From: Liad Kaufman <liad.kaufman@xxxxxxxxx>
Since the TDLS peer station might not receive the teardown
packet (e.g., when in PS), this makes sure the packet is
retransmitted - this time through the AP - if the TDLS peer
didn't ACK the packet.
Signed-off-by: Liad Kaufman <liad.kaufman@xxxxxxxxx>
Reviewed-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Arik Nemtsov <arik@xxxxxxxxxx>
---
include/linux/ieee80211.h | 25 ++++++++++++++++++++
net/mac80211/ieee80211_i.h | 4 ++++
net/mac80211/mlme.c | 12 ++++++++++
net/mac80211/status.c | 55 ++++++++++++++++++++++++++++++++++++++++--
net/mac80211/tdls.c | 59 +++++++++++++++++++++++++++++++++++++---------
5 files changed, 142 insertions(+), 13 deletions(-)
diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index f65b544..4e2bb91 100644
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -19,6 +19,7 @@
#include <linux/types.h>
#include <linux/if_ether.h>
#include <asm/byteorder.h>
+#include <asm/unaligned.h>
/*
* DS bit usage
@@ -2418,6 +2419,30 @@ static inline bool ieee80211_check_tim(const struct ieee80211_tim_ie *tim,
return !!(tim->virtual_map[index] & mask);
}
+/**
+ * ieee80211_get_tdls_action - get tdls packet action (or -1, if not tdls packet)
+ * @skb: the skb containing the frame, length will not be checked
+ * @hdr_size: the size of the ieee80211_hdr that starts at skb->data
+ *
+ * This function assumes the frame is a data frame, and that the network header
+ * is in the correct place.
+ */
+static inline int ieee80211_get_tdls_action(struct sk_buff *skb, u32 hdr_size)
+{
+ if (!skb_is_nonlinear(skb) &&
+ skb->len > (skb_network_offset(skb) + 2)) {
+ /* Point to where the indication of TDLS should start */
+ const u8 *tdls_data = skb_network_header(skb) - 2;
+
+ if (get_unaligned_be16(tdls_data) == ETH_P_TDLS &&
+ tdls_data[2] == WLAN_TDLS_SNAP_RFTYPE &&
+ tdls_data[3] == WLAN_CATEGORY_TDLS)
+ return tdls_data[4];
+ }
+
+ return -1;
+}
+
/* convert time units */
#define TU_TO_JIFFIES(x) (usecs_to_jiffies((x) * 1024))
#define TU_TO_EXP_TIME(x) (jiffies + TU_TO_JIFFIES(x))
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 208953d..bc6f12f 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -525,8 +525,12 @@ struct ieee80211_if_managed {
struct ieee80211_vht_cap vht_capa; /* configured VHT overrides */
struct ieee80211_vht_cap vht_capa_mask; /* Valid parts of vht_capa */
+ /* TDLS support */
u8 tdls_peer[ETH_ALEN] __aligned(2);
struct delayed_work tdls_peer_del_work;
+ struct sk_buff *orig_teardown_skb; /* The original teardown skb */
+ struct sk_buff *teardown_skb; /* A copy to send through the AP */
+ spinlock_t teardown_lock; /* To lock changing teardown_skb */
/* WMM-AC TSPEC support */
struct ieee80211_sta_tx_tspec tx_tspec[IEEE80211_NUM_ACS];
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 213a420..dc7f088 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -3998,6 +3998,11 @@ void ieee80211_sta_setup_sdata(struct ieee80211_sub_if_data *sdata)
ifmgd->req_smps = IEEE80211_SMPS_AUTOMATIC;
else
ifmgd->req_smps = IEEE80211_SMPS_OFF;
+
+ /* Setup TDLS data */
+ spin_lock_init(&ifmgd->teardown_lock);
+ ifmgd->teardown_skb = NULL;
+ ifmgd->orig_teardown_skb = NULL;
}
/* scan finished notification */
@@ -4860,6 +4865,13 @@ void ieee80211_mgd_stop(struct ieee80211_sub_if_data *sdata)
}
if (ifmgd->auth_data)
ieee80211_destroy_auth_data(sdata, false);
+ spin_lock_bh(&ifmgd->teardown_lock);
+ if (ifmgd->teardown_skb) {
+ kfree_skb(ifmgd->teardown_skb);
+ ifmgd->teardown_skb = NULL;
+ ifmgd->orig_teardown_skb = NULL;
+ }
+ spin_unlock_bh(&ifmgd->teardown_lock);
del_timer_sync(&ifmgd->timer);
sdata_unlock(sdata);
}
diff --git a/net/mac80211/status.c b/net/mac80211/status.c
index 9612d89..71de2d3 100644
--- a/net/mac80211/status.c
+++ b/net/mac80211/status.c
@@ -390,6 +390,46 @@ ieee80211_add_tx_radiotap_header(struct ieee80211_local *local,
}
}
+/*
+ * Handles the tx for TDLS teardown frames.
