd,
 			struct ieee80211_tx_info *info, u8 sta_id)
 {
+	struct ieee80211_tx_info *skb_info = IEEE80211_SKB_CB(skb);
 	struct ieee80211_hdr *hdr = (void *)skb->data;
 	__le16 fc = hdr->frame_control;
 	u32 tx_flags = le32_to_cpu(tx_cmd->tx_flags);
@@ -185,7 +186,7 @@ void iwl_mvm_set_tx_cmd(struct iwl_mvm *mvm, struct sk_buff *skb,
 	tx_cmd->tx_flags = cpu_to_le32(tx_flags);
 	/* Total # bytes to be transmitted */
 	tx_cmd->len = cpu_to_le16((u16)skb->len +
-		(uintptr_t)info->driver_data[0]);
+		(uintptr_t)skb_info->driver_data[0]);
 	tx_cmd->next_frame_len = 0;
 	tx_cmd->life_time = cpu_to_le32(TX_CMD_LIFE_TIME_INFINITE);
 	tx_cmd->sta_id = sta_id;
@@ -327,10 +328,11 @@ static void iwl_mvm_set_tx_cmd_crypto(struct iwl_mvm *mvm,
  */
 static struct iwl_device_cmd *
 iwl_mvm_set_tx_params(struct iwl_mvm *mvm, struct sk_buff *skb,
-		      int hdrlen, struct ieee80211_sta *sta, u8 sta_id)
+		      struct ieee80211_tx_info *info, int hdrlen,
+		      struct ieee80211_sta *sta, u8 sta_id)
 {
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
-	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
+	struct ieee80211_tx_info *skb_info = IEEE80211_SKB_CB(skb);
 	struct iwl_device_cmd *dev_cmd;
 	struct iwl_tx_cmd *tx_cmd;
 
@@ -350,10 +352,10 @@ iwl_mvm_set_tx_params(struct iwl_mvm *mvm, struct sk_buff *skb,
 
 	iwl_mvm_set_tx_cmd_rate(mvm, tx_cmd, info, sta, hdr->frame_control);
 
-	memset(&info->status, 0, sizeof(info->status));
-	memset(info->driver_data, 0, sizeof(info->driver_data));
+	memset(&skb_info->status, 0, sizeof(skb_info->status));
+	memset(skb_info->driver_data, 0, sizeof(skb_info->driver_data));
 
-	info->driver_data[1] = dev_cmd;
+	skb_info->driver_data[1] = dev_cmd;
 
 	return dev_cmd;
 }
@@ -361,22 +363,25 @@ iwl_mvm_set_tx_params(struct iwl_mvm *mvm, struct sk_buff *skb,
 int iwl_mvm_tx_skb_non_sta(struct iwl_mvm *mvm, struct sk_buff *skb)
 {
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
-	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
+	struct ieee80211_tx_info *skb_info = IEEE80211_SKB_CB(skb);
+	struct ieee80211_tx_info info;
 	struct iwl_device_cmd *dev_cmd;
 	struct iwl_tx_cmd *tx_cmd;
 	u8 sta_id;
 	int hdrlen = ieee80211_hdrlen(hdr->frame_control);
 
-	if (WARN_ON_ONCE(info->flags & IEEE80211_TX_CTL_AMPDU))
+	memcpy(&info, skb->cb, sizeof(info));
+
+	if (WARN_ON_ONCE(info.flags & IEEE80211_TX_CTL_AMPDU))
 		return -1;
 
-	if (WARN_ON_ONCE(info->flags & IEEE80211_TX_CTL_SEND_AFTER_DTIM &&
-			 (!info->control.vif ||
-			  info->hw_queue != info->control.vif->cab_queue)))
+	if (WARN_ON_ONCE(info.flags & IEEE80211_TX_CTL_SEND_AFTER_DTIM &&
+			 (!info.control.vif ||
+			  info.hw_queue != info.control.vif->cab_queue)))
 		return -1;
 
 	/* This holds the amsdu headers length */
-	info->driver_data[0] = (void *)(uintptr_t)0;
+	skb_info->driver_data[0] = (void *)(uintptr_t)0;
 
 	/*
 	 * IWL_MVM_OFFCHANNEL_QUEUE is used for ROC packets that can be used
@@ -385,7 +390,7 @@ int iwl_mvm_tx_skb_non_sta(struct iwl_mvm *mvm, struct sk_buff *skb)
 	 * and hence needs to be sent on the aux queue
 	 */
 	if (IEEE80211_SKB_CB(skb)->hw_queue == IWL_MVM_OFFCHANNEL_QUEUE &&
-	    info->control.vif->type == NL80211_IFTYPE_STATION)
+	    info.control.vif->type == NL80211_IFTYPE_STATION)
 		IEEE80211_SKB_CB(skb)->hw_queue = mvm->aux_queue;
 
