curl-functions.m4

  AC_REQUIRE([CURL_INCLUDES_WINSOCK2])dnl
  AC_REQUIRE([CURL_INCLUDES_UNISTD])dnl
  #
  tst_links_gethostname="unknown"
  tst_proto_gethostname="unknown"
  tst_compi_gethostname="unknown"
  tst_allow_gethostname="unknown"
  #
  AC_MSG_CHECKING([if gethostname can be linked])
  AC_LINK_IFELSE([
    AC_LANG_PROGRAM([[
      $curl_includes_winsock2
      $curl_includes_unistd
    ]],[[
      if(0 != gethostname(0, 0))
        return 1;
    ]])
  ],[
    AC_MSG_RESULT([yes])
    tst_links_gethostname="yes"
  ],[
    AC_MSG_RESULT([no])
    tst_links_gethostname="no"
  ])
  #
  if test "$tst_links_gethostname" = "yes"; then
    AC_MSG_CHECKING([if gethostname is prototyped])
    AC_EGREP_CPP([gethostname],[
      $curl_includes_winsock2
      $curl_includes_unistd
    ],[
      AC_MSG_RESULT([yes])
      tst_proto_gethostname="yes"
    ],[
      AC_MSG_RESULT([no])
      tst_proto_gethostname="no"
    ])
  fi
  #
  if test "$tst_proto_gethostname" = "yes"; then
    AC_MSG_CHECKING([if gethostname is compilable])
    AC_COMPILE_IFELSE([
      AC_LANG_PROGRAM([[
        $curl_includes_winsock2
        $curl_includes_unistd
      ]],[[
        if(0 != gethostname(0, 0))
          return 1;
      ]])
    ],[
      AC_MSG_RESULT([yes])
      tst_compi_gethostname="yes"
    ],[
      AC_MSG_RESULT([no])
      tst_compi_gethostname="no"
    ])
  fi
  #
  if test "$tst_compi_gethostname" = "yes"; then
    AC_MSG_CHECKING([if gethostname usage allowed])
    if test "x$curl_disallow_gethostname" != "xyes"; then
      AC_MSG_RESULT([yes])
      tst_allow_gethostname="yes"
    else
      AC_MSG_RESULT([no])
      tst_allow_gethostname="no"
    fi
  fi
  #
  AC_MSG_CHECKING([if gethostname might be used])
  if test "$tst_links_gethostname" = "yes" &&
     test "$tst_proto_gethostname" = "yes" &&
     test "$tst_compi_gethostname" = "yes" &&
     test "$tst_allow_gethostname" = "yes"; then
    AC_MSG_RESULT([yes])
    AC_DEFINE_UNQUOTED(HAVE_GETHOSTNAME, 1,
      [Define to 1 if you have the gethostname function.])
    ac_cv_func_gethostname="yes"
  else
    AC_MSG_RESULT([no])
    ac_cv_func_gethostname="no"
  fi
])


dnl CURL_CHECK_FUNC_GETIFADDRS
dnl -------------------------------------------------
dnl Verify if getifaddrs is available, prototyped, can
dnl be compiled and seems to work. If all of these are
dnl true, and usage has not been previously disallowed
dnl with shell variable curl_disallow_getifaddrs, then
dnl HAVE_GETIFADDRS will be defined.

AC_DEFUN([CURL_CHECK_FUNC_GETIFADDRS], [
  AC_REQUIRE([CURL_INCLUDES_STDLIB])dnl
  AC_REQUIRE([CURL_INCLUDES_IFADDRS])dnl
  #
  tst_links_getifaddrs="unknown"
  tst_proto_getifaddrs="unknown"
  tst_compi_getifaddrs="unknown"
  tst_works_getifaddrs="unknown"
  tst_allow_getifaddrs="unknown"
  #
  AC_MSG_CHECKING([if getifaddrs can be linked])
  AC_LINK_IFELSE([
    AC_LANG_FUNC_LINK_TRY([getifaddrs])
  ],[
    AC_MSG_RESULT([yes])
    tst_links_getifaddrs="yes"
  ],[
    AC_MSG_RESULT([no])
    tst_links_getifaddrs="no"
  ])
  #
  if test "$tst_links_getifaddrs" = "yes"; then
    AC_MSG_CHECKING([if getifaddrs is prototyped])
    AC_EGREP_CPP([getifaddrs],[
      $curl_includes_ifaddrs
    ],[
      AC_MSG_RESULT([yes])
      tst_proto_getifaddrs="yes"
    ],[
      AC_MSG_RESULT([no])
      tst_proto_getifaddrs="no"
    ])
  fi
  #
  if test "$tst_proto_getifaddrs" = "yes"; then
    AC_MSG_CHECKING([if getifaddrs is compilable])
    AC_COMPILE_IFELSE([
      AC_LANG_PROGRAM([[
        $curl_includes_ifaddrs
      ]],[[
        if(0 != getifaddrs(0))
          return 1;
      ]])
    ],[
      AC_MSG_RESULT([yes])
      tst_compi_getifaddrs="yes"
    ],[
      AC_MSG_RESULT([no])
      tst_compi_getifaddrs="no"
    ])
  fi
  #
  dnl only do runtime verification when not cross-compiling
  if test "x$cross_compiling" != "xyes" &&
    test "$tst_compi_getifaddrs" = "yes"; then
    AC_MSG_CHECKING([if getifaddrs seems to work])
    AC_RUN_IFELSE([
      AC_LANG_PROGRAM([[
        $curl_includes_stdlib
        $curl_includes_ifaddrs
      ]],[[
        struct ifaddrs *ifa = 0;
        int error;

