TCP Wrappers 7.6 compatible IPv6 tcp wrapper

			written by Kazunori Fujiwara <fujiwara@rcac.tdi.co.jp>
			release: 980106
			rewrite for english: 2000/2/15

Goal:

  I need secure IPv6 environment.
  I need IPv6 tcp_wrappers_7.6. (at that time, no tcp_wrappers ipv6 patch)

Compatibility:

  struct request_info *request_init(struct requestinfo * req, args)
  struct request_info *fromhost(struct requestinfo *req)
  int hosts_access(struct request_info *req)
  void refuse(struct request_info *req)
  void clean_request(struct request_info *req)
  void clean_exit(struct request_info *req)
  int allow_severity ... syslog priority when allow
  int deny_severity  ... syslog priority when deny

Change from tcp_wrappers:
  configuration file:
    filename is /etc/hosts.access
    configuration file description is changed.

      service definition
         multiple allow/deny lines
      next service definitions
         multiple allow/deny lines
      End of file

    separate tcpd execution option and libwrap check option.
    read datailed MEMO file

Environment (OS)
  4.4BSD-Lite OS with KAME
    tested on FreeBSD-2.2.5R, BSD/OS3.0, BSD/OS3.1, FreeBSD-3.x
    (needs -DINET6)

  4.4BSD IPv6 OS
    FreeBSD-4.x
    (needs -DINET6)

TODO:
  Good English manual and documents
  catch up with this two years IPv6 API.
   (struct sockaddr_storage, getaddrinfo() and so on.)
