[][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-5.4/999-1762-v5.18-net-macsec-Support-XPN-frame-handling-IEEE-802.1AEbw.patch b/target/linux/mediatek/patches-5.4/999-1762-v5.18-net-macsec-Support-XPN-frame-handling-IEEE-802.1AEbw.patch
new file mode 100644
index 0000000..357977e
--- /dev/null
+++ b/target/linux/mediatek/patches-5.4/999-1762-v5.18-net-macsec-Support-XPN-frame-handling-IEEE-802.1AEbw.patch
@@ -0,0 +1,479 @@
+From a21ecf0e033807b976967286e6c392f48ee2049f Mon Sep 17 00:00:00 2001
+From: Era Mayflower <mayflowerera@gmail.com>
+Date: Mon, 9 Mar 2020 19:47:01 +0000
+Subject: macsec: Support XPN frame handling - IEEE 802.1AEbw
+
+Support extended packet number cipher suites (802.1AEbw) frames handling.
+This does not include the needed netlink patches.
+
+    * Added xpn boolean field to `struct macsec_secy`.
+    * Added ssci field to `struct_macsec_tx_sa` (802.1AE figure 10-5).
+    * Added ssci field to `struct_macsec_rx_sa` (802.1AE figure 10-5).
+    * Added salt field to `struct macsec_key` (802.1AE 10.7 NOTE 1).
+    * Created pn_t type for easy access to lower and upper halves.
+    * Created salt_t type for easy access to the "ssci" and "pn" parts.
+    * Created `macsec_fill_iv_xpn` function to create IV in XPN mode.
+    * Support in PN recovery and preliminary replay check in XPN mode.
+
+In addition, according to IEEE 802.1AEbw figure 10-5, the PN of incoming
+frame can be 0 when XPN cipher suite is used, so fixed the function
+`macsec_validate_skb` to fail on PN=0 only if XPN is off.
+
+Signed-off-by: Era Mayflower <mayflowerera@gmail.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+ drivers/net/macsec.c | 130 +++++++++++++++++++++++++++++++++++++--------------
+ include/net/macsec.h |  45 ++++++++++++++++--
+ 2 files changed, 136 insertions(+), 39 deletions(-)
+
+diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
+index 6ec6fc191a6e4..6c71e250cccb0 100644
+--- a/drivers/net/macsec.c
++++ b/drivers/net/macsec.c
+@@ -19,6 +19,7 @@
+ #include <net/gro_cells.h>
+ #include <net/macsec.h>
+ #include <linux/phy.h>
++#include <linux/byteorder/generic.h>
+ 
+ #include <uapi/linux/if_macsec.h>
+ 
+@@ -68,6 +69,16 @@ struct macsec_eth_header {
+ 	     sc;					\
+ 	     sc = rtnl_dereference(sc->next))
+ 
++#define pn_same_half(pn1, pn2) (!(((pn1) >> 31) ^ ((pn2) >> 31)))
++
++struct gcm_iv_xpn {
++	union {
++		u8 short_secure_channel_id[4];
++		ssci_t ssci;
++	};
++	__be64 pn;
++} __packed;
++
+ struct gcm_iv {
+ 	union {
+ 		u8 secure_channel_id[8];
+@@ -372,8 +383,8 @@ static const struct macsec_ops *macsec_get_ops(struct macsec_dev *macsec,
+ 	return __macsec_get_ops(macsec->offload, macsec, ctx);
+ }
+ 
