Unsolicited broadcast probe response tranmission is used for in-band
discovery in 6GHz band (IEEE P802.11ax/D6.0 26.17.2.3.2, AP behavior for
fast passive scanning).
v3: Rebased. Removed check for 6Ghz, drivers should add that check.
v2: Removed flag 'enabled' and changed 6GHz frequency range as per
IEEE P802.11ax/D6.1.
Aloka Dixit (2):
nl80211: Unsolicited broadcast probe response support
mac80211: Unsolicited broadcast probe response support
include/net/cfg80211.h | 18 ++++++++++++++
include/net/mac80211.h | 21 ++++++++++++++++
include/uapi/linux/nl80211.h | 32 ++++++++++++++++++++++++
net/mac80211/cfg.c | 42 ++++++++++++++++++++++++++++++++
net/mac80211/ieee80211_i.h | 7 ++++++
net/mac80211/tx.c | 26 ++++++++++++++++++++
net/wireless/nl80211.c | 47 ++++++++++++++++++++++++++++++++++++
7 files changed, 193 insertions(+)
--
2.25.0
This patch adds mac80211 support to configure unsolicited
broadcast probe response transmission for in-band discovery in 6GHz.
Changes include functions to store and retrieve probe response template,
and packet interval (0 - 20 TUs).
Setting interval to 0 disables the unsolicited broadcast probe response
transmission.
Signed-off-by: Aloka Dixit <[email protected]>
---
include/net/mac80211.h | 21 +++++++++++++++++++
net/mac80211/cfg.c | 42 ++++++++++++++++++++++++++++++++++++++
net/mac80211/ieee80211_i.h | 7 +++++++
net/mac80211/tx.c | 26 +++++++++++++++++++++++
4 files changed, 96 insertions(+)
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 11d5610d2ad5..90800558725c 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -317,6 +317,8 @@ struct ieee80211_vif_chanctx_switch {
* @BSS_CHANGED_TWT: TWT status changed
* @BSS_CHANGED_HE_OBSS_PD: OBSS Packet Detection status changed.
* @BSS_CHANGED_HE_BSS_COLOR: BSS Color has changed
+ * @BSS_CHANGED_UNSOL_BCAST_PROBE_RESP: Unsolicited broadcast probe response
+ * status changed.
*
*/
enum ieee80211_bss_change {
@@ -350,6 +352,7 @@ enum ieee80211_bss_change {
BSS_CHANGED_TWT = 1<<27,
BSS_CHANGED_HE_OBSS_PD = 1<<28,
BSS_CHANGED_HE_BSS_COLOR = 1<<29,
+ BSS_CHANGED_UNSOL_BCAST_PROBE_RESP = 1<<30,
/* when adding here, make sure to change ieee80211_reconfig */
};
@@ -607,6 +610,8 @@ struct ieee80211_ftm_responder_params {
* @he_oper: HE operation information of the AP we are connected to
* @he_obss_pd: OBSS Packet Detection parameters.
* @he_bss_color: BSS coloring settings, if BSS supports HE
+ * @unsol_bcast_probe_resp_interval: Unsolicited broadcast probe response
+ * interval.
*/
struct ieee80211_bss_conf {
const u8 *bssid;
@@ -674,6 +679,7 @@ struct ieee80211_bss_conf {
} he_oper;
struct ieee80211_he_obss_pd he_obss_pd;
struct cfg80211_he_bss_color he_bss_color;
+ u32 unsol_bcast_probe_resp_interval;
};
/**
@@ -6558,4 +6564,19 @@ u32 ieee80211_calc_tx_airtime(struct ieee80211_hw *hw,
*/
bool ieee80211_set_hw_80211_encap(struct ieee80211_vif *vif, bool enable);
+
+/**
+ * ieee80211_get_unsol_bcast_probe_resp_tmpl - Get unsolicited broadcast
+ * probe response template.
+ * @hw: pointer obtained from ieee80211_alloc_hw().
+ * @vif: &struct ieee80211_vif pointer from the add_interface callback.