 	/*
@@ -398,14 +403,14 @@ int iwl_mvm_tx_skb_non_sta(struct iwl_mvm *mvm, struct sk_buff *skb)
 	 * AUX station.
 	 */
 	sta_id = mvm->aux_sta.sta_id;
-	if (info->control.vif) {
+	if (info.control.vif) {
 		struct iwl_mvm_vif *mvmvif =
-			iwl_mvm_vif_from_mac80211(info->control.vif);
+			iwl_mvm_vif_from_mac80211(info.control.vif);
 
-		if (info->control.vif->type == NL80211_IFTYPE_P2P_DEVICE ||
-		    info->control.vif->type == NL80211_IFTYPE_AP)
+		if (info.control.vif->type == NL80211_IFTYPE_P2P_DEVICE ||
+		    info.control.vif->type == NL80211_IFTYPE_AP)
 			sta_id = mvmvif->bcast_sta.sta_id;
-		else if (info->control.vif->type == NL80211_IFTYPE_STATION &&
+		else if (info.control.vif->type == NL80211_IFTYPE_STATION &&
 			 is_multicast_ether_addr(hdr->addr1)) {
 			u8 ap_sta_id = ACCESS_ONCE(mvmvif->ap_sta_id);
 
@@ -414,19 +419,18 @@ int iwl_mvm_tx_skb_non_sta(struct iwl_mvm *mvm, struct sk_buff *skb)
 		}
 	}
 
-	IWL_DEBUG_TX(mvm, "station Id %d, queue=%d\n", sta_id, info->hw_queue);
+	IWL_DEBUG_TX(mvm, "station Id %d, queue=%d\n", sta_id, info.hw_queue);
 
-	dev_cmd = iwl_mvm_set_tx_params(mvm, skb, hdrlen, NULL, sta_id);
+	dev_cmd = iwl_mvm_set_tx_params(mvm, skb, &info, hdrlen, NULL, sta_id);
 	if (!dev_cmd)
 		return -1;
 
-	/* From now on, we cannot access info->control */
 	tx_cmd = (struct iwl_tx_cmd *)dev_cmd->payload;
 
 	/* Copy MAC header from skb into command buffer */
 	memcpy(tx_cmd->hdr, hdr, hdrlen);
 
-	if (iwl_trans_tx(mvm->trans, skb, dev_cmd, info->hw_queue)) {
+	if (iwl_trans_tx(mvm->trans, skb, dev_cmd, info.hw_queue)) {
 		iwl_trans_free_tx_cmd(mvm->trans, dev_cmd);
 		return -1;
 	}
@@ -445,11 +449,11 @@ int iwl_mvm_tx_skb_non_sta(struct iwl_mvm *mvm, struct sk_buff *skb)
 
 #ifdef CONFIG_INET
 static int iwl_mvm_tx_tso(struct iwl_mvm *mvm, struct sk_buff *skb,
+			  struct ieee80211_tx_info *info,
 			  struct ieee80211_sta *sta,
 			  struct sk_buff_head *mpdus_skb)
 {
 	struct iwl_mvm_sta *mvmsta = iwl_mvm_sta_from_mac80211(sta);
-	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 	struct ieee80211_hdr *hdr = (void *)skb->data;
 	unsigned int mss = skb_shinfo(skb)->gso_size;
 	struct sk_buff *tmp, *next;
@@ -544,6 +548,8 @@ static int iwl_mvm_tx_tso(struct iwl_mvm *mvm, struct sk_buff *skb,
 
 	/* This skb fits in one single A-MSDU */
 	if (num_subframes * mss >= tcp_payload_len) {
+		struct ieee80211_tx_info *skb_info = IEEE80211_SKB_CB(skb);
+
 		/*
 		 * Compute the length of all the data added for the A-MSDU.
 		 * This will be used to compute the length to write in the TX
@@ -552,11 +558,10 @@ static int iwl_mvm_tx_tso(struct iwl_mvm *mvm, struct sk_buff *skb,
 		 * already had one set of SNAP / IP / TCP headers.
 		 */
 		num_subframes = DIV_ROUND_UP(tcp_payload_len, mss);
-		info = IEEE80211_SKB_CB(skb);
 		amsdu_add = num_subframes * sizeof(struct ethhdr) +
 			(num_subframes - 1) * (snap_ip_tcp + pad);
 		/* This holds the amsdu headers length */
-		info->driver_data[0] = (void *)(uintptr_t)amsdu_add;
+		skb_info->driver_data[0] = (void *)(uintptr_t)amsdu_add;
 
