Create "username" and "password" DHCP options, ready for placing this

information in NVS.

src/include/gpxe/dhcp.h

  */
 #define DHCP_EB_BIOS_DRIVE DHCP_ENCAP_OPT ( DHCP_EB_ENCAP, 0xbd )
 
+/** Username
+ *
+ * This will be used as the username for any required authentication.
+ * It is expected that this option's value will be held in
+ * non-volatile storage, rather than transmitted as part of a DHCP
+ * packet.
+ */
+#define DHCP_EB_USERNAME DHCP_ENCAP_OPT ( DHCP_EB_ENCAP, 0xbe )
+
+/** Password
+ *
+ * This will be used as the password for any required authentication.
+ * It is expected that this option's value will be held in
+ * non-volatile storage, rather than transmitted as part of a DHCP
+ * packet.
+ */
+#define DHCP_EB_PASSWORD DHCP_ENCAP_OPT ( DHCP_EB_ENCAP, 0xbf )
+
 /** Maximum normal DHCP option */
 #define DHCP_MAX_OPTION 254
 

src/tests/dhcptest.c

 
 static int test_dhcp_iscsi_boot ( struct net_device *netdev, char *iscsiname ) {
 	char *initiator_iqn = "iqn.1900-01.localdomain.localhost:initiator";
-	char *username = "joe";
-	char *password = "secret";
+	char username[32];
+	char password[32];
 	char *target_iqn;
 	union {
 		struct sockaddr_in sin;
 	}
 	inet_aton ( iscsiname, &target.sin.sin_addr );
 
+	dhcp_snprintf ( username, sizeof ( username ),
+			find_global_dhcp_option ( DHCP_EB_USERNAME ) );
+	dhcp_snprintf ( password, sizeof ( password ),
+			find_global_dhcp_option ( DHCP_EB_PASSWORD ) );
+
 	return test_iscsiboot ( initiator_iqn, &target.st, target_iqn,
 				username, password, netdev );
 }