        error = getifaddrs(&ifa);
        if(error || !ifa)
          exit(1); /* fail */
        else
          exit(0);
      ]])
    ],[
      AC_MSG_RESULT([yes])
      tst_works_getifaddrs="yes"
    ],[
      AC_MSG_RESULT([no])
      tst_works_getifaddrs="no"
    ])
  fi
  #
  if test "$tst_compi_getifaddrs" = "yes" &&
    test "$tst_works_getifaddrs" != "no"; then
    AC_MSG_CHECKING([if getifaddrs usage allowed])
    if test "x$curl_disallow_getifaddrs" != "xyes"; then
      AC_MSG_RESULT([yes])
      tst_allow_getifaddrs="yes"
    else
      AC_MSG_RESULT([no])
      tst_allow_getifaddrs="no"
    fi
  fi
  #
  AC_MSG_CHECKING([if getifaddrs might be used])
  if test "$tst_links_getifaddrs" = "yes" &&
     test "$tst_proto_getifaddrs" = "yes" &&
     test "$tst_compi_getifaddrs" = "yes" &&
     test "$tst_allow_getifaddrs" = "yes" &&
     test "$tst_works_getifaddrs" != "no"; then
    AC_MSG_RESULT([yes])
    AC_DEFINE_UNQUOTED(HAVE_GETIFADDRS, 1,
      [Define to 1 if you have a working getifaddrs function.])
    ac_cv_func_getifaddrs="yes"
  else
    AC_MSG_RESULT([no])
    ac_cv_func_getifaddrs="no"
  fi
])


dnl CURL_CHECK_FUNC_GETSERVBYPORT_R
dnl -------------------------------------------------
dnl Verify if getservbyport_r is available, prototyped,
dnl and can be compiled. If all of these are true, and
dnl usage has not been previously disallowed with
dnl shell variable curl_disallow_getservbyport_r, then
dnl HAVE_GETSERVBYPORT_R will be defined.

