[PATCH wpan-next v5] mac802154: Ensure proper scan-level filtering

From: Miquel Raynal <miquel.raynal@bootlin.com>
To: Alexander Aring <alex.aring@gmail.com>,
	Stefan Schmidt <stefan@datenfreihafen.org>,
	linux-wpan@vger.kernel.org
Cc: "David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Eric Dumazet <edumazet@google.com>,
	netdev@vger.kernel.org, David Girault <david.girault@qorvo.com>,
	Romuald Despres <romuald.despres@qorvo.com>,
	Frederic Blain <frederic.blain@qorvo.com>,
	Nicolas Schodet <nico@ni.fr.eu.org>,
	Guilhem Imberton <guilhem.imberton@qorvo.com>,
	Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
	Miquel Raynal <miquel.raynal@bootlin.com>
Subject: [PATCH wpan-next v5] mac802154: Ensure proper scan-level filtering
Date: Tue, 18 Oct 2022 20:35:40 +0200	[thread overview]
Message-ID: <20221018183540.806471-1-miquel.raynal@bootlin.com> (raw)

We now have a fine grained filtering information so let's ensure proper
filtering in scan mode, which means that only beacons are processed.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---

Changes in v4:
* dev_dbg call with: s/!beacon/non-beacon/.
* Rebased on top of wpan-next but there is still a commit that has not
  been merged (went through a fixes PR), but is already in Linus' tree
  and was present in my branch when I generated this patch.

 net/mac802154/rx.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/net/mac802154/rx.c b/net/mac802154/rx.c
index 14bc646b9ab7..2ae23a2f4a09 100644
--- a/net/mac802154/rx.c
+++ b/net/mac802154/rx.c
@@ -34,6 +34,7 @@ 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;
 	__le16 span, sshort;
 	int rc;
 
@@ -42,6 +43,17 @@ ieee802154_subif_frame(struct ieee802154_sub_if_data *sdata,
 	span = wpan_dev->pan_id;
 	sshort = wpan_dev->short_addr;
 
+	/* Level 3 filtering: Only beacons are accepted during scans */
+	if (sdata->required_filtering == IEEE802154_FILTERING_3_SCAN &&
+	    sdata->required_filtering > wpan_phy->filtering) {
+		if (mac_cb(skb)->type != IEEE802154_FC_TYPE_BEACON) {
+			dev_dbg(&sdata->dev->dev,
+				"drop non-beacon frame (0x%x) during scan\n",
+				mac_cb(skb)->type);
+			goto fail;
+		}
+	}
+
 	switch (mac_cb(skb)->dest.mode) {
 	case IEEE802154_ADDR_NONE:
 		if (hdr->source.mode != IEEE802154_ADDR_NONE)
@@ -277,10 +289,6 @@ void ieee802154_rx(struct ieee802154_local *local, struct sk_buff *skb)
 
 	ieee802154_monitors_rx(local, skb);
 
-	/* TODO: Handle upcomming receive path where the PHY is at the
-	 * IEEE802154_FILTERING_NONE level during a scan.
-	 */
-
 	/* Level 1 filtering: Check the FCS by software when relevant */
 	if (local->hw.phy->filtering == IEEE802154_FILTERING_NONE) {
 		crc = crc_ccitt(0, skb->data, skb->len);
-- 
2.34.1

