[PATCH net-next v4 5/5] macsec: Add MACsec rx_handler change support

[Emeel Hakim <ehakim@nvidia.com>]

Offloading device drivers will mark offloaded MACsec SKBs with the
corresponding SCI in the skb_metadata_dst so the macsec rx handler will
know to which interface to divert those skbs, in case of a marked skb
and a mismatch on the dst MAC address, divert the skb to the macsec
net_device where the macsec rx_handler will be called.

Example of such a case is having a MACsec with VLAN as an inner header
ETHERNET | SECTAG | VLAN packet.

Signed-off-by: Emeel Hakim <ehakim@nvidia.com>
---
 drivers/net/macsec.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
index 25616247d7a5..4e58d2b4f0e1 100644
--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -1016,14 +1016,18 @@ static enum rx_handler_result handle_not_macsec(struct sk_buff *skb)
 		struct sk_buff *nskb;
 		struct pcpu_secy_stats *secy_stats = this_cpu_ptr(macsec->stats);
 		struct net_device *ndev = macsec->secy.netdev;
+		struct macsec_rx_sc *rx_sc_found = NULL;
 
 		/* 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 (md_dst && md_dst->type == METADATA_MACSEC &&
-			    (!find_rx_sc(&macsec->secy, md_dst->u.macsec_info.sci)))
+			rx_sc_found = (md_dst && md_dst->type == METADATA_MACSEC) ?
+				      find_rx_sc(&macsec->secy, md_dst->u.macsec_info.sci) : NULL;
+
+			if (md_dst && md_dst->type == METADATA_MACSEC && !rx_sc_found) {
 				continue;
+			}
 
 			if (ether_addr_equal_64bits(hdr->h_dest,
 						    ndev->dev_addr)) {
@@ -1048,6 +1052,14 @@ static enum rx_handler_result handle_not_macsec(struct sk_buff *skb)
 
 				__netif_rx(nskb);
 			}
+
+			if (md_dst && md_dst->type == METADATA_MACSEC && rx_sc_found) {
+				skb->dev = ndev;
+				skb->pkt_type = PACKET_HOST;
+				ret = RX_HANDLER_ANOTHER;
+				goto out;
+			}
+
 			continue;
 		}
 
-- 
2.21.3