AC_DEFUN([CURL_CHECK_FUNC_GETSERVBYPORT_R], [
  AC_REQUIRE([CURL_INCLUDES_NETDB])dnl
  #
  tst_links_getservbyport_r="unknown"
  tst_proto_getservbyport_r="unknown"
  tst_compi_getservbyport_r="unknown"
  tst_allow_getservbyport_r="unknown"
  tst_nargs_getservbyport_r="unknown"
  #
  AC_MSG_CHECKING([if getservbyport_r can be linked])
  AC_LINK_IFELSE([
    AC_LANG_FUNC_LINK_TRY([getservbyport_r])
  ],[
    AC_MSG_RESULT([yes])
    tst_links_getservbyport_r="yes"
  ],[
    AC_MSG_RESULT([no])
    tst_links_getservbyport_r="no"
  ])
  #
  if test "$tst_links_getservbyport_r" = "yes"; then
    AC_MSG_CHECKING([if getservbyport_r is prototyped])
    AC_EGREP_CPP([getservbyport_r],[
      $curl_includes_netdb
    ],[
      AC_MSG_RESULT([yes])
      tst_proto_getservbyport_r="yes"
    ],[
      AC_MSG_RESULT([no])
      tst_proto_getservbyport_r="no"
    ])
  fi
  #
  if test "$tst_proto_getservbyport_r" = "yes"; then
    if test "$tst_nargs_getservbyport_r" = "unknown"; then
      AC_MSG_CHECKING([if getservbyport_r takes 4 args.])
      AC_COMPILE_IFELSE([
        AC_LANG_PROGRAM([[
          $curl_includes_netdb
        ]],[[
          if(0 != getservbyport_r(0, 0, 0, 0))
            return 1;
        ]])
      ],[
        AC_MSG_RESULT([yes])
        tst_compi_getservbyport_r="yes"
        tst_nargs_getservbyport_r="4"
      ],[
        AC_MSG_RESULT([no])
        tst_compi_getservbyport_r="no"
      ])
    fi
    if test "$tst_nargs_getservbyport_r" = "unknown"; then
      AC_MSG_CHECKING([if getservbyport_r takes 5 args.])
      AC_COMPILE_IFELSE([
        AC_LANG_PROGRAM([[
          $curl_includes_netdb
        ]],[[
          if(0 != getservbyport_r(0, 0, 0, 0, 0))
            return 1;
        ]])
      ],[
        AC_MSG_RESULT([yes])
        tst_compi_getservbyport_r="yes"
        tst_nargs_getservbyport_r="5"
      ],[
        AC_MSG_RESULT([no])
        tst_compi_getservbyport_r="no"
      ])
    fi
    if test "$tst_nargs_getservbyport_r" = "unknown"; then
      AC_MSG_CHECKING([if getservbyport_r takes 6 args.])
      AC_COMPILE_IFELSE([
        AC_LANG_PROGRAM([[
          $curl_includes_netdb
        ]],[[
          if(0 != getservbyport_r(0, 0, 0, 0, 0, 0))
            return 1;
        ]])
      ],[
        AC_MSG_RESULT([yes])
        tst_compi_getservbyport_r="yes"
        tst_nargs_getservbyport_r="6"
      ],[
        AC_MSG_RESULT([no])
        tst_compi_getservbyport_r="no"
      ])
    fi
    AC_MSG_CHECKING([if getservbyport_r is compilable])
    if test "$tst_compi_getservbyport_r" = "yes"; then
      AC_MSG_RESULT([yes])
    else
      AC_MSG_RESULT([no])
    fi
  fi
  #
  if test "$tst_compi_getservbyport_r" = "yes"; then
    AC_MSG_CHECKING([if getservbyport_r usage allowed])
    if test "x$curl_disallow_getservbyport_r" != "xyes"; then
      AC_MSG_RESULT([yes])
      tst_allow_getservbyport_r="yes"
    else
      AC_MSG_RESULT([no])
      tst_allow_getservbyport_r="no"
    fi
  fi
  #
  AC_MSG_CHECKING([if getservbyport_r might be used])
  if test "$tst_links_getservbyport_r" = "yes" &&
     test "$tst_proto_getservbyport_r" = "yes" &&
     test "$tst_compi_getservbyport_r" = "yes" &&
     test "$tst_allow_getservbyport_r" = "yes"; then
    AC_MSG_RESULT([yes])
    AC_DEFINE_UNQUOTED(HAVE_GETSERVBYPORT_R, 1,
      [Define to 1 if you have the getservbyport_r function.])
    AC_DEFINE_UNQUOTED(GETSERVBYPORT_R_ARGS, $tst_nargs_getservbyport_r,
      [Specifies the number of arguments to getservbyport_r])
    if test "$tst_nargs_getservbyport_r" -eq "4"; then
      AC_DEFINE(GETSERVBYPORT_R_BUFSIZE, sizeof(struct servent_data),
        [Specifies the size of the buffer to pass to getservbyport_r])
    else
      AC_DEFINE(GETSERVBYPORT_R_BUFSIZE, 4096,
        [Specifies the size of the buffer to pass to getservbyport_r])
    fi
    ac_cv_func_getservbyport_r="yes"
  else
    AC_MSG_RESULT([no])
    ac_cv_func_getservbyport_r="no"
  fi
])


dnl CURL_CHECK_FUNC_GMTIME_R
dnl -------------------------------------------------
dnl Verify if gmtime_r is available, prototyped, can
dnl be compiled and seems to work. If all of these are
dnl true, and usage has not been previously disallowed
dnl with shell variable curl_disallow_gmtime_r, then
dnl HAVE_GMTIME_R will be defined.