+-/* validate MACsec packet according to IEEE 802.1AE-2006 9.12 */
+-static bool macsec_validate_skb(struct sk_buff *skb, u16 icv_len)
++/* validate MACsec packet according to IEEE 802.1AE-2018 9.12 */
++static bool macsec_validate_skb(struct sk_buff *skb, u16 icv_len, bool xpn)
+ {
+ 	struct macsec_eth_header *h = (struct macsec_eth_header *)skb->data;
+ 	int len = skb->len - 2 * ETH_ALEN;
+@@ -398,8 +409,8 @@ static bool macsec_validate_skb(struct sk_buff *skb, u16 icv_len)
+ 	if (h->unused)
+ 		return false;
+ 
+-	/* rx.pn != 0 (figure 10-5) */
+-	if (!h->packet_number)
++	/* rx.pn != 0 if not XPN (figure 10-5 with 802.11AEbw-2013 amendment) */
++	if (!h->packet_number && !xpn)
+ 		return false;
+ 
+ 	/* length check, f) g) h) i) */
+@@ -411,6 +422,15 @@ static bool macsec_validate_skb(struct sk_buff *skb, u16 icv_len)
+ #define MACSEC_NEEDED_HEADROOM (macsec_extra_len(true))
+ #define MACSEC_NEEDED_TAILROOM MACSEC_STD_ICV_LEN
+ 
++static void macsec_fill_iv_xpn(unsigned char *iv, ssci_t ssci, u64 pn,
++			       salt_t salt)
++{
++	struct gcm_iv_xpn *gcm_iv = (struct gcm_iv_xpn *)iv;
++
++	gcm_iv->ssci = ssci ^ salt.ssci;
++	gcm_iv->pn = cpu_to_be64(pn) ^ salt.pn;
++}
++
+ static void macsec_fill_iv(unsigned char *iv, sci_t sci, u32 pn)
+ {
+ 	struct gcm_iv *gcm_iv = (struct gcm_iv *)iv;
+@@ -446,14 +466,19 @@ void macsec_pn_wrapped(struct macsec_secy *secy, struct macsec_tx_sa *tx_sa)
+ }
+ EXPORT_SYMBOL_GPL(macsec_pn_wrapped);
+ 
+-static u32 tx_sa_update_pn(struct macsec_tx_sa *tx_sa, struct macsec_secy *secy)
++static pn_t tx_sa_update_pn(struct macsec_tx_sa *tx_sa,
++			    struct macsec_secy *secy)
+ {
+-	u32 pn;
++	pn_t pn;
+ 
+ 	spin_lock_bh(&tx_sa->lock);
+-	pn = tx_sa->next_pn;
+ 
+-	tx_sa->next_pn++;
++	pn = tx_sa->next_pn_halves;
++	if (secy->xpn)
++		tx_sa->next_pn++;
++	else
++		tx_sa->next_pn_halves.lower++;
++
+ 	if (tx_sa->next_pn == 0)
+ 		__macsec_pn_wrapped(secy, tx_sa);
+ 	spin_unlock_bh(&tx_sa->lock);
+@@ -568,7 +593,7 @@ static struct sk_buff *macsec_encrypt(struct sk_buff *skb,
+ 	struct macsec_tx_sa *tx_sa;
+ 	struct macsec_dev *macsec = macsec_priv(dev);
+ 	bool sci_present;
+-	u32 pn;
++	pn_t pn;
+ 
+ 	secy = &macsec->secy;
+ 	tx_sc = &secy->tx_sc;
+@@ -610,12 +635,12 @@ static struct sk_buff *macsec_encrypt(struct sk_buff *skb,
+ 	memmove(hh, eth, 2 * ETH_ALEN);
+ 
+ 	pn = tx_sa_update_pn(tx_sa, secy);
+-	if (pn == 0) {
++	if (pn.full64 == 0) {
+ 		macsec_txsa_put(tx_sa);
+ 		kfree_skb(skb);
+ 		return ERR_PTR(-ENOLINK);
+ 	}
+-	macsec_fill_sectag(hh, secy, pn, sci_present);
++	macsec_fill_sectag(hh, secy, pn.lower, sci_present);
+ 	macsec_set_shortlen(hh, unprotected_len - 2 * ETH_ALEN);
+ 
+ 	skb_put(skb, secy->icv_len);
