xfrm: Add support for SM4 symmetric cipher algorithm

This patch adds SM4 encryption algorithm entry to ealg_list.
Signed-off-by: Xu Jia <xujia39@huawei.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

include/uapi/linux/pfkeyv2.h

@@ -330,6 +330,7 @@ struct sadb_x_filter {
 #define SADB_X_EALG_AES_GCM_ICV16	20
 #define SADB_X_EALG_CAMELLIACBC		22
 #define SADB_X_EALG_NULL_AES_GMAC	23
+#define SADB_X_EALG_SM4CBC		24
 #define SADB_EALG_MAX                   253 /* last EALG */
 /* private allocations should use 249-255 (RFC2407) */
 #define SADB_X_EALG_SERPENTCBC  252     /* draft-ietf-ipsec-ciph-aes-cbc-00 */

net/xfrm/xfrm_algo.c

@@ -572,6 +572,27 @@ static struct xfrm_algo_desc ealg_list[] = {
 		.sadb_alg_maxbits = 288
 	}
 },
+{
+	.name = "cbc(sm4)",
+	.compat = "sm4",
+
+	.uinfo = {
+		.encr = {
+			.geniv = "echainiv",
+			.blockbits = 128,
+			.defkeybits = 128,
+		}
+	},
+
+	.pfkey_supported = 1,
+
+	.desc = {
+		.sadb_alg_id = SADB_X_EALG_SM4CBC,
+		.sadb_alg_ivlen	= 16,
+		.sadb_alg_minbits = 128,
+		.sadb_alg_maxbits = 256
+	}
+},
 };
 
 static struct xfrm_algo_desc calg_list[] = {