AC_DEFUN([CURL_CHECK_FUNC_GMTIME_R], [
  AC_REQUIRE([CURL_INCLUDES_STDLIB])dnl
  AC_REQUIRE([CURL_INCLUDES_TIME])dnl
  #
  tst_links_gmtime_r="unknown"
  tst_proto_gmtime_r="unknown"
  tst_compi_gmtime_r="unknown"
  tst_works_gmtime_r="unknown"
  tst_allow_gmtime_r="unknown"
  #
  AC_MSG_CHECKING([if gmtime_r can be linked])
  AC_LINK_IFELSE([
    AC_LANG_FUNC_LINK_TRY([gmtime_r])
  ],[
    AC_MSG_RESULT([yes])
    tst_links_gmtime_r="yes"
  ],[
    AC_MSG_RESULT([no])
    tst_links_gmtime_r="no"
  ])
  #
  if test "$tst_links_gmtime_r" = "yes"; then
    AC_MSG_CHECKING([if gmtime_r is prototyped])
    AC_EGREP_CPP([gmtime_r],[
      $curl_includes_time
    ],[
      AC_MSG_RESULT([yes])
      tst_proto_gmtime_r="yes"
    ],[
      AC_MSG_RESULT([no])
      tst_proto_gmtime_r="no"
    ])
  fi
  #
  if test "$tst_proto_gmtime_r" = "yes"; then
    AC_MSG_CHECKING([if gmtime_r is compilable])
    AC_COMPILE_IFELSE([
      AC_LANG_PROGRAM([[
        $curl_includes_time
      ]],[[
        if(0 != gmtime_r(0, 0))
          return 1;
      ]])
    ],[
      AC_MSG_RESULT([yes])
      tst_compi_gmtime_r="yes"
    ],[
      AC_MSG_RESULT([no])
      tst_compi_gmtime_r="no"
    ])
  fi
  #
  dnl only do runtime verification when not cross-compiling
  if test "x$cross_compiling" != "xyes" &&
    test "$tst_compi_gmtime_r" = "yes"; then
    AC_MSG_CHECKING([if gmtime_r seems to work])
    AC_RUN_IFELSE([
      AC_LANG_PROGRAM([[
        $curl_includes_stdlib
        $curl_includes_time
      ]],[[
        time_t local = 1170352587;
        struct tm *gmt = 0;
        struct tm result;
        gmt = gmtime_r(&local, &result);
        if(gmt)
          exit(0);
        else
          exit(1);
      ]])
    ],[
      AC_MSG_RESULT([yes])
      tst_works_gmtime_r="yes"
    ],[
      AC_MSG_RESULT([no])
      tst_works_gmtime_r="no"
    ])
  fi
  #
  if test "$tst_compi_gmtime_r" = "yes" &&
    test "$tst_works_gmtime_r" != "no"; then
    AC_MSG_CHECKING([if gmtime_r usage allowed])
    if test "x$curl_disallow_gmtime_r" != "xyes"; then
      AC_MSG_RESULT([yes])
      tst_allow_gmtime_r="yes"
    else
      AC_MSG_RESULT([no])
      tst_allow_gmtime_r="no"
    fi
  fi
  #
  AC_MSG_CHECKING([if gmtime_r might be used])
  if test "$tst_links_gmtime_r" = "yes" &&
     test "$tst_proto_gmtime_r" = "yes" &&
     test "$tst_compi_gmtime_r" = "yes" &&
     test "$tst_allow_gmtime_r" = "yes" &&
     test "$tst_works_gmtime_r" != "no"; then
    AC_MSG_RESULT([yes])
    AC_DEFINE_UNQUOTED(HAVE_GMTIME_R, 1,
      [Define to 1 if you have a working gmtime_r function.])
    ac_cv_func_gmtime_r="yes"
  else
    AC_MSG_RESULT([no])
    ac_cv_func_gmtime_r="no"
  fi
])


dnl CURL_CHECK_FUNC_INET_NTOA_R
dnl -------------------------------------------------
dnl Verify if inet_ntoa_r is available, prototyped,
dnl and can be compiled. If all of these are true, and
dnl usage has not been previously disallowed with
dnl shell variable curl_disallow_inet_ntoa_r, then
dnl HAVE_INET_NTOA_R will be defined.

