[PATCH 0/2] wifi: mac80211: extend rx API with link_id for MLO connection

[PATCH 0/2] wifi: mac80211: extend rx API with link_id for MLO connection

[Vasanthakumar]

From: Vasanthakumar Thiagarajan <quic_vthiagar@quicinc.com>

In MLO, the frames can be received on any of the affiliated links.
When the address translation for rx frames are done in fw/hw, it
is very important to have an explicit link information reported
for every rx frame to mac80211. Per-link processing includes
stats update, GTK/IGTK/BIGTK retrieval and so on. This patch
set only tries to use the link at the top level APIs, deep
rx handlers are yet to be changed to use the respective
link accordingly.

This series is prepared on top of the latest mld branch.

Changes from RFC:

- Re-arranged the code changes across the patches
- Add a valid flag for link_id in rs_status
- Remove logic involving unspecified link_id

Vasanthakumar Thiagarajan (2):
  wifi: mac80211: add link information in ieee80211_rx_status
  wifi: mac80211: use the corresponding link for stats update

 include/net/mac80211.h |   5 ++
 net/mac80211/rx.c      | 130 ++++++++++++++++++++++++++++++++++++++---
 2 files changed, 128 insertions(+), 7 deletions(-)

-- 
2.17.1

[PATCH 1/2] wifi: mac80211: add link information in ieee80211_rx_status

[Vasanthakumar]

From: Vasanthakumar Thiagarajan <quic_vthiagar@quicinc.com>

In MLO, when the address translation from link to MLD is done
in fw/hw, it is necessary to be able to have some information
on the link on which the frame has been received. Extend the
rx API to include link_id and a valid flag in ieee80211_rx_status.
Also make chanes to mac80211 rx APIs to make use of the reported
link_id after sanity checks.

Signed-off-by: Vasanthakumar Thiagarajan <quic_vthiagar@quicinc.com>
---
 include/net/mac80211.h |  5 +++
 net/mac80211/rx.c      | 95 +++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 99 insertions(+), 1 deletion(-)

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index f198af600b5e..703f811c4711 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1480,6 +1480,10 @@ enum mac80211_rx_encoding {
  *	each A-MPDU but the same for each subframe within one A-MPDU
  * @ampdu_delimiter_crc: A-MPDU delimiter CRC
  * @zero_length_psdu_type: radiotap type of the 0-length PSDU
+ * @link_valid: if the link which is identified by @link_id is valid. This flag
+ *	is set only when connection is MLO.
+ * @link_id: id of the link used to receive the packet. This is used along with
+ *	@link_valid.
  */
 struct ieee80211_rx_status {
 	u64 mactime;
@@ -1504,6 +1508,7 @@ struct ieee80211_rx_status {
 	s8 chain_signal[IEEE80211_MAX_CHAINS];
 	u8 ampdu_delimiter_crc;
 	u8 zero_length_psdu_type;
+	u8 link_valid:1, link_id:4;
 };
 
 static inline u32
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 57df21e2170a..80f2e3bc5e70 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -4508,6 +4508,15 @@ void ieee80211_check_fast_rx_iface(struct ieee80211_sub_if_data *sdata)
 	mutex_unlock(&local->sta_mtx);
 }
 
+static bool
+ieee80211_rx_is_valid_sta_link_id(struct ieee80211_sta *sta, u8 link_id)
+{
+	if (!sta->mlo)
+		return false;
+
+	return !!(sta->valid_links & BIT(link_id));
+}
+
 static void ieee80211_rx_8023(struct ieee80211_rx_data *rx,
 			      struct ieee80211_fast_rx *fast_rx,
 			      int orig_len)
@@ -4827,6 +4836,7 @@ static void __ieee80211_rx_handle_8023(struct ieee80211_hw *hw,
 				       struct list_head *list)
 {
 	struct ieee80211_local *local = hw_to_local(hw);
+	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 	struct ieee80211_fast_rx *fast_rx;
 	struct ieee80211_rx_data rx;
 
@@ -4847,7 +4857,31 @@ static void __ieee80211_rx_handle_8023(struct ieee80211_hw *hw,
 
 	rx.sta = container_of(pubsta, struct sta_info, sta);
 	rx.sdata = rx.sta->sdata;
-	rx.link = &rx.sdata->deflink;
+
+	if (status->link_valid &&
+	    !ieee80211_rx_is_valid_sta_link_id(pubsta, status->link_id))
+		goto drop;
+
+	/*
+	 * TODO: Should the frame be dropped if the right link_id is not
+	 * available? Or may be it is fine in the current form to proceed with
+	 * the frame processing because with frame being in 802.3 format,
+	 * link_id is used only for stats purpose and updating the stats on
+	 * the deflink is fine?
+	 */
+	if (status->link_valid)
+		rx.link_id = status->link_id;
+
+	if (rx.link_id >= 0) {
+		struct ieee80211_link_data *link;
+
+		link =  rcu_dereference(rx.sdata->link[rx.link_id]);
+		if (!link)
+			goto drop;
+		rx.link = link;
+	} else {
+		rx.link = &rx.sdata->deflink;
+	}
 
