[PATCH wpan/next v3 6/9] net: mac802154: Add promiscuous software filtering

[Miquel Raynal <miquel.raynal@bootlin.com>]

Currently, the promiscuous mode was not as open as it should. It was not
a big deal because until now promiscuous modes were only used on monitor
interfaces, which would never go this far in the filtering. But as we
might now use this promiscuous mode with NODEs or COORDs, it becomes
necessary to really forward the packets to the upper layers without
additional filtering when relevant. Let's add the necessary logic to
handle this situation.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
 net/mac802154/rx.c | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/net/mac802154/rx.c b/net/mac802154/rx.c
index bd1a92fceef7..8a8c5a4a2f28 100644
--- a/net/mac802154/rx.c
+++ b/net/mac802154/rx.c
@@ -196,10 +196,31 @@ __ieee802154_rx_handle_packet(struct ieee802154_local *local,
 	int ret;
 	struct ieee802154_sub_if_data *sdata;
 	struct ieee802154_hdr hdr;
+	struct sk_buff *skb2;
 
+	/* Level 2 filtering: Avoid further processing in IEEE 802.15.4 promiscuous modes */
+	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
+		if (!ieee802154_sdata_running(sdata))
+			continue;
+
+		if (sdata->required_filtering < IEEE802154_FILTERING_1_FCS ||
+		    sdata->required_filtering > IEEE802154_FILTERING_2_PROMISCUOUS)
+			continue;
+
+		skb2 = skb_clone(skb, GFP_ATOMIC);
+		if (skb2) {
+			skb2->dev = sdata->dev;
+			ieee802154_deliver_skb(skb2);
+
+			sdata->dev->stats.rx_packets++;
+			sdata->dev->stats.rx_bytes += skb->len;
+		}
+	}
+
+	/* Common filtering between level 3 and 4: frame headers validity */
 	ret = ieee802154_parse_frame_start(skb, &hdr);
 	if (ret) {
-		pr_debug("got invalid frame\n");
+		dev_dbg(&sdata->dev->dev, "invalid frame headers\n");
 		kfree_skb(skb);
 		return;
 	}
@@ -208,7 +229,7 @@ __ieee802154_rx_handle_packet(struct ieee802154_local *local,
 		if (!ieee802154_sdata_running(sdata))
 			continue;
 
-		if (sdata->required_filtering == IEEE802154_FILTERING_NONE)
+		if (sdata->required_filtering <= IEEE802154_FILTERING_2_PROMISCUOUS)
 			continue;
 
 		ieee802154_subif_frame(sdata, skb, &hdr);
-- 
2.34.1