AC_DEFUN([CURL_CHECK_FUNC_INET_NTOA_R], [
  AC_REQUIRE([CURL_INCLUDES_ARPA_INET])dnl
  #
  tst_links_inet_ntoa_r="unknown"
  tst_proto_inet_ntoa_r="unknown"
  tst_compi_inet_ntoa_r="unknown"
  tst_allow_inet_ntoa_r="unknown"
  tst_nargs_inet_ntoa_r="unknown"
  #
  AC_MSG_CHECKING([if inet_ntoa_r can be linked])
  AC_LINK_IFELSE([
    AC_LANG_FUNC_LINK_TRY([inet_ntoa_r])
  ],[
    AC_MSG_RESULT([yes])
    tst_links_inet_ntoa_r="yes"
  ],[
    AC_MSG_RESULT([no])
    tst_links_inet_ntoa_r="no"
  ])
  #
  if test "$tst_links_inet_ntoa_r" = "yes"; then
    AC_MSG_CHECKING([if inet_ntoa_r is prototyped])
    AC_EGREP_CPP([inet_ntoa_r],[
      $curl_includes_arpa_inet
    ],[
      AC_MSG_RESULT([yes])
      tst_proto_inet_ntoa_r="yes"
    ],[
      AC_MSG_RESULT([no])
      tst_proto_inet_ntoa_r="no"
    ])
  fi
  #
  if test "$tst_proto_inet_ntoa_r" = "yes"; then
    if test "$tst_nargs_inet_ntoa_r" = "unknown"; then
      AC_MSG_CHECKING([if inet_ntoa_r takes 2 args.])
      AC_COMPILE_IFELSE([
        AC_LANG_PROGRAM([[
          $curl_includes_arpa_inet
        ]],[[
          struct in_addr addr;
          if(0 != inet_ntoa_r(addr, 0))
            return 1;
        ]])
      ],[
        AC_MSG_RESULT([yes])
        tst_compi_inet_ntoa_r="yes"
        tst_nargs_inet_ntoa_r="2"
      ],[
        AC_MSG_RESULT([no])
        tst_compi_inet_ntoa_r="no"
      ])
    fi
    if test "$tst_nargs_inet_ntoa_r" = "unknown"; then
      AC_MSG_CHECKING([if inet_ntoa_r takes 3 args.])
      AC_COMPILE_IFELSE([
        AC_LANG_PROGRAM([[
          $curl_includes_arpa_inet
        ]],[[
          struct in_addr addr;
          if(0 != inet_ntoa_r(addr, 0, 0))
            return 1;
        ]])
      ],[
        AC_MSG_RESULT([yes])
        tst_compi_inet_ntoa_r="yes"
        tst_nargs_inet_ntoa_r="3"
      ],[
        AC_MSG_RESULT([no])
        tst_compi_inet_ntoa_r="no"
      ])
    fi
    AC_MSG_CHECKING([if inet_ntoa_r is compilable])
    if test "$tst_compi_inet_ntoa_r" = "yes"; then
      AC_MSG_RESULT([yes])
    else
      AC_MSG_RESULT([no])
    fi
  fi
  #
  if test "$tst_compi_inet_ntoa_r" = "yes"; then
    AC_MSG_CHECKING([if inet_ntoa_r usage allowed])
    if test "x$curl_disallow_inet_ntoa_r" != "xyes"; then
      AC_MSG_RESULT([yes])
      tst_allow_inet_ntoa_r="yes"
    else
      AC_MSG_RESULT([no])
      tst_allow_inet_ntoa_r="no"
    fi
  fi
  #
  AC_MSG_CHECKING([if inet_ntoa_r might be used])
  if test "$tst_links_inet_ntoa_r" = "yes" &&
     test "$tst_proto_inet_ntoa_r" = "yes" &&
     test "$tst_compi_inet_ntoa_r" = "yes" &&
     test "$tst_allow_inet_ntoa_r" = "yes"; then
    AC_MSG_RESULT([yes])
    AC_DEFINE_UNQUOTED(HAVE_INET_NTOA_R, 1,
      [Define to 1 if you have the inet_ntoa_r function.])
    dnl AC_DEFINE_UNQUOTED(INET_NTOA_R_ARGS, $tst_nargs_inet_ntoa_r,
    dnl   [Specifies the number of arguments to inet_ntoa_r])
    #
    if test "$tst_nargs_inet_ntoa_r" -eq "2"; then
      AC_DEFINE(HAVE_INET_NTOA_R_2, 1, [inet_ntoa_r() takes 2 args])
    elif test "$tst_nargs_inet_ntoa_r" -eq "3"; then
      AC_DEFINE(HAVE_INET_NTOA_R_3, 1, [inet_ntoa_r() takes 3 args])
    fi
    #
    ac_cv_func_inet_ntoa_r="yes"
  else
    AC_MSG_RESULT([no])
    ac_cv_func_inet_ntoa_r="no"
  fi
])


dnl CURL_CHECK_FUNC_INET_NTOP
dnl -------------------------------------------------
dnl Verify if inet_ntop is available, prototyped, can
dnl be compiled and seems to work. If all of these are
dnl true, and usage has not been previously disallowed
dnl with shell variable curl_disallow_inet_ntop, then
dnl HAVE_INET_NTOP will be defined.