 		__skb_queue_tail(mpdus_skb, skb);
 		return 0;
@@ -596,11 +601,14 @@ static int iwl_mvm_tx_tso(struct iwl_mvm *mvm, struct sk_buff *skb,
 			ip_hdr(tmp)->id = htons(ip_base_id + i * num_subframes);
 
 		if (tcp_payload_len > mss) {
+			struct ieee80211_tx_info *skb_info =
+				IEEE80211_SKB_CB(tmp);
+
 			num_subframes = DIV_ROUND_UP(tcp_payload_len, mss);
-			info = IEEE80211_SKB_CB(tmp);
 			amsdu_add = num_subframes * sizeof(struct ethhdr) +
 				(num_subframes - 1) * (snap_ip_tcp + pad);
-			info->driver_data[0] = (void *)(uintptr_t)amsdu_add;
+			skb_info->driver_data[0] =
+				(void *)(uintptr_t)amsdu_add;
 			skb_shinfo(tmp)->gso_size = mss;
 		} else {
 			qc = ieee80211_get_qos_ctl((void *)tmp->data);
@@ -622,6 +630,7 @@ static int iwl_mvm_tx_tso(struct iwl_mvm *mvm, struct sk_buff *skb,
 }
 #else /* CONFIG_INET */
 static int iwl_mvm_tx_tso(struct iwl_mvm *mvm, struct sk_buff *skb,
+			  struct ieee80211_tx_info *info,
 			  struct ieee80211_sta *sta,
 			  struct sk_buff_head *mpdus_skb)
 {
@@ -636,10 +645,10 @@ static int iwl_mvm_tx_tso(struct iwl_mvm *mvm, struct sk_buff *skb,
  * Sets the fields in the Tx cmd that are crypto related
  */
 static int iwl_mvm_tx_mpdu(struct iwl_mvm *mvm, struct sk_buff *skb,
+			   struct ieee80211_tx_info *info,
 			   struct ieee80211_sta *sta)
 {
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
-	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 	struct iwl_mvm_sta *mvmsta;
 	struct iwl_device_cmd *dev_cmd;
 	struct iwl_tx_cmd *tx_cmd;
@@ -660,7 +669,8 @@ static int iwl_mvm_tx_mpdu(struct iwl_mvm *mvm, struct sk_buff *skb,
 	if (WARN_ON_ONCE(mvmsta->sta_id == IWL_MVM_STATION_COUNT))
 		return -1;
 
-	dev_cmd = iwl_mvm_set_tx_params(mvm, skb, hdrlen, sta, mvmsta->sta_id);
+	dev_cmd = iwl_mvm_set_tx_params(mvm, skb, info, hdrlen,
+					sta, mvmsta->sta_id);
 	if (!dev_cmd)
 		goto drop;
 
@@ -736,7 +746,8 @@ int iwl_mvm_tx_skb(struct iwl_mvm *mvm, struct sk_buff *skb,
 		   struct ieee80211_sta *sta)
 {
 	struct iwl_mvm_sta *mvmsta = iwl_mvm_sta_from_mac80211(sta);
-	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
+	struct ieee80211_tx_info *skb_info = IEEE80211_SKB_CB(skb);
+	struct ieee80211_tx_info info;
 	struct sk_buff_head mpdus_skbs;
 	unsigned int payload_len;
 	int ret;
@@ -747,21 +758,23 @@ int iwl_mvm_tx_skb(struct iwl_mvm *mvm, struct sk_buff *skb,
 	if (WARN_ON_ONCE(mvmsta->sta_id == IWL_MVM_STATION_COUNT))
 		return -1;
 
+	memcpy(&info, skb->cb, sizeof(info));
+
 	/* This holds the amsdu headers length */
-	info->driver_data[0] = (void *)(uintptr_t)0;
+	skb_info->driver_data[0] = (void *)(uintptr_t)0;
 
 	if (!skb_is_gso(skb))
-		return iwl_mvm_tx_mpdu(mvm, skb, sta);
+		return iwl_mvm_tx_mpdu(mvm, skb, &info, sta);
 
 	payload_len = skb_tail_pointer(skb) - skb_transport_header(skb) -
 		tcp_hdrlen(skb) + skb->data_len;
 
 	if (payload_len <= skb_shinfo(skb)->gso_size)
-		return iwl_mvm_tx_mpdu(mvm, skb, sta);
+		return iwl_mvm_tx_mpdu(mvm, skb, &info, sta);
 
 	__skb_queue_head_init(&mpdus_skbs);
 
-	ret = iwl_mvm_tx_tso(mvm, skb, sta, &mpdus_skbs);
+	ret = iwl_mvm_tx_tso(mvm, skb, &info, sta, &mpdus_skbs);
 	if (ret)
 		return ret;
 
@@ -771,7 +784,7 @@ int iwl_mvm_tx_skb(struct iwl_mvm *mvm, struct sk_buff *skb,
 	while (!skb_queue_empty(&mpdus_skbs)) {
 		skb = __skb_dequeue(&mpdus_skbs);
 
-		ret = iwl_mvm_tx_mpdu(mvm, skb, sta);
+		ret = iwl_mvm_tx_mpdu(mvm, skb, &info, sta);
 		if (ret) {
 			__skb_queue_purge(&mpdus_skbs);
 			return ret;