+AC_CHECK_MEMBER([struct sockaddr.sa_len],
+ [AC_DEFINE([HAVE_SOCKADDR_SA_LEN],,[Define if struct sockaddr has sa_len field])],
+ [],[#include <sys/types.h>
+#include <sys/socket.h>])
+AC_CHECK_MEMBER([struct addrinfo.ai_flags],
+ [AC_DEFINE([HAVE_STRUCT_ADDRINFO],,[Define if struct addrinfo declared])],
+ [],[#include <sys/types.h>
+#include <sys/socket.h>
+#include <netdb.h>])