[PATCH 4.4 312/312] mac80211: add ieee80211_is_any_nullfunc()

From: Greg Kroah-Hartman
Date: Fri May 08 2020 - 08:49:17 EST


From: Thomas Pedersen <thomas@xxxxxxxxxxxx>

commit 30b2f0be23fb40e58d0ad2caf8702c2a44cda2e1 upstream.

commit 08a5bdde3812 ("mac80211: consider QoS Null frames for STA_NULLFUNC_ACKED")
Fixed a bug where we failed to take into account a
nullfunc frame can be either non-QoS or QoS. It turns out
there is at least one more bug in
ieee80211_sta_tx_notify(), introduced in
commit 7b6ddeaf27ec ("mac80211: use QoS NDP for AP probing"),
where we forgot to check for the QoS variant and so
assumed the QoS nullfunc frame never went out

Fix this by adding a helper ieee80211_is_any_nullfunc()
which consolidates the check for non-QoS and QoS nullfunc
frames. Replace existing compound conditionals and add a
couple more missing checks for QoS variant.

Signed-off-by: Thomas Pedersen <thomas@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20200114055940.18502-3-thomas@xxxxxxxxxxxx
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
include/linux/ieee80211.h | 9 +++++++++
net/mac80211/mlme.c | 2 +-
net/mac80211/rx.c | 8 +++-----
net/mac80211/status.c | 5 ++---
net/mac80211/tx.c | 2 +-
5 files changed, 16 insertions(+), 10 deletions(-)

--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -607,6 +607,15 @@ static inline bool ieee80211_is_qos_null
}

/**
+ * ieee80211_is_any_nullfunc - check if frame is regular or QoS nullfunc frame
+ * @fc: frame control bytes in little-endian byteorder
+ */
+static inline bool ieee80211_is_any_nullfunc(__le16 fc)
+{
+ return (ieee80211_is_nullfunc(fc) || ieee80211_is_qos_nullfunc(fc));
+}
+
+/**
* ieee80211_is_bufferable_mmpdu - check if frame is bufferable MMPDU
* @fc: frame control field in little-endian byteorder
*/
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -2283,7 +2283,7 @@ void ieee80211_sta_tx_notify(struct ieee
if (!ieee80211_is_data(hdr->frame_control))
return;

- if (ieee80211_is_nullfunc(hdr->frame_control) &&
+ if (ieee80211_is_any_nullfunc(hdr->frame_control) &&
sdata->u.mgd.probe_send_count > 0) {
if (ack)
ieee80211_sta_reset_conn_monitor(sdata);
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1110,8 +1110,7 @@ ieee80211_rx_h_check_dup(struct ieee8021
return RX_CONTINUE;

if (ieee80211_is_ctl(hdr->frame_control) ||
- ieee80211_is_nullfunc(hdr->frame_control) ||
- ieee80211_is_qos_nullfunc(hdr->frame_control) ||
+ ieee80211_is_any_nullfunc(hdr->frame_control) ||
is_multicast_ether_addr(hdr->addr1))
return RX_CONTINUE;

@@ -1487,8 +1486,7 @@ ieee80211_rx_h_sta_process(struct ieee80
* Drop (qos-)data::nullfunc frames silently, since they
* are used only to control station power saving mode.
*/
- if (ieee80211_is_nullfunc(hdr->frame_control) ||
- ieee80211_is_qos_nullfunc(hdr->frame_control)) {
+ if (ieee80211_is_any_nullfunc(hdr->frame_control)) {
I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);

/*
@@ -1977,7 +1975,7 @@ static int ieee80211_drop_unencrypted(st

/* Drop unencrypted frames if key is set. */
if (unlikely(!ieee80211_has_protected(fc) &&
- !ieee80211_is_nullfunc(fc) &&
+ !ieee80211_is_any_nullfunc(fc) &&
ieee80211_is_data(fc) && rx->key))
return -EACCES;

--- a/net/mac80211/status.c
+++ b/net/mac80211/status.c
@@ -474,8 +474,7 @@ static void ieee80211_report_ack_skb(str
rcu_read_lock();
sdata = ieee80211_sdata_from_skb(local, skb);
if (sdata) {
- if (ieee80211_is_nullfunc(hdr->frame_control) ||
- ieee80211_is_qos_nullfunc(hdr->frame_control))
+ if (ieee80211_is_any_nullfunc(hdr->frame_control))
cfg80211_probe_status(sdata->dev, hdr->addr1,
cookie, acked,
GFP_ATOMIC);
@@ -905,7 +904,7 @@ void ieee80211_tx_status(struct ieee8021
I802_DEBUG_INC(local->dot11FailedCount);
}

- if (ieee80211_is_nullfunc(fc) && ieee80211_has_pm(fc) &&
+ if (ieee80211_is_any_nullfunc(fc) && ieee80211_has_pm(fc) &&
ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS) &&
!(info->flags & IEEE80211_TX_CTL_INJECTED) &&
local->ps_sdata && !(local->scanning)) {
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -291,7 +291,7 @@ ieee80211_tx_h_check_assoc(struct ieee80
if (unlikely(test_bit(SCAN_SW_SCANNING, &tx->local->scanning)) &&
test_bit(SDATA_STATE_OFFCHANNEL, &tx->sdata->state) &&
!ieee80211_is_probe_req(hdr->frame_control) &&
- !ieee80211_is_nullfunc(hdr->frame_control))
+ !ieee80211_is_any_nullfunc(hdr->frame_control))
/*
* When software scanning only nullfunc frames (to notify
* the sleep state to the AP) and probe requests (for the