Cygwin/w32api IPv6 extention

                                                            2007/02/10
                                                           Jun-ya Kato
                                                          kato@win6.jp

Microsoft Windows XP has initially IPv6 function.  Also Microsoft has
developed IPv6 protocol stack and SDK for Windows 2000.  Currently,
although IPv6 stack is on technology preview stage, basic APIs in
RFC2553 are ready to use.  Cygwin IPv6 extention use these APIs to
provides some of APIs in RFC2553 for Cygwin/Mingw+w32api programming
environment.  Implemented APIs are listed as following:

  types expressing address and constants
    struct in6_addr
    struct sockaddr_in6
    struct sockaddr_storage
    struct addrinfo
    struct in6_addr in6addr_loopback, in6addr_any

  functions
    getaddrinfo()
    gai_strerror()
    freeaddrinfo()
    getnameinfo()
    gethostbyname2() (incomplete)
    inet_pton()
    inet_ntop()

  address test functions (implemented with pre-processor macro)
    IN6_IS_ADDR_LOOPBACK()
    IN6_IS_ADDR_UNSPECIFIED()
     ...

Our Development Platform:
  - Windows XP Professional
  - Cygwin-1.5.24-2
  - gcc-3.4.4

Tested Network Applications:

  The latest application list is shown on
  http://win6.jp/Cygwin/index.html.


  Current List:
    openssh-4.5p1
    inetutils-1.3.2-14 + IPv6 patch (*1)
    cvs-1.11.0-1 + IPv6 patch(*2)

    wget-1.6 + IPv6 patch(*2)
    ncftp-3.0.3 + IPv6 patch(*2)
    rsync-2.4.6 + IPv6 patch(*2)
    ruby-1.6.2
    w3m-0.1.10

  for Mingw+w32api
    Emacs 21.1 (*1)

  (*1) IPv6 patch is avaliable on
            http://win6.jp/Cygwin/
  (*2) IPv6 patches are provided by KAME project.
            http://www.kame.net/

Installation:

  untar under archive at cygwin root directory

    bin/cygwin1.dll (*)
    lib/lib*.a
    lib/w32api/lib*.a
    usr/include/*

  (*) rename new-cygwin1.dll to cygwin1.dll and all applications using
      cygwin1.dll must be terminated before copying.

Not Implemented Features:

  IPv6 extention still is on very tentative stage and doesn't have
  many implemented features.
    -IPsec and Multicast aren't supported
    -ioctl for network interfaces. (eg. get IPv6 address)
    -Mingw+w32api isn't functional
    -gethostbyaddr(..., AF_INET6): if address family AF_INET6 is
     given on Windows 2000, it can't return correct hostent.