mac80211: allow drivers to support NL80211_SCAN_FLAG_RANDOM_ADDR

Allow drivers to support NL80211_SCAN_FLAG_RANDOM_ADDR with software
based scanning and generate a random MAC address for them for every
scan request with the flag.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

7 files changed, 92 insertions, 38 deletions

diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h
index ba0d2cb5df12..5f5fc3f3ee7c 100644
--- a/net/mac80211/driver-ops.h
+++ b/net/mac80211/driver-ops.h
@@ -380,23 +380,26 @@ static inline int drv_sched_scan_stop(struct ieee80211_local *local,
 	return ret;
 }
 
-static inline void drv_sw_scan_start(struct ieee80211_local *local)
+static inline void drv_sw_scan_start(struct ieee80211_local *local,
+				     struct ieee80211_sub_if_data *sdata,
+				     const u8 *mac_addr)
 {
 	might_sleep();
 
-	trace_drv_sw_scan_start(local);
+	trace_drv_sw_scan_start(local, sdata, mac_addr);
 	if (local->ops->sw_scan_start)
-		local->ops->sw_scan_start(&local->hw);
+		local->ops->sw_scan_start(&local->hw, &sdata->vif, mac_addr);
 	trace_drv_return_void(local);
 }
 
-static inline void drv_sw_scan_complete(struct ieee80211_local *local)
+static inline void drv_sw_scan_complete(struct ieee80211_local *local,
+					struct ieee80211_sub_if_data *sdata)
 {
 	might_sleep();
 
-	trace_drv_sw_scan_complete(local);
+	trace_drv_sw_scan_complete(local, sdata);
 	if (local->ops->sw_scan_complete)
-		local->ops->sw_scan_complete(&local->hw);
+		local->ops->sw_scan_complete(&local->hw, &sdata->vif);
 	trace_drv_return_void(local);
 }
 
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index dd27180060b9..cf95d033bcbf 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1249,6 +1249,7 @@ struct ieee80211_local {
 	struct work_struct sched_scan_stopped_work;
 	struct ieee80211_sub_if_data __rcu *sched_scan_sdata;
 	struct cfg80211_sched_scan_request __rcu *sched_scan_req;
+	u8 scan_addr[ETH_ALEN];
 
 	unsigned long leave_oper_channel_time;
 	enum mac80211_scan_state next_scan_state;
@@ -1901,12 +1902,14 @@ int ieee80211_build_preq_ies(struct ieee80211_local *local, u8 *buffer,
 			     u8 bands_used, u32 *rate_masks,
 			     struct cfg80211_chan_def *chandef);
 struct sk_buff *ieee80211_build_probe_req(struct ieee80211_sub_if_data *sdata,
-					  u8 *dst, u32 ratemask,
+					  const u8 *src, const u8 *dst,
+					  u32 ratemask,
 					  struct ieee80211_channel *chan,
 					  const u8 *ssid, size_t ssid_len,
 					  const u8 *ie, size_t ie_len,
 					  bool directed);
-void ieee80211_send_probe_req(struct ieee80211_sub_if_data *sdata, u8 *dst,
+void ieee80211_send_probe_req(struct ieee80211_sub_if_data *sdata,
+			      const u8 *src, const u8 *dst,
 			      const u8 *ssid, size_t ssid_len,
 			      const u8 *ie, size_t ie_len,
 			      u32 ratemask, bool directed, u32 tx_flags,
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 45490a202d9c..d29589a09065 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -2225,7 +2225,8 @@ static void ieee80211_mgd_probe_ap_send(struct ieee80211_sub_if_data *sdata)
 		else
 			ssid_len = ssid[1];
 
-		ieee80211_send_probe_req(sdata, dst, ssid + 2, ssid_len, NULL,
+		ieee80211_send_probe_req(sdata, sdata->vif.addr, NULL,
+					 ssid + 2, ssid_len, NULL,
 					 0, (u32) -1, true, 0,
 					 ifmgd->associated->channel, false);
 		rcu_read_unlock();
@@ -2328,7 +2329,7 @@ struct sk_buff *ieee80211_ap_probereq_get(struct ieee80211_hw *hw,
 	else
 		ssid_len = ssid[1];
 