+@@ -646,7 +671,10 @@ static struct sk_buff *macsec_encrypt(struct sk_buff *skb,
+ 		return ERR_PTR(-ENOMEM);
+ 	}
+ 
+-	macsec_fill_iv(iv, secy->sci, pn);
++	if (secy->xpn)
++		macsec_fill_iv_xpn(iv, tx_sa->ssci, pn.full64, tx_sa->key.salt);
++	else
++		macsec_fill_iv(iv, secy->sci, pn.lower);
+ 
+ 	sg_init_table(sg, ret);
+ 	ret = skb_to_sgvec(skb, sg, 0, skb->len);
+@@ -698,13 +726,14 @@ static bool macsec_post_decrypt(struct sk_buff *skb, struct macsec_secy *secy, u
+ 	u32 lowest_pn = 0;
+ 
+ 	spin_lock(&rx_sa->lock);
+-	if (rx_sa->next_pn >= secy->replay_window)
+-		lowest_pn = rx_sa->next_pn - secy->replay_window;
++	if (rx_sa->next_pn_halves.lower >= secy->replay_window)
++		lowest_pn = rx_sa->next_pn_halves.lower - secy->replay_window;
+ 
+ 	/* Now perform replay protection check again
+ 	 * (see IEEE 802.1AE-2006 figure 10-5)
+ 	 */
+-	if (secy->replay_protect && pn < lowest_pn) {
++	if (secy->replay_protect && pn < lowest_pn &&
++	    (!secy->xpn || pn_same_half(pn, lowest_pn))) {
+ 		spin_unlock(&rx_sa->lock);
+ 		u64_stats_update_begin(&rxsc_stats->syncp);
+ 		rxsc_stats->stats.InPktsLate++;
+@@ -753,8 +782,15 @@ static bool macsec_post_decrypt(struct sk_buff *skb, struct macsec_secy *secy, u
+ 		}
+ 		u64_stats_update_end(&rxsc_stats->syncp);
+ 
+-		if (pn >= rx_sa->next_pn)
+-			rx_sa->next_pn = pn + 1;
++		// Instead of "pn >=" - to support pn overflow in xpn
++		if (pn + 1 > rx_sa->next_pn_halves.lower) {
++			rx_sa->next_pn_halves.lower = pn + 1;
++		} else if (secy->xpn &&
++			   !pn_same_half(pn, rx_sa->next_pn_halves.lower)) {
++			rx_sa->next_pn_halves.upper++;
++			rx_sa->next_pn_halves.lower = pn + 1;
++		}
++
+ 		spin_unlock(&rx_sa->lock);
+ 	}
+ 
+@@ -841,6 +877,7 @@ static struct sk_buff *macsec_decrypt(struct sk_buff *skb,
+ 	unsigned char *iv;
+ 	struct aead_request *req;
+ 	struct macsec_eth_header *hdr;
++	u32 hdr_pn;
+ 	u16 icv_len = secy->icv_len;
+ 
+ 	macsec_skb_cb(skb)->valid = false;
+@@ -860,7 +897,21 @@ static struct sk_buff *macsec_decrypt(struct sk_buff *skb,
+ 	}
+ 
+ 	hdr = (struct macsec_eth_header *)skb->data;
+-	macsec_fill_iv(iv, sci, ntohl(hdr->packet_number));
++	hdr_pn = ntohl(hdr->packet_number);
++
++	if (secy->xpn) {
++		pn_t recovered_pn = rx_sa->next_pn_halves;
++
++		recovered_pn.lower = hdr_pn;
++		if (hdr_pn < rx_sa->next_pn_halves.lower &&
++		    !pn_same_half(hdr_pn, rx_sa->next_pn_halves.lower))
++			recovered_pn.upper++;
++
++		macsec_fill_iv_xpn(iv, rx_sa->ssci, recovered_pn.full64,
++				   rx_sa->key.salt);
++	} else {
++		macsec_fill_iv(iv, sci, hdr_pn);
++	}
+ 
+ 	sg_init_table(sg, ret);
+ 	ret = skb_to_sgvec(skb, sg, 0, skb->len);
+@@ -1001,7 +1052,7 @@ static rx_handler_result_t macsec_handle_frame(struct sk_buff **pskb)