 	fast_rx = rcu_dereference(rx.sta->fast_rx);
 	if (!fast_rx)
@@ -4877,7 +4911,19 @@ static bool ieee80211_rx_for_interface(struct ieee80211_rx_data *rx,
 		rx->sta = link_sta->sta;
 		rx->link_id = link_sta->link_id;
 	} else {
+		struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
+
 		rx->sta = sta_info_get_bss(rx->sdata, hdr->addr2);
+		if (rx->sta) {
+			if (status->link_valid &&
+			    !ieee80211_rx_is_valid_sta_link_id(&rx->sta->sta,
+							       status->link_id))
+				return false;
+
+			rx->link_id = status->link_valid ? status->link_id : -1;
+		} else {
+			rx->link_id = -1;
+		}
 	}
 
 	return ieee80211_prepare_and_rx_handle(rx, skb, consume);
@@ -4893,6 +4939,7 @@ static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
 					 struct list_head *list)
 {
 	struct ieee80211_local *local = hw_to_local(hw);
+	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 	struct ieee80211_sub_if_data *sdata;
 	struct ieee80211_hdr *hdr;
 	__le16 fc;
@@ -4937,10 +4984,39 @@ static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
 
 	if (ieee80211_is_data(fc)) {
 		struct sta_info *sta, *prev_sta;
+		u8 link_id = status->link_id;
 
 		if (pubsta) {
 			rx.sta = container_of(pubsta, struct sta_info, sta);
 			rx.sdata = rx.sta->sdata;
+
+			if (status->link_valid &&
+			    !ieee80211_rx_is_valid_sta_link_id(pubsta, link_id))
+				goto out;
+
+			if (status->link_valid)
+				rx.link_id = status->link_id;
+
+			/*
+			 * In MLO connection, fetch the link_id using addr2
+			 * when the driver does not pass link_id in status.
+			 * When the address translation is already performed by
+			 * driver/hw, the valid link_id must be passed in
+			 * status.
+			 */
+
+			if (!status->link_valid && pubsta->mlo) {
+				struct ieee80211_hdr *hdr = (void *)skb->data;
+				struct link_sta_info *link_sta;
+
+				link_sta = link_sta_info_get_bss(rx.sdata,
+								 hdr->addr2);
+				if (!link_sta)
+					goto out;
+
+				rx.link_id = link_sta->link_id;
+			}
+
 			if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
 				return;
 			goto out;
@@ -4954,6 +5030,13 @@ static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
 				continue;
 			}
 
+			if ((status->link_valid &&
+			     !ieee80211_rx_is_valid_sta_link_id(&prev_sta->sta,
+								link_id)) ||
+			    (!status->link_valid && prev_sta->sta.mlo))
+				continue;
+
+			rx.link_id = status->link_valid ? link_id : -1;
 			rx.sta = prev_sta;
 			rx.sdata = prev_sta->sdata;
 			ieee80211_prepare_and_rx_handle(&rx, skb, false);
@@ -4962,6 +5045,13 @@ static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
 		}
 
 		if (prev_sta) {
+			if ((status->link_valid &&
+			     !ieee80211_rx_is_valid_sta_link_id(&prev_sta->sta,
+								link_id)) ||
+			    (!status->link_valid && prev_sta->sta.mlo))
+				goto out;
+
+			rx.link_id = status->link_valid ? link_id : -1;
 			rx.sta = prev_sta;
 			rx.sdata = prev_sta->sdata;
 
@@ -5104,6 +5194,9 @@ void ieee80211_rx_list(struct ieee80211_hw *hw, struct ieee80211_sta *pubsta,
 		}
 	}
 
+	if (WARN_ON_ONCE(status->link_id >= IEEE80211_LINK_UNSPECIFIED))
+		goto drop;
+
 	status->rx_flags = 0;
 
 	kcov_remote_start_common(skb_get_kcov_handle(skb));
-- 
2.17.1

[PATCH 2/2] wifi: mac80211: use the corresponding link for stats update

[Vasanthakumar]

From: Vasanthakumar Thiagarajan <quic_vthiagar@quicinc.com>

With link_id reported in rx_status for MLO connection, do the
stats update on the appropriate link instead of always deflink.