+ * If the frame wasn't ACKed by the peer - it will be re-sent through the AP
+ */
+static void ieee80211_tdls_td_tx_handle(struct ieee80211_local *local,
+ struct ieee80211_sub_if_data *sdata,
+ struct sk_buff *skb, u32 flags)
+{
+ struct sk_buff *teardown_skb;
+ struct sk_buff *orig_teardown_skb;
+ bool is_teardown = false;
+
+ /* Get the teardown data we need and free the lock */
+ spin_lock(&sdata->u.mgd.teardown_lock);
+ teardown_skb = sdata->u.mgd.teardown_skb;
+ orig_teardown_skb = sdata->u.mgd.orig_teardown_skb;
+ if ((skb == orig_teardown_skb) && teardown_skb) {
+ sdata->u.mgd.teardown_skb = NULL;
+ sdata->u.mgd.orig_teardown_skb = NULL;
+ is_teardown = true;
+ }
+ spin_unlock(&sdata->u.mgd.teardown_lock);
+
+ if (is_teardown) {
+ /* This mechanism relies on being able to get ACKs */
+ WARN_ON(!(local->hw.flags &
+ IEEE80211_HW_REPORTS_TX_ACK_STATUS));
+
+ /* Check if peer has ACKed */
+ if (flags & IEEE80211_TX_STAT_ACK) {
+ dev_kfree_skb_any(teardown_skb);
+ } else {
+ tdls_dbg(sdata,
+ "TDLS Resending teardown through AP\n");
+
+ ieee80211_subif_start_xmit(teardown_skb, skb->dev);
+ }
+ }
+}
+
static void ieee80211_report_used_skb(struct ieee80211_local *local,
struct sk_buff *skb, bool dropped)
{
@@ -426,8 +466,19 @@ static void ieee80211_report_used_skb(struct ieee80211_local *local,
if (!sdata) {
skb->dev = NULL;
} else if (info->flags & IEEE80211_TX_INTFL_MLME_CONN_TX) {
- ieee80211_mgd_conn_tx_status(sdata, hdr->frame_control,
- acked);
+ unsigned int hdr_size =
+ ieee80211_hdrlen(hdr->frame_control);
+
+ /* Check to see if packet is a TDLS teardown packet */
+ if (ieee80211_is_data(hdr->frame_control) &&
+ (ieee80211_get_tdls_action(skb, hdr_size) ==
+ WLAN_TDLS_TEARDOWN))
+ ieee80211_tdls_td_tx_handle(local, sdata, skb,
+ info->flags);
+ else
+ ieee80211_mgd_conn_tx_status(sdata,
+ hdr->frame_control,
+ acked);
} else if (ieee80211_is_nullfunc(hdr->frame_control) ||
ieee80211_is_qos_nullfunc(hdr->frame_control)) {
cfg80211_probe_status(sdata->dev, hdr->addr1,
diff --git a/net/mac80211/tdls.c b/net/mac80211/tdls.c
index b4f368e..d4fe091 100644
--- a/net/mac80211/tdls.c
+++ b/net/mac80211/tdls.c
@@ -512,20 +512,22 @@ ieee80211_tdls_prep_mgmt_packet(struct wiphy *wiphy, struct net_device *dev,
struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
struct ieee80211_local *local = sdata->local;
struct sk_buff *skb = NULL;
+ u32 flags = 0;
bool send_direct;
struct sta_info *sta;
int ret;
- skb = dev_alloc_skb(local->hw.extra_tx_headroom +
- max(sizeof(struct ieee80211_mgmt),
- sizeof(struct ieee80211_tdls_data)) +
- 50 + /* supported rates */
- 7 + /* ext capab */
- 26 + /* max(WMM-info, WMM-param) */
- 2 + max(sizeof(struct ieee80211_ht_cap),
- sizeof(struct ieee80211_ht_operation)) +
- extra_ies_len +
- sizeof(struct ieee80211_tdls_lnkie));
+ skb = netdev_alloc_skb(dev,
+ local->hw.extra_tx_headroom +
+ max(sizeof(struct ieee80211_mgmt),
+ sizeof(struct ieee80211_tdls_data)) +
+ 50 + /* supported rates */
+ 7 + /* ext capab */
+ 26 + /* max(WMM-info, WMM-param) */
+ 2 + max(sizeof(struct ieee80211_ht_cap),
+ sizeof(struct ieee80211_ht_operation)) +
+ extra_ies_len +
+ sizeof(struct ieee80211_tdls_lnkie));
if (!skb)
return -ENOMEM;
@@ -623,9 +625,44 @@ ieee80211_tdls_prep_mgmt_packet(struct wiphy *wiphy, struct net_device *dev,
break;
}
+ /*
+ * Set the WLAN_TDLS_TEARDOWN flag to indicate a teardown in progress.
+ * Later, if no ACK is returned from peer, we will re-send the teardown
+ * packet through the AP.
+ */
+ if ((action_code == WLAN_TDLS_TEARDOWN) &&
+ (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS)) {
+ struct sta_info *sta = NULL;
+ bool try_resend; /* Should we keep skb for possible resend */
+
+ /* If not sending directly to peer - no point in keeping skb */
+ rcu_read_lock();
+ sta = sta_info_get(sdata, peer);
+ try_resend = sta && test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH);
+ rcu_read_unlock();
+
+ spin_lock_bh(&sdata->u.mgd.teardown_lock);
+ if (try_resend && !sdata->u.mgd.teardown_skb) {
+ /* Mark it as requiring TX status callback */
+ flags |= IEEE80211_TX_CTL_REQ_TX_STATUS |
+ IEEE80211_TX_INTFL_MLME_CONN_TX;
+
+ /*
+ * skb is copied since mac80211 will later set
+ * properties that might not be the same as the AP,
+ * such as encryption, QoS, addresses, etc.
+ *
+ * No problem if skb_copy() fails, so no need to check.
+ */
+ sdata->u.mgd.teardown_skb = skb_copy(skb, GFP_ATOMIC);
+ sdata->u.mgd.orig_teardown_skb = skb;
+ }
+ spin_unlock_bh(&sdata->u.mgd.teardown_lock);
+ }
+
/* disable bottom halves when entering the Tx path */
local_bh_disable();
- ret = ieee80211_subif_start_xmit(skb, dev);
+ __ieee80211_subif_start_xmit(skb, dev, flags);
local_bh_enable();
return ret;
--
1.9.1
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