AC_DEFUN([CURL_CHECK_FUNC_INET_NTOP], [
  AC_REQUIRE([CURL_INCLUDES_STDLIB])dnl
  AC_REQUIRE([CURL_INCLUDES_ARPA_INET])dnl
  AC_REQUIRE([CURL_INCLUDES_STRING])dnl
  #
  tst_links_inet_ntop="unknown"
  tst_proto_inet_ntop="unknown"
  tst_compi_inet_ntop="unknown"
  tst_works_inet_ntop="unknown"
  tst_allow_inet_ntop="unknown"
  #
  AC_MSG_CHECKING([if inet_ntop can be linked])
  AC_LINK_IFELSE([
    AC_LANG_FUNC_LINK_TRY([inet_ntop])
  ],[
    AC_MSG_RESULT([yes])
    tst_links_inet_ntop="yes"
  ],[
    AC_MSG_RESULT([no])
    tst_links_inet_ntop="no"
  ])
  #
  if test "$tst_links_inet_ntop" = "yes"; then
    AC_MSG_CHECKING([if inet_ntop is prototyped])
    AC_EGREP_CPP([inet_ntop],[
      $curl_includes_arpa_inet
    ],[
      AC_MSG_RESULT([yes])
      tst_proto_inet_ntop="yes"
    ],[
      AC_MSG_RESULT([no])
      tst_proto_inet_ntop="no"
    ])
  fi
  #
  if test "$tst_proto_inet_ntop" = "yes"; then
    AC_MSG_CHECKING([if inet_ntop is compilable])
    AC_COMPILE_IFELSE([
      AC_LANG_PROGRAM([[
        $curl_includes_arpa_inet
      ]],[[
        if(0 != inet_ntop(0, 0, 0, 0))
          return 1;
      ]])
    ],[
      AC_MSG_RESULT([yes])
      tst_compi_inet_ntop="yes"
    ],[
      AC_MSG_RESULT([no])
      tst_compi_inet_ntop="no"
    ])
  fi
  #
  dnl only do runtime verification when not cross-compiling
  if test "x$cross_compiling" != "xyes" &&
    test "$tst_compi_inet_ntop" = "yes"; then
    AC_MSG_CHECKING([if inet_ntop seems to work])
    AC_RUN_IFELSE([
      AC_LANG_PROGRAM([[
        $curl_includes_stdlib
        $curl_includes_arpa_inet
        $curl_includes_string
      ]],[[
        char ipv6res[sizeof("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255")];
        char ipv4res[sizeof "255.255.255.255"];
        unsigned char ipv6a[26];
        unsigned char ipv4a[5];
        char *ipv6ptr = 0;
        char *ipv4ptr = 0;
        /* - */
        ipv4res[0] = '\0';
        ipv4a[0] = 0xc0;
        ipv4a[1] = 0xa8;
        ipv4a[2] = 0x64;
        ipv4a[3] = 0x01;
        ipv4a[4] = 0x01;
        /* - */
        ipv4ptr = inet_ntop(AF_INET, ipv4a, ipv4res, sizeof(ipv4res));
        if(!ipv4ptr)
          exit(1); /* fail */
        if(ipv4ptr != ipv4res)
          exit(1); /* fail */
        if(!ipv4ptr[0])
          exit(1); /* fail */
        if(memcmp(ipv4res, "192.168.100.1", 13) != 0)
          exit(1); /* fail */
        /* - */
        ipv6res[0] = '\0';
        memset(ipv6a, 0, sizeof(ipv6a));
        ipv6a[0] = 0xfe;
        ipv6a[1] = 0x80;
        ipv6a[8] = 0x02;
        ipv6a[9] = 0x14;
        ipv6a[10] = 0x4f;
        ipv6a[11] = 0xff;
        ipv6a[12] = 0xfe;
        ipv6a[13] = 0x0b;
        ipv6a[14] = 0x76;
        ipv6a[15] = 0xc8;
        ipv6a[25] = 0x01;
        /* - */
        ipv6ptr = inet_ntop(AF_INET6, ipv6a, ipv6res, sizeof(ipv6res));
        if(!ipv6ptr)
          exit(1); /* fail */
        if(ipv6ptr != ipv6res)
          exit(1); /* fail */
        if(!ipv6ptr[0])
          exit(1); /* fail */
        if(memcmp(ipv6res, "fe80::214:4fff:fe0b:76c8", 24) != 0)
          exit(1); /* fail */
        /* - */
        exit(0);
      ]])
    ],[
      AC_MSG_RESULT([yes])
      tst_works_inet_ntop="yes"
    ],[
      AC_MSG_RESULT([no])
      tst_works_inet_ntop="no"
    ])
  fi
  #
  if test "$tst_compi_inet_ntop" = "yes" &&
    test "$tst_works_inet_ntop" != "no"; then
    AC_MSG_CHECKING([if inet_ntop usage allowed])
    if test "x$curl_disallow_inet_ntop" != "xyes"; then
      AC_MSG_RESULT([yes])
      tst_allow_inet_ntop="yes"
    else
      AC_MSG_RESULT([no])
      tst_allow_inet_ntop="no"
    fi
  fi
  #
  AC_MSG_CHECKING([if inet_ntop might be used])
  if test "$tst_links_inet_ntop" = "yes" &&
     test "$tst_proto_inet_ntop" = "yes" &&
     test "$tst_compi_inet_ntop" = "yes" &&
     test "$tst_allow_inet_ntop" = "yes" &&
     test "$tst_works_inet_ntop" != "no"; then
    AC_MSG_RESULT([yes])
    AC_DEFINE_UNQUOTED(HAVE_INET_NTOP, 1,
      [Define to 1 if you have a IPv6 capable working inet_ntop function.])
    ac_cv_func_inet_ntop="yes"
  else
    AC_MSG_RESULT([no])
    ac_cv_func_inet_ntop="no"
  fi
])


dnl CURL_CHECK_FUNC_INET_PTON
dnl -------------------------------------------------
dnl Verify if inet_pton is available, prototyped, can
dnl be compiled and seems to work. If all of these are
dnl true, and usage has not been previously disallowed
dnl with shell variable curl_disallow_inet_pton, then
dnl HAVE_INET_PTON will be defined.

