Portability issues (2)

If you are implementing independent software package,
What to do if there's no getaddrinfo/getnameinfo?

Use GNU autoconf
Supply minimal code, as yourcode/missing/getaddrinfo.c
AC_REPLACE_FUNCS() lets you use this as the last resort.
kame/racoon/configure.in is a good example.

AC_CHECK_LIB(getaddrinfo, inet6)
AC_CHECK_FUNCS(getaddrinfo)

AC_REPLACE_FUNCS(getaddrinfo getnameinfo)