macsec: Netlink support of XPN cipher suites (IEEE 802.1AEbw)

Netlink support of extended packet number cipher suites,
allows adding and updating XPN macsec interfaces.

Added support in:
    * Creating interfaces with GCM-AES-XPN-128 and GCM-AES-XPN-256 suites.
    * Setting and getting 64bit packet numbers with of SAs.
    * Setting (only on SA creation) and getting ssci of SAs.
    * Setting salt when installing a SAK.

Added 2 cipher suite identifiers according to 802.1AE-2018 table 14-1:
    * MACSEC_CIPHER_ID_GCM_AES_XPN_128
    * MACSEC_CIPHER_ID_GCM_AES_XPN_256

In addition, added 2 new netlink attribute types:
    * MACSEC_SA_ATTR_SSCI
    * MACSEC_SA_ATTR_SALT

Depends on: macsec: Support XPN frame handling - IEEE 802.1AEbw.
Signed-off-by: Era Mayflower <mayflowerera@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/macsec.h

@@ -11,6 +11,9 @@
 #include <uapi/linux/if_link.h>
 #include <uapi/linux/if_macsec.h>
 
+#define MACSEC_DEFAULT_PN_LEN 4
+#define MACSEC_XPN_PN_LEN 8
+
 #define MACSEC_SALT_LEN 12
 #define MACSEC_NUM_AN 4 /* 2 bits for the association number */
 

include/uapi/linux/if_macsec.h

@@ -22,9 +22,11 @@
 
 #define MACSEC_KEYID_LEN 16
 
-/* cipher IDs as per IEEE802.1AEbn-2011 */
+/* cipher IDs as per IEEE802.1AE-2018 (Table 14-1) */
 #define MACSEC_CIPHER_ID_GCM_AES_128 0x0080C20001000001ULL
 #define MACSEC_CIPHER_ID_GCM_AES_256 0x0080C20001000002ULL
+#define MACSEC_CIPHER_ID_GCM_AES_XPN_128 0x0080C20001000003ULL
+#define MACSEC_CIPHER_ID_GCM_AES_XPN_256 0x0080C20001000004ULL
 
 /* deprecated cipher ID for GCM-AES-128 */
 #define MACSEC_DEFAULT_CIPHER_ID     0x0080020001000001ULL
@@ -88,11 +90,13 @@ enum macsec_sa_attrs {
 	MACSEC_SA_ATTR_UNSPEC,
 	MACSEC_SA_ATTR_AN,     /* config/dump, u8 0..3 */
 	MACSEC_SA_ATTR_ACTIVE, /* config/dump, u8 0..1 */
-	MACSEC_SA_ATTR_PN,     /* config/dump, u32 */
+	MACSEC_SA_ATTR_PN,     /* config/dump, u32/u64 (u64 if XPN) */
 	MACSEC_SA_ATTR_KEY,    /* config, data */
 	MACSEC_SA_ATTR_KEYID,  /* config/dump, 128-bit */
 	MACSEC_SA_ATTR_STATS,  /* dump, nested, macsec_sa_stats_attr */
 	MACSEC_SA_ATTR_PAD,
+	MACSEC_SA_ATTR_SSCI,   /* config/dump, u32 - XPN only */
+	MACSEC_SA_ATTR_SALT,   /* config, 96-bit - XPN only */
 	__MACSEC_SA_ATTR_END,
 	NUM_MACSEC_SA_ATTR = __MACSEC_SA_ATTR_END,
 	MACSEC_SA_ATTR_MAX = __MACSEC_SA_ATTR_END - 1,