AC_DEFUN([CURL_CHECK_FUNC_INET_PTON], [
  AC_REQUIRE([CURL_INCLUDES_STDLIB])dnl
  AC_REQUIRE([CURL_INCLUDES_ARPA_INET])dnl
  AC_REQUIRE([CURL_INCLUDES_STRING])dnl
  #
  tst_links_inet_pton="unknown"
  tst_proto_inet_pton="unknown"
  tst_compi_inet_pton="unknown"
  tst_works_inet_pton="unknown"
  tst_allow_inet_pton="unknown"
  #
  AC_MSG_CHECKING([if inet_pton can be linked])
  AC_LINK_IFELSE([
    AC_LANG_FUNC_LINK_TRY([inet_pton])
  ],[
    AC_MSG_RESULT([yes])
    tst_links_inet_pton="yes"
  ],[
    AC_MSG_RESULT([no])
    tst_links_inet_pton="no"
  ])
  #
  if test "$tst_links_inet_pton" = "yes"; then
    AC_MSG_CHECKING([if inet_pton is prototyped])
    AC_EGREP_CPP([inet_pton],[
      $curl_includes_arpa_inet
    ],[
      AC_MSG_RESULT([yes])
      tst_proto_inet_pton="yes"
    ],[
      AC_MSG_RESULT([no])
      tst_proto_inet_pton="no"
    ])
  fi
  #
  if test "$tst_proto_inet_pton" = "yes"; then
    AC_MSG_CHECKING([if inet_pton is compilable])
    AC_COMPILE_IFELSE([
      AC_LANG_PROGRAM([[
        $curl_includes_arpa_inet
      ]],[[
        if(0 != inet_pton(0, 0, 0))
          return 1;
      ]])
    ],[
      AC_MSG_RESULT([yes])
      tst_compi_inet_pton="yes"
    ],[
      AC_MSG_RESULT([no])
      tst_compi_inet_pton="no"
    ])
  fi
  #
  dnl only do runtime verification when not cross-compiling
  if test "x$cross_compiling" != "xyes" &&
    test "$tst_compi_inet_pton" = "yes"; then
    AC_MSG_CHECKING([if inet_pton seems to work])
    AC_RUN_IFELSE([
      AC_LANG_PROGRAM([[
        $curl_includes_stdlib
        $curl_includes_arpa_inet
        $curl_includes_string
      ]],[[
        unsigned char ipv6a[16+1];
        unsigned char ipv4a[4+1];
        const char *ipv6src = "fe80::214:4fff:fe0b:76c8";
        const char *ipv4src = "192.168.100.1";
        /* - */
        memset(ipv4a, 1, sizeof(ipv4a));
        if(1 != inet_pton(AF_INET, ipv4src, ipv4a))
          exit(1); /* fail */
        /* - */
        if( (ipv4a[0] != 0xc0) ||
            (ipv4a[1] != 0xa8) ||
            (ipv4a[2] != 0x64) ||
            (ipv4a[3] != 0x01) ||
            (ipv4a[4] != 0x01) )
          exit(1); /* fail */
        /* - */
        memset(ipv6a, 1, sizeof(ipv6a));
        if(1 != inet_pton(AF_INET6, ipv6src, ipv6a))
          exit(1); /* fail */
        /* - */
        if( (ipv6a[0]  != 0xfe) ||
            (ipv6a[1]  != 0x80) ||
            (ipv6a[8]  != 0x02) ||
            (ipv6a[9]  != 0x14) ||
            (ipv6a[10] != 0x4f) ||
            (ipv6a[11] != 0xff) ||
            (ipv6a[12] != 0xfe) ||
            (ipv6a[13] != 0x0b) ||
            (ipv6a[14] != 0x76) ||
            (ipv6a[15] != 0xc8) ||
            (ipv6a[16] != 0x01) )
          exit(1); /* fail */
        /* - */
        if( (ipv6a[2]  != 0x0) ||
            (ipv6a[3]  != 0x0) ||
            (ipv6a[4]  != 0x0) ||
            (ipv6a[5]  != 0x0) ||
            (ipv6a[6]  != 0x0) ||
            (ipv6a[7]  != 0x0) )
          exit(1); /* fail */
        /* - */
        exit(0);
      ]])
    ],[
      AC_MSG_RESULT([yes])
      tst_works_inet_pton="yes"
    ],[
      AC_MSG_RESULT([no])
      tst_works_inet_pton="no"
    ])
  fi
  #
  if test "$tst_compi_inet_pton" = "yes" &&
    test "$tst_works_inet_pton" != "no"; then
    AC_MSG_CHECKING([if inet_pton usage allowed])
    if test "x$curl_disallow_inet_pton" != "xyes"; then
      AC_MSG_RESULT([yes])
      tst_allow_inet_pton="yes"
    else
      AC_MSG_RESULT([no])
      tst_allow_inet_pton="no"
    fi
  fi
  #
  AC_MSG_CHECKING([if inet_pton might be used])
  if test "$tst_links_inet_pton" = "yes" &&
     test "$tst_proto_inet_pton" = "yes" &&
     test "$tst_compi_inet_pton" = "yes" &&
     test "$tst_allow_inet_pton" = "yes" &&
     test "$tst_works_inet_pton" != "no"; then
    AC_MSG_RESULT([yes])
    AC_DEFINE_UNQUOTED(HAVE_INET_PTON, 1,
      [Define to 1 if you have a IPv6 capable working inet_pton function.])
    ac_cv_func_inet_pton="yes"
  else
    AC_MSG_RESULT([no])
    ac_cv_func_inet_pton="no"
  fi
])