+ 	struct macsec_rxh_data *rxd;
+ 	struct macsec_dev *macsec;
+ 	sci_t sci;
+-	u32 pn;
++	u32 hdr_pn;
+ 	bool cbit;
+ 	struct pcpu_rx_sc_stats *rxsc_stats;
+ 	struct pcpu_secy_stats *secy_stats;
+@@ -1072,7 +1123,7 @@ static rx_handler_result_t macsec_handle_frame(struct sk_buff **pskb)
+ 	secy_stats = this_cpu_ptr(macsec->stats);
+ 	rxsc_stats = this_cpu_ptr(rx_sc->stats);
+ 
+-	if (!macsec_validate_skb(skb, secy->icv_len)) {
++	if (!macsec_validate_skb(skb, secy->icv_len, secy->xpn)) {
+ 		u64_stats_update_begin(&secy_stats->syncp);
+ 		secy_stats->stats.InPktsBadTag++;
+ 		u64_stats_update_end(&secy_stats->syncp);
+@@ -1104,13 +1155,16 @@ static rx_handler_result_t macsec_handle_frame(struct sk_buff **pskb)
+ 	}
+ 
+ 	/* First, PN check to avoid decrypting obviously wrong packets */
+-	pn = ntohl(hdr->packet_number);
++	hdr_pn = ntohl(hdr->packet_number);
+ 	if (secy->replay_protect) {
+ 		bool late;
+ 
+ 		spin_lock(&rx_sa->lock);
+-		late = rx_sa->next_pn >= secy->replay_window &&
+-		       pn < (rx_sa->next_pn - secy->replay_window);
++		late = rx_sa->next_pn_halves.lower >= secy->replay_window &&
++		       hdr_pn < (rx_sa->next_pn_halves.lower - secy->replay_window);
++
++		if (secy->xpn)
++			late = late && pn_same_half(rx_sa->next_pn_halves.lower, hdr_pn);
+ 		spin_unlock(&rx_sa->lock);
+ 
+ 		if (late) {
+@@ -1139,7 +1193,7 @@ static rx_handler_result_t macsec_handle_frame(struct sk_buff **pskb)
+ 		return RX_HANDLER_CONSUMED;
+ 	}
+ 
+-	if (!macsec_post_decrypt(skb, secy, pn))
++	if (!macsec_post_decrypt(skb, secy, hdr_pn))
+ 		goto drop;
+ 
+ deliver:
+@@ -1666,7 +1720,7 @@ static int macsec_add_rxsa(struct sk_buff *skb, struct genl_info *info)
+ 
+ 	if (tb_sa[MACSEC_SA_ATTR_PN]) {
+ 		spin_lock_bh(&rx_sa->lock);
+-		rx_sa->next_pn = nla_get_u32(tb_sa[MACSEC_SA_ATTR_PN]);
++		rx_sa->next_pn_halves.lower = nla_get_u32(tb_sa[MACSEC_SA_ATTR_PN]);
+ 		spin_unlock_bh(&rx_sa->lock);
+ 	}
+ 
+@@ -1873,7 +1927,7 @@ static int macsec_add_txsa(struct sk_buff *skb, struct genl_info *info)
+ 	}
+ 
+ 	spin_lock_bh(&tx_sa->lock);
+-	tx_sa->next_pn = nla_get_u32(tb_sa[MACSEC_SA_ATTR_PN]);
++	tx_sa->next_pn_halves.lower = nla_get_u32(tb_sa[MACSEC_SA_ATTR_PN]);
+ 	spin_unlock_bh(&tx_sa->lock);
+ 
+ 	if (tb_sa[MACSEC_SA_ATTR_ACTIVE])
+@@ -2137,9 +2191,11 @@ static int macsec_upd_txsa(struct sk_buff *skb, struct genl_info *info)
+ 	u8 assoc_num;
+ 	struct nlattr *tb_sa[MACSEC_SA_ATTR_MAX + 1];
+ 	bool was_operational, was_active;
+-	u32 prev_pn = 0;
++	pn_t prev_pn;
+ 	int ret = 0;
+ 
++	prev_pn.full64 = 0;
++
+ 	if (!attrs[MACSEC_ATTR_IFINDEX])
+ 		return -EINVAL;
+ 
+@@ -2159,8 +2215,8 @@ static int macsec_upd_txsa(struct sk_buff *skb, struct genl_info *info)
+ 
