| Message ID | 1561595753-11351-1-git-send-email-srirrama@codeaurora.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 1a50014ff2d3047c8a1f5cd268026d4fcf8e41bf |
| Delegated to: | Kalle Valo |
| Headers | show |
| Series | ath11k: Add probe response throttling logic | expand |
Sriram R <srirrama@codeaurora.org> writes: > Drop probe response packets when the pending management tx > count has reached a certain threshold, so as to prioritize > other mgmt packets like auth and assoc to be sent on time > for establishing successful connections. > This might be required in dense networks, multi-vap scenarios > or due to emulated probe requests (DoS attack), > which could lead to association failures due to failure to > send auth/assoc packets as high probe response traffic occupies the > limited target mgmt transmit queue. > Currently the threshold is set to 3/4th of the target management > tx queue. > > Signed-off-by: Sriram R <srirrama@codeaurora.org> [...] > --- a/drivers/net/wireless/ath/ath11k/wmi.c > +++ b/drivers/net/wireless/ath/ath11k/wmi.c > @@ -3366,6 +3366,9 @@ static int wmi_process_mgmt_tx_comp(struct ath11k *ar, u32 desc_id, > > ieee80211_tx_status_irqsafe(ar->hw, msdu); > > + WARN_ON(atomic_read(&ar->num_pending_mgmt_tx) == 0); In the pending branch I changed this to WARN_ON_ONCE() so that we don't excessively spam the logs: https://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git/commit/?h=pending-ath11k&id=02d5ce6ef5feff4bbc80afd800586bd15879b714
On 2019-07-16 17:43, Kalle Valo wrote: > Sriram R <srirrama@codeaurora.org> writes: > >> Drop probe response packets when the pending management tx >> count has reached a certain threshold, so as to prioritize >> other mgmt packets like auth and assoc to be sent on time >> for establishing successful connections. >> This might be required in dense networks, multi-vap scenarios >> or due to emulated probe requests (DoS attack), >> which could lead to association failures due to failure to >> send auth/assoc packets as high probe response traffic occupies the >> limited target mgmt transmit queue. >> Currently the threshold is set to 3/4th of the target management >> tx queue. >> >> Signed-off-by: Sriram R <srirrama@codeaurora.org> > > [...] > >> --- a/drivers/net/wireless/ath/ath11k/wmi.c >> +++ b/drivers/net/wireless/ath/ath11k/wmi.c >> @@ -3366,6 +3366,9 @@ static int wmi_process_mgmt_tx_comp(struct >> ath11k *ar, u32 desc_id, >> >> ieee80211_tx_status_irqsafe(ar->hw, msdu); >> >> + WARN_ON(atomic_read(&ar->num_pending_mgmt_tx) == 0); > > In the pending branch I changed this to WARN_ON_ONCE() so that we don't > excessively spam the logs: > > https://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git/commit/?h=pending-ath11k&id=02d5ce6ef5feff4bbc80afd800586bd15879b714 Fine Kalle. Thanks for making this change. Regards, Sriram.R
Sriram R <srirrama@codeaurora.org> wrote: > Drop probe response packets when the pending management tx > count has reached a certain threshold, so as to prioritize > other mgmt packets like auth and assoc to be sent on time > for establishing successful connections. > This might be required in dense networks, multi-vap scenarios > or due to emulated probe requests (DoS attack), > which could lead to association failures due to failure to > send auth/assoc packets as high probe response traffic occupies the > limited target mgmt transmit queue. > Currently the threshold is set to 3/4th of the target management > tx queue. > > Signed-off-by: Sriram R <srirrama@codeaurora.org> > Signed-off-by: Kalle Valo <kvalo@codeaurora.org> Patch applied to ath11k-bringup branch of ath.git, thanks. 1a50014ff2d3 ath11k: Add probe response throttling logic