dnl CURL_CHECK_FUNC_IOCTL
dnl -------------------------------------------------
dnl Verify if ioctl is available, prototyped, and
dnl can be compiled. If all of these are true, and
dnl usage has not been previously disallowed with
dnl shell variable curl_disallow_ioctl, then
dnl HAVE_IOCTL will be defined.

AC_DEFUN([CURL_CHECK_FUNC_IOCTL], [
  AC_REQUIRE([CURL_INCLUDES_STROPTS])dnl
  #
  tst_links_ioctl="unknown"
  tst_proto_ioctl="unknown"
  tst_compi_ioctl="unknown"
  tst_allow_ioctl="unknown"
  #
  AC_MSG_CHECKING([if ioctl can be linked])
  AC_LINK_IFELSE([
    AC_LANG_FUNC_LINK_TRY([ioctl])
  ],[
    AC_MSG_RESULT([yes])
    tst_links_ioctl="yes"
  ],[
    AC_MSG_RESULT([no])
    tst_links_ioctl="no"
  ])
  #
  if test "$tst_links_ioctl" = "yes"; then
    AC_MSG_CHECKING([if ioctl is prototyped])
    AC_EGREP_CPP([ioctl],[
      $curl_includes_stropts
    ],[
      AC_MSG_RESULT([yes])
      tst_proto_ioctl="yes"
    ],[
      AC_MSG_RESULT([no])
      tst_proto_ioctl="no"
    ])
  fi
  #
  if test "$tst_proto_ioctl" = "yes"; then
    AC_MSG_CHECKING([if ioctl is compilable])
    AC_COMPILE_IFELSE([
      AC_LANG_PROGRAM([[
        $curl_includes_stropts
      ]],[[
        if(0 != ioctl(0, 0, 0))
          return 1;
      ]])
    ],[
      AC_MSG_RESULT([yes])
      tst_compi_ioctl="yes"
    ],[
      AC_MSG_RESULT([no])
      tst_compi_ioctl="no"
    ])
  fi
  #
  if test "$tst_compi_ioctl" = "yes"; then
    AC_MSG_CHECKING([if ioctl usage allowed])
    if test "x$curl_disallow_ioctl" != "xyes"; then
      AC_MSG_RESULT([yes])
      tst_allow_ioctl="yes"
    else
      AC_MSG_RESULT([no])
      tst_allow_ioctl="no"
    fi
  fi
  #
  AC_MSG_CHECKING([if ioctl might be used])
  if test "$tst_links_ioctl" = "yes" &&
     test "$tst_proto_ioctl" = "yes" &&
     test "$tst_compi_ioctl" = "yes" &&
     test "$tst_allow_ioctl" = "yes"; then
    AC_MSG_RESULT([yes])
    AC_DEFINE_UNQUOTED(HAVE_IOCTL, 1,
      [Define to 1 if you have the ioctl function.])
    ac_cv_func_ioctl="yes"
    CURL_CHECK_FUNC_IOCTL_FIONBIO
    CURL_CHECK_FUNC_IOCTL_SIOCGIFADDR
  else
    AC_MSG_RESULT([no])
    ac_cv_func_ioctl="no"
  fi
])


dnl CURL_CHECK_FUNC_IOCTL_FIONBIO
dnl -------------------------------------------------
dnl Verify if ioctl with the FIONBIO command is
dnl available, can be compiled, and seems to work. If
dnl all of these are true, then HAVE_IOCTL_FIONBIO
dnl will be defined.

AC_DEFUN([CURL_CHECK_FUNC_IOCTL_FIONBIO], [
  #
  tst_compi_ioctl_fionbio="unknown"
  tst_allow_ioctl_fionbio="unknown"
  #
  if test "$ac_cv_func_ioctl" = "yes"; then
    AC_MSG_CHECKING([if ioctl FIONBIO is compilable])
    AC_COMPILE_IFELSE([
      AC_LANG_PROGRAM([[
        $curl_includes_stropts
      ]],[[
        int flags = 0;
        if(0 != ioctl(0, FIONBIO, &flags))
          return 1;