-	skb = ieee80211_build_probe_req(sdata, cbss->bssid,
+	skb = ieee80211_build_probe_req(sdata, sdata->vif.addr, cbss->bssid,
 					(u32) -1, cbss->channel,
 					ssid + 2, ssid_len,
 					NULL, 0, true);
@@ -3649,7 +3650,8 @@ static int ieee80211_probe_auth(struct ieee80211_sub_if_data *sdata)
 		 * Direct probe is sent to broadcast address as some APs
 		 * will not answer to direct packet in unassociated state.
 		 */
-		ieee80211_send_probe_req(sdata, NULL, ssidie + 2, ssidie[1],
+		ieee80211_send_probe_req(sdata, sdata->vif.addr, NULL,
+					 ssidie + 2, ssidie[1],
 					 NULL, 0, (u32) -1, true, 0,
 					 auth_data->bss->channel, false);
 		rcu_read_unlock();
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index e75e64b8042c..ae842678b629 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -184,9 +184,21 @@ void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
 		return;
 
 	if (ieee80211_is_probe_resp(mgmt->frame_control)) {
-		/* ignore ProbeResp to foreign address */
-		if ((!sdata1 || !ether_addr_equal(mgmt->da, sdata1->vif.addr)) &&
-		    (!sdata2 || !ether_addr_equal(mgmt->da, sdata2->vif.addr)))
+		struct cfg80211_scan_request *scan_req;
+		struct cfg80211_sched_scan_request *sched_scan_req;
+
+		scan_req = rcu_dereference(local->scan_req);
+		sched_scan_req = rcu_dereference(local->sched_scan_req);
+
+		/* ignore ProbeResp to foreign address unless scanning
+		 * with randomised address
+		 */
+		if (!(sdata1 &&
+		      (ether_addr_equal(mgmt->da, sdata1->vif.addr) ||
+		       scan_req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)) &&
+		    !(sdata2 &&
+		      (ether_addr_equal(mgmt->da, sdata2->vif.addr) ||
+		       sched_scan_req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)))
 			return;
 
 		elements = mgmt->u.probe_resp.variable;
@@ -284,6 +296,9 @@ static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
 					 bands_used, req->rates, &chandef);
 	local->hw_scan_req->req.ie_len = ielen;
 	local->hw_scan_req->req.no_cck = req->no_cck;
+	ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
+	ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
+			req->mac_addr_mask);
 
 	return true;
 }
@@ -294,6 +309,7 @@ static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
 	bool hw_scan = local->ops->hw_scan;
 	bool was_scanning = local->scanning;
 	struct cfg80211_scan_request *scan_req;
+	struct ieee80211_sub_if_data *scan_sdata;
 
 	lockdep_assert_held(&local->mtx);
 
@@ -332,6 +348,9 @@ static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
 	if (scan_req != local->int_scan_req)
 		cfg80211_scan_done(scan_req, aborted);
 	RCU_INIT_POINTER(local->scan_req, NULL);
+
+	scan_sdata = rcu_dereference_protected(local->scan_sdata,
+					       lockdep_is_held(&local->mtx));
 	RCU_INIT_POINTER(local->scan_sdata, NULL);
 
 	local->scanning = 0;
@@ -342,7 +361,7 @@ static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
 
 	if (!hw_scan) {
 		ieee80211_configure_filter(local);
-		drv_sw_scan_complete(local);
+		drv_sw_scan_complete(local, scan_sdata);
 		ieee80211_offchannel_return(local);
 	}
 
@@ -368,7 +387,8 @@ void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
 }
 EXPORT_SYMBOL(ieee80211_scan_completed);
 
