Here is a list of all struct and union fields with links to the structures/unions they belong to:

### - u -

- udp : socklist_struct
- udp_use_num : xfrhandler_struct
- udp_waiting : xfrd_struct
- udp_waiting_first : xfrhandler_struct
- udp_waiting_last : xfrhandler_struct
- udp_waiting_next : xfrd_struct
- uid : engine_struct
- update_since_last_prepare : tsig_rr_struct
- use_syslog : engineconfig_struct
- user_data : netio_handler_struct
- username : engineconfig_struct