[PATCH v2 0/3] mac80211: do not use low data rates for data frames with no ack flag

[PATCH v2 0/3] mac80211: do not use low data rates for data frames with no ack flag

[Philipp Borgers]

Version 2 of this patch set adds a helper function that checks if a frame is a
data frame taking hardware encapsulation into account. Suggested by Johannes
Berg and Felix Fietkau.

The refactoring of the rc_no_data_or_no_ack_use_min function makes use of this
new function too. I added a comment about the refactoring too. Suggested by
Kalle Valo.

Best Regards

Philipp Borgers

Philipp Borgers (3):
  mac80211: add ieee80211_is_tx_data helper function
  mac80211: do not use low data rates for data frames with no ack flag
  mac80211: refactor rc_no_data_or_no_ack_use_min function

 include/net/mac80211.h | 18 ++++++++++++++++++
 net/mac80211/rate.c    | 10 +++++-----
 2 files changed, 23 insertions(+), 5 deletions(-)

-- 
2.31.1

[PATCH v2 1/3] mac80211: add ieee80211_is_tx_data helper function

[Philipp Borgers]

Add a helper function that checks if a frame is a data frame. Frames
with hardware encapsulation enabled are data frames.

Signed-off-by: Philipp Borgers <borgers@mi.fu-berlin.de>
---
 include/net/mac80211.h | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 445b66c6eb7e..a2a88c545561 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -6747,4 +6747,22 @@ struct sk_buff *ieee80211_get_fils_discovery_tmpl(struct ieee80211_hw *hw,
 struct sk_buff *
 ieee80211_get_unsol_bcast_probe_resp_tmpl(struct ieee80211_hw *hw,
 					  struct ieee80211_vif *vif);
+
+/**
+ * ieee80211_is_tx_data - check if frame is a data frame
+ *
+ * The function is used to check if a frame is a data frame. Frames with
+ * hardware encapsulation enabled are data frames.
+ *
+ * @skb: the frame to be transmitted.
+ */
+static inline bool ieee80211_is_tx_data(struct sk_buff *skb)
+{
+	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
+	struct ieee80211_hdr *hdr = (void *) skb->data;
+
+	return (info->flags & IEEE80211_TX_CTL_HW_80211_ENCAP ||
+			ieee80211_is_data(hdr->frame_control));
+}
+
 #endif /* MAC80211_H */
-- 
2.31.1

[PATCH v2 2/3] mac80211: do not use low data rates for data frames with no ack flag

[Philipp Borgers]

Data Frames with no ack flag set should be handled by the rate
controler. Make sure we reach the rate controler by returning early
from rate_control_send_low if the frame is a data frame with no ack
flag.

Signed-off-by: Philipp Borgers <borgers@mi.fu-berlin.de>
---
 net/mac80211/rate.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/mac80211/rate.c b/net/mac80211/rate.c
index 63652c39c8e0..fa1c73d0ceff 100644
--- a/net/mac80211/rate.c
+++ b/net/mac80211/rate.c
@@ -396,6 +396,10 @@ static bool rate_control_send_low(struct ieee80211_sta *pubsta,
 	int mcast_rate;
 	bool use_basicrate = false;
 
+	if (ieee80211_is_tx_data(txrc->skb) &&
+			(info->flags & IEEE80211_TX_CTL_NO_ACK))
+		return false;
+
 	if (!pubsta || rc_no_data_or_no_ack_use_min(txrc)) {
 		__rate_control_send_low(txrc->hw, sband, pubsta, info,
 					txrc->rate_idx_mask);
-- 
2.31.1

[PATCH v2 3/3] mac80211: refactor rc_no_data_or_no_ack_use_min function

[Philipp Borgers]

Use newly introduced helper function ieee80211_is_tx_data to check if
frame is a data frame. Takes into account that hardware encapsulation
can be enabled for a frame and therefore no ieee80211 header is present.

Signed-off-by: Philipp Borgers <borgers@mi.fu-berlin.de>
---
 net/mac80211/rate.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/net/mac80211/rate.c b/net/mac80211/rate.c
index fa1c73d0ceff..208bd0c2b671 100644
--- a/net/mac80211/rate.c
+++ b/net/mac80211/rate.c
@@ -297,15 +297,11 @@ void ieee80211_check_rate_mask(struct ieee80211_sub_if_data *sdata)
 static bool rc_no_data_or_no_ack_use_min(struct ieee80211_tx_rate_control *txrc)
 {
 	struct sk_buff *skb = txrc->skb;
-	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
-	__le16 fc;
-
-	fc = hdr->frame_control;
 
 	return (info->flags & (IEEE80211_TX_CTL_NO_ACK |
 			       IEEE80211_TX_CTL_USE_MINRATE)) ||
-		!ieee80211_is_data(fc);
+		!ieee80211_is_tx_data(skb);
 }
 
 static void rc_send_low_basicrate(struct ieee80211_tx_rate *rate,
-- 
2.31.1