-static int ieee80211_start_sw_scan(struct ieee80211_local *local)
+static int ieee80211_start_sw_scan(struct ieee80211_local *local,
+				   struct ieee80211_sub_if_data *sdata)
 {
 	/* Software scan is not supported in multi-channel cases */
 	if (local->use_chanctx)
@@ -387,7 +407,7 @@ static int ieee80211_start_sw_scan(struct ieee80211_local *local)
 	 * nullfunc frames and probe requests will be dropped in
 	 * ieee80211_tx_h_check_assoc().
 	 */
-	drv_sw_scan_start(local);
+	drv_sw_scan_start(local, sdata, local->scan_addr);
 
 	local->leave_oper_channel_time = jiffies;
 	local->next_scan_state = SCAN_DECISION;
@@ -463,7 +483,7 @@ static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
 
 	for (i = 0; i < scan_req->n_ssids; i++)
 		ieee80211_send_probe_req(
-			sdata, NULL,
+			sdata, local->scan_addr, NULL,
 			scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
 			scan_req->ie, scan_req->ie_len,
 			scan_req->rates[band], false,
@@ -543,6 +563,13 @@ static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
 	rcu_assign_pointer(local->scan_req, req);
 	rcu_assign_pointer(local->scan_sdata, sdata);
 
+	if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
+		get_random_mask_addr(local->scan_addr,
+				     req->mac_addr,
+				     req->mac_addr_mask);
+	else
+		memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
+
 	if (local->ops->hw_scan) {
 		__set_bit(SCAN_HW_SCANNING, &local->scanning);
 	} else if ((req->n_channels == 1) &&
@@ -559,7 +586,7 @@ static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
 
 		/* Notify driver scan is starting, keep order of operations
 		 * same as normal software scan, in case that matters. */
-		drv_sw_scan_start(local);
+		drv_sw_scan_start(local, sdata, local->scan_addr);
 
 		ieee80211_configure_filter(local); /* accept probe-responses */
 
@@ -589,8 +616,9 @@ static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
 	if (local->ops->hw_scan) {
 		WARN_ON(!ieee80211_prep_hw_scan(local));
 		rc = drv_hw_scan(local, sdata, local->hw_scan_req);
-	} else
-		rc = ieee80211_start_sw_scan(local);
+	} else {
+		rc = ieee80211_start_sw_scan(local, sdata);
+	}
 
 	if (rc) {
 		kfree(local->hw_scan_req);
diff --git a/net/mac80211/trace.h b/net/mac80211/trace.h
index 7f76e2f25744..eb91505eb43e 100644
--- a/net/mac80211/trace.h
+++ b/net/mac80211/trace.h
@@ -596,14 +596,33 @@ DEFINE_EVENT(local_sdata_evt, drv_sched_scan_stop,
 	TP_ARGS(local, sdata)
 );
 
-DEFINE_EVENT(local_only_evt, drv_sw_scan_start,
-	TP_PROTO(struct ieee80211_local *local),
-	TP_ARGS(local)
+TRACE_EVENT(drv_sw_scan_start,
+	TP_PROTO(struct ieee80211_local *local,
+		 struct ieee80211_sub_if_data *sdata,
+		 const u8 *mac_addr),
+
+	TP_ARGS(local, sdata, mac_addr),
+
+	TP_STRUCT__entry(
+		LOCAL_ENTRY
+		VIF_ENTRY
+		__array(char, mac_addr, ETH_ALEN)
+	),
+
+	TP_fast_assign(
+		LOCAL_ASSIGN;
+		VIF_ASSIGN;
+		memcpy(__entry->mac_addr, mac_addr, ETH_ALEN);
+	),
+
+	TP_printk(LOCAL_PR_FMT ", " VIF_PR_FMT ", addr:%pM",
+		  LOCAL_PR_ARG, VIF_PR_ARG, __entry->mac_addr)
 );
 
