[PATCH v2] mac80211: enable QoS support for nl80211 ctrl port

[PATCH v2] mac80211: enable QoS support for nl80211 ctrl port

[Markus Theil]

This patch unifies sending control port frames
over nl80211 and AF_PACKET sockets a little more.

Before this patch, EAPOL frames got QoS prioritization
only when using AF_PACKET sockets.

__ieee80211_select_queue only selects a QoS-enabled queue
for control port frames, when the control port protocol
is set correctly on the skb. For the AF_PACKET path this
works, but the nl80211 path used ETH_P_802_3.

Another check for injected frames in wme.c then prevented
the QoS TID to be copied in the frame.

In order to fix this, get rid of the frame injection marking
for nl80211 ctrl port and set the correct ethernet protocol.

Please note:
An erlier version of this path tried to prevent
frame aggregation for control port frames in order to speed up
the initial connection setup a little. This seemed to cause
issues on my older Intel dvm-based hardware, and was therefore
removed again. Future commits which try to reintroduce this
have to check carefully how hw behaves with aggregated and
non-aggregated traffic for the same TID.
My NIC: Intel(R) Centrino(R) Ultimate-N 6300 AGN, REV=0x74

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Markus Theil <markus.theil@tu-ilmenau.de>
---
v2: remove aggregation bypass for control port frames
 net/mac80211/status.c |  8 ++------
 net/mac80211/tx.c     | 12 +++++-------
 2 files changed, 7 insertions(+), 13 deletions(-)

diff --git a/net/mac80211/status.c b/net/mac80211/status.c
index 3485610755ef..9baf185ee4c7 100644
--- a/net/mac80211/status.c
+++ b/net/mac80211/status.c
@@ -628,16 +628,12 @@ static void ieee80211_report_ack_skb(struct ieee80211_local *local,
 		u64 cookie = IEEE80211_SKB_CB(skb)->ack.cookie;
 		struct ieee80211_sub_if_data *sdata;
 		struct ieee80211_hdr *hdr = (void *)skb->data;
-		__be16 ethertype = 0;
-
-		if (skb->len >= ETH_HLEN && skb->protocol == cpu_to_be16(ETH_P_802_3))
-			skb_copy_bits(skb, 2 * ETH_ALEN, &ethertype, ETH_TLEN);

 		rcu_read_lock();
 		sdata = ieee80211_sdata_from_skb(local, skb);
 		if (sdata) {
-			if (ethertype == sdata->control_port_protocol ||
-			    ethertype == cpu_to_be16(ETH_P_PREAUTH))
+			if (skb->protocol == sdata->control_port_protocol ||
+			    skb->protocol == cpu_to_be16(ETH_P_PREAUTH))
 				cfg80211_control_port_tx_status(&sdata->wdev,
 								cookie,
 								skb->data,
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 6422da6690f7..2087d096513e 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1182,9 +1182,7 @@ ieee80211_tx_prepare(struct ieee80211_sub_if_data *sdata,
 			tx->sta = rcu_dereference(sdata->u.vlan.sta);
 			if (!tx->sta && sdata->wdev.use_4addr)
 				return TX_DROP;
-		} else if (info->flags & (IEEE80211_TX_INTFL_NL80211_FRAME_TX |
-					  IEEE80211_TX_CTL_INJECTED) ||
-			   tx->sdata->control_port_protocol == tx->skb->protocol) {
+		} else if (tx->sdata->control_port_protocol == tx->skb->protocol) {
 			tx->sta = sta_info_get_bss(sdata, hdr->addr1);
 		}
 		if (!tx->sta && !is_multicast_ether_addr(hdr->addr1))
@@ -3934,7 +3932,8 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb,
 	if (IS_ERR(sta))
 		sta = NULL;

-	if (local->ops->wake_tx_queue) {
+	if (local->ops->wake_tx_queue ||
+	    skb->protocol == sdata->control_port_protocol) {
 		u16 queue = __ieee80211_select_queue(sdata, sta, skb);
 		skb_set_queue_mapping(skb, queue);
 		skb_get_hash(skb);
@@ -5430,8 +5429,7 @@ int ieee80211_tx_control_port(struct wiphy *wiphy, struct net_device *dev,
 	if (cookie)
 		ctrl_flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;

-	flags |= IEEE80211_TX_INTFL_NL80211_FRAME_TX |
-		 IEEE80211_TX_CTL_INJECTED;
+	flags |= IEEE80211_TX_INTFL_NL80211_FRAME_TX;

 	skb = dev_alloc_skb(local->hw.extra_tx_headroom +
 			    sizeof(struct ethhdr) + len);
@@ -5448,7 +5446,7 @@ int ieee80211_tx_control_port(struct wiphy *wiphy, struct net_device *dev,
 	ehdr->h_proto = proto;

 	skb->dev = dev;
-	skb->protocol = htons(ETH_P_802_3);
+	skb->protocol = proto;
 	skb_reset_network_header(skb);
 	skb_reset_mac_header(skb);

--
2.29.2

Re: [PATCH v2] mac80211: enable QoS support for nl80211 ctrl port

[Johannes Berg]

Hi,

Seems reasonable to me, all in all, but

> @@ -3934,7 +3932,8 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb,
>  	if (IS_ERR(sta))
>  		sta = NULL;
> 
> -	if (local->ops->wake_tx_queue) {
> +	if (local->ops->wake_tx_queue ||
> +	    skb->protocol == sdata->control_port_protocol) {
>  		u16 queue = __ieee80211_select_queue(sdata, sta, skb);
>  		skb_set_queue_mapping(skb, queue);
>  		skb_get_hash(skb);

I don't understand this part.

Why not do the necessary setup in ieee80211_tx_control_port(), instead
of potentially overwriting it for EAPOL-over-AF_PACKET frames here?

johannes