Signed-off-by: Vasanthakumar Thiagarajan <quic_vthiagar@quicinc.com>
---
 net/mac80211/rx.c | 35 +++++++++++++++++++++++++++++------
 1 file changed, 29 insertions(+), 6 deletions(-)

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 80f2e3bc5e70..7f350886039a 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -4524,19 +4524,30 @@ static void ieee80211_rx_8023(struct ieee80211_rx_data *rx,
 	struct ieee80211_sta_rx_stats *stats;
 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
 	struct sta_info *sta = rx->sta;
+	struct link_sta_info *link_sta;
 	struct sk_buff *skb = rx->skb;
 	void *sa = skb->data + ETH_ALEN;
 	void *da = skb->data;
 
-	stats = &sta->deflink.rx_stats;
+	if (rx->link_id >= 0) {
+		link_sta = rcu_dereference(sta->link[rx->link_id]);
+		if (WARN_ON_ONCE(!link_sta)) {
+			dev_kfree_skb(rx->skb);
+			return;
+		}
+	} else {
+		link_sta = &sta->deflink;
+	}
+
+	stats = &link_sta->rx_stats;
 	if (fast_rx->uses_rss)
-		stats = this_cpu_ptr(sta->deflink.pcpu_rx_stats);
+		stats = this_cpu_ptr(link_sta->pcpu_rx_stats);
 
 	/* statistics part of ieee80211_rx_h_sta_process() */
 	if (!(status->flag & RX_FLAG_NO_SIGNAL_VAL)) {
 		stats->last_signal = status->signal;
 		if (!fast_rx->uses_rss)
-			ewma_signal_add(&sta->deflink.rx_stats_avg.signal,
+			ewma_signal_add(&link_sta->rx_stats_avg.signal,
 					-status->signal);
 	}
 
@@ -4552,7 +4563,7 @@ static void ieee80211_rx_8023(struct ieee80211_rx_data *rx,
 
 			stats->chain_signal_last[i] = signal;
 			if (!fast_rx->uses_rss)
-				ewma_signal_add(&sta->deflink.rx_stats_avg.chain_signal[i],
+				ewma_signal_add(&link_sta->rx_stats_avg.chain_signal[i],
 						-signal);
 		}
 	}
@@ -4628,7 +4639,8 @@ static bool ieee80211_invoke_fast_rx(struct ieee80211_rx_data *rx,
 		u8 da[ETH_ALEN];
 		u8 sa[ETH_ALEN];
 	} addrs __aligned(2);
-	struct ieee80211_sta_rx_stats *stats = &sta->deflink.rx_stats;
+	struct link_sta_info *link_sta;
+	struct ieee80211_sta_rx_stats *stats;
 
 	/* for parallel-rx, we need to have DUP_VALIDATED, otherwise we write
 	 * to a common data structure; drivers can implement that per queue
@@ -4729,8 +4741,19 @@ static bool ieee80211_invoke_fast_rx(struct ieee80211_rx_data *rx,
 	return true;
  drop:
 	dev_kfree_skb(skb);
+
+	if (rx->link_id >= 0) {
+		link_sta = rcu_dereference(sta->link[rx->link_id]);
+		if (!link_sta)
+			return true;
+	} else {
+		link_sta = &sta->deflink;
+	}
+
 	if (fast_rx->uses_rss)
-		stats = this_cpu_ptr(sta->deflink.pcpu_rx_stats);
+		stats = this_cpu_ptr(link_sta->pcpu_rx_stats);
+	else
+		stats = &link_sta->rx_stats;
 
 	stats->dropped++;
 	return true;
-- 
2.17.1

Re: [PATCH 0/2] wifi: mac80211: extend rx API with link_id for MLO connection

[Kalle Valo]

Vasanthakumar <quic_vthiagar@quicinc.com> writes:

> From: Vasanthakumar Thiagarajan <quic_vthiagar@quicinc.com>

Your last name is missing from SMTP From header:

From:   Vasanthakumar <quic_vthiagar@quicinc.com>

If you fix that git doesn't need to add a second From header to the mail
body.

-- 
https://patchwork.kernel.org/project/linux-wireless/list/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

Re: [PATCH 0/2] wifi: mac80211: extend rx API with link_id for MLO connection

[Vasanthakumar Thiagarajan]

On 9/1/2022 4:05 PM, Kalle Valo wrote:
> Vasanthakumar <quic_vthiagar@quicinc.com> writes:
> 
>> From: Vasanthakumar Thiagarajan <quic_vthiagar@quicinc.com>
> 
> Your last name is missing from SMTP From header:
> 
> From:   Vasanthakumar <quic_vthiagar@quicinc.com>
> 
> If you fix that git doesn't need to add a second From header to the mail
> body.
> 

Sure, ill fix this. Thanks for pointing this out.

Vasanth