[RFC 08/18] net: macsec: support multicast/broadcast when offloading

[Igor Russkikh <irusskikh@marvell.com>]

From: Mark Starovoytov <mstarovoitov@marvell.com>

The idea is simple. If the frame is an exact match for the controlled port
(based on DA comparison), then we simply divert this skb to matching port.

Multicast/broadcast messages are delivered to all ports.

Signed-off-by: Mark Starovoytov <mstarovoitov@marvell.com>
Signed-off-by: Igor Russkikh <irusskikh@marvell.com>
---
 drivers/net/macsec.c | 51 +++++++++++++++++++++++++++++++++-----------
 1 file changed, 38 insertions(+), 13 deletions(-)

diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
index 066d61238b11..01da47b47f64 100644
--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -952,22 +952,53 @@ static enum rx_handler_result handle_not_macsec(struct sk_buff *skb)
 {
 	/* Deliver to the uncontrolled port by default */
 	enum rx_handler_result ret = RX_HANDLER_PASS;
+	struct ethhdr *hdr = eth_hdr(skb);
 	struct macsec_rxh_data *rxd;
 	struct macsec_dev *macsec;
 
 	rcu_read_lock();
 	rxd = macsec_data_rcu(skb->dev);
 
-	/* 10.6 If the management control validateFrames is not
-	 * Strict, frames without a SecTAG are received, counted, and
-	 * delivered to the Controlled Port
-	 */
 	list_for_each_entry_rcu(macsec, &rxd->secys, secys) {
 		struct sk_buff *nskb;
 		struct pcpu_secy_stats *secy_stats = this_cpu_ptr(macsec->stats);
+		struct net_device *ndev = macsec->secy.netdev;
 
-		if (!macsec_is_offloaded(macsec) &&
-		    macsec->secy.validate_frames == MACSEC_VALIDATE_STRICT) {
+		/* If h/w offloading is enabled, HW decodes frames and strips
+		 * the SecTAG, so we have to deduce which port to deliver to.
+		 */
+		if (macsec_is_offloaded(macsec) && netif_running(ndev)) {
+			if (ether_addr_equal_64bits(hdr->h_dest,
+						    ndev->dev_addr)) {
+				/* exact match, divert skb to this port */
+				skb->dev = ndev;
+				skb->pkt_type = PACKET_HOST;
+				ret = RX_HANDLER_ANOTHER;
+				goto out;
+			} else if (is_multicast_ether_addr_64bits(
+					   hdr->h_dest)) {
+				/* multicast frame, deliver on this port too */
+				nskb = skb_clone(skb, GFP_ATOMIC);
+				if (!nskb)
+					break;
+
+				nskb->dev = ndev;
+				if (ether_addr_equal_64bits(hdr->h_dest,
+							    ndev->broadcast))
+					nskb->pkt_type = PACKET_BROADCAST;
+				else
+					nskb->pkt_type = PACKET_MULTICAST;
+
+				netif_rx(nskb);
+			}
+			continue;
+		}
+
+		/* 10.6 If the management control validateFrames is not
+		 * Strict, frames without a SecTAG are received, counted, and
+		 * delivered to the Controlled Port
+		 */
+		if (macsec->secy.validate_frames == MACSEC_VALIDATE_STRICT) {
 			u64_stats_update_begin(&secy_stats->syncp);
 			secy_stats->stats.InPktsNoTag++;
 			u64_stats_update_end(&secy_stats->syncp);
@@ -979,19 +1010,13 @@ static enum rx_handler_result handle_not_macsec(struct sk_buff *skb)
 		if (!nskb)
 			break;
 
-		nskb->dev = macsec->secy.netdev;
+		nskb->dev = ndev;
 
 		if (netif_rx(nskb) == NET_RX_SUCCESS) {
 			u64_stats_update_begin(&secy_stats->syncp);
 			secy_stats->stats.InPktsUntagged++;
 			u64_stats_update_end(&secy_stats->syncp);
 		}
-
-		if (netif_running(macsec->secy.netdev) &&
-		    macsec_is_offloaded(macsec)) {
-			ret = RX_HANDLER_EXACT;
-			goto out;
-		}
 	}
 
 out:
-- 
2.17.1