+ *
+ * The driver is responsible for freeing the returned skb.
+ *
+ * Return: Unsolicited broadcast probe response template. %NULL on error.
+ */
+struct sk_buff *
+ieee80211_get_unsol_bcast_probe_resp_tmpl(struct ieee80211_hw *hw,
+ struct ieee80211_vif *vif);
+
#endif /* MAC80211_H */
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 9b360544ad6f..3db24325f545 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -837,6 +837,32 @@ static int ieee80211_set_probe_resp(struct ieee80211_sub_if_data *sdata,
return 0;
}
+static int
+ieee80211_set_unsol_bcast_probe_resp(struct ieee80211_sub_if_data *sdata,
+ struct cfg80211_unsol_bcast_probe_resp *params)
+{
+ struct unsol_bcast_probe_resp_data *new, *old = NULL;
+
+ sdata->vif.bss_conf.unsol_bcast_probe_resp_interval =
+ params->interval;
+
+ if (!params->tmpl || !params->tmpl_len) /* Optional template */
+ return 0;
+
+ old = sdata_dereference(sdata->u.ap.unsol_bcast_probe_resp, sdata);
+ new = kzalloc(sizeof(*new) + params->tmpl_len, GFP_KERNEL);
+ if (!new)
+ return -ENOMEM;
+ new->len = params->tmpl_len;
+ memcpy(new->data, params->tmpl, params->tmpl_len);
+ rcu_assign_pointer(sdata->u.ap.unsol_bcast_probe_resp, new);
+
+ if (old)
+ kfree_rcu(old, rcu_head);
+
+ return 0;
+}
+
static int ieee80211_set_ftm_responder_params(
struct ieee80211_sub_if_data *sdata,
const u8 *lci, size_t lci_len,
@@ -1103,6 +1129,15 @@ static int ieee80211_start_ap(struct wiphy *wiphy, struct net_device *dev,
}
changed |= err;
+ err = ieee80211_set_unsol_bcast_probe_resp(sdata,
+ ¶ms->unsol_bcast_probe_resp);
+ if (err < 0) {
+ ieee80211_vif_release_channel(sdata);
+ return err;
+ } else if (err == 0) {
+ changed |= BSS_CHANGED_UNSOL_BCAST_PROBE_RESP;
+ }
+
err = drv_start_ap(sdata->local, sdata);
if (err) {
old = sdata_dereference(sdata->u.ap.beacon, sdata);
@@ -1158,6 +1193,7 @@ static int ieee80211_stop_ap(struct wiphy *wiphy, struct net_device *dev)
struct ieee80211_local *local = sdata->local;
struct beacon_data *old_beacon;
struct probe_resp *old_probe_resp;
+ struct unsol_bcast_probe_resp_data *old_unsol_bcast_probe_resp;
struct cfg80211_chan_def chandef;
sdata_assert_lock(sdata);
@@ -1166,6 +1202,9 @@ static int ieee80211_stop_ap(struct wiphy *wiphy, struct net_device *dev)
if (!old_beacon)
return -ENOENT;
old_probe_resp = sdata_dereference(sdata->u.ap.probe_resp, sdata);
+ old_unsol_bcast_probe_resp =
+ sdata_dereference(sdata->u.ap.unsol_bcast_probe_resp,
+ sdata);
/* abort any running channel switch */
mutex_lock(&local->mtx);
@@ -1189,9 +1228,12 @@ static int ieee80211_stop_ap(struct wiphy *wiphy, struct net_device *dev)
/* remove beacon and probe response */
RCU_INIT_POINTER(sdata->u.ap.beacon, NULL);
RCU_INIT_POINTER(sdata->u.ap.probe_resp, NULL);
+ RCU_INIT_POINTER(sdata->u.ap.unsol_bcast_probe_resp, NULL);
kfree_rcu(old_beacon, rcu_head);
if (old_probe_resp)
kfree_rcu(old_probe_resp, rcu_head);
+ if (old_unsol_bcast_probe_resp)
+ kfree_rcu(old_unsol_bcast_probe_resp, rcu_head);
kfree(sdata->vif.bss_conf.ftmr_params);
sdata->vif.bss_conf.ftmr_params = NULL;
