RxRPC: Declare the security index constants symbolically

Declare the security index constants symbolically rather than just referring
to them numerically.

Signed-off-by: David Howells <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

include/linux/rxrpc.h

···
 #define RXRPC_SECURITY_AUTH	1	/* authenticated packets */
 #define RXRPC_SECURITY_ENCRYPT	2	/* encrypted packets */
 
+/*
+ * RxRPC security indices
+ */
+#define RXRPC_SECURITY_NONE	0	/* no security protocol */
+#define RXRPC_SECURITY_RXKAD	2	/* kaserver or kerberos 4 */
+#define RXRPC_SECURITY_RXGK	4	/* gssapi-based */
+#define RXRPC_SECURITY_RXK5	5	/* kerberos 5 */
 
 #endif /* _LINUX_RXRPC_H */

net/rxrpc/ar-key.c

···
 		       tsec->ticket[6], tsec->ticket[7]);
 
 	ret = -EPROTONOSUPPORT;
-	if (tsec->security_index != 2)
+	if (tsec->security_index != RXRPC_SECURITY_RXKAD)
 		goto error;
 
 	key->type_data.x[0] = tsec->security_index;
···
 	_debug("key %d", key_serial(key));
 
 	data.kver = 1;
-	data.tsec.security_index = 2;
+	data.tsec.security_index = RXRPC_SECURITY_RXKAD;
 	data.tsec.ticket_len = 0;
 	data.tsec.expiry = expiry;
 	data.tsec.kvno = 0;

net/rxrpc/rxkad.c

···
 	__be32	checksum;	/* decrypted data checksum */
 };
 
-MODULE_DESCRIPTION("RxRPC network protocol type-2 security (Kerberos)");
+MODULE_DESCRIPTION("RxRPC network protocol type-2 security (Kerberos 4)");
 MODULE_AUTHOR("Red Hat, Inc.");
 MODULE_LICENSE("GPL");
 
···
 	if (!call->conn->cipher)
 		return 0;
 
-	if (sp->hdr.securityIndex != 2) {
+	if (sp->hdr.securityIndex != RXRPC_SECURITY_RXKAD) {
 		*_abort_code = RXKADINCONSISTENCY;
 		_leave(" = -EPROTO [not rxkad]");
 		return -EPROTO;
···
 static struct rxrpc_security rxkad = {
 	.owner				= THIS_MODULE,
 	.name				= "rxkad",
-	.security_index			= RXKAD_VERSION,
+	.security_index			= RXRPC_SECURITY_RXKAD,
 	.init_connection_security	= rxkad_init_connection_security,
 	.prime_packet_security		= rxkad_prime_packet_security,
 	.secure_packet			= rxkad_secure_packet,