-DEFINE_EVENT(local_only_evt, drv_sw_scan_complete,
-	TP_PROTO(struct ieee80211_local *local),
-	TP_ARGS(local)
+DEFINE_EVENT(local_sdata_evt, drv_sw_scan_complete,
+	TP_PROTO(struct ieee80211_local *local,
+		 struct ieee80211_sub_if_data *sdata),
+	TP_ARGS(local, sdata)
 );
 
 TRACE_EVENT(drv_get_stats,
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 0cb41d1a1f20..66ddbbeccd20 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -2961,19 +2961,16 @@ struct sk_buff *ieee80211_nullfunc_get(struct ieee80211_hw *hw,
 EXPORT_SYMBOL(ieee80211_nullfunc_get);
 
 struct sk_buff *ieee80211_probereq_get(struct ieee80211_hw *hw,
-				       struct ieee80211_vif *vif,
+				       const u8 *src_addr,
 				       const u8 *ssid, size_t ssid_len,
 				       size_t tailroom)
 {
-	struct ieee80211_sub_if_data *sdata;
-	struct ieee80211_local *local;
+	struct ieee80211_local *local = hw_to_local(hw);
 	struct ieee80211_hdr_3addr *hdr;
 	struct sk_buff *skb;
 	size_t ie_ssid_len;
 	u8 *pos;
 
-	sdata = vif_to_sdata(vif);
-	local = sdata->local;
 	ie_ssid_len = 2 + ssid_len;
 
 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*hdr) +
@@ -2988,7 +2985,7 @@ struct sk_buff *ieee80211_probereq_get(struct ieee80211_hw *hw,
 	hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 					 IEEE80211_STYPE_PROBE_REQ);
 	eth_broadcast_addr(hdr->addr1);
-	memcpy(hdr->addr2, vif->addr, ETH_ALEN);
+	memcpy(hdr->addr2, src_addr, ETH_ALEN);
 	eth_broadcast_addr(hdr->addr3);
 
 	pos = skb_put(skb, ie_ssid_len);
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 0ad534abc008..bb9664cb8831 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -1523,7 +1523,8 @@ int ieee80211_build_preq_ies(struct ieee80211_local *local, u8 *buffer,
 };
 
 struct sk_buff *ieee80211_build_probe_req(struct ieee80211_sub_if_data *sdata,
-					  u8 *dst, u32 ratemask,
+					  const u8 *src, const u8 *dst,
+					  u32 ratemask,
 					  struct ieee80211_channel *chan,
 					  const u8 *ssid, size_t ssid_len,
 					  const u8 *ie, size_t ie_len,
@@ -1548,8 +1549,8 @@ struct sk_buff *ieee80211_build_probe_req(struct ieee80211_sub_if_data *sdata,
 	else
 		chandef.chan = chan;
 
-	skb = ieee80211_probereq_get(&local->hw, &sdata->vif,
-				     ssid, ssid_len, 100 + ie_len);
+	skb = ieee80211_probereq_get(&local->hw, src, ssid, ssid_len,
+				     100 + ie_len);
 	if (!skb)
 		return NULL;
 
@@ -1571,7 +1572,8 @@ struct sk_buff *ieee80211_build_probe_req(struct ieee80211_sub_if_data *sdata,
 	return skb;
 }
 
-void ieee80211_send_probe_req(struct ieee80211_sub_if_data *sdata, u8 *dst,
+void ieee80211_send_probe_req(struct ieee80211_sub_if_data *sdata,
+			      const u8 *src, const u8 *dst,
 			      const u8 *ssid, size_t ssid_len,
 			      const u8 *ie, size_t ie_len,
 			      u32 ratemask, bool directed, u32 tx_flags,
@@ -1579,7 +1581,7 @@ void ieee80211_send_probe_req(struct ieee80211_sub_if_data *sdata, u8 *dst,
 {
 	struct sk_buff *skb;
 
-	skb = ieee80211_build_probe_req(sdata, dst, ratemask, channel,
+	skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
 					ssid, ssid_len,
 					ie, ie_len, directed);
 	if (skb) {