mac802154: Handle passive scanning

Implement the core hooks in order to provide the softMAC layer support
for passive scans. Scans are requested by the user and can be aborted.

Changing channels manually is prohibited during scans.

The implementation uses a workqueue triggered at a certain interval
depending on the symbol duration for the current channel and the
duration order provided. More advanced drivers with internal scheduling
capabilities might require additional care but there is none mainline
yet.

Received beacons during a passive scan are processed in a work queue and
their result forwarded to the upper layer.

Active scanning is not supported yet.

Co-developed-by: David Girault <david.girault@qorvo.com>
Signed-off-by: David Girault <david.girault@qorvo.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Alexander Aring <aahringo@redhat.com>
Link: https://lore.kernel.org/r/20230103165644.432209-7-miquel.raynal@bootlin.com
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>

1 files changed, 35 insertions, 1 deletions

diff --git a/net/mac802154/rx.c b/net/mac802154/rx.c
index c2aae2a6d6a6..2b0a80571097 100644
--- a/net/mac802154/rx.c
+++ b/net/mac802154/rx.c
@@ -29,12 +29,31 @@ static int ieee802154_deliver_skb(struct sk_buff *skb)
 	return netif_receive_skb(skb);
 }
 
+void mac802154_rx_beacon_worker(struct work_struct *work)
+{
+	struct ieee802154_local *local =
+		container_of(work, struct ieee802154_local, rx_beacon_work);
+	struct cfg802154_mac_pkt *mac_pkt;
+
+	mac_pkt = list_first_entry_or_null(&local->rx_beacon_list,
+					   struct cfg802154_mac_pkt, node);
+	if (!mac_pkt)
+		return;
+
+	mac802154_process_beacon(local, mac_pkt->skb, mac_pkt->page, mac_pkt->channel);
+
+	list_del(&mac_pkt->node);
+	kfree_skb(mac_pkt->skb);
+	kfree(mac_pkt);
+}
+
 static int
 ieee802154_subif_frame(struct ieee802154_sub_if_data *sdata,
 		       struct sk_buff *skb, const struct ieee802154_hdr *hdr)
 {
-	struct wpan_dev *wpan_dev = &sdata->wpan_dev;
 	struct wpan_phy *wpan_phy = sdata->local->hw.phy;
+	struct wpan_dev *wpan_dev = &sdata->wpan_dev;
+	struct cfg802154_mac_pkt *mac_pkt;
 	__le16 span, sshort;
 	int rc;
 
@@ -106,6 +125,21 @@ ieee802154_subif_frame(struct ieee802154_sub_if_data *sdata,
 
 	switch (mac_cb(skb)->type) {
 	case IEEE802154_FC_TYPE_BEACON:
+		dev_dbg(&sdata->dev->dev, "BEACON received\n");
+		if (!mac802154_is_scanning(sdata->local))
+			goto fail;
+
+		mac_pkt = kzalloc(sizeof(*mac_pkt), GFP_ATOMIC);
+		if (!mac_pkt)
+			goto fail;
+
+		mac_pkt->skb = skb_get(skb);
+		mac_pkt->sdata = sdata;
+		mac_pkt->page = sdata->local->scan_page;
+		mac_pkt->channel = sdata->local->scan_channel;
+		list_add_tail(&mac_pkt->node, &sdata->local->rx_beacon_list);
+		queue_work(sdata->local->mac_wq, &sdata->local->rx_beacon_work);
+		return NET_RX_SUCCESS;
 	case IEEE802154_FC_TYPE_ACK:
 	case IEEE802154_FC_TYPE_MAC_CMD:
 		goto fail;