[][Add macsec HW offload backport from kernel 5.18]

[Description]
Add macsec HW offload backport from kernel 5.18.

[Release-log]
N/A

Change-Id: I5b143fe620ec4bcae4075d1d85db5e41c8d48717
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/5981730
diff --git a/target/linux/mediatek/patches-5.4/999-1786-v5.18-net-macsec-Verify-that-send_sci-is-on-when-setting-Tx-sci-explicitly.patch b/target/linux/mediatek/patches-5.4/999-1786-v5.18-net-macsec-Verify-that-send_sci-is-on-when-setting-Tx-sci-explicitly.patch
new file mode 100644
index 0000000..bc78ff3
--- /dev/null
+++ b/target/linux/mediatek/patches-5.4/999-1786-v5.18-net-macsec-Verify-that-send_sci-is-on-when-setting-Tx-sci-explicitly.patch
@@ -0,0 +1,43 @@
+From d0cfa548dbde354de986911d3913897b5448faad Mon Sep 17 00:00:00 2001
+From: Lior Nahmanson <liorna@nvidia.com>
+Date: Sun, 30 Jan 2022 13:37:52 +0200
+Subject: net: macsec: Verify that send_sci is on when setting Tx sci
+ explicitly
+
+When setting Tx sci explicit, the Rx side is expected to use this
+sci and not recalculate it from the packet.However, in case of Tx sci
+is explicit and send_sci is off, the receiver is wrongly recalculate
+the sci from the source MAC address which most likely be different
+than the explicit sci.
+
+Fix by preventing such configuration when macsec newlink is established
+and return EINVAL error code on such cases.
+
+Fixes: c09440f7dcb3 ("macsec: introduce IEEE 802.1AE driver")
+Signed-off-by: Lior Nahmanson <liorna@nvidia.com>
+Reviewed-by: Raed Salem <raeds@nvidia.com>
+Signed-off-by: Raed Salem <raeds@nvidia.com>
+Link: https://lore.kernel.org/r/1643542672-29403-1-git-send-email-raeds@nvidia.com
+Signed-off-by: Jakub Kicinski <kuba@kernel.org>
+---
+ drivers/net/macsec.c | 9 +++++++++
+ 1 file changed, 9 insertions(+)
+
+--- a/drivers/net/macsec.c
++++ b/drivers/net/macsec.c
+@@ -4047,6 +4047,15 @@ static int macsec_newlink(struct net *ne
+ 	    !macsec_check_offload(macsec->offload, macsec))
+ 		return -EOPNOTSUPP;
+ 
++	/* send_sci must be set to true when transmit sci explicitly is set */
++	if ((data && data[IFLA_MACSEC_SCI]) &&
++	    (data && data[IFLA_MACSEC_INC_SCI])) {
++		u8 send_sci = !!nla_get_u8(data[IFLA_MACSEC_INC_SCI]);
++
++		if (!send_sci)
++			return -EINVAL;
++	}
++
+ 	if (data && data[IFLA_MACSEC_ICV_LEN])
+ 		icv_len = nla_get_u8(data[IFLA_MACSEC_ICV_LEN]);
+ 	mtu = real_dev->mtu - icv_len - macsec_extra_len(true);