Remove check for the mandatory IPv6 support

IPv6 Advanced Socket API (:rfc:`3542`) is a hard requirement, remove the
autoconf check to speed up the ./configure run a little bit.

diff --git a/configure.ac b/configure.ac
index 42679e1f029d48e687025e6992838a84212e75dd..7261d4451e4497a96db0f212d629a1af84ccab5f 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -886,31 +886,6 @@ AC_CHECK_HEADERS([execinfo.h],
                 [AC_SEARCH_LIBS([backtrace_symbols], [execinfo],
                                 [AC_CHECK_FUNCS([backtrace_symbols])])])
 
-#
-# We do the IPv6 compilation checking after libtool so that we can put
-# the right suffix on the files.
-#
-AC_MSG_CHECKING([for IPv6 structures])
-AC_COMPILE_IFELSE(
-  [AC_LANG_PROGRAM(
-     [[
-       #include <sys/types.h>
-       #include <sys/socket.h>
-       #include <netinet/in.h>
-     ]],
-     [[
-       struct sockaddr_in6 sin6;
-       struct in6_addr in6;
-       struct in6_pktinfo in6_pi;
-       struct sockaddr_storage storage;
-       in6 = in6addr_any;
-       in6 = in6addr_loopback;
-       sin6.sin6_scope_id = 0;
-       return (0);
-     ]])],
-  [AC_MSG_RESULT([yes])],
-  [AC_MSG_FAILURE([IPv6 support is mandatory])])
-
 #
 # Allow forcibly disabling TCP Fast Open support as autodetection might yield
 # confusing results on some systems (e.g. FreeBSD; see set_tcp_fastopen()