+ 	if (tb_sa[MACSEC_SA_ATTR_PN]) {
+ 		spin_lock_bh(&tx_sa->lock);
+-		prev_pn = tx_sa->next_pn;
+-		tx_sa->next_pn = nla_get_u32(tb_sa[MACSEC_SA_ATTR_PN]);
++		prev_pn = tx_sa->next_pn_halves;
++		tx_sa->next_pn_halves.lower = nla_get_u32(tb_sa[MACSEC_SA_ATTR_PN]);
+ 		spin_unlock_bh(&tx_sa->lock);
+ 	}
+ 
+@@ -2198,7 +2254,7 @@ static int macsec_upd_txsa(struct sk_buff *skb, struct genl_info *info)
+ cleanup:
+ 	if (tb_sa[MACSEC_SA_ATTR_PN]) {
+ 		spin_lock_bh(&tx_sa->lock);
+-		tx_sa->next_pn = prev_pn;
++		tx_sa->next_pn_halves = prev_pn;
+ 		spin_unlock_bh(&tx_sa->lock);
+ 	}
+ 	tx_sa->active = was_active;
+@@ -2218,9 +2274,11 @@ static int macsec_upd_rxsa(struct sk_buff *skb, struct genl_info *info)
+ 	struct nlattr *tb_rxsc[MACSEC_RXSC_ATTR_MAX + 1];
+ 	struct nlattr *tb_sa[MACSEC_SA_ATTR_MAX + 1];
+ 	bool was_active;
+-	u32 prev_pn = 0;
++	pn_t prev_pn;
+ 	int ret = 0;
+ 
++	prev_pn.full64 = 0;
++
+ 	if (!attrs[MACSEC_ATTR_IFINDEX])
+ 		return -EINVAL;
+ 
+@@ -2243,8 +2301,8 @@ static int macsec_upd_rxsa(struct sk_buff *skb, struct genl_info *info)
+ 
+ 	if (tb_sa[MACSEC_SA_ATTR_PN]) {
+ 		spin_lock_bh(&rx_sa->lock);
+-		prev_pn = rx_sa->next_pn;
+-		rx_sa->next_pn = nla_get_u32(tb_sa[MACSEC_SA_ATTR_PN]);
++		prev_pn = rx_sa->next_pn_halves;
++		rx_sa->next_pn_halves.lower = nla_get_u32(tb_sa[MACSEC_SA_ATTR_PN]);
+ 		spin_unlock_bh(&rx_sa->lock);
+ 	}
+ 
+@@ -2277,7 +2335,7 @@ static int macsec_upd_rxsa(struct sk_buff *skb, struct genl_info *info)
+ cleanup:
+ 	if (tb_sa[MACSEC_SA_ATTR_PN]) {
+ 		spin_lock_bh(&rx_sa->lock);
+-		rx_sa->next_pn = prev_pn;
++		rx_sa->next_pn_halves = prev_pn;
+ 		spin_unlock_bh(&rx_sa->lock);
+ 	}
+ 	rx_sa->active = was_active;
+@@ -2796,7 +2854,7 @@ dump_secy(struct macsec_secy *secy, struct net_device *dev,
+ 		}
+ 
+ 		if (nla_put_u8(skb, MACSEC_SA_ATTR_AN, i) ||
+-		    nla_put_u32(skb, MACSEC_SA_ATTR_PN, tx_sa->next_pn) ||
++		    nla_put_u32(skb, MACSEC_SA_ATTR_PN, tx_sa->next_pn_halves.lower) ||
+ 		    nla_put(skb, MACSEC_SA_ATTR_KEYID, MACSEC_KEYID_LEN, tx_sa->key.id) ||
+ 		    nla_put_u8(skb, MACSEC_SA_ATTR_ACTIVE, tx_sa->active)) {
+ 			nla_nest_cancel(skb, txsa_nest);
+@@ -2900,7 +2958,7 @@ dump_secy(struct macsec_secy *secy, struct net_device *dev,
+ 			nla_nest_end(skb, attr);
+ 
+ 			if (nla_put_u8(skb, MACSEC_SA_ATTR_AN, i) ||
+-			    nla_put_u32(skb, MACSEC_SA_ATTR_PN, rx_sa->next_pn) ||
++			    nla_put_u32(skb, MACSEC_SA_ATTR_PN, rx_sa->next_pn_halves.lower) ||
+ 			    nla_put(skb, MACSEC_SA_ATTR_KEYID, MACSEC_KEYID_LEN, rx_sa->key.id) ||
+ 			    nla_put_u8(skb, MACSEC_SA_ATTR_ACTIVE, rx_sa->active)) {
+ 				nla_nest_cancel(skb, rxsa_nest);
+diff --git a/include/net/macsec.h b/include/net/macsec.h