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index ec1a71ac65f2..b54108ef3560 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -272,6 +272,12 @@ struct probe_resp {
u8 data[];
};
+struct unsol_bcast_probe_resp_data {
+ struct rcu_head rcu_head;
+ int len;
+ u8 data[];
+};
+
struct ps_data {
/* yes, this looks ugly, but guarantees that we can later use
* bitmap_empty :)
@@ -287,6 +293,7 @@ struct ps_data {
struct ieee80211_if_ap {
struct beacon_data __rcu *beacon;
struct probe_resp __rcu *probe_resp;
+ struct unsol_bcast_probe_resp_data __rcu *unsol_bcast_probe_resp;
/* to be used after channel switch. */
struct cfg80211_beacon_data *next_beacon;
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index e9ce658141f5..3657dc799ca5 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -4998,6 +4998,32 @@ struct sk_buff *ieee80211_proberesp_get(struct ieee80211_hw *hw,
}
EXPORT_SYMBOL(ieee80211_proberesp_get);
+struct sk_buff *
+ieee80211_get_unsol_bcast_probe_resp_tmpl(struct ieee80211_hw *hw,
+ struct ieee80211_vif *vif)
+{
+ struct sk_buff *skb = NULL;
+ struct unsol_bcast_probe_resp_data *tmpl = NULL;
+ struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
+
+ if (sdata->vif.type != NL80211_IFTYPE_AP)
+ return NULL;
+
+ rcu_read_lock();
+ tmpl = rcu_dereference(sdata->u.ap.unsol_bcast_probe_resp);
+ if (!tmpl) {
+ rcu_read_unlock();
+ return NULL;
+ }
+
+ skb = dev_alloc_skb(tmpl->len);
+ if (skb)
+ skb_put_data(skb, tmpl->data, tmpl->len);
+ rcu_read_unlock();
+ return skb;
+}
+EXPORT_SYMBOL(ieee80211_get_unsol_bcast_probe_resp_tmpl);
+
struct sk_buff *ieee80211_pspoll_get(struct ieee80211_hw *hw,
struct ieee80211_vif *vif)
{
--
2.25.0
On 7/16/2020 1:05 AM, Aloka Dixit wrote:
> Unsolicited broadcast probe response tranmission is used for in-band
> discovery in 6GHz band (IEEE P802.11ax/D6.0 26.17.2.3.2, AP behavior for
> fast passive scanning).
>
> v3: Rebased. Removed check for 6Ghz, drivers should add that check.
I have not seen any comments in v2 so could you motivate this removal.
It is a sanity check that is always needed so doing it in the nl80211
api seems the proper place.
Regards,
Arend
On 2020-07-16 02:35, Arend Van Spriel wrote:
> On 7/16/2020 1:05 AM, Aloka Dixit wrote:
>> Unsolicited broadcast probe response tranmission is used for in-band
>> discovery in 6GHz band (IEEE P802.11ax/D6.0 26.17.2.3.2, AP behavior
>> for
>> fast passive scanning).
>>
>> v3: Rebased. Removed check for 6Ghz, drivers should add that check.
>
> I have not seen any comments in v2 so could you motivate this removal.
> It is a sanity check that is always needed so doing it in the nl80211
> api seems the proper place.
>
> Regards,
> Arend
Hi Arend,
I found that if any application sends
NL80211_ATTR_UNSOL_BCAST_PROBE_RESP with
NL80211_UNSOL_BCAST_PROBE_RESP_INT=0 (which means disable) for 2.4/5GHz,
the check here resulted in AP not being brought up.
Technically disabling this feature for 2.4/5GHz is not required as it is
disabled by default but it should not cause issues if done so
explicitly. Hence I removed the check here so that drivers can decide to
use/ignore this attribute.