--- a/ChangeLog	Fri May 08 13:21:34 2009 +0200
+++ b/ChangeLog	Fri May 08 16:21:34 2009 +0200
@@ -1,3 +1,11 @@
+2009-05-07  Simon Josefsson  <simon@josefsson.org>
+
+	* modules/sys_socket (Makefile.am): Substitute
+	HAVE_STRUCT_SOCKADDR_STORAGE.  Depend on alignof.
+	* m4/sys_socket_h.m4: Check for sockaddr_storage.
+	* lib/sys_socket.in.h (sockaddr_storage): Define when needed.
+	* tests/test-sys_socket.c: Check sockaddr_storage.
+
 2009-05-08  Bruno Haible  <bruno@clisp.org>
 
 	Use module 'alignof'.

--- a/lib/sys_socket.in.h	Fri May 08 13:21:34 2009 +0200
+++ b/lib/sys_socket.in.h	Fri May 08 16:21:34 2009 +0200
@@ -43,6 +43,24 @@
 #ifndef _GL_SYS_SOCKET_H
 #define _GL_SYS_SOCKET_H
 
+#if !@HAVE_STRUCT_SOCKADDR_STORAGE@
+#include <alignof.h>
+/* Code taken from glibc sysdeps/unix/sysv/linux/bits/socket.h on
+   2009-05-08, licensed under LGPLv2.1+, plus portability fixes. */
+#define __ss_aligntype  unsigned long int
+#define _SS_SIZE	256
+#define _SS_PADSIZE	(_SS_SIZE - (max (sizeof (sa_family_t),		\
+					  alignof (__ss_aligntype))	\
+				     + sizeof (__ss_aligntype)))
+
+struct sockaddr_storage
+{
+  sa_family_t ss_family;      /* Address family, etc.  */
+  __ss_aligntype __ss_align;  /* Force desired alignment.  */
+  char __ss_padding[_SS_PADSIZE];
+};
+#endif
+
 #if @HAVE_SYS_SOCKET_H@
 
 /* A platform that has <sys/socket.h>.  */

--- a/m4/sys_socket_h.m4	Fri May 08 13:21:34 2009 +0200
+++ b/m4/sys_socket_h.m4	Fri May 08 16:21:34 2009 +0200
@@ -1,5 +1,5 @@
 # sys_socket_h.m4 serial 12
-dnl Copyright (C) 2005-2008 Free Software Foundation, Inc.
+dnl Copyright (C) 2005-2009 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
@@ -40,6 +40,22 @@
   else
     SYS_SOCKET_H='sys/socket.h'
   fi
+  AC_CHECK_TYPES([struct sockaddr_storage],,,[
+  /* sys/types.h is not needed according to POSIX, but the
+     sys/socket.h in i386-unknown-freebsd4.10 and
+     powerpc-apple-darwin5.5 required it. */
+#include <sys/types.h>
+#ifdef HAVE_SYS_SOCKET_H
+#include <sys/socket.h>
+#endif
+#ifdef HAVE_WS2TCPIP_H
+#include <ws2tcpip.h>
+#endif
+])
+  if test $ac_cv_type_struct_sockaddr_storage = no; then
+    HAVE_STRUCT_SOCKADDR_STORAGE=0
+    SYS_SOCKET_H='sys/socket.h'
+  fi
   if test -n "$SYS_SOCKET_H"; then
     dnl Check prerequisites of the <sys/socket.h> replacement.
     gl_CHECK_NEXT_HEADERS([sys/socket.h])
@@ -114,4 +130,5 @@
   GNULIB_SENDTO=0;      AC_SUBST([GNULIB_SENDTO])
   GNULIB_SETSOCKOPT=0;  AC_SUBST([GNULIB_SETSOCKOPT])
   GNULIB_SHUTDOWN=0;    AC_SUBST([GNULIB_SHUTDOWN])
+  HAVE_STRUCT_SOCKADDR_STORAGE=1; AC_SUBST([HAVE_STRUCT_SOCKADDR_STORAGE])
 ])

--- a/modules/sys_socket	Fri May 08 13:21:34 2009 +0200
+++ b/modules/sys_socket	Fri May 08 16:21:34 2009 +0200
@@ -10,6 +10,7 @@
 include_next
 link-warning
 errno
+alignof
 
 configure.ac:
 gl_HEADER_SYS_SOCKET
@@ -44,6 +45,7 @@
 	      -e 's|@''GNULIB_SHUTDOWN''@|$(GNULIB_SHUTDOWN)|g' \
 	      -e 's|@''HAVE_WINSOCK2_H''@|$(HAVE_WINSOCK2_H)|g' \
 	      -e 's|@''HAVE_WS2TCPIP_H''@|$(HAVE_WS2TCPIP_H)|g' \
+	      -e 's|@''HAVE_STRUCT_SOCKADDR_STORAGE''@|$(HAVE_STRUCT_SOCKADDR_STORAGE)|g' \
 	      -e '/definition of GL_LINK_WARNING/r $(LINK_WARNING_H)' \
 	      < $(srcdir)/sys_socket.in.h; \
 	} > $@-t

--- a/tests/test-sys_socket.c	Fri May 08 13:21:34 2009 +0200
+++ b/tests/test-sys_socket.c	Fri May 08 16:21:34 2009 +0200
@@ -1,5 +1,5 @@
 /* Test of <sys/socket.h> substitute.
-   Copyright (C) 2007 Free Software Foundation, Inc.
+   Copyright (C) 2007, 2009 Free Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -30,6 +30,8 @@
 int
 main ()
 {
+  struct sockaddr_storage x;
+
   /* Check some errno values.  */
   switch (0)
     {
@@ -43,5 +45,7 @@
       break;
     }
 
+  x.ss_family = 42;
+
   return 0;
 }