Revert "macsec: Detect if Rx skb is macsec-related for offloading devices that update md_dst"

This reverts commit 6c3020dc817f8d08fc0ea48dd004782e7c204d92 which is
commit 642c984dd0e37dbaec9f87bd1211e5fac1f142bf upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: I70a62bf17080aad4ed45ab65272bd14a6eb1819a
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

1 files changed, 10 insertions, 36 deletions

diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
index 778fb77c5a93..9663050a852d 100644
--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -996,12 +996,10 @@ static enum rx_handler_result handle_not_macsec(struct sk_buff *skb)
 	struct metadata_dst *md_dst;
 	struct macsec_rxh_data *rxd;
 	struct macsec_dev *macsec;
-	bool is_macsec_md_dst;
 
 	rcu_read_lock();
 	rxd = macsec_data_rcu(skb->dev);
 	md_dst = skb_metadata_dst(skb);
-	is_macsec_md_dst = md_dst && md_dst->type == METADATA_MACSEC;
 
 	list_for_each_entry_rcu(macsec, &rxd->secys, secys) {
 		struct sk_buff *nskb;
@@ -1012,42 +1010,14 @@ static enum rx_handler_result handle_not_macsec(struct sk_buff *skb)
 		 * the SecTAG, so we have to deduce which port to deliver to.
 		 */
 		if (macsec_is_offloaded(macsec) && netif_running(ndev)) {
-			const struct macsec_ops *ops;
+			struct macsec_rx_sc *rx_sc = NULL;
 
-			ops = macsec_get_ops(macsec, NULL);
+			if (md_dst && md_dst->type == METADATA_MACSEC)
+				rx_sc = find_rx_sc(&macsec->secy, md_dst->u.macsec_info.sci);
 
-			if (ops->rx_uses_md_dst && !is_macsec_md_dst)
+			if (md_dst && md_dst->type == METADATA_MACSEC && !rx_sc)
 				continue;
 
-			if (is_macsec_md_dst) {
-				struct macsec_rx_sc *rx_sc;
-
-				/* All drivers that implement MACsec offload
-				 * support using skb metadata destinations must
-				 * indicate that they do so.
-				 */
-				DEBUG_NET_WARN_ON_ONCE(!ops->rx_uses_md_dst);
-				rx_sc = find_rx_sc(&macsec->secy,
-						   md_dst->u.macsec_info.sci);
-				if (!rx_sc)
-					continue;
-				/* device indicated macsec offload occurred */
-				skb->dev = ndev;
-				skb->pkt_type = PACKET_HOST;
-				eth_skb_pkt_type(skb, ndev);
-				ret = RX_HANDLER_ANOTHER;
-				goto out;
-			}
-
-			/* This datapath is insecure because it is unable to
-			 * enforce isolation of broadcast/multicast traffic and
-			 * unicast traffic with promiscuous mode on the macsec
-			 * netdev. Since the core stack has no mechanism to
-			 * check that the hardware did indeed receive MACsec
-			 * traffic, it is possible that the response handling
-			 * done by the MACsec port was to a plaintext packet.
-			 * This violates the MACsec protocol standard.
-			 */
 			if (ether_addr_equal_64bits(hdr->h_dest,
 						    ndev->dev_addr)) {
 				/* exact match, divert skb to this port */
@@ -1063,10 +1033,14 @@ static enum rx_handler_result handle_not_macsec(struct sk_buff *skb)
 					break;
 
 				nskb->dev = ndev;
-				eth_skb_pkt_type(nskb, 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);
-			} else if (ndev->flags & IFF_PROMISC) {
+			} else if (rx_sc || ndev->flags & IFF_PROMISC) {
 				skb->dev = ndev;
 				skb->pkt_type = PACKET_HOST;
 				ret = RX_HANDLER_ANOTHER;