diff --git a/drivers/net/wireless/ath/ath11k/core.h b/drivers/net/wireless/ath/ath11k/core.h index af5c66f..9023367 100644 --- a/drivers/net/wireless/ath/ath11k/core.h +++ b/drivers/net/wireless/ath/ath11k/core.h @@ -25,6 +25,11 @@ #define ATH11K_TX_MGMT_NUM_PENDING_MAX 512 +#define ATH11K_TX_MGMT_TARGET_MAX_SUPPORT_WMI 64 + +/* Pending management packets threshold for dropping probe responses */ +#define ATH11K_PRB_RSP_DROP_THRESHOLD ((ATH11K_TX_MGMT_TARGET_MAX_SUPPORT_WMI * 3) / 4) + #define ATH11K_INVALID_HW_MAC_ID 0xFF enum ath11k_supported_bw { @@ -485,6 +490,7 @@ struct ath11k { struct idr txmgmt_idr; /* protects txmgmt_idr data */ spinlock_t txmgmt_idr_lock; + atomic_t num_pending_mgmt_tx; /* cycle count is reported twice for each visited channel during scan. * access protected by data_lock diff --git a/drivers/net/wireless/ath/ath11k/mac.c b/drivers/net/wireless/ath/ath11k/mac.c index 1a4a333..b8035ec 100644 --- a/drivers/net/wireless/ath/ath11k/mac.c +++ b/drivers/net/wireless/ath/ath11k/mac.c @@ -3392,17 +3392,32 @@ static void ath11k_mgmt_over_wmi_tx_work(struct work_struct *work) ath11k_warn(ar->ab, "failed to transmit management frame %d\n", ret); ieee80211_free_txskb(ar->hw, skb); + } else { + atomic_inc(&ar->num_pending_mgmt_tx); } } } -static int ath11k_mac_mgmt_tx(struct ath11k *ar, struct sk_buff *skb) +static int ath11k_mac_mgmt_tx(struct ath11k *ar, struct sk_buff *skb, + bool is_prb_rsp) { struct sk_buff_head *q = &ar->wmi_mgmt_tx_queue; if (test_bit(ATH11K_FLAG_CRASH_FLUSH, &ar->ab->dev_flags)) return -ESHUTDOWN; + /* Drop probe response packets when the pending management tx + * count has reached a certain threshold, so as to prioritize + * other mgmt packets like auth and assoc to be sent on time + * for establishing successful connections. + */ + if (is_prb_rsp && + atomic_read(&ar->num_pending_mgmt_tx) > ATH11K_PRB_RSP_DROP_THRESHOLD) { + ath11k_warn(ar->ab, + "dropping probe response as pending queue is almost full\n"); + return -ENOSPC; + } + if (skb_queue_len(q) == ATH11K_TX_MGMT_NUM_PENDING_MAX) { ath11k_warn(ar->ab, "mgmt tx queue is full\n"); return -ENOSPC; @@ -3423,10 +3438,12 @@ static void ath11k_mac_op_tx(struct ieee80211_hw *hw, struct ieee80211_vif *vif = info->control.vif; struct ath11k_vif *arvif = ath11k_vif_to_arvif(vif); struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; + bool is_prb_rsp; int ret; if (ieee80211_is_mgmt(hdr->frame_control)) { - ret = ath11k_mac_mgmt_tx(ar, skb); + is_prb_rsp = ieee80211_is_probe_resp(hdr->frame_control); + ret = ath11k_mac_mgmt_tx(ar, skb, is_prb_rsp); if (ret) { ath11k_warn(ar->ab, "failed to queue management frame %d\n", ret); @@ -3601,6 +3618,8 @@ static void ath11k_mac_op_stop(struct ieee80211_hw *hw) rcu_assign_pointer(ar->ab->pdevs_active[ar->pdev_idx], NULL); synchronize_rcu(); + + atomic_set(&ar->num_pending_mgmt_tx, 0); } static void diff --git a/drivers/net/wireless/ath/ath11k/wmi.c b/drivers/net/wireless/ath/ath11k/wmi.c index 46a3e0f..6dad499 100644 --- a/drivers/net/wireless/ath/ath11k/wmi.c +++ b/drivers/net/wireless/ath/ath11k/wmi.c @@ -3366,6 +3366,9 @@ static int wmi_process_mgmt_tx_comp(struct ath11k *ar, u32 desc_id, ieee80211_tx_status_irqsafe(ar->hw, msdu); + WARN_ON(atomic_read(&ar->num_pending_mgmt_tx) == 0); + atomic_dec(&ar->num_pending_mgmt_tx); + return 0; }
Drop probe response packets when the pending management tx count has reached a certain threshold, so as to prioritize other mgmt packets like auth and assoc to be sent on time for establishing successful connections. This might be required in dense networks, multi-vap scenarios or due to emulated probe requests (DoS attack), which could lead to association failures due to failure to send auth/assoc packets as high probe response traffic occupies the limited target mgmt transmit queue. Currently the threshold is set to 3/4th of the target management tx queue. Signed-off-by: Sriram R <srirrama@codeaurora.org> --- drivers/net/wireless/ath/ath11k/core.h | 6 ++++++ drivers/net/wireless/ath/ath11k/mac.c | 23 +++++++++++++++++++++-- drivers/net/wireless/ath/ath11k/wmi.c | 3 +++ 3 files changed, 30 insertions(+), 2 deletions(-)