+index 92e43db8b5667..43cd54e178770 100644
+--- a/include/net/macsec.h
++++ b/include/net/macsec.h
+@@ -11,18 +11,45 @@
+ #include <uapi/linux/if_link.h>
+ #include <uapi/linux/if_macsec.h>
+ 
++#define MACSEC_SALT_LEN 12
++#define MACSEC_NUM_AN 4 /* 2 bits for the association number */
++
+ typedef u64 __bitwise sci_t;
++typedef u32 __bitwise ssci_t;
+ 
+-#define MACSEC_NUM_AN 4 /* 2 bits for the association number */
++typedef union salt {
++	struct {
++		u32 ssci;
++		u64 pn;
++	} __packed;
++	u8 bytes[MACSEC_SALT_LEN];
++} __packed salt_t;
++
++typedef union pn {
++	struct {
++#if defined(__LITTLE_ENDIAN_BITFIELD)
++		u32 lower;
++		u32 upper;
++#elif defined(__BIG_ENDIAN_BITFIELD)
++		u32 upper;
++		u32 lower;
++#else
++#error	"Please fix <asm/byteorder.h>"
++#endif
++	};
++	u64 full64;
++} pn_t;
+ 
+ /**
+  * struct macsec_key - SA key
+  * @id: user-provided key identifier
+  * @tfm: crypto struct, key storage
++ * @salt: salt used to generate IV in XPN cipher suites
+  */
+ struct macsec_key {
+ 	u8 id[MACSEC_KEYID_LEN];
+ 	struct crypto_aead *tfm;
++	salt_t salt;
+ };
+ 
+ struct macsec_rx_sc_stats {
+@@ -64,12 +91,17 @@ struct macsec_tx_sc_stats {
+  * @next_pn: packet number expected for the next packet
+  * @lock: protects next_pn manipulations
+  * @key: key structure
++ * @ssci: short secure channel identifier
+  * @stats: per-SA stats
+  */
+ struct macsec_rx_sa {
+ 	struct macsec_key key;
++	ssci_t ssci;
+ 	spinlock_t lock;
+-	u32 next_pn;
++	union {
++		pn_t next_pn_halves;
++		u64 next_pn;
++	};
+ 	refcount_t refcnt;
+ 	bool active;
+ 	struct macsec_rx_sa_stats __percpu *stats;
+@@ -110,12 +142,17 @@ struct macsec_rx_sc {
+  * @next_pn: packet number to use for the next packet
+  * @lock: protects next_pn manipulations
+  * @key: key structure
++ * @ssci: short secure channel identifier
+  * @stats: per-SA stats
+  */
+ struct macsec_tx_sa {
+ 	struct macsec_key key;
++	ssci_t ssci;
+ 	spinlock_t lock;
+-	u32 next_pn;
++	union {
++		pn_t next_pn_halves;
++		u64 next_pn;
++	};
+ 	refcount_t refcnt;
+ 	bool active;
+ 	struct macsec_tx_sa_stats __percpu *stats;
+@@ -152,6 +189,7 @@ struct macsec_tx_sc {
+  * @key_len: length of keys used by the cipher suite
+  * @icv_len: length of ICV used by the cipher suite
+  * @validate_frames: validation mode
++ * @xpn: enable XPN for this SecY
+  * @operational: MAC_Operational flag
+  * @protect_frames: enable protection for this SecY
+  * @replay_protect: enable packet number checks on receive
+@@ -166,6 +204,7 @@ struct macsec_secy {
+ 	u16 key_len;
+ 	u16 icv_len;
+ 	enum macsec_validation_type validate_frames;
++	bool xpn;
+ 	bool operational;
+ 	bool protect_frames;
+ 	bool replay_protect;
+-- 
+cgit 1.2.3-1.el7
+