AC_CHECK_HEADERS_ONCE([netinet/in.h arpa/inet.h])
AC_CHECK_DECLS([inet_pton],,,[#include <arpa/inet.h>])
AC_REQUIRE([gl_SOCKET_FAMILIES])
AC_CHECK_HEADERS_ONCE([netinet/in.h arpa/inet.h])
AC_CHECK_DECLS([inet_pton],,,[#include <arpa/inet.h>])
AC_REQUIRE([gl